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Sample records for hcci combustion performance

  1. The effect of the composition of hydrocarbon streams on physical properties and HCCI combustion performance

    Energy Technology Data Exchange (ETDEWEB)

    Gieleciak, R. [National Centre for Upgrading Technology, Devon, AB (Canada); Natural Resources Canada, Devon, AB (Canada). CanmetENERGY

    2009-07-01

    Advanced combustion engines have been developed in tandem with evolving fuels and combustion strategies. Advanced analytical methods such as NMR and two dimensional gas chromatography (2D-GC) are also becoming both more powerful and easier to use. Statistical analysis can be used to link the very complex fuel analysis data sets from these methods to fuel chemistry, fuel properties and engine performance. This poster highlighted a study that applied an advanced statistical analysis technique to 2D-GC data for 17 oil sands derived fuels and correlated results to measured fuel chemical/physical properties, and then to HCCI engine performance. In the HCCI mode, ignition occurs by compression of the homogeneous fuel/air mixture. Advanced combustion strategies must satisfy the need for high efficiency, low emissions, and drivability. The 2D-GC was shown to be an emerging analytical technique which separates compounds in fuels to enable the identification of individual compounds and group compounds by chemistry and boiling points. The Q(2d)RPR technique allows correlations to be developed between the 2D-GC data and fuel chemical / physical properties and engine performance data. tabs., figs.

  2. Experimental investigation on the effect of intake air temperature and air-fuel ratio on cycle-to-cycle variations of HCCI combustion and performance parameters

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, Rakesh Kumar; Agarwal, Avinash Kumar [Engine Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

    2011-04-15

    Combustion in HCCI engines is a controlled auto ignition of well-mixed fuel, air and residual gas. Since onset of HCCI combustion depends on the auto ignition of fuel/air mixture, there is no direct control on the start of combustion process. Therefore, HCCI combustion becomes unstable rather easily, especially at lower and higher engine loads. In this study, cycle-to-cycle variations of a HCCI combustion engine fuelled with ethanol were investigated on a modified two-cylinder engine. Port injection technique is used for preparing homogeneous charge for HCCI combustion. The experiments were conducted at varying intake air temperatures and air-fuel ratios at constant engine speed of 1500 rpm and P-{theta} diagram of 100 consecutive combustion cycles for each test conditions at steady state operation were recorded. Consequently, cycle-to-cycle variations of the main combustion parameters and performance parameters were analyzed. To evaluate the cycle-to-cycle variations of HCCI combustion parameters, coefficient of variation (COV) of every parameter were calculated for every engine operating condition. The critical optimum parameters that can be used to define HCCI operating ranges are 'maximum rate of pressure rise' and 'COV of indicated mean effective pressure (IMEP)'. (author)

  3. Universal autoignition models for designer fuels in HCCI combustion

    Energy Technology Data Exchange (ETDEWEB)

    Vandersickel, A.; Boulouchos, K.; Wright, Y.M. [LAV - Aerothermochemistry and Combustion Systems Laboratory - Institute of Energy Technology, ETH Zurich (Switzerland)], email: vandersickel@lav.mavt.ethz.ch

    2010-07-01

    In the energy sector, stringent regulations have been implemented on combustion emissions in order to address health and environmental concerns and help improve air quality. A novel combustion mode, homogeneous charge compression ignition (HCCI), can improve the emissions performance of an engine in terms of NOx and soot release over that of diesel while maintaining the same efficiencies. However, problems of ignition timing control arise with HCCI. The aim of this paper is to determine how fuel properties impact the HCCI ignition process and operating range. This study was carried out as part of a collaboration among several universities and automotive companies and 10 fuels were investigated experimentally and numerically using Arrhenius' model and a lumped reaction model. The two ignition models were successfully adapted to describe the behavior of the studied fuels; atomizer engine experiments validated their results. Further work will be conducted to optimize the reaction mechanism for the remaining process fuels.

  4. Investigation the performance of 0-D and 3-d combustion simulation softwares for modelling HCCI engine with high air excess ratios

    Directory of Open Access Journals (Sweden)

    Gökhan Coşkun

    2017-10-01

    Full Text Available In this study, performance of zero and three dimensional simulations codes that used for simulate a homogenous charge compression ignition (HCCI engine fueled with Primary Reference Fuel PRF (85% iso-octane and 15% n-heptane were investigated. 0-D code, called as SRM Suite (Stochastic Reactor Model which can simulate engine combustion by using stochastic reactor model technique were used. Ansys-Fluent which can simulate computational fluid dynamics (CFD was used for 3-D engine combustion simulations. Simulations were evaluated for both commercial codes in terms of combustion, heat transfer and emissions in a HCCI engine. Chemical kinetic mechanisms which developed by Tsurushima including 33 species and 38 reactions for surrogate PRF fuel were used for combustion simulations. Analysis showed that both codes have advantages over each other.

  5. Review of homogeneous charge compression ignition (HCCI) combustion engines and exhaust gas recirculation (EGR) effects on HCCI

    Science.gov (United States)

    Akma Tuan Kamaruddin, Tengku Nordayana; Wahid, Mazlan Abdul; Sies, Mohsin Mohd

    2012-06-01

    This paper describes the development in ICE which leads to the new advanced combustion mode named Homogeneous Charge Compression Ignition (HCCI). It explains regarding the theory and working principle of HCCI plus the difference of the process in gasoline and diesel fuelled engines. Many of pioneer and recent research works are discussed to get the current state of art about HCCI. It gives a better indication on the potential of this method in improving the fuel efficiency and emission produced by the vehicles' engine. Apart from the advantages, the challenges and future trend of this technology are also included. HCCI is applying few types of control strategy in producing the optimum performance. This paper looks into Exhaust Gas Recirculation (EGR) as one of the control strategies.

  6. An experimental investigation into combustion and performance characteristics of an HCCI gasoline engine fueled with n-heptane, isopropanol and n-butanol fuel blends at different inlet air temperatures

    International Nuclear Information System (INIS)

    Uyumaz, Ahmet

    2015-01-01

    Highlights: • Combustion was retarded with the increase of the amount of isopropanol and n-butanol in the test fuels. • Combustion was advanced with the increase of air inlet temperature on HCCI combustion. • Isopropanol seems more suitable fuel due to controlling the HCCI combustion and preventing knocking. • Almost zero NO emissions were measured when alcohol used except for n-heptane and B20 test fuels. - Abstract: An experimental study was conducted in a single cylinder, four stroke port injection Ricardo Hydra test engine in order to determine the effects of pure n-heptane, the blends of n-heptane and n-butanol fuels B20, B30, B40 (including 20%, 30%, 40% n-butanol and 80%, 70%, 60% n-heptane by vol. respectively) and the blends of n-heptane and isopropanol fuels P20, P30, P40 (including 20%, 30%, 40% isopropanol and 80%, 70%, 60% n-heptane by vol. respectively) on HCCI combustion. Combustion and performance characteristics of n-heptane, n-butanol and isopropanol were investigated at constant engine speed of 1500 rpm and λ = 2 in a HCCI engine. The effects of inlet air temperature were also examined on HCCI combustion. The test results showed that the start of combustion was advanced with the increasing of inlet air temperature for all test fuels. Start of combustion delayed with increasing percentage of n-butanol and isopropanol in the test fuels. Knocking combustion was seen with B20 and n-heptane test fuels. Minimum combustion duration was observed in case of using B40. Almost zero NO emissions were measured with test fuels apart from n-heptane and B20. The test results also showed that CO and HC emissions decreased with the increase of inlet air temperature for all test fuels. Isopropanol showed stronger resistance for knocking compared to n-butanol in HCCI combustion due to its higher octane number. It was determined that n-butanol was more advantageous according to isopropanol as thermal efficiency. As a result it was found that the HCCI

  7. Establishment of Combustion Model for Isooctane HCCI Marine Diesel Engine and Research on the Combustion Characteristic

    Directory of Open Access Journals (Sweden)

    Li Biao

    2016-01-01

    Full Text Available The homogeneous charge compression ignition (HCCI combustion mode applied in marine diesel engine is expected to be one of alternative technologies to decrease nitrogen oxide (NOX emission and improve energy utilization rate. Applying the chemical-looping combustion (CLC mechanism inside the cylinder, a numerical study on the HCCI combustion process is performed taking a marine diesel engine as application object. The characteristic feature of combustion process is displayed. On this basis, the formation and emission of NOX are analyzed and discussed. The results indicate that the HCCI combustion mode always exhibit two combustion releasing heats: low-temperature reaction and high-temperature reaction. The combustion phase is divided into low-temperature reaction zone, high-temperature reaction zone and negative temperature coefficient (NTC zone. The operating conditions of the high compression ratio, high intake air temperature, low inlet pressure and small excess air coefficient would cause the high in-cylinder pressure which often leads engine detonation. The low compression ratio, low intake air temperature and big excess air coefficient would cause the low combustor temperature which is conducive to reduce NOX emissions. These technological means and operating conditions are expected to meet the NOX emissions limits in MARPOL73/78 Convention-Annex VI Amendment.

  8. Fuel and Additive Characterization for HCCI Combustion

    International Nuclear Information System (INIS)

    Aceves, S M; Flowers, D; Martinez-Frias, J; Espinosa-Loza, F; Pitz, W J; Dibble, R

    2003-01-01

    This paper shows a numerical evaluation of fuels and additives for HCCl combustion. First, a long list of candidate HCCl fuels is selected. For all the fuels in the list, operating conditions (compression ratio, equivalence ratio and intake temperature) are determined that result in optimum performance under typical operation for a heavy-duty engine. Fuels are also characterized by presenting Log(p)-Log(T) maps for multiple fuels under HCCl conditions. Log(p)-Log(T) maps illustrate important processes during HCCl engine operation, including compression, low temperature heat release and ignition. Log(p)-Log(T) diagrams can be used for visualizing these processes and can be used as a tool for detailed analysis of HCCl combustion. The paper also includes a ranking of many potential additives. Experiments and analyses have indicated that small amounts (a few parts per million) of secondary fuels (additives) may considerably affect HCCl combustion and may play a significant role in controlling HCCl combustion. Additives are ranked according to their capability to advance HCCl ignition. The best additives are listed and an explanation of their effect on HCCl combustion is included

  9. Effects of cetane number on HCCI combustion efficiency and emissions

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, V.; Neill, W.S.; Guo, H.; Chippior, W.L. [National Research Council of Canada, Ottawa, ON (Canada); Fairbridge, C. [Natural Resources Canada, Ottawa, ON (Canada); Mitchell, K. [Shell Canada Ltd., Calgary, AB (Canada)

    2009-07-01

    Homogeneous charge compression ignition (HCCI) is a form of internal combustion in which well-mixed fuel and oxidizer are compressed to the point of auto-ignition. This exothermic reaction releases chemical energy into a sensible form that can be transformed in an engine into work and heat. The effects of cetane number on HCCI combustion efficiency and emissions were examined in this presentation. The presentation discussed the experimental setup, fuels, experimental procedures, and results. The setup included an enhanced fuel injector/vaporizer consisting of an OEM gasoline port fuel injector, air blast for improved atomization, and heated section to improved vaporization. A minimally processed and low cetane number fuel derived from oil sands was used as the base fuel in the study. Two sets of experiments were devised and described to evaluate each test fuel. One set used controlled input conditions exhaust gas recirculation (EGR)-air-fuel ratio (AFR) while the other set employed controlled engine outputs (such as speed and load). Results were presented for hydroprocessing; cetane improver addition; blending with supercetane renewable diesel; and a comparison of fuels with similar cetane numbers. It was concluded that increasing the fuel cetane number shifted the AFR-EGR operating window for HCCI combustion towards higher AFT (leaner mixtures) and reduced the cyclic variations. tabs., figs.

  10. Gasoline Engine HCCI Combustion - Extending the high load limit

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, Daniel

    2012-07-01

    There is an increasing global focus on reducing emissions of greenhouse gases. For the automotive industry this means reducing CO2 emissions of the vehicles manufactured, which is synonymous with reducing their fuel consumption or adapting them for using renewable fuels. This thesis is based on a project aimed at improving the efficiency of gasoline engines in the lower load/speed region. The focus was mainly on a combustion strategy called homogeneous charge compression ignition (HCCI), but also on homogeneous lean and stratified lean spark-ignited combustion. In contrast to traditional stoichiometric spark-ignited combustion, HCCI can operate with diluted mixtures, which leads to better cycle efficiency, smaller pumping losses and smaller heat losses. However, at relatively high loads, HCCI combustion becomes excessively rapid, generating in-cylinder pressure oscillations (ringing), which are perceived as noise by the human ear. The main objective of the project was to identify ways to avoid this ringing behaviour in order to increase the upper load limit of HCCI. This is vital to avoid the need for mode switches to spark-ignited combustion at higher loads and to operate the engine as much as possible in the more effective HCCI mode. The strategy for reducing ringing investigated most extensively in the project was charge stratification, achieved by injecting part of the fuel late in the compression stroke. Available literature on effects of this strategy gave conflicting indications, both positive and negative effects have been reported, depending on the type of fuel and engine used. It was soon found that the strategy is effective for reducing ringing, but with resulting increases of NOX emissions. Further, in order for the strategy to be effective, global air/fuel ratios must not be much leaner than stoichiometric. The increases in NOX emissions were countered by shifting the ratio towards stoichiometric using exhaust gas recirculation (EGR), allowing a three

  11. EMISSION AND COMBUSTION CHARACTERISTICS OF DIFFERENT FUELS IN A HCCI ENGINE

    OpenAIRE

    S. Sendilvelan; S.Mohanamurugan

    2011-01-01

    Different intake valve timings and fuel injection amounts were tested in order to identify their effects on exhaust emissions and combustion characteristics using variable valve actuation (VVA) in a Homogeneous Charge Compression Ignition (HCCI) engine. The HCCI engine is a promising concept for future automobile engines and stationary power plants. The two-stage ignition process in a HCCI engine creates advanced ignition and stratified combustion, which makes the ignition timing and combus...

  12. Combustion Homogeneity and Emission Analysis during the Transition from CI to HCCI for FACE I Gasoline

    KAUST Repository

    Vedharaj, S.

    2017-10-10

    Low temperature combustion concepts are studied recently to simultaneously reduce NOX and soot emissions. Optical studies are performed to study gasoline PPC in CI engines to investigate in-cylinder combustion and stratification. It is imperative to perform emission measurements and interpret the results with combustion images. In this work, we attempt to investigate this during the transition from CI to HCCI mode for FACE I gasoline (RON = 70) and its surrogate, PRF70. The experiments are performed in a single cylinder optical engine that runs at a speed of 1200 rpm. Considering the safety of engine, testing was done at lower IMEP (3 bar) and combustion is visualized using a high-speed camera through a window in the bottom of the bowl. From the engine experiments, it is clear that intake air temperature requirement is different at various combustion modes to maintain the same combustion phasing. While a fixed intake air temperature is required at HCCI condition, it varies at PPC and CI conditions between FACE I gasoline and PRF70. Three zones are identified 1) SOI = -180 to -80 CAD (aTDC) is HCCI zone 2) SOI = -40 to -20 CAD (aTDC) is PPC zone 3) After SOI = -15 CAD (aTDC) is CI zone. Combustion duration, ignition delay, start of combustion and CA90 (crank angle at which 90% of fuel burnt) are comparable between FACE I gasoline and PRF70. The combustion images show a prominent soot flame at CI condition, while only blue coloured premixed flames are visible at PPC condition for both the fuels. PRF70 seems to have a pronounced premixed effect when compared to FACE I gasoline at early injections, showing a decreased level of stratification. NOX emission and soot concentration decreases from CI condition and attains a constant zero value at HCCI condition for both FACE I gasoline and PRF70. CO and CO2 emissions matches between FACE I gasoline and PRF70 at PPC and CI condition, while CO emission is lower for PRF70 at HCCI condition.

  13. Combustion Homogeneity and Emission Analysis during the Transition from CI to HCCI for FACE I Gasoline

    KAUST Repository

    Vedharaj, S.; Vallinayagam, R; An, Yanzhao; Izadi Najafabadi, Mohammad; Somers, Bart; Chang, Junseok; Johansson, Bengt

    2017-01-01

    Low temperature combustion concepts are studied recently to simultaneously reduce NOX and soot emissions. Optical studies are performed to study gasoline PPC in CI engines to investigate in-cylinder combustion and stratification. It is imperative to perform emission measurements and interpret the results with combustion images. In this work, we attempt to investigate this during the transition from CI to HCCI mode for FACE I gasoline (RON = 70) and its surrogate, PRF70. The experiments are performed in a single cylinder optical engine that runs at a speed of 1200 rpm. Considering the safety of engine, testing was done at lower IMEP (3 bar) and combustion is visualized using a high-speed camera through a window in the bottom of the bowl. From the engine experiments, it is clear that intake air temperature requirement is different at various combustion modes to maintain the same combustion phasing. While a fixed intake air temperature is required at HCCI condition, it varies at PPC and CI conditions between FACE I gasoline and PRF70. Three zones are identified 1) SOI = -180 to -80 CAD (aTDC) is HCCI zone 2) SOI = -40 to -20 CAD (aTDC) is PPC zone 3) After SOI = -15 CAD (aTDC) is CI zone. Combustion duration, ignition delay, start of combustion and CA90 (crank angle at which 90% of fuel burnt) are comparable between FACE I gasoline and PRF70. The combustion images show a prominent soot flame at CI condition, while only blue coloured premixed flames are visible at PPC condition for both the fuels. PRF70 seems to have a pronounced premixed effect when compared to FACE I gasoline at early injections, showing a decreased level of stratification. NOX emission and soot concentration decreases from CI condition and attains a constant zero value at HCCI condition for both FACE I gasoline and PRF70. CO and CO2 emissions matches between FACE I gasoline and PRF70 at PPC and CI condition, while CO emission is lower for PRF70 at HCCI condition.

  14. GM's HCCI. In-vehicle experience with a future combustion system; GM's HCCI. Erfahrungen mit einem zukuenftigen Verbrennungssystem im Fahrzeugeinsatz

    Energy Technology Data Exchange (ETDEWEB)

    Pritze, Stefan; Koenigstein, Achim [Adam Opel GmbH, Ruesselsheim (Germany); Rayl, Allen; Chang, Chen-Fang; Najt, Paul; Grebe, Uwe D. [General Motors LLC, Warren/Ponitac, MI (United States)

    2010-07-01

    Homogeneous Charge Compression Ignition (HCCI) stands at General Motors (GM) for the auto-ignition of a homogeneous air-fuel mixture in a gasoline engine. HCCI enables unthrottle operation under part load conditions with the high potential for fuel consumption reduction at lowest NO{sub x} emission levels even with lean mixtures. It is capable to use worldwide available fuel qualities with conventional exhaust aftertreatment. Important requirements for the application in a vehicle are the realization of a large usable steady state map covering lowest engine loads including idle operation and an outstanding transient combustion performance in terms of robustness and responsiveness. The prerequisites to achieve this were set based on a spray-guided gasoline direct injection with a strategy to control the residuals by trapping and recompressing them in the combustion chamber and sensing of individual cylinder pressure. The main characteristics of the combustion system will be discussed. The application in a vehicle sets new targets in terms of engine controller requirements and the complexity of the control algorithms. Considering only indirect control of combustion being very sensitive against extraneous impacts, it becomes extremely challenging to realize robust transitions among the various operation modes. The results achieved with the integration of the presented HCCI combustion system in prototype vehicles of the midsize segment support the chosen development path. Further improvements can be expected considering the latest achievements of the combustion system development. (orig.)

  15. Reduction of HCCI combustion noise through piston crown design

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr; Schramm, Jesper

    2010-01-01

    . The largest and most consistent reduction in noise level was however achieved with a diesel bowl type piston. The increased surface area as well as the larger crevice volumes of the experimental piston crowns generally resulted in lower IMEP than the flat piston. While the crevice volumes can be reduced...... away from the engine. The experiments were conducted in a diesel engine that was run in HCCI combustion mode with a fixed quantity of DME as fuel. The results show that combustion knock is effectively suppressed by limiting the size of the volume in which the combustion occurs. Splitting...... the compression volume into four smaller volumes placed between the perimeter of the piston and the cylinder liner increased the noise to a higher level than that generated with a flat piston crown. This was due to resonance between the four volumes. Using eight volumes instead decreased the noise. The noise...

  16. An optimized chemical kinetic mechanism for HCCI combustion of PRFs using multi-zone model and genetic algorithm

    International Nuclear Information System (INIS)

    Neshat, Elaheh; Saray, Rahim Khoshbakhti

    2015-01-01

    Highlights: • A new chemical kinetic mechanism for PRFs HCCI combustion is developed. • New mechanism optimization is performed using genetic algorithm and multi-zone model. • Engine-related combustion and performance parameters are predicted accurately. • Engine unburned HC and CO emissions are predicted by the model properly. - Abstract: Development of comprehensive chemical kinetic mechanisms is required for HCCI combustion and emissions prediction to be used in engine development. The main purpose of this study is development of a new chemical kinetic mechanism for primary reference fuels (PRFs) HCCI combustion, which can be applied to combustion models to predict in-cylinder pressure and exhaust CO and UHC emissions, accurately. Hence, a multi-zone model is developed for HCCI engine simulation. Two semi-detailed chemical kinetic mechanisms those are suitable for premixed combustion are used for n-heptane and iso-octane HCCI combustion simulation. The iso-octane mechanism contains 84 species and 484 reactions and the n-heptane mechanism contains 57 species and 296 reactions. A simple interaction between iso-octane and n-heptane is considered in new mechanism. The multi-zone model is validated using experimental data for pure n-heptane and iso-octane. A new mechanism is prepared by combination of these two mechanisms for n-heptane and iso-octane blended fuel, which includes 101 species and 594 reactions. New mechanism optimization is performed using genetic algorithm and multi-zone model. Mechanism contains low temperature heat release region, which decreases with increasing octane number. The results showed that the optimized chemical kinetic mechanism is capable of predicting engine-related combustion and performance parameters. Also after implementing the optimized mechanism, engine unburned HC and CO emissions predicted by the model are in good agreement with the corresponding experimental data

  17. Development of a new reduced hydrogen combustion mechanism with NO_x and parametric study of hydrogen HCCI combustion using stochastic reactor model

    International Nuclear Information System (INIS)

    Maurya, Rakesh Kumar; Akhil, Nekkanti

    2017-01-01

    Highlights: • PDF based stochastic reactor model used for study of hydrogen HCCI engine. • New reduced hydrogen combustion mechanism with NOx developed (30 species and 253 reactions). • Mechanism predicts cylinder pressure and captures NO_x emission trend with sufficient accuracy. • Parametric study of hydrogen HCCI engine over wide range of speed and load conditions. • Hydrogen HCCI operating range increases with compression ratio & decreases with engine speed. - Abstract: Hydrogen is a potential alternative and renewable fuel for homogenous charge compression ignition (HCCI) engine to achieve higher efficiency and zero emissions of CO, unburned hydrocarbons as well as other greenhouse gases such as CO_2 and CH_4. In this study, a detailed hydrogen oxidation mechanism with NO_x was developed by incorporating additional species and NO_x reactions to the existing hydrogen combustion mechanism (10 species and 40 reactions). The detailed hydrogen combustion mechanism used in this study consists of 39 species and 311 reactions. A reduced mechanism consisting 30 species and 253 reactions was also developed by using directed relation graph (DRG) method from detailed mechanism. Developed mechanisms were validated with experimental data by HCCI engine simulation using stochastic reactor model. Sensitivity analysis was performed to identify the most important reactions in hydrogen combustion and NO_x formation in HCCI engine. Pathway analysis was also performed to analyze the important reaction pathways at different temperatures. Results revealed that H2 + HO2 [=] H + H2O2 and O2 + NNH [=] N2 + HO2 are the most significant reactions in the hydrogen HCCI combustion and NO_x formation respectively. Detailed parametric study of HCCI combustion was conducted using developed chemical kinetic model. Numerical simulations are performed at different engine operating condition by varying engine speed (1000–3000 rpm), intake air temperature (380–460 K), and compression

  18. EMISSION AND COMBUSTION CHARACTERISTICS OF DIFFERENT FUELS IN A HCCI ENGINE

    Directory of Open Access Journals (Sweden)

    S. Sendilvelan

    2011-06-01

    Full Text Available Different intake valve timings and fuel injection amounts were tested in order to identify their effects on exhaust emissions and combustion characteristics using variable valve actuation (VVA in a Homogeneous Charge Compression Ignition (HCCI engine. The HCCI engine is a promising concept for future automobile engines and stationary power plants. The two-stage ignition process in a HCCI engine creates advanced ignition and stratified combustion, which makes the ignition timing and combustion rate controllable. Meanwhile, the periphery of the fuel-rich zone leads to fierce burning, which results in slightly high NOx emissions. The experiments were conducted in a modified single cylinder water-cooled diesel engine. In this experiment we use diesel, bio-diesel (Jatropha and gasoline as the fuel at different mixing ratios. HCCI has advantages in high thermal efficiency and low emissions and could possibly become a promising combustion method in internal combustion engines.

  19. Mixture preparation and combustion in an optically-accessible HCCI, diesel engine; La preparation du melange et de la combustion dans un moteur Diesel, HCCI a acces optique

    Energy Technology Data Exchange (ETDEWEB)

    Kashdan, J.; Bruneaux, G. [Institut Francais du Petrole, 92 - Rueil-Malmaison (France)

    2006-07-01

    Planar laser-induced fluorescence (LIF) imaging techniques have been applied in order to study the mixture preparation and combustion process in a single cylinder, optically-accessible homogeneous charge, compression ignition (HCCI) engine. In particular, the influence of piston bowl geometry on the in-cylinder mixture distribution and subsequent combustion process has been investigated. A new optically-accessible piston design enabled the application of LIF diagnostics directly within the combustion chamber bowl. Firstly, laser-induced exciplex fluorescence (LIEF) was exploited in order to characterise the in-cylinder fuel spray and vapour distribution. Subsequently a detailed study of the two-stage HCCI combustion process was conducted by a combination of direct chemiluminescence imaging, laser-induced fluorescence (LIF) of the intermediate species formaldehyde (CH{sub 2}O) which is present during the cool flame and LIF of the OH radical which is subsequently present in the reaction and burned gas zones at higher temperature. Finally, spectrometry measurements were performed with the objective of determining the origin of the emitting species of the chemiluminescence signal. The experiments were performed on a single cylinder optical engine equipped with a direct-injection, common rail injection system and narrow angle injector. The experimental results presented reveal the significant role of the combustion chamber geometry on the mixture preparation and combustion characteristics for late HCCI injection strategies particularly in such cases where liquid impingement is unavoidable. Planar LIF 355 imaging revealed the presence of the intermediate species formaldehyde allowing the temporal and spatial detection of auto-ignition precursors prior to the signal observed by chemiluminescence in the early stages of the cool flame. Formaldehyde was then rapidly consumed at the start of main combustion which was marked not only by the increase in the main heat release

  20. A Study on the Effects of Compression Ratio, Engine Speed and Equivalence Ratio on HCCI Combustion of DME

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr; Schramm, Jesper

    2007-01-01

    An experimental study has been carried out on the homogeneous charge compression ignition (HCCI) combustion of Dimethyl Ether (DME). The study was performed as a parameter variation of engine speed and compression ratio on excess air ratios of approximately 2.5, 3 and 4. The compression ratio was...

  1. A parametric investigation of hydrogen hcci combustion using a multi-zone model approach

    International Nuclear Information System (INIS)

    Komninos, N.P.; Hountalas, D.T.; Rakopoulos, C.D.

    2007-01-01

    The purpose of the present study is to examine the effect of various operating variables of a homogeneous charge compression ignition (HCCI) engine fueled with hydrogen, using a multi-zone model developed by the authors. The multi-zone model consists of zones, which are allotted spatial locations within the combustion chamber. The model takes into account heat transfer between the zones and the combustion chamber walls, providing a spatial temperature distribution during the closed part of the engine cycle, i.e. compression, combustion and expansion. Mass transfer between zones is also accounted for, based on the geometric configuration of the zones, and includes the flow of mass in and out of the crevice regions, represented by the crevice zone. Combustion is incorporated using chemical kinetics based on a chemical reaction mechanism for the oxidation of hydrogen. This chemical reaction mechanism also includes the reactions for nitrogen oxides formation. Using the multi-zone model a parametric investigation is conducted, in order to determine the effect of engine speed, equivalence ratio, compression ratio, inlet pressure and inlet temperature, on the performance, combustion characteristics and emissions of an HCCI engine fueled with hydrogen

  2. Modeling and controller design architecture for cycle-by-cycle combustion control of homogeneous charge compression ignition (HCCI) engines – A comprehensive review

    International Nuclear Information System (INIS)

    Fathi, Morteza; Jahanian, Omid; Shahbakhti, Mahdi

    2017-01-01

    Highlights: • Addressing accuracy-speed compromise of HCCI representation is very important. • Phasing, load, exhaust temperature and emissions are the most important outputs. • Separability between the effects of the inputs on the outputs is of great interest. • Existing actuation systems combining inputs are favorable. • An HCCI controller should be a fast and robust one to become a viable solution. - Abstract: Homogeneous charge compression ignition (HCCI) combustion engines are advantageous in terms of good fuel economy and low levels of soot-nitrogen oxides (NOx) emissions. However, they are accompanied with some intrinsic challenges, the most important of which is the lack of any direct control method for ignition trigger. Thus, implementation of HCCI combustion is in fact a control problem, and an optimized control structure is required for attaining the inherent benefits of HCCI. The control structure consists of a proper representation of engine processes; a suitable selection of state variables; useful and applicable set of inputs, outputs and observers; appropriate fixed or variable set-points for controlled parameters; instrumentations including sensors and actuators; and an applicable control law implemented in a controller. The present paper aims at addressing these issues altogether by introducing HCCI engine control structure in progress and presenting highlights from literature. Research should result in appropriately controlled HCCI engines which can provide desired load at rated speed with acceptable performance and emissions characteristics.

  3. Experimental study of combustion and emission characteristics of ethanol fuelled port injected homogeneous charge compression ignition (HCCI) combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, Rakesh Kumar; Agarwal, Avinash Kumar [Engine Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

    2011-04-15

    The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for in reciprocating engines. The HCCI combustion engine offers significant benefits in terms of its high efficiency and ultra low emissions. In this investigation, port injection technique is used for preparing homogeneous charge. The combustion and emission characteristics of a HCCI engine fuelled with ethanol were investigated on a modified two-cylinder, four-stroke engine. The experiment is conducted with varying intake air temperature (120-150 C) and at different air-fuel ratios, for which stable HCCI combustion is achieved. In-cylinder pressure, heat release analysis and exhaust emission measurements were employed for combustion diagnostics. In this study, effect of intake air temperature on combustion parameters, thermal efficiency, combustion efficiency and emissions in HCCI combustion engine is analyzed and discussed in detail. The experimental results indicate that the air-fuel ratio and intake air temperature have significant effect on the maximum in-cylinder pressure and its position, gas exchange efficiency, thermal efficiency, combustion efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operation points, NO{sub x} emissions are lower than 10 ppm however HC and CO emissions are higher. (author)

  4. Blending Behavior of Ethanol with PRF 84 and FACE A Gasoline in HCCI Combustion Mmode

    KAUST Repository

    Waqas, Muhammad Umer

    2017-09-04

    The blending of ethanol with PRF (Primary reference fuel) 84 was investigated and compared with FACE (Fuels for Advanced Combustion Engines) A gasoline surrogate which has a RON of 83.9. Previously, experiments were performed at four HCCI conditions but the chemical effect responsible for the non-linear blending behavior of ethanol with PRF 84 and FACE A was not understood. Hence, in this study the experimental measurements were simulated using zero-dimensional HCCI engine model with detailed chemistry in CHEMKIN PRO. Ethanol was used as an octane booster for the above two base fuels in volume concentration of 0%, 2%, 5% and 10%. The geometrical data and the intake valve closure conditions were used to match the simulated combustion phasing with the experiments. Low temperature heat release (LTHR) was detected by performing heat release analysis. LTHR formation depended on the base fuel type and the engine operating conditions suggesting that the base fuel composition has an important role in the formation of LTHR. The effect of ethanol on LTHR was explained by low temperature chemistry reactions and OH/HO evolution. A strong correlation of low temperature oxidation reactions of base fuels with ethanol was found to be responsible for the observed blending effects.

  5. Controlling cyclic combustion timing variations using a symbol-statistics predictive approach in an HCCI engine

    International Nuclear Information System (INIS)

    Ghazimirsaied, Ahmad; Koch, Charles Robert

    2012-01-01

    Highlights: ► Misfire reduction in a combustion engine based on chaotic theory methods. ► Chaotic theory analysis of cyclic variation of a HCCI engine near misfire. ► Symbol sequence approach is used to predict ignition timing one cycle-ahead. ► Prediction is combined with feedback control to lower HCCI combustion variation. ► Feedback control extends the HCCI operating range into the misfire region. -- Abstract: Cyclic variation of a Homogeneous Charge Compression Ignition (HCCI) engine near misfire is analyzed using chaotic theory methods and feedback control is used to stabilize high cyclic variations. Variation of consecutive cycles of θ Pmax (the crank angle of maximum cylinder pressure over an engine cycle) for a Primary Reference Fuel engine is analyzed near misfire operation for five test points with similar conditions but different octane numbers. The return map of the time series of θ Pmax at each combustion cycle reveals the deterministic and random portions of the dynamics near misfire for this HCCI engine. A symbol-statistic approach is used to predict θ Pmax one cycle-ahead. Predicted θ Pmax has similar dynamical behavior to the experimental measurements. Based on this cycle ahead prediction, and using fuel octane as the input, feedback control is used to stabilize the instability of θ Pmax variations at this engine condition near misfire.

  6. Reaction Mechanisms and HCCI Combustion Processes of Mixtures of n-Heptane and the Butanols

    Directory of Open Access Journals (Sweden)

    Hu eWang

    2015-03-01

    Full Text Available A reduced primary reference fuel (PRF-Alcohol-Di-tert-butyl Peroxide (DTBP mechanism with 108 species and 435 reactions, including sub-mechanisms of PRF, methanol, ethanol, DTBP and the four butanol isomers, is proposed for homogeneous charge compression ignition (HCCI engine combustion simulations of butanol isomers/n-heptane mixtures. HCCI experiments fuelled with butanol isomer/n-heptane mixtures on two different engines are conducted for the validation of proposed mechanism. The mechanism has been validated against shock tube ignition delays, laminar flame speeds, species profiles in premixed flames and engine HCCI combustion data, and good agreements with experimental results are demonstrated under various validation conditions. It is found that although the reactivity of neat tert-butanol is the lowest, mixtures of tert-butanol/n-heptane exhibit the highest reactivity among the butanol isomer/n-heptane mixtures if the n-heptane blending ratio exceeds 20% (mole. Kinetic analysis shows that the highest C-H bond energy in the tert-butanol molecule is partially responsible for this phenomenon. It is also found that the reaction tC4H9OH+CH3O2 =tC4H9O+CH3O2H plays important role and eventually produces the OH radical to promote the ignition and combustion. The proposed mechanism is able to capture HCCI combustion processes of the butanol/n-heptane mixtures under different operating conditions. In addition, the trend that tert-butanol /n-heptane has the highest reactivity is also captured in HCCI combustion simulations. The results indicate that the current mechanism can be used for HCCI engine predictions of PRF and alcohol fuels.

  7. Optical Study of Flow and Combustion in an HCCI Engine with Negative Valve Overlap

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Trevor S [Jaguar Cars Ltd., Whitley Engineering Centre, Coventry. CV3 4LF (United Kingdom); Xu Hongming [Jaguar Cars Ltd., Whitley Engineering Centre, Coventry. CV3 4LF (United Kingdom); Richardson, Steve [Jaguar Cars Ltd., Whitley Engineering Centre, Coventry. CV3 4LF (United Kingdom); Wyszynski, Miroslaw L [University of Birmingham, Edgbaston, Birmingham. B15 2TT (United Kingdom); Megaritis, Thanos [University of Birmingham, Edgbaston, Birmingham. B15 2TT (United Kingdom)

    2006-07-15

    One of the most widely used methods to enable Homogeneous Charge Compression Ignition (HCCI) combustion is using negative valve overlapping to trap a sufficient quantity of hot residual gas. The characteristics of air motion with specially designed valve events having reduced valve lift and durations associated with HCCI engines and their effect on subsequent combustion are not yet fully understood. In addition, the ignition process and combustion development in such engines are very different from those in conventional spark-ignition or diesel compression ignition engines. Very little data has been reported concerning optical diagnostics of the flow and combustion in the engine using negative valve overlapping. This paper presents an experimental investigation into the in-cylinder flow characteristics and combustion development in an optical engine operating in HCCI combustion mode. PIV measurements have been taken under motored engine conditions to provide a quantitative flow characterisation of negative valve overlap in-cylinder flows. The ignition and combustion process was imaged using a high resolution charge coupled device (CCD) camera and the combustion imaging data was supplemented by simultaneously recorded in-cylinder pressure data which assisted the analysis of the images. It is found that the flow characteristics with negative valve overlapping are less stable and more valve event driven than typical spark ignition in-cylinder flows, while the combustion initiation locations are not uniformly distributed.

  8. A Study on the Effects of Compression Ratio, Engine Speed and Equivalence Ratio on HCCI Combustion of DME

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr; Schramm, Jesper

    2007-01-01

    An experimental study has been carried out on the homogeneous charge compression ignition (HCCI) combustion of Dimethyl Ether (DME). The study was performed as a parameter variation of engine speed and compression ratio on excess air ratios of approximately 2.5, 3 and 4. The compression ratio...... was adjusted in steps to find suitable regions of operation, and the effect of engine speed was studied at 1000, 2000 and 3000 RPM. It was found that leaner excess air ratios require higher compression ratios to achieve satisfactory combustion. Engine speed also affects operation significantly....

  9. Combustion optimization and HCCI modeling for ultra low emission

    Energy Technology Data Exchange (ETDEWEB)

    Koten, Hasan; Yilmaz, Mustafa; Zafer Gul, M. [Marmara University Mechanical Engineering Department (Turkey)], E-mail: hasan.koten@marmara.edu.tr

    2011-07-01

    With the coming shortage of fossil fuels and the rising concerns over the environment it is important to develop new technologies both to reduce energy consumption and pollution at the same time. In the transportation sector, new combustion processes are under development to provide clean diesel combustion with no particulate or NOx emissions. However, these processes have issues such as limited power output, high levels of unburned hydrocarbons, and carbon monoxide emissions. The aim of this paper is to present a methodology for optimizing combustion performance. The methodology consists of the use of a multi-objective genetic algorithm optimization tool; homogeneous charge compression ignition engine cases were studied with the ECFM-3Z combustion model. Results showed that injected fuel mass led to a decrease in power output, a finding which is in keeping with previous research. This paper presented on optimization tool which can be useful in improving the combustion process.

  10. Fundamental phenomena affecting low temperature combustion and HCCI engines, high load limits and strategies for extending these limits

    KAUST Repository

    Saxena, Samveg; Bedoya, Ivá n D.

    2013-01-01

    Low temperature combustion (LTC) engines are an emerging engine technology that offers an alternative to spark-ignited and diesel engines. One type of LTC engine, the homogeneous charge compression ignition (HCCI) engine, uses a well-mixed fuel–air charge like spark-ignited engines and relies on compression ignition like diesel engines. Similar to diesel engines, the use of high compression ratios and removal of the throttling valve in HCCI allow for high efficiency operation, thereby allowing lower CO2 emissions per unit of work delivered by the engine. The use of a highly diluted well-mixed fuel–air charge allows for low emissions of nitrogen oxides, soot and particulate matters, and the use of oxidation catalysts can allow low emissions of unburned hydrocarbons and carbon monoxide. As a result, HCCI offers the ability to achieve high efficiencies comparable with diesel while also allowing clean emissions while using relatively inexpensive aftertreatment technologies. HCCI is not, however, without its challenges. Traditionally, two important problems prohibiting market penetration of HCCI are 1) inability to achieve high load, and 2) difficulty in controlling combustion timing. Recent research has significantly mitigated these challenges, and thus HCCI has a promising future for automotive and power generation applications. This article begins by providing a comprehensive review of the physical phenomena governing HCCI operation, with particular emphasis on high load conditions. Emissions characteristics are then discussed, with suggestions on how to inexpensively enable low emissions of all regulated emissions. The operating limits that govern the high load conditions are discussed in detail, and finally a review of recent research which expands the high load limits of HCCI is discussed. Although this article focuses on the fundamental phenomena governing HCCI operation, it is also useful for understanding the fundamental phenomena in reactivity controlled

  11. Fundamental phenomena affecting low temperature combustion and HCCI engines, high load limits and strategies for extending these limits

    KAUST Repository

    Saxena, Samveg

    2013-10-01

    Low temperature combustion (LTC) engines are an emerging engine technology that offers an alternative to spark-ignited and diesel engines. One type of LTC engine, the homogeneous charge compression ignition (HCCI) engine, uses a well-mixed fuel–air charge like spark-ignited engines and relies on compression ignition like diesel engines. Similar to diesel engines, the use of high compression ratios and removal of the throttling valve in HCCI allow for high efficiency operation, thereby allowing lower CO2 emissions per unit of work delivered by the engine. The use of a highly diluted well-mixed fuel–air charge allows for low emissions of nitrogen oxides, soot and particulate matters, and the use of oxidation catalysts can allow low emissions of unburned hydrocarbons and carbon monoxide. As a result, HCCI offers the ability to achieve high efficiencies comparable with diesel while also allowing clean emissions while using relatively inexpensive aftertreatment technologies. HCCI is not, however, without its challenges. Traditionally, two important problems prohibiting market penetration of HCCI are 1) inability to achieve high load, and 2) difficulty in controlling combustion timing. Recent research has significantly mitigated these challenges, and thus HCCI has a promising future for automotive and power generation applications. This article begins by providing a comprehensive review of the physical phenomena governing HCCI operation, with particular emphasis on high load conditions. Emissions characteristics are then discussed, with suggestions on how to inexpensively enable low emissions of all regulated emissions. The operating limits that govern the high load conditions are discussed in detail, and finally a review of recent research which expands the high load limits of HCCI is discussed. Although this article focuses on the fundamental phenomena governing HCCI operation, it is also useful for understanding the fundamental phenomena in reactivity controlled

  12. Chemistry Impacts in Gasoline HCCI

    Energy Technology Data Exchange (ETDEWEB)

    Szybist, James P [ORNL; Bunting, Bruce G [ORNL

    2006-09-01

    The use of homogeneous charge compression ignition (HCCI) combustion in internal combustion engines is of interest because it has the potential to produce low oxides of nitrogen (NOx) and particulate matter (PM) emissions while providing diesel-like efficiency. In HCCI combustion, a premixed charge of fuel and air auto-ignites at multiple points in the cylinder near top dead center (TDC), resulting in rapid combustion with very little flame propagation. In order to prevent excessive knocking during HCCI combustion, it must take place in a dilute environment, resulting from either operating fuel lean or providing high levels of either internal or external exhaust gas recirculation (EGR). Operating the engine in a dilute environment can substantially reduce the pumping losses, thus providing the main efficiency advantage compared to spark-ignition (SI) engines. Low NOx and PM emissions have been reported by virtually all researchers for operation under HCCI conditions. The precise emissions can vary depending on how well mixed the intake charge is, the fuel used, and the phasing of the HCCI combustion event; but it is common for there to be no measurable PM emissions and NOx emissions <10 ppm. Much of the early HCCI work was done on 2-stroke engines, and in these studies the CO and hydrocarbon emissions were reported to decrease [1]. However, in modern 4-stroke engines, the CO and hydrocarbon emissions from HCCI usually represent a marked increase compared with conventional SI combustion. This literature review does not report on HCCI emissions because the trends mentioned above are well established in the literature. The main focus of this literature review is the auto-ignition performance of gasoline-type fuels. It follows that this discussion relies heavily on the extensive information available about gasoline auto-ignition from studying knock in SI engines. Section 2 discusses hydrocarbon auto-ignition, the octane number scale, the chemistry behind it, its

  13. Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing

    Science.gov (United States)

    Saxena, Samveg

    Homogeneous Charge Compression Ignition (HCCI) engines are one of the most promising engine technologies for the future of energy conversion from clean, efficient combustion. HCCI engines allow high efficiency and lower CO2 emission through the use of high compression ratios and the removal of intake throttle valves (like Diesel), and allow very low levels of urban pollutants like nitric oxide and soot (like Otto). These engines, however, are not without their challenges, such as low power density compared with other engine technologies, and a difficulty in controlling combustion timing. This dissertation first addresses the power output limits. The particular strategies for enabling high power output investigated in this dissertation focus on avoiding five critical limits that either damage an engine, drastically reduce efficiency, or drastically increase emissions: (1) ringing limits, (2) peak in-cylinder pressure limits, (3) misfire limits, (4) low intake temperature limits, and (5) excessive emissions limits. The research shows that the key factors that enable high power output, sufficient for passenger vehicles, while simultaneously avoiding the five limits defined above are the use of: (1) high intake air pressures allowing improved power output, (2) highly delayed combustion timing to avoid ringing limits, and (3) using the highest possible equivalence ratio before encountering ringing limits. These results are revealed by conducting extensive experiments spanning a wide range of operating conditions on a multi-cylinder HCCI engine. Second, this dissertation discusses strategies for effectively sensing combustion characteristics on a HCCI engine. For effective feedback control of HCCI combustion timing, a sensor is required to quantify when combustion occurs. Many laboratory engines use in-cylinder pressure sensors but these sensors are currently prohibitively expensive for wide-scale commercialization. Instead, ion sensors made from inexpensive sparkplugs

  14. Naphtha vs. dieseline – The effect of fuel properties on combustion homogeneity in transition from CI combustion towards HCCI

    KAUST Repository

    Vallinayagam, R.

    2018-03-20

    The scope of this research study pertains to compare the combustion and emission behavior between naphtha and dieseline at different combustion modes. In this study, US dieseline (50% US diesel + 50% RON 91 gasoline) and EU dieseline (45% EU diesel + 55% RON 97 gasoline) with derived cetane number (DCN) of 36 are selected for experimentation in an optical engine. Besides naphtha and dieseline, PRF60 is also tested as a surrogate fuel for naphtha. For the reported fuel with same RON = 60, the effect of physical properties on combustion homogeneity when moving from homogenized charge compression ignition (HCCI) to compression ignition (CI) combustion is studied.The combustion phasing of naphtha at an intake air temperature of 95 °C is taken as the baseline data. The engine experimental results show that higher and lower intake air temperature is required for dieseline mixtures to have same combustion phasing as that of naphtha at HCCI and CI conditions due to the difference in the physical properties. Especially at HCCI mode, due to wider distillation range of dieseline, the evaporation of the fuel is affected so that the gas phase mixture becomes too lean to auto-ignite. However, at partially premixed combustion (PPC) conditions, all test fuels required almost same intake air temperature to match up with the combustion phasing of baseline naphtha. From the rate of heat release and combustion images, it was found that naphtha and PRF60 showed improved premixed combustion when compared dieseline mixtures. The stratification analysis shows that combustion is more stratified for dieseline whereas it is premixed for naphtha and PRF60. The level of stratification linked with soot emission showed that soot concentration is higher at stratified CI combustion whereas near zero soot emissions were noted at PPC mode.

  15. Experimental study of biogas combustion in an HCCI engine for power generation with high indicated efficiency and ultra-low NOx emissions

    International Nuclear Information System (INIS)

    Bedoya, Iván D.; Saxena, Samveg; Cadavid, Francisco J.; Dibble, Robert W.; Wissink, Martin

    2012-01-01

    Highlights: ► In this paper, we study biogas combustion in an HCCI engine operating at 1800 rpm. ► At low loads, slight changes in inlet conditions strongly affect cyclic variations. ► At high loads, slight changes in inlet conditions strongly affect ringing intensity. ► Indicated efficiency at high loads is close to 45% and IMEP g is close to 7.5 bar. ► NO x emissions are below the US-2010 limit of 0.27 g/kW h. - Abstract: Combustion parameters and the main exhaust emissions from a biogas fueled HCCI engine are investigated in this study. The study was conducted on a 4-cylinder, 1.9L Volkswagen TDI Diesel engine, which was modified to run in HCCI mode with biogas by means of inlet charge temperature control, boosted intake pressure, and a sonic flow device upstream of the inlet manifold to control biogas composition and the equivalence ratio. For simulating typical power generation conditions, the engine was coupled to an AC motor generator operating at 1800 rpm. In the startup process, gasoline was used in HCCI mode for all cylinders. During the tests, biogas was used in cylinders 2 and 3, and gasoline was used in cylinders 1 and 4 to allow for more stable engine coolant and oil temperatures. The tests were performed through an experimental factorial design to evaluate the effect of inlet charge temperature, boost pressures, and the equivalence ratio of the biogas–air mixture on HCCI combustion parameters and emissions. For biogas at lower equivalence ratios, slight increases in inlet charge temperature and boost pressures enhanced combustion parameters and reduced CO and HC emissions. For biogas at higher equivalence ratios, the effects of inlet charge conditions on HCCI combustion and CO and HC emissions were attenuated; however, ringing intensities and NO x emissions were increased with higher inlet charge temperature and higher boosted pressures. The maximum gross indicated mean effective pressure was 7.4 bar, the maximum gross indicated

  16. An experimental study for the effects of boost pressure on the performance and exhaust emissions of a DI-HCCI gasoline engine

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa Canakci [Kocaeli University, Izmit (Turkey). Department of Mechanical Education

    2008-07-15

    As an alternative combustion mode, the HCCI combustion has some benefits compared to conventional SI and CI engines, such as low NOx emission and high thermal efficiency. However, this combustion mode can produce higher UHC and CO emissions than those of conventional engines. In the naturally aspirated HCCI engines, the low engine output power limits its use in the current engine technologies. Intake air pressure boosting is a common way to improve the engine output power which is widely used in high performance SI and CI engine applications. Therefore, in this study, the effect of inlet air pressure on the performance and exhaust emissions of a DI-HCCI gasoline engine has been investigated after converting a heavy-duty diesel engine to a HCCI direct-injection gasoline engine. The experiments were performed at three different inlet air pressures while operating the engine at the same equivalence ratio and intake air temperature as in normally aspirated HCCI engine condition at different engine speeds. The SOI timing was set dependently to achieve the maximum engine torque at each test condition. The effects of inlet air pressure both on the emissions such as CO, UHC and NOx and on the performance parameters such as BSFC, torque, thermal and combustion efficiencies have been discussed. The relationships between the emissions are also provided. 34 refs., 19 figs., 4 tabs.

  17. Combustion visualization and experimental study on spark induced compression ignition (SICI) in gasoline HCCI engines

    International Nuclear Information System (INIS)

    Wang Zhi; He Xu; Wang Jianxin; Shuai Shijin; Xu Fan; Yang Dongbo

    2010-01-01

    Spark induced compression ignition (SICI) is a relatively new combustion control technology and a promising combustion mode in gasoline engines with high efficiency. SICI can be divided into two categories, SACI and SI-CI. This paper investigated the SICI combustion process using combustion visualization and engine experiment respectively. Ignition process of SICI was captured by high speed photography in an optical engine with different compression ratios. The results show that SICI is a combustion mode combined with partly flame propagation and main auto-ignition. The spark ignites the local mixture near spark electrodes and the flame propagation occurs before the homogeneous mixture is auto-ignited. The heat release from central burned zone due to the flame propagation increases the in-cylinder pressure and temperature, resulting in the unburned mixture auto-ignition. The SICI combustion process can be divided into three stages of the spark induced stage, the flame propagation stage and the compression ignition stage. The SICI combustion mode is different from the spark ignition (SI) knocking in terms of the combustion and emission characteristics. Furthermore, three typical combustion modes including HCCI, SICI, SI, were compared on a gasoline direct injection engine with higher compression ratio and switchable cam-profiles. The results show that SICI has an obvious combustion characteristic with two-stage heat release and lower pressure rise rate. The SICI combustion mode can be controlled by spark timings and EGR rates and utilized as an effective method for high load extension on the gasoline HCCI engine. The maximum IMEP of 0.82 MPa can be achieved with relatively low NO x emission and high thermal efficiency. The SICI combustion mode can be applied in medium-high load region for high efficiency gasoline engines.

  18. Combustion visualization and experimental study on spark induced compression ignition (SICI) in gasoline HCCI engines

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhi, E-mail: wangzhi@tsinghua.edu.c [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China); He Xu; Wang Jianxin; Shuai Shijin; Xu Fan; Yang Dongbo [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China)

    2010-05-15

    Spark induced compression ignition (SICI) is a relatively new combustion control technology and a promising combustion mode in gasoline engines with high efficiency. SICI can be divided into two categories, SACI and SI-CI. This paper investigated the SICI combustion process using combustion visualization and engine experiment respectively. Ignition process of SICI was captured by high speed photography in an optical engine with different compression ratios. The results show that SICI is a combustion mode combined with partly flame propagation and main auto-ignition. The spark ignites the local mixture near spark electrodes and the flame propagation occurs before the homogeneous mixture is auto-ignited. The heat release from central burned zone due to the flame propagation increases the in-cylinder pressure and temperature, resulting in the unburned mixture auto-ignition. The SICI combustion process can be divided into three stages of the spark induced stage, the flame propagation stage and the compression ignition stage. The SICI combustion mode is different from the spark ignition (SI) knocking in terms of the combustion and emission characteristics. Furthermore, three typical combustion modes including HCCI, SICI, SI, were compared on a gasoline direct injection engine with higher compression ratio and switchable cam-profiles. The results show that SICI has an obvious combustion characteristic with two-stage heat release and lower pressure rise rate. The SICI combustion mode can be controlled by spark timings and EGR rates and utilized as an effective method for high load extension on the gasoline HCCI engine. The maximum IMEP of 0.82 MPa can be achieved with relatively low NO{sub x} emission and high thermal efficiency. The SICI combustion mode can be applied in medium-high load region for high efficiency gasoline engines.

  19. Numerical investigation of ethanol fuelled HCCI engine using stochastic reactor model. Part 2: Parametric study of performance and emissions characteristics using new reduced ethanol oxidation mechanism

    International Nuclear Information System (INIS)

    Maurya, Rakesh Kumar; Akhil, Nekkanti

    2016-01-01

    Highlights: • Newly developed reduced ethanol mechanism (47 species and 272 reactions) used. • Engine maps over wide range are developed for performance and emissions parameters. • HCCI operating range increases with compression ratio & decreases with engine speed. • Maximum combustion efficiency up to 99% and thermal efficiency up to 50% is achieved. • Maximum N_2O emission found up to 2.7 ppm and lower load have higher N_2O emission. - Abstract: Ethanol fuelled homogenous charge compression ignition engine offers a better alternative to tackle the problems of achieving higher engine efficiency and lower emissions using renewable fuel. Present study computationally investigates the HCCI operating range of ethanol at different compression ratios by varying inlet air temperature and engine speed using stochastic reactor model. A newly developed reduced ethanol oxidation mechanism with NO_x having 47 species and 272 reactions is used for simulation. HCCI operating range for compression ratios 17, 19 and 21 are investigated and found to be increasing with compression ratio. Simulations are conducted for engine speeds ranging from 1000 to 3000 rpm at different intake temperatures (range 365–465 K). Parametric study of combustion and emission characteristics is conducted and engine maps are developed at most efficient inlet temperatures. HCCI operating range is defined using combustion efficiency (>85%) and maximum pressure rise rate (<5 MPa/ms). In HCCI operating range, higher efficiency is found at higher engine loads and lower engine speeds. Emission characteristics of species (NO_x, N_2O, CO, CH_4, C_2H_4, C_2H_6, CH_3CHO, and HCHO) found in significant amount is also analysed for ethanol fulled HCCI engine. Emission maps for different species are presented and discussed for wide range of speed and load conditions. Some of unregulated species such as aldehydes are emitted in significantly higher quantities from ethanol fuelled HCCI engine at higher load

  20. Comparison of combustion characteristics of n-butanol/ethanol–gasoline blends in a HCCI engine

    International Nuclear Information System (INIS)

    He, Bang-Quan; Liu, Mao-Bin; Zhao, Hua

    2015-01-01

    Highlights: • The blends with alcohol autoignite early in the conditions highly diluted by exhaust. • n-Butanol is more reactive than ethanol in the blend with the same alcohol content. • Autoignition timing delays with retarding IVO timing for all alcohol–gasoline blends. • Advanced autoignition for the blends with alcohol leads to lower thermal efficiency. - Abstract: As a sustainable biofuel, n-butanol can be used in conventional spark ignition (SI) and compression ignition (CI) engines in order to reduce the dependence on fossil fuel. Homogeneous charge compression ignition (HCCI) is a novel combustion to improve the thermal efficiency of conventional SI engines at part loads. To understand the effect of alcohol structure on HCCI combustion under stoichiometric conditions highly diluted by exhaust gases, the combustion characteristics of n-butanol, ethanol and their blends with gasoline were investigated on a single cylinder port fuel injection gasoline engine with fixed intake/exhaust valve lifts at the same operating conditions in this study. The results show that autoignition timing for alcohol–gasoline blends is dependent on alcohol types and its concentration in the blend, engine speed and intake valve opening (IVO)/exhaust valve closing (EVC) timing. In the operating conditions with the residual gases more than 38% by mass in the mixture, alcohol–gasoline blends autoignite more easily than gasoline. Autoignition timing for n-butanol–gasoline blend is earlier than that for ethanol–gasoline blend with the same alcohol volume fraction at 1500 rpm in most cases while the autoignition timings for the blends with alcohol are relatively close at 2000 rpm at the same IVO/EVC timing. Combustion stability is improved with advanced EVC timing at a fixed IVO timing, which is benefit for the improvement in the thermal efficiency in the case of alcohol–gasoline blends. In addition, n-butanol–gasoline blends autoignite earlier than their ethanol

  1. Numerical Investigation Into Effect of Fuel Injection Timing on CAI/HCCI Combustion in a Four-Stroke GDI Engine

    Science.gov (United States)

    Cao, Li; Zhao, Hua; Jiang, Xi; Kalian, Navin

    2006-02-01

    The Controlled Auto-Ignition (CAI) combustion, also known as Homogeneous Charge Compression Ignition (HCCI), was achieved by trapping residuals with early exhaust valve closure in conjunction with direct injection. Multi-cycle 3D engine simulations have been carried out for parametric study on four different injection timings in order to better understand the effects of injection timings on in-cylinder mixing and CAI combustion. The full engine cycle simulation including complete gas exchange and combustion processes was carried out over several cycles in order to obtain the stable cycle for analysis. The combustion models used in the present study are the Shell auto-ignition model and the characteristic-time combustion model, which were modified to take the high level of EGR into consideration. A liquid sheet breakup spray model was used for the droplet breakup processes. The analyses show that the injection timing plays an important role in affecting the in-cylinder air/fuel mixing and mixture temperature, which in turn affects the CAI combustion and engine performance.

  2. Modeling and Simulation of a Free-Piston Engine with Electrical Generator Using HCCI Combustion

    Science.gov (United States)

    Alrbai, Mohammad

    Free-piston engines have the potential to challenge the conventional crankshaft engines by their design simplicity and higher operational efficiency. Many studies have been performed to overcome the limitations of the free-piston devices especially the stability and control issues. The investigations within the presented dissertation aim to satisfy many objectives by employing the approach of chemical kinetics to present the combustion process in the free-piston engine. This approach in addition to its advanced accuracy over the empirical methods, it has many other features like the ability to analyze the engine emissions. The effect of the heat release rate (HRR) on the engine performance is considered as the main objective. Understanding the relation between the HRR and the piston dynamics helps in enhancing the system efficiency and identifying the parameters that affect the overall performance. The dissertation covers some other objectives that belongs to the combustion phasing. Exhaust gas recirculation (EGR), equivalence ratio and the intake temperature represent the main combustion parameters, which have been discussed in this dissertation. To obtain the stability in system performance, the model requires a proper controller to simulate the operation and manage the different system parameters; for this purpose, different controlling techniques have been employed. In addition, the dissertation considers some other topics like engine emissions, fuels and fuels mechanisms. The model of the study describes the processes within a single cylinder, two stroke engine, which includes springs to support higher frequencies, reduce cyclic variations and sustain the engine compression ratio. An electrical generator presents the engine load; the generator supports different load profiles and play the key role in controlling the system. The 1st law of thermodynamics and Newton's 2nd law are applied to couple the piston dynamics with the engine thermodynamics. The model

  3. Experimental and numerical analysis of the performance and exhaust gas emissions of a biogas/n-heptane fueled HCCI engine

    KAUST Repository

    Kozarac, Darko; Taritas, Ivan; Vuilleumier, David; Saxena, Samveg; Dibble, Robert W.

    2016-01-01

    The use of highly reactive fuel as an ignition promoter enables operation of biogas fueled homogeneous charge compression ignition (HCCI) engine at low intake temperatures with practical control of combustion phasing. In order to gain some insight into this operation mode the influence of addition of n-heptane on combustion, performance, emissions and control of combustion phasing of a biogas fueled HCCI engine is experimentally researched and presented in this paper. Additionally, the performance analysis of the practical engine solution for such operation is estimated by using the numerical simulation of entire engine. The results showed that the introduction of highly reactive fuel results with a significant change in operating conditions and with a change in optimum combustion phasing. The addition of n-heptane resulted in lower nitrogen oxides and increased carbon monoxide emissions, while the unburned hydrocarbons emissions were strongly influenced by combustion phasing and at optimal conditions are lowered compared to pure biogas operation. The results also showed a practical operation range for strategies that use equivalence ratio as a control of load. Simulation results showed that the difference in performance between pure biogas and n-heptane/biogas operation is even greater when the practical engine solution is taken into account.

  4. Experimental and numerical analysis of the performance and exhaust gas emissions of a biogas/n-heptane fueled HCCI engine

    KAUST Repository

    Kozarac, Darko

    2016-09-12

    The use of highly reactive fuel as an ignition promoter enables operation of biogas fueled homogeneous charge compression ignition (HCCI) engine at low intake temperatures with practical control of combustion phasing. In order to gain some insight into this operation mode the influence of addition of n-heptane on combustion, performance, emissions and control of combustion phasing of a biogas fueled HCCI engine is experimentally researched and presented in this paper. Additionally, the performance analysis of the practical engine solution for such operation is estimated by using the numerical simulation of entire engine. The results showed that the introduction of highly reactive fuel results with a significant change in operating conditions and with a change in optimum combustion phasing. The addition of n-heptane resulted in lower nitrogen oxides and increased carbon monoxide emissions, while the unburned hydrocarbons emissions were strongly influenced by combustion phasing and at optimal conditions are lowered compared to pure biogas operation. The results also showed a practical operation range for strategies that use equivalence ratio as a control of load. Simulation results showed that the difference in performance between pure biogas and n-heptane/biogas operation is even greater when the practical engine solution is taken into account.

  5. Blending Octane Number of Toluene with Gasoline-like and PRF Fuels in HCCI Combustion Mode

    KAUST Repository

    Waqas, Muhammad Umer

    2018-04-03

    Future internal combustion engines demand higher efficiency but progression towards this is limited by the phenomenon called knock. A possible solution for reaching high efficiency is Octane-on-Demand (OoD), which allows to customize the antiknock quality of a fuel through blending of high-octane fuel with a low octane fuel. Previous studies on Octane-on-Demand highlighted efficiency benefits depending on the combination of low octane fuel with high octane booster. The author recently published works with ethanol and methanol as high-octane fuels. The results of this work showed that the composition and octane number of the low octane fuel is significant for the blending octane number of both ethanol and methanol. This work focuses on toluene as the high octane fuel (RON 120). Aromatics offers anti-knock quality and with high octane number than alcohols, this work will address if toluene can provide higher octane enhancement. Our aim is to investigate the impact of three gasoline-like fuels and two Primary Reference Fuels (PRFs). More specifically, fuels are FACE (Fuels for Advanced Combustion Engines) I, FACE J, FACE A, PRF 70 and PRF 84. A CFR engine was used to conduct the experiments in HCCI mode. For this combustion mode, the engine operated at four specific conditions based on RON and MON conditions. The octane numbers corresponding to four HCCI numbers were obtained for toluene concentration of 0, 2, 5, 10, 15 and 20%. Results show that the blending octane number of toluene varies non-linearly and linearly with the increase in toluene concentration depending on the base fuel, experimental conditions and the concentration of toluene. As a result, the blending octane number can range from close to 150 with a small fraction of toluene to a number closer to that of toluene, 120, with larger fractions.

  6. A numerical study of HCCI combustion of PRF mixtures compared with PCCI experiments

    Energy Technology Data Exchange (ETDEWEB)

    Van Wijngaarden, B.

    2008-09-15

    For automotive applications engines that produce less soot and NOx are desired. For that reason the Homogeneous Charge Compression Ignition (HCCI) principle is investigated all over the world, including the technical universities of Berlin (TUB) and Eindhoven. HCCI combines a homogeneous charge, as in an Otto engine with the autoignition principle of a Diesel engine. Auto-ignition and almost instantaneous combustion of a homogeneous charge leads to almost zero soot emissions, lower temperatures and thereby much lower NOx emissions. Auto-ignition timing however, depends on the fuel and its chemistry, which is very sensitive to the applied conditions, being pressure, temperature, equivalence ratio ({phi}), dilution with EGR and engine speed. To study this systematically a 0D model with PRF fuels is used (Primary Reference Fuels are n-heptane, iso-octane and mixtures). A 0D model is chosen because it excludes complex fluid dynamics and thereby allows the use of detailed combustion mechanisms, describing the (PRF) chemistry. Furthermore the model has a multi zone possibility to evaluate in-homogeneities of the charge. PRF fuels are used because n-heptane (CN=55) auto-ignites like a diesel and iso-octane (ON=100) approaches gasoline. For the PRF chemistry three combustion mechanisms were selected, of which two were validated showing a great difference in predicted ignition delay and sensitivity to changes. Furthermore the model was validated with a PCCI (Premixed Charge Compression Ignition) experiment. Extensive comparisons with PCCI experiments from the TUB showed that when the moment of injection was used to launch the chemistry in the model, only the Soyhan mechanism predicted the ignition close to the experimental ignition moment. Furthermore a 7 zone model was able to approach the experimental CO and NOX emissions. Finally none of the mechanisms was able to predict a pressure profile similar to the experiments. More zones and or a better mechanism could improve

  7. The effects of key parameters on the transition from SI combustion to HCCI combustion in a two-stroke free piston linear engine

    International Nuclear Information System (INIS)

    Hung, Nguyen Ba; Lim, Ocktaeck; Iida, Norimasa

    2015-01-01

    Highlights: • A free piston engine is modeled and simulated by three mathematical models. • The models include dynamic model, linear alternator model and thermodynamic model. • The SI-HCCI transition is successful if the key parameters are adjusted suitably. • Spring stiffness has a strong influence on reducing peak temperature in HCCI mode. • Adjusting spark timing helps the SI-HCCI transition to be more convenient. - Abstract: An investigation was conducted to examine the effects of key parameters such as intake temperature, equivalence ratio, engine load, intake pressure, spark timing and spring stiffness on the transition from SI combustion to HCCI combustion in a two-stroke free piston linear engine. Operation of the free piston engine was simulated based on the combination of three mathematical models including a dynamic model, a linear alternator model and a thermodynamic model. These mathematical models were combined and solved by a program written in Fortran. To validate the mathematical models, the simulation results were compared with experimental data in the SI mode. For the transition from SI combustion to HCCI combustion, the simulation results show that if the equivalence ratio is decreased, the intake temperature and engine load should be increased to get a successful SI-HCCI transition. However, the simulation results also show that the in-cylinder pressure is decreased, while the peak in-cylinder temperature in HCCI mode is increased significantly if the intake temperature is increased so much. Beside the successful SI-HCCI transition, the increase of intake pressure from P in = 1.1 bar to P in = 1.6 bar is one of solutions to reduce peak in-cylinder temperature in HCCI mode. However, the simulation results also indicate that if the intake pressure is increased so much (P in = 1.6 bar), the engine knocking problem is occurred. Adjusting spring stiffness from k = 2.9 N/mm to k = 14.7 N/mm is also considered one of useful solutions for

  8. Effects of premixed diethyl ether (DEE) on combustion and exhaust emissions in a HCCI-DI diesel engine

    International Nuclear Information System (INIS)

    Cinar, Can; Can, Ozer; Sahin, Fatih; Yucesu, H. Serdar

    2010-01-01

    In this study, the effects of premixed ratio of diethyl ether (DEE) on the combustion and exhaust emissions of a single-cylinder, HCCI-DI engine were investigated. The experiments were performed at the engine speed of 2200 rpm and 19 N m operating conditions. The amount of the premixed DEE was controlled by a programmable electronic control unit (ECU) and the DEE injection was conducted into the intake air charge using low pressure injector. The premixed fuel ratio (PFR) of DEE was changed from 0% to 40% and results were compared to neat diesel operation. The percentages of premixed fuel were calculated from the energy ratio of premixed DEE fuel to total energy rate of the fuels. The experimental results show that single stage ignition was found with the addition of premixed DEE fuel. Increasing and phasing in-cylinder pressure and heat release were observed in the premixed stage of the combustion. Lower diffusion combustion was also occurred. Cycle-to cycle variations were very small with diesel fuel and 10% DEE premixed fuel ratio. Audible knocking occurred with 40% DEE premixed fuel ratio. NO x -soot trade-off characteristics were changed and improvements were found simultaneously. NO x and soot emissions decreased up to 19.4% and 76.1%, respectively, while exhaust gas temperature decreased by 23.8%. On the other hand, CO and HC emissions increased.

  9. A modelling study into the effects of variable valve timing on the gas exchange process and performance of a 4-valve DI homogeneous charge compression ignition (HCCI) engine

    International Nuclear Information System (INIS)

    Mahrous, A-F.M.; Potrzebowski, A.; Wyszynski, M.L.; Xu, H.M.; Tsolakis, A.; Luszcz, P.

    2009-01-01

    Homogeneous charge compression ignition (HCCI) combustion mode is a relatively new combustion technology that can be achieved by using specially designed cams with reduced lift and duration. The auto-ignition in HCCI engine can be facilitated by adjusting the timing of the exhaust-valve-closing and, to some extent, the timing of the intake-valve-opening so as to capture a proportion of the hot exhaust gases in the engine cylinder during the gas exchange process. The effects of variable valve timing strategy on the gas exchange process and performance of a 4-valve direct injection HCCI engine were computationally investigated using a 1D fluid-dynamic engine cycle simulation code. A non-typical intake valve strategy was examined; whereby the intake valves were assumed to be independently actuated with the same valve-lift profile but at different timings. Using such an intake valves strategy, the obtained results showed that the operating range of the exhaust-valve-timing within which the HCCI combustion can be facilitated and maintained becomes much wider than that of the typical intake-valve-timing case. Also it was found that the engine parameters such as load and volumetric efficiency are significantly modified with the use of the non-typical intake-valve-timing. Additionally, the results demonstrated the potential of the non-typical intake-valve strategy in achieving and maintaining the HCCI combustion at much lower loads within a wide range of valve timings. Minimizing the pumping work penalty, and consequently improving the fuel economy, was shown as an advantage of using the non-typical intake-valve-timing with the timing of the early intake valve coupled with a symmetric degree of exhaust-valve-closing timing

  10. A modelling study into the effects of variable valve timing on the gas exchange process and performance of a 4-valve DI homogeneous charge compression ignition (HCCI) engine

    Energy Technology Data Exchange (ETDEWEB)

    Mahrous, A-F.M. [School of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Lecturer at the Department of Mechanical Power Engineering, Faculty of Engineering (Shebin El-Kom), Menoufiya University, Shebin El-Kom (Egypt); Potrzebowski, A.; Wyszynski, M.L.; Xu, H.M.; Tsolakis, A.; Luszcz, P. [School of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2009-02-15

    Homogeneous charge compression ignition (HCCI) combustion mode is a relatively new combustion technology that can be achieved by using specially designed cams with reduced lift and duration. The auto-ignition in HCCI engine can be facilitated by adjusting the timing of the exhaust-valve-closing and, to some extent, the timing of the intake-valve-opening so as to capture a proportion of the hot exhaust gases in the engine cylinder during the gas exchange process. The effects of variable valve timing strategy on the gas exchange process and performance of a 4-valve direct injection HCCI engine were computationally investigated using a 1D fluid-dynamic engine cycle simulation code. A non-typical intake valve strategy was examined; whereby the intake valves were assumed to be independently actuated with the same valve-lift profile but at different timings. Using such an intake valves strategy, the obtained results showed that the operating range of the exhaust-valve-timing within which the HCCI combustion can be facilitated and maintained becomes much wider than that of the typical intake-valve-timing case. Also it was found that the engine parameters such as load and volumetric efficiency are significantly modified with the use of the non-typical intake-valve-timing. Additionally, the results demonstrated the potential of the non-typical intake-valve strategy in achieving and maintaining the HCCI combustion at much lower loads within a wide range of valve timings. Minimizing the pumping work penalty, and consequently improving the fuel economy, was shown as an advantage of using the non-typical intake-valve-timing with the timing of the early intake valve coupled with a symmetric degree of exhaust-valve-closing timing. (author)

  11. Blending Octane Number of Ethanol on a Volume and Molar Basis in SI and HCCI Combustion Modes

    KAUST Repository

    Waqas, Muhammad Umer; Morganti, Kai; Masurier, Jean-Baptiste; Johansson, Bengt

    2017-01-01

    The blending behavior of ethanol in five different hydrocarbon base fuels with octane numbers of approximately 70 and 84 was examined under Spark-Ignited (SI) and Homogeneous Charge Compression Ignited (HCCI) operating conditions. The Blending octane number (BON) was used to characterize the blending behavior on both a volume and molar basis. Previous studies have shown that the blending behavior of ethanol generally follows several well-established rules. In particular, non-linear blending effects are generally observed on a volume basis (i.e. BON > RON or MON of pure ethanol; 108 and 89, respectively), while linear blending effects are generally observed on a molar basis (i.e. BON = RON or MON of pure ethanol). This work firstly demonstrates that the non-linear volumetric blending effects traditionally observed under SI operating conditions are also observed under HCCI operating conditions. In keeping with previous studies, the degree of this non-linearity is shown to be a function of the base fuel composition and octane number. By contrast, the molar blending approach is shown to behave differently depending on the chosen combustion mode, with some non-linearity observed under HCCI operating conditions (i.e. BON RON or MON of pure ethanol). This suggests that the well-established blending rules for SI operating conditions may not always be relevant to other combustion modes that operate with globally lean or diluted air-fuel mixtures. This has implications for the design of future fuel specifications.

  12. Blending Octane Number of Ethanol on a Volume and Molar Basis in SI and HCCI Combustion Modes

    KAUST Repository

    Waqas, Muhammad Umer

    2017-10-08

    The blending behavior of ethanol in five different hydrocarbon base fuels with octane numbers of approximately 70 and 84 was examined under Spark-Ignited (SI) and Homogeneous Charge Compression Ignited (HCCI) operating conditions. The Blending octane number (BON) was used to characterize the blending behavior on both a volume and molar basis. Previous studies have shown that the blending behavior of ethanol generally follows several well-established rules. In particular, non-linear blending effects are generally observed on a volume basis (i.e. BON > RON or MON of pure ethanol; 108 and 89, respectively), while linear blending effects are generally observed on a molar basis (i.e. BON = RON or MON of pure ethanol). This work firstly demonstrates that the non-linear volumetric blending effects traditionally observed under SI operating conditions are also observed under HCCI operating conditions. In keeping with previous studies, the degree of this non-linearity is shown to be a function of the base fuel composition and octane number. By contrast, the molar blending approach is shown to behave differently depending on the chosen combustion mode, with some non-linearity observed under HCCI operating conditions (i.e. BON RON or MON of pure ethanol). This suggests that the well-established blending rules for SI operating conditions may not always be relevant to other combustion modes that operate with globally lean or diluted air-fuel mixtures. This has implications for the design of future fuel specifications.

  13. Use of catalytic reforming to aid natural gas HCCI combustion in engines: experimental and modelling results of open-loop fuel reforming

    Energy Technology Data Exchange (ETDEWEB)

    Peucheret, S.; Wyszynski, M.L.; Lehrle, R.S. [Future Power Systems Group, Mechanical Engineering, The University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Golunski, S. [Johnson Matthey, Technology Centre, Blount' s Court, Sonning Common, Reading RG4 9NH (United Kingdom); Xu, H. [Jaguar Land Rover Research, Jaguar Land Rover W/2/021, Abbey Road, Coventry CV3 4LF (United Kingdom)

    2005-12-01

    The potential of the homogeneous charge compression ignition (HCCI) combustion process to deliver drastically reduced emissions of NO{sub x} and improved fuel economy from internal combustion engines is well known. The process is, however, difficult to initiate and control, especially when methane or natural gas are used as fuel. To aid the HCCI combustion of natural gas, hydrogen addition has been successfully used in this study. This hydrogen can be obtained from on-line reforming of natural gas. Methane reforming is achieved here by reaction with engine exhaust gas and air in a small scale monolith catalytic reactor. The benchmark quantity of H{sub 2} required to enhance the feasibility and engine load range of HCCI combustion is 10%. For low temperature engine exhaust gas, typical for HCCI engine operating conditions, experiments show that additional air is needed to produce this quantity. Experimental results from an open-loop fuel exhaust gas reforming system are compared with two different models of basic thermodynamic equilibria calculations. At the low reactor inlet temperatures needed for the HCCI application (approx. 400 deg C) the simplified three-reaction thermodynamic equilibrium model is in broad agreement with experimental results, while for medium (550-650 deg C) inlet temperature reforming with extra air added, the high hydrogen yields predicted from the multi-component equilibrium model are difficult to achieve in a practical reformer. (author)

  14. Experimental and numerical investigation of hetero-/homogeneous combustion-based HCCI of methane–air mixtures in free-piston micro-engines

    International Nuclear Information System (INIS)

    Chen, Junjie; Liu, Baofang; Gao, Xuhui; Xu, Deguang

    2016-01-01

    Highlights: • Single-shot experiments and a transient model of micro-engine were presented. • Coupled combustion can significantly improve in-cylinder temperatures. • Coupled combustion can reduce mass losses and compression ratios. • Heterogeneous reactions cause earlier ignition. • Heat losses result in higher mass losses. - Abstract: The hetero-/homogenous combustion-based HCCI (homogeneous charge compression ignition) of fuel–lean methane–air mixtures over alumina-supported platinum catalysts was investigated experimentally and numerically in free-piston micro-engines without ignition sources. Single-shot experiments were carried out in the purely homogeneous and coupled hetero-/homogeneous combustion modes, involved temperature measurements, capturing the visible combustion image sequences, exhaust gas analysis, and the physicochemical characterization of catalysts. Simulations were performed with a two-dimensional transient model that includes detailed hetero-/homogeneous chemistry and transport, leakage, and free-piston motion to gain physical insight and to explore the hetero-/homogeneous combustion characteristics. The micro-engine performance concerning combustion efficiency, mass loss, energy density, and free-piston dynamics was investigated. The results reveal that both purely homogeneous and coupled hetero-/homogeneous combustion of methane–air mixtures in a narrow cylinder with a diameter of 3 mm and a height of approximately 0.3 mm are possible. The coupled hetero-/homogeneous mode can not only significantly improve the combustion efficiency, in-cylinder temperature and pressure, output power and energy density, but also reduce the mass loss because of its lower compression ratio and less time spent around TDC (top dead center) and during the expansion stroke, indicating that this coupled mode is a promising combustion scheme for micro-engine. Heat losses result in higher mass losses. Heterogeneous reactions cause earlier ignition

  15. Quasi-Dimensional Modelling and Parametric Studies of a Heavy-Duty HCCI Engine

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Pandey

    2011-01-01

    Full Text Available A quasi-dimensional modelling study is conducted for the first time for a heavy duty, diesel-fuelled, multicylinder engine operating in HCCI mode. This quasidimensional approach involves a zero-dimensional single-zone homogeneous charge compression ignition (HCCI combustion model along with a one-dimensional treatment of the intake and exhaust systems. A skeletal chemical kinetic scheme for n-heptane was used in the simulations. Exhaust gas recirculation (EGR and compression ratio (CR were the two parameters that were altered in order to deal with the challenges of combustion phasing control and operating load range extension. Results from the HCCI mode simulations show good potential when compared to conventional diesel performance with respect to important performance parameters such as peak firing pressure, specific fuel consumption, peak pressure rise, and combustion noise. This study shows that HCCI combustion mode can be employed at part load of 25% varying the EGR rates between 0 and 60%.

  16. Blending Behavior of Ethanol with PRF 84 and FACE A Gasoline in HCCI Combustion Mmode

    KAUST Repository

    Waqas, Muhammad Umer; Atef, Nour; Singh, Eshan; Masurier, Jean-Baptiste; Sarathy, Mani; Johansson, Bengt

    2017-01-01

    but the chemical effect responsible for the non-linear blending behavior of ethanol with PRF 84 and FACE A was not understood. Hence, in this study the experimental measurements were simulated using zero-dimensional HCCI engine model with detailed chemistry

  17. HCCI Combustion Engines Final Report CRADA No. TC02032.0

    Energy Technology Data Exchange (ETDEWEB)

    Aceves, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lyford-Pike, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-08

    This was a collaborative effort between Lawrence Livermore National Security, LLC (formerly The Regents of the University of California)/Lawrence Livermore National Laboratory (LLNL) and Cummins Engine Company (Cwnmins), to advance the state of the art on HomogeneousCharge Compression-Ignition (HCCI) engines, resulting in a clean, high-efficiency alternative to diesel engines.

  18. Experimental and numerical investigation of ion signals in boosted HCCI combustion using cesium and potassium acetate additives

    International Nuclear Information System (INIS)

    Mack, J. Hunter; Butt, Ryan H.; Chen, Yulin; Chen, Jyh-Yuan; Dibble, Robert W.

    2016-01-01

    Highlights: • HCCI engine experiments show that CsOAc and KOAc additives increased the ion SNR. • The ion signal is more apparent at higher equivalence ratios. • An increase in intake pressure produces a decrease in the ion signal. • Use of metal acetates as additives yielded reductions in IMEP g and maximum ROHR. • A numerical model predicted peak ion signal, CA50, and p intake dependence. - Abstract: A sparkplug ion sensor can be used to measure the ion current in a homogeneous charge compression ignition (HCCI) engine, providing insight into the ion chemistry inside the cylinders during combustion. HCCI engines typically operate at lean equivalence ratios (ϕ) at which the ion current becomes increasingly indistinguishable from background noise. This paper investigates the effect of fuel additives on the ion signal at low equivalence ratios, determines side effects of metal acetate addition, and validates numerical model for ionization chemistry. Cesium acetate (CsOAc) and potassium acetate (KOAc) were used as additives to ethanol as the primary fuel. Concentration levels of 100, 200, and 400 mg/L of metal acetate-in-ethanol are investigated at equivalence ratios of 0.08, 0.20, and 0.30. The engine experiments were conducted at a boosted intake pressure of 1.8 bar absolute and compared to naturally aspirated results. Combustion timing was maintained at 2.5° after top-dead-center (ATDC), as defined by the crank angle degree (CAD) where 50% of the cumulative heat release occurs (CA50). CsOAc consistently produced the strongest ion signals at all conditions when compared to KOAc. The ion signal was found to decrease with increased intake pressure; an increase in the additive concentration increased the ion signal for all cases. However, the addition of the metal acetates decreased the gross indicated mean effective pressure (IMEP g ), maximum rate of heat release (ROHR), and peak cylinder pressure. Experimental results were used to validate ion chemistry

  19. Exergoeconomic analysis and multi-objective optimization of an ejector refrigeration cycle powered by an internal combustion (HCCI) engine

    International Nuclear Information System (INIS)

    Sadeghi, Mohsen; Mahmoudi, S.M.S.; Khoshbakhti Saray, R.

    2015-01-01

    Highlights: • Ejector refrigeration systems powered by HCCI engine is proposed. • A new two-dimensional model is developed for the ejector. • Multi-objective optimization is performed for the proposed system. • Pareto frontier is plotted for multi-objective optimization. - Abstract: Ejector refrigeration systems powered by low-grade heat sources have been an attractive research subject for a lot of researchers. In the present work the waste heat from exhaust gases of a HCCI (homogeneous charge compression ignition) engine is utilized to drive the ejector refrigeration system. Considering the frictional effects on the ejector wall, a new two-dimensional model is developed for the ejector. Energy, exergy and exergoeconomic analysis performed for the proposed system using the MATLAB software. In addition, considering the exergy efficiency and the product unit cost of the system as objective functions, a multi-objective optimization is performed for the system to find the optimum design variables including the generator, condenser and evaporator temperatures. The product unit cost is minimized while the exergy efficiency is maximized using the genetic algorithm. The optimization results are obtained as a set of optimal points and the Pareto frontier is plotted for multi-objective optimization. The results of the optimization show that ejector refrigeration cycle is operating at optimum state based on exergy efficiency and product unit cost when generator, condenser and evaporator work at 94.54 °C, 33.44 °C and 0.03 °C, respectively

  20. Direct numerical simulations of ignition of a lean n-heptane/air mixture with temperature and composition inhomogeneities relevant to HCCI and SCCI combustion

    KAUST Repository

    Luong, Minh Bau

    2015-12-01

    The effects of temperature and composition stratifications on the ignition of a lean n-heptane/air mixture at three initial mean temperatures under elevated pressure are investigated using direct numerical simulations (DNSs) with a 58-species reduced mechanism. Two-dimensional DNSs are performed by varying several key parameters: initial mean temperature, T0, and the variance of temperature and equivalence ratio (T\\' and φ\\') with different T-φcorrelations. It is found that for cases with φ\\' only, the overall combustion occurs more quickly and the mean heat release rate (HRR) increases more slowly with increasing φ\\' regardless of T0. For cases with T\\' only, however, the overall combustion is retarded/advanced in time with increasing T\\' for low/high T0 relative to the negative-temperature coefficient (NTC) regime resulting from a longer/shorter overall ignition delay of the mixture. For cases with uncorrelated T-φfields, the mean HRR is more distributed over time compared to the corresponding cases with T\\' or φ\\' only. For negatively-correlated cases, however, the temporal evolution of the overall combustion exhibits quite non-monotonic behavior with increasing T\\' and φ\\' depending on T0. All of these characteristics are found to be primarily related to the 0-D ignition delays of initial mixtures, the relative timescales between 0-D ignition delay and turbulence, and the dominance of the deflagration mode during the ignition. These results suggest that an appropriate combination of T\\' and φ\\' together with a well-prepared T-φdistribution can alleviate an excessive pressure-rise rate (PRR) and control ignition-timing in homogeneous charge compression-ignition (HCCI) combustion. In addition, critical species and reactions for the ignition of n-heptane/air mixture through the whole ignition process are estimated by comparing the temporal evolution of the mean mass fractions of important species with the overall reaction pathways of n

  1. Controlling the heat release in HCCI combustion of DME with methanol and EGR

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr; Schramm, Jesper; Yanai, Tadanori

    2010-01-01

    quantity required was determined. The added methanol increased the BMEP by increasing the total heat release and retarding the combustion to after TDC. Engine knock was reduced with increasing quantities of methanol. The highest BMEP was achieved when the equivalence ratio of methanol was around 0.......12 at 1000 RPM, and around 0.76 at 1800 RPM. EGR was also used to retarding the timing. With a moderate amount of EGR the effect on the combustion was not notable, but as the equivalence ratio approached unity the combustion was increasingly delayed and the rate of reaction reduced. Engine knock seized...

  2. Blending Octane Number of Toluene with Gasoline-like and PRF Fuels in HCCI Combustion Mode

    KAUST Repository

    Waqas, Muhammad Umer; Masurier, Jean-Baptiste; Sarathy, Mani; Johansson, Bengt

    2018-01-01

    Future internal combustion engines demand higher efficiency but progression towards this is limited by the phenomenon called knock. A possible solution for reaching high efficiency is Octane-on-Demand (OoD), which allows to customize the antiknock

  3. Session 4: On-board exhaust gas reforming for improved performance of natural gas HCCI engines

    Energy Technology Data Exchange (ETDEWEB)

    Amieiro, A.; Golunski, S.; James, D. [Johnson Matthey Technology Centre, Sonning Common, Reading (United Kingdom); Miroslaw, Wyszynski; Athanasios, Megaritis; Peucheret, S. [Birmingham Univ., School of Engineering, Future Power Systems Research Group (United Kingdom); Hongming, Xu [Jaguar Cars Ltd, W/2/021 Engineering Centre, Whitley, Coventry (United Kingdom)

    2004-07-01

    Although natural gas (NG) is a non-renewable energy source, it is still a very attractive alternative fuel for transportation - it is inexpensive, abundant, and easier to refine than petroleum. Unfortunately the minimum spark energy required for NG ignition is higher than for liquid fuels, and engine performance is reduced since the higher volume of NG limits the air breathing capacity of the cylinders. On the other hand, the flammability range of NG is wider than for other hydrocarbons, so the engine can operate under leaner conditions. Environmentally, the use of NG is particularly attractive since it has a low flame temperature (resulting in reduced NO{sub x} emissions) and a low carbon content compared to diesel or gasoline (resulting in less CO, CO{sub 2} and particulate). In addition, NG is easily made sulphur-free, and has a high octane rating (RON = 110-130) which makes it suitable for high compression engine applications. Exhaust gas recirculation (EGR) into an engine is known to reduce both flame temperature and speed, and therefore produce lower NO{sub x} emissions. In general, a given volume of exhaust gas has a greater effect on flame speed and NO{sub x} emissions than the same quantity of excess air, although there is a limit to the amount of exhaust gas recirculation that can be used without inhibiting combustion. However, hydrogen addition to exhaust gas recirculation has been proved to reduce emissions while increasing flame speed, so improving both the emissions and the thermal efficiency of the engine. On-board reforming of some of the fuel, by reaction with exhaust gas during EGR, is a novel way of adding hydrogen to an engine. We have carried out reforming tests on mixtures of natural gas and exhaust gas at relatively low temperatures (400-600 C), to mimic the low availability of external heat within the integrated system. The reforming catalyst is a nickel-free formulation, containing precious metals promoted by metal oxides. The roles of

  4. Naphtha vs. dieseline – The effect of fuel properties on combustion homogeneity in transition from CI combustion towards HCCI

    KAUST Repository

    Vallinayagam, R.; An, Yanzhao; S.Vedharaj; Sim, Jaeheon; Chang, Junseok; Johansson, Bengt

    2018-01-01

    The scope of this research study pertains to compare the combustion and emission behavior between naphtha and dieseline at different combustion modes. In this study, US dieseline (50% US diesel + 50% RON 91 gasoline) and EU dieseline (45% EU diesel

  5. Blending Octane Number of Ethanol in HCCI, SI and CI Combustion Modes

    KAUST Repository

    Waqas, Muhammad

    2016-10-17

    The effect of ethanol blended with three FACE (Fuels for Advanced Combustion Engines) gasolines, I, J and A corresponding to RON 70.3, 71.8 and 83.5, respectively, were compared to PRF70 and PRF84 with the same ethanol concentrations, these being 2%, 5%, 10%, 15% and 20% by volume. A Cooperative Fuel Research (CFR) engine was used to understand the blending effect of ethanol with FACE gasolines and PRFs in spark-ignited and homogeneous charge compression ignited mode. Blending octane numbers (BON) were obtained for both the modes. All the fuels were also tested in an ignition quality tester to obtain Blending Derived Cetane numbers (BDCN). It is shown that fuel composition and octane number are important characteristics of all the base fuels that have a significant impact on octane increase with ethanol. The dependency of octane number for the base fuel on the blending octane number depended on the combustion mode operated. The aromatic composition in the base fuel, effects blending octane number of the mixture, for fuels with higher aromatic content lower blending octane numbers were observed for ethanol concentration.

  6. Blending Octane Number of Ethanol in HCCI, SI and CI Combustion Modes

    KAUST Repository

    Waqas, Muhammad; Naser, Nimal; Sarathy, Mani; Morganti, Kai; Al-Qurashi, Khalid; Johansson, Bengt

    2016-01-01

    The effect of ethanol blended with three FACE (Fuels for Advanced Combustion Engines) gasolines, I, J and A corresponding to RON 70.3, 71.8 and 83.5, respectively, were compared to PRF70 and PRF84 with the same ethanol concentrations, these being 2%, 5%, 10%, 15% and 20% by volume. A Cooperative Fuel Research (CFR) engine was used to understand the blending effect of ethanol with FACE gasolines and PRFs in spark-ignited and homogeneous charge compression ignited mode. Blending octane numbers (BON) were obtained for both the modes. All the fuels were also tested in an ignition quality tester to obtain Blending Derived Cetane numbers (BDCN). It is shown that fuel composition and octane number are important characteristics of all the base fuels that have a significant impact on octane increase with ethanol. The dependency of octane number for the base fuel on the blending octane number depended on the combustion mode operated. The aromatic composition in the base fuel, effects blending octane number of the mixture, for fuels with higher aromatic content lower blending octane numbers were observed for ethanol concentration.

  7. Evaluation of heat transfer correlations for HCCI engine modeling

    NARCIS (Netherlands)

    Soyhan, H.S.; Yasar, H.; Walmsley, H.; Head, B.; Kalghatgi, G.T.; Sorusbay, C.

    2009-01-01

    Combustion in HCCI engines is a controlled auto-ignition of well-mixed fuel, air and residual gas. The thermal conditions of the combustion chamber are governed by chemical kinetics strongly coupled with heat transfer from the hot gas to the walls. The heat losses have a critical effect on HCCI

  8. Homogeneous Charge Compression Ignition Combustion: Challenges and Proposed Solutions

    Directory of Open Access Journals (Sweden)

    Mohammad Izadi Najafabadi

    2013-01-01

    Full Text Available Engine and car manufacturers are experiencing the demand concerning fuel efficiency and low emissions from both consumers and governments. Homogeneous charge compression ignition (HCCI is an alternative combustion technology that is cleaner and more efficient than the other types of combustion. Although the thermal efficiency and NOx emission of HCCI engine are greater in comparison with traditional engines, HCCI combustion has several main difficulties such as controlling of ignition timing, limited power output, and weak cold-start capability. In this study a literature review on HCCI engine has been performed and HCCI challenges and proposed solutions have been investigated from the point view of Ignition Timing that is the main problem of this engine. HCCI challenges are investigated by many IC engine researchers during the last decade, but practical solutions have not been presented for a fully HCCI engine. Some of the solutions are slow response time and some of them are technically difficult to implement. So it seems that fully HCCI engine needs more investigation to meet its mass-production and the future research and application should be considered as part of an effort to achieve low-temperature combustion in a wide range of operating conditions in an IC engine.

  9. Combustion stratification for naphtha from CI combustion to PPC

    NARCIS (Netherlands)

    Vallinayagam, R.; Vedharaj, S.; An, Y.; Dawood, A.; Izadi Najafabadi, M.; Somers, L.M.T.; Johansson, B.H.

    2017-01-01

    This study demonstrated the change in combustion homogeneity from conventional diesel combustion via partially premixed combustion towards HCCI. Experiments are performed in an optical diesel engine at a speed of 1200 rpm with diesel fuel. Single injection strategy is employed and the fuel is

  10. Dual-fuel HCCI operation with DME/LPG/gasoline/hydrogen

    International Nuclear Information System (INIS)

    Bae, C.

    2009-01-01

    The advantages of homogeneous charge compression ignition (HCCI) engines include usage of the different type of fuels, ultra low nitrogen oxide and particulate matter emissions and improved fuel economy. Disadvantages include an excessive combustion rate, engine noise, and hydrocarbon and carbon emissions. An experiment on dual-fuel HCCI operation with dimethyl ether (DME)/liquefied petroleum gas (LPG)/gasoline/hydrogen was presented. The advantages and disadvantages were first presented and the dual-fuel HCCI combustion engine was illustrated through an experimental apparatus. The experimental conditions were also presented in terms of engine speed, DME injection quantity, LPC injection quantity, and LPC composition. Experimental results were discussed for output performance and indicated mean effective pressure (IMEP). It was concluded that the effect of LPG composition in a DME-LPG dual-fueled HCCI engine at various injection quantity and injective timing were observed. Specifically, it was found that propane was a more effective way to increase IMEP in this study, and that in a DME HCCI engine, higher load limit was extended by using LPG as an ignition inhibitor. tabs., figs.

  11. Miniature free-piston homogeneous charge compression ignition engine-compressor concept - Part II: modeling HCCI combustion in small scales with detailed homogeneous gas phase chemical kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Aichlmayr, H.T.; Kittelson, D.B.; Zachariah, M.R. [The University of Minnesota, Minneapolis (United States). Departments of Mechanical Engineering and Chemistry

    2002-10-01

    Operational maps for crankshaft-equipped miniature homogeneous charge compression ignition engines are established using performance estimation, detailed chemical kinetics, and diffusion models for heat transfer and radical loss. In this study, radical loss was found to be insignificant. In contrast, heat transfer was found to be increasingly significant for 10, 1, and 0.1 W engines, respectively. Also, temperature-pressure trajectories and ignition delay time maps are used to explore relationships between engine operational parameters and HCCI. Lastly, effects of engine operating conditions and design on the indicated fuel conversion efficiency are investigated. (author)

  12. Homogeneous Charge Compression Ignition Combustion of Dimethyl Ether

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr

    This thesis is based on experimental and numerical studies on the use of dimethyl ether (DME) in the homogeneous charge compression ignition (HCCI) combustion process. The first paper in this thesis was published in 2007 and describes HCCI combustion of pure DME in a small diesel engine. The tests...... were designed to investigate the effect of engine speed, compression ratio and equivalence ratio on the combustion timing and the engine performance. It was found that the required compression ratio depended on the equivalence ratio used. A lower equivalence ratio requires a higher compression ratio...... before the fuel is burned completely, due to lower in-cylinder temperatures and lower reaction rates. The study provided some insight in the importance of operating at the correct compression ratio, as well as the operational limitations and emission characteristics of HCCI combustion. HCCI combustion...

  13. Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME

    Energy Technology Data Exchange (ETDEWEB)

    John Pratapas; Daniel Mather; Anton Kozlovsky

    2007-03-31

    The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen's significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an

  14. A turbulent time scale based k–ε model for probability density function modeling of turbulence/chemistry interactions: Application to HCCI combustion

    International Nuclear Information System (INIS)

    Maroteaux, Fadila; Pommier, Pierre-Lin

    2013-01-01

    Highlights: ► Turbulent time evolution is introduced in stochastic modeling approach. ► The particles number is optimized trough a restricted initial distribution. ► The initial distribution amplitude is modeled by magnitude of turbulence field. -- Abstract: Homogenous Charge Compression Ignition (HCCI) engine technology is known as an alternative to reduce NO x and particulate matter (PM) emissions. As shown by several experimental studies published in the literature, the ideally homogeneous mixture charge becomes stratified in composition and temperature, and turbulent mixing is found to play an important role in controlling the combustion progress. In a previous study, an IEM model (Interaction by Exchange with the Mean) has been used to describe the micromixing in a stochastic reactor model that simulates the HCCI process. The IEM model is a deterministic model, based on the principle that the scalar value approaches the mean value over the entire volume with a characteristic mixing time. In this previous model, the turbulent time scale was treated as a fixed parameter. The present study focuses on the development of a micro-mixing time model, in order to take into account the physical phenomena it stands for. For that purpose, a (k–ε) model is used to express this micro-mixing time model. The turbulence model used here is based on zero dimensional energy cascade applied during the compression and the expansion cycle; mean kinetic energy is converted to turbulent kinetic energy. Turbulent kinetic energy is converted to heat through viscous dissipation. Besides, in this study a relation to calculate the initial heterogeneities amplitude is proposed. The comparison of simulation results against experimental data shows overall satisfactory agreement at variable turbulent time scale

  15. HCCI engine control and optimization

    OpenAIRE

    Killingsworth, Nicholas J.

    2007-01-01

    Homogeneous charge compression ignition (HCCI) engines have the benefit of high efficiency with low emissions of nitrogen oxides and particulates. These benefits are due to the autoignition process of the dilute mixture of fuel and air during compression. However, because there is no direct ignition trigger, control of ignition is inherently more difficult than in standard internal combustion engines. This difficulty necessitates that a feedback controller be used to keep the engine at a desi...

  16. Auto-Ignition of Iso-Stoichiometric Blends of Gasoline-Ethanol-Methanol (GEM) in SI, HCCI and CI Combustion Modes

    KAUST Repository

    Waqas, Muhammad

    2017-03-28

    Gasoline-ethanol-methanol (GEM) blends, with constant stoichiometric air-to-fuel ratio (iso-stoichiometric blending rule) and equivalent to binary gasoline-ethanol blends (E2, E5, E10 and E15 in % vol.), were defined to investigate the effect of methanol and combined mixtures of ethanol and methanol when blended with three FACE (Fuels for Advanced Combustion Engines) Gasolines, I, J and A corresponding to RON 70.2, 73.8 and 83.9, respectively, and their corresponding Primary Reference Fuels (PRFs). A Cooperative Fuel Research (CFR) engine was used under Spark Ignition and Homogeneous Charge Compression Ignited modes. An ignition quality tester was utilized in the Compression Ignition mode. One of the promising properties of GEM blends, which are derived using the iso-stoichiometric blending rule, is that they maintain a constant octane number, which has led to the introduction of methanol as a drop-in fuel to supplement bio-derived ethanol. A constant RON/HCCI fuel number/derived Research octane number property was observed in all three combustion modes for high RON fuels, but for low RON fuels, the iso-stoichiometric blending rule for constant octane number did not appear to be valid. The chemical composition and octane number of the base fuel also influenced the behavior of the GEM blends under different conditions.

  17. Auto-Ignition of Iso-Stoichiometric Blends of Gasoline-Ethanol-Methanol (GEM) in SI, HCCI and CI Combustion Modes

    KAUST Repository

    Waqas, Muhammad; Naser, Nimal; Sarathy, Mani; Feijs, Jeroen; Morganti, Kai; Nyrenstedt, Gustav; Johansson, Bengt

    2017-01-01

    Gasoline-ethanol-methanol (GEM) blends, with constant stoichiometric air-to-fuel ratio (iso-stoichiometric blending rule) and equivalent to binary gasoline-ethanol blends (E2, E5, E10 and E15 in % vol.), were defined to investigate the effect of methanol and combined mixtures of ethanol and methanol when blended with three FACE (Fuels for Advanced Combustion Engines) Gasolines, I, J and A corresponding to RON 70.2, 73.8 and 83.9, respectively, and their corresponding Primary Reference Fuels (PRFs). A Cooperative Fuel Research (CFR) engine was used under Spark Ignition and Homogeneous Charge Compression Ignited modes. An ignition quality tester was utilized in the Compression Ignition mode. One of the promising properties of GEM blends, which are derived using the iso-stoichiometric blending rule, is that they maintain a constant octane number, which has led to the introduction of methanol as a drop-in fuel to supplement bio-derived ethanol. A constant RON/HCCI fuel number/derived Research octane number property was observed in all three combustion modes for high RON fuels, but for low RON fuels, the iso-stoichiometric blending rule for constant octane number did not appear to be valid. The chemical composition and octane number of the base fuel also influenced the behavior of the GEM blends under different conditions.

  18. HCCI Engine Optimization and Control

    Energy Technology Data Exchange (ETDEWEB)

    Rolf D. Reitz

    2005-09-30

    The goal of this project was to develop methods to optimize and control Homogeneous-Charge Compression Ignition (HCCI) engines, with emphasis on diesel-fueled engines. HCCI offers the potential of nearly eliminating IC engine NOx and particulate emissions at reduced cost over Compression Ignition Direct Injection engines (CIDI) by controlling pollutant emissions in-cylinder. The project was initiated in January, 2002, and the present report is the final report for work conducted on the project through December 31, 2004. Periodic progress has also been reported at bi-annual working group meetings held at USCAR, Detroit, MI, and at the Sandia National Laboratories. Copies of these presentation materials are available on CD-ROM, as distributed by the Sandia National Labs. In addition, progress has been documented in DOE Advanced Combustion Engine R&D Annual Progress Reports for FY 2002, 2003 and 2004. These reports are included as the Appendices in this Final report.

  19. Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME

    Energy Technology Data Exchange (ETDEWEB)

    Pratapas, John; Mather, Daniel; Kozlovsky, Anton

    2013-03-31

    The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen’s significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an

  20. Thermodynamic analysis of an HCCI engine based system running on natural gas

    International Nuclear Information System (INIS)

    Djermouni, Mohamed; Ouadha, Ahmed

    2014-01-01

    Highlights: • A thermodynamic analysis of an HCCI based system has been carried out. • A thermodynamic model has been developed taking into account the gas composition resulting from the combustion process. • The specific heat of the working fluid is temperature dependent. - Abstract: This paper attempts to carry out a thermodynamic analysis of a system composed of a turbocharged HCCI engine, a mixer, a regenerator and a catalytic converter within the meaning of the first and the second law of thermodynamics. For this purpose, a thermodynamic model has been developed taking into account the gas composition resulting from the combustion process and the specific heat temperature dependency of the working fluid. The analysis aims in particular to examine the influence of the compressor pressure ratio, ambient temperature, equivalence ratio, engine speed and the compressor isentropic efficiency on the performance of the HCCI engine. Results show that thermal and exergetic efficiencies increase with increasing the compressor pressure ratio. However, the increase of the ambient temperature involves a decrease of the engine efficiencies. Furthermore, the variation of the equivalence ratio improves considerably both thermal and exergetic efficiencies. As expected, the increase of the engine speed enhances the engine performances. Finally, an exergy losses mapping of the system show that the maximum exergy losses occurs in the HCCI engine

  1. Effect of different heat transfer models on HCCI engine simulation

    International Nuclear Information System (INIS)

    Neshat, Elaheh; Saray, Rahim Khoshbakhti

    2014-01-01

    Highlights: • A new multi zone model is developed for HCCI combustion modeling. • New heat transfer model is used for prediction of heat transfer in HCCI engines. • Model can predict engine combustion, performance and emission characteristics well. • Appropriate mass and heat transfer models cause to accurate prediction of CO, UHC and NOx. - Abstract: Heat transfer from engine walls has an important role on engine combustion, performance and emission characteristics. The main focus of this study is offering a new relation for calculation of convective heat transfer from in-cylinder charge to combustion chamber walls of HCCI engines and providing the ability of new model in comparison with the previous models. Therefore, a multi zone model is developed for homogeneous charge compression ignition engine simulation. Model consists of four different types of zones including core zone, boundary layer zone, outer zones, which are between core and boundary layer, and crevice zone. Conductive heat transfer and mass transfer are considered between neighboring zones. For accurate calculation of initial conditions at inlet valve closing, multi zone model is coupled with a single zone model, which simulates gas exchange process. Various correlations are used as convective heat transfer correlations. Woschni, modified Woschni, Hohenberg and Annand correlations are used as convective heat transfer models. The new convection model, developed by authors, is used, too. Comparative analyses are done to recognize the accurate correlation for prediction of engine combustion, performance and emission characteristics in a wide range of operating conditions. The results indicate that utilization of various heat transfer models, except for new convective heat transfer model, leads to significant differences in prediction of in-cylinder pressure and exhaust emissions. Using Woschni, Chang and new model, convective heat transfer coefficient increases near top dead center, sharply

  2. Analysis on reduced chemical kinetic model of N-heptane for HCCI combustion. Paper no. IGEC-1-072

    International Nuclear Information System (INIS)

    Yao, M.; Zheng, Z.

    2005-01-01

    Because of high complexity coupled with multidimensional fluid dynamics, it is difficult to apply detailed chemical kinetic model to simulate practical engines. A reduced model of n-heptane has been developed on the basic of detailed mechanism by sensitivity analysis and reaction path analysis of every stage of combustion. The new reduced mechanism consists of 35 species and 41 reactions, and it is effective in engine condition. The results show that it gives predictions similar to the detailed model in ignition timing, in-cylinder temperature and pressure. Furthermore, the reduced mechanism can be used to simulate boundary condition of partial combustion in good agreement with the detailed mechanism. (author)

  3. Comparison of Gasoline and Primary Reference Fuel in the Transition from HCCI to PPC

    KAUST Repository

    Li, Changle; Tunestal, Per; Tuner, Martin; Johansson, Bengt

    2017-01-01

    Our previous research investigated the sensitivity of combustion phasing to intake temperature and injection timing during the transition from homogeneous charge compression ignition (HCCI) to partially premixed combustion (PPC) fuelled with generic

  4. Flex Fuel Optimized SI and HCCI Engine

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Guoming [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Schock, Harold [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Yang, Xiaojian [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Huisjen, Andrew [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Stuecken, Tom [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Moran, Kevin [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Zhen, Ren [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Zhang, Shupeng [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Opra, John [Chrysler Corporation, Auburn Hill, MI (United States); Reese, Ron [Chrysler Corporation, Auburn Hill, MI (United States)

    2013-12-20

    The central objective of the proposed work is to demonstrate an HCCI (homogeneous charge compression ignition) capable SI (spark ignited) engine that is capable of fast and smooth mode transition between SI and HCCI combustion modes. The model-based control technique was used to develop and validate the proposed control strategy for the fast and smooth combustion mode transition based upon the developed control-oriented engine; and an HCCI capable SI engine was designed and constructed using production ready two-step valve-train with electrical variable valve timing actuating system. Finally, smooth combustion mode transition was demonstrated on a metal engine within eight engine cycles. The Chrysler turbocharged 2.0L I4 direct injection engine was selected as the base engine for the project and the engine was modified to fit the two-step valve with electrical variable valve timing actuating system. To develop the model-based control strategy for stable HCCI combustion and smooth combustion mode transition between SI and HCCI combustion, a control-oriented real-time engine model was developed and implemented into the MSU HIL (hardware-in-the-loop) simulation environment. The developed model was used to study the engine actuating system requirement for the smooth and fast combustion mode transition and to develop the proposed mode transition control strategy. Finally, a single cylinder optical engine was designed and fabricated for studying the HCCI combustion characteristics. Optical engine combustion tests were conducted in both SI and HCCI combustion modes and the test results were used to calibrate the developed control-oriented engine model. Intensive GT-Power simulations were conducted to determine the optimal valve lift (high and low) and the cam phasing range. Delphi was selected to be the supplier for the two-step valve-train and Denso to be the electrical variable valve timing system supplier. A test bench was constructed to develop control strategies for

  5. A new technology to overcome the limits of HCCI engine through fuel modification

    International Nuclear Information System (INIS)

    Bahng, GunWoong; Jang, Dongsoon; Kim, Youngtae; Shin, Misoo

    2016-01-01

    Highlights: • Problems of HCCI engine can be overcome by adopting fuel modification. • Gasoline vapor with HHO gas showed drastic improvement of fuel efficiency. • Performance of single cylinder engine shows fuel efficiency more than double. - Abstract: The energy efficiency of internal combustion engine reached to about 30% only recently. To increase the efficiency, homogeneous charge compression ignition (HCCI) has been proposed, however, there is no available commercial engine yet. The main problem lies in the delayed heating rate in spite of fast reaction of homogeneous charged state of HCCI with excess air. To overcome this difficulty, a modification of fuel by vaporization of liquid gasoline with water electrolysis gas and air was adopted in order to warrant the fast and high temperature rise. Experiments were carried out with single cylinder engines supplied from the four different manufacturers. Experimental results show that fuel consumption was decreased by more than 50% compared to the case of supplying liquid fuel. It is believed it was due to the combined effects of the high and fast heating potential of water electrolysis gas together with the efficient turbulence mixing effect of vaporized fuel with excess air. By this method, the drawbacks caused by lean burn in the HCCI engine such as small power range can be overcome.

  6. Numerical simulation and validation of SI-CAI hybrid combustion in a CAI/HCCI gasoline engine

    Science.gov (United States)

    Wang, Xinyan; Xie, Hui; Xie, Liyan; Zhang, Lianfang; Li, Le; Chen, Tao; Zhao, Hua

    2013-02-01

    SI-CAI hybrid combustion, also known as spark-assisted compression ignition (SACI), is a promising concept to extend the operating range of CAI (Controlled Auto-Ignition) and achieve the smooth transition between spark ignition (SI) and CAI in the gasoline engine. In this study, a SI-CAI hybrid combustion model (HCM) has been constructed on the basis of the 3-Zones Extended Coherent Flame Model (ECFM3Z). An ignition model is included to initiate the ECFM3Z calculation and induce the flame propagation. In order to precisely depict the subsequent auto-ignition process of the unburned fuel and air mixture independently after the initiation of flame propagation, the tabulated chemistry concept is adopted to describe the auto-ignition chemistry. The methodology for extracting tabulated parameters from the chemical kinetics calculations is developed so that both cool flame reactions and main auto-ignition combustion can be well captured under a wider range of thermodynamic conditions. The SI-CAI hybrid combustion model (HCM) is then applied in the three-dimensional computational fluid dynamics (3-D CFD) engine simulation. The simulation results are compared with the experimental data obtained from a single cylinder VVA engine. The detailed analysis of the simulations demonstrates that the SI-CAI hybrid combustion process is characterised with the early flame propagation and subsequent multi-site auto-ignition around the main flame front, which is consistent with the optical results reported by other researchers. Besides, the systematic study of the in-cylinder condition reveals the influence mechanism of the early flame propagation on the subsequent auto-ignition.

  7. Direct numerical simulations of exhaust gas recirculation effect on multistage autoignition in the negative temperature combustion regime for stratified HCCI flow conditions by using H2O2 addition

    Science.gov (United States)

    El-Asrag, Hossam A.; Ju, Yiguang

    2013-04-01

    Direct numerical simulations (DNSs) of a stratified flow in a homogeneous compression charge ignition (HCCI) engine are performed to investigate the exhaust gas recirculation (EGR) and temperature/mixture stratification effects on the autoignition of synthetic dimethyl ether (DME) in the negative temperature combustion region. Detailed chemistry for a DME/air mixture is employed and solved by a hybrid multi-time scale (HMTS) algorithm to reduce the computational cost. The effect of ? to mimic the EGR effect on autoignition are studied. The results show that adding ? enhances autoignition by rapid OH radical pool formation (34-46% reduction in ignition delay time) and changes the ignition heat release rates at different ignition stages. Sensitivity analysis is performed and the important reactions pathways affecting the autoignition are specified. The DNS results show that the scales introduced by thermal and mixture stratifications have a strong effect after the low temperature chemistry (LTC) ignition especially at the locations of high scalar dissipation rates. Compared to homogenous ignition, stratified ignitions show similar first autoignition delay times, but 18% reduction in the second and third ignition delay times. The results also show that molecular transport plays an important role in stratified low temperature ignition, and that the scalar mixing time scale is strongly affected by local ignition in the stratified flow. Two ignition-kernel propagation modes are observed: a wave-like, low-speed, deflagrative mode and a spontaneous, high-speed, ignition mode. Three criteria are introduced to distinguish these modes by different characteristic time scales and Damkhöler numbers using a progress variable conditioned by an ignition kernel indicator. The low scalar dissipation rate flame front is characterized by high displacement speeds and high mixing Damkhöler number. The proposed criteria are applied successfully at the different ignition stages and

  8. Simulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanol

    KAUST Repository

    Singh, Eshan

    2017-03-28

    The blending of ethanol with primary reference fuel (PRF) mixtures comprising n-heptane and iso-octane is known to exhibit a non-linear octane response; however, the underlying chemistry and intermolecular interactions are poorly understood. Well-designed experiments and numerical simulations are required to understand these blending effects and the chemical kinetic phenomenon responsible for them. To this end, HCCI engine experiments were previously performed at four different conditions of intake temperature and engine speed for various PRF/ethanol mixtures. Transfer functions were developed in the HCCI engine to relate PRF mixture composition to autoignition tendency at various compression ratios. The HCCI blending octane number (BON) was determined for mixtures of 2-20 vol % ethanol with PRF70. In the present work, the experimental conditions were considered to perform zero-dimensional HCCI engine simulations with detailed chemical kinetics for ethanol/PRF blends. The simulations used the actual engine geometry and estimated intake valve closure conditions to replicate the experimentally measured start of combustion (SOC) for various PRF mixtures. The simulated HCCI heat release profiles were shown to reproduce the experimentally observed trends, specifically on the effectiveness of ethanol as a low temperature chemistry inhibitor at various concentrations. Detailed analysis of simulated heat release profiles and the evolution of important radical intermediates (e.g., OH and HO) were used to show the effect of ethanol blending on controlling reactivity. A strong coupling between the low temperature oxidation reactions of ethanol and those of n-heptane and iso-octane is shown to be responsible for the observed blending effects of ethanol/PRF mixtures.

  9. Simulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanol

    KAUST Repository

    Singh, Eshan; Waqas, Muhammad; Johansson, Bengt; Sarathy, Mani

    2017-01-01

    The blending of ethanol with primary reference fuel (PRF) mixtures comprising n-heptane and iso-octane is known to exhibit a non-linear octane response; however, the underlying chemistry and intermolecular interactions are poorly understood. Well-designed experiments and numerical simulations are required to understand these blending effects and the chemical kinetic phenomenon responsible for them. To this end, HCCI engine experiments were previously performed at four different conditions of intake temperature and engine speed for various PRF/ethanol mixtures. Transfer functions were developed in the HCCI engine to relate PRF mixture composition to autoignition tendency at various compression ratios. The HCCI blending octane number (BON) was determined for mixtures of 2-20 vol % ethanol with PRF70. In the present work, the experimental conditions were considered to perform zero-dimensional HCCI engine simulations with detailed chemical kinetics for ethanol/PRF blends. The simulations used the actual engine geometry and estimated intake valve closure conditions to replicate the experimentally measured start of combustion (SOC) for various PRF mixtures. The simulated HCCI heat release profiles were shown to reproduce the experimentally observed trends, specifically on the effectiveness of ethanol as a low temperature chemistry inhibitor at various concentrations. Detailed analysis of simulated heat release profiles and the evolution of important radical intermediates (e.g., OH and HO) were used to show the effect of ethanol blending on controlling reactivity. A strong coupling between the low temperature oxidation reactions of ethanol and those of n-heptane and iso-octane is shown to be responsible for the observed blending effects of ethanol/PRF mixtures.

  10. Validation of a reduced chemical mechanism coupled to CFD model in a 2-stroke HCCI engine

    NARCIS (Netherlands)

    Izadi Najafabadi, M.; Somers, B.; Nuraini, A.

    2015-01-01

    Homogeneous Charge Compression Ignition (HCCI) combustion technology has demonstrated a profound potential to decrease both emissions and fuel consumption. In this way, the significance of the 2-stroke HCCI engine has been underestimated as it can provide more power stroke in comparison to a

  11. Numerical modeling on homogeneous charge compression ignition combustion engine fueled by diesel-ethanol blends

    OpenAIRE

    Hanafi H.; Hasan M.M; Rahman M.M; Noor M.M; Kadirgama K.; Ramasamy D.

    2016-01-01

    This paper investigates the performance and emission characteristics of HCCI engines fueled with oxygenated fuels (ethanol blend). A modeling study was conducted to investigate the impact of ethanol addition on the performance, combustion and emission characteristics of a Homogeneous Charge Compression Ignition (HCCI) engine fueled by diesel. One dimensional simulation was conducted using the renowned commercial software for diesel and its blend fuels with 5% (E5) and 10% ethanol (E10) (in vo...

  12. Utilization of waste heat from a HCCI (homogeneous charge compression ignition) engine in a tri-generation system

    International Nuclear Information System (INIS)

    Sarabchi, N.; Khoshbakhti Saray, R.; Mahmoudi, S.M.S.

    2013-01-01

    The waste heat from exhaust gases and cooling water of Homogeneous charge compression ignition engines (HCCI) are utilized to drive an ammonia-water cogeneration cycle (AWCC) and some heating processes, respectively. The AWCC is a combination of the Rankine cycle and an absorption refrigeration cycle. Considering the chemical kinetic calculations, a single zone combustion model is developed to simulate the natural gas fueled HCCI engine. Also, the performance of AWCC is simulated using the Engineering Equation Solver software (EES). Through combining these two codes, a detailed thermodynamic analysis is performed for the proposed tri-generation system and the effects of some main parameters on the performances of both the AWCC and the tri-generation system are investigated in detail. The cycle performance is then optimized for the fuel energy saving ratio (FESR). The enhancement in the FESR could be up to 28.56%. Under optimized condition, the second law efficiency of proposed system is 5.19% higher than that of the HCCI engine while the reduction in CO 2 emission is 4.067% as compared with the conventional separate thermodynamic systems. Moreover, the results indicate that the engine, in the tri-generation system and the absorber, in the bottoming cycle has the most contribution in exergy destruction. - Highlights: • A new thermodynamic tri-generation system is proposed for waste heat recovery of HCCI engine. • A single zone combustion model is developed to simulate the natural gas fueled HCCI engine. • The proposed tri-generation cycle is analyzed from the view points of both first and second laws of thermodynamics. • In the considered cycle, enhancements of 28.56% in fuel energy saving ratio and 5.19% in exergy efficiency are achieved

  13. Thermodynamic energy and exergy analysis of three different engine combustion regimes

    International Nuclear Information System (INIS)

    Li, Yaopeng; Jia, Ming; Chang, Yachao; Kokjohn, Sage L.; Reitz, Rolf D.

    2016-01-01

    Highlights: • Energy and exergy distributions of three different combustion regimes are studied. • CDC demonstrates the highest utilization efficiency of heat transfer and exhaust. • HCCI achieves the highest energy and exergy efficiencies over CDC and RCCI. • HCCI and RCCI demonstrate lower exergy destruction than CDC. • Combustion temperature, rate, duration and regime affect exergy destruction. - Abstract: Multi-dimensional models were coupled with a detailed chemical mechanism to investigate the energy and exergy distributions of three different combustion regimes in internal combustion engines. The results indicate that the 50% heat release point (CA50) considerably affects fuel efficiency and ringing intensity (RI), in which RI is used to quantify the knock level. Moreover, the burn duration from the 10% heat release point (CA10) to CA50 dominates RI, and the position of 90% heat release point (CA90) affects fuel efficiency. The heat transfer losses of conventional diesel combustion (CDC) strongly depend on the local temperature gradient, while it is closely related to the heat transfer area for homogeneous charge compression ignition (HCCI) and reactivity controlled compression ignition (RCCI). Among the three combustion regimes, CDC has the largest utilization efficiency for heat transfer and exhaust energy due to its higher temperature in the heat transfer layer and higher exhaust pressure and temperature. The utilization efficiency of heat transfer and exhaust in RCCI is less affected by the variation of CA50 compared to those in CDC and HCCI. Exergy destruction is closely related to the homogeneity of in-cylinder temperature and equivalence ratio during combustion process, the combustion temperature, the chemical reaction rate, and the combustion duration. Under the combined effect, HCCI and RCCI demonstrate lower exergy destruction than CDC at the same load. Overall, the variations of the exergy distribution for the three combustion regimes

  14. Development of High Efficiency Clean Combustion Engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, Craig; Gonzalez, Manual; Russell, Durrett

    2011-06-30

    This report summarizes activities related to the revised STATEMENT OF PROJECT OBJECTIVES (SOPO) dated June 2010 for the Development of High-Efficiency Clean Combustion engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines (COOPERATIVE AGREEMENT NUMBER DE-FC26-05NT42415) project. In both the spark- (SI) and compression-ignition (CI) development activities covered in this program, the goal was to develop potential production-viable internal combustion engine system technologies that both reduce fuel consumption and simultaneously met exhaust emission targets. To be production-viable, engine technologies were also evaluated to determine if they would meet customer expectations of refinement in terms of noise, vibration, performance, driveability, etc. in addition to having an attractive business case and value. Prior to this activity, only proprietary theoretical / laboratory knowledge existed on the combustion technologies explored The research reported here expands and develops this knowledge to determine series-production viability. Significant SI and CI engine development occurred during this program within General Motors, LLC over more than five years. In the SI program, several engines were designed and developed that used both a relatively simple multi-lift valve train system and a Fully Flexible Valve Actuation (FFVA) system to enable a Homogeneous Charge Compression Ignition (HCCI) combustion process. Many technical challenges, which were unknown at the start of this program, were identified and systematically resolved through analysis, test and development. This report documents the challenges and solutions for each SOPO deliverable. As a result of the project activities, the production viability of the developed clean combustion technologies has been determined. At this time, HCCI combustion for SI engines is not considered production-viable for several reasons. HCCI combustion is excessively sensitive to control variables

  15. Fuels for homogeneous charge compression ignition (HCCI) engines. Automotive fuels survey. Part 6

    Energy Technology Data Exchange (ETDEWEB)

    Van Walwijk, M.

    2001-01-01

    Homogeneous charge compression ignition (HCCI) is a third mode of operation for internal combustion engines, beside spark ignition and conventional compression ignition. This report concentrates on the requirements that HCCI operation puts on fuels for these engines. For readers with limited time available, this summary describes the main findings. Policy makers that need some more background information may turn directly to chapter 7, 'Fuels for HCCI engines'. The rest of this report can be considered as a reference guide for more detailed information. The driving force to investigate HCCI engines is the potential of low emissions and simultaneously high energy efficiency. HCCI is gaining attention the last few years. However, HCCI engines are still in the research phase. After many experiments with prototype engines, people have now started working on computer simulations of the combustion process, to obtain a fundamental understanding of HCCI combustion and to steer future engine developments. In HCCI engines, an air/fuel mixture is prepared before it enters the combustion chamber. The homogeneous mixture is in the combustion chamber compressed to auto-ignition. Unlike in conventional engines, combustion starts at many different locations simultaneously and the speed of combustion is very high, so there is no flame front. Lean air/fuel mixtures (excess air) are used to control combustion speed. Because of the excess air, combustion temperature is relatively low, resulting in low NOx emissions. When the fuel is vaporised to a truly homogeneous mixture, complete combustion results in low particulate emissions. The most important advantages of HCCI engines are: - Emissions of NOx and particulates are very low. - Energy efficiency is high. It is comparable to diesel engines. - Many different fuels (one at a time) can be used in the HCCI concept. There are also some hurdles to overcome: - Controlling combustion is difficult, it complicates engine design

  16. Identification of the dynamic operating envelope of HCCI engines using class imbalance learning.

    Science.gov (United States)

    Janakiraman, Vijay Manikandan; Nguyen, XuanLong; Sterniak, Jeff; Assanis, Dennis

    2015-01-01

    Homogeneous charge compression ignition (HCCI) is a futuristic automotive engine technology that can significantly improve fuel economy and reduce emissions. HCCI engine operation is constrained by combustion instabilities, such as knock, ringing, misfires, high-variability combustion, and so on, and it becomes important to identify the operating envelope defined by these constraints for use in engine diagnostics and controller design. HCCI combustion is dominated by complex nonlinear dynamics, and a first-principle-based dynamic modeling of the operating envelope becomes intractable. In this paper, a machine learning approach is presented to identify the stable operating envelope of HCCI combustion, by learning directly from the experimental data. Stability is defined using thresholds on combustion features obtained from engine in-cylinder pressure measurements. This paper considers instabilities arising from engine misfire and high-variability combustion. A gasoline HCCI engine is used for generating stable and unstable data observations. Owing to an imbalance in class proportions in the data set, the models are developed both based on resampling the data set (by undersampling and oversampling) and based on a cost-sensitive learning method (by overweighting the minority class relative to the majority class observations). Support vector machines (SVMs) and recently developed extreme learning machines (ELM) are utilized for developing dynamic classifiers. The results compared against linear classification methods show that cost-sensitive nonlinear ELM and SVM classification algorithms are well suited for the problem. However, the SVM envelope model requires about 80% more parameters for an accuracy improvement of 3% compared with the ELM envelope model indicating that ELM models may be computationally suitable for the engine application. The proposed modeling approach shows that HCCI engine misfires and high-variability combustion can be predicted ahead of time

  17. Fuel Combustion and Engine Performance | Transportation Research | NREL

    Science.gov (United States)

    Fuel Combustion and Engine Performance Fuel Combustion and Engine Performance Photo of a gasoline emissions in advanced engine technologies. Photo by Dennis Schroeder, NREL NREL's combustion research and combustion and engine research activities include: Developing experimental and simulation research platforms

  18. Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

    Science.gov (United States)

    Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

    2008-10-07

    This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

  19. Proceedings of IEA combustion 2009 : IEA 31. task leaders meeting on energy conservation and emissions reduction in combustion

    International Nuclear Information System (INIS)

    2009-01-01

    The International Energy Agency (IEA) supports research and development in energy technology. This meeting provided a forum to discuss combustion processes, which is fundamental to achieving further improvements in fuel use efficiency, reducing the production of pollutants such as nitrogen oxides, and facilitating the transition to alternative fuels. The presentations demonstrated recent studies in improving the efficiency and fuel flexibility of automotive engines; improving the performance of industrial furnaces; emissions formation and control mechanisms; and fuel injection and fuel/air mixing. The conference also highlighted studies involving hydrogen combustion, alternative fuels, particulate diagnostics, fuel sprays, gas turbines, and advanced combustion processes such as homogeneous charge compression ignition (HCCI). The sessions were entitled: HCCI fuels; sprays; nanoparticle diagnostics; alternative fuels; hydrogen internal combustion engines; turbines; energy security; and collaborative task planning. All 45 presentations from the conference have been catalogued separately for inclusion in this database. refs., tabs., figs.

  20. Analysis of benefits of using internal exhaust gas recirculation in biogas-fueled HCCI engines

    International Nuclear Information System (INIS)

    Kozarac, Darko; Vuilleumier, David; Saxena, Samveg; Dibble, Robert W.

    2014-01-01

    Highlights: • The influence of EGR on combustion of biogas fueled HCCI was investigated. • The aim was to reduce intake temperature requirement by internal EGR. • Combustion products caused the delay of combustion in similar conditions. • Internal EGR enabled by negative valve overlap increased cylinder temperature. • This increase was not enough to significantly reduce the intake temperature. - Abstract: This paper describes a numerical study that analyzed the influence of combustion products (CP) concentration on the combustion characteristics (combustion timing and combustion duration) of a biogas fueled homogeneous charge compression ignition (HCCI) engine and the possibility of reducing the high intake temperature requirement necessary for igniting biogas in a HCCI engine by using internal exhaust gas recirculation (EGR) enabled by negative valve overlap (NVO). An engine model created in AVL Boost, and validated against experimental engine data, was used in this study. The results show, somewhat counter-intuitively, that when CP concentrations are increased the required intake temperature for maintaining the same combustion timing must be increased. When greater NVO is used to increase the in-cylinder CP concentration, the in-cylinder temperature does increase, but the chemical dilution influence of CP almost entirely counteracts this thermal effect. Additionally, it has been observed that with larger fractions of CP some instability of combustion in the calculation was obtained which indicates that the increase of internal EGR might produce some combustion instability

  1. Advanced Start of Combustion Sensor Phases I and II-A: Feasibility Demonstration, Design and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Chad Smutzer

    2010-01-31

    Homogeneous Compressed Charge Ignition (HCCI) has elevated the need for Start of Combustion (SOC) sensors. HCCI engines have been the exciting focus of engine research recently, primarily because HCCI offers higher thermal efficiency than the conventional Spark Ignition (SI) engines and significantly lower NOx and soot emissions than conventional Compression Ignition (CI) engines, and could be fuel neutral. HCCI has the potential to unify all the internal combustion engine technology to achieve the high-efficiency, low-emission goal. However, these advantages do not come easy. It is well known that the problems encountered with HCCI combustion center on the difficulty of controlling the Start of Combustion. TIAX has an SOC sensor under development which has shown promise. In previous work, including a DOE-sponsored SBIR project, TIAX has developed an accelerometer-based method which was able to determine SOC within a few degrees crank angle for a range of operating conditions. A signal processing protocol allows reconstruction of the combustion pressure event signal imbedded in the background engine vibration recorded by the accelerometer. From this reconstructed pressure trace, an algorithm locates the SOC. This SOC sensor approach is nonintrusive, rugged, and is particularly robust when the pressure event is strong relative to background engine vibration (at medium to high engine load). Phase I of this project refined the previously developed technology with an engine-generic and robust algorithm. The objective of the Phase I research was to answer two fundamental questions: Can the accelerometer-based SOC sensor provide adequate SOC event capture to control an HCCI engine in a feedback loop? And, will the sensor system meet cost, durability, and software efficiency (speed) targets? Based upon the results, the answer to both questions was 'YES'. The objective of Phase II-A was to complete the parameter optimization of the SOC sensor prototype in order

  2. Research on cylinder processes of gasoline homogenous charge compression ignition (HCCI) engine

    Science.gov (United States)

    Cofaru, Corneliu

    2017-10-01

    This paper is designed to develop a HCCI engine starting from a spark ignition engine platform. The engine test was a single cylinder, four strokes provided with carburetor. The results of experimental research on this version were used as a baseline for the next phase of the work. After that, the engine was modified for a HCCI configuration, the carburetor was replaced by a direct fuel injection system in order to control precisely the fuel mass per cycle taking into account the measured intake air-mass. To ensure that the air - fuel mixture auto ignite, the compression ratio was increased from 9.7 to 11.5. The combustion process in HCCI regime is governed by chemical kinetics of mixture of air-fuel, rein ducted or trapped exhaust gases and fresh charge. To modify the quantities of trapped burnt gases, the exchange gas system was changed from fixed timing to variable valve timing. To analyze the processes taking place in the HCCI engine and synthesizing a control system, a model of the system which takes into account the engine configuration and operational parameters are needed. The cylinder processes were simulated on virtual model. The experimental research works were focused on determining the parameters which control the combustion timing of HCCI engine to obtain the best energetic and ecologic parameters.

  3. Numerical analysis of knock during HCCI in a high compression ratio methanol engine based on LES with detailed chemical kinetics

    International Nuclear Information System (INIS)

    Zhen, Xudong; Wang, Yang

    2015-01-01

    Highlights: • Knock during HCCI in a high compression ratio methanol engine was modeled. • A detailed methanol mechanism was used to simulate the knocking combustion. • Compared with the SI engines, the HCCI knocking combustion burnt faster. • The reaction rate of HCO had two obvious peaks, one was positive, and another was negative. • Compared with the SI engines, the values of the reaction rates of CH 2 O, H 2 O 2 , and HO 2 were higher, and it had negative peaks. - Abstract: In this study, knock during HCCI (homogeneous charge compression ignition) was studied based on LES (large eddy simulation) with methanol chemical kinetics (84-reaction, 21-species) in a high compression ratio methanol engine. The non-knocking and knocking combustion of SI (spark ignition) and HCCI engines were compared. The results showed that the auto-ignition spots were initially occurred near the combustion chamber wall. The knocking combustion burnt faster during HCCI than SI methanol engine. The HCO reaction rate was different from SI engine, it had two obvious peaks, one was positive peak, and another was negative peak. Compared with the SI methanol engine, in addition to the concentration of HCO, the concentrations of the other intermediate products and species such as CO, OH, CH 2 O, H 2 O 2 , HO 2 were increased significantly; the reaction rates of CH 2 O, H 2 O 2 , and HO 2 had negative peaks, and whose values were several times higher than SI methanol engine

  4. Intermediate temperature heat release in an HCCI engine fueled by ethanol/n-heptane mixtures: An experimental and modeling study

    KAUST Repository

    Vuilleumier, David

    2014-03-01

    This study examines intermediate temperature heat release (ITHR) in homogeneous charge compression ignition (HCCI) engines using blends of ethanol and n-heptane. Experiments were performed over the range of 0-50% n-heptane liquid volume fractions, at equivalence ratios 0.4 and 0.5, and intake pressures from 1.4bar to 2.2bar. ITHR was induced in the mixtures containing predominantly ethanol through the addition of small amounts of n-heptane. After a critical threshold, additional n-heptane content yielded low temperature heat release (LTHR). A method for quantifying the amount of heat released during ITHR was developed by examining the second derivative of heat release, and this method was then used to identify trends in the engine data. The combustion process inside the engine was modeled using a single-zone HCCI model, and good qualitative agreement of pre-ignition pressure rise and heat release rate was found between experimental and modeling results using a detailed n-heptane/ethanol chemical kinetic model. The simulation results were used to identify the dominant reaction pathways contributing to ITHR, as well as to verify the chemical basis behind the quantification of the amount of ITHR in the experimental analysis. The dominant reaction pathways contributing to ITHR were found to be H-atom abstraction from n-heptane by OH and the addition of fuel radicals to O2. © 2013 The Combustion Institute.

  5. Intermediate temperature heat release in an HCCI engine fueled by ethanol/n-heptane mixtures: An experimental and modeling study

    KAUST Repository

    Vuilleumier, David; Kozarac, Darko; Mehl, Marco; Saxena, Samveg; Pitz, William J.; Dibble, Robert W.; Chen, Jyhyuan; Sarathy, Mani

    2014-01-01

    This study examines intermediate temperature heat release (ITHR) in homogeneous charge compression ignition (HCCI) engines using blends of ethanol and n-heptane. Experiments were performed over the range of 0-50% n-heptane liquid volume fractions, at equivalence ratios 0.4 and 0.5, and intake pressures from 1.4bar to 2.2bar. ITHR was induced in the mixtures containing predominantly ethanol through the addition of small amounts of n-heptane. After a critical threshold, additional n-heptane content yielded low temperature heat release (LTHR). A method for quantifying the amount of heat released during ITHR was developed by examining the second derivative of heat release, and this method was then used to identify trends in the engine data. The combustion process inside the engine was modeled using a single-zone HCCI model, and good qualitative agreement of pre-ignition pressure rise and heat release rate was found between experimental and modeling results using a detailed n-heptane/ethanol chemical kinetic model. The simulation results were used to identify the dominant reaction pathways contributing to ITHR, as well as to verify the chemical basis behind the quantification of the amount of ITHR in the experimental analysis. The dominant reaction pathways contributing to ITHR were found to be H-atom abstraction from n-heptane by OH and the addition of fuel radicals to O2. © 2013 The Combustion Institute.

  6. Numerical investigation of ethanol fuelled HCCI engine using stochastic reactor model. Part 1: Development of a new reduced ethanol oxidation mechanism

    International Nuclear Information System (INIS)

    Maurya, Rakesh Kumar; Akhil, Nekkanti

    2016-01-01

    Highlights: • Stochastic reactor model used for numerical study of HCCI engine. • New reduced oxidation mechanism with NOx developed (47 species and 272 reactions). • Mechanism predicts cylinder pressure and heat release with sufficient accuracy. • Mechanism was able to capture the trend in NO x emission with sufficient accuracy. - Abstract: Ethanol is considered a potential biofuel for internal combustion engines. In this study, homogeneous charge compression ignition (HCCI) simulations of ethanol engine experiments were performed using stochastic reactor model (SRM). Detailed ethanol oxidation mechanism is developed by including NO x reaction in existing detailed oxidation mechanism with 57 species and 383 reactions. Detailed ethanol mechanism with NO x used in this study contains 76 species and 495 reactions. This mechanism was reduced by direct relation graph (DRG) method, which was validated with the experimental results. Existing Lu’s 40-species skeletal mechanism with NO formation were also compared with detailed and reduced mechanisms for predicting maximum cylinder pressure, maximum heat release rate and crank angle position of maximum cylinder pressure in HCCI engine. Reduced mechanism developed in this study exhibited the best resemblance with the experimental data. This reduced mechanism was also validated by measured engine cylinder pressure curves and measured ignition delays in constant volume reactors. The results showed that reduced mechanism is capable of predicting HCCI engine performance parameters with sufficient accuracy. Sensitivity analysis was conducted to determine the influential reactions in ethanol oxidation. Results also show that detailed and reduced mechanism was able to predict NO x emission in good agreement with the corresponding experimental data.

  7. Ozone applied to the homogeneous charge compression ignition engine to control alcohol fuels combustion

    International Nuclear Information System (INIS)

    Masurier, J.-B.; Foucher, F.; Dayma, G.; Dagaut, P.

    2015-01-01

    Highlights: • Ozone was useful to control combustion phasing of alcohol fuels in HCCI engine. • Ozone helps to improve the combustion and advance its phasing. • Butanol is more impacted by ozone than methanol and ethanol. • HCCI combustion parameters may be controlled by managing ozone concentration. • Kinetics demonstrates that alcohol fuels are initially oxidized by O-atoms. - Abstract: The present investigation examines the impact of seeding the intake of an HCCI engine with ozone, one of the most oxidizing chemical species, on the combustion of three alcohol fuels: methanol, ethanol and n-butanol. The research was performed through engine experiments and constant volume computations. The results showed that increasing the ozone concentration led to an improvement in combustion coupled with a combustion advance. It was also observed, by comparing the results for each fuel selected, that n-butanol is the most impacted by ozone seeding and methanol the least. Further analyses of the experimental results showed that the alcohol fuel combustion can be controlled with ozone, which presents an interesting potential. Finally, computation results confirmed the experimental results observed. They also showed that in presence of ozone, alcohol fuels are not initially oxidized by molecular oxygen but by O-atoms coming from the ozone decomposition.

  8. Experimental investigation of homogeneous charge compression ignition combustion of biodiesel fuel with external mixture formation in a CI engine.

    Science.gov (United States)

    Ganesh, D; Nagarajan, G; Ganesan, S

    2014-01-01

    In parallel to the interest in renewable fuels, there has also been increased interest in homogeneous charge compression ignition (HCCI) combustion. HCCI engines are being actively developed because they have the potential to be highly efficient and to produce low emissions. Even though HCCI has been researched extensively, few challenges still exist. These include controlling the combustion at higher loads and the formation of a homogeneous mixture. To obtain better homogeneity, in the present investigation external mixture formation method was adopted, in which the fuel vaporiser was used to achieve excellent HCCI combustion in a single cylinder air-cooled direct injection diesel engine. In continuation of our previous works, in the current study a vaporised jatropha methyl ester (JME) was mixed with air to form a homogeneous mixture and inducted into the cylinder during the intake stroke to analyze the combustion, emission and performance characteristics. To control the early ignition of JME vapor-air mixture, cooled (30 °C) Exhaust gas recirculation (EGR) technique was adopted. The experimental result shows 81% reduction in NOx and 72% reduction in smoke emission.

  9. A Comprehensive Numerical Study on Effects of Natural Gas Composition on the Operation of an HCCI Engine Une étude numérique complète sur les effets de la composition du gaz naturel carburant sur le réglage d’un moteur HCCI

    Directory of Open Access Journals (Sweden)

    Jahanian O.

    2011-11-01

    Full Text Available Homogeneous Charge Compression Ignition (HCCI engine is a promising idea to reduce fuel consumption and engine emissions. Natural Gas (NG, usually referred as clean fuel, is an appropriate choice for HCCI engines due to its suitable capability of making homogenous mixture with air. However, varying composition of Natural Gas strongly affects the auto-ignition characteristics of in-cylinder mixture and the performance of the HCCI engine. This paper has focused on the influence of Natural Gas composition on engine operation in HCCI mode. Six different compositions of Natural Gas (including pure methane have been considered to study the engine performance via a thermo-kinetic zero-dimensional model. The simulation code covers the detailed chemical kinetics of Natural Gas combustion, which includes Zeldovich extended mechanism to evaluate NOx emission. Validations have been made using experimental data from other works to ensure the accuracy needed for comparison study. The equivalence ratio and the compression ratio are held constant but the engine speed and mixture initial temperature are changed for comparison study. Results show that the peak value of pressure/temperature of in-cylinder mixture is dependent of fuel Wobbe number. Furthermore, engine gross indicated power is linearly related to fuel Wobbe number. Gross indicated work, gross mean effective pressure, and NOx are the other parameters utilized to compare the performance of engine using different fuel compositions. Le moteur HCCI (Homogeneous Charge Compression Ignition, ou à allumage par compression d’une charge homogène est une idée prometteuse pour réduire la consommation de carburant et les émissions polluantes. Le gaz naturel, considéré généralement comme un carburant propre, est un choix approprié pour les moteurs HCCI en raison de sa capacité à former avec l’air un mélange homogène. Cependant, la composition du gaz naturel influe fortement sur les caract

  10. Method for reduction of the NOX emissions in marine auxiliary diesel engine using the fuel mixtures containing biodiesel using HCCI combustion.

    Science.gov (United States)

    Puškár, Michal; Kopas, Melichar; Puškár, Dušan; Lumnitzer, Ján; Faltinová, Eva

    2018-02-01

    The marine auxiliary diesel engines installed in the large transoceanic ships are used in order to generate the electricity but at the same time these engines are able to produce a significant amount of the harmful exhaust gas emissions. Therefore the International Maritime Organisation (IMO) concluded an agreement, which has to control generating of gaseous emissions in maritime transport. From this reason started to be used some of the alternative fuels in this branch. There was performed a study, which investigated emissions of the auxiliary marine diesel engine during application of the experimental fuels. The different testing fuels were created using the ratios 0%, 50%, 80% and 100% between the biodiesel and the ULSDF (Ultra Low Sulphur Diesel Fuel). The experimental measurements were performed at the different engine loading levels and various engine speeds in order to investigate an influence of the mixed fuels on the engine operational characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. DETAILED CHEMICAL KINETIC MODELING OF ISO-OCTANE SI-HCCI TRANSITION

    Energy Technology Data Exchange (ETDEWEB)

    Havstad, M A; Aceves, S M; McNenly, M J; Piggott, W T; Edwards, K D; Wagner, R M; Daw, C S; Finney, C A

    2009-10-12

    The authors describe a CHEMKIN-based multi-zone model that simulates the expected combustion variations in a single-cylinder engine fueled with iso-octane as the engine transitions from spark-ignited (ST) combustion to homogeneous charge compression ignition (HCCI) combustion. The model includes a 63-species reaction mechanism and mass and energy balances for the cylinder and the exhaust flow. For this study they assumed that the SI-to-HCCI transition is implemented by means of increasing the internal exhaust gas recirculation (EGR) at constant engine speed. This transition scneario is consistent with that implemented in previously reported experimental measurements on an experimental engine equipped with variable valve actuation. They find that the model captures many of the important experimental trends, including stable SI combustion at low EGR ({approx} 0.10), a transition to highly unstable combustion at intermediate EGR, and finally stable HCCI combustion at very high EGR ({approx} 0.75). Remaining differences between the predicted and experimental instability patterns indicate that there is further room for model improvement.

  12. Comparison of Gasoline and Primary Reference Fuel in the Transition from HCCI to PPC

    KAUST Repository

    Li, Changle

    2017-10-10

    Our previous research investigated the sensitivity of combustion phasing to intake temperature and injection timing during the transition from homogeneous charge compression ignition (HCCI) to partially premixed combustion (PPC) fuelled with generic gasoline. The results directed particular attention to the relationship between intake temperature and combustion phasing which reflected the changing of stratification level with the injection timing. To confirm its applicability with the use of different fuels, and to investigate the effect of fuel properties on stratification formation, primary reference fuels (PRF) were tested using the same method: a start of injection sweep from -180° to -20° after top dead center with constant combustion phasing by tuning the intake temperature. The present results are further developed compared with those of our previous work, which were based on generic gasoline. In the present work, a three-stage fuel-air stratification development process was observed during the transition from HCCI to PPC. Moreover, a transition stage was observed between the HCCI and PPC stages. Within this transition stage, both the combustion and emission characteristics deteriorated. The allocation of this transition area was mainly determined by the geometric design of the fuel injector and combustion chamber. Some differences in charge stratification were observed between the PRF and gasoline. The NO emissions of the PRF were comparable to those of gasoline. However, the NO emissions surged during the transition stage, indicating that the PRF combustion was probably more stratified. The soot emissions from PRF and gasoline were both much higher in the PPC than the HCCI mode, though the PRF produced much less soot than did gasoline in the PPC mode.

  13. AN EXPERIMENTAL NOX REDUCTION POTENTIAL INVESTIGATION OF THE PARTIAL HCCI APPLICATION, ON A HIGH PRESSURE FUEL INJECTION EQUIPPED DIESEL ENGINE BY IMPLEMENTING FUMIGATION OF GASOLINE PORT INJECTION

    OpenAIRE

    ERGENÇ, Alp Tekin; YÜKSEK, Levent; ÖZENER, Orkun; IŞIN, Övün

    2016-01-01

    This work investigates the effects of partial HCCI (Homogeneous charge compression ignition) application on today's modern diesel engine tail pipe NOx emissions. Gasoline fumigation is supplied via a port fuel injection system located in the intake port of DI(Direct injection) diesel engine to maintain partial HCCI conditions and also diesel fuel injected directly into the combustion chamber before TDC(Top dead center). A single cylinder direct injection diesel research engine equipped w...

  14. Investigation of a wet ethanol operated HCCI engine based on first and second law analyses

    International Nuclear Information System (INIS)

    Khaliq, Abdul; Trivedi, Shailesh K.; Dincer, Ibrahim

    2011-01-01

    In this paper, a conceptual wet ethanol operated homogeneous charge compression ignition (HCCI) engine is proposed to shift the energy balance in favor of ethanol. The investigated option, HCCI engine is a relatively new type of engine that has some fundamental differences with respect to other prime movers. Combined first and second law of thermodynamic approach is applied for a HCCI engine operating on wet ethanol and computational analysis is performed to investigate the effects of turbocharger compressor ratio, ambient temperature, and compressor adiabatic efficiency on first law efficiency, second law efficiency, and exergy destruction in each component. First law and second law efficiencies are found to be an increasing function of the turbocharger pressure ratio, while they are found to be a decreasing function of the ambient temperature. The effect of turbocharger pressure ratio on exergy destruction is found to be more significant than compressor efficiency and ambient temperature. Exergy analysis indicates that maximum exergy is destroyed in HCCI engine which represents about 90.09% of the total exergy destruction in the overall system. Around 4.39% exergy is destroyed by the process of heat transfer in fuel vaporizer and heat exchanger. Catalytic converter contributes about 4.08% of the total exergy destruction. This will provide some original information on the role of operating variables and will be quite useful in obtaining the optimum design of ethanol fuelled HCCI engines. - Highlights: → Direct utilization of wet ethanol in HCCI engines shift the energy balance in favor of ethanol. → First and second law efficiencies of wet ethanol operated HCCI engine increases with the increase in the turbocharger pressure ratio and its polytropic efficiency. → Second law analysis provides a suitable ranking among the components of the system in terms of exergy destruction. → Analysis of the results clearly showed that the highest irreversibility sources

  15. Update on Engine Combustion Research at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Jay Keller; Gurpreet Singh

    2001-01-01

    The objectives of this paper are to describe the research efforts in diesel engine combustion at Sandia National Laboratories' Combustion Research Facility and to provide recent experimental results. We have four diesel engine experiments supported by the Department of Energy, Office of Heavy Vehicle Technologies: a one-cylinder version of a Cummins heavy-duty engine, a diesel simulation facility, a one-cylinder Caterpillar engine to evaluate combustion of alternative fuels, and a homogeneous-charge, compression ignition (HCCI) engine. Recent experimental results of diesel combustion research will be discussed and a description will be given of our HCCI experimental program and of our HCCI modeling work

  16. Study on the knock tendency and cyclical variations of a HCCI engine fueled with n-butanol/n-heptane blends

    International Nuclear Information System (INIS)

    Li, Gang; Zhang, Chunhua; Zhou, Jiawang

    2017-01-01

    Highlights: • The HCCI combustion was achieved on an engine fueled by n-butanol/n-heptane blends. • The knock tendency and cyclical variation of the HCCI combustion were studied. • The knock tendency can be weakened by increasing the blending ratio of n-butanol. • The knock tendency and cyclical variation are sensitive to the combustion phasing. • Cyclical variation always shows an opposite trend with the knock tendency. - Abstract: The homogeneous charge compression ignition (HCCI) combustion operation is conducted in the 2nd cylinder of a natural-aspirated four-stroke diesel engine. In the HCCI combustion mode, the n-butanol, n-heptane and their blends are injected into the intake port to form a lean homogeneous air-fuel mixture, which is consumed by the autoignition after compression. The objective of this study is to investigate the knock tendency and the cyclical variations of the HCCI engine. Experimental results show that the volume fraction of n-butanol affects the knock tendency greatly, which obviously decreases as the n-butanol volume fraction increases. The knocking combustion in the HCCI combustion is characterized by the high heat release rate (HRR). Both elevating the engine speed and raising the intake temperature contributes to an obvious increase in HRR and the knock tendency. But the HRR and knock tendency may slightly decrease when the engine speed reaches to 1400 rev/min and intake temperature reaches to 160 °C. Furthermore, the knock tendency can be weakened by increasing the excess air-fuel ratio. Cyclical variations of the HCCI engine are quantified by the coefficient of variation for the peak pressure (COV_P_m_a_x) and it exhibits an almost opposite trend to the knock tendency. The COV_P_m_a_x may considerably increase along with either increasing the blending ratio of n-butanol or increasing the excess air-fuel ratio. Moreover, it is reveled that the COV_P_m_a_x is sensitive to the relative position of peak HRR. The cyclical

  17. Thermodynamic control-oriented modeling of cycle-to-cycle exhaust gas temperature in an HCCI engine

    International Nuclear Information System (INIS)

    Dehghani Firoozabadi, M.; Shahbakhti, M.; Koch, C.R.; Jazayeri, S.A.

    2013-01-01

    Highlights: • First thermodynamic model in the literature to predict exhaust temperature in HCCI engines. • The model can be used for integrated control of HCCI combustion and exhaust temperature. • The model is experimentally validated at over 300 steady state and transient conditions. • Results show a good agreement between predicted and measured exhaust temperatures. • Sensitivity of exhaust gas temperature to variation of engine variables is shown. - Abstract: Model-based control of Homogenous Charge Compression Ignition (HCCI) engine exhaust temperature is a viable solution to optimize efficiency of both engine and the exhaust aftertreatment system. Low exhaust temperature in HCCI engines can limit the abatement of hydrocarbon (HC) and carbon monoxide (CO) emissions in an exhaust aftertreatment system. A physical–empirical model is described for control of exhaust temperature in HCCI engines. This model captures cycle-to-cycle dynamics affecting exhaust temperature and is based on thermodynamic relations and semi-empirical correlations. It incorporates intake and exhaust gas flow dynamics, residual gas mixing, and fuel burn rate and is validated with experimental data from a single cylinder engine at over 300 steady state and transient conditions. The validation results indicate a good agreement between predicted and measured exhaust gas temperature

  18. MTU series 1600 HCCI engine with extremely low exhaust emissions over the entire engine map; HCCI-Motor der MTU Baureihe 1600 mit extrem niedrigen Abgasemissionen im gesamten Motorkennfeld

    Energy Technology Data Exchange (ETDEWEB)

    Teetz, Christoph; Bergmann, Dirk; Sauer, Christina; Schneemann, Arne [MTU, Friedrichshafen (Germany); Eichmeier, Johannes; Spicher, Ulrich [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). IFKM

    2012-11-01

    The main challenge when developing off-highway engines is to keep emissions within the limits to apply in the future while maintaining low fuel consumption and low CO{sub 2} output. In the USA in particular, diesel engines in the 130 - 560 kW power range are to be subject from 2014 to EPA Tier 4 legislation, which imposes limits of 0.4 g/kWh for NO{sub x} and 0.02 g/kWh for particulate matter. Diesel units can only satisfy those requirements using a combination of in-engine measures and exhaust aftertreatment systems (SCR, particulate filters), which makes them a good deal more complex and expensive. In the face of CO{sub 2} emissions regulations and the growing demand for diesel fuel, greater emphasis is now being placed on alternative fuels. Homogeneous Charge Compression Ignition or 'HCCI' provides an alternative to complex exhaust aftertreatment systems which generates virtually no soot or nitrous oxide emissions. It does, however, present new challenges with respect to combustion control and engine load. Up to the present, it has not been possible to exploit the full potential of this combustion process over the entire engine map, since the high ignition performance of diesel fuel at high loads results in excessively early combustion and inadmissible pressure gradients. The pre-development department of MTU Friedrichshafen worked with the Institute of Internal Combustion Engines at the Karlsruhe Institute of Technology (KIT) to devise a research prototype for an industrial application which would allow semi-homogenous combustion with controlled self-ignition over the full engine map. The engine is based on a 6-cylinder version of the MTU Series 1600 unit and has a rated output of 300 kW. The fuels - gasoline or ethanol and diesel - are mixed in such a way as to avoid the disadvantages associated with most HCCI processes. Since the use of ethanol also enhances combustion efficiency, it has a two-fold positive effect on the CO{sub 2} situation. With

  19. Fuel and combustion stratification study of Partially Premixed Combustion

    NARCIS (Netherlands)

    Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

    2016-01-01

    Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a

  20. Development of HCCI Engines for Dimethyl Ether

    DEFF Research Database (Denmark)

    Hansen, Kim Rene; Pedersen, Troels Dyhr; Schramm, Jesper

    This report has been prepared for the Danish Energy Agency. It summarizes the results of the project entitled: “Development of HCCI engines for DME”. The project has been financed by “EFP 06”. The chapters about theoretical and experimental studies have been written using the language and termino......This report has been prepared for the Danish Energy Agency. It summarizes the results of the project entitled: “Development of HCCI engines for DME”. The project has been financed by “EFP 06”. The chapters about theoretical and experimental studies have been written using the language...

  1. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-08-17

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  2. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-01-01

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  3. Fuel and combustion stratification study of Partially Premixed Combustion

    OpenAIRE

    Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

    2016-01-01

    Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a clear definition of “fuel and combustion stratifications” is obvious in literature. Hence, it is difficult to compare stratification levels of different PPC strategies or other combustion concepts. T...

  4. On Cyclic Variability in a Residual Effected HCCI Engine with Direct Gasoline Injection during Negative Valve Overlap

    Directory of Open Access Journals (Sweden)

    Jacek Hunicz

    2014-01-01

    Full Text Available This study contributes towards describing the nature of cycle-by-cycle variability in homogeneous charge compression ignition (HCCI engines. Experimental measurements were performed using a single cylinder research engine operated in the negative valve overlap (NVO mode and fuelled with direct gasoline injection. Both stoichiometric and lean mixtures were applied in order to distinguish between different exhaust-fuel reactions during the NVO period and their propagation into the main event combustion. The experimental results show that the mode of cycle-by-cycle variability depends on the NVO phenomena. Under stoichiometric mixture conditions, neither variability in the main event indicated mean effective pressure (IMEP nor the combustion timing was affected by the NVO phenomena; however, long period oscillations in IMEP were observed. In contrast, for lean mixture, where fuel oxidation during the NVO period took place, distinctive correlations between NVO phenomena and the main event combustion parameters were observed. A wavelet analysis revealed the presence of both long-term and short-term oscillations in IMEP, in accordance with the extent of NVO phenomena. Characteristic patterns in IMEP were recognized using an in-house algorithm.

  5. Chemical Kinetic Models for Advanced Engine Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, William J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mehl, Marco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Westbrook, Charles K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-10-22

    The objectives for this project are as follows: Develop detailed chemical kinetic models for fuel components used in surrogate fuels for compression ignition (CI), homogeneous charge compression ignition (HCCI) and reactivity-controlled compression-ignition (RCCI) engines; and Combine component models into surrogate fuel models to represent real transportation fuels. Use them to model low-temperature combustion strategies in HCCI, RCCI, and CI engines that lead to low emissions and high efficiency.

  6. Auto-ignition modelling: analysis of the dilution effects by the unburnt gases and of the interactions with turbulence for diesel homogeneous charge compression ignition (HCCI) engines; Modelisation de l'auto-inflammation: analyse des effets de la dilution par les gaz brules et des interactions avec la turbulence dediee aux moteurs Diesel a charge homogene

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, G.

    2005-09-15

    Homogeneous Charge Compression Ignition (HCCI) is an alternative engine combustion process that offers the potential for substantial reductions in both NO{sub x} and particulate matter still providing high Diesel-like efficiencies. Combustion in HCCI mode takes place essentially by auto-ignition. It is mainly controlled by the chemical kinetics. It is therefore necessary to introduce detailed chemistry effects in combustion CFD codes in order to properly model the HCCI combustion process. The objective of this work is to develop an auto-ignition model including detailed chemical kinetics and its interactions with turbulence. Also, a comprehensive study has been performed to analyze the chemical influence of CO and H{sub 2} residual species on auto-ignition, which can be present in the exhaust gases. A new auto-ignition model, TKI-PDF (Tabulated Kinetics for Ignition - with turbulent mixing interactions through a pdf approach) dedicated to RANS 3D engine combustion CFD calculations is proposed. The TKI-PDF model is formulated in order to accommodate the detailed chemical kinetics of auto-ignition coupled with turbulence/chemistry interactions. The complete model development and its validation against experimental results are presented in two parts. The first part of this work describes the detailed chemistry input to the model. The second part is dedicated to the turbulent mixing description. A method based on a progress variable reaction rate tabulation is used. A look-up table for the progress variable reaction rates has been built through constant volume complex chemistry simulations. Instantaneous local reaction rates inside the CFD computational cell are then calculated by linear interpolation inside the look-up table depending on the local thermodynamic conditions. In order to introduce the turbulent mixing effects on auto-ignition, a presumed pdf approach is used. The model has been validated in different levels. First, the detailed kinetic approach was

  7. Effects of backing board materials on wood combustion performance

    Science.gov (United States)

    Mathew J. Hagge; Kenneth M. Bryden; Mark A. Dietenberger

    2004-01-01

    Cone calorimeter tests show that backing board materials do not affect the ignition time, initial heat release rate, or the total heat released of combustion for redwood slabs. However, it has been observed that backing board materials alter combustion performance by altering the secondary heat release peak observed when the pyrolysis reaction front nears the unheated...

  8. Influence of Coal Quality on Combustion Performance

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der; Glarborg, Peter; Dam-Johansen, Kim

    1998-01-01

    mixing pattern on NO formation under these conditions. Emissions from the opposed fired plant with all combustion air introduced through the burners could only be qualitatively reproduced by the pilot furnace. Under single stage conditions the test rig provided higher NO levels. Carbon in ash levels did...... not show any correlation between the coals and the furnaces. An engineering, mathematical model has been developed describing radiation heat transfer and coal combustion in full scale furnaces. The model has been validated against measured temperatures and the amount of carbon in fly ash. The model...

  9. Combustion synthesis of graphene and ultracapacitor performance

    Indian Academy of Sciences (India)

    Graphene sheets are synthesized by a simple method starting from graphitic oxide as a precursor. Reaction of graphitic oxide at 250 °C with a combustion mixture of urea and ammonium nitrate results in the formation of thin graphene sheets. Graphene formation is characterized by XRD, TGA, XPS and TEM. Graphene ...

  10. Injector tip for an internal combustion engine

    Science.gov (United States)

    Shyu, Tsu Pin; Ye, Wen

    2003-05-20

    This invention relates to a the tip structure of a fuel injector as used in a internal combustion engine. Internal combustion engines using Homogeneous Charge Compression Ignition (HCCI) technology require a tip structure that directs fuel spray in a downward direction. This requirement necessitates a tip design that is capable of withstanding mechanical stresses associated with the design.

  11. Combustion

    CERN Document Server

    Glassman, Irvin

    1987-01-01

    Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

  12. Combustion

    CERN Document Server

    Glassman, Irvin

    2008-01-01

    Combustion Engineering, a topic generally taught at the upper undergraduate and graduate level in most mechanical engineering programs, and many chemical engineering programs, is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation. It covers the physics and chemistry of this process and the engineering applications-from the generation of power such as the internal combustion automobile engine to the gas turbine engine. Renewed concerns about energy efficiency and fuel costs, along with continued concerns over toxic and particulate emissions have kept the interest in this vital area of engineering high and brought about new developments in both fundamental knowledge of flame and combustion physics as well as new technologies for flame and fuel control. *New chapter on new combustion concepts and technologies, including discussion on nanotechnology as related to combustion, as well as microgravity combustion, microcombustion, and catalytic combustion-all ...

  13. Residential Electrostatic Precipitator - Performance at efficient and poor combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Baefver, Linda; Yngvesson, Johan; Niklasson, Fredrik

    2012-07-01

    The performance of a pilot residential electrostatic precipitator R{sub E}SP (Applied Plasma Physics AS), was investigated at laboratory. Measurements of TSP (Total Suspended Particles), content of organic and elemental carbon, and mass size distribution of particles upstream and downstream of ESP were performed. Values for PM1 (particles < 1 {mu}m) were calculated from the particle size distributions. Concentrations and size distributions with respect to particle numbers were measured in separate tests. Gas concentrations, temperatures and boiler parameters were also measured. The TSP concentrations upstream of the R{sub E}SP were varied in range of 15-390 mg/m{sub N}{sup 3}. Up to concentrations of about 300 mg/m{sub N}{sup 3}, the TSP-concentrations out from the ESP were less than 20 mg/m{sub N}{sup 3}, which is well below the German emission limit for wood stoves. The removal efficiencies with respect to mass were about 87% at efficient combustion and 93% at poor combustion. Corresponding values with respect to number concentrations were about 97% at efficient combustion and almost 99% at poor combustion. The better performance at poor combustion may be explained by lower flue gas temperature, leading to longer residence time in the ESP. High removal efficiencies were also found with respect to particulate organic and elemental carbon.

  14. Investigation of combustion and thermodynamic performance of a lean burn catalytic combustion gas turbine system

    International Nuclear Information System (INIS)

    Yin Juan; Weng Yiwu

    2011-01-01

    The goals of this research were to investigate the combustion and thermodynamic performance of a lean burn catalytic combustion gas turbine. The characteristics of lean burn catalytic combustion were investigated by utilising 1D heterogeneous plug flow model which was validated by experiments. The effects of operating parameters on catalytic combustion were numerically analysed. The system models were built in ASPEN Plus and three independent design variables, i.e. compressor pressure ratio (PR), regenerator effectiveness (RE) and turbine inlet temperature (TIT) were selected to analyse the thermodynamic performance of the thermal cycle. The main results show that: simulations from 1D heterogeneous plug flow model can capture the trend of catalytic combustion and describe the behavior of the catalytic monolith in detail. Inlet temperature is the most significant parameter that impacts operation of the catalytic combustor. When TIT and RE are constant, the increase of PR results in lowering the inlet temperature of the catalytic combustor, which results in decreasing methane conversion. The peak thermal efficiency and the optimal PR at a constant TIT increase with the increase of TIT; and at the constant PR, the thermal efficiency increases with the increase of TIT. However, with lower TIT conditions, the optimal PR and the peak efficiency at a constant TIT of the LBCCGT cycle are relative low to that of the conventional cycle. When TIT and PR are constant, the decrease of RE may result in lower methane conversion. The influences of RE on the methane conversion and the thermal efficiency are more significant at higher PRs. The higher thermal efficiency for the lower RE is achieved at lower PR.

  15. Combustion

    CERN Document Server

    Glassman, Irvin

    1997-01-01

    This Third Edition of Glassman's classic text clearly defines the role of chemistry, physics, and fluid mechanics as applied to the complex topic of combustion. Glassman's insightful introductory text emphasizes underlying physical and chemical principles, and encompasses engine technology, fire safety, materials synthesis, detonation phenomena, hydrocarbon fuel oxidation mechanisms, and environmental considerations. Combustion has been rewritten to integrate the text, figures, and appendixes, detailing available combustion codes, making it not only an excellent introductory text but also an important reference source for professionals in the field. Key Features * Explains complex combustion phenomena with physical insight rather than extensive mathematics * Clarifies postulates in the text using extensive computational results in figures * Lists modern combustion programs indicating usage and availability * Relates combustion concepts to practical applications.

  16. Combustion performance evaluation of air staging of palm oil blends.

    Science.gov (United States)

    Mohd Jaafar, Mohammad Nazri; Eldrainy, Yehia A; Mat Ali, Muhammad Faiser; Wan Omar, W Z; Mohd Hizam, Mohd Faizi Arif

    2012-02-21

    The problems of global warming and the unstable price of petroleum oils have led to a race to develop environmentally friendly biofuels, such as palm oil or ethanol derived from corn and sugar cane. Biofuels are a potential replacement for fossil fuel, since they are renewable and environmentally friendly. This paper evaluates the combustion performance and emission characteristics of Refined, Bleached, and Deodorized Palm Oil (RBDPO)/diesel blends B5, B10, B15, B20, and B25 by volume, using an industrial oil burner with and without secondary air. Wall temperature profiles along the combustion chamber axis were measured using a series of thermocouples fitted axially on the combustion chamber wall, and emissions released were measured using a gas analyzer. The results show that RBDPO blend B25 produced the maximum emission reduction of 56.9% of CO, 74.7% of NOx, 68.5% of SO(2), and 77.5% of UHC compared to petroleum diesel, while air staging (secondary air) in most cases reduces the emissions further. However, increasing concentrations of RBDPO in the blends also reduced the energy released from the combustion. The maximum wall temperature reduction was 62.7% for B25 at the exit of the combustion chamber.

  17. Using biofuel tracers to study alternative combustion regimes

    International Nuclear Information System (INIS)

    Mack, J.H.; Flowers, D.L.; Buchholz, B.A.; Dibble, R.W.

    2007-01-01

    Interest in the use of alternative fuels and engines is increasing as the price of petroleum climbs. The inherently higher efficiency of Diesel engines has led to increased adoption of Diesels in Europe, capturing approximately 40% of the new passenger car market. Unfortunately, lower CO 2 emissions are countered with higher nitrogen oxides (NO x ) and particulate matter (PM) emissions and higher noise. Adding oxygenated compounds to the fuel helps reduce PM emissions. However, relying on fuel alone to reduce PM is unrealistic due to economic constraints and difficult due to the emerging PM standards. Keeping peak combustion temperature below 1700 K inhibits NO x formation. Altering the combustion regime to burn at temperatures below the NO x threshold and accept a wide variety of fuels seems like a promising alternative for future engines. Homogeneous charge compression ignition (HCCI) is a possible solution. Fuel and air are well mixed prior to intake into a cylinder (homogeneous charge) and ignition occurs by compression of the fuel-air mixture by the piston. HCCI is rapid and relatively cool, producing little NO x and PM. Unfortunately, it is hard to control since HCCI is initiated by temperature and pressure instead of a spark or direct fuel injection. We investigate biofuel HCCI combustion, and use intrinsically labeled biofuels as tracers of HCCI combustion. Data from tracer experiments are used to improve our combustion modeling

  18. The Low Load Limit of Gasoline Partially Premixed Combustion (PPC) - Experiments in a Light Duty Diesel Engine

    OpenAIRE

    Borgqvist, Patrick

    2013-01-01

    The decreasing oil supply, more stringent pollutant legislations and strong focus on decreasing carbon dioxide emissions drives the research of more efficient and clean combustion engines. One such combustion engine concept is Homogeneous Charge Compression Ignition (HCCI) which potentially achieves high efficiency and low NOx and soot emissions. One practical realization of HCCI in SI engines is to use a variable valve train to trap hot residual gases in order to increase the temperature of ...

  19. DNS Study of the Ignition of n-Heptane Fuel Spray under HCCI Conditions

    Science.gov (United States)

    Wang, Yunliang; Rutland, Christopher J.

    2004-11-01

    Direct numerical simulations are carried out to investigate the mixing and auto-ignition processes of n-heptane fuel spray in a turbulent field using a skeletal chemistry mechanism with 44 species and 112 reactions. For the solution of the carrier gas fluid, we use the Eulerian method, while for the fuel spray, the Lagrangian method is used. We use an eighth-order finite difference scheme to calculate spacial derivatives and a fourth-order Runge-Kutta scheme for the time integration. The initial gas temperature is 926 K and the initial gas pressure is 30 atmospheres. The initial global equivalence ratio based on the fuel concentration is around 0.4. The initial droplet diameter is 60 macrons and the droplet temperature is 300 K. Evolutions of averaged temperature, species mass fraction, heat release and reaction rate are presented. Contours of temperature and species mass fractions are presented. The objective is to understand the mechanism of ignition under Homogeneous Charged Compression Ignition (HCCI) conditions, aiming at providing some useful information of HCCI combustion, which is one of the critical issues to be resolved.

  20. The effect of insulated combustion chamber surfaces on direct-injected diesel engine performance, emissions, and combustion

    Science.gov (United States)

    Dickey, Daniel W.; Vinyard, Shannon; Keribar, Rifat

    1988-01-01

    The combustion chamber of a single-cylinder, direct-injected diesel engine was insulated with ceramic coatings to determine the effect of low heat rejection (LHR) operation on engine performance, emissions, and combustion. In comparison to the baseline cooled engine, the LHR engine had lower thermal efficiency, with higher smoke, particulate, and full load carbon monoxide emissions. The unburned hydrocarbon emissions were reduced across the load range. The nitrous oxide emissions increased at some part-load conditions and were reduced slightly at full loads. The poor LHR engine performance was attributed to degraded combustion characterized by less premixed burning, lower heat release rates, and longer combustion duration compared to the baseline cooled engine.

  1. Combustion and environmental performance of clean coal end products

    Energy Technology Data Exchange (ETDEWEB)

    Skodras, G.; Sakellaropoulos, G. [Centre for Research and Technology, Hellas, Ptolemaidas-Kozanis, Ptolemaida (Greece). Inst. for Solid Fuel Technolgy and Applications]|[Aristotle Univ. of Thessaloniki, Thessaloniki (Greece). Dept. of Chemical Engineering, Chemical Process Engineering Lab]|[Chemical Process Engineering Research Inst., Thessaloniki (Greece). Lab. of Solid Fuels and Environment; Someus, E. [Thermal Desorption Technology Group (Greece); Grammelis, P.; Amarantos, P.S. [Centre for Research and Technology, Hellas, Ptolemaidas-Kozanis, Ptolemaida (Greece). Inst. for Solid Fuel Technolgy and Applications; Palladas, A.; Basinas, P.; Natas, P.; Prokopidou, M.; Diamantopoulou, I.; Sakellaropoulos, G. [Aristotle Univ. of Thessaloniki, Thessaloniki (Greece). Dept. of Chemical Engineering, Chemical Process Engineering Lab

    2006-07-01

    Clean and affordable power production is needed in order to achieve sustainable economic development. This paper focused on clean coal technologies in which coal-fired power plants are used in conjunction with large amounts of renewable energy sources to offer a high level of process safety and long term management of all residual operation streams. Thermal Desorption Recycle-Reduce-Reuse Technology (TDT-3R) was described as being a promising solid fuel pretreatment process for clean energy production up to 300 MWe capacities. TDT-3R is based on low temperature carbonisation fuel pre-treatment principles, which produce cleansed anthracite type fuels from coal and other carbonaceous material such as biomass and organic wastes. The combustion efficiency of such clean coals and the environmental performance of the TDT-3R process were investigated in this study via pilot scale tests of clean fuel production. Tests included flue gas emissions monitoring, raw fuel and product characterisation and thermogravimetric tests, polychlorinated dibenzo-p-dioxins and dibenzo-furans, and heavy metals analyses, and toxicity tests. Raw material included coal and biomass, such as willow, straw and demolition wood. The fuels were heated in a rotary kiln operating at 550 degrees C under slightly vacuum conditions. Clean coals were tested either alone or in conjunction with biomass fuels in a pilot scale combustion facility at Dresden, Germany. The clean coal samples were shown to have higher fixed carbon and ash content and lower volatiles compared to the respective raw coal samples. The major advantage of the TDT-3R process is the production of fuels with much lower pollutants content. Low nitrogen, sulphur, chlorine and heavy metal contents result in produced fuels that have excellent environmental performance, allow boiler operation in higher temperatures and overall better efficiency. Moreover, the use of clean fuels reduces deposition problems in the combustion chamber due to the

  2. Consequences of sludge composition on combustion performance derived from thermogravimetry analysis

    International Nuclear Information System (INIS)

    Li, Meiyan; Xiao, Benyi; Wang, Xu; Liu, Junxin

    2015-01-01

    Highlights: • Volatiles, particularly proteins, play a key role in sludge combustion. • Sludge combustion performance varies with different sludge organic concentrations. • Carbohydrates significantly affect the combustion rate in the second stage. • Combustion performance of digested sludge is more negative compared with others. - Abstract: Wastewater treatment plants produce millions of tons of sewage sludge. Sewage sludge is recognized as a promising feedstock for power generation via combustion and can be used for energy crisis adaption. We aimed to investigate the quantitative effects of various sludge characteristics on the overall sludge combustion process performance. Different types of sewage sludge were derived from numerous wastewater treatment plants in Beijing for further thermogravimetric analysis. Thermogravimetric–differential thermogravimetric curves were used to compare the performance of the studied samples. Proximate analytical data, organic compositions, elementary composition, and calorific value of the samples were determined. The relationship between combustion performance and sludge composition was also investigated. Results showed that the performance of sludge combustion was significantly affected by the concentration of protein, which is the main component of volatiles. Carbohydrates and lipids were not correlated with combustion performance, unlike protein. Overall, combustion performance varied with different sludge organic composition. The combustion rate of carbohydrates was higher than those of protein and lipid, and carbohydrate weight loss mainly occurred during the second stage (175–300 °C). Carbohydrates have a substantial effect on the rate of system combustion during the second stage considering the specific combustion feature. Additionally, the combustion performance of digested sewage sludge is more negative than the others

  3. Consequences of sludge composition on combustion performance derived from thermogravimetry analysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meiyan; Xiao, Benyi; Wang, Xu; Liu, Junxin, E-mail: jxliu@rcees.ac.cn

    2015-01-15

    Highlights: • Volatiles, particularly proteins, play a key role in sludge combustion. • Sludge combustion performance varies with different sludge organic concentrations. • Carbohydrates significantly affect the combustion rate in the second stage. • Combustion performance of digested sludge is more negative compared with others. - Abstract: Wastewater treatment plants produce millions of tons of sewage sludge. Sewage sludge is recognized as a promising feedstock for power generation via combustion and can be used for energy crisis adaption. We aimed to investigate the quantitative effects of various sludge characteristics on the overall sludge combustion process performance. Different types of sewage sludge were derived from numerous wastewater treatment plants in Beijing for further thermogravimetric analysis. Thermogravimetric–differential thermogravimetric curves were used to compare the performance of the studied samples. Proximate analytical data, organic compositions, elementary composition, and calorific value of the samples were determined. The relationship between combustion performance and sludge composition was also investigated. Results showed that the performance of sludge combustion was significantly affected by the concentration of protein, which is the main component of volatiles. Carbohydrates and lipids were not correlated with combustion performance, unlike protein. Overall, combustion performance varied with different sludge organic composition. The combustion rate of carbohydrates was higher than those of protein and lipid, and carbohydrate weight loss mainly occurred during the second stage (175–300 °C). Carbohydrates have a substantial effect on the rate of system combustion during the second stage considering the specific combustion feature. Additionally, the combustion performance of digested sewage sludge is more negative than the others.

  4. Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based Combustion Control

    NARCIS (Netherlands)

    Leskens, M.

    2013-01-01

    The combustion of municipal solid waste (MSW) is used for its inertisation, reduction of its volume and the conversion of its energy content into heat and/or electricity. Operation and control of modern large scale MSW combustion (MSWC) plants is determined by economic and environmental objectives

  5. Impact of higher n-butanol addition on combustion and performance of GDI engine in stoichiometric combustion

    International Nuclear Information System (INIS)

    Chen, Zheng; Yang, Feng; Xue, Shuo; Wu, Zhenkuo; Liu, Jingping

    2015-01-01

    Highlights: • Effects of 0–50% n-butanol addition on GDI engine are experimentally studied. • Higher n-butanol fractions increase combustion pressure and fasten burning rate. • Higher n-butanol fractions increase BSFC but improve BTE. • Higher n-butanol fractions enhance combustion stability but increase knock intensity. • Higher n-butanol fractions reduce exhaust temperature and NOx emissions. - Abstract: An experimental study was carried out on a turbocharged gasoline direct injection (GDI) engine fueled by n-butanol/gasoline blends. Effects of n-butanol percents (15%, 30%, and 50%) on combustion and performance of the engine operating on stoichiometric combustion condition were discussed and also compared with pure gasoline in this paper. The results indicate that n-butanol/gasoline blends increase combustion pressure and pressure rise rate, fasten burning rate, and shorten ignition delay and combustion duration, as compared to pure gasoline. Moreover, these trends are impacted more evidently with increased n-butanol fraction in the blends. In addition, higher n-butanol percent of gasoline blends increase combustion temperature but decrease the temperature in the later stage of expansion stroke, which contributes to the control of exhaust temperature at high-load. With regards to engine performance, higher n-butanol percent in the blends results in increased brake specific fuel consumption (BSFC) and higher brake thermal efficiency (BTE). However, higher n-butanol addition helps to improve combustion stability but shows slightly higher knock possibility in high-load. In that case, the knock trend could be weakened by retarding ignition timing. Moreover, higher n-butanol addition significantly decreases NOx emissions, but it increases CO emissions obviously.

  6. Effect of oxygen content on n-heptane auto-ignition characteristics in a HCCI engine

    International Nuclear Information System (INIS)

    Wu, Zhijun; Kang, Zhe; Deng, Jun; Hu, Zongjie; Li, Liguang

    2016-01-01

    Highlights: • n-Heptane HCCI combustion under air and oxygen intake was compared. • n-Heptane auto-ignition postponed due to higher specific heat capacity as oxygen increase. • The increment of heat release fraction during low temperature reaction is studied. • Oxygen enrichment lead to suppressed negative temperature coefficient. • The mechanism of low temperature reaction enhancement as oxygen increase is investigated. - Abstract: To take maximum advantage of the high efficiency of homogeneous charge compression ignition combustion mode and internal combustion Rankine cycle concept, in this study, the n-heptane auto-ignition characteristics have been investigated using a compression ignition internal combustion Rankine cycle engine test bench and a zero-dimensional thermodynamic model coupled with a detailed kinetic model. The n-heptane auto-ignition process shows that under both air and oxygen intake, a typical two-stage combustion in which oxygen enrichment has very minor effects on the n-heptane high temperature reaction. The higher specific heat capacity of oxygen compared with nitrogen leads to an overall increased specific heat capacity, which lowers the in-cylinder temperature during compression stroke, thereby delaying the low temperature reaction initial timing. The higher oxygen content also improves the H-atom abstraction, first O_2 addition, second O_2 addition and peroxyalkylhydroperoxide isomerization, thereby improving the overall reaction rate and the heat release fraction of low temperature reaction. As a result, the in-cylinder temperature at the end of low temperature reaction also increases, thereby shortening significantly the negative temperature coefficient duration compared with a combustion cycle using air as oxidizer.

  7. Studies of MHD generator performance with oxygen enriched coal combustion

    Science.gov (United States)

    Wormhoudt, J.; Yousefian, V.; Kolb, C. E.; Martinez-Sanchez, M.

    1980-07-01

    This paper presents calculations made using the Aerodyne PACKAGE (Plasma Analysis, Chemical Kinetics, and Generator Efficiency) computer code which bear on two questions which arise in connection with choices between oxygen enrichment and air preheating to attain the high combustion temperatures needed for open-cycle, coal-fired MHD power generation. The first question is which method produces the highest enthalpy extraction per unit channel length. The second is, in test facilities intended to study tradeoffs between oxygen enrichment and preheated air, can good generator performance be obtained from the same physical channel for different combustor compositions. The answer to the first question is found to depend on what combustor conditions are taken to be comparable. As for the second question, it is found that operation with channel input from off-design combustor conditions can cause serious problems, which can be partially alleviated by changing the channel load factors.

  8. Numerical modeling on homogeneous charge compression ignition combustion engine fueled by diesel-ethanol blends

    Directory of Open Access Journals (Sweden)

    Hanafi H.

    2016-01-01

    Full Text Available This paper investigates the performance and emission characteristics of HCCI engines fueled with oxygenated fuels (ethanol blend. A modeling study was conducted to investigate the impact of ethanol addition on the performance, combustion and emission characteristics of a Homogeneous Charge Compression Ignition (HCCI engine fueled by diesel. One dimensional simulation was conducted using the renowned commercial software for diesel and its blend fuels with 5% (E5 and 10% ethanol (E10 (in vol. under full load condition at variable engine speed ranging from 1000 to 2750 rpm with 250 rpm increment. The model was then validated with other researcher’s experimental result. Model consists of intake and exhaust systems, cylinder, head, valves and port geometries. Performance tests were conducted for volumetric efficiency, brake engine torque, brake power, brake mean effective pressure, brake specific fuel consumption, and brake thermal efficiency, while exhaust emissions were analyzed for carbon monoxide (CO and unburned hydrocarbons (HC. The results showed that blending diesel with ethanol increases the volumetric efficiency, brake specific fuel consumption and brake thermal efficiency, while it decreases brake engine torque, brake power and brake mean effective pressure. In term of emission characteristics, the CO emissions concentrations in the engine exhaust decrease significantly with ethanol as additive. But for HC emission, its concentration increase when apply in high engine speed. In conclusion, using Ethanol as fuel additive blend with Diesel operating in HCCI shows a good result in term of performance and emission in low speed but not recommended to use in high speed engine. Ethanol-diesel blends need to researched more to make it commercially useable.

  9. Advancing the Limits of Dual Fuel Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Koenigsson, Fredrik

    2012-07-01

    There is a growing interest in alternative transport fuels. There are two underlying reasons for this interest; the desire to decrease the environmental impact of transports and the need to compensate for the declining availability of petroleum. In the light of both these factors the Diesel Dual Fuel, DDF, engine is an attractive concept. The primary fuel of the DDF engine is methane, which can be derived both from renewables and from fossil sources. Methane from organic waste; commonly referred to as biomethane, can provide a reduction in greenhouse gases unmatched by any other fuel. The DDF engine is from a combustion point of view a hybrid between the diesel and the otto engine and it shares characteristics with both. This work identifies the main challenges of DDF operation and suggests methods to overcome them. Injector tip temperature and pre-ignitions have been found to limit performance in addition to the restrictions known from literature such as knock and emissions of NO{sub x} and HC. HC emissions are especially challenging at light load where throttling is required to promote flame propagation. For this reason it is desired to increase the lean limit in the light load range in order to reduce pumping losses and increase efficiency. It is shown that the best results in this area are achieved by using early diesel injection to achieve HCCI/RCCI combustion where combustion phasing is controlled by the ratio between diesel and methane. However, even without committing to HCCI/RCCI combustion and the difficult control issues associated with it, substantial gains are accomplished by splitting the diesel injection into two and allocating most of the diesel fuel to the early injection. HCCI/RCCI and PPCI combustion can be used with great effect to reduce the emissions of unburned hydrocarbons at light load. At high load, the challenges that need to be overcome are mostly related to heat. Injector tip temperatures need to be observed since the cooling effect of

  10. A numerical study on the effect of various combustion bowl parameters on the performance, combustion, and emission behavior on a single cylinder diesel engine.

    Science.gov (United States)

    Balasubramanian, Dhinesh; Sokkalingam Arumugam, Sabari Rajan; Subramani, Lingesan; Joshua Stephen Chellakumar, Isaac JoshuaRamesh Lalvani; Mani, Annamalai

    2018-01-01

    A numerical study was carried out to study the effect of various combustion bowl parameters on the performance behavior, combustion characteristics, and emission magnitude on a single cylinder diesel engine. A base combustion bowl and 11 different combustion bowls were created by varying the aspect ratio, reentrancy ratio, and bore to bowl ratio. The study was carried out at engine rated speed and a full throttle performance condition, without altering the compression ratio. The results revealed that the combustion bowl parameters could have a huge impact on the performance behavior, combustion characteristics, and emission magnitude of the engine. The bowl parameters, namely throat diameter and toroidal radius, played a crucial role in determining the performance behavior of the combustion bowls. It was observed that the combustion bowl parameters, namely central pip distance, throat diameter, and bowl depth, also could have an impact on the combustion characteristics. And throat diameter and toroidal radius, central pip distance, and toroidal corner radius could have a consequent effect on the emission magnitude of the engine. Of the different combustion bowls tested, combustion bowl 4 was preferable to others owing to the superior performance of 3% of higher indicated mean effective pressure and lower fuel consumption. Interestingly, trade-off for NO x emission was higher only by 2.85% compared with the base bowl. The sensitivity analysis proved that bowl depth, bowl diameter, toroidal radius, and throat diameter played a vital role in the fuel consumption parameter and emission characteristics even at the manufacturing tolerance variations.

  11. A reduced mechanism for predicting the ignition timing of a fuel blend of natural-gas and n-heptane in HCCI engine

    International Nuclear Information System (INIS)

    Bahlouli, Keyvan; Atikol, Ugur; Khoshbakhti Saray, R.; Mohammadi, Vahid

    2014-01-01

    Highlights: • A two-stage reduction process is used to produce two reduced mechanisms. • The mechanisms are combined to develop a reaction mechanism for a fuel blend. • The genetic algorithm is used for optimization of reaction constants. • The developed reduced mechanism can be used to predict the ignition timing in HCCI engine for a fuel blend. - Abstract: One of the main challenges associated with homogeneous charge compression ignition (HCCI) combustion engine application is the lack of direct control on ignition timing. One of the solutions to this problem is mixing two fuels with various properties at a variety of ratios on a cycle-by-cycle basis. In the current study, a reduced mechanism for a fuel blend of natural-gas and n-heptane is proposed. The approach is validated for the prediction of ignition timing in the HCCI combustion engine. A single-zone combustion model is used to simulate the HCCI engine. A two-stage reduction process is used to produce two reduced mechanisms of existing semi-detailed GRI-Mech. 3.0 mechanism that contains 53 species and 325 reactions and Golovichev’s mechanism consisting of 57 species and 290 reactions for natural gas and n-heptane fuels, respectively. Firstly, the unimportant species and related reactions are identified by employing the directed relation graph with error propagation (DRGEP) reduction method and then, to extend reduction, the principal component analysis (PCA) method is utilized. To evaluate the validity of the reduced mechanism, representative engine combustion parameters such as peak pressure, maximum heat release, and CA50 are used. The reduced mechanism of GRI-Mech. 3.0 mechanism, containing 19 species and 39 reactions, and the reduced mechanism of Golovichev’s mechanism, consisting of 40 species and 95 reactions, provide good prediction for the mentioned parameters in comparison with those of detailed mechanisms. The combination of the generated reduced mechanisms is used to develop a

  12. Four-Stroke, Internal Combustion Engine Performance Modeling

    Science.gov (United States)

    Wagner, Richard C.

    In this thesis, two models of four-stroke, internal combustion engines are created and compared. The first model predicts the intake and exhaust processes using isentropic flow equations augmented by discharge coefficients. The second model predicts the intake and exhaust processes using a compressible, time-accurate, Quasi-One-Dimensional (Q1D) approach. Both models employ the same heat release and reduced-order modeling of the cylinder charge. Both include friction and cylinder loss models so that the predicted performance values can be compared to measurements. The results indicate that the isentropic-based model neglects important fluid mechanics and returns inaccurate results. The Q1D flow model, combined with the reduced-order model of the cylinder charge, is able to capture the dominant intake and exhaust fluid mechanics and produces results that compare well with measurement. Fluid friction, convective heat transfer, piston ring and skirt friction and temperature-varying specific heats in the working fluids are all shown to be significant factors in engine performance predictions. Charge blowby is shown to play a lesser role.

  13. Combustion performance of porous silicon-based energetic composites

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Benjamin Aaron [Los Alamos National Laboratory; Son, Steve F [Los Alamos National Laboratory; Asay, Blaine W [Los Alamos National Laboratory; Cho, Kevin Y [PURDUE UNIV

    2009-01-01

    The combustion performance of oxidizer filled porous silicon(PSi) was studied. PSi samples with diameters of 2.54 cm were fabricated by electrochemical etching. The % porosity of the samples ranged from 55 to 82%. The samples were cut into 3-5 mm strips and filled with the oxidizers NaClO{sub 4} x 1H{sub 2}O, Ca(ClO{sub 4}){sub 2} x 4H{sub 2}O, S and perfluoropolyether (PFPE). The filled PSi was then burned by igniting the sample with a hot NiChrome{trademark} wire. The burns were recorded using high speed photography from which bring rates were calculated. That burning rates showed a strong dependency on quality of the oxidizer loading. The % porosity did not appear to have a direct affect on the burning rates for those studied. PSi loaded with NaClO{sub 4} x 1H{sub 2}O produced burning rates that ranged from 216-349 cm/s. PSi loaded with Ca(ClO{sub 4}){sub x}x 4 H{sub 2}O had burning rates of 154-285 cm/s. An S filled PSi sample burned a rate of 16 to 290 cm/s, and perfluoropolyether loaded PSi burned at a rate of 1.4 cm/s.

  14. 40 CFR 60.1025 - Do subpart E new source performance standards also apply to my municipal waste combustion unit?

    Science.gov (United States)

    2010-07-01

    ... standards also apply to my municipal waste combustion unit? 60.1025 Section 60.1025 Protection of... NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste Combustion Units for Which... municipal waste combustion unit? If this subpart AAAA applies to your municipal waste combustion unit, then...

  15. Combustion Mode Design with High Efficiency and Low Emissions Controlled by Mixtures Stratification and Fuel Reactivity

    Directory of Open Access Journals (Sweden)

    Hu eWang

    2015-08-01

    Full Text Available This paper presents a review on the combustion mode design with high efficiency and low emissions controlled by fuel reactivity and mixture stratification that have been conducted in the authors’ group, including the charge reactivity controlled homogeneous charge compression ignition (HCCI combustion, stratification controlled premixed charge compression ignition (PCCI combustion, and dual-fuel combustion concepts controlled by both fuel reactivity and mixture stratification. The review starts with the charge reactivity controlled HCCI combustion, and the works on HCCI fuelled with both high cetane number fuels, such as DME and n-heptane, and high octane number fuels, such as methanol, natural gas, gasoline and mixtures of gasoline/alcohols, are reviewed and discussed. Since single fuel cannot meet the reactivity requirements under different loads to control the combustion process, the studies related to concentration stratification and dual-fuel charge reactivity controlled HCCI combustion are then presented, which have been shown to have the potential to achieve effective combustion control. The efforts of using both mixture and thermal stratifications to achieve the auto-ignition and combustion control are also discussed. Thereafter, both charge reactivity and mixture stratification are then applied to control the combustion process. The potential and capability of thermal-atmosphere controlled compound combustion mode and dual-fuel reactivity controlled compression ignition (RCCI/highly premixed charge combustion (HPCC mode to achieve clean and high efficiency combustion are then presented and discussed. Based on these results and discussions, combustion mode design with high efficiency and low emissions controlled by fuel reactivity and mixtures stratification in the whole operating range is proposed.

  16. Analysis of Transition from HCCI to CI via PPC with Low Octane Gasoline Fuels Using Optical Diagnostics and Soot Particle Analysis

    KAUST Repository

    An, Yanzhao; Vallinayagam, R; Vedharaj, S; Masurier, Jean-Baptiste; Dawood, Alaaeldin; Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt

    2017-01-01

    In-cylinder visualization, combustion stratification, and engine-out particulate matter (PM) emissions were investigated in an optical engine fueled with Haltermann straight-run naphtha fuel and corresponding surrogate fuel. The combustion mode was transited from homogeneous charge compression ignition (HCCI) to conventional compression ignition (CI) via partially premixed combustion (PPC). Single injection strategy with the change of start of injection (SOI) from early to late injections was employed. The high-speed color camera was used to capture the in-cylinder combustion images. The combustion stratification was analyzed based on the natural luminosity of the combustion images. The regulated emission of unburned hydrocarbon (UHC), carbon monoxide (CO) and nitrogen oxides (NO) were measured to evaluate the combustion efficiency together with the in-cylinder rate of heat release. Soot mass concentration was measured and linked with the combustion stratification and the integrated red channel intensity of the high-speed images for the soot emissions. The nucleation nanoscale particle number and the particle size distribution were sampled to understand the effect of combustion mode switch.

  17. Analysis of Transition from HCCI to CI via PPC with Low Octane Gasoline Fuels Using Optical Diagnostics and Soot Particle Analysis

    KAUST Repository

    An, Yanzhao

    2017-10-10

    In-cylinder visualization, combustion stratification, and engine-out particulate matter (PM) emissions were investigated in an optical engine fueled with Haltermann straight-run naphtha fuel and corresponding surrogate fuel. The combustion mode was transited from homogeneous charge compression ignition (HCCI) to conventional compression ignition (CI) via partially premixed combustion (PPC). Single injection strategy with the change of start of injection (SOI) from early to late injections was employed. The high-speed color camera was used to capture the in-cylinder combustion images. The combustion stratification was analyzed based on the natural luminosity of the combustion images. The regulated emission of unburned hydrocarbon (UHC), carbon monoxide (CO) and nitrogen oxides (NO) were measured to evaluate the combustion efficiency together with the in-cylinder rate of heat release. Soot mass concentration was measured and linked with the combustion stratification and the integrated red channel intensity of the high-speed images for the soot emissions. The nucleation nanoscale particle number and the particle size distribution were sampled to understand the effect of combustion mode switch.

  18. Effects of oxygen enriched combustion on pollution and performance characteristics of a diesel engine

    Directory of Open Access Journals (Sweden)

    P. Baskar

    2016-03-01

    Full Text Available Oxygen enriched combustion is one of the attractive combustion technologies to control pollution and improve combustion in diesel engines. An experimental test was conducted on a single cylinder direct injection diesel engine to study the impact of oxygen enrichment on pollution and performance parameters by increasing the oxygen concentration of intake air from 21 to 27% by volume. The tests results show that the combustion process was improved as there is an increase in thermal efficiency of 4 to 8 percent and decrease in brake specific fuel consumption of 5 to 12 percent. There is also a substantial decrease in unburned hydro carbon, carbon mono-oxide and smoke density levels to the maximum of 40, 55 and 60 percent respectively. However, there is a considerable increase in nitrogen oxide emissions due to increased combustion temperature and extra oxygen available which needs to be addressed.

  19. Numerical study of influence of biofuels on the combustion characteristics and performance of aircraft engine system

    International Nuclear Information System (INIS)

    Zhou, Li; Liu, Zeng-wen; Wang, Zhan-xue

    2015-01-01

    The atomization and combustion flowfield of the combustion chamber with swirl-nozzle were simulated using different biofuels; the thermodynamic cycle of the aircraft engine system were also analyzed, influences of biofuels on the combustion characteristics and performance of aircraft engine system were explored. Results show that viscosity and caloric value are key factors affecting the atomization and combustion characteristics of biofuels, and then dominate the distribution of the temperature and NO concentration. Due to the characteristic of low viscosity and low caloric value for biofuels adopted, the biofuels accumulate near the head of combustion chamber, and the corresponding NO emission is lower than that it has for conventional kerosene. When biofuels with low caloric value are used under the operation condition which is same as the condition for the conventional kerosene, lower turbine inlet temperature, lower thrust and higher specific fuel consumption would be achieved for the aircraft engine. - Highlights: • Influences of biofuels properties on combustion characteristic are explored. • Effects of biofuels on cycle parameters of aircraft engine are discussed. • Viscosity and caloric value are key factors affecting combustion of biofuels. • NO emission becomes lower when biofuels with low caloric value is adopted. • The performance of aircraft engine becomes worse for biofuels with low caloric value.

  20. Review of Heavy-Duty Engine Combustion Research at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Robert W. Carling; Gurpreet Singh

    2000-01-01

    The objectives of this paper are to describe the research efforts in diesel engine combustion at Sandia National Laboratories' Combustion Research Facility and to provide recent experimental results. We have four diesel engine experiments supported by the Department of Energy, Office of Heavy Vehicle Technologies: a one-cylinder version of a Cummins heavy-duty engine, a diesel simulation facility, a one-cylinder Caterpillar engine to evaluate combustion of alternative fuels, and a homogeneous-charge, compression-ignition (HCCI) engine facility is under development. Recent experimental results to be discussed are: the effects of injection timing and diluent addition on late-combustion soot burnout, diesel-spray ignition and premixed-burn behavior, a comparison of the combustion characteristics of M85 (a mixture of 85% methanol and 15% gasoline) and DF2 (No.2 diesel reference fuel), and a description of our HCCI experimental program and modeling work

  1. Combustion Performance of a Staged Hybrid Rocket with Boron addition

    Science.gov (United States)

    Lee, D.; Lee, C.

    2018-04-01

    In this paper, the effect of boron on overall system specific impulse was investigated. Additionally, a series of combustion tests was carried out to analyze and evaluate the effect of boron addition on O/F variation and radial temperature profiles. To maintain the hybrid rocket engine advantages, upper limit of boron contents in solid fuel was set to be 10 wt%. The results also suggested that, when adding boron to solid fuel, it helped to provide more uniform radial temperature distribution and also to increase specific impulse by 3.2%.

  2. Influence of moist combustion gas on performance of a sub-critical turbine

    International Nuclear Information System (INIS)

    Yang Wenbin; Su Ming

    2005-01-01

    In the HAT cycle, as the absolute humidity of the moist combustion gas increases, the performance of the turbine will also change. In this paper, one model to calculate the thermodynamic properties of the moist combustion gas is introduced, and another model to calculate the performance of the turbine is formulated based on the equations of one dimensional flow. Using these models with the geometric parameters of the turbine fixed, at the design working condition, the performance of the turbine is calculated and analyzed for different absolute humidities. Finally, some conclusions about the turbine performance are presented

  3. E25 stratified torch ignition engine performance, CO_2 emission and combustion analysis

    International Nuclear Information System (INIS)

    Rodrigues Filho, Fernando Antonio; Moreira, Thiago Augusto Araujo; Valle, Ramon Molina; Baêta, José Guilherme Coelho; Pontoppidan, Michael; Teixeira, Alysson Fernandes

    2016-01-01

    Highlights: • A torch ignition engine prototype was built and tested. • Significant reduction of BSFC was achieved due to the use of the torch ignition system. • Low cyclic variability characterized the lean combustion process of the torch ignition engine prototype. • The torch ignition system allowed an average reduction of 8.21% at the CO_2 specific emissions. - Abstract: Vehicular emissions significantly increase atmospheric air pollution and the greenhouse effect. This fact associated with the fast growth of the global motor vehicle fleet demands technological solutions from the scientific community in order to achieve a decrease in fuel consumption and CO_2 emission, especially of fossil fuels to comply with future legislation. To meet this goal, a prototype stratified torch ignition engine was designed from a commercial baseline engine. In this system, the combustion starts in a pre-combustion chamber where the pressure increase pushes the combustion jet flames through a calibrated nozzle to be precisely targeted into the main chamber. These combustion jet flames are endowed with high thermal and kinetic energy being able to promote a stable lean combustion process. The high kinetic and thermal energy of the combustion jet flame results from the load stratification. This is carried out through direct fuel injection in the pre-combustion chamber by means of a prototype gasoline direct injector (GDI) developed for low fuel flow rate. During the compression stroke, lean mixture coming from the main chamber is forced into the pre-combustion chamber and, a few degrees before the spark timing, fuel is injected into the pre-combustion chamber aiming at forming a slightly rich mixture cloud around the spark plug which is suitable for the ignition and kernel development. The performance of the torch ignition engine running with E25 is presented for different mixture stratification levels, engine speed and load. The performance data such as combustion phasing

  4. Influence of Process Parameters on Coal Combustion Performance

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der

    investigated experimentally in a 400 MWe corner fired boiler with over fire air, a 350 MWe opposed fired boiler, and in a 160 kWt pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project "Atmospheric......The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount...... of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms...

  5. Ameliorer les performances environnementales des centrales a charbon pulverise via la co-combustion de combustible derive de dechets

    Science.gov (United States)

    Vekemans, Odile Geraldine

    interactions between ReEF(TM) components take place during its devolatilization. During the second step of this study, performances of the co-firing of coal and sorbent are compared to that of co-combustion of coal and ReEF(TM) without sorbent. This is carried out in a reactor specially build for this study, capable of reproducing the contact mode between gas and particles, the concentrations, the temperature gradient and the pressure typical of pulverized coal boiler. SO2 emissions reduction around 20% are observed in presence of CaCO3 and of Ca(OH)2 compared to the coal baseline, reduction that generally increased with the increase of sorbent molar ratio compared to sulfur (also called stoic). As for the co-combustion of 20%th of ReEF(TM) and coal, a SO2 emission reduction around 20% is also measured, with no clear effect of ReEF(TM) composition (fiber to plastic ratio). On the other hand, the HCl level that is negligible during coal combustion with and without sorbent, reaches around 20ppm in presence of ReEF(TM), and increases proportionally with the ReEF(TM) plastic content. The first step of this work consists in the study of the co-combustion of coal and ReEF(TM) containing limestone (CaCO3), a mix of sodium bicarbonate (NaHCO3) and limestone, as well as a mix of trona (Na2CO3.NaHCO3.H2O) and limestone. The amount of sorbent in the ReEF(TM) as well as the feeding parameters are adjusted to reach a 20%th feeding of ReEF(TM) compared to coal, to inject sorbents at a stoic of 1, 2 and 2.5 and to obtain Na/Ca molar ratios of 0, 0.1 with trona and NaHCO3, and 0.5 with NaHCO 3 only. Globally, as in the case of sorbent alone, the increase of the total stoic of the feed leads to increased SO2 capture. For a given stoic, to combine waste and limestone in the ReEF(TM), compared to using limestone alone, allows to reach higher levels of SO2 emissions reduction. The combination of sodium-based and calcium-based sorbent even leads to record SO2 emissions reduction of more than 50

  6. Effect of hydrogen-diesel combustion on the performance and combustion parameters of a dual fuelled diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Bose, P.K.; Banerjee, Rahul; Deb, Madhujit [Mechanical Engineering Department, National Institute of Technology, Agartala, Tripura-799055 (India)

    2013-07-01

    Petroleum crude is expected to remain main source of transport fuels at least for the next 20 to 30 years. The petroleum crude reserves however, are declining and consumption of transport fuels particularly in the developing countries is increasing at high rates. Severe shortage of liquid fuels derived from petroleum may be faced in the second half of this century. In this paper, experiments are performed in a fur stroke, single cylinder, compression ignition diesel engine with dual fuel mode. Diesel and hydrogen are used as pilot liquid and primary gaseous fuel, respectively. The objective of this study is to find out the effects on combustion and performance parameters observed at diesel hydrogen fuel mixture for all the different loadings (2kg,4kg,6kg,8kg,10kg and 12kg) in the engine.

  7. Effect of flame-tube head structure on combustion chamber performance

    Science.gov (United States)

    Gu, Minqqi

    1986-01-01

    The experimental combustion performance of a premixed, pilot-type flame tube with various head structures is discussed. The test study covers an extensive area: efficiency of the combustion chamber, quality of the outlet temperature field, limit of the fuel-lean blowout, ignition performance at ground starting, and carbon deposition. As a result of these tests, a nozzle was found which fits the premixed pilot flame tube well. The use of this nozzle optimized the performance of the combustion chamber. The tested models had premixed pilot chambers with two types of air-film-cooling structures, six types of venturi-tube structures, and secondary fuel nozzles with two small spray-cone angles.

  8. Oxygen enriched combustion system performance study. Phase 2: 100 percent oxygen enriched combustion in regenerative glass melters, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tuson, G.B.; Kobayashi, H.; Campbell, M.J.

    1994-08-01

    The field test project described in this report was conducted to evaluate the energy and environmental performance of 100% oxygen enriched combustion (100% OEC) in regenerative glass melters. Additional objectives were to determine other impacts of 100% OEC on melter operation and glass quality, and to verify on a commercial scale that an on-site Pressure Swing Adsorption oxygen plant can reliably supply oxygen for glass melting with low electrical power consumption. The tests constituted Phase 2 of a cooperative project between the United States Department of Energy, and Praxair, Inc. Phase 1 of the project involved market and technical feasibility assessments of oxygen enriched combustion for a range of high temperature industrial heating applications. An assessment of oxygen supply options for these applications was also performed during Phase 1, which included performance evaluation of a pilot scale 1 ton per day PSA oxygen plant. Two regenerative container glass melters were converted to 100% OEC operation and served as host sites for Phase 2. A 75 ton per day end-fired melter at Carr-Lowrey Glass Company in Baltimore, Maryland, was temporarily converted to 100% OEC in mid- 1990. A 350 tpd cross-fired melter at Gallo Glass Company in Modesto, California was rebuilt for permanent commercial operation with 100% OEC in mid-1991. Initially, both of these melters were supplied with oxygen from liquid storage. Subsequently, in late 1992, a Pressure Swing Adsorption oxygen plant was installed at Gallo to supply oxygen for 100% OEC glass melting. The particular PSA plant design used at Gallo achieves maximum efficiency by cycling the adsorbent beds between pressurized and evacuated states, and is therefore referred to as a Vacuum/Pressure Swing Adsorption (VPSA) plant.

  9. The scaling of performance and losses in miniature internal combustion engines

    Science.gov (United States)

    Menon, Shyam Kumar

    Miniature glow ignition internal combustion (IC) piston engines are an off--the--shelf technology that could dramatically increase the endurance of miniature electric power supplies and the range and endurance of small unmanned air vehicles provided their overall thermodynamic efficiencies can be increased to 15% or better. This thesis presents the first comprehensive analysis of small (system is developed that is capable of making reliable measurements of engine performance and losses in these small engines. Methodologies are also developed for measuring volumetric, heat transfer, exhaust, mechanical, and combustion losses. These instruments and techniques are used to investigate the performance of seven single-cylinder, two-stroke, glow fueled engines ranging in size from 15 to 450 g (0.16 to 7.5 cm3 displacement). Scaling rules for power output, overall efficiency, and normalized power are developed from the data. These will be useful to developers of micro-air vehicles and miniature power systems. The data show that the minimum length scale of a thermodynamically viable piston engine based on present technology is approximately 3 mm. Incomplete combustion is the most important challenge as it accounts for 60-70% of total energy losses. Combustion losses are followed in order of importance by heat transfer, sensible enthalpy, and friction. A net heat release analysis based on in-cylinder pressure measurements suggest that a two--stage combustion process occurs at low engine speeds and equivalence ratios close to 1. Different theories based on burning mode and reaction kinetics are proposed to explain the observed results. High speed imaging of the combustion chamber suggests that a turbulent premixed flame with its origin in the vicinity of the glow plug is the primary driver of combustion. Placing miniature IC engines on a turbulent combustion regime diagram shows that they operate in the 'flamelet in eddy' regime whereas conventional--scale engines operate

  10. Performance Evaluation of a High Bandwidth Liquid Fuel Modulation Valve for Active Combustion Control

    Science.gov (United States)

    Saus, Joseph R.; DeLaat, John C.; Chang, Clarence T.; Vrnak, Daniel R.

    2012-01-01

    At the NASA Glenn Research Center, a characterization rig was designed and constructed for the purpose of evaluating high bandwidth liquid fuel modulation devices to determine their suitability for active combustion control research. Incorporated into the rig s design are features that approximate conditions similar to those that would be encountered by a candidate device if it were installed on an actual combustion research rig. The characterized dynamic performance measures obtained through testing in the rig are planned to be accurate indicators of expected performance in an actual combustion testing environment. To evaluate how well the characterization rig predicts fuel modulator dynamic performance, characterization rig data was compared with performance data for a fuel modulator candidate when the candidate was in operation during combustion testing. Specifically, the nominal and off-nominal performance data for a magnetostrictive-actuated proportional fuel modulation valve is described. Valve performance data were collected with the characterization rig configured to emulate two different combustion rig fuel feed systems. Fuel mass flows and pressures, fuel feed line lengths, and fuel injector orifice size was approximated in the characterization rig. Valve performance data were also collected with the valve modulating the fuel into the two combustor rigs. Comparison of the predicted and actual valve performance data show that when the valve is operated near its design condition the characterization rig can appropriately predict the installed performance of the valve. Improvements to the characterization rig and accompanying modeling activities are underway to more accurately predict performance, especially for the devices under development to modulate fuel into the much smaller fuel injectors anticipated in future lean-burning low-emissions aircraft engine combustors.

  11. Effect of excess air on second-generation PFB combustion plant performance and economics

    International Nuclear Information System (INIS)

    Robertson, A.; Garland, R.; Newby, R.; Rehmat, A.; Rubow, L.; Bonk, D.

    1990-01-01

    This paper presents a conceptual design of a 1.4-MPa (14-atm) coal-fired second-generation pressurized fluidized bed (PFB) combustion plant and identifies the performance and economic changes that result as the excess air and thus gas turbine-to-steam turbine power ratio, is changed. The performance of these plants, another second- generation PFB combustion plant, and a conventional pulverized-coal (PC)-fired plant with wet limestone flue gas desulfurization is compared. Depending upon the conditions selected, the PFB combustion plant can achieve a 45 percent efficiency (based on the higher heating value of the coal used as fuel) and a cost of electricity at least 20 percent lower than that of the conventional PC-fired plant

  12. Thermogravimetric investigation on the degradation properties and combustion performance of bio-oils.

    Science.gov (United States)

    Ren, Xueyong; Meng, Jiajia; Moore, Andrew M; Chang, Jianmin; Gou, Jinsheng; Park, Sunkyu

    2014-01-01

    The degradation properties and combustion performance of raw bio-oil, aged bio-oil, and bio-oil from torrefied wood were investigated through thermogravimetric analysis. A three-stage process was observed for the degradation of bio-oils, including devolatilization of the aqueous fraction and light compounds, transition of the heavy faction to solid, and combustion of carbonaceous residues. Pyrolysis kinetics parameters were calculated via the reaction order model and 3D-diffusion model, and combustion indexes were used to qualitatively evaluate the thermal profiles of tested bio-oils for comparison with commercial oils such as fuel oils. It was found that aged bio-oil was more thermally instable and produced more combustion-detrimental carbonaceous solid. Raw bio-oil and bio-oil from torrefied wood had comparable combustion performance to fuel oils. It was considered that bio-oil has a potential to be mixed with or totally replace the fuel oils in boilers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Performance, combustion and emission analysis of mustard oil biodiesel and octanol blends in diesel engine

    Science.gov (United States)

    Devarajan, Yuvarajan; Munuswamy, Dinesh Babu; Nagappan, Beemkumar; Pandian, Amith Kishore

    2018-01-01

    Biodiesels from the mustard oil promise to be an alternative to the conventional diesel fuel due to their similarity in properties. Higher alcohols are added to neat Mustard oil biodiesel (M100) to vary the properties of biodiesel for improving its combustion, emission and performance characteristics. N-Octanol has the ability to act as an oxygen buffer during combustion which contributes to the catalytic effect and accelerates the combustion process. N-Octanol is dispersed to neat Mustard oil biodiesel in the form of emulsions at different dosage levels of 10, 20 and 30% by volume. Three emulsion fuels prepared for engine testing constitutes of 90% of biodiesel and 10% of n-Octanol (M90O10), 80% of biodiesel and 20% of n-Octanol (M80O20) and 70% of biodiesel and 30% of n-Octanol (M70O30) by volume respectively. AVL 5402 diesel engine is made to run on these fuels to study the effect of n-Octanol on combustion, emission and performance characteristics of the mustard oil biodiesel. Experimental results show that addition of n-octanol has a positive effect on performance, combustion and emission characteristics owing to its inbuilt oxygen content. N-octanol was found to be the better oxidizing catalyst as it was more effective in reducing HC and CO emissions. A significant reduction in NOx emission was found when fuelled with emulsion techniques. The blending of n-octanol to neat Mustard oil biodiesel reduces the energy and fuel consumption and a marginal increase in brake thermal efficiency. Further, n-octanol also reduces the ignition delay and aids the combustion.

  14. Performance, combustion and emission analysis of mustard oil biodiesel and octanol blends in diesel engine

    Science.gov (United States)

    Devarajan, Yuvarajan; Munuswamy, Dinesh Babu; Nagappan, Beemkumar; Pandian, Amith Kishore

    2018-06-01

    Biodiesels from the mustard oil promise to be an alternative to the conventional diesel fuel due to their similarity in properties. Higher alcohols are added to neat Mustard oil biodiesel (M100) to vary the properties of biodiesel for improving its combustion, emission and performance characteristics. N-Octanol has the ability to act as an oxygen buffer during combustion which contributes to the catalytic effect and accelerates the combustion process. N-Octanol is dispersed to neat Mustard oil biodiesel in the form of emulsions at different dosage levels of 10, 20 and 30% by volume. Three emulsion fuels prepared for engine testing constitutes of 90% of biodiesel and 10% of n-Octanol (M90O10), 80% of biodiesel and 20% of n-Octanol (M80O20) and 70% of biodiesel and 30% of n-Octanol (M70O30) by volume respectively. AVL 5402 diesel engine is made to run on these fuels to study the effect of n-Octanol on combustion, emission and performance characteristics of the mustard oil biodiesel. Experimental results show that addition of n-octanol has a positive effect on performance, combustion and emission characteristics owing to its inbuilt oxygen content. N-octanol was found to be the better oxidizing catalyst as it was more effective in reducing HC and CO emissions. A significant reduction in NOx emission was found when fuelled with emulsion techniques. The blending of n-octanol to neat Mustard oil biodiesel reduces the energy and fuel consumption and a marginal increase in brake thermal efficiency. Further, n-octanol also reduces the ignition delay and aids the combustion.

  15. Multidimensional modeling of the effect of Exhaust Gas Recirculation (EGR) on exergy terms in an HCCI engine fueled with a mixture of natural gas and diesel

    International Nuclear Information System (INIS)

    Jafarmadar, Samad; Nemati, Peyman; Khodaie, Rana

    2015-01-01

    Highlights: • The exergy efficiency decreases by 41.3%. • The irreversibility increases by 46.80%. • The cumulative heat loss exergy decreases by 68.10%. • The cumulative work exergy decreases by 63.4%. • The exhaust losses exergy increases by 28.79%. - Abstract: One of the most important issues in HCCI engines is auto-ignition timing control. EGR introduction into intake charge can be a method to control combustion phasing and its duration. In the current study, a FORTRAN-based code which includes 10 species (O_2, N_2, H_2O, CO_2, CO, H_2, OH, O, N, NO) associated with combustion products was employed to study the exergy analysis in a dual fuel (natural gas + diesel) HCCI engine at four EGR (exhaust gas recirculation) mass fractions (0%, 10%, 20%, and 30%) while the diesel fuel amount was held constant. In order to achieve this task, a 3-D CFD code was employed to model the energy balance during a closed cycle of running engine simulation. Moreover, an efficient Extend Coherent Flame Model-Three Zone model (ECFM-3Z) method was employed to analyze the combustion process. With crank positions at different EGR mass fractions, the exergy terms were identified and calculated separately. It was found that as EGR mass fraction increased from 0% to 30% (in 10% increment steps), exergy efficiency decreased from 48.9% to 28.7%. Furthermore, with the change in EGR mass fraction, the cumulative heat loss exergy decreased from 10.1% to 5.64% of mixture fuels chemical exergy.

  16. NEDO project reports. High performance industrial furnace development project - High temperature air combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-21

    For the purpose of reducing energy consumption, a NEDO project 'Developmental research on high efficiency industrial furnaces' was carried out from FY 1993 to FY 1999 by The Japan Industrial Furnaces Manufacturers Association, and the paper outlined the details of the project. Industrial furnaces handled in this R and D can bring 30% reduction of the energy consumption and approximately 50% NOx reduction, and were given the 9th Nikkei global environmental technology prize. In the study of combustion phenomena of high temperature air combustion, the paper arranged characteristics of flame, the base of gaseous fuel flame, the base of liquid fuel flame, the base of solid fuel flame, etc. Concerning high temperature air combustion models for simulation, fluid dynamics and heat transfer models, and reaction and NOx models, etc. As to impacts of high temperature air combustion on performance of industrial furnaces, energy conservation, lowering of pollution, etc. In relation to a guide for the design of high efficiency industrial furnaces, flow charts, conceptual design, evaluation method for heat balance and efficiency using charts, combustion control system, applicability of high efficiency industrial furnaces, etc. (NEDO)

  17. NEDO project reports. High performance industrial furnace development project - High temperature air combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-21

    For the purpose of reducing energy consumption, a NEDO project 'Developmental research on high efficiency industrial furnaces' was carried out from FY 1993 to FY 1999 by The Japan Industrial Furnaces Manufacturers Association, and the paper outlined the details of the project. Industrial furnaces handled in this R and D can bring 30% reduction of the energy consumption and approximately 50% NOx reduction, and were given the 9th Nikkei global environmental technology prize. In the study of combustion phenomena of high temperature air combustion, the paper arranged characteristics of flame, the base of gaseous fuel flame, the base of liquid fuel flame, the base of solid fuel flame, etc. Concerning high temperature air combustion models for simulation, fluid dynamics and heat transfer models, and reaction and NOx models, etc. As to impacts of high temperature air combustion on performance of industrial furnaces, energy conservation, lowering of pollution, etc. In relation to a guide for the design of high efficiency industrial furnaces, flow charts, conceptual design, evaluation method for heat balance and efficiency using charts, combustion control system, applicability of high efficiency industrial furnaces, etc. (NEDO)

  18. The influence of charge stratification on the spectral signature of partially premixed combustion in a light-duty optical engine

    KAUST Repository

    Najafabadi, M. Izadi

    2017-03-25

    The origin of light emission during low-temperature combustion in a light-duty IC engine is investigated by high-speed spectroscopy in both HCCI and PPC regimes. Chemiluminescence and thermal radiation are expected to be the dominant sources of light emission during combustion. A method has been developed to distinguish chemiluminescence from thermal radiation, and different chemiluminescing species could be identified. Different combustion modes and global equivalence ratios are analyzed in this manner. The results indicate that the spectral signature (270–540 nm range) of the combustion is highly dependent on the stratification level. A significant broadband chemiluminescence signal is detected and superimposed on all spectra. This broadband chemiluminescence signal can reach up to 100 percent of the total signal in HCCI combustion, while it drops to around 80 percent for stratified combustion (PPC). We show that this broadband signal can be used as a measure for the heat release rate. The broadband chemiluminescence did also correlate with the equivalence ratio quite well in both HCCI and PPC regimes, suggesting that the total emission in the spectral region of 330–400 nm can serve as a proxy of equivalence ratio and the rate of heat release. Regarding C2* chemiluminescence, we see two different chemical mechanisms for formation of C2* in the PPC regime: first during the early stage of combustion by the breakup of bigger molecules and the second during the late stage of combustion when soot particles are forming.

  19. Meta-control of combustion performance with a data mining approach

    Science.gov (United States)

    Song, Zhe

    Large scale combustion process is complex and proposes challenges of optimizing its performance. Traditional approaches based on thermal dynamics have limitations on finding optimal operational regions due to time-shift nature of the process. Recent advances in information technology enable people collect large volumes of process data easily and continuously. The collected process data contains rich information about the process and, to some extent, represents a digital copy of the process over time. Although large volumes of data exist in industrial combustion processes, they are not fully utilized to the level where the process can be optimized. Data mining is an emerging science which finds patterns or models from large data sets. It has found many successful applications in business marketing, medical and manufacturing domains The focus of this dissertation is on applying data mining to industrial combustion processes, and ultimately optimizing the combustion performance. However the philosophy, methods and frameworks discussed in this research can also be applied to other industrial processes. Optimizing an industrial combustion process has two major challenges. One is the underlying process model changes over time and obtaining an accurate process model is nontrivial. The other is that a process model with high fidelity is usually highly nonlinear, solving the optimization problem needs efficient heuristics. This dissertation is set to solve these two major challenges. The major contribution of this 4-year research is the data-driven solution to optimize the combustion process, where process model or knowledge is identified based on the process data, then optimization is executed by evolutionary algorithms to search for optimal operating regions.

  20. Performance of Combustion Engineering fuel in operating PWRs

    International Nuclear Information System (INIS)

    Andrews, M.G.; Freeburn, H.R.; Wohlsen, W.D.

    1979-01-01

    Performance data on fuel assembly components from seven (7) operating reactors are presented, and discussed in detail where potential problems have occurred and been resolved. Fuel rod performance has continually improved over the last four (4) years with the gradual changeover to the current C-E fuel design. The reliability level is estimated at better than 99.99%, based on activity levels obtained through January 1979 at each plant. Control rod guide tubes have shown various degrees of wear caused by vibration of the control rods in their fully-withdrawn position. The retrofit of wear sleeves within the top portion of the affected guide tubes during routine refueling has permitted the use of these fuel assemblies with no significant loss in performance or safety margins

  1. Impact of CO_2-enriched combustion air on micro-gas turbine performance for carbon capture

    International Nuclear Information System (INIS)

    Best, Thom; Finney, Karen N.; Ingham, Derek B.; Pourkashanian, Mohamed

    2016-01-01

    Power generation is one of the largest anthropogenic greenhouse gas emission sources; although it is now reducing in carbon intensity due to switching from coal to gas, this is only part of a bridging solution that will require the utilization of carbon capture technologies. Gas turbines, such as those at the UK Carbon Capture Storage Research Centre's Pilot-scale Advanced CO_2 Capture Technology (UKCCSRC PACT) National Core Facility, have high exhaust gas mass flow rates with relatively low CO_2 concentrations; therefore solvent-based post-combustion capture is energy intensive. Exhaust gas recirculation (EGR) can increase CO_2 levels, reducing the capture energy penalty. The aim of this paper is to simulate EGR through enrichment of the combustion air with CO_2 to assess changes to turbine performance and potential impacts on complete generation and capture systems. The oxidising air was enhanced with CO_2, up to 6.29%vol dry, impacting mechanical performance, reducing both engine speed by over 400 revolutions per minute and compression temperatures. Furthermore, it affected complete combustion, seen in changes to CO and unburned hydrocarbon emissions. This impacted on turbine efficiency, which increased specific fuel consumption (by 2.9%). CO_2 enhancement could therefore result in significant efficiency gains for the capture plant. - Highlights: • Experimental investigation of the impact of exhaust gas recirculation (EGR) on GT performance. • Combustion air was enhanced with CO_2 to simulate EGR. • EGR impact was ascertained by CO and unburned hydrocarbon changes. • Primary factor influencing performance was found to be oxidiser temperature. • Impact of CO_2 enhancement on post-combustion capture efficiency.

  2. Numerical Study on the Performance Characteristics of Hydrogen Fueled Port Injection Internal Combustion Engine

    OpenAIRE

    Rosli A. Bakar; Mohammed K. Mohammed; M. M. Rahman

    2009-01-01

    This study was focused on the engine performance of single cylinder hydrogen fueled port injection internal combustion engine. GT-Power was utilized to develop the model for port injection engine. One dimensional gas dynamics was represented the flow and heat transfer in the components of the engine model. The governing equations were introduced first, followed by the performance parameters and model description. Air-fuel ratio was varied from stoichiometric limit to a lean limit and the rota...

  3. A Review on Homogeneous Charge Compression Ignition and Low Temperature Combustion by Optical Diagnostics

    Directory of Open Access Journals (Sweden)

    Chao Jin

    2015-01-01

    Full Text Available Optical diagnostics is an effective method to understand the physical and chemical reaction processes in homogeneous charge compression ignition (HCCI and low temperature combustion (LTC modes. Based on optical diagnostics, the true process on mixing, combustion, and emissions can be seen directly. In this paper, the mixing process by port-injection and direct-injection are reviewed firstly. Then, the combustion chemical reaction mechanism is reviewed based on chemiluminescence, natural-luminosity, and laser diagnostics. After, the evolution of pollutant emissions measured by different laser diagnostic methods is reviewed and the measured species including NO, soot, UHC, and CO. Finally, a summary and the future directions on HCCI and LTC used optical diagnostics are presented.

  4. Effects of Injection Timing on Fluid Flow Characteristics of Partially Premixed Combustion Based on High-Speed Particle Image Velocimetry

    KAUST Repository

    Izadi Najafabadi, Mohammad

    2017-03-28

    Partially Premixed Combustion (PPC) is a promising combustion concept ,based on judicious tuning of the charge stratification, to meet the increasing demands of emission legislation and to improve fuel efficiency. Longer ignition delays of PPC in comparison with conventional diesel combustion provide better fuel/air mixture which decreases soot and NO emissions. Moreover, a proper injection timing and strategy for PPC can improve the combustion stability as a result of a higher level of fuel stratification in comparison with the Homogeneous Charge Compression Ignition (HCCI) concept. Injection timing is the major parameter with which to affect the level of fuel and combustion stratification and to control the combustion phasing and the heat release behavior. The scope of the present study is to investigate the fluid flow characteristics of PPC at different injection timings. To this end, high-speed Particle Image Velocimetry (PIV) is implemented in a light-duty optical engine to measure fluid flow characteristics, including the flow fields, mean velocity and cycle-resolved turbulence, inside the piston bowl as well as the squish region with a temporal resolution of 1 crank angle degree at 800 rpm. Two injectors, having 5 and 7 holes, were compared to see their effects on fluid flow and heat release behavior for different injection timings. Reactive and non-reactive measurements were performed to distinguish injection-driven and combustion-driven turbulence. Formation of vortices and higher turbulence levels enhance the air/fuel interaction, changing the level of fuel stratification and combustion duration. Results demonstrate clearly how turbulence level correlates with heat release behavior, and provide a quantitative dataset for validation of numerical simulations.

  5. Performance of a supercharged direct-injection stratified-charge rotary combustion engine

    Science.gov (United States)

    Bartrand, Timothy A.; Willis, Edward A.

    1990-01-01

    A zero-dimensional thermodynamic performance computer model for direct-injection stratified-charge rotary combustion engines was modified and run for a single rotor supercharged engine. Operating conditions for the computer runs were a single boost pressure and a matrix of speeds, loads and engine materials. A representative engine map is presented showing the predicted range of efficient operation. After discussion of the engine map, a number of engine features are analyzed individually. These features are: heat transfer and the influence insulating materials have on engine performance and exhaust energy; intake manifold pressure oscillations and interactions with the combustion chamber; and performance losses and seal friction. Finally, code running times and convergence data are presented.

  6. Combustion performance of an aluminum melting furnace operating with liquid fuel

    Energy Technology Data Exchange (ETDEWEB)

    Nieckele, Angela Ourivio; Naccache, Monica Feijo; Gomes, Marcos Sebastiao de P. [Pontificia Universidade Catolica (PUC-Rio), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica], E-mails: nieckele@puc-rio.br, naccache@puc-rio.br, mspgomes@puc-rio.br

    2010-10-15

    The characteristics associated with the delivery of the fuel to be used as the energy source in any industrial combustion equipment are of extreme importance, as for example, in improving the performance of the combustion process and in the preservation of the equipment. A clean and efficient combustion may be achieved by carefully selecting the fuel and oxidant, as well as the operational conditions of the delivery system for both. In the present work, numerical simulations were carried out using the commercial code FLUENT for analyzing some of the relevant operational conditions inside an aluminum reverb furnace employing liquid fuel and air as the oxidant. Different fuel droplets sizes as well as inlet droplet stream configurations were examined. These characteristics, associated with the burner geometry and the fuel dispersion and delivery system may affect the flame shape, and consequently the temperature and the heat flux distribution within the furnace. Among the results obtained in the simulations, it was shown the possible damages to the equipment, which may occur as a result of the combustion process, if the flame is too long or too intense and concentrated. (author)

  7. Numerical Investigation on Aerodynamic and Combustion Performance of Chevron Mixer Inside an Afterburner.

    Science.gov (United States)

    Yong, Shan; JingZhou, Zhang; Yameng, Wang

    2014-11-01

    To improve the performance of the afterburner for the turbofan engine, an innovative type of mixer, namely, the chevron mixer, was considered to enhance the mixture between the core flow and the bypass flow. Computational fluid dynamics (CFD) simulations investigated the aerodynamic performances and combustion characteristics of the chevron mixer inside a typical afterburner. Three types of mixer, namely, CC (chevrons tilted into core flow), CB (chevrons tilted into bypass flow), and CA (chevrons tilted into core flow and bypass flow alternately), respectively, were studied on the aerodynamic performances of mixing process. The chevrons arrangement has significant effect on the mixing characteristics and the CA mode seems to be advantageous for the generation of the stronger streamwise vortices with lower aerodynamic loss. Further investigations on combustion characteristics for CA mode were performed. Calculation results reveal that the local temperature distribution at the leading edge section of flame holder is improved under the action of streamwise vortices shedding from chevron mixers. Consequently, the combustion efficiency increased by 3.5% compared with confluent mixer under the same fuel supply scheme.

  8. Co-combustion performance of coal with rice husks and bamboo

    Energy Technology Data Exchange (ETDEWEB)

    Kwong, P.C.W.; Chao, C.Y.H.; Wang, J.H.; Cheung, C.W.; Kendall, G. [Hong Kong University of Science & Technology, Kowloon (China). Dept. of Mechanical Engineering

    2007-11-15

    Biomass has been regarded as an important form of renewable energy due to the reduction of greenhouse gas emission such as carbon dioxide. An experimental study of co-combustion of coal and biomass was performed in a laboratory-scale combustion facility. Rice husks and bamboo were the selected biomass fuels in this study due to their abundance in the Asia-Pacific region. Experimental parameters including the biomass blending ratio in the fuel mixture, relative moisture content and biomass grinding size were investigated. Both energy release data and pollutant emission information were obtained. Due to the decrease in the heating value from adding biomass in the fuel mixture, the combustion temperature and energy output from the co-firing process were reduced compared with coal combustion. On the other hand, gaseous pollutant emissions including carbon monoxide (CO), carbon dioxide (CO{sub 2}), nitrogen oxides (NOx) and sulfur dioxide (SO{sub 2}) were reduced and minimum energy-based emission factors were found in the range of 10-30% biomass blending ratio. With an increase in the moisture content in the biomass, decreases in combustion temperature, SO{sub 2}, NOx and CO{sub 2} emissions were observed, while an increase in CO emissions was found. It has also been observed that chemical kinetics may play an important role compared to mass diffusion in the co-firing process and the change in biomass grinding size does not have much effect on the fuel burning rate and pollutant emissions tinder the current experimental conditions.

  9. Combustion, emission and engine performance characteristics of used cooking oil biodiesel - A review

    Energy Technology Data Exchange (ETDEWEB)

    Enweremadu, C.C. [Department of Mechanical Engineering, Vaal University of Technology, Private Bag X021, Vanderbijlpark 1900 (South Africa); Rutto, H.L. [Department of Chemical Engineering, Vaal University of Technology, Private Bag X021, Vanderbijlpark 1900 (South Africa)

    2010-12-15

    As the environment degrades at an alarming rate, there have been steady calls by most governments following international energy policies for the use of biofuels. One of the biofuels whose use is rapidly expanding is biodiesel. One of the economical sources for biodiesel production which doubles in the reduction of liquid waste and the subsequent burden of sewage treatment is used cooking oil (UCO). However, the products formed during frying, such as free fatty acid and some polymerized triglycerides, can affect the transesterification reaction and the biodiesel properties. This paper attempts to collect and analyze published works mainly in scientific journals about the engine performance, combustion and emissions characteristics of UCO biodiesel on diesel engine. Overall, the engine performance of the UCO biodiesel and its blends was only marginally poorer compared to diesel. From the standpoint of emissions, NOx emissions were slightly higher while un-burnt hydrocarbon (UBHC) emissions were lower for UCO biodiesel when compares to diesel fuel. There were no noticeable differences between UCO biodiesel and fresh oil biodiesel as their engine performances, combustion and emissions characteristics bear a close resemblance. This is probably more closely related to the oxygenated nature of biodiesel which is almost constant for every biodiesel (biodiesel has some level of oxygen bound to its chemical structure) and also to its higher viscosity and lower calorific value, which have a major bearing on spray formation and initial combustion. (author)

  10. Spark Ignition Engine Combustion, Performance and Emission Products from Hydrous Ethanol and Its Blends with Gasoline

    Directory of Open Access Journals (Sweden)

    Musaab O. El-Faroug

    2016-11-01

    Full Text Available This paper reviews the serviceability of hydrous ethanol as a clean, cheap and green renewable substitute fuel for spark ignition engines and discusses the comparative chemical and physical properties of hydrous ethanol and gasoline fuels. The significant differences in the properties of hydrous ethanol and gasoline fuels are sufficient to create a significant change during the combustion phase of engine operation and consequently affect the performance of spark-ignition (SI engines. The stability of ethanol-gasoline-water blends is also discussed. Furthermore, the effects of hydrous ethanol, and its blends with gasoline fuel on SI engine combustion characteristics, cycle-to-cycle variations, engine performance parameters, and emission characteristics have been highlighted. Higher water solubility in ethanol‑gasoline blends may be obviously useful and suitable; nevertheless, the continuous ability of water to remain soluble in the blend is significantly affected by temperature. Nearly all published engine experimental results showed a significant improvement in combustion characteristics and enhanced engine performance for the use of hydrous ethanol as fuel. Moreover, carbon monoxide and oxides of nitrogen emissions were also significantly decreased. It is also worth pointing out that unburned hydrocarbon and carbon dioxide emissions were also reduced for the use of hydrous ethanol. However, unregulated emissions such as acetaldehyde and formaldehyde were significantly increased.

  11. Performance and combustion characteristics of direct-injection stratified-charge rotary engines

    Science.gov (United States)

    Nguyen, Hung Lee

    1987-01-01

    Computer simulations of the direct-injection stratified-charge (DISC) Wankel engine have been used to calculate heat release rates and performance and efficiency characteristics of the 1007R engine. Engine pressure data have been used in a heat release analysis to study the effects of heat transfer, leakage, and crevice flows. Predicted engine performance data are compared with experimental test data over a range of engine speeds and loads. An examination of methods to improve the performance of the Wankel engine with faster combustion, reduced leakage, higher compression ratio, and turbocharging is presented.

  12. Effects of setting new source performance standards for fluidized-bed combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    1978-02-01

    This study was undertaken for the US Environmental Protection Agency to examine the potential consequences of revisions in New Source Performance Standards (NSPS) on fluidized-bed combustor-based steam electric generators of greater than 250,000,000 Btu. A study of the appropriateness and differential effects of alternate regulatory approaches to the standards-setting process was made. Problems dealing with an emerging technology such as fluidized-bed combustion were emphasized. Finally, an examination was made of the potential benefits of fluidized-bed combustion (FBC) systems relative to conventional coal-fired systems equipped with scrubbers. Information is included on the relative advantages and disadvantages of utility-sized fluidized-bed combustors, the technical consequences of NSPS alternatives, policy implications concerning NSPS for steam-electric generators, and cost models for atmospheric and pressurized FBC systems. (LCL)

  13. Experimental validation of a kinetic multi-component mechanism in a wide HCCI engine operating range for mixtures of n-heptane, iso-octane and toluene: Influence of EGR parameters

    International Nuclear Information System (INIS)

    Machrafi, Hatim

    2008-01-01

    The parameters that are present in exhaust gas recirculation (EGR) are believed to provide an important contribution to control the auto-ignition process of the homogeneous charge compression ignition (HCCI) in an engine. For the investigation of the behaviour of the auto-ignition process, a kinetic multi-component mechanism has been developed in former work, containing 62 reactions and 49 species for mixtures of n-heptane, iso-octane and toluene. This paper presents an experimental validation of this mechanism, comparing the calculated pressure, heat release, ignition delays and CO 2 emissions with experimental data performed on a HCCI engine. The validation is performed in a broad range of EGR parameters by varying the dilution by N 2 and CO 2 from 0 to 46 vol.%, changing the EGR temperature from 30 to 120 deg. C, altering the addition of CO and NO from 0 to 170 ppmv and varying the addition of CH 2 O from 0 to 1400 ppmv. These validations were performed respecting the HCCI conditions for the inlet temperature and the equivalence ratio. The results showed that the mechanism is validated experimentally in dilution ranges going up to 21-30 vol.%, depending on the species of dilution and over the whole range of the EGR temperature. The mechanism is validated over the whole range of CO and CH 2 O addition. As for the addition of NO, the mechanism is validated quantitatively up to 50 ppmv and qualitatively up to 170 ppmv

  14. Examining Methods to Reduce Wall-Wetting under HCCI conditions

    Energy Technology Data Exchange (ETDEWEB)

    Van Erp, D.D.T.M.

    2009-01-15

    HCCI engines (Homogeneous Charge Compression Ignition) are very promising in the reduction of soot and NOx, but several problems must be tackled. Collision of the liquid fuel spray against the cylinder wall (Wall-wetting) is a major problem. Low gas temperatures and low gas densities (typical 600 - 800 K and 5 - 7.4 kg/m{sup 3}) at the moment of the fuel injection slow down the evaporation process of the liquid fuel in the spray and causes wall-wetting. This report investigates different promising measures that can reduce the penetration of the liquid fuel core, in order to prevent wall-wetting. From literature it turns out that the measures, listed below, are the most promising for liquid core length (LL) reduction without changing the design of the injector or the engine design: Increasing the fuel temperature, Changing the fuel pressure, Decrease of injector hole diameter, Multiple injections (first very short injections are examined). Each of the measures will be investigated by a liquid length prediction model (Siebers) and in an experimental setup, the EHPC (Eindhoven High Pressure Cell). A high pressure vessel with optical access makes it possible to visualize the liquid core and the vapor phase of the fuel spray by Mie and Schlieren, respectively. Changes to the setup are made to heat up the fuel up to 120C. Furthermore, changes to the fuel spray visualization techniques have been made. Where in previous experiments the Mie and Schlieren techniques were carried out separately from each other, in this work both visualization techniques are combined to save measurement time and to deal with the same experimental conditions. The combined recording of Mie and Schlieren works well for high gas temperatures and densities. But the combined technique fails for low gas temperatures and densities (below 700K and 7.4 kg/m3), due to the poor contrast between the liquid core and the vapor phase. In further examination of liquid length reducing measures, only the Mie

  15. Study on gasoline HCCI engine equipped with electromagnetic variable valve timing system; Untersuchung an einem HCCI Verbrennungsmotor mit elektromagnetisch variablem Ventiltriebsystem

    Energy Technology Data Exchange (ETDEWEB)

    Urata, Y.; Awasaka, M.; Takanashi, J.; Kimura, N. [Honda R and D Co., Ltd. (Japan)

    2004-07-01

    First, this paper describes a study on the technology behind the electromagnetic variable valve timing system. This system provides highly efficient and stable valve opening/closing control. At first, the main purposes of this mechanism were nonthrottling technology that is expected to a reduction in fuel consumption and improving the engine torque with optimal valve timing on stichomythic spark ignited engine. In resent years, increasing attention has been paid to a homogeneous charge compression ignition (HCCI). We also used this mechanism on HCCI study with controlling the amount of internal EGR and intake air. Schemes to extend the operational region of gasoline compression ignition were explored using single (optical) and 4-cylinder 4-stroke engines equipped with an electromagnetic variable valve timing system. This paper focuses mainly on the use of direct fuel injection devices (multi-hole and pintle types), exhaust gas recirculation (EGR) through valve timing, and their effects on the compression ignition operating ranges, and emissions. Also considered is charge boost HCCI using a mechanical supercharger. (orig.)

  16. Carbohydrate-Assisted Combustion Synthesis To Realize High-Performance Oxide Transistors.

    Science.gov (United States)

    Wang, Binghao; Zeng, Li; Huang, Wei; Melkonyan, Ferdinand S; Sheets, William C; Chi, Lifeng; Bedzyk, Michael J; Marks, Tobin J; Facchetti, Antonio

    2016-06-08

    Owing to high carrier mobilities, good environmental/thermal stability, excellent optical transparency, and compatibility with solution processing, thin-film transistors (TFTs) based on amorphous metal oxide semiconductors (AOSs) are promising alternatives to those based on amorphous silicon (a-Si:H) and low-temperature (IGZO) TFTs suffer from low carrier mobilities and/or inferior bias-stress stability versus their sputtered counterparts. Here we report that three types of environmentally benign carbohydrates (sorbitol, sucrose, and glucose) serve as especially efficient fuels for IGZO film combustion synthesis to yield high-performance TFTs. The results indicate that these carbohydrates assist the combustion process by lowering the ignition threshold temperature and, for optimal stoichiometries, enhancing the reaction enthalpy. IGZO TFT mobilities are increased to >8 cm(2) V(-1) s(-1) on SiO2/Si gate dielectrics with significantly improved bias-stress stability. The first correlations between precursor combustion enthalpy and a-MO densification/charge transport are established.

  17. Investigation of the effects of renewable diesel fuels on engine performance, combustion, and emissions

    KAUST Repository

    Ogunkoya, Dolanimi

    2015-01-01

    A study was undertaken to investigate renewable fuels in a compression-ignition internal combustion engine. The focus of this study was the effect of newly developed renewable fuels on engine performance, combustion, and emissions. Eight fuels were investigated, and they include diesel, jet fuel, a traditional biodiesel (fatty acid methyl ester: FAME), and five next generation biofuels. These five fuels were derived using a two-step process: hydrolysis of the oil into fatty acids (if necessary) and then a thermo-catalytic process to remove the oxygen via a decarboxylation reaction. The fuels included a fed batch deoxygenation of canola derived fatty acids (DCFA), a fed batch deoxygenation of canola derived fatty acids with varying amounts of H2 used during the deoxygenation process (DCFAH), a continuous deoxygenation of canola derived fatty acids (CDCFA), fed batch deoxygenation of lauric acid (DLA), and a third reaction to isomerize the products of the deoxygenated canola derived fatty acid alkanes (IPCF). Diesel, jet fuel, and biodiesel (FAME) have been used as benchmarks for comparing with the newer renewable fuels. The results of the experiments show slightly lower mechanical efficiency but better brake specific fuel consumption for the new renewable fuels. Results from combustion show shorter ignition delays for most of the renewable (deoxygenated) fuels with the exception of fed batch deoxygenation of lauric acid. Combustion results also show lower peak in-cylinder pressures, reduced rate of increase in cylinder pressure, and lower heat release rates for the renewable fuels. Emission results show an increase in hydrocarbon emissions for renewable deoxygenated fuels, but a general decrease in all other emissions including NOx, greenhouse gases, and soot. Results also demonstrate that isomers of the alkanes resulting from the deoxygenation of the canola derived fatty acids could be a potential replacement to conventional fossil diesel and biodiesel based on the

  18. Investigation on the lean combustion performance of a hydrogen-enriched n-butanol engine

    International Nuclear Information System (INIS)

    Zhang, Bo; Ji, Changwei; Wang, Shuofeng

    2017-01-01

    Highlights: • H_2 addition avails improving thermal efficiency of n-butanol engines. • Lean burn limit of n-butanol engine is extended by H_2 addition. • H_2 addition shortens the n-butanol engine combustion duration. • HC and CO from the n-butanol engine are decreased by H_2 addition. - Abstract: n-Butanol is a feasible fuel candidate for spark-ignition engines. The current paper carried out an experiment to explore effects of hydrogen addition on further improving the performance of a n-butanol engine under the part load and lean conditions. Within the test, the engine intake pressure and speed were respectively kept at 61.5 kPa and 1400 rpm. The volumetric fractions of hydrogen in the total intake gas (hydrogen + air) were constrained at 0 and 3%, respectively. Under a certain hydrogen blending level, the global excess air ratio of in-cylinder charge which was changed from the stoichiometric to near the lean burn limit was adjusted by varying the n-butanol injection duration. The experimental results confirmed that the brake thermal efficiency was heightened and the lean burn limit was extended after the hydrogen addition. Besides, compared with the pure n-butanol combustion, the hydrogen enrichment enables the engine to gain dropped ignition delay and rapid combustion duration. Moreover, CO and HC from the pure n-butanol engine were reduced by the hydrogen addition. NOx were generally reduced when the excess air ratio was raised. This suggested that NOx from the hydrogen-enriched butanol engine could also be controlled by lean combustion.

  19. Experimental study of hydrogen as a fuel additive in internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Saanum, Inge

    2008-07-01

    . % hydrogen to the methane, but 5 vol. % hydrogen also resulted in a noticeable increase. The flame structure was also influenced by the hydrogen addition as the flame front had a higher tendency to become wrinkled or cellular. The effect is believed to mainly be caused by a reduction in the effective Lewis number of the mixture. In the gas engine experiments, the effect of adding 25 vol. % hydrogen to natural gas was investigated when the engine was run on lean air/fuel mixtures and on stoichiometric mixtures with exhaust gas recirculation. The hydrogen addition was found to extend the lean limit of stable combustion and hence caused lower NO{sub x} emissions. The brake thermal efficiency increased with the hydrogen addition, both for the fuel lean and the stoichiometric mixtures with exhaust gas recirculation. This is mainly because of shorter combustion durations when the hydrogen mixture was used, leading to thermodynamically improved cycles. Two types of experiments were performed in compression ignition engines. First, homogenous charge compression ignition (HCCI) experiments were performed in a single cylinder engine fueled with natural gas and diesel oil. As HCCI engines have high thermal efficiency and low NO{sub x} and PM emissions it may be more favorable to use natural gas in HCCI engines than in spark ignition engines. The mixture of natural gas, diesel oil and air was partly premixed before combustion. The natural gas/diesel ratio was used to control the ignition timing as the fuels have very different ignition properties. The natural gas was also replaced by a 20 vol. % hydrogen/natural gas mixture to study the effect of hydrogen on the ignition and combustion process. Also, rape seed methyl ester (RME) was tested instead of the diesel oil. The combustion phasing was found to mainly be controlled by the amount of liquid fuel injected. The last experiments with compression ignition were performed by using a standard Scania diesel engine where the possibilities

  20. Experimental study on combustion modes and thrust performance of a staged-combustor of the scramjet with dual-strut

    Science.gov (United States)

    Yang, Qingchun; Chetehouna, Khaled; Gascoin, Nicolas; Bao, Wen

    2016-05-01

    To enable the scramjet operate in a wider flight Mach number, a staged-combustor with dual-strut is introduced to hold more heat release at low flight Mach conditions. The behavior of mode transition was examined using a direct-connect model scramjet experiment along with pressure measurements. The typical operating modes of the staged-combustor are analyzed. Fuel injection scheme has a significant effect on the combustor operating modes, particularly for the supersonic combustion mode. Thrust performances of the combustor with different combustion modes and fuel distributions are reported in this paper. The first-staged strut injection has a better engine performance in the operation of subsonic combustion mode. On the contrast, the second-staged strut injection has a better engine performance in the operation of supersonic combustion mode.

  1. Robust active combustion control for the optimization of environmental performance and energy efficiency

    Science.gov (United States)

    Demayo, Trevor Nat

    Criteria pollutant regulations, climate change concerns, and energy conservation efforts are placing strict constraints in the design and operation of advanced, stationary combustion systems. To ensure minimal pollutant emissions and maximal efficiency at every instant of operation while preventing reaction blowout, combustion systems need to react and adapt in real-time to external changes. This study describes the development, demonstration, and evaluation of a multivariable feedback control system, designed to maximize the performance of natural gas-fired combustion systems. A feedback sensor array was developed to monitor reaction stability and measure combustion performance as a function of NOx, CO, and O, emissions. Acoustic and UV chemiluminescent emissions were investigated for use as stability indicators. Modulated signals of CH* and CO2* chemiluminescence were found to correlate well with the onset of lean blowout. A variety of emissions sensors were tested and evaluated, including conventional CEMS', micro-fuel cells, a zirconia NOx transducer, and a rapid response predictive NOx sensor based on UV flame chemiluminescence. A dual time-scale controller was designed to actively optimize operating conditions by maximizing a multivariable performance function J using a linear direction set search algorithm. The controller evaluated J under slow, quasi steady-state conditions, while dynamically monitoring the reaction zone at high speed for pre-blowout instabilities or boundary condition violations. To establish the input control parameters, two burner systems were selected: a 30 kW air-swirl, generic research burner, and a 120 kW scaled, fuel-staged, industrial boiler burner. The parameters, chosen to most affect burner performance, consisted of air swirl intensity and excess air for the generic burner, and fuel-staging and excess air for the boiler burner. A set of optimization parameters was also established to ensure efficient and deterministic

  2. COMBUSTION AND PERFORMANCE CHARACTERISTICS OF A SMALL SPARK IGNITION ENGINE FUELLED WITH HCNG

    Directory of Open Access Journals (Sweden)

    A. SONTHALIA

    2015-04-01

    Full Text Available Due to environmental concerns and fossil fuel depletion, large scale researches were carried out involving the use of natural gas in internal combustion engines. Natural gas is a clean burning fuel that is available from large domestic natural reserve. When it is used as a fuel in SI engines, it reduces emissions to meet EURO-III norms with carburettors and EURO-IV norms with manifold injection. Countries like India with fewer natural fossil fuel reserves depend heavily on oil imported from Middle East Asian countries and on the other hand combustion of fossil fuel has negative impact on air quality in urban areas. Use of CNG as a fuel in internal combustion engines can reduce the intensiveness of these pervasive problems. The performance of CNG can further be improved by addition of small percentages of hydrogen to it to overcome the drawbacks like lower energy density of the fuel, drop in engine power and engine out exhaust emissions. When hydrogen is added to CNG it is called as Hythane or Hydrogen enriched Compressed Natural Gas (HCNG. This can be considered as a first step towards promotion of hydrogen in automobiles. In this study, the effects of mixing hydrogen with CNG on a small air cooled four stroke SI engine’s performance, emissions and heat release rate was analyzed. A comparison of performance and emission by running engine separately on gasoline, hydrogen, CNG and HCNG was done. The results show a significant decrease in HC, CO and NOx emissions and marginal increase in specific energy consumption when fuelled with HCNG.

  3. Influence of process parameters on coal combustion performance. Review, experiments and engineering modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lans, R.P. van der

    1997-04-01

    The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on a simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms of a reactor configuration. The influence of coal type and process conditions on NO formation and carbon burnout has been investigated experimentally in a 400 MW{sub e} corner fired boiler with over fire air, a 350 MW{sub e} opposed fired boiler, and in a 160 kW{sub t} pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project `Atmospheric Pressure Combustion of Pulverized Coal and Coal Based Blends for Power Generation`. On the pilot scale test both single stage and air staged tests were performed. A simple, one-dimensional combustion and radiation heat transfer model has been developed for the furnace of full scale boilers. The model has been applied to the two boilers mentioned above, and is validated against measured temperatures and carbon in ash concentrations. A mixing study has been performed in order to initiate an investigation of the potential of chemical engineering models to predict NO from pulverized fuel burners. (EG) 11 refs.

  4. Compositional Effects of Gasoline Fuels on Combustion, Performance and Emissions in Engine

    KAUST Repository

    Ahmed, Ahfaz; Waqas, Muhammad; Naser, Nimal; Singh, Eshan; Roberts, William L.; Chung, Suk-Ho; Sarathy, Mani

    2016-01-01

    to interpret differences in combustion behavior of gasoline fuels that show similar knock characteristics in a cooperative fuel research (CFR) engine, but may behave differently in direct injection spark ignition (DISI) engines or any other engine combustion

  5. Optimizing Performance of Combustion Chemistry Solvers on Intel's Many Integrated Core (MIC) Architectures

    Energy Technology Data Exchange (ETDEWEB)

    Sitaraman, Hariswaran [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Grout, Ray W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-06-09

    This work investigates novel algorithm designs and optimization techniques for restructuring chemistry integrators in zero and multidimensional combustion solvers, which can then be effectively used on the emerging generation of Intel's Many Integrated Core/Xeon Phi processors. These processors offer increased computing performance via large number of lightweight cores at relatively lower clock speeds compared to traditional processors (e.g. Intel Sandybridge/Ivybridge) used in current supercomputers. This style of processor can be productively used for chemistry integrators that form a costly part of computational combustion codes, in spite of their relatively lower clock speeds. Performance commensurate with traditional processors is achieved here through the combination of careful memory layout, exposing multiple levels of fine grain parallelism and through extensive use of vendor supported libraries (Cilk Plus and Math Kernel Libraries). Important optimization techniques for efficient memory usage and vectorization have been identified and quantified. These optimizations resulted in a factor of ~ 3 speed-up using Intel 2013 compiler and ~ 1.5 using Intel 2017 compiler for large chemical mechanisms compared to the unoptimized version on the Intel Xeon Phi. The strategies, especially with respect to memory usage and vectorization, should also be beneficial for general purpose computational fluid dynamics codes.

  6. A University Consortium on Low Temperature Combustion for High Efficiency, Ultra-Low Emission Engines

    Energy Technology Data Exchange (ETDEWEB)

    Assanis, Dennis N. [Univ. of Michigan, Ann Arbor, MI (United States); Atreya, Arvind [Univ. of Michigan, Ann Arbor, MI (United States); Chen, Jyh-Yuan [Univ. of California, Berkeley, CA (United States); Cheng, Wai K. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Dibble, Robert W. [Univ. of California, Berkeley, CA (United States); Edwards, Chris [Stanford Univ., CA (United States); Filipi, Zoran S. [Univ. of Michigan, Ann Arbor, MI (United States); Gerdes, Christian [Stanford Univ., CA (United States); Im, Hong [Univ. of Michigan, Ann Arbor, MI (United States); Lavoie, George A. [Univ. of Michigan, Ann Arbor, MI (United States); Wooldridge, Margaret S. [Univ. of Michigan, Ann Arbor, MI (United States)

    2009-12-31

    The objective of the University consortium was to investigate the fundamental processes that determine the practical boundaries of Low Temperature Combustion (LTC) engines and develop methods to extend those boundaries to improve the fuel economy of these engines, while operating with ultra low emissions. This work involved studies of thermal effects, thermal transients and engine management, internal mixing and stratification, and direct injection strategies for affecting combustion stability. This work also examined spark-assisted Homogenous Charge Compression Ignition (HCCI) and exhaust after-treatment so as to extend the range and maximize the benefit of Homogenous Charge Compression Ignition (HCCI)/ Partially Premixed Compression Ignition (PPCI) operation. In summary the overall goals were; Investigate the fundamental processes that determine the practical boundaries of Low Temperature Combustion (LTC) engines; Develop methods to extend LTC boundaries to improve the fuel economy of HCCI engines fueled on gasoline and alternative blends, while operating with ultra low emissions; and Investigate alternate fuels, ignition and after-treatment for LTC and Partially Premixed compression Ignition (PPCI) engines.

  7. Effect of swirl on the performance and combustion of a biogas fuelled spark ignition engine

    International Nuclear Information System (INIS)

    Porpatham, E.; Ramesh, A.; Nagalingam, B.

    2013-01-01

    Highlights: • Tests were conducted on a biogas fuelled SI engine with normal and masked valve. • Improvement in brake power and brake thermal efficiency with masked valve. • Lean misfire limit is extended with enhanced swirl from 0.68 to 0.65. • Enhanced swirl decreases HC level from1530 ppm to 1340 ppm and increases NO emission from 2250 ppm to 3440 ppm. • The reduction in ignition delay and higher heat release rate with enhanced swirl. - Abstract: The influence of swirl on the performance, emissions and combustion in a constant speed Spark Ignition (SI) engine was studied experimentally. A single cylinder diesel engine was modified to operate as a biogas operated spark ignition engine. The engine was operated at 1500 rpm at throttle opening of 25% and 100% at various equivalence ratios. The tests covered a range of equivalence ratios from rich to lean operating limits and also at an optimum compression ratio of 13:1 with normal and masked intake valve to enhance swirl. The spark timing was set to MBT (Minimum advance for Best Torque). It was found that masked valve configuration enhanced the power output and brake thermal efficiency at full throttle. The lean limit of combustion also got extended. Heat release rates indicated enhanced combustion rates with masked valve, which are mainly responsible for the improvement in thermal efficiency. NO level increased with masked valve as compared to normal configuration. The spark timings were to be retarded by about 6 °CA and 4 °CA when compared to normal configuration at 25% and 100% throttle respectively

  8. Effect of external hot EGR dilution on combustion, performance and particulate emissions of a GDI engine

    International Nuclear Information System (INIS)

    Xie, Fangxi; Hong, Wei; Su, Yan; Zhang, Miaomiao; Jiang, Beiping

    2017-01-01

    Highlights: • Effect of hot EGR on combustion and PN emission is investigated on a GDI engine. • Appropriate addition of hot EGR can reduce fuel consumption, NO_x and PN emission. • Relationship between BSFC and emissions of hot EGR is better than cooled EGR. • Condition with low-medium speeds and medium loads are more suitable for hot EGR. - Abstract: In this paper, an experimental investigation about the influence of hot EGR addition on the engine combustion, performance and particulate number emission was conducted at a spark-ignition gasoline direct injection (GDI) engine. Meanwhile, the different effects between cooled and hot EGR addition methods were compared and the variations of fuel consumption and particle number emissions under six engine operating conditions with different speeds and loads were analyzed. The research result indicated that increasing hot EGR ratio properly with adjustment of ignition timing could effectively improve the relationship among brake-specific fuel consumption (BSFC), NO_x and particle number emissions. When hot EGR ratio increased to 20%, not only BSFC but also the NO_x and particle number emissions were reduced, which were about 7%, 87% and 36% respectively. Compared with cooled EGR, the flame development and propagation speeds were accelerated, and cycle-by-cycle combustion variation decreased with hot EGR. Meanwhile, using hot EGR made the engine realize a better relationship among fuel consumption, NO_x and particle number emissions. The biggest improvements of BSFC, NO_x and particle number emissions were obtained at low-medium speed and medium load engine conditions by hot EGR addition method. While engine speed increased and load decreased, the improvement of engine fuel consumption and emission reduced with hot EGR method.

  9. Combustion Characteristics of C5 Alcohols and a Skeletal Mechanism for Homogeneous Charge Compression Ignition Combustion Simulation

    KAUST Repository

    Park, Sungwoo

    2015-10-27

    C5 alcohols are considered alternative fuels because they emit less greenhouse gases and fewer harmful pollutants. In this study, the combustion characteristics of 2-methylbutanol (2-methyl-1-butanol) and isopentanol (3-methyl-1-butanol) and their mixtures with primary reference fuels (PRFs) were studied using a detailed chemical kinetic model obtained from merging previously published mechanisms. Ignition delay times of the C5 alcohol/air mixtures were compared to PRFs at 20 and 40 atm. Reaction path analyses were conducted at intermediate and high temperatures to identify the most influential reactions controlling ignition of C5 alcohols. The direct relation graph with expert knowledge methodology was used to eliminate unimportant species and reactions in the detailed mechanism, and the resulting skeletal mechanism was tested at various homogeneous charge compression ignition (HCCI) engine combustion conditions. These simulations were used to investigate the heat release characteristics of the methyl-substituted C5 alcohols, and the results show relatively strong reactions at intermediate temperatures prior to hot ignition. C5 alcohol blending in PRF75 in HCCI combustion leads to a significant decrease of low-temperature heat release (LTHR) and a delay of the main combustion. The heat release features demonstrated by C5 alcohols can be used to improve the design and operation of advanced engine technologies.

  10. Combustion Characterization of Bio-derived Fuels and Additives

    DEFF Research Database (Denmark)

    Hashemi, Hamid

    Climate change has become a serious concern nowadays. The main reason is believed to be the high emission of greenhouse gases, namely CO2 which is mainly produced from the combustion of fossil fuels. At the same time, energy demand has increased exponentially while the energy supply mainly depends...... on fossil fuels, especially for transportation. The practical strategy to address such problems in medium term is to increase the efficiency of combustion-propelled energy-production systems, as well as to reduce the net release of CO2 and other harmful pollutants, likely by using nonconventional fuels....... Modern internal combustion engines such as Homogeneous Charge Compression Ignition (HCCI) engines are more efficient and fuel-flexible compared to the conventional engines, making opportunities to reduce the release of greenhouse and other polluting gases to the environment. Combustion temperature...

  11. Performance, emission and combustion analysis of a compression ignition engine using biofuel blends

    Directory of Open Access Journals (Sweden)

    Ors Ilker

    2017-01-01

    Full Text Available This study aimed to investigate the effects on performance, emission, and combustion characteristics of adding biodiesel and bioethanol to diesel fuel. Diesel fuel and blend fuels were tested in a water-cooled compression ignition engine with direct injection. Test results showed that brake specific fuel consumption and volumetric efficiency increased by about 30.6% and 3.7%, respectively, with the addition of bioethanol to binary blend fuels. The results of the blend fuel’s combustion analysis were similar to the diesel fuel’s results. Bioethanol increased maximal in-cylinder pressure compared to biodiesel and diesel fuel at both 1400 rpm and 2800 rpm. Emissions of CO increased by an amount of about 80% for fuels containing a high level of bioethanol when compared to CO emissions for diesel fuel. Using biodiesel, NO emissions increased by an average of 31.3%, HC emissions decreased by an average of 39.25%, and smoke opacity decreased by an average of 6.5% when compared with diesel fuel. In addition, when using bioethanol, NO emissions and smoke opacity decreased by 55% and 17% on average, respectively, and HC emissions increased by an average of 53% compared with diesel fuel.

  12. Spray-combustion synthesis: efficient solution route to high-performance oxide transistors.

    Science.gov (United States)

    Yu, Xinge; Smith, Jeremy; Zhou, Nanjia; Zeng, Li; Guo, Peijun; Xia, Yu; Alvarez, Ana; Aghion, Stefano; Lin, Hui; Yu, Junsheng; Chang, Robert P H; Bedzyk, Michael J; Ferragut, Rafael; Marks, Tobin J; Facchetti, Antonio

    2015-03-17

    Metal-oxide (MO) semiconductors have emerged as enabling materials for next generation thin-film electronics owing to their high carrier mobilities, even in the amorphous state, large-area uniformity, low cost, and optical transparency, which are applicable to flat-panel displays, flexible circuitry, and photovoltaic cells. Impressive progress in solution-processed MO electronics has been achieved using methodologies such as sol gel, deep-UV irradiation, preformed nanostructures, and combustion synthesis. Nevertheless, because of incomplete lattice condensation and film densification, high-quality solution-processed MO films having technologically relevant thicknesses achievable in a single step have yet to be shown. Here, we report a low-temperature, thickness-controlled coating process to create high-performance, solution-processed MO electronics: spray-combustion synthesis (SCS). We also report for the first time, to our knowledge, indium-gallium-zinc-oxide (IGZO) transistors having densification, nanoporosity, electron mobility, trap densities, bias stability, and film transport approaching those of sputtered films and compatible with conventional fabrication (FAB) operations.

  13. In-cylinder diesel spray combustion simulations using parallel computation: A performance benchmarking study

    International Nuclear Information System (INIS)

    Pang, Kar Mun; Ng, Hoon Kiat; Gan, Suyin

    2012-01-01

    Highlights: ► A performance benchmarking exercise is conducted for diesel combustion simulations. ► The reduced chemical mechanism shows its advantages over base and skeletal models. ► High efficiency and great reduction of CPU runtime are achieved through 4-node solver. ► Increasing ISAT memory from 0.1 to 2 GB reduces the CPU runtime by almost 35%. ► Combustion and soot processes are predicted well with minimal computational cost. - Abstract: In the present study, in-cylinder diesel combustion simulation was performed with parallel processing on an Intel Xeon Quad-Core platform to allow both fluid dynamics and chemical kinetics of the surrogate diesel fuel model to be solved simultaneously on multiple processors. Here, Cartesian Z-Coordinate was selected as the most appropriate partitioning algorithm since it computationally bisects the domain such that the dynamic load associated with fuel particle tracking was evenly distributed during parallel computations. Other variables examined included number of compute nodes, chemistry sizes and in situ adaptive tabulation (ISAT) parameters. Based on the performance benchmarking test conducted, parallel configuration of 4-compute node was found to reduce the computational runtime most efficiently whereby a parallel efficiency of up to 75.4% was achieved. The simulation results also indicated that accuracy level was insensitive to the number of partitions or the partitioning algorithms. The effect of reducing the number of species on computational runtime was observed to be more significant than reducing the number of reactions. Besides, the study showed that an increase in the ISAT maximum storage of up to 2 GB reduced the computational runtime by 50%. Also, the ISAT error tolerance of 10 −3 was chosen to strike a balance between results accuracy and computational runtime. The optimised parameters in parallel processing and ISAT, as well as the use of the in-house reduced chemistry model allowed accurate

  14. The energetic performance of a novel hybrid solar thermal and chemical looping combustion plant

    International Nuclear Information System (INIS)

    Jafarian, Mehdi; Arjomandi, Maziar; Nathan, Graham J.

    2014-01-01

    Highlights: • A hybrid solar chemical looping combustion power cycle is reported. • The cycle is studied for two configurations, with and without an after-burner. • The oxygen carrier particles are used as storage medium for solar thermal energy. • Total solar shares of 41.4% and 60% are achieved with and without the after-burner. • Efficiencies of 50% and 44.0% are achieved with and without the after-burner. - Abstract: The overall energetic performance of a gas turbine combined cycle powered by a hybrid cycle between a solar thermal and a chemical looping combustion (CLC) system firing methane is reported for two configurations. In one case, the outlet from the air reactor is fed directly to a gas turbine, while in the other an after-burner, also firing methane, is added to increase the gas turbine inlet temperature. The cycle is simulated using Aspen Plus software for the average diurnal profile of normal irradiance for Port Augusta, South Australia. The first law efficiency, total solar absorption efficiency, average and peak fractional power boosts, total solar share, net solar to electrical efficiency, fraction of pressurised CO 2 , incremental CO 2 avoidance and the exergy efficiency for both cycles are reported. The calculations predict a first law efficiency of 50.0% for the cycle employing an after-burner, compared with 44.0% for that without the after-burner. However, this is achieved at the cost of decreasing the solar share from 60.0%, without the after-burner, to 41.4% with it. Also reported is the sensitivity analysis of performance to variations in key operating parameters. The sensitivity analysis shows that further improvements to the performance of the cycle are possible

  15. Preliminary results on performance testing of a turbocharged rotary combustion engine

    Science.gov (United States)

    Meng, P. R.; Rice, W. J.; Schock, H. J.; Pringle, D. P.

    1982-01-01

    The performance of a turbocharged rotary engine at power levels above 75 kW (100 hp) was studied. A twin rotor turbocharged Mazda engine was tested at speeds of 3000 to 6000 rpm and boost pressures to 7 psi. The NASA developed combustion diagnostic instrumentation was used to quantify indicated and pumping mean effect pressures, peak pressure, and face to face variability on a cycle by cycle basis. Results of this testing showed that a 5900 rpm a 36 percent increase in power was obtained by operating the engine in the turbocharged configuration. When operating with lean carburetor jets at 105 hp (78.3 kW) and 4000 rpm, a brake specific fuel consumption of 0.45 lbm/lb-hr was measured.

  16. Experiential study on temperature and emission performance of micro burner during porous media combustion

    Science.gov (United States)

    Janvekar, Ayub Ahmed; Abdullah, M. Z.; Ahmad, Z. A.; Abas, A.; Ismail, A. K.; Hussien, A. A.; Kataraki, P. S.; Ishak, M. H. H.; Mazlan, M.; Zubair, A. F.

    2018-05-01

    Addition of porous materials in reaction zone give rise to significant improvements in combustion performance. In this work, a dual layered micro porous media burner was tested for stable flame and emissions. Reaction and preheat layer was made up of discrete (zirconia) and foam (porcelain) type of materials respectively. Three different thickness of reaction zone was tested, each with 10, 20 and 30mm. Interestingly, only 20mm thick layer can able to show better thermal efficiency of 72% as compared to 10 and 30mm. Best equivalence ratio came out to be 0.7 for surface and 0.6 for submerged flame conditions. Moreover, emission was continuously monitored to detect presence of NOx and CO, which were under controlled limits.

  17. Ignition delay time correlation of fuel blends based on Livengood-Wu description

    KAUST Repository

    Khaled, Fathi; Badra, Jihad; Farooq, Aamir

    2017-01-01

    observed for combustion phasing in homogeneous charge compression ignition (HCCI) predictions between simulations performed with detailed chemistry and calculations using the developed ignition delay correlation.

  18. Performance, Emissions and Combustion Characteristics of a Single Cylinder Diesel Engine Fuelled with Blends of Jatropha Methyl Ester and Diesel

    Directory of Open Access Journals (Sweden)

    Debasish Padhee

    2014-05-01

    Full Text Available In order to meet the energy requirements, there has been growing interest in alternative fuels like biodiesels, ethyl alcohol, biogas, hydrogen and producer gas to provide a suitable diesel substitute for internal combustion engines. An experimental investigation was performed to study the performance, emissions and combustion characteristics of diesel engine fuelled with blends of Jatropha methyl ester and diesel. In the present work three different fuel blends of Jatropha methyl ester (B10, B20, B40 and B100 were used. The increments in load on the engine increase the brake thermal efficiency, exhaust gas temperature and lowered the brake specific fuel consumption. The biodiesel blends produce lower carbon monoxide & unburned hydrocarbon emission and higher carbon dioxide & oxides of nitrogen than neat diesel fuel. From the results it was observed that the ignition delays decreased with increase in concentration of biodiesel in biodiesel blends with diesel. The combustion characteristics of single-fuel for biodiesel and diesel have similar combustion pressure and HRR patterns at different engine loads but it was observed that the peak cylinder pressure and heat release rate were lower for biodiesel blends compared to those of diesel fuel combustion.

  19. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.; Vedharaj, S.; An, Yanzhao; Dawood, Alaaeldin; Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt

    2017-01-01

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON

  20. Improving lithium-ion battery performances by adding fly ash from coal combustion on cathode film

    Energy Technology Data Exchange (ETDEWEB)

    Dyartanti, Endah Retno; Jumari, Arif, E-mail: arifjumari@yahoo.com; Nur, Adrian; Purwanto, Agus [Research Group of Battery & Advanced Material, Department of Chemical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A Kentingan, Surakarta Indonesia 57126 (Indonesia)

    2016-02-08

    A lithium battery is composed of anode, cathode and a separator. The performance of lithium battery is also influenced by the conductive material of cathode film. In this research, the use of fly ash from coal combustion as conductive enhancer for increasing the performances of lithium battery was investigated. Lithium iron phosphate (LiFePO{sub 4}) was used as the active material of cathode. The dry fly ash passed through 200 mesh screen, LiFePO{sub 4} and acethylene black (AB), polyvinylidene fluoride (PVDF) as a binder and N-methyl-2-pyrrolidone (NMP) as a solvent were mixed to form slurry. The slurry was then coated, dried and hot pressed to obtain the cathode film. The ratio of fly ash and AB were varied at the values of 1%, 2%, 3%, 4% and 5% while the other components were at constant. The anode film was casted with certain thickness and composition. The performance of battery lithium was examined by Eight Channel Battery Analyzer, the composition of the cathode film was examined by XRD (X-Ray Diffraction), and the structure and morphology of the anode film was analyzed by SEM (Scanning Electron Microscope). The composition, structure and morphology of cathode film was only different when fly ash added was 4% of AB or more. The addition of 2% of AB on cathode film gave the best performance of 81.712 mAh/g on charging and 79.412 mAh/g on discharging.

  1. Investigating the effects of LPG on spark ignition engine combustion and performance

    International Nuclear Information System (INIS)

    Bayraktar, Hakan; Durgun, Orhan

    2005-01-01

    A quasi-dimensional spark ignition (SI) engine cycle model is used to predict the cycle, performance and exhaust emissions of an automotive engine for the cases of using gasoline and LPG. Governing equations of the mathematical model mainly consist of first order ordinary differential equations derived for cylinder pressure and temperature. Combustion is simulated as a turbulent flame propagation process and during this process, two different thermodynamic regions consisting of unburned gases and burned gases that are separated by the flame front are considered. A computer code for the cycle model has been prepared to perform numerical calculations over a range of engine speeds and fuel-air equivalence ratios. In the computations performed at different engine speeds, the same fuel-air equivalence ratios are selected for each fuel to make realistic comparisons from the fuel economy and fuel consumption points of view. Comparisons show that if LPG fueled SI engines are operated at the same conditions with those of gasoline fueled SI engines, significant improvements in exhaust emissions can be achieved. However, variations in various engine performance parameters and the effects on the engine structural elements are not promising

  2. Combustion Performance and Exhaust Emission of DI Diesel Engine Using Various Sources of Waste Cooking Oil

    Science.gov (United States)

    Afiq, Mohd; Azuhairi, Mohd; Jazair, Wira

    2010-06-01

    In Malaysia, more than 200-tone of cooking oil are used by domestic users everyday. After frying process, about a quarter of these cooking oil was remained and drained into sewage system. This will pollutes waterways and affects the ecosystem. The use of waste cooking oil (WCO) for producing bio-diesel was considered in economical factor which current production cost of bio-diesel production is higher in Malaysia due to higher price of palm oil. Thus, the aim of this study is to investigate the most suitable source of WCO to become a main source of bio-diesel for bio-diesel production in this country. To perform this research, three type of WCO were obtained from house's kitchen, cafeteria and mamak's restaurant. In this study, prospect of these bio-diesel source was evaluated based on its combustion performance and exhaust emissions operated in diesel engine in the form of waste cooking oil methyl ester (WCOME) and have been compared with pure diesel fuel. A 0.6 liter, single-cylinder, air-cooled direct injection diesel engine was used to perform this experiment. Experiment was done at variable engine loads and constant engine speed. As the result, among three stated WCOMEs, the one collected from house's kitchen gives the best performance in term of brake specific fuel consumption (bsfc) and brake power (BP) with lowest soot emission.

  3. Preparation of porous Al2O3-Ti-C perform by combustion synthesis

    Directory of Open Access Journals (Sweden)

    K.Granat

    2009-04-01

    Full Text Available Using combustion synthesis porous ceramic preforms for composite reinforcing were produced. Prepared mixture of alumina Saffilfibres, Ti powder and graphite flakes, after drying were placed in waveguide of microwave reactor. Supplied with constant power of 540Wmagnetron ignited and maintained reaction in flowing stream of CO2 gas. Al2O3 fibres should improve preliminary endurance of perform,whereas Ti powder processed to hard titanium carbides and oxides. During microwave heating ignited plasma additionally improveprocess and partly fused metallic Ti. Recorded temperature curves were similar for various samples. The highest synthesis temperature revealed samples containing 10% of Al2O3 , 10% of Ti and 5% of graphite, all percentages atomic. Microscopic observation showed considerable microstructure inhomogeneity of some samples. Both irregular component ordering and partly processed Ti particles inside preform exclude them for subsequent infiltration. Chemical analyze EDS of Ti based compounds partly confirmed work purpose, evidencing presence of Ti oxides and carbides. Independently of graphite content these compounds formed folded strips around solid or empty volume. Depends on CO2 availability, reaction could be slowed down resulting in more compacted Ti compounds. Created as a result of combustion synthesis Ti compound after infiltration with liquid metal properly bounded with the matrix. It could be assumed that redox reaction proceeded and on surface of Ti compound alumina and Al-Ti compounds were created. The preforms of proper strength and homogeneous structure were infiltrated with AlSi7Mg by squeeze casting method. In relation to typical composite reinforced only with fibres no significant increase of defects quantity was observed. Preliminary examination of mechanical properties confirmed that assumed work purpose is reasonable.

  4. Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

    Directory of Open Access Journals (Sweden)

    Zheng-gang Xiao

    2014-06-01

    Full Text Available Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN (TEGDN propellants to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

  5. Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

    International Nuclear Information System (INIS)

    Westbrook, C.K.

    2000-01-01

    Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another

  6. Combustion physics

    Science.gov (United States)

    Jones, A. R.

    1985-11-01

    Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

  7. Improving of diesel combustion-pollution-fuel economy and performance by gasoline fumigation

    International Nuclear Information System (INIS)

    Şahin, Zehra; Durgun, Orhan

    2013-01-01

    Highlights: • The effects of gasoline fumigation on the engine performance and NO x emission were investigated in Ford XLD 418 T automotive diesel engine. • Gasoline at approximately (2, 4, 6, 8 10, and 12)% (by vol.) ratios was injected into intake air by a carburetor. • GF enhances effective power and reduces brake specific fuel consumption, cost, and NO x emission. - Abstract: One of the most important objectives of the studies worldwide is to improve combustion of diesel engine to meet growing energy needs and to reduce increasing environmental pollution. To accomplish this goal, especially to reduce pollutant emissions, researchers have focused their interest on the field of alternative fuels and alternative solutions. Gasoline fumigation (GF) is one of these alternative solutions, by which diesel combustion, fuel economy, and engine performance are improved, and environmental pollution is decreased. In the fumigation method, gasoline is injected into intake air, either by a carburetor, which main nozzle section is adjustable or by a simple injection system. In the present experimental study, a simple carburetor was used, and the effects of gasoline fumigation at (2, 4, 6, 8, 10, 12)% (by vol.) gasoline ratios on the combustion, NO x emission, fuel economy, and engine performance sophisticatedly investigated for a fully instrumented, four-cylinder, water-cooled indirect injection (IDI), Ford XLD 418 T automotive diesel engine. Tests were conducted for each of the above gasoline fumigation ratios at three different speeds and for (1/1, 3/4, and 1/2) fuel delivery ratios (FDRs). GF test results showed that NO x emission is lower than that of neat diesel fuel (NDF). NO x emission decreases approximately 4.20%, 2.50%, and 9.65% for (1/1, 3/4, and 1/2) FDRs, respectively. Effective power increases approximately 2.38% for 1/1 FDR. At (2500 and 3000) rpms, effective power decreases at low gasoline ratios, but it increases at high gasoline ratios for 3/4 and 1

  8. Performance of candidate gas turbine abradeable seal materials in high temperature combustion atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Simms, N.J. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Norton, J.F. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Consultant in Corrosion Science and Technology, Hemel Hempstead, Herts HP1 1SR (United Kingdom); McColvin, G. [Siemens Industrial Turbines Ltd., Lincoln, LN5 7FD (United Kingdom)

    2005-11-01

    The development of abradeable gas turbine seals for higher temperature duties has been the target of an EU-funded R and D project, ADSEALS, with the aim of moving towards seals that can withstand surface temperatures as high as {proportional_to} 1100 C for periods of at least 24,000 h. The ADSEALS project has investigated the manufacturing and performance of a number of alternative materials for the traditional honeycomb seal design and novel alternative designs. This paper reports results from two series of exposure tests carried out to evaluate the oxidation performance of the seal structures in combustion gases and under thermal cycling conditions. These investigations formed one part of the evaluation of seal materials that has been carried out within the ADSEALS project. The first series of three tests, carried out for screening purposes, exposed candidate abradeable seal materials to a simulated natural gas combustion environment at temperatures within the range 1050-1150 C in controlled atmosphere furnaces for periods of up to {proportional_to} 2,500 h with fifteen thermal cycles. The samples were thermally cycled to room temperature on a weekly basis to enable the progress of the degradation to be monitored by mass change and visual observation, as well as allowing samples to be exchanged at planned intervals. The honeycombs were manufactured from PM2000 and Haynes 214. The backing plates for the seal constructions were manufactured from Haynes 214. Some seals contained fillers or had been surface treated (e.g. aluminised). The second series of three tests were carried out in a natural gas fired ribbon furnace facility that allowed up to sixty samples of candidate seal structures (including honeycombs, hollow sphere structures and porous ceramics manufactured from an extended range of materials including Aluchrom YHf, PM2Hf, Haynes 230, IN738LC and MarM247) to be exposed simultaneously to a stream of hot combustion gas. In this case the samples were cooled

  9. Real-time, adaptive machine learning for non-stationary, near chaotic gasoline engine combustion time series.

    Science.gov (United States)

    Vaughan, Adam; Bohac, Stanislav V

    2015-10-01

    Fuel efficient Homogeneous Charge Compression Ignition (HCCI) engine combustion timing predictions must contend with non-linear chemistry, non-linear physics, period doubling bifurcation(s), turbulent mixing, model parameters that can drift day-to-day, and air-fuel mixture state information that cannot typically be resolved on a cycle-to-cycle basis, especially during transients. In previous work, an abstract cycle-to-cycle mapping function coupled with ϵ-Support Vector Regression was shown to predict experimentally observed cycle-to-cycle combustion timing over a wide range of engine conditions, despite some of the aforementioned difficulties. The main limitation of the previous approach was that a partially acasual randomly sampled training dataset was used to train proof of concept offline predictions. The objective of this paper is to address this limitation by proposing a new online adaptive Extreme Learning Machine (ELM) extension named Weighted Ring-ELM. This extension enables fully causal combustion timing predictions at randomly chosen engine set points, and is shown to achieve results that are as good as or better than the previous offline method. The broader objective of this approach is to enable a new class of real-time model predictive control strategies for high variability HCCI and, ultimately, to bring HCCI's low engine-out NOx and reduced CO2 emissions to production engines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas

    International Nuclear Information System (INIS)

    Papagiannakis, R.G.; Hountalas, D.T.

    2004-01-01

    Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high autoignition temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions

  11. Thermodynamic performance evaluation of combustion gas turbine cogeneration system with reheat

    International Nuclear Information System (INIS)

    Khaliq, A.; Kaushik, S.C.

    2004-01-01

    This communication presents thermodynamic methodology for the performance evaluation of combustion gas turbine cogeneration system with reheat. The energetic and exergetic efficiencies have been defined. The effects of process steam pressure and pinch point temperature used in the design of heat recovery steam generator, and reheat on energetic and exergetic efficiencies have been investigated. From the results obtained in graphs it is observed that the power to heat ratio increases with an increase in pinch point, but the first-law efficiency and second-law efficiency decreases with an increase in pinch point. The power to heat ratio and second-law efficiency increases significantly with increase in process steam pressure, but the first-law efficiency decreases with the same. Results also show that inclusion of reheat, provide significant improvement in electrical power output, process heat production, fuel-utilization (energetic) efficiency and second-law (exergetic) efficiency. This methodology may be quite useful in the selection and comparison of combined energy production systems from thermodynamic performance point of view

  12. Experimental validation of a kinetic multi-component mechanism in a wide HCCI engine operating range for mixtures of n-heptane, iso-octane and toluene: Influence of EGR parameters

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim [LGPPTS, Ecole Nationale Superieure de Chimie de Paris/ Universite Pierre et Marie Curie (Paris 6), 11, rue de Pierre et Marie Curie, 75231 Paris Cedex 05 (France)

    2008-11-15

    The parameters that are present in exhaust gas recirculation (EGR) are believed to provide an important contribution to control the auto-ignition process of the homogeneous charge compression ignition (HCCI) in an engine. For the investigation of the behaviour of the auto-ignition process, a kinetic multi-component mechanism has been developed in former work, containing 62 reactions and 49 species for mixtures of n-heptane, iso-octane and toluene. This paper presents an experimental validation of this mechanism, comparing the calculated pressure, heat release, ignition delays and CO{sub 2} emissions with experimental data performed on a HCCI engine. The validation is performed in a broad range of EGR parameters by varying the dilution by N{sub 2} and CO{sub 2} from 0 to 46 vol.%, changing the EGR temperature from 30 to 120 C, altering the addition of CO and NO from 0 to 170 ppmv and varying the addition of CH{sub 2}O from 0 to 1400 ppmv. These validations were performed respecting the HCCI conditions for the inlet temperature and the equivalence ratio. The results showed that the mechanism is validated experimentally in dilution ranges going up to 21-30 vol.%, depending on the species of dilution and over the whole range of the EGR temperature. The mechanism is validated over the whole range of CO and CH{sub 2}O addition. As for the addition of NO, the mechanism is validated quantitatively up to 50 ppmv and qualitatively up to 170 ppmv. (author)

  13. Electrochemical Performance of LixMn2-yFeyO4-zClz Synthesized Through In-Situ Glycine Nitrate Combustion

    Science.gov (United States)

    2016-06-13

    Electrochemical Performance of LixMn2-yFeyO4-zClz Synthesized Through In-Situ Glycine Nitrate Combustion Ashley L. Ruth, Paula C. Latorre, and...sites as well as the formation of Mn3+ ions via the Jahn- Teller effect. The use of the glycine nitrate combustion synthesis produces small particles at...advantage of submicron ceramic synthesis, namely the glycine nitrate combustion process (GNP), we propose the capability for in-situ B-site doping

  14. Improved correlations of hydrogen content versus combustion performance related properties of aviation turbine fuels

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, J.M.; Sharma, R.L.; Sagu, M.L.; Tiwari, G.B. (Indian Institute of Petroleum, Dehradun (India))

    1994-01-01

    In recent years the hydrogen content of Aviation Fuels has generated considerable interest. Various investigators have suggested correlation of hydrogen content with combustion related properties of aviation turbine fuel (ATF). A suitable threshold value of hydrogen content 13.8 wt% is being considered as a waiver of specifications such as specific energy, aniline gravity product, smoke point, aromatic content, naphthalenes and luminometer number. In the present paper relationship between the hydrogen content and combustion related properties has been examined and improved correlations of hydrogen content with several combustion related properties have been developed by incorporating a characterization factor in the equations. The supporting threshold value of a hydrogen content of 13.8wt% is verified with 25 data points for waiving of combustion properties such as specific energy, aniline gravity product, smoke point and aromatic content from aviation turbine fuel. 6 refs., 12 figs., 2 tabs.

  15. Experimental investigation on combustion performance of cavity-strut injection of supercritical kerosene in supersonic model combustor

    Science.gov (United States)

    Sun, Ming-bo; Zhong, Zhan; Liang, Jian-han; Wang, Hong-bo

    2016-10-01

    Supersonic combustion with cavity-strut injection of supercritical kerosene in a model scramjet engine was experimentally investigated in Mach 2.92 facility with the stagnation temperatures of approximately 1430 K. Static pressure distribution in the axial direction was determined using pressure transducers installed along the centerline of the model combustor top walls. High speed imaging camera was used to capture flame luminosity and combustion region distribution. Multi-cavities were used to and stabilize the combustion in the supersonic combustor. Intrusive injection by thin struts was used to enhance the fuel-air mixing. Supercritical kerosene at temperatures of approximately 780 K and various pressures was prepared using a heat exchanger driven by the hot gas from a pre-burner and injected at equivalence ratios of approximately 1.0. In the experiments, combustor performances with different strut injection schemes were investigated and compared to direct wall injection scheme based on the measured static pressure distributions, the specific thrust increments and the images obtained by high-speed imaging camera. The experimental results showed that the injection by thin struts could obtain an enhanced mixing in the field but could not acquire a steady flame when mixing field cannot well match cavity separation region. There is no significant difference on performance between different schemes since the unsteady intermittent and oscillating flame leads to no actual combustion efficiency improvement.

  16. Comparisons of Particulate Size Distributions from Multiple Combustion Strategies

    Science.gov (United States)

    Zhang, Yizhou

    In this study, a comparison of particle size distribution (PSD) measurements from eight different combustion strategies was conducted at four different load-speed points. The PSDs were measured using a scanning mobility particle sizer (SMPS) together with a condensation particle counter (CPC). To study the influence of volatile particles, PSD measurements were performed with and without a volatile particle remover (thermodenuder, TD) at both low and high dilution ratios. The common engine platform utilized in the experiment helps to eliminate the influence of background particulate and ensures similarity in dilution conditions. The results show a large number of volatile particles were present under LDR sample conditions for most of the operating conditions. The use of a TD, especially when coupled with HDR, was demonstrated to be effective at removing volatile particles and provided consistent measurements across all combustion strategies. The PSD comparison showed that gasoline premixed combustion strategies such as HCCI and GCI generally have low PSD magnitudes for particle sizes greater than the Particle Measurement Programme (PMP) cutoff diameter (23 nm), and the PSDs were highly nuclei-mode particle dominated. The strategies using diesel as the only fuel (DLTC and CDC) generally showed the highest particle number emissions for particles larger than 23 nm and had accumulation-mode particle dominated PSDs. A consistent correlation between the increase of the direct-injection of diesel fuel and a higher fraction of accumulation-mode particles was observed over all combustion strategies. A DI fuel substitution study and injector nozzle geometry study were conducted to better understand the correlation between PSD shape and DI fueling. It was found that DI fuel properties has a clear impact on PSD behavior for CDC and NG DPI. Fuel with lower density and lower sooting tendency led to a nuclei-mode particle dominated PSD shape. For NG RCCI, accumulation

  17. Evaluation of a combined cycle based on an HCCI (Homogenous Charge Compression Ignition) engine heat recovery employing two organic Rankine cycles

    International Nuclear Information System (INIS)

    Khaljani, M.; Saray, R. Khoshbakhti; Bahlouli, K.

    2016-01-01

    In this work, a combined power cycle which includes a HCCI (Homogenous Charge Compression Ignition) engine and two ORCs (Organic Rankine Cycles) is introduced. In the proposed cycle, the waste heats from the engine cooling water and exhaust gases are utilized to drive the ORCs. A parametric study is conducted to show the effects of decision parameters on the performance and on the total cost rate of cycle. Results of the parametric study reveal that increasing the pinch point temperature difference of evaporator and temperature of the condenser leads to reduction in both exergy efficiency and total cost rate of the bottoming cycle. There is a specific evaporator temperature where exergy efficiency is improved, but the total cost rate of the bottoming cycle is maximized. Also, a multi-objective optimization strategy is performed to achieve the best system design parameters from both thermodynamic and economic aspects. The exergy efficiency and the total cost rate of the system have been considered as objective functions. Optimization results indicate that the exergy efficiency of the cycle increases from 44.96% for the base case to 46.02%. Also, approximately1.3% reduction in the cost criteria is achieved. Results of the multi-objective optimization justify the results obtained through the parametric study and demonstrate that the design parameters of both ORCs have conflict effect on the objective functions. - Highlights: • Two Organic Rankine bottoming cycles are coupled with an HCCI Engine. • Exergetic and Exergo-economic analysis of the bottoming cycle are reported. • The system is optimized using multi-objective genetic algorithm. • Objective functions are exergy efficiency and total cost rate of the system. • The exergy efficiency of the cycle increases from 44.96% to 46.02%.

  18. Off-design performance of a chemical looping combustion (CLC) combined cycle: effects of ambient temperature

    Science.gov (United States)

    Chi, Jinling; Wang, Bo; Zhang, Shijie; Xiao, Yunhan

    2010-02-01

    The present work investigates the influence of ambient temperature on the steady-state off-design thermodynamic performance of a chemical looping combustion (CLC) combined cycle. A sensitivity analysis of the CLC reactor system was conducted, which shows that the parameters that influence the temperatures of the CLC reactors most are the flow rate and temperature of air entering the air reactor. For the ambient temperature variation, three off-design control strategies have been assumed and compared: 1) without any Inlet Guide Vane (IGV) control, 2) IGV control to maintain air reactor temperature and 3) IGV control to maintain constant fuel reactor temperature, aside from fuel flow rate adjusting. Results indicate that, compared with the conventional combined cycle, due to the requirement of pressure balance at outlet of the two CLC reactors, CLC combined cycle shows completely different off-design thermodynamic characteristics regardless of the control strategy adopted. For the first control strategy, temperatures of the two CLC reactors both rise obviously as ambient temperature increases. IGV control adopted by the second and the third strategy has the effect to maintain one of the two reactors' temperatures at design condition when ambient temperature is above design point. Compare with the second strategy, the third would induce more severe decrease of efficiency and output power of the CLC combined cycle.

  19. Study on Combustion Performance of Diesel Engine Fueled by Synthesized Waste Cooking Oil Biodiesel Blends

    Directory of Open Access Journals (Sweden)

    Duraid F. Maki

    2018-02-01

    Full Text Available The waste cooking oil or used cooking oil is the best source of biodiesel synthesizing because it enters into the so-called W2E field whereas not only get rid of the used cooking oils but produce energy from waste fuel. In this study, biodiesel was synthesized from the used cooking oil and specifications are tested. From 1 liter of used cooking oil, 940 ml is gained. The remaining of liter is glycerin and water. Blend of 20% of biodiesel with 80% of net diesel by volume is formed. Blends of 100% diesel and 100% biodiesel are prepared too. The diesel engine combustion performance is studied. Brake thermal efficiency, brake specific fuel consumption, volumetric efficiency, mean effective pressure, and engine outlet temperature. Cylinder pressure variation with crank angle is analyzed. At last not least, the concentrations of hydro carbon and nitrogen pollutants are measured. The results showed significant enhancement in engine power and pollutant gases emitted. There is positive compatible with other critical researches.

  20. Cost effective simulation-based multiobjective optimization in the performance of an internal combustion engine

    Science.gov (United States)

    Aittokoski, Timo; Miettinen, Kaisa

    2008-07-01

    Solving real-life engineering problems can be difficult because they often have multiple conflicting objectives, the objective functions involved are highly nonlinear and they contain multiple local minima. Furthermore, function values are often produced via a time-consuming simulation process. These facts suggest the need for an automated optimization tool that is efficient (in terms of number of objective function evaluations) and capable of solving global and multiobjective optimization problems. In this article, the requirements on a general simulation-based optimization system are discussed and such a system is applied to optimize the performance of a two-stroke combustion engine. In the example of a simulation-based optimization problem, the dimensions and shape of the exhaust pipe of a two-stroke engine are altered, and values of three conflicting objective functions are optimized. These values are derived from power output characteristics of the engine. The optimization approach involves interactive multiobjective optimization and provides a convenient tool to balance between conflicting objectives and to find good solutions.

  1. Numerical simulation of catalysis combustion inside micro free-piston engine

    International Nuclear Information System (INIS)

    Wang, Qian; Zhang, Di; Bai, Jin; He, Zhixia

    2016-01-01

    Highlights: • A modeling study is applied on methane HCCI process of micro power device. • Mathematical formulas are established to predict the combustion characteristics. • Impacts of catalysis on the combustion characteristics are analyzed respectively. • The catalyst can improve the work steadily and reliability of micro power device. - Abstract: In order to investigate the catalytic combustion characteristics concerning homogeneous charge compression ignition (HCCI) in micro power device, numerical simulations with a 3D computation model that coupled motion of free piston and fluid dynamics of methane–air mixture flow were carried out and detailed gas-phase and surface catalytic reaction mechanisms of methane–air mixture were applied to the catalytic reactions model, a series of mathematical formula are established to predict the characteristics of compression ignition condition, impacts of catalysis on temperature, pressure, work capacity and other factors were analyzed respectively. Simulation results reveal that catalytic combustion facilitates the improvement of energy conversion efficiency and extends the ignition limit of methane–air mixture obviously, the ignition timing is brought forward as well, while compression ratio decreases and ignition delay period shrinks significantly. Numerical results demonstrate that the existence of catalytic wall helped to restrain the peak combustion pressure and maximum rate of pressure rise contributing to the steadily and reliability of operation inside micro free-piston power device.

  2. Laser-assisted homogeneous charge ignition in a constant volume combustion chamber

    Science.gov (United States)

    Srivastava, Dhananjay Kumar; Weinrotter, Martin; Kofler, Henrich; Agarwal, Avinash Kumar; Wintner, Ernst

    2009-06-01

    Homogeneous charge compression ignition (HCCI) is a very promising future combustion concept for internal combustion engines. There are several technical difficulties associated with this concept, and precisely controlling the start of auto-ignition is the most prominent of them. In this paper, a novel concept to control the start of auto-ignition is presented. The concept is based on the fact that most HCCI engines are operated with high exhaust gas recirculation (EGR) rates in order to slow-down the fast combustion processes. Recirculated exhaust gas contains combustion products including moisture, which has a relative peak of the absorption coefficient around 3 μm. These water molecules absorb the incident erbium laser radiations ( λ=2.79 μm) and get heated up to expedite ignition. In the present experimental work, auto-ignition conditions are locally attained in an experimental constant volume combustion chamber under simulated EGR conditions. Taking advantage of this feature, the time when the mixture is thought to "auto-ignite" could be adjusted/controlled by the laser pulse width optimisation, followed by its resonant absorption by water molecules present in recirculated exhaust gas.

  3. Experimental validation of concentration profiles in an HCCI engine, modelled by a multi-component kinetic mechanism: Outline for auto-ignition and emission control

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim, E-mail: hatim-machrafi@enscp.f [UPMC Universite Paris 06, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France); Universite de Liege, Thermodynamique des Phenomenes Irreversibles, 17, Allee du Six-Aout, 4000 Liege (Belgium)

    2010-10-15

    In order to contribute to the auto-ignition and emission control for Homogeneous Charge Compression Ignition (HCCI), a kinetic multi-component mechanism, containing 62 reactions and 49 species for mixtures of n-heptane, iso-octane and toluene is validated in this work, comparing for the concentration profiles of the fuel, the total hydrocarbons, O{sub 2}, CO{sub 2}, CO, acetaldehyde and iso-butene. These species are sampled during the combustion and quantified. For these measurements an automotive exhaust analyser, a gas chromatograph, coupled to a mass spectrometer and a flame ionisation detector are used, depending on the species to be measured. The fuel, total hydrocarbons, O{sub 2}, CO{sub 2}, iso-butene and acetaldehyde showed a satisfactory quantitative agreement between the mechanism and the experiments. Both the experiments and the modelling results showed the same formation behaviour of the different species. An example is shown of how such a validated mechanism can provide for a set of information of the behaviour of the auto-ignition process and the emission control as a function of engine parameters.

  4. Experimental validation of concentration profiles in an HCCI engine, modelled by a multi-component kinetic mechanism: Outline for auto-ignition and emission control

    International Nuclear Information System (INIS)

    Machrafi, Hatim

    2010-01-01

    In order to contribute to the auto-ignition and emission control for Homogeneous Charge Compression Ignition (HCCI), a kinetic multi-component mechanism, containing 62 reactions and 49 species for mixtures of n-heptane, iso-octane and toluene is validated in this work, comparing for the concentration profiles of the fuel, the total hydrocarbons, O 2 , CO 2 , CO, acetaldehyde and iso-butene. These species are sampled during the combustion and quantified. For these measurements an automotive exhaust analyser, a gas chromatograph, coupled to a mass spectrometer and a flame ionisation detector are used, depending on the species to be measured. The fuel, total hydrocarbons, O 2 , CO 2 , iso-butene and acetaldehyde showed a satisfactory quantitative agreement between the mechanism and the experiments. Both the experiments and the modelling results showed the same formation behaviour of the different species. An example is shown of how such a validated mechanism can provide for a set of information of the behaviour of the auto-ignition process and the emission control as a function of engine parameters.

  5. Performance and combustion analysis of Mahua biodiesel on a single cylinder compression ignition engine using electronic fuel injection system

    Directory of Open Access Journals (Sweden)

    Gunasekaran Anandkumar

    2016-01-01

    Full Text Available In this investigation, experiment is carried out on a 1500 rpm constant speed single cylinder Diesel engine. The test is carried out with Neat diesel, neat biodiesel, and blend B20. The engine considered was run with electronic fuel injection system supported by common rail direct injection to obtain high atomization and effective air utilization inside the combustion chamber. The performance of the engine in terms of break thermal efficiency and brake specific energy consumption was found and compared. The B20 blend shows 1.11% decrease in break thermal efficiency and 3.35% increase in brake specific energy consumption than diesel. The combustion characteristics found are in-cylinder pressure, rate of pressure rise, and heat release rate and compared for peak pressure load to understand the nature of combustion process. For each fuel test run, the maximum peak pressure is observed at part load condition. The rate of change of pressure and heat release rate of diesel is high compared to pure biodiesel and B20 blend. The diffusion combustion is observed to be predominant in case of B100 than B20 and Neat diesel.

  6. Technical and environmental performance of 10 kW understocker boiler during combustion of biomass and conventional fuels

    Directory of Open Access Journals (Sweden)

    Junga Robert

    2017-01-01

    Full Text Available This paper treats about the impact fuels from biomass wastes and coal combustion on a small boiler operation and the emission of pollutants in this process. Tests were performed in laboratory conditions on a water boiler with retort furnace and the capacity of 10 kW. Fuels from sewage sludge and agriculture wastes (PBZ fuel and a blend of coal with laying hens mature (CLHM were taken into account. The results in emission changes of NOx, CO2, CO and SO2 and operating parameters of the tested boiler during combustion were investigated. The obtained results were compared with corresponding results of flame coal (GFC. Combustion of the PBZ fuel turned out to be a stable process in the tested boiler but the thermal output has decreased in about 30% compared to coal combustion, while CO and NOx emission has increased. Similar effect was observed when 15% of the poultry litter was added to the coal. In this case thermal output has also decreased (in about 20% and increase of CO and NOx emission was observed. As a conclusion, it can be stated that more effective control system with an adaptive air regulation and a modified heat exchanger could be useful in order to achieve the nominal power of the tested boiler.

  7. Technical and environmental performance of 10 kW understocker boiler during combustion of biomass and conventional fuels

    Science.gov (United States)

    Junga, Robert; Wzorek, Małgorzata; Kaszubska, Mirosława

    2017-10-01

    This paper treats about the impact fuels from biomass wastes and coal combustion on a small boiler operation and the emission of pollutants in this process. Tests were performed in laboratory conditions on a water boiler with retort furnace and the capacity of 10 kW. Fuels from sewage sludge and agriculture wastes (PBZ fuel) and a blend of coal with laying hens mature (CLHM) were taken into account. The results in emission changes of NOx, CO2, CO and SO2 and operating parameters of the tested boiler during combustion were investigated. The obtained results were compared with corresponding results of flame coal (GFC). Combustion of the PBZ fuel turned out to be a stable process in the tested boiler but the thermal output has decreased in about 30% compared to coal combustion, while CO and NOx emission has increased. Similar effect was observed when 15% of the poultry litter was added to the coal. In this case thermal output has also decreased (in about 20%) and increase of CO and NOx emission was observed. As a conclusion, it can be stated that more effective control system with an adaptive air regulation and a modified heat exchanger could be useful in order to achieve the nominal power of the tested boiler.

  8. Improved Recovery Boiler Performance Through Control of Combustion, Sulfur, and Alkali Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Larry L.

    2008-06-09

    This project involved the following objectives: 1. Determine black liquor drying and devolatilization elemental and total mass release rates and yields. 2. Develop a public domain physical/chemical kinetic model of black liquor drop combustion, including new information on drying and devolatilization. 3. Determine mechanisms and rates of sulfur scavenging in recover boilers. 4. Develop non-ideal, public-domain thermochemistry models for alkali salts appropriate for recovery boilers 5. Develop data and a one-dimensional model of a char bed in a recovery boiler. 6. Implement all of the above in comprehensive combustion code and validate effects on boiler performance. 7. Perform gasification modeling in support of INEL and commercial customers. The major accomplishments of this project corresponding to these objectives are as follows: 1. Original data for black liquor and biomass data demonstrate dependencies of particle reactions on particle size, liquor type, gas temperature, and gas composition. A comprehensive particle submodel and corresponding data developed during this project predicts particle drying (including both free and chemisorbed moisture), devolatilization, heterogeneous char oxidation, char-smelt reactions, and smelt oxidation. Data and model predictions agree, without adjustment of parameters, within their respective errors. The work performed under these tasks substantially exceeded the original objectives. 2. A separate model for sulfur scavenging and fume formation in a recovery boiler demonstrated strong dependence on both in-boiler mixing and chemistry. In particular, accurate fume particle size predictions, as determined from both laboratory and field measurements, depend on gas mixing effects in the boilers that lead to substantial particle agglomeration. Sulfur scavenging was quantitatively predicted while particle size required one empirical mixing factor to match data. 3. Condensed-phase thermochemistry algorithms were developed for salt

  9. Theoretical modeling of combustion characteristics and performance parameters of biodiesel in DI diesel engine with variable compression ratio

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dawody, Mohamed F.; Bhatti, S.K. [Department of Mechanical Engineering, Andhra University (India)

    2013-07-01

    Increasing of costly and depleting fossil fuels are prompting researchers to use edible as well as non-edible vegetable oils as a promising alternative to petro-diesel fuels. A comprehensive computer code using ''Quick basic'' language was developed for the diesel engine cycle to study the combustion and performance characteristics of a single cylinder, four stroke, direct injection diesel engine with variable compression ratio. The engine operates on diesel fuel and 20% (mass basis) of biodiesel (derived from soybean oil) blended with diesel. Combustion characteristics such as cylinder pressure, heat release fraction, heat transfer and performance characteristics such as brake power; and brake specific fuel consumption (BSFC) were analyzed. On the basis of the first law of thermodynamics the properties at each degree crank angle was calculated. Wiebe function is used to calculate the instantaneous heat release rate. The computed results are validated through the results obtained in the simulation Diesel-rk software.

  10. Combustion characteristics, performance and exhaust emissions of a diesel engine fueled with a waste cooking oil biodiesel mixture

    International Nuclear Information System (INIS)

    Can, Özer

    2014-01-01

    Highlights: • High quality biodiesel fuels can be produced by using different waste cooking oils. • Biodiesel fuel blends (in 5 and 10% vol) can be used without any negative effects. • Effects of biodiesel addition on the combustion and exhaust emissions were investigated. - Abstract: In this study, a mixture of biodiesel fuels produced from two different kinds of waste cooking oils was blended in 5% and 10% with No. 2 diesel fuel. The biodiesel/No. 2 diesel fuel blends were tested in a single-cylinder, direct injection, four-stroke, natural aspirated diesel engine under four different engine loads (BMEP 0.48–0.36–0.24–0.12 MPa) and 2200 rpm engine speed. Despite of the earlier start of injection, the detailed combustion and engine performance results showed that the ignition delay with the biodiesel addition was decreased for the all engine loads with the earlier combustion timings due to higher cetane number of biodiesel fuel. Meanwhile the maximum heat release rate and the in-cylinder pressure rise rate were slightly decreased and the combustion duration was generally increased with the biodiesel addition. However, significant changings were not observed on the maximum in-cylinder pressures. In addition, it was observed that the indicated mean effective pressure values were slightly varied depending on the start of combustion timing and the center of heat release location. It was found that 5% and 10% biodiesel fuel addition resulted in slightly increment on break specific fuel consumption (up to 4%) and reduction on break thermal efficiency (up to 2.8%). The biodiesel additions also increased NO x emissions up to 8.7% and decreased smoke and total hydrocarbon emissions for the all engine loads. Although there were no significant changes on CO emissions at the low and medium engine loads, some reductions were observed at the full engine load. Also, CO 2 emissions were slightly increased for the all engine loads

  11. Investigation of micro burner performance during porous media combustion for surface and submerged flames

    Science.gov (United States)

    Janvekar, Ayub Ahmed; Abdullah, M. Z.; Ahmad, Z. A.; Abas, Aizat; Hussien, Ahmed A.; Kataraki, Pramod S.; Mohamed, Mazlan; Husin, Azmi; Fadzli, Khairil

    2018-05-01

    Porous media combustion is considered to be one of the popular choice due to its tremendous advantages. Such type of combustion liberates not only super stable flame but also maintains emissions parameters below thresholds level. Present study incorporates reaction and preheat layer with discrete and foam type of materials respectively. Burner was made to run in ultra-lean mode. Optimum equivalence ratio was found out to be 0.7 for surface flame, while 0.6 during submerged flame condition. Maximum thermal efficiency was noted to be 81%. Finally, emissions parameters where recorded continuously to measure NOx and CO, which were under global limits.

  12. Experimental studies on the combustion characteristics and performance of a direct injection engine fueled with biodiesel/diesel blends

    International Nuclear Information System (INIS)

    Qi, D.H.; Chen, H.; Geng, L.M.; Bian, Y. ZH.

    2010-01-01

    Biodiesel is an alternative diesel fuel that can be produced from different kinds of vegetable oils. It is an oxygenated, non-toxic, sulphur-free, biodegradable, and renewable fuel and can be used in diesel engines without significant modification. However, the performance, emissions and combustion characteristics will be different for the same biodiesel used in different types of engine. In this study, the biodiesel produced from soybean crude oil was prepared by a method of alkaline-catalyzed transesterification. The effects of biodiesel addition to diesel fuel on the performance, emissions and combustion characteristics of a naturally aspirated DI compression ignition engine were examined. Biodiesel has different properties from diesel fuel. A minor increase in brake specific fuel consumption (BSFC) and decrease in brake thermal efficiency (BTE) for biodiesel and its blends were observed compared with diesel fuel. The significant improvement in reduction of carbon monoxide (CO) and smoke were found for biodiesel and its blends at high engine loads. Hydrocarbon (HC) had no evident variation for all tested fuels. Nitrogen oxides (NOx) were slightly higher for biodiesel and its blends. Biodiesel and its blends exhibited similar combustion stages to diesel fuel. The use of transesterified soybean crude oil can be partially substituted for the diesel fuel at most operating conditions in terms of the performance parameters and emissions without any engine modification.

  13. Combustion, performance, and emission characteristics of low heat rejection engine operating on various biodiesels and vegetable oils

    International Nuclear Information System (INIS)

    Abedin, M.J.; Masjuki, H.H.; Kalam, M.A.; Sanjid, A.; Ashraful, A.M.

    2014-01-01

    Highlights: • Combustion, performance, and emissions of low heat rejection engine are studied. • Comparative assessment is carried out for different fuels and coating materials. • Alternative coating materials are suggested for engine. • Thermal efficiency is increased and fuel consumption is decreased for all fuels. • Exhaust emissions have improved except nitrogen oxides emission. - Abstract: Internal combustion engine with its combustion chamber walls insulated by thermal barrier coating materials is referred to as low heat rejection engine or LHR engine. The main purpose of this concept is to reduce engine coolant heat losses, hence improve engine performance. Most of the researchers have reported that the thermal coating increases thermal efficiency, and reduces exhaust emissions. In contrast to the above expectations, a few researchers reported that almost there was no improvement in thermal efficiency. This manuscript investigates the contradictory results in order to find out the exact scenario. A wide range of coating materials has been studied in order to justify their feasibility of implementation in engine. The influence of coating material, thickness, and technique on engine performance and emissions has been studied critically to accelerate the LHR engine evolution. The objectives of higher thermal efficiency, improved fuel economy, and lower emissions are accomplishable but much more investigations with improved engine modification, and design are required to explore full potentiality of LHR engine

  14. Impacts of a jet's exit flow pattern on mixing and combustion performance

    Energy Technology Data Exchange (ETDEWEB)

    Nathan, G.J.; Mi, J.; Newbold, G.J.R.; Nobes, D.S. [Turbulence, Energy and Combustion Group, School of Mechanical Engineering, The University of Adelaide, South Australia 5005 (Australia); Alwahabi, Z.T. [Turbulence, Energy and Combustion Group, Chemical Engineering, The University of Adelaide, South Australia 5005 (Australia)

    2006-09-15

    The influence of modifying a jet's exit flow pattern on both the near and far-field turbulent mixing processes and on the resulting combustion performance, is explored. This reveals that, in contradiction to some common assumptions, increasing the coherence of large-scale motions can decrease molecular mixing rates, and yet can still be beneficial in some applications. Even relatively minor changes to the exit flow pattern of a non-reacting round jet, through changes to the nozzle profile are found to propagate downstream into the far field, apparently through the underlying turbulent structure. Importantly, while a jet from a smoothly contracting nozzle is found to have higher rates of entrainment, mean spread and mean decay of the scalar field than does a long pipe jet, it has a lower rate of molecular mixing. That is, increased large-scale mixing does not necessarily result in increased fine-scale mixing. A range of devices are reviewed which enhance, or stimulate the large-scale, coherent motions in an emerging jet using acoustic, mechanical or fluidic methods. The available evidence suggests that those methods which induce instantaneously asymmetric flow structure are more effective at increasing the near-field spreading than are those which induce instantaneously axisymmetric flow structure. Only limited data are available of the effects of such near-field changes on the far-field properties. Nevertheless, the available data reveal a clear trend that this near-field flow undergoes a transition to a far-field state whose spread and decay is comparable with that of a steady jet, albeit being indelibly altered by the near-field excitation. It also suggests that 'self-exciting' devices (i.e. that are not externally forced), cause a net reduction in the total entrainment relative to the unexcited jet, due to the losses induced by the device itself. Nevertheless, the changes which they can impart to the flow, such as redistributing the turbulent

  15. Impacts of a jet's exit flow pattern on mixing and combustion performance

    Energy Technology Data Exchange (ETDEWEB)

    Nathan, G J; Mi, J; Newbold, G J.R.; Nobes, D S [Turbulence, Energy and Combustion Group, School of Mechanical Engineering, The University of Adelaide, South Australia 5005 (Australia); Alwahabi, Z T [Turbulence, Energy and Combustion Group, Chemical Engineering, The University of Adelaide, South Australia 5005 (Australia)

    2006-09-15

    The influence of modifying a jet's exit flow pattern on both the near and far-field turbulent mixing processes and on the resulting combustion performance, is explored. This reveals that, in contradiction to some common assumptions, increasing the coherence of large-scale motions can decrease molecular mixing rates, and yet can still be beneficial in some applications. Even relatively minor changes to the exit flow pattern of a non-reacting round jet, through changes to the nozzle profile are found to propagate downstream into the far field, apparently through the underlying turbulent structure. Importantly, while a jet from a smoothly contracting nozzle is found to have higher rates of entrainment, mean spread and mean decay of the scalar field than does a long pipe jet, it has a lower rate of molecular mixing. That is, increased large-scale mixing does not necessarily result in increased fine-scale mixing. A range of devices are reviewed which enhance, or stimulate the large-scale, coherent motions in an emerging jet using acoustic, mechanical or fluidic methods. The available evidence suggests that those methods which induce instantaneously asymmetric flow structure are more effective at increasing the near-field spreading than are those which induce instantaneously axisymmetric flow structure. Only limited data are available of the effects of such near-field changes on the far-field properties. Nevertheless, the available data reveal a clear trend that this near-field flow undergoes a transition to a far-field state whose spread and decay is comparable with that of a steady jet, albeit being indelibly altered by the near-field excitation. It also suggests that 'self-exciting' devices (i.e. that are not externally forced), cause a net reduction in the total entrainment relative to the unexcited jet, due to the losses induced by the device itself. Nevertheless, the changes which they can impart to the flow, such as redistributing the turbulent energy from the

  16. Compositional Effects of Gasoline Fuels on Combustion, Performance and Emissions in Engine

    KAUST Repository

    Ahmed, Ahfaz

    2016-10-17

    Commercial gasoline fuels are complex mixtures of numerous hydrocarbons. Their composition differs significantly owing to several factors, source of crude oil being one of them. Because of such inconsistency in composition, there are multiple gasoline fuel compositions with similar octane ratings. It is of interest to comparatively study such fuels with similar octane ratings and different composition, and thus dissimilar physical and chemical properties. Such an investigation is required to interpret differences in combustion behavior of gasoline fuels that show similar knock characteristics in a cooperative fuel research (CFR) engine, but may behave differently in direct injection spark ignition (DISI) engines or any other engine combustion modes. Two FACE (Fuels for Advanced Combustion Engines) gasolines, FACE F and FACE G with similar Research and Motor Octane Numbers but dissimilar physical properties were studied in a DISI engine under two sets of experimental conditions; the first set involved early fuel injection to allow sufficient time for fuel-air mixing hence permitting operation similar to homogenous DISI engines, while the second set consists of advance of spark timings to attain MBT (maximum brake torque) settings. These experimental conditions are repeated across different load points to observe the effect of increasing temperature and pressure on combustion and emission parameters. The differences in various engine-out parameters are discussed and interpreted in terms of physical and thermodynamic properties of the fuels.

  17. Influence of injection timing on performance, combustion and emission characteristics of Jatropha biodiesel engine

    International Nuclear Information System (INIS)

    Ganapathy, T.; Gakkhar, R.P.; Murugesan, K.

    2011-01-01

    Highlights: → The effect of injection timing, load and speed on BSFC, BTE, peak pressure, HRR, CO, HC, NO and smoke were investigated. → Advanced injection timing caused reduced BSFC, CO, HC, smoke and increased BTE, P max , HRR max and NO for Jatropha biodiesel. → At 15 N m, 1800 rpm and 340 CAD, reduction in BSFC, CO, HC and smoke were 5.1%, 2.5%, 1.2% and 1.5% for Jatropha biodiesel. → Increase in BTE, P max , HRR max and NO at 15 N m, 1800 rpm and 340 CAD were 5.3%, 1.8%, 26% and 20% for Jatropha biodiesel. → Optimal injection timing for Jatropha biodiesel with minimum BSFC, CO, HC, smoke and maximum BTE, P max , HRR is 340 CAD. -- Abstract: The study of effect of injection timing along with engine operating parameters in Jatropha biodiesel engine is important as they significantly affect its performance and emissions. The present paper focuses on the experimental investigation of the influence of injection timing, load torque and engine speed on the performance, combustion and emission characteristics of Jatropha biodiesel engine. For this purpose, the experiments were conducted using full factorial design consisting of (3 3 ) with 27 runs for each fuel, diesel and Jatropha biodiesel. The effect of variation of above three parameters on brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), peak cylinder pressure (P max ), maximum heat release rate (HRR max ), CO, HC, NO emissions and smoke density were investigated. It has been observed that advance in injection timing from factory settings caused reduction in BSFC, CO, HC and smoke levels and increase in BTE, P max , HRR max and NO emission with Jatropha biodiesel operation. However, retarded injection timing caused effects in the other way. At 15 N m load torque, 1800 rpm engine speed and 340 crank angle degree (CAD) injection timing, the percentage reduction in BSFC, CO, HC and smoke levels were 5.1%, 2.5%, 1.2% and 1.5% respectively. Similarly the percentage increase in BTE, P

  18. Influence of cooled exhaust gas recirculation on performance, emissions and combustion characteristics of LPG fuelled lean burn SI engine

    Science.gov (United States)

    Ravi, K.; Pradeep Bhasker, J.; Alexander, Jim; Porpatham, E.

    2017-11-01

    On fuel perspective, Liquefied Petroleum Gas (LPG) provides cleaner emissions and also facilitates lean burn signifying less fuel consumption and emissions. Lean burn technology can attain better efficiencies and lesser combustion temperatures but this temperature is quite sufficient to facilitate formation of nitrogen oxide (NOx). Exhaust Gas Recirculation (EGR) for NOx reduction has been considered allover but extremely little literatures exist on the consequence of EGR on lean burn LPG fuelled spark ignition (SI) engine. The following research is carried out to find the optimal rate of EGR addition to reduce NOx emissions without settling on performance and combustion characteristics. A single cylinder diesel engine is altered to operate as LPG fuelled SI engine at a compression ratio of 10.5:1 and arrangements to provide different ratios of cooled EGR in the intake manifold. Investigations are done to arrive at optimum ratio of the EGR to reduce emissions without compromising on performance. Significant reductions in NOx emissions alongside HC and CO emissions were seen. Higher percentages of EGR further diluted the charge and lead to improper combustion and thus increased hydrocarbon emissions. Cooled EGR reduced the peak in-cylinder temperature which reduced NOx emissions but lead to misfire at lower lean limits.

  19. Experimental investigations of the effect of pilot injection on performance, emissions and combustion characteristics of Karanja biodiesel fuelled CRDI engine

    International Nuclear Information System (INIS)

    Dhar, Atul; Agarwal, Avinash Kumar

    2015-01-01

    Highlights: • Effect of multiple injections on CRDI engine performance, emission and combustion. • Effect of multiple injections, injection pressures and injection timings on biodiesel. • Lower biodiesel blends showed lower BSCO, BSHC but higher BSNOx emissions. • Maximum cylinder pressure at higher FIP was higher at same SOPI and SOMI. • Combustion duration of KOME50 was higher than mineral diesel. - Abstract: Pilot and post injections are being used in modern diesel engines for improving engine performance in addition to meeting stringent emission norms. Biodiesel produced from different feedstocks is gaining global recognition as partial replacement for mineral diesel in compression ignition (CI) engines. In this study, 10%, 20% and 50% Karanja biodiesel blends were used for investigation of pilot injections, injection pressures and injection timings on biodiesel blends. Experiments were carried out in a single cylinder CRDI research engine in multiple injection mode at 500 and 1000 bar fuel injection pressure (FIP) under varying start of pilot injection (SOPI) and start of main injection (SOMI) timings. Brake specific fuel consumption (BSFC) increased with increasing Karanja biodiesel concentration in test fuels however brake thermal efficiency (BTE) of biodiesel blends was slightly higher than mineral diesel. Lower biodiesel blends showed lower brake specific carbon monoxide (BSCO) and brake specific hydrocarbon (BSHC) emissions than mineral diesel. Brake specific nitrogen oxides (BSNOx) emissions from KOME20 and KOME10 were higher than mineral diesel. Combustion duration of KOME50 was also higher than mineral diesel

  20. Research Combustion Laboratory (RCL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Research Combustion Laboratory (RCL) develops aerospace propulsion technology by performing tests on propulsion components and materials. Altitudes up to 137,000...

  1. Performance and Combustion Characteristics Analysis of Multi-Cylinder CI Engine Using Essential Oil Blends

    Directory of Open Access Journals (Sweden)

    S. M. Ashrafur Rahman

    2018-03-01

    Full Text Available Essential oils are derived from not-fatty parts of plants and are mostly used in aromatherapy, as well as cosmetics and perfume production. The essential oils market is growing rapidly due to their claimed health benefits. However, because only therapeutic grade oil is required in the medicinal sector, there is a substantial low-value waste stream of essential oils that can be used in the transportation and agricultural sectors. This study investigated the influence of orange, eucalyptus, and tea tree oil on engine performance and combustion characteristics of a multi-cylinder compression ignition engine. Orange, eucalyptus, and tea tree oil were blended with diesel at 10% by volume. For benchmarking, neat diesel and 10% waste cooking biodiesel-diesel blend were also tested. The selected fuels were used to conduct engine test runs with a constant engine speed (1500 RPM (revolutions per minute at four loads. As the load increased, frictional power losses decreased for all of the fuel samples and thus mechanical efficiency increased. At higher loads (75% and 100%, only orange oil-diesel blends produced comparable power to diesel and waste cooking biodiesel-diesel blends. Fuel consumption (brake and indicated for the essential oil-diesel blends was higher when compared to base diesel and waste cooking biodiesel-diesel blends. Thermal efficiency for the essential oil-diesel blends was comparable to base diesel and waste cooking biodiesel-diesel blends. At higher loads, blow-by was lower for essential oil blends as compared to base diesel and waste cooking biodiesel-diesel blends. At 50% and 100% load, peak pressure was lower for all of the essential oil-diesel blends when compared to base diesel and waste cooking biodiesel-diesel blends. From the heat release rate curve, the essential oil-diesel blends ignition delay times were longer because the oils have lower cetane values. Overall, the low-value streams of these essential oils were found to be

  2. Internal combustion engine report: Spark ignited ICE GenSet optimization and novel concept development

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; Blarigan, P. Van [Sandia National Labs., Livermore, CA (United States)

    1998-08-01

    In this manuscript the authors report on two projects each of which the goal is to produce cost effective hydrogen utilization technologies. These projects are: (1) the development of an electrical generation system using a conventional four-stroke spark-ignited internal combustion engine generator combination (SI-GenSet) optimized for maximum efficiency and minimum emissions, and (2) the development of a novel internal combustion engine concept. The SI-GenSet will be optimized to run on either hydrogen or hydrogen-blends. The novel concept seeks to develop an engine that optimizes the Otto cycle in a free piston configuration while minimizing all emissions. To this end the authors are developing a rapid combustion homogeneous charge compression ignition (HCCI) engine using a linear alternator for both power take-off and engine control. Targeted applications include stationary electrical power generation, stationary shaft power generation, hybrid vehicles, and nearly any other application now being accomplished with internal combustion engines.

  3. Effect of biodiesel on the performance and combustion parameters of a turbocharged compression ignition engine

    International Nuclear Information System (INIS)

    Shah, A.N.; Baluch, A.H.; Chao, H.

    2009-01-01

    Direct injection compression ignition engines have proved to be the best option in heavy duty applications like transportation and power generation ,but rapid depleting sources of conventional fossil fuels, their rising prices and ever increasing environmental issues are the major concerns. Alternative fuels, particularly bio fuels are receiving increasing attention during the last few years. Biodiesel has already been commercialized in the transport sector. In the present work, a turbocharged intercooled and DI diesel engine has been alternatively fuelled with biodiesel and its 20% blend with commercial diesel. The experimental results show that BSFC, maximum combustion pressure and start of injection angle increase; on the other hand BSEC, maximum rate of pressure rise, ignition lag and premixed combustion amount decrease however HRR duration remains almost unaffected in the case of biodiesel as compared to commercial diesel. (author)

  4. Emission performance and combustion efficiency of a conical fluidized-bed combustor firing various biomass fuels

    International Nuclear Information System (INIS)

    Permchart, W.; Kouprianov, V.I.

    2004-01-01

    This paper summarizes the results of an experimental study on combustion of three distinct biomass fuels (sawdust, rice husk and pre-dried sugar cane bagasse) in a single fluidized-bed combustor (FBC) with a conical bed using silica sand as the inert bed material. Temperature, CO, NO and O 2 concentrations along the combustor height as well as in flue (stack) gas were measured in the experimental tests. The effects of fuel properties and operating conditions (load and excess air) on these variables were investigated. Both CO and NO axial profiles were found to have a maximum whose location divides conventionally the combustor volume into formation (lower) and reduction (upper) regions for these pollutants. Based on CO emission and unburned carbon content in fly ash, the combustion efficiency of the conical FBC was quantified for the selected biomass fuels fired under different operating conditions. (Author)

  5. COMBUSTION AND PERFORMANCE CHARACTERISTICS OF A SMALL SPARK IGNITION ENGINE FUELLED WITH HCNG

    OpenAIRE

    A. SONTHALIA; C. RAMESHKUMAR; U. SHARMA; A. PUNGANUR; S. ABBAS

    2015-01-01

    Due to environmental concerns and fossil fuel depletion, large scale researches were carried out involving the use of natural gas in internal combustion engines. Natural gas is a clean burning fuel that is available from large domestic natural reserve. When it is used as a fuel in SI engines, it reduces emissions to meet EURO-III norms with carburettors and EURO-IV norms with manifold injection. Countries like India with fewer natural fossil fuel reserves depend heavily on oil imported fro...

  6. Effect of hydrogen addition on combustion and emissions performance of a gasoline rotary engine at part load and stoichiometric conditions

    International Nuclear Information System (INIS)

    Ji, Changwei; Su, Teng; Wang, Shuofeng; Zhang, Bo; Yu, Menghui; Cong, Xiaoyu

    2016-01-01

    Highlights: • The performance of a H_2-blended gasoline rotary engine was studied. • The p, Bmep, T_m_a_x and η_b increased after H_2 blending. • Both the CA0-10 and CA10-90 were shortened by the H_2 addition. • H_2 addition resulted in the reduced HC, CO and CO_2 emissions. - Abstract: The rotary engines may encounter high fuel consumption and emissions due to its narrow and long combustion chamber design. The low ignition energy and high flame speed of hydrogen may help improve the combustion of rotary engines. In this paper, a gasoline rotary engine equipped with gasoline and hydrogen injectors was developed to investigate the combustion and emissions of hydrogen-blended gasoline rotary engines. The engine was run at 3000 rpm and a manifolds absolute pressure of 37.5 kPa with the stoichiometric excess air ratio. The spark timing was set to be 25°CA before the top dead center. The engine was first fueled with the pure gasoline and then blended with the hydrogen. The hydrogen volume fractions in the intake were gradually increased from 0% to 5.2%. The results showed that the combustion pressure, brake mean effective pressure, cylinder temperature and thermal efficiency were simultaneously increased after the hydrogen blending. The crank angle of peak pressure was advanced with the hydrogen addition. The hydrogen enrichment was effective on reducing flame development and propagation periods. HC emissions were reduced by 44.8% when the hydrogen volume fraction in the intake was raised from 0% to 5.2%, CO and CO_2 emissions were also reduced after the hydrogen blending.

  7. Enhanced RAMAC performance in subdetonative propulsion mode with semi-combustible projectile

    Energy Technology Data Exchange (ETDEWEB)

    Legendre, J.F.; Giraud, M. [French-German Res. Inst., Saint-Louis (France)

    2000-11-01

    Investigations are carried out at ISL to determine the experimental conditions required to accelerate a projectile in the mass range from 1.5 to 2 kg up to a muzzle velocity of 3 km/s while keeping the maximum acceleration below 40,000 g. Therefore, two smooth-bore ram-accelerators denoted RAMAC 30-II and RAMAC 90, in caliber 30 and 90 mm respectively, are being operated in the thermally choked propulsion mode. Different material configurations for the projectile afterbody have been investigated, while keeping an aluminum nose cone. Besides afterbodies made of aluminum or magnesium alloy only, a third configuration is presented relying on a short magnesium part fitted to the base of an aluminum afterbody. This configuration denoted as ''semi-combustible'' is designed so that magnesium particles are steadily injected and burnt-out within the combustion zone at the base, therefore providing an additional heat release and consequently a significantly greater forward thrust. Experimental results achieved in both 30 and 90 mm along a 300-caliber-long ram-section and using up to three different gaseous mixtures are presented. To date, for a given semi-combustible projectile and an injection velocity into the ram-section of 1380 m/s, a maximum muzzle velocity of 2380 m/s has been achieved in RAMAC 30-II and 2180 m/s in RAMAC 90, the initial projectile mass being 69 g and 1608 g respectively. (orig.)

  8. Cylinder pressure, performance parameters, heat release, specific heats ratio and duration of combustion for spark ignition engine

    International Nuclear Information System (INIS)

    Shehata, M.S.

    2010-01-01

    An experimental work were conducted for investigating cylinder pressure, performance parameters, heat release, specific heat ratio and duration of combustion for multi cylinder spark ignition engine (SIE). Ccylinder pressure was measured for gasoline, kerosene and Liquefied Petroleum Gases (LPG) separately as a fuel for SIE. Fast Fourier Transformations (FFT) was used to cylinder pressure data transform from time domain into frequency domain to develop empirical correlation for calculating cylinder pressures at different engine speeds and different fuels. In addition, Inverse Fast Fourier Transformations (IFFT) was used to cylinder pressure reconstruct into time domain. The results gave good agreement between the measured cylinder pressure and the reconstructed cylinder pressure in time domain with different engine speeds and different fuels. The measured cylinder pressure and hydraulic dynamotor were the sours of data for calculating engine performance parameters. First law of thermodynamics and single zone heat release model with temperature dependant specific heat ratio γ(T) were the main tools for calculating heat release and heat transfer to cylinder walls. Third order empirical correlation for calculating γ(T) was one of the main gains of the present study. The correlation gave good agreement with other researchers with wide temperatures range. For kerosene, cylinder pressure is higher than for gasoline and LPG due to high volumetric efficiency where kerosene density (mass/volume ratio) is higher than gasoline and LPG. In addition, kerosene heating value is higher than gasoline that contributes in heat release rate and pressure increases. Duration of combustion for different engine speeds was determined using four different methods: (I) Mass fuel burnt, (II) Entropy change, (III) Temperature dependant specific heat ratio γ(T), and (IV) Logarithmic scale of (P and V). The duration of combustion for kerosene is smaller than for gasoline and LPG due to high

  9. Cylinder pressure, performance parameters, heat release, specific heats ratio and duration of combustion for spark ignition engine

    Energy Technology Data Exchange (ETDEWEB)

    Shehata, M.S. [Mechanical Engineering Technology Department, Higher Institute of Technology, Banha University, 4Zagalol Street, Benha, Galubia 1235 Z (Egypt)

    2010-12-15

    An experimental work were conducted for investigating cylinder pressure, performance parameters, heat release, specific heat ratio and duration of combustion for multi cylinder spark ignition engine (SIE). Ccylinder pressure was measured for gasoline, kerosene and Liquefied Petroleum Gases (LPG) separately as a fuel for SIE. Fast Fourier Transformations (FFT) was used to cylinder pressure data transform from time domain into frequency domain to develop empirical correlation for calculating cylinder pressures at different engine speeds and different fuels. In addition, Inverse Fast Fourier Transformations (IFFT) was used to cylinder pressure reconstruct into time domain. The results gave good agreement between the measured cylinder pressure and the reconstructed cylinder pressure in time domain with different engine speeds and different fuels. The measured cylinder pressure and hydraulic dynamotor were the source of data for calculating engine performance parameters. First law of thermodynamics and single zone heat release model with temperature dependant specific heat ratio {gamma}(T) were the main tools for calculating heat release and heat transfer to cylinder walls. Third order empirical correlation for calculating {gamma}(T) was one of the main gains of the present study. The correlation gave good agreement with other researchers with wide temperatures range. For kerosene, cylinder pressure is higher than for gasoline and LPG due to high volumetric efficiency where kerosene density (mass/volume ratio) is higher than gasoline and LPG. In addition, kerosene heating value is higher than gasoline that contributes in heat release rate and pressure increases. Duration of combustion for different engine speeds was determined using four different methods: (I) Mass fuel burnt, (II) Entropy change, (III) Temperature dependant specific heat ratio {gamma}(T), and (IV) Logarithmic scale of (P and V). The duration of combustion for kerosene is smaller than for gasoline and

  10. Environmental Performance of Hypothetical Canadian Pre-Combustion Carbon Dioxide Capture Processes Using Life-Cycle Techniques

    Directory of Open Access Journals (Sweden)

    Lakkana Piewkhaow

    2016-03-01

    Full Text Available The methodology of life-cycle assessment was applied in order to evaluate the environmental performance of a hypothetical Saskatchewan lignite-fueled Integrated Gasification Combined Cycle (IGCC electricity generation, with and without pre-combustion carbon dioxide (CO2 capture from a full life-cycle perspective. The emphasis here is placed on environmental performance associated with air contaminants of the comparison between IGCC systems (with and without CO2 capture and a competing lignite pulverized coal-fired electricity generating station in order to reveal which technology offers the most positive environmental effects. Moreover, ambient air pollutant modeling was also conducted by using American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD air dispersion modeling to determine the ground-level concentration of pollutants emitted from four different electricity generating stations. This study assumes that all stations are located close to Estevan. The results showed a significant reduction in greenhouse gas (GHG emissions and acidification potential by applying both post-combustion and pre-combustion CO2 capture processes. The GHG emissions were found to have reduced by 27%–86%, and IGCC systems were found to compare favorably to pulverized coal systems. However, in other environmental impact categories, there are multiple environmental trade-offs depending on the capture technology used. In the case of post-combustion capture, it was observed that the environmental impact category of eutrophication potential, summer smog, and ozone depletion increased due to the application of the CO2 capture process and the surface mining coal operation. IGCC systems, on the other hand, showed the same tendency as the conventional coal-fired electricity generation systems, but to a lesser degree. This is because the IGCC system is a cleaner technology that produces lower pollutant emission levels than the electricity

  11. Analysis of the performance, emission and combustion characteristics of a turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends using kernel-based extreme learning machine.

    Science.gov (United States)

    Silitonga, Arridina Susan; Hassan, Masjuki Haji; Ong, Hwai Chyuan; Kusumo, Fitranto

    2017-11-01

    The purpose of this study is to investigate the performance, emission and combustion characteristics of a four-cylinder common-rail turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends. A kernel-based extreme learning machine (KELM) model is developed in this study using MATLAB software in order to predict the performance, combustion and emission characteristics of the engine. To acquire the data for training and testing the KELM model, the engine speed was selected as the input parameter, whereas the performance, exhaust emissions and combustion characteristics were chosen as the output parameters of the KELM model. The performance, emissions and combustion characteristics predicted by the KELM model were validated by comparing the predicted data with the experimental data. The results show that the coefficient of determination of the parameters is within a range of 0.9805-0.9991 for both the KELM model and the experimental data. The mean absolute percentage error is within a range of 0.1259-2.3838. This study shows that KELM modelling is a useful technique in biodiesel production since it facilitates scientists and researchers to predict the performance, exhaust emissions and combustion characteristics of internal combustion engines with high accuracy.

  12. Comparison of catalytic converter performance in internal combustion engine fueled with Ron 95 and Ron 97 gasoline

    Science.gov (United States)

    Leman, A. M.; Rahman, Fakhrurrazi; Jajuli, Afiqah; Feriyanto, Dafit; Zakaria, Supaat

    2017-09-01

    Generating ideal stability between engine performance, fuel consumption and emission is one of the main challenges in the automotive industry. The characteristics of engine combustion and creation of emission might simply change with different types of operating parameters. This study aims in investigating the relationship between two types of fuels on the performance and exhaust emission of internal combustion engine using ceramic and metallic catalytic converters. Experimental tests were performed on Mitsubishi 4G93 engine by applying several ranges of engine speeds to determine the conversion of pollutant gases released by the engine. The obtained results specify that the usage of RON 97 equipped with metallic converters might increase the conversion percentage of 1.31% for CO and 126 ppm of HC gases. The metallic converters can perform higher conversion compared to ceramic because in the high space velocities, metallic has higher surface geometry area and higher amount of transverse Peclet number (Pi). Ceramic converters achieved conversion at 2496 ppm of NOx gas, which is higher than the metallic converter.

  13. Effect of injection timing on combustion and performance of a direct injection diesel engine running on Jatropha methyl ester

    Energy Technology Data Exchange (ETDEWEB)

    Jindal, S. [Mechanical Engineering Department, College of Technology & Engineering, Maharana Pratap University of Agriculture and Technology, Udaipur 313001 (India)

    2011-07-01

    The present study aims at evaluation of effect of injection timing on the combustion, performance and emissions of a small power diesel engine, commonly used for agriculture purpose, running on pure biodiesel, prepared from Jatropha (Jatropha curcas) vegetable oil. The effect of varying injection timing was evaluated in terms of thermal efficiency, specific fuel consumption, power and mean effective pressure, exhaust temperature, cylinder pressure, rate of pressure rise and the heat release rate. It was found that retarding the injection timing by 3 degrees enhances the thermal efficiency by about 8 percent.

  14. Technical and environmental performance of 10 kW understocker boiler during combustion of biomass and conventional fuels

    OpenAIRE

    Junga Robert; Wzorek Małgorzata; Kaszubska Mirosława

    2017-01-01

    This paper treats about the impact fuels from biomass wastes and coal combustion on a small boiler operation and the emission of pollutants in this process. Tests were performed in laboratory conditions on a water boiler with retort furnace and the capacity of 10 kW. Fuels from sewage sludge and agriculture wastes (PBZ fuel) and a blend of coal with laying hens mature (CLHM) were taken into account. The results in emission changes of NOx, CO2, CO and SO2 and operating parameters of the tested...

  15. Environmental performance of the Kvaerner BFB boilers for MSW combustion -- Analysis of gaseous emissions and solid residues

    International Nuclear Information System (INIS)

    Lundberg, M.; Hagman, U.; Andersson, B.A.; Olofsson, J.

    1997-01-01

    Kvaerner Pulping AB (formerly Kvaerner EnviroPower AB) has, due to the stringent demands on emissions performance, developed a state-of-the-art bubbling fluidized bed boiler (BFB) designed for waste fuel firing with very low emissions to the air. A complete evaluation of the environmental performance of the Kvaerner BFB technique for MSW combustion is now possible thanks to a thorough characterization study of the solid residues from the Lidkoeping plant. This paper gives an overall mapping of the emissions performance. Data from the operating plants on solid residue characteristics and leachability, heavy metal and dioxin emissions, nitrogen oxides, carbon monoxide, acid gases, and other emissions to air are presented. Comparisons are made with legislative limits and data from the mass burning technique. It is concluded that the emissions are low compared both with data from traditional mass burn incinerators and with legislative limits in the USA and Europe. Furthermore, the bottom and cyclone ash characteristics are shown not to cause any particular problem from an environmental point of view, and that the leachability is well below the existing legislative limits in Europe and the USA. The results show that fluidized bed combustion of municipal solid waste is a very competitive alternative to the traditional mass burning technique in every respect

  16. Optical Engines as Representative Tools in the Development of New Combustion Engine Concepts Moteurs transparents comme outils représentatifs dans le développement de nouveaux concepts des moteurs à combustion interne

    Directory of Open Access Journals (Sweden)

    Kashdan J.

    2011-11-01

    Full Text Available Single cylinder optical engines are used for Internal Combustion (IC engine research as they allow for the application of qualitative and quantitative non-intrusive, diagnostic techniques to study in-cylinder flow, mixing, combustion and emissions phenomena. Such experimental data is not only important for the validation of computational models but can also provide a detailed insight into the physical processes occurring in-cylinder which is useful for the further development of new combustion strategies such as gasoline Homogeneous Charge Compression Ignition (HCCI and Diesel Low Temperature Combustion (LTC. In this context, it is therefore important to ensure that the performance of optical engines is comparable to standard all-metal engines. A comparison of optical and all-metal engine combustion and emissions performance was performed within the present study. The objective was to investigate the principal differences between optical and all-metal engines and understand how these differences ultimately affect mixing, combustion and emissions formation processes. Experimental results reveal the significant impact of differences in combustion chamber wall temperatures between optical and standard engine piston bowls on combustion phasing and engine-out emissions. Quantitative measurements of piston wall temperatures using a laser-induced phosphorescence technique were performed which allowed the subsequent definition of appropriate engine operating strategies so as to compensate for differences in heat transfer properties. Furthermore, differences in combustion chamber geometry were also studied. Geometrical differences can arise as a result of dynamic (compressive/tensile and thermal loading of the extended piston-liner assembly on the optical engine, potentially leading to changes in the effective Compression Ratio. In addition, intake charge dilution in optical engines is often achieved via the use of simulated Exhaust Gas Recirculation

  17. INVESTIGATION OF COMBUSTION, PERFORMANCE AND EMISSION CHARACTERISTICS OF SPARK IGNITION ENGINE FUELLED WITH BUTHANOL – GASOLINE MIXTURE AND A HYDROGEN ENRICHED AIR

    OpenAIRE

    Alfredas Rimkus; Mindaugas Melaika; Jonas Matijošius; Šarūnas Mikaliūnas; Saugirdas Pukalskas

    2016-01-01

    In this study, spark ignition engine fuelled with buthanol-gasoline mixture and a hydrogen-enriched air was investigated. Engine performance, emissions and combustion characteristics were investigated with different buthanol (10% and 20% by volume) gasoline mixtures and additionally supplied oxygen and hydrogen (HHO) gas mixture (3.6 l/min) in the sucked air. Hydrogen, which is in the HHO gas, improves gasoline and gasoline-buthanol mixture combustion, increases indicated pressure during comb...

  18. Performance of calcium manganate as oxygen carrier in chemical looping combustion of biochar in a 10 kW pilot

    International Nuclear Information System (INIS)

    Schmitz, Matthias; Linderholm, Carl Johan

    2016-01-01

    Highlights: • A manganese-based perovskite material was used as oxygen carrier in chemical looping combustion. • The oxygen carrier’s performance was superior to materials previously tested in this reactor throughout the testing period. • Under stable conditions, oxygen demand was as low as 2.1% with a carbon capture efficiency of up to 98%. • No signs of agglomeration were detected. • Gaseous oxygen was released at all relevant fuel reactor temperatures. - Abstract: Chemical looping combustion (CLC) and chemical looping with oxygen uncoupling (CLOU) are carbon capture technologies which achieve gas separation by means of cycling oxidation and reduction of a solid oxygen carrier. In this study, the performance and CLOU properties of an oxygen carrier with perovskite structure, CaMn_0_._9Mg_0_._1O_3_−_δ_, were investigated in a 10 kW pilot. The fuel consisted of biochar with very low sulphur content. Around 37 h of operation with fuel were carried out in the 10 kW chemical looping combustor. Previous operational experience in this unit has been achieved using different natural minerals as oxygen carrier – mainly ilmenite and manganese ore. Parametric studies performed in this work included variation of fuel flow, solids circulation rate, temperature and fluidization gas in the fuel reactor. The oxygen carrier was exposed to a total 73 h of hot fluidization (T > 600 °C). No hard particle agglomerations were formed during the experiments. An oxygen demand as low as 2.1% could be reached under stable operating conditions, with a carbon capture efficiency of up to 98%. CLOU properties were observed at all fuel reactor temperatures, ensuring stable operation even without steam as gasification agent present in the fuel reactor. The results suggest that CaMn_0_._9Mg_0_._1O_3_−_δ is suitable for the use as oxygen carrier in chemical looping combustion of solid biochar and offers higher gas conversion than previously tested materials without CLOU

  19. Performance and optimization of a combustion interface for isotope ratio monitoring gas chromatography/mass spectrometry

    Science.gov (United States)

    Merritt, D. A.; Freeman, K. H.; Ricci, M. P.; Studley, S. A.; Hayes, J. M.

    1995-01-01

    Conditions and systems for on-line combustion of effluents from capillary gas chromatographic columns and for removal of water vapor from product streams were tested. Organic carbon in gas chromatographic peaks 15 s wide and containing up to 30 nanomoles of carbon was quantitatively converted to CO2 by tubular combustion reactors, 200 x 0.5 mm, packed with CuO or NiO. No auxiliary source of O2 was required because oxygen was supplied by metal oxides. Spontaneous degradation of CuO limited the life of CuO reactors at T > 850 degrees C. Since NiO does not spontaneously degrade, its use might be favored, but Ni-bound carbon phases form and lead to inaccurate isotopic results at T Water must be removed from the gas stream transmitted to the mass spectrometer or else protonation of CO2 will lead to inaccuracy in isotopic analyses. Although thresholds for this effect vary between mass spectrometers, differential permeation of H2O through Nafion tubing was effective in both cases tested, but the required length of the Nafion membrane was 4 times greater for the more sensitive mass spectrometer.

  20. A life cycle assessment of environmental performances of two combustion- and gasification-based waste-to-energy technologies.

    Science.gov (United States)

    Arena, Umberto; Ardolino, Filomena; Di Gregorio, Fabrizio

    2015-07-01

    An attributional life cycle analysis (LCA) was developed to compare the environmental performances of two waste-to-energy (WtE) units, which utilize the predominant technologies among those available for combustion and gasification processes: a moving grate combustor and a vertical shaft gasifier coupled with direct melting. The two units were assumed to be fed with the same unsorted residual municipal waste, having a composition estimated as a European average. Data from several plants in operation were processed by means of mass and energy balances, and on the basis of the flows and stocks of materials and elements inside and throughout the two units, as provided by a specific substance flow analysis. The potential life cycle environmental impacts related to the operations of the two WtE units were estimated by means of the Impact 2002+ methodology. They indicate that both the technologies have sustainable environmental performances, but those of the moving grate combustion unit are better for most of the selected impact categories. The analysis of the contributions from all the stages of each specific technology suggests where improvements in technological solutions and management criteria should be focused to obtain further and remarkable environmental improvements. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Influence of Antioxidant Addition in Jatropha Biodiesel on the Performance, Combustion and Emission Characteristics of a DI Diesel Engine

    Science.gov (United States)

    Arockiasamy, Prabu; Ramachandran Bhagavathiammal, Anand

    2018-04-01

    An experimental investigation is conducted on a single-cylinder DI diesel engine, to evaluate the performance, combustion and emission characteristics of Jatropha biodiesel with the addition of antioxidants namely, Succinimide (C4H5NO2), N,N-Dimethyl p-phenylenediamine dihydrochloride (C8H14Cl2N2) and N-Phenyl- p-phenylenediamine (C6H5NHC6H4NH2) at 500, 1000 and 2000 ppm. The performance, combustion and emission characteristic tests are conducted at a constant speed of 1500 rpm, injection pressure of 215 bar, injection timing of 26° before top dead centre for the nine test fuels and the experimental results are compared with neat diesel and neat biodiesel as base fuels. The experimental results show that the addition of antioxidant in biodiesel suppresses the NO emission by quenching the OH radicals that are produced by the reaction of hydrocarbon radicals with molecular nitrogen. The maximum percentage reduction of NO emission by 5, 6 and 7% are observed for N-Phenyl- p-phenylenediamine, N,N-Dimethyl p-phenylenediamine dihydrochloride and Succinimide blended test fuels at 2000 ppm antioxidant addition with biodiesel.

  2. Determination of performance and combustion characteristics of a diesel engine fueled with canola and waste palm oil methyl esters

    Energy Technology Data Exchange (ETDEWEB)

    Ozsezen, Ahmet Necati [Department of Automotive Engineering Technology, Kocaeli University, 41380 Izmit (Turkey); Alternative Fuels R and D Center, Kocaeli University, 41040 Izmit (Turkey); Canakci, Mustafa, E-mail: canakci@kocaeli.edu.t [Department of Automotive Engineering Technology, Kocaeli University, 41380 Izmit (Turkey); Alternative Fuels R and D Center, Kocaeli University, 41040 Izmit (Turkey)

    2011-01-15

    In this study, the performance, combustion and injection characteristics of a direct injection diesel engine have been investigated experimentally when it was fueled with canola oil methyl ester (COME) and waste (frying) palm oil methyl ester (WPOME). In order to determine the performance and combustion characteristics, the experiments were conducted at constant engine speeds under the full load condition of the engine. The results indicated that when the test engine was fueled with WPOME or COME instead of petroleum based diesel fuel (PBDF), the brake power reduced by 4-5%, while the brake specific fuel consumption increased by 9-10%. On the other hand, methyl esters caused reductions in carbon monoxide (CO) by 59-67%, in unburned hydrocarbon (HC) by 17-26%, in carbon dioxide (CO{sub 2}) by 5-8%, and smoke opacity by 56-63%. However, both methyl esters produced more nitrogen oxides (NO{sub x}) emissions by 11-22% compared with those of the PBDF over the speed range.

  3. Determination of performance and combustion characteristics of a diesel engine fueled with canola and waste palm oil methyl esters

    International Nuclear Information System (INIS)

    Ozsezen, Ahmet Necati; Canakci, Mustafa

    2011-01-01

    In this study, the performance, combustion and injection characteristics of a direct injection diesel engine have been investigated experimentally when it was fueled with canola oil methyl ester (COME) and waste (frying) palm oil methyl ester (WPOME). In order to determine the performance and combustion characteristics, the experiments were conducted at constant engine speeds under the full load condition of the engine. The results indicated that when the test engine was fueled with WPOME or COME instead of petroleum based diesel fuel (PBDF), the brake power reduced by 4-5%, while the brake specific fuel consumption increased by 9-10%. On the other hand, methyl esters caused reductions in carbon monoxide (CO) by 59-67%, in unburned hydrocarbon (HC) by 17-26%, in carbon dioxide (CO 2 ) by 5-8%, and smoke opacity by 56-63%. However, both methyl esters produced more nitrogen oxides (NO x ) emissions by 11-22% compared with those of the PBDF over the speed range.

  4. Combustion, performance and emissions of a diesel power generator fueled with biodiesel-kerosene and biodiesel-kerosene-diesel blends

    International Nuclear Information System (INIS)

    Bayındır, Hasan; Işık, Mehmet Zerrakki; Argunhan, Zeki; Yücel, Halit Lütfü; Aydın, Hüseyin

    2017-01-01

    High percentages of biodiesel blends or neat biodiesel cannot be used in diesel engines due to high density and viscosity, and poor atomization properties that lead to some engine operational problems. Biodiesel was produced from canola oil by transesterification process. Test fuels were prepared by blending 80% of the biodiesel with 20% of kerosene (B80&K20) and 80% of the biodiesel with 10% of kerosene and 10% diesel fuel (B80&K10&D10). Fuels were used in a 4 cylinders diesel engine that was loaded with a generator. Combustion, performance and emission characteristics of the blend fuels and D2 in the diesel engine for certain loads of 3.6, 7.2 and 10.8 kW output power and 1500 rpm constant engine speed were experimented and deeply analyzed. It was found that kerosene contained blends had quite similar combustion characteristics with those of D2. Mass fuel consumption and Bscf were slightly increased for blend fuels. HC emissions slightly increased while NOx emissions considerably reduced for blends. It was resulted that high percentages of biodiesel can be a potential substitute for diesel fuel provided that it is used as blending fuel with certain amounts of kerosene. - Highlights: • Effects of kerosene and diesel addition to biodiesel in a diesel engine were investigated. • B80&K10 and B80&K10&D10 were tested and comparisons have been made with D2. • Similar fuel properties and combustion parameters have been found for all fuels. • Heat release initiated earlier for B80&K10 and B80&K10&D10. • CO and NOx emissions are lowered for B80&K10 and B80&K10&D10.

  5. EXPERIMENTAL STUDY OF HOMOGENEOUS MIXTURE COMPRESSION IGNITION IN INTERNAL COMBUSTION ENGINES

    OpenAIRE

    ANTHONY OSWALDO ROQUE CCACYA

    2010-01-01

    Com o intuito de reduzir as emissões e melhorar a combustão em uma maior faixa de rotação e carga de um motor, foi proposto o estudo da combustão por compressão de misturas homogêneas (HCCI), este processo apresenta altas eficiências e baixas emissões, principalmente de NOx e fuligem. Assim, o objetivo do presente trabalho é a determinação das faixas de operação estável em um motor diesel, de alta taxa de compressão (20:1). O combustível utilizado foi gasolina tipo A, tendo em vista a sua gra...

  6. PERFORMANCE, EMISSION, AND COMBUSTION CHARACTERISTICS OF A CI ENGINE USING LIQUID PETROLEUM GAS AND NEEM OIL IN DUAL FUEL MODE

    Directory of Open Access Journals (Sweden)

    Palanimuthu Vijayabalan

    2010-01-01

    Full Text Available Increased environmental awareness and depletion of resources are driving the industries to develop viable alternative fuels like vegetable oils, compresed natural gas, liquid petroleum gas, producer gas, and biogas in order to provide suitable substitute to diesel for compression ignition engine. In this investigation, a single cylinder, vertical, air-cooled diesel engine was modified to use liquid petroleum gas in dual fuel mode. The liquefied petroleum gas, was mixed with air and supplied through intake manifold. The liquid fuel neem oil or diesel was injected into the combustion chamber. The performance, emission, and combustion characteristics were studied and compared for neat fuel and dual fuel mode. The experimental results on dual fuel engine show a reduction in oxides of nitrogen up to 70% of the rated power and smoke in the entire power range. However the brake thermal efficiency was found decreased in low power range due to lower calorific value of liquid petroleum gas, and increase in higher power range due to the complete burning of liquid petroleum gas. Hydrocarbon and carbon monoxide emissions were increased significantly at lower power range and marginal variation in higher power range.

  7. Influence of distillation on performance, emission, and combustion of a DI diesel engine, using tyre pyrolysis oil diesel blends

    Directory of Open Access Journals (Sweden)

    Murugan Sivalingam

    2008-01-01

    Full Text Available Conversion of waste to energy is one of the recent trends in minimizing not only the waste disposal but also could be used as an alternate fuel for internal combustion engines. Fuels like wood pyrolysis oil, rubber pyrolysis oil are also derived through waste to energy conversion method. Early investigations report that tyre pyrolysis oil derived from vacuum pyrolysis method seemed to possess properties similar to diesel fuel. In the present work, the crude tyre pyrolisis oil was desulphurised and distilled to improve the properties and studied the use of it. Experimental studies were conducted on a single cylinder four-stroke air cooled engine fuelled with two different blends, 30% tyre pyrolysis oil and 70% diesel fuel (TPO 30 and 30% distilled tyre pyrolysis oil and 70% diesel fuel (DTPO 30. The results of the performance, emission and combustion characteristics of the engine indicated that NOx is reduced by about 8% compared to tire pyrolysis oil and by about 10% compared to diesel fuel. Hydrocarbon emission is reduced by about 2% compared to TPO 30 operation. Smoke increased for DTPO 30 compared to TPO 30 and diesel fuel.

  8. INVESTIGATION OF COMBUSTION, PERFORMANCE AND EMISSION CHARACTERISTICS OF SPARK IGNITION ENGINE FUELLED WITH BUTHANOL – GASOLINE MIXTURE AND A HYDROGEN ENRICHED AIR

    Directory of Open Access Journals (Sweden)

    Alfredas Rimkus

    2016-09-01

    Full Text Available In this study, spark ignition engine fuelled with buthanol-gasoline mixture and a hydrogen-enriched air was investigated. Engine performance, emissions and combustion characteristics were investigated with different buthanol (10% and 20% by volume gasoline mixtures and additionally supplied oxygen and hydrogen (HHO gas mixture (3.6 l/min in the sucked air. Hydrogen, which is in the HHO gas, improves gasoline and gasoline-buthanol mixture combustion, increases indicated pressure during combustion phase and decreases effective specific fuel consumption. Buthanol addition decreases the rate of heat release, the combustion temperature and pressure are lower which have an influence on lower nitrous oxide (NOx emission in exhaust gases. Buthanol lowers hydrocarbon (HC formation, but it increases carbon monoxide (CO concentration and fuel consumption. Combustion process analysis was carried out using AVL BOOST software. Experimental research and combustion process numerical simulation showed that using balanced buthanol and hydrogen addition, optimal efficient and ecological parameters could be achieved when engine is working with optimal spark timing, as it would work on gasoline fuel.

  9. Laboratory evaluation of the particle size effect on the performance of an elastomeric half-mask respirator against ultrafine combustion particles.

    Science.gov (United States)

    He, Xinjian; Grinshpun, Sergey A; Reponen, Tiina; Yermakov, Michael; McKay, Roy; Haruta, Hiroki; Kimura, Kazushi

    2013-08-01

    This study quantified the particle size effect on the performance of elastomeric half-mask respirators, which are widely used by firefighters and first responders exposed to combustion aerosols. One type of elastomeric half-mask respirator equipped with two P-100 filters was donned on a breathing manikin while challenged with three combustion aerosols (originated by burning wood, paper, and plastic). Testing was conducted with respirators that were fully sealed, partially sealed (nose area only), or unsealed to the face of a breathing manikin to simulate different faceseal leakages. Three cyclic flows with mean inspiratory flow (MIF) rates of 30, 85, and 135 L/min were tested for each combination of sealing condition and combustion material. Additional testing was performed with plastic combustion particles at other cyclic and constant flows. Particle penetration was determined by measuring particle number concentrations inside and outside the respirator with size ranges from 20 to 200 nm. Breathing flow rate, particle size, and combustion material all had significant effects on the performance of the respirator. For the partially sealed and unsealed respirators, the penetration through the faceseal leakage reached maximum at particle sizes >100 nm when challenged with plastic aerosol, whereas no clear peaks were observed for wood and paper aerosols. The particles aerosolized by burning plastic penetrated more readily into the unsealed half-mask than those aerosolized by the combustion of wood and paper. The difference may be attributed to the fact that plastic combustion particles differ from wood and paper particles by physical characteristics such as charge, shape, and density. For the partially sealed respirator, the highest penetration values were obtained at MIF = 85 L/min. The unsealed respirator had approximately 10-fold greater penetration than the one partially sealed around the bridge of the nose, which indicates that the nose area was the primary leak

  10. Effect of using hydrogen in the power and performance of an internal combustion engine

    Directory of Open Access Journals (Sweden)

    Edwin Tamayo

    2016-12-01

    Full Text Available This study analyzed the real working parameters of an Otto cycle internal combustion engine, using as fuel hydrogen plus gasoline. Two stoichiometric equations were determined. In the first equation, the reagents are octane and air, in the second equation was added the quantity of 3.86 H2 moles obtained from a hydrogen cell. Two sets of equations, for consumption and power, were determined from the chemical equations, working at the conditions of Quito: altitude 2850 msnm, 72.794 kPa of atmospheric pressure and 300 K of temperature. A single cylinder engine powered with hydrogen plus gasoline was used for getting real data of engine power, using mixtures of air-gasoline and hydrogen; the theoretical power without H2 was 3.91 HP and with H2 5.41 HP, it increased 27.1%, the real power is 3.78 HP without H2 and 4.66 HP with H2, it increased 16.7%. Theoretical fuel consumption is 401.61 g/kWh and addition of H2 is less to 373.52 g/kWh, the actual consumption that indicates the manufacturer is 395 g/kWh.

  11. Effectiveness of oxygen enriched hydrogen-HHO gas addition on DI diesel engine performance, emission and combustion characteristics

    Directory of Open Access Journals (Sweden)

    Premkartikkumar S.R.

    2014-01-01

    Full Text Available Nowadays, more researches focus on protecting the environment. Present investigation concern with the effectiveness of Oxygen Enriched hydrogen- HHO gas addition on performance, emission and combustion characteristics of a DI diesel engine. Here the Oxygen Enriched hydrogen-HHO gas was produced by the process of water electrolysis. When potential difference is applied across the anode and cathode electrodes of the electrolyzer, water is transmuted into Oxygen Enriched hydrogen-HHO gas. The produced gas was aspirated into the cylinder along with intake air at the flow rates of 1 lpm and 3.3 lpm. The results show that when Oxygen Enriched hydrogen-HHO gas was inducted, the brake thermal efficiency of the engine increased by 11.06%, Carbon monoxide decreased by 15.38%, Unburned hydrocarbon decreased by 18.18%, Carbon dioxide increased by 6.06%, however, the NOX emission increased by 11.19%.

  12. Influence of the combustion chamber during the transient performance of gas turbines; Influencias da camara de combustao durante o transitorio de turbinas a gas

    Energy Technology Data Exchange (ETDEWEB)

    Cunha Alves, M.A. da [Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP (Brazil). Inst. de Pesquisas e Desenvolvimento

    1991-12-31

    It has been realised that heat transfer and others secondary effects have an important influence on the transient performance of a gas turbine, but until very recently, modelling was carried out either assuming adiabatic conditions, or using expedient but unrealistic models to simulate these effects. This work describes the effects of combustion chamber heat storage and of dead time lag of the combustion process, during a gas turbine transient. These effects have been investigated and the analysis has indicated that these effects do not play an important role in the transient performance of the engine analysed, but in certain circumstances they may become important. (author). 5 refs., 4 figs.

  13. Influence of low-temperature combustion and dimethyl ether-diesel blends on performance, combustion, and emission characteristics of common rail diesel engine: a CFD study.

    Science.gov (United States)

    Lamani, Venkatesh Tavareppa; Yadav, Ajay Kumar; Narayanappa, Kumar Gottekere

    2017-06-01

    Due to presence of more oxygen, absence of carbon-carbon (C-C) bond in chemical structure, and high cetane number of dimethyl ether (DME), pollution from DME operated engine is less compared to diesel engine. Hence, the DME can be a promising alternative fuel for diesel engine. The present study emphasizes the effect of various exhaust gas recirculation (EGR) rates (0-20%) and DME/Diesel blends (0-20%) on combustion characteristics and exhaust emissions of common rail direct injection (CRDI) engine using three-dimensional computational fluid dynamics (CFD) simulation. Extended coherent flame model-3 zone (ECFM-3Z) is implemented to carry out combustion analysis, and k-ξ-f model is employed for turbulence modeling. Results show that in-cylinder pressure marginally decreases with employing EGR compared to without EGR case. As EGR rate increases, nitrogen oxide (NO) formation decreases, whereas soot increases marginally. Due to better combustion characteristics of DME, indicated thermal efficiency (ITE) increases with the increases in DME/diesel blend ratio. Adverse effect of EGR on efficiency for blends is less compared to neat diesel, because the anoxygenated region created due to EGR is compensated by extra oxygen present in DME. The trade-off among NO, soot, carbon monoxide (CO) formation, and efficiency is studied by normalizing the parameters. Optimum operating condition is found at 10% EGR rate and 20% DME/diesel blend. The maximum indicated thermal efficiency was observed for DME/diesel ratio of 20% in the present range of study. Obtained results are validated with published experimental data and found good agreement.

  14. STUDIES AND EXPERIMENTAL RESEARCH CONCERNING THE PERFORMANCES OF THE INTERNAL COMBUSTION ENGINE, CONTROLLED OVER THE POWERTRAIN CONTROL MODULE

    Directory of Open Access Journals (Sweden)

    Narcis URICANU

    2012-05-01

    Full Text Available the paper present how can be controlled a road vehicle through a powertrain control module, a type of ECU, programmable ECU (Electronic Control Unit, when we want to increase the performances of the engine, compared with the standard performances of the engine. The programmable ECU is a control system which replaces the ECU from the vehicle and is able to manage, better than the standard ECU, the behaviour of the spark ignition engine on increasing the performances. Sports cars need to obtain the best performances from them engine, the specific regimes at which them must function impose certain limits which will be achieved during the competition. Nowadays the vehicles designers and engineering, working for the production cars, have adopted many solutions from the race cars area, due to the advantage offered by these elements (lightweight materials, fasts responses, high speeds and system like programmable ECU. To obtain more power on the engine, we have to find and applied the best solution concerning the internal combustion processes and the consequences concerning the exhaust. This papers present who can be increased the performances of the spark ignition engine through the air-flow ratio, controlled by the programmable ECU and with the sensors help, like water temperature sensor, intake air temperature sensor, throttle position sensor, lambda sensor

  15. <研究論文>DME燃料による予混合圧縮自己着火機関の特性

    OpenAIRE

    嶽間沢, 秀孝

    2009-01-01

    It converted so that a small engine could be operated by Homogeneous Charge Compression Ignition (HCCI) combustion with dimethyl ether (DME). It is difficult to control auto-ignition timing in HCCI combustion. The sound performances and the exhaust temperature of compression ignition combustion engine fueled with DME and diesel fuel were investigated. As a result, it succeeded in continuous smokeless operation of an efficient internal combustion engine by DME homogeneous charge system.

  16. Effect of the Miller cycle on the performance of turbocharged hydrogen internal combustion engines

    International Nuclear Information System (INIS)

    Luo, Qing-he; Sun, Bai-gang

    2016-01-01

    Highlights: • The Miller cycle can increase power density for turbocharged hydrogen engines. • The boundaries is limited by the turbocharged system and valve lift. • Broke power and BSFC of using Miller cycle is the best in three technical methods. - Abstract: Hydrogen is a promising energy carrier, and the port fuel injection (PFI) is a fuel-flexible, durable, and relatively cheap method of energy conversion. However, the contradiction of increasing the power density and controlling NOx emissions limits the wide application of PFI hydrogen internal combustion engines. To address this issue, two typical thermodynamic cycles—the Miller and Otto cycles—are studied based on the calculation model proposed in this study. The thermodynamic cycle analyses of the two cycles are compared and results show that the thermal efficiency of the Miller cycle (η_M_i_l_l_e_r) is higher than η_O_t_t_o, when the multiplied result of the inlet pressure and Miller cycle coefficient (δ_Mγ_M) is larger than that of the Otto cycle (i.e., the value of the inlet pressure ratio multiplied by the Miller cycle coefficient is larger than the value of the inlet pressure ratio of the Otto cycle). The results also show that the intake valve closure (IVC) of the Miller cycle is limited by the inlet pressure and valve lift. The two factors show the boundaries of the Miller cycle in increasing the power density of the turbocharged PFI hydrogen engine. The ways of lean burn + Otto cycle (LO), stoichiometric equivalence ratio burn + EGR + Otto cycle (SEO) and Miller cycle in turbocharged hydrogen engine are compared, the results show that the Miller cycle has the highest power density and the lowest BSFC among the three methods at an engine speed of 2800 rpm and NOx emissions below 100 ppm. The brake power of the Miller cycle increases by 37.7% higher than that of the LO and 26.3% higher than that of SEO, when γ_M is 0.7. The BSFC of the Miller cycle decreases by 16% lower than that of

  17. Performance, emission, and combustion characteristics of twin-cylinder common rail diesel engine fuelled with butanol-diesel blends.

    Science.gov (United States)

    Lamani, Venkatesh Tavareppa; Yadav, Ajay Kumar; Gottekere, Kumar Narayanappa

    2017-10-01

    Nitrogen oxides and smoke are the substantial emissions for the diesel engines. Fuels comprising high-level oxygen content can have low smoke emission due to better oxidation of soot. The objective of the paper is to assess the potential to employ oxygenated fuel, i.e., n-butanol and its blends with the neat diesel from 0 to 30% by volume. The experimental and computational fluid dynamic (CFD) simulation is carried out to estimate the performance, combustion, and exhaust emission characteristics of n-butanol-diesel blends for various injection timings (9°, 12°, 15°, and 18°) using modern twin-cylinder, four-stroke, common rail direct injection (CRDI) engine. Experimental results reveal the increase in brake thermal efficiency (BTE) by ~ 4.5, 6, and 8% for butanol-diesel blends of 10% (Bu10), 20% (Bu20), and 30% (Bu30), respectively, compared to neat diesel (Bu0). Maximum BTE for Bu0 is 38.4%, which is obtained at 12° BTDC; however, for Bu10, Bu20 and Bu30 are 40.19, 40.9, and 41.7%, which are obtained at 15° BTDC, respectively. Higher flame speed of n-butanol-diesel blends burn a large amount of fuel in the premixed phase, which improves the combustion as well as emission characteristics. CFD and experimental results are compared and validated for all fuel blends for in-cylinder pressure and nitrogen oxides (NO x ), and found to be in good agreement. Both experimental and simulation results witnessed in reduction of smoke opacity, NO x , and carbon monoxide emissions with the increasing n-butanol percentage in diesel fuel.

  18. Power generation and gaseous emissions performance of an internal combustion engine fed with blends of soybean and beef tallow biodiesel.

    Science.gov (United States)

    Schirmer, Waldir Nagel; Gauer, Mayara Ananda; Tomaz, Edson; Rodrigues, Paulo Rogério Pinto; de Souza, Samuel Nelson Melegari; Chaves, Luiz Inácio; Villetti, Lucas; Olanyk, Luciano Zart; Cabral, Alexandre Rodrigues

    2016-01-01

    This study aimed to compare the performance of an internal combustion engine fed with blends of biodiesel produced from soybean and diesel, and blends of biodiesel produced from beef tallow and diesel. Performance was evaluated in terms of power generated at low loading conditions (0.5, 1.0 and 1.5 kW) and emission of organic and inorganic pollutants. In order to analyse inorganic gases (CO, SO2 and NOx), an automatic analyser was used and the organic emissions (benzene, toluene, ethylbenzene and xylene - BTEX) were carried out using a gas chromatograph. The results indicate that the introduction of the two biodiesels in the fuel caused a reduction in CO, SO2 and BTEX emissions. In addition, the reduction was proportional to the increase in loading regime. Beef tallow biodiesels presented better results regarding emission than soybean biodiesels. The use of pure biodiesels also presented a net reduction in pollutant gas emissions without hindering the engine generator performance.

  19. Investigation of Atomization and Combustion Performance of Renewable Biofuels and the Effects of Ethanol Blending in Biodiesel

    Science.gov (United States)

    Silver, Adam Gregory

    This thesis presents results from an experimental investigation of the macroscopic and microscopic atomization and combustion behavior of B99 biodiesel, ethanol, B99-ethanol blends, methanol, and an F-76-Algae biodiesel blend. In addition, conventional F-76 and Diesel #2 sprays were characterized as a base case to compare with. The physical properties and chemical composition of each fuel were measured in order to characterize and predict atomization performance. A variety of B99-ethanol fuel blends were used which demonstrate a tradeoff between lower density, surface tension, and viscosity with a decrease in the air to liquid ratio. A plain jet air-blast atomizer was used for both non-reacting and reacting tests. The flow rates for the alternative fuels were set by matching the power input provided by the baseline fossil fuels in order to simulate use as a drop in replacement. For this study, phase Doppler interferometry is employed to gain information on drop size, SMD, velocity, and volume flux distribution across the spray plume. A high speed camera is used to gather high speed cinematography of the sprays for observing breakup characteristics and providing additional insight. Reacting flow tests captured NOx, CO, and UHC emissions along with high speed footage used to predict soot levels based on flame luminosity. The results illustrate how the fuel type impacts the atomization and spray characteristics. The air-blast atomizer resulted in similar atomization performance among the DF2, F-76, and the F-76/Algae blend. While methanol and ethanol are not suitable candidates for this air-blast configuration and B99 produces significantly larger droplets, the addition of ethanol decreased drop sizes for all B99-ethanol blends by approximately 5 microns. In regards to reacting conditions, increased ethanol blending to B99 consistently lowered NOx emissions while decreasing combustion efficiency. Overall, lower NOx and CO emissions were achieved with the fuel blends

  20. Improving the performance and emission characteristics of a single cylinder diesel engine having reentrant combustion chamber using diesel and Jatropha methyl esters.

    Science.gov (United States)

    Premnath, S; Devaradjane, G

    2015-11-01

    The emissions from the Compression ignition (CI) engines introduce toxicity to the atmosphere. The undesirable carbon deposits from these engines are realized in the nearby static or dynamic systems such as vehicles, inhabitants, etc. The objective of this research work is to improve the performance and emission characteristics of a diesel engine in the modified re-entrant combustion chamber using a diesel and Jatropha methyl ester blend (J20) at three different injection pressures. From the literature, it is revealed that the shape of the combustion chamber and the fuel injection pressure have an impact on the performance and emission parameters of the CI engine. In this work, a re-entrant combustion chamber with three different fuel injection pressures (200, 220 and 240bars) has been used in the place of the conventional hemispherical combustion chamber for diesel and J20. From the experimental results, it is found that the re-entrant chamber improves the brake thermal efficiency of diesel and J20 in all the tested conditions. It is also found that the 20% blend of Jatropha methyl ester showed 4% improvement in the brake thermal efficiency in the re-entrant chamber at the maximum injection pressure. Environmental safety directly relates to the reduction in the undesirable effects on both living and non-living things. Currently environmental pollution is of major concern. Even with the stringent emission norms new methods are required to reduce the harmful effects from automobiles. The toxicity of carbon monoxide (CO) is well known. In the re-entrant combustion chamber, the amount of CO emission is reduced by 26% when compared with the conventional fuel operation of the engine. Moreover, the amount of smoke is reduced by 24% and hydrocarbons (HC) emission by 24%. Thus, the modified re-entrant combustion chamber reduces harmful pollutants such as unburned HC and CO as well as toxic smoke emissions. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Combustion, performance, and selective catalytic reduction of NOx for a diesel engine operated with combined tri fuel (H_2, CH_4, and conventional diesel)

    International Nuclear Information System (INIS)

    Abu-Jrai, Ahmad M.; Al-Muhtaseb, Ala'a H.; Hasan, Ahmad O.

    2017-01-01

    In this study, the effect of tri fuel (ULSD, H_2, and CH_4) operation under real exhaust gas conditions with different gaseous fuel compositions on the combustion characteristics, engine emissions, and selective catalytic reduction (SCR) after treatment was examined at low, medium, and high engine loads. Pt/Al_2O_3-SCR reactor was used and operated at different exhaust gas temperatures. Results revealed that at low load, the two gaseous fuels (H_2 and CH_4) have the same trend on combustion proccess, where both reduce the in-cylinder pressure and rate of heat release. At the high engine load there was a considerable influence appeared as an increase of the premixed combustion phase and a significant decrease of the total combustion duration. In terms of emissions, it was observed that at high engine load, fuels with high CH_4 content tend to reduce NOx formation, whereas, fuels with high H_2 content tend to reduce PM formation, moreover, combustion of tri fuel with 50:50 fuel mixture resulted in lower BSFC compared to the other ratios and hence, the best engine efficiency. The hydrocarbon-SCR catalyst has shown satisfactory performance in NOx reduction under real diesel exhaust gas in a temperature window of 180–280 °C for all engine loads. - Highlights: • Effect of tri fuel (ULSD, H_2, CH_4) on combustion and engine emissions was examined. • Fuel with high CH_4 content (H50-M50 and H25-M75) tend to reduce NOx formation. • Fuel with high H_2 content (H75-M25 and H50-M50) tend to reduce PM formation. • Increasing the percentage of H_2 in the feed gas improved the NO_x reduction. • The hydrocarbon-SCR catalyst has shown satisfactory performance in NO_x reduction.

  2. Fuels and Combustion | Transportation Research | NREL

    Science.gov (United States)

    Fuels and Combustion Fuels and Combustion This is the March 2015 issue of the Transportation and , combustion strategy, and engine design hold the potential to maximize vehicle energy efficiency and performance of low-carbon fuels in internal combustion engines with a whole-systems approach to fuel chemistry

  3. The study of stability, combustion characteristics and performance of water in diesel emulsion fuel

    Directory of Open Access Journals (Sweden)

    Syafiq Zulkifli

    2017-01-01

    Full Text Available A single cylinder diesel engine study of water in diesel emulsions was conducted to investigate the stability effect of emulsion fuel on three different fuel blends and the water emulsification effect on the engine performance. Emulsified fuels contained 2% of surfactant including Span 80 Tween 80 and tested 10 HLB number. The blends also varied of 5%, 10% and 15% of water in diesel ratios namely as BSW5, BSW10 and BSW15. The fuel blends performance was tested using a single cylinder, direct injection diesel engine, operating at 1860 rpm. The results on stability reveal that high shear homogenizer yields more stability on emulsion fuel than mechanical stirrer and ultrasonic water bath. The engine performance results show that the ignition delay and peak pressure increase with the increment of water percentage up to 15%. However, the results indicate the increment of water percentage is also shows a significant decrease in engine power.

  4. Theoretical Study for The Influence of Biodiesel Addition on The Combustion, Performance and Emissions Parameters of Single Cylinder Diesel Engine

    Directory of Open Access Journals (Sweden)

    Mohamed F. Al-Dawody

    2017-08-01

    Full Text Available This study examines the characteristics of combustion, performance and emission of constant speed compression ignition engine fed with different percentages of diesel fuel and rapeseed methyl ester (RME on a volume basis by using the well-known software simulation Diesel-RK. As the percentage of RME increased, the maximal pressure is noticed to be closer to top dead center (TDC. It was found that 47.27 %, 81.06 %, 82.56 % and 93.36 % reduction in the Bosch smoke number is obtainable with 10% RME, 20% RME, 50% RME and 100% RME respectively, compared with ordinary diesel. The blends of RME are noticed to emit higher NOx emissions. The result signals that 10% RME is the promising ratio of blending which reports less performance variations and reduced carbon emissions as well. The effect of variable injection timings is studied to moderate biodiesel NOx effects on the 10% RME and 18 degree crank angle before top dead center (BTDC was recorded as the advisable injection timing which gives a promising reduction in NOx emissions.

  5. Comparative Study of Performance and Combustion Characteristics of Conventional and Low Heat Rejection (Mullite Coated) Diesel Engines

    Science.gov (United States)

    Patond, S. B.; Chaple, S. A.; Shrirao, P. N.; Shaikh, P. I.

    2013-06-01

    Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al2O3·2SiO2 (mullite) (Al2O3 = 60%, SiO2 = 40%) over a 150 μm thickness of NiCrAlY bond coat. The working conditions for the conventional engine (without coating) and LHR (mullite coated) engine were kept exactly same to ensure a comparison between the two configurations of the engine. This paper is intended to emphasis on performance and combustion characteristics of conventional and LHR (Mullite coated) diesel engines under identical conditions. Tests were carried out at same operational constraints i.e. air-fuel ratio and engine speed conditions for both conventional engine (without coating) and LHR (mullite coated) engines. The results showed that, there was as much as 1.8 % increasing on brake power for LHR (mullite coated) engine compared to conventional engine (without coating) at full load The average decrease in brake specific fuel consumption in the LHR engine compared with the conventional engine was 1.76 % for full engine load. However, there was increasing on cylinder gas pressure and net heat release rate for LHR engine compared to conventional engine. Also the results revealed that, there was as much as 22% increasing on exhaust gas temperature for LHR engine compared to conventional engine at full engine load.

  6. Comparative Study of Performance and Combustion Characteristics of Conventional and Low Heat Rejection (Mullite Coated) Diesel Engines

    International Nuclear Information System (INIS)

    Patond, S B; Chaple, S A; Shrirao, P N; Shaikh, P I

    2013-01-01

    Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al 2 O 3 ·2SiO 2 (mullite) (Al 2 O 3 = 60%, SiO 2 = 40%) over a 150 μm thickness of NiCrAlY bond coat. The working conditions for the conventional engine (without coating) and LHR (mullite coated) engine were kept exactly same to ensure a comparison between the two configurations of the engine. This paper is intended to emphasis on performance and combustion characteristics of conventional and LHR (Mullite coated) diesel engines under identical conditions. Tests were carried out at same operational constraints i.e. air-fuel ratio and engine speed conditions for both conventional engine (without coating) and LHR (mullite coated) engines. The results showed that, there was as much as 1.8 % increasing on brake power for LHR (mullite coated) engine compared to conventional engine (without coating) at full load The average decrease in brake specific fuel consumption in the LHR engine compared with the conventional engine was 1.76 % for full engine load. However, there was increasing on cylinder gas pressure and net heat release rate for LHR engine compared to conventional engine. Also the results revealed that, there was as much as 22% increasing on exhaust gas temperature for LHR engine compared to conventional engine at full engine load.

  7. Effect of injection pressure on performance, emission, and combustion characteristics of diesel-acetylene-fuelled single cylinder stationary CI engine.

    Science.gov (United States)

    Srivastava, Anmesh Kumar; Soni, Shyam Lal; Sharma, Dilip; Jain, Narayan Lal

    2018-03-01

    In this paper, the effect of injection pressure on the performance, emission, and combustion characteristics of a diesel-acetylene fuelled single cylinder, four-stroke, direct injection (DI) diesel engine with a rated power of 3.5 kW at a rated speed of 1500 rpm was studied. Experiments were performed in dual-fuel mode at four different injection pressures of 180, 190, 200, and 210 bar with a flow rate of 120 LPH of acetylene and results were compared with that of baseline diesel operation. Experimental results showed that highest brake thermal efficiency of 27.57% was achieved at injection pressure of 200 bar for diesel-acetylene dual-fuel mode which was much higher than 23.32% obtained for baseline diesel. Carbon monoxide, hydrocarbon, and smoke emissions were also measured and found to be lower, while the NO x emissions were higher at 200 bar in dual fuel mode as compared to those in other injection pressures in dual fuel mode and also for baseline diesel mode. Peak cylinder pressure, net heat release rate, and rate of pressure rise were also calculated and were higher at 200 bar injection pressure in dual fuel mode.

  8. Combustion engineering

    CERN Document Server

    Ragland, Kenneth W

    2011-01-01

    Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

  9. Performance and Stability Enhancement of Perovskite-Type Nanomaterials Applied for Carbon Capture Utilizing Oxyfuel Combustion

    Directory of Open Access Journals (Sweden)

    Qiuwan Shen

    2017-02-01

    Full Text Available A new series of Ba-Co-Operovskite-type oxygen carriers has been successfully synthesized by the microwave-assisted sol-gel method and further applied for producing an O2/CO2 mixture gas. The oxygen adsorption/desorption performance of synthesized samples was studied in a fixed-bed reactor system. Effects of A/B-site substitution on the oxygen desorption performance of Ba-Co-O–based perovskites are also included. Furthermore, the effects of operating conditions including the adsorption time and temperature as well as the desorption temperature on oxygen production performance were investigated in detail. The results indicated that BaCoO3-δ exhibited an excellent oxygen desorption performance among the synthesized A/B-site–substituted ACoO3-δ and BaBO3-δ samples, and that the optimal adsorption time, adsorption temperature and desorption temperatureforBaCoO3-δ were determined to be 20min, 850◦Cand850◦C, respectively, in this study.

  10. Investigating the pros and cons of browns gas and varying EGR on combustion, performance, and emission characteristics of diesel engine.

    Science.gov (United States)

    Thangaraj, Suja; Govindan, Nagarajan

    2018-01-01

    The significance of mileage to the fruitful operation of a trucking organization cannot be downplayed. Fuel is one of the biggest variable expenses in a trucking wander. An attempt is made in this research to improve the combustion efficiency of a diesel engine for better fuel economy by introducing hydroxy gas which is also called browns gas or HHO gas in the suction line, without compromising performance and emission. Brown's gas facilitates the air-fuel mixture to ignite faster and efficient combustion. By considering safety and handling issues in automobiles, HHO gas generation by electrolysis of water in the presence of sodium bicarbonate electrolytes (NaHCO 3 ) and usage was explored in this research work over compressed pure hydrogen, due to generation and capacity of immaculate hydrogen as of now confines the application in diesel engine operation. Brown's gas was utilized as a supplementary fuel in a single-cylinder, four-stroke compression ignition (CI) engine. Experiments were carried out on a constant speed engine at 1500 rpm, result shows at constant HHO flow rate of 0.73 liter per minute (LPM), brake specific fuel consumption (BSFC) decreases by 7% at idle load to 16% at full load, and increases brake thermal efficiency (BTE) by 8.9% at minimum load to 19.7% at full load. In the dual fuel (diesel +HHO) operation, CO emissions decreases by 19.4, 64.3, and 34.6% at 25, 50, and 75% load, respectively, and unburned hydrocarbon (UHC) emissions decreased by 11.3% at minimum load to 33.5% at maximum load at the expense of NO x emission increases by 1.79% at 75% load and 1.76% at full load than neat diesel operation. The negative impact of an increase in NO x is reduced by adding EGR. It was evidenced in this experimental work that the use of Brown's gas with EGR in the dual fuel mode in a diesel engine improves the fuel efficiency, performance, and reduces the exhaust emissions.

  11. Combustion phenomenon, performance and emissions of a diesel engine with aviation turbine JP-8 fuel and rapeseed biodiesel blends

    International Nuclear Information System (INIS)

    Labeckas, Gvidonas; Slavinskas, Stasys

    2015-01-01

    Highlights: • The 5 vol% RME added to JP-8 fuel improved lubricity 1.7 times according corrected wear scar diameter, μm. • The reverse trends revealed in the autoignition delay when operating with identical fuel blends J10 and B10. • The brake thermal efficiency increased by 1.0–3.6% when running on bio-fuels J5–J30 at speed of 2200 rpm. • The NO_x emissions increased by 5.2% when operating on bio-jet fuel J30 at full load and speed of 2200 rpm. • CO, HC emissions and smoke decreased with biofuel J20 and higher blends at both speeds of 1400 and 2200 rpm. - Abstract: The article presents the test results of an engine operating with diesel fuel (B5), turbine type JP-8 fuel and its 5 vol%, 10 vol%, 20 vol%, and 30 vol% blends with rapeseed oil methyl ester (RME). Additional fuel blend B10 was prepared by pouring 10 vol% of RME to diesel fuel to extend interpretation of the test results. The purpose of this study was to examine the effects of using jet-biodiesel fuel blends J5, J10, J20, J30, and B10 on the start of injection, ignition delay, combustion history, heat release, engine performance, and exhaust emissions. The engine performance parameters were examined at light 15% (1400 rpm) and 10% (2200 rpm), medium 50%, and high 100% loads and the two speeds: 1400 rpm at which maximum torque occurs and a rated speed of 2200 rpm. The autoignition delay and maximum heat release rate decreased, maximum cylinder pressure, and pressure gradients increased, whereas brake specific fuel consumption changed little and brake thermal efficiency was 1.0–3.6% higher when running with fuel blends J5 to J30 at rated speed compared with the data measured with neat jet fuel. The NO_x emissions increased slightly, but the CO, THC emissions, and smoke opacity boosted up significantly when using jet fuel blend J10 with a smooth reduction of unburned hydrocarbons for jet-biodiesel fuel blends with higher CN ratings. Operation at a full (100%) load with fuel blend J10

  12. Engine performance, combustion, and emissions study of biomass to liquid fuel in a compression-ignition engine

    International Nuclear Information System (INIS)

    Ogunkoya, Dolanimi; Fang, Tiegang

    2015-01-01

    Highlights: • Renewable biomass to liquid (BTL) fuel was tested in a direct injection diesel engine. • Engine performance, in-cylinder pressure, and exhaust emissions were measured. • BTL fuel reduces pollutant emission for most conditions compared with diesel and biodiesel. • BTL fuel leads to high thermal efficiency and lower fuel consumption compared with diesel and biodiesel. - Abstract: In this work, the effects of diesel, biodiesel and biomass to liquid (BTL) fuels are investigated in a single-cylinder diesel engine at a fixed speed (2000 rpm) and three engine loads corresponding to 0 bar, 1.26 bar and 3.77 bar brake mean effective pressure (BMEP). The engine performance, in-cylinder combustion, and exhaust emissions were measured. Results show an increase in indicated work for BTL and biodiesel at 1.26 bar and 3.77 bar BMEP when compared to diesel but a decrease at 0 bar. Lower mechanical efficiency was observed for BTL and biodiesel at 1.26 bar BMEP but all three fuels had roughly the same mechanical efficiency at 3.77 bar BMEP. BTL was found to have the lowest brake specific fuel consumption (BSFC) and the highest brake thermal efficiency (BTE) among the three fuels tested. Combustion profiles for the three fuels were observed to vary depending on the engine load. Biodiesel was seen to have the shortest ignition delay among the three fuels regardless of engine loads. Diesel had the longest ignition delay at 0 bar and 3.77 bar BMEP but had the same ignition delay as BTL at 1.26 bar BMEP. At 1.26 bar and 3.77 bar BMEP, BTL had the lowest HC emissions but highest HC emissions at no load conditions when compared to biodiesel and diesel. When compared to diesel and biodiesel BTL had lower CO and CO 2 emissions. At 0 bar and 1.26 bar BMEP, BTL had higher NOx emissions than diesel fuel but lower NOx than biodiesel at no load conditions. At the highest engine load tested, NOx emissions were observed to be highest for diesel fuel but lowest for BTL. At 1

  13. Experimental investigation of CI engine combustion, performance and emissions in DEE–kerosene–diesel blends of high DEE concentration

    International Nuclear Information System (INIS)

    Patil, K.R.; Thipse, S.S.

    2015-01-01

    Highlights: • First ever study on DEE–kerosene–diesel blends used in CI engine. • DEE–diesel blends have reduced the trade-off between PM and NOx of diesel engine. • Optimum performance blend has been found as DE15D. • Adulteration effects of kerosene with diesel have also been investigated. • Additions of kerosene with DE15D blend have deteriorated the overall engine performance. - Abstract: An experimental investigation had been carried out to evaluate the effects of oxygenated cetane improver diethyl ether (DEE) blends with kerosene and diesel on the combustion, performance and emission characteristics of a direct injection diesel engine. Initially, 2%, 5%, 8%, 10%, 15%, 20% and 25% DEE (by volume) were blended into diesel. The DEE–diesel blends have reduced the trade-off between PM and NOx of diesel engine and the optimum performance blend has been found as DE15D. Similarly, 5%, 10% and 15% kerosene (by volume) were blended into diesel to investigate the adulteration effect. In addition, a study was carried out to evaluate the effects of kerosene adulteration on DE15D by blending with 5%, 10% and 15% kerosene (by volume). The engine tests were carried out at 10%, 25%, 50%, 75% and 100% of full load for all test fuels. Laboratory fuel tests showed that the DEE is completely miscible with diesel and kerosene in any proportion. It was observed that the density, kinematic viscosity and calorific value of the blends decreases, while the oxygen content and cetane number of the blends increases with the concentration of DEE addition. The experimental test results showed that the DEE–kerosene–diesel blends have low brake thermal efficiency, high brake specific fuel consumption, high smoke at full load, low smoke at part load, overall low NO, almost similar CO, high HC at full load and low HC at part load as compared to DE15D blend

  14. Experimental study on emissions and performance of an internal combustion engine fueled with gasoline and gasoline/n-butanol blends

    International Nuclear Information System (INIS)

    Elfasakhany, Ashraf

    2014-01-01

    Highlights: • Using of 3 and 7 vol.% n-butanol blends in SI engine is studied for the first time. • Engine performance and emissions depend on both engine speed and blend rates. • CO and UHC for blended fuels are maximum at 3000–3100 r/min. • The higher the rate of n-butanol, the lower the emissions and performance. • This study strongly supports using low blend rates of n-butanol (<10 vol.%) in ICE. - Abstract: In this paper, exhaust emissions and engine performance have been experimentally studied for neat gasoline and gasoline/n-butanol blends in a wide range of working speeds (2600–3400 r/min) without any tuning or modification on the gasoline engine systems. The experiment has the ability of evaluating performance and emission characteristics, such as break power, torque, in-cylinder pressure, volumetric efficiency, exhaust gas temperature and concentrations of CO 2 , CO and UHC. Results of the engine test indicated that using n-butanol–gasoline blended fuels slightly decrease the output torque, power, volumetric efficiency, exhaust gas temperature and in-cylinder pressure of the engine as a result of the leaning effect caused by the n-butanol addition; CO, CO 2 and UHC emissions decrease dramatically for blended fuels compared to neat gasoline because of the improved combustion since n-butanol has extra oxygen, which allows partial reduction of the CO and UHC through formation of CO 2 . It was also noted that the exhaust emissions depend on the engine speed rather than the n-butanol contents

  15. Advanced Materials and Manufacturing for Low-Cost, High-Performance Liquid Rocket Combustion Chambers, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Silicided niobium alloy (C103) combustion chambers have been used extensively in both NASA and DoD liquid rocket propulsion systems. Niobium alloys offer a good...

  16. Fuel characterisation, engine performance, combustion and exhaust emissions with a new renewable Licella biofuel

    International Nuclear Information System (INIS)

    Nabi, Md Nurun; Rahman, Md Mostafizur; Islam, Muhammad Aminul; Hossain, Farhad M.; Brooks, Peter; Rowlands, William N.; Tulloch, John; Ristovski, Zoran D.; Brown, Richard J.

    2015-01-01

    Highlights: • A new biofuel produced by hydrothermal liquefaction is investigated. • Licella biofuel blends showed no significant changes in engine performance. • Licella blends showed higher THC and NO emissions. • PM and PN emissions were observed to be lower for all Licella blends. • Hydrothermal liquefaction Licella biofuel is suitable for use in diesel engine. - Abstract: The current study investigates the opportunity of using Licella biofuel as a partly renewable fuel provided by Licella P/L. Hereafter this fuel will be referred to as Licella biofuel. The renewable component of the Licella biofuel was made from the hydrothermal conversion of Australian pinus radiata wood flour using Licella’s proprietary Cat-HTR™ technology. The diesel-soluble component of the hydrothermal product was extracted into road diesel to give a blended fuel containing approximately 30% renewable material with the balance from diesel. This was further blended with a regular diesel fuel (designated R0) to give fuels for testing containing 5%, 10% and 20% renewable fuel (designated R5, R10 and R20). Some of the key fuel properties were measured for R30 and compared with those of regular diesel fuel. The engine experiment was conducted on a four-cylinder turbocharged common rail direct injection diesel engine. All experiments were performed with a constant speed and five different engine loads. Exhaust emissions including particulate matter (PM) mass and numbers, nitric oxide (NO), total unburnt hydrocarbon (THC), carbon dioxide (CO 2 ) and performance parameters including brake power (BP), indicated power (IP), brake mean effective pressure (BMEP), indicated mean effective pressure (IMEP), mechanical efficiency (ME), brake thermal efficiency (BTE) and brake specific energy consumption (BSEC) were investigated for all four blends (R0, R5, R10 and R20). Among other engine parameters, in-cylinder pressure, heat release rate (HRR) and pressure (P) versus volume (V) diagrams

  17. System and method for improving performance of a fluid sensor for an internal combustion engine

    Science.gov (United States)

    Kubinski, David [Canton, MI; Zawacki, Garry [Livonia, MI

    2009-03-03

    A system and method for improving sensor performance of an on-board vehicle sensor, such as an exhaust gas sensor, while sensing a predetermined substance in a fluid flowing through a pipe include a structure for extending into the pipe and having at least one inlet for receiving fluid flowing through the pipe and at least one outlet generally opposite the at least one inlet, wherein the structure redirects substantially all fluid flowing from the at least one inlet to the sensor to provide a representative sample of the fluid to the sensor before returning the fluid through the at least one outlet.

  18. Effect of Combustion-chamber Shape on the Performance of a Prechamber Compression-ignition Engine

    Science.gov (United States)

    Moore, C S; Collins, J H , Jr

    1934-01-01

    The effect on engine performance of variations in the shape of the prechamber, the shape and direction of the connecting passage, the chamber volume using a tangential passage, the injection system, and the direction od the fuel spray in the chamber was investigated using a 5 by 7 inch single-cylinder compression-ignition engine. The results show that the performance of this engine can be considerably improved by selecting the best combination of variables and incorporating them in a single design. The best combination as determined from these tests consisted of a disk-shaped chamber connected to the cylinder by means of a flared tangential passage. The fuel was injected through a single-orifice nozzle directed normal to the air swirl and in the same plane. At an engine speed of 1,500 r.p.m. and with the theoretical fuel quantity for no excess air, the engine developed a brake mean effective pressure of 115 pounds per square inch with a fuel consumption of 0.49 pound per brake horsepower-hour and an explosion pressure of 820 pounds per square inch. A brake mean effective pressure of 100 pounds per square inch with a brake-fuel consumption of 0.44 pound per horsepower-hour at 1,500 r.p.m. was obtained.

  19. Combustion performance of cellulosic biomass in a gasifier-based cookstove

    Science.gov (United States)

    Sulaiman, Shaharin A.; Romli, Raffisyazana

    2012-06-01

    Depletion in fossil fuel and increase in the world population may change the trend in future kitchens in households. Cooking with LPG fuel may one day become impossible and households would have to consider alternatives such as electric stoves. One other solution to this problem is through the use of biomass cook stoves. However, traditional cook stoves, predominantly used in the households, are not efficient and its utilizations for domestic cooking have been a major contributor to the ill effects related in respiratory and other health problem. Improved cook stoves programs implemented in the developing world attempt to address these problems. Biomass gasification appears to have significant potential in Asia for domestic cooking applications. Gasifier-based cook stoves are fuel efficient in comparison to traditional cook stove. The objective of this paper is to study the performance of various type of cellulosic biomass in a gasifier-based cook stove. The biomass considered in this study are oil palm fronds, dried leaves, wood sticks, coconut shells, bagasse, charcoal, and saw dust. The samples are analyzed in order to study their chemical properties. The thermochemical properties of the biomass were characterized. The performance of the each of the samples is studied by observing the time taken to boil water. It is found that oil palm fronds are the best type of biomass for the gasifer cook stove. It is also concluded that the higher the carbon content and the calorific value in a biomass, the lesser the time taken to boil the water.

  20. A Study on Performance, Combustion and Emission Characteristics of Compression Ignition Engine Using Fish Oil Biodiesel Blends

    Science.gov (United States)

    Ramesha, D. K.; Thimmannachar, Rajiv K.; Simhasan, R.; Nagappa, Manjunath; Gowda, P. M.

    2012-07-01

    Bio-fuel is a clean burning fuel made from natural renewable energy resource; it operates in C. I. engine similar to the petroleum diesel. The rising cost of diesel and the danger caused to the environment has led to an intensive and desperate search for alternative fuels. Among them, animal fats like the fish oil have proven to be a promising substitute to diesel. In this experimental study, A computerized 4-stroke, single cylinder, constant speed, direct injection diesel engine was operated on fish oil-biodiesel of different blends. Three different blends of 10, 20, and 30 % by volume were used for this study. Various engine performance, combustion and emission parameters such as Brake Thermal Efficiency, Brake Specific Fuel Consumption, Heat Release Rate, Peak Pressure, Exhaust Gas Temperature, etc. were recorded from the acquired data. The data was recorded with the help of an engine analysis software. The recorded parameters were studied for varying loads and their corresponding graphs have been plotted for comparison purposes. Petroleum Diesel has been used as the reference. From the properties and engine test results it has been established that fish oil biodiesel is a better replacement for diesel without any engine modification.

  1. The effect of ethanol–diesel–biodiesel blends on combustion, performance and emissions of a direct injection diesel engine

    International Nuclear Information System (INIS)

    Labeckas, Gvidonas; Slavinskas, Stasys; Mažeika, Marius

    2014-01-01

    Highlights: • Ethanol–diesel–biodiesel blends were tested at the same air–fuel ratios and three ranges of speed. • The fuel oxygen mass content reflects changes in the autoignition delay more predictably than the cetane number does. • Using of composite blend E15B suggests the brake thermal efficiency the same as the normal diesel fuel. • Adding of ethanol to diesel fuel reduces the NO x emission for richer air–fuel mixtures at all engine speeds. • The ethanol effect on CO, HC emissions and smoke opacity depends on the air–fuel ratio and engine speed. - Abstract: The article presents the test results of a four-stroke, four-cylinder, naturally aspirated, DI 60 kW diesel engine operating on diesel fuel (DF) and its 5 vol% (E5), 10 vol% (E10), and 15 vol% (E15) blends with anhydrous (99.8%) ethanol (E). An additional ethanol–diesel–biodiesel blend E15B was prepared by adding the 15 vol% of ethanol and 5 vol% of biodiesel (B) to diesel fuel (80 vol%). The purpose of the research was to examine the influence of the ethanol and RME addition to diesel fuel on start of injection, autoignition delay, combustion and maximum heat release rate, engine performance efficiency and emissions of the exhaust when operating over a wide range of loads and speeds. The test results were analysed and compared with a base diesel engine running at the same air–fuel ratios of λ = 5.5, 3.0 and 1.5 corresponding to light, medium and high loads. The same air–fuel ratios predict that the energy content delivered per each engine cycle will be almost the same for various ethanol–diesel–biodiesel blends that eliminate some side effects and improve analyses of the test results. A new approach revealed an important role of the fuel bound oxygen, which reflects changes of the autoignition delay more predictably than the cetane number does. The influence of the fuel oxygen on maximum heat release rate, maximum combustion pressure, NO x , CO emissions and smoke opacity

  2. Free Energy and Internal Combustion Engine Cycles

    OpenAIRE

    Harris, William D.

    2012-01-01

    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  3. 78 FR 54606 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2013-09-05

    ... Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines AGENCY... hazardous air pollutants for stationary reciprocating internal combustion engines and the standards of performance for stationary internal combustion engines. Subsequently, the EPA received three petitions for...

  4. Determining the optimum conditions for modified diesel fuel combustion considering its emission, properties and engine performance

    International Nuclear Information System (INIS)

    Fayyazbakhsh, Ahmad; Pirouzfar, Vahid

    2016-01-01

    Highlights: • Gas emissions, fuel properties and performance engine modeling. • Optimization of new modified fuel prepared from n-Butanol and Nano particles. • Model accuracy analysis. - Abstract: This essay scrutinizes an experimental study conducted to appraise the influence of using n-Butanol with diesel fuel in 5% and 10% (volume) n-Butanol, 1% nitro methane (NM), injection timing and two Nano-particles (alumina and a type of silica powder) on the engine performance (brake specific fuel consumption and engine power), fuel properties (Cetane number and flash point) and exhaust emissions (soot, NO_x and CO) of an engine with 4-cylinder (with a system of common rail fuel injection), intercooling, cooled exhaust gas recirculation (EGR), and turbocharged. The tests are conducted by varying the engine load (25 and 75 nm) and changing engine speed (1500 and 2200 rpm). Normal Butanol presents better brake specific fuel consumption (BSFC) but this blend doesn’t reflect better engine power. All the percentages of n-Butanol in the fuel make Cetane number decrease but adding 1% of nitro methane makes Cetane number increase. For all the n-Butanol, the percentage flash makes the fuel decrease in comparison to pure diesel fuel. The current experimental study demonstrates that adding the n-Butanol and nitro methane to diesel fuel direct into diminishing soot emission. In contrast, this blend raises NO_x and CO emissions. Furthermore, this research indicates that the increase of engine speed dwindle air pollutants and enhances BSFC. It also remarks that power gets increased at low engine speed. However, power gets reducedat high speed. This article represents that the increasing of engine load leads to increasing all of air pollutant, increasing of power and decreasing of brake specific fuel consumption. Both the Cetane number and flash point are independent from engine speed and engine load. The present paper shows that the effect of silica with high percentage of n

  5. High performance Solid Rocket Motor (SRM) submerged nozzle/combustion cavity flowfield assessment

    Science.gov (United States)

    Freeman, J. A.; Chan, J. S.; Murph, J. E.; Xiques, K. E.

    1987-01-01

    Two and three dimensional internal flowfield solutions for critical points in the Space Shuttle solid rocket booster burn time were developed using the Lockheed Huntsville GIM/PAID Navier-Stokes solvers. These perfect gas, viscous solutions for the high performance motor characterize the flow in the aft segment and nozzle of the booster. Two dimensional axisymmetric solutions were developed at t = 20 and t = 85 sec motor burn times. The t = 85 sec solution indicates that the aft segment forward inhibitor stub produces vortices with are shed and convected downwards. A three dimensional 3.5 deg gimbaled nozzle flowfield solution was developed for the aft segment and nozzle at t = 9 sec motor burn time. This perfect gas, viscous analysis, provided a steady state solution for the core region and the flow through the nozzle, but indicated that unsteady flow exists in the region under the nozzle nose and near the flexible boot and nozzle/case joint. The flow in the nozzle/case joint region is characterized by low magnitude pressure waves which travel in the circumferential direction. From the two and three dimensional flowfield calculations presented it can be concluded that there is no evidence from these results that steady state gas dynamics is the primary mechanism resulting in the nozzle pocketing erosion experienced on SRM nozzles 8A or 17B. The steady state flowfield results indicate pocketing erosion is not directly initiated by a steady state gas dynamics phenomenon.

  6. Numerical analysis of loads effect on combustion performance and NO{sub x} emissions of a 220 MW pulverized coal boiler

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jun; Yang, Weihong; Blasiak, Wlodzimierz [Royal Institute of Technology (KTH), Stockholm (Sweden). Div. of Energy and Furnace Technology; Jankowski, Radoslaw; Kotecki, Michal; Szewczyk, Dariusz [Industrial Combustion Systems (ICS) Company, Poznan (Poland); Brzdekiewicz, Artur [Remak-Rozruch SA, Opole (Poland)

    2013-07-01

    This paper presents numerical study on the combustion performance and NO{sub x} emissions of a 220 MW pulverized coal boiler. Three different loads have been simulated with combusting coal, 200, 170 and 140 MW, respectively. In order to get as precise as possible numerical analysis results, two-step simulation method has been adopted in this work, namely, air supply system simulation and furnace simulation. After air supply system simulation, the results have been taken as the initial and boundary conditions for furnace simulation. The comparison between the measured values and predicted results from 200 MW case shows much better agreement. According to the simulation results, the adopted two-step simulation method is reasonable and suitable for predicting the characters of the flow and combustion process. It is concluded that the distributions of temperature, O{sub 2} and CO concentration inside furnace with different loads shows good similarly. The total NOx emissions decreased with the boiler load reducing, and fuel NO{sub x} has the same trend as total NO{sub x}, and fuel NO{sub x} account for about 66% in total NO{sub x} in all the three cases. More important, thermal NO{sub x} slowly decreased with the rise of boiler load. More detailed results presented in this paper enhance the understanding of combustion processes and complex flow patterns of front-wall pulverized coal boilers.

  7. Effects of Pilot Injection Timing and EGR on Combustion, Performance and Exhaust Emissions in a Common Rail Diesel Engine Fueled with a Canola Oil Biodiesel-Diesel Blend

    Directory of Open Access Journals (Sweden)

    Jun Cong Ge

    2015-07-01

    Full Text Available Biodiesel as a clean energy source could reduce environmental pollution compared to fossil fuel, so it is becoming increasingly important. In this study, we investigated the effects of different pilot injection timings from before top dead center (BTDC and exhaust gas recirculation (EGR on combustion, engine performance, and exhaust emission characteristics in a common rail diesel engine fueled with canola oil biodiesel-diesel (BD blend. The pilot injection timing and EGR rate were changed at an engine speed of 2000 rpm fueled with BD20 (20 vol % canola oil and 80 vol % diesel fuel blend. As the injection timing advanced, the combustion pressure, brake specific fuel consumption (BSFC, and peak combustion pressure (Pmax changed slightly. Carbon monoxide (CO and particulate matter (PM emissions clearly decreased at BTDC 20° compared with BTDC 5°, but nitrogen oxide (NOx emissions increased slightly. With an increasing EGR rate, the combustion pressure and indicated mean effective pressure (IMEP decreased slightly at BTDC 20° compared to other injection timings. However, the Pmax showed a remarkable decrease. The BSFC and PM emissions increased slightly, but the NOx emission decreased considerably.

  8. Development and validation of a multi-zone combustion model for performance and nitric oxide formation in syngas fueled spark ignition engine

    International Nuclear Information System (INIS)

    Rakopoulos, C.D.; Michos, C.N.

    2008-01-01

    The development of a zero-dimensional, multi-zone combustion model is presented for predicting the performance and nitric oxide (NO) emissions of a spark ignition (SI) engine. The model is validated against experimental data from a multi-cylinder, four-stroke, turbocharged and aftercooled, SI gas engine running with syngas fuel. This alternative fuel, the combustible part of which consists mainly of CO and H 2 with the rest containing non-combustible gases, has been recently identified as a promising substitute of fossil fuels in view of environmentally friendly engine operation. The basic concept of the model is the division of the burned gas into several distinct zones, unlike the simpler two-zone models, for taking into account the temperature stratification of the burned mixture during combustion. This is especially important for accurate NO emissions predictions, since NO formation is strongly temperature dependent. The multi-zone formulation provides the chemical species concentrations gradient existing in the burned zones, as well as the relative contribution of each burned zone to the total in-cylinder NO formation. The burning rate required as input to the model is expressed as a Wiebe function, fitted to experimentally derived burn rates. All model's constants are calibrated at one operating point and then kept unchanged. Zone-resolved combustion related information is obtained, assisting in the understanding of the complex phenomena occurring during combustion in SI engines. Combustion characteristics of the lean-burn gas engine tested are provided for the complete load range, aiding the interpretation of its performance and knocking tendency. Computed NO emissions from the multi-zone model for various values of the engine load (i.e. air-fuel ratios) are presented and found to be in good agreement with the respective experimental ones, providing confidence for the predictive capability of the model. The superiority of the multi-zone model over its two

  9. Combustion performance, flame, and soot characteristics of gasoline–diesel pre-blended fuel in an optical compression-ignition engine

    International Nuclear Information System (INIS)

    Jeon, Joonho; Lee, Jong Tae; Kwon, Sang Il; Park, Sungwook

    2016-01-01

    Highlights: • Gasoline–diesel pre-blended fuel was investigated in an optical direct-injection diesel engine. • KIVA3V-CHEMKIN code modeled blended fuel spray and combustion with discrete multi-component model. • Flame and soot characteristics in the combustion chamber were shown by optical kits. • Combustion performance and soot emissions for gasoline–diesel blended fuel were discussed. - Abstract: Among the new combustion technologies available for internal combustion engines to enhance performance and reduce exhausted emissions, the homogeneous charge compression ignition method is one of the most effective strategies for the compression-ignition engine. There are some challenges to realize the homogeneous charge compression ignition method in the compression-ignition engine. The use of gasoline–diesel blended fuel has been suggested as an alternative strategy to take advantages of homogeneous charge compression ignition while overcoming its challenges. Gasoline and diesel fuels are reference fuels for the spark-ignition and compression-ignition engines, respectively, both of which are widely used. The application of both these fuels together in the compression-ignition engine has been investigated using a hybrid injection system combining port fuel injection (gasoline) and direct injection (diesel); this strategy is termed reactivity controlled compression ignition. However, the pre-blending of gasoline and diesel fuels for direct injection systems has been rarely studied. For the case of direct injection of pre-blended fuel into the cylinder, various aspects of blended fuels should be investigated, including their spray breakup, fuel/air mixing, combustion development, and emissions. In the present study, the use of gasoline–diesel pre-blended fuel in an optical single-cylinder compression-ignition engine was investigated under various conditions of injection timing and pressure. Furthermore, KIVA-3V release 2 code was employed to model the

  10. Experimental investigation of performance, exhaust emission and combustion parameters of stationary compression ignition engine using ethanol fumigation in dual fuel mode

    International Nuclear Information System (INIS)

    Jamuwa, D.K.; Sharma, D.; Soni, S.L.

    2016-01-01

    Highlights: • Potential of renewable fuels as diesel replacement is being emphasized. • Effect of ethanol fumigation on the performance of diesel engine is investigated. • NOx, CO_2 and smoke decreases with simultaneous increase in HC and CO. • Increase in ignition delay with decrease in combustion duration for ethanol substitution observed. - Abstract: Dwindling reserves and steeply increasing prices of the fossil-fuels, concern over climatic change due to release of anthropogenic greenhouse gases and the strict environmental regulations have motivated the researchers for the search for renewable alternative fuel that has clean burning characteristics and may be produced indigenously. Alcohols, being oxygenated fuel improve the combustion and reduce greenhouse gas emissions, thus enhancing agrarian economies and encouraging national economy as a whole. The objective of this paper is to investigate the thermal performance, exhaust emissions and combustion behaviour of small capacity compression ignition engine using fumigated ethanol. Fumigated ethanol at different flow rates is supplied to the cylinder during suction with the help of a simplified low cost ethanol fuelling system. With ethanol fumigation, brake thermal efficiency decreased upto 11.2% at low loads due to deteriorated combustion, whereas improved combustion increased efficiency up to 6% at higher loads, as compared to pure diesel. Maximum reduction of 22%, 41% and 27% respectively in nitrogen oxide, smoke and carbon-di-oxide emissions with simultaneous increase in hydrocarbon and carbon-mono-oxide emissions upto maximum of 144% and 139% respectively for different rates of ethanol fumigation have been observed, when compared to pure diesel operation. This is due to the changes in physico-chemical properties of air fuel mixture, viz combustion temperature, oxygen concentration, latent heat of vaporisation, fuel distribution, cetane number and ignition delay, that occurred with addition of

  11. Multi-objective optimization of combustion, performance and emission parameters in a jatropha biodiesel engine using Non-dominated sorting genetic algorithm-II

    Science.gov (United States)

    Dhingra, Sunil; Bhushan, Gian; Dubey, Kashyap Kumar

    2014-03-01

    The present work studies and identifies the different variables that affect the output parameters involved in a single cylinder direct injection compression ignition (CI) engine using jatropha biodiesel. Response surface methodology based on Central composite design (CCD) is used to design the experiments. Mathematical models are developed for combustion parameters (Brake specific fuel consumption (BSFC) and peak cylinder pressure (Pmax)), performance parameter brake thermal efficiency (BTE) and emission parameters (CO, NO x , unburnt HC and smoke) using regression techniques. These regression equations are further utilized for simultaneous optimization of combustion (BSFC, Pmax), performance (BTE) and emission (CO, NO x , HC, smoke) parameters. As the objective is to maximize BTE and minimize BSFC, Pmax, CO, NO x , HC, smoke, a multiobjective optimization problem is formulated. Nondominated sorting genetic algorithm-II is used in predicting the Pareto optimal sets of solution. Experiments are performed at suitable optimal solutions for predicting the combustion, performance and emission parameters to check the adequacy of the proposed model. The Pareto optimal sets of solution can be used as guidelines for the end users to select optimal combination of engine output and emission parameters depending upon their own requirements.

  12. Natural Gas Variability In California: Environmental Impacts And Device Performance Combustion Modeling of Pollutant Emissions From a Residential Cooking Range

    Energy Technology Data Exchange (ETDEWEB)

    Tonse, S. R.; Singer, B. C.

    2011-07-01

    As part of a larger study of liquefied natural gas impacts on device performance and pollutant emissions for existing equipment in California, this report describes a cmoputer modeling study of a partially premixed flame issueing from a single cooktop burner port. The model consisted of a reactive computational fluid dynamics three-dimensional spatial grid and a 71-species chemical mechanism with propane combustion capability. Simulations were conducted with a simplified fuel mixture containing methane, ethane, and propane in proportions that yield properties similar to fuels distributed throughout much of California now and in recent years (baseline fuel), as well as with two variations of simulated liquefied natural gas blends. A variety of simulations were conducted with baseline fuel to explore the effect of several key parameters on pollutant formation and other flame characteristics. Simulations started with fuel and air issuing through the burner port, igniting, and continuing until the flame was steady with time. Conditions at this point were analyzed to understand fuel, secondary air and reaction product flows, regions of pollutant formation, and exhaust concentrations of carbon monoxide, nitric oxide and formaldehyde. A sensitivity study was conducted, varying the inflow parameters of this baseline gs about real-world operating conditions. Flame properties responded as expected from reactive flow theory. In the simulation, carbon monoxide levels were influenced more by the mixture's inflow velocity than by the gas-to-air ratio in the mixture issuing from the inflow port. Additional simulations were executed at two inflow conditions - high heat release and medium heat release - to examine the impact of replacing the baseline gas with two mixtures representative of liquefied natural gas. Flame properties and pollutant generation rates were very similar among the three fuel mixtures.

  13. An assessment on performance, emission and combustion characteristics of single cylinder diesel engine powered by Cymbopogon flexuosus biofuel

    International Nuclear Information System (INIS)

    Dhinesh, B.; Isaac JoshuaRamesh Lalvani, J.; Parthasarathy, M.; Annamalai, K.

    2016-01-01

    Highlights: • Cymbopogon Flexuosus biofuel is used as an alternative energy source. • Cymbopogon flexuosus biofuel 20% + Diesel 80% blend profile stayed close to diesel. • Resulting in higher thermal efficiency and reduced fuel consumption. • Reduced hydrocarbon, carbon monoxide and smoke emission. • Oxides of nitrogen and carbon di-oxide emission was marginally higher. - Abstract: The novelty of this manuscript is that it discusses about the experimental analysis of a new biofuel feedstock as an alternative fuel that has not drawn much attention among the researchers. An exploration for a new biofuel feedstock resulted in Cymbopogon flexuosus as an alternative energy source. Raw oil of Cymbopogon flexuosus was obtained through steam distillation process. Cymbopogon flexuosus biofuel was blended with diesel fuel in various proportions on volume basis, namely 10, 20, 30, 40, and 100 percent and its properties were assessed according to American Society for Testing and Materials standards. The considered test fuel was experimentally analysed in a single cylinder diesel engine at 1500 rpm for its performance, emission and combustion characteristics. Among various blends, Fuel blend of Cymbopogon flexuosus biofuel 20% + diesel 80% fuel profile stayed close to diesel fuel resulting in higher thermal efficiency and lower hydrocarbon, carbon monoxide, and smoke emission. However, oxides of nitrogen and carbon dioxide emission was marginally higher for the test fuel considered. Cylinder pressure and heat release rate curves were lower at full load condition as compared with diesel fuel. Against the grim background of fossil fuel depletion, Fuel blend of Cymbopogon flexuosus biofuel 20% + diesel 80% fuel acts as a promising alternative fuel and brings hope to the nation as well as the research world.

  14. An assessment on performance, combustion and emission behavior of a diesel engine powered by ceria nanoparticle blended emulsified biofuel

    International Nuclear Information System (INIS)

    Annamalai, M.; Dhinesh, B.; Nanthagopal, K.; SivaramaKrishnan, P.; Isaac JoshuaRamesh Lalvani, J.; Parthasarathy, M.; Annamalai, K.

    2016-01-01

    Highlights: • A novel biofuel, lemongrass is used as a renewable energy source. • Emulsion prepared using 5% of water, 93% of lemongrass oil and 2% of surfactant. • Emulsified nano biofuel performance profile stayed closer to diesel fuel. • Drastic reduction in HC, CO, NO_X and marginal decrease of smoke compared with diesel. - Abstract: The consequence of using cerium oxide (CeO_2) nanoparticle as additive in Lemongrass Oil (LGO) emulsion fuel was experimentally investigated in a single cylinder, constant speed diesel engine. A novel biofuel plant was introduced in this project, namely lemongrass whose binomial name is Cymbopogon flexuosus. The main objective of the project is to reduce the level of harmful pollutants in the exhaust such as unburned hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NO_X), and smoke. The engine performance could also be increased due to the addition of CeO_2 nanoparticle. The LGO emulsion fuel was prepared in the proportion of 5% of water, 93% of LGO and 2% of span80 by volume basis. Span80 acted as surfactant and it would reduce surface tension between the liquids with a hydrophilic-lipophilic balance (HLB) value of 4.2. The ceria nanoparticle was dispersed with the LGO emulsion fuel in the dosage of 30 ppm (ppm). The diesel engine performance, combustion behavior and emission magnitude were compared with diesel and LGO as the base fuels. The whole investigation was conducted with a single cylinder diesel engine using the following fuels, namely neat diesel, neat LGO, LGO emulsion and LGO nano emulsion fuels respectively. The LGO emulsion fuel could reduce smoke and NO_X emissions and could improve Brake Thermal Efficiency (BTE), Brake Specific Energy Consumption (BSEC) compared with neat LGO despite the marginal increase in HC and CO emissions. For ceria nanoparticle blended test fuel, the drastic reduction of carbon monoxide (CO), unburned hydrocarbon (HC), oxides of nitrogen (NO_X) and marginal decrease of

  15. Advances for laser ignition of internal combustion and rocket engines

    International Nuclear Information System (INIS)

    Schwarz, E.

    2011-01-01

    field laser physics. Unfortunately, there is no standard definition for the plasma threshold in the literature. Consequently, a clear definition of the focal volume is missing. For this reason it was tried to find a theoretical formula for the volume. This formula is based on the assumption that the focal volume encloses the space where the threshold intensity is higher than Ith =I0/2 or, alternatively, Ith = I0/e2. Laser energy transmission is one of the most important loss factors during plasma development by laser-induced optical breakdown and provides important information about the energy contained in the plasma. Hence, a number of plasma experiments were carried out. In our experiments is was found that for decreasing focal volume the plasma threshold energy (MPE) and the energy transmission can be reduced respectively. In order to investigate the possibility if laser-induced ignition can be made more efficient with respect to the laser pulse energy, several ignition experiments were performed. For these experiments a combustion chamber was employed at a filling pressure of 11 bar and a temperature of 110 o C involving different focal sizes. The thermal ignition experiments were carried out to demonstrate in principle the feasibility of thermal ignition via resonant absorption of IR radiation. By evaluating these results with respect to laser ignition of engines, it is conceivable to employ laser thermal ignition as an innovative ignition mechanism. As in HCCI (homogeneous charge compression ignition) engines and rocket engines, ignition occurs at specific elevated pressures and temperatures, it can be assumed that the ignition energies are in the range between 20 to 100 mJ. Furthermore, different laser ignition system concepts were developed and evaluated regarding to their qualification for rocket engine ignition. As a consequence of its highest rating in our study, resonant ignition should be considered an interesting alternative to laser spark ignition

  16. The effects of ethanol addition with waste pork lard methyl ester on performance, emission and combustion characteristics of a diesel engine

    Directory of Open Access Journals (Sweden)

    John Panneer Selvam Dharmaraj

    2014-01-01

    Full Text Available In the recent research, as a result of depletion of world petroleum reserves, considerable attention has been focused on the use of different alternative fuels in diesel engines. The present work aims to ensure the possibility of adding ethanol as an additive with animal fat biodiesel that is tested as an alternative fuel for diesel in a CI engine. In this study, biodiesel is obtained from waste pork lard by base-catalyzed transesterification with methanol when potassium hydroxide as catalyst. 2.5%, 5% and 7.5% by volume of ethanol is blended with neat biodiesel in order to improve performance and combustion characteristics of a diesel engine. The experimental work is carried out in a 3.7 kW, single cylinder, naturally aspirated, water cooled, direct injection diesel engine for different loads and at a constant speed of 1500 rpm. The performance, emission and combustion characteristics of biodiesel-ethanol blends are investigated by comparing them with neat biodiesel and standard diesel. The experimental test results showed that the combustion and performance characteristics improved with the increase in percentage of ethanol addition with biodiesel. When compared to neat biodiesel and standard diesel, an increase in brake thermal efficiency of 5.8% and 4.1% is obtained for BEB7.5 blend at full load of the engine. With the increase in percentage of ethanol fraction in the blends, peak cylinder pressure and the corresponding heat release rate are increased. Biodiesel-ethanol blends exhibit longer ignition delay and shorter combustion duration when compared to neat biodiesel. Optimum reduction in carbon monoxide, unburned hydrocarbon and smoke emission are attained while using BEB5 blend at full load of the engine. However, there is an adverse effect in case of nitrogen oxide emission.

  17. Higher alcohol–biodiesel–diesel blends: An approach for improving the performance, emission, and combustion of a light-duty diesel engine

    International Nuclear Information System (INIS)

    Imdadul, H.K.; Masjuki, H.H.; Kalam, M.A.; Zulkifli, N.W.M.; Alabdulkarem, Abdullah; Rashed, M.M.; Teoh, Y.H.; How, H.G.

    2016-01-01

    Highlights: • The fuel properties of higher alcohol blended biodiesel were improved. • Higher alcohol shows remarkable increase in the BP, BTE and decrease the BSFC. • Alcohols mixed with biodiesel diminishes HC, CO and smoke significantly. • CO 2 emissions of pentanol blended fuel decreases at maximum speed. • Higher alcohol blended biodiesel showed improved combustion. - Abstract: Pentanol is a long-chain alcohol with five carbons in its molecular structure and is produced from renewable feedstock, which may help to improve the challenging problems of energy security and environmental issues. In this investigation, the performance, emission, and combustion characteristics of a single-cylinder, four-stroke, water-cooled, direct-injection diesel engine were evaluated by using 10%, 15%, and 20% pentanol and Calophyllum inophyllum (CI) biodiesel blends in diesel under different speed conditions. The fuel properties of the blended fuels were measured and compared. Combustion attributes, such as cylinder pressure and heat-release rate, were also analyzed. Results indicated that increasing the proportion of pentanol in biodiesel blends improved the fuel properties compared with 20% blend of CI biodiesel (CI 20). The modified blends of pentanol showed reduced brake-specific fuel consumption with higher brake thermal efficiency and brake power than CI 20. Although the modified test blends showed a slightly higher nitric oxide emission, the carbon monoxide emission and unburned hydrocarbon emission for 15% and 20% blends of pentanol showed even better reduction than CI 20. Smoke emission was also reduced significantly. The carbon dioxide emission of the test blends were reduced at the maximum speed condition compared to CI 20. In terms of combustion, the modified test fuels exhibited a significant improvement, thus indicating better performance and emission. This study concluded that the 15% and 20% blends of biodiesel, diesel, and pentanol can optimize engine

  18. Combustion performance of pyrolysis oil/ethanol blends in a residential-scale oil-fired boiler

    Science.gov (United States)

    A 40 kWth oil-fired commercial boiler was fueled with blends of biomass pyrolysis oil (py-oil) and ethanol to determine the feasibility of using these blends as a replacement for fuel oil in home heating applications. An optimal set of test parameters was determined for the combustion of these blend...

  19. Experimental investigation of the fluid dynamic efficiency of a high performance multi-valve internal combustion engine during the intake phase: Influence of valve-valve interference phenomena

    Directory of Open Access Journals (Sweden)

    Algieri Angelo

    2013-01-01

    Full Text Available The purpose of the present work is the analysis of the fluid dynamic behavior of a high performance internal combustion engine during the intake phase. In particular, a four-valve spark-ignition engine has been characterized at the steady flow rig. Dimensionless discharge coefficients have been used to define the global fluid dynamic efficiency of the intake system, while the Laser Doppler Anemometry (LDA technique has been employed to evaluate the mean flow in the valve curtain area and to characterise the interference phenomena between the two intake valves. The investigation has shown the significant influence of the valve lift on the volumetric efficiency of the intake apparatus. Moreover, the experimental analysis has highlighted that the valve-valve interference phenomena have a relevant impact on the head breathability, on the flow development within the combustion chamber and on the velocity standard deviations.

  20. Effect of fuel injection pressure and injection timing of Karanja biodiesel blends on fuel spray, engine performance, emissions and combustion characteristics

    International Nuclear Information System (INIS)

    Agarwal, Avinash Kumar; Dhar, Atul; Gupta, Jai Gopal; Kim, Woong Il; Choi, Kibong; Lee, Chang Sik; Park, Sungwook

    2015-01-01

    Highlights: • Effect of FIP on microscopic spray characteristics. • Effect of FIP and SOI timing on CRDI engine performance, emissions and combustion. • Fuel injection duration shortened, peak injection rate increased with increasing FIP. • SMD (D 32 ) and AMD (D 10 ) of fuel droplets decreased for lower biodiesel blends. • Increase in biodiesel blend ratio and FIP, fuel injection duration decreased. - Abstract: In this investigation, effect of 10%, 20% and 50% Karanja biodiesel blends on injection rate, atomization, engine performance, emissions and combustion characteristics of common rail direct injection (CRDI) type fuel injection system were evaluated in a single cylinder research engine at 300, 500, 750 and 1000 bar fuel injection pressures at different start of injection timings and constant engine speed of 1500 rpm. The duration of fuel injection slightly decreased with increasing blend ratio of biodiesel (Karanja Oil Methyl Ester: KOME) and significantly decreased with increasing fuel injection pressure. The injection rate profile and Sauter mean diameter (D 32 ) of the fuel droplets are influenced by the injection pressure. Increasing fuel injection pressure generally improves the thermal efficiency of the test fuels. Sauter mean diameter (D 32 ) and arithmetic mean diameter (D 10 ) decreased with decreasing Karanja biodiesel content in the blend and significantly increased for higher blends due to relatively higher fuel density and viscosity. Maximum thermal efficiency was observed at the same injection timing for biodiesel blends and mineral diesel. Lower Karanja biodiesel blends (up to 20%) showed lower brake specific hydrocarbon (BSHC) and carbon monoxide (BSCO) emissions in comparison to mineral diesel. For lower Karanja biodiesel blends, combustion duration was shorter than mineral diesel however at higher fuel injection pressures, combustion duration of 50% blend was longer than mineral diesel. Up to 10% Karanja biodiesel blends in a CRDI

  1. An investigation of the engine performance, emissions and combustion characteristics of coconut biodiesel in a high-pressure common-rail diesel engine

    International Nuclear Information System (INIS)

    How, H.G.; Masjuki, H.H.; Kalam, M.A.; Teoh, Y.H.

    2014-01-01

    An experimental investigation on engine performance, emissions, combustion and vibration characteristics with coconut biodiesel fuels was conducted in a high-pressure common-rail diesel engine under five different load operations (0.17, 0.34, 0.52, 0.69 and 0.86 MPa). The test fuels included a conventional diesel fuel and four different fuel blends of coconut biodiesel (B10, B20, B30 and B50). The results showed that biodiesel blended fuels have significant influences on the BSFC (brake specific fuel consumption) and BSEC (brake specific energy consumption) at all engine loads. In general, the use of coconut biodiesel blends resulted in a reduction of BSCO (brake specific carbon monoxide) and smoke emissions regardless of the load conditions. A large reduction of 52.4% in smoke opacity was found at engine load of 0.86 MPa engine load with B50. For combustion characteristics, a slightly shorter ignition delay and longer combustion duration were found with the use of biodiesel blends under all loading operations. It was found that generally the biodiesel blends produced lower peak heat release rate than baseline diesel. The vibration results showed that the largest reduction of 13.7% in RMS (root mean square) of acceleration was obtained with B50 at engine load of 0.86 MPa with respect to the baseline diesel. - Highlights: • The performance, emissions and combustion characteristics of biodiesel were studied. • A tangible increase in BSFC was observed at all engine loads with coconut biodiesel. • A slightly shorter ignition delay was found with the use of biodiesel blends. • The vibrations for coconut biodiesel blends in diesel engine were investigated. • B50 achieved the largest reduction in RMS of acceleration at 0.86 MPa engine load

  2. Numerical study of the enhancement of combustion performance in a scramjet combustor due to injection of electric-discharge-activated oxygen molecules

    International Nuclear Information System (INIS)

    Starik, A M; Bezgin, L V; Kopchenov, V I; Loukhovitski, B I; Sharipov, A S; Titova, N S

    2013-01-01

    A comprehensive analysis of the efficiency of an approach based on the injection of a thin oxygen stream, subjected to a tailored electric discharge, into a supersonic H 2 –air flow to enhance the combustion performance in the mixing layer and in the scramjet combustor is conducted. It is shown that for such an approach there exist optimal values of reduced electric field E/N and transversal dimension d of the injected oxygen stream, which provide the minimal length of induction zone in the mixing layer. The optimal values of E/N and d depend on air flow parameters and the specific energy put into the oxygen. The injection of a thin oxygen stream (d = 1 mm) subjected to an electric discharge with E/N = 50–100 Td, which produces mostly singlet oxygen O 2 (a  1 Δ g ) and O 2 (b 1 Σ g + ) molecules and atomic oxygen, allows one to arrange stable combustion in a scramjet duct at an extremely low air temperature T air  = 900 K and pressure P air  = 0.3 bar even at a small specific energy put into the oxygen E s  = 0.2 J ncm −3 , and to provide rather high combustion completeness η = 0.73. The advance in the energy released during combustion is much higher (hundred times), in this case, than the energy supplied to the oxygen stream in the electric discharge. This approach also makes it possible to ensure the rather high combustion completeness in the scramjet combustor with reduced length. The main reason for the combustion enhancement of the H 2 –air mixture in the scramjet duct is the intensification of chain-branching reactions due to the injection of a small amount of cold non-equilibrium oxygen plasma comprising highly reactive species, O 2 (a  1 Δ g ) and O 2 (b 1 Σ g + ) molecules and O atoms, into the H 2 –air supersonic flow. (paper)

  3. Experimental study of the effects of natural gas injection timing on the combustion performance and emissions of a turbocharged common rail dual-fuel engine

    International Nuclear Information System (INIS)

    Yang, Bo; Wei, Xing; Xi, Chengxun; Liu, Yifu; Zeng, Ke; Lai, Ming-Chia

    2014-01-01

    Highlights: • Natural gas injection timing has obvious effects on combustion of dual-fuel engine. • Combustion performance is improved with optimized natural gas injection timing. • BSHC and BSCO decreased with retarded natural gas injection timing at low load. • BSNO x increased at part load while reduced at high load with delay N.G. injection. • PM is very low and insensitive to the variation of natural gas injection timing. - Abstract: Natural gas combustion with pilot ignition has been considered to be one of the most promising ways to utilize natural gas in existing diesel engine without serious engine modification and it has been widely researched all over the world. In this study, three experiments of different loads (BMEP 0.240 MPa, 0.480 MPa and 0.767 MPa) were performed on a 2.8 L four-cylinder, natural gas manifold injection dual-fuel engine to investigate the effects of natural gas injection timing on engine combustion performance and emissions. The pilot injection parameters (pilot injection timing and pressure) and natural gas injection pressure remain constant at a speed of 1600 rpm in the experiment. The cylinder pressure, HRR, CoV imep , flame development duration, CA50 and brake thermal efficiency were analyzed. The results indicated that under low and part engine loads, the flame development duration and CA50 can be reduced by properly retarding natural gas injection timing, while the CoV imep increased with retarded natural gas injection timing. As a result, the brake thermal efficiency is increased and the combustion stability slightly deteriorates. Meanwhile, under low and part engine loads, PM emissions in the dual-fuel engine is much lower than that in conventional diesel engines, furthermore, at high load, the PM emissions are near zero. CO and HC emissions are reduced with retarded natural gas injection timing under low and part loads, however, NO x emissions are slightly increased. Under high load, the flame development duration

  4. Biofuels combustion.

    Science.gov (United States)

    Westbrook, Charles K

    2013-01-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  5. Effect of A-site deficiency in LaMn_0_._9Co_0_._1O_3 perovskites on their catalytic performance for soot combustion

    International Nuclear Information System (INIS)

    Dinamarca, Robinson; Garcia, Ximena; Jimenez, Romel; Fierro, J.L.G.; Pecchi, Gina

    2016-01-01

    Highlights: • A-site defective perovskites increases the oxidation state of the B-cation. • Not always non-stoichiometric perovskites exhibit higher catalytic activity in soot combustion. • The highly symmetric cubic crystalline structure diminishes the redox properties of perovskites. - Abstract: The influence of lanthanum stoichiometry in Ag-doped (La_1_-_xAg_xMn_0_._9Co_0_._1O_3) and A-site deficient (La_1_-_xMn_0_._9Co_0_._1O_3_-_δ) perovskites with x equal to 10, 20 and 30 at.% has been investigated in catalysts for soot combustion. The catalysts were prepared by the amorphous citrate method and characterized by XRD, nitrogen adsorption, XPS, O_2-TPD and TPR. The formation of a rhombohedral excess-oxygen perovskite for Ag-doped and a cubic perovskite structure for an A-site deficient series is confirmed. The efficient catalytic performance of the larger Ag-doped perovskite structure is attributed to the rhombohedral crystalline structure, Ag_2O segregated phases and the redox pair Mn"4"+/Mn"3"+. A poor catalytic activity for soot combustion was observed with A-site deficient perovskites, despite the increase in the redox pair Mn"4"+/Mn"3"+, which is attributed to the cubic crystalline structure.

  6. Study of alcohol fuel of butanol and ethanol effect on the compression ignition (CI) engine performance, combustion and emission characteristic

    Science.gov (United States)

    Aziz, M. A.; Yusop, A. F.; Mat Yasin, M. H.; Hamidi, M. A.; Alias, A.; Hussin, H.; Hamri, S.

    2017-10-01

    Diesel engine which is one of the larger contributors to total consumption for petroleum is an attractive power unit used widely in many fields. However, diesel engines are among the main contributors to air pollutions for the large amount of emissions, such as CO, CO2 and NOx lead to an adverse effect on human health. Many researches have been done to find alternative fuels that are clean and efficient. Biodiesel is preferred as an alternative source for diesel engine which produces lower emission of pollutants. This study has focused on the evaluation of diesel and alcohol-diesel fuel properties and also the performance, combustion and exhaust emission from diesel engine fuelled with diesel and alcohol. Butanol and ethanol is blend with diesel fuel at 1:9 ratio. There are three test fuel that is tested which Diesel (100% diesel), D90BU10 (10% Butanol and 90% diesel) and D90E10 (10% Ethanol and 90% diesel). The comparison between diesel and alcohol-diesel blend has been made in terms of fuel properties characterization, engine performance such as brake power (BP) and brake specific fuel consumption (BSFC) also the in cylinder maximum pressure characteristic. Thus, exhaust gas emission of CO, CO2, NOx and O2 emission also has been observed at constant load of 50% but in different operating engine speed (1100 rpm, 1400 rpm, 1700 rpm, 2000 rpm and 2300 rpm). The results show the addition of 10% of each butanol and ethanol to diesel fuel had decreased the fuel density about 0.3% to 0.5% compared to mineral diesel. In addition, viscosity and energy content are also decrease. The addition of 10% butanol had improved the fuel cetane number however the ethanol blends react differently. In term of engine performance, as the engine speed increased, BP output also increase respectively. Hence, the alcohol blends fuel generates lower BP compared to diesel, plus BSFC for all test fuel shows decreasing trend at low and medium speed, however increased gradually at higher engine

  7. Effects of Canola Oil Biodiesel Fuel Blends on Combustion, Performance, and Emissions Reduction in a Common Rail Diesel Engine

    Directory of Open Access Journals (Sweden)

    Sam Ki Yoon

    2014-12-01

    Full Text Available In this study, we investigated the effects of canola oil biodiesel (BD to improve combustion and exhaust emissions in a common rail direct injection (DI diesel engine using BD fuel blended with diesel. Experiments were conducted with BD blend amounts of 10%, 20%, and 30% on a volume basis under various engine speeds. As the BD blend ratio increased, the combustion pressure and indicated mean effective pressure (IMEP decreased slightly at the low engine speed of 1500 rpm, while they increased at the middle engine speed of 2500 rpm. The brake specific fuel consumption (BSFC increased at all engine speeds while the carbon monoxide (CO and particulate matter (PM emissions were considerably reduced. On the other hand, the nitrogen oxide (NOx emissions only increased slightly. When increasing the BD blend ratio at an engine speed of 2000 rpm with exhaust gas recirculation (EGR rates of 0%, 10%, 20%, and 30%, the combustion pressure and IMEP tended to decrease. The CO and PM emissions decreased in proportion to the BD blend ratio. Also, the NOx emissions decreased considerably as the EGR rate increased whereas the BD blend ratio only slightly influenced the NOx emissions.

  8. The development and experimental validation of a reduced ternary kinetic mechanism for the auto-ignition at HCCI conditions, proposing a global reaction path for ternary gasoline surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim; Cavadias, Simeon; Amouroux, Jacques [UPMC Universite Paris 06, LGPPTS, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France)

    2009-02-15

    To acquire a high amount of information of the behaviour of the Homogeneous Charge Compression Ignition (HCCI) auto-ignition process, a reduced surrogate mechanism has been composed out of reduced n-heptane, iso-octane and toluene mechanisms, containing 62 reactions and 49 species. This mechanism has been validated numerically in a 0D HCCI engine code against more detailed mechanisms (inlet temperature varying from 290 to 500 K, the equivalence ratio from 0.2 to 0.7 and the compression ratio from 8 to 18) and experimentally against experimental shock tube and rapid compression machine data from the literature at pressures between 9 and 55 bar and temperatures between 700 and 1400 K for several fuels: the pure compounds n-heptane, iso-octane and toluene as well as binary and ternary mixtures of these compounds. For this validation, stoichiometric mixtures and mixtures with an equivalence ratio of 0.5 are used. The experimental validation is extended by comparing the surrogate mechanism to experimental data from an HCCI engine. A global reaction pathway is proposed for the auto-ignition of a surrogate gasoline, using the surrogate mechanism, in order to show the interactions that the three compounds can have with one another during the auto-ignition of a ternary mixture. (author)

  9. Transient flow combustion

    Science.gov (United States)

    Tacina, R. R.

    1984-01-01

    Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

  10. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    This report is a presentation of work carried out on Phase II of the HIPPS program under DOE contract DE-AC22-95PC95144 from June 1995 to March 2001. The objective of this report is to emphasize the results and achievements of the program and not to archive every detail of the past six years of effort. These details are already available in the twenty-two quarterly reports previously submitted to DOE and in the final report from Phase I. The report is divided into three major foci, indicative of the three operational groupings of the program as it evolved, was restructured, or overtaken by events. In each of these areas, the results exceeded DOE goals and expectations. HIPPS Systems and Cycles (including thermodynamic cycles, power cycle alternatives, baseline plant costs and new opportunities) HITAF Components and Designs (including design of heat exchangers, materials, ash management and combustor design) Testing Program for Radiative and Convective Air Heaters (including the design and construction of the test furnace and the results of the tests) There are several topics that were part of the original program but whose importance was diminished when the contract was significantly modified. The elimination of the subsystem testing and the Phase III demonstration lessened the relevance of subtasks related to these efforts. For example, the cross flow mixing study, the CFD modeling of the convective air heater and the power island analysis are important to a commercial plant design but not to the R&D product contained in this report. These topics are of course, discussed in the quarterly reports under this contract. The DOE goal for the High Performance Power Plant System ( HIPPS ) is high thermodynamic efficiency and significantly reduced emissions. Specifically, the goal is a 300 MWe plant with > 47% (HHV) overall efficiency and {le} 0.1 NSPS emissions. This plant must fire at least 65% coal with the balance being made up by a premium fuel such as natural gas

  11. Investigation on the Effects of Internal EGR by Variable Exhaust Valve Actuation with Post Injection on Auto-ignited Combustion and Emission Performance

    Directory of Open Access Journals (Sweden)

    Insu Cho

    2018-04-01

    Full Text Available Variable valve mechanisms are usually applied to a gasoline combustion engine to improve its power performance by controlling the amount of intake air according to the operating load. These mechanisms offer one possibility of resolving the conflict of objectives between a further reduction of raw emissions and an improvement in fuel efficiency. In recent years, variable valve control systems have become extremely important in the diesel combustion engine. Importantly, it has been shown that there are several potential benefits of applying variable valve timing (VVT to a compression ignition engine. Valve train variability could offer one option to achieve the reduction goals of engine-out emissions and fuel consumption. The aim of this study was to investigate the effects on part load combustion and emission performance of internal exhaust gas recirculation (EGR by variable exhaust valve lift actuation using a cam-in-cam system, which is an electronically variable valve device with a variable inside cam retarded to about 30 degrees. Numerical simulation based on GT-POWER has been performed to predict the NOx reduction strategy at the part load operating point of 1200 rpm in a four-valve diesel engine. A GT-POWER model of a common-rail direct injection engine with internal EGR was built and verified with experimental data. As a result, large potential for reducing NOx emissions through the use of exhaust valve control has been identified. Namely, it is possible to utilize heat efficiently as recompression of retarded post injection with downscaled specification of the exhaust valve rather than the intake valve, even if the CIC V1 condition with a reduction of the exhaust valve has a higher internal EGR rate of about 2% compared to that of the CIC V2 condition.

  12. Effect of compression ratio on performance, combustion and emission characteristics of a dual fuel diesel engine run on raw biogas

    International Nuclear Information System (INIS)

    Bora, Bhaskor J.; Saha, Ujjwal K.; Chatterjee, Soumya; Veer, Vijay

    2014-01-01

    Highlights: • Maximum brake thermal efficiency of 20.04% was obtained in dual fuel mode. • Compression ratio of 18 produced the maximum brake thermal efficiency. • Maximum replacement of diesel was found to be 79.46% at a compression ratio of 18. • CO gets reduced by 26.22% with the increase of compression ratio from 16 to18. • HC gets reduced by 41.97% with the increase of compression ratio from 16 to18. - Abstract: The energy consumption of the world is increasing at a staggering rate due to population explosion. The extensive use of energy has led to fossil fuel depletion and the rise in pollution. Renewable energy holds the key solution to these aforementioned problems. Biogas, one such renewable fuel, can be used in a diesel engine under dual fuel mode for the generation of power. This work attempts to unfold the effect of compression ratio on the performance, combustion and emission characteristics of a dual fuel diesel engine run on raw biogas. For this investigation, a 3.5 kW single cylinder, direct injection, water cooled, variable compression ratio diesel engine is converted into a biogas run dual fuel diesel engine by connecting a venturi gas mixer at the inlet manifold. Experiments have been conducted at various compression ratios (18, 17.5, 17 and 16) and under different loading conditions fixing the standard injection timing at 23° before top dead centre. At 100% load, the brake thermal efficiencies of the dual fuel mode are found to be 20.04%, 18.25%, 17.07% and 16.42% at compression ratios of 18, 17.5, 17 and 16, respectively, whereas at the same load, the diesel mode shows an efficiency of 27.76% at a compression ratio of 17.5. The maximum replacement of the precious fossil fuel is found to be 79.46%, 76.1%, 74% and 72% at compression ratios of 18, 17.5, 17 and 16, respectively at 100% load. For the dual fuel mode, on an average, there is a reduction in carbon monoxide as well as hydrocarbon emission by 26.22% and 41.97% when compression

  13. Combustion characteristics of a charcoal slurry in a direct injection diesel engine and the impact on the injection system performance

    International Nuclear Information System (INIS)

    Soloiu, Valentin; Lewis, Jeffery; Yoshihara, Yoshinobu; Nishiwaki, Kazuie

    2011-01-01

    The paper presents the research results pertaining to the renewable biomass charcoal-diesel slurries and their use as alternative fuels for combustion in diesel generating plants. The utilization of charcoal slurry fuel aims to reduce diesel oil consumption and would decrease fossil green house emissions into the atmosphere. The paper investigates the formulation, emulsification, sprays, combustion, injection system operation, and subsequent wear with charcoal-diesel slurries. In the research, cedar wood chips were used for the production of charcoal to be emulsified with diesel oil. The slurry's viscosity of 27 cP achieved the target ( o C. Charcoal slurry displayed a high vaporization rate of 75% by wt. at 300 o C. Engine investigations showed that the top combustion pressure at 1200 rpm and 100% load (7.8 brake mean effective pressure (bmep)) was 79 bar for diesel fuel and 78 bar for the charcoal slurry fuel. From the injection and heat release history was found an ignition delay of 1.7 ms for diesel that increased to 2.1 ms for the slurry fuel. A higher net heat release for charcoal slurry was observed, up to 180 J/crank angle degrees (CAD) compared with the diesel at 145 J/CAD The maximum combustion temperature reached 2300 K for diesel and 2330 K for slurry. The heat fluxes for both fuels have similar values and trends during the entire cycle showing the good compatibility of charcoal slurry with a diesel type combustion and low soot radiation. The exhaust temperatures were about 40-50 o C higher for charcoal slurry at 19 o before top dead center (BTDC) injection timing. The engine's bsfc increased as expected due to the lower heating value of the slurry fuel. The smoke Bosch no. was lower for the slurry fuel at any load, and is believed that the oxygen from the charcoal had a beneficial effect. The measured emissions of slurry fuel were better at 13 o BTDC than those of diesel fuel with the original engine settings and the remaining 6-10% oxygen content in

  14. Performance analysis of single stage libr-water absorption machine operated by waste thermal energy of internal combustion engine: Case study

    Science.gov (United States)

    Sharif, Hafiz Zafar; Leman, A. M.; Muthuraman, S.; Salleh, Mohd Najib Mohd; Zakaria, Supaat

    2017-09-01

    Combined heating, cooling, and power is also known as Tri-generation. Tri-generation system can provide power, hot water, space heating and air -conditioning from single source of energy. The objective of this study is to propose a method to evaluate the characteristic and performance of a single stage lithium bromide-water (LiBr-H2O) absorption machine operated with waste thermal energy of internal combustion engine which is integral part of trigeneration system. Correlations for computer sensitivity analysis are developed in data fit software for (P-T-X), (H-T-X), saturated liquid (water), saturated vapor, saturation pressure and crystallization temperature curve of LiBr-H2O Solution. Number of equations were developed with data fit software and exported into excel work sheet for the evaluation of number of parameter concerned with the performance of vapor absorption machine such as co-efficient of performance, concentration of solution, mass flow rate, size of heat exchangers of the unit in relation to the generator, condenser, absorber and evaporator temperatures. Size of vapor absorption machine within its crystallization limits for cooling and heating by waste energy recovered from exhaust gas, and jacket water of internal combustion engine also presented in this study to save the time and cost for the facilities managers who are interested to utilize the waste thermal energy of their buildings or premises for heating and air conditioning applications.

  15. Characterization of size, number, concentration and morphology of particulate matter emitted from a high performance diesel combustion system using biomass derived fuels

    Energy Technology Data Exchange (ETDEWEB)

    Bhardwaj, Om Parkash; Krishnamurthy, Ketan; Kremer, Florian; Pischinger, Stefan [RWTH Aachen Univ. (Germany). Inst. for Combustion Engines; Berg, Angelika von; Roth, Georg [RWTH Aachen Univ. (Germany). Inst. of Crystallography; Lueers, Bernhard; Kolbeck, Andreas; Koerfer, Thomas [FEV GmbH, Aachen (Germany)

    2013-06-01

    Motor vehicle emissions have been identified as a major source of particulates. Although the low limits of particulate matter cause a need for a particulate trap in most of the present day diesel engines, the physical and chemical characterization of particles with the measures of size, number, volatility and reactivity etc. is of increasing interest with respect to the regeneration frequency and regeneration efficiency of a particulate trap. Within the Cluster of Excellence ''Tailor-Made Fuels from Biomass (TMFB)'' at RWTH Aachen University, the Institute for Combustion Engines carried out a detailed investigation program to explore the potential of future biofuel candidates for future combustion systems. The experiments for particulate measurements and analysis were conducted on a EURO 6 compliant High Efficiency Diesel Combustion System (HECS) with petroleum based diesel fuel as reference and today's biofuel (i.e. FAME) as well as a potential future biomass derived fuel candidate (i.e. 2-MTHF I DBE), being developed under TMFB approach. Soot samples collected on polycarbonate filters were analyzed using SEM; revealing vital informations regarding particle size distribution. Furthermore, thermophoretic sampling was also performed on copper grids and samples were analyzed using TEM to determine its graphitic micro-structure. In addition, X-Ray diffraction (XRD) measurements were also performed to get further quantitative information regarding crystal lattice parameters and structure of investigated soot. The results indicate more than 90% reduction in the mass and number concentrations of engine out particle emissions using future biomass derived fuel candidate. A good co-relation was observed between TEM micro-structure results and quantitative crystal lattice and structure information obtained from XRD studies, indicating higher reactivity for soot emitted from 2-MTHF/DBE. (orig.)

  16. Autoignition characterization of primary reference fuels and n-heptane/n-butanol mixtures in a constant volume combustion device and homogeneous charge compression ignition engine

    KAUST Repository

    Baumgardner, Marc E.

    2013-12-19

    In this study, the autoignition behavior of primary reference fuels (PRF) and blends of n-heptane/n-butanol were examined in a Waukesha Fuel Ignition Tester (FIT) and a Homogeneous Charge Compression Engine (HCCI). Fourteen different blends of iso-octane, n-heptane, and n-butanol were tested in the FIT - 28 test runs with 25 ignition measurements for each test run, totaling 350 individual tests in all. These experimental results supported previous findings that fuel blends with high alcohol content can exhibit very different ignition delay periods than similarly blended reference fuels. The experiments further showed that n-butanol blends behaved unlike PRF blends when comparing the autoignition behavior as a function of the percentage of low reactivity component. The HCCI and FIT experimental results favorably compared against single and multizone models with detailed chemical kinetic mechanisms - both an existing mechanism as well as one developed during this study were used. The experimental and modeling results suggest that that the FIT instrument is a valuable tool for analysis of high pressure, low temperature chemistry, and autoignition for future fuels in advanced combustion engines. Additionally, in both the FIT and engine experiments the fraction of low temperature heat release (fLTHR) was found to correlate very well with the crank angle of maximum heat release and shows promise as a useful metric for fuel reactivity in advanced combustion applications. © 2013 American Chemical Society.

  17. Effects of chlorine and sulphur on particle formation in wood combustion performed in a laboratory scale reactor

    Energy Technology Data Exchange (ETDEWEB)

    Olli Sippula; Terttaliisa Lind; Jorma Jokiniemi [University of Kuopio, Kuopio (Finland). Fine Particle and Aerosol Technology Laboratory, Department of Environmental Sciences

    2008-09-15

    Fine particle formation in wood combustion was studied in a laboratory scale laminar flow reactor at various flue gas chlorine and sulphur concentrations. Aerosol samples were quenched at around 850{sup o}C using a porous tube diluter. Fine particle number concentrations, mass concentrations, size distributions and chemical compositions were measured. In addition, flue gas composition, including SO{sub 2} and HCl, was monitored. Experimental results were interpreted by thermodynamic equilibrium calculations. Addition of HCl clearly raised fine particle mass concentration (PM1.0) which was because of increased release of ash-forming material to fine particles. Especially the release of K, Na, Zn and Cd to fine particles increased. These species form chlorides which apparently increases their volatilization from the fuel. When a sufficient amount of SO{sub 2} was supplied in a chlorine rich combustion (S/Cl molar ratio from 4.7 to 7.5), most of the HCl stayed in the gas phase, release of ash-forming elements decreased and also fine particle concentrations dropped significantly. The sulphation of alkali metals is suggested to play a key role in the observed decrease in the fine particle concentration. It seems that the formation of sulphates leads to alkali metal retention in the coarse particle fraction. 27 refs., 11 figs., 1 tab.

  18. Effect of oxygen enriched combustion and water–diesel emulsion on the performance and emissions of turbocharged diesel engine

    International Nuclear Information System (INIS)

    Liang, Youcai; Shu, Gequn; Wei, Haiqiao; Zhang, Wei

    2013-01-01

    Highlights: • Emulsion is effective to mitigate increased NOx caused by OEC. • OEC and WDE have significant influence on particle mode formation. • OEC and WDE have significant influence on combustion characteristics. • The application potential of combination of OEC and WDE has been proved. - Abstract: Oxygen enriched combustion (OEC) is potential to improve emissions, thermal efficiency and brake power output of diesel engine. The purpose of this investigation is to study whether it is feasible to apply water diesel emulsion to mitigate the increasing NOx caused by OEC with comparable BSFC and power output. Effect of OEC on particle size and number concentration was also analyzed in this paper. Oxygen concentration of intake air varied from 21% to 24% by volume. Water content in tested fuels was 0%, 10%, 20%, and 30% by volume respectively. The result indicated that lower BSFC, higher cylinder pressure and shorter ignition delay were observed when OEC was applied, while opposite trends were found when using WDE. Reduction of PM and NOx can be realized simultaneously by applying OE combined with WDE. Particle number concentration of nucleation mode increases with increasing oxygen concentration, while that of accumulation mode decreases. Optimal operating condition was realized when water content in emulsion was below 20% along with low oxygen enrichment

  19. Tubular combustion

    CERN Document Server

    Ishizuka, Satoru

    2014-01-01

    Tubular combustors are cylindrical tubes where flame ignition and propagation occur in a spatially confined, highly controlled environment, in a nearly flat, elongated geometry. This allows for some unique advantages where extremely even heat dispersion is required over a large surface while still maintaining fuel efficiency. Tubular combustors also allow for easy flexibility in type of fuel source, allowing for quick changeover to meet various needs and changing fuel pricing. This new addition to the MP sustainable energy series will provide the most up-to-date research on tubular combustion--some of it only now coming out of private proprietary protection. Plentiful examples of current applications along with a good explanation of background theory will offer readers an invaluable guide on this promising energy technology. Highlights include: * An introduction to the theory of tubular flames * The "how to" of maintaining stability of tubular flames through continuous combustion * Examples of both small-scal...

  20. Advanced Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [NETL

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  1. The effect of rapeseed oil biodiesel fuel on combustion, performance, and the emission formation process within a heavy-duty DI diesel engine

    International Nuclear Information System (INIS)

    Lešnik, Luka; Biluš, Ignacijo

    2016-01-01

    Highlights: • Sub-models for parameter determination can be derived using experimental results. • Proposed sub-models can be used for calculation of model parameters. • Biodiesel fuel reduces emissions compared to diesel fuel on full engine load. • Usage of biodiesel fuel slow down the emission formation rate. • Oxygen content in biodiesel fuel decreases the amount of formatted CO emissions. - Abstract: This study presents the influence of biodiesel fuel and blends with mineral diesel fuel on diesel engine performance, the combustion process, and the formation of emissions. The study was conducted numerically and experimentally. The aim of the study was to test the possibility of replacing mineral diesel fuel with biodiesel fuel made from rapeseed oil. Pure biodiesel fuel and three blends of biodiesel fuel with mineral diesel fuel were tested experimentally for that purpose on a heavy-duty bus diesel engine. The engine’s performance, in-cylinder pressure, fuel consumption, and the amount of produced NO_x and CO emissions were monitored during experimental measurements, which were repeated numerically using the AVL BOOST simulation program. New empirical sub-models are proposed for determining a combustion model and emission models parameters. The proposed sub-models allow the determination of necessary combustion and emission model parameters regarding the properties of the tested fuel and the engine speed. When increasing the percentage of biodiesel fuel within the fuel blends, the reduction in engine torque and brake mean effective pressures are obtained for most of the test regimes. The reduction is caused due to the lower calorific value of the biodiesel fuel. Higher oxygen content in biodiesel fuel contributes to a better oxidation process within the combustion chamber when running on pure biodiesel or its blends. Better oxidation further results in a reduction of the formatted carbon and nitrogen oxides. The reduction of carbon emission is also

  2. Low Concentration Fe-Doped Alumina Catalysts Using Sol-Gel and Impregnation Methods: The Synthesis, Characterization and Catalytic Performance during the Combustion of Trichloroethylene

    Directory of Open Access Journals (Sweden)

    Carolina Solis Maldonado

    2014-03-01

    Full Text Available The role of iron in two modes of integration into alumina catalysts was studied at 0.39 wt% Fe and tested in trichloroethylene combustion. One modified alumina was synthesized using the sol-gel method with Fe added in situ during hydrolysis; another modification was performed using calcined alumina, prepared using the sol-gel method and impregnated with Fe. Several characterization techniques were used to study the level of Fe modification in the γ-Al2O3 phase formed and to correlate the catalytic properties during trichloroethylene (TCE combustion. The introduction of Fe in situ during the sol-gel process influenced the crystallite size, and three iron species were generated, namely, magnetite, maghemite and hematite. The impregnated Fe-alumina formed hematite and maghemite, which were highly dispersed on the γ-Al2O3 surface. The X-ray photoelectron spectra (XPS, FT-IR and Mössbauer spectroscopy analyses revealed how Fe interacted with the γ-Al2O3 lattice in both catalysts. The impregnated Fe-catalyst showed the best catalytic performance compared to the catalyst that was Fe-doped in situ by the sol-gel method; both had better catalytic activity than pure alumina. This difference in activity was correlated with the accessibility of the reactants to the hematite iron species on the surface. The chlorine poisoning for all three catalysts was less than 1.8%.

  3. High-performance carbon-coated ZnMn2O4 nanocrystallite supercapacitors with tailored microstructures enabled by a novel solution combustion method

    Science.gov (United States)

    Abdollahifar, Mozaffar; Huang, Sheng-Siang; Lin, Yu-Hsiang; Lin, Yan-Cheng; Shih, Bing-Yi; Sheu, Hwo-Shuenn; Liao, Yen-Fa; Wu, Nae-Lih

    2018-02-01

    Although ZnMn2O4 is widely studied as Li-ion battery anodes, it remains a challenge to tailor suitable microstructures of the oxide for supercapacitor applications. Carbon-coated ZnMn2O4 (C@ZMO) nanocrystallites showing high-performance pseudocapacitor behaviours in neutral aqueous electrolyte are for the first time successfully synthesised via a novel solution combustion process using polyethylene glycol as a multifunctional microstructure-directing agent. Controlling the molecular weight and amount of the polymer in the combustion solution enables the formation of highly-crystalline C@ZMO having substantially higher, by more than 5 folds, specific surface areas with mesoporous structures and conformal carbon coating via the one-pot synthesis process. The resulting C@ZMO supercapacitor electrodes in Na2SO4(aq) electrolyte exhibit ideal capacitive behaviours with specific capacitances up to 150 F g-1 and cycle stability showing no capacitance fade after 10,000 cycles at 60% of full capacity and >99% Coulombic efficiency. This study not only illustrates a new powerful synthesis route capable of producing conductive mesoporous crystalline oxide-based nanomaterials for energy storage applications but also reveals a new class of high-performance pseudocapacitive materials for neutral aqueous electrolytes.

  4. Low Concentration Fe-Doped Alumina Catalysts Using Sol-Gel and Impregnation Methods: The Synthesis, Characterization and Catalytic Performance during the Combustion of Trichloroethylene.

    Science.gov (United States)

    Maldonado, Carolina Solis; De la Rosa, Javier Rivera; Lucio-Ortiz, Carlos J; Hernández-Ramírez, Aracely; Barraza, Felipe F Castillón; Valente, Jaime S

    2014-03-12

    The role of iron in two modes of integration into alumina catalysts was studied at 0.39 wt% Fe and tested in trichloroethylene combustion. One modified alumina was synthesized using the sol-gel method with Fe added in situ during hydrolysis; another modification was performed using calcined alumina, prepared using the sol-gel method and impregnated with Fe. Several characterization techniques were used to study the level of Fe modification in the γ-Al₂O₃ phase formed and to correlate the catalytic properties during trichloroethylene (TCE) combustion. The introduction of Fe in situ during the sol-gel process influenced the crystallite size, and three iron species were generated, namely, magnetite, maghemite and hematite. The impregnated Fe-alumina formed hematite and maghemite, which were highly dispersed on the γ-Al₂O 3 surface. The X-ray photoelectron spectra (XPS), FT-IR and Mössbauer spectroscopy analyses revealed how Fe interacted with the γ-Al₂O₃ lattice in both catalysts. The impregnated Fe-catalyst showed the best catalytic performance compared to the catalyst that was Fe-doped in situ by the sol-gel method; both had better catalytic activity than pure alumina. This difference in activity was correlated with the accessibility of the reactants to the hematite iron species on the surface. The chlorine poisoning for all three catalysts was less than 1.8%.

  5. Effect of small proportion of butanol additive on the performance, emission, and combustion of Australian native first- and second-generation biodiesel in a diesel engine.

    Science.gov (United States)

    Rahman, Md Mofijur; Rasul, Mohammad Golam; Hassan, Nur Md Sayeed; Azad, Abul Kalam; Uddin, Md Nasir

    2017-10-01

    This paper aims to investigate the effect of the addition of 5% alcohol (butanol) with biodiesel-diesel blends on the performance, emissions, and combustion of a naturally aspirated four stroke multi-cylinder diesel engine at different engine speeds (1200 to 2400 rpm) under full load conditions. Three types of local Australian biodiesel, namely macadamia biodiesel (MB), rice bran biodiesel (RB), and waste cooking oil biodiesel (WCB), were used for this study, and the data was compared with results for conventional diesel fuel (B0). Performance results showed that the addition of butanol with diesel-biodiesel blends slightly lowers the engine efficiency. The emission study revealed that the addition of butanol additive with diesel-biodiesel blends lowers the exhaust gas temperature (EGT), carbon monoxide (CO), nitrogen oxide (NOx), and particulate matter (PM) emissions whereas it increases hydrocarbon (HC) emissions compared to B0. The combustion results indicated that in-cylinder pressure (CP) for additive added fuel is higher (0.45-1.49%), while heat release rate (HRR) was lower (2.60-9.10%) than for B0. Also, additive added fuel lowers the ignition delay (ID) by 23-30% than for B0. Finally, it can be recommended that the addition of 5% butanol with Australian biodiesel-diesel blends can significantly lower the NOx and PM emissions.

  6. Scalable Synthesis of Triple-Core-Shell Nanostructures of TiO2 @MnO2 @C for High Performance Supercapacitors Using Structure-Guided Combustion Waves.

    Science.gov (United States)

    Shin, Dongjoon; Shin, Jungho; Yeo, Taehan; Hwang, Hayoung; Park, Seonghyun; Choi, Wonjoon

    2018-03-01

    Core-shell nanostructures of metal oxides and carbon-based materials have emerged as outstanding electrode materials for supercapacitors and batteries. However, their synthesis requires complex procedures that incur high costs and long processing times. Herein, a new route is proposed for synthesizing triple-core-shell nanoparticles of TiO 2 @MnO 2 @C using structure-guided combustion waves (SGCWs), which originate from incomplete combustion inside chemical-fuel-wrapped nanostructures, and their application in supercapacitor electrodes. SGCWs transform TiO 2 to TiO 2 @C and TiO 2 @MnO 2 to TiO 2 @MnO 2 @C via the incompletely combusted carbonaceous fuels under an open-air atmosphere, in seconds. The synthesized carbon layers act as templates for MnO 2 shells in TiO 2 @C and organic shells of TiO 2 @MnO 2 @C. The TiO 2 @MnO 2 @C-based electrodes exhibit a greater specific capacitance (488 F g -1 at 5 mV s -1 ) and capacitance retention (97.4% after 10 000 cycles at 1.0 V s -1 ), while the absence of MnO 2 and carbon shells reveals a severe degradation in the specific capacitance and capacitance retention. Because the core-TiO 2 nanoparticles and carbon shell prevent the deformation of the inner and outer sides of the MnO 2 shell, the nanostructures of the TiO 2 @MnO 2 @C are preserved despite the long-term cycling, giving the superior performance. This SGCW-driven fabrication enables the scalable synthesis of multiple-core-shell structures applicable to diverse electrochemical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Analysis of a combustion, performance and emission characteristics of a CNG-B20 fuelled diesel engine under dual fuel mode

    Directory of Open Access Journals (Sweden)

    Pankaj S. Shelke

    2016-09-01

    Full Text Available The Carbon dioxide (CO2 is one of the primary greenhouse gases emitted by various human activities. CO2 is naturally present in the atmosphere as part of carbon cycle. Human activities are altering the carbon cycle by adding or removing CO2 to the atmosphere. The main human activity that emits the CO2 is combustion of fossil fuels for energy and transportation. Compression ignition (CI engines emit high amount of CO2 emission as it is the end product of complete combustion of hydro carbon fuels. Moreover, they emit higher NOx (nitrogen oxides and PM (particulate matter emissions and have higher fuel consumption. In the present study, experimental investigations were carried out on a CI engine under dual fuel mode with biodiesel as a pilot fuel and compressed natural gas (CNG as a main fuel. The effects of 10 % and 20 % CNG energy shares on performance and emission characteristics of the engine at rated (100% loads were studied. Experimental results indicate the beneficial of CNG addition on improvement in the engine efficiency, and reduction in NOx and CO2 emissions. The NOx and CO2 emissions decreased by 14.24 % and 30 % respectively at the rated load with biodiesel + CNG (20 % energy share as compared to base diesel. No knocking combustion was observed during the tests which confirm the smooth operation. The dual fuel operation with combination of CNG-biodiesel is an effective method to reduce NOx and CO2 emissions with an additional benefit of lower specific energy consumption.

  8. Performance, combustion timing and emissions from a light duty vehicle at different altitudes fueled with animal fat biodiesel, GTL and diesel fuels

    International Nuclear Information System (INIS)

    Ramos, Ángel; García-Contreras, Reyes; Armas, Octavio

    2016-01-01

    Highlights: • Effects of altitude, alternative fuels and driving conditions on emissions have been studied. • Combustion timing was studied by means of on-line thermodynamic diagnosis. • Altitude particularly increases the combustion duration of paraffinic fuels. • Altitude increases NOx emissions more than ten times compared to the sea level. • Effect of fuels on particulate matter is masked when diesel particle filters work efficiently. - Abstract: The altitude effect on performance, emissions and thermodynamic diagnosis under real world driving conditions has been evaluated using two alternative fuels and a diesel fuel. Three places, at different altitudes, were selected for the tests, from 0 to 2500 m above the sea level. Besides, two type of circuits (Urban and Extra-urban) have been selected in order to evaluate these two driving pattern conditions. A light duty diesel vehicle equipped with the same after-treatment system as Euro 5 engines was used as test vehicle. Thermodynamic diagnosis shows that, when the engine works with two pre-injection events (mainly at high altitude and without EGR) the ignition delay agrees of the cetane number of fuels. At urban conditions, altitude increases the combustion duration of all fuels and particularly with paraffinic fuels. The effect of altitude on THC and CO emissions is not noticeable, but at high altitude, NOx emissions during extra-urban tests were around three times higher than those from testing along the urban circuit. Besides, compared to circuits next to the sea level, these emissions at both circuits (urban and extra-urban) were around ten times higher, respectively, than the limits established by the Euro standards. The effect of fuels on pollutant emissions was masked by the variability associated to real driving conditions.

  9. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.

    2017-03-28

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

  10. Scrutinizing the combustion, performance and emissions of safflower biodiesel–kerosene fueled diesel engine used as power source for a generator

    International Nuclear Information System (INIS)

    Aydın, Hüseyin

    2016-01-01

    Highlights: • Effects of kerosene addition to biodiesel in a diesel engine were investigated. • S90&K10, S75&K25 and S50&K50 were tested and comparisons have been made with D2. • Patterns of combustion parameters have found be quite similar for blend fuels and D2. • The highest efficiency value is obtained for S50&K50 blend. • HC emissions a bit increased and NOx emissions were decreased. - Abstract: When neat biodiesel or its blends with diesel fuel that contain high amounts of biodiesel are used in diesel engines some operational problems such as poor injection, bad atomization and incomplete combustion occur mainly due to higher viscosity and surface tension. Engine problems with the use of biodiesel–fuel blends that contain higher percentages of biodiesel need to be solved in order to utilize the advantages of biodiesel in environmental and economical ways. The mentioned problems can also be solved by blending biodiesel with another low density or viscosity fuel such as kerosene. In present study biodiesel was produced from safflower oil. S90&K10, S75&K25 and S50&K50 were prepared by blending biodiesel with kerosene. A 4 cylinder diesel engine that was used to drive an electric generator was used to deeply investigate the similarity of combustion, performance and emission characteristics of the blend fuels to D2. All experiments were carried out at constant loads of 3.6, 7.2 and 10.8 kW generated powers. Patterns of combustion parameters found to be quite similar for blends and D2 fuel. NO_x emissions were considerably decreased with percentages of 68.2%, 56.9% and 55.1% for S50&K50, S75&K25 and S90&K10, respectively while unburned HC emissions were a bit increased. Mass fuel consumption and BSFC were slightly increased for S75&K25 and S90&K10, but they were decreased with an average increase in BTE by 3.84% for S50&K50 fuel when compared to D2. Eventually, it was concluded that high percentages of safflower oil biodiesel can be a potential

  11. Sound quality assessment of Diesel combustion noise using in-cylinder pressure components

    Science.gov (United States)

    Payri, F.; Broatch, A.; Margot, X.; Monelletta, L.

    2009-01-01

    The combustion process in direct injection (DI) Diesel engines is an important source of noise, and it is thus the main reason why end-users could be reluctant to drive vehicles powered with this type of engine. This means that the great potential of Diesel engines for environment preservation—due to their lower consumption and the subsequent reduction of CO2 emissions—may be lost. Moreover, the advanced combustion concepts—e.g. the HCCI (homogeneous charge compression ignition)—developed to comply with forthcoming emissions legislation, while maintaining the efficiency of current engines, are expected to be noisier because they are characterized by a higher amount of premixed combustion. For this reason many efforts have been dedicated by car manufacturers in recent years to reduce the overall level and improve the sound quality of engine noise. Evaluation procedures are required, both for noise levels and sound quality, that may be integrated in the global engine development process in a timely and cost-effective manner. In previous published work, the authors proposed a novel method for the assessment of engine noise level. A similar procedure is applied in this paper to demonstrate the suitability of combustion indicators for the evaluation of engine noise quality. These indicators, which are representative of the peak velocity of fuel burning and the resonance in the combustion chamber, are well correlated with the combustion noise mark obtained from jury testing. Quite good accuracy in the prediction of the engine noise quality has been obtained with the definition of a two-component regression, which also permits the identification of the combustion process features related to the resulting noise quality, so that corrective actions may be proposed.

  12. Analysis of combustion performance and emission of extended expansion cycle and iEGR for low heat rejection turbocharged direct injection diesel engines

    Directory of Open Access Journals (Sweden)

    Shabir Mohd F.

    2014-01-01

    Full Text Available Increasing thermal efficiency in diesel engines through low heat rejection concept is a feasible technique. In LHR engines the high heat evolution is achieved by insulating the combustion chamber surfaces and coolant side of the cylinder with partially stabilized zirconia of 0.5 mm thickness and the effective utilization of this heat depend on the engine design and operating conditions. To make the LHR engines more suitable for automobile and stationary applications, the extended expansion was introduced by modifying the inlet cam for late closing of intake valve through Miller’s cycle for extended expansion. Through the extended expansion concept the actual work done increases, exhaust blow-down loss reduced and the thermal efficiency of the LHR engine is improved. In LHR engines, the formation of nitric oxide is more, to reduce the nitric oxide emission, the internal EGR is incorporated using modified exhaust cam with secondary lobe. Modifications of gas exchange with internal EGR resulted in decrease in nitric oxide emissions. In this work, the parametric studies were carried out both theoretically and experimentally. The combustion, performance and emission parameters were studied and were found to be satisfactory.

  13. Infrared monitoring of combustion

    International Nuclear Information System (INIS)

    Bates, S.C.; Morrison, P.W. Jr.; Solomon, P.R.

    1991-01-01

    In this paper, the use of Fourier Transform Infrared (FT-IR) spectroscopy for combustion monitoring is described. A combination of emission, transmission, and reflection FT-IR spectroscopy yields data on the temperature and composition of the gases, surfaces and suspended particles in the combustion environment. Detection sensitivity of such trace exhaust gases as CO, CO 2 , SO 2 , NO x , and unburned hydrocarbons is at the ppm level. Tomographic reconstruction converts line-of-sight measurements into spatially resolved temperature and concentration data. Examples from various combustion processes are used to demonstrate the capabilities of the technique. Industrial measurements are described that have been performed directly in the combustion zone and in the exhaust duct of a large chemical recovery boiler. Other measurements of hot slag show how FT-IR spectroscopy can determine the temperature and optical properties of surfaces. In addition, experiments with water droplets show that transmission FT-IR data yield spectra that characterize particle size and number density

  14. Performance, combustion, and emission characteristics of a diesel engine fueled by biodiesel-diesel mixtures with multi-walled carbon nanotubes additives

    International Nuclear Information System (INIS)

    El-Seesy, Ahmed I.; Abdel-Rahman, Ali K.; Bady, Mahmoud; Ookawara, S.

    2017-01-01

    Highlights: • Considerable improvements in the combustion of JB20D50MWCNTs compared to pure JB20D. • p_m_a_x, dp/dθ_m_a_x and dQg/dθ_m_a_x increased by 7%, 4% and 4%, respectively. • Brake specific fuel consumption decreased by 15%. • NO_x, CO, and UHC reduced by 35%, 50%, and 60%, respectively. • Significant enhancement in all engine performance was achieved at a concentration of 40 mg/l. - Abstract: In this work, the effects of adding Multi-Walled Carbon nanotubes (MWCNTs) to Jojoba methyl ester-diesel blended fuel (JB20D) on performance, combustion and emissions characteristics of a compression-ignition engine were experimentally investigated. The JB20D with 10, 20, 30, 40 and 50 mg/l of MWCNTs were examined at different engine loads and speeds. Compared to pure diesel, the use of JB20D without MWCNTs caused a slight decrease in the engine performance and an increase in the engine emissions at most examined conditions. The MWCNTs–B20D blended fuel attained a maximum increase of 16% in the brake thermal efficiency and a decrease of 15% in the brake specific fuel consumption at the dose level of 50 mg/l compared to JB20D. The MWCNTs-JB20D blended fuel also brought about an enhancement in combustion characteristics where the peak cylinder pressure, the maximum rate of pressure rise and the peak heat release rate were increased by 7%, 4%, and 4%, respectively, at the same dose level. According to the measured emissions, a significant reduction of engine emissions was achieved at the dose level of 20 mg/l, where NO_x, CO, and UHC were reduced by 35%, 50%, and 60%, respectively. According to the obtained results, the recommended concentration of MWCNTs in JB20D was concluded to be 40 mg/l, which could give significant improvements in overall the parameters of engine performance and emissions with a good balance between them.

  15. Calibration and validation of a model for simulating thermal and electric performance of an internal combustion engine-based micro-cogeneration device

    International Nuclear Information System (INIS)

    Rosato, A.; Sibilio, S.

    2012-01-01

    The growing worldwide demand for more efficient and less polluting forms of energy production has led to a renewed interest in the use of micro-cogeneration technologies in the residential. Among the others technologies, internal combustion engine-based micro-cogeneration devices are a market-ready technology gaining an increasing appeal thanks to their high efficiency, fuel flexibility, low emissions, low noise and vibration. In order to explore and assess the feasibility of using internal combustion engine-based cogeneration systems in the residential sector, an accurate and practical simulation model that can be used to conduct sensitivity and what-if analyses is needed. A residential cogeneration device model has been developed within IEA/ECBCS Annex 42 and implemented into a number of building simulation programs. This model is potentially able to accurately predict the thermal and electrical outputs of the residential cogeneration devices, but it relies almost entirely on empirical data because the model specification uses experimental measurements contained within a performance map to represent the device specific performance characteristics coupled with thermally massive elements to characterize the device's dynamic thermal performance. At the Built Environment Control Laboratory of Seconda Università degli studi di Napoli, an AISIN SEIKI micro-cogeneration device based on natural gas fuelled reciprocating internal combustion engine is available. This unit has been intensively tested in order to calibrate and validate the Annex 42 model. This paper shows in detail the series of experiments conducted for the calibration activity and examines the validity of this model by contrasting simulation predictions to measurements derived by operating the system in electric load following control strategy. The statistical comparison was made both for the whole database and the segregated data by system mode operation. The good agreement found in the predictions of

  16. Low-Temperature Combustion of High Octane Fuels in a Gasoline Compression Ignition Engine

    Directory of Open Access Journals (Sweden)

    Khanh Duc Cung

    2017-12-01

    Full Text Available Gasoline compression ignition (GCI has been shown as one of the advanced combustion concepts that could potentially provide a pathway to achieve cleaner and more efficient combustion engines. Fuel and air in GCI are not fully premixed compared to homogeneous charge compression ignition (HCCI, which is a completely kinetic-controlled combustion system. Therefore, the combustion phasing can be controlled by the time of injection, usually postinjection in a multiple-injection scheme, to mitigate combustion noise. Gasoline usually has longer ignition delay than diesel. The autoignition quality of gasoline can be indicated by research octane number (RON. Fuels with high octane tend to have more resistance to autoignition, hence more time for fuel-air mixing. In this study, three fuels, namely, aromatic, alkylate, and E30, with similar RON value of 98 but different hydrocarbon compositions were tested in a multicylinder engine under GCI combustion mode. Considerations of exhaust gas recirculating (EGR, start of injection, and boost were investigated to study the sensitivity of dilution, local stratification, and reactivity of the charge, respectively, for each fuel. Combustion phasing (location of 50% of fuel mass burned was kept constant during the experiments. This provides similar thermodynamic conditions to study the effect of fuels on emissions. Emission characteristics at different levels of EGR and lambda were revealed for all fuels with E30 having the lowest filter smoke number and was also most sensitive to the change in dilution. Reasonably low combustion noise (<90 dB and stable combustion (coefficient of variance of indicated mean effective pressure <3% were maintained during the experiments. The second part of this article contains visualization of the combustion process obtained from endoscope imaging for each fuel at selected conditions. Soot radiation signal from GCI combustion were strong during late injection and also more intense

  17. Engine combustion network (Ecn) : characterization and comparison of boundary conditions for different combustion vessels

    NARCIS (Netherlands)

    Meijer, M.; Somers, L.M.T.; Johnson, J.; Naber, J.; Lee, S.Y.; Malbec, L.M.; Bruneaux, G.; Pickett, L.M.; Bardi, M.; Payri, R.; Bazyn, T.

    2012-01-01

    The Engine Combustion Network (ECN) is a worldwide group of institutions using combustion vessels and/or performing computational fluid dynamics (CFD) simulation, whose aim is to advance the state of spray and combustion knowledge at engine-relevant conditions. A key activity is the use of spray

  18. Combustion performance and pollutant emissions analysis using diesel/gasoline/iso-butanol blends in a diesel engine

    International Nuclear Information System (INIS)

    Wei, Mingrui; Li, Song; Xiao, Helin; Guo, Guanlun

    2017-01-01

    Highlights: • The diesel/gasoline/iso-butanol blends were investigated in a CI engine. • Blend with gasoline or iso-butanol produce higher HC emission. • CO increase at low loads and decrease at medium and high loads with blend fuels. • Gasoline or iso-butanol decrease large particles but increase small particles. • Blend fuels reduce total PM number and mass concentrations. - Abstract: In this study, the effects of diesel/gasoline/iso-butanol blends, including pure diesel (D100), diesel (70%)/gasoline (30%) (D70G30, by mass), diesel (70%)/iso-butanol (30%) (D70B30) and diesel (70%)/gasoline (15%)/iso-butanol (15%) (D70G15B15), on combustion and exhaust pollutant emissions characteristics in a four-cylinder diesel engine were experimentally investigated under various engine load conditions with a constant speed of 1800 rpm. The results indicated that D70G30, D70G15B15 and D70B30 delayed the ignition timing and shortened the combustion duration compared to D100. Additionally, CA50 was retarded when engine fuelled with D70G30, D70G15B15 and D70B30 at low engine load conditions, but it was advanced at medium and high engine loads. The maximum pressure rise rates (MPRRs) of D70G30, D70G15B15 and D70B30 were increased compared with D100 except for at engine load of 0.13 MPa BMEP (brake mean effective pressure). Meanwhile, D70G15B15 and D70B30 produced higher brake specific fuel consumption (BSFC) than that of D100. The effects of diesel blend with gasoline or iso-butanol on exhaust pollutant emissions were varied with loads. CO emissions were increased obviously and NOx emissions were decreased under low engine loads. However, CO emissions were decreased and NOx emissions were slightly increased under the medium and high engine load conditions. However, D70G30, D70G15B15 and D70B30 leaded to higher HC emissions than D100 regardless the variation of engine load. Moreover, the particulate matter (PM) (diameter, number and mass concentrations) emissions by using

  19. 77 FR 37361 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2012-06-21

    ... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines AGENCY: Environmental Protection... Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance...

  20. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

  1. Combustion Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Combustion Research Laboratory facilitates the development of new combustion systems or improves the operation of existing systems to meet the Army's mission for...

  2. The impact of the weather conditions on the cooling performance of the heat pump driven by an internal natural gas combustion engine

    Science.gov (United States)

    Janovcová, Martina; Jandačka, Jozef; Malcho, Milan

    2015-05-01

    Market with sources of heat and cold offers unlimited choice of different power these devices, design technology, efficiency and price categories. New progressive technologies are constantly discovering, about which is still little information, which include heat pumps powered by a combustion engine running on natural gas. A few pieces of these installations are in Slovakia, but no studies about their work and effectiveness under real conditions. This article deals with experimental measurements of gas heat pump efficiency in cooling mode. Since the gas heat pump works only in system air - water, air is the primary low - energy source, it is necessary to monitor the impact of the climate conditions for the gas heat pump performance.

  3. The impact of the weather conditions on the cooling performance of the heat pump driven by an internal natural gas combustion engine

    Directory of Open Access Journals (Sweden)

    Janovcová Martina

    2015-01-01

    Full Text Available Market with sources of heat and cold offers unlimited choice of different power these devices, design technology, efficiency and price categories. New progressive technologies are constantly discovering, about which is still little information, which include heat pumps powered by a combustion engine running on natural gas. A few pieces of these installations are in Slovakia, but no studies about their work and effectiveness under real conditions. This article deals with experimental measurements of gas heat pump efficiency in cooling mode. Since the gas heat pump works only in system air – water, air is the primary low – energy source, it is necessary to monitor the impact of the climate conditions for the gas heat pump performance.

  4. Combustion, Performance, and Emission Evaluation of a Diesel Engine with Biodiesel Like Fuel Blends Derived From a Mixture of Pakistani Waste Canola and Waste Transformer Oils

    Directory of Open Access Journals (Sweden)

    Muhammad Qasim

    2017-07-01

    Full Text Available The aim of this work was to study the combustion, performance, and emission characteristics of a 5.5 kW four-stroke single-cylinder water-cooled direct-injection diesel engine operated with blends of biodiesel-like fuel (BLF15, BLF20 & BLF25 obtained from a 50:50 mixture of transesterified waste transformer oil (TWTO and waste canola oil methyl esters (WCOME with petroleum diesel. The mixture of the waste oils was named as biodiesel-like fuel (BLF.The engine fuelled with BLF blends was evaluated in terms of combustion, performance, and emission characteristics. FTIR analysis was carried out to know the functional groups in the BLF fuel. The experimental results revealed the shorter ignition delay and marginally higher brake specific fuel consumption (BSFC, brake thermal efficiency (BTE and exhaust gas temperature (EGT values for BLF blends as compared to diesel. The hydrocarbon (HC and carbon monoxide (CO emissions were decreased by 10.92–31.17% and 3.80–6.32%, respectively, as compared to those of diesel fuel. Smoke opacity was significantly reduced. FTIR analysis has confirmed the presence of saturated alkanes and halide groups in BLF fuel. In comparison to BLF20 and BLF25, the blend BLF15 has shown higher brake thermal efficiency and lower fuel consumption values. The HC, CO, and smoke emissions of BLF15 were found lower than those of petroleum diesel. The fuel blend BLF15 is suggested to be used as an alternative fuel for diesel engines without any engine modification.

  5. Stearic acid coating on circulating fluidized bed combustion fly ashes and its effect on the mechanical performance of polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Nina [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Zhang, Ping, E-mail: pingzhang@swust.edu.cn [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Song, Lixian; Kang, Ming; Lu, Zhongyuan [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Zheng, Rong [Sichuan Jinhe Group Co., Ltd., Mianyang 621010 (China)

    2013-08-15

    The aim of this work was to test circulating fluidized bed combustion fly ashes (CFAs) for its potential to be utilized in polymer composites manufacturing to improve its toughness. CFAs was coated by stearic acid and used in the composite of polypropylene/ethylene vinyl acetate/high density polyethylene (PP/EVA/HDPE) by molding process method. The resulting coated and uncoated CFAs were fully characterized by particle size analyzer, contact angles, powder X-ray diffraction (XRD), thermogravimetric analysis/differential thermal analysis (TGA/DTA), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stearic acid coated onto the surface of CFAs particles in the physical and chemical ways, and the total clad ratio reached 2.05% by measuring TGA/DTA curve. The percentage of CFAs particles focused to a narrow range 2–4 μm and the median mean size was 3.2 μm more than uncoated CFAs. The properties of hydrophobic and dispersive of CFAs particles improved and original activity was reserved after stearic acid coating. The stearic acid was verified as a coupling agent by how much effect it had on the mechanical properties. It showed the elongation at break of PP/EVA/HDPE reinforced with 15 wt% coated CFAs (c-CFAs) was 80.20% and higher than that of the uncoated. The stearic acid treatment of CFAs is a very promising approach to improve the mechanical strength due to the incorporation of stearic acid on the CFAs surface, and hence, further enhances the potential for recycling CFAs as a suitable filler material in polymer composites.

  6. Stearic acid coating on circulating fluidized bed combustion fly ashes and its effect on the mechanical performance of polymer composites

    International Nuclear Information System (INIS)

    Yao, Nina; Zhang, Ping; Song, Lixian; Kang, Ming; Lu, Zhongyuan; Zheng, Rong

    2013-01-01

    The aim of this work was to test circulating fluidized bed combustion fly ashes (CFAs) for its potential to be utilized in polymer composites manufacturing to improve its toughness. CFAs was coated by stearic acid and used in the composite of polypropylene/ethylene vinyl acetate/high density polyethylene (PP/EVA/HDPE) by molding process method. The resulting coated and uncoated CFAs were fully characterized by particle size analyzer, contact angles, powder X-ray diffraction (XRD), thermogravimetric analysis/differential thermal analysis (TGA/DTA), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stearic acid coated onto the surface of CFAs particles in the physical and chemical ways, and the total clad ratio reached 2.05% by measuring TGA/DTA curve. The percentage of CFAs particles focused to a narrow range 2–4 μm and the median mean size was 3.2 μm more than uncoated CFAs. The properties of hydrophobic and dispersive of CFAs particles improved and original activity was reserved after stearic acid coating. The stearic acid was verified as a coupling agent by how much effect it had on the mechanical properties. It showed the elongation at break of PP/EVA/HDPE reinforced with 15 wt% coated CFAs (c-CFAs) was 80.20% and higher than that of the uncoated. The stearic acid treatment of CFAs is a very promising approach to improve the mechanical strength due to the incorporation of stearic acid on the CFAs surface, and hence, further enhances the potential for recycling CFAs as a suitable filler material in polymer composites.

  7. Effect of Hydrogen Addition on Methane HCCI Engine Ignition Timing and Emissions Using a Multi-zone Model

    Science.gov (United States)

    Wang, Zi-han; Wang, Chun-mei; Tang, Hua-xin; Zuo, Cheng-ji; Xu, Hong-ming

    2009-06-01

    Ignition timing control is of great importance in homogeneous charge compression ignition engines. The effect of hydrogen addition on methane combustion was investigated using a CHEMKIN multi-zone model. Results show that hydrogen addition advances ignition timing and enhances peak pressure and temperature. A brief analysis of chemical kinetics of methane blending hydrogen is also performed in order to investigate the scope of its application, and the analysis suggests that OH radical plays an important role in the oxidation. Hydrogen addition increases NOx while decreasing HC and CO emissions. Exhaust gas recirculation (EGR) also advances ignition timing; however, its effects on emissions are generally the opposite. By adjusting the hydrogen addition and EGR rate, the ignition timing can be regulated with a low emission level. Investigation into zones suggests that NOx is mostly formed in core zones while HC and CO mostly originate in the crevice and the quench layer.

  8. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  9. Effect of Biodiesel Fuel Injection Timing and Venture for Gaseous Fuel Induction on the Performance, Emissions and Combustion Characteristics of Dual Fuel Engine

    Directory of Open Access Journals (Sweden)

    Mallikarjun Bhovi

    2018-02-01

    Full Text Available Advancing or retarding pilot fuel injection timing in a diesel engine provided with either conventional mechanical fuel injection (CMFIS or high pressure injection as in common rail fuel injection (CRDI systems can significantly affect its performance and tail pipe emissions. Performance of diesel engine when fueled with various biofuels as well as gaseous fuels tends to vary with subsequent changes in pilot fuel injection timings. Biodiesel derived from rubber seed oil called Rubber Seed Oil Methyl Ester (RuOME and hydrogen (H2 and hydrogen enriched compressed natural gas called (HCNG both being renewable fuels when used in diesel engines modified to operate in dual fuel mode can provide complete replacement for fossil diesel. In the present study, effect of injection timings and venture design for gas mixing on the performance, combustion and emission characteristics of dual fuel engine fitted with both CMFIS and CRDI injection systems and operated on RuOME and HCNG/hydrogen has been investigated. Results showed that high pressure CRDI assisted injection of RuOME with optimized mixing chamber (carburetor for hydrogen induction in dual fuel engine performed improved compared to that with CMFIS. In addition, for the same fuel combinations, CRDI resulted in lower biodiesel consumption, lower carbon monoxide (BSCO and hydrocarbon (BSHC emissions and increased NOx emissions than CMFIS operation.

  10. Desempeño y emisiones de un motor de combustión interna con combustible dual Diesel – Gas natural ;Performance and emissions study of an internal combustion engine with dual fuel diesel - natural gas

    Directory of Open Access Journals (Sweden)

    Juan Miguel Mantilla González

    2015-04-01

    Full Text Available Muchos de los problemas reportados para los sistemas duales diesel- gas natural ocurren por mala dosificación del gas. Por esta razón se adaptó un sistema de alimentación dual con inyección electrónica de gas natural a un motor de combustión interna encendido por compresión. Se plantea un diseño experimental controlando el dosado de gas natural.Como resultado se obtiene un análisis comparativo entre los valoresde desempeño y emisiones desde la operación Diesel y Diesel-Gas natural. A partir de este análisis es posible observar que el desempeño del motor no se ve afectado por la operación del motor bajo el esquema Dual Diesel-GN, es decir que el motor funcionando bajo modo dual puede sostener las cargas solicitadas al motor. También se observa que la eficiencia volumétrica mejora bajo todas las condiciones de operación dual y las emisiones son mejores sólo cuando el motor trabaja a altas cargas. Many of the problems reported for dual diesel-natural gas systems occur due to poor gas dosage. For this reason a natural gas electronic injection feeding system was adapted to a compression ignitios internal combustion engine. An experimental design controlling the natural gas dosage is considered. As a result a comparative analysis between performance and emissions from the Diesel-and diesel-Natural Gas operation is obtained. From this analysis it is possible to see that engine performance is not affected by operation of the engine under the dual mode, i.e. the motor running under dual mode can support the loads applied to the engine. It is also observed that the volumetric efficiency improves under all conditions of operation and emissions from the dual mode of operation are better only when working at high engine loads.

  11. Fabrication of a Combustion-Reacted High-Performance ZnO Electron Transport Layer with Silver Nanowire Electrodes for Organic Solar Cells.

    Science.gov (United States)

    Park, Minkyu; Lee, Sang-Hoon; Kim, Donghyuk; Kang, Juhoon; Lee, Jung-Yong; Han, Seung Min

    2018-02-28

    Herein, a new methodology for solution-processed ZnO fabrication on Ag nanowire network electrode via combustion reaction is reported, where the amount of heat emitted during combustion was minimized by controlling the reaction temperature to avoid damaging the underlying Ag nanowires. The degree of participation of acetylacetones, which are volatile fuels in the combustion reaction, was found to vary with the reaction temperature, as revealed by thermogravimetric and compositional analyses. An optimized processing temperature of 180 °C was chosen to successfully fabricate a combustion-reacted ZnO and Ag nanowire hybrid electrode with a sheet resistance of 30 Ω/sq and transmittance of 87%. A combustion-reacted ZnO on Ag nanowire hybrid structure was demonstrated as an efficient transparent electrode and electron transport layer for the PTB7-Th-based polymer solar cells. The superior electrical conductivity of combustion-reacted ZnO, compared to that of conventional sol-gel ZnO, increased the external quantum efficiency over the entire absorption range, whereas a unique light scattering effect due to the presence of nanopores in the combustion-derived ZnO further enhanced the external quantum efficiency in the 450-550 nm wavelength range. A power conversion efficiency of 8.48% was demonstrated for the PTB7-Th-based polymer solar cell with the use of a combustion-reacted ZnO/Ag NW hybrid transparent electrode.

  12. Rotary combustion device

    NARCIS (Netherlands)

    2008-01-01

    Rotary combustion device (1) with rotary combustion chamber (4). Specific measures are taken to provide ignition of a combustible mixture. It is proposed that a hollow tube be provided coaxially with the axis of rotation (6), so that a small part of the mixture is guided into the combustion chamber.

  13. LES and RANS modeling of pulverized coal combustion in swirl burner for air and oxy-combustion technologies

    International Nuclear Information System (INIS)

    Warzecha, Piotr; Boguslawski, Andrzej

    2014-01-01

    Combustion of pulverized coal in oxy-combustion technology is one of the effective ways to reduce the emission of greenhouse gases into the atmosphere. The process of transition from conventional combustion in air to the oxy-combustion technology, however, requires a thorough investigations of the phenomena occurring during the combustion process, that can be greatly supported by numerical modeling. The paper presents the results of numerical simulations of pulverized coal combustion process in swirl burner using RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) methods for turbulent flow. Numerical simulations have been performed for the oxyfuel test facility located at the Institute of Heat and Mass Transfer at RWTH Aachen University. Detailed analysis of the flow field inside the combustion chamber for cold flow and for the flow with combustion using different numerical methods for turbulent flows have been done. Comparison of the air and oxy-coal combustion process for pulverized coal shows significant differences in temperature, especially close to the burner exit. Additionally the influence of the combustion model on the results has been shown for oxy-combustion test case. - Highlights: • Oxy-coal combustion has been modeled for test facility operating at low oxygen ratio. • Coal combustion process has been modeled with simplified combustion models. • Comparison of oxy and air combustion process of pulverized coal has been done. • RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) results for pulverized coal combustion process have been compared

  14. Solution-combustion synthesized aluminium-doped spinel (LiAl(subx)Mn(sub2-x)O(sub4) as a high-performance lithium-ion battery cathode material

    CSIR Research Space (South Africa)

    Kebede, MA

    2015-06-01

    Full Text Available High-performing (LiAl(subx)Mn(sub2-x)O(sub4) (x = 0, 0.125, 0.25, 0.375, and 0.5) spinel cathode materials for lithium-ion battery were developed using a solution combustion method. The as-synthesized cathode materials have spinel cubic structure...

  15. 77 FR 60341 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2012-10-03

    ... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines AGENCY: Environmental Protection... Pollutants for Stationary Reciprocating Internal Combustion Engines to solicit comment on specific issues...

  16. 77 FR 33811 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2012-06-07

    ... 63 National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines; Proposed Rule #0;#0... Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source...

  17. Low-Cost, Lightweight, High-Performance CMC Combustion Chamber for HAN-Based Monopropellant Engines, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Non-toxic storable liquid propulsion systems are of great interest for use in future exploration missions. Efficient propulsive performance and long-duration storage...

  18. High Performance Multiphase Combustion Tool Using Level Set-Based Primary Atomization Coupled with Flamelet Models, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovative methodologies proposed in this STTR Phase 2 project will enhance Loci-STREAM which is a high performance, high fidelity simulation tool already being...

  19. High Performance Multiphase Combustion Tool Using Level Set-Based Primary Atomization Coupled with Flamelet Models, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovative methodologies proposed in this STTR Phase 1 project will enhance Loci-STREAM which is a high performance, high fidelity simulation tool already being...

  20. Experimental investigation on the availability, performance, combustion and emission distinctiveness of bael oil/ diesel/ diethyl ether blends powered in a variable compression ratio diesel engine

    Science.gov (United States)

    Krishnamoorthi, M.; Malayalamurthi, R.

    2018-02-01

    The present work aims at experimental investigation on the combined effect of injection timing (IT) and injection pressure (IP) on the performance and emissions characteristics, and exergy analysis of a compression-ignition (CI) engine powered with bael oil blends. The tests were conducted using ternary blends of bael oil, diethyl ether (DEE) and neat diesel (D) at various engine loads at a constant engine speed (1500 rpm). With B2 (60%D + 30%bael oil+10%DEE) fuel, the brake thermal efficiency (BTE) of the engine is augmented by 3.5%, reduction of 4.7% of oxides of nitrogen (NOx) emission has been observed at 100% engine load with 250 bar IP. B2 fuel exhibits 7% lower scale of HC emissions compared to that of diesel fuel at 100% engine load in 23 °bTDC IT. The increment in both cooling water and exhaust gas availabilities lead to increasing exergy efficiency with increasing load. The exergy efficiency of about 62.17% has been recorded by B2 fuel at an injection pressure of 230 IP bar with 100% load. On the whole, B2 fuel displays the best performance and combustion characteristics. It also exhibits better characteristics of emissions level in terms of lower HC, smoke opacity and NOx.

  1. Effect of water-containing acetone–butanol–ethanol gasoline blends on combustion, performance, and emissions characteristics of a spark-ignition engine

    International Nuclear Information System (INIS)

    Li, Yuqiang; Nithyanandan, Karthik; Lee, Timothy H.; Donahue, Robert Michael; Lin, Yilu; Lee, Chia-Fon; Liao, Shengming

    2016-01-01

    Highlights: • Water-containing ABE (acetone–butanol–ethanol) was used an alternative fuel. • Water-containing ABE and gasoline blends were investigated in an SI engine. • Water-containing ABE and gasoline blends can enhance engine torque. • Water-containing ABE and gasoline blends can reduce CO, UHC and NO_x emissions. - Abstract: Bio-butanol has proved to be a promising alternative fuel in recent years; it is typically produced from ABE (acetone–butanol–ethanol) fermentation from non-edible biomass feedstock. The high costs for dehydration and recovery from dilute fermentation broth have so far prohibited bio-butanol’s use in internal combustion engines. There is an interesting in studying the intermediate fermentation product, i.e. water-containing ABE as a potential fuel. However, most previous studies covered the use of water-containing ABE–diesel blends. In addition, previous studies on SI engines fueled with ABE did not consider the effect of water. Therefore, the evaluation of water-containing ABE gasoline blends in a port fuel-injected spark-ignition (SI) engine was carried out in this study. Effect of adding ABE and water into gasoline on combustion, performance and emissions characteristics was investigated by testing gasoline, ABE30, ABE85, ABE29.5W0.5 and ABE29W1 (29 vol.% ABE, 1 vol.% water and 70 vol.% gasoline). In addition, ABE29W1 was compared with gasoline under various equivalence ratios (Φ = 0.83–1.25) and engine loads (3 and 5 bar BMEP). It was found that ABE29W1 generally had higher engine toque (3.1–8.2%) and lower CO (9.8–35.1%), UHC (27.4–78.2%) and NO_x (4.1–39.4%) than those of gasoline. The study indicated that water-containing ABE could be used in SI engines as an alternative fuel with good engine performance and low emissions.

  2. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking......-column’’ approach and includes the energy equations for both the fuel and the gas accounting for heat transfer between the two phases. The model gives important insight into the combustion process and provides inlet conditions for a computational fluid dynamics analysis of the freeboard. The model predictions...... indicate the existence of two distinct combustion modes. Combustion air temperature and mass flow-rate are the two parameters determining the mode. There is a significant difference in reaction rates (ignition velocity) and temperature levels between the two modes. Model predictions were compared...

  3. Reduced NOX combustion method

    International Nuclear Information System (INIS)

    Delano, M.A.

    1991-01-01

    This patent describes a method for combusting fuel and oxidant to achieve reduced formation of nitrogen oxides. It comprises: It comprises: heating a combustion zone to a temperature at least equal to 1500 degrees F.; injecting into the heated combustion zone a stream of oxidant at a velocity within the range of from 200 to 1070 feet per second; injecting into the combustion zone, spaced from the oxidant stream, a fuel stream at a velocity such that the ratio of oxidant stream velocity to fuel stream velocity does not exceed 20; aspirating combustion gases into the oxidant stream and thereafter intermixing the aspirated oxidant stream and fuel stream to form a combustible mixture; combusting the combustible mixture to produce combustion gases for the aspiration; and maintaining the fuel stream substantially free from contact with oxidant prior to the intermixture with aspirated oxidant

  4. Direct numerical simulations of ignition of a lean n-heptane/air mixture with temperature and composition inhomogeneities relevant to HCCI and SCCI combustion

    KAUST Repository

    Luong, Minh Bau; Yu, Gwang Hyeon; Lu, Tianfeng; Chung, Suk-Ho; Yoo, Chun Sang

    2015-01-01

    The effects of temperature and composition stratifications on the ignition of a lean n-heptane/air mixture at three initial mean temperatures under elevated pressure are investigated using direct numerical simulations (DNSs) with a 58-species

  5. Extending the Performance of Net Shape Molded Fiber Reinforced Polymer Composite Valves for Use in Internal Combustion Engines

    Science.gov (United States)

    2007-06-01

    fatigue performance of 21 steel and wear surfaces require surface hardening treatments 28. Ceramic and ceramic-head valves have been demonstrated and...0.7- 0.0 6 O2 0.4 010.1 a 0.2 0.4 CA 0.8 1 0 0.1 0.2 02 u 0.4 Oh CA6 0. O hC &0. 313 Case 3: thick-iso-a normalized plots Si IES B8..E4 -4-FO 2.554

  6. Assessment of Literature Related to Combustion Appliance Venting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

    2015-02-01

    In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

  7. Effects of stepwise gas combustion on NOx generation

    International Nuclear Information System (INIS)

    Woperane Seredi, A.; Szepesi, E.

    1999-01-01

    To decrease NO x emission from gas boilers, the combustion process of gas has been modified from continuous combustion to step-wise combustion. In this process the combustion temperature, the temperature peaks in the flame, the residence time of combustion products in the high-temperature zone and the oxygen partial pressure are changed advantageously. Experiments were performed using multistage burners, and the NO x emission was recorded. It was found that the air factor of the primary combustion space has a determining effect on the NO x reduction. (R.P.)

  8. Techniques de combustion Combustin Techniques

    Directory of Open Access Journals (Sweden)

    Perthuis E.

    2006-11-01

    Full Text Available L'efficacité d'un processus de chauffage par flamme est étroitement liée à la maîtrise des techniques de combustion. Le brûleur, organe essentiel de l'équipement de chauffe, doit d'une part assurer une combustion complète pour utiliser au mieux l'énergie potentielle du combustible et, d'autre part, provoquer dans le foyer les conditions aérodynamiques les plus propices oux transferts de chaleur. En s'appuyant sur les études expérimentales effectuées à la Fondation de Recherches Internationales sur les Flammes (FRIF, au Groupe d'Étude des Flammes de Gaz Naturel (GEFGN et à l'Institut Français du Pétrole (IFP et sur des réalisations industrielles, on présente les propriétés essentielles des flammes de diffusion aux combustibles liquides et gazeux obtenues avec ou sans mise en rotation des fluides, et leurs répercussions sur les transferts thermiques. La recherche des températures de combustion élevées conduit à envisager la marche à excès d'air réduit, le réchauffage de l'air ou son enrichissement à l'oxygène. Par quelques exemples, on évoque l'influence de ces paramètres d'exploitation sur l'économie possible en combustible. The efficiency of a flame heating process is closely linked ta the mastery of, combustion techniques. The burner, an essential element in any heating equipment, must provide complete combustion sa as to make optimum use of the potential energy in the fuel while, at the same time, creating the most suitable conditions for heat transfers in the combustion chamber. On the basis of experimental research performed by FRIF, GEFGN and IFP and of industrial achievements, this article describesthe essential properties of diffusion flames fed by liquid and gaseous fuels and produced with or without fluid swirling, and the effects of such flames on heat transfers. The search for high combustion temperatures means that consideration must be given to operating with reduced excess air, heating the air or

  9. An experimental assessment on the influence of high octane fuels on biofuel based dual fuel engine performance, emission, and combustion

    Directory of Open Access Journals (Sweden)

    Masimalai Senthilkumar

    2017-01-01

    Full Text Available This paper presents an experimental study on the effect of different high octane fuels (such as eucalyptus oil, ethanol, and methanol on engine’s performance behaviour of a biofuel based dual fuel engine. A single cylinder Diesel engine was modified and tested under dual fuel mode of operation. Initially the engine was run using neat diesel, neat mahua oil as fuels. In the second phase, the engine was operated in dual fuel mode by using a specially designed variable jet carburettor to supply the high octane fuels. Engine trials were made at 100% and 40% loads (power outputs with varying amounts of high octane fuels up-to the maximum possible limit. The performance and emission characteristics of the engine were obtained and analysed. Results indicated significant improvement in brake thermal efficiency simultaneous reduction in smoke and NO emissions in dual fuel operation with all the inducted fuels. At 100% load the brake thermal efficiency increased from 25.6% to a maximum of 32.3, 30.5, and 28.4%, respectively, with eucalyptus oil, ethanol, and methanol as primary fuels. Smoke was reduced drastically from 78% with neat mahua oil a minimum of 41, 48, and 53%, respectively, with eucalyptus oil, ethanol, and methanol at the maximum efficiency point. The optimal energy share for the best engine behaviour was found to be 44.6, 27.3, and 23.2%, respectively, for eucalyptus oil, ethanol, and methanol at 100% load. Among the primary fuels tested, eucalyptus oil showed the maximum brake thermal efficiency, minimum smoke and NO emissions and maximum energy replacement for the optimal operation of the engine.

  10. Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

  11. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani; Oß wald, Patrick; Hansen, Nils; Kohse-Hö inghaus, Katharina

    2014-01-01

    . While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides

  12. Numerical investigation of biogas flameless combustion

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Bagheri, Ghobad; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • Fuel consumption decreases from 3.24 g/s in biogas conventional combustion to 1.07 g/s in flameless mode. • The differences between reactants and products temperature intensifies irreversibility in traditional combustion. • The temperature inside the chamber is uniform in biogas flameless mode and exergy loss decreases in this technique. • Low O 2 concentration in the flameless mode confirms a complete and quick combustion process in flameless regime. - Abstract: The purpose of this investigation is to analyze combustion characteristics of biogas flameless mode based on clean technology development strategies. A three dimensional (3D) computational fluid dynamic (CFD) study has been performed to illustrate various priorities of biogas flameless combustion compared to the conventional mode. The effects of preheated temperature and wall temperature, reaction zone and pollutant formation are observed and the impacts of combustion and turbulence models on numerical results are discussed. Although preheated conventional combustion could be effective in terms of fuel consumption reduction, NO x formation increases. It has been found that biogas is not eligible to be applied in furnace heat up due to its low calorific value (LCV) and it is necessary to utilize a high calorific value fuel to preheat the furnace. The required enthalpy for biogas auto-ignition temperature is supplied by enthalpy of preheated oxidizer. In biogas flameless combustion, the mean temperature of the furnace is lower than traditional combustion throughout the chamber. Compared to the biogas flameless combustion with uniform temperature, very high and fluctuated temperatures are recorded in conventional combustion. Since high entropy generation intensifies irreversibility, exergy loss is higher in biogas conventional combustion compared to the biogas flameless regime. Entropy generation minimization in flameless mode is attributed to the uniform temperature inside the chamber

  13. Report on research achievement in relation with developing fundamental combustion control technologies in fiscal 1998. Research and development of high-performance industrial furnaces; 1998 nendo nensho seigyo kiban gijutsu no kaihatsu ni kansuru kenkyu seika hokokusho. Koseino kogyoro nado ni kansuru kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Development is intended to be made on fundamental combustion control technologies applicable to high-performance industrial furnaces that can reduce energy consumption and respond to environment preservation requirements. With an intention to achieve reduction in combustion exhaust gases such as carbon dioxide and nitrogen oxides, fundamental studies will be made on factors to decide flame shapes as represented by high-temperature combustion and flame shape control by utilizing microgravity environment, and researches will be made on combustion systems. Devices required for the experiments were fabricated to evaluate critical combustion characteristics of flames in furnaces including industrial furnaces, analyze and evaluate flame control parameters, and study low-pollution combustion technologies. Experimental methods acquired by 1997 were used for the experiments under the microgravity environment. Evaluation experiments were performed on flame shape control technologies and flame radiation characteristics, and basic experiments on the low-pollution combustion technologies. With these experiments, elucidation of the combustion mechanisms was launched by analyzing and evaluating the acquired data. A flame experimenting device for high-temperature preheated air completed by fiscal 1997 was used to acquire such combustion characteristics data as NOx discharge characteristics when the high-temperature preheated air is used. Based on the result thereof, verification was carried out on simulation models. (NEDO)

  14. Maximal combustion temperature estimation

    International Nuclear Information System (INIS)

    Golodova, E; Shchepakina, E

    2006-01-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

  15. Effect of Di-Tertiary Butyl Peroxide on the performance, combustion and emission characteristics of ethanol blended cotton seed methyl ester fuelled automotive diesel engine

    International Nuclear Information System (INIS)

    Kumar, K. Senthil; Raj, R. Thundil Karuppa

    2016-01-01

    Highlights: • Effect of di-tertiary butyl peroxide on ethanol blended biodiesel is investigated. • Cetane enhanced ethanol up to 10% can be blended with cotton seed biodiesel. • Nitrogen oxides emissions are lower for cetane enhanced ethanol biodiesels. • Performance characteristics of cetane improved ethanol biodiesels are reasonable. • Cetane enhanced ethanol blended biodiesel is an promising renewable energy source. - Abstract: An experimental study is carried out to examine and analyze the influence of Di-Tertiary Butyl Peroxide in bioethanol diesel blends on the performance, combustion and emission characteristics in a single cylinder, 4-stroke, naturally aspirated, automotive diesel engine for variable speed at full load conditions. Esterified cotton seed oil of 5% by volume is emulsified with 95% pure diesel to get the base fuel (BE0) for the experiments. Bioethanol diesel blends are produced from base fuel by adding 5% and 10% pure ethanol on a volumetric basis to obtain BE5 and BE10 respectively. The bioethanol fuels are low in Cetane number and hence Di-Tertiary Butyl Peroxide a Cetane enhancer is added by 0.4% by volume to produce BE5CN0.4% and BE10CN0.4% emulsions respectively. It is found from the experiments carried out, that an inverse trend exists between brake thermal efficiency and percentage of ethanol in base fuel. This is due to the lower calorific value of ethanol and an improvement in brake thermal efficiency is observed with ignition improver added blends. The presence of Cetane improver significantly reduced oxides of nitrogen and unburned hydro carbon emissions for overall engine speed and carbon monoxide emissions for low to medium speed range.

  16. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  17. Anpassning av ett avgassystem för en motkolvstvåtaktsmotor med HCCI-förbränning

    OpenAIRE

    LAINEZ MARTÍ, JAVIER

    2010-01-01

    Målet för detta examensarbete har varit att förbättra driften av en motkolvs tvåtaktsmotormed HCCI-förbränning. Huvudfokus för arbetet har varit på gasväxlingsprocessen, dåfrämst avgasprocessen.Motorn har studerats med utgångspunkt från hur en tvåtakts Otto-cykel fungerar.Gasväxlingsprocessen i tvåtaktsmotorer kännetecknas av behovet av att snabbt få ut denförbrända gasen och införa ny blandning vid varje expansionstakt, samt avsaknaden avventiler. Behovet att kunna kontrollera gasflödet geno...

  18. Combustion instability modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States); Sheppard, E.J. [Tuskeggee Univ., Tuskegee, AL (United States). Dept. of Aerospace Engineering

    1995-12-31

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors. The present study represents a coordinated effort between industry, government and academia to investigate gas turbine combustion dynamics. Specific study areas include development of advanced diagnostics, definition of controlling phenomena, advancement of analytical and numerical modeling capabilities, and assessment of the current status of our ability to apply these tools to practical gas turbine combustors. The present work involves four tasks which address, respectively, (1) the development of a fiber-optic probe for fuel-air ratio measurements, (2) the study of combustion instability using laser-based diagnostics in a high pressure, high temperature flow reactor, (3) the development of analytical and numerical modeling capabilities for describing combustion instability which will be validated against experimental data, and (4) the preparation of a literature survey and establishment of a data base on practical experience with combustion instability.

  19. Thermally accurate LES of the stability-emission performance of staged gas-turbine combustion; Simulation aux grandes echelles de la combustion etagee dans les turbines a gaz et son interaction stabilite-polluants-thermique

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, P.

    2005-06-15

    Modern gas turbines use turbulent lean partially premixed combustion in order to minimise nitrous oxide (NO{sub X}) emissions while ensuring flashback safety. The Large-Eddy Simulation (LES) of such a device is the goal of this work. Focus is laid on correctly predicting the NO{sub X} emissions, which are influenced by four factors: heat transfer, mixing quality, combustion modelling and thermo-acoustic stability. As NO{sub X} reaction rates are strongly influenced by temperature, heat transfer by radiation and convection is included. Radiation is predicted by a model, which assumes that the gases are optically thin. Convective heat transfer is included via a newly developed and validated wall-function approach based on the logarithmic law of the wall for temperature. An optimised 2-step reduced chemical reaction scheme for lean methane combustion is presented. This scheme is used for the LES in conjunction with an additional third reaction, fitted to produce the same NO{sub X} reaction rates as in the complete reaction mechanism. Turbulence is accounted for with the thickened flame model in a form, which is optimised for changing equivalence ratios and mesh-resolutions. Mixing is essential not only for predicting flame stabilisation, but also for pollutant emissions as NO{sub X} reaction rates depend exponentially on equivalence ratio. Therefore the full burner geometry, including 16 fuel injections is resolved in LES. Additionally, effusion cooling and film cooling is accounted for in a simplified manner. The non-reacting flow is extensively validated with experimental results. As mixture-fraction fluctuations do not only arise from turbulence, but also from thermo-acoustic instabilities, care was taken to provide acoustic boundary conditions that come close to reality. The resulting LES shows a strong thermo-acoustic instability, comparing well with experimental observations. By making the boundaries completely anechoic it is shown that when the instability

  20. Uncertainties in hydrogen combustion

    International Nuclear Information System (INIS)

    Stamps, D.W.; Wong, C.C.; Nelson, L.S.

    1988-01-01

    Three important areas of hydrogen combustion with uncertainties are identified: high-temperature combustion, flame acceleration and deflagration-to-detonation transition, and aerosol resuspension during hydrogen combustion. The uncertainties associated with high-temperature combustion may affect at least three different accident scenarios: the in-cavity oxidation of combustible gases produced by core-concrete interactions, the direct containment heating hydrogen problem, and the possibility of local detonations. How these uncertainties may affect the sequence of various accident scenarios is discussed and recommendations are made to reduce these uncertainties. 40 references

  1. Urea-nitrate combustion synthesis of MgO/MgAl2O4 nanocatalyst used in biodiesel production from sunflower oil: Influence of fuel ratio on catalytic properties and performance

    International Nuclear Information System (INIS)

    Rahmani Vahid, Behgam; Haghighi, Mohammad

    2016-01-01

    Graphical abstract: As a base catalyst for biodiesel production, MgAl 2 O 4 spinel was successfully synthesized by combustion method with MgO, as the active phase, dispersed on the catalyst surface. The nanocatalysts were characterized by XRD, FESEM, EDX, BET-BJH, TGA and FTIR analyses, so as to optimize the concentration of urea (as fuel) in the combustion synthesis. Analyzing the effect of fuel ratio on the combustion synthesized MgAl 2 O 4 , it was revealed that the synthesized base catalyst with a fuel ratio of 1.5 was of the best specifications for biodiesel production process. Future researches may investigate the catalyst reusability and mild reaction conditions, so as to achieve more economical production of biodiesel. - Highlights: • Efficient synthesis of MgAl 2 O 4 spinel by solution combustion method. • Improvement of catalytic activity and stability by optimum ratio fuel. • Enhanced dispersion of MgO over MgAl 2 O 4 spinel. • Production of biodiesel over MgO/MgAl 2 O 4 at relatively mild reaction conditions. - Abstract: MgO/MgAl 2 O 4 nanocatalyst was synthesized by a simple, cost-effective and rapid method and used in biodiesel production from sunflower oil. MgAl 2 O 4 was synthesized by combustion method at different fuel ratios and then active phase of MgO was dispersed on the samples by impregnation method. The nanocatalysts were characterized by XRD, FESEM, EDX, BET-BJH, TGA and FTIR analyses, so as to optimize the concentration of urea (as fuel) in the combustion synthesis. The physicochemical properties of the nanocatalyst confirmed the sample synthesized with fuel ratio of 1.5 has high surface area, effective morphology and texture properties. Finally, in order to evaluate catalytic activity of the samples in biodiesel production, the transesterification reaction was performed. The results indicated the catalyst prepared by combustion synthesis with a fuel ratio of 1.5 was optimum specifications for biodiesel production. Using this

  2. New class of combustion processes

    International Nuclear Information System (INIS)

    Merzhanov, A.G.; Borovinskaya, I.P.

    1975-01-01

    A short review is given of the results of work carried out since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion, fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion, and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds

  3. Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

    Science.gov (United States)

    Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

    2015-01-01

    Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

  4. Distributed Low Temperature Combustion: Fundamental Understanding of Combustion Regime Transitions

    Science.gov (United States)

    2016-09-07

    behaviour as compared to ethanol. The latter fuel has also been considered along with methane. Work has also been performed on the further assessment of... behaviour as compared to ethanol. The latter fuel has also been considered along with methane. Work has also been performed on the further assess- ment of...identification of various combustion gas states. A range of Damköhler numbers (Da) from the conventional propagating flamelet regime well into the distributed

  5. Annual Report: Advanced Combustion (30 September 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey [NETL; Richards, George

    2012-09-30

    The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.

  6. Combustion modeling in internal combustion engines

    Science.gov (United States)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  7. An experimental and numerical analysis of the HCCI auto-ignition process of primary reference fuels, toluene reference fuels and diesel fuel in an engine, varying the engine parameters

    OpenAIRE

    Machrafi, Hatim; Cavadias, Simeon; Gilbert, Philippe

    2008-01-01

    For a future HCCI engine to operate under conditions that adhere to environmental restrictions, reducing fuel consumption and maintaining or increasing at the same time the engine efficiency, the choice of the fuel is crucial. For this purpose, this paper presents an auto-ignition investigation concerning the primary reference fuels, toluene reference fuels and diesel fuel, in order to study the effect of linear alkanes, branched alkanes and aromatics on the auto-ignition. The auto-ignition o...

  8. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  9. Combustion performance and emission analysis of diesel engine fuelled with water-in-diesel emulsion fuel made from low-grade diesel fuel

    International Nuclear Information System (INIS)

    Ithnin, Ahmad Muhsin; Ahmad, Mohamad Azrin; Bakar, Muhammad Aiman Abu; Rajoo, Srithar; Yahya, Wira Jazair

    2015-01-01

    Highlights: • Effect of using emulsified fuel made from low-grade fuel in engine are investigated. • Specific fuel consumption of the engine is reduced overall for all types of W/D. • Comparable maximum in-cylinder pressure and pressure rise rate compared to D2. • NOx and PM are found to be reduced for all types of W/D. • CO and CO 2 emissions increase compared to D2 at low load and high load. - Abstract: In the present research, an experiment is designed and conducted to investigate the effect of W/D originating from low-grade diesel fuel (D2) on the combustion performance and emission characteristics of a direct injection diesel engine under varying engine loads (25–100%) and constant engine speed (3000 rpm). Four types of W/D are tested, which consist of different water percentages (5%, 10%, 15% and 20%), with constant 2% of surfactant and labelled as E5, E10, E15 and E20, respectively. The specific fuel consumption (SFC) of the engine when using each type of W/D is found to be reduced overall. This is observed when the total amount of diesel fuel in the emulsion is compared with that of neat D2. E20 shows a comparable maximum in-cylinder pressure and pressure rise rate (PRR) compared to D2 in all load conditions. In addition, it produces the highest maximum rate of heat release (MHRR) in almost every load compared to D2 and other W/Ds. NOx and PM are found to be reduced for all types of W/D. The carbon monoxide (CO) and carbon dioxide (CO 2 ) emissions increase compared to D2 at low load and high load, respectively. Overall, it is observed that the formation of W/D from low-grade diesel is an appropriate alternative fuel method that can bring about greener exhaust emissions and fuel savings without deteriorating engine performance

  10. Demonstration of advanced combustion NO(sub X) control techniques for a wall-fired boiler. Project performance summary, Clean Coal Technology Demonstration Program

    International Nuclear Information System (INIS)

    None

    2001-01-01

    The project represents a landmark assessment of the potential of low-NO(sub x) burners, advanced overtire air, and neural-network control systems to reduce NO(sub x) emissions within the bounds of acceptable dry-bottom, wall-fired boiler performance. Such boilers were targeted under the Clean Air Act Amendments of 1990 (CAAA). Testing provided valuable input to the Environmental Protection Agency ruling issued in March 1994, which set NO(sub x) emission limits for ''Group 1'' wall-fired boilers at 0.5 lb/10(sup 6) Btu to be met by January 1996. The resultant comprehensive database served to assist utilities in effectively implementing CAAA compliance. The project is part of the U.S. Department of Energy's Clean Coal Technology Demonstration Program established to address energy and environmental concerns related to coal use. Five nationally competed solicitations sought cost-shared partnerships with industry to accelerate commercialization of the most advanced coal-based power generation and pollution control technologies. The Program, valued at over$5 billion, has leveraged federal funding twofold through the resultant partnerships encompassing utilities, technology developers, state governments, and research organizations. This project was one of 16 selected in May 1988 from 55 proposals submitted in response to the Program's second solicitation. Southern Company Services, Inc. (SCS) conducted a comprehensive evaluation of the effects of Foster Wheeler Energy Corporation's (FWEC) advanced overfire air (AOFA), low-NO(sub x) burners (LNB), and LNB/AOFA on wall-fired boiler NO(sub x) emissions and other combustion parameters. SCS also evaluated the effectiveness of an advanced on-line optimization system, the Generic NO(sub x) Control Intelligent System (GNOCIS). Over a six-year period, SCS carried out testing at Georgia Power Company's 500-MWe Plant Hammond Unit 4 in Coosa, Georgia. Tests proceeded in a logical sequence using rigorous statistical analyses to

  11. Lump wood combustion process

    Science.gov (United States)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  12. Flameless Combustion Workshop

    National Research Council Canada - National Science Library

    Gutmark, Ephraim

    2005-01-01

    .... "Flameless Combustion" is characterized by high stability levels with virtually no thermoacoustic instabilities, very low lean stability limits and therefore extremely low NOx production, efficient...

  13. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  14. Multi-stage combustion using nitrogen-enriched air

    Science.gov (United States)

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14

    Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

  15. Assessment of n-pentanol/Calophyllum inophyllum/diesel blends on the performance, emission, and combustion characteristics of a constant-speed variable compression ratio direct injection diesel engine.

    Science.gov (United States)

    Ramakrishnan, Purnachandran; Kasimani, Ramesh; Peer, Mohamed Shameer; Rajamohan, Sakthivel

    2018-05-01

    Alcohol is used as an additive for a long time with the petroleum-based fuels. In this study, the higher alcohol, n-pentanol, was used as an additive to Calophyllum inophyllum (CI) biodiesel/diesel blends at 10, 15, and 20% by volume. In all blends, the ratio of CI was maintained at 20% by volume. The engine characteristics of the pentanol fuel blends were compared with the diesel and CI20 (Calophyllum inophyllum 20% and diesel 80%) biodiesel blend. The nitrogen oxide (NO) emission of the pentanol fuel blends showed an increased value than CI20 and neat diesel fuel. The carbon dioxide (CO 2 ) also increased with increase in pentanol addition with the fuel blends than CI20 fuel blend and diesel. The carbon monoxide (CO) and hydrocarbon (HC) emissions were decreased with increase in pentanol proportion in the blend than the CI20 fuel and diesel. The smoke emission was reduced and the combustion characteristics of the engine were also improved by using pentanol blended fuels. From this investigation, it is suggested that 20% pentanol addition with the biodiesel/diesel fuel is suitable for improved performance and combustion characteristics of a diesel engine without any engine modifications, whereas CO 2 and NO emissions increased with addition of pentanol due to effective combustion.

  16. Effect of A-site deficiency in LaMn{sub 0.9}Co{sub 0.1}O{sub 3} perovskites on their catalytic performance for soot combustion

    Energy Technology Data Exchange (ETDEWEB)

    Dinamarca, Robinson [Department of Physical Chemistry, Faculty of Chemical Sciences, University of Concepción, Concepción (Chile); Garcia, Ximena; Jimenez, Romel [Department of Chemical Engineering, Faculty of Engineering, University of Concepción, Concepción (Chile); Fierro, J.L.G. [Instituto de Catálisis y Petroleoquímica, CSIC, Cantoblanco, 28049 Madrid (Spain); Pecchi, Gina, E-mail: gpecchi@udec.cl [Department of Physical Chemistry, Faculty of Chemical Sciences, University of Concepción, Concepción (Chile)

    2016-09-15

    Highlights: • A-site defective perovskites increases the oxidation state of the B-cation. • Not always non-stoichiometric perovskites exhibit higher catalytic activity in soot combustion. • The highly symmetric cubic crystalline structure diminishes the redox properties of perovskites. - Abstract: The influence of lanthanum stoichiometry in Ag-doped (La{sub 1-x}Ag{sub x}Mn{sub 0.9}Co{sub 0.1}O{sub 3}) and A-site deficient (La{sub 1-x}Mn{sub 0.9}Co{sub 0.1}O{sub 3-δ}) perovskites with x equal to 10, 20 and 30 at.% has been investigated in catalysts for soot combustion. The catalysts were prepared by the amorphous citrate method and characterized by XRD, nitrogen adsorption, XPS, O{sub 2}-TPD and TPR. The formation of a rhombohedral excess-oxygen perovskite for Ag-doped and a cubic perovskite structure for an A-site deficient series is confirmed. The efficient catalytic performance of the larger Ag-doped perovskite structure is attributed to the rhombohedral crystalline structure, Ag{sub 2}O segregated phases and the redox pair Mn{sup 4+}/Mn{sup 3+}. A poor catalytic activity for soot combustion was observed with A-site deficient perovskites, despite the increase in the redox pair Mn{sup 4+}/Mn{sup 3+}, which is attributed to the cubic crystalline structure.

  17. Effects of operating conditions and fuel properties on emission performance and combustion efficiency of a swirling fluidized-bed combustor fired with a biomass fuel

    International Nuclear Information System (INIS)

    Kuprianov, Vladimir I.; Kaewklum, Rachadaporn; Chakritthakul, Songpol

    2011-01-01

    This work reports an experimental study on firing 80 kg/h rice husk in a swirling fluidized-bed combustor (SFBC) using an annular air distributor as the swirl generator. Two NO x emission control techniques were investigated in this work: (1) air staging of the combustion process, and (2) firing rice husk as moisturized fuel. In the first test series for the air-staged combustion, CO, NO and C x H y emissions and combustion efficiency were determined for burning 'as-received' rice husk at fixed excess air of 40%, while secondary-to-primary air ratio (SA/PA) was ranged from 0.26 to 0.75. The effects of SA/PA on CO and NO emissions from the combustor were found to be quite weak, whereas C x H y emissions exhibited an apparent influence of air staging. In the second test series, rice husks with the fuel-moisture content of 8.4% to 35% were fired at excess air varied from 20% to 80%, while the flow rate of secondary air was fixed. Radial and axial temperature and gas concentration (O 2 , CO, NO) profiles in the reactor, as well as CO and NO emissions, are discussed for the selected operating conditions. The temperature and gas concentration profiles for variable fuel quality exhibited significant effects of both fuel-moisture and excess air. As revealed by experimental results, the emission of NO from this SFBC can be substantially reduced through moisturizing rice husk, while CO is effectively mitigated by injection of secondary air into the bed splash zone, resulting in a rather low emission of CO and high (over 99%) combustion efficiency of the combustor for the ranges of operating conditions and fuel properties.

  18. Systematic application of flame diagnostics techniques for performance and emissions development of modern combustion systems; Systematischer Einsatz der Flammendiagnostik fuer die Leistungs- und Emissionsentwicklung moderner Brennverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Winklhofer, E.; Beidl, C.; Hirsch, A.; Piock, W. [AVL List GmbH, Graz (Austria)

    2004-07-01

    In engine engineering, the information and benefits gained from optical flame diagnostics, especially in the combination with thermodynamic and CFD analysis of airflow and combustion are well accepted. It is, however, a specific challenge to implement techniques which are well established in basic engine R and D into the processes of series development or engine calibration. Any technique taken over from successfull predevelopment applications, is expected to equally well support series development. But in order to do this, it must also be suited to easily blend into the procedures of standard multicylinder engine tests. Development speed and results quality improve consideraly, whenever engineers within their routine engine tests gain knowledge about and evaluation of flame properties which allow identification of possible improvements of combustion efficiency, power density and emissions in an early, upfront development phase. Diagnostic systems employed for such tasks make use of fiber optic sensors which in spark ignited engines may be implanted into the bodies of sensor spark plugs. Their mechanic, thermal and electric properties comply with those of the originals, thus enabling their continuous use on the test bed. The arrangement of standard fiber optic channels allows flame radiation monitoring either within the axial proximity of the sensor plug, or of the entire combustion chamber compression volume. Signal recording and signal analysis is accomplished with Visiolution system techniques. Test results are evaluated on the basis of Visiolution algorithms. Data reduction schemes provide numerical figures of merit, describing, e. g. direction, velocity and symmetry of a spark ignited flame kernel. When knock center distribution is analysed, actual distribution statistics are checked against best concept distributions, whenever diffusion flames are detected against expectations of ideal premixed flames, their position, timing and intensity is evaluated. Such

  19. COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

    Directory of Open Access Journals (Sweden)

    Nureddin Dinler

    2010-01-01

    Full Text Available Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion equations were solved. The k-e turbulence model was employed. The fuel mass fraction transport equation was used for modeling of the combustion. For this purpose a computational fluid dynamics code was developed by using the finite volume method with FORTRAN programming code. The moving mesh was utilized to simulate the piston motion. The developed code simulates four strokes of engine continuously. In the case of laminar flow combustion, Arrhenius type combustion equations were employed. In the case of turbulent flow combustion, eddy break-up model was employed. Results were given for rich, stoichiometric, and lean mixtures in contour graphs. Contour graphs showed that lean mixture (l = 1.1 has longer combustion duration.

  20. Combustive management of oil spills

    International Nuclear Information System (INIS)

    1992-01-01

    Extensive experiments with in situ incineration were performed on a desert site at the University of Arizona with very striking results. The largest incinerator, 6 feet in diameter with a 30 foot chimney, developed combustion temperatures of 3000, F, and attendant soot production approximately 1000 times less than that produced by conventional in situ burning. This soot production, in fact, is approximately 30 times less than current allowable EPA standards for incinerators and internal combustion engines. Furthermore, as a consequence of the high temperature combustion, the bum rate was established at a very high 3400 gallons per hour for this particular 6 foot diameter structure. The rudimentary design studies we have carried out relative to a seagoing 8 foot diameter incinerator have predicted that a continuous burn rate of 7000 gallons per hour is realistic. This structure was taken as a basis for operational design because it is compatible with C130 flyability, and will be inexpensive enough ($120,000 per copy) to be stored at those seaside depots throughout the US coast line in which the requisite ancillary equipments (booms, service tugs, etc.) are already deployed. The LOX experiments verified our expectations with respect to combustion of debris and various highly weathered or emulsified oils. We have concluded, however, that the use of liquid oxygen in actual beach clean up is not promising because the very high temperatures associated with this combustion are almost certain to produce environmentally deleterious effects on the beach surface and its immediately sublying structures. However, the use of liquid oxygen augmentation for shore based and flyable incinerators may still play an important role in handing the problem of accumulated debris

  1. Strobes: An oscillatory combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

    2012-01-01

    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the

  2. Catalytically enhanced combustion process

    International Nuclear Information System (INIS)

    Rodriguez, C.

    1992-01-01

    This patent describes a fuel having improved combustion efficiency. It comprises a petroleum based liquid hydrocarbon; and a combustion catalyst comprising from about 18 to about 21 weight percent naphthalene, from about 75 to about 80 weight percent toluene, and from about 2.8 to about 3.2 weight percent benzyl alcohol

  3. Fifteenth combustion research conference

    International Nuclear Information System (INIS)

    1993-01-01

    The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers

  4. COMBUSTION OPTIMIZATION IN SPARK IGNITION ENGINES

    OpenAIRE

    Barhm Mohamad; Gabor Szebesi; Betti Bollo

    2017-01-01

    The blending technique used in internal combustion engines can reduce emission of toxic exhaust components and noises, enhance overall energy efficiency and reduce fuel costs. The aim of the study was to compare the effects of dual alcohols (methanol and ethanol) blended in gasoline fuel (GF) against performance, combustion and emission characteristics. Problems arise in the fuel delivery system when using the highly volatile methanol - gasoline blends. This problem is reduced by using specia...

  5. Dynamic estimator for determining operating conditions in an internal combustion engine

    Science.gov (United States)

    Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

    2016-01-05

    Methods and systems are provided for estimating engine performance information for a combustion cycle of an internal combustion engine. Estimated performance information for a previous combustion cycle is retrieved from memory. The estimated performance information includes an estimated value of at least one engine performance variable. Actuator settings applied to engine actuators are also received. The performance information for the current combustion cycle is then estimated based, at least in part, on the estimated performance information for the previous combustion cycle and the actuator settings applied during the previous combustion cycle. The estimated performance information for the current combustion cycle is then stored to the memory to be used in estimating performance information for a subsequent combustion cycle.

  6. Combustion instability modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States)] [and others

    1995-10-01

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. Clearly, the key to successful gas turbine development is based on understanding the effects of geometry and operating conditions on combustion instability, emissions (including UHC, CO and NO{sub x}) and performance. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors.

  7. PDF Modeling of Turbulent Combustion

    National Research Council Canada - National Science Library

    Pope, Stephen B

    2006-01-01

    .... The PDF approach to turbulent combustion has the advantages of fully representing the turbulent fluctuations of species and temperature, and of allowing realistic combustion chemistry to be implemented...

  8. Enhancement of exergy efficiency in combustion systems using flameless mode

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • Exergy efficiency in flameless combustion mode is 13% more than conventional combustion. • The maximum exergy efficiency in flameless combustion mode is achieved when oxidizer contains 10% oxygen. • Exergy destruction of flameless combustion is maximized when CO 2 is used for dilution of oxidizer. - Abstract: An exergitic-based analysis of methane (CH 4 ) conventional and flameless combustion in a lab-scale furnace is performed to determine the rate of pollutant formation and the effective potential of a given amount of fuel in the various combustion modes. The effects of inlet air temperature on exergy efficiency and pollutant formation of conventional combustion in various equivalence ratios are analyzed. The rate of exergy destruction in different conditions of flameless combustion (various equivalence ratios, oxygen concentration in the oxidizer and the effects of diluent) are computed using three-dimensional (3D) computational fluid dynamic (CFD). Fuel consumption reduction and exergy efficiency augmentation are the main positive consequences of using preheated air temperature in conventional combustion, however pollutants especially NO x formation increases dramatically. Low and moderate temperature inside the chamber conducts the flameless combustion system to low level pollutant formation. Fuel consumption and exergy destruction reduce drastically in flameless mode in comparison with conventional combustion. Exergy efficiency of conventional and flameless mode is 75% and 88% respectively in stoichiometric combustion. When CO 2 is used for dilution of oxidizer, chemical exergy increases due to high CO 2 concentration in the combustion products and exergy efficiency reduces around 2% compared to dilution with nitrogen (N 2 ). Since the rate of irreversibilities in combustion systems is very high in combined heat and power (CHP) generation and other industries, application of flameless combustion could be effective in terms of pollutant

  9. COMBUSTION OF BIOMASS AND CHARCOAL MADE FROM BABASSU NUTSHELL

    Directory of Open Access Journals (Sweden)

    Thiago de Paula Protásio

    2017-03-01

    Full Text Available In recent years, studies have examined the use of lignocellulosic wastes for energy generation. However, there is a lack of information on the combustibility of the residual biomass, especially the bark and charcoal of babassu nut. In this study, thermogravimetric analysis (TGA, differential thermal analysis (DTA and differential scanning calorimetry (DSC were used to achieve the following objectives: to evaluate the combustion of the residual biomass from the babassu nut; to evaluate the combustion of charcoal produced from this biomass, considering different final carbonization temperatures; and to determine the effect of the final carbonization temperature on the thermal stability of charcoal and on its performance in combustion. Thermal analyses were performed in synthetic air. In order to evaluate the characteristics of charcoal combustion and fresh biomass, the ignition temperature (Ti, the burnout temperature (Tf, characteristic combustion index (S, ignition index (Di, time corresponding to the maximum combustion rate (tp, and ignition time (tig were considered. The combustion of the babassu nutshell occurred in three phases and it was observed that this lignocellulosic material is suitable for the direct generation of heat. The increase in the final carbonization temperature caused an increase in the ignition temperature, as well as in the burnout temperature, the ignition time and the time corresponding to the maximum combustion rate. The results indicate that the increase in the carbonization temperature causes a decrease in combustion reactivity and, consequently, the charcoals produced at lower temperatures are easier to ignite and exhibit better performance in ignition.

  10. Study of experimental validation for combustion analysis of GOTHIC code

    International Nuclear Information System (INIS)

    Lee, J. Y.; Yang, S. Y.; Park, K. C.; Jeong, S. H.

    2001-01-01

    In this study, present lumped and subdivided GOTHIC6 code analyses of the premixed hydrogen combustion experiment at the Seoul National University and comparison with the experiment results. The experimental facility has 16367 cc free volume and rectangular shape. And the test was performed with unit equivalence ratio of the hydrogen and air, and with various location of igniter position. Using the lumped and mechanistic combustion model in GOTHIC6 code, the experiments were simulated with the same conditions. In the comparison between experiment and calculated results, the GOTHIC6 prediction of the combustion response does not compare well with the experiment results. In the point of combustion time, the lumped combustion model of GOTHIC6 code does not simulate the physical phenomena of combustion appropriately. In the case of mechanistic combustion model, the combustion time is predicted well, but the induction time of calculation data is longer than the experiment data remarkably. Also, the laminar combustion model of GOTHIC6 has deficiency to simulate combustion phenomena unless control the user defined value appropriately. And the pressure is not a proper variable that characterize the three dimensional effect of combustion

  11. Combustion stratification study of partially premixed combustion using Fourier transform analysis of OH* chemiluminescence images

    KAUST Repository

    Izadi Najafabadi, Mohammad

    2017-11-06

    A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.

  12. Fuel Combustion Laboratory | Transportation Research | NREL

    Science.gov (United States)

    Fuel Combustion Laboratory Fuel Combustion Laboratory NREL's Fuel Combustion Laboratory focuses on designs, using both today's technology and future advanced combustion concepts. This lab supports the combustion chamber platform for fuel ignition kinetics research, was acquired to expand the lab's

  13. Oxy-coal Combustion Studies

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, J. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Lighty, J. [Univ. of Utah, Salt Lake City, UT (United States); Ring, T. [Univ. of Utah, Salt Lake City, UT (United States); Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Thornock, J. [Univ. of Utah, Salt Lake City, UT (United States); Y Jia, W. Morris [Univ. of Utah, Salt Lake City, UT (United States); Pedel, J. [Univ. of Utah, Salt Lake City, UT (United States); Rezeai, D. [Univ. of Utah, Salt Lake City, UT (United States); Wang, L. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, J. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States)

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  14. Combustion of environmentally altered molybdenum trioxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Kevin; Pantoya, Michelle L. [Mechanical Engineering Department, Texas Tech University, 2500 Broadway, Lubbock, TX 79409 (United States)

    2006-06-15

    Nanocomposite thermite mixtures are currently under development for many primer applications due to their high energy densities, high ignition sensitivity, and low release of toxins into the environment. However, variability and inconsistencies in combustion performance have not been sufficiently investigated. Environmental interactions with the reactants are thought to be a contributing factor to these variabilities. Combustion velocity experiments were conducted on aluminum (Al) and molybdenum trioxide (MoO{sub 3}) mixtures to investigate the role of environmental interactions such as light exposure and humidity. While the Al particles were maintained in an ambient, constant environment, the MoO{sub 3} particles were exposed to UV or fluorescent light, and highly humid environments. Results show that UV and fluorescent lighting over a period of days does not significantly contribute to performance deterioration. However, a humid environment severely decreases combustion performance if the oxidizer particles are not heat-treated. Heat treatment of the MoO{sub 3} greatly increases the material's ability to resist water absorption, yielding more repeatable combustion performance. This work further quantifies the role of the environment in the decrease of combustion performance of nanocomposites over time. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  15. Second law comparison of oxy-fuel combustion and post-combustion carbon dioxide separation

    International Nuclear Information System (INIS)

    Simpson, Adam P.; Simon, A.J.

    2007-01-01

    To define 2nd law efficiency targets for novel separation technologies, a simplified model of a power plant with two forms of CO 2 capture was developed. In this investigation, oxy-fuel combustion and post-combustion CO 2 separation were compared on an exergetic basis. Using exergy balances and black-box models of power plant components, multiple scenarios were run to determine the impact of plant configuration and separation unit efficiency on overall plant performance. Second law efficiency values from the literature were used to set the baseline performance of various CO 2 separation configurations. Assumed advances in 2nd law efficiency were used to determine the potential for overall system performance improvement. It was found that the 2nd law efficiency of air separation must reach a critical value before the thermodynamics of oxy-fuel combustion become favorable. Changes in operating equivalence ratio significantly move the tipping-point between post-combustion and oxy-fuel strategies

  16. Sandia Combustion Research: Technical review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  17. Toxic combustion products from pesticide fires. Executive summary

    NARCIS (Netherlands)

    Molag, M.; Bartelds, H.; Weger, D. de

    1992-01-01

    In order to obtain reliable data on the generation of toxic combustion products and to get more insight into the risks of fires in pesticide warehouses TNO performed the research project 'Toxic combustion products from pesticide fires'. The following research activities have been performed during

  18. Shale oil combustion

    International Nuclear Information System (INIS)

    Al-dabbas, M.A.

    1992-05-01

    A 'coutant' carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion produc