WorldWideScience

Sample records for hcci engine operating

  1. 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

  2. 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

  3. 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...

  4. 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.

  5. 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 electrical variable valve timing (VVT) actuating system and satisfactory electrical VVT responses were obtained. Target engine control system was designed and fabricated at MSU for both single-cylinder optical and multi-cylinder metal engines. Finally, the developed control-oriented engine model was successfully implemented into the HIL simulation environment. The Chrysler 2.0L I4 DI engine was modified to fit the two-step vale with electrical variable valve timing actuating system. A used prototype engine was used as the base engine and the cylinder head was modified for the two-step valve with electrical VVT actuating system. Engine validation tests indicated that cylinder #3 has very high blow-by and it cannot be reduced with new pistons and rings. Due to the time constraint, it was decided to convert the four-cylinder engine into a single cylinder engine by blocking both intake and exhaust ports of the unused cylinders. The model-based combustion mode transition control algorithm was developed in the MSU HIL simulation environment and the Simulink based control strategy was implemented into the target engine controller. With both single-cylinder metal engine and control strategy ready, stable HCCI combustion was achived with COV of 2.1% Motoring tests were conducted to validate the actuator transient operations including valve lift, electrical variable valve timing, electronic throttle, multiple spark and injection controls. After the actuator operations were confirmed, 15-cycle smooth combustion mode transition from SI to HCCI combustion was achieved; and fast 8-cycle smooth combustion mode transition followed. With a fast electrical variable valve timing actuator, the number of engine cycles required for mode transition can be reduced down to five. It was also found that the combustion mode transition is sensitive to the charge air and engine coolant temperatures and regulating the corresponding temperatures to the target levels during the combustion mode

  6. 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...

  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. 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

  9. 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

  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. 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%.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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...

  1. 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

  2. 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)

  3. 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.

  4. 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.

  5. 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.)

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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)

  15. 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

  16. 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

  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. 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....

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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)

  4. 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

  5. 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

  6. 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)

  7. 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

  8. 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

  9. 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)

  10. 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

  11. 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

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

    Science.gov (United States)

    Alrbai, Mohammad

    governing equations represent a single zone perfectly stirred reactor (PSR) which contain a perfect mixing ideal gas mixture. The chemical kinetics approach is applied using Cantera/ MATLABRTM toolbox, which presents the combustion process. In this research, a homogenous charge compression ignition (HCCI) at different operational conditions is used. HCCI engines have high efficiencies and low emissions and can work within a wide range of fuels. The results have been presented in a multi-cycle simulation and a parametric study forms. In the case of the multi-cycle simulation, a 100 cycles of the engine operation have been simulated. The overall work that is delivered to the electrical generator presents 47% of the total fuel energy. The model indicates an average frequency of 125 Hz along the operational cycles. In order to eliminate the cyclic variations and ensure a continuous operation, a proportional derivative (PD) controller has been employed. The controller adjusts the generator load in order to minimize the difference between the bottom dead center (BDC) locations along the operation cycles. The PD controller shows weakness in achieving the full steady state operation, for this purpose; a proportional integral (PI) controller has been implemented. The PI controller seeks to achieve a specific compression ratio. The results show that; the PI controller indicates unique behavior after 15 cycles of operation where the model ended to fluctuate between two compression ratios only. The complex relation between the thermodynamics and the dynamics of the engine is the greatest challenge in examining the effectiveness of the PI controller. In the parametric investigations, EGR examinations show that NOx emission is reduced to less than the half, as 30 % of EGR is used; this occurs due to the EGR thermal and dilution effects, which cause significant drop in the peak bulk temperature and CO emissions as well. Under the applied conditions, EGR has the ability to raise the work

  13. 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...

  14. 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

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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

    water, oxygen and methane have been studied, as a function of space velocity, allowing us to assess the relative contributions of partial oxidation, steam reforming and water gas shift to the overall process of hydrogen formation. From this study we are able to identify the optimum auto-thermal conditions for the reforming process, and predict the behaviour of the reformer under different phases of engine operation. The reforming catalyst has been scaled up from a packed bed of granules to a full-sized monolithic reactor, which has been close-coupled with a Jaguar V6 engine. This integrated prototype has been tested with the engine running on natural gas in HCCI (homogeneous charge compression ignition) mode. The reformer adds 5-15% hydrogen to the recirculated exhaust gas, resulting in substantial improvements in the performance and emissions of the engine. (authors)

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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)

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. An experimental and numerical analysis of the influence of the inlet temperature, equivalence ratio and compression ratio on the HCCI auto-ignition process of Primary Reference Fuels in an engine

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim [UPMC Universite Paris 06, LGPPTS, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert (France); Cavadiasa, Simeon [UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert (France)

    2008-11-15

    In order to understand better the auto-ignition process in an HCCI engine, the influence of some important parameters on the auto-ignition is investigated. The inlet temperature, the equivalence ratio and the compression ratio were varied and their influence on the pressure, the heat release and the ignition delays were measured. The inlet temperature was changed from 25 to 70 C and the equivalence ratio from 0.18 to 0.41, while the compression ratio varied from 6 to 13.5. The fuels that were investigated were PRF40 and n-heptane. These three parameters appeared to decrease the ignition delays, with the inlet temperature having the least influence and the compression ratio the most. A previously experimentally validated reduced surrogate mechanism, for mixtures of n-heptane, iso-octane and toluene, has been used to explain observations of the auto-ignition process. The same kinetic mechanism is used to better understand the underlying chemical and physical phenomena that make the influence of a certain parameter change according to the operating conditions. This can be useful for the control of the auto-ignition process in an HCCI engine. (author)

  16. 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.

  17. 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.

  18. 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

  19. 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

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim; Cavadias, Simeon [UPMC Universite Paris 06, LGPPTS, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert, 2, place de la Gare de Ceinture, 78210 St Cyr-I' Ecole (France); Gilbert, Philippe [UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert, 2, place de la Gare de Ceinture, 78210 St Cyr-I' Ecole (France)

    2008-11-15

    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 of these fuels has been studied at inlet temperatures from 25 to 120 C, at equivalence ratios from 0.18 to 0.53 and at compression ratios from 6 to 13.5, in order to extend the range of investigation and to assess the usability of these parameters to control the auto-ignition. It appeared that both iso-octane and toluene delayed the ignition with respect to n-heptane, while toluene has the strongest effect. This means that aromatics have higher inhibiting effects than branched alkanes. In an increasing order, the inlet temperature, equivalence ratio and compression ratio had a promoting effect on the ignition delays. A previously experimentally validated reduced surrogate mechanism, for mixtures of n-heptane, iso-octane and toluene, has been used to explain observations of the auto-ignition process. (author)

  20. 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%.

  1. 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.

  2. 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.)

  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. 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

  6. An experimental and numerical analysis of the influence of the inlet temperature, equivalence ratio and compression ratio on the HCCI auto-ignition process of Primary Reference Fuels in an engine

    OpenAIRE

    Machrafi, Hatim; Cavadias

    2008-01-01

    In order to understand better the auto-ignition process in an HCCI engine, the influence of some important parameters on the auto-ignition is investigated. The inlet temperature, the equivalence ratio and the compression ratio were varied and their influence on the pressure, the heat release and the ignition delays were measured, The inlet temperature was changed from 25 to 70 degrees C and the equivalence ratio from 0.18 to 0.41, while the compression ratio varied from 6 to 13.5. The fuels t...

  7. 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.

  8. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    Science.gov (United States)

    Duffy, Kevin P [Metamora, IL; Kieser, Andrew J [Morton, IL; Rodman, Anthony [Chillicothe, IL; Liechty, Michael P [Chillicothe, IL; Hergart, Carl-Anders [Peoria, IL; Hardy, William L [Peoria, IL

    2008-05-27

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  9. 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

  10. 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.

  11. 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.

  12. Piping engineering and operation

    International Nuclear Information System (INIS)

    1993-01-01

    The conference 'Piping Engineering and Operation' was organized by the Institution of Mechanical Engineers in November/December 1993 to follow on from similar successful events of 1985 and 1989, which were attended by representatives from all sectors of the piping industry. Development of engineering and operation of piping systems in all aspects, including non-metallic materials, are highlighted. The range of issues covered represents a balance between current practices and implementation of future international standards. Twenty papers are printed. Two, which are concerned with pressurized pipes or steam lines in the nuclear industry, are indexed separately. (Author)

  13. 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.

  14. Engineering co-operation

    Energy Technology Data Exchange (ETDEWEB)

    Hryniszak, W

    1981-06-01

    A purposeful employment policy for human energy is basic to solving the energy dilemma, but a lack of understanding about human behavior has allowed man's exploitive characteristics to dominate during the Inductrial Revolution. England is dependent on trade to survive, but the importance of size in world competition is seen in the trend toward multinational and partnership enterprises. Reflecting this increasing competition, the engineering industries see a need for government policies that acknowledge the importance of technology and the effects of those policies on productivity. Engineering progress requires the creativity of optimistic idealism and the realism of implementing new ideas. The training and nurturing of human resources should begin by broadening the education of engineers to emphasize the concepts of quality and cooperation between government and industry. Engineers and scientists, who work within society, need to understand national demands and to operate in accordance with the highest moral standards. (DCK)

  15. 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.

  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. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. Engine and method for operating an engine

    Science.gov (United States)

    Lauper, Jr., John Christian; Willi, Martin Leo [Dunlap, IL; Thirunavukarasu, Balamurugesh [Peoria, IL; Gong, Weidong [Dunlap, IL

    2008-12-23

    A method of operating an engine is provided. The method may include supplying a combustible combination of reactants to a combustion chamber of the engine, which may include supplying a first hydrocarbon fuel, hydrogen fuel, and a second hydrocarbon fuel to the combustion chamber. Supplying the second hydrocarbon fuel to the combustion chamber may include at least one of supplying at least a portion of the second hydrocarbon fuel from an outlet port that discharges into an intake system of the engine and supplying at least a portion of the second hydrocarbon fuel from an outlet port that discharges into the combustion chamber. Additionally, the method may include combusting the combustible combination of reactants in the combustion chamber.

  3. 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

  4. 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...

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Engine systems and methods of operating an engine

    Energy Technology Data Exchange (ETDEWEB)

    Scotto, Mark Vincent

    2018-01-23

    One embodiment of the present invention is a unique method for operating an engine. Another embodiment is a unique engine system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for engines and engine systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

  10. Engine systems and methods of operating an engine

    Science.gov (United States)

    Scotto, Mark Vincent

    2015-08-25

    One embodiment of the present invention is a unique method for operating an engine. Another embodiment is a unique engine system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for engines and engine systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Nuclear thermal rocket engine operation and control

    International Nuclear Information System (INIS)

    Gunn, S.V.; Savoie, M.T.; Hundal, R.

    1993-06-01

    The operation of a typical Rover/Nerva-derived nuclear thermal rocket (NTR) engine is characterized and the control requirements of the NTR are defined. A rationale for the selection of a candidate diverse redundant NTR engine control system is presented and the projected component operating requirements are related to the state of the art of candidate components and subsystems. The projected operational capabilities of the candidate system are delineated for the startup, full-thrust, shutdown, and decay heat removal phases of the engine operation. 9 refs

  16. Engineering Process Monitoring for Control Room Operation

    OpenAIRE

    Bätz, M

    2001-01-01

    A major challenge in process operation is to reduce costs and increase system efficiency whereas the complexity of automated process engineering, control and monitoring systems increases continuously. To cope with this challenge the design, implementation and operation of process monitoring systems for control room operation have to be treated as an ensemble. This is only possible if the engineering of the monitoring information is focused on the production objective and is lead in close coll...

  17. 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

  18. 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

  19. Engineering Process Monitoring for Control Room Operation

    CERN Document Server

    Bätz, M

    2001-01-01

    A major challenge in process operation is to reduce costs and increase system efficiency whereas the complexity of automated process engineering, control and monitoring systems increases continuously. To cope with this challenge the design, implementation and operation of process monitoring systems for control room operation have to be treated as an ensemble. This is only possible if the engineering of the monitoring information is focused on the production objective and is lead in close collaboration of control room teams, exploitation personnel and process specialists. In this paper some principles for the engineering of monitoring information for control room operation are developed at the example of the exploitation of a particle accelerator at the European Laboratory for Nuclear Research (CERN).

  20. 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

  1. 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

  2. An Operational Standpoint in Electrical Engineering

    Directory of Open Access Journals (Sweden)

    Frédéric Rotella

    2013-12-01

    Full Text Available In electrical engineering education exists a major difficulty for first level students, namely the Laplace transform. The question is: does this ubiquitous tool is needed in an electrical engineering course? Our answer is: Obviously, not. Based on an operational standpoint the paper describes some guidelines and results for a primer on handling signals and linear systems without using the Laplace transform. The main advantage is that the operational standpoint leads to simplified proofs for well-known results.

  3. Mass Transfer Operations for the Practicing Engineer

    CERN Document Server

    Theodore, Louis

    2011-01-01

    Part of the Essential Engineering Calculations Series, this book presents step-by-step solutions of the basic principles of mass transfer operations, including sample problems and solutions and their applications, such as distillation, absorption, and stripping. Presenting the subject from a strictly pragmatic point of view, providing both the principles of mass transfer operations and their applications, with clear instructions on how to carry out the basic calculations needed, the book also covers topics useful for readers taking their professional exams.

  4. Fundamental Interactions in Gasoline Compression Ignition Engines with Fuel Stratification

    Science.gov (United States)

    Wolk, Benjamin Matthew

    Transportation accounted for 28% of the total U.S. energy demand in 2011, with 93% of U.S. transportation energy coming from petroleum. The large impact of the transportation sector on global climate change necessitates more-efficient, cleaner-burning internal combustion engine operating strategies. One such strategy that has received substantial research attention in the last decade is Homogeneous Charge Compression Ignition (HCCI). Although the efficiency and emissions benefits of HCCI are well established, practical limits on the operating range of HCCI engines have inhibited their application in consumer vehicles. One such limit is at high load, where the pressure rise rate in the combustion chamber becomes excessively large. Fuel stratification is a potential strategy for reducing the maximum pressure rise rate in HCCI engines. The aim is to introduce reactivity gradients through fuel stratification to promote sequential auto-ignition rather than a bulk-ignition, as in the homogeneous case. A gasoline-fueled compression ignition engine with fuel stratification is termed a Gasoline Compression Ignition (GCI) engine. Although a reasonable amount of experimental research has been performed for fuel stratification in GCI engines, a clear understanding of how the fundamental in-cylinder processes of fuel spray evaporation, mixing, and heat release contribute to the observed phenomena is lacking. Of particular interest is gasoline's pressure sensitive low-temperature chemistry and how it impacts the sequential auto-ignition of the stratified charge. In order to computationally study GCI with fuel stratification using three-dimensional computational fluid dynamics (CFD) and chemical kinetics, two reduced mechanisms have been developed. The reduced mechanisms were developed from a large, detailed mechanism with about 1400 species for a 4-component gasoline surrogate. The two versions of the reduced mechanism developed in this work are: (1) a 96-species version and (2

  5. Freight railway operator timetabling and engine scheduling

    DEFF Research Database (Denmark)

    Bach, Lukas; Gendreau, M.; Wøhlk, Sanne

    2015-01-01

    In this paper we consider timetable design at a European freight railway operator. The timetable is designed by choosing the time of service for customer unit train demands among a set of discrete points. These discrete points are all found within the a time-window. The objective of the model...... is to minimize cost while adhering to constraints regarding infrastructure usage, demand coverage, and engine availability. The model is solved by a column generation scheme where feasible engine schedules are designed in a label setting algorithm with time-dependent cost and service times....

  6. 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.

  7. Nuclear operations summary Engineering organization for Plowshare nuclear operations

    Energy Technology Data Exchange (ETDEWEB)

    Broadman, Gene A [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-15

    The availability of nuclear explosives for peaceful projects has given the engineer a new dimension in his thinking. He can now seek methods of adapting Plowshare to a variety of industrial applications. The full potential of the Plowshare Program can only be attained when industry begins to use nuclear explosives on a regular basis, for economically sound projects. It is the purpose of this paper to help the engineer familiarize himself with Plowshare technology to hasten the day when 'Plowsharee goes commercial'. An engineering project utilizing nuclear exposives ordinarily involves three main phases: Phase I (a) The theoretical and empirical analysis of effects. (b) Projected economic and/or scientific evaluation. (c) A safety analysis. Phase II (a) Field construction. (b) Safe detonation of the nuclear explosive. (c) Data acquisition. Phase III The evaluation and/or exploitation of the results. This paper will be restricted to Phase II, referred to collectively as the 'nuclear operation'.

  8. 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.

  9. 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)

  10. Use of a single-zone thermodynamic model with detailed chemistry to study a natural gas fueled homogeneous charge compression ignition engine

    International Nuclear Information System (INIS)

    Zheng Junnian; Caton, Jerald A.

    2012-01-01

    Highlights: ► Auto-ignition characteristics of a natural gas fueled HCCI engine. ► Engine speed had the greatest effect on the auto-ignition process. ► Increases of C 2 H 6 or C 3 H 8 improved the auto-ignition process. ► Engine performance was not sensitive to small changes in C 2 H 6 or C 3 H 8 . ► Nitric oxides concentrations decreased as engine speed or EGR level was increased. - Abstract: A single zone thermodynamic model with detailed chemical kinetics was used to simulate a natural gas fueled homogeneous charge compression ignition (HCCI) engine. The model employed Chemkin and used chemical kinetics for natural gas with 53 species and 325 reactions. This simulation was used to complete analyses for a modified 0.4 L single cylinder engine. The engine possessed a compression ratio of 21.5:1, and had a bore and stroke of 86 and 75 mm, respectively. Several sets of parametric studies were completed to investigate the minimal initial temperature, engine performance, and nitric oxide emissions of HCCI engine operation. The results show significant changes in combustion characteristics with varying engine operating conditions. Effects of varying equivalence ratios (0.3–1.0), engine speeds (1000–4000 RPM), EGR (0–40%), and fuel compositions were determined and analyzed in detail. In particular, every 0.1 increase in equivalence ratio or 500 rpm increase in engine speed requires about a 5 K higher initial temperature for complete combustion, and leads to around 0.7 bar increase in IMEP.

  11. 14 CFR 29.939 - Turbine engine operating characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall, surge, of flameout) are...

  12. 14 CFR 25.939 - Turbine engine operating characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine operating characteristics... engine operating characteristics. (a) Turbine engine operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall, surge, or flameout) are present, to a...

  13. 14 CFR 27.939 - Turbine engine operating characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall, surge, or flameout) are...

  14. 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.

  15. Experimental optimization of a direct injection homogeneous charge compression ignition gasoline engine using split injections with fully automated microgenetic algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Canakci, M. [Kocaeli Univ., Izmit (Turkey); Reitz, R.D. [Wisconsin Univ., Dept. of Mechanical Engineering, Madison, WI (United States)

    2003-03-01

    Homogeneous charge compression ignition (HCCI) is receiving attention as a new low-emission engine concept. Little is known about the optimal operating conditions for this engine operation mode. Combustion under homogeneous, low equivalence ratio conditions results in modest temperature combustion products, containing very low concentrations of NO{sub x} and particulate matter (PM) as well as providing high thermal efficiency. However, this combustion mode can produce higher HC and CO emissions than those of conventional engines. An electronically controlled Caterpillar single-cylinder oil test engine (SCOTE), originally designed for heavy-duty diesel applications, was converted to an HCCI direct injection (DI) gasoline engine. The engine features an electronically controlled low-pressure direct injection gasoline (DI-G) injector with a 60 deg spray angle that is capable of multiple injections. The use of double injection was explored for emission control and the engine was optimized using fully automated experiments and a microgenetic algorithm optimization code. The variables changed during the optimization include the intake air temperature, start of injection timing and the split injection parameters (per cent mass of fuel in each injection, dwell between the pulses). The engine performance and emissions were determined at 700 r/min with a constant fuel flowrate at 10 MPa fuel injection pressure. The results show that significant emissions reductions are possible with the use of optimal injection strategies. (Author)

  16. 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

  17. The Corps Engineer Battalion in Contingency Operations

    National Research Council Canada - National Science Library

    Raymer, James

    2001-01-01

    .... The central research question asks: Is the proposed echelons above division engineer battalion design a better one for active and reserve component corps engineer forces to respond in a contingency...

  18. Experimental and modeling study of hydrogen/syngas production and particulate emissions from a natural gas-fueled partial oxidation engine

    International Nuclear Information System (INIS)

    McMillian, Michael H.; Lawson, Seth A.

    2006-01-01

    In this study, a combustion model was first applied to conditions representing varying compression ratios and equivalence ratios to investigate engine exhaust composition from partial oxidation (POX) of natural gas in reciprocating engines. The model was experimentally validated over a range of equivalence ratios from 1.3 to 1.6 with a spark-ignited single cylinder engine fueled by natural gas. The modeling results matched well with engine gaseous emission data over the experimental range. The model was also extended to higher equivalence ratios to predict H 2 and CO production at engine conditions and stoichiometries representative of homogeneous charge compression ignition (HCCI) engine operation. Secondly, over the same experimental range of equivalence ratios, particulate samples were taken to determine both total particulate mass production (g/hph) via gravimetric measurement as well as particle size distribution and loading via a scanning mobility particle sizer (SMPS). While experiments indicate hydrogen yields up to 11% using spark ignition (SI), modeling results indicate that greater than 20% H 2 yield may be possible in HCCI operation. Over the experimental range, rich-burn particulate matter (PM) production is no greater than that from typical lean-burn operation. Finally, an energy balance was performed over the range of engine experimental operation. (author)

  19. Accessible engineering drawings for visually impaired machine operators.

    Science.gov (United States)

    Ramteke, Deepak; Kansal, Gayatri; Madhab, Benu

    2014-01-01

    An engineering drawing provides manufacturing information to a machine operator. An operator plans and executes machining operations based on this information. A visually impaired (VI) operator does not have direct access to the drawings. Drawing information is provided to them verbally or by using sample parts. Both methods have limitations that affect the quality of output. Use of engineering drawings is a standard practice for every industry; this hampers employment of a VI operator. Accessible engineering drawings are required to increase both independence, as well as, employability of VI operators. Today, Computer Aided Design (CAD) software is used for making engineering drawings, which are saved in CAD files. Required information is extracted from the CAD files and converted into Braille or voice. The authors of this article propose a method to make engineering drawings information directly accessible to a VI operator.

  20. 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 ...

  1. 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...

  2. Enhanced Engine Performance During Emergency Operation Using a Model-Based Engine Control Architecture

    Science.gov (United States)

    Csank, Jeffrey T.; Connolly, Joseph W.

    2016-01-01

    This paper discusses the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft. The MBEC methodology is applied to the Commercial Modular Aero-Propulsion System Simulation 40k (CMAPSS40k) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control. During an emergency scenario, normally-conservative engine operating limits may be relaxed to increase the performance of the engine and overall survivability of the aircraft; this comes at the cost of additional risk of an engine failure. The MBEC architecture offers the advantage of estimating key engine parameters that are not directly measureable. Estimating the unknown parameters allows for tighter control over these parameters, and on the level of risk the engine will operate at. This will allow the engine to achieve better performance than possible when operating to more conservative limits on a related, measurable parameter.

  3. Cold neutron fluoroscopy of operating automotive engines

    International Nuclear Information System (INIS)

    Stewart, P.A.E.; Heritage, J.

    1983-01-01

    The application of neutron fluoroscopy in the automotive industry is a natural extension of previous studies with aircraft engines. This paper describes investigations with two sub-compact car engines. The extent and manner in which lubricants reached the various parts of the engines are compared and contrasted. The paper goes on to describe a study of the deposits inside turbochargers and postulates future topics worthy of investigation. The authors confirm that there is a place for neutron fluoroscopy both as a design tool and for investigations of ''in-service'' phenomena. (Auth.)

  4. Connecting engineering operations to strategic management: a framework for decision making in engineering offshoring

    DEFF Research Database (Denmark)

    Hansen, Zaza Nadja Lee; Ahmed-Kristensen, Saeema

    2012-01-01

    of the organisation. The Global Decision-Making (GDM) framework described here is a decision-making framework for engineering offshoring decisions for product development activities. The framework proposes that risks in engineering offshoring can be reduced by connecting engineering operations to strategic management...

  5. Enhanced Engine Control for Emergency Operation

    Science.gov (United States)

    Litt, Jonathan S.

    2012-01-01

    C-MAPSS40k engine simulation has been developed and is available to the public. The authenticity of the engine performance and controller enabled the development of realistic enhanced control modes through controller modification alone. Use of enhanced control modes improved stability and control of an impaired aircraft. - Fast Response is useful for manual manipulation of the throttles - Use of Fast Response improved stability as part of a yaw rate feedback system. - Use of Overthrust shortened takeoff distance, but was generally useful in flight, too. Initial lack of pilot familiarity resulted in discomfort, especially with yaw rate feedback, but that was the only drawback, overall the pilot found the enhanced modes very helpful.

  6. ADVANCED COMPRESSOR ENGINE CONTROLS TO ENHANCE OPERATION, RELIABILITY AND INTEGRITY

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Bourn; Jess W. Gingrich; Jack A. Smith

    2004-03-01

    This document is the final report for the ''Advanced Compressor Engine Controls to Enhance Operation, Reliability, and Integrity'' project. SwRI conducted this project for DOE in conjunction with Cooper Compression, under DOE contract number DE-FC26-03NT41859. This report addresses an investigation of engine controls for integral compressor engines and the development of control strategies that implement closed-loop NOX emissions feedback.

  7. CO Emissions from Gas Engines Operating on Biomass Producer Gas

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Jensen, T. K.; Henriksen, Ulrik Birk

    2004-01-01

    High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. CO emissions from engines operating on biomass producer gases are high, especially at very lean conditions where...

  8. Hige Compression Ratio Turbo Gasoline Engine Operation Using Alcohol Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Heywood, John [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Jo, Young Suk [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lewis, Raymond [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Bromberg, Leslie [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Heywood, John [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2016-01-29

    The overall objective of this project was to quantify the potential for improving the performance and efficiency of gasoline engine technology by use of alcohols to suppress knock. Knock-free operation is obtained by direct injection of a second “anti-knock” fuel such as ethanol, which suppresses knock when, with gasoline fuel, knock would occur. Suppressing knock enables increased turbocharging, engine downsizing, and use of higher compression ratios throughout the engine’s operating map. This project combined engine testing and simulation to define knock onset conditions, with different mixtures of gasoline and alcohol, and with this information quantify the potential for improving the efficiency of turbocharged gasoline spark-ignition engines, and the on-vehicle fuel consumption reductions that could then be realized. The more focused objectives of this project were therefore to: Determine engine efficiency with aggressive turbocharging and downsizing and high compression ratio (up to a compression ratio of 13.5:1) over the engine’s operating range; Determine the knock limits of a turbocharged and downsized engine as a function of engine speed and load; Determine the amount of the knock-suppressing alcohol fuel consumed, through the use of various alcohol-gasoline and alcohol-water gasoline blends, for different driving cycles, relative to the gasoline consumed; Determine implications of using alcohol-boosted engines, with their higher efficiency operation, in both light-duty and medium-duty vehicle sectors.

  9. US Army Corps of Engineers Reachback Operations Center

    Data.gov (United States)

    Federal Laboratory Consortium — Providing Relevant Solutions to the Armed Forces and the NationThe USACE Reachback Operation Center at the U.S. Army Engineer Research and Development Center (ERDC)...

  10. Linear engine development for series hybrid electric vehicles

    Science.gov (United States)

    Toth-Nagy, Csaba

    modes of engine operation experimentally. The two modes were direct injection compression ignition (DICI) and "pseudo" homogeneously charged compression ignition (PHCCI). Simulation was performed to include HCCI operation in the study. The study showed that the HCCI operation resulted in higher peak cylinder pressure than that of DICI operation. A combined genetic algorithm-artificial neural network predictor model was used along with the simulation model to find the combination of engine parameters that yielded the highest engine efficiency. The predictor-simulator model suggested the most efficient combination of engine parameters.

  11. DEVELOPMENT OF OPERATING DRIVE SYSTEMS IN ENGINEERING EQUIPMENT

    Directory of Open Access Journals (Sweden)

    A. A. Kotlobai

    2015-01-01

    Full Text Available Engineering machines being in operational service with military units of  engineer troops are fit to their purpose and their application is relevant in modern conditions. Maintenance of operating conditions in engineering equipment which was produced earlier by the USSR enterprises is considered as a rather complicated task due to lack of spare parts because their production has been discontinued.One of the approaches used for maintenance of engineering equipment combat capabilities is modernization of operating drive systems that presupposes replacement of mechanical systems in working element drives by hydrostatic drives which are realized while using modern element base. Usage of hydraulic units in drive systems being in mass production for replacement of mechanical systems manufactured earlier in small batches makes it possible to reduce labour inputs for maintenance and repair of machines. The paper presents some possibilities for development of operating drive systems in engineering equipment. The proposed approach is given through an example of  engineering obstacle-clearing vehicle (IMR-2M and excavation machines (MDK-3 and MDK-2M.Application of a hydraulic drive in working elements of the excavation machines permits to withdraw from cardan  shafts, a gear box, a rotary gear and an overload clutch. A hydraulic motor of the cutter and thrower drive is mounted  on a working element gearbox. While executing modernization of hydraulic systems in excavation machines a pump unit has been proposed for the cutter and thrower drive which consists of a controlled pump and a system for automatic maintenance of the pump operational parameters. While developing the operating drive systems in engineering equipment in accordance with the proposed requirements it is possible to simplify drive systems of working elements and  ensure reliable machinery operation in the units of engineer troops. 

  12. Managing complexity challenges for industrial engineering and operations management

    CERN Document Server

    López-Paredes, Adolfo; Pérez-Ríos, José

    2014-01-01

    This book presents papers by experts in the field of Industrial Engineering, covering topics in business strategy; modelling and simulation in operations research; logistics and production; service systems; innovation and knowledge; and project management. The focus of operations and production management has evolved from product and manufacturing to the capabilities of firms and collaborative management. Nowadays, Industrial Engineering is concerned with the study of how to design, modify, control and improve the performance of complex systems. It has extended its scope to any physical landscape populated by social agents. This raises a major challenge to Industrial Engineering:  managing complexity. This volume shows how experts are dealing with this challenge.

  13. 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.

  14. Database reliability engineering designing and operating resilient database systems

    CERN Document Server

    Campbell, Laine

    2018-01-01

    The infrastructure-as-code revolution in IT is also affecting database administration. With this practical book, developers, system administrators, and junior to mid-level DBAs will learn how the modern practice of site reliability engineering applies to the craft of database architecture and operations. Authors Laine Campbell and Charity Majors provide a framework for professionals looking to join the ranks of today’s database reliability engineers (DBRE). You’ll begin by exploring core operational concepts that DBREs need to master. Then you’ll examine a wide range of database persistence options, including how to implement key technologies to provide resilient, scalable, and performant data storage and retrieval. With a firm foundation in database reliability engineering, you’ll be ready to dive into the architecture and operations of any modern database. This book covers: Service-level requirements and risk management Building and evolving an architecture for operational visibility ...

  15. Control room human engineering influences on operator performance

    International Nuclear Information System (INIS)

    Finlayson, F.C.

    1977-01-01

    Three general groups of factors influence operator performance in fulfilling their responsibilities in the control room: (1) control room and control system design, informational data displays (operator inputs) as well as control board design (for operator output); (2) operator characteristics, including those skills, mental, physical, and emotional qualities which are functions of operator selection, training, and motivation; (3) job performance guides, the prescribed operating procedures for normal and emergency operations. This paper presents some of the major results of an evaluation of the effect of human engineering on operator performance in the control room. Primary attention is given to discussion of control room and control system design influence on the operator. Brief observations on the influences of operator characteristics and job performance guides (operating procedures) on performance in the control room are also given. Under the objectives of the study, special emphasis was placed on the evaluation of the control room-operator relationships for severe emergency conditions in the power plant. Consequently, this presentation is restricted largely to material related to emergency conditions in the control room, though it is recognized that human engineering of control systems is of equal (or greater) importance for many other aspects of plant operation

  16. A Risk Assessment Architecture for Enhanced Engine Operation

    Science.gov (United States)

    Litt, Jonathan S.; Sharp. Lauren M.; Guo, Ten-Huei

    2010-01-01

    On very rare occasions, in-flight emergencies have occurred that required the pilot to utilize the aircraft's capabilities to the fullest extent possible, sometimes using actuators in ways for which they were not intended. For instance, when flight control has been lost due to damage to the hydraulic systems, pilots have had to use engine thrust to maneuver the plane to the ground and in for a landing. To assist the pilot in these situations, research is being performed to enhance the engine operation by making it more responsive or able to generate more thrust. Enabled by modification of the propulsion control, enhanced engine operation can increase the probability of a safe landing during an inflight emergency. However, enhanced engine operation introduces risk as the nominal control limits, such as those on shaft speed, temperature, and acceleration, are exceeded. Therefore, an on-line tool for quantifying this risk must be developed to ensure that the use of an enhanced control mode does not actually increase the overall danger to the aircraft. This paper describes an architecture for the implementation of this tool. It describes the type of data and algorithms required and the information flow, and how the risk based on engine component lifing and operability for enhanced operation is determined.

  17. Engineering Design and Operation Report: Biological ...

    Science.gov (United States)

    Many regions in the United States have excessive levels of ammonia in their drinking water sources (e.g., ground and surface waters) as a result of naturally occurring processes, agricultural and urban runoff, concentrated animal feeding operations, municipal wastewater treatment plants, and other sources. Ammonia is not regulated by the U.S. Environmental Protection Agency (EPA) as a contaminant. Based on a 2003 World Health Organization (WHO) assessment, ammonia levels in groundwater are typically below 0.2 milligrams per liter (mg/L), and do not pose a direct health concern at levels expected in drinking water (WHO 2003); however, they may pose a concern when nitrification of significant levels of ammonia from the source water occurs in the drinking water distribution system. Specifically, this nitrification, which is the conversion of the ammonia to nitrite and nitrate by bacteria, leads to water quality issues, such as potential corrosion problems, oxidant demand, taste and odor complaints, and elevated nitrite levels (Bremer et al.,2001; Fleming et al., 2005; Lee et al., 1980; Odell et al., 1996; Rittman & Snoeyink, 1984; Suffet et al., 1996). The EPA’s regulatory limits for nitrite and nitrate (at the entry point to the distribution system) are 0.1 and 10 mg N/L, respectively. Ammonia in water may also pose problems with water treatment effectiveness. For example, in source waters containing both ammonia and arsenic, the ammonia may negatively impact

  18. Research on the NPP human factors engineering operating experience review

    International Nuclear Information System (INIS)

    Ren Xiangchen; Miao Hongxing; Ning Zhonghe

    2006-01-01

    This paper addresses the importance of the human factors engineering (HFE) for the design of nuclear power plant (NPP), especially for the design of human-machine interface in the NPP. It also summarizes the scope and content of the NPP HFE. The function, scope, content and process of the NPP human factors engineering operating experience review (OER) are mainly focused on, and significantly discussed. Finally, it briefly introduces the situation of the studies on the OER in China. (authors)

  19. Business process re-engineering in service operations

    International Nuclear Information System (INIS)

    McClintock, J.W.

    1995-01-01

    The concept of business process re-engineering, and how it was applied to the operations of the Consumers Gas Company were discussed. Business process re-engineering was defined as the improvement of the efficiency of the customer-service process, and the overall improvement of practices and operations. The re-engineering project was said to involve a thorough analysis of information technology, current limitations, and business operational needs, undertaken on an enterprise-wide basis. Viewed generically,a re-engineering project was said to have six major components: (1) business drivers (i.e. the articulation of the Company's strategic issues); (2) benchmark measures; (3) future state process models; (4) cost/benefit analysis; (5) a change management plan; and (6) a development plan. Business improvements expected to result from the project include reduced cost of operation, reduction of waste, and a substantially complete re-design of the business process. Management of the project involved a team approach, and help of a consultant to identify the scope of the re-design, its limitations, and future state. A life expectancy of approximately 10 years was given for the re-engineering plan, with annual benefits (in terms of cost reduction) of $4.6 million by the year 2000

  20. Qualification of engine-mounted components due to operational vibration

    International Nuclear Information System (INIS)

    Lee, B.J.; Bayat, A.

    1994-01-01

    The Emergency Diesel Generator (EDG) in a Nuclear Power Plant is considered to be an essential component of the plant for its safe operation. Failures of auxiliary components directly mounted on the EDG creates costly repairs, and compromises the engine's availability and reliability. Although IEEE-323 and Section III of the ASME code require addressing of safety-related components due to mechanically induced vibration, very few guidelines exist in the nuclear industry to show how this may be accounted for. Most engine vendors rely on the empirical experience data as the basis of their evaluation for vibration. Upgrade of engine controls, addition of monitoring components and other engine modifications require design and installation of new mechanical and electrical components to be mounted directly on the engine. This necessitates the evaluation of such components for engine-induced vibration which is considered to be one of the most severe design parameters. This paper presents a methodology to evaluate three categories of components; structural, mechanical, and electrical under engine vibration. The discussion for the characteristics and manipulation of engine vibration profile to be used for each component evaluation is also given. In addition, the suitability of analytical verses testing approaches is discussed for each category. An example application of the methodology is presented for a typical EDG which is currently undergoing major controls upgrade and monitoring modification

  1. An investigation into the RCCI engine operation under low load and its achievable operational range at different engine speeds

    International Nuclear Information System (INIS)

    Wang, Yifeng; Zhu, ZhongWen; Yao, Mingfa; Li, Tie; Zhang, Weijing; Zheng, Zunqing

    2016-01-01

    Highlights: • The response of allowable RCCI operating range to engine speed variation is studied. • The RCCI and diesel LTC engine operations at are compared at low engine load. • The potential of expanding RCCI operating range at low engine speed is explored. - Abstract: Reactivity controlled compression ignition (RCCI) is demonstrated as a promising combustion strategy to achieve high efficiency and clean combustion. However, less effort has been devoted to examine the achievable RCCI operational range over a wide range of engine speed. In addition, previous studies have found that superior EGR rate and high diesel/gasoline fuel ratio are required to ease the extension of the low-load operating range of RCCI regime. Even then, relatively high CO and HC (unburned hydrocarbon) emissions and the accompanying fuel con-sum ption penalty still remain a problem to be resolved. Therefore, in this work the potential of diesel-fueled LTC to achieve simultaneously low NOx and soot emissions while maintaining high thermal efficiency at low load (IMEP ≈0.23–0.26 MPa) is investigated and compared with the gasoline/diesel RCCI strategy. The results show that the diesel LTC operation can yield slightly higher soot and NOx emissions (soot: 0.002 g/kW h, NOx: 0.446 g/kW h), but CO and HC emissions as well as the fuel consumption are much lower than the RCCI strategy, implying the diesel LTC regime may be more suitable for low-load operations. In addition, the RCCI operational range at speeds ranging from 900 to 2500 r/min is determined, the results show that the maximum achievable load (IMEP) increases with an increase in speed, and a maximum IMEP of 1.2 MPa can be achieved at an engine speed of 2300 r/min. Ultra-low NOx and soot emissions (soot < 0.003 g/kW h, NOx < 0.4 g/kW h) can be achieved under the maximum loading conditions at each speed investigated. However, high levels of CO and HC emissions still remain a big problem to be solved. The lowest fuel consumption

  2. A Study on Homogeneous Charge Compression Ignition Gasoline Engines

    Science.gov (United States)

    Kaneko, Makoto; Morikawa, Koji; Itoh, Jin; Saishu, Youhei

    A new engine concept consisting of HCCI combustion for low and midrange loads and spark ignition combustion for high loads was introduced. The timing of the intake valve closing was adjusted to alter the negative valve overlap and effective compression ratio to provide suitable HCCI conditions. The effect of mixture formation on auto-ignition was also investigated using a direct injection engine. As a result, HCCI combustion was achieved with a relatively low compression ratio when the intake air was heated by internal EGR. The resulting combustion was at a high thermal efficiency, comparable to that of modern diesel engines, and produced almost no NOx emissions or smoke. The mixture stratification increased the local A/F concentration, resulting in higher reactivity. A wide range of combustible A/F ratios was used to control the compression ignition timing. Photographs showed that the flame filled the entire chamber during combustion, reducing both emissions and fuel consumption.

  3. Performance of Naturally Aspirating IC Engines Operating at High ...

    African Journals Online (AJOL)

    The loss of power and the increase of fuel consumption of naturally aspirating IC engines operating with low atmospheric pressure at high altitude as well as changes in the mixture quality with non adapting mixture formation systems are principally known. Other effects like the additional advance of ignition timing in petrol ...

  4. Plasma engineering analyses of tokamak reactor operating space

    International Nuclear Information System (INIS)

    Houlberg, W.; Attenberger, S.E.

    1981-01-01

    A comprehensive method is presented for analyzing the potential physics operating regime of fusion reactor plasmas with detailed transport codes. Application is made to the tokamak Fusion Engineering Device (FED). The relationships between driven and ignited operation and supplementary heating requirements are examined. The reference physics models give a finite range of density and temperature over which physics objectives can be reached. Uncertainties in the confinement scaling and differences in supplementary heating methods can expand or contract this operating regime even to the point of allowing ignition with the more optimistic models

  5. Control of harmful hydrocarbon species in the exhaust of modern advanced GDI engines

    Science.gov (United States)

    Hasan, A. O.; Abu-jrai, A.; Turner, D.; Tsolakis, A.; Xu, H. M.; Golunski, S. E.; Herreros, J. M.

    2016-03-01

    A qualitative and quantitative analysis of toxic but currently non-regulated hydrocarbon compounds ranging from C5-C11, before and after a zoned three-way catalytic converter (TWC) in a modern gasoline direct injection (GDI) engine has been studied using gas chromatography-mass spectrometry (GC-MS). The GDI engine has been operated under conventional and advanced combustion modes, which result in better fuel economy and reduced levels of NOx with respect to standard SI operation. However, these fuel-efficient conditions are more challenging for the operation of a conventional TWC, and could lead to higher level of emissions released to the environment. Lean combustion leads to the reduction in pumping losses, fuel consumption and in-cylinder emission formation rates. However, lean HCCI will lead to high levels of unburnt HCs while the presence of oxygen will lower the TWC efficiency for NOx control. The effect on the catalytic conversion of the hydrocarbon species of the addition of hydrogen upstream the catalyst has been also investigated. The highest hydrocarbon engine-out emissions were produced for HCCI engine operation at low engine load operation. The catalyst was able to remove most of the hydrocarbon species to low levels (below the permissible exposure limits) for standard and most of the advanced combustion modes, except for naphthalene (classified as possibly carcinogenic to humans by the International Agency for Research on Cancer) and methyl-naphthalene (which has the potential to cause lung damage). However, when hydrogen was added upstream of the catalyst, the catalyst conversion efficiency in reducing methyl-naphthalene and naphthalene was increased by approximately 21%. This results in simultaneous fuel economy and environmental benefits from the effective combination of advanced combustion and novel aftertreatment systems.

  6. Quantum heat engine operating between thermal and spin reservoirs

    Science.gov (United States)

    Wright, Jackson S. S. T.; Gould, Tim; Carvalho, André R. R.; Bedkihal, Salil; Vaccaro, Joan A.

    2018-05-01

    Landauer's erasure principle is a cornerstone of thermodynamics and information theory [R. Landauer, IBM J. Res. Dev. 5, 183 (1961), 10.1147/rd.53.0183]. According to this principle, erasing information incurs a minimum energy cost. Recently, Vaccaro and Barnett [J. A. Vaccaro and S. M. Barnett, Proc. R. Soc. A 467, 1770 (2011), 10.1098/rspa.2010.0577] explored information erasure in the context of multiple conserved quantities and showed that the erasure cost can be solely in terms of spin angular momentum. As Landauer's erasure principle plays a fundamental role in heat engines, their result considerably widens the possible configurations that heat engines can have. Motivated by this, we propose here an optical heat engine that operates under a single thermal reservoir and a spin angular momentum reservoir coupled to a three-level system with two energy degenerate ground states. The proposed heat engine operates without producing waste heat and goes beyond the traditional Carnot engine where the working fluid is subjected to two thermal baths at different temperatures.

  7. Effects of Injection Scheme on Rotating Detonation Engine Operation

    Science.gov (United States)

    Chacon, Fabian; Duvall, James; Gamba, Mirko

    2017-11-01

    In this work, we experimentally investigate the operation and performance characteristics of a rotating detonation engine (RDE) operated with different fuel injection schemes and operating conditions. In particular, we investigate the detonation and operation characteristics produced with an axial flow injector configuration and semi-impinging injector configurations. These are compared to the characteristics produced with a canonical radial injection system (AFRL injector). Each type produces a different flowfield and mixture distribution, leading to a different detonation initiation, injector dynamic response, and combustor pressure rise. By using a combination of diagnostics, we quantify the pressure loses and gains in the system, the ability to maintain detonation over a range of operating points, and the coupling between the detonation and the air/fuel feed lines. We particularly focus on how this coupling affects both the stability and the performance of the detonation wave. This work is supported by the DOE/UTSR program under project DE-FE0025315.

  8. The internationalization of SMEs operating in the engineering industry

    Directory of Open Access Journals (Sweden)

    Lenka Procházková

    2012-01-01

    Full Text Available The importance of small and medium enterprises (SMEs in the national economies of EU countries has been always growing. For these reasons, the increasing attention is paid to small and medium-sized enterprises also in the Czech economy. The paper is focused on the globalization of small and medium enterprises, in particular, identifying the key success factors of small and medium-sized businesses that operate in the engineering industry. For the purpose of fulfilling the objective of the article, the level of success of SMEs in foreign markets is established with the aggregate indicator of success. Subsequently the results of the primary research among the Czech engineering companies are presented, based on this research the factors affecting the success of these entities of engineering industry in foreign markets are defined.

  9. Solid waste operations complex engineering verification program plan

    International Nuclear Information System (INIS)

    Bergeson, C.L.

    1994-01-01

    This plan supersedes, but does not replace, the previous Waste Receiving and Processing/Solid Waste Engineering Development Program Plan. In doing this, it does not repeat the basic definitions of the various types or classes of development activities nor provide the rigorous written description of each facility and assign the equipment to development classes. The methodology described in the previous document is still valid and was used to determine the types of verification efforts required. This Engineering Verification Program Plan will be updated on a yearly basis. This EVPP provides programmatic definition of all engineering verification activities for the following SWOC projects: (1) Project W-026 - Waste Receiving and Processing Facility Module 1; (2) Project W-100 - Waste Receiving and Processing Facility Module 2A; (3) Project W-112 - Phase V Storage Facility; and (4) Project W-113 - Solid Waste Retrieval. No engineering verification activities are defined for Project W-112 as no verification work was identified. The Acceptance Test Procedures/Operational Test Procedures will be part of each project's Title III operation test efforts. The ATPs/OTPs are not covered by this EVPP

  10. Shiraz solar power plant operation with steam engine

    International Nuclear Information System (INIS)

    Yaghoubi, M.; Azizian, K.

    2004-01-01

    The present industrial developments and daily growing need of energy, as well as economical and environmental problem caused by fossil fuels consumption, resulted certain constraint for the future demand of energy. During the past two decades great attention has been made to use renewable energy for different sectors. In this regard for the first time in Iran, design and construction of a 250 K W Solar power plant in Shiraz, Iran is being carried out and it will go to operation within next year. The important elements of this power plant is an oil cycle and a steam cycle, and several studies have been done about design and operation of this power plant, both for steady state and transient conditions. For the steam cycle, initially a steam turbine was chosen and due to certain limitation it has been replaced by a steam engine. The steam engine is able to produce electricity with hot or saturated vapor at different pressures and temperatures. In this article, the effects of installing a steam engine and changing its vapor inlet pressure and also the effects of sending hot or saturated vapor to generate electricity are studied. Various cycle performance and daily electricity production are determined. The effects of oil cycle temperature on the collector field efficiency, and daily, monthly and annual amount of electricity production is calculated. Results are compared with the steam cycle output when it contains a steam turbine. It is found that with a steam engine it is possible to produce more annual electricity for certain conditions

  11. Human and organization factors: engineering operating safety into offshore structures

    International Nuclear Information System (INIS)

    Bea, Robert G.

    1998-01-01

    History indicates clearly that the safety of offshore structures is determined primarily by the humans and organizations responsible for these structures during their design, construction, operation, maintenance, and decommissioning. If the safety of offshore structures is to be preserved and improved, then attention of engineers should focus on to how to improve the reliability of the offshore structure 'system,' including the people that come into contact with the structure during its life-cycle. This article reviews and discusss concepts and engineering approaches that can be used in such efforts. Two specific human factor issues are addressed: (1) real-time management of safety during operations, and (2) development of a Safety Management Assessment System to help improve the safety of offshore structures

  12. Method for plant operation guidance by knowledge engineering technique

    International Nuclear Information System (INIS)

    Kiguchi, Takashi; Yoshida, Kenichi; Motoda, Hiroshi; Kobayashi, Setsuo

    1983-01-01

    A method for plant operation guidance has been developed by using the Knowledge Engineering technique. The method is characterized by its capability of handling plant dynamics. The knowledge-base includes plant simulation programs as tools to evaluate dynamic behaviors as well as production rules of ''if..., then...'' type. The inference engine is thus capable of predicting plant dynamics and making decisions in accordance with time progress. The performance of the guidance method was evaluated by simulation tests assuming various abnormal situations of a BWR power plant. It was shown that the method can detect each of the abnormal events along the course of their occurrence, and provide the guidance for corrective actions. The operation guidance method proposed in this paper is general and is applicable not only to nuclear power plants but also to other plants such as chemical production plants and fossile power plants. (author)

  13. Engineering to Control Noise, Loading, and Optimal Operating Points

    International Nuclear Information System (INIS)

    Mitchell R. Swartz

    2000-01-01

    Successful engineering of low-energy nuclear systems requires control of noise, loading, and optimum operating point (OOP) manifolds. The latter result from the biphasic system response of low-energy nuclear reaction (LENR)/cold fusion systems, and their ash production rate, to input electrical power. Knowledge of the optimal operating point manifold can improve the reproducibility and efficacy of these systems in several ways. Improved control of noise, loading, and peak production rates is available through the study, and use, of OOP manifolds. Engineering of systems toward the OOP-manifold drive-point peak may, with inclusion of geometric factors, permit more accurate uniform determinations of the calibrated activity of these materials/systems

  14. 46 CFR 113.35-13 - Mechanical engine order telegraph systems; operation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Mechanical engine order telegraph systems; operation...) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-13 Mechanical engine order telegraph systems; operation. If more than one transmitter operates a...

  15. Integrated initial training program for a CEGB operations engineer

    International Nuclear Information System (INIS)

    Tompsett, P.A.

    1987-01-01

    This paper considers the overall training programs undertaken by a newly appointed Operations Engineer at one of the Central Electricity Generating Board's (CEGB) Advanced Gas Cooled Reactor (AGR) nuclear power stations. The training program is designed to equip him with the skills and knowledge necessary for him to discharge his duties safely and effectively. In order to assist the learning process and achieve and integrated program, aspects of reactor technology and operation, initially the subject of theoretical presentations at the CEGB's Nuclear Power Training Center (NPTC) are reinforced by either simulation and/or practical experience on site. In the later stages plant-specific simulators, operated by trained tutors, are incorporated into the training program to provide the trainee with practical experience of plant operation. The trainee's performance is assessed throughout the program to provide feedback to the trainee, the trainers and station management

  16. 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.

  17. A Study of a Diesel Engine Based Micro-CHP System

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, C.R.; Andrews, J.; Tutu, N.; Butcher, T.

    2010-08-31

    This project, funded by New York State Energy Research and Development Agency (NYSERDA), investigated the potential for an oil-fired combined heat and power system (micro-CHP system) for potential use in residences that use oil to heat their homes. Obviously, this requires the power source to be one that uses heating oil (diesel). The work consisted of an experimental study using a diesel engine and an analytical study that examined potential energy savings and benefits of micro-CHP systems for 'typical' locations in New York State. A search for a small diesel engine disclosed that no such engines were manufactured in the U.S. A single cylinder engine manufactured in Germany driving an electric generator was purchased for the experimental work. The engine was tested using on-road diesel fuel (15 ppm sulfur), and biodiesel blends. One of the main objectives was to demonstrate the possibility of operation in the so-called HCCI (Homogeneous Charge Compression Ignition) mode. The HCCI mode of operation of engines is being explored as a way to reduce the emission of smoke, and NOx significantly without exhaust treatment. This is being done primarily in the context of engines used in transportation applications. However, it is felt that in a micro-CHP application using a single cylinder engine, such an approach would confer those emission benefits and would be much easier to implement. This was demonstrated successfully by injecting the fuel into the engine air intake using a heated atomizer made by Econox Technologies LLC to promote significant vaporization before entering the cylinder. Efficiency and emission measurements were made under different electrical loads provided by two space heaters connected to the generator in normal and HCCI modes of operation. The goals of the analytical work were to characterize, from the published literature, the prime-movers for micro-CHP applications, quantify parametrically the expected energy savings of using micro

  18. Installation, Operation, and Operator's Maintenance of Diesel-Engine-Driven Generator Sets.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, contains three study units dealing with the skills needed by individuals responsible for the installation, operation, and maintenance of diesel engine-driven generator sets. The first two units cover…

  19. Performance of a RBCC Engine in Rocket-Operation

    Science.gov (United States)

    Tomioka, Sadatake; Kubo, Takahiro; Noboru Sakuranaka; Tani, Koichiro

    Combination of a scramjet (supersonic combustion ramjet) flow-pass with embedded rocket engines (the combined system termed as Rocket-based Combined Cycle engine) are expected to be the most effective propulsion system for space launch vehicles. Either SSTO (Single Stage To Orbit) system or TSTO (Two Stage To Orbit) system with separation at high altitude needs final stage acceleration in space, so that the RBCC (Rocket Based Combined Cycle) engine should be operated as rocket engines. Performance of the scramjet combustor as the extension to the rocket nozzle, was experimentally evaluated by injecting inert gas at various pressure through the embedded rocket chamber while the whole sub-scaled model was placed in a low pressure chamber connected to an air-driven ejector system. The results showed that the thrust coefficient was about 1.2, the low value being found to mainly due to the friction force on the scramjet combustor wall, while blocking the scramjet flow pass’s opening to increase nozzle extension thrust surface, was found to have little effects on the thrust performance. The combustor was shortened to reduce the friction loss, however, degree of reduction was limited as friction decreased rapidly with distance from the onset of the scramjet combustor.

  20. Idling operation apparatus for multicylinder fuel injection engine

    Energy Technology Data Exchange (ETDEWEB)

    Kanahira, A

    1974-11-20

    A device to cut off the fuel supply to a number of cylinders at idling is described for those engines equipped with multicylinder fuel injection systems. The discontinuation of the fuel gas supply to the cylinders is made by a magnetically operated valve which is related to the accelerator. When the engine is idling, a switch activates the magnetic valve and the tube leading to the cylinder closes while a valve on the tube leading to a dual tank opens, and the pumped gas returns to the tank. This valve is installed on several cylinders, but not on all. Thus, at idling only a certain number of cylinders are firing, which lowers the hydrocarbon levels in the exhaust gas since non-firing cylinders intake and discharge only air.

  1. The reliability of structural systems operating at high temperature: Replacing engineering judgement with operational experience

    International Nuclear Information System (INIS)

    Chevalier, M.J.; Smith, D.J.; Dean, D.W.

    2012-01-01

    Deterministic assessments are used to assess the integrity of structural systems operating at high temperature by providing a lower bound lifetime prediction, requiring considerable engineering judgement. However such a result may not satisfy the structural integrity assessment purpose if the results are overly conservative or conversely plant observations (such as failures) could undermine the assessment result if observed before the lower bound lifetime. This paper develops a reliability methodology for high temperature assessments and illustrates the impact and importance of managing the uncertainties within such an analysis. This is done by separating uncertainties into three classifications; aleatory uncertainty, quantifiable epistemic uncertainty and unquantifiable epistemic uncertainty. The result is a reliability model that can predict the behaviour of a structural system based upon plant observations, including failure and survival data. This can be used to reduce the over reliance upon engineering judgement which is prevalent in deterministic assessments. Highlights: ► Deterministic assessments are shown to be heavily reliant upon engineering judgment. ► Based upon the R5 procedure, a reliability model for a structural system is developed. ► Variables must be classified as either aleatory or epistemic to model their impact on reliability. ► Operation experience is then used to reduce reliance upon engineering judgment. ► This results in a model which can predict system behaviour and learn from operational experience.

  2. Remote operations in a Fusion Engineering Research Facility (FERF)

    International Nuclear Information System (INIS)

    Doggett, J.N.

    1975-01-01

    The proposed Fusion Engineering Research Facility (FERF) has been designed for the test and evaluation of materials that will be exposed to the hostile radiation environment created by fusion reactors. Because the FERF itself must create a very hostile radiation environment, extensive remote handling procedures will be required as part of its routine operations as well as for both scheduled and unscheduled maintenance. This report analyzes the remote-handling implications of a vertical- rather than horizontal-orientation of the FERF magnet, describes the specific remote-handling facilities of the proposed FERF installation and compares the FERF remote-handling system with several other existing and proposed facilities. (U.S.)

  3. 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

  4. Environmental impact of offshore operation reduced using innovative engineering solutions

    International Nuclear Information System (INIS)

    Ritchie, C.J.; Wensel, E.A.; Edelblum, L.S.; Beal, D.

    1994-01-01

    The North Dauphin Island Tract 73 platform is located in eleven feet (3.4 m) of water and one mile (1.6 km) from shore in Mobile Bay, Alabama. The platform is designed to dehydrate and compress up to 70 MMSCFD (1.98 x 10 6 SM 3 ) from five remote gas production wells. Located near the city of Mobile, Alabama, the surrounding metropolitan and coastal areas has multiple uses including manufacturing, tourism, commercial and sport fishing, and wetlands and wildlife conservation. The multiple and interdependent economic uses of the area required that the platform be designed to minimize any adverse environmental impact. A cost-effective environmental engineering solution was desired at the design phase of the project. A water catchment, containment and disposal system was designed to meet the zero discharge requirement. Pollution from air emissions was reduced by the installation of lean burning engines. A floatover installation process was used to prevent dredging of the bay, thus protecting the bay water quality. An aesthetically concealing paint and lighting scheme was chosen and applied to the entire structure. These cost-effective engineering solutions during the design phase of the project saved time and money over the life of the project. All regulatory permits were obtained in a timely manner, with little or no opposition. The operator of the North Dauphin Island Development won several environmental awards due to the implementation of innovative solutions and their commitment to conservation of the natural environment

  5. Emission Characteristics for a Homogeneous Charged Compression Ignition Diesel Engine with Exhaust Gas Recirculation Using Split Injection Methodology

    Directory of Open Access Journals (Sweden)

    Changhee Lee

    2017-12-01

    Full Text Available Due to the serious issues caused by air pollution and global warming, emission regulations are becoming stricter. New technologies that reduce NOx and PM emissions are needed. To cope with these social exhaust gas regulation demands, many advanced countries are striving to develop eco-friendly vehicles in order to respond to stricter emissions regulations. The homogeneous charged compression ignition engine (HCCI incorporates a multi-stage combustion engine with multiple combustion modes, catalyst, direct fuel injection and partial mixing combustion. In this study, the HCCI combustion was applied to analyze and review the results of engines applying HCCI combustion without altering the conventional engine specifications. The optimization of exhaust gas recirculation (EGR and compression ratio changes provides an optimal fuel economy. In this study, potential for optimum economy within the range of IMEP 0.8 MPa has been evaluated.

  6. Design of stirling engine operating at low temperature difference

    Directory of Open Access Journals (Sweden)

    Sedlák Josef

    2018-01-01

    Full Text Available There are many sources of free energy available in the form of heat that is often simply wasted. The aim of this paper is to design and build a low temperature differential Stirling engine that would be powered exclusively from heat sources such as waste hot water or focused solar rays. A prototype is limited to a low temperature differential modification because of a choice of ABSplus plastic as a construction material for its key parts. The paper is divided into two parts. The first part covers a brief history of Stirling engine and its applications nowadays. Moreover, it describes basic principles of its operation that are supplemented by thermodynamic relations. Furthermore, an analysis of applied Fused Deposition Modelling has been done since the parts with more complex geometry had been manufactured using this additive technology. The second (experimental part covers 4 essential steps of a rapid prototyping method - Computer Aided Design of the 3D model of Stirling engine using parametric modeller Autodesk Inventor, production of its components using 3D printer uPrint, assembly and final testing. Special attention was devoted to last two steps of the process since the surfaces of the printed parts were sandpapered and sprayed. Parts, where an ABS plus plastic would have impeded the correct function, had been manufactured from aluminium and brass by cutting operations. Remaining parts had been bought in a hardware store as it would be uneconomical and unreasonable to manufacture them. Last two chapters of the paper describe final testing, mention the problems that appeared during its production and propose new approaches that could be used in the future to improve the project.

  7. High field, low current operation of engineering test reactors

    International Nuclear Information System (INIS)

    Schwartz, J.; Cohn, D.R.; Bromberg, L.; Williams, J.E.C.

    1987-06-01

    Steady state engineering test reactors with high field, low current operation are investigated and compared to high current, lower field concepts. Illustrative high field ETR parameters are R = 3 m, α ∼ 0.5 m, B ∼ 10 T, β = 2.2% and I = 4 MA. For similar wall loading the fusion power of an illustrative high field, low current concept could be about 50% that of a lower field device like TIBER II. This reduction could lead to a 50% decrease in tritium consumption, resulting in a substantial decrease in operating cost. Furthermore, high field operation could lead to substantially reduced current drive requirements and cost. A reduction in current drive source power on the order of 40 to 50 MW may be attainable relative to a lower field, high current design like TIBER II implying a possible cost savings on the order of $200 M. If current drive is less efficient than assumed, the savings could be even greater. Through larger β/sub p/ and aspect ratio, greater prospects for bootstrap current operation also exist. Further savings would be obtained from the reduced size of the first wall/blanket/shield system. The effects of high fields on magnet costs are very dependent on technological assumptions. Further improvements in the future may lie with advances in superconducting and structural materials

  8. Modal extraction on a diesel engine in operation

    DEFF Research Database (Denmark)

    Møller, Nis; Herlufsen, Henrik; Brincker, Rune

    2000-01-01

    In this paper an output only modal testing and identification of a diesel engine is presented. The only loading on the engine is the unknown loading from the engine itself. Two test cases were considered: engine run-up, and engine Run-Down. The response data were analyzed using two different...

  9. Method for operating a spark-ignition, direct-injection internal combustion engine

    Science.gov (United States)

    Narayanaswamy, Kushal; Koch, Calvin K.; Najt, Paul M.; Szekely, Jr., Gerald A.; Toner, Joel G.

    2015-06-02

    A spark-ignition, direct-injection internal combustion engine is coupled to an exhaust aftertreatment system including a three-way catalytic converter upstream of an NH3-SCR catalyst. A method for operating the engine includes operating the engine in a fuel cutoff mode and coincidentally executing a second fuel injection control scheme upon detecting an engine load that permits operation in the fuel cutoff mode.

  10. Energy management handbook for building operating engineers student workbook

    Energy Technology Data Exchange (ETDEWEB)

    1979-09-01

    The handbook provides operating engineers with the basic information needed to implement specific energy conservation opportunities, and additional information is presented relative to the formulation and development of the energy management plan. Chapters are entitled: The Need for Energy Management (International Factors, The US Energy Situation, Energy and the Building Owner); The Fundamentals of Energy Consumption in Buildings (Energy Basics, Heat Basics, Heat Flow and the Building Envelope, Air and Comfort, Factors Affecting Energy Use In Buildings); Principles of Energy Conservation (Building Energy Consumption Characteristics); Planning the Energy Management Program (Obtaining Commitment and Support, Establishing the Energy Use Index, Organizing to Develop the Plan, Developing and Implementing the Plan); Conducting a Survey of Facilities and Operations (The Energy Audit, Preparation of Building and Systems Profile, Measurement and Instrumentation); Guidelines for Energy Conservation (Operator ECO's, Owner ECO'S); Developing the Draft Final Plan (Analyze Survey Findings, Putting the Plan on Paper, Review and Submit); Implementing the Program (Developing the Final Plan, Implementing the Plan, Monitoring and Updating the Program). A glossary is included and specific information on degree days and cooling hours for some selected cities and a computer energy study data for the New York Hilton are included in appendices. (MCW)

  11. Costs and benefits of lunar oxygen: Engineering, operations, and economics

    Science.gov (United States)

    Sherwood, Brent; Woodcock, Gordon R.

    1991-01-01

    Oxygen is the most commonly discussed lunar resource. It will certainly not be the easiest to retrieve, but oxygen's fundamental place in propulsion and life support guarantees it continued attention as a prime candidate for early in situ resource utilization (ISRU). The findings are reviewed of recent investigation, sponsored by NASA-Ames, into the kinds of technologies, equipment, and scenarios (the engineering and operations costs) that will be required even to initiate lunar oxygen production. The infrastructure necessary to surround and support a viable oxygen-processing operation is explained. Selected details are used to illustrate the depth of technology challenges, extent of operations burdens, and complexity of decision linkages. Basic assumptions, and resulting timelines and mass manifests, are listed. These findings are combined with state-of-the-art knowledge of lunar and Mars propulsion options in simple economic input/output and internal-rate-of-return models, to compare production costs with performance benefits. Implications for three realistic scales of exploration architecture - expeditionary, aggressive science, and industrialization/settlement - are discussed. Conclusions are reached regarding the contextual conditions within which production of lunar oxygen (LLOX) is a reasonable activity. LLOX appears less useful for Mars missions than previously hoped. Its economical use in low Earth orbit hinges on production of lunar hydrogen as well. LLOX shows promise for lunar ascent/descent use, but that depends strongly on the plant mass required.

  12. Autonomous Cryogenic Load Operations: Knowledge-Based Autonomous Test Engineer

    Science.gov (United States)

    Schrading, J. Nicolas

    2013-01-01

    The Knowledge-Based Autonomous Test Engineer (KATE) program has a long history at KSC. Now a part of the Autonomous Cryogenic Load Operations (ACLO) mission, this software system has been sporadically developed over the past 20 years. Originally designed to provide health and status monitoring for a simple water-based fluid system, it was proven to be a capable autonomous test engineer for determining sources of failure in the system. As part of a new goal to provide this same anomaly-detection capability for a complicated cryogenic fluid system, software engineers, physicists, interns and KATE experts are working to upgrade the software capabilities and graphical user interface. Much progress was made during this effort to improve KATE. A display of the entire cryogenic system's graph, with nodes for components and edges for their connections, was added to the KATE software. A searching functionality was added to the new graph display, so that users could easily center their screen on specific components. The GUI was also modified so that it displayed information relevant to the new project goals. In addition, work began on adding new pneumatic and electronic subsystems into the KATE knowledge base, so that it could provide health and status monitoring for those systems. Finally, many fixes for bugs, memory leaks, and memory errors were implemented and the system was moved into a state in which it could be presented to stakeholders. Overall, the KATE system was improved and necessary additional features were added so that a presentation of the program and its functionality in the next few months would be a success.

  13. Autonomous Cryogenic Load Operations: KSC Autonomous Test Engineer

    Science.gov (United States)

    Shrading, Nicholas J.

    2012-01-01

    The KSC Autonomous Test Engineer (KATE) program has a long history at KSC. Now a part of the Autonomous Cryogenic Load Operations (ACLO) mission, this software system has been sporadically developed over the past 20+ years. Originally designed to provide health and status monitoring for a simple water-based fluid system, it was proven to be a capable autonomous test engineer for determining sources of failure in. the system, As part.of a new goal to provide this same anomaly-detection capability for a complicated cryogenic fluid system, software engineers, physicists, interns and KATE experts are working to upgrade the software capabilities and graphical user interface. Much progress was made during this effort to improve KATE. A display ofthe entire cryogenic system's graph, with nodes for components and edges for their connections, was added to the KATE software. A searching functionality was added to the new graph display, so that users could easily center their screen on specific components. The GUI was also modified so that it displayed information relevant to the new project goals. In addition, work began on adding new pneumatic and electronic subsystems into the KATE knowledgebase, so that it could provide health and status monitoring for those systems. Finally, many fixes for bugs, memory leaks, and memory errors were implemented and the system was moved into a state in which it could be presented to stakeholders. Overall, the KATE system was improved and necessary additional features were added so that a presentation of the program and its functionality in the next few months would be a success.

  14. The HAL 9000 Space Operating System Real-Time Planning Engine Design and Operations Requirements

    Science.gov (United States)

    Stetson, Howard; Watson, Michael D.; Shaughnessy, Ray

    2012-01-01

    In support of future deep space manned missions, an autonomous/automated vehicle, providing crew autonomy and an autonomous response planning system, will be required due to the light time delays in communication. Vehicle capabilities as a whole must provide for tactical response to vehicle system failures and space environmental effects induced failures, for risk mitigation of permanent loss of communication with Earth, and for assured crew return capabilities. The complexity of human rated space systems and the limited crew sizes and crew skills mix drive the need for a robust autonomous capability on-board the vehicle. The HAL 9000 Space Operating System[2] designed for such missions and space craft includes the first distributed real-time planning / re-planning system. This paper will detail the software architecture of the multiple planning engine system, and the interface design for plan changes, approval and implementation that is performed autonomously. Operations scenarios will be defined for analysis of the planning engines operations and its requirements for nominal / off nominal activities. An assessment of the distributed realtime re-planning system, in the defined operations environment, will be provided as well as findings as it pertains to the vehicle, crew, and mission control requirements needed for implementation.

  15. Modeling of a bioethanol combustion engine under different operating conditions

    International Nuclear Information System (INIS)

    Hedfi, Hachem; Jedli, Hedi; Jbara, Abdessalem; Slimi, Khalifa

    2014-01-01

    Highlights: • Bioethanol/gasoline blends’ fuel effects on engine’s efficiency, CO and NOx emissions. • Fuel consumption and EGR optimizations with respect to estimated engine’s work. • Ignition timing and blends’ effects on engine’s efficiency. • Rich mixture, gasoline/bioethanol blends and EGR effects on engine’s efficiency. - Abstract: A physical model based on a thermodynamic analysis was designed to characterize the combustion reaction parameters. The time-variations of pressure and temperature required for the calculation of specific heat ratio are obtained from the solution of energy conservation equation. The chemical combustion of biofuel is modeled by an overall reaction in two-steps. The rich mixture and EGR were varied to obtain the optimum operating conditions for the engine. The NOx formation is modeled by using an eight-species six-step mechanism. The effect of various formation steps of NOx in combustion is considered via a phenomenological model of combustion speed. This simplified model, which has been validated by the most available published results, is used to characterize and control, in real time, the impact of biofuel on engine performances and NOx emissions as well. It has been demonstrated that a delay of the ignition timing leads to an increase of the gas mixture temperature and cylinder pressure. Furthermore, it has been found that the CO is lower near the stoichiometry. Nevertheless, we notice that lower rich mixture values result in small NOx emission rates

  16. Autonomous Cryogenics Loading Operations Simulation Software: Knowledgebase Autonomous Test Engineer

    Science.gov (United States)

    Wehner, Walter S., Jr.

    2013-01-01

    Working on the ACLO (Autonomous Cryogenics Loading Operations) project I have had the opportunity to add functionality to the physics simulation software known as KATE (Knowledgebase Autonomous Test Engineer), create a new application allowing WYSIWYG (what-you-see-is-what-you-get) creation of KATE schematic files and begin a preliminary design and implementation of a new subsystem that will provide vision services on the IHM (Integrated Health Management) bus. The functionality I added to KATE over the past few months includes a dynamic visual representation of the fluid height in a pipe based on number of gallons of fluid in the pipe and implementing the IHM bus connection within KATE. I also fixed a broken feature in the system called the Browser Display, implemented many bug fixes and made changes to the GUI (Graphical User Interface).

  17. 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

  18. 67. The safety engineering at driving of destroyed hearth and repair of bath fettling during operation

    International Nuclear Information System (INIS)

    Ivanov, A.V.

    1993-01-01

    The safety engineering at driving of destroyed hearth and repair of bath fettling during operation was considered. All operational conditions at driving of destroyed hearth and repair of bath fettling during operation were studied.

  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. Research and Exploration for Operational Research Education in Industry and Engineering Subject

    Science.gov (United States)

    Wu, Yu-hua; Wang, Feng-ming; Du, Gang

    2007-01-01

    On the basic of exploring the relationship of industry engineering and operational research technique, the thesis analyzes the location and utility of the operational research education in the whole industry engineering subject education. It brings forward the system design about operational research and relative class among industry engineering…

  1. Combustion and operating characteristics of spark-ignition engines

    Science.gov (United States)

    Heywood, J. B.; Keck, J. C.; Beretta, G. P.; Watts, P. A.

    1980-01-01

    The spark-ignition engine turbulent flame propagation process was investigated. Then, using a spark-ignition engine cycle simulation and combustion model, the impact of turbocharging and heat transfer variations or engine power, efficiency, and NO sub x emissions was examined.

  2. Computer-aided operations engineering with integrated models of systems and operations

    Science.gov (United States)

    Malin, Jane T.; Ryan, Dan; Fleming, Land

    1994-01-01

    CONFIG 3 is a prototype software tool that supports integrated conceptual design evaluation from early in the product life cycle, by supporting isolated or integrated modeling, simulation, and analysis of the function, structure, behavior, failures and operation of system designs. Integration and reuse of models is supported in an object-oriented environment providing capabilities for graph analysis and discrete event simulation. Integration is supported among diverse modeling approaches (component view, configuration or flow path view, and procedure view) and diverse simulation and analysis approaches. Support is provided for integrated engineering in diverse design domains, including mechanical and electro-mechanical systems, distributed computer systems, and chemical processing and transport systems. CONFIG supports abstracted qualitative and symbolic modeling, for early conceptual design. System models are component structure models with operating modes, with embedded time-related behavior models. CONFIG supports failure modeling and modeling of state or configuration changes that result in dynamic changes in dependencies among components. Operations and procedure models are activity structure models that interact with system models. CONFIG is designed to support evaluation of system operability, diagnosability and fault tolerance, and analysis of the development of system effects of problems over time, including faults, failures, and procedural or environmental difficulties.

  3. DPM evolution: a disk operations management engine for DPM

    Science.gov (United States)

    Manzi, A.; Furano, F.; Keeble, O.; Bitzes, G.

    2017-10-01

    The DPM (Disk Pool Manager) project is the most widely deployed solution for storage of large data repositories on Grid sites, and is completing the most important upgrade in its history, with the aim of bringing important new features, performance and easier long term maintainability. Work has been done to make the so-called “legacy stack” optional, and substitute it with an advanced implementation that is based on the fastCGI and RESTful technologies. Beside the obvious gain in making optional several legacy components that are difficult to maintain, this step brings important features together with performance enhancements. Among the most important features we can cite the simplification of the configuration, the possibility of working in a totally SRM-free mode, the implementation of quotas, free/used space on directories, and the implementation of volatile pools that can pull files from external sources, which can be used to deploy data caches. Moreover, the communication with the new core, called DOME (Disk Operations Management Engine) now happens through secure HTTPS channels through an extensively documented, industry-compliant protocol. For this leap, referred to with the codename “DPM Evolution”, the help of the DPM collaboration has been very important in the beta testing phases, and here we report about the technical choices.

  4. Intelligent engineering and technology for nuclear power plant operation

    International Nuclear Information System (INIS)

    Wang, P.P.; Gu, X.

    1996-01-01

    The Three-Mile-Island accident has drawn considerable attention by the engineering, scientific, management, financial, and political communities as well as society at large. This paper surveys possible causes of the accident studied by various groups. Research continues in this area with many projects aimed at specifically improving the performance and operation of a nuclear power plant using the contemporary technologies available. In addition to the known cause of the accident and suggest a strategy for coping with these problems in the future. With the increased use of intelligent methodologies called computational intelligence or soft-computing, a substantially larger collection of powerful tools are now available for our designers to use in order to tackle these sensitive and difficult issues. These intelligent methodologies consists of fuzzy logic, genetic algorithms, neural networks, artificial intelligence and expert systems, pattern recognition, machine intelligence, and fuzzy constraint networks. Using the Three-Mile-Island experience, this paper offers a set of specific recommendations for future designers to take advantage of the powerful tools of intelligent technologies that we are now able to master and encourages the adoption of a novel methodology called fuzzy constraint network

  5. Ethical issues in engineering models: an operations researcher's reflections.

    Science.gov (United States)

    Kleijnen, J

    2011-09-01

    This article starts with an overview of the author's personal involvement--as an Operations Research consultant--in several engineering case-studies that may raise ethical questions; e.g., case-studies on nuclear waste, water management, sustainable ecology, military tactics, and animal welfare. All these case studies employ computer simulation models. In general, models are meant to solve practical problems, which may have ethical implications for the various stakeholders; namely, the modelers, the clients, and the public at large. The article further presents an overview of codes of ethics in a variety of disciples. It discusses the role of mathematical models, focusing on the validation of these models' assumptions. Documentation of these model assumptions needs special attention. Some ethical norms and values may be quantified through the model's multiple performance measures, which might be optimized. The uncertainty about the validity of the model leads to risk or uncertainty analysis and to a search for robust models. Ethical questions may be pressing in military models, including war games. However, computer games and the related experimental economics may also provide a special tool to study ethical issues. Finally, the article briefly discusses whistleblowing. Its many references to publications and websites enable further study of ethical issues in modeling.

  6. Conversion of a gasoline internal combustion engine to operate on hydrogen fuel

    International Nuclear Information System (INIS)

    Bates, M.; Dincer, I.

    2009-01-01

    This study deals with the conversion of a gasoline spark ignition internal combustion engine to operate on hydrogen fuel while producing similar power, economy and reliability as gasoline. The conversion engine will have the fuel system redesigned and ignition and fuel timing changed. Engine construction material is of great importance due to the low ignition energy of hydrogen, making aluminum a desirable material in the intake manifold and combustion chamber. The engine selected to convert is a 3400 SFI dual over head cam General Motors engine. Hydrogen reacts with metals causing hydrogen embrittlement which leads to failure due to cracking. There are standards published by American Society of Mechanical Engineers (ASME) to avoid such a problem. Tuning of the hydrogen engine proved to be challenging due to the basic tuning tools of a gasoline engine such as a wide band oxygen sensor that could not measure the 34:1 fuel air mixture needed for the hydrogen engine. Once the conversion was complete the engine was tested on a chassis dynamometer to compare the hydrogen horsepower and torque produced to that of a gasoline engine. Results showed that the engine is not operating correctly. The engine is not getting the proper amount of fuel needed for complete combustion when operated in a loaded state over 3000 rpm. The problem was found to be the use of the stock injector driver that could not deliver enough power for the proper operation of the larger CM4980 injectors. (author)

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Internal combustion engine for natural gas compressor operation

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, Christopher; Babbitt, Guy

    2016-12-27

    This application concerns systems and methods for compressing natural gas with an internal combustion engine. In a representative embodiment, a method is featured which includes placing a first cylinder of an internal combustion engine in a compressor mode, and compressing a gas within the first cylinder, using the cylinder as a reciprocating compressor. In some embodiments a compression check valve system is used to regulate pressure and flow within cylinders of the engine during a compression process.

  12. 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.

  13. Engineering Task Plan to Expand the Environmental Operational Envelope of Core Sampling

    International Nuclear Information System (INIS)

    BOGER, R.M.

    1999-01-01

    This Engineering Task Plan authorizes the development of an Alternative Generation and Analysis (AGA). The AGA will determine how to expand the environmental operating envelope during core sampling operations

  14. Homogeneous charge compression ignition compared with Otto-Atkinson in a passenger car size engine

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, Andreas

    2000-07-01

    The use of Homogeneous Charge Compression Ignition (HCCI) was investigated in an ordinary SI (spark ignition) engine, in this case a modified Volvo 850, working on one cylinder only, the others towed. The major purpose of this study was to examine whether there were the same kind of throttle losses in this engine as in a Diesel engine (Volvo TD 100). One reason for throttling is that HCCI causes very cold exhaust gases. The Diesel engine has a larger cylinder volume (1.6 compared to 0.5 litre), working at low engine speed (1000 rpm) and only two valves with comparably small area. The smaller Volvo 850 engine has four valves and was in this examination working at up to 3500 rpm. To make the engine run by HCCI following modifications were made. The compression was set to 20:1 by changing the piston. To affect the ignition an electrical heater was installed near the air inlet. Mixing iso-octane (ON 100) and N-heptane (ON 0) set the octane number. A couple of camshafts with different cam-profiles were used to achieve the right valve opening duration depending on which kind of combustion that was studied. There could then also be a comparison between Otto and HCCI combustion both working with wide-open throttle. To obtain comparable indicated mean effective pressure (IMEP) the engine was working with late (LIVC) or early inlet valve closing (EIVC) at SI combustion. Measurements were taken involving in-cylinder pressure, temperature, speed, fuel-consumption, emissions etc. Regarding emissions there were special consideration taken to hydrocarbon and NO{sub x}, which are known to be extremely high respectively low with HCCI combustion. Important questions that should be answered were: * How does higher engine speed affect the combustion ?, * How does the engine size affect emissions ?, * How much is the valve area affecting gas exchange losses ?, and * How high is the efficiency with HCCI compared with Otto (LIVC/EIVC) ?. The best results are achieved at an indicated mean

  15. CO and PAH emissions from engines operating on producer gas

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper

    2005-01-01

    High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. The standing regulations concerning CO emissions from gas engine based power plants in most EU countries are so ...

  16. Selection of stirling engine parameter and modes of joint operation with the Topaz II

    International Nuclear Information System (INIS)

    Kirillov, E.Y.; Ogloblin, B.G.; Shalaev, A.I.

    1996-01-01

    In addition to a high-temperature thermionic conversion cycle, application of a low-temperature machine cycle, such as the Stirling engine, is being considered. To select the optimum mode for joint operation of the Topaz II system and Stirling engine, output electric parameters are obtained as a function of thermal power released in the TFE fuel cores. The hydraulic diagram used for joint operation of the Topaz II and the Stirling engine is considered. Requirements to hydraulic characteristics of the Stirling engine heat exchanges are formulated. Scope of necessary modifications to mount the Stirling Engine on the Topaz II is estimated. copyright 1996 American Institute of Physics

  17. Towards artificial intelligence based diesel engine performance control under varying operating conditions using support vector regression

    Directory of Open Access Journals (Sweden)

    Naradasu Kumar Ravi

    2013-01-01

    Full Text Available Diesel engine designers are constantly on the look-out for performance enhancement through efficient control of operating parameters. In this paper, the concept of an intelligent engine control system is proposed that seeks to ensure optimized performance under varying operating conditions. The concept is based on arriving at the optimum engine operating parameters to ensure the desired output in terms of efficiency. In addition, a Support Vector Machines based prediction model has been developed to predict the engine performance under varying operating conditions. Experiments were carried out at varying loads, compression ratios and amounts of exhaust gas recirculation using a variable compression ratio diesel engine for data acquisition. It was observed that the SVM model was able to predict the engine performance accurately.

  18. Cycle Engine Modelling Of Spark Ignition Engine Processes during Wide-Open Throttle (WOT) Engine Operation Running By Gasoline Fuel

    International Nuclear Information System (INIS)

    Rahim, M F Abdul; Rahman, M M; Bakar, R A

    2012-01-01

    One-dimensional engine model is developed to simulate spark ignition engine processes in a 4-stroke, 4 cylinders gasoline engine. Physically, the baseline engine is inline cylinder engine with 3-valves per cylinder. Currently, the engine's mixture is formed by external mixture formation using piston-type carburettor. The model of the engine is based on one-dimensional equation of the gas exchange process, isentropic compression and expansion, progressive engine combustion process, and accounting for the heat transfer and frictional losses as well as the effect of valves overlapping. The model is tested for 2000, 3000 and 4000 rpm of engine speed and validated using experimental engine data. Results showed that the engine is able to simulate engine's combustion process and produce reasonable prediction. However, by comparing with experimental data, major discrepancy is noticeable especially on the 2000 and 4000 rpm prediction. At low and high engine speed, simulated cylinder pressures tend to under predict the measured data. Whereas the cylinder temperatures always tend to over predict the measured data at all engine speed. The most accurate prediction is obtained at medium engine speed of 3000 rpm. Appropriate wall heat transfer setup is vital for more precise calculation of cylinder pressure and temperature. More heat loss to the wall can lower cylinder temperature. On the hand, more heat converted to the useful work mean an increase in cylinder pressure. Thus, instead of wall heat transfer setup, the Wiebe combustion parameters are needed to be carefully evaluated for better results.

  19. Effects of ethanol on combustion and emissions of a gasoline engine operating with different combustion modes

    OpenAIRE

    Ojapah, MM; Zhao, H; Zhang, Y

    2016-01-01

    The introduction of fuel economy and CO2 emission legislations for passenger cars in many countries and regions has spurred the research and development of more efficient gasoline engines. The pumping loss at part-load operations is a major factor for the higher fuel consumption of spark ignition (SI) gasoline engines than the diesel engines. Various approaches have been identified to reduce the pumping loss at part-load operations, leading to improved fuel economy, including Early Intake Val...

  20. Fuel operation of EDF nuclear fleet presentation of the centralized organization for operational engineering at the nuclear generation division

    International Nuclear Information System (INIS)

    Paulin, Ph.

    2006-01-01

    The main feature of EDF Nuclear Fleet is the standardization, with 'series' of homogeneous plants (same equipment, fuel and operation technical documents). For fuel operation, this standardization is related to the concept of 'fuel management scheme' (typical fuel reloads with fixed number and enrichment of fresh assemblies) for a whole series of plants. The context of the Nuclear Fleet lead to the choice of a centralized organization for fuel engineering at the Nuclear Generation Division (DPN), located at UNIPE (National Department for Fleet Operation Engineering) in Lyon. The main features of this organization are the following: - Centralization of the engineering activities for fuel operation support in the Fuel Branch of UNIPE, - Strong real-time link with the nuclear sites, - Relations with various EDF Departments in charge of design, nuclear fuel supply and electricity production optimization. The purposes of the organization are: - Standardization of operational engineering services and products, - Autonomy with independent methods and computing tools, - Reactivity with a technical assistance for sites (24 hours 'hot line'), - Identification of different levels (on site and off site) to solve core operation problems, - Collection, analysis and valorization of operation feedback, - Contribution to fuel competence global management inside EDF. This paper briefly describes the organization. The main figures of annual engineering production are provided. A selection of examples illustrates the contribution to the Nuclear Fleet performance. (authors)

  1. Performance and emissions of a modified small engine operated on producer gas

    International Nuclear Information System (INIS)

    Homdoung, N.; Tippayawong, N.; Dussadee, N.

    2015-01-01

    Highlights: • A small agricultural diesel engine was converted into a spark ignited engine. • The modified engine operated solely on producer gas at various loads and speeds. • It run successfully at high compression ratio, without knocking. • Improvement in efficiency and specific energy consumption at higher CR was evident. - Abstract: Existing agricultural biomass may be upgraded converted to a gaseous fuel via a downdraft gasifier for spark ignition engines. In this work, a 0.6 L, naturally aspirated single cylinder compression ignition engine was converted into a spark ignition engine and coupled to a 5 kW dynamometer. The conventional swirl combustion chamber was replaced by a cavity chamber. The effect of variable compression ratios between 9.7 and 17:1, and engine speeds between 1000 and 2000 rpm and loads between 20% and 100% of engine performance were investigated in terms of engine torque, power output, thermal efficiency, specific fuel consumption and emissions. It was found that the modified engine was able to operate well with producer gas at higher compression ratios than with gasoline. The brake thermal efficiency was lower than the original diesel engine at 11.3%. Maximum brake power was observed to be 3.17 kW, and the best BSFC of 0.74 kg/kWh was achieved. Maximum brake thermal efficiency of 23.9% was obtained. The smoke density of the engine was lower than the diesel engine, however, CO emission was higher with similar HC emission

  2. Comparative first- and second-law parametric study of transient diesel engine operation

    International Nuclear Information System (INIS)

    Rakopoulos, C.D.; Giakoumis, E.G.

    2006-01-01

    A computer model is developed for studying the first- and second-law (availability) balances of a turbocharged diesel engine, operating under transient load conditions. Special attention is paid to the direct comparison between the results from the two laws, for various operating parameters of the engine. The model simulates the transient operation on a degree crank angle basis, using a detailed analysis of mechanical friction, a separate consideration for the processes of each cylinder during a cycle ('multi-cylinder' model) and a mathematical model of the fuel pump. Experimental data taken from a marine duty, turbocharged diesel engine, located at the authors' laboratory, are used for the evaluation of the model's predictive capabilities. The first-law (e.g., engine speed, fuel pump rack position, engine load, etc.) and second-law (e.g., irreversibilities, heat loss and exhaust gases) terms for the diesel engine cylinder are both computed and depicted in comparison, using detailed diagrams, for various engine operating parameters. It is revealed that, at least for the specific engine type and operation, a thermodynamic, dynamic or design parameter can have a conflicting impact on the engine transient response as regards energy and availability properties, implying that both a first- and second-law optimization is needed for best performance evaluation

  3. Evaluation of turbine microjet engine operating parameters in conditions conducive to inlet freezing

    Directory of Open Access Journals (Sweden)

    Markowski Jaroslaw

    2017-01-01

    Full Text Available The problem of turbine microjet engine operation is related to flight conditions of unmanned aircraft. These flights are often performed at low altitudes, where, in autumn and winter conditions, the air can be characterized by high humidity and low temperature. Such operating conditions may cause freezing the turbine engine inlet. In particular, this problem may be related to microengines, which most often are not equipped with a de-icing installation. Frosting of the inlet violates the air flow conditions at the engine inlet and may cause unstable operation and even outages, which eventually may lead to a loss of aircraft’s stability and breakdown. Therefore, an attempt was made to evaluate the changes in operational parameters of the turbine microjet engine under conditions leading to the freezing of the inlet. The engine test was performed in stationary conditions and the analysis of the obtained results are presented in this article.

  4. Development of an engine system simulation software package - ESIM

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, Olof

    2000-10-01

    A software package, ESIM is developed for simulating internal combustion engine systems, including models for engine, manifolds, turbocharger, charge-air cooler (inter cooler) and inlet air heater. This study focus on the thermodynamic treatment and methods used in the models. It also includes some examples of system simulations made with these models for validation purposes. The engine model can be classified as a zero-dimensional, single zone model. It includes calculation of the valve flow process, models for heat release and models for in-cylinder, exhaust port and manifold heat transfer. Models are developed for handling turbocharger performance and charge air cooler characteristics. The main purpose of the project related to this work is to use the ESIM software to study heat balance and performance of homogeneous charge compression ignition (HCCI) engine systems. A short description of the HCCI engine is therefore included, pointing out the difficulties, or challenges regarding the HCCI engine, from a system perspective. However, the relations given here, and the code itself, is quite general, making it possible to use these models to simulate spark ignited, as well as direct injected engines.

  5. Stochastic Stirling Engine Operating in Contact with Active Baths

    Directory of Open Access Journals (Sweden)

    Ruben Zakine

    2017-04-01

    Full Text Available A Stirling engine made of a colloidal particle in contact with a nonequilibrium bath is considered and analyzed with the tools of stochastic energetics. We model the bath by non Gaussian persistent noise acting on the colloidal particle. Depending on the chosen definition of an isothermal transformation in this nonequilibrium setting, we find that either the energetics of the engine parallels that of its equilibrium counterpart or, in the simplest case, that it ends up being less efficient. Persistence, more than non-Gaussian effects, are responsible for this result.

  6. Stochastic Stirling Engine Operating in Contact with Active Baths

    Science.gov (United States)

    Zakine, Ruben; Solon, Alexandre; Gingrich, Todd; van Wijland, Frédéric

    2017-04-01

    A Stirling engine made of a colloidal particle in contact with a nonequilibrium bath is considered and analyzed with the tools of stochastic energetics. We model the bath by non Gaussian persistent noise acting on the colloidal particle. Depending on the chosen definition of an isothermal transformation in this nonequilibrium setting, we find that either the energetics of the engine parallels that of its equilibrium counterpart or, in the simplest case, that it ends up being less efficient. Persistence, more than non Gaussian effects, are responsible for this result.

  7. Experimental studies of the air hybrid engine charging operation

    OpenAIRE

    Zhao, H; Ma, T; Lee, CY

    2014-01-01

    Over the last few years, theoretical and modelling studies have been carried out on the feasibility and potential of novel mild air hybrid engine concepts based on production components. These mild air hybrid concepts are able to convert vehicle brake energy into pneumatic energy in the form of compressed air stored in the air tank. The compressed air can then be used to crank-start the engine by either injecting and expanding in the cylinder or driving a production air starter. Thus, the reg...

  8. 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

  9. Numerical Modelling of the Operation of a Novel Two Stroke V4 Engine

    Directory of Open Access Journals (Sweden)

    Albert Boretti

    2017-02-01

    Full Text Available The paper presents simulations of the operation of a novel two-stroke engine for road Super Sport motorcycles. Two-stroke engines were preferred to four-stroke engines in Grand Prix motorcycle racing until the start of the Moto GP era when new rules phased out the two-stroke engines. Reasons for the change were the poor fuel economy and significant pollutant emissions. The paper discusses the opportunity of a came back at least in road Super Sport motorcycles thanks to the recent advantages in direct injection and precise lubrication for two-stroke engines, plus the opportunity to use jet ignition, based on performance simulations.

  10. Training of engineers for nuclear power station operation

    International Nuclear Information System (INIS)

    Myerscough, P.B.

    1980-01-01

    The requirements for staffing and training of a nuclear electric utility are described. Current training facilities at the Central Electricity Generating Board are applicable to gas-cooled technology with the possibility of the introduction of a thermal water system and fast reactors in the future. The CEGB training centres provide for the initial training of operational staff, revision training of experienced operational staff, and training of non-operational staff from the stations and supporting departments. Details are given of the content of the training courses which also provide simulation facilities of the basic dynamics of the CEGB stations. Further developments in simulation will include dynamics of the boiler and turbine plants in Magnox stations. The flexibility of the AGR simulations will enable the training exercises to be adjusted to meet changing operating patterns for each AGR station. (U.K.)

  11. Franchising partnerships for roads engineering infrastructure operation and maintenance

    CSIR Research Space (South Africa)

    Wall, K

    2008-07-01

    Full Text Available This is a presentation delivered at the 27th SATC (Southern African Transport Conference) conference 2008, focusing on franchising principles and applying these principles to water services infrastructure, operation and maintenance...

  12. ARM Operations and Engineering Procedure Mobile Facility Site Startup

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, Jimmy W

    2015-05-01

    This procedure exists to define the key milestones, necessary steps, and process rules required to commission and operate an Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF), with a specific focus toward on-time product delivery to the ARM Data Archive. The overall objective is to have the physical infrastructure, networking and communications, and instrument calibration, grooming, and alignment (CG&A) completed with data products available from the ARM Data Archive by the Operational Start Date milestone.

  13. Use of the LITEE Lorn Manufacturing Case Study in a Senior Chemical Engineering Unit Operations Laboratory

    Science.gov (United States)

    Abraham, Nithin Susan; Abulencia, James Patrick

    2011-01-01

    This study focuses on the effectiveness of incorporating the Laboratory for Innovative Technology and Engineering Education (LITEE) Lorn Manufacturing case into a senior level chemical engineering unit operations course at Manhattan College. The purpose of using the case study is to demonstrate the relevance of ethics to chemical engineering…

  14. Investigation into the impact of privatizing civil engineering operations in Louisiana DOTD : [technical summary].

    Science.gov (United States)

    2013-06-01

    This report documents an investigation into the possibility of privatizing the civil engineering operations in the Louisiana Department : of Transportation and Development (DOTD). The study was conducted in response to House Resolution 105 of the Lou...

  15. Investigation into the impact of privatizing civil engineering operations in Louisiana DOTD.

    Science.gov (United States)

    2013-06-01

    The purpose of this study is to investigate the impact of privatizing all civil engineering operations in : the Louisiana Department of Transportation and Development (DOTD). It was investigated by : conducting a national and international literature...

  16. Modelling and Operation of Diesel Engine Exhaust Gas Cleaning Systems

    DEFF Research Database (Denmark)

    Åberg, Andreas

    . Challenges with this technology include dosing the appropriate amount of urea to reach sufficient NOx conversion, while at the same time keeping NH3- slip from the exhaust system below the legislation. This requires efficient control algorithms. The focus of this thesis is modelling and control of the SCR...... parameters were estimated using bench-scale monolith isothermal data. Validation was done by simulating the out-put from a full-scale SCR monolith that was treating real engine gases from the European Transient Cycle (ETC). Results showed that the models were successfully calibrated, and that some......, and simulating the system....

  17. Idaho National Engineering Laboratory Waste Management Operations Roadmap Document

    International Nuclear Information System (INIS)

    Bullock, M.

    1992-04-01

    At the direction of the Department of Energy-Headquarters (DOE-HQ), the DOE Idaho Field Office (DOE-ID) is developing roadmaps for Environmental Restoration and Waste Management (ER ampersand WM) activities at Idaho National Engineering Laboratory (INEL). DOE-ID has convened a select group of contractor personnel from EG ampersand G Idaho, Inc. to assist DOE-ID personnel with the roadmapping project. This document is a report on the initial stages of the first phase of the INEL's roadmapping efforts

  18. Internal combustion engine for natural gas compressor operation

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, Christopher L.; Babbitt, Guy; Turner, Christopher; Echter, Nick; Weyer-Geigel, Kristina

    2016-04-19

    This application concerns systems and methods for compressing natural gas with an internal combustion engine. In a representative embodiment, a system for compressing a gas comprises a reciprocating internal combustion engine including at least one piston-cylinder assembly comprising a piston configured to travel in a cylinder and to compress gas in the cylinder in multiple compression stages. The system can further comprise a first pressure tank in fluid communication with the piston-cylinder assembly to receive compressed gas from the piston-cylinder assembly until the first pressure tank reaches a predetermined pressure, and a second pressure tank in fluid communication with the piston-cylinder assembly and the first pressure tank. The second pressure tank can be configured to receive compressed gas from the piston-cylinder assembly until the second pressure tank reaches a predetermined pressure. When the first and second pressure tanks have reached the predetermined pressures, the first pressure tank can be configured to supply gas to the piston-cylinder assembly, and the piston can be configured to compress the gas supplied by the first pressure tank such that the compressed gas flows into the second pressure tank.

  19. Applying Web-Based Tools for Research, Engineering, and Operations

    Science.gov (United States)

    Ivancic, William D.

    2011-01-01

    Personnel in the NASA Glenn Research Center Network and Architectures branch have performed a variety of research related to space-based sensor webs, network centric operations, security and delay tolerant networking (DTN). Quality documentation and communications, real-time monitoring and information dissemination are critical in order to perform quality research while maintaining low cost and utilizing multiple remote systems. This has been accomplished using a variety of Internet technologies often operating simultaneously. This paper describes important features of various technologies and provides a number of real-world examples of how combining Internet technologies can enable a virtual team to act efficiently as one unit to perform advanced research in operational systems. Finally, real and potential abuses of power and manipulation of information and information access is addressed.

  20. Automated support for system's engineering and operations - The development of new paradigms

    Science.gov (United States)

    Truszkowski, Walt; Hall, Gardiner A.; Jaworski, Allan; Zoch, David

    1992-01-01

    Technological developments in spacecraft ground operations are reviewed. The technological, operations-oriented, managerial, and economic factors driving the evolution of the Mission Operations Control Center (MOCC), and its predecessor the Operational Control Center are examined. The functional components of the various MOCC subsystems are outlined. A brief overview is given of the concepts behind the The Knowledge-Based Software Engineering Environment, the Generic Spacecraft Analysis Assistant, and the Knowledge From Pictures tool.

  1. Operational and engineering developments in the management of low-level radioactive waste at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Kendall, E.W.; McKinney, J.D.; Wehmann, G.

    1979-01-01

    The Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory is a site for shallow land disposal and storage of solid radioactive waste. It is currently operated for ERDA by EG and G Idaho, Inc. The facility has accepted radioactive waste since July 1952. Both transuranic and non-transuranic wastes are handled at the complex. This document describes the operational and engineering developments in waste handling and storage practices that have been developed during the 25 years of waste handling operations. Emphasis is placed on above-ground transuranic waste storage, subsurface transuranic waste retrieval, and beta/gamma compaction disposal. The proposed future programs for the RWMC including a Molten Salt Combustion Facility and Production Scale Retrieval Project are described

  2. French en engineering and operation rules for plutonium facilities

    International Nuclear Information System (INIS)

    Bertolotti, G.; Drain, F.; Dubois, G.; Monnatte, J.; Mathieu, P.

    1998-01-01

    COGEMA is operating large size purifying and conditioning plutonium facilities at LA HAGUE and MOX fuels fabrication plant at Marcoule. A high safety standard is recognised for these facilities. It is mainly based on : - prevention of spreading of radioactive materials to workers and environment by physical barriers ensuring static containment and by a cascade of pressure differentials ensuring dynamic containment, - radiation shielding and remote controlled processes ensuring very low dose to workers, - prevention of criticality accident by criticality control methods and double contingency principle, - prevention of fire risks by control of ignition sources, adequate management of combustible materials, physical separation between zones where there is a risk of fire and the remainder of the facility. The facilities are operated while respecting safety requirements as described in the General Operating Rules. The equipment involved in safety functions are monitored and periodically checked. Continuous improvement by incorporation of feed back of safety experience results in: - effective decrease of exposure to operating staff; - reduction of solid waste, liquid and gaseous effluents; - no significant incident recorded. (author)

  3. Military Engineer Contribution to Operational Art: The Hybrid Threat Environment

    Science.gov (United States)

    2015-05-22

    insurgency forces from the population. UNPIK, or the “ donkeys ,” was the UN’s irregular force, acting in concert with its regular conventional...Eighth Army exploited this opportunity, arming and training the refugees for operations against the rear of the PRC.78 The “ donkeys ” conducted numerous

  4. Online probabilistic operational safety assessment of multi-mode engineering systems using Bayesian methods

    International Nuclear Information System (INIS)

    Lin, Yufei; Chen, Maoyin; Zhou, Donghua

    2013-01-01

    In the past decades, engineering systems become more and more complex, and generally work at different operational modes. Since incipient fault can lead to dangerous accidents, it is crucial to develop strategies for online operational safety assessment. However, the existing online assessment methods for multi-mode engineering systems commonly assume that samples are independent, which do not hold for practical cases. This paper proposes a probabilistic framework of online operational safety assessment of multi-mode engineering systems with sample dependency. To begin with, a Gaussian mixture model (GMM) is used to characterize multiple operating modes. Then, based on the definition of safety index (SI), the SI for one single mode is calculated. At last, the Bayesian method is presented to calculate the posterior probabilities belonging to each operating mode with sample dependency. The proposed assessment strategy is applied in two examples: one is the aircraft gas turbine, another is an industrial dryer. Both examples illustrate the efficiency of the proposed method

  5. Numerical Modelling of the Operation of a Novel Two Stroke V4 Engine

    OpenAIRE

    Albert Boretti

    2017-01-01

    The paper presents simulations of the operation of a novel two-stroke engine for road Super Sport motorcycles. Two-stroke engines were preferred to four-stroke engines in Grand Prix motorcycle racing until the start of the Moto GP era when new rules phased out the two-stroke engines. Reasons for the change were the poor fuel economy and significant pollutant emissions. The paper discusses the opportunity of a came back at least in road Super Sport motorcycles thanks to the recent advantages i...

  6. Experimental Investigation of the Effects of Some Operating Diesel Engine Variables on Emitted Particulate Matters (PM

    Directory of Open Access Journals (Sweden)

    Adel M. Saleh

    2012-03-01

    Full Text Available The diesel engine is the most efficient prime mover commonly available today. Diesel engines move a large portion of the world’s goods, power much of the world’s equipment, and generate electricity more economically than any other device in their size range. But the diesel is one of the largest contributors to environmental pollution problems worldwide, and will remain so, with large increases expected in vehicle population. This experimental study has been conducted with direct injection diesel engine and particulate matters (PM concentrations were measured at variable operating variables. The results show that PM concentrations influence by changing equivalence ratio, load, engine speed and injection timing

  7. 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

  8. Dynamic Value Engineering Method Optimizing the Risk on Real Time Operating System

    Directory of Open Access Journals (Sweden)

    Prashant Kumar Patra

    2014-04-01

    Full Text Available The value engineering is the umbrella of the many more sub-system like quality assurance, quality control, quality function design and development for manufacturability. The system engineering & value engineering is two part of the coin. The value engineering is the high level of technology management for every aspect of engineering fields. The value engineering is the high utilization of System Product (i.e. Processor, Memory & Encryption key, Services, Business and Resources at minimal cost. The high end operating system providing highest services at optimal cost & time. The value engineering provides the maximum performance, accountability, reliability, integrity and availability of processor, memory, encryption key and other inter dependency sub-components. The value engineering is the ratio of the maximum functionality of individual components to the optimal cost. VE=k [(P, M, E, C, A]/optimal cost. Where k is the proportionality constant. The VE is directly proportional to performance of individual components and inversely proportional to the minimal cost. The VE is directly proportional to the risk assessment. The VE maximize the business throughput & decision process mean while minimize the risk and down time. We have to develop the dynamic value engineering model & mechanism for risk optimization over a complex real time operating system This proposed composition model definite will be resolve our objective at top high level. Product

  9. General concept of a gas engine for a hybrid vehicle, operating on methanol dissociation products

    International Nuclear Information System (INIS)

    Tartakovsky, L.; Aleinikov, Y.; Fainberg, V.; Garbar, A.; Gutman, M.; Hetsroni, G.; Schindler, Y.; Zvirin, Y.

    1998-01-01

    The paper presents a general concept of a hybrid propulsion system, based on an SI internal combustion engine fueled by methanol dissociation products (MDP). The proposed hybrid propulsion scheme is a series hybrid, which allows the engine to be operated in an on-off mode at constant optimal regime. The engine is fed by gaseous products of methanol dissociation (mainly hydrogen and carbon monoxide) emerging from an on-board catalytic reformer. The general scheme and base operation features of the propulsion system are described. The benefits that may be achieved by combining the well-known idea of on-board methanol dissociation with the hybrid vehicle concept are discussed. The proposed scheme is compared with those of systems operating on gasoline, liquid methanol, hydrogen and also with the multi-regime (not hybrid) engine fed by MDP

  10. The Increase of Operational Safety of Ships by Improving Diagnostic Methods for Marine Diesel Engine

    Directory of Open Access Journals (Sweden)

    Kazimierz Witkowski

    2017-06-01

    Full Text Available This article shows the importance of the diagnostic improvement methods of marine engines to boost the economy and safety of operation of marine cargo ships. The need to implement effective diagnostic methods is justified by presenting statistical data of marine diesel engines failure and the cost of their operation. Based on the own research has been proven, for the chosen example, that indicator diagrams and analysis of indicated parameters have limited utility in the diagnosis of damages of marine engine, although this is a method commonly used in operational practice. To achieve greater diagnostic effectiveness, when, based on indicator diagrams, are calculated and then the characteristics of heat release is analyzed - net of heat release characteristics and the intensity of the heat release, it was demonstrated. This procedure is particularly effective in the diagnosis of damage of injection system components marine diesel engine.

  11. Investigation of Continuous Gas Engine CHP Operation on Biomass Producer Gas

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Jensen, Torben Kvist

    2005-01-01

    More than 2000 hours of gas engine operation with producer gas from biomass as fuel has been conducted on the gasification CHP demonstration and research plant, named “Viking” at the Technical University of Denmark. The gas engine is an integrated part of the entire gasification plant. The excess...... operates with varying excess of air due to variation in gas composition and thus stoichiometry, and a second where the excess of air in the exhaust gas is fixed and the flow rate of produced gas from the gasifier is varying. The interaction between the gas engine and the gasification system has been...... investigated. The engine and the plant are equipped with continuously data acquisition that monitors the operation including the composition of the producer gas and the flow. Producer gas properties and contaminations have been investigated. No detectable tar or particle content was observed...

  12. Operational Issues in the Development of a Cost-Effective Reusable LOX/LH2 Engine

    Science.gov (United States)

    Ballard, Richard O.

    2003-01-01

    The NASA Space Launch Initiative (SLI) was initiated in early 2001 to conduct technology development and to reduce the business and technical risk associated with developing the next-generation reusable launch system. In the field of main propulsion, two LOXLH2 rocket engine systems, the Pratt & Whitney / Aerojet Joint Venture (JV) COBRA and the Rocketdyne RS-83, were funded to develop a safe, economical, and reusable propulsion system. Given that a large-thrust reusable rocket engine program had not been started in the U.S. since 1971, with the Space Shuttle Main Engine (SSME), this provided an opportunity to build on the experience developed on the SSME system, while exploiting advances in technology that had occurred in the intervening 30 years. One facet of engine development that was identified as being especially vital in order to produce an optimal system was in the areas of operability and maintainability. In order to achieve the high levels of performance required by the Space Shuttle, the SSME system is highly complex with very tight tolerances and detailed requirements. Over the lifetime of the SSME program, the engine has required a high level of manpower to support the performance of inspections, maintenance (scheduled and unscheduled) and operations (prelaunch and post-flight). As a consequence, the labor- intensive needs of the SSME provide a significant impact to the overall cost efficiency of the Space Transportation System (STS). One of the strategic goals of the SLI is to reduce cost by requiring the engine(s) to be easier (Le. less expensive) to operate and maintain. The most effective means of accomplishing this goal is to infuse the operability and maintainability features into the engine design from the start. This paper discusses some of the operational issues relevant to a reusable LOx/LH2 main engine, and the means by which their impact is mitigated in the design phase.

  13. Systems engineering studies of on-orbit assembly operation

    Science.gov (United States)

    Morgenthaler, George W.

    1991-01-01

    While the practice of construction has a long history, the underlying theory of construction is relatively young. Very little has been documented as to techniques of logistic support, construction planning, construction scheduling, construction testing, and inspection. The lack of 'systems approaches' to construction processes is certainly one of the most serious roadblocks to the construction of space structures. System engineering research efforts at CSC are aimed at developing concepts and tools which contribute to a systems theory of space construction. The research is also aimed at providing means for trade-offs of design parameters for other research areas in CSC. Systems engineering activity at CSC has divided space construction into the areas of orbital assembly, lunar base construction, interplanetary transport vehicle construction, and Mars base construction. A brief summary of recent results is given. Several models for 'launch-on-time' were developed. Launch-on-time is a critical concept to the assembly of such Earth-orbiting structures as the Space Station Freedom, and to planetary orbiters such as the Mars transfer vehicle. CSC has developed a launch vehicle selection model which uses linear programming to find optimal combinations of launch vehicles of various sizes (Atlas, Titan, Shuttles, HLLV's) to support SEI missions. Recently, the Center developed a cost trade-off model for studying on orbit assembly logistics. With this model it was determined that the most effective size of the HLLV would be in the range of 120 to 200 metric tons to LEO, which is consistent with the choices of General Stafford's Synthesis Group Report. A second-generation Dynamic Construction Activities Model ('DYCAM') process model has been under development, based on our past results in interruptability and our initial DYCAM model. This second-generation model is built on the paradigm of knowledge-based expert systems. It is aimed at providing answers to two questions: (1

  14. The operating experience and incident analysis for High Flux Engineering Test Reactor

    International Nuclear Information System (INIS)

    Zhao Guang

    1999-01-01

    The paper describes the incidents analysis for High Flux Engineering test reactor (HFETR) and introduces operating experience. Some suggestion have been made to reduce the incidents of HFETR. It is necessary to adopt new improvements which enhance the safety and reliability of operation. (author)

  15. Effect of exhaust gas recirculation on diesel engine nitrogen oxide reduction operating with jojoba methyl ester

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, H.E. [Mechanical Power Department, Faculty of Engineering, Mattaria, Helwan University, 9 k Eltaaweniat, Nasr Road, P.O. Box 11718, Cairo (Egypt)

    2009-10-15

    Jojoba methyl ester (JME) has been used as a renewable fuel in numerous studies evaluating its potential use in diesel engines. These studies showed that this fuel is good gas oil substitute but an increase in the nitrogenous oxides emissions was observed at all operating conditions. The aim of this study mainly was to quantify the efficiency of exhaust gas recirculation (EGR) when using JME fuel in a fully instrumented, two-cylinder, naturally aspirated, four-stroke direct injection diesel engine. The tests were carried out in three sections. Firstly, the measured performance and exhaust emissions of the diesel engine operating with diesel fuel and JME at various speeds under full load are determined and compared. Secondly, tests were performed at constant speed with two loads to investigate the EGR effect on engine performance and exhaust emissions including nitrogenous oxides (NO{sub x}), carbon monoxide (CO), unburned hydrocarbons (HC) and exhaust gas temperatures. Thirdly, the effect of cooled EGR with high ratio at full load on engine performance and emissions was examined. The results showed that EGR is an effective technique for reducing NO{sub x} emissions with JME fuel especially in light-duty diesel engines. With the application of the EGR method, the CO and HC concentration in the engine-out emissions increased. For all operating conditions, a better trade-off between HC, CO and NO{sub x} emissions can be attained within a limited EGR rate of 5-15% with very little economy penalty. (author)

  16. Performance and emission characteristics of biogas used in diesel engine operation

    International Nuclear Information System (INIS)

    Makareviciene, Violeta; Sendzikiene, Egle; Pukalskas, Saugirdas; Rimkus, Alfredas; Vegneris, Ricardas

    2013-01-01

    Highlights: • Biogas is an environmentally friendly biofuel for diesel engines. • Results of diesel engine tests when fuelling with biogas are presented. • Engine and environmental characteristics depends on carbon dioxide content in biogas. • Using biogas in a diesel engine requires certain operational modifications. - Abstract: The objective of this study it to evaluate the impact of the carbon dioxide concentration in biogas on the operating characteristics and exhaust gas emissions of a diesel engine running on a mixture of biogas and mineral diesel fuel. The tests were carried out in two stages. In the first stage, the impact of different biogas compositions and the exhaust gas recirculation system (EGR) on the engine parameters was determined. Lower pollutant levels were measured in the studies without the EGR system, except for the nitrogen oxides NO x levels. The NO x concentration decrease was directly proportional to the concentration of methane in the common fuel mixture. In the second stage, the gas with the highest methane content was used to determine the impact of the start of injection timing on the engine operating parameters. As the methane content in the common fuel mixture increased, the start of injection timing had to be progressively advanced to increase the thermal efficiency and to lower the fuel consumption, the CO and HC concentrations and the smokiness of the exhaust; however, advancing the start of injection timing increased NO x pollution

  17. Managing your engineering consultants: Steps for simultaneously improving operations, project implementation, and your bottom line

    International Nuclear Information System (INIS)

    Kirchen, E.R.; Perilloux, B.L.

    1997-01-01

    The domestic oil and gas industry has responded to depleting reserves and increasing operating costs by downsizing the overhead required to maintain production and processing facilities. For many companies this downsizing has resulted in a reduced in-house engineering staff and a greater reliance on consulting engineering services. To get the most benefit from consulting engineering companies, the partnership between consultants and the oil and gas company needs to be carefully considered. Unfortunately, these partnerships are often developed at the home office with visionary goals in mind, only to be implemented reluctantly on a local level. A better strategy is to implement partnering tools on the local level and allow these partnerships to develop naturally, and at times, uniquely, at each location. The following such tools detailed in this paper are: manpower leveraging -- using field-trained consulting engineers to address project design/implementation and field/construction support so that the operating company's engineers may focus on management and detailed development of high-return projects; enhanced project scope and design review -- developing and reviewing project scope(s) and preliminary engineering designs to minimize engineering/construction costs as well as optimize the operability and constructability of the project; and consulting rate standardization -- understanding and structuring the consultant's rates so that neither side is exploited and so that the project is staffed in the interest of project execution and not maximum profits for the consultant

  18. Impact of Turbocharger Non-Adiabatic Operation on Engine Volumetric Efficiency and Turbo Lag

    Directory of Open Access Journals (Sweden)

    S. Shaaban

    2012-01-01

    Full Text Available Turbocharger performance significantly affects the thermodynamic properties of the working fluid at engine boundaries and hence engine performance. Heat transfer takes place under all circumstances during turbocharger operation. This heat transfer affects the power produced by the turbine, the power consumed by the compressor, and the engine volumetric efficiency. Therefore, non-adiabatic turbocharger performance can restrict the engine charging process and hence engine performance. The present research work investigates the effect of turbocharger non-adiabatic performance on the engine charging process and turbo lag. Two passenger car turbochargers are experimentally and theoretically investigated. The effect of turbine casing insulation is also explored. The present investigation shows that thermal energy is transferred to the compressor under all circumstances. At high rotational speeds, thermal energy is first transferred to the compressor and latter from the compressor to the ambient. Therefore, the compressor appears to be “adiabatic” at high rotational speeds despite the complex heat transfer processes inside the compressor. A tangible effect of turbocharger non-adiabatic performance on the charging process is identified at turbocharger part load operation. The turbine power is the most affected operating parameter, followed by the engine volumetric efficiency. Insulating the turbine is recommended for reducing the turbine size and the turbo lag.

  19. The Preparation for and Execution of Engineering Operations for the Mars Curiosity Rover Mission

    Science.gov (United States)

    Samuels, Jessica A.

    2013-01-01

    The Mars Science Laboratory Curiosity Rover mission is the most complex and scientifically packed rover that has ever been operated on the surface of Mars. The preparation leading up to the surface mission involved various tests, contingency planning and integration of plans between various teams and scientists for determining how operation of the spacecraft (s/c) would be facilitated. In addition, a focused set of initial set of health checks needed to be defined and created in order to ensure successful operation of rover subsystems before embarking on a two year science journey. This paper will define the role and responsibilities of the Engineering Operations team, the process involved in preparing the team for rover surface operations, the predefined engineering activities performed during the early portion of the mission, and the evaluation process used for initial and day to day spacecraft operational assessment.

  20. Modeling the dynamic and thermodynamic operation of Stirling engines by means of an equivalent electrical circuit

    International Nuclear Information System (INIS)

    Cascella, Franco; Sorin, Mikhail; Formosa, Fabien; Teyssedou, Alberto

    2017-01-01

    Highlights: • A model based on the electrical analogy theory has been developed to predict the operation of a Stirling engine. • The models takes into account the continuity, the momentum and the energy conservation equations. • The model predicts the operating conditions of the RE100 Free piston Stirling engine. • The model is sensible to the modeling of the effects of the machine load. - Abstract: The Stirling engines are inherently efficient; their thermodynamic cycles reach the Carnot efficiency. These technologies are suitable to operate under any low temperature difference between the hot and the cold sources. For these reasons, these engines can be considered as reliable power conversion systems to promote the conversion of low-grade waste heat generated by industrial plants. The need of a model to predict the behavior of these engines is of primary importance. Nevertheless, a great difficulty is encountered in developing such a model since it is not simple to take into account coupled thermodynamic and dynamic effects. This is the main reason why several models make use of electrical analogies to describe Stirling engines (in particular, free-piston machines): by assuming the pressure equivalent to a voltage and the flow rate to an electrical current, a coupled dynamic-thermodynamic analysis of the engine can be performed. In this paper, an electrical circuit whose behavior is equivalent to that of the engine is derived from the electrical analogy theory. To this aim, we propose an electrical analogy model based on the three conservation laws (mass, momentum and energy). Since limited experimental information is available in the open literature, the results obtained with the proposed model are compared with the experimental data collected at the NASA Lewis Research center for a free-piston Stirling engine i.e., the RE-1000 engine.

  1. Conversion of diesel engines to dual fuel (propane/diesel) operations

    Energy Technology Data Exchange (ETDEWEB)

    Pepper, S W; DeMaere, D A

    1984-02-01

    A device to convert a diesel engine to dual fuel (propane/diesel) operation was developed and evaluated. Preliminary experimentation has indicated that as much as 30% of the diesel fuel consumed in diesel engines could be displaced with propane, accompanied by an improvement in fuel efficiency, engine maintenance and an overall reduction in emission levels. Dual fuel operations in both transportation and stationary applications would then project a saving of ca 90,000 barrels of diesel fuel per day by the year 1990. A turbo-charged 250 hp diesel engine was directly coupled to a dynamometer under laboratory conditions, and operated at speeds between 500 and 2500 rpm and at various torque levels. At each rpm/torque point the engine first operated on diesel fuel alone, and then increasing quantities of propane were induced into the air intake until detonation occured. Results indicate that the proportion of propane that can be safely induced into a diesel engine varies considerably with rpm and torque so that a sophisticated metering system would be required to maximize diesel oil displacement by propane. Conversion is not cost effective at 1983 price levels.

  2. Dual fuel operation of used transformer oil with acetylene in a DI diesel engine

    International Nuclear Information System (INIS)

    Behera, Pritinika; Murugan, S.; Nagarajan, G.

    2014-01-01

    Highlights: • Utilisation of Used transformer oil (UTO) as a fuel in a diesel engine. • UTO with acetylene in a diesel engine, on a dual fuel mode technique. • Analysis of combustion characteristics of the diesel engine. • Analysis of performance and emission characteristics of the diesel engine. - Abstract: Used transformer oil (UTO) is a waste oil obtained from power transformers and welding transformers. It possesses considerable heating value and properties similar to diesel fuel. A preliminary investigation on the utilization of the UTO in a single cylinder, four stroke small powered direct injection (DI) diesel engine revealed that at an optimum injection timing of 20°CA the engine exhibited lower nitric oxide (NO) and higher smoke emissions, compared to that of diesel operation. In order to improve the performance and reduce the smoke emission, a dual fuel operation was attempted in the present investigation. Acetylene was inducted as a primary fuel at four different flow rates viz 132 g/h, 198 g/h, 264 g/h and 330 g/h along with the air, to study the combustion, performance and emission behavior of a four-stroke, 4.4 kW diesel engine, while the UTO was injected as pilot fuel with the optimized injection timing. The experimental results were compared with diesel-acetylene dual fuel operation in the same engine. Acetylene aspiration reduced the ignition delay and maximum cylinder pressure by about 3°CA, and 25% respectively at full load in comparison with the sole UTO operation. Higher thermal efficiency and lower exhaust gas were also observed at full load. Smoke was reduced by about 13.7%, in comparison with the UTO operation at full load

  3. 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

  4. Multi-operation cryptographic engine: VLSI design and implementation

    International Nuclear Information System (INIS)

    Selimis, George; Koufopavlou, Odysseas

    2005-01-01

    The environment of smart card lacks of system resources but the commercial and economic transactions via smart cards demand the use of certificated and secure cryptographic methods. In this paper a cryptographic approach in hardware for smart cards is proposed. The proposed system supports two basic operations of cryptography, authentication and encryption. The basic component of system is the one round of DES algorithm which supports the DES, Triple DES and the ANSI X9.17 standards. The proposed system is efficient in terms of area resources and techniques for low power consumption have applied. Due to the fact that the system is for smart card applications the overall throughput outperforms the typical smart card throughput standards

  5. Does the Future Engineer Force Transition Engineer Units between Offensive and Stability Operations in Ways That Achieve Responsiveness, Versatility, Agility, Effectiveness, and Efficiency?

    National Research Council Canada - National Science Library

    London, David T

    2005-01-01

    .... The main question is as follows: Does the FEF transition engineer units between offensive and stability operations in ways that achieve responsiveness, versatility, agility, effectiveness, and efficiency...

  6. Experience and co-operation in the development of nuclear engineering education

    International Nuclear Information System (INIS)

    Brochard, D.; Gladieux, A.

    1998-01-01

    This paper presents various aspects of the international co-operation set up at the Institut National des Sciences et Techniques Nucleaires (INSTN) for developing the nuclear engineering education in a European framework, with the Tempus programmes, or worldwide, through the IAEA technical co-operation programme. As such co-operation mainly relies on the courses established in the INSTN for national purposes, a short presentation of them is made first. (author)

  7. Effects of Engine Cooling Water Temperature on Performance and Emission Characteristics of a Ci Engine Operated with Biofuel Blend

    Directory of Open Access Journals (Sweden)

    Abul Hossain

    2017-03-01

    Full Text Available The temperature of the coolant is known to have significant influence on engine performance and emissions. Whereas existing literature describes the effects of coolant temperature in engines using fossil derived fuels, very few studies have investigated these effects when biofuel is used. In this study, Jatropha oil was blended separately with ethanol and butanol. It was found that the 80% jatropha oil + 20% butanol blend was the most suitable alternative, as its properties were closest to that of fossil diesel. The coolant temperature was varied between 50°C and 95°C. The combustion process enhanced for both diesel and biofuel blend, when the coolant temperature was increased. The carbon dioxide emissions for both diesel and biofuel blend were observed to increase with temperature. The carbon monoxide, oxygen and lambda values were observed to decrease with temperature. When the engine was operated using diesel, nitrogen oxides emissions correlated in an opposite manner to smoke opacity; however, nitrogen oxides emissions and smoke opacity correlated in an identical manner for biofuel blend. Brake specific fuel consumption was observed to decrease as the temperature was increased and was higher on average when the biofuel was used. The study concludes that both biofuel blend and fossil diesel produced identical correlations between coolant temperature and engine performance. The trends of nitrogen oxides and smoke emissions with cooling temperatures were not identical to fossil diesel when biofuel blend was used in the engine.

  8. A study of operating parameters on the linear spark ignition engine

    International Nuclear Information System (INIS)

    Lim, Ocktaeck; Hung, Nguyen Ba; Oh, Seokyoung; Kim, Gangchul; Song, Hanho; Iida, Norimasa

    2015-01-01

    Highlights: • An experimental and simulation study of a linear engine is conducted. • The effects of operating parameters on the generating power are investigated. • The air gap length has a significant influence on the generating power. • The generating power of the linear engine is optimized with the value of 111.3 W. • There are no problems for the linear engine after 100 h of durable test. - Abstract: In this paper, we present our experiment and simulation study of a free piston linear engine based on operating conditions and structure of the linear engine for generating electric power. The free piston linear engine includes a two-stroke free piston engine, linear generators, and compressors. In the experimental study, the effects of key parameters such as input caloric value, equivalence ratio, spark timing delay, electrical resistance, and air gap length on the piston dynamics and electric power output are investigated. Propane is used as a fuel in the free piston linear engine, and it is premixed with the air to make a homogeneous charge before go into the cylinder. The air and fuel mass flow rate are varied by a mass flow controller. The experimental results show that the maximum generating power is found with the value of 111 W at the input caloric value of 5.88 kJ/s, spark timing delay of 1.5 ms, equivalence ratio of 1.0, electric resistance of 30 Ω, and air gap length of 1.0 mm. In order to check the durability of the linear engine, a durable test is conducted during 100 h. The experimental results show that there are no problems for the linear engine after about one hundred hours of the durable test. Beside experimental study, a simulation study is conducted to predict operating behavior of the linear engine. In the simulation study, the two-stroke free piston linear engine is modeled and simulated through a combination of three mathematical models including a dynamic model, a linear alternator model and a thermodynamic model. These

  9. Prediction of knock limited operating conditions of a natural gas engine

    International Nuclear Information System (INIS)

    Soylu, Seref

    2005-01-01

    Computer models of engine processes are valuable tools for predicting and analyzing engine performance and allow exploration of many engine design alternatives in an inexpensive fashion. In the present work, a zero-dimensional, two zone thermodynamic model was used to determine the knock limited operating conditions of a natural gas engine. Experimentally based burning rate models were used for flame initiation and propagation calculations. A knock model was incorporated with the zero-dimensional model. Comparison of the measured and calculated cylinder pressure data indicated that the model is able to match the measured cylinder pressure data with less than 8% error in magnitudes if the computations are started at the experimental spark timing. The knock predictions agreed with the measurements also. With the established knock model, it is possible not only to investigate whether knock is observed with changing operating and design parameters, but also to evaluate their effects on the maximum possible knock intensity

  10. Build Up and Operation of an Axial Turbine Driven by a Rotary Detonation Engine

    Science.gov (United States)

    2012-03-01

    RDEs ) offer advantages over pulsed detonation engines (PDEs) due to a steadier exhaust and fewer total system losses. All previous research on...the integration and testing of an axial turbine driven by a rotary detonation engine ( RDE ) to determine turbine operability. In pursuit of this...objective, convergent nozzle sections were placed on the RDE to simulate the back-pressurization that would occur when placing the turbine behind the RDE

  11. Research into operational parameters of diesel engines running on RME biodiesel

    Directory of Open Access Journals (Sweden)

    S. Lebedevas

    2006-12-01

    Full Text Available The results of motor experimental researches on operational parameters of diesel engines F2L511 and A41 are presented in the publication. Change of harmful emission of exhaust gases was determined and evaluated, fuel economy and thrust characteristics of diesel engines running on RME biodiesel compared to diesel fuel. The influence of technical condition of fuel injection aggregates was evaluated for parameters of harmful emission of diesel engines running on biodiesel by simulation of setback of fuel injection in alowable range of technical conditions – the coking of nozzles of fuel injector. The complex improvement of all ecological parameters was evaluated by optimisation of fuel injection phase of diesel engines running on RME biodiesel. Objectives and aspects of further researches on indicator process of diesel engines were determined.

  12. Correction of engineering servicing regularity of transporttechnological machines in operational process

    Science.gov (United States)

    Makarova, A. N.; Makarov, E. I.; Zakharov, N. S.

    2018-03-01

    In the article, the issue of correcting engineering servicing regularity on the basis of actual dependability data of cars in operation is considered. The purpose of the conducted research is to increase dependability of transport-technological machines by correcting engineering servicing regularity. The subject of the research is the mechanism of engineering servicing regularity influence on reliability measure. On the basis of the analysis of researches carried out before, a method of nonparametric estimation of car failure measure according to actual time-to-failure data was chosen. A possibility of describing the failure measure dependence on engineering servicing regularity by various mathematical models is considered. It is proven that the exponential model is the most appropriate for that purpose. The obtained results can be used as a separate method of engineering servicing regularity correction with certain operational conditions taken into account, as well as for the technical-economical and economical-stochastic methods improvement. Thus, on the basis of the conducted researches, a method of engineering servicing regularity correction of transport-technological machines in the operational process was developed. The use of that method will allow decreasing the number of failures.

  13. Study on evaluation of construction reliability for engineering project based on fuzzy language operator

    Science.gov (United States)

    Shi, Yu-Fang; Ma, Yi-Yi; Song, Ping-Ping

    2018-03-01

    System Reliability Theory is a research hotspot of management science and system engineering in recent years, and construction reliability is useful for quantitative evaluation of project management level. According to reliability theory and target system of engineering project management, the defination of construction reliability appears. Based on fuzzy mathematics theory and language operator, value space of construction reliability is divided into seven fuzzy subsets and correspondingly, seven membership function and fuzzy evaluation intervals are got with the operation of language operator, which provides the basis of corresponding method and parameter for the evaluation of construction reliability. This method is proved to be scientific and reasonable for construction condition and an useful attempt for theory and method research of engineering project system reliability.

  14. 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.

  15. Analysis of Modifications on a Spark Ignition Engine for Operation with Natural Gas

    Directory of Open Access Journals (Sweden)

    Ramasamy D.

    2016-01-01

    Full Text Available Transportation is one of the key contributors to petroleum usage and emissions to the atmosphere. According to researchers, there are many ways to use transport by using renewable energy sources. Of these solutions, the immediate solution which requires less modification to current engine technology is by using gaseous fuels. Natural gas is the fuel of choice for minor modification to current engines. As it can be derived from anaerobic digestion process, the potential as a renewable energy source is tremendous, especially for an agricultural country such a Malaysia. The aim in the future will be operating an engine with natural gas only with pipelines straight to houses for easy filling. The fuel is light and can be easily carried in vehicles when in compressed form. As such, Compressed Natural Gas (CNG is currently used in bi-fuel engines, but is mostly not optimized in term of their performance. The focus of the paper is to optimize a model of natural gas engine by one dimensional flow modeling for operation with natural gas. The model is analyzed for performance and emission characteristics produced by a gasoline engine and later compared with natural gas. The average performance drop is about 15% from its gasoline counterpart. The 4% benchmark indicates that the modification to ignition timing and compression ratio does improve engine performance using natural gas as fuel.

  16. Principles of Design And Operations Of Wastewater Treatment Pond Systems For Plant Operators, Engineers, And Managers

    Science.gov (United States)

    Wastewater pond systems provide reliable, low cost, and relatively low maintenance treatment for municipal and industrial discharges. However, they do have certain design, operations, and maintenance requirements. While the basic models have not changed in the 30-odd years sinc...

  17. Operation experiences of landfill gas engines; Motorer foer deponigas - Tillgaenglighet och drifterfarenheter

    Energy Technology Data Exchange (ETDEWEB)

    Dejfors, Charlotte; Grimberger, Goeran [AaF-Energikonsult Stockholm AB (Sweden)

    2000-06-01

    The gas that is obtained from landfilled waste is produced by bacteria that digest organic material in an anaerobic environment. Landfill gas consists mainly of methane, carbon dioxide and water vapour. It may be used either as auxiliary fuel in boilers close to the landfill or to generate electricity by means of a gas engine. Several plants where landfill gas is used in gas engines have had serious problems, a. o. with burned exhaust valves. These problems may occur already after a short period of operation, which influences the profitability. The purposes of the project reported were to collect operational experience in Sweden with engines using landfill gas as fuel, to identify which problems there are and which actions or improvements have been implemented in order to correct for these problems. Today, there are 9 facilities where landfill gas is used to fuel a total of 13 gas engines. In addition, there is an engine in Goeteborg which has scarcely been in operation after its installation because there is not enough gas. Contact has been taken with all these facilities. Many have pointed out that the gas engines are sensitive in the vicinity of maximum load, where the control system requires an even gas flow and a stable composition of the gas. A counter-measure in the facilities is to avoid running the engine at full load. All engines are equipped with a lean-NO{sub x} system in order to minimise NO{sub x} emissions. Many have remarked that the lean-NO{sub x} system shuts the engine off when emissions exceed the allowed limits. There is a consensus that spark plugs and ignition cables have created operational problems. These have been changed more frequently than originally expected. Another problem, which has caused operational problems and a need for maintenance, is deposits mainly in the combustion chamber, in valves and cylinder heads. Deposits and high exhaust gas temperature have led to burnt exhaust gas valves and cylinder heads on half of the engines

  18. Supercharging system behavior for high altitude operation of an aircraft 2-stroke Diesel engine

    International Nuclear Information System (INIS)

    Carlucci, Antonio Paolo; Ficarella, Antonio; Laforgia, Domenico; Renna, Alessandro

    2015-01-01

    Highlights: • Different supercharging architectures have been compared for an aircraft 2T engine. • The supercharging architectures are compared to minimize the fuel consumption. • The architecture with the highest conversion efficiency was determined. - Abstract: Different studies on both 2- and 4-stroke engines have shown how the choice of different supercharging architectures can influence engine performance. Among them, architectures coupling one turbocharger with a mechanical compressor or two turbochargers are found to be the most performing in terms of engine output power and efficiency. However, defining the best supercharging architecture for aircraft 2-stroke engines is a quite complex task because the supercharging system as well as the ambient conditions influence the engine performance/efficiency. This is due to the close interaction between supercharging, trapping, scavenging and combustion processes. The aim of the present work is the comparison between different architectures (single turbocharger, double turbocharger, single turbocharger combined with a mechanical compressor, single turbocharger with an electrically-assisted turbocharger, with intercooler or aftercooler) designed to supercharge an aircraft 2-stroke Diesel engine for general aviation and unmanned aerial vehicles characterized by a very high altitude operation and long fuel distance. A 1D model of the engine purposely designed has been used to compare the performance of the different supercharging systems in terms of power, fuel consumption, and their effect on trapping and scavenging efficiency at different altitudes. The analysis shows that the engine target power is reached by a 2 turbochargers architecture; in this way, in fact, the cylinder filling, and consequently the engine performance, are maximized. Moreover, it is shown that the performance of a 2 turbochargers architecture performance can be further improved connecting electrically and not mechanically the low

  19. Determination of engineering safety factor -routine in Hungary (a methodology for the normal operation local power engineering safety factors)

    International Nuclear Information System (INIS)

    Szecsenyi, Z.; Korpas, L.; Bona, G.; Kereszturi, A.

    2010-01-01

    From the late nineties Paks Nuclear Power Plant-in collaboration with KFKI Atomic Energy Research Institute (KFKI AEKI)- is developing a system for determining the normal operation local power engineering safety factors. The system is based on a Monte Carlo sampling of the uncertain model input parameters. Additionally, the comparison of the calculation to the in-core measurements plays essential role for determining some important input parameters. By using new fuel types and the corresponding more recent detailed technological data, the applied method is being improved from time to time. Presently, the actually used and authorized engineering safety factors at Paks NPP are determined by using this method. In the paper, the system.s main properties are described (not going beyond the possible extent). The main points are as follows:-Mathematical definition of the engineering safety factor;-Sources of the uncertainties;-Input error propagation method constituting the basis of the system;-Flow-chart of the subsequent steps of the determination Finally, in the paper the engineering safety factors values of some selected parameters are presented as examples for demonstration of the capability of the method. (Authors)

  20. Experimental investigation and modeling of an aircraft Otto engine operating with gasoline and heavier fuels

    Science.gov (United States)

    Saldivar Olague, Jose

    A Continental "O-200" aircraft Otto-cycle engine has been modified to burn diesel fuel. Algebraic models of the different processes of the cycle were developed from basic principles applied to a real engine, and utilized in an algorithm for the simulation of engine performance. The simulation provides a means to investigate the performance of the modified version of the Continental engine for a wide range of operating parameters. The main goals of this study are to increase the range of a particular aircraft by reducing the specific fuel consumption of the engine, and to show that such an engine can burn heavier fuels (such as diesel, kerosene, and jet fuel) instead of gasoline. Such heavier fuels are much less flammable during handling operations making them safer than aviation gasoline and very attractive for use in flight operations from naval vessels. The cycle uses an electric spark to ignite the heavier fuel at low to moderate compression ratios, The stratified charge combustion process is utilized in a pre-chamber where the spray injection of the fuel occurs at a moderate pressure of 1200 psi (8.3 MPa). One advantage of fuel injection into the combustion chamber instead of into the intake port, is that the air-to-fuel ratio can be widely varied---in contrast to the narrower limits of the premixed combustion case used in gasoline engines---in order to obtain very lean combustion. Another benefit is that higher compression ratios can be attained in the modified cycle with heavier fuels. The combination of injection into the chamber for lean combustion, and higher compression ratios allow to limit the peak pressure in the cylinder, and to avoid engine damage. Such high-compression ratios are characteristic of Diesel engines and lead to increase in thermal efficiency without pre-ignition problems. In this experimental investigation, operations with diesel fuel have shown that considerable improvements in the fuel efficiency are possible. The results of

  1. FORMALIZATION OF DIESEL ENGINE OPERATION CONSIDERING THE EVALUATION OF VELOCITY DURING THE COMBUSTION PROCESSES

    Directory of Open Access Journals (Sweden)

    V. P. Litvinenko

    2015-10-01

    Full Text Available Purpose. Under modern conditions the applying methods and design models as well as the evaluation of the operational characteristics of diesel engines do not completely take into consideration the specifics of the combustion processes. In part, such situation is characterized by the complexity of considering of varied by its nature processes that haven’t been completely investigated. In this context it is necessary to find the new methods and models which would provide relatively simple solutions through the use of integrated factors based on the analysis of parameters of diesel engines. Methodology. The proposed algorithms for the estimating of the combustion process in the form of volumetric and linear velocities is based on the well-known parameters of power and mean effective pressure and allows to compare the efficiency of their behavior in various versions of diesel engines. Findings. The author specified that the volumetric / linear velocity ratio is characterized by some strength and depends on the geometric dimensions of the cylinder-piston group. Due to the assumptions it has become possible to consider the operation of a diesel engine as a system comprising: 1 the subsystem that provides the possibility of obtaining the thermal energy; 2 the subsystem providing the thermal energy transformation; 3 the subsystem that provides the necessary diesel engine power depending on terms of combustion of air-fuel mixture. Originality. The author of the paper proposed the indices of volumetric and linear combustion velocity of air-fuel mixture in the engine cylinder, that allow to obtain the comparative value in different modifications taking into account the possible choice of optimum ratio. Practical value. The usage of indices of volumetric and linear velocities of the combustion processes in the engine cylinder combined with a mathematical model will simplify the method of diesels calculating. Parametric indices of the mentioned velocities

  2. Diluted Operation of a Heavy-Duty Natural Gas Engine - Aiming at Improved Effciency, Emission and Maximum Load

    OpenAIRE

    Kaiadi, Mehrzad

    2011-01-01

    Most heavy-duty engines are diesel operated. Severe emission regulations, high fuel prices, high technology costs (e.g. catalysts, fuel injection systems) and unsustainably in supplying fuel are enough reasons to convenience engine developers to explore alternative technologies or fuels. Using natural gas/biogas can be a very good alternative due to the attractive fuel properties regarding emission reduction and engine operation. Heavy-duty diesel engines can be easily converted for natur...

  3. Engineering development of a digital replacement protection system at an operating US PWR nuclear power plant: Installation and operational experiences

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.H. [Duke Power Co., Seneca, SC (United States)

    1995-04-01

    The existing Reactor Protection Systems (RPSs) at most US PWRs are systems which reflect 25 to 30 year-old designs, components and manufacturing techniques. Technological improvements, especially in relation to modern digital systems, offer improvements in functionality, performance, and reliability, as well as reductions in maintenance and operational burden. The Nuclear power industry and the US nuclear regulators are poised to move forward with the issues that have slowed the transition to modern digital replacements for nuclear power plant safety systems. The electric utility industry is now more than ever being driven by cost versus benefit decisions. Properly designed, engineered, and installed digital systems can provide adequate cost-benefit and allow continued nuclear generated electricity. This paper describes various issues and areas related to an ongoing RPS replacement demonstration project which are pertinant for a typical US nuclear plant to consider cost-effective replacement of an aging analog RPS with a modern digital RPS. The following subject areas relative to the Oconee Nuclear Station ISAT{trademark} Demonstrator project are discussed: Operator Interface Development; Equipment Qualification; Validation and Verification of Software; Factory Testing; Field Changes and Verification Testing; Utility Operational, Engineering and Maintenance; Experiences with Demonstration System; and Ability to operate in parallel with the existing Analog RPS.

  4. Engineering development of a digital replacement protection system at an operating US PWR nuclear power plant: Installation and operational experiences

    International Nuclear Information System (INIS)

    Miller, M.H.

    1995-01-01

    The existing Reactor Protection Systems (RPSs) at most US PWRs are systems which reflect 25 to 30 year-old designs, components and manufacturing techniques. Technological improvements, especially in relation to modern digital systems, offer improvements in functionality, performance, and reliability, as well as reductions in maintenance and operational burden. The Nuclear power industry and the US nuclear regulators are poised to move forward with the issues that have slowed the transition to modern digital replacements for nuclear power plant safety systems. The electric utility industry is now more than ever being driven by cost versus benefit decisions. Properly designed, engineered, and installed digital systems can provide adequate cost-benefit and allow continued nuclear generated electricity. This paper describes various issues and areas related to an ongoing RPS replacement demonstration project which are pertinant for a typical US nuclear plant to consider cost-effective replacement of an aging analog RPS with a modern digital RPS. The following subject areas relative to the Oconee Nuclear Station ISAT trademark Demonstrator project are discussed: Operator Interface Development; Equipment Qualification; Validation and Verification of Software; Factory Testing; Field Changes and Verification Testing; Utility Operational, Engineering and Maintenance; Experiences with Demonstration System; and Ability to operate in parallel with the existing Analog RPS

  5. Engineering approach to relative quantitative assessment of safety culture and related social issues in NPP operation

    International Nuclear Information System (INIS)

    Sivokon, V.; Gladyshev, M.; Malkin, S.

    2005-01-01

    The report is devoted to presentation of engineering approach and software tool developed for Safety Culture (SC) assessment as well as to the results of their implementation at Smolensk NPP. The engineering approach is logic evolution of the IAEA ASSET method broadly used at European NPPs in 90-s. It was implemented at Russian and other plants including Olkiluoto NPP in Finland. The approach allows relative quantitative assessing and trending the aspects of SC by the analysis of evens features and causes, calculation and trending corresponding indicators. At the same time plant's operational performances and related social issues, including efficiency of plant operation and personnel reliability, can be monitored. With the help of developed tool the joint team combined from personnel of Smolensk NPP and RRC 'Kurchatov Institute' ('KI') issued the SC self-assessment report, which identifies: families of recurrent events, main safety and operational problems ; their trends and importance to SC and plant efficiency; recommendations to enhance SC and operational performance

  6. Availability analysis of a turbocharged diesel engine operating under transient load conditions

    International Nuclear Information System (INIS)

    Rakopoulos, C.D.; Giakoumis, E.G.

    2004-01-01

    A computer analysis is developed for studying the energy and availability performance of a turbocharged diesel engine, operating under transient load conditions. The model incorporates many novel features for the simulation of transient operation, such as detailed analysis of mechanical friction, separate consideration for the processes of each cylinder during a cycle ('multi-cylinder' model) and mathematical modeling of the fuel pump. This model has been validated against experimental data taken from a turbocharged diesel engine, located at the authors' laboratory and operated under transient conditions. The availability terms for the diesel engine and its subsystems are analyzed, i.e. cylinder for both the open and closed parts of the cycle, inlet and exhaust manifolds, turbocharger and aftercooler. The present analysis reveals, via multiple diagrams, how the availability properties of the diesel engine and its subsystems develop during the evolution of the engine cycles, assessing the importance of each property. In particular the irreversibilities term, which is absent from any analysis based solely on the first-law of thermodynamics, is given in detail as regards transient response as well as the rate and cumulative terms during a cycle, revealing the magnitude of contribution of all the subsystems to the total availability destruction

  7. Methodology for risk assessment and reliability applied for pipeline engineering design and industrial valves operation

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Dierci [Universidade Federal Fluminense (UFF), Volta Redonda, RJ (Brazil). Escola de Engenharia Industrial e Metalurgia. Lab. de Sistemas de Producao e Petroleo e Gas], e-mail: dsilveira@metal.eeimvr.uff.br; Batista, Fabiano [CICERO, Rio das Ostras, RJ (Brazil)

    2009-07-01

    Two kinds of situations may be distinguished for estimating the operating reliability when maneuvering industrial valves and the probability of undesired events in pipelines and industrial plants: situations in which the risk is identified in repetitive cycles of operations and situations in which there is a permanent hazard due to project configurations introduced by decisions during the engineering design definition stage. The estimation of reliability based on the influence of design options requires the choice of a numerical index, which may include a composite of human operating parameters based on biomechanics and ergonomics data. We first consider the design conditions under which the plant or pipeline operator reliability concepts can be applied when operating industrial valves, and then describe in details the ergonomics and biomechanics risks that would lend itself to engineering design database development and human reliability modeling and assessment. This engineering design database development and reliability modeling is based on a group of engineering design and biomechanics parameters likely to lead to over-exertion forces and working postures, which are themselves associated with the functioning of a particular plant or pipeline. This approach to construct based on ergonomics and biomechanics for a more common industrial valve positioning in the plant layout is proposed through the development of a methodology to assess physical efforts and operator reach, combining various elementary operations situations. These procedures can be combined with the genetic algorithm modeling and four elements of the man-machine systems: the individual, the task, the machinery and the environment. The proposed methodology should be viewed not as competing to traditional reliability and risk assessment bur rather as complementary, since it provides parameters related to physical efforts values for valves operation and workspace design and usability. (author)

  8. Systems Engineering Approach To Ground Combat Vehicle Survivability In Urban Operations

    Science.gov (United States)

    2016-09-01

    GROUND COMBAT VEHICLE SURVIVABILITY IN URBAN OPERATIONS 5. FUNDING NUMBERS N/A 6. AUTHOR(S) Luhai Wong 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS...distance of 100m in the model , which is reasonable due to the constrained nature of an urban environment. This thesis also uses the key parameters...ENGINEERING APPROACH TO GROUND COMBAT VEHICLE SURVIVABILITY IN URBAN OPERATIONS by Luhai Wong September 2016 Thesis Advisor: Christopher A

  9. Evaluation of Biodiesel Fuels to Reduce Fossil Fuel Use in Corps of Engineers Floating Plant Operations

    Science.gov (United States)

    2016-07-01

    ER D C/ CH L TR -1 6- 11 Dredging Operations and Environmental Research Program Evaluation of Biodiesel Fuels to Reduce Fossil Fuel Use... Fuels to Reduce Fossil Fuel Use in Corps of Engineers Floating Plant Operations Michael Tubman and Timothy Welp Coastal and Hydraulics Laboratory...sensitive emissions, increase use of renewable energy, and reduce the use of fossil fuels was conducted with funding from the U.S. Army Corps of

  10. Power plant technology 2014. Strategies, systems engineering and operation; Kraftwerkstechnik 2014. Strategien, Anlagentechnik und Betrieb

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, Michael; Hurtado, Antonio

    2014-07-01

    The book on power plant technology 2014 (strategies, systems engineering and operation) covers the following issues: Climate, politics and economy; wind power; fossil-fuel power plants, flexible power plants - plant operation, flexible power plants- materials, materials for energy technology, fuel feed and incineration, modeling of the water-vapor-circuit, corrosion, deposits and cleaning, vapor turbines, GUD power plants, fluidized bed combustion, energetic biomass use, combined heat and power generation and decentralized units, storage facilities, emissions - mitigation and measuring techniques.

  11. Operation of neat pine oil biofuel in a diesel engine by providing ignition assistance

    International Nuclear Information System (INIS)

    Vallinayagam, R.; Vedharaj, S.; Yang, W.M.; Lee, P.S.

    2014-01-01

    Highlights: • Operational feasibility of neat pine oil biofuel has been examined. • Pine oil suffers lower cetane number, which mandates for necessary ignition assistance. • Ignition support is provided by preheating the inlet air and incorporating a glow plug. • At an inlet air temperature of 60 °C, the BTE for pine oil was found to be in par with diesel. • CO and smoke emissions were reduced by 13.2% and 16.8%, respectively, for neat pine oil. - Abstract: The notion to provide ignition support for the effective operation of lower cetane fuels in a diesel engine has been ably adopted in the present study for the sole fuel operation of pine oil biofuel. Having noted that the lower cetane number and higher self-ignition temperature of pine oil biofuel would inhibit its direct use in a diesel engine, combined ignition support in the form of preheating the inlet air and installing a glow plug in the cylinder head has been provided to improve the auto-ignition of pine oil. While, an air preheater, installed in the inlet manifold of the engine, preheated the inlet air so as to provide ignition assistance partially, the incorporation of glow plug in the cylinder head imparted the further required ignition support appropriately. Subsequently, the operational feasibility of neat pine oil biofuel has been examined in a single cylinder diesel engine and the engine test results were analyzed. From the experimental investigation, though the engine performance and emissions such as CO (carbon monoxide) and smoke were noted to be better for pine oil with an inlet air temperature of 40 °C, the engine suffered the setback of knocking due to delayed SOC (start of combustion). However, with the ignition support through glow plug and preheating of inlet air, the engine knocking was prevented and the normal operation of the engine was ensured. Categorically, at an inlet air temperature of 60 °C, BTE (brake thermal efficiency) was found to be in par with diesel, while

  12. A thermodynamic study for the optimization of stable operation of free piston Stirling engines

    Energy Technology Data Exchange (ETDEWEB)

    Rogdakis, E.D.; Bormpilas, N.A.; Koniakos, I.K. [National Technical Univerisity, Athens (Greece). Dept. of Mechanical Engineering

    2004-03-01

    One of the most novel applications of the Stirling cycle is in the free piston configuration that was initially designed by W. Beale. In free piston Stirling engines (FPSEs), there are no mechanical linkages coupling the pistons or displacers, the motions of the reciprocating components follow the working gas pressure variations. Fillipo de Monte and G. Benvenuto have recently proposed a linearization technique of the dynamic balance equations. The aim of this paper is to predict the thermodynamic conditions for stable operation of FPSEs and their modeling. The equations of the angular velocity are solved analytically in terms of the working gas mass and the displacer-piston phase angle of the machine. Using the criterion of stable engine cyclic steady operation, a mathematically rigorous form is obtained for the main parameters of the engine. Furthermore, for simplicity reasons, thermodynamic magnitudes are obtained using the Schmidt analysis (isothermal model). (author)

  13. A thermodynamic study for the optimization of stable operation of free piston Stirling engines

    International Nuclear Information System (INIS)

    Rogdakis, E.D.; Bormpilas, N.A.; Koniakos, I.K.

    2004-01-01

    One of the most novel applications of the Stirling cycle is in the free piston configuration that was initially designed by W. Beale. In free piston Stirling engines (FPSEs), there are no mechanical linkages coupling the pistons or displacers, the motions of the reciprocating components follow the working gas pressure variations. Fillipo de Monte and G. Benvenuto have recently proposed a linearization technique of the dynamic balance equations. The aim of this paper is to predict the thermodynamic conditions for stable operation of FPSEs and their modeling. The equations of the angular velocity are solved analytically in terms of the working gas mass and the displacer-piston phase angle of the machine. Using the criterion of stable engine cyclic steady operation, a mathematically rigorous form is obtained for the main parameters of the engine. Furthermore, for simplicity reasons, thermodynamic magnitudes are obtained using the Schmidt analysis (isothermal model)

  14. Using model based systems engineering for the development of the Large Synoptic Survey Telescope's operational plan

    Science.gov (United States)

    Selvy, Brian M.; Claver, Charles; Willman, Beth; Petravick, Don; Johnson, Margaret; Reil, Kevin; Marshall, Stuart; Thomas, Sandrine; Lotz, Paul; Schumacher, German; Lim, Kian-Tat; Jenness, Tim; Jacoby, Suzanne; Emmons, Ben; Axelrod, Tim

    2016-08-01

    We† provide an overview of the Model Based Systems Engineering (MBSE) language, tool, and methodology being used in our development of the Operational Plan for Large Synoptic Survey Telescope (LSST) operations. LSST's Systems Engineering (SE) team is using a model-based approach to operational plan development to: 1) capture the topdown stakeholders' needs and functional allocations defining the scope, required tasks, and personnel needed for operations, and 2) capture the bottom-up operations and maintenance activities required to conduct the LSST survey across its distributed operations sites for the full ten year survey duration. To accomplish these complimentary goals and ensure that they result in self-consistent results, we have developed a holistic approach using the Sparx Enterprise Architect modeling tool and Systems Modeling Language (SysML). This approach utilizes SysML Use Cases, Actors, associated relationships, and Activity Diagrams to document and refine all of the major operations and maintenance activities that will be required to successfully operate the observatory and meet stakeholder expectations. We have developed several customized extensions of the SysML language including the creation of a custom stereotyped Use Case element with unique tagged values, as well as unique association connectors and Actor stereotypes. We demonstrate this customized MBSE methodology enables us to define: 1) the rolls each human Actor must take on to successfully carry out the activities associated with the Use Cases; 2) the skills each Actor must possess; 3) the functional allocation of all required stakeholder activities and Use Cases to organizational entities tasked with carrying them out; and 4) the organization structure required to successfully execute the operational survey. Our approach allows for continual refinement utilizing the systems engineering spiral method to expose finer levels of detail as necessary. For example, the bottom-up, Use Case

  15. Evaluation of different design space description methods for analysing combustion engine operation limits

    NARCIS (Netherlands)

    Kieft, Nataša

    2014-01-01

    Over the last 20 years large efforts have been made in developing and optimising modelling techniques for DoE usage in engine calibration. A prerequisite for optimally applying DoE test designs is the detailed knowledge of the engine’s operating boundaries enclosing the ‘design space’. Known

  16. Integrated Emission Management strategy for cost-optimal engine-aftertreatment operation

    NARCIS (Netherlands)

    Cloudt, R.P.M.; Willems, F.P.T.

    2011-01-01

    A new cost-based control strategy is presented that optimizes engine-aftertreatment performance under all operating conditions. This Integrated Emission Management strategy minimizes fuel consumption within the set emission limits by on-line adjustment of air management based on the actual state of

  17. COOPERATIVE MODE OF ELECTRIC MOTOR AND INTERNAL COMBUSTION ENGINE OPERATION IN THE CONVERSION HYBRID CAR

    Directory of Open Access Journals (Sweden)

    V. Dvadnenko

    2016-12-01

    Full Text Available In the given article the authors proposed a method to control the car, which is converted into a hybrid one. The electric motor and combustion engine operate alternately in the car. They proposed a device for implementing this method and a circuit design for the device in question. They also calculated the dynamics of the vehicle under the joint acceleration.

  18. Model Reduction in Chemical Engineering : Case studies applied to process analysis, design and operation

    NARCIS (Netherlands)

    Dorneanu, B.

    2011-01-01

    During the last decades, models have become widely used for supporting a broad range of chemical engineering activities, such as product and process design and development, process monitoring and control, real time optimization of plant operation or supply chain management. Although tremendous

  19. Report to NASA Committee on Aircraft Operating Problems Relative to Aviation Safety Engineering and Research Activities

    Science.gov (United States)

    1963-01-01

    The following report highlights some of the work accomplished by the Aviation Safety Engineering and Research Division of the Flight Safety Foundations since the last report to the NASA Committee on Aircraft Operating Problems on 22 May 1963. The information presented is in summary form. Additional details may be provided upon request of the reports themselves may be obtained from AvSER.

  20. International Co-Operation in Control Engineering Education Using Online Experiments

    Science.gov (United States)

    Henry, Jim; Schaedel, Herbert M.

    2005-01-01

    This paper describes the international co-operation experience in teaching control engineering with laboratories being conducted remotely by students via the Internet. This paper describes how the students ran the experiments and their personal experiences with the laboratory. A tool for process identification and controller tuning based on…

  1. An investigation of the acoustic characteristics of a compression ignition engine operating with biodiesel blends

    Science.gov (United States)

    Zhen, D.; Tesfa, B.; Yuan, X.; Wang, R.; Gu, F.; Ball, A. D.

    2012-05-01

    In this paper, an experimental investigation has been carried out on the acoustic characteristics of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The experiment was conducted on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine which runs with biodiesel (B50 and B100) and pure diesel. The signals of acoustic, vibration and in-cylinder pressure were measured during the experiment. To correlate the combustion process and the acoustic characteristics, both phenomena have been investigated. The acoustic analysis resulted in the sound level being increased with increasing of engine loads and speeds as well as the sound characteristics being closely correlated to the combustion process. However, acoustic signals are highly sensitive to the ambient conditions and intrusive background noise. Therefore, the spectral subtraction was employed to minimize the effects of background noise in order to enhance the signal to noise ratio. In addition, the acoustic characteristics of CI engine running with different fuels (biodiesel blends and diesel) was analysed for comparison. The results show that the sound energy level of acoustic signals is slightly higher when the engine fuelled by biodiesel and its blends than that of fuelled by normal diesel. Hence, the acoustic characteristics of the CI engine will have useful information for engine condition monitoring and fuel content estimation.

  2. Experimental study of combustion noise radiation during transient turbocharged diesel engine operation

    International Nuclear Information System (INIS)

    Giakoumis, Evangelos G.; Dimaratos, Athanasios M.; Rakopoulos, Constantine D.

    2011-01-01

    Diesel engine noise radiation has drawn increased attention in recent years since it is associated with the passengers' and pedestrians' discomfort, a fact that has been acknowledged by the manufacturers and the legislation in many countries. In the current study, experimental tests were conducted on a truck, turbocharged diesel engine in order to investigate the mechanism of combustion noise emission under various transient schedules experienced during daily driving conditions, namely acceleration and load increase. To this aim, a fully instrumented test bed was set up in order to capture the development of key engine and turbocharger variables during the transient events. Analytical diagrams are provided to explain the behavior of combustion noise radiation in conjunction with cylinder pressure (spectrum), turbocharger and governor/fuel pump response. Turbocharger lag was found to be the main cause for the noise spikes during all test cases examined, with the engine injection timing calibration and the slow adjustment of cylinder wall temperature to the new fueling conditions playing a vital role. The analysis was extended with a quasi-steady approximation of transient combustion noise using steady-state maps, in order to better highlight the effect of dynamic engine operation on combustion noise emissions. -- Highlights: → Studying the effects of acceleration and load increase on the combustion noise radiation from a turbocharged diesel engine. → Turbocharger lag was the most notable contributor for the behavior of combustion noise radiation. → Turbocharged diesel engine behaves noisier at acceleration compared with the steady-state operation. → Fuel limiter, governing and engine injection timing calibration play a decisive role on the emission of combustion noise. → Transient noise radiation was smoothed the slower the acceleration and the smaller the demanded speed increase.

  3. The training and assessment of operations engineers at Hinkley Point 'B' nuclear power station

    International Nuclear Information System (INIS)

    Walsey, B.A.; Howard, J.D.

    1986-01-01

    The Nuclear Power Training Centre at Oldbury-on-Severn was established to provide a common training of staff at all nuclear power stations operated by the Central Electricity Generating Board, following the ''Standard Specification for the Nuclear Training of Staff at CEGB Nuclear Power Stations''. The paper deals with the following aspects of AGR Stations: The Legislation applicable to these stations. The current training requirements for Operations Staff. The development of training for operations staff at Hinkley Point 'B' including training for career progression within the Operations Department. A detailed explanation of the training package developed for Reactor Desk Drivers at Hinkley 'B'. Revision training of Operations staff to ensure that they continue to run the plant in a safe and commercially viable manner. The training of Shift Operations Engineers for their duties under the Station Emergency Plan. (author)

  4. DEVELOPMENT OF OPERATIONAL CONCEPTS FOR ADVANCED SMRs: THE ROLE OF COGNITIVE SYSTEMS ENGINEERING

    Energy Technology Data Exchange (ETDEWEB)

    Jacques Hugo; David Gertman

    2014-04-01

    Advanced small modular reactors (AdvSMRs) will use advanced digital instrumentation and control systems, and make greater use of automation. These advances not only pose technical and operational challenges, but will inevitably have an effect on the operating and maintenance (O&M) cost of new plants. However, there is much uncertainty about the impact of AdvSMR designs on operational and human factors considerations, such as workload, situation awareness, human reliability, staffing levels, and the appropriate allocation of functions between the crew and various automated plant systems. Existing human factors and systems engineering design standards and methodologies are not current in terms of human interaction requirements for dynamic automated systems and are no longer suitable for the analysis of evolving operational concepts. New models and guidance for operational concepts for complex socio-technical systems need to adopt a state-of-the-art approach such as Cognitive Systems Engineering (CSE) that gives due consideration to the role of personnel. This approach we report on helps to identify and evaluate human challenges related to non-traditional concepts of operations. A framework - defining operational strategies was developed based on the operational analysis of Argonne National Laboratory’s Experimental Breeder Reactor-II (EBR-II), a small (20MWe) sodium-cooled reactor that was successfully operated for thirty years. Insights from the application of the systematic application of the methodology and its utility are reviewed and arguments for the formal adoption of CSE as a value-added part of the Systems Engineering process are presented.

  5. EDF EPR project: operating principles validation and human factor engineering program

    International Nuclear Information System (INIS)

    Lefebvre, B.; Berard, E.; Arpino, J.-M.

    2005-01-01

    This article describes the specificities of the operating principles chosen by EDF for the EPR project as a result of an extensive Human Factor Engineering program successfully implemented in an industrial project context. The design process and its achievements benefit of the EDF experience feedback not only in term of NPP operation - including the fully computerized control room of the N4-serie - but also in term of NPP designer. The elements exposed hereafter correspond to the basic design phase of EPR HMI which has been completed and successfully validated by the end of 2003. The article aims to remind the context of the project which basically consists in designing a modern and efficient HMI taking into account the operating needs while relying on proven and reliable technologies. The Human Factor Engineering program implemented merges these both aspects by : 1) being fully integrated within the project activities and scheduling; 2) efficiently taking into account the users needs as well as the feasibility constraints by relying on a multidisciplinary design team including HF specialists, I and C specialists, Process specialists and experienced operator representatives. The resulting design process makes a wide use of experience feedback and experienced operator knowledge to complete largely the existing standards for providing a fully useable and successful design method in an industrial context. The article underlines the design process highlights that largely contribute to the successful implementation of a Human Factor Engineering program for EPR. (authors)

  6. Analysis of unregulated emissions from an off-road diesel engine during realistic work operations

    Science.gov (United States)

    Lindgren, Magnus; Arrhenius, Karine; Larsson, Gunnar; Bäfver, Linda; Arvidsson, Hans; Wetterberg, Christian; Hansson, Per-Anders; Rosell, Lars

    2011-09-01

    Emissions from vehicle diesel engines constitute a considerable share of anthropogenic emissions of pollutants, including many non-regulated compounds such as aromatic hydrocarbons and alkenes. One way to reduce these emissions might be to use fuels with low concentrations of aromatic hydrocarbons, such as Fischer-Tropsch (F-T) diesels. Therefore this study compared Swedish Environmental Class 1 diesel (EC1) with the F-T diesel fuel Ecopar™ in terms of emissions under varied conditions (steady state, controlled transients and realistic work operations) in order to identify factors influencing emissions in actual operation. Using F-T diesel reduced emissions of aromatic hydrocarbons, but not alkenes. Emissions were equally dependent on work operation character (load, engine speed, occurrence of transients) for both fuels. There were indications that the emissions originated from unburnt fuel, rather than from combustion products.

  7. ANALYSIS OF OPERATING PARAMETERS AND INDICATORS OF A COMPRESSION IGNITION ENGINE FUELLED WITH LPG

    Directory of Open Access Journals (Sweden)

    Krzysztof GARBALA

    2016-12-01

    Full Text Available This article presents the possibilities for using alternative fuels to power vehicles equipped with compression ignition (CI engines (diesel. Systems for using such fuels have been discussed. Detailed analysis and research covered the LPG STAG autogas system, which is used to power dual-fuel engine units (LPG+diesel. A description of the operation of the autogas system and installation in a vehicle has been presented. The basic algorithms of the controller, which is an actuating element of the whole system, have been discussed. Protection systems of a serial production engine unit to guarantee its factorycontrolled durability standards have been presented. A long-distance test drive and examinations of the engine over 150,000 km in a Toyota Hilux have been performed. Operating parameters and performance indicators of the engine with STAG LPG+diesel fuelling have been verified. Directions and perspectives for the further development of such a system in diesel-powered cars have been also indicated.

  8. Impact of alternative fuels on the operational and environmental performance of a small turbofan engine

    International Nuclear Information System (INIS)

    Gaspar, R.M.P.; Sousa, J.M.M.

    2016-01-01

    Highlights: • A wide range of alternative fuels is studied in a small two-spool turbofan engine. • Impact of fuel properties on flame temperature and droplet evaporation considered. • Performance and pollutant emissions at different operating conditions are analyzed. • Use of alternative fuels generally leads to an improved performance of the engine. • Mostly reductions in soot emissions, but also cuts in NO_x and CO, are obtained. - Abstract: A wide range of alternative jet fuels is studied in this work for use in a small two-spool turbofan engine. These embrace the five production pathways currently approved by the American Society for Testing and Materials. Both neat products and blends (within certified limits) have been considered. The present analysis is based on a 0-D thermodynamic modeling of the aero-engine for off-design and transient simulations. In addition, the selected approach incorporates fuel effects on combustion and the impact of fuel properties on the flame temperature, as well as on the droplet evaporation rate. Predicted performance and pollutant emission outputs for the alternative fuels are presented at different operating conditions, namely: take-off, top of climb, cruise, low power and ground idle. The results are discussed and comprehensively compared with data available in the literature. It was concluded that the combustion of alternative fuels generally leads to enhancements in engine performance with respect to the use of conventional kerosene. Reductions in pollutant emissions occur mostly in soot, but also in nitrogen oxides and carbon monoxide, depending on the fuel and operating conditions. In contrast, increased emissions of unburned hydrocarbons are generally observed. Concerns about the aero-engine dynamic response are raised only in very few cases, involving the use of neat products.

  9. Using Web 2.0 Techniques in NASA's Ares Engineering Operations Network (AEON) Environment - First Impressions

    Science.gov (United States)

    Scott, David W.

    2010-01-01

    The Mission Operations Laboratory (MOL) at Marshall Space Flight Center (MSFC) is responsible for Engineering Support capability for NASA s Ares rocket development and operations. In pursuit of this, MOL is building the Ares Engineering and Operations Network (AEON), a web-based portal to support and simplify two critical activities: Access and analyze Ares manufacturing, test, and flight performance data, with access to Shuttle data for comparison Establish and maintain collaborative communities within the Ares teams/subteams and with other projects, e.g., Space Shuttle, International Space Station (ISS). AEON seeks to provide a seamless interface to a) locally developed engineering applications and b) a Commercial-Off-The-Shelf (COTS) collaborative environment that includes Web 2.0 capabilities, e.g., blogging, wikis, and social networking. This paper discusses how Web 2.0 might be applied to the typically conservative engineering support arena, based on feedback from Integration, Verification, and Validation (IV&V) testing and on searching for their use in similar environments.

  10. Investigation on combustion parameters of palm biodiesel operating with a diesel engine

    Directory of Open Access Journals (Sweden)

    M.H.M. Yasin

    2015-12-01

    Full Text Available Biodiesel is a renewable and decomposable fuel which is derived from edible and non-edible oils. It has different properties compared to conventional diesel but can be used directly in diesel engines. Different fuel properties characterise different combustion-phasing parameters such as cyclic variations of Indicated Mean Effective Pressure (IMEP and maximum pressure (Pmax. In this study, cyclic variations of combustion parameters such as IMEP and Pmax were investigated using a multi-cylinder diesel engine operating with conventional diesel and palm biodiesel. The experiments were conducted using different engine loads; 20, 40, and 60% at a constant engine speed of 2500 rpm. The coefficient of variation (COV and standard deviation of parameters were used to evaluate the cyclic variations of the combustion phasing parameters for the test fuels at specific engine test conditions. It was observed that palm biodiesel has lower COV IMEP compared to conventional diesel but is higher in COV Pmax at higher engine loads respectively. In addition, palm biodiesel tends to have a higher recurrence for the frequency distribution for maximum pressure. It can be concluded from the study that the fuel properties of palm biodiesel have influenced most of the combustion parameters.

  11. The Influence of Fuel Sulfur on the Operation of Large Two-Stroke Marine Diesel Engines

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Faurskov

    The present work focusses on SO3/H2SO4 formation and sulfuric acid (H2SO4) condensation in a large low speed 2-stroke marine diesel engine. SO3 formation is treated theoretically from a formulated multizone engine model described in this work that includes a detailed and validated sulfur reaction...... mechanism. Model results show that for a large marine engine generally about 3 % - 6 % of the fuel sulfur converts to SO3 while the remainder leaves the engine as SO2 from which the SO3 is formed during the expansion stroke. SO3 formation scales with the cylinder pressure and inversely with the engine speed...... as also demonstrated by a number of SO3 experiments described in this work. The experiments are carried out with a heavy duty medium speed 4 stroke diesel engine operating on heavy fuel oil including ≈ 2 wt. % sulfur. SO3 was measured successfully in the exhaust gas with the PENTOL SO3 analyzer...

  12. SEU blending project, concept to commercial operation, Part 4: engineering design

    International Nuclear Information System (INIS)

    Ingalls, D.G.; Ioffe, M.S.; Oliver, A.J.; Smith, T.P.; Ozberk, E.

    2005-01-01

    The process development test program for production of Slightly Enriched Uranium (SEU) dioxide powder and Blend of Dysprosium and Uranium (BDU) oxide powder was initiated almost simultaneously with the conceptual engineering study for the commercial plant in 2001. During the very early phases of the project it was recognized that meeting the challenging requirements would necessitate wide expertise from different departments within the Cameco operations as well as consultants from outside the Company. The project team formed reflected this recognition. The conceptual engineering study was the lead into preparation of the engineering design study in 2003, which provided the process description based on the research and development program being carried out at Cameco Technology Development (CTD), project description, and project cost estimates. The detailed engineering phase commenced in June 2004 and was in progress at the the time when this paper was presented. The detailed engineering phase is addressing all aspects of the commercial plant including all health and safety, environment and security related issues, nuclear safety, training program, all product quality assurance issues, quality management issues, powder and fuel bundle transportation issues, all regulatory requirements, establishing project execution plans and budget, and strategies to control the costs. At the end of the detailed engineering phase, construction packages will be ready for tender, and major pieces of equipment will be selected and procured. (author)

  13. Optimizing the Performance of a 50cc Compression Ignition Two-Stroke Engine Operating on Dimethyl Ether

    DEFF Research Database (Denmark)

    Hansen, Kim Rene; Dolriis, J.D.; Hansson, C.

    2011-01-01

    The paper describes the optimization of a 50cc crankcase scavenged two-stroke diesel engine operating on dimethyl ether (DME). The optimization is primarily done with respect to engine efficiency. The underlying idea behind the work is that the low weight, low internal friction and low engine...

  14. 14 CFR 63.23 - Special purpose flight engineer and flight navigator certificates: Operation of U.S.-registered...

    Science.gov (United States)

    2010-01-01

    ... purpose flight engineer and flight navigator certificates: Operation of U.S.-registered civil airplanes... flight engineer or flight navigator duties on a civil airplane of U.S. registry, leased to a person not a... certificate holder is performing flight engineer or flight navigator duties on the U.S.-registered civil...

  15. Surgical PACS for the digital operating room. Systems engineering and specification of user requirements.

    Science.gov (United States)

    Korb, Werner; Bohn, Stefan; Burgert, Oliver; Dietz, Andreas; Jacobs, Stephan; Falk, Volkmar; Meixensberger, Jürgen; Strauss, Gero; Trantakis, Christos; Lemke, Heinz U

    2006-01-01

    For better integration of surgical assist systems into the operating room, a common communication and processing plattform that is based on the users needs is needed. The development of such a system, a Surgical Picture Aquisition and Communication System (S-PACS), according the systems engineering cycle is oulined in this paper. The first two steps (concept and specification) for the engineering of the S-PACS are discussed.A method for the systematic integration of the users needs', the Quality Function Deployment (QFD), is presented. The properties of QFD for the underlying problem and first results are discussed. Finally, this leads to a first definition of an S-PACS system.

  16. Lessons Learned from Engineering a Multi-Mission Satellite Operations Center

    Science.gov (United States)

    Madden, Maureen; Cary, Everett, Jr.; Esposito, Timothy; Parker, Jeffrey; Bradley, David

    2006-01-01

    NASA's Small Explorers (SMEX) satellites have surpassed their designed science-lifetimes and their flight operations teams are now facing the challenge of continuing operations with reduced funding. At present, these missions are being re-engineered into a fleet-oriented ground system at Goddard Space Flight Center (GSFC). When completed, this ground system will provide command and control of four SMEX missions and will demonstrate fleet automation and control concepts. As a path-finder for future mission consolidation efforts, this ground system will also demonstrate new ground-based technologies that show promise of supporting longer mission lifecycles and simplifying component integration. One of the core technologies being demonstrated in the SMEX Mission Operations Center is the GSFC Mission Services Evolution Center (GMSEC) architecture. The GMSEC architecture uses commercial Message Oriented Middleware with a common messaging standard to realize a higher level of component interoperability, allowing for interchangeable components in ground systems. Moreover, automation technologies utilizing the GMSEC architecture are being evaluated and implemented to provide extended lights-out operations. This mode of operation will provide routine monitoring and control of the heterogeneous spacecraft fleet. The operational concepts being developed will reduce the need for staffed contacts and is seen as a necessity for fleet management. This paper will describe the experiences of the integration team throughout the re-enginering effort of the SMEX ground system. Additionally, lessons learned will be presented based on the team's experiences with integrating multiple missions into a fleet-automated ground system.

  17. Integration of emergency action levels with Combustion Engineering Emergency Operating Procedures

    International Nuclear Information System (INIS)

    Faletti, D.W.; Jamison, J.D.

    1985-09-01

    This report documents the development of a method for integrating Emergency Action Levels (EALs) with plant-specific Emergency Operating Procedures (EOPs) using the Combustion Engineering Owners' Group Emergency Operating Procedure Technical Guidelines (CEOG EOPTFs). EALs are discrete conditions or values of plant operating parameters which, if exceeded, require declaration of an appropriate level of emergency. At most operating plants, the EALs and event classification procedures are totally separate from the Emergency Operating Procedures used by the plant staff to control the plant during abnormal conditions. Control room personnel using the EOPs to deal with abnormal plant conditions must recognize when plant safety is sufficiently degraded that an emergency declaration may be warranted, and then enter a separate classification procedure containing EALs for a number of plant conditions and parameters. The operator then compares the existing plant conditions to the EALs and makes an emergency declaration accordingly. Using the Combustion Engineering Owners' Group Technical Guidelines document, a set of emergency class definitions and criteria were developed based on the status of the three main fission product barriers (fuel cladding, primary coolant system and containment). The EOPTGs were then annotated with suggested guidance to a procedure writer. The proposed method was tested by applying it to the reactor accident sequences that were shown in the reactor safety study to dominate accident risk. The object of the test was to determine if an EAL set linked to the EOP annotations would produce timely and accurate classification of the risk-dominant sequences. 6 refs., 13 figs., 31 tabs

  18. Comparative research on response stereotypes for daily operation tasks of Chinese and American engineering students.

    Science.gov (United States)

    Yu, Rui-Feng; Chan, Alan H S

    2004-02-01

    A group of Mainland Chinese engineering students were asked to respond to 12 questions by indicating their design conventions and expectations about operations, directions-of-motion, and descriptions of movement for items such as doors, keys, taps, and knobs. Chi-square tests demonstrated strong response stereotypes for tasks of all 12 questions. A comparison of the stereotype strengths found here with that of Hong Kong Chinese and American engineering students reported earlier indicated that stereotype strengths of engineering students from the three regions were generally different. For some cases stereotype characteristics of two regions were more alike than the other, and also for some subjects in the three regions performed similarly. The Mainland and Hong Kong Chinese were more alike in making their choices on questions of conceptual compatibility, while more consistent preferences on movement compatibility and spatial compatibility were noted between the Mainland Chinese and American students than Hong Kong Chinese.

  19. Studies on exhaust emissions of mahua oil operated compression ignition engine.

    Science.gov (United States)

    Kapilan, N; Reddy, R P

    2009-07-01

    The world is confronted with fossil fuel depletion and environmental degradation. The energy demand and pollution problems lead to research for an alternative renewable energy sources. Vegetable oils and biodiesel present a very promising alternative fuel to diesel. In this work, an experimental work was carried out to study the feasibility of using raw mahua oil (MO) as a substitute for diesel in dual fuel engine. A single cylinder diesel engine was modified to work in dual fuel mode and liquefied petroleum gas (LPG) was used as primary fuel and mahua oil was used as pilot fuel. The results show that the performance of the dual fuel engine at the injector opening pressure of 220 bar and the advanced injection timing of 30 degrees bTDC results in performance close to diesel base line (DBL) operation and lower smoke and oxides of nitrogen emission.

  20. A comprehensive study on the emission characteristics of E-diesel dual-fuel engine

    Directory of Open Access Journals (Sweden)

    A. Avinash

    2016-03-01

    Full Text Available Each year, the ultimate goal of emission legislation is to force technology to the point where a practically viable zero emission vehicle becomes a reality. Albeit the direction to reach this target is a formidable challenge, homogeneous charge compression ignition (HCCI is a new combustion concept to produce ultra low nitrogen oxides (NOx and smoke emissions. By the way, an endeavor has been made in this work to achieve a simultaneous reduction in both NOx and smoke levels in a direct injection compression ignition engine converted to operate on premixed charge compression ignition mode. Indeed, these promises were made possible in this work by preparing premixed fuel–air mixture outside the engine cylinder. For this purpose, ethanol was injected in the intake port at various premixed ratios (5%, 10%, 15%, 20%, 25% and 30% and conventional diesel was injected as usual. It was extrapolated from the experimental results that e-diesel operation can significantly reduce NOx and smoke levels. In addition, NOx and smoke levels reduced in this experimental study with increase in premixed fraction. Nevertheless, unburned hydrocarbons (UBHC and carbon monoxide (CO emissions exhibited reverse trend with increase in premixed fraction and the maximum value of HC and CO emission levels was noted with 30% premixed fraction.

  1. Experimental investigation on dual fuel operation of acetylene in a DI diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmanan, T. [Department of Mechanical Engineering, Rajarajeswari Engineering College, Adayalampattu, Chennai, 600095 (India); Nagarajan, G. [Internal Combustion Engineering Division, College of Engineering, Anna University, Chennai, 600025 (India)

    2010-05-15

    Depletion of fossils fuels and environmental degradation have prompted researchers throughout the world to search for a suitable alternative fuel for diesel engine. One such step is to utilize renewable fuels in diesel engines by partial or total replacement of diesel in dual fuel mode. In this study, acetylene gas has been considered as an alternative fuel for compression ignition engine, which has excellent combustion properties. Investigation has been carried out on a single cylinder, air cooled, direct injection (DI), compression ignition engine designed to develop the rated power output of 4.4 kW at 1500 rpm under variable load conditions, run on dual fuel mode with diesel as injected primary fuel and acetylene inducted as secondary gaseous fuel at various flow rates. Acetylene aspiration resulted in lower thermal efficiency. Smoke, HC and CO emissions reduced, when compared with baseline diesel operation. With acetylene induction, due to high combustion rates, NO{sub x} emission significantly increased. Peak pressure and maximum rate of pressure rise also increased in the dual fuel mode of operation due to higher flame speed. It is concluded that induction of acetylene can significantly reduce smoke, CO and HC emissions with a small penalty on efficiency. (author)

  2. IMPROVEMENT OF PERFORMANCE OF DUAL FUEL ENGINE OPERATED AT PART LOAD

    Directory of Open Access Journals (Sweden)

    N. Kapilan

    2010-12-01

    Full Text Available Rising petroleum prices, an increasing threat to the environment from exhaust emissions, global warming and the threat of supply instabilities has led to the choice of inedible Mahua oil (MO as one of the main alternative fuels to diesel oil in India. In the present work, MO was converted into biodiesel by transesterification using methanol and sodium hydroxide. The cost of Mahua oil biodiesel (MOB is higher than diesel. Hence liquefied petroleum gas (LPG, which is one of the cheapest gaseous fuels available in India, was fumigated along with the air to reduce the operating cost and to reduce emissions. The dual fuel engine resulted in lower efficiency and higher emissions at part load. Hence in the present work, the injection time was varied and the performance of the dual fuel engine was studied. From the engine tests, it is observed that an advanced injection time results in higher efficiency and lower emissions. Hence, advancing the injection timing is one of the ways of increasing the efficiency of LPG+MOB dual fuel engine operated at part load.

  3. Tailpipe emissions and engine performance of a light-duty diesel engine operating on petro- and bio-diesel fuel blends.

    Science.gov (United States)

    2014-06-01

    This report summarizes the experimental apparatus developed in the Transportation Air Quality Laboratory (TAQ Lab) at the University of Vermont to compare light-duty diesel engine performance and exhaust emissions when operating on petroleum diesel (...

  4. Operation of a T63 Turbine Engine Using F24 Contaminated Skydrol 5 Hydraulic Fluid

    Science.gov (United States)

    2016-09-01

    hydraulic fluids were originally developed by the Douglas Aircraft Company during the 1940s to reduce fire risk from leaking high pressure mineral oil...thermal load demands in modern hydraulic systems and reduced density to lower weight impact on the aircraft. Eastman Chemical is the current producer of...AFRL-RQ-WP-TM-2016-0155 OPERATION OF A T63 TURBINE ENGINE USING F24 CONTAMINATED SKYDROL 5 HYDRAULIC FLUID Matthew J. Wagner (AFRL/RQTM) James

  5. Ethical Issues in Engineering Models: An Operations Researcher?s Reflections

    OpenAIRE

    Kleijnen, J.

    2010-01-01

    This article starts with an overview of the author?s personal involvement?as an Operations Research consultant?in several engineering case-studies that may raise ethical questions; e.g., case-studies on nuclear waste, water management, sustainable ecology, military tactics, and animal welfare. All these case studies employ computer simulation models. In general, models are meant to solve practical problems, which may have ethical implications for the various stakeholders; namely, the modelers...

  6. Prototype of a Graphical CONOPS (Concept of Operations) Development Environment for Agile Systems Engineering

    Science.gov (United States)

    2013-08-30

    issued new acquisition guidance that places increased emphasis on system engineering early in the lifecycle to balance operational performance with...Linux, MS-Windows, Mac OS X, BSD, Sun Solaris, Nintendo Wii , Sony PlayStation 3, and Apple iPhone. It will also run on x86, x86-64, IA64, PowerPC...web-based tool inspired by the Kanban paradigm for managing projects. Each project was represented by its on board , with each board containing a

  7. Engineering evaluation/conceptual plan for the 200-UP-1 groundwater operable unit interim remedial measure

    International Nuclear Information System (INIS)

    Myers, D.A.; Swanson, L.C.; Weeks, R.S.; Giacinto, J.; Gustafson, F.W.; Ford, B.H.; Wittreich, C.; Parnell, S.; Green, J.

    1995-04-01

    This report presents an engineering evaluation and conceptual plan for an interim remedial measure (ERM) to address a uranium and technetium-99 groundwater plume and an associated nitrate contamination plume in the 200-UP-1 Groundwater Operable Unit located in the 200 West Area of the Hanford Site. This report provides information regarding the need and potentially achievable objectives and goals for an IRM and evaluates alternatives to contain elevated concentrations of uranium, technetium-99, nitrate, and carbon tetrachloride and to obtain information necessary to develop final remedial actions for the operable unit

  8. System Coordination of Survivability and Safety of Complex Engineering Objects Operation

    Directory of Open Access Journals (Sweden)

    Nataliya Pankratova

    2014-11-01

    Full Text Available A system strategy to estimation the guaranteed survivability and safety of complex engineering objects (CEO operation is proposed. The principles that underlie the strategy of the guaranteed safety of CEO operation provide a flexible approach to timely detection, recognition, forecast, and system diagnostics of risk factors and situations, to formulation and implementation of a rational decision in a practicable time within an unremovable time constraint. Implementation of the proposed strategy is shown on example of diagnostics of electromobile-refrigerator functioning in real mode.

  9. Simulators and their use in the training of CEGB reactor operations engineers

    International Nuclear Information System (INIS)

    Madden, V.J.; Tompsett, P.A.

    1988-01-01

    The development of simulators in the Central Electricity Generating Board's nuclear power training are traced, and, in describing the overall training programme of an advanced gas-cooled reactor operations engineer, the contribution made by a range of simulation devices from concept through to full-scope replica simulators is indicated. The capabilities of today's simulators are such that they are also making other contributions to the commissioning and safe operation of nuclear power plants. They are being successfully used for ergonomic and procedure validation work and the testing and commissioning of software for automatic control systems, and data and alarm processing systems. (author)

  10. Low-cost engineering techniques in sustainable operation of a rural clean water plant in thailand

    International Nuclear Information System (INIS)

    Pengchai, P.; Keawkhun, K.; Suwapaet, N.

    2012-01-01

    Problems of water supply in many rural regions of Thailand result from the lack of awareness and financial limitations. Payanghang Clean Water Plant is an example of the rural water plant that has been suffering from the poor operation since 2003. The objective of this study was to modify the operation processes of this water plant to achieve cleaner water and better financial condition. Low-cost engineering techniques, such as the use of floating switches in filtration ponds, the use of water drip system for alum dosing and the addition of Tamarindus indica Linn seed solution was applied. As a result, 76% of turbidity removal efficiency was derived. Although, the difference was not statistically significant at 95% confidence level, higher removal efficiency in comparison with the one before modification (65%) suggested better operation. In the view of financial aspect, l07 dollars (1 baht = 0.0326 U.S. dollar) benefit was obtained from 7 month-operation period. (author)

  11. Extending the Operational Envelope of a Turbofan Engine Simulation into the Sub-Idle Region

    Science.gov (United States)

    Chapman, Jeffryes Walter; Hamley, Andrew J.; Guo, Ten-Huei; Litt, Jonathan S.

    2016-01-01

    In many non-linear gas turbine simulations, operation in the sub-idle region can lead to model instability. This paper lays out a method for extending the operational envelope of a map based gas turbine simulation to include the sub-idle region. This method develops a multi-simulation solution where the baseline component maps are extrapolated below the idle level and an alternate model is developed to serve as a safety net when the baseline model becomes unstable or unreliable. Sub-idle model development takes place in two distinct operational areas, windmilling/shutdown and purge/cranking/startup. These models are based on derived steady state operating points with transient values extrapolated between initial (known) and final (assumed) states. Model transitioning logic is developed to predict baseline model sub-idle instability, and transition smoothly and stably to the backup sub-idle model. Results from the simulation show a realistic approximation of sub-idle behavior as compared to generic sub-idle engine performance that allows the engine to operate continuously and stably from shutdown to full power.

  12. Initial closed operation of the CELSS Test Facility Engineering Development Unit

    Science.gov (United States)

    Kliss, M.; Blackwell, C.; Zografos, A.; Drews, M.; MacElroy, R.; McKenna, R.; Heyenga, A. G.

    2003-01-01

    As part of the NASA Advanced Life Support Flight Program, a Controlled Ecological Life Support System (CELSS) Test Facility Engineering Development Unit has been constructed and is undergoing initial operational testing at NASA Ames Research Center. The Engineering Development Unit (EDU) is a tightly closed, stringently controlled, ground-based testbed which provides a broad range of environmental conditions under which a variety of CELSS higher plant crops can be grown. Although the EDU was developed primarily to provide near-term engineering data and a realistic determination of the subsystem and system requirements necessary for the fabrication of a comparable flight unit, the EDU has also provided a means to evaluate plant crop productivity and physiology under controlled conditions. This paper describes the initial closed operational testing of the EDU, with emphasis on the hardware performance capabilities. Measured performance data during a 28-day closed operation period are compared with the specified functional requirements, and an example of inferring crop growth parameters from the test data is presented. Plans for future science and technology testing are also discussed. Published by Elsevier Science Ltd on behalf of COSPAR.

  13. Application of integrated logistic techniques to operation, maintenance and re engineering processes in Nuclear Power plants

    International Nuclear Information System (INIS)

    Santiago Diez, P.

    1997-01-01

    This paper addresses the advisability of adapting and applying management and Integrated Logistic engineering techniques to nuclear power plants instead of using more traditional maintenance management methods. It establishes a historical framework showing the origins of integrated approaches based on traditional logistic support concepts, their phases and the real results obtained in the aeronautic world where they originated. It reviews the application of integrated management philosophy, and logistic support and engineering analysis techniques regarding Availability, Reliability and Maintainability (ARM) and shows their inter dependencies in different phases of the system's life (Design, Development and Operation). It describes how these techniques are applied to nuclear power plant operation, their impact on plant availability and the optimisation of maintenance and replacement plans. The paper analyses the need for data (type and volume), which will have to be collected, and the different tools to manage such data. It examines the different CALS tools developed by EA for engineering and for logistic management. It also explains the possibility of using these tools for process and data operations through the INTERNET. It also focuses on the qualities of some simple examples of possible applications, and how they would be used in the framework of Integrated Logistic Support (ILS). (Author)

  14. 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.

  15. 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.

  16. Investigation of split injection in a single cylinder optical diesel engine

    OpenAIRE

    Díez Rodríguez, Álvaro

    2009-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Over the last decade, the diesel engine has made dramatic progress in its performance and market penetration. However, in order to meet future emissions legislations, Nitrogen Oxide (NOx) and particulate matter (PM) emissions will need to be reduced simultaneously. Nowadays researchers are focused on different combustion modes like homogeneous charge compression ignition (HCCI) combustion and...

  17. 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.

  18. Design study of pyrochemical process operation by using virtual engineering models

    International Nuclear Information System (INIS)

    Kakehi, I.; Tozawa, K.; Matsumoto, T.; Tanaka, K.

    2000-04-01

    This report describes accomplishment of simulations of Pyrochemical Process Operation by using virtual engineering models. The pyrochemical process using molten salt electrorefining would introduce new technologies for new fuels of particle oxide, particle nitride and metallic fuels. This system is a batch treatment system of reprocessing and re-fabrication, which transports products of solid form from a process to next process. As a results, this system needs automated transport system for process operations by robotics. In this study, a simulation code system has been prepared, which provides virtual engineering environment to evaluate the pyrochemical process operation of a batch treatment system using handling robots. And the simulation study has been conducted to evaluate the required system functions, which are the function of handling robots, the interactions between robot and process equipment, and the time schedule of process, in the automated transport system by robotics. As a result of simulation of the process operation, which we have designed, the automated transport system by robotics of the pyrochemical process is realistic. And the issues for the system development have been pointed out. (author)

  19. Dual fuel mode operation in diesel engines using renewable fuels: Rubber seed oil and coir-pith producer gas

    Energy Technology Data Exchange (ETDEWEB)

    Ramadhas, A.S.; Jayaraj, S.; Muraleedharan, C. [Department of Mechanical Engineering, National Institute of Technology Calicut, Calicut-673601 (India)

    2008-09-15

    Partial combustion of biomass in the gasifier generates producer gas that can be used as supplementary or sole fuel for internal combustion engines. Dual fuel mode operation using coir-pith derived producer gas and rubber seed oil as pilot fuel was analyzed for various producer gas-air flow ratios and at different load conditions. The engine is experimentally optimized with respect to maximum pilot fuel savings in the dual fuel mode operation. The performance and emission characteristics of the dual fuel engine are compared with that of diesel engine at different load conditions. Specific energy consumption in the dual-fuel mode of operation with oil-coir-pith operation is found to be in the higher side at all load conditions. Exhaust emission was found to be higher in the case of dual fuel mode of operation as compared to neat diesel/oil operation. Engine performance characteristics are inferior in fully renewable fueled engine operation but it suitable for stationary engine application, particularly power generation. (author)

  20. Modelling the Turbocharger Cut Off Application Due to Slow Steaming Operation 12RTA96C-B Engine

    Directory of Open Access Journals (Sweden)

    Karsten Wehner

    2017-09-01

    Full Text Available Out of the total operational costs of a ship, fuel costs account for by far the highest proportion. In view of the global economic situation and the rising oil prices, shipowners and charterers are looking for solutions to cut costs by reducing fuel consumption. Low load operation, also well-known as “slow steaming”, represents the currently most effective and popular measure to cut fuel costs and, in consequence, the total operational costs for increased competitiveness in the market. Low load operation is possible and there is an increasing trend to operate in these very low engine load ranges. As the engines were not designed for this operational condition, various retrofit modifications to the engine can compensate for this. By using low load operation, the reduction of the RPM gives problems when sailing at low speed.  A turbocharger (TC compresses inlet air to a high pressure and after cooling this compressed air it results in higher mass of air in the cylinder. But when running at a low power load this air reaches temperatures that are too low for an optimal combustion process. One of the solution comes from the company Wärtsilä. They install so called “low steam engine kits”. When this kit is installed it allows the engine operators to cut off one turbocharger of the engine, this result’s in a higher RPM for the operating turbochargers. When the remaining TC’s have a higher RPM their efficiency improves and gives the engine more air for combustion.The goal of this Bachelor thesis is to make a calculation modelling and prove that by switching off one or more turbocharger on the system will improve the efficiency in slow steaming operation. Beside that, this thesis is aims to estimated the performance of the engine in both operation condition.

  1. System and method of cylinder deactivation for optimal engine torque-speed map operation

    Science.gov (United States)

    Sujan, Vivek A; Frazier, Timothy R; Follen, Kenneth; Moon, Suk-Min

    2014-11-11

    This disclosure provides a system and method for determining cylinder deactivation in a vehicle engine to optimize fuel consumption while providing the desired or demanded power. In one aspect, data indicative of terrain variation is utilized in determining a vehicle target operating state. An optimal active cylinder distribution and corresponding fueling is determined from a recommendation from a supervisory agent monitoring the operating state of the vehicle of a subset of the total number of cylinders, and a determination as to which number of cylinders provides the optimal fuel consumption. Once the optimal cylinder number is determined, a transmission gear shift recommendation is provided in view of the determined active cylinder distribution and target operating state.

  2. 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.

  3. Application of Hydrogen Assisted Lean Operation to Natural Gas-Fueled Reciprocating Engines (HALO)

    Energy Technology Data Exchange (ETDEWEB)

    Chad Smutzer

    2006-01-01

    Two key challenges facing Natural Gas Engines used for cogeneration purposes are spark plug life and high NOx emissions. Using Hydrogen Assisted Lean Operation (HALO), these two keys issues are simultaneously addressed. HALO operation, as demonstrated in this project, allows stable engine operation to be achieved at ultra-lean (relative air/fuel ratios of 2) conditions, which virtually eliminates NOx production. NOx values of 10 ppm (0.07 g/bhp-hr NO) for 8% (LHV H2/LHV CH4) supplementation at an exhaust O2 level of 10% were demonstrated, which is a 98% NOx emissions reduction compared to the leanest unsupplemented operating condition. Spark ignition energy reduction (which will increase ignition system life) was carried out at an oxygen level of 9%, leading to a NOx emission level of 28 ppm (0.13 g/bhp-hr NO). The spark ignition energy reduction testing found that spark energy could be reduced 22% (from 151 mJ supplied to the coil) with 13% (LHV H2/LHV CH4) hydrogen supplementation, and even further reduced 27% with 17% hydrogen supplementation, with no reportable effect on NOx emissions for these conditions and with stable engine torque output. Another important result is that the combustion duration was shown to be only a function of hydrogen supplementation, not a function of ignition energy (until the ignitability limit was reached). The next logical step leading from these promising results is to see how much the spark energy reduction translates into increase in spark plug life, which may be accomplished by durability testing.

  4. Effect of Alcohol on Diesel Engine Combustion Operating with Biodiesel-Diesel Blend at Idling Conditions

    Science.gov (United States)

    Mahmudul, H. M.; Hagos, Ftwi. Y.; A, M. Mukhtar N.; Mamat, Rizalman; Abdullah, A. Adam

    2018-03-01

    Biodiesel is a promising alternative fuel to run the automotive engine. However, its blends have not been properly investigated during idling as it is the main problem to run the vehicles in a big city. The purpose of this study is to evaluate the impact of alcohol additives such as butanol and ethanol on combustion parameters under idling conditions when a single cylinder diesel engine operates with diesel, diesel-biodiesel blends, and diesel biodiesel-alcohol blends. The engine combustion parameters such as peak pressure, heat release rate and ignition delay were computed. This investigation has revealed that alcohol blends with diesel and biodiesel, BU20 blend yield higher maximum peak cylinder pressure than diesel. B5 blend was found with the lowest energy release among all. B20 was slightly lower than diesel. BU20 blend was seen with the highest peak energy release where E20 blend was found advance than diesel. Among all, the blends alcohol component revealed shorter ignition delay. B5 and B20 blends were influenced by biodiesel interference and the burning fraction were found slightly slower than conventional diesel where BU20 and E20 blends was found slightly faster than diesel So, based on the result, it can be said that among the alcohol blends butanol and ethanol can be promising alternative at idling conditions and can be used without any engine modifications.

  5. A Systems Engineering Framework for Design, Construction and Operation of the Next Generation Nuclear Plant

    International Nuclear Information System (INIS)

    Edward J. Gorski; Charles V. Park; Finis H. Southworth

    2004-01-01

    Not since the International Space Station has a project of such wide participation been proposed for the United States. Ten countries, the European Union, universities, Department of Energy (DOE) laboratories, and industry will participate in the research and development, design, construction and/or operation of the fourth generation of nuclear power plants with a demonstration reactor to be built at a DOE site and operational by the middle of the next decade. This reactor will be like no other. The Next Generation Nuclear Plant (NGNP) will be passively safe, economical, highly efficient, modular, proliferation resistant, and sustainable. In addition to electrical generation, the NGNP will demonstrate efficient and cost effective generation of hydrogen to support the President's Hydrogen Initiative. To effectively manage this multi-organizational and technologically complex project, systems engineering techniques and processes will be used extensively to ensure delivery of the final product. The technological and organizational challenges are complex. Research and development activities are required, material standards require development, hydrogen production, storage and infrastructure requirements are not well developed, and the Nuclear Regulatory Commission may further define risk-informed/performance-based approach to licensing. Detailed design and development will be challenged by the vast cultural and institutional differences across the participants. Systems engineering processes must bring the technological and organizational complexity together to ensure successful product delivery. This paper will define the framework for application of systems engineering to this $1.5B - $1.9B project

  6. 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.

  7. Numerical analysis of a downsized spark-ignition engine fueled by butanol/gasoline blends at part-load operation

    International Nuclear Information System (INIS)

    Scala, F.; Galloni, E.; Fontana, G.

    2016-01-01

    Highlights: • Bio-fuels will reduce the overall CO_2 emission. • The properties of butanol/gasoline–air mixtures have been determined. • A 1-D model of a SI engine has been calibrated and validated. • The butanol content reduces the combustion duration. • The optimal ignition timing slightly changes. - Abstract: In this paper, the performance of a turbocharged SI engine, firing with butanol/gasoline blends, has been investigated by means of numerical simulations of the engine behavior. When engine fueling is switched from gasoline to alcohol/gasoline mixture, engine control parameters must be adapted. The main necessary modifications in the Electronic Control Unit have been highlighted in the paper. Numerical analyses have been carried out at partial load operation and at two different engine speeds (3000 and 4000 rpm). Several n-butanol/gasoline mixtures, differing for the alcohol contents, have been analyzed. Such engine performances as torque and indicated efficiency have been evaluated. Both these characteristics decrease with the alcohol contents within the mixtures. On the contrary, when the engine is fueled by neat n-butanol, torque and efficiency reach values about 2% higher than those obtained with neat gasoline. Furthermore, the optimal spark timing, for alcohol/gasoline mixture operation, must be retarded (up to 13%) in comparison with the correspondent values of the gasoline operation. In general, engine performance and operation undergo little variations when fuel supplying is switched from gasoline to alcohol/gasoline blends.

  8. Protocol of a randomized controlled trial of the Tobacco Tactics website for operating engineers

    Directory of Open Access Journals (Sweden)

    Duffy Sonia A

    2012-05-01

    Full Text Available Abstract Background Recent research indicates that 35 percent of blue-collar workers in the US currently smoke while only 20 percent of white-collar workers smoke. Over the last year, we have been working with heavy equipment operators, specifically the Local 324 Training Center of the International Union of Operating Engineers, to study the epidemiology of smoking, which is 29% compared to 21% among the general population. For the current study funded by the National Cancer Institute (1R21CA152247-01A1, we have developed the Tobacco Tactics website which will be compared to the state supported 1-800-QUIT-NOW telephone line. Outcome evaluation will compare those randomized to the Tobacco Tactics web-based intervention to those randomized to the 1-800-QUIT-NOW control condition on: a 30-day and 6-month quit rates; b cotinine levels; c cigarettes smoked/day; d number of quit attempts; and e nicotine addiction. Process evaluation will compare the two groups on the: a contacts with intervention; b medications used; c helpfulness of the nurse/coach; and d willingness to recommend the intervention to others. Methods/Design This will be a randomized controlled trial (N = 184. Both interventions will be offered during regularly scheduled safety training at Local 324 Training Center of the International Union of Operating Engineers and both will include optional provision of over-the-counter nicotine replacement therapy and the same number of telephone contacts. However, the Tobacco Tactics website has graphics tailored to Operating Engineers, tailored cessation feedback from the website, and follow up nurse counseling offered by multimedia options including phone and/or email, and/or e-community. Primary Analysis of Aim 1 will be conducted by using logistic regression to compare smoking habits (e.g., quit rates of those in the intervention arm to those in the control arm. Primary analyses for Aim 2 will compare process measures (e.g., medications

  9. Summary of facility and operating experience on helium engineering demonstration loop (HENDEL)

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Yoshihiro; Fujisaki, Katsuo; Kobayashi, Toshiaki; Kato, Michio; Ota, Yukimaru; Watanabe, Syuji; Kobayashi, Hideki; Mogi, Haruyoshi [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1996-07-01

    The HENDEL is a test facility to perform full scale demonstration tests on the core internals and high temperature components for the High Temperature Engineering Test Reactor(HTTR). The main systems consist of Mother(M) and Adapter(A), fuel stack Test(T{sub 1}) and in-core structure Test(T{sub 2}) sections. The (M+A) section can supply high temperature helium gas to the test section. The M+A section completed in March 1982 has been operated for about 22900 hours till February 1995. The T{sub 1} and T{sub 2} sections, completed in March 1983 and June 1986, have been operated for about 19400 and 16700 hours, respectively. In this period, a large number of tests have been conducted to verify the performance and safety features of the HTTR components. The results obtained from these tests have been effectively applied to the detailed design, licensing procedures and construction of the HTTR. The operating experience of the HENDEL for more than 10 years also brought us establishment of the technique of operation of a large scale helium gas loop, handling of helium gas and maintenance of high temperature facilities. The technique will be available for the operation of the HTTR. This paper mainly describes the summary of plant facirities, operating experience and maintenance on the HENDEL. (author)

  10. Operation, test, research and development of the High Temperature Engineering Test Reactor (HTTR). FY2013

    International Nuclear Information System (INIS)

    2014-12-01

    The High Temperature Engineering Test Reactor (HTTR), a graphite-moderated and helium gas-cooled reactor with 30MW of thermal power, constructed at the Oarai Research and Development Center of the Japan Atomic Energy Agency (JAEA) is the first high-temperature gas-cooled reactor (HTGR) in Japan. The HTTR was attained at the full power operation of 30MW in December 2001 and achieved the 950degC of outlet coolant temperature at the outside the reactor pressure vessel in June 2004. To establish and upgrade basic technologies for HTGRs, we have obtained demonstration test data necessary for several R and Ds, and accumulated operation and maintenance experience of HTGRs throughout the HTTR's operation such as rated power operations, safety demonstration tests and long-term high temperature operations, and so on. In fiscal year 2013, we started to prepare the application document of reactor installation license for the HTTR to prove conformity with the new research reactor's safety regulatory requirements taken effect from December 2013. We had been making effort to restart the HTTR which was stopped since the 2011 when the Pacific coast of Tohoku Earthquake (2011.3.11) occurred. This report summarizes activities and results of HTTR operation, maintenance, and several R and Ds, which were carried out in the fiscal year 2013. (author)

  11. Operation, test, research and development of the High Temperature Engineering Test Reactor (HTTR). FY2014

    International Nuclear Information System (INIS)

    2016-02-01

    The High Temperature Engineering Test Reactor (HTTR), a graphite-moderated and helium gas-cooled reactor with 30 MW of thermal power, constructed at the Oarai Research and Development Center of the Japan Atomic Energy Agency is the first high-temperature gas-cooled reactor (HTGR) in Japan. The HTTR was attained at the full power operation of 30 MW in December 2001 and achieved the 950degC of coolant outlet temperature at outside of the reactor pressure vessel in June 2004. To establish and upgrade basic technologies for HTGRs, we have obtained demonstration test data necessary for several R and Ds, and accumulated operation and maintenance experience of HTGRs throughout the HTTR's operation such as rated power operations, safety demonstration tests and long-term high temperature operations, and so on. In fiscal year 2014, we started to apply the application document of reactor installation license for the HTTR to prove conformity with the new research reactor's safety regulatory requirements taken effect from December 2013. We had been making effort to restart the HTTR which was stopped since the 2011 by the Pacific coast of Tohoku Earthquake. This report summarizes activities and results of HTTR operation, maintenance, and several R and Ds, which were carried out in the fiscal year 2014. (author)

  12. Virtual Environment Computer Simulations to Support Human Factors Engineering and Operations Analysis for the RLV Program

    Science.gov (United States)

    Lunsford, Myrtis Leigh

    1998-01-01

    The Army-NASA Virtual Innovations Laboratory (ANVIL) was recently created to provide virtual reality tools for performing Human Engineering and operations analysis for both NASA and the Army. The author's summer research project consisted of developing and refining these tools for NASA's Reusable Launch Vehicle (RLV) program. Several general simulations were developed for use by the ANVIL for the evaluation of the X34 Engine Changeout procedure. These simulations were developed with the software tool dVISE 4.0.0 produced by Division Inc. All software was run on an SGI Indigo2 High Impact. This paper describes the simulations, various problems encountered with the simulations, other summer activities, and possible work for the future. We first begin with a brief description of virtual reality systems.

  13. Operational modal analysis of civil engineering structures an introduction and guide for applications

    CERN Document Server

    Rainieri, Carlo

    2014-01-01

    This book covers all aspects of operational modal analysis for civil engineering, from theoretical background to applications, including measurement hardware, software development, and data processing. In particular, this book provides an extensive description and discussion of OMA methods, their classification and relationship, and advantages and drawbacks. The authors cover both the well-established theoretical background of OMA methods and the most recent developments in the field, providing detailed examples to help the reader better understand the concepts and potentialities of the technique. Additional material is provided (data, software) to help practitioners and students become familiar with OMA. Covering a range of different aspects of OMA, always with the application in mind, the practical perspective adopted in this book makes it ideal for a wide range of readers from researchers to field engineers; graduate and undergraduate students; and technicians interested in structural dynamics, system iden...

  14. Linear algebra and linear operators in engineering with applications in Mathematica

    CERN Document Server

    Davis, H Ted

    2000-01-01

    Designed for advanced engineering, physical science, and applied mathematics students, this innovative textbook is an introduction to both the theory and practical application of linear algebra and functional analysis. The book is self-contained, beginning with elementary principles, basic concepts, and definitions. The important theorems of the subject are covered and effective application tools are developed, working up to a thorough treatment of eigenanalysis and the spectral resolution theorem. Building on a fundamental understanding of finite vector spaces, infinite dimensional Hilbert spaces are introduced from analogy. Wherever possible, theorems and definitions from matrix theory are called upon to drive the analogy home. The result is a clear and intuitive segue to functional analysis, culminating in a practical introduction to the functional theory of integral and differential operators. Numerous examples, problems, and illustrations highlight applications from all over engineering and the physical ...

  15. Engineering analysis activities in support of susquehanna unit 1 startup testing and cycle 1 operations

    International Nuclear Information System (INIS)

    Miller, G.D.; Kukielka, C.A.; Olson, L.M.; Refling, J.G.; Roscioli, A.J.; Somma, S.A.

    1985-01-01

    The engineering analysis group is responsible for all nuclear plant systems analysis and reactor analysis activities, excluding fuel management analysis, at Pennsylvania Power and Light Company. These activities include making pretest and posttest predictions of startup tests; analyzing unplanned or unexpected transient events; providing technical training to plant personnel; assisting in the development of emergency drill scenarios; providing engineering evaluations to support design and technical specification changes, and evaluating, assessing, and resolving a number of license conditions. Many of these activities have required the direct use of RETRAN models. Two RETRAN analyses that were completed to support plant operations - a pretest analysis of the turbine trip startup test, and a posttest analysis of the loss of startup transformer event - are investigated. For each case, RETRAN results are compared with available plant data and comparisons are drawn on the acceptability of the performance of the plant systems

  16. Cycle to Cycle Variation Study in a Dual Fuel Operated Engine

    KAUST Repository

    Pasunurthi, Shyamsundar

    2017-03-28

    The standard capability of engine experimental studies is that ensemble averaged quantities like in-cylinder pressure from multiple cycles and emissions are reported and the cycle to cycle variation (CCV) of indicated mean effective pressure (IMEP) is captured from many consecutive combustion cycles for each test condition. However, obtaining 3D spatial distribution of all the relevant quantities such as fuel-air mixing, temperature, turbulence levels and emissions from such experiments is a challenging task. Computational Fluid Dynamics (CFD) simulations of engine flow and combustion can be used effectively to visualize such 3D spatial distributions. A dual fuel engine is considered in the current study, with manifold injected natural gas (NG) and direct injected diesel pilot for ignition. Multiple engine cycles in 3D are simulated in series like in the experiments to investigate the potential of high fidelity RANS simulations coupled with detailed chemistry, to accurately predict the CCV. Cycle to cycle variation (CCV) is expected to be due to variabilities in operating and boundary conditions, in-cylinder stratification of diesel and natural gas fuels, variation in in-cylinder turbulence levels and velocity flow-fields. In a previous publication by the authors [1], variabilities in operating and boundary conditions are incorporated into several closed cycle simulations performed in parallel. Stochastic variations/stratifications of fuel-air mixture, turbulence levels, temperature and internal combustion residuals cannot be considered in such closed cycle simulations. In this study, open cycle simulations with port injection of natural gas predicted the combined effect of the stratifications on the CCV of in-cylinder pressure. The predicted Coefficient of Variation (COV) of cylinder pressure is improved compared to the one captured by closed cycle simulations in parallel.

  17. Altitude-Wind-Tunnel Investigation of a 4000-Pound-Thrust Axial-Flow Turbojet Engine. II - Operational Characteristics. II; Operational Characteristics

    Science.gov (United States)

    Fleming, William A.

    1948-01-01

    An investigation was conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of an axial flow-type turbojet engine with a 4000-pound-thrust rating over a range of pressure altitudes from 5,000 to 50,OOO feet, ram pressure ratios from 1.00 to 1.86, and temperatures from 60 deg to -50 deg F. The low-flow (standard) compressor with which the engine was originally equipped was replaced by a high-flow compressor for part of the investigation. The effects of altitude and airspeed on such operating characteristics as operating range, stability of combustion, acceleration, starting, operation of fuel-control systems, and bearing cooling were investigated. With the low-flow compressor, the engine could be operated at full speed without serious burner unbalance at altitudes up to 50,000 feet. Increasing the altitude and airspeed greatly reduced the operable speed range of the engine by raising the minimum operating speed of the engine. In several runs with the high-flow compressor the maximum engine speed was limited to less than 7600 rpm by combustion blow-out, high tail-pipe temperatures, and compressor stall. Acceleration of the engine was relatively slow and the time required for acceleration increased with altitude. At maximum engine speed a sudden reduction in jet-nozzle area resulted in an immediate increase in thrust. The engine started normally and easily below 20,000 feet with each configuration. The use of a high-voltage ignition system made possible starts at a pressure altitude of 40,000 feet; but on these starts the tail-pipe temperatures were very high, a great deal of fuel burned in and behind the tail-pipe, and acceleration was very slow. Operation of the engine was similar with both fuel regulators except that the modified fuel regulator restricted the fuel flow in such a manner that the acceleration above 6000 rpm was very slow. The bearings did not cool properly at high altitudes and high engine speeds with a low

  18. Re-Engineering the ISS Payload Operations Control Center During Increased Utilization and Critical Onboard Events

    Science.gov (United States)

    Dudley, Stephanie R. B.; Marsh, Angela L.

    2014-01-01

    With an increase in utilization and hours of payload operations being executed onboard the International Space Station (ISS), upgrading the NASA Marshall Space Flight Center (MSFC) Huntsville Operations Support Center (HOSC) ISS Payload Control Area (PCA) was essential to gaining efficiencies and assurance of current and future payload health and science return. PCA houses the Payload Operations Integration Center (POIC) responsible for the execution of all NASA payloads onboard the ISS. POIC Flight Controllers are responsible for the operation of voice, stowage, command, telemetry, video, power, thermal, and environmental control in support of ISS science experiments. The methodologies and execution of the PCA refurbishment were planned and performed within a four-month period in order to assure uninterrupted operation of ISS payloads and minimal impacts to payload operations teams. To vacate the PCA, three additional HOSC control rooms were reconfigured to handle ISS real-time operations, Backup Control Center (BCC) to Mission Control in Houston, simulations, and testing functions. This involved coordination and cooperation from teams of ISS operations controllers, multiple engineering and design disciplines, management, and construction companies performing an array of activities simultaneously and in sync delivering a final product with no issues that impacted the schedule. For each console operator discipline, studies of Information Technology (IT) tools and equipment layouts, ergonomics, and lines of sight were performed. Infusing some of the latest IT into the project was an essential goal in ensuring future growth and success of the ISS payload science returns. Engineering evaluations led to a state of the art Video Wall implementation and more efficient ethernet cabling distribution providing the latest products and the best solution for the POIC. These engineering innovations led to cost savings for the project. Constraints involved in the management of

  19. Human Factors Engineering (HFE) insights for advanced reactors based upon operating experience

    International Nuclear Information System (INIS)

    Higgins, J.; Nasta, K.

    1997-01-01

    The NRC Human Factors Engineering Program Review Model (HFE PRM, NUREG-0711) was developed to support a design process review for advanced reactor design certification under 10CFR52. The HFE PRM defines ten fundamental elements of a human factors engineering program. An Operating Experience Review (OER) is one of these elements. The main purpose of an OER is to identify potential safety issues from operating plant experience and ensure that they are addressed in a new design. Broad-based experience reviews have typically been performed in the past by reactor designers. For the HFE PRM the intent is to have a more focussed OER that concentrates on HFE issues or experience that would be relevant to the human-system interface (HSI) design process for new advanced reactors. This document provides a detailed list of HFE-relevant operating experience pertinent to the HSI design process for advanced nuclear power plants. This document is intended to be used by NRC reviewers as part of the HFE PRM review process in determining the completeness of an OER performed by an applicant for advanced reactor design certification. 49 refs

  20. Radioisotope Stirling Engine Powered Airship for Low Altitude Operation on Venus

    Science.gov (United States)

    Colozza, Anthony J.

    2012-01-01

    The feasibility of a Stirling engine powered airship for the near surface exploration of Venus was evaluated. The heat source for the Stirling engine was limited to 10 general purpose heat source (GPHS) blocks. The baseline airship utilized hydrogen as the lifting gas and the electronics and payload were enclosed in a cooled insulated pressure vessel to maintain the internal temperature at 320 K and 1 Bar pressure. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the Venus surface based on the available thermal power. The atmospheric conditions on Venus were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Venus surface. From this baseline design additional trades were made to see how other factors affected the design such as the internal temperature of the payload chamber and the flight altitude. In addition other lifting methods were evaluated such as an evacuated chamber, heated atmospheric gas and augmented heated lifting gas. However none of these methods proved viable.

  1. Integrated System Health Management: Pilot Operational Implementation in a Rocket Engine Test Stand

    Science.gov (United States)

    Figueroa, Fernando; Schmalzel, John L.; Morris, Jonathan A.; Turowski, Mark P.; Franzl, Richard

    2010-01-01

    This paper describes a credible implementation of integrated system health management (ISHM) capability, as a pilot operational system. Important core elements that make possible fielding and evolution of ISHM capability have been validated in a rocket engine test stand, encompassing all phases of operation: stand-by, pre-test, test, and post-test. The core elements include an architecture (hardware/software) for ISHM, gateways for streaming real-time data from the data acquisition system into the ISHM system, automated configuration management employing transducer electronic data sheets (TEDS?s) adhering to the IEEE 1451.4 Standard for Smart Sensors and Actuators, broadcasting and capture of sensor measurements and health information adhering to the IEEE 1451.1 Standard for Smart Sensors and Actuators, user interfaces for management of redlines/bluelines, and establishment of a health assessment database system (HADS) and browser for extensive post-test analysis. The ISHM system was installed in the Test Control Room, where test operators were exposed to the capability. All functionalities of the pilot implementation were validated during testing and in post-test data streaming through the ISHM system. The implementation enabled significant improvements in awareness about the status of the test stand, and events and their causes/consequences. The architecture and software elements embody a systems engineering, knowledge-based approach; in conjunction with object-oriented environments. These qualities are permitting systematic augmentation of the capability and scaling to encompass other subsystems.

  2. Use of diesel engines in industrial trucks operated in enclosed spaces

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, W; Reibold, G

    1981-01-01

    Report on emission investigations on a fork-lifter equipped with a low-pollutant MWM-engine, tests were carried out in enclosed spaces. The aim was to clarify if the maximum MPC at a place of work listed in a table of waste gas components can be observed even under unfavourable operating conditions of the fork lifter. The test is described, results are analysed. It is proved that there are no health hazards for the staff even under the extreme conditions chosen for the test.

  3. Application of exergy analysis to the thermodynamical study of operation cycles of diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Zellat, M

    1987-01-01

    To simulate the operation cycle of a diesel engine a general methodology is proposed, called as exergy theory, based on the simultaneous application of the first and second principles of thermodynamics. This analysis accounts for the exergy losses in function of what can be recovered from the second principle and give a more fruitful representation than the pure energy analysis which takes into account only the first principle. The concept of a recovery power turbine RPT, linked to the driving shaft and declutchable is described. The yield increase in nominal power and at half-charge when the RPT is disconnected, is explained by exergy analysis.

  4. Designing Green Networks and Network Operations Saving Run-the-Engine Costs

    CERN Document Server

    Minoli, Daniel

    2011-01-01

    In recent years the confluence of socio-political trends toward environmental responsibility and the pressing need to reduce Run-the-Engine (RTE) costs has given birth to a nascent discipline of Green IT. A clear and concise introduction to green networks and green network operations, this book examines analytical measures and discusses virtualization, network computing, and web services as approaches for green data centers and networks. It identifies some strategies for green appliance and end devices and examines the methodical steps that can be taken over time to achieve a seamless migratio

  5. Comparison of defects in ProTaper hand-operated and engine-driven instruments after clinical use.

    Science.gov (United States)

    Cheung, G S P; Bian, Z; Shen, Y; Peng, B; Darvell, B W

    2007-03-01

    To compare the type of defects and mode of material failure of engine-driven and hand-operated ProTaper instruments after clinical use. A total of 401 hand-operated and 325 engine-driven ProTaper instruments were discarded from an endodontic clinic over 17 months. Those that had fractured were examined for plastic deformation in lateral view and remounted for fractographical examination in scanning electron microscope. The mode of fracture was classified as 'fatigue' or 'shear' failure. The lengths of fractured segments in both instruments were recorded. Any distortion in hand instrument was noted. Data were analysed using chi-square, Fisher's exact or Student's t-test, where appropriate. Approximately 14% of all discarded hand-operated instruments and 14% of engine-driven instruments were fractured. About 62% of hand instruments failed because of shear fracture, compared with approximately 66% of engine-driven instruments as a result of fatigue (P hand instruments were affected by shear, and either remained intact or was fractured, compared with 5% of engine-driven instruments (P hand versus engine-driven group (P hand instruments were discarded intact but distorted (rarely for engine-driven instruments); all were in the form of unscrewing of the flutes. The location of defects in hand Finishing instruments was significantly closer to the tip than that for Shaping instruments (P ProTaper engine-driven and hand-operated instruments appeared to be different, with shear failure being more prevalent in the latter.

  6. Robust, cost-optimal and compliant engine and aftertreatment operation using air-path control and tailpipe emission feedback

    NARCIS (Netherlands)

    Ramachandran, S.; Hommen, G.; Mentink, P.; Seykens, X.L.J.; Willems, F.P.T.; Kupper, F.

    2016-01-01

    Heavy-duty diesel engines are used in a wide range of applications. For varying operating environments, the engine and aftertreatment system must comply with the real-world emission legislation limits. Simultaneously, minimal fuel consumption and good drivability are crucial for economic

  7. Operation of a cryogenic rocket engine an outline with down-to-earth and up-to-space remarks

    CERN Document Server

    Kitsche, Wolfgang

    2010-01-01

    This book presents the operational aspects of the rocket engine on a test facility. It will be useful to engineers and scientists who are in touch with the test facility. To aerospace students it shall provide an insight of the job on the test facility. And to interest readers it shall provide an impression of this thrilling area of aerospace.

  8. Study of the operation of a diesel engine YaMZ-240 in the regime of gas generator

    Energy Technology Data Exchange (ETDEWEB)

    Degtyarev, G I

    1979-01-01

    Results are presented from studying the diesel engine of type YaMZ-240 during its operation in a mode of idling with increased counter pressure at the exhaust. The possibility is indicated of using the energy of exhaust gases of the engine in the fuel feeding system for mixture-formation and adding steam to the explosive mixture.

  9. Benefits of sequential turbocharging in improving high torque/low speed operation of medium speed diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Danyluk, P.; Gutoski, G. [Coltec Industries Inc., Fairbanks Morse Engine Division (United States); Chen, S.K. [PEI Consultants (United States)

    1998-12-31

    This paper describes the benefits of sequential turbocharging in improving the operating envelope of a medium speed diesel engine. In particular, the high torque, low speed performance envelope can be greatly extended over that of a standard medium speed engine and, in addition, can offer improved operating range over what has been achieved with compressor air bypass/waste gate systems. This paper compares the three approaches on the basis of possible operating envelopes for a specific application, the new U.S. Navy LPD-17 amphibious assault ship, which has a very demanding requirement for high torque at low engine speed and low ambient temperatures. Comparison is made to the earlier approach to extend the operating envelope on the U.S. Navy LSD-41 class engines. The LSD-41 fleet has been in service since 1985 running with a compressor air bypass system developed jointly by Lockheed Shipyard and Coltec Industries for the U.S. Navy. (au)

  10. Operating experiences since rise-to-power test in high temperature engineering test reactor (HTTR)

    International Nuclear Information System (INIS)

    Tochio, Daisuke; Watanabe, Shuji; Motegi, Toshihiro; Kawano, Shuichi; Kameyama, Yasuhiko; Sekita, Kenji; Kawasaki, Kozo

    2007-03-01

    The rise-to-power test of the High Temperature Engineering Test Reactor (HTTR) was actually started in April 2000. The rated thermal power of 30MW and the rated reactor outlet coolant temperature of 850degC were achieved in the middle of Dec. 2001. After that, the reactor thermal power of 30MW and the reactor outlet coolant temperature of 950degC were achieved in the final rise-to-power test in April 2004. After receiving the operation licensing at 850degC, the safety demonstration tests have conducted to demonstrate inherent safety features of the HTGRs as well as to obtain the core and plant transient data for validation of safety analysis codes and for establishment of safety design and evaluation technologies. This paper summarizes the HTTR operating experiences for six years from start of the rise-to-power test that are categorized into (1) Operating experiences related to advanced gas-cooled reactor design, (2) Operating experiences for improvement of the performance, (3) Operating experiences due to fail of system and components. (author)

  11. Operation, test, research and development of the high temperature engineering test reactor (HTTR). FY2003

    International Nuclear Information System (INIS)

    2005-03-01

    The High Temperature Engineering Test Reactor (HTTR) constructed at the Oarai Research Establishment of The Japan Atomic Energy Research Institute (JAERI) is the first high-temperature gas-cooled reactor (HTGR) in Japan, which is a graphite-moderated and helium gas-cooled reactor with 30MW of thermal power. Coolant of helium-gas circulates under the pressure of about 4Mpa, and the reactor inlet and outlet temperature are 395degC and 950degC (maximum), respectively coated particle fuel is used as fuel, and the HTTR core is composed of graphite prismatic blocks. The full power operation of 30MW was attained in December, 2001, and then JAERI received the commissioning license for the HTTR in March, 2002. Since 2002, we have been carrying out rated power operation, safety demonstration tests and several R and Ds, etc., and conducted the high-temperature test operation of 950degC in April, 2004. This report summarizes activities and test results on HTTR operation and maintenance as well as safety demonstration tests and several R and Ds, which were carried out in the fiscal year of 2003 before the high temperature test operation of 950degC. (author)

  12. Effects of Direct Fuel Injection Strategies on Cycle-by-Cycle Variability in a Gasoline Homogeneous Charge Compression Ignition Engine: Sample Entropy Analysis

    Directory of Open Access Journals (Sweden)

    Jacek Hunicz

    2015-01-01

    Full Text Available In this study we summarize and analyze experimental observations of cyclic variability in homogeneous charge compression ignition (HCCI combustion in a single-cylinder gasoline engine. The engine was configured with negative valve overlap (NVO to trap residual gases from prior cycles and thus enable auto-ignition in successive cycles. Correlations were developed between different fuel injection strategies and cycle average combustion and work output profiles. Hypothesized physical mechanisms based on these correlations were then compared with trends in cycle-by-cycle predictability as revealed by sample entropy. The results of these comparisons help to clarify how fuel injection strategy can interact with prior cycle effects to affect combustion stability and so contribute to design control methods for HCCI engines.

  13. Value engineering on the designed operator work tools for brick and rings wells production

    Science.gov (United States)

    Ayu Bidiawati J., R.; Muchtiar, Yesmizarti; Wariza, Ragil Okta

    2017-06-01

    Operator working tools in making brick and ring wells were designed and made, and the value engineering was calculated to identify and develop the function of these tools in obtaining the balance between cost, reliability and appearance. This study focused on the value of functional components of the tools and attempted to increase the difference between the costs incurred by the generated values. The purpose of this study was to determine the alternatives of tools design and to determine the performance of each alternative. The technique was developed using FAST method that consisted of five stages: information, creative, analytical, development and presentation stage. The results of the analysis concluded that the designed tools have higher value and better function description. There were four alternative draft improvements for operator working tools. The best alternative was determined based on the rank by using matrix evaluation. Best performance was obtained by the alternative II, amounting to 98.92 with a value of 0.77.

  14. Preserving the Near-Earth Space Environment with Green Engineering and Operations

    Science.gov (United States)

    Johnson, Nicholas L.

    2009-01-01

    Green engineering and operations are essential to preserving the near-Earth space environment for future generations. The U.S. and the international aerospace community have been proactive in addressing the threat of the increasing orbital debris population and the risks to people and property from reentering debris. NASA has led this activity first by devoting resources to thoroughly understand the technical issues and then by developing effective and acceptable policies and guidelines. NASA also worked closely with the international community to ensure that the US aerospace industry was not placed at an economic disadvantage. In the long term, the removal of large orbital debris will be essential to the sustainability of space operations.

  15. Application of Space Environmental Observations to Spacecraft Pre-Launch Engineering and Spacecraft Operations

    Science.gov (United States)

    Barth, Janet L.; Xapsos, Michael

    2008-01-01

    This presentation focuses on the effects of the space environment on spacecraft systems and applying this knowledge to spacecraft pre-launch engineering and operations. Particle radiation, neutral gas particles, ultraviolet and x-rays, as well as micrometeoroids and orbital debris in the space environment have various effects on spacecraft systems, including degradation of microelectronic and optical components, physical damage, orbital decay, biasing of instrument readings, and system shutdowns. Space climate and weather must be considered during the mission life cycle (mission concept, mission planning, systems design, and launch and operations) to minimize and manage risk to both the spacecraft and its systems. A space environment model for use in the mission life cycle is presented.

  16. Auto-ignition control in turbocharged internal combustion engines operating with gaseous fuels

    International Nuclear Information System (INIS)

    Duarte, Jorge; Amador, Germán; Garcia, Jesus; Fontalvo, Armando; Vasquez Padilla, Ricardo; Sanjuan, Marco; Gonzalez Quiroga, Arturo

    2014-01-01

    Control strategies for auto-ignition control in turbocharged internal combustion engines operating with gaseous fuels are presented. Ambient temperature and ambient pressure are considered as the disturbing variables. A thermodynamic model for predicting temperature at the ignition point is developed, adjusted and validated with a large experimental data-set from high power turbocharged engines. Based on this model, the performance of feedback and feedforward auto-ignition control strategies is explored. A robustness and fragility analysis for the Feedback control strategies is presented. The feedforward control strategy showed the best performance however its implementation entails adding a sensor and new control logic. The proposed control strategies and the proposed thermodynamic model are useful tools for increasing the range of application of gaseous fuels with low methane number while ensuring a safe running in internal combustion engines. - Highlights: • A model for predicting temperature at the ignition point. • Robust PID, modified PID, and feedforward strategies for auto-ignition control. • λ′ were the best set of tuning equations for calculating controller parameters. • Robust PID showed significant improvements in auto-ignition control. • Feedforward control showed the best performance

  17. Regulated and unregulated emissions from an internal combustion engine operating on ethanol-containing fuels

    Science.gov (United States)

    Poulopoulos, S. G.; Samaras, D. P.; Philippopoulos, C. J.

    In the present work, the effect of ethanol addition to gasoline on regulated and unregulated emissions is studied. A 4-cylinder OPEL 1.6 L internal combustion engine equipped with a hydraulic brake dynamometer was used in all the experiments. For exhaust emissions treatment a typical three-way catalyst was used. Among the various compounds detected in exhaust emissions, the following ones were monitored at engine and catalyst outlet: methane, hexane, ethylene, acetaldehyde, acetone, benzene, 1,3-butadiene, toluene, acetic acid and ethanol. Addition of ethanol in the fuel up to 10% w/w had as a result an increase in the Reid vapour pressure of the fuel, which indicates indirectly increased evaporative emissions, while carbon monoxide tailpipe emissions were decreased. For ethanol-containing fuels, acetaldehyde emissions were appreciably increased (up to 100%), especially for fuel containing 3% w/w ethanol. In contrast, aromatics emissions were decreased by ethanol addition to gasoline. Methane and ethanol were the most resistant compounds to oxidation while ethylene was the most degradable compound over the catalyst. Ethylene, methane and acetaldehyde were the main compounds present at engine exhaust while methane, acetaldehyde and ethanol were the main compounds in tailpipe emissions for ethanol fuels after the catalyst operation.

  18. Investigation of the I-40 Jet-Propulsion Engine in the Cleveland Altitude Wind Tunnel. V - Operational Characteristics. 5; Operational Characteristics

    Science.gov (United States)

    Golladay, Richard L.; Gendler, Stanley L.

    1947-01-01

    An investigation has been conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of the I-40 jet-propulsion engine over a range of pressure altitudes from 10,000 to 50,000 feet and ram-pressure ratios from 1.00 to 1.76. Engine operational data were obtained with the engine in the standard configuration and with various modifications of the fuel system, the electrical system, and the combustion chambers. The effects of altitude and airspeed on operating speed range, starting, windmilli.ng, acceleration, speed regulation, cooling, and vibration of the standard and modified engines were determined, and damage to parts was noted. Maximum engine speed was obtainable at all altitudes and airspeeds wi th each fuel-control system investigated. The minimum idling speed was raised by increases in altitude and airspeed. The lowest minimum stable speeds were obtained with the standard configuration using 40-gallon nozzles with individual metering plugs. The engine was started normally at altitudes as high as 20,000 feet with all of the fuel systems and ignition combinations except one. Ignition at 70,000 feet was difficult and, although successful ignition occurred, acceleration was slow and usually characterized by excessive tail-pipe temperature. During windmilling investigations of the engine equipped with the standard fuel system, the engine could not be started at ram-pressure ratios of 1.1 to 1.7 at altitudes of 10,000, 20,000 and 30,000 feet. When equipped with the production barometric and Monarch 40-gallon nozzles, the engine accelerated in 12 seconds from an engine speed of 6000 rpm to 11,000 rpm at 20,000 feet and an average tail-pipe temperature of 11000 F. At the same altitude and temperature, all the engine configurations had approximately the same rate of acceleration. The Woodward governor produced the safest accelerations, inasmuch as it could be adjusted to automatically prevent acceleration blow out. The engine speed was

  19. Enhancements to the Idaho National Engineering Laboratory motor-operated valve assessment software

    International Nuclear Information System (INIS)

    Holbrook, M.R.; Watkins, J.C.

    1994-01-01

    In January 1991, the U.S. Nuclear Regulatory Commission (USNRC) commenced Part 1 inspections to review licensee's motor-operated valve (MOV) programs that were developed to address Generic Letter 89-10, open-quotes Safety-Related Motor-Operated Valve Testing and Surveillanceclose quotes. In support, of this effort, the Isolation Valve Assessment (IVA) software, Version 3.10, was developed by the Idaho National Engineering Laboratory (INEL) to enable rapid in-depth review of MOV sizing and torque switch setting calculations. In 1994, the USNRC commenced Part 2 inspections, which involve a more in-depth review of MOV in situ testing relative to design-basis assumptions. The purpose of this paper is to describe the latest INEL and industry research that has been incorporated into Version 4.00 of the IVA software to support the latest round of inspections. Major improvements include (a) using dynamic and static test results to determine MOV performance parameters and validate design-basis engineering assumptions, (b) determining the stem/stem-nut coefficient of friction using new research-based techniques, (c) adding the ability to evaluate globe valves, and (d) incorporating new methods to account for the effects of high ambient temperature on the output torque of alternating current (ac) motors

  20. Oxygen sensor equipped engine operation on methanol/gasoline blends and phase separation problems

    Energy Technology Data Exchange (ETDEWEB)

    Last, A J; Lawson, A; Simmons, E W; Mackay, D; Tsang, M; Maund, G B

    1980-01-01

    A study was made to address problems related to Canadian utilization of methanol/gasoline blends. These problems are: (1) cold weather operation; (2) water sensitivity to phase separation in winter; (3) vehicle compatibility: fuel/air ratio control, flexibility for vehicle movement outside of areas where methanol might be available. Specifically, the operation of the HydroShear (an in-line hydraulic emulsifier) on the two separated phases of a methanol/gasoline/water blend was examined. Fuel maps, by engine dynamometer testing, were generated using methanol/gasoline blends containing 15% to 65% methanol. The capability of an oxygen sensor, located in the exhaust system, to control the fuel/air ratio was found to be adequate within the 15% to 65% methanol/gasoline blends. A fuel injected Volvo 244DL with lambda-sond emission control and a carburetted Chevrolet Monza with 3-way catalyst closed loop feedback emission control system were the two engines selected for this study.

  1. COMBUSTION CHARACTERISTICS OF DIESEL ENGINE OPERATING ON JATROPHA OIL METHYL ESTER

    Directory of Open Access Journals (Sweden)

    Doddayaraganalu Amasegoda Dhananjaya

    2010-01-01

    Full Text Available Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed interest of scientific community to look for alternative fuels of bio-origin such as vegetable oils. Vegetable oils can be produced from forests, vegetable oil crops, and oil bearing biomass materials. Non-edible vegetable oils such as jatropha oil, linseed oil, mahua oil, rice bran oil, karanji oil, etc., are potentially effective diesel substitute. Vegetable oils have reasonable energy content. Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in diesel engines with very little or no engine modifications. This is because it has combustion characteristics similar to petroleum diesel. The current paper reports a study carried out to investigate the combustion, performance and emission characteristics of jatropha oil methyl ester and its blend B20 (80% petroleum diesel and 20% jatropha oil methyl ester and diesel fuel on a single-cylinder, four-stroke, direct injections, water cooled diesel engine. This study gives the comparative measures of brake thermal efficiency, brake specific energy consumption, smoke opacity, HC, NOx, ignition delay, cylinder peak pressure, and peak heat release rates. The engine performance in terms of higher thermal efficiency and lower emissions of blend B20 fuel operation was observed and compared with jatropha oil methyl ester and petroleum diesel fuel for injection timing of 20° bTDC, 23° bTDC and 26° bTDC at injection opening pressure of 220 bar.

  2. Tailored Materials for High Efficiency CIDI Engines

    Energy Technology Data Exchange (ETDEWEB)

    Grant, G.J.; Jana, S.

    2012-03-30

    The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

  3. Standard forms and entanglement engineering of multimode Gaussian states under local operations

    International Nuclear Information System (INIS)

    Serafini, Alessio; Adesso, Gerardo

    2007-01-01

    We investigate the action of local unitary operations on multimode (pure or mixed) Gaussian states and single out the minimal number of locally invariant parameters which completely characterize the covariance matrix of such states. For pure Gaussian states, central resources for continuous-variable quantum information, we investigate separately the parameter reduction due to the additional constraint of global purity, and the one following by the local-unitary freedom. Counting arguments and insights from the phase-space Schmidt decomposition and in general from the framework of symplectic analysis, accompany our description of the standard form of pure n-mode Gaussian states. In particular, we clarify why only in pure states with n ≤ 3 modes all the direct correlations between position and momentum operators can be set to zero by local unitary operations. For any n, the emerging minimal set of parameters contains complete information about all forms of entanglement in the corresponding states. An efficient state engineering scheme (able to encode direct correlations between position and momentum operators as well) is proposed to produce entangled multimode Gaussian resources, its number of optical elements matching the minimal number of locally invariant degrees of freedom of general pure n-mode Gaussian states. Finally, we demonstrate that so-called 'block-diagonal' Gaussian states, without direct correlations between position and momentum, are systematically less entangled, on average, than arbitrary pure Gaussian states

  4. Operation, test, research and development of the high temperature engineering test reactor (HTTR). (FY2005)

    International Nuclear Information System (INIS)

    2007-03-01

    The High Temperature Engineering Test Reactor (HTTR) constructed at the Oarai Research and Development Center of the Japan Atomic Energy Agency (JAEA) is the first high-temperature gas-cooled reactor (HTGR) in Japan, which is a graphite-moderated and helium gas-cooled reactor with 30 MW of thermal power. The full power operation of 30 MW was attained in December, 2001, and then JAERI (JAEA) received the commissioning license for the HTTR in March, 2002. Since 2002, we have been carrying out rated power operation, safety demonstration tests and several R and Ds, etc., and conducted the high-temperature test operation of 950degC in April, 2004. In fiscal 2005 year, periodical inspection and overhaul of reactivity control system were conducted, and safety demonstration tests were promoted. This report summarizes activities and test results on HTTR operation and maintenance as well as safety demonstration tests and several R and Ds, which were carried out in the fiscal year of 2005. (author)

  5. Presumptions of effective operation of diesel engines running on rme biodiesel. Research on kinetics of combustion of RME biodiesel

    Directory of Open Access Journals (Sweden)

    A. Vaicekauskas

    2007-06-01

    Full Text Available The results of experimental research on kinetics of fuel combustion of diesel engine A41are presented in the publication. The change of characteristics of indicated work (in-cylinder pressure and temperature, period of induction, heat release and heat release rate and fuel injection (fuel injection pressure, fuel injection phases was determined in diesel engine running on RME biodiesel being compared to diesel fuel. The results of researches were used to explain experimentally determined changes of operational and ecological characteristics of diesel engine running on RME biodiesel. In addition, the reliability of diesel engine A41 running on RME biodiesel was evaluated. The presumptions of effective operation of diesel engines running on RME biodiesel were formulated.

  6. Simulator Investigation of Pilot Aids for Helicopter Terminal Area Operations with One Engine Inoperative

    Science.gov (United States)

    Iseler, Laura; Chen, Robert; Dearing, Munro; Decker, William; Aiken, Edwin W. (Technical Monitor)

    1995-01-01

    Two recent piloted simulation experiments have investigated advanced display concepts applied to civil transport helicopter terminal area operations. Civil Category A helicopter operations apply to multi-engine helicopters wherein a safe recovery (land or fly out) is required in the event of a single engine failure. The investigation used the NASA Ames Research Center Vertical Motion Simulator, which has a full six degrees of freedom, to simulate the flight task as closely as possible. The goal of these experiments was to use advanced cockpit displays to improve flight safety and enhance the mission performance of Category A terminal area operations in confined areas. The first experiment investigated the use of military display formats to assist civil rotorcraft in performing a Category A takeoff in confined terminal areas. Specifically, it addressed how well a difficult hovering backup path could be followed using conventional instruments in comparison to panel mounted integrated displays. The hovering backup takeoff, which enables pilots to land back to the confined area pad in the event of an engine failure, was chosen since it is a difficult task to perform. Seven NASA and Army test pilots participated in the experiment. Evaluations, based on task performance and pilot workload, showed that an integrated display enabled the pilot to consistently achieve adequate or desired performance with reasonable pilot workload. Use of conventional instruments, however, frequently resulted in unacceptable performance (poor flight path tracking), higher pilot workload, and poor situational awareness. Although OEI landbacks were considered a visual task, the improved performance on the backup portion, in conjunction with increased situational awareness resulting from use of integrated displays, enabled the pilots to handle an engine failure and land back safely. In contrast, use of conventional instruments frequently led to excessive rates of sink at touchdown. A second

  7. Modeling vehicle interior noise exposure dose on freeways: Considering weaving segment designs and engine operation.

    Science.gov (United States)

    Li, Qing; Qiao, Fengxiang; Yu, Lei; Shi, Junqing

    2017-07-05

    Vehicle interior noise functions at the dominant frequencies of 500 Hz below and around 800 Hz, which fall into the bands that may impair hearing. Recent studies demonstrated that freeway commuters are chronically exposed to vehicle interior noise, bearing the risk of hearing impairment. The interior noise evaluation process is mostly conducted in a laboratory environment. The test results and the developed noise models may underestimate or ignore the noise effects from dynamic traffic and road conditions and configuration. However, the interior noise is highly associated with vehicle maneuvering. The vehicle maneuvering on a freeway weaving segment is more complex because of its nature of conflicting areas. This research is intended to explore the risk of the interior noise exposure on freeway weaving segments for freeway commuters and to improve the interior noise estimation by constructing a decision tree learning-based noise exposure dose (NED) model, considering weaving segment designs and engine operation. On-road driving tests were conducted on 12 subjects on State Highway 288 in Houston, Texas. On-board Diagnosis (OBD) II, a smartphone-based roughness app, and a digital sound meter were used to collect vehicle maneuvering and engine information, International Roughness Index, and interior noise levels, respectively. Eleven variables were obtainable from the driving tests, including the length and type of a weaving segment, serving as predictors. The importance of the predictors was estimated by their out-of-bag-permuted predictor delta errors. The hazardous exposure level of the interior noise on weaving segments was quantified to hazard quotient, NED, and daily noise exposure level, respectively. Results showed that the risk of hearing impairment on freeway is acceptable; the interior noise level is the most sensitive to the pavement roughness and is subject to freeway configuration and traffic conditions. The constructed NED model shows high predictive

  8. SLUDGE TREATMENT PROJECT ENGINEERED CONTAINER RETRIEVAL AND TRANSFER SYSTEM PRELMINARY DESIGN HAZARD AND OPERABILITY STUDY

    Energy Technology Data Exchange (ETDEWEB)

    CARRO CA

    2011-07-15

    This Hazard and Operability (HAZOP) study addresses the Sludge Treatment Project (STP) Engineered Container Retrieval and Transfer System (ECRTS) preliminary design for retrieving sludge from underwater engineered containers located in the 105-K West (KW) Basin, transferring the sludge as a sludge-water slurry (hereafter referred to as 'slurry') to a Sludge Transport and Storage Container (STSC) located in a Modified KW Basin Annex, and preparing the STSC for transport to T Plant using the Sludge Transport System (STS). There are six, underwater engineered containers located in the KW Basin that, at the time of sludge retrieval, will contain an estimated volume of 5.2 m{sup 3} of KW Basin floor and pit sludge, 18.4 m{sup 3} of 105-K East (KE) Basin floor, pit, and canister sludge, and 3.5 m{sup 3} of settler tank sludge. The KE and KW Basin sludge consists of fuel corrosion products (including metallic uranium, and fission and activation products), small fuel fragments, iron and aluminum oxide, sand, dirt, operational debris, and biological debris. The settler tank sludge consists of sludge generated by the washing of KE and KW Basin fuel in the Primary Clean Machine. A detailed description of the origin of sludge and its chemical and physical characteristics can be found in HNF-41051, Preliminary STP Container and Settler Sludge Process System Description and Material Balance. In summary, the ECRTS retrieves sludge from the engineered containers and hydraulically transfers it as a slurry into an STSC positioned within a trailer-mounted STS cask located in a Modified KW Basin Annex. The slurry is allowed to settle within the STSC to concentrate the solids and clarify the supernate. After a prescribed settling period the supernate is decanted. The decanted supernate is filtered through a sand filter and returned to the basin. Subsequent batches of slurry are added to the STSC, settled, and excess supernate removed until the prescribed quantity of sludge is

  9. The Effect of Acoustic Disturbances on the Operation of the Space Shuttle Main Engine Fuel Flowmeter

    Science.gov (United States)

    Marcu, Bogdan; Szabo, Roland; Dorney, Dan; Zoladz, Tom

    2007-01-01

    The Space Shuttle Main Engine (SSME) uses a turbine fuel flowmeter (FFM) in its Low Pressure Fuel Duct (LPFD) to measure liquid hydrogen flowrates during engine operation. The flowmeter is required to provide accurate and robust measurements of flow rates ranging from 10000 to 18000 GPM in an environment contaminated by duct vibration and duct internal acoustic disturbances. Errors exceeding 0.5% can have a significant impact on engine operation and mission completion. The accuracy of each sensor is monitored during hot-fire engine tests on the ground. Flow meters which do not meet requirements are not flown. Among other parameters, the device is screened for a specific behavior in which a small shift in the flow rate reading is registered during a period in which the actual fuel flow as measured by a facility meter does not change. Such behavior has been observed over the years for specific builds of the FFM and must be avoided or limited in magnitude in flight. Various analyses of the recorded data have been made prior to this report in an effort to understand the cause of the phenomenon; however, no conclusive cause for the shift in the instrument behavior has been found. The present report proposes an explanation of the phenomenon based on interactions between acoustic pressure disturbances in the duct and the wakes produced by the FFM flow straightener. Physical insight into the effects of acoustic plane wave disturbances was obtained using a simple analytical model. Based on that model, a series of three-dimensional unsteady viscous flow computational fluid dynamics (CFD) simulations were performed using the MSFC PHANTOM turbomachinery code. The code was customized to allow the FFM rotor speed to change at every time step according to the instantaneous fluid forces on the rotor, that, in turn, are affected by acoustic plane pressure waves propagating through the device. The results of the simulations show the variation in the rotation rate of the flowmeter

  10. Sludge Treatment Project Engineered Container Retrieval And Transfer System Prelminary Design Hazard And Operability Study

    International Nuclear Information System (INIS)

    Carro, C.A.

    2011-01-01

    This Hazard and Operability (HAZOP) study addresses the Sludge Treatment Project (STP) Engineered Container Retrieval and Transfer System (ECRTS) preliminary design for retrieving sludge from underwater engineered containers located in the 105-K West (KW) Basin, transferring the sludge as a sludge-water slurry (hereafter referred to as 'slurry') to a Sludge Transport and Storage Container (STSC) located in a Modified KW Basin Annex, and preparing the STSC for transport to T Plant using the Sludge Transport System (STS). There are six, underwater engineered containers located in the KW Basin that, at the time of sludge retrieval, will contain an estimated volume of 5.2 m 3 of KW Basin floor and pit sludge, 18.4 m 3 of 105-K East (KE) Basin floor, pit, and canister sludge, and 3.5 m 3 of settler tank sludge. The KE and KW Basin sludge consists of fuel corrosion products (including metallic uranium, and fission and activation products), small fuel fragments, iron and aluminum oxide, sand, dirt, operational debris, and biological debris. The settler tank sludge consists of sludge generated by the washing of KE and KW Basin fuel in the Primary Clean Machine. A detailed description of the origin of sludge and its chemical and physical characteristics can be found in HNF-41051, Preliminary STP Container and Settler Sludge Process System Description and Material Balance. In summary, the ECRTS retrieves sludge from the engineered containers and hydraulically transfers it as a slurry into an STSC positioned within a trailer-mounted STS cask located in a Modified KW Basin Annex. The slurry is allowed to settle within the STSC to concentrate the solids and clarify the supernate. After a prescribed settling period the supernate is decanted. The decanted supernate is filtered through a sand filter and returned to the basin. Subsequent batches of slurry are added to the STSC, settled, and excess supernate removed until the prescribed quantity of sludge is collected. The sand

  11. Installation, maintenance and operating manual for the Lucas-type fuel injection system of the 3 B rotary engine

    Science.gov (United States)

    1985-01-01

    The installation procedure, maintenance, adjustment and operation of a Lucas type fuel injection system for 13B rotary racing engine is outlined. Components of the fuel injection system and installation procedure and notes are described. Maintenance, adjustment, and operation are discussed.

  12. Investigation of spray characteristics from a low-pressure common rail injector for use in a homogeneous charge compression ignition engine

    Science.gov (United States)

    Lee, Kihyung; Reitz, Rolf D.

    2004-03-01

    Homogeneous charge compression ignition (HCCI) combustion provides extremely low levels of pollutant emissions, and thus is an attractive alternative for future IC engines. In order to achieve a uniform mixture distribution within the engine cylinder, the characteristics of the fuel spray play an important role in the HCCI engine concept. It is well known that high-pressure common rail injection systems, mainly used in diesel engines, achieve poor mixture formation because of the possibility of direct fuel impingement on the combustion chamber surfaces. This paper describes spray characteristics of a low-pressure common rail injector which is intended for use in an HCCI engine. Optical diagnostics including laser diffraction and phase Doppler methods, and high-speed camera photography, were applied to measure the spray drop diameter and to investigate the spray development process. The drop sizing results of the laser diffraction method were compared with those of a phase Doppler particle analyser (PDPA) to validate the accuracy of the experiments. In addition, the effect of fuel properties on the spray characteristics was investigated using n-heptane, Stoddard solvent (gasoline surrogate) and diesel fuel because HCCI combustion is sensitive to the fuel composition. The results show that the injector forms a hollow-cone sheet spray rather than a liquid jet, and the atomization efficiency is high (small droplets are produced). The droplet SMD ranged from 15 to 30 µm. The spray break-up characteristics were found to depend on the fuel properties. The break-up time for n-heptane is shorter and the drop SMD is smaller than that of Stoddard solvent and diesel fuel.

  13. The safe operation zone of the spark ignition engine working with dual renewable supplemented fuels (hydrogen+ethyl alcohol)

    Energy Technology Data Exchange (ETDEWEB)

    Al-Baghdadi, Maher Abdul-Resul Sadiq [Babylon Univ., Dept. of Mechanical Engineering, Babylon (Iraq)

    2001-04-01

    The effect of the amount of hydrogen/ethyl alcohol addition on the performance and pollutant emission of a four-stroke spark ignition engine has been studied. The results of the study show that all engine performance parameters have been improved when operating the gasoline spark ignition engine with dual addition of hydrogen and ethyl alcohol. The important improvements of alcohol addition are to reduce the NOx emission while increasing the higher useful compression ratio and output power of hydrogen-supplemented engine. An equation has been derived from experimental data to specify the least quantity of ethyl alcohol blended with gasoline and satisfying constant NOx emission when hydrogen is added. A chart limiting the safe operation zone of the engine fueled with dual renewable supplemented fuel, (hydrogen and ethyl alcohol) has been produced. The safe zone provides lower NOx and CO emission, lower s.f.c. and higher brake power compared to an equivalent gasoline engine. When ethyl alcohol is increased over 30%, it causes unstable engine operation which can be related to the fact that the fuel is not vaporized, and this causes a reduction in both brake power and efficiency. (Author)

  14. Development of Diesel Engine Operated Forklift Truck for Explosive Gas Atmospheres

    Science.gov (United States)

    Vishwakarma, Rajendra Kumar; Singh, Arvind Kumar; Ahirwal, Bhagirath; Sinha, Amalendu

    2018-02-01

    For the present study, a prototype diesel engine operated Forklift truck of 2 t capacity is developed for explosive gas atmosphere. The parts of the Forklift truck are assessed against risk of ignition of the explosive gases, vapors or mist grouped in Gr. IIA and having ignition temperature more than 200°C. Identification of possible sources of ignition and their control or prevention is the main objective of this work. The design transformation of a standard Forklift truck into a special Forklift truck is made on prototype basis. The safety parameters of the improved Forklift truck are discussed in this paper. The specially designed Forklift truck is useful in industries where explosive atmospheres may present during normal working conditions and risk of explosion is a concern during handling or transportation of materials. This indigenous diesel engine based Forklift truck for explosive gas atmosphere classified as Zone 1 and Zone 2 area and gas group IIA is developed first time in India in association with the Industry.

  15. Sustainable application of reciprocating gas engines operating on coal mine methane

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.; Teo, T. [Caterpillar China Investment Co., Beijing (China); Tnay, C.H. [Westrac Inc., Beijing (China)

    2008-07-01

    According to the World Coal Institute, coal provides 25 per cent of worldwide primary energy needs and generates 40 per cent of the world's electricity. China produces the largest amount of hard coal. The anthropogenic release of methane (CH{sub 4}) into the environment is a byproduct of the coal mining process. The global warming potential of this methane continues to draw attention around the world. In particular, China's government has recognized the need for environmental responsibility in the pursuit of greater power production. The Kyoto Protocol requires developed countries to reduce their greenhouse gas emissions and targets must be met within a five-year time frame between 2008 and 2012. Sequestering coal mine methane (CMM) as an alternative fuel for reciprocating gas engine generator sets is a mature and proven technology for greenhouse gas mitigation. Prior to commissioning CMM-fueled power systems, the methane gas composition must be evaluated. An integrated systems approach can then be used to develop a CMM-fueled power project. This paper discussed the sustainable application of reciprocating gas engines operating on coal mine methane. It discussed the Kyoto Protocol, clean development mechanism, and CMM as compared to other fuel sources. It was concluded that there is considerable opportunity for growth in the Asia-Pacific region for electric power applications using CMM. 4 refs., 12 figs.

  16. Integrating experiences from operations into engineering design: modelling knowledge transfer in the offshore oil industry

    DEFF Research Database (Denmark)

    Souza da Conceição, Carolina; Broberg, Ole; Paravizo, Esdras

    2017-01-01

    of knowledge registered in the systems without standards to categorise and store this knowledge, to being difficult to access and retrieve the knowledge in the systems. Discussion: Transferring knowledge and experiences from users brings human factors into play and modelling the knowledge transfer process...... and workwise distance between operations and engineering design teams, integrating human factors and transferring knowledge are key aspects when designing for better performance systems. Research Objective: Based on an in-depth empirical investigation in an offshore oil company, this study aims to provide......Summative Statement: Integrating human factors and users’ experiences in design projects is a well-known challenge. This study focus on the specific challenges for transferring these experiences and how using a knowledge transfer model can help this integration on the design of high-risk productive...

  17. Cogeneration with natural gas fired internal combustion engines: Italian utility's 10 years operating experience

    International Nuclear Information System (INIS)

    Montermini, G.P.

    1992-01-01

    This paper describes the experience that AGAC, an Italian gas and water utility, has acquired in the operation of a 116 Km long district heating network serving about 40,000 inhabitants. The network is powered by a mix of methane fuelled Otto and diesel cycle engines, coal fired fluidized bed boilers, and methane fired boilers producing annually about 153,000 kW of thermal energy, 2,300 kW of cooling energy, and 28.8 million kWh of electric power. This paper reports on the performance of this system in terms of production and sales trends, equipment efficiency and compatibility with new European Communities air pollution standards

  18. Engineering, installation, testing, and initial operation of the DIII-D Advanced Divertor

    International Nuclear Information System (INIS)

    Andersen, P.M.; Baxi, C.B.; Reis, E.E.; Schaffer, M.J.; Smith, J.P.

    1990-09-01

    The Advanced Divertor (AD) for General Atomics tokamak, DIII-D, was installed in the summer of 1990. The AD has enabled two classes of physics experiments to be run: divertor biasing and divertor baffling. Both are new experiments for DIII-D. The AD has two principal components: (1) a continuous ring electrode; and (2) a toroidally symmetric baffle. The tokamak can be run in bias baffle or standard DIII-D divertor modes by accurate positioning of the outer divertor strike point through the use of the DIII-D control system. The paper covers design, analysis, fabrication, installation, instrumentation, testing, initial operation, and future plans for the Advanced Divertor from an engineering viewpoint. 2 refs., 5 figs

  19. Influence of Compression Ratio on the Performance and Emission Characteristics of Annona Methyl Ester Operated DI Diesel Engine

    Directory of Open Access Journals (Sweden)

    Senthil Ramalingam

    2014-09-01

    Full Text Available This study aims to find the optimum performance and emission characteristics of single cylinder variable compression ratio (VCR engine with different blends of Annona methyl ester (AME as fuel. The performance parameters such as specific fuel consumption (SFC, brake thermal efficiency (BTE, and emission levels of HC, CO, Smoke, and NOx were compared with the diesel fuel. It is found that, at compression ratio of 17: 1 for A20 blended fuel (20% AME + 80% Diesel shows better performance and lower emission level which is very close to neat diesel fuel. The engine was operated with different values of compression ratio (15, 16, and 17 to find out best possible combination for operating engine with blends of AME. It is also found that the increase of compression ratio increases the BTE and reduces SFC and has lower emission without any engine in design modifications.

  20. Preliminary Performance Data on Westinghouse Electronic Power Regulator Operating on J34-WE-32 Turbojet Engine in Altitude Wind Tunnel

    Science.gov (United States)

    Ketchum, James R.; Blivas, Darnold; Pack, George J.

    1950-01-01

    The behavior of the Westinghouse electronic power regulator operating on a J34-WE-32 turbojet engine was investigated in the NACA Lewis altitude wind tunnel at the request of the Bureau of Aeronautics, Department of the Navy. The object of the program was to determine the, steady-state stability and transient characteristics of the engine under control at various altitudes and ram pressure ratios, without afterburning. Recordings of the response of the following parameters to step changes in power lever position throughout the available operating range of the engine were obtained; ram pressure ratio, compressor-discharge pressure, exhaust-nozzle area, engine speed, turbine-outlet temperature, fuel-valve position, jet thrust, air flow, turbine-discharge pressure, fuel flow, throttle position, and boost-pump pressure. Representative preliminary data showing the actual time response of these variables are presented. These data are presented in the form of reproductions of oscillographic traces.

  1. 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

  2. Chinese engineers and scientists urge leadership to change Three Gorges Dam operating plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-26

    An appeal to the Chinese Leadership by a group of senior engineers, water management experts and academics about the dire consequences of filling the Three Gorges reservoir on the Yangtze River to 175 metres, is reported. Originally, the plan was to keep water levels behind the Three Gorges Dam at 156 metres for the first ten years of operation, in order to allow for resettlement of people displaced by building the dam, and to evaluate the impact of silt deposits on navigation and ports at the upper end of the reservoir. Plans have changed in 1997; the water level is now scheduled to rise to 175 metres in the sixth year of the dam's operation in order to maximize the dam's power output. The appeal by 53 experts warned the Chinese Government that the filling of the reservoir to 175 metres would displace 1.13 million people and raise the water level in the Yangtze River more than 10 metres at Chongqing City, submerging drainage outlets and backing up the city's sewage, as well as increase silt deposits, blocking shipping traffic along the Yangtze River. A parallel is drawn with the Sanmenxia Dam on the Yellow River. It was completed in 1960; it has proven to be useless for controlling floods while producing only one-third of its expected output due to massive silt build-up in the reservoir.

  3. Investigation of wear of insulation of traction engines of locomotives in operation

    Directory of Open Access Journals (Sweden)

    Nefedov Roman

    2018-01-01

    Full Text Available The article analyzes reliability of traction electric motors in operation. It is shown that the greatest number of failure falls on the winding of the armature. Investigation of the causes of increased wear of the armature winding insulation was carried out using the dynamic thermal model of the electric motor. The model is represented by 150 final elements and takes into account the conditions of thermal conductivity between the nodes and heat transfer to the cooling air. Verification of the model was carried out by comparison with the results of thermal tests of electric motors of the series HБ-406 and ЭД-118. The field of temperatures in the traction motor under various loads was investigated. It is shown that in stationary mode the temperature change along the armature winding can reach 60C. Modeling of thermal dynamic processes in the engine during its operation on the locomotive allowed to identify the most stressed nodes. It is shown that the resource of the electric motor is determined by the wear of the insulation of the frontal part of the armature winding on the side of the traction drive of the locomotive.

  4. Chinese engineers and scientists urge leadership to change Three Gorges Dam operating plan

    International Nuclear Information System (INIS)

    2000-01-01

    An appeal to the Chinese Leadership by a group of senior engineers, water management experts and academics about the dire consequences of filling the Three Gorges reservoir on the Yangtze River to 175 metres, is reported. Originally, the plan was to keep water levels behind the Three Gorges Dam at 156 metres for the first ten years of operation, in order to allow for resettlement of people displaced by building the dam, and to evaluate the impact of silt deposits on navigation and ports at the upper end of the reservoir. Plans have changed in 1997; the water level is now scheduled to rise to 175 metres in the sixth year of the dam's operation in order to maximize the dam's power output. The appeal by 53 experts warned the Chinese Government that the filling of the reservoir to 175 metres would displace 1.13 million people and raise the water level in the Yangtze River more than 10 metres at Chongqing City, submerging drainage outlets and backing up the city's sewage, as well as increase silt deposits, blocking shipping traffic along the Yangtze River. A parallel is drawn with the Sanmenxia Dam on the Yellow River. It was completed in 1960; it has proven to be useless for controlling floods while producing only one-third of its expected output due to massive silt build-up in the reservoir

  5. Development of evaluation method of fuel failure fraction during the High Temperature Engineering Test Reactor operation

    Energy Technology Data Exchange (ETDEWEB)

    Sawa, Kazuhiro; Yoshimuta, Shigeharu; Tobita, Tsutomu; Sato, Masashi [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1997-05-01

    The High Temperature Engineering Test Reactor (HTTR) uses coated particles as fuel. During normal operation, short-lived noble gases are mainly released by diffusion from fuel particles with defects in their coating layers (i.e., failed particle). Since noble gases do not plate out on the inner surfaces of primary cooling system, their activities in primary coolant reflect fuel failure fraction in the core. An evaluation method was developed to predict failure fraction of coated fuel particles during normal operation of the HTTR. The method predicts core-average and hot plenum regionwise failure fractions based on the fractional releases, (R/B)s, of noble gases. The (R/B)s are calculated by fission gas concentration measurements in the primary cooling system of the HTTR. Recent fabrication data show that through-coatings failure fraction is extremely low. Then, fractional release from matrix contamination uranium, which is background for accurate evaluation of the fuel failure fraction, should be precisely predicted. This report describes an evaluation method of fuel failure fraction from measurements in the HTTR together with a fission gas release model from fuel compact containing failed particles and matrix contamination uranium. (author)

  6. Spent fuel storage cask testing and operational experience at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Eslinger, L.E.; Schmitt, R.C.

    1989-01-01

    Spent-fuel storage cask research, development, and demonstration activities are being performed for the U.S. Department of Energy's (DOE's) Office of Civilian Radioactive Waste Management (OCRWM) as a part of the storage cask testing program. The cask testing program at federal sites and other locations supports the Nuclear Waste Policy Act (NWPA) and DOE objectives for cooperative demonstrations with the cask vendors and utilities for development of at-reactor dry cask storage capabilities for spent nuclear fuel assemblies. One research and development program for the storage cask performance testing of metal storage cask was initiated through a cooperative agreement between Virginia Power and DOE in 1984. The performance testing was conducted for the DOE and the Electric Power Research Institute by the Pacific Northwest laboratory, operated for DOE by Battelle Memorial Institute, and the Idaho National Engineering Laboratory (INEL), operated for DOE by EG ampersand G Idaho, Inc. In 1988 a cooperative agreement was entered into by DOE with Pacific Sierra Nuclear Associates (PSN) for performance testing of the PSN concrete Ventilated Storage Cask. Another closely related activity involving INEL is a transportable storage cask project identified as the Nuclear Fuel Services Spent-Fuel Shipping/Storage Cask Demonstration Project. The purpose of this project is to demonstrate the feasibility of packing, transporting, and storing commercial spent fuel in dual-purpose transport/storage casks

  7. Modeling and numerical simulation of greenhouse gas emissions from a stationary Diesel engine operating with ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Bergel, Andre; Viana, Sarah de Resende; Martins, Cristiane Aparecida [Instituto Tecnologica da Aeronautica - ITA, Sao Jose dos Campos, SP (Brazil)], e-mail: cmartins@ita.br; Souza, Francisco Jose de [Universidade Federal de Uberlandia (UFU), MG (Brazil)], e-mail: fjsouza@mecanica.ufu.br

    2010-07-01

    The present work aims at modeling and simulating a stationary, compression ignition motor, operating with ethanol at different levels of EGR. The objective is to quantify the influence of these parameters in the atmospheric pollutant emissions (CO, NO{sub X} and Particulate Matter). Specifications of a diesel engine were used, with compression ratio 19:1, operating with ethanol with a percentile of EGR of 0, 10, 20 and 30%. In the simulation, the combustion model, ECFM-3Z, and the turbulence model k-{zeta}-f were used, besides conditions for the temperatures of the combustion chamber, piston, cylinder head and glow plug. The spray characterization was done through the calculation of the injected fuel mass and parameters like spray angle, droplet size, number of holes, position of the injector and others. For the reduction of the simulation time, the crank angle range of is only 130[CAD], beginning at 30 deg BTDC and concluding at 100 deg ATDC. The assessment of the influence of the different EGR concentrations felt for the analysis of pollutant contained in the end of simulation. A very small delay in the ignition of the fuel injected and the emission of a minor amount of nitrogen oxides were observed in all cases as the EGR level used was increased. (author)

  8. Optimal operation of a micro-combined cooling, heating and power system driven by a gas engine

    International Nuclear Information System (INIS)

    Kong, X.Q.; Wang, R.Z.; Li, Y.; Huang, X.H.

    2009-01-01

    The objective of this paper is to investigate the problem of energy management and optimal operation of cogeneration system for micro-combined cooling, heating and power production (CCHP). The energy system mainly consists of a gas engine, an adsorption chiller, a gas boiler, a heat exchanger and an electric chiller. On the basis of an earlier experimental research of the micro-CCHP system, a non-linear-programming cost-minimization optimization model is presented to determine the optimum operational strategies for the system. It is shown that energy management and optimal operation of the micro-CCHP system is dependent upon load conditions to be satisfied and energy cost. In view of energy cost, it would not be optimal to operate the gas engine when the electric-to-gas cost ratio (EGCR) is very low. With higher EGCR, the optimum operational strategy of the micro-CCHP system is independent of energy cost

  9. Review and evaluation of Transamerica Delaval, Inc., diesel engine reliability and operability: Grand Gulf Nuclear Station Unit 1

    International Nuclear Information System (INIS)

    1984-07-01

    PNL and its consultants conclude that the TDI diesel engines at the GGNS have the needed operability and reliability to fulfill their intended (auxiliary) emergency power function for the first refueling cycle. This conclusion is reached with a number of understandings regarding limits to the engine requirements, NRC concurrence with MP and L findings/conclusions regarding items to be supplied to NRC, limitations on the engine Brake Mean Effective Pressure (BMEP), and MP and L's implementation of the modifications to their proposed surveillance and maintenance program

  10. Durability testing of medium speed diesel engine components designed for operating on coal/water slurry fuel

    Science.gov (United States)

    McDowell, R. E.; Giammarise, A. W.; Johnson, R. N.

    1994-01-01

    Over 200 operating cylinder hours were run on critical wearing engine parts. The main components tested included cylinder liners, piston rings, and fuel injector nozzles for coal/water slurry fueled operation. The liners had no visible indication of scoring nor major wear steps found on their tungsten carbide coating. While the tungsten carbide coating on the rings showed good wear resistance, some visual evidence suggests adhesive wear mode was present. Tungsten carbide coated rings running against tungsten carbide coated liners in GE 7FDL engines exhibit wear rates which suggest an approximate 500 to 750 hour life. Injector nozzle orifice materials evaluated were diamond compacts, chemical vapor deposited diamond tubes, and thermally stabilized diamond. Based upon a total of 500 cylinder hours of engine operation (including single-cylinder combustion tests), diamond compact was determined to be the preferred orifice material.

  11. Visualizing feasible operating ranges within tissue engineering systems using a "windows of operation" approach: a perfusion-scaffold bioreactor case study.

    Science.gov (United States)

    McCoy, Ryan J; O'Brien, Fergal J

    2012-12-01

    Tissue engineering approaches to developing functional substitutes are often highly complex, multivariate systems where many aspects of the biomaterials, bio-regulatory factors or cell sources may be controlled in an effort to enhance tissue formation. Furthermore, success is based on multiple performance criteria reflecting both the quantity and quality of the tissue produced. Managing the trade-offs between different performance criteria is a challenge. A "windows of operation" tool that graphically represents feasible operating spaces to achieve user-defined levels of performance has previously been described by researchers in the bio-processing industry. This paper demonstrates the value of "windows of operation" to the tissue engineering field using a perfusion-scaffold bioreactor system as a case study. In our laboratory, perfusion bioreactor systems are utilized in the context of bone tissue engineering to enhance the osteogenic differentiation of cell-seeded scaffolds. A key challenge of such perfusion bioreactor systems is to maximize the induction of osteogenesis but minimize cell detachment from the scaffold. Two key operating variables that influence these performance criteria are the mean scaffold pore size and flow-rate. Using cyclooxygenase-2 and osteopontin gene expression levels as surrogate indicators of osteogenesis, we employed the "windows of operation" methodology to rapidly identify feasible operating ranges for the mean scaffold pore size and flow-rate that achieved user-defined levels of performance for cell detachment and differentiation. Incorporation of such tools into the tissue engineer's armory will hopefully yield a greater understanding of the highly complex systems used and help aid decision making in future translation of products from the bench top to the market place. Copyright © 2012 Wiley Periodicals, Inc.

  12. Comparative performance of direct injection diesel engine operating on ethanol, petrol and rapeseed oil blends

    International Nuclear Information System (INIS)

    Labeckas, Gvidonas; Slavinskas, Stasys

    2009-01-01

    This article presents the bench testing results of a four stroke, four cylinder, direct injection, unmodified, diesel engine operating on pure rapeseed oil (RO) and its 2.5 vol%, 5 vol%, 7.5 vol% and 10 vol% blends with ethanol (ERO), petrol (PRO) and both improving agents applied in equal proportions as 50:50 vol% (EPRO). The purpose of the research is to examine the effect of ethanol and petrol addition into RO on the biofuel kinematical viscosity, brake mean effective pressure (bmep), brake specific fuel consumption (bsfc) of a diesel engine and its brake thermal efficiency (bte). Addition into RO from 2.5 to 7.5 vol% of ethanol and petrol its viscosity at ambient temperature of 20 deg. C diminishes by 9.2-28.3% and 14.1-31.7%, respectively. Heating up to the temperature of 60 deg. C the viscosity of pure RO, blends ERO2.5-7.5 and PRO2.5-10 further diminishes 4.2, 3.9-3.8 and 3.9-3.6 times. At 1800 min -1 speed, the maximum brake mean effective pressure (bmep) higher up to 1.6% comparing with that of pure RO (0.77 MPa) ensure three agent blends EPRO5-7.5, whereas at rated 2200 min -1 speed, the bmep higher by 5.6% can be obtained when fuelling the engine with blend PRO2.5. Brake specific fuel consumption (bsfc) at maximum torque (240.2 g/kWh) and rated power (234.0 g/kWh) is correspondingly lower by 3.4% and 5.5% in comparison with pure RO when biofuel blends EPRO5 and PRO2.5 are used. The biggest brake thermal efficiency at maximum torque (0.40-0.41) and rated power (0.42-0.43) relative to that of RO (0.39) suggest blends PRO2.5 and EPRO5-7.5, respectively

  13. 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

  14. 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...

  15. Use of radioisotopes for monitoring the operating conditions of marine Diesel engines

    International Nuclear Information System (INIS)

    Backofen, R.; Strickert, H.

    1981-01-01

    For assessing wear in marine Diesel engines a two-sample activation technique has been developed. The procedure is described, taking the determination of wear of piston rings in the running engine as an example

  16. Micro-cogeneration units based on Stirling engine for heating and their real operation

    Science.gov (United States)

    Čierny, Jaroslav; Patsch, Marek

    2014-08-01

    This article was deal with micro-cogeneration units based on Stirling engine. We watched problematic of real working Stirling engine. The article also contain hookup of unit constructed at University of Zilina.

  17. <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.

  18. Development of FJR710 turbofan engine and its operation with STOL research aircraft ASUKA''. FJR710 turbofan engine no kaihatsu to STOL jikkenki asuka ni yoru un prime yo

    Energy Technology Data Exchange (ETDEWEB)

    Nose, H; Morita, M; Sasaki, M [National Aerospace Lab., Tokyo (Japan)

    1990-07-05

    Flight experiment of ASUKA, STOL experimental m/c ended in March, 1990. In order to successively meet the future airplane development, operations have been operated to collect the technical results obtained from the development of experimental machines, flight experiment and related ground tests to form a data base. This report outlines the process of development of the FJR engines, and outlined the aerial engine test, the status of engine operation and the result of developing the reliability enhancement which has been conducted also after the end of the operations. It was demonstrated by the flight experiment of the experimental machine that such methods as the engine matching adopted in the engine mounting, nacelle design and engine mounting design were appropriate. The results of the technical development for the reliability improvement which had been in parallel were applied to the mounted engine and controlled to the safe and efficient flight experiments. 11 refs., 17 figs., 3 tabs.

  19. Performance and emission characteristics of a DI compression ignition engine operated on Honge, Jatropha and sesame oil methyl esters

    Energy Technology Data Exchange (ETDEWEB)

    Banapurmath, N.R.; Tewari, P.G. [Department of Mechanical Engineering, B.V.B. College of Engineering and Technology, Vidyanagar, Poona-Bangalore Road, Hubli 580031 (India); Hosmath, R.S. [Department of Mechanical Engineering, K.L.E' s C.E.T., Belgaum (India)

    2008-09-15

    The high viscosity of vegetable oils leads to problem in pumping and spray characteristics. The inefficient mixing of vegetable oils with air contributes to incomplete combustion. The best way to use vegetable oils as fuel in compression ignition (CI) engines is to convert it into biodiesel. Biodiesel is a methyl or ethyl ester of fatty acids made from vegetable oils (both edible and non-edible) and animal fat. The main resources for biodiesel production can be non-edible oils obtained from plant species such as Pongamia pinnata (Honge oil), Jatropha curcas (Ratanjyot), Hevea brasiliensis (Rubber) and Calophyllum inophyllum (Nagchampa). Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in CI engines with very little or no engine modifications. This is because it has properties similar to mineral diesel. This paper presents the results of investigations carried out on a single-cylinder, four-stroke, direct-injection, CI engine operated with methyl esters of Honge oil, Jatropha oil and sesame oil. Comparative measures of brake thermal efficiency, smoke opacity, HC, CO, NO{sub X}, ignition delay, combustion duration and heat release rates have been presented and discussed. Engine performance in terms of higher brake thermal efficiency and lower emissions (HC, CO, NO{sub X}) with sesame oil methyl ester operation was observed compared to methyl esters of Honge and Jatropha oil operation. (author)

  20. Generic evaluation of feedwater transients and small break loss-of-coolant accidents in combustion engineering designed operating plants

    International Nuclear Information System (INIS)

    1980-01-01

    The purpose of this report is to summarize the results of a generic evaluation of feedwater transients, small break loss-of-coolant accidents (LOCAs), and other TMI-2-related events in the Combustion Engineering (CE)-designed operating plants and to establish or confirm the bases for their continued operation. The results of this evaluation are presented in this report in the form of a set of findings and recommendations in each of the principal review areas

  1. The design, fabrication and operation of the mechanical systems for the Neutral Beam Engineering Test Facility

    International Nuclear Information System (INIS)

    Patterson, J.A.; Fong, M.; Koehler, G.W.; Low, W.; Purgalis, P.; Wells, R.P.

    1983-01-01

    The Neutral Beam Engineering Test Facility (NBETF) at the Lawrence Berkeley Laboratory (LBL) is a National Test Facility used to develop long pulse Neutral Beam Sources. The Facility will test sources up to 120 keV, 50 A, with 30 s beam-on times with a 10% duty factor. For this application, an actively cooled beam dump is required and one has been constructed capable of dissipating a wide range of power density profiles. The flexibility of the design is achieved by utilizing a standard modular panel design which is incorporated into a moveable support structure comprised of eight separately controllable manipulator assemblies. The thermal hydraulic design of the panels permits the dissipation of 2 kW/cm 2 anywhere on the panel surface. The cooling water requirements of the actively cooled dump system are provided by the closed loop Primary High Pressure Cooling Water System. To minimize the operating costs of continuously running this high power system, a variable speed hydraulic drive is used for the main pump. During beam pulses, the pump rotates at high speed, then cycles to low speed upon completion of the beam shot. A unique neutralizer design has been installed into the NBETF beamline. This is a gun-drilled moveable brazed assembly which provides continuous armoring of the beamline near the source. The unit penetrates the source mounting valve during operation and retracts to permit the valve to close as needed. The beamline also has an inertially cooled duct calorimeter assembly. This assembly is a moveable hinged matrix of copper plates that can be used as a beam stop up to pulse lengths of 50 ms. The beamline is also equipped with many beam scraper plates of differing detail design and dissipation capabilities

  2. Resin-based preparation of HTGR fuels: operation of an engineering-scale uranium loading system

    International Nuclear Information System (INIS)

    Haas, P.A.

    1977-10-01

    The fuel particles for recycle of 233 U to High-Temperature Gas-Cooled Reactors are prepared from uranium-loaded carboxylic acid ion exchange resins which are subsequently carbonized, converted, and refabricated. The development and operation of individual items of equipment and of an integrated system are described for the resin-loading part of the process. This engineering-scale system was full scale with respect to a hot demonstration facility, but was operated with natural uranium. The feed uranium, which consisted of uranyl nitrate solution containing excess nitric acid, was loaded by exchange with resin in the hydrogen form. In order to obtain high loadings, the uranyl nitrate must be acid deficient; therefore, nitric acid was extracted by a liquid organic amine which was regenerated to discharge a NaNO 3 or NH 4 NO 3 solution waste. Water was removed from the uranyl nitrate solution by an evaporator that yielded condensate containing less than 0.5 ppM of uranium. The uranium-loaded resin was washed with condensate and dried to a controlled water content via microwave heating. The loading process was controlled via in-line measurements of the pH and density of the uranyl nitrate. The demonstrated capacity was 1 kg of uranium per hour for either batch loading contractors or a continuous column as the resin loading contractor. Fifty-four batch loading runs were made without a single failure of the process outlined in the chemical flowsheet or any evidence of inability to control the conditions dictated by the flowsheet

  3. Best of the lot : engineered measurement-while-drilling tool improves efficiency of operations

    Energy Technology Data Exchange (ETDEWEB)

    Mahony, J.

    2010-10-15

    NuEra Oilfield Services Inc. combines various technologies, including advanced bearing assemblies and compact wireless decoders that interface with downhole directional tools, to engineer unique, purpose-built measurement-while-drilling (MWD) tool string packages. The 9-metre-long MWD tool string is lowered into the drill pipe from the surface. The directional module monitors the position of the drill bit, which the driller can monitor using an electronic drilling recorder at the surface. The directional drillstring uses a mud motor with adjustable bent housing to correct the direction of the well, as the system cannot steer while drilling. At bottomhole, mud circulation continues after the rotation of the drillstring has been stopped, driving the mud motor, which in turn drives the drill bit, permitting a new direction to be taken even though the drillstring is not turning. The operator points the bent housing in a new direction and slides the bit along before restarting the rotation of the drillstring. The NuEra drillstring uses a new bearing pack that makes the mud motor more robust and longer-lived, preventing costly down time for operators. The bearing pack is designed to distribute the load geometrically so that only one-third of the weight-on-bit is on the bearings at any point in time, which extends bearing life and reduces repair costs. The custom selection and mating of superior components made by different tool manufacturers has resulted in the MWD tool string that is reliable and able to pump more and carry more weight. 1 ref., 2 figs.

  4. Description and Operational Experiences of the Engineering Test Facility - Helium Technology (ETF-HT)

    International Nuclear Information System (INIS)

    Zhang Zuoyi; Yang Mingde; Bo Hanliang; Duan Riqqiang; Zhu Hongye

    2014-01-01

    This paper presents the configuration of the Engineering Test Facility - Helium Technology (ETF-HT) and the information of its key components and subsystems, which is located in the Changping campus of Tsinghua University. The ETF-HT facility began to be constructed in Jan. 2009. The main objective of the facility is to test and verify the thermo-hydraulic performance of one full-sized modular unit of HTR-PM helically coiled SG assembly. In the ETF-HT facility, electricity energy is used to heat the loop helium, centrifugal blower is used to circulate the helium medium, and the heat sink is one would-tested SG module. Up to now, except for the tested SG module, preheater and hot gas duct under way of construction, the other components has been installed in situ. Via the temporary connection of the installed components, the preliminary operation of the loop has been carried out to test its performances as can be done, which include the loop leak tightness, blower pneumatic performance and electrical heater at partial thermal load. (author)

  5. Design, fabrication and operation of the mechanical systems for the Neutral Beam Engineering Test Facility

    International Nuclear Information System (INIS)

    Paterson, J.A.; Biagi, L.A.; Fong, M.; Koehler, G.W.; Low, W.; Purgalis, P.; Wells, R.P.

    1983-12-01

    The Neutral Beam Engineering Test Facility (NBETF) at Lawrence Berkeley Laboratory (LBL) is a National Test Facility used to develop long pulse Neutral Beam Sources. The Facility will test sources up to 120 keV, 50 A, with 30 s beam-on times with a 10% duty factor. For this application, an actively cooled beam dump is required and one has been constructed capable of dissipating a wide range of power density profiles. The flexibility of the design is achieved by utilizing a standard modular panel design which is incorporated into a moveable support structure comprised of eight separately controllable manipulator assemblies. A unique neutralizer design has been installed into the NBETF beamline. This is a gun-drilled moveable brazed assembly which provides continuous armoring of the beamline near the source. The unit penetrates the source mounting valve during operation and retracts to permit the valve to close as needed. The beamline is also equpped with many beam scraper plates of differing detail design and dissipation capabilities

  6. Effect of oxygenate additive on diesel engine fuel consumption and emissions operating with biodiesel-diesel blend at idling conditions

    Science.gov (United States)

    Mahmudul, H. M.; Hagos, F. Y.; Mamat, R.; Noor, M. M.; Yusri, I. M.

    2017-10-01

    Biodiesel is promising alternative fuel to run the automotive engine but idling is the main problem to run the vehicles in a big city. Vehicles running with idling condition cause higher fuel supply and higher emission level due to being having fuel residues in the exhaust. The purpose of this study is to evaluate the impact of alcohol additive on fuel consumption and emissions parameters under idling conditions when a multicylinder diesel engine operates with the diesel-biodiesel blend. The study found that using 5% butanol as an additive with B5 (5% Palm biodiesel + 95% diesel) blends fuel lowers brake specific fuel consumption and CO emissions by 38% and 20% respectively. But the addition of butanol increases NOx and CO2 emissions. Based on the result it can be said that 5% butanol can be used in a diesel engine with B5 without any engine modifications to tackle the idling problem.

  7. Performance of a hybrid hydrogen–gasoline engine under various operating conditions

    International Nuclear Information System (INIS)

    Ji, Changwei; Wang, Shuofeng; Zhang, Bo

    2012-01-01

    Highlights: ► We develop a combustion strategy for the hybrid hydrogen–gasoline engine (HHGE). ► The HHGE produced much lower HC and CO emissions at cold start. ► The H 2 -gasoline blends were effective for improving engine performance at idle and part loads. ► The HHGE could run smoothly at lean conditions. -- Abstract: This paper proposed a new combustion strategy for the spark-ignited (SI) engines. A gasoline engine was converted into a hybrid hydrogen–gasoline engine (HHGE) by adding a hydrogen injection system and a hybrid electronic control unit. Different from the conventional gasoline and hydrogen–enriched gasoline engines, the HHGE is fueled with the pure hydrogen at cold start to produce almost zero emissions, with the hydrogen–gasoline blends at idle and part loads to further improve thermal efficiency and reduce emissions, and with the pure gasoline to ensure the engine power output at high loads. Because the HHGE is fueled with the pure gasoline at high loads and speeds, experiments are only conducted at clod start, idle and part load conditions. Since lean combustion avails the further improvement of the engine performance, the HHGE was fueled with the lean mixtures in all tests. The experimental results showed that the hybrid hydrogen–gasoline engine was started successfully with the pure hydrogen, which produced 94.7% and 99.5% reductions in HC and CO emissions within 100 s from the onset of the cold start, compared with the original gasoline engine. At an excess air ratio of 1.37 and idle conditions, indicated thermal efficiency of the 3% hydrogen–blended gasoline engine was 46.3% higher than that of the original engine. Moreover, the engine cyclic variation was eased, combustion duration was shortened and HC, CO and NOx emissions were effectively reduced for the hybrid hydrogen–gasoline engines.

  8. Comparison of the combustion engine operating parameters and the ecological indicators of an urban bus in dynamic type approval tests and in actual operating conditions

    Directory of Open Access Journals (Sweden)

    Rymaniak Lukasz

    2017-01-01

    Full Text Available The article presents the considerations regarding a city bus combustion engine performanceparameters in dynamic type approval tests and in real operating conditions when servicing an urban bus line. A comparison of the designated engine operating time shares with respect to load and crankshaft rotational speed was made. The analysis included the ETC and WHTC tests, which showed significant discrepancies in the work areas of internal combustion engines in these test when compared to actual driving conditions. The details of the type approval tests used and the method of their denormalization for the drive unit were presented. The vehicle used for this research was an eighteen meter city bus equipped with a CI engine with a displacement of 9.2 dm3. The latest PEMS mobile equipment technology was used to conduct the road measurements. This allowed the emission indicators for CO, HC, NOx and PM to be determined, including specific emissions. The obtained values were then compared with the Euro V limits.The analysis of the test results was supplemented with the calculation of fuel consumption using the carbonbalance method.

  9. Nuclear decontamination and decommissioning operations at the Idaho National Engineering and Environmental Laboratory (INEEL)

    International Nuclear Information System (INIS)

    Meservey, R.H.; Kenoyer, D.J.; Frazee, B.J.

    1997-01-01

    The Idaho National engineering and Environmental Laboratory (INEEL) is home of the largest concentration of nuclear reactors in the world. In addition to the reactors, many fuel reprocessing, laboratory, and other nuclear support facilities have been operated at the INEEL. Many have already been decontaminated and decommissioned (D and D) and many more are in the planning stages for such activities. A full time D and D program has been in existence at the INEEL for the past 20 years. Starting with a long range plan for D and D of all surplus contaminated facilities at the INEEL, and ending with the verification of the free release of those facilities after decommissioning, all aspects of D and D activities are covered. Topics covered in this paper include the INEEL D and D Long Range Plan, the D and D Porject Managers Handbook, the use of ASTM Standard Guides in decommissioning operations, and the INEEL D and D Technology Logic Diagrams. The identification and preparation of safety plans, environmental documentation, and operational procedures will also be covered in the presentation. The selection and use of advanced technologies to improve safety, reduce costs, and shorten D and D schedules is very important to the nuclear industry. In addition to a discussion of the D and D Technology Logic Diagrams, a discussion of new and improved technologies in use at the INEEL and other department of energy facilities will be presented. This will include brief discussions of work being performed at three Department of Energy Large Scale D and D Technology Demonstration projects. These include technology demonstrations at a Test Reactor, Uranium Fabrication Plant, and a large Production Reactor. Unique technologies which have been developed and tested at the INEEL will also be covered in the presentation. These include the biological decontamination of concrete, a laser enhanced zero added waste cutting, abraiding, and drilling technology, and the development of an

  10. A Data Filter for Identifying Steady-State Operating Points in Engine Flight Data for Condition Monitoring Applications

    Science.gov (United States)

    Simon, Donald L.; Litt, Jonathan S.

    2010-01-01

    This paper presents an algorithm that automatically identifies and extracts steady-state engine operating points from engine flight data. It calculates the mean and standard deviation of select parameters contained in the incoming flight data stream. If the standard deviation of the data falls below defined constraints, the engine is assumed to be at a steady-state operating point, and the mean measurement data at that point are archived for subsequent condition monitoring purposes. The fundamental design of the steady-state data filter is completely generic and applicable for any dynamic system. Additional domain-specific logic constraints are applied to reduce data outliers and variance within the collected steady-state data. The filter is designed for on-line real-time processing of streaming data as opposed to post-processing of the data in batch mode. Results of applying the steady-state data filter to recorded helicopter engine flight data are shown, demonstrating its utility for engine condition monitoring applications.

  11. Putting ROSE to Work: A Proposed Application of a Request-Oriented Scheduling Engine for Space Station Operations

    Science.gov (United States)

    Jaap, John; Muery, Kim

    2000-01-01

    Scheduling engines are found at the core of software systems that plan and schedule activities and resources. A Request-Oriented Scheduling Engine (ROSE) is one that processes a single request (adding a task to a timeline) and then waits for another request. For the International Space Station, a robust ROSE-based system would support multiple, simultaneous users, each formulating requests (defining scheduling requirements), submitting these requests via the internet to a single scheduling engine operating on a single timeline, and immediately viewing the resulting timeline. ROSE is significantly different from the engine currently used to schedule Space Station operations. The current engine supports essentially one person at a time, with a pre-defined set of requirements from many payloads, working in either a "batch" scheduling mode or an interactive/manual scheduling mode. A planning and scheduling process that takes advantage of the features of ROSE could produce greater customer satisfaction at reduced cost and reduced flow time. This paper describes a possible ROSE-based scheduling process and identifies the additional software component required to support it. Resulting changes to the management and control of the process are also discussed.

  12. 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.

  13. A new systems engineering approach to streamlined science and mission operations for the Far Ultraviolet Spectroscopic Explorer (FUSE)

    Science.gov (United States)

    Butler, Madeline J.; Sonneborn, George; Perkins, Dorothy C.

    1994-01-01

    The Mission Operations and Data Systems Directorate (MO&DSD, Code 500), the Space Sciences Directorate (Code 600), and the Flight Projects Directorate (Code 400) have developed a new approach to combine the science and mission operations for the FUSE mission. FUSE, the last of the Delta-class Explorer missions, will obtain high resolution far ultraviolet spectra (910 - 1220 A) of stellar and extragalactic sources to study the evolution of galaxies and conditions in the early universe. FUSE will be launched in 2000 into a 24-hour highly eccentric orbit. Science operations will be conducted in real time for 16-18 hours per day, in a manner similar to the operations performed today for the International Ultraviolet Explorer. In a radical departure from previous missions, the operations concept combines spacecraft and science operations and data processing functions in a single facility to be housed in the Laboratory for Astronomy and Solar Physics (Code 680). A small missions operations team will provide the spacecraft control, telescope operations and data handling functions in a facility designated as the Science and Mission Operations Center (SMOC). This approach will utilize the Transportable Payload Operations Control Center (TPOCC) architecture for both spacecraft and instrument commanding. Other concepts of integrated operations being developed by the Code 500 Renaissance Project will also be employed for the FUSE SMOC. The primary objective of this approach is to reduce development and mission operations costs. The operations concept, integration of mission and science operations, and extensive use of existing hardware and software tools will decrease both development and operations costs extensively. This paper describes the FUSE operations concept, discusses the systems engineering approach used for its development, and the software, hardware and management tools that will make its implementation feasible.

  14. NOx, Soot, and Fuel Consumption Predictions under Transient Operating Cycle for Common Rail High Power Density Diesel Engines

    Directory of Open Access Journals (Sweden)

    N. H. Walke

    2016-01-01

    Full Text Available Diesel engine is presently facing the challenge of controlling NOx and soot emissions on transient cycles, to meet stricter emission norms and to control emissions during field operations. Development of a simulation tool for NOx and soot emissions prediction on transient operating cycles has become the most important objective, which can significantly reduce the experimentation time and cost required for tuning these emissions. Hence, in this work, a 0D comprehensive predictive model has been formulated with selection and coupling of appropriate combustion and emissions models to engine cycle models. Selected combustion and emissions models are further modified to improve their prediction accuracy in the full operating zone. Responses of the combustion and emissions models have been validated for load and “start of injection” changes. Model predicted transient fuel consumption, air handling system parameters, and NOx and soot emissions are in good agreement with measured data on a turbocharged high power density common rail engine for the “nonroad transient cycle” (NRTC. It can be concluded that 0D models can be used for prediction of transient emissions on modern engines. How the formulated approach can also be extended to transient emissions prediction for other applications and fuels is also discussed.

  15. CO and PAH Emissions from Engines Operating on Biomass Producer Gas

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Jensen, Torben Kvist; Henriksen, Ulrik Birk

    2003-01-01

    High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. The standing regulations concerning CO emissions from producer gas engine based power plants in most EU countrie...

  16. Method of operating a thermal engine powered by a chemical reaction

    Science.gov (United States)

    Ross, J.; Escher, C.

    1988-06-07

    The invention involves a novel method of increasing the efficiency of a thermal engine. Heat is generated by a non-linear chemical reaction of reactants, said heat being transferred to a thermal engine such as Rankine cycle power plant. The novel method includes externally perturbing one or more of the thermodynamic variables of said non-linear chemical reaction. 7 figs.

  17. Systems Engineering Management Plan for Tank Farm Restoration and Safety Operations, Project W-314

    International Nuclear Information System (INIS)

    MCGREW, D.L.

    2000-01-01

    The Systems Engineering Management Plan for Project W-314 has been prepared within the guidelines of HNF-SD-WM-SEMP-002, TWRS Systems Engineering Management Plan. The activities within this SEMP have been tailored, in accordance with the TWRS SEMP and DOE Order 430.1, Life Cycle Asset Management, to meet the needs of the project

  18. IMPROVMENT OF EFFECTIVE POWER OF THE DIESEL, ENGINE OPERATING ON MIXED BIODIESEL FUEL

    Directory of Open Access Journals (Sweden)

    A. Levterov

    2014-02-01

    Full Text Available The results of calculation and experimental studies of ways to increase the effective power of the bіodiesel engine and determine the effect of this increase on the economic and environmental performance of the diesel engine are presented in the given paper.

  19. 14 CFR 33.5 - Instruction manual for installing and operating the engine.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Instruction manual for installing and... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES General § 33.5 Instruction manual for... not part of the engine type design, the interface conditions and reliability requirements for those...

  20. Lessons Learned on University Education Programs of Chemical Engineering Principles for Nuclear Plant Operations - 13588

    International Nuclear Information System (INIS)

    Ryu, Jun-hyung

    2013-01-01

    University education aims to supply qualified human resources for industries. In complex large scale engineering systems such as nuclear power plants, the importance of qualified human resources cannot be underestimated. The corresponding education program should involve many topics systematically. Recently a nuclear engineering program has been initiated in Dongguk University, South Korea. The current education program focuses on undergraduate level nuclear engineering students. Our main objective is to provide industries fresh engineers with the understanding on the interconnection of local parts and the entire systems of nuclear power plants and the associated systems. From the experience there is a huge opportunity for chemical engineering disciple in the context of giving macroscopic overview on nuclear power plant and waste treatment management by strengthening the analyzing capability of fundamental situations. (authors)

  1. Artificial neural networks for dynamic monitoring of simulated-operating parameters of high temperature gas cooled engineering test reactor (HTTR)

    International Nuclear Information System (INIS)

    Seker, Serhat; Tuerkcan, Erdinc; Ayaz, Emine; Barutcu, Burak

    2003-01-01

    This paper addresses to the problem of utilisation of the artificial neural networks (ANNs) for detecting anomalies as well as physical parameters of a nuclear power plant during power operation in real time. Three different types of neural network algorithms were used namely, feed-forward neural network (back-propagation, BP) and two types of recurrent neural networks (RNN). The data used in this paper were gathered from the simulation of the power operation of the Japan's High Temperature Engineering Testing Reactor (HTTR). For the wide range of power operation, 56 signals were generated by the reactor dynamic simulation code for several hours of normal power operation at different power ramps between 30 and 100% nominal power. Paper will compare the outcomes of different neural networks and presents the neural network system and the determination of physical parameters from the simulated operating data

  2. Minimum Specific Fuel Consumption of a Liquid-Cooled Multicylinder Aircraft Engine as Affected by Compression Ratio and Engine Operating Conditions

    Science.gov (United States)

    Brun, Rinaldo J.; Feder, Melvin S.; Harries, Myron L.

    1947-01-01

    An investigation was conducted on a 12-cylinder V-type liquid-cooled aircraft engine of 1710-cubic-inch displacement to determine the minimum specific fuel consumption at constant cruising engine speed and compression ratios of 6.65, 7.93, and 9.68. At each compression ratio, the effect.of the following variables was investigated at manifold pressures of 28, 34, 40, and 50 inches of mercury absolute: temperature of the inlet-air to the auxiliary-stage supercharger, fuel-air ratio, and spark advance. Standard sea-level atmospheric pressure was maintained at the auxiliary-stage supercharger inlet and the exhaust pressure was atmospheric. Advancing the spark timing from 34 deg and 28 deg B.T.C. (exhaust and intake, respectively) to 42 deg and 36 deg B.T.C. at a compression ratio of 6.65 resulted in a decrease of approximately 3 percent in brake specific fuel consumption. Further decreases in brake specific fuel consumption of 10.5 to 14.1 percent (depending on power level) were observed as the compression ratio was increased from 6.65 to 9.68, maintaining at each compression ratio the spark advance required for maximum torque at a fuel-air ratio of 0.06. This increase in compression ratio with a power output of 0.585 horsepower per cubic inch required a change from . a fuel- lend of 6-percent triptane with 94-percent 68--R fuel at a compression ratio of 6.65 to a fuel blend of 58-percent, triptane with 42-percent 28-R fuel at a compression ratio of 9.68 to provide for knock-free engine operation. As an aid in the evaluation of engine mechanical endurance, peak cylinder pressures were measured on a single-cylinder engine at several operating conditions. Peak cylinder pressures of 1900 pounds per square inch can be expected at a compression ratio of 9.68 and an indicated mean effective pressure of 320 pounds per square inch. The engine durability was considerably reduced at these conditions.

  3. A Continuing Education Short Course and Engineering Curriculum to Accelerate Workforce Development in Wind Power Plant Design, Construction, and Operations

    Energy Technology Data Exchange (ETDEWEB)

    Tinjum, James [Univ. of Wisconsin, Madison, WI (United States)

    2012-11-29

    Significant advances in wind turbine technology and wind turbine power plant capabilities are appearing in the U.S. Sites that only 10 years ago might have been overlooked are being considered for build out. However, the development of a skilled workforce in the engineering fields and construction trades lags the potential market, especially if the industry is expected to site, design, construct, and operate sufficient wind power plant sites to meet the potential for 20% wind energy by 2030. A select few firms have penetrated the engineer-procure-construction (EPC) market of wind power plant construction. Competition and know-how in this market is vital to achieve cost-effective, design-construct solutions. The industry must produce or retrain engineers, contractors, and technicians to meet ambitious goals. Currently, few universities offer undergraduate or graduate classes that teach the basics in designing, building, and maintaining wind power plants that are safe, efficient, and productive.

  4. Application of integrated computer-aided engineering for design, construction and operation of nuclear power plant

    International Nuclear Information System (INIS)

    Kyung-shick Min; Byung-hun Lee

    1987-01-01

    Computer-aided-engineering (CAE) is an essential tool for modern nuclear power plant engineering. It greatly varies in definition, application, and technology from project to project and company to company. Despite the fast growing technologies and applications of CAE, its complexty and variety have thrown aonther puzzle to management of a nuclear project. Without due consideration of an integrated CAE system in early planning stage, the overall efficiency of a nuclear project would slow down due to the inefficiency in data flow. In this paper, practices and perspectives of CAE appliation are discussed under the Korea Power Engineering Company (KOPEC) philosophy in CAE approach. (author)

  5. Impacts of fuel formulation and engine operating parameters on the nanostructure and reactivity of diesel soot

    Science.gov (United States)

    Yehliu, Kuen

    This study focuses on the impacts of fuel formulations on the reactivity and nanostructure of diesel soot. A 2.5L, 4-cylinder, turbocharged, common rail, direct injection light-duty diesel engine was used in generating soot samples. The impacts of engine operating modes and the start of combustion on soot reactivity were investigated first. Based on preliminary investigations, a test condition of 2400 rpm and 64 Nm, with single and split injection strategies, was chosen for studying the impacts of fuel formulation on the characteristics of diesel soot. Three test fuels were used: an ultra low sulfur diesel fuel (BP15), a pure soybean methyl-ester (B100), and a synthetic Fischer-Tropsch fuel (FT) produced in a gas-to-liquid process. The start of injection (SOI) and fuel rail pressures were adjusted such that the three test fuels have similar combustion phasing, thereby facilitating comparisons between soots from the different fuels. Soot reactivity was investigated by thermogravimetric analysis (TGA). According to TGA, B100 soot exhibits the fastest oxidation on a mass basis followed by BP15 and FT derived soots in order of apparent rate constant. X-ray photoelectron spectroscopy (XPS) indicates no relation between the surface oxygen content and the soot reactivity. Crystalline information for the soot samples was obtained using X-ray diffraction (XRD). The basal plane diameter obtained from XRD was inversely related to the apparent rate constants for soot oxidation. For comparison, high resolution transmission electron microscopy (HRTEM) provided images of the graphene layers. Quantitative image analysis proceeded by a custom algorithm. B100 derived soot possessed the shortest mean fringe length and greatest mean fringe tortuosity. This suggests soot (nano)structural disorder correlates with a faster oxidation rate. Such results are in agreement with the X-ray analysis, as the observed fringe length is a measure of basal plane diameter. Moreover the relation

  6. The systems engineering design of a smart Forward Operating Base surveillance system for forward operating base protection

    OpenAIRE

    Craft, Timothy L.

    2013-01-01

    Approved for public release; distribution is unlimited Forward operating bases are vulnerable to terrorist activity due to their location and limited resources. Threat awareness under these conditions is paramount to the safety of the personnel and to mission accomplishment. In the absence of the manpower required to maintain complete and continuous monitoring of the FOBs surroundings, an automated surveillance system is needed. The Smart FOB Surveillance System (SFSS) employs a multi-agen...

  7. 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.

  8. System of systems engineering - the link between operational needs and system requirements

    CSIR Research Space (South Africa)

    Smith, CJ

    2012-06-01

    Full Text Available Recently, defence capability development practices have moved towards approaches that include capability based planning and traditional systems engineering methodologies. Internationally, defence force capability development efforts struggle...

  9. Operation, analysis, and design of signalized intersections : a module for the introductory course in transportation engineering.

    Science.gov (United States)

    2014-02-01

    This report presents materials that can be used as the basis for a module on signalized intersections in the introductory : course in transportation engineering. The materials were developed based on studies of the work of students who took : this in...

  10. Cycle to Cycle Variation Study in a Dual Fuel Operated Engine

    KAUST Repository

    Pasunurthi, Shyamsundar; Jupudi, Ravichandra; Wijeyakulasuriya, Sameera; Gubba, Sreenivasa Rao; Im, Hong G.; Jaasim, Mohammed; Primus, Roy; Klingbeil, Adam; Finney, Charles

    2017-01-01

    The standard capability of engine experimental studies is that ensemble averaged quantities like in-cylinder pressure from multiple cycles and emissions are reported and the cycle to cycle variation (CCV) of indicated mean effective pressure (IMEP

  11. The physical work environment and end-user requirements: Investigating marine engineering officers' operational demands and ship design.

    Science.gov (United States)

    Mallam, Steven C; Lundh, Monica

    2016-08-12

    Physical environments influence how individuals perceive a space and behave within it. Previous research has revealed deficiencies in ship engine department work environments, and their impact on crew productivity, health and wellbeing. Connect operational task demands to pragmatic physical design and layout solutions by implementing a user-centric perspective. Three focus groups, each consisting of three marine engineers participated in this study. Focus groups were divided into two sessions: first, to investigate the end-user's operational requirements and their relationship with ship physical design and layout. Second, criteria formulated from group discussions were applied to a ship design case study. All focus group sessions were audio recorded and transcribed verbatim. The data were analyzed using Grounded Theory. Design choices made in a ships general arrangement were described to inherently influence how individuals and teams are able to function within the system. Participants detailed logistical relationships between key areas, stressing that the work environment and physical linkages must allow for flexibility of work organization and task execution. Traditional engine control paradigms do not allow effective mitigation of traditional engine department challenges. The influence of technology and modernization of ship systems can facilitate improvement of physical environments and work organization if effectively utilized.

  12. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE - MANIFOLD DESIGN FOR CONTROLLING ENGINE AIR BALANCE

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Bourn; Ford A. Phillips; Ralph E. Harris

    2005-12-01

    This document provides results and conclusions for Task 15.0--Detailed Analysis of Air Balance & Conceptual Design of Improved Air Manifolds in the ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure'' project. SwRI{reg_sign} is conducting this project for DOE in conjunction with Pipeline Research Council International, Gas Machinery Research Council, El Paso Pipeline, Cooper Compression, and Southern Star, under DOE contract number DE-FC26-02NT41646. The objective of Task 15.0 was to investigate the perceived imbalance in airflow between power cylinders in two-stroke integral compressor engines and develop solutions via manifold redesign. The overall project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity.

  13. Heat exchanger operation in the externally heated air valve engine with separated settling chambers

    International Nuclear Information System (INIS)

    Kazimierski, Zbyszko; Wojewoda, Jerzy

    2014-01-01

    The crucial role in the externally heated air valve engine is played by its heat exchangers which work in a closed cycle. These are: a heater and a cooler and they are subject to a numerical analysis in the paper. Both of them are equipped with fixed volumes that are separate settling chambers causing that heat exchangers behave as almost stationary recuperators and analysis of the stationary behaviour is the main goal of the paper. Power and efficiency of the engine must be not lower than their averaged values for the same engine working in unsteady conditions. The results of calculations confirm such a statement. The pressure drop in the exchanger is another natural phenomenon presented. It has been overcome by use of additional blowers and the use of them is an additional focus of the presented analysis. A separation of settling chambers and additional blowers is a novelty in the paper. There is also a pre-heater applied in the engine which does not differ from well-known heat exchangers met in energy generation devices. The main objective of the paper is to find the behaviour of the engine model under stationary conditions of the heat exchangers and compare it with the non-stationary ones. - Highlights: • Externally heated air engine combined with forced working gas flow (supercharging). • Separate settling chambers allow for achieving stable and constant heat exchange parameters. • Pressure drop in heat exchangers overcome by additional blowers. • Reciprocating piston air engine, cam governing system, standard lubrication for externally heated engine. • Different fuels: oil, coal, gas, biomass also solar or nuclear energy

  14. Fuel injection system and method of operating the same for an engine

    Science.gov (United States)

    Topinka, Jennifer Ann [Niskayuna, NY; DeLancey, James Peter [Corinth, NY; Primus, Roy James [Niskayuna, NY; Pintgen, Florian Peter [Niskayuna, NY

    2011-02-15

    A fuel injector is coupled to an engine. The fuel injector includes an injection opening configured to vary in cross-section between a open state and a fully closed state. The fuel injector is configured to provide a plurality of discrete commanded fuel injections into an engine cylinder by modulating the size of the injection opening without completely closing the opening to the fully closed state.

  15. Situation Desperate: U.S. Army Engineer Disaster Relief Operations, Origins to 1950

    Science.gov (United States)

    2011-01-01

    the Sabine River sub- office, for example, relayed the following sad report to headquarters: “I regret to report the loss of all property in my...doctor with typhoid vaccine ; the cows and horses and dogs of every description wandering up and down the levees; the fur- niture, every kind of...215 Sabine River, 59 Sacramento Engineer District, 237, 238 Sacramento River, 186, 237 St. Francis River, 85, 87 St. Joe River, 217 St. Louis Engineer

  16. Thermal balance of a four stroke SI engine operating on hydrogen as a supplementary fuel

    International Nuclear Information System (INIS)

    Yueksel, F.; Ceviz, M.A.

    2003-01-01

    This paper investigates the effects of adding constant quantity hydrogen to gasoline-air mixture on SI engine thermal balance and performance. A four stroke, four-cylinder SI engine was used for conducting this study. Thermal balance tests were conducted for engine thermal efficiency, heat loss through the exhaust gases, heat loss to the cooling water and unaccounted losses (i.e. heat lost by lubricating oil, radiation), while performance tests were in respect to the brake power, specific fuel consumption and air ratio. Hydrogen supplementations were used with three different and fixed mass flow rates; 0.129, 0.168 and 0.208 kg h -1 at near three-fourth throttle opening position and variable engine speed ranging from 1000 to 4500 rpm. The results showed that supplementation of hydrogen to gasoline decreases the heat loss to cooling water and unaccounted losses, and the heat loss through the exhaust gas is nearly the same with pure gasoline experiments. Additionally, specific fuel consumption decreases, while the engine thermal efficiency and the air ratio increase. Engine performance parameters such as thermal efficiency and specific fuel consumption improved the level of the ratio of hydrogen mass flow rate to that of gasoline up to 5%

  17. Model-Based Systems Engineering With the Architecture Analysis and Design Language (AADL) Applied to NASA Mission Operations

    Science.gov (United States)

    Munoz Fernandez, Michela Miche

    2014-01-01

    The potential of Model Model Systems Engineering (MBSE) using the Architecture Analysis and Design Language (AADL) applied to space systems will be described. AADL modeling is applicable to real-time embedded systems- the types of systems NASA builds. A case study with the Juno mission to Jupiter showcases how this work would enable future missions to benefit from using these models throughout their life cycle from design to flight operations.

  18. Afghan National Engineer Brigade: Despite U.S. Training Efforts, the Brigade is Incapable of Operating Independently

    Science.gov (United States)

    2016-01-01

    For more information , contact SIGAR Public Affairs at (703) 545-5974 or sigar.pentagon.ccr.mbx.public-affairs@mail.mil. WHAT SIGAR REVIEWED To...training—army staff on leave for holidays, political events, low literacy levels, and security concerns—also delayed NEB training. In addition, a Joint...training provides basic information on military engineering, such as mobility, countermobility, and survivability operations, as well as the

  19. Backup power working group best practices handbook for maintenance and operation of engine generators, Volume 1. Revision 1

    International Nuclear Information System (INIS)

    Gross, R.; Padgett, A.B.; Burrows, K.P.; Fairchild, P.N.; Lam, T.; Janes, J.

    1997-01-01

    This handbook is divided into the four chapters. Chapter one covers the design, procurement, storage, handling and testing of diesel fuel oil to be used in DOE backup power supplies. Chapter two discusses the selection of automatic transfer switches to be used in DOE backup power supplies. Chapter three is about low voltage open frame air circuit breaker operation, testing, and maintenance for DOE backup power supplies. And chapter four covers installation, design, and maintenance of engine cooling water and jacket water systems

  20. The Design and Research of the Operation Status Detector for Marine Engine Room Power Plant Based on Noise

    Directory of Open Access Journals (Sweden)

    Li Hang

    2016-01-01

    Full Text Available Designed in this paper, based on the noise of ship engine room power plant running status of detector, is mainly used in the operation of the power plant of acoustic shell size to determine when the machine running state, this device is composed of signal disposal and alarm display adjustment part of two parts. Detector that can show the size of the voice, if exceed the set limit alarm value, the detector can sound an alarm, to remind staff equipment fails, it shall timely inspection maintenance, improve the safety of the operation of the ship.

  1. Engineering evaluation/conceptual plan for the 200-UP-1 Groundwater Operable Unit interim remedial measure. Revision 2

    International Nuclear Information System (INIS)

    1996-03-01

    This report presents an engineering evaluation and conceptual plan for an interim remedial measure (IRM) to address a uranium and technetium-99 groundwater plume in the 200-UP-1 Groundwater Operable Unit located in the 200 West Area of the Hanford Site. This report provides information regarding the need for an IRM and its potentially achievable objectives and goals. The report also evaluates alternatives to contain elevated concentrations of uranium and technetium-99 and to obtain information necessary to develop final remedial actions for the operable unit

  2. Experimental Evaluation of SI Engine Operation Supplemented by Hydrogen Rich Gas from a Compact Plasma Boosted Reformer

    International Nuclear Information System (INIS)

    J. B. Green, Jr.; N. Domingo; J. M. E. Storey; R.M. Wagner; J.S. Armfield; L. Bromberg; D. R. Cohn; A. Rabinovich; N. Alexeev

    2000-01-01

    It is well known that hydrogen addition to spark-ignited (SI) engines can reduce exhaust emissions and increase efficiency. Micro plasmatron fuel converters can be used for onboard generation of hydrogen-rich gas by partial oxidation of a wide range of fuels. These plasma-boosted microreformers are compact, rugged, and provide rapid response. With hydrogen supplement to the main fuel, SI engines can run very lean resulting in a large reduction in nitrogen oxides (NO x ) emissions relative to stoichiometric combustion without a catalytic converter. This paper presents experimental results from a microplasmatron fuel converter operating under variable oxygen to carbon ratios. Tests have also been carried out to evaluate the effect of the addition of a microplasmatron fuel converter generated gas in a 1995 2.3-L four-cylinder SI production engine. The tests were performed with and without hydrogen-rich gas produced by the plasma boosted fuel converter with gasoline. A one hundred fold reduction in NO x due to very lean operation was obtained under certain conditions. An advantage of onboard plasma-boosted generation of hydrogen-rich gas is that it is used only when required and can be readily turned on and off. Substantial NO x reduction should also be obtainable by heavy exhaust gas recirculation (EGR) facilitated by use of hydrogen-rich gas with stoichiometric operation

  3. Performance and exhaust emission characteristics of direct-injection Diesel engine when operating on shale oil

    International Nuclear Information System (INIS)

    Labeckas, Gvidonas; Slavinskas, Stasys

    2005-01-01

    This article presents the comparative bench testing results of a naturally aspirated, four stroke, four cylinder, water cooled, direct injection Diesel engine when running on Diesel fuel and shale oil that is produced in Estonia from local oil shale. The purpose of this research is to investigate the possibility of practical usage of the shale oil as the alternative fuel for a high speed Diesel engine as well as to evaluate the combustion efficiency, brake specific fuel consumption, emission composition changes and the smoke opacity of the exhausts. Test results show that when fuelling a fully loaded engine with shale oil, the brake specific fuel consumption at the maximum torque and rated power is correspondingly higher by 12.3% and 20.4%. However, the brake thermal efficiencies do not differ widely and their maximum values remain equal to 0.36-0.37 for Diesel fuel and 0.32-0.33 for shale oil. The total nitrogen oxide emissions from the shale oil at engine partial loads remain considerably lower although when running at the maximum torque and rated power, the NO x emissions become correspondingly higher by 21.8% and 27.6%. The smoke opacity of the fully loaded engine at a wide range of speeds is lower by 30-35%, whereas the carbon monoxide and unburned hydrocarbon emissions in the exhausts at moderate and full load regimes do not undergo significant changes

  4. Biofuel and Hydrogen Influence for Operation Parameters of Spark Ignition Engine

    Directory of Open Access Journals (Sweden)

    Martynas Damaševičius

    2016-12-01

    Full Text Available Paper presents research of efficient and ecological parameters of gasoline engine working with biobuthanol (10% and 20% by volume and addi-tionaly supplying oxygen and hydrogen (HHO gas mixture (3.6 l/min, which was obtained from from water by electrolysis. Biobuthanol addition decreases rate of heat release, the combustion temperature and pressure are lower, which has an influence on lower nitrous oxide (NOx emission in exhaust gases. However, biobuthanol increases carbon monoxide (CO concentration. Biobuthanol fuel has a simplier molecular structure, therefore the concentration of HC in the exhaust gas is decreasing. Due to lower heating value of biobuthanol fuel and slower combustion process, the engine efficiency decreases and specific fuel consumptions increase. The change of engine energetical indicators due to biobuthanol, can be compensated with advanced ignition angle. Using experimental investigation, it was determined, that negative biobuthanol influence for the combustion process and engine efficient inicators can be compensated also by additional supplied HHO gas, in which the hydrogen element iprove fuel mixture com-bustion. Fuel combustion process analysis was carried out using AVL BOOST software. Experimental research and combustion process numerical simulation showed that using balanced biobuthanol and hydrogen addition, optimal efficient and ecological parameters could be achieved, when engine is working for petrol fuel typical optimal spark timing.

  5. 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...

  6. Performance analysis of waste heat recovery with a dual loop organic Rankine cycle (ORC) system for diesel engine under various operating conditions

    International Nuclear Information System (INIS)

    Yang, Fubin; Dong, Xiaorui; Zhang, Hongguang; Wang, Zhen; Yang, Kai; Zhang, Jian; Wang, Enhua; Liu, Hao; Zhao, Guangyao

    2014-01-01

    Highlights: • Dual loop ORC system is designed to recover waste heat from a diesel engine. • R245fa is used as working fluid for the dual loop ORC system. • Waste heat characteristic under engine various operating conditions is analyzed. • Performance of the combined system under various operating conditions is studied. • The waste heat from coolant and intake air has considerable potential for recovery. - Abstract: To take full advantage of the waste heat from a diesel engine, a set of dual loop organic Rankine cycle (ORC) system is designed to recover exhaust energy, waste heat from the coolant system, and released heat from turbocharged air in the intercooler of a six-cylinder diesel engine. The dual loop ORC system consists of a high temperature loop ORC system and a low temperature loop ORC system. R245fa is selected as the working fluid for both loops. Through the engine test, based on the first and second laws of thermodynamics, the performance of the dual loop ORC system for waste heat recovery is discussed based on the analysis of its waste heat characteristics under engine various operating conditions. Subsequently, the diesel engine-dual loop ORC combined system is presented, and the effective thermal efficiency and the brake specific fuel consumption (BSFC) are chosen to evaluate the operating performances of the diesel engine-dual loop ORC combined system. The results show that, the maximum waste heat recovery efficiency (WHRE) of the dual loop ORC system can reach 5.4% under engine various operating conditions. At the engine rated condition, the dual loop ORC system achieves the largest net power output at 27.85 kW. Compared with the diesel engine, the thermal efficiency of the combined system can be increased by 13%. When the diesel engine is operating at the high load region, the BSFC can be reduced by a maximum 4%

  7. Matrix Operations for Engineers and Scientists An Essential Guide in Linear Algebra

    CERN Document Server

    Jeffrey, Alan

    2010-01-01

    Engineers and scientists need to have an introduction to the basics of linear algebra in a context they understand. Computer algebra systems make the manipulation of matrices and the determination of their properties a simple matter, and in practical applications such software is often essential. However, using this tool when learning about matrices, without first gaining a proper understanding of the underlying theory, limits the ability to use matrices and to apply them to new problems. This book explains matrices in the detail required by engineering or science students, and it discusses linear systems of ordinary differential equations. These students require a straightforward introduction to linear algebra illustrated by applications to which they can relate. It caters of the needs of undergraduate engineers in all disciplines, and provides considerable detail where it is likely to be helpful. According to the author the best way to understand the theory of matrices is by working simple exercises designe...

  8. Experimental Research in Operation Management in Engine Room by using Language Sentiment/Opinion Analysis

    Directory of Open Access Journals (Sweden)

    Dimitris Papachristos

    2014-12-01

    Full Text Available The paper argues for the necessity of a combination MMR methods (questionnaire, interview and sentiment/opinion techniques to personal satisfaction analysis at the maritime and training education and proposes a generic, but practical research approach for this purpose. The proposed approach concerns the personal satisfaction evaluation of Engine Room simulator systems and combines the speech recording (sentiment/opinion analysis for measuring emotional user responses with usability testing (SUS tool. The experimental procedure presented here is a primary effort to research the emotion analysis (satisfaction of the users-students in Engine Room Simulators. Finally, the ultimate goal of this research is to find and test the critical factors that influence the educational practice and user’s satisfaction of Engine Room Simulator Systems and the ability to conduct full-time system control by the marine crew.

  9. The Study of the Performance of Engine Operating on Petroleum and Ethanol Blends

    Directory of Open Access Journals (Sweden)

    Marius Mažeika

    2011-04-01

    Full Text Available Test results indicate that a fully loaded engine, fed with 10 vol % ethanol and petrol blends, has power output reduced by 1.67–3.2% at 1400 and 1800 rev/min, while the specific fuel consumption can be slightly increased (up to 4% at 1400 rev/min, and slightly decreased at 1800 rev/min. Carbon monoxide CO emissions of the fully loaded engine running on biofuel blend E10 are reduced by about 0–50% compared to those observed when petrol is used. To introduce ethanol and petrol blends with higher E20 concentration as an engine fuel, special adjustment of the fuel system is needed.Article in Lithuanian

  10. Engineering Competencies in International Development Co-operation - the Case of Capacity Development in Environment (CDE)

    DEFF Research Database (Denmark)

    Wangel, Arne

    2001-01-01

    The focus of the paper is the need for engineers to develop new competencies, when they are involved in international development cooperation. Drawing on the case of the Post-RIO strategy of capacity development in environment in developing countries, the paper reviews a recent response...... of such courses, which give emphasis to local views on institutional development and policy change. engineers from industrialised countries have a long tradition of working in the third world: building infrastructure to facilitate exports of raw materials during colonial times; implementing development aid...... on the transfer of managerial models across cultures, on how to develop inter-cultural competence in management, and on the significance of differences in engineering and industrial culture. Second, the concepts of dynamic assimilation and local learning processes and their implications for the practicing...

  11. Experimental and regression analysis for multi cylinder diesel engine operated with hybrid fuel blends

    Directory of Open Access Journals (Sweden)

    Gopal Rajendiran

    2014-01-01

    Full Text Available The purpose of this research work is to build a multiple linear regression model for the characteristics of multicylinder diesel engine using multicomponent blends (diesel- pungamia methyl ester-ethanol as fuel. Nine blends were tested by varying diesel (100 to 10% by Vol., biodiesel (80 to 10% by vol. and keeping ethanol as 10% constant. The brake thermal efficiency, smoke, oxides of nitrogen, carbon dioxide, maximum cylinder pressure, angle of maximum pressure, angle of 5% and 90% mass burning were predicted based on load, speed, diesel and biodiesel percentage. To validate this regression model another multi component fuel comprising diesel-palm methyl ester-ethanol was used in same engine. Statistical analysis was carried out between predicted and experimental data for both fuel. The performance, emission and combustion characteristics of multi cylinder diesel engine using similar fuel blends can be predicted without any expenses for experimentation.

  12. Parallel Multi-cycle LES of an Optical Pent-roof DISI Engine Under Motored Operating Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Van Dam, Noah; Sjöberg, Magnus; Zeng, Wei; Som, Sibendu

    2017-10-15

    The use of Large-eddy Simulations (LES) has increased due to their ability to resolve the turbulent fluctuations of engine flows and capture the resulting cycle-to-cycle variability. One drawback of LES, however, is the requirement to run multiple engine cycles to obtain the necessary cycle statistics for full validation. The standard method to obtain the cycles by running a single simulation through many engine cycles sequentially can take a long time to complete. Recently, a new strategy has been proposed by our research group to reduce the amount of time necessary to simulate the many engine cycles by running individual engine cycle simulations in parallel. With modern large computing systems this has the potential to reduce the amount of time necessary for a full set of simulated engine cycles to finish by up to an order of magnitude. In this paper, the Parallel Perturbation Methodology (PPM) is used to simulate up to 35 engine cycles of an optically accessible, pent-roof Directinjection Spark-ignition (DISI) engine at two different motored engine operating conditions, one throttled and one un-throttled. Comparisons are made against corresponding sequential-cycle simulations to verify the similarity of results using either methodology. Mean results from the PPM approach are very similar to sequential-cycle results with less than 0.5% difference in pressure and a magnitude structure index (MSI) of 0.95. Differences in cycle-to-cycle variability (CCV) predictions are larger, but close to the statistical uncertainty in the measurement for the number of cycles simulated. PPM LES results were also compared against experimental data. Mean quantities such as pressure or mean velocities were typically matched to within 5- 10%. Pressure CCVs were under-predicted, mostly due to the lack of any perturbations in the pressure boundary conditions between cycles. Velocity CCVs for the simulations had the same average magnitude as experiments, but the experimental data showed

  13. Advanced Light-Duty SI Engine Fuels Research: Multiple Optical Diagnostics of Well-mixed and Stratified Operation.

    Energy Technology Data Exchange (ETDEWEB)

    Sjoberg, Carl Magnus Goran [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Vuilleumier, David [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2018-02-01

    Ever tighter fuel economy standards and concerns about energy security motivate efforts to improve engine efficiency and to develop alternative fuels. This project contributes to the science base needed by industry to develop highly efficient direct injection spark ignition (DISI) engines that also beneficially exploit the different properties of alternative fuels. Here, the emphasis is on lean operation, which can provide higher efficiencies than traditional non-dilute stoichiometric operation. Since lean operation can lead to issues with ignition stability, slow flame propagation and low combustion efficiency, the focus is on techniques that can overcome these challenges. Specifically, fuel stratification is used to ensure ignition and completeness of combustion but this technique has soot and NOx emissions challenges. For ultra-lean well-mixed operation, turbulent deflagration can be combined with controlled end-gas autoignition to render mixed-mode combustion for sufficiently fast heat release. However, such mixed-mode combustion requires very stable inflammation, motivating studies on the effects of near-spark flow and turbulence, and the use of small amounts of fuel stratification near the spark plug.

  14. Simulation research on operation scheme of dissymmetrical main engine of CODOG propulsion system

    Directory of Open Access Journals (Sweden)

    HUANG Bin

    2018-02-01

    Full Text Available [Objectives] How to maintain propulsion capability in a CODOG propulsion system damage situation has important significance. [Methods] A ‘Hull-Engine-CPP-Rudder’ simulation model of a CODOG marine power plant is established on Simulink using the modularized method, and a dissymmetrical main engine urgent working mode is proposed and simulated. [Results] The results show that in the dissymmetrical working mode, two different engines cannot work simultaneously at designed capacity. However, by adjusting the pitch of the CPP, one engine can work at designed capacity and the other can work at partial load capacity; under this working mode, if high speed is demanded, the gas turbine should work at designed capacity. The CPP pitch driven by diesel should be maintained at a high value near the maximum. The maximum speed of this working mode is 84.4% of the designed speed, which is higher than the speed of the single shaft working mode driven by a gas turbine. [Conclusions] The research results of this paper can provide useful references for the design of ship propulsion systems.

  15. Power system engineering planning, design, and operation of power systems and equipment

    CERN Document Server

    Schlabbach, Juergen

    2014-01-01

    With its focus on the requirements and procedures of tendering and project contracting, this book enables the reader to adapt the basics of power systems and equipment design to special tasks and engineering projects, e.g. the integration of renewable energy sources.

  16. Operational Issues in the Development of a Cost-Effective Reusable LOX/LH2 Engine

    Science.gov (United States)

    Ballard, Richard O.

    2005-01-01

    Contents include the following: SLI initiated under NASA Research Announcement (NRA) 8-30. Strategic Objectives. Make spaceflight safer (1 in 10000 mission LOV). Make spaceflight cheaper ($1000/lb payload). Two prototype LOX/LH2 engine systems funded under Cycle-1 of NRA8-30. COBRA (Pratt & Whitney / Aerojet). RS-83 (Rocketdyne).

  17. Development of an Optimal Controller and Validation Test Stand for Fuel Efficient Engine Operation

    Science.gov (United States)

    Rehn, Jack G., III

    There are numerous motivations for improvements in automotive fuel efficiency. As concerns over the environment grow at a rate unmatched by hybrid and electric automotive technologies, the need for reductions in fuel consumed by current road vehicles has never been more present. Studies have shown that a major cause of poor fuel consumption in automobiles is improper driving behavior, which cannot be mitigated by purely technological means. The emergence of autonomous driving technologies has provided an opportunity to alleviate this inefficiency by removing the necessity of a driver. Before autonomous technology can be relied upon to reduce gasoline consumption on a large scale, robust programming strategies must be designed and tested. The goal of this thesis work was to design and deploy an autonomous control algorithm to navigate a four cylinder, gasoline combustion engine through a series of changing load profiles in a manner that prioritizes fuel efficiency. The experimental setup is analogous to a passenger vehicle driving over hilly terrain at highway speeds. The proposed approach accomplishes this using a model-predictive, real-time optimization algorithm that was calibrated to the engine. Performance of the optimal control algorithm was tested on the engine against contemporary cruise control. Results indicate that the "efficient'' strategy achieved one to two percent reductions in total fuel consumed for all load profiles tested. The consumption data gathered also suggests that further improvements could be realized on a different subject engine and using extended models and a slightly modified optimal control approach.

  18. A comparative experimental study on engine operating on premixed charge compression ignition and compression ignition mode

    Directory of Open Access Journals (Sweden)

    Bhiogade Girish E.

    2017-01-01

    Full Text Available New combustion concepts have been recently developed with the purpose to tackle the problem of high emissions level of traditional direct injection Diesel engines. A good example is the premixed charge compression ignition combustion. A strategy in which early injection is used causing a burning process in which the fuel burns in the premixed condition. In compression ignition engines, soot (particulate matter and NOx emissions are an extremely unsolved issue. Premixed charge compression ignition is one of the most promising solutions that combine the advantages of both spark ignition and compression ignition combustion modes. It gives thermal efficiency close to the compression ignition engines and resolves the associated issues of high NOx and particulate matter, simultaneously. Premixing of air and fuel preparation is the challenging part to achieve premixed charge compression ignition combustion. In the present experimental study a diesel vaporizer is used to achieve premixed charge compression ignition combustion. A vaporized diesel fuel was mixed with the air to form premixed charge and inducted into the cylinder during the intake stroke. Low diesel volatility remains the main obstacle in preparing premixed air-fuel mixture. Exhaust gas re-circulation can be used to control the rate of heat release. The objective of this study is to reduce exhaust emission levels with maintaining thermal efficiency close to compression ignition engine.

  19. EMISSIONS FROM TWO OUTBOARD ENGINES OPERATING ON REFORMULATED GASOLINE CONTAINING MTBE

    Science.gov (United States)

    Air and water pollutant emissions were measured from two 9.9 HP outboard engines: a two-stroke Evinrude and its four-stroke Honda counterpart. In addition to the measurement of regulated air pollutants, speciated organic pollutants and particulate matter emissions were determi...

  20. PERFORMANCE AND EMISSION CHARACTERISTICS OF A CI ENGINE OPERATED ON VEGETABLE OILS AS ALTERNATIVE FUELS

    Directory of Open Access Journals (Sweden)

    K. Rajagopal

    2011-12-01

    Full Text Available An experimental analysis was done using a four-stroke, single cylinder, constant speed, water-cooled diesel engine, which was interfaced with Engine software. Performance and emission characteristics were evaluated for three non-edible vegetable oils, i.e. thumba, jojoba, neem oil, as well as jojoba methyl ester, to study the effect of injection pressure at 205, 220, 240 and 260 bar with a variation in injection timing at 23°bTDC and 28°bTDC. The performance of jojoba methyl ester improved with an increase in injection pressure. A maximum brake thermal efficiency of 29.72% was obtained with lower emissions compared to the other vegetable oils; this might be explained by low viscosity and better combustion. Further investigations were carried out with a new lubricant, SAE 5W-30, which improved the performance of the CI engine by 1.59%. All of the abovementioned investigations were fruitful and these results are expected to lead to substantial contributions in the development of a viable vegetable oil engine.

  1. An Engineered Resupply System for Humanitarian Assistance and Disaster Relief Operations

    Science.gov (United States)

    2017-09-01

    relevant and timely relief. Conduct Supply refers to the procurement, warehousing, and managing of relief supplies. Conduct Deployment and Distribution ...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release. Distribution is unlimited. AN ENGINEERED...Approved OMB No. 0704–0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time

  2. Intelligent Engine Systems Work Element 1.2: Malfunction and Operator Error Reduction

    Science.gov (United States)

    Wiseman, Matthew

    2005-01-01

    Jet engines, although highly reliable and safe, do experience malfunctions that cause flight delays, passenger stress, and in some cases, in conjunction with inappropriate crew response, contribute to airplane accidents. On rare occasions, the anomalous engine behavior is not recognized until it is too late for the pilots to do anything to prevent or mitigate the resulting engine malfunction causing in-flight shutdowns (IFSDs), aborted takeoffs (ATOs), or loss of thrust control (LOTC). In some cases, the crew response to a myriad of external stimuli and existing training procedures is the source of the problem mentioned above. The problem is the reduction of jet engine malfunctions (IFSDs, ATOs, and LOTC) and inappropriate crew response (PSM+ICR) through the use of evolving and advanced technologies. The solution is to develop the overall system health maintenance architecture, detection and accommodation technologies, processes, and enhanced crew interfaces that would enable a significant reduction in IFSDs, ATOs, and LOTC. This program defines requirements and proposes a preliminary design concept of an architecture that enables the realization of the solution.

  3. Rotation of a piston pin in the small connecting rod eye during engine operation; Drehung eines Kolbenbolzens im kleinen Pleuelauge waehrend des Motorbetriebs

    Energy Technology Data Exchange (ETDEWEB)

    Wachtmeister, Georg; Hubert, Andreas [Technische Univ. Muenchen (DE). Lehrstuhl fuer Verbrennungskraftmaschinen (LVK)

    2008-12-15

    A constant increase of powerful combustion engines has lead to higher loads on the crankshaft drive and piston pin. To ensure a robust design the effective forces and movements at the piston pin have to be known. At the Technische Universitaet Muenchen, Chair of Internal Combustion Engines, a research project looked into the piston pins movement during engine operation. The main goal was to determine the rotary movements of the piston pin by measurement at a 4-l gas SI engine as a function of the engine load and speed and to clarify the mechanisms that cause the rotary movement of the piston pin especially in the small connecting rod eye. (orig.)

  4. Design study of shaft face seal with self-acting lift augmentation. 5: Performance in simulated gas turbine engine operation

    Science.gov (United States)

    Ludwig, L. P.; Johnson, R. L.

    1971-01-01

    The feasibility and the noncontact operation of the self-acting seal was demonstrated over a range of simulated gas turbine engine conditions from 200 to 500 ft/sec sliding speed. Sealed pressure differentials were 50 to 300 psi and sealed temperatures were 150 to 1200 F. Low leakage (about 1/10 that of conventional labyrinth seals) was exhibited in two endurance runs (200 and 338 hr) at 400 ft/sec, 200 psi and 1000 F (gas temperature). For these endurance runs, the self-acting pad wear was less than 3.8 micrometers (0.00015 in.); this low wear was attributed to the noncontact operation of the primary seal. Operating problems identified were fretting wear of the secondary seal and erosion of the primary seal by hard particles.

  5. Advantages of variable-speed operation of hydraulic turbo-engines; Vorteile durch den drehzahlvariablen Betrieb von hydraulischen Stroemungsmaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Harbort, T. [Stuttgart Univ. (Germany). Inst. fuer Stroemungsmechanik und Hydraulische Stroemungsmaschinen

    1997-12-31

    The performance of current hydraulic turbo-engines in the variable speed sector is monitored and judged. The study covers radial and axial engines as well as Pelton turbines. Variable-speed operation of hydraulic turbo-engines can be realized by means of different combinations of electrical rotating machines and frequency converters. The operating range of the frequency converter plays an important role in the optimization of performance and is taken into account. The smoothness of run of reaction turbines and their cavitation performance can be enhanced by speed regulation. But above all, efficiency is more or less substantially enhanced during partial load or in the case of greatly varying heights of drop. The latter holds true also of Pelton turbines. (orig.) [Deutsch] Das Betriebsverhalten der gaengigen hydraulischen Stroemungsmaschinen wird in Hinblick auf den drehzahlvariablen Betrieb erfasst und beurteilt. Die Untersuchung erfolgt fuer Radialmaschinen, Axialmaschinen und Peltonturbinen. Der drehzahlvariable Betrieb hydraulischer Stroemungsmaschinen kann mit verschiedenen Kombinationen von elektrischen Maschinen und Frequenzumrichtern realisiert werden. Der Arbeitsbereich des Frequenzumrichters spielt eine wichtige Rolle fuer die Optimierung des Betriebsverhaltens und wird beruecksichtigt. Bei Ueberdruckturbinen kann man durch Drehzahlregelung eine groessere Laufruhe sowie ein guenstigeres Kavitationsverhalten erreichen. Vor allem aber sind im Teillastbereich oder bei stark schwankenden Fallhoehen mehr oder weniger grosse Wirkungsgradgewinne erzielbar. Das letztere gilt auch fuer Peltonturbinen. (orig.)

  6. Development of operation and maintenance technology for HTGRs by using HTTR (High Temperature engineering Test Reactor)

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Atsushi, E-mail: shimizu.atsushi35@jaea.go.jp [HTTR Operation Section, Department of HTTR, Oarai Research and Development Center, Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki 311-1393 (Japan); Kawamoto, Taiki [HTTR Operation Section, Department of HTTR, Oarai Research and Development Center, Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki 311-1393 (Japan); Tochio, Daisuke [HTTR Reactor Engineering Section, Department of HTTR, Oarai Research and Development Center, Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki 311-1393 (Japan); Saito, Kenji; Sawahata, Hiroaki; Honma, Fumitaka; Furusawa, Takayuki; Saikusa, Akio [HTTR Operation Section, Department of HTTR, Oarai Research and Development Center, Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki 311-1393 (Japan); Takada, Shoji [HTTR Reactor Engineering Section, Department of HTTR, Oarai Research and Development Center, Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki 311-1393 (Japan); Shinozaki, Masayuki [HTTR Operation Section, Department of HTTR, Oarai Research and Development Center, Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki 311-1393 (Japan)

    2014-05-01

    To establish the technical basis of HTGR (High Temperature Gas cooled Reactor), the long term high temperature operation using HTTR was carried out in the high temperature test operation mode during 50-day since January till March, 2010. It is necessary to establish the technical basis of operation and maintenance by demonstrating the stability of plant during long-term operation and the reliability of components and facilities special to HTGRs, in order to attain the stable supply of the high temperature heat to the planned heat utilization system of HTTR. Test data obtained in the operation were evaluated for the technical issues which were extracted before the operation. As the results, it was confirmed that the temperatures and flow rate of primary and secondary coolant were well controlled within sufficiently small deviation against the disturbance by the atmospheric temperature variation in daily. Stability and reliability of the components and facility special to HTGRs was demonstrated through the long term high temperature operation by evaluating the heat transfer performance of high temperature components, the stability performance of pressure control to compensate helium gas leak, the reliability of the dynamic components such as helium gas circulators, the performance of heat-up protection of radiation shielding. Through the long term high temperature operation of HTTR, the technical basis for the operation and maintenance technology of HTGRs was established.

  7. Development of operation and maintenance technology for HTGRs by using HTTR (High Temperature engineering Test Reactor)

    International Nuclear Information System (INIS)

    Shimizu, Atsushi; Kawamoto, Taiki; Tochio, Daisuke; Saito, Kenji; Sawahata, Hiroaki; Honma, Fumitaka; Furusawa, Takayuki; Saikusa, Akio; Takada, Shoji; Shinozaki, Masayuki

    2014-01-01

    To establish the technical basis of HTGR (High Temperature Gas cooled Reactor), the long term high temperature operation using HTTR was carried out in the high temperature test operation mode during 50-day since January till March, 2010. It is necessary to establish the technical basis of operation and maintenance by demonstrating the stability of plant during long-term operation and the reliability of components and facilities special to HTGRs, in order to attain the stable supply of the high temperature heat to the planned heat utilization system of HTTR. Test data obtained in the operation were evaluated for the technical issues which were extracted before the operation. As the results, it was confirmed that the temperatures and flow rate of primary and secondary coolant were well controlled within sufficiently small deviation against the disturbance by the atmospheric temperature variation in daily. Stability and reliability of the components and facility special to HTGRs was demonstrated through the long term high temperature operation by evaluating the heat transfer performance of high temperature components, the stability performance of pressure control to compensate helium gas leak, the reliability of the dynamic components such as helium gas circulators, the performance of heat-up protection of radiation shielding. Through the long term high temperature operation of HTTR, the technical basis for the operation and maintenance technology of HTGRs was established

  8. 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.

  9. Developing Tele-Operated Laboratories for Manufacturing Engineering Education. Platform for E-Learning and Telemetric Experimentation (PeTEX

    Directory of Open Access Journals (Sweden)

    A. Erman Tekkaya

    2010-09-01

    Full Text Available The aim of the PeTEX-project is to establish an e-Learning platform for the development, implementation, and delivery of educational training programs in the field of manufacturing engineering. The PeTEX team designs both: a technical platform for eLearning based on “Moodle” including distributed tele-operated experimentation facilities, and didactic and socio-technical requirements for a successful online learning community. User interfaces are deployed for remote access to instruments, data analysis and multiplexed data access via network protocols. Hence, the platform provides complex tools in order to perform various activities to support the educational process, from telemetric experimentation to virtual project groups for an entire community to the purpose of domain specific learning. This paper describes important steps of interdisciplinary participatory design and development of a remote lab-prototype in the field of manufacturing engineering.

  10. Construction and operational experiences of engineered barrier test facility for near surface disposal of LILW

    International Nuclear Information System (INIS)

    Park, Jin Beak; Park, Se Moon; Kim, Chang Lak

    2003-01-01

    Engineered barrier test facility is specially designed to demonstrate the performance of engineered barrier system for the near-surface disposal facility under the domestic environmental conditions. Comprehensive measurement systems are installed within each test cell. Long-and short-term monitoring of the multi-layered cover system can be implemented according to different rainfall scenarios with artificial rainfall system. Monitoring data on the water content, temperature, matric potential, lateral drainage and percolation of cover-layer system can be systematically managed by automatic data acquisition system. The periodic measurement data are collected and will be analyzed by a dedicated database management system, and provide a basis for performance verification of the disposal cover design

  11. Coal-water slurry fuel internal combustion engine and method for operating same

    Science.gov (United States)

    McMillian, Michael H.

    1992-01-01

    An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.

  12. Experience in the operation of the diesel engines of emergency generating sets at Fessenheim and Bugey

    International Nuclear Information System (INIS)

    Dorey, J.

    1982-01-01

    The reliability parameters of the diesel engines in the emergency generating sets at Fessenheim and Bugey have been evaluated using informations assembled through the System for Collecting Reliability Data. The results thus obtained have been compared with those resulting from a previous theoretical study. Secondly, an examination of the incident report shows up certain difficulties in the evaluation of reliability that are specific to stand-by equipment [fr

  13. Coupled Lagrangian impingement spray model for doublet impinging injectors under liquid rocket engine operating conditions

    Directory of Open Access Journals (Sweden)

    Qiang WEI

    2017-08-01

    Full Text Available To predict the effect of the liquid rocket engine combustion chamber conditions on the impingement spray, the conventional uncoupled spray model for impinging injectors is extended by considering the coupling of the jet impingement process and the ambient gas field. The new coupled model consists of the plain-orifice sub-model, the jet-jet impingement sub-model and the droplet collision sub-model. The parameters of the child droplet are determined with the jet-jet impingement sub-model using correlations about the liquid jet parameters and the chamber conditions. The overall model is benchmarked under various impingement angles, jet momentum and off-center ratios. Agreement with the published experimental data validates the ability of the model to predict the key sp