WorldWideScience
1

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

International Nuclear Information System (INIS)

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

2

Selective gas exhaustion method  

International Nuclear Information System (INIS)

The present invention provides a method capable of evacuating gases at an exhaustion rate which varies depending on the kind of gases. For example, in a thermonuclear experimental device, a hydrogen gas exhaustion rate is determined to 0 and an exhaustion rate for other impure gases is made greater. Namely, a baffle plate is cooled to a temperature to a level at which the vapor pressure of gases to evacuate a baffle plate is required in a pump incorporating a baffle plate, for example, a cryopump or a sorption pump. In this case, the level of the vapor pressure required for evacuating the exhaustion gas ingredients is 1 x 10-8 Torr or less, preferably, 1 x 10-9 Torr. In a thermonuclear experimental device, a gas having a lower boiling point next to hydrogen is neon, but neon is scarcely present in natural world. Nitrogen has a lower boiling point next thereto, and if the temperature is lowered to such a level that the vapor pressure for evacuating gases such as nitrogen, and carbon monoxide, oxygen, fluorine, argon or methane having a boiling point at or lower than nitrogen is required. Then, evacuation rate sufficient for gases other than hydrogen gas can be obtained. (I.S.)

3

Development of a tunable diode laser sensor for measurements of gas turbine exhaust temperature  

Science.gov (United States)

A tunable diode laser (TDL) temperature sensor is designed, constructed, tested, and demonstrated in the exhaust of an industrial gas turbine. Temperature is determined from the ratio of the measured absorbance of two water vapor overtone transitions in the near infrared where telecommunication diode lasers are available. Design rules are developed to select the optimal pair of transitions for direct absorption measurements using spectral simulations by systematically examining the absorption strength, spectral isolation, and temperature sensitivity to maximize temperature accuracy in the core flow and minimize sensitivity to water vapor in the cold boundary layer. The contribution to temperature uncertainty from the spectroscopic database is evaluated and precise line-strength data are measured for the selected transitions. Gas-temperature measurements in a heated cell are used to verify the sensor accuracy (over the temperature range of 350 to 1000 K, ?T˜2 K for the optimal line pair and ?T˜5 K for an alternative line pair). Field measurements of exhaust-gas temperature in an industrial gas turbine demonstrate the practical utility of TDL sensing in harsh industrial environments.

Liu, X.; Jeffries, J. B.; Hanson, R. K.; Hinckley, K. M.; Woodmansee, M. A.

2006-03-01

4

Gas turbine exhaust system  

Energy Technology Data Exchange (ETDEWEB)

An exhaust system for a gas turbine has a main axial duct which feeds a heat exchanger to make use of the residual heat in the exhaust gases. The heat exchanger may in some circumstances be overloaded so a branch duct is taken from the main duct - conventionally by means of a T-junction with a flap valve closing off either the main (axial) outlet or the branch outlet. The branch duct is then taken to an exhaust stack. Turbulence at the T-junction causes poor flow upstream of the junction and corresponding poor turbine performance. The invention provides a junction in which the main axial duct passes smoothly through a bypass chamber which surrounds the axial duct. Slots in the axial duct within the chamber permit passage of the exhaust gases to the bypass duct. Rotating blade valves in the two duct outlets control the relative flow of exhaust to heat exchanger and exhaust stack. (author)

Hannis, J.M.

1993-05-19

5

Exhaust gas filter  

International Nuclear Information System (INIS)

A filter material formed by joining glass clothes to both surfaces of a glass fiber non-woven fabric is used. The filter material is disposed at the inside of a square filter material support frame made of stainless steel. The filter material is attached in a zig-zag manner in the flowing direction of the exhaust gases so as to increase the filtration area. Separators, for example, made of stainless steel are inserted between the filter materials. The separator is corrugated so as to sandwich and support the filter materials from both sides by the ridged crests. The longitudinal bottom of the separator formed by corrugating it defines a flow channel of the exhaustion gases. The longitudinal bottom is also used as a channel for back blowing air. With such a constitution, combustion gases of radioactive miscellaneous solid wastes can be completely filtered. In addition, a back wash can be conducted under high temperature. (I.N.)

6

Comparison of sound, exhaust gas temperature and smoke opacity characteristics of methyl esters of vegetable oils blends  

Directory of Open Access Journals (Sweden)

Full Text Available Experimental studies were conducted to evaluate the sound, exhaust gas temperature and smoke opacity characteristics of a single cylinder, four stroke engine fuelled with Vegetable oil methyl ester and its blends with standard diesel. Among different vegetable oils which can be used as alternate fuels, five vegetable oils, i.e., Nerium (Nerium oleander, Jatropha (Jatropha curcas, Pongamia (Pongamia pinnata, Mahua (Madhuca indica and Neem (Azadirachta indica oils were selected for analysis. Tests has been conducted using the fuel blends of 20%, 40%, 60% and 80% biodiesel with standard diesel, with an engine speed of 1800 rpm. It has found that the sound, exhaust gas temperature and smoke opacity characteristics of vegetable oil methyl ester and its diesel blends closely followed those of standard diesel.

S. Prabhakar

2011-10-01

7

Device for purifying exhaust gas  

International Nuclear Information System (INIS)

Purpose: To ensure the reliability in collection of krypton even on accident in liquidizing distillation tower. Constitution: Exhaust gas flows through active carbon adsorption tower where short half-life rare gas in exhaust gas is separated by adsorption, then through heat exchanger, then continuous distillation tower where krypton 85 is separated, then through batch distillation tower where krypton 85 is condensed, and then flows into storing cylinder. On accident in liquidizing distillation tower, at the first period exhaust gas flows through series connected active carbon adsorption tower, krypton 85 adsorbed in adsorption tower being transferred to cooling type adsorption tower, at the next period exhaust gas flows through tower, krypton 85 adsorbed in adsorption tower being transferred to tower. (M. K.)

8

Instantaneous exhaust temperature measurements using thermocouple compensation techniques  

OpenAIRE

This paper discusses a method of measuring the instantaneous exhaust gas temperature by thermocouples. Measuring the exhaust gas temperature is useful for a better understanding of engine processes. Thermocouples do not measure the instantaneous exhaust gas temperature because of their limited dynamic response. A thermocouple compensation technique has been developed to estimate the time constant in situ. This method has been commissioned in a simulation study and a controlled experiment with...

Kar, K.; Roberts, S.; Stone, R.; Oldfield, M.; French, B.

2004-01-01

9

Clean exhaust gas  

International Nuclear Information System (INIS)

Brown-coal coke has properties that make it a suitable base material for adsorbents and catalysts of the types used for the purification of flue gas from waste incineration plants. It is less expensive than activated carbon. Brown-coal coke makes it possible to keep pollutant concentrations well within the limit values laid down in the relevant regulations. (orig.)

10

Elevated exhaust temperature, zoned, electrically-heated particulate matter filter  

Science.gov (United States)

A system includes an electrical heater and a particulate matter (PM) filter that is arranged one of adjacent to and in contact with the electrical heater. A control module selectively increases an exhaust gas temperature of an engine to a first temperature and that initiates regeneration of the PM filter using the electrical heater while the exhaust gas temperature is above the first temperature. The first temperature is greater than a maximum exhaust gas temperature at the PM filter during non-regeneration operation and is less than an oxidation temperature of the PM.

Gonze, Eugene V [Pinckney, MI; Bhatia, Garima [Bangalore, IN

2012-04-17

11

Effects of exhaust temperature on helicopter infrared signature  

International Nuclear Information System (INIS)

The effects of exhaust temperature on infrared signature (in 3–5 ?m band) for a helicopter equipped with integrative infrared suppressor were numerically investigated. The internal flow of exhaust gas and the external downwash flow, as well as the mixing between exhaust gas and downwash were simulated by CFD software to determine the temperature distributions on the helicopter skin and in the exhaust plume. Based on the skin and plume temperature distributions, a forward–backward ray-tracing method was used to calculate the infrared radiation intensity from the helicopter with a narrow-band model. The results show that for a helicopter with its integrative infrared suppressor embedded inside its rear airframe, the exhaust temperature has significant influence on the plume radiation characteristics, while the helicopter skin radiation intensity has little impact. When the exhaust temperature is raised from 900 K to 1200 K, the plume radiation intensity in 3–5 ?m band is increased by about 100%, while the skin radiation intensity is increased by only about 5%. In general, the effects of exhaust temperature on helicopter infrared radiation intensity are mainly concentrated on plume, especially obvious for a lower skin emissivity case. -- Highlights: ? The effect of exhaust temperature on infrared signature for a helicopter is numerically investigated. ? The impact of exhaust temperature on helicopter skin temperature is revealed. ? The impact of exhaust temperature on plume radiation characteristics is revealed. ? The impact of exhaust temperature on helicopter skin radiation is revealed. ? The impact of exhaust temperature on helicopter's total infrared radiation intensity is revealed

12

Exhaust gas recirculation system for an internal combustion engine  

Science.gov (United States)

An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

Wu, Ko-Jen

2013-05-21

13

Method of controlling temperature of a thermoelectric generator in an exhaust system  

Energy Technology Data Exchange (ETDEWEB)

A method of controlling the temperature of a thermoelectric generator (TEG) in an exhaust system of an engine is provided. The method includes determining the temperature of the heated side of the TEG, determining exhaust gas flow rate through the TEG, and determining the exhaust gas temperature through the TEG. A rate of change in temperature of the heated side of the TEG is predicted based on the determined temperature, the determined exhaust gas flow rate, and the determined exhaust gas temperature through the TEG. Using the predicted rate of change of temperature of the heated side, exhaust gas flow rate through the TEG is calculated that will result in a maximum temperature of the heated side of the TEG less than a predetermined critical temperature given the predicted rate of change in temperature of the heated side of the TEG. A corresponding apparatus is provided.

Prior, Gregory P; Reynolds, Michael G; Cowgill, Joshua D

2013-05-21

14

40 CFR 1065.127 - Exhaust gas recirculation.  

Science.gov (United States)

...2010-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION...ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use the exhaust...

2010-07-01

15

Low exhaust temperature electrically heated particulate matter filter system  

Science.gov (United States)

A system includes a particulate matter (PM) filter, a sensor, a heating element, and a control module. The PM filter includes with an upstream end that receives exhaust gas, a downstream end and multiple zones. The sensor detects a temperature of the exhaust gas. The control module controls current to the heating element to convection heat one of the zones and initiate a regeneration process. The control module selectively increases current to the heating element relative to a reference regeneration current level when the temperature is less than a predetermined temperature.

Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI); Bhatia, Garima (Bangalore, IN)

2012-02-14

16

Coke-free dry reforming of model diesel fuel by a pulsed spark plasma at low temperatures using an exhaust gas recirculation (EGR) system  

Science.gov (United States)

Dry reforming of diesel fuel, an endothermic reaction, is an attractive process for on-board hydrogen/syngas production to increase energy efficiency. For operating this dry reforming process in a vehicle, we can use the exhaust gas from an exhaust gas recirculation (EGR) system as a source of carbon dioxide. Catalytic dry reforming of heavy hydrocarbon is a very difficult reaction due to the high accumulation of carbon on the catalyst. Therefore, we attempted to use a non-equilibrium pulsed plasma for the dry reforming of model diesel fuel without a catalyst. We investigated dry reforming of model diesel fuel (n-dodecane) with a low-energy pulsed spark plasma, which is a kind of non-equilibrium plasma at a low temperature of 523 K. Through the reaction, we were able to obtain syngas (hydrogen and carbon monoxide) and a small amount of C2 hydrocarbon without coke formation at a ratio of CO2/Cfuel = 1.5 or higher. The reaction can be conducted at very low temperatures such as 523 K. Therefore, it is anticipated as a novel and effective process for on-board syngas production from diesel fuel using an EGR system.

Sekine, Yasushi; Furukawa, Naotsugu; Matsukata, Masahiko; Kikuchi, Eiichi

2011-07-01

17

Coke-free dry reforming of model diesel fuel by a pulsed spark plasma at low temperatures using an exhaust gas recirculation (EGR) system  

International Nuclear Information System (INIS)

Dry reforming of diesel fuel, an endothermic reaction, is an attractive process for on-board hydrogen/syngas production to increase energy efficiency. For operating this dry reforming process in a vehicle, we can use the exhaust gas from an exhaust gas recirculation (EGR) system as a source of carbon dioxide. Catalytic dry reforming of heavy hydrocarbon is a very difficult reaction due to the high accumulation of carbon on the catalyst. Therefore, we attempted to use a non-equilibrium pulsed plasma for the dry reforming of model diesel fuel without a catalyst. We investigated dry reforming of model diesel fuel (n-dodecane) with a low-energy pulsed spark plasma, which is a kind of non-equilibrium plasma at a low temperature of 523 K. Through the reaction, we were able to obtain syngas (hydrogen and carbon monoxide) and a small amount of C2 hydrocarbon without coke formation at a ratio of CO2/Cfuel = 1.5 or higher. The reaction can be conducted at very low temperatures such as 523 K. Therefore, it is anticipated as a novel and effective process for on-board syngas production from diesel fuel using an EGR system.

18

Cartridge for purifying exhaust gas  

Energy Technology Data Exchange (ETDEWEB)

A cartridge is disclosed for purifying exhaust gases from the internal combustion engine of an automotive vehicle or some other source comprising a catalyst support matrix wound of metal foil and a metal jacket housing said support matrix wherein a press fit exists between the exterior of the support matrix and the interior surface of the jacket and the support matrix and the jacket are welded or brazed together within the area of the press fit. Processes and apparatus for producing the cartridge of the invention are also disclosed.

Bardong, H.; Haller, K.; Hesse, W.; Nonnenmann, M.

1981-08-04

19

High speed exhaust gas recirculation valve  

Science.gov (United States)

In order to minimize pollutants such as Nox, internal combustion engines typically include an exhaust gas recirculation (EGR) valve that can be used to redirect a portion of exhaust gases to an intake conduit, such as an intake manifold, so that the redirected exhaust gases will be recycled. It is desirable to have an EGR valve with fast-acting capabilities, and it is also desirable to have the EGR valve take up as little space as possible. An exhaust gas recirculation valve is provided that includes an exhaust passage tube, a valve element pivotally mounted within the exhaust passage tube, a linear actuator; and a gear train. The gear train includes a rack gear operatively connected to the linear actuator, and at least one rotatable gear meshing with the rack gear and operatively connected to the valve element to cause rotation of the valve element upon actuation of the linear actuator. The apparatus provides a highly compact package having a high-speed valve actuation capability.

Fensom, Rod (Peterborough, GB); Kidder, David J. (Peterborough, GB)

2005-01-18

20

Exhaust gas treatment by electron beam irradiation  

International Nuclear Information System (INIS)

Among global environmental problems, atmospheric pollution has been discussed since relatively old days, and various countermeasures have been taken, but recently in connection with acid rain, the efficient and economical treatment technology is demanded. As the denitration and desulfurization technology for the exhaust gas from the combustion of fossil fuel, the incineration of city trash and internal combustion engines, three is the treatment method by electron beam irradiation. By irradiating electron beam to exhaust gas, nitrogen oxides and sulfur oxides are oxidized to nitric acid and sulfuric acid, and by promoting the neutralization of these acids with injected alkali, harmless salts are recovered. This method has the merit that nitrogen oxides and surfur oxides can be removed efficiently with a single system. In this report, as for the exhaust gas treatment by electron beam irradiation, its principle, features, and the present status of research and development are described, and in particular, the research on the recent exhaust gas treatment in city trash incineration is introduced. This treatment method is a dry process, accordingly, waste water disposal is unnecessary. The reaction products are utilized as fertilizer, and waste is not produced. (K.I.)

21

46 CFR 63.25-7 - Exhaust gas boilers.  

Science.gov (United States)

... 2010-10-01 false Exhaust gas boilers. 63.25-7 Section 63.25-7...MARINE ENGINEERING AUTOMATIC AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-7 Exhaust gas...

2010-10-01

22

Exhaust gas purification apparatus for motor vehicles  

Energy Technology Data Exchange (ETDEWEB)

A device is disclosed for treating exhaust gases from an internal combustion engine having a gas inlet adapted to be connected to the exhaust of the internal combustion engine and a plurality of serially arranged interconnected reaction chambers. The first of the chambers is connected to the gas inlet and includes a gas outlet forming a gas inlet into a second chamber. The second of the chambers has a gas outlet forming a gas inlet with a third chamber, and so on. The last reaction chamber has a gas outlet to atmosphere. A perforated gas deflector plate is mounted transversely of the path of gas flow in alignment with each outlet of the reaction chambers and spaced inwardly into the reaction chamber associated with the outlet. Means are provided for spraying purifying fluid containing an aqueous solution of sodium percarbonate and sodium bicarbonate into each reaction chamber and drain means associated with each reaction chamber draining the remains of the aqueous solution from the housing.

Sohda, K.; Sohda, K.; Sohda, S.

1981-11-24

23

Cycle-by-cycle variations in exhaust temperatures using thermocouple compensation techniques  

OpenAIRE

Exhaust gas temperatures in a 1.4 L, sparked ignition engine have been measured using fine wire thermocouples at different loads and speeds. However the thermocouples are not fast enough to resolve the rapid change in exhaust temperature. This paper discusses a new thermocouple compensation technique to resolve the cycle-by-cycle variations in exhaust temperature by segmentation. Simulation results show that the technique can find the lower time constants during blowdown, reducing the bias fr...

Kar, K.; Swain, A.; Raine, R.; Roberts, S.; Stone, R.

2006-01-01

24

30 CFR 36.47 - Tests of exhaust-gas cooling system.  

Science.gov (United States)

...or the temperature of adiabatic saturation, if this...Water consumed in cooling the exhaust gas under...percent that required for adiabatic saturation of the exhaust-gas...of that required for adiabatic saturation shall be...be available in the cooling system or in...

2010-07-01

25

Second law analysis of a low temperature combustion diesel engine: Effect of injection timing and exhaust gas recirculation  

International Nuclear Information System (INIS)

For diesel engines, low temperature combustion (LTC) with a high level of EGR and late injection becomes attractive because of its potential of simultaneous reduction of nitrogen oxides (NOx) and particulate matter (PM) emissions. However, detailed thermodynamic evaluations including second law analysis of the LTC are few. The current work employed an engine cycle simulation incorporating the second law of thermodynamics to evaluate the energy and exergy distribution of various processes in a low temperature combustion diesel engine. After validation with experimental data at eight operating conditions including four different EGR levels and two different injection timings, the model was used to evaluate the effect of EGR level and injection timing on the first and second law parameters. As EGR was increased, intake temperature and equivalence ratio increased. Results showed that for the case at 0% EGR level with conventional injection timing, about 30% of the fuel exergy was destructed during combustion processes, and as EGR level increased to 45% (intake temperature and equivalence ratio also increased), the combustion destructed exergy decreased to 20% of the fuel exergy. This was largely due to the related combustion temperature increase. For both conventional (?6.5° aTDC) and late (1.5° aTDC) injection timings, the percentage of exergy transfer through flows increases as EGR increases, which is attributed to the retarded ignition by increasing EGR. Other parameters such as energy and exergy transfer due to heat transfer, blow-by, and unburned fuel also were determined as a function of EGR level and injection timing. -- Highlights: ? Exergy destruction during combustion decreased as intake temperature increased. ? Both conventional and late injection timings (LTC cases) were examined. ? For conventional injection timings, the combustion efficiency remains constant as EGR increases. ? For late injections and high EGR, combustion was incomplete. ? Late injection cases had lower percentage of heat transfer exergy.

26

Exhaust gas recirculation for advanced diesel combustion cycles  

International Nuclear Information System (INIS)

Highlights: • Analysis of the incremental (cycle-by-cycle) build-up of EGR. • Proposed one-step equations for transient/steady-state gas concentration estimation. • Defined an in-cylinder excess-air ratio to account for the recycled oxygen with EGR. • Demonstrated the use of intake oxygen as a reliable measure of EGR effectiveness. • Demonstrated the impact of engine load and intake pressure on EGR effectiveness. - Abstract: Modern diesel engines tend to utilize significantly large quantities of exhaust gas recirculation (EGR) and high intake pressures across the engine load range to meet NOx targets. At such high EGR rates, the combustion process and exhaust emissions tend to exhibit a marked sensitivity to small changes in the EGR quantity, resulting in unintended deviations from the desired engine performance characteristics (energy efficiency, emissions, stability). An accurate estimation of EGR and its effect on the intake dilution are, therefore, necessary to enable its application during transient engine operation or unstable combustion regimes. In this research, a detailed analysis that includes estimation of the transient (cycle-by-cycle) build-up of EGR and the time (engine cycles) required to reach the steady-state EGR operation has been carried out. One-step global equations to calculate the transient and steady-state gas concentrations in the intake and exhaust are proposed. The effects of engine load and intake pressure on EGR have been examined and explained in terms of intake charge dilution and in-cylinder excess-air ratio. The EGR analysis is validated against a wide range of empirical data that include low temperature combustion cycles, intake pressure and load sweeps. This research intends to not only formulate a clear understanding of EGR application for advanced diesel combustion but also to set forth guidelines for transient analysis of EGR

27

Measuring Carbon Monoxide in Auto Exhaust by Gas Chromatography.  

Science.gov (United States)

Presents a simple and reliable technique using commonly available equipment for monitoring carbon monoxide in automobile exhaust. The experiment utilizes a gas chromatograph and a thermal conductivity detector (TCD). (DDR)

Jaffe, Dan; Herndon, Scott

1995-01-01

28

Gas flow means for improving efficiency of exhaust hoods  

International Nuclear Information System (INIS)

Apparatus is described for inhibiting the flow of contaminants in an exhaust enclosure toward an individual located adjacent an opening into the exhaust enclosure by providing a gas flow toward a source of contaminants from a position in front of an individual to urge said contaminants away from the individual toward a gas exit port. The apparatus comprises a gas manifold which may be worn by a person as a vest. The manifold has a series of gas outlets on a front face thereof facing away from the individual and toward the contaminants to thereby provide a flow of gas from the front of the individual toward the contaminants. 15 figures

29

Methane oxidation over noble metal catalysts as related to controlling natural gas vehicle exhaust emissions  

International Nuclear Information System (INIS)

Natural gas has considerable potential as an alternative automotive fuel. This paper reports on methane, the principal hydrocarbon species in natural-gas engine exhaust, which has extremely low photochemical reactivity but is a powerful greenhouse gas. Therefore, exhaust emissions of unburned methane from natural-gas vehicles are of particular concern. This laboratory reactor study evaluates noble metal catalysts for their potential in the catalytic removal of methane from natural-gas vehicle exhaust. Temperature run-up experiments show that the methane oxidation activity decreases in the order Pd/Al2O3 > Rh/Al2O3 > Pt/Al2O3. Also, for all the noble metal catalysts studied, methane conversion can be maximized by controlling the O2 concentration of the feedstream at a point somewhat rich (reducing) of stoichiometry

30

Particulate exhaust emissions from an experimental combustor. [gas turbine engine  

Science.gov (United States)

The concentration of dry particulates (carbon) in the exhaust of an experimental gas turbine combustor was measured at simulated takeoff operating conditions and correlated with the standard smoke-number measurement. Carbon was determined quantitatively from a sample collected on a fiberglass filter by converting the carbon in the smoke sample to carbon dioxide and then measuring the volume of carbon dioxide formed by gas chromatography. At a smoke of 25 (threshold of visibility of the smoke plume for large turbojets) the carbon concentration was 2.8 mg carbon/cu m exhaust gas, which is equivalent to an emission index of 0.17 g carbon/kg fuel.

Norgren, C. T.; Ingebo, R. D.

1975-01-01

31

Low-pressure-ratio regenerative exhaust-heated gas turbine  

Energy Technology Data Exchange (ETDEWEB)

A design study of coal-burning gas-turbine engines using the exhaust-heated cycle and state-of-the-art components has been completed. In addition, some initial experiments on a type of rotary ceramic-matrix regenerator that would be used to transfer heat from the products of coal combustion in the hot turbine exhaust to the cool compressed air have been conducted. Highly favorable results have been obtained on all aspects on which definite conclusions could be drawn.

Tampe, L.A.; Frenkel, R.G.; Kowalick, D.J.; Nahatis, H.M.; Silverstein, S.M.; Wilson, D.G.

1991-01-01

32

Method for controlling exhaust gas heat recovery systems in vehicles  

Science.gov (United States)

A method of operating a vehicle including an engine, a transmission, an exhaust gas heat recovery (EGHR) heat exchanger, and an oil-to-water heat exchanger providing selective heat-exchange communication between the engine and transmission. The method includes controlling a two-way valve, which is configured to be set to one of an engine position and a transmission position. The engine position allows heat-exchange communication between the EGHR heat exchanger and the engine, but does not allow heat-exchange communication between the EGHR heat exchanger and the oil-to-water heat exchanger. The transmission position allows heat-exchange communication between the EGHR heat exchanger, the oil-to-water heat exchanger, and the engine. The method also includes monitoring an ambient air temperature and comparing the monitored ambient air temperature to a predetermined cold ambient temperature. If the monitored ambient air temperature is greater than the predetermined cold ambient temperature, the two-way valve is set to the transmission position.

Spohn, Brian L.; Claypole, George M.; Starr, Richard D

2013-06-11

33

Metal supports for exhaust gas catalysts  

Energy Technology Data Exchange (ETDEWEB)

Since 1979, metal supports as pre-catalysts have been mass-produced and installed in export models of German automobiles bound for the United States and Japan. The close-to-engine installation directly behind the exhaust manifold places specially high demands on the thermal and mechanical durability of the metal supports. Sueddeutsche Kuehlerfabrik Behr produces these metal supports under the name of ''Metalit''. The development, properties and special advantages of these metal supports are covered. The successful use of hundreds of thousands of metal supports, a number of automobile manufacturers are working on programs to employ the Metalit concept for primary catalysts.

Nonnenmann, M.

1985-01-01

34

Emission Characteristics for Single Cylinder DI Diesel Engine with EGR (Exhaust Gas Recirculation System  

Directory of Open Access Journals (Sweden)

Full Text Available This paper includes experimental investigations of various exhaust gas recirculation rates on engine emission characteristics like NOx, HC, CO, CO2, exhaust gas temperature by AVL gas meter. By passing exhaust gas from venturi meter and regulating it with EGR valve so as to find out its effect on critical NOx emission and other harmful HC,CO & NOx emission parameter. So to reduce such harmful gases exhaust gas recirculation is economical and effective method to control emission. We cant reduced it 100% but up to little bit extent we can reduce it from CI as well as in SI type of CI engine. Some external coupling technology like EGR of cold type installed with turbo intercooler, hydrogen, oxygen enriched air to displace fresh intake air volume and so reduced amount of oxygen in combustion chamber to control peak temperature of cylinder. in this paper we have also look toward some coal trapping method installed with dampener cause to break bond between NO at high temperature.

Pratik G. Sapre

2014-09-01

35

A method for removal of CO from exhaust gas using pulsed corona discharge.  

Science.gov (United States)

An experimental study of the oxidation of CO in exhaust gas from a motorcycle has been carried out using plasma chemical reactions in a pulsed corona discharge. In the process, some main parameters, such as the initial CO concentration, amplitude and frequency of pulses, residence time, reactor volume, and relative humidity (RH), as well as their effects on CO removal characteristics, were investigated. O3, which is beneficial to reducing CO, was produced during CO removal. When the exhaust gas was at ambient temperature, more than 80% CO removal efficiency was realized at an initial concentration of 288 ppm in a suitable range of the parameters. PMID:11288300

Li, X; Yang, L; Lei, Y; Wang, J; Lu, Y

2000-10-01

36

Method and apparatus for the treatment of diesel exhaust gas:  

OpenAIRE

The invention relates to a method for the oxidation of carbon- and/or hydrocarbon- and/or combustable organic compounds containing liquid or solid particulate contaminants in gas streams, more in particular soot in exhaust gasses of diesel engines, comprising the treatment of said gas streams in a turbulent flow precipitator, of which at least part of the surface shows catalytic activity for non-selective oxidation

Hardeveld, R.; Makkee, M.; Moulijn, J. A.; Jelles, S. J.

2001-01-01

37

IC ENGINE SUPERCHARGING AND EXHAUST GAS RECIRCULATION USING JET COMPRESSOR  

Directory of Open Access Journals (Sweden)

Full Text Available Supercharging is a process which is used to improve the performance of an engine by increasing the specific power output whereas exhaust gas recirculation reduces the NOx produced by engine because of supercharging. In a conventional engine, supercharger functions as a compressor for the forced induction of the charge taking mechanical power from the engine crankshaft. In this study, supercharging is achieved using a jet compressor. In the jet compressor, the exhaust gas is used as the motive stream and the atmospheric air as the propelled stream. When high pressure motive stream from the engine exhaust is expanded in the nozzle, a low pressure is created at the nozzle exit. Due to this low pressure, atmospheric air is sucked into the expansion chamber of the compressor, where it is mixed and pressurized with the motive stream. The pressure of the mixed stream is further increased in the diverging section of the jet compressor. A percentage volume of the pressurized air mixture is then inducted back into the engine as supercharged air and the balance is let out as exhaust. This process not only saves the mechanical power required for supercharging but also dilutes the constituents of the engine exhaust gas thereby reducing the emission and the noise level generated from the engine exhaust. The geometrical design parameters of the jet compressor were obtained by solving the governing equations using the method of constant rate of momentum change. Using the theoretical design parameters of the jet compressor, a computational fluid dinamics analysis using FLUENT software was made to evaluate the performance of the jet compressor for the application of supercharging an IC engine. This evaluation turned out to be an efficient diagnostic tool for determining performance optimization and design of the jet compressor. A jet compressor was also fabricated for the application of supercharging and its performance was studied.

Adhimoulame Kalaisselvane

2010-01-01

38

Estimating IC engine exhaust gas lambda and oxygen from the response of a universal exhaust gas oxygen sensor  

International Nuclear Information System (INIS)

Universal exhaust gas oxygen sensors (UEGOs) are in widespread use in internal combustion engines where they are used to measure lambda (the non-dimensional air–fuel ratio) and oxygen concentration (XO2). The sensors are used on production engines and for research and development. In a previous paper, a model of the UEGO sensor was presented, based on a solution of the Stefan–Maxwell equations for an axisymmetric geometry, and it was shown that for a known gas composition, predictions of the sensor response agreed well with experiment. In the present paper, the more ‘practical’ problem is addressed: how well can such a model predict ? and XO2 based on the sensor response? For IC engine applications, a chemistry model is required in order to predict ?, and such a model is also desirable for an accurate prediction of XO2. A fast (matrix exponential) method of solving the Stefan–Maxwell equations is also introduced, which offers the possibility of a near real-time computation of ? and XO2, with application, for example, to bench instruments. Extensive results are presented showing how the interpretation of the UEGO response may be compromised by uncertainties. These uncertainties may relate not only to the sensor itself, such as temperature, pressure and mean pore diameter, but also the chemistry model. (paper)

39

Experimental study on exhaust gas after treatment using limestone  

Directory of Open Access Journals (Sweden)

Full Text Available In this study a simple low-cost exhaust gas after-treatment filter using limestone was developed and tested on a four cylinder DI diesel engine coupled with dynamometer under variable engine running conditions. Limestone was placed in cast iron housing through which exhaust gases passes. The concentration of both carbon dioxide and nitrogen oxides were measured with and without the filter in place. It was found that both pollutants were decreased significantly when the filter is in place, with no increase in the fuel consumption rate.

Sakhrieh Ahmad

2013-01-01

40

Test Program for High Efficiency Gas Turbine Exhaust Diffuser  

Energy Technology Data Exchange (ETDEWEB)

This research relates to improving the efficiency of flow in a turbine exhaust, and thus, that of the turbine and power plant. The Phase I SBIR project demonstrated the technical viability of “strutlets” to control stalls on a model diffuser strut. Strutlets are a novel flow-improving vane concept intended to improve the efficiency of flow in turbine exhausts. Strutlets can help reduce turbine back pressure, and incrementally improve turbine efficiency, increase power, and reduce greenhouse gas emmission. The long-term goal is a 0.5 percent improvement of each item, averaged over the US gas turbine fleet. The strutlets were tested in a physical scale model of a gas turbine exhaust diffuser. The test flow passage is a straight, annular diffuser with three sets of struts. At the end of Phase 1, the ability of strutlets to keep flow attached to struts was demonstrated, but the strutlet drag was too high for a net efficiency advantage. An independently sponsored followup project did develop a highly-modified low-drag strutlet. In combination with other flow improving vanes, complicance to the stated goals was demonstrated for for simple cycle power plants, and to most of the goals for combined cycle power plants using this particular exhaust geometry. Importantly, low frequency diffuser noise was reduced by 5 dB or more, compared to the baseline. Appolicability to other diffuser geometries is yet to be demonstrated.

Norris, Thomas R.

2009-12-31

41

Study of recycling exhaust gas energy of hybrid pneumatic power system with CFD  

International Nuclear Information System (INIS)

A hybrid pneumatic power system (HPPS) is integrated by an internal combustion engine (ICE), a high efficiency turbine, an air compressor and an energy merger pipe, which can not only recycle and store exhaust gas energy but also convert it into useful mechanical energy. Moreover, it can make the ICE operate in its optimal state of maximum efficiency; and thus, it can be considered an effective solution to improve greatly the exhaust emissions and increase the overall energy efficiency of the HPPS. However, in this system, the flow energy merger of both high pressure compressed air flow and high temperature exhaust gas flow of the ICE greatly depends on the merging capability of the energy merger pipe. If the compressed air pressure (Pair) at the air inlet is too high, smooth transmission and mixture of the exhaust gas flow are prevented, which will interfere with the operation condition of the ICE. This shortcoming is mostly omitted in the previous studies. The purpose of this paper is to study the effect of the level of Pair and the contraction of cross-section area (CSA) at the merging position on the flow energy merger and determine their optimum adjustments for a better merging process by using computation fluid dynamics (CFD). In addition, the CFD model was validated on the basis of the experimental data, including the temperature and static pressure of the merger flow at the outlet of the energy merger pipe. It was found that the simulatiorger pipe. It was found that the simulation results were in good agreement with the experimental data. The simulation results show that exhaust gas recycling efficiency and merger flow energy are significantly dependent on the optimum adjustment of the CSA for changes in Pair. Under these optimum adjustments, the exhaust gas recycling efficiency can reach about 83%. These results will be valuable bases to research and design the energy merger pipe of the HPPS.

42

40 CFR 89.421 - Exhaust gas analytical system; CVS bag sample.  

Science.gov (United States)

... § 89.421 Exhaust gas analytical system; CVS bag sample...drawing of the exhaust gas analytical system used for analyzing...information and coordinate the functions of the component systems...component description. The analytical system, Figure 4 in...

2010-07-01

43

40 CFR 91.423 - Exhaust gas analytical system; CVS grab sample.  

Science.gov (United States)

... § 91.423 Exhaust gas analytical system; CVS grab sample...drawing of the exhaust gas analytical system used for analyzing...information and coordinate the functions of the component systems...component description. The analytical system, Figure 4...

2010-07-01

44

40 CFR 90.423 - Exhaust gas analytical system; CVS grab sample.  

Science.gov (United States)

... § 90.423 Exhaust gas analytical system; CVS grab sample...drawing of the exhaust gas analytical systems used for analyzing...information and coordinate the functions of the component systems...component description. The analytical system, Figure 4...

2010-07-01

45

Fiber metal acoustic material for gas turbine exhaust environments  

International Nuclear Information System (INIS)

FELTMETAL fiber metal acoustic materials function as broad band acoustic absorbers. Their acoustic energy absorbance occurs through viscous flow losses as sound waves pass through the tortuous pore structure of the material. Exhaust gas noise attenuation requirements are reviewed. Their selection process for higher performance materials is discussed. A new FELTMETAL fiber metal acoustic material has been designed for use in gas turbine auxiliary power unit exhaust environments without supplemental cooling. The physical and acoustic properties of mesh supported fiber metal acoustic medium FM 827 are discussed. Exposure testing was conducted under conditions which simulated auxiliary power unit operation. Weight gain and tensile strength data as a function of time of exposure at 6500C (12020F) are reported. Fabrication of components with fiber metal acoustic materials is easily accomplished using standard roll forming and gas tungsten arc welding practices

46

Fiber metal acoustic material for gas turbine exhaust environments  

Energy Technology Data Exchange (ETDEWEB)

FELTMETAL fiber metal acoustic materials function as broad band acoustic absorbers. Their acoustic energy absorbance occurs through viscous flow losses as sound waves pass through the tortuous pore structure of the material. Exhaust gas noise attenuation requirements are reviewed. Their selection process for higher performance materials is discussed. A new FELTMETAL fiber metal acoustic material has been designed for use in gas turbine auxiliary power unit exhaust environments without supplemental cooling. The physical and acoustic properties of mesh supported fiber metal acoustic medium FM 827 are discussed. Exposure testing was conducted under conditions which simulated auxiliary power unit operation. Weight gain and tensile strength data as a function of time of exposure at 650{sup 0}C (1202{sup 0}F) are reported. Fabrication of components with fiber metal acoustic materials is easily accomplished using standard roll forming and gas tungsten arc welding practices.

Beaton, M.S. (Brunswick Corp., Technetics Div., Energy Conservation Systems, DeLand, FL (US))

1989-01-01

47

Exhaust gas treatment in testing nuclear rocket engines  

International Nuclear Information System (INIS)

With the exception of the last test series of the Rover program, Nuclear Furnace 1, test-reactor and rocket engine hydrogen gas exhaust generated during the Rover/NERVA program was released directly to the atmosphere, without removal of the associated fission products and other radioactive debris. Current rules for nuclear facilities (DOE Order 5480.6) are far more protective of the general environment; even with the remoteness of the Nevada Test Site, introduction of potentially hazardous quantities of radioactive waste into the atmosphere must be scrupulously avoided. The Rocketdyne treatment concept features a diffuser to provide altitude simulation and pressure recovery, a series of heat exchangers to gradually cool the exhaust gas stream to 100 K, and an activated charcoal bed for adsorption of inert gases. A hydrogen-gas fed ejector provides auxiliary pumping for startup and shutdown of the engine. Supplemental filtration to remove particulates and condensed phases may be added at appropriate locations in the system. The clean hydrogen may be exhausted to the atmosphere and flared, or the gas may be condensed and stored for reuse in testing. The latter approach totally isolates the working gas from the environment

48

Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine  

Energy Technology Data Exchange (ETDEWEB)

A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

2014-05-13

49

Emission &Performance characteristics of single cylinder CI engine using cold EGR (Exhaust Gas Recirculation.  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we studied the effect of exhaust gas recirculation for reduction of harmful gases like NOx,CO2 etc. at a same time effects of cold EGR on performance of engine such as brake thermal efficiency, cylinder pressure, cylinder temperature exhaust temperature.etc Above parameter studied for stationary water cooled DI Diesel single cylinder engine by looking towards running(2014 and upcoming emission Norms. Also to incorporate technology to study effects of EGR on combustion temperature and so to reduce NOx by surveying emissions papers to have outlook of EGR Route system and important equipment that need to be furnished in further study in same project to have smooth and positive effects from performance side under study. Professor Avinash M.Wankhade et al found that while re-circulating exhaust gas it reduced about 65.26% of NOx which is improved results of Avinash Wankhade et al and Pratik Sapre et al under guidance of Dr.S.B.Thakare et al[ ].Use of EGR significantly reduced NO emissions at normal condition when passing 20% of EGR. The Particulate emissions increased as EGR rate is increased but we don’t deserve it so to vanish this effets further experiments can be done with blending diesel with fish methyl oil ester, sun flower oil methyl ester[14]. This reduces NOx as well HC.So Exhaust gas was recalculated in intake stroke and cooled by intercooler of partially cooled type via venturi meter.

Avinash M.Wankhade

2014-12-01

50

Metal substrate for automotive exhaust gas catalysts  

Energy Technology Data Exchange (ETDEWEB)

Behr has been producing its metal substrate Metalit for installation in Daimler-Benz vehicles since 1979. This was the first and has remained the only volume-production of it in the world up to now. Several hundred thousand metal substrates have been supplied, giving the company broad-based, positive feedback from users in the USA and Japan. Metal's physical properties and the technology developed by Behr all help make metal substrates particularly well suited for applications in motor vehicles. The advantages of metal substrates are outlined in this article. They offer high catalytic efficiency, stability under high temperatures, high tensile and dynamic strength, a short warm-up period and low pressure drop. Special attention is given to cost factors, the substrate's modest space requirements and very simple canning.

Nonnenmann, M.

1984-12-01

51

Flow in non-symmetric gas turbine exhaust ducts  

Science.gov (United States)

An experimental and computational study of non-symmetric single-port gas turbine exhaust ducts has been carried out. The geometry of the exhaust duct incorporates an annular to rectangular transition with a 160° turn. The focus of the study was to determine the effect of inlet conditions and duct geometry on the flow structure and the level of overall pressure losses in the duct flow. As part of this work, the appropriateness of boundary conditions for both experimental and computational studies was investigated. The experimental studies were carried out using a ½-scale cold flow apparatus capable of measuring the flow conditions at the inlet and outlet of the duct. Inlet conditions varied included the level of swirl and circumferential total pressure distribution. Computational fluid dynamic (CFD) studies were carried out using a commercial solver using k - epsilon turbulence modeling and non-equilibrium wall functions. The computational solutions were benchmarked against experimental values, allowing CFD to be used to extend the range of inlet conditions beyond the range that could be obtained experimentally, to those more typical of an engine installation. Results show that inlet conditions have a significant effect on the flow structure in the exhaust duct. Total pressure losses in the exhaust duct increase as the circumferential inlet total pressure distribution becomes more non-uniform. This results in losses measured on a standard cold-flow apparatus under-predicting those that would exist on a duct installed on a gas turbine. However, trends in the geometric variables identified experimentally using cold flow were confirmed computationally with inlet conditions more typical of an exhaust duct mounted on an engine.

Cunningham, Mark H.

52

An Experimental Study of Different Effects of EGR Rates on The Performance And Exhaust Emissions of The Stratified Charge Piston Direct Injection Compressed Natural Gas Engine  

OpenAIRE

Exhaust Gas Recirculation (EGR) is one of the principal techniques used to control spark ignition NOX. A fraction of the exhaust gas is recycled through a control valve from the exhaust to the engine intake system. However, EGR has different effect on performance, combustion and emissions production that are difficult to distinguish such as increase of intake temperature, delay of Rate Of Heat Rrelease (ROHR), decrease of peak heat release, decrease in oxygen concentration etc. Therefor...

Wasiu, Saheed O.; Aziz, A. Rashid A.; Sulaiman, Shaharin A.

2011-01-01

53

Exhaust gas bypass valve control for thermoelectric generator  

Energy Technology Data Exchange (ETDEWEB)

A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve is provided. The method includes: determining a mass flow of exhaust exiting an engine; determining a desired exhaust pressure based on the mass flow of exhaust; comparing the desired exhaust pressure to a determined exhaust pressure; and determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve.

Reynolds, Michael G; Yang, Jihui; Meisner, Greogry P.; Stabler, Francis R.; De Bock, Hendrik Pieter (Peter) Jacobus; Anderson, Todd Alan

2012-09-04

54

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

55

Laboratory Scale of Liquid Coal Fuel Combustion Process and Exhaust Gas Formation  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Much research of coal has been already undertaken to ascertain the possibilities of coal being used as substitute for heavy fuel oil in the transportation sector. The effects of using coal as transportation fuel to the environment must also be considered. This study will review several aspects of the coal oil combustion process including combustion behavior, flame stability, some emissions from exhaust gas; CO, NOx and the particulate matter in a well insulated laboratory scale furnace for more stable of combustion. Approach: New way for preparation for liquid coal oil steady combustion on a 2.75 m horizontal boiler with four annular segment tubes, a water jacket system and a system for measurement of water temperature inside was archived. Data was gained by applying liquid coal in the experiment. Detailed preparation and setting for steady combustion of coal oil and formation of the exhaust gas were discussed based on data sampling from four sample points in each centre of the angular tube segments. Results: Preparation for coal oil combustion is an important point in the successful of combustion. Heating coal fuel to than 100°C, heating the fuel line to the same temperature and providing enough air pressure for atomization of coal oil until 0.1 MPa allows coal fuel smoothly atomized in the semi gas phase. There was enough of air combustion via a blower with 4500 L min-1 of flow rate and a 24 L min-1 of water flow rate in the water jacket transforms the energy of the fuel to the heat. Uncolored of the exhaust gas and the physical inspection describes the completion of combustion. This result close-relates with the pollutants formation in the exhaust gas. Conclusion: By conducting a deep research process, there is a chance for the substitute of heavy fuel oil with liquid coal fuel with no special treatment needed in combustion process without ignoring the contribution of the combustion results as an environmental problem.

Kartika K. Hendratna

2010-01-01

56

Parasitic load control system for exhaust temperature control  

Science.gov (United States)

A parasitic load control system is provided. The system may include an exhaust producing engine and a fuel pumping mechanism configured to pressurize fuel in a pressure chamber. The system may also include an injection valve configured to cause fuel pressure to build within the pressure chamber when in a first position and allow injection of fuel from the pressure chamber into one or more combustion chambers of the engine when in a second position. The system may further include a controller configured to independently regulate the pressure in the pressure chamber and the injection of fuel into the one or more combustion chambers, to increase a load on the fuel pumping mechanism, increasing parasitic load on the engine, thereby increasing a temperature of the exhaust produced by the engine.

Strauser, Aaron D. (Washington, IL); Coleman, Gerald N. (Peterborough, GB); Coldren, Dana R. (Fairbury, IL)

2009-04-28

57

Exhaust Gas Recirculation in Gas Turbines for Reduction of CO2 Emissions; Combustion Testing with Focus on Stability and Emissions  

OpenAIRE

Exhaust gas recirculation can be applied with the intention of reducing CO2 emissions. When a fraction of the exhaust gas is injected in the entry of a gas turbine, the amount of CO2 in the exhaust gas not being recirculated will be higher and less complicated to capture. However, with this change in combustion air composition, especially the reduced concentration of oxygen, the combustion process will be affected. The lower oxygen concentration decreases the stability and the increased amoun...

Hustad, Johan E.; Røkke, Petter E.

2005-01-01

58

Exhaust Gas Recirculation in Gas Turbines for Reduction of CO2 Emissions; Combustion Testing with Focus on Stability and Emissions  

Directory of Open Access Journals (Sweden)

Full Text Available Exhaust gas recirculation can be applied with the intention of reducing CO2 emissions. When a fraction of the exhaust gas is injected in the entry of a gas turbine, the amount of CO2 in the exhaust gas not being recirculated will be higher and less complicated to capture. However, with this change in combustion air composition, especially the reduced concentration of oxygen, the combustion process will be affected. The lower oxygen concentration decreases the stability and the increased amount of CO2, H2O and N2 will decrease the combustion temperature and thus, the NOx emissions. Testing has been performed on a 65 kW gas turbine combustor, to investigate the effect of adding N2, CO2 and O2 in the combustion process, with focus on stability and emissions of NOx. Results show that adding N2 and CO2 decreases the NOx emissions, whereas O2 addition increases the NOx emissions. The tests have been performed both in a diffusion flame (pilot burner and a premixed flame (main burner, and for additives being injected with the fuel or with the air stream. Addition into the fuel stream is proven to affect the NOx emissions the most. The stability limits of the flames are indicated with respect to mass-based additive-to-fuel ratios.

Johan E. Hustad

2005-12-01

59

40 CFR 86.1311-94 - Exhaust gas analytical system; CVS bag sample.  

Science.gov (United States)

...consists of a gas chromatograph (GC), equipped...detector. The analysis for formaldehyde...The exhaust gas analytical...from the CO analysis stream. ...essentially free of CO2 and water...consisting of a gas chromatograph combined...

2010-07-01

60

78 FR 63015 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...  

Science.gov (United States)

...Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate...EPA also proposed adopting the gas turbine engine test procedures of the...Exhaust Emissions (New Aircraft Gas Turbine Engines) 0 3. Amend Sec....

2013-10-23

61

Fiber metal acoustic materials for gas turbine exhaust environments  

Energy Technology Data Exchange (ETDEWEB)

FELTMETAL fiber metal acoustic materials function as broad band acoustic absorbers. This acoustic energy absorbance occurs through viscous flow losses as sound waves pass through the tortuous pore structure of the material. A new FELTMETAL fiber metal acoustic material has been designed for use in gas turbine auxiliary power unit exhaust environments without supplemental cooling. The physical and acoustic properties of FM 827 are discussed. Exposure tests were conducted under conditions which simulated auxiliary power unit operation. Weight gain and tensile strength data as a function of time of exposure at 650{degrees}C (1202{degrees}F) are reported. Fabrication of components with fiber metal acoustic materials is easily accomplished using standard roll forming and gas tungsten arc welding practices.

Beaton. M.S. (Brunswick Corp., Technetics Div., Energy Conservation Systems, DeLand (FL))

1988-01-01

62

An experimental study on the effects of exhaust gas on spruce (Picea abies L. Karst.)  

Energy Technology Data Exchange (ETDEWEB)

Motor vehicle exhausts are significant contributors to air pollution. Besides fine particles and inorganic gases, like CO, SO{sub 2} and NO{sub x}, exhaust gas contains a large group of aromatic hydrocarbon compounds, many of which are phytotoxic. In field studies, exhausts are found to have both direct and indirect harmful effects on roadside plants. However, only few experimental studies have been made about the effects of exhaust gas emissions on coniferous trees. The aim of this study was to survey the effects of exhausts on spruce (Picea abies L. Karst.) in standardized conditions. The concentrations of major exhaust gas components in the chamber atmosphere were detected simultaneously. The effects of exhaust on epistomatal waxes of first-year spruce needles are described. (author)

Hautala, E.L.; Holopainen, J.; Kaerenlampi, L. [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Surakka, J.; Ruuskanen, J. [Kuopio Univ. (Finland). Dept. of Environmental Sciences

1995-12-31

63

Steady-state modelling of the universal exhaust gas oxygen (UEGO) sensor  

International Nuclear Information System (INIS)

The universal exhaust gas oxygen (UEGO) sensor is a well-established device which was developed for the measurement of relative air fuel ratio in internal combustion engines. There is, however, little information available which allows for the prediction of the UEGO's behaviour when exposed to arbitrary gas mixtures, pressures and temperatures. Here we present a steady-state model for the sensor, based on a solution of the Stefan–Maxwell equation, and which includes a momentum balance. The response of the sensor is dominated by a diffusion barrier, which controls the rate of diffusion of gas species between the exhaust and a cavity. Determination of the diffusion barrier characteristics, especially the mean pore size, porosity and tortuosity, is essential for the purposes of modelling, and a measurement technique based on identification of the sensor pressure giving zero temperature sensitivity is shown to be a convenient method of achieving this. The model, suitably calibrated, is shown to make good predictions of sensor behaviour for large variations of pressure, temperature and gas composition. (paper)

64

A predictive algorithm to ensure thermal protection for a diesel exhaust gas after-treatment device  

Energy Technology Data Exchange (ETDEWEB)

In this paper a predictive control algorithm is presented aiming at triggering an operating mode used for thermal protection of an after-treatment component. An inversion thermal model of the after-treatment component is used to calculate for a pre-assigned substrate maximum temperature, the desired oxygen concentration and the desired exhaust gas temperature at the inlet to the after-treatment component. These are then compared to pre-calibration thresholds and then used to activate/deactivate the thermal protection combustion mode. (orig.)

Yacoub, Yasser; Dubkov, Alexei; Roettger, Daniel; Carberry, Brendan [Ford Forschungszentrum Aachen GmbH (Germany)

2008-07-01

65

Performance of humid air turbine with exhaust gas expanded to below ambient pressure based on microturbine  

Energy Technology Data Exchange (ETDEWEB)

A new type of HAT cycle comprising HAT and Inverted Brayton cycles, named BAHAT in this paper, is proposed to enhance the microturbine's performance. By adding an exhaust compressor after flue gas condenser, the gas expander expands to a pressure lower than ambient. Simulation and parameter optimization results show that the electricity efficiency and specific work of BAHAT are about 2 percentage points and 20% higher than that of HAT cycle respectively when turbine inlet temperature is 950 deg. C. The working pressure of aftercooler, humidifier and turbine hot section is only about 0.4 MPa though the optimal total pressure ratio is about 9-10. The drops of compression work and outlet water temperature of humidifier are considered the main factors to enhance BAHAT's efficiency. In addition, the exhaust compressor inlet gas temperature affects BAHAT's efficiency and water recovery ratio apparently. It is also shown that it is easy to achieve water self-support for BAHAT, mixing makeup water to the water loop before entering economizer shows the best thermodynamic performance, and air leakage to the bottom cycle influences both efficiency and water recovery ratio of BAHAT.

Wan Kuifang [Key Laboratory of Advanced Energy and Power, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang Shijie, E-mail: zhangsj@mail.etp.ac.c [Key Laboratory of Advanced Energy and Power, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Wang Jing [Key Laboratory of Advanced Energy and Power, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Xiao Yunhan [Key Laboratory of Advanced Energy and Power, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China)

2010-11-15

66

Performance of humid air turbine with exhaust gas expanded to below ambient pressure based on microturbine  

International Nuclear Information System (INIS)

A new type of HAT cycle comprising HAT and Inverted Brayton cycles, named BAHAT in this paper, is proposed to enhance the microturbine's performance. By adding an exhaust compressor after flue gas condenser, the gas expander expands to a pressure lower than ambient. Simulation and parameter optimization results show that the electricity efficiency and specific work of BAHAT are about 2 percentage points and 20% higher than that of HAT cycle respectively when turbine inlet temperature is 950 deg. C. The working pressure of aftercooler, humidifier and turbine hot section is only about 0.4 MPa though the optimal total pressure ratio is about 9-10. The drops of compression work and outlet water temperature of humidifier are considered the main factors to enhance BAHAT's efficiency. In addition, the exhaust compressor inlet gas temperature affects BAHAT's efficiency and water recovery ratio apparently. It is also shown that it is easy to achieve water self-support for BAHAT, mixing makeup water to the water loop before entering economizer shows the best thermodynamic performance, and air leakage to the bottom cycle influences both efficiency and water recovery ratio of BAHAT.

67

Performance of humid air turbine with exhaust gas expanded to below ambient pressure based on microturbine  

Energy Technology Data Exchange (ETDEWEB)

A new type of HAT cycle comprising HAT and Inverted Brayton cycles, named BAHAT in this paper, is proposed to enhance the microturbine's performance. By adding an exhaust compressor after flue gas condenser, the gas expander expands to a pressure lower than ambient. Simulation and parameter optimization results show that the electricity efficiency and specific work of BAHAT are about 2 percentage points and 20% higher than that of HAT cycle respectively when turbine inlet temperature is 950 C. The working pressure of aftercooler, humidifier and turbine hot section is only about 0.4 MPa though the optimal total pressure ratio is about 9-10. The drops of compression work and outlet water temperature of humidifier are considered the main factors to enhance BAHAT's efficiency. In addition, the exhaust compressor inlet gas temperature affects BAHAT's efficiency and water recovery ratio apparently. It is also shown that it is easy to achieve water self-support for BAHAT, mixing makeup water to the water loop before entering economizer shows the best thermodynamic performance, and air leakage to the bottom cycle influences both efficiency and water recovery ratio of BAHAT. (author)

Kuifang Wan; Jing Wang [Key Laboratory of Advanced Energy and Power, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Shijie Zhang; Yunhan Xiao [Key Laboratory of Advanced Energy and Power, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China)

2010-11-15

68

Practical Possibilities of High-Altitude Flight with Exhaust-Gas Turbines in Connection with Spark Ignition Engines Comparative Thermodynamic and Flight Mechanical Investigations  

Science.gov (United States)

As a means of preparing for high-altitude flight with spark-ignition engines in conjunction with exhaust-gas turbosuperchargers, various methods of modifying the exhaust-gas temperatures, which are initially higher than a turbine can withstand are mathematically compared. The thermodynamic results first obtained are then examined with respect to the effect on flight speed, climbing speed, ceiling, economy, and cruising range. The results are so presented in a generalized form that they may be applied to every appropriate type of aircraft design and a comparison with the supercharged engine without exhaust-gas turbine can be made.

Weise, A.

1947-01-01

69

Removal of methane from compressed natural gas fueled vehicle exhaust  

International Nuclear Information System (INIS)

The objective of this paper is to investigate the modes of methane (CH4) removal from simulated compressed natural gas (CNG) fueled vehicle exhaust under net oxidizing, net reducing, and stoichiometric conditions. Model reaction studies were conducted. The results suggest that the oxidation of methane with oxygen contributes to the removal of methane under net oxidizing conditions. In contrast, the oxidation of methane with oxygen as well as nitric oxide contributes to its removal under net reducing conditions. The steam reforming reaction does not significantly contribute to the removal of methane. The methane conversions under net reducing conditions are higher than those observed under net oxidizing conditions. The study shows that the presence of carbon monoxide in the feed gas leads to a gradual decrease in the methane conversion with increasing redox ratio, under net oxidizing conditions. a minimum in methane conversion is observed at a redox ratio of 0. 8. The higher activity for the methane-oxygen reaction resulting from a lowering in the overall oxidation state of palladium and the contribution of the methane-nitric oxide reaction toward the removal of CH4 appear to account for the higher CH4 conversions observed under net reducing conditions

70

Comments on the low frequency radiation impedance of a duct exhausting a hot gas.  

Science.gov (United States)

The influence of convection and temperature on the radiation impedance of an open duct termination exhausting a hot gas is commonly described by a complex theory. A simplified analytical expression is proposed for low frequencies. Both models assume a free jet with uniform velocity bounded by infinitely thin shear layers. The convective velocity that should be assumed when applying these models to a non-uniform outflow is uncertain. A simplified version of the so-called Vortex Sound Theory demonstrates that the convective velocity one should assume is lower than the jet centerline velocity. PMID:25096151

Hirschberg, Avraham; Hoeijmakers, Maarten

2014-08-01

71

Neuralfussy multivariable control applied to the control of velocity, power, and exhaust gas temperature of a turbo gas unit; Control neurodifuso multivariable aplicado al control de velocidad, potencia y temperatura de gases de escape de una unidad turbogas  

Energy Technology Data Exchange (ETDEWEB)

The electric power demand in Mexico has forced to the electric sector to be in a constant search of methods and systems that, among other objectives, improve the operation of the generating power stations of electric power continually. As part of their mission, the Electrical Research Institute (IIE) has promoted and leaning the applied research and the technological development to improve the indexes of security, readiness, dependability, efficiency and durability of central generating by means of the development and the installation of big digital systems of information and control. At the present time, inside the scheme of electric power generation, the gas turbine (UTG) represent 7% of the generation of the national electric sector [1]. These units have become the dominant way of the new electric generation in the U.S, either in simple cycle or combined. The above-mentioned, is attributable at less installation cost for generated kilowatt, to the shortest construction programs, at first floor levels of emission of pollutants and competitive operation costs. The control system of the gas turbine is based on conventional control algorithms of the type PI [2]. This control scheme is dedicated for regulation tasks and rejection to interferences, and it doesn't stop pursuit of reference points. The controllers act all on a control valve, that which represents a strong interaction among the same ones, for example an adjustment in the parameters of the algorithm of the digital PI of temperature, it can improve their acting but it can also affect the acting of the speed control or that of power. The gas turbine presents a non lineal behavior and variant in the time, mainly in the starting stage where several important disturbances are presented. At the moment, the controllers used in the scheme of control of the turbines are lineal, which are syntonized for a specific operation point and they are conserved this way by indefinite time. In this thesis the formulation of a controller feedback multivariable is presented, designed with the combination of the technologies of fuzzy logic and neural networks with the purpose of improving the control of speed, power and temperature of the UTG. This proposed control is used in conjunction with the scheme of conventional control of the existent UTG, to integrate a strategy of control hybrid feedback. The control feedback is compound for a fuzzy inference system of multiple entrances and a left exit designed with entrance data and exit of the plant. The controller feed forward is compound for conventional controllers type PI in this type of units. With this strategy, the controller feedback provides a bigger contribution in the control sign the effort of the conventional controllers' PI control and the strong interaction that it exists among them diminishing. The controllers PI feed forward contribute a smaller control sign used for fine adjustments in the control sign. [Spanish] La demanda de energia electrica en Mexico ha obligado al sector electrico a estar en una busqueda constante de metodos y sistemas que, entre otros objetivos, mejoren continuamente la operacion de las centrales generadoras de energia electrica. Como parte de su mision, el Instituto de Investigaciones Electricas (IIE) ha promovido y apoyado la investigacion aplicada y el desarrollo tecnologico para mejorar los indices de seguridad, disponibilidad, confiabilidad, eficiencia y durabilidad de centrales generadoras mediante el desarrollo y la implantacion de grandes sistemas digitales de informacion y control. En la actualidad, dentro del esquema de generacion de energia electrica, las unidades turbogas (UTG) representan 7% de la generacion del sector electrico nacional [1]. Estas unidades se han convertido en el modo dominante de la nueva generacion electrica en los EE.UU, ya sea en ciclo simple o combinado. Lo anterior, es atribuible al menor costo de instalacion por kilowatt generado, a los programas de construccion mas cortos, a bajos niveles de emision de contaminantes y costos de operacion competitivo

Segura Ozuna, Victor Octavio

2004-11-15

72

Temperature monitoring of vehicle engine exhaust gases under vibration condition using optical fibre temperature sensor systems  

Energy Technology Data Exchange (ETDEWEB)

Two optical approaches, comprising and contracting both the fluorescence decay lifetime and the fibre Bragg grating (FBG) methods, were developed and evaluated for temperature monitoring of exhaust gases for use on a vehicle engine. The FBGs used in the system were written into specially designed Bi-Ge co-doped photosensitive fibres, to enable them to sustain high temperatures to over 800{sup 0}C, which is far beyond that of FBGs written into most commercial photosensitive fibres. The sensors were subjected to a range of vibration tests, as a part of an optical exhaust monitoring network under development, and results from the test carried out are reported.

Zhao, W Z [School of Eng. and Math. Sciences, City University, Northampton Square, London EC1V 0HB (United Kingdom); Suna, T [School of Eng. and Math. Sciences, City University, Northampton Square, London EC1V 0HB (United Kingdom); Grattana, K T V [School of Eng. and Math. Sciences, City University, Northampton Square, London EC1V 0HB (United Kingdom); Shen, Y H [Department of Physics, Zhejiang University, Hangzhou, China, 310027 (China); Wei, C L [Department of Elec. Eng. and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ (United Kingdom); Al-Shamma' a, A I [Department of Elec. Eng. and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ (United Kingdom)

2006-07-15

73

The combustion of pulverized coal in simulated turbine exhaust gas: effects on NO[sub x], combustion efficiency and flame structure  

Energy Technology Data Exchange (ETDEWEB)

A large proportion of electric power generation world-wide is derived from the combustion of pulverised coal in large power-plant boilers coupled to steam turbines, with overall efficiencies typically in the range 35-39%. One method of improving the overall efficiency of such a power plant or to increase the power output is to re-power the existing boilers using gas turbines in a combined-cycle system. In this configuration the hot turbine exhaust gas is used as the oxidant for burning the pulverised coal in the existing boiler, to raise steam. Because of the low oxygen content and the high temperature of the turbine exhaust gas, many issues exist as to the flexibility of this technology in practice, particularly with respect to flame stability, burnout and pollutant emissions such as NO[sub x], CO and unburnt hydrocarbons. This paper presents the results of a preliminary study on the combustion of pulverised coal in simulated turbine exhaust gas at 1.3 MW thermal input. A generic experimental burner was used. Simulated turbine exhaust gas was produced from two natural-gas-fired turbine exhaust-gas generators with independent control of oxygen and temperature levels. The simulated turbine exhaust gas was used as main oxidant and as the coal transport medium. In the simulated turbine exhaust gas, oxygen concentration ranged between 10 and 21%. and temperatures ranged between 400 and 600[degree]C. Two coals were fired - Goettelborn (HVBa) and Obed Mountain (HVBc). Stable combustion was obtained for turbine exhaust-gas oxygen levels down to 11%; this observation was relatively insensitive to turbine exhaust-gas temperature. Dependent on coal type, NO[sub x] emissions ranged from 120 ppm (0%O[sub 2]) for turbine exhaust-gas oxygen levels of 11%, to 1100 ppm (0%O[sub 2]) at 21% oxygen. Burnout expectedly fell as turbine exhaust-gas oxygen level was reduced. This latter phenomenon was more significant for the Goettelborn coal. 6 refs., 9 figs., 1 tab.

Smart, J.P.; Kamp, W.L. van de (International Flame Research Foundation, IJmuiden (Netherlands))

1994-06-01

74

Use of exhaust gas recirculation as a control approach for thermoacoustic instabilities  

Energy Technology Data Exchange (ETDEWEB)

Investigation into exhaust gas recirculation (EGR) as a method for reducing costs of postcombustion carbon capture in gas turbine systems reveals that EGR offers potential applications as a control strategy for thermoacoustic instabilities. Introduction of EGR allows semi-independent variation of the operating parameter of flame temperature and characteristic flame length scales, known to play a primary role in the phase of the thermoacoustic coupling mechanism. Measurements were made showing the ability of EGR to reduce the amplitude of thermoacoustic oscillations over a range of operating conditions in a laboratory scale, swirled dump combustor, without affecting the flame temperature. Theoretical analysis was also performed to investigate the limitations on the ability of this approach to influence dynamics.

Ranalli, J.; Ferguson, D.

2011-10-09

75

Test procedures for measuring exhaust emissions from natural gas transmission engines  

International Nuclear Information System (INIS)

This paper reports on the measurement of exhaust components from large natural gas transmission engines involves collection of the exhaust sample, transfer of the sample to the analytical instrumentation, measurement of individual component concentrations, and calculations of emission results in terms of mass, fuel specific, and brake specific rates. The major exhaust components measured include nitrogen oxides (NOx), total hydrocarbons (THC), carbon dioxide (CO2), carbon monoxide (CO), and oxygen (O2). Collection of the exhaust sample requires proper probe design and placement in the exhaust system. Transfer of the sample to the analytical instruments must maintain sample integrity from the point where the sample is removed from the exhaust stream to the point at which the sample enters the instrument for analysis. Various analytical techniques are used to measure the exhaust emission concentrations

76

Data reduction and evaluation procedures. [concerning exhaust gas analysis  

Science.gov (United States)

The computational procedures that are involved in exhaust emissions data reduction and the use of these computational procedures for determining the quality of the data that is obtained from exhaust measurements were considered. Four problem areas were calculated: (1) the various methods for performing the carbon balance, (2) the method for calculating water correction factors, (3) the method for calculating the exhaust molecular weight, and (4) assessing the quality of the data.

Mirsky, W.

1976-01-01

77

Design of a DBD System for On-Board Treatment of the Exhaust Gas  

International Nuclear Information System (INIS)

This study is a part of the investigation of the diesel engine exhaust cleaning processes concerning a design of a compact, low power dielectric barrier discharge (DBD) system for on-board treatment of the exhaust gas in combination with a catalyst. The activated gas molecules and reduction agents which are produced by the discharge make the operation of the catalyst more efficient. The effect of the discharge frequency, power and geometry on the gas composition is described in our previous publication

78

Development of exhaust gas treatment technologies for environment protection  

International Nuclear Information System (INIS)

Full text: The emission of carbon dioxide (CO2) and other pollutants which result from burning fossil fuels has been identified as the major contributor to global warming and climate change. However, for the immediate term over the next 10 - 20 years at least, the world will continue to rely on fossil fuels as the source of primary energy. The challenge for the fossil fuel industry is to find cost-effective solutions that will reduce the release of CO2 and other pollutants into the atmosphere. The focus of this paper is on the ability to treat the exhaust gas from fossil fuel power plants in order to capture and store the CO2 and remove other pollutants such as SOx and NOx which are released in the atmosphere. In summary, capture/separation costs represent the largest financial impediment for this types of plants. Hence, efficient, cost-effective capture/separation technologies will need to be developed in order to allow their large-scale use. (authors)

79

Evaluating tractor performance and exhaust gas emissions using biodiesel from cotton seed oil  

Science.gov (United States)

Alternative fuels for diesel engines, such as biodiesel, have attracted much attention recently due to increasing fuel prices and the imperative to reduce emissions. The exhaust gas emissions from tractors and other agricultural machinery make a significant contribution to these emissions. The use of biodiesel in internal combustion engines (ICE) has been reported to give comparable performance to conventional diesel (CD), but with generally lower emissions. There is however, contradictory evidence of NO emissions being both higher and lower from the use of biodiesel. In this work, agriculture tractor engine performance and its emission using both CD and biodiesel from cotton seed oil (CSO-B20) mixed at a 20% blend ration has been evaluated and compared. The PTO test results showed comparable exhaust emissions between CD and CSO-B20. However, the use of CSO-B20 led to reductions in the thermal efficiency and exhaust temperature and an increase in the brake specific fuel consumption (BSFC), when compared to CD.

Al-lwayzy, Saddam H.; Yusaf, Talal; Jensen, Troy

2012-09-01

80

Evaluating tractor performance and exhaust gas emissions using biodiesel from cotton seed oil  

International Nuclear Information System (INIS)

Alternative fuels for diesel engines, such as biodiesel, have attracted much attention recently due to increasing fuel prices and the imperative to reduce emissions. The exhaust gas emissions from tractors and other agricultural machinery make a significant contribution to these emissions. The use of biodiesel in internal combustion engines (ICE) has been reported to give comparable performance to conventional diesel (CD), but with generally lower emissions. There is however, contradictory evidence of NO emissions being both higher and lower from the use of biodiesel. In this work, agriculture tractor engine performance and its emission using both CD and biodiesel from cotton seed oil (CSO-B20) mixed at a 20% blend ration has been evaluated and compared. The PTO test results showed comparable exhaust emissions between CD and CSO-B20. However, the use of CSO-B20 led to reductions in the thermal efficiency and exhaust temperature and an increase in the brake specific fuel consumption (BSFC), when compared to CD.

81

Exhaust Gas Heat Recovery for C.I Engine-A Review  

OpenAIRE

The focus of the study is to review the modern changes and technologies on waste heat recovery of exhaust gas from internal combustion engine. These include the thermoelectric generator, turbocharger, exhaust gas through I.C engine. Due to the total heat supplied to the engine in the form of fuel around 30-40%, heat is converting in to the use full mechanical work and residual parts of the wastage heat 60-70% as friction, exhaust gas and engine cooling system. Waste heat relea...

Baleshwar Kumar Singh,; Dr. Nitin Shrivastava

2014-01-01

82

Exhaust purification with on-board ammonia production  

Science.gov (United States)

A method of ammonia production for a selective catalytic reduction system is provided. The method includes producing an exhaust gas stream within a cylinder group, wherein the first exhaust gas stream includes NOx. The exhaust gas stream may be supplied to an exhaust passage and cooled to a predetermined temperature range, and at least a portion of the NOx within the exhaust gas stream my be converted into ammonia.

Robel, Wade J. (Peoria, IL); Driscoll, James Joshua (Dunlap, IL); Coleman, Gerald N. (Helpston, GB)

2010-10-12

83

Evaluation of SI engine exhaust gas emissions upstream and downstream of the catalytic converter  

International Nuclear Information System (INIS)

The conversion efficiency of a catalytic converter, mounted on a vehicle equipped with a 2.8 l spark ignition engine, was evaluated under steady state operating conditions. The inlet and outlet chemical species concentration, temperature and air fuel ratio (A/F) were measured as a function of the brake mean effective pressure (BMEP) and engine speed (rpm). Oil temperature, coolant temperature, brake power and spark advance were also monitored. In parallel, a mathematical model for the catalytic converter has been developed. The main inputs of the model are the temperature, flow rate, chemical species mass flow and local A/F ratio as measured at the catalyst inlet section. The main conclusions are: (i) the exhaust gas and substrate wall temperatures at the catalyst outlet increase with BMEP and rpm; (ii) the HC conversion efficiency increases with the value of BMEP up to a maximum beyond which it decreases; (iii) the CO conversion efficiencies typically increase with BMEP; (iv) the NO x conversion efficiency remains nearly constant regardless of BMEP and rpm; (v) except for idle, the NO x conversion efficiency is typically the highest, followed in turn by the CO and HC conversion efficiencies; (vi) conversion efficiencies are lower for idle conditions, which can be a problem under traffic conditions where idle is a common situation; (vii) regardless of rpm and load, for the same flow rate the conversion efficiency is about the same; (viii) the modficiency is about the same; (viii) the model predictions slightly over estimate the exhaust gas temperature data at the catalyst outlet section with the observed differences decreasing with BMEP and engine speed; (ix) in general, the model predictions of the conversion efficiencies are satisfactory

84

Use of the JET active gas handling plant exhaust detritiation system during and after DTE1  

Energy Technology Data Exchange (ETDEWEB)

The Exhaust Detritiation System (EDS) of the JET Active Gas Handling Plant has operated continuously for the last three years. The system has been used during the active commissioning phase, during the DTE1 deuterium-tritium experiment and subsequently during the Remote Tile Exchange (RTE) operation. The Exhaust Detritiation System is one of the key safety systems which permits the operation of the JET machine with tritium. This paper describes the experience gained of operating the Exhaust Detritiation System throughout the tritium operations at JET. The design and the construction and commissioning of the Exhaust Detritiation System have been discussed previously. (authors)

Brennan, P.D.; Bainbridge, N.; Bell, A.C. [JET Joint Undertaking, Abingdon, Oxon (United Kingdom)] [and others

1998-07-01

85

Use of the JET active gas handling plant exhaust detritiation system during and after DTE1  

International Nuclear Information System (INIS)

The Exhaust Detritiation System (EDS) of the JET Active Gas Handling Plant has operated continuously for the last three years. The system has been used during the active commissioning phase, during the DTE1 deuterium-tritium experiment and subsequently during the Remote Tile Exchange (RTE) operation. The Exhaust Detritiation System is one of the key safety systems which permits the operation of the JET machine with tritium. This paper describes the experience gained of operating the Exhaust Detritiation System throughout the tritium operations at JET. The design and the construction and commissioning of the Exhaust Detritiation System have been discussed previously. (authors)

86

LPG fueled diesel engine using diethyl ether with exhaust gas recirculation  

Energy Technology Data Exchange (ETDEWEB)

The present investigation was to study the effect of Exhaust Gas Recirculation (EGR) on homogeneous charge ignition engine. A stationary four stroke, single cylinder, direct injection (DI) diesel engine capable of developing 3.7 kW at 1500 rpm was modified to operate in HCCI mode. In the present work the diesel engine was operated on 100% Liquified Petroleum Gas (LPG). The LPG has a low cetane number (<3), therefore Diethyl ether (DEE) was added to the LPG for ignition purpose. DEE is an excellent ignition enhancer (cetane number >125) and has a low auto ignition temperature (160 C). Experimental results showed that by EGR technique, at part loads the brake thermal efficiency increases by about 2.5% and at full load, NO concentration could be considerably reduced to about 68% as compared to LPG operation without EGR. However, higher EGR percentage affects the combustion rate and significant reduction in peak pressure at maximum load. (author)

Miller Jothi, N.K.; Nagarajan, G.; Renganarayanan, S. [Department of Mechanical Engineering, Anna University, Chennai - 600 025 (India)

2008-04-15

87

Exhaust gas aftertreatment with online burner; Abgasnachbehandlung mit Online-Brenner  

Energy Technology Data Exchange (ETDEWEB)

In order to fulfil continuously tightened emission standards, modern Diesel engines for on and off road have to meet demands of catalytic exhaust gas aftertreatment with their thermomanagement. With an online burner from Huss Technologies, even with low load duty cycles, catalytic exhaust gas aftertreatment is possible. Diesel engine development can therefore be redirected again more on efficiency enhancement and other direct customer demands. (orig.)

Rembor, Hans-Joerg; Bischler, Thomas [Huss Technologies GmbH, Nuernberg (Germany)

2010-09-15

88

Health risks with automobile exhaust gas. Jidosha haishutsu gas no kenko risk  

Energy Technology Data Exchange (ETDEWEB)

This paper describes mainly the health survey on residents living along automobile roads for effects of nitrogen dioxide and photochemical oxidant, and the relation of diesel car exhaust gas with lung cancer and cryptomeria pollinosis. A questionnaire survey using American Thoracic Society (ATS) - DLD system reports a result suggestive of relation between children's asthmatic disease and NO2. A significant correlation is discerned between prevalence of adults' cough and phlegm disease and NO2 concentration. According to the health survey on residents living along automobile roads, respiratory organ disease prevalence by territories showed a trend that corresponds to the concentration level of air pollution with nitrogen dioxide. Acute symptoms due to photochemical oxidant are eye and respiratory organ stimulation. Development of lung tumors due to diesel exhaust gas and its toxicity are related with its particle components. Their relation with an increase in allergic rhinitis is also discussed. Immediate automobile exhaust control regulations and administrative actions are expected. 31 refs., 12 figs., 3 tabs.

Yokoyama, E.; Uchiyama, I. (The Institute of Public Health, Tokyo (Japan))

1992-09-01

89

Measurement of exhaust gas recirculation rate by laser-induced fluorescence in engine  

International Nuclear Information System (INIS)

The objective of this study is to measure by planar laser-induced fluorescence the exhaust gas recirculation (EGR) rate in the combustion chamber of an optical engine to quantify the stratification phenomena used in the new combustion strategy. From the results obtained in a high pressure–high temperature (HP–HT) facility, the tracer chosen for this aim is 3-pentanone. This paper presents a quantitative measurement of the EGR rate in the engine and a post-processing model with a correction and calibration procedure by considering the influence of temperature and pressure on the absorption cross-section and the 3-pentanone fluorescence quantum yield from the results established in the HP–HT facility. The stratification phenomena are quantified by using 3-pentanone fluorescence for two different configurations of EGR introduction in the engine. The local fluorescence measurements in the HP–HT facility are also compared with planar fluorescence measurements in the optical engine

90

Use of exhaust gas as sweep flow to enhance air separation membrane performance  

Science.gov (United States)

An intake air separation system for an internal combustion engine is provided with purge gas or sweep flow on the permeate side of separation membranes in the air separation device. Exhaust gas from the engine is used as a purge gas flow, to increase oxygen flux in the separation device without increasing the nitrogen flux.

Dutart, Charles H. (Washington, IL); Choi, Cathy Y. (Morton, IL)

2003-01-01

91

Exhaust gas concentration of CNG fuelled direct injection engine at MBT timing  

International Nuclear Information System (INIS)

Full text: This paper presents an experimental result of exhaust gas concentration of high compression engine fuelled with compressed natural gas (CNG) at maximum brake torque (MBT). The engine uses central direct injection (DI) technique to inject the CNG into the cylinder. The engine geometry bases on gasoline engine with 14:1 compression ratio and called CNGDI engine. The injectors are positioned within a certain degrees of spark plug location. The objective of the experiment is to study the influence and significant of MBT timing in CNGDI engine towards exhaust gases. The experimental tests were carried out using computer-controlled eddy-current dynamometer, which measures the CNGDI engine performance. At MBT region, exhaust gas concentration as such CO, HC, NOx, O2 and CO2, were recorded and analyzed during the test using the Horiba analyzer. A closed loop wide band lambda sensor has been mounted at the exhaust manifold to indicate the oxygen level during the exercise. (author)

92

Turbine exhaust diffuser with region of reduced flow area and outer boundary gas flow  

Science.gov (United States)

An exhaust diffuser system and method for a turbine engine. The outer boundary may include a region in which the outer boundary extends radially inwardly toward the hub structure and may direct at least a portion of an exhaust flow in the diffuser toward the hub structure. At least one gas jet is provided including a jet exit located on the outer boundary. The jet exit may discharge a flow of gas downstream substantially parallel to an inner surface of the outer boundary to direct a portion of the exhaust flow in the diffuser toward the outer boundary to effect a radially outward flow of at least a portion of the exhaust gas flow toward the outer boundary to balance an aerodynamic load between the outer and inner boundaries.

Orosa, John

2014-03-11

93

Laser mass spectrometry for time-resolved multicomponent analysis of exhaust gas  

Energy Technology Data Exchange (ETDEWEB)

A new analytical method for the fast analysis of trace substances in gas mixtures has been developed incorporating a pulsed tunable laser system and a reflectron time-of-flight mass spectrometer. The technique is especially designed for the time-resolved detection of air pollutants in the exhaust gas of motor engines. The purpose of this new analytical method is to achieve high time resolution (< 100 ms), high sensitivity (down to 1 ppm), high quantitative precision (10%), and applicability to most exhaust emission components. The main difficulties for the analysis arise from the large number of components which show very different and rapidly varying concentrations. For a preliminary list of 25 exhaust emission components, all essential parameters have been determined. First results obtained from a real exhaust gas sample are presented. 27 refs., 13 figs., 2 tabs.

Weickhardt, C.; Boesl, U.; Schlag, E.W. (Technische Universitaet Muenchen, Garching (Germany))

1994-04-01

94

Effect of operating and sampling conditions on the exhaust gas composition of small-scale power generators.  

Science.gov (United States)

Small stationary diesel engines, like in generator sets, have limited emission control measures and are therefore responsible for 44% of the particulate matter (PM) emissions in the United States. The diesel exhaust composition depends on operating conditions of the combustion engine. Furthermore, the measurements are influenced by the used sampling method. This study examines the effect of engine loading and exhaust gas dilution on the composition of small-scale power generators. These generators are used in different operating conditions than road-transport vehicles, resulting in different emission characteristics. Experimental data were obtained for gaseous volatile organic compounds (VOC) and PM mass concentration, elemental composition and nitrate content. The exhaust composition depends on load condition because of its effect on fuel consumption, engine wear and combustion temperature. Higher load conditions result in lower PM concentration and sharper edged particles with larger aerodynamic diameters. A positive correlation with load condition was found for K, Ca, Sr, Mn, Cu, Zn and Pb adsorbed on PM, elements that originate from lubricating oil or engine corrosion. The nitrate concentration decreases at higher load conditions, due to enhanced nitrate dissociation to gaseous NO at higher engine temperatures. Dilution on the other hand decreases PM and nitrate concentration and increases gaseous VOC and adsorbed metal content. In conclusion, these data show that operating and sampling conditions have a major effect on the exhaust gas composition of small-scale diesel generators. Therefore, care must be taken when designing new experiments or comparing literature results. PMID:22442670

Smits, Marianne; Vanpachtenbeke, Floris; Horemans, Benjamin; De Wael, Karolien; Hauchecorne, Birger; Van Langenhove, Herman; Demeestere, Kristof; Lenaerts, Silvia

2012-01-01

95

Control method for turbocharged diesel engines having exhaust gas recirculation  

Science.gov (United States)

A method of controlling the airflow into a compression ignition engine having an EGR and a VGT. The control strategy includes the steps of generating desired EGR and VGT turbine mass flow rates as a function of the desired and measured compressor mass airflow values and exhaust manifold pressure values. The desired compressor mass airflow and exhaust manifold pressure values are generated as a function of the operator-requested fueling rate and engine speed. The EGR and VGT turbine mass flow rates are then inverted to corresponding EGR and VGT actuator positions to achieve the desired compressor mass airflow rate and exhaust manifold pressure. The control strategy also includes a method of estimating the intake manifold pressure used in generating the EGR valve and VGT turbine positions.

Kolmanovsky, Ilya V. (Ypsilanti, MI); Jankovic, Mrdjan J (Birmingham, MI); Jankovic, Miroslava (Birmingham, MI)

2000-03-14

96

Reduction of low temperature engine pollutants by understanding the exhaust species interactions in a diesel oxidation catalyst.  

Science.gov (United States)

The interactions between exhaust gas species and their effect (promotion or inhibition) on the light-off and activity of a diesel oxidation catalyst (DOC) for the removal of pollutants are studied, using actual engine exhaust gases from the combustion of diesel, alternative fuels (rapeseed methyl ester and gas-to-liquid fuel) and diesel/propane dual fuel combustion. The activity of the catalyst was recorded during a heating temperature ramp where carbon monoxide (CO) and hydrocarbon (HC) light-off curves were obtained. From the catalyst activity tests, it was found that the presence of species including CO, medium-heavy HC, alkenes, alkanes, and NOx and their concentration influence the catalyst ability to reduce CO and total HC emissions before release to the atmosphere. CO could inhibit itself and other species oxidation (e.g., light and medium-heavy hydrocarbons) while suffering from competitive adsorption with NO. Hydrocarbon species were also found to inhibit their own oxidation as well as CO through adsorption competition. On the other hand, NO2 was found to promote low temperature HC oxidation through its partial reduction, forming NO. The understanding of these exhaust species interactions within the DOC could aid the design of an efficient aftertreatment system for the removal of diesel exhaust pollutants. PMID:24450781

Lefort, I; Herreros, J M; Tsolakis, A

2014-02-18

97

Exhaust gas catalysts for heavy-duty vehicles fuelled by alcohol or biogas  

Energy Technology Data Exchange (ETDEWEB)

The long-term objective for the project is to develop tailor-made exhaust gas catalysts for heavy-duty ethanol fuelled diesel vehicles operating in urban traffic. Due to special problems, related to emissions of unregulated compounds emanating from ethanol fuelled buses in Swedish fleet tests, a catalyst research programme has been initiated. The engineering target was to achieve a light-off temperature (T{sub 50}) for ethanol conversion below 110 deg C and a selectivity for total oxidation over 90 %. In this report results from laboratory-reactor tests are described. The results indicate that by combining two different precious metals both activity and selectivity can be positively affected compared to the properties of the corresponding mono metallic catalysts. The best results show a light-off temperature for ethanol conversion below 100 deg C. The base metal oxides were more selective for total oxidation than the corresponding precious metal catalysts. The results also indicate a considerable interaction between support and active material which affects the product distribution in catalytic oxidation of ethanol. At temperatures below 250 deg C the by-product formation can be quite high and the major by-product is acetaldehyde. The metal support interaction also has a certain influence on the oxidation of NO to NO{sub 2}. The results show that the NO{sub 2} formation can be suppressed without considerably affecting the activity of the catalyst. This report also includes a preliminary life cycle analysis (LCA) and life cycle cost (LCC) estimate for exhaust gas catalysts intended for heavy-duty ethanol vehicles in urban traffic. 22 refs, numerous figs and tabs

Pettersson, L.J.; Wahlberg, A.M.; Jaeraas, S.G. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

1997-06-01

98

Suicide by carbon monoxide from car exhaust-gas in Denmark 1995-1999  

DEFF Research Database (Denmark)

In the period 1995-1999 there were 388 car exhaust-gas suicides in Denmark. Of these 343 (88.4%) were men and 45 (11.6%) were women, the average age being 47 years. The car exhaust-gas suicides made up 9.3% of all suicides in Denmark in the period. The corresponding rate was 11.7% for men and 3.7% for women. In rural areas a larger part of all suicides were committed with car exhaust-gas compared to the more densely populated areas. Mental disease was diagnosed in 124 (32.0%) cases. A suicide note was found in 165 (42.5%) cases. A hose was fitted to the exhaust pipe in 334 (86.1%) cases. Of these the 234 (60.3%) occurred outside, typically in a forest area, while 76 (19.6%) occurred in a closed garage. All the 54 (13.9%) cases with no hose fitted to the exhaust pipe occurred in a garage. Seven (1.8%) victims were found in a burning or burnt-out car, where the following investigation revealed that it was actually a car exhaust-gas suicide. Carboxyhemoglobin was measured in 26 (6.7%) victims. In two of these victims no carboxyhemoglobin was found, as they had survived for some time after the poisoning. The average saturation of the remaining victims was 67%, the lowest saturation being 20% and the highest being 84%. In the period 1969-1987 the number of car exhaust-gas suicides in Denmark increased from 50 to approximately 190 per year and the rate of car exhaust-gas suicides compared to all suicides increased from approximately 5% to approximately 13%. In 1987-1999 these figures decreased from approximately 190 to 63 per year and from 13% to approximately 8%. During these 30 years the number of passenger cars in Denmark doubled, which explains the increase in car exhaust-gas suicides during 1969-1987. A possible explanation for the decrease in 1987-1999 is the introduction of the catalytic converter, which was made mandatory in 1990. We anticipate that car exhaust-gas suicides will continue to decrease in numbers, as more cars are equipped with catalytic converters.

Thomsen, Asser H; Gregersen, Markil

2006-01-01

99

Implications of increased gas throughputs at ITER on the torus exhaust pumping system  

International Nuclear Information System (INIS)

The reference design of the ITER torus exhaust pumping system is based on 8 cryopumps, connected via 4 ducts to the torus. The exhaust gas flows will pass through the divertor into the pumping slots, at divertor pressures between 1 and 10 Pa. The pumping port and divertor geometry has limited conductance which reduces drastically the available pumping speed for the whole machine. Based on the transitional flow code ITERVAC, a conductance study is currently going on to model the complete divertor and pumping port geometry as a network in full detail and to assess the overall conductance at varied flow range conditions. This paper will report the relevant results of this study. The reference fueling rate has been recently increased; the resulting changes in the pump heat loads and operating envelopes are discussed. The maximum allowed hydrogenic gas accumulation is limited by oxy-hydrogen deflagration safety considerations: increased gas flows will lead to shortened pumping times. As the pumping system is operated in transitional flow regime, increased flows will change the overall conductance and directly re-influence the available divertor pressures. Higher gas flows will result in higher pressures inside the cryopump volume and lead to increased heat loads on the 4.5 K and 80 K cooling circuits of the cryopumps. Depending on the heat loads, the outlet temperatures of the coolant will tend to increase which, if unmitigated, could affect the pumping speed for helium, ould affect the pumping speed for helium, or, alternatively, the cryogenic flows might needed to be increased, which then has an impact on thermohydraulics and pressure losses across the pumps cryocircuits. To mitigate the potential deleterious influence on helium pumping speed, means to provide a lower coolant inlet temperature are being studied by ITER. Massive gas injection is the proposed concept to safely terminate a disrupting plasma discharge. Many aspects of this type of disruption mitigation need more investigation, but the first results of modelling the effects of massive gas injection are given for the current design of the ITER pumping system. This paper will present the results of a study on the different effects and their mutual influences and consequences. As ITER is an experimental device, it would be desirable to add as much flexibility to the pumping system as possible without increasing cost significantly. (author)

100

Diesel engine exhaust gas recirculation--a review on advanced and novel concepts  

International Nuclear Information System (INIS)

Exhaust gas recirculation (EGR) is effective to reduce nitrogen oxides (NOx) from Diesel engines because it lowers the flame temperature and the oxygen concentration of the working fluid in the combustion chamber. However, as NOx reduces, particulate matter (PM) increases, resulting from the lowered oxygen concentration. When EGR further increases, the engine operation reaches zones with higher instabilities, increased carbonaceous emissions and even power losses. In this research, the paths and limits to reduce NOx emissions from Diesel engines are briefly reviewed, and the inevitable uses of EGR are highlighted. The impact of EGR on Diesel operations is analyzed and a variety of ways to implement EGR are outlined. Thereafter, new concepts regarding EGR stream treatment and EGR hydrogen reforming are proposed

101

Platform for a Hydrocarbon Exhaust Gas Sensor Utilizing a Pumping Cell and a Conductometric Sensor  

Directory of Open Access Journals (Sweden)

Full Text Available Very often, high-temperature operated gas sensors are cross-sensitive to oxygen and/or they cannot be operated in oxygen-deficient (rich atmospheres. For instance, some metal oxides like Ga2O3 or doped SrTiO3 are excellent materials for conductometric hydrocarbon detection in the rough atmosphere of automotive exhausts, but have to be operated preferably at a constant oxygen concentration. We propose a modular sensor platform that combines a conductometric two-sensor-setup with an electrochemical pumping cell made of YSZ to establish a constant oxygen concentration in the ambient of the conductometric sensor film. In this paper, the platform is introduced, the two-sensor-setup is integrated into this new design, and sensing performance is characterized. Such a platform can be used for other sensor principles as well.

Ralf Moos

2009-09-01

102

Carbon Dioxide Emission Analysis of Chilled Water Production by Using Gas Turbine Exhaust Heat  

Directory of Open Access Journals (Sweden)

Full Text Available Carbon dioxide from exhaust heat emission is one of the major contributorsto the environmental pollutant in power generation plants. This problem could be addressed if the emitted exhaust heat is recovered. In cogeneration plant, the exhaust heat from the gas turbine is used to generate steam usingHeat Recovery Steam Generator. The steam from Heat Recovery Steam Generator is then used for chilled water generation in Steam Absorption Chillers by absorption process. This study analyzed the total estimated amount of CO2 released to the environment due to chilled water production by using gas turbine exhaust heat. University Teknologi PetronasMalaysia cogeneration system is used as a case study. The energy balance principlewas adopted for the analysis. Results indicate that approximately 44% of CO2is avoided from being released to the environment by this process.

Adzuieen Nordin

2013-12-01

103

Study on the combustion characteristics of a premixed combustion system with exhaust gas recirculation  

International Nuclear Information System (INIS)

The boiler of a premixed combustion system with EGR (exhaust gas recirculation) is investigated to explore the potential for increasing thermal efficiency and lowering pollutant emissions. To achieve this purpose, a thermodynamic analysis is performed to predict the effect of EGR on the thermodynamic efficiency for various equivalence ratios. Experiments of a preheated air condensing boiler with EGR were conducted to measure the changes in the thermal efficiency and the characteristics of the pollutant emission. Finally, a 1-D premixed code was calculated to understand the effect of the EGR method on the NO reduction mechanism. The results of the thermodynamic analysis show that the thermodynamic efficiency is not changed because the temperature and the amount of the exhaust gas are unchanged, even though the EGR method is implemented in the system. However, when the EGR method is used with an equivalence ratio near 1.00, it is experimentally verified that the thermal efficiency increases and the NOx concentration decreases. Based on the results from numerical calculations, it is shown that the NO production rates of N + O2 ? NO + O and N + OH ? NO + H are remarkably changed due to the decrease in the flame temperature and the NO mole fraction is decreased. - Highlights: • Premixed combustion system with EGR is studied for a high efficiency and low NOx. • All research is performed with various EGR and equivalence ratios. • It verified that efficiency increases and the NOx emission decreases with EGR method. • NO production rates are remarkably changed by N + O2 ? NO + O and N + OH ? NO + H with EGR

104

Experimental observation of carbon dioxide reduction in exhaust gas from hydrocarbon fuel burning  

International Nuclear Information System (INIS)

A high-negative voltage at the cathode initiates a dark discharge, resulting in a reduction of the carbon dioxide concentration in exhaust gas from the burning of hydrocarbon fuel. An experiment indicated that nearly 44% of the carbon dioxide in exhaust gas disappears after a high-voltage application to the cathode. The energy needed for the endothermic reaction of the carbon dioxide dissociation corresponding to this concentration reduction is provided mainly by the internal energy reduction of the discharge gas, which is nearly 20 times the electrical energy for electron emission.

105

Low-pressure-ratio regenerative exhaust-heated gas turbine. Final report  

Energy Technology Data Exchange (ETDEWEB)

A design study of coal-burning gas-turbine engines using the exhaust-heated cycle and state-of-the-art components has been completed. In addition, some initial experiments on a type of rotary ceramic-matrix regenerator that would be used to transfer heat from the products of coal combustion in the hot turbine exhaust to the cool compressed air have been conducted. Highly favorable results have been obtained on all aspects on which definite conclusions could be drawn.

Tampe, L.A.; Frenkel, R.G.; Kowalick, D.J.; Nahatis, H.M.; Silverstein, S.M.; Wilson, D.G.

1991-01-01

106

Heat-pipe assisted thermoelectric generators for exhaust gas applications  

OpenAIRE

Millions of hybrid cars are already running on our roads with the purpose of reducing fossil fuel dependence. One of their main advantages is the recovery of wasted energy, namely by brake recovery. However, there are other sources of wasted energy in a car powered by an internal combustion engine, such as the heat lost through the cooling system, lubrication system (oil coolers) and in the exhaust system. These energies can be recuperated by the use of thermoelectric generators (TEG) based o...

Gonc?alves, L. M.; Martins, Jorge; Antunes, Joaquim; Rocha, Romeu; Brito, F. P.

2010-01-01

107

40 CFR 86.1511 - Exhaust gas analysis system.  

Science.gov (United States)

...Heavy-Duty Engines, New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines...Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Light-Duty...

2010-07-01

108

40 CFR 86.1509 - Exhaust gas sampling system.  

Science.gov (United States)

...Heavy-Duty Engines, New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines...Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Light-Duty...

2010-07-01

109

Application of the water gas shift reaction to fusion fuel exhaust streams  

International Nuclear Information System (INIS)

In a Fusion Fuel Clean Up (FCU) system, impurities will be removed from the fusion reactor exhaust and neutral beam line streams. Tritium in this impurity stream will be recovered and recycled to the fuel stream. In one flowsheet configuration of the Tritium Systems Test Assembly (TSTA), tritium is recovered from a simulated impurity stream via uranium hot metal beds and recycled to an isotope separation system. This study has shown, however, that the catalyzed water gas shift reaction, by which (H,D,T)2O and CO are converted to (H,D,T)2 and CO2 is a better method of (H,D,T)2O reduction than the hot metal beds. Catalytic reactors were designed, built and tested to provide data for the design of a prototype reactor to replace the hot metal beds in the FCU system. The prototype reactor contains only 10 g of catalyst and is expected to last at least 5 years. The reactor is small (1.3 cm OD x 13 cm long), operates at low temperatures (approximately 490 K) and will convert water to hydrogen, at a CO/H2O ratio of 1.5, with an efficiency of greater than 98 percent. Results show that the catalytic reactor is very stable even during upset conditions. Wide ranges of flow and a CO/H2O ratio variance from 1.3 upward have little effect on the conversion efficiency. Short term high temperature excursions do not affect the catalyst and lower temperatures will simply decrease the reaction rate resulting in lower conversions. The reactor appears to be unaffected by NO2, CO2, O2 and N2 in the feed stream at concentration levels expected in a fusion reactor exhaust stream

110

Performance analysis for the characteristics of hybrid type absorption chiller operated by exhaust gas and hot water  

International Nuclear Information System (INIS)

The characteristics of hybrid type absorption chiller are studied numerically to use a waste hot water and exhaust hot gas effectively. As the partial load decreases, COP decreases but COPf increases. It is because of the system more rely upon the single effect cycle compare to the double effect cycle. So the consumption ratio of fuels increase and the save ratio decrease as the partial load decreases. For the same reason, as the inlet temperature and flow rate of hot water increase COP decreases but COPf increases. As the inlet temperature of the hot gas increase, COPf increases. It is because of the consumption ratio of fuels decreases as the inlet temperature of the hot gas increase.

111

Removal of Carbon Dioxide Gas From the Exhaust Gases Generated at the Takoradi Thermal Power Station  

Directory of Open Access Journals (Sweden)

Full Text Available Takoradi Thermal Power Station (TTPS generates electricity by burning fossil-fuel and hence it also generates greenhouse gases especially carbon dioxide, which is vented into the atmosphere. These greenhouse gases are pollutants known to cause global warming. A method for the removal of carbon dioxide gas from the exhaust gases generated at TTPS is proposed in this research. It aims at reducing the plant’s carbon dioxide emission into the atmosphere and hence reducing the plant’s rate of pollution into the atmosphere. The method employed is a modification of a method known as the Fluor Daniel ECONAMINE FG process. This method removes carbon dioxide from exhaust gas by using an amine solution which comes into “contact” with the exhaust gas in a counter-current manner. This method has been applied by 23 companies which produce CO2 on a large scale. However, before TTPS apply this method a cost feasibility study is recommended.

M. Charles

2010-10-01

112

Method for producing a cartridge for purifying exhaust gas  

Energy Technology Data Exchange (ETDEWEB)

A cartridge is disclosed for purifying exhaust gases from the internal combustion engine of a automotive vehicle or some other source comprising a catalyst support matrix wound of metal foil and a metal jacket housing said support matrix wherein a press fit exists between the exterior of the support matrix and the interior surface of the jacket and the support matrix and the jacket are welded or brazed together within the area of the press fit. Processes and apparatus for producing the cartridge of the invention are also disclosed.

Nonnenmann, M.; Bardong, H.; Haller, K.; Hesse, W.

1983-08-30

113

Process for manufacturing a cartridge for purifying exhaust gas  

Energy Technology Data Exchange (ETDEWEB)

A cartridge for purifying exhaust gases from the internal combustion engine of an automotive vehicle or some other source comprising a catalyst support matrix wound of metal foil and a metal jacket housing said support matrix wherein a press fit exists between the exterior of the support matrix and the interior surface of the jacket and the support matrix and the jacket are welded or brazed together within the area of the press fit. Processes and apparatus for producing the cartridge of the invention are also disclosed.

Nonnenmann, M.; Bardong, H.; Haller, K.; Hesse, W.

1985-05-28

114

Process for reducing harmful substances in exhaust gas/exhaust air by means of photosynthesising algae and device to carry out the process. Verfahren zur Minderung von Abgas-/Abluft-Schadstoffen mittels photosynthetisierender Algen und Vorrichtung zur Durchfuehrung des Verfahrens  

Energy Technology Data Exchange (ETDEWEB)

The process reported here uses the photosynthesis properties of micro-organisms which can stand extremes of harmful substances (micro-algae: cyanidium caldarium), using light energy to fix carbon dioxide, SO/sub 2/ and NO/sub x/ in biological compounds. Metal ions can be accumulated simultaneously. The process provides for the uncomplicated direct introduction of exhaust gas/exhaust air (temperature range: 40-80/sup 0/C) into the lighted culture. If sunlight is used, the process has a very favourable energy balance, as the harmful substances are converted biologically into compounds rich in energy, which can be reused (e.g. biogas).

Schimmelpfeng, L.; Thormaelen, C.

1986-09-25

115

Energy efficient exhaust gas purification from waste incineration; Energieeffiziente Abgasreinigung bei der Abfallverbrennung  

Energy Technology Data Exchange (ETDEWEB)

Due to the increasing demands on the climate protection and the dwindling resources of primary energy, power generation from waste materials increasingly becomes important. The constantly increasing prices of primary energy give new incentives to use the energetic potentials in the exhaust gas. The energy efficiency of a thermal waste treatment plant depends on several factors. The boiler with the associated steam condenser system offers a great potential for the optimization. The author of the contribution under consideration reports on the potentials of energy optimization of exhaust gas purification procedures behind waste incineration plants. Basic possibilities of energy optimization are considered and presented in concrete existing plants as well as new plants.

Karpf, R. [ete.a Ingenieurgesellschaft mbH, Lich (Germany)

2011-07-01

116

HEAT TRANSFER IN EXHAUST SYSTEM OF A COLD START ENGINE AT LOW ENVIRONMENTAL TEMPERATURE  

Directory of Open Access Journals (Sweden)

Full Text Available During the engine cold start, there is a significantly increased emission of harmful engine exhaust gases, particularly at very low environmental temperatures. Therefore, reducing of emission during that period is of great importance for the reduction of entire engine emission. This study was conducted to test the activating speed of the catalyst at low environmental temperatures. The research was conducted by use of mathematical model and developed computer programme for calculation of non-stationary heat transfer in engine exhaust system. During the research, some of constructional parameters of exhaust system were adopted and optimized at environmental temperature of 22 ?C. The combination of design parameters giving best results at low environmental temperatures was observed. The results showed that the temperature in the environment did not have any significant influence on pre-catalyst light-off time.

Snežana D Petkovi?

2010-01-01

117

Technologies for increasing CO2 concentration in exhaust gas from natural gas-fired power production with post-combustion, amine-based CO2 capture  

OpenAIRE

Enhanced CO2 concentration in exhaust gas is regarded as a potentially effective method to reduce thehigh electrical efficiency penalty caused by CO2 chemical absorption in post-combustion capturesystems. The present work evaluates the effect of increasing CO2 concentration in the exhaust gas of gasturbine based power plant by four different methods: exhaust gas recirculation (EGR), humidification(EvGT), supplementary firing (SFC) and external firing (EFC). Efforts have been focused on the im...

Li, Hailong; Ditaranto, M.; Berstad, D.

2011-01-01

118

Reformulation of engine gasoline to reduce exhaust emissions in Finnish conditions. Effect of gasoline aromatics, olefins and T90 temperature on exhaust emissions  

International Nuclear Information System (INIS)

The research work focused on the effects of gasoline composition, i.e. aromatics and olefin contents and 90 % point of distillation, on exhaust emissions. The experimental part comprised exhaust gas measurements for 13 catalyst cars at +22 deg C and for one non-catalyst car at +22 deg C according to FTP75 driving cycle. Regulated emissions (THC, CO and NOx), non-regulated emissions (hydrocarbons and aldehydes), carbon dioxide and fuel consumption were measured. The high aromatics contents of eight test fuels were about 40 vol% and the low ones about 15 vol%, the high olefin contents were about 15 vol% and the low ones about 2 vol%, and the high T90 temperatures about +170 deg C and the low ones +145 deg C. The results were treated in two ways: effects of each single change in characteristics, and those of simultaneous changes in all fuel characteristics studied. The lowest CO and THC emissions for the catalyst cars at +22 deg C were obtained by reducing the aromatics content and the T90 temperature of the fuel, while the reduction of the olefin content increased respective emissions. The NOx emission increased when the aromatics content and T90 temperature were reduced, and decreased slightly when the olefin content was reduced. The CO2 emission and the fuel consumption (kg/100 km) were affected, i.e. reduced, only by a reduction in the aromatics content. However, the fuel consumption in volume units (1/100 kg) increased. The results a units (1/100 kg) increased. The results at -7 deg C for THC and NOx emissions were along the same lines as at +22 deg C, except for the CO emission, which decreased when the olefin content was reduced and increased when the T90 temperature was lowered

119

HPLC analysis of aldehydes in automobile exhaust gas: Comparison of exhaust odor and irritation in different types of gasoline and diesel engines  

International Nuclear Information System (INIS)

This study investigated high performance liquid chromatography (HPLC) to identify and measure aldehydes from automobile exhaust gas. Four aldehydes: formaldehyde (HCHO), acetaldehyde (CH3CHO), acrolein (H2C=CHCHO) and propionaldehyde (CH3CH2CHO) and one ketone, acetone (CH3)2CO are separated. The other higher aldehydes in exhaust gas are very small and cannot be separated. A new method of gas sampling, hereafter called bag sampling in HPLC is introduced instead of the trapping gas sampling method. The superiority of the bag sampling method is its transient gas checking capability. In the second part of this study, HPLC results are applied to compare exhaust odor and irritation of exhaust gases in different types of gasoline and diesel engines. Exhaust odor, irritation and aldehydes are found worst in direct injection (DI) diesel engines and best in some good multi-point injection (MPI) gasoline and direct injection gasoline (DIG) engines. Indirect injection (IDI) diesel engines showed odor, irritation and aldehydes in between the levels of MPI gasoline, DIG and DI diesel engines

120

CHEMICAL COMPOSITION OF EXHAUST PARTICLES FROM GAS TURBINE ENGINES  

Science.gov (United States)

A program was conducted to chemically characterize particulate emissions from a current technology, high population, gas turbine engine. Attention was focused on polynuclear aromatic compounds, phenols, nitrosamines and total organics. Polynuclear aromatic hydrocarbons (PAH) were...

121

An overview of exhaust emissions regulatory requirements and control technology for stationary natural gas engines  

International Nuclear Information System (INIS)

In this paper a practical overview of stationary natural gas engine exhaust emissions control technology and trends in emissions regulatory requirements is presented. Selective and non-selective catalytic reduction and lean burn technologies are compared. Particular emphasis is focussed on implications of the Clean Air Act of 1990. Recent emissions reduction conversion kit developments and a practical approach to continuous monitoring are discussed

122

Characterization and control of exhaust gas from diesel engine firing coal-water mixture  

Energy Technology Data Exchange (ETDEWEB)

Exhaust from the GE-TS single cylinder diesel engine, fitted with hardened metal, and diamond-tipped metal fuel injection nozzles, and firing coal-water mixture (CWM) has been characterized with respect to gas composition, particulate size distribution, and particulate filtration characteristics. The measured flue gas compositions are roughly in keeping with results from combustion calculations. The time variations of the hydrocarbon, CO, and NO{sub x} concentrations are also understood in terms of known reaction mechanisms.

Samuel, E.A.; Gal, E.; Mengel, M.; Arnold, M.

1990-03-01

123

Characterization and control of exhaust gas from diesel engine firing coal-water mixture  

Energy Technology Data Exchange (ETDEWEB)

Exhaust from the GE-TS single cylinder diesel engine, fitted with hardened metal, and diamond-tipped metal fuel injection nozzles, and firing coal-water mixture (CWM) has been characterized with respect to gas composition, particulate size distribution, and particulate filtration characteristics. The measured flue gas compositions are roughly in keeping with results from combustion calculations. The time variations of the hydrocarbon, CO, and NO[sub x] concentrations are also understood in terms of known reaction mechanisms.

Samuel, E.A.; Gal, E.; Mengel, M.; Arnold, M.

1990-03-01

124

Application of a power recovery system to gas turbine exhaust gases  

International Nuclear Information System (INIS)

This paper discusses the application of a power recovery system to recover waste heat from the exhaust gases of gas turbines and convert this energy into shaft horsepower. Also discussed are power cycles, selection of power fluid, equipment selection, and application of the power recovery system to various gas turbines. Several charts and tables are included: process flow diagram, cycle efficiencies, curve for estimating recoverable horsepower

125

Method and apparatus to selectively reduce NO.sub.x in an exhaust gas feedstream  

Science.gov (United States)

A method and apparatus are described to selectively reduce NO.sub.x emissions of an internal combustion engine. An exhaust aftertreatment system includes an injection device operative to dispense a hydrocarbon reductant upstream of a silver-alumina catalytic reactor device. A control system determines a NO.sub.x concentration and hydrocarbon/NOx ratio based upon selected parameters of the exhaust gas feedstream and dispenses hydrocarbon reductant during lean engine operation. Included is a method to control elements of the feedstream during lean operation. The hydrocarbon reductant may include engine fuel.

Schmieg, Steven J. (Troy, MI); Blint, Richard J. (Shelby Township, MI); Den, Ling (Sterling Heights, MI); Viola, Michael B. (Macomb Township, MI); Lee, Jong-Hwan (Rochester Hills, MI)

2011-08-30

126

40 CFR 86.511-90 - Exhaust gas analytical system.  

Science.gov (United States)

...plus methanol in the case of methanol-fueled motorcycles), carbon...113°±8 °C)) for methanol-fueled vehicles) for...The analytical system for methanol consists of a gas chromatograph...indicating silica gel to remove water vapor and containing...

2010-07-01

127

Exhaust Gas Heat Recovery for C.I Engine-A Review  

Directory of Open Access Journals (Sweden)

Full Text Available The focus of the study is to review the modern changes and technologies on waste heat recovery of exhaust gas from internal combustion engine. These include the thermoelectric generator, turbocharger, exhaust gas through I.C engine. Due to the total heat supplied to the engine in the form of fuel around 30-40%, heat is converting in to the use full mechanical work and residual parts of the wastage heat 60-70% as friction, exhaust gas and engine cooling system. Waste heat release in the form of fumes in environment through I.C engine, which also includes the exhaust gases. The side effects are global warming, greenhouse effects and entropy increases etc. Therefore, it is required to use the waste heat in to useful work. The recovery of waste heat not only conserves fossil fuel but also control the environment pollution. Therefore, main objective of this paper is to evaluate (waste heat recovery system technology based on the total waste heat converted into the useful mechanical work and possible methods to recovery of the waste heat from I.C engine. As a result, waste heat recovery from the I.C engines and utilization shall be remain best technique in future automobile application save the fuel and protect the environment.

Baleshwar Kumar Singh,

2014-11-01

128

Responses of spruce seedlings (Picea abies) to exhaust gas under laboratory conditions. 2. ultrasonic changes and stomatal behaviour  

International Nuclear Information System (INIS)

This study examines the effects of exhaust gas exposure on the epistomatal wax structure and mesophyll ultrastructure in needles of Norway spruce (Picea abies (L.) Karst.) seedlings. Stomatal diffusive resistance was also measured. Two independent exhaust gas fumigations were performed: 100 and 200 ppb measured as NOx, for 10 days and 50, 100 and 200 ppb NOx for 19 days. The obstructive effect of exhaust gas exposure on epistomatal wax tubules was apparent. The stomata became covered by flat and solid wax resulting from the structural degradation of the wax crystalloids. Increasing the exhaust gas concentration in the chamber atmosphere exacerbated the degradation of the wax structure. Exhaust gas exposure induced aggregation and electron translucence of plastoglobuli, swelling of thylakoids, increase of cytoplasmic lipids and slight increase of vesiculation of cytoplasm in mesophyll cells of current and previous year needles. These changes were exemplified in current year needles. Damage to the epicuticular waxes and mesophyll ultrastructure of spruce needles most likely reflects the NOx and volatile hydrocarbon fraction. The alterations in epicuticular waxes and mesophyll ultrastructure can be related to accelerated senescence of the youngest, photosynthetically active, needle generation. The exhaust gas also resulted in decreased diffusive stomatal resistance at night which indicates that the exhaust gas exposure disturbed the gas ee exhaust gas exposure disturbed the gas exchange of spruce seedlings. The results show that even relatively short-term exposure to realistic concentrations of exhaust gas in the atmosphere can induce rather severe injuries to the needle surface structure as well as ultra-structure at the cellular level. (author)

129

Ceramic hot film sensor for exhaust gas mass flow measurements in automotive applications; Keramischer Heissfilmsensor zur Abgasmassenstrommessung in automotiven Anwendungen  

Energy Technology Data Exchange (ETDEWEB)

Due to increasingly stringent emission standards, a number of internal measures as well as exhaust gas aftertreatment systems have become state-of-the-art technology for passenger car and heavy duty engines. However, the full potential of these measures, for example the cooled external exhaust gas recirculation, can only be utilized if the engine control is adapted adequately well in all engine states. Thus, the requirements for future engine controls become more demanding and consequently the standards for sensors used in the control loop will increase. In this context this article introduces a new exhaust gas mass flow sensor based or the principle of hot film anemometry. The sensor comprising a ceramic sensor element is developed especially for the use in engine exhaust gases providing the exhaust gas mass flow as a direct measurement and control variable. Next to the sensor technology first results of engine tests are presented in this paper. (orig.)

Dismon, Heinrich; Grimm, Karsten; Toennesmann, Andres; Nigrin, Sven [Pierburg GmbH, Neuss (Germany); Wienand, Karlheinz; Muziol, Matthias [Heraeus Sensor Technology GmbH, Kleinostheim (Germany)

2008-07-01

130

Hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel  

International Nuclear Information System (INIS)

A hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel was discussed in this presentation. A schematic diagram of the experimental study was first presented. The single cylinder, water-cooled, supercharged test engine was illustrated. Results were presented for the following: fuel energy and energy share (hydrogen and diesel fuel); pressure history and rate of heat release; engine performance and exhaust emissions; effect of nitrogen dilution on heat value per cycle; effect of N2 dilution on pressure history and rate of heat release; and engine performance and exhaust emissions. This presentation demonstrated that smooth and knock-free engine operation results from the use of hydrogen in a supercharged dual-fuel engine for leaner fuel-air equivalence ratios maintaining high thermal efficiency. It was possible to attain mor3 than 90 per cent hydrogen-energy substitution to the diesel fuel with zero smoke emissions. figs.

131

Turbine exhaust diffuser with a gas jet producing a coanda effect flow control  

Science.gov (United States)

An exhaust diffuser system and method for a turbine engine includes an inner boundary and an outer boundary with a flow path defined therebetween. The inner boundary is defined at least in part by a hub structure that has an upstream end and a downstream end. The outer boundary may include a region in which the outer boundary extends radially inward toward the hub structure and may direct at least a portion of an exhaust flow in the diffuser toward the hub structure. The hub structure includes at least one jet exit located on the hub structure adjacent to the upstream end of the tail cone. The jet exit discharges a flow of gas substantially tangential to an outer surface of the tail cone to produce a Coanda effect and direct a portion of the exhaust flow in the diffuser toward the inner boundary.

Orosa, John; Montgomery, Matthew

2014-02-11

132

Electron beam degradation of simulated toluene-containing exhaust gas  

International Nuclear Information System (INIS)

With toluene as an example, experimental investigation on VOCs treatment by electron beam irradiation was carried out. The system uses 0.8 MeV electron beams to irradiate simulated toluene-containing gases to 5kGy-40kGy for investigatiing effects of initial concentration, absorbed dose, humidity on toluene removal rate. The toluene removal rate increased with absorbed dose. With 0.5-l.2Nm3/h of the gas flow at an initial toluene concentration of 1600mg/Nm3, the toluene removal rate was 46.5% at 10kGy and 72.2% at 40kGy. And increasing humidity increased the toluene removal rate, too. Qualitative analysis on by-products of the toluene degradation was made by means of Gas Chromatogram-Mass Spectrometer (GC/MS) and Chromatography of Ions (IC). It was found that the by-products consist of mainly benzaldehyde and formic acid, plus a little benzoic acid, benzyl alcohol, methyl pyridine, nitrotoluene, o-cresol, phenol and benzoin ethyl etherl. Mechanisms of the E-beam toluene removal, i.e. the contributions of OH free radicals and O2 to the oxidation of toluene, were discussed. (authors)

133

Analysis of Exhaust Gas Waste Heat Recovery and Pollution Processing for Z12V190 Diesel Engine  

OpenAIRE

With the increasingly prominent problem regarding rapid economy development and the gradually serious environmental pollution, the waste heat recovery and waste gas pollution processing have received significant attention. Z12V190 diesel engine has high fuel consumption and low thermal efficiency and releases large amounts of exhaust gas and waste heat into the atmosphere, causing serious problems of energy waste and environmental pollution. In this work, the diesel engine exhaust gas compone...

Hou Xuejun; Gao Deli

2012-01-01

134

Micro- and Nanostructural Characteristics of Particles Before and After an Exhaust Gas Recirculation System Scrubber.  

DEFF Research Database (Denmark)

This work provides insight into the morphology and mixing state of submicron particles in diesel exhaust from a ship engine with an exhaust gas recirculation scrubber. Particles from this low-speed ship engine on test bed were collected using a microiner-tial impactor with transmission electron microscopy (TEM) grids on two stages. Micro- and nanostructural characteristics of sin-gle particles were studied by TEM. Image analysis was carried out on overview and high-resolution images, revealing influence of the exhaust gas treatment (scrubber) on the particle morphology and mixing state. Soot agglomerates were found to be collapsed after scrubber, reflected by their change in fractal dimension (fly) from 1.88 to 2.13. Soot was predominantly found internally mixed with other components, with a higher degree of internal mix-ing observed after scrubber. Soot nanostructural characteristics on the near atomic scale such as layer distance, lamella length, and tortuosity were not observed to be influenced by the scrub-ber. We also found that particles in the size range between 30 and 50 nm, which were abundant in the exhaust before and after scrubber, were not graphitic soot. Furthermore, we found indications that these particles are composed of other crystalline material (salts).

Lieke, Kirsten Inga; RosenØrn, Thomas

2013-01-01

135

Micro- and Nanostructural Characteristics of Particles Before and After an Exhaust Gas Recirculation System Scrubber  

DEFF Research Database (Denmark)

This work provides insight into the morphology and mixing state of submicron particles in diesel exhaust from a ship engine with an exhaust gas recirculation scrubber. Particles from this low-speed ship engine on test bed were collected using a microinertial impactor with transmission electron microscopy (TEM) grids on two stages. Micro- and nanostructural characteristics of single particles were studied by TEM. Image analysis was carried out on overview and high-resolution images, revealing influence of the exhaust gas treatment (scrubber) on the particle morphology and mixing state. Soot agglomerates were found to be collapsed after scrubber, reflected by their change in fractal dimension (D-f ) from 1.88 to 2.13. Soot was predominantly found internally mixed with other components, with a higher degree of internal mixing observed after scrubber. Soot nanostructural characteristics on the near atomic scale such as layer distance, lamella length, and tortuosity were not observed to be influenced by the scrubber. We also found that particles in the size range between 30 and 50nm, which were abundant in the exhaust before and after scrubber, were not graphitic soot. Furthermore, we found indications that these particles are composed of other crystalline material (salts). Copyright 2013 American Association for Aerosol Research

Lieke, Kirsten Inga; Rosenorn, Thomas

2013-01-01

136

Efficiency of thermoelectric recuperators of the exhaust gas energy of internal combustion engines  

Science.gov (United States)

Results of computer simulation of thermoelectric generators (TEG) using the exhaust heat of internal combustion engines are presented. Sectionalized generator schematics whereby maximum efficiency is achieved for cases of real temperature dependences of the most suitable thermoelectric materials are considered. A model optimized for minimum cost is considered as well. Results of experimental research on generator that employs exhaust heat from heat and electricity cogeneration plant with a diesel engine are presented. Computer simulation is verified by the test results. The outlook for application of such heat recuperators in stationary plants is considered.

Anatychuk, L. I.; Kuz, R. V.; Rozver, Yu. Yu.

2012-06-01

137

Experimental research on exhaust gas purifying facilities in incinerating treatment of radioactive wastes  

International Nuclear Information System (INIS)

Among the research on the incinerating treatment of combustible low level wastes, three items, that is, combustible low level radioactive wastes and incinerating treatment method, wet type exhaust gas purifying facilities and ceramic filter type dry exhaust gas purifying facilities, were selected, and experimental research was carried out on the main theme of exhaust gas purification in the incineration of low level radioactive wastes. The definition of combustible low level radioactive wastes was decided, and the wastes conforming to this criteria were investigated and classified. The combustible low level wastes generated in the Tokai Research Establishment were classified and weighed, and the results reflected well the state of activities. The change of radioactive wastes to radioactive aerosol, radioactive gas and residue by incineration was investigated. The effect of volume reduction by incineration was studied. The decontamination performance of wet purifying system, the release of tritium steam, the cooling capacity of scrubbers and their corrosion, the construction of the test incinerator using ceramic filters, and the various tests on ceramic filters are reported. (K.I.)

138

Matrix for a catalytic reactor for exhaust gas cleaning on internal combustion engines. Matrix fuer einen katalytischen Reaktor zur Abgasreinigung bei Brennkraftmaschinen  

Energy Technology Data Exchange (ETDEWEB)

The invention concerns a matrix for a catalytic reactor for exhaust gas cleaning on internal combustion engines, consisting of one or more temperature resistant steel sheets or steel tapes coated with catalyst material, at least one of which is corrugated to form flow ducts for the exhaust gas. The purpose of the invention is to create such a matrix so that a displacement of the coatings in the direction of the flow of exhaust gas is avoided with certainty, and also so that turbulent flow of the gas in the matrix ducts is created. According to the invention, this problem is solved by such a matrix, by providing at least one of the steel sheets or steel tapes with local projections and/or indentations, which combine in a form-locking way with the adjacent steel sheet or steel tape positions to prevent mutual displacement in the direction of flow of the exhaust gas. According to the design of the invention, the projections or indentations are made as punched fins in the surface of the steel sheet.

Nonnenmann, M.; Bardong, H.; Haller, K.; Humpolik, B.; Kluna, V.

1981-04-30

139

Demonstration of high temperature thermoelectric waste heat recovery from exhaust gases of a combustion engine  

Energy Technology Data Exchange (ETDEWEB)

The energy efficiency of passenger cars becomes increasingly important due to a growing awareness in terms of climate change and shortages of resources associated with rising fuel prices. In addition to the efforts towards the optimization of the engine's internal efficiency, waste heat recovery is the main objective. In this respect, thermoelectric (TE) devices seem to be suited as heat recuperation systems. Thermoelectric generators allow for direct transformation of thermal into electrical energy. In order to thoroughly investigate this type of recovery system a TE demonstrator was mounted on the muffler of a VW Touran and tested. The waste heat of the exhaust gas was converted into electricity with a conversion rate of {proportional_to}. 3.5%. The limiting factor was the low thermal stability of the commercial modules used in this pre-study to elaborate reference values. Thermoelectric modules based on sustainable and temperature-stable materials are being developed to improve the measured values. A thermoelectric test generator with perovskite-type oxide modules was constructed confirm the function and stability at elevated temperatures. Despite all the advantages of this material class, the TE performance is still to be improved. A quantitative measure of a material's TE performance is the temperature-independent Figure of Merit ZT. ZT increases with decreasing thermal and increasing electrical conductivity. An approach to thermal conductivity reduction is nanostructuring of the material. The Ultrasonic Spray Combustion (USC) technique allows to produce powders with a grain size on the nanoscale and was tested in this study. (orig.)

Trottmann, Matthias; Weidenkaff, Anke; Populoh, Sascha; Brunko, Oliver; Veziridis, Angelika; Bach, Christian; Cabalzar, Urs [Empa, Duebendorf (Switzerland)

2011-07-01

140

X-ray photoelectron spectroscopic analysis of fabric filter for incineration exhaust gas treatment  

International Nuclear Information System (INIS)

Polymer fabric filters used for the incinerator exhaust gas cleaning were analyzed by X-ray photoelectron spectroscopy (XPS) in order to investigate degradation of the filters. On the other hand, depth profile of coating materials on a glass fabric filter after heat treatment was observed by XPS under Ar sputtering. Sulfur bound to benzoic carbon on polyphenylene sulfide filter was thought to change to the high oxidized states such as -SO3 and/or -SO4, and carbon in carbonyl group (-C(O)-) bound to benzoic carbon on the polyimide filter to change to O=C-O- state. The result showed that the chain state bond of both polymers was broken by oxidants in the exhaust gas at 170-200degC. Two layers having a silicon compound and polytetrafuluoroethylene coated on glass fabric filter was found to be mixed after heat treatment at 200degC for 120h. (author)

141

5th international exhaust gas and particulate emissions forum. Proceedings; 5. Internationales Forum Abgas- und Partikelemissionen. Beitraege  

Energy Technology Data Exchange (ETDEWEB)

The Proceedings of the 5th International Exhaust Gas and Particulate Emissions Forum contains 22 printed contributions as well as a CD-ROM. The titles of them are: (1) Diesel Emissions Control in the United States - 2010 and Beyond; (2) The MBE90 commercial vehicle engine for EPA '07 emissions regulations; (3) Concepts for engines and exhaust-gas cleaning systems for heavy duty trucks of the future; (4) HD Engine Technology for Near-Zero Emissions and Lowest Cost of Ownership; (5) (Partially-) Homogeneous Diesel Combustion; (6) Exhaust gas sensors for NOx storage catalysts and ammonia-SCR systems; (7) Sensors for modern exhaust gas after-treatment systems; (8) New reducing agents for low NOx-SCR Techno-logy; (9) Exhaust gas Aftertreatment on Lean Burn Gasoline Direct Injection Engines: The System of TWC and NOx-Storage Catalyst; (10) New Platinum/Palladium based catalyzed filter technologies for future passenger car applications; (11) Development of a Roadway Hydrocarbon Sorption Model and Characterization of a Novel PM Generator; (12) Requirements for current and future particulate measurement instrumentation from the point of view of the Physikalisch-Technische Bundesanstalt; (13) Standardized dilution conditions for gravimetric PM sampling - measures to assure results that correlate; (14) Particle Counting according PMP; (15) Future high-confidence measurement of diesel particulate emissions for approval and development; (16) New developments in optical instrumentation for exhaust gas; (17) Simultaneous Detection of Gaseous and Particulate Exhaust Components by Photoacoustic Spectroscopy; (18) Boundaries of modern exhaust gas instrumentation; (19) Raising quality and reducing application effort through efficient data input to the particulate filter load model for a EURO5 diesel car; (20) Stop-start operation of diesel engines - modified require-ment for exhaust gas after-treatment?; (21) Particulates emission with Biodiesel B30 impact on CSF management; (22) Diesel engine soot and NOx emission modelling. (orig)

NONE

2008-12-11

142

Study on using acetylene in dual fuel mode with exhaust gas recirculation  

International Nuclear Information System (INIS)

Interest in employing gaseous fuels to internal combustion (IC) engines whether for stationary or mobile automotive applications has gained importance because of the economical, sustainable and environmental technical features associated with their usage. However, the incidence of preignition and knock remains a significant barrier in achieving their optimum performance potential. With the advent of latest technologies, the above barriers are eliminated. One such technique is timed manifold injection (TMI) of the gaseous fuel, which is controlled electronically to precisely monitor the induction of fuel to overcome the preignition problem in the intake. In the present investigation, acetylene was injected in the intake manifold in a single cylinder diesel engine, with a gas flow rate of 240 g/h, start of injection time is 10o aTDC and 90o CA (9.9 ms) duration, operated in dual fuel mode. In order to decrease the NOx emissions from acetylene-diesel engine, cooled EGR was employed. The cylinder pressure, brake thermal efficiency and emissions such as NOx, smoke, CO, HC, CO2 and exhaust gas temperature were studied. Dual fuel operation with acetylene induction coupled with cooled EGR results in lowered NOx emissions and improved part load performance. -- Highlights: ? Acetylene was tried in SI engines, but due to backfire further research was hindered as an alternative fuel. ? But it is not tried in CI engine. Timed manifold injection was tried in diesel engine in the present work to combat backfire. ? Author was successful in running the diesel engine in dual fuel mode. ? 21% maximum diesel replacement was achieved. Author is confident that acetylene will be commercialised as a fuel for diesel engine in future.

143

The Impact of Temperature Effect on Exhaust Manifold Thermal Modal Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available The impact of temperature effect on exhaust manifold modal analysis is analyzed in this study. Firstly, the temperature field is mapped from the CFD software and then heat conduction process is analyzed in FEM software with the temperature field boundary conditions. At last the modal analysis that considers temperature effect is done. The frequency and vibration mode between cold modal and thermal modal’s are compared. The result shows that temperature has a great influence on the manifold mode and it is very valuable to product design.

Bin Zou

2013-08-01

144

Experimental Study on a Novel Low-temperature Automobile Exhaust Thermoelectric Generator  

OpenAIRE

To further study on Automobile Exhaust Thermoelectric Generator (AETEG), an experiment setup based on low-temperature Thermoelectric Modules (TEMs) of Bi2Te3 materials, cold source of single-column cooling boxes and heat exchanger of herring-bone interior cavity was constructed. The hot source and cold source temperatures with different output powers and rotate speeds of engine were analyzed and the influences of the main operation conditions such as differ...

Rui Quan; Guangyou Yang; Liang Huang

2013-01-01

145

The effect of coal rank and particle size on the combustion of pulverized coal in turbine exhaust gas  

Energy Technology Data Exchange (ETDEWEB)

Many power producers are using a gas turbine in the topping cycle to increase electricity generation efficiency. According to EPRI, rotor inlet temperatures could increase to around 1426{degree}C if novel engine materials and cooling technologies were incorporated into the gas turbines. In such power plants, the temperature of the Turbine Exhaust Gas (TEG) from the gas turbine is over 600{degree}C, heat is recovered, and used for steam generation. This gives higher temperatures and low oxygen levels of around 13% in the TEG. However, combustion difficulties may occur with reduced residence times and lower oxygen partial pressure. At the IFRF studies were executed (TEG1) to investigate using TEG as an oxidant for coal combustion. Two high volatile bituminous coals were evaluated for different conditions of TEG, Gottelborn and Obed Mountain, and were fired at a thermal input of approximately 1.1. MW. The main parameters affecting NO{sub x} level in the flue gas were TEG O{sub 2} level and burner swirl number. TEG temperature, TEG velocity and excess air level had a limited effect on NO{sub x} emissions. The main parameters affecting burnout level were coal type, TEG O{sub 2} level and flame type. TEG temperature and flue gas oxygen level showed a marginal effect on burnout. Burnout was relatively insensitive to TEG velocity, but burnout levels varied substantially with coal type. Flame luminosity changed when lower oxygen levels were present in the TEG, differences between high and low NO{sub x} flames could be seen. In this JOULE2 Extension TEG2 experiment, high and medium volatile bituminous coals were evaluated for flame stability, luminosity, burnout and NO{sub x}. Particle size distributions were varied to identify the effect of finer grinding on flame characteristics. 4 refs., 23 figs., 3 tabs.

Daimon, J.; Kamp, W.L. van de [International Flame Research Foundation, IJmuiden (Netherlands)

1998-12-31

146

Hydrocarbons in the exhaust gas of biogas-driven combined heat and power units; Kohlenwasserstoffverbindungen im Abgas biogasbetriebener Blockheizkraftwerke  

Energy Technology Data Exchange (ETDEWEB)

To determine exhaust gas emissions and electrical efficiency, several biogas driven co-generation units (CGU) were measured on site. If only the concentrations of nitrogen oxides (NO{sub x}) in the exhaust gas were to be minimized, this resulted in increased emissions of unburnt hydrocarbons and a lower electrical efficiency of the engines. Also, the exhaust gas concentrations of NO{sub x} and formaldehyde were found to be interdependent. Lowest formaldehyde emissions were measured in conjunction with NO{sub x}-values far above limit values. The use of a catalytic converter effectively reduced CO and formaldehyde levels in the exhaust gas, but showed little effect on remaining hydrocarbons. (orig.)

Aschmann, Volker; Effenberger, Mathias; Gronauer, Andreas [Bayerische Landesanstalt fuer Landwirtschaft (LfL), Freising (DE). Inst. fuer Landtechnik und Tierhaltung (ILT)

2010-07-01

147

Integrated exhaust gas analysis system for aircraft turbine engine component testing  

Science.gov (United States)

An integrated exhaust gas analysis system was designed and installed in the hot-section facility at the Lewis Research Center. The system is designed to operate either manually or automatically and also to be operated from a remote station. The system measures oxygen, water vapor, total hydrocarbons, carbon monoxide, carbon dioxide, and oxides of nitrogen. Two microprocessors control the system and the analyzers, collect data and process them into engineering units, and present the data to the facility computers and the system operator. Within the design of this system there are innovative concepts and procedures that are of general interest and application to other gas analysis tasks.

Summers, R. L.; Anderson, R. C.

1985-01-01

148

A Gas Chromatograph/Mass Spectrometer System for UltraLow-Emission Combustor Exhaust Studies  

Science.gov (United States)

A gas chromatograph (GC)/mass spectrometer (MS) system that allows the speciation of unburnt hydrocarbons in the combustor exhaust has been developed at the NASA Lewis Research Center. Combustion gas samples are withdrawn through a water-cooled sampling probe which, when not in use, is protected from contamination by a high-pressure nitrogen purge. The sample line and its connecting lines, filters, and valves are all ultraclean and are heated to avoid condensation. The system has resolution to the parts-per-billion (ppb) level.

Brabbs, Theodore A.; Wey, Chowen Chou

1996-01-01

149

Burner for burning exhaust gases  

International Nuclear Information System (INIS)

A burner is described for burning exhaust gases, particularly those from nuclear plants, using means of oxidation, which is space-saving, easy to handle and safe to operate, and which supplies little secondary exhaust gas. Mixing chambers are situated in a high temperature part, with tangentially fixed incoming pipes for the means of oxidation. The high temperature part is also heated by two or more separately controlled heating windings. (orig.)

150

An experimental investigation on hydrogen as a dual fuel for diesel engine system with exhaust gas recirculation technique  

Energy Technology Data Exchange (ETDEWEB)

With higher rate of depletion of the non-renewable fuels, the quest for an appropriate alternative fuel has gathered great momentum. Though diesel engines are the most trusted power sources in the transportation industry, due to stringent emission norms and rapid depletion of petroleum resources there has been a continuous effort to use alternative fuels. Hydrogen is one of the best alternatives for conventional fuels. Hydrogen has its own benefits and limitations in its use as a conventional fuel in automotive engine system. In the present investigation, hydrogen-enriched air is used as intake charge in a diesel engine adopting exhaust gas recirculation (EGR) technique with hydrogen flow rate at 20 l/min. Experiments are conducted in a single-cylinder, four-stroke, water-cooled, direct-injection diesel engine coupled to an electrical generator. Performance parameters such as specific energy consumption, brake thermal efficiency are determined and emissions such as oxides of nitrogen, hydrocarbon, carbon monoxide, particulate matter, smoke and exhaust gas temperature are measured. Usage of hydrogen in dual fuel mode with EGR technique results in lowered smoke level, particulate and NO{sub x} emissions. (author)

Saravanan, N.; Nagarajan, G.; Kalaiselvan, K.M.; Dhanasekaran, C. [Internal Combustion Engineering Division, Department of Mechanical Engineering, College of Engineering, Guindy, Anna University, Chennai 600025 (India)

2008-03-15

151

Catalysts as Sensors—A Promising Novel Approach in Automotive Exhaust Gas Aftertreatment  

Directory of Open Access Journals (Sweden)

Full Text Available Sensors that detect directly and in situ the status of automotive exhaust gas catalysts by monitoring the electrical properties of the catalyst coating itself are overviewed. Examples included in this review are the in-situ determination of the electrical impedance of three-way catalysts based on ceria-zirconia solutions and of lean NOx traps of earth-alkaline based coatings, as well as approaches to determine the ammonia loading in Fe-SCR-zeolites with electrical ac measurements. Even more sophisticated approaches based on interactions with electromagnetic waves are also reviewed. For that purpose, metallic stick-like antennas are inserted into the exhaust pipe. The catalyst properties are measured in a contactless manner, directly indicating the catalyst status. The radio frequency probes gauge the oxygen loading degree of three-way catalysts, the NOx-loading of lean NOx traps, and the soot loading of Diesel particulate filters

Ralf Moos

2010-07-01

152

Environmental policy constraints for acidic exhaust gas scrubber discharges from ships.  

Science.gov (United States)

Increasingly stringent environmental legislation on sulphur oxide emissions from the combustion of fossil fuels onboard ships (International Maritime Organization (IMO) Regulation 14) can be met by either refining the fuel to reduce sulphur content or by scrubbing the exhaust gases. Commonly used open loop marine scrubbers discharge warm acidic exhaust gas wash water into the sea, depressing its pH. The focus on this paper is on the physics and chemistry behind the disposal of acidic discharges in seawater. The IMO Marine Environment Protection Committee (MEPC 59/24/Add.1 Annex 9) requires the wash water to reach a pH greater than 6.5 at a distance of 4m from the point of discharge. We examine the engineering constraints, specifically size and number of ports, to identify the challenges of meeting regulatory compliance. PMID:25284442

Ülpre, H; Eames, I

2014-11-15

153

A unified approach to assess performance of different techniques for recovering exhaust heat from gas turbines  

International Nuclear Information System (INIS)

Exhaust heat from gas turbines can be recovered externally or internally to the cycle itself. Of the technology options for external recovery, the combined gas-steam power plant is by far the most effective and commonly used worldwide. For internal recovery conventional solutions are based on thermodynamic regeneration and steam injection, while innovative solutions rely on humid air regeneration and steam reforming of fuel. In this paper a unified approach for analysing different exhaust heat recovery techniques is proposed. It has been possible to define a characteristic internal heat recovery plane, based on a few meaningful parameters and to identify an innovative scheme for repowering existing combined cycles. The characteristic plane indicates directly the performance obtainable with the different recovery techniques, showing that performances close to combined cycle plants (external recovery) can only be achieved with combined recovery techniques (humid air regeneration, steam reforming of fuel). The innovative repowering scheme, which requires the addition of a gas turbine and one-pressure level HRSG to an existing combined gas-steam power plant, significantly increases power output with fairly high marginal efficiency.

154

A GAS TEMPERATURE PROFILE BY INFRARED EMISSION-ABSORPTION SPECTROSCOPY  

Science.gov (United States)

This computer program calculates the temperature profile of a flame or hot gas. Emphasis is on profiles found in jet engine or rocket engine exhaust streams containing water vapor or carbon dioxide as radiating gases. The temperature profile is assumed to be axisymmetric with a functional form controlled by two variable parameters. The parameters are calculated using measurements of gas radiation at two wavelengths in the infrared spectrum. Infrared emission and absorption measurements at two or more wavelengths provide a method of determining a gas temperature profile along a path through the gas by using a radiation source and receiver located outside the gas stream being measured. This permits simplified spectral scanning of a jet or rocket engine exhaust stream with the instrumentation outside the exhaust gas stream. This program provides an iterative-cyclic computation in which an initial assumed temperature profile is altered in shape until the computed emission and absorption agree, within specified limits, with the actual instrument measurements of emission and absorption. Temperature determination by experimental measurements of emission and absorption at two or more wavelengths is also provided by this program. Additionally, the program provides a technique for selecting the wavelengths to be used for determining the temperature profiles prior to the beginning of the experiment. By using this program feature, the experimenter has a higher probability of selecting wavelengths which will result in accurate temperature profile measurements. This program provides the user with a technique for determining whether this program will be sufficiently accurate for his particular application, as well as providing a means of finding the solution. The input to the program consists of four types of data: (1) computer program control constants, (2) measurements of gas radiance and transmittance at selected wavelengths, (3) tabulations from the literature of gas transmission parameters at selected wavelengths, and (4) independently determined or estimated profiles of partial pressures of the gas reaction products. The output consists of error figures for the temperature and partial pressure profiles in tabular form. This program is written in FORTRAN IV for execution on an UNIVAC 1100 series computer with a main memory requirement of 21K of 36 bit words. This program was developed in 1977.

Buchele, D. R.

1994-01-01

155

Matrix for a catalytic reactor for cleaning of exhaust gas from internal combustion engines. Matrix fuer einen katalytischen Reaktor zur Abgasreinigung bei Brennkraftmaschinen  

Energy Technology Data Exchange (ETDEWEB)

The invention concerns a matrix for a catalytic reactor for cleaning of exhaust gas from internal combustion engines. It consists of one or more temperature resistant steel sheets or steel tapes coated with catalyst material, at one of which is corrugated in order to form flow ducts for the exhaust gas, where the steel sheets are coated with catalyst material before or after the manufacture of the matrix. The purpose of the invention was to create such a matrix so that as much turbulent flow as possible is generated in its ducts, and particularly to reduce the length of the matrix. According to this invention, the problem is solved by having holes extending over the whole length of the sheet or tape with flat or corrugated steel sheet or steel tape, so that individual narrow strips of sheet or tape follow one another in the direction of flow of the exhaust gas. This ensures that the gas flow can mix between the individual narrow strips of sheet, and is divided in the subsequent narrow strip, so that new parts of the gas flow come into contact with the surface of the subsequent narrow strip.

Nonnenmann, M.

1980-07-31

156

Multiple Exhaust Nozzle Effects on J-2X Gas Generator Outlet Impedance  

Science.gov (United States)

The current test setup of the J-2X gas generator system uses a multiple nozzle configuration to exhaust hot gases to drive the propellant supply turbines. Combustion stability assessment of this gas generator design requires knowledge of the impedance effects the multiple nozzle configuration creates on the combustion chamber acoustic modes. Parallel work between NASA and Sierra Engineering is presented, showing two methods used to calculate the effective end impedance resulting from multiple nozzle configurations. The NASA method is a simple estimate of the effective impedance using the long wavelength approximation. Sierra Engineering has developed a more robust numerical integration method implemented in ROCCID to accommodate for multiple nozzles. Analysis using both methods are compared to J-2X gas generator test data collected over the past year.

Kenny, R. Jeremy; Muss, Jeffrey; Hulka, James R.; Casiano, Matthew

2010-01-01

157

Evaluation of an exhaust gas evacuation system during propane-fueled lift truck maintenance  

International Nuclear Information System (INIS)

Exposure to carbon monoxide (CO) gas in the workplace can cause health problem. CO gas is colourless and odourless, and exposure to it can cause intoxication, particularly for mechanics working on internal combustion engines fed by propane-fueled lift trucks. Regular procedures for evacuating the gases emitted during routine mechanical repairs involve the use of rigid evacuating pipes attached to the building and hooked to a flexible pipe at the end of the exhaust pipe. With lift trucks, this procedure is limited because of the configuration of these vehicles, and also because this type of work is often done in places without access to permanent mechanical ventilation. The object of this study was to propose a new evacuation method for CO gas fumes that would lower the exposures of fumes for mechanics and for workstations. It identified the criteria that should be considered, such as the configuration of the existing exhaust system of lift trucks, and feasibility of using this system at a variety of on-site locations. The design of the device was described and evaluated. 7 refs., 6 tabs., 8 figs., 3 appendices

158

Exhaust gas fuel reforming of Diesel fuel by non-thermal arc discharge for NOx trap regeneration application  

OpenAIRE

The present study is dedicated to the reforming of diesel fuel with diesel engine exhaust gas (i.e., air, CO2, and H2O mixture) using a nonthermal plasma torch for a NOx trap regeneration application. The plasma technology developed is based on a high voltage/low current nonthermal plasma torch. In the first part of the paper, experimental results on synthesis gas production from exhaust gas fuel reforming of diesel fuel are reported. In the second part of the paper, these experimental result...

Lebouvier, Alexandre; Fresnet, Franc?ois; Fabry, Fre?de?ric; Boch, Vale?rie; Rohani, Vandad-julien; Cauneau, Franc?ois; Fulcheri, Laurent

2011-01-01

159

Effect of Operating and Sampling Conditions on the Exhaust Gas Composition of Small-Scale Power Generators  

OpenAIRE

Small stationary diesel engines, like in generator sets, have limited emission control measures and are therefore responsible for 44% of the particulate matter (PM) emissions in the United States. The diesel exhaust composition depends on operating conditions of the combustion engine. Furthermore, the measurements are influenced by the used sampling method. This study examines the effect of engine loading and exhaust gas dilution on the composition of small-scale power generators. These gener...

Smits, Marianne; Vanpachtenbeke, Floris; Horemans, Benjamin; Wael, Karolien; Hauchecorne, Birger; Langenhove, Herman; Demeestere, Kristof; Lenaerts, Silvia

2012-01-01

160

Study of SI engine fueled with methanol vapor and dissociation gas based on exhaust heat dissociating methanol  

International Nuclear Information System (INIS)

Highlights: • The full load power decreases successively from gasoline engine, methanol vapor engine to dissociated methanol engine. • Both power and thermal efficiency of dissociated methanol engine can be improved by boosting pressure. • The conversion efficiency of recovered exhaust gas energy is largely influenced by the BMEP. • At the same BMEP, dissociated methanol engine has higher thermal efficiency than methanol vapor engine and gasoline engine. - Abstract: To improve the fuel efficiency of internal combustion (IC) engine and also achieve the goal of direct usage of methanol fuel on IC engine, an approach of exhaust heat dissociating methanol was investigated, which is a kind of method for IC engine exhaust heat recovery (EHR). A bottom cycle system is coupled with the IC engine exhaust system, which uses the exhaust heat to evaporate and dissociate methanol in its catalytic cracker. The methanol dissociation gas (including methanol vapor) is used as the fuel for IC engine. This approach was applied to both naturally aspirated (NA) engine and turbocharged engine, and the engine performance parameters were predicted by the software GT-power under various kinds of operating conditions. The improvement to IC engine performance and the conversion efficiency of recovered exhaust gas energy can be evaluated by comparing the performances of IC engine fueled with various kinds of fuels (or their compositions). Results show that, from gasoline engine, methanol vapor engine to dissociated methanol engine, the full load power decreases successively in the entire speed area due to the declining of volumetric efficiency, while it is contrary in the thermal efficiency at the same brake mean effective pressure (BMEP) level because of the improving of fuel heating value. With the increase of BMEP, the conversion efficiency of recovered exhaust gas energy is promoted. All those results indicate that the approach of exhaust heat dissociating methanol has large energy saving potential with great application prospect to IC engines

161

DOE 6430.1a compliance checklist for the rotary mode core sampling exhauster flammable gas interlock  

International Nuclear Information System (INIS)

This document examines the Safety Class I criteria in DOE 6430.1a and determines applicability to the rotary mode core sampling exhauster flammable gas interlock. Purpose of the interlock is to prevent the design basis accident of deflagration in single shell flammable gas watchlist tank

162

49 CFR 325.91 - Exhaust systems.  

Science.gov (United States)

...reduction, such as exhaust gas leaks or alteration or deterioration of muffler elements, (small traces of soot on flexible exhaust...supercharger driven by exhaust gases); or (c) Is equipped...designed as an exhaust gas driven cargo...

2010-10-01

163

Fuel composition and secondary organic aerosol formation: gas-turbine exhaust and alternative aviation fuels.  

Science.gov (United States)

A series of smog chamber experiments were performed to investigate the effects of fuel composition on secondary particulate matter (PM) formation from dilute exhaust from a T63 gas-turbine engine. Tests were performed at idle and cruise loads with the engine fueled on conventional military jet fuel (JP-8), Fischer-Tropsch synthetic jet fuel (FT), and a 50/50 blend of the two fuels. Emissions were sampled into a portable smog chamber and exposed to sunlight or artificial UV light to initiate photo-oxidation. Similar to previous studies, neat FT fuel and a 50/50 FT/JP-8 blend reduced the primary particulate matter emissions compared to neat JP-8. After only one hour of photo-oxidation at typical atmospheric OH levels, the secondary PM production in dilute exhaust exceeded primary PM emissions, except when operating the engine at high load on FT fuel. Therefore, accounting for secondary PM production should be considered when assessing the contribution of gas-turbine engine emissions to ambient PM levels. FT fuel substantially reduced secondary PM formation in dilute exhaust compared to neat JP-8 at both idle and cruise loads. At idle load, the secondary PM formation was reduced by a factor of 20 with the use of neat FT fuel, and a factor of 2 with the use of the blend fuel. At cruise load, the use of FT fuel resulted in no measured formation of secondary PM. In every experiment, the secondary PM was dominated by organics with minor contributions from sulfate when the engine was operated on JP-8 fuel. At both loads, FT fuel produces less secondary organic aerosol than JP-8 because of differences in the composition of the fuels and the resultant emissions. This work indicates that fuel reformulation may be a viable strategy to reduce the contribution of emissions from combustion systems to secondary organic aerosol production and ultimately ambient PM levels. PMID:22732009

Miracolo, Marissa A; Drozd, Greg T; Jathar, Shantanu H; Presto, Albert A; Lipsky, Eric M; Corporan, Edwin; Robinson, Allen L

2012-08-01

164

Effect on combined cycle efficiency of stack gas temperature constraints to avoid acid corrosion  

Science.gov (United States)

To avoid condensation of sulfuric acid in the gas turbine exhaust when burning fuel oils contaning sulfur, the exhaust stack temperature and cold-end heat exchanger surfaces must be kept above the condensation temperature. Raising the exhaust stack temperature, however, results in lower combined cycle efficiency compared to that achievable by a combined cycle burning a sulfur-free fuel. The maximum difference in efficiency between the use of sulfur-free and fuels containing 0.8 percent sulfur is found to be less than one percentage point. The effect of using a ceramic thermal barrier coating (TBC) and a fuel containing sulfur is also evaluated. The combined-cycle efficiency gain using a TBC with a fuel containing sulfur compared to a sulfur-free fuel without TBC is 0.6 to 1.0 percentage points with air-cooled gas turbines and 1.6 to 1.8 percentage points with water-cooled gas turbines.

Nainiger, J. J.

1980-01-01

165

Effects of powdery silica on NOsub(x) and SO2 removals by electron beam irradiation in coal-fired exhaust gas  

International Nuclear Information System (INIS)

Test gases with contents similar to actual coal-fired exhaust gases are brought into contact with water-containing powdery silica after being irradiated with electron beam, and the effects of silica on removal NO sub(x) and SO sub(x) are examined. The investigation is carried out in the temperature range from 80 to 220 0C. Results obtained lead to conclusions as follows. (1) Removal of NO sub(x) and SO sub(x) from exhaust gas can be performed effectively by bringing it into contact with water-containing powdery silica after irradiation of electron beam. The degree of NO sub(x) removal increases with increasing temperature (irradiation temperature and silica bath temperature). (2) An increase in degree of NO sub(x) removal is also observed when a test exhaust gas containing ammonia is brought into the silica bath after irradiation. (3) The acceleration of NO sub(x) removal below 200 0C results from oxidation of NO to NO2 caused by electron beam irradiation plus reaction of NO2 produced above with the absorbed water existing on the silica surface (3NO2 + H2O ? 2HNO3 + NO). The resulting NHO3 molecules are then fixed on the silica surface. Part of the NO2 molecules are reduced to NO by the above reaction and released back into the gas. (4) It can be expected that the NO molecules released when the irradiated gas comes into contact with silica will be immediately oxidized ith silica will be immediately oxidized to NO2 and removed from the gas if silica coexists with it during the irradiation. This suggests a process which may further improve the degree of NO sub(x) removal. (Nogami, K.)

166

ZIGBEE Based Implementation on Exhaust Gas Detection Services Oriented System Research  

Directory of Open Access Journals (Sweden)

Full Text Available The vehicle exhaust gas emission is directly related with the quality of air. This paper describes theresearch and development of an ZIGBEE based exhaust gas detection system applying the service orientedarchitecture for the purpose of environmental protection. An edge engine supporting the EPC global ALEspecification, a complex event processing engine dealing with the complex streaming ZIGBEE events and servicebus, which are involved in the architecture of the system, are discussed both separately and in a whole picture. Theedge engine is composed of four modules, which are kernel module, device management module, events filter module,and configuration module. It provides features to encapsulate the applications from device interfaces; to process the raw observations captured by the readers and sensors; and to provide an application-level interface formanaging readers and querying ZIGBEE observations. Event processing engine consists of a network of event processing agents running in parallel that interact using a dedicated event processing infrastructure, which provides an abstract communication mechanism and allows dynamic reconfiguration of the communication topology between agents at run-time. Web Services and asynchronous APIs are pivotal system implementation for flexiblecomponents reuse, dynamic configuration and optimized performance. Service bus, through its service integrationand management capabilities, is the backbone of the system. Lastly, the system is proven to be effective with highperformance in the benchmark.

SK SABIHA BEGUM

2013-02-01

167

Effects of exhaust gas recirculation on the thermal efficiency and combustion characteristics for premixed combustion system  

International Nuclear Information System (INIS)

In this research, a boiler in a premixed combustion system used to achieve exhaust gas recirculation was investigated as a way to achieve high thermal efficiencies and low pollutant emissions. The effects of various exhaust gas recirculation (EGR) ratios, equivalence ratios and boiler capacities on thermal efficiency, NOx and CO emissions and the flame behavior on the burner surface were examined both experimentally and numerically. The results of the experiments showed that when EGR was used, the NOx and CO concentrations decreased and the thermal efficiency increased. In the case of a 15% EGR ratio at an equivalence ratio of 0.90, NOx concentrations were found to be smaller than for the current operating condition of the boiler, and the thermal efficiency was approximately 4.7% higher. However, unlike NOx concentrations, although the EGR ratio was increased to 20% at an equivalence ratio of 0.90, the CO concentration was higher than in the current operating condition of the boiler. From the viewpoint of burner safety, the red glow on the burner surface was noticeably reduced when EGR was used. These results confirmed that the EGR method is advantageous from the standpoint of reducing emission concentrations and ensuring burner safety. -- Highlights: ? The premixed boiler system applied EGR was investigated to achieve high thermal efficiencies and low pollutant emissions. ? Thermal efficiency and emission characteristics were examined with EGR ratios, equivalence ratios and boiler capacities. ? EGR method is advantageous from the standpoint of reducing emission concentrations and ensuring burner safety.

168

Oxidation and exhaust gas corrosion resistance of the cobalt base clad layers  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: Purpose of this work is describing the behaviour of the cobalt base cladding layers after treatment in hot air (750°C, 200 hours and exhaust gases (700°C, two month.Design/methodology/approach: The layers were produced by two cladding, laser and PTA, cladding technique. Cladding was conducted with a high power diode laser HDPL ROFIN SINAR DL 020 and Plasma Transformed Arc method. The layers consisted of three multitracking sublayers. The cobalt base layers were evaluated by microstructure investigations (optical and scanning electron microscope SEM, chemical analysis and micro hardness measurements.Findings: The microstructure of the investigated layers did not change much, neither on the top part nor in the clad/steel interface after treatment in both environments. On the outer surfaces the oxide layers were observed which consisted generally of chromium and iron oxides. The compositions of this scales were reviled by the EDS analyze. The changes in chemical compositions before and after oxidation and after corrosion in exhaust gases in the dendritic regions and micro regions were confirmed by the semi-quantitative chemical analysis (EDS. Neither the oxidation nor exposition for two month in exhaust gases did not influence on the morphology of the clad layers in any region however changes in chemical composition were observed. For both sort of clads the oxide layers were observed on the surface. The proposed layers are resistant for the hot exhausted gases.Research limitations/implications: The future researches should be done on microstructural and kinetic analyze of high temperature corrosion for higher temperature and times of the process.Practical implications: The clad layers, of this composition, were designed as a method to prolong service time for the ship engine exhausted valve and after this investigation the first valve heads with laser clad layer were installed in working ship engine.Originality/value: The chemical composition of the powder was new one. Also using the laser cladding technique for ship engine parts subject of interesting.

H. Smolenska

2008-12-01

169

Exhaust-gas measurements from NASAs HYMETS arc jet.  

Energy Technology Data Exchange (ETDEWEB)

Arc-jet wind tunnels produce conditions simulating high-altitude hypersonic flight such as occurs upon entry of space craft into planetary atmospheres. They have traditionally been used to study flight in Earth's atmosphere, which consists mostly of nitrogen and oxygen. NASA is presently using arc jets to study entry into Mars' atmosphere, which consists of carbon dioxide and nitrogen. In both cases, a wide variety of chemical reactions take place among the gas constituents and with test articles placed in the flow. In support of those studies, we made measurements using a residual gas analyzer (RGA) that sampled the exhaust stream of a NASA arc jet. The experiments were conducted at the HYMETS arc jet (Hypersonic Materials Environmental Test System) located at the NASA Langley Research Center, Hampton, VA. This report describes our RGA measurements, which are intended to be used for model validation in combination with similar measurements on other systems.

Miller, Paul Albert

2010-11-01

170

Optimization of a thermoelectric generator subsystem for high temperature PEM fuel cell exhaust heat recovery  

DEFF Research Database (Denmark)

In previous work, a thermoelectric (TE) exhaust heat recovery subsystem for a high temperature polymer electrolyte membrane (HT-PEM) fuel cell stack was developed and modeled. Numerical simulations were conducted and have identified an optimized subsystem configuration and 4 types of compact heat exchangers with superior performance for further analysis. In this work, the on-design performances of the 4 heat exchangers are more thoroughly assessed on their corresponding optimized subsystem configurations. Afterward, their off-design performances are compared on the whole working range of the fuel cell stack. All through this study, different electrical connection styles of all the thermoelectric generator (TEG) modules in the subsystem and their influences are also discussed. In the end, the subsystem configuration is further optimized and a higher subsystem power output is achieved. All TEG modules are now connected into branches. The procedures of designing and optimizing this TE exhaust heat recovery subsystem are drawn out. The contribution of TE exhaust heat recovery to the HT-PEM fuel cell power system is preliminarily concluded. Its feasibility is also discussed.

Xin, Gao; Andreasen, SØren Juhl

2014-01-01

171

40 CFR 86.110-90 - Exhaust gas sampling system; diesel vehicles.  

Science.gov (United States)

...shall be maintained to a constant value within ±5 percent...temperature is maintained at a constant temperature (±5.0...inlet gas temperature remains constant (±5.0 °F (2.8...86.139. (iv) A ratio of net weights will...

2010-07-01

172

Effect of hydroxy (HHO) gas addition on performance and exhaust emissions in compression ignition engines  

Energy Technology Data Exchange (ETDEWEB)

In this study, hydroxy gas (HHO) was produced by the electrolysis process of different electrolytes (KOH{sub (aq)}, NaOH{sub (aq)}, NaCl{sub (aq)}) with various electrode designs in a leak proof plexiglass reactor (hydrogen generator). Hydroxy gas was used as a supplementary fuel in a four cylinder, four stroke, compression ignition (CI) engine without any modification and without need for storage tanks. Its effects on exhaust emissions and engine performance characteristics were investigated. Experiments showed that constant HHO flow rate at low engine speeds (under the critical speed of 1750 rpm for this experimental study), turned advantages of HHO system into disadvantages for engine torque, carbon monoxide (CO), hydrocarbon (HC) emissions and specific fuel consumption (SFC). Investigations demonstrated that HHO flow rate had to be diminished in relation to engine speed below 1750 rpm due to the long opening time of intake manifolds at low speeds. This caused excessive volume occupation of hydroxy in cylinders which prevented correct air to be taken into the combustion chambers and consequently, decreased volumetric efficiency was inevitable. Decreased volumetric efficiency influenced combustion efficiency which had negative effects on engine torque and exhaust emissions. Therefore, a hydroxy electronic control unit (HECU) was designed and manufactured to decrease HHO flow rate by decreasing voltage and current automatically by programming the data logger to compensate disadvantages of HHO gas on SFC, engine torque and exhaust emissions under engine speed of 1750 rpm. The flow rate of HHO gas was measured by using various amounts of KOH, NaOH, NaCl (catalysts). These catalysts were added into the water to diminish hydrogen and oxygen bonds and NaOH was specified as the most appropriate catalyst. It was observed that if the molality of NaOH in solution exceeded 1% by mass, electrical current supplied from the battery increased dramatically due to the too much reduction of electrical resistance. HHO system addition to the engine without any modification resulted in increasing engine torque output by an average of 19.1%, reducing CO emissions by an average of 13.5%, HC emissions by an average of 5% and SFC by an average of 14%. (author)

Yilmaz, Ali Can; Uludamar, Erinc; Aydin, Kadir [Department of Mechanical Engineering, Cukurova University, 01330 Adana (Turkey)

2010-10-15

173

NOx remediation in oxygen-rich exhaust gas using atmospheric pressure non-thermal plasma generated by a pulsed nanosecond dielectric barrier discharge  

International Nuclear Information System (INIS)

It is clearly seen that the application of non-thermal plasmas (NTP) to remove NOx from gas mixture containing a large amount of oxygen (O2) is dominated by NO to NO2 oxidation. Experiments have been conducted using a NTP generated by a nanosecond pulsed dielectric barrier discharge in synthetic exhaust gas, prepared from N2, O2, NO, H2O, and C3H6, over a large range of gas temperature (20-300 deg. C). Results show that the NOx removal rate significantly increased with increasing specific energy deposition. For example, at a temperature of 100 deg. C and an energy deposition of 27 J l-1, 92% of the NO molecules have been removed. The W values for NO is dramatically reduced to values scaling from approx. 15 eV at 27 J l-1 down to approx. 4 eV at 7 J l-1. NOx removal efficiency around 43% was obtained at a temperature of 260 deg. C and a space velocity of 60 000 h-1 for a specific input energy of 27 J l-1. W values for NOx were less than approx. 30 eV. Such treatments in exhaust gas with and without the presence of water vapour induced reactions leading to the production of a large variety of by-products such as acetaldehyde, propylene oxide, formic acid, methyl nitrate, and nitromethane. (author)

174

Effect of the Sequence of the Thermoelectric Generator and the Three-Way Catalytic Converter on Exhaust Gas Conversion Efficiency  

Science.gov (United States)

The potential for thermoelectric exhaust heat recovery in vehicles has increased with recent improvements in the efficiency of thermoelectric generators (TEGs). The problem with using thermoelectric generators for vehicle applications is whether the device is compatible with the original vehicle exhaust system, which determines the quality of the exhaust gas treatment and the realization of energy conservation and emission reduction. Based on ANSYS CFX simulation analysis of the impact of two positional relationships between the TEG and three-way catalytic converter in the exhaust system on the working efficiency of both elements, it is concluded that the layout with the front three-way catalytic converter has an advantage over the other layout mode under current conditions. New ideas for an improvement program are proposed to provide the basis for further research.

Su, Chuqi; Tong, Naiqiang; Xu, Yuman; Chen, Shan; Liu, Xun

2013-07-01

175

Exhaust Emission Characteristics of Diesel Engine Operating on Biodiesel and its Blends at Elevated Temperature of Air  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, performance and exhaust emission characteristics of Pongamia Pinnata oil blends (B10,B20,B30 and B50 with mineral diesel were investigated in preheated intake air conditions in a single cylinder 4-Stroke direct injection CI engine at 75 % maximum load and its rated engine speed 1500 rpm. Two types of heat exchanger designed to preheat the suction air and the heating is accomplished by both engine cooling water and exhaust gases. Two types of heat exchanger includes concentric tube counter flow heat exchanger (to recover heat from engine exhaust gases and shell and tube heat exchanger (to recover heat from engine jacket cooling water is mounted along intake manifold to preheat the suction air. Test is carried out at atmospheric air temperature (30oC, preheated air temperature of 45oC,60oC and75oC.Exhaust emission characteristics such as Carbon Dioxide(CO2,Carbon monoxide(CO,Unburned Hydrocarbon (HC and Nitrogen Oxide(NO. Experimental investigation revealed that except Nitrogen Oxide (NO emission and other exhaust emission parameters such as CO2,CO and HC are decreased with mineral diesel and among other biodiesel blends a drastic reduction in exhaust emission is observed for Biodiesel blend ratio B20 for all preheated air temperature .However the Nitrogen Oxide (NO emission increases with increase in biodiesel mixtures for all preheated air temperature.

K.Sureshkumar

2014-10-01

176

Process and apparatus for separating and recovering krypton-85 from exhaust gas of nuclear reactor or the like  

International Nuclear Information System (INIS)

An apparatus is described for separating and recovering radioactive krypton-85 contained in an exhaust gas of a nuclear reactor or the like, which comprises a plurality of adsorption beds connected in parallel with respect to a passageway for the exhaust gas, each being packed with activated carbon, wherein adsorption and desorption of krypton-85 in each of the beds are alternatively and repeatedly performed by operating valves disposed between each of the beds and means for reducing pressure in the beds to be desorbed in accordance with a predetermined time schedule. The adsorption and concentration efficiencies are markedly increased by combining the above adsorption apparatus and a distillation apparatus

177

A study on exhaust gas emissions from ships in Turkish Straits  

International Nuclear Information System (INIS)

The Turkish Straits, i.e. Istanbul (Bosphorus) and Canakkale (Dardanellen), which connect Black Sea and Aegean Sea, have a continuously increasing maritime traffic. Especially, the maritime traffic on Bosphorus (Istanbul Strait) that connects the continents of Europe and Asia is too complex due to geographical conditions. The maritime traffic in the Turkish Straits includes the ships, which are in use in domestic transport, the transit passing ships with various aims and fishing, sport or strolling ships. In this paper, fuel consumption and exhaust gas emissions NOx, CO, CO2, VOC, PM exhausted from ships such as transit vessels, which are passing both Bosphorus and Dardanellen, and passenger ships used in domestic transport on the Bosphorus are calculated. In order to do this the general characteristics, the main engine systems, the fuel types, cruising times and speeds of all vessels are taken into consideration. The calculated NOx emissions on the Bosphorus are 2720t from domestic passenger ships and 4357t from transit ships. In this case it is clear that the transit ships cause more than half of the total amount of emissions from ships on the Bosphorus. The amount of nitrogen oxide emissions from domestic passenger ships used for public transport in Istanbul Strait is equal to approx. 4% of nitrogen oxide emissions from motor vehicles in Istanbul. Finally, the future emissions from ships in Turkish Straits are discussed. (Author)Turkish Straits are discussed. (Author)

178

Automobile exhaust gas as a source of aqueous phase OH radical in the atmosphere and its effects on physiological status of pine trees.  

Science.gov (United States)

Free radical generation potential of automobile exhaust gas was examined by measuring hydroxyl (OH) radical photo-formation rates in exhaust gas-scrubbing water. Effects of automobile exhausts on physiological status of Japanese red pine trees (Pinus densiflora Sieb. et Zucc.) were also investigated to elucidate the mechanism how the free radicals derived from exhaust gas damage higher plants. Gasoline and diesel exhaust gases were scrubbed into pure water. Potential photo-formation rates of OH radical in aqueous phase (normalized to sun light intensity of clear sky midday on May 1 at 34°N) for gasoline and diesel cars were ave. 51 and 107 ? Mh?¹ m?³ of exhaust gas, respectively. Nitrite was a dominant source (ca. 70-90%) of photochemical formation of OH radical in both gasoline and diesel car exhausts. The scrubbed solution of diesel car exhaust gas was sprayed for six times per week to needles of pine tree seedlings in open top chambers. Control, exhaust+mannitol (added as OH radical scavenger), and nitrite+nitrate standard solution (equivalent levels existed in the exhaust gas) were also sprayed. Two months sprays indicated that the sprayed solutions of diesel exhaust and nitrite+nitrate caused a decrease of maximum photosynthetic rate and stomata conductance in pine needles while the control and exhaust+mannitol solution showed no effects on photosynthetic activities of pine needles. These results indicated that OH radicals generated mainly from photolysis of nitrite occurring in the scrubbing solution of exhaust gas are responsible for the decrease of photosynthetic activities of pine needles. PMID:21767866

Sakugawa, Hiroshi; Matsuda, Toshihide; Nakatani, Nobutake

2011-10-01

179

The Effect of Ambient Temperature and Exercise to the Level of Exhaustion on  

Directory of Open Access Journals (Sweden)

Full Text Available Background: The increase in the amount of heat shock protein and C-reactive protein occurring as a result of stress was done with the aims of returning cell homeostasis, successful restoration of cell injury and protection of cell against more injuries. Materials and Methods: Fifteen climber and 15 non athlete subjects were chosen. A selected aerobic test was done by the subjects using Monark bicycle under two different conditions. Before starting the test, the subjects were exposed to a normal condition with the temperature of 24±2°C for an hour and a blood sample was taken from all the subjects. Then immediately, the subjects took the selected aerobic test to the level of exhaustion and blood sample was taken again. A week later, these subjects were exposed to a heated environment with the temperature of 38±2°C, followed by blood sample taking. Finally, the test was done by the subjects to the level of exhaustion and the last blood sample was taken. Then, the amount of heat shock protein (HSP and C - reactive protein (CRP in blood samples was measured. Results: A meaningful difference was observed in the changes of heat shock proteins (p=0.012 and C-reactive protein (p=0.02 between athlete and non athlete subjects. There was no meaningful difference in CRP and HSP in normal and hot condition for non athlete subjects before and after the test. But the result of the study demonstrates that There was a meaningful difference for athletes in both conditions before and after the test (p=0.002. Conclusion: Based on the study, it is claimed that while an athlete is exposed to several stressful conditions (e.g. high temperature and physical exercise, compared to a non athlete, the reaction of his body cells is more significant in order to prevent the injury.

Somaye Kasharafifard

2014-06-01

180

NO{sub x} reduction from a heavy-duty diesel engine with direct injection of natural gas and cooled exhaust gas recirculation  

Energy Technology Data Exchange (ETDEWEB)

A heavy-duty ISX diesel engine has been commissioned for single-cylinder operation fuelled with pilot diesel ignited natural gas injected directly into the cylinder. The stock ISX engine was modified by replacing the diesel fuelling system with a high-pressure natural gas system, replacing the turbocharger with an independently controlled supercharger and installing a variable-flow exhaust gas recirculation (EGR) system. A study of the impact of cooled EGR on engine performance and gaseous emissions was carried out. Various engine speeds, loads and injection timings were tested over a range of EGR fractions. A preliminary study of the effect of EGR 'type' - supplemental or replacement - was also carried out. The results indicate that the NO{sub x} emissions varied linearly with the intake oxygen mass fraction (representative of the EGR fraction) until NO{sub x} emissions reached 20 per cent of their non-EGR levels. Further NO{sub x} reductions were achieved with higher EGR fractions, but the rate of reduction was significantly reduced. The NO{sub x} reductions were found to be independent of engine speed and load. An overall activation energy for NO{sub x} formation was determined by correlating the NO{sub x} reductions with a representative flame temperature. The emissions of combustion by-products, including carbon monoxide (CO)and unburned total hydrocarbons (THC) increased significantly at higher EGR fractions. The engine performance and efficiency were not significantly affected except at very high EGR fractions. (Author)

McTaggart-Cowan, G.; Bushe, W.K.; Hill, P.G. [British Columbia Univ., Dept. of Mechanical Engineering, Vancouver, BC (Canada); Munshi, S.R. [Westport Innovations Inc., Vancouver, BC (Canada)

2004-06-01

181

Numerical Simulation of Exhaust Gas Cooling in Channels with Periodic Elbows for Application in Compact Heat Recovery Systems  

International Nuclear Information System (INIS)

Miniature and Micro devices represent the new frontier for advanced heat and mass transfer technology. Due to the small length scales, the use of CFD is very useful for designing and optimizing microfluidic devices since experimentation and visualization at these scales can be difficult. In this work a high temperature air microfluidic cooling strategy for applications such as compact waste heat recovery, exhaust gas recirculation and fuel cell thermal management is proposed. Initially, the application of a simple straight microchannel is considered. In an effort to partially compensate for the poor thermal properties of air, right-angle bends are introduced in order to induce Dean vortices which periodically restart the thermal boundary layer development, thus improving the heat transfer and fluid mixing. Numerical simulations in the range of 100 ? ReDh ? 1000 have been carried out for channels of square cross-section. Channel wall lengths of 1.0 mm are investigated for elbow spacings of 5 mm, 10 mm and 15 mm. High temperature air (300°C) at atmospheric inlet pressure is the working fluid. The results indicate that the elbows substantially improve the local and average heat transfer in the channels while increasing the pressure drop. Design considerations are discussed which take into account the heat transfer and pressure drop characteristics of the channels.

182

CO{sub 2} separation from exhaust gas; CO{sub 2} separasjon fra eksosgass  

Energy Technology Data Exchange (ETDEWEB)

When Saga wanted to reduce the CO{sub 2} emissions from Snorre B, cleaning of CO{sub 2} from exhaust gas was one of several options considered. CO{sub 2} cleaning using membrane/amine technology is under development. Saga required that the technology should be qualified and that the yield of the Snorre B project should not be reduced. This presentation discusses qualification of combined membrane/amine technology, environmental issues, economic issues and implementation on the Snorre B platform. Flue gas from the gas turbine is passed to a CO{sub 2} absorption and desorption stage from which the CO{sub 2} is passed on for compression and disposal while the cleaned flue is let out. The membrane is situated between the flue gas and the absorbent liquid. The pores are large enough for the CO{sub 2} to pass through quickly and small enough to prevent the liquid from penetrating into the pores. The packing factor is high, 500 - 1000 m2/m3, there is no formation of froth, ducts or entrainment of the liquid. New technology implies 65 - 70% size reduction of the main equipment and 39 - 40% reduction of the energy consumption. Research on amines brings out new chemicals which imply 80% reduction in the consumption of chemicals and the quantity of special waste produced. If a CO{sub 2} cleaning plant is installed on a LM 2500, the CO{sub 2} emissions can be reduced by 97,200 ton/year given the right operational conditions. Although it was decided in 1998 not to install the module with the CO{sub 2} pilot cleaning plant, Snorre B is still a good environmental project having CO{sub 2} emission within the values set by Miljoesok.

Magelssen, Paul Fr. [Saga Petroleum A/S, Forus (Norway)

1998-07-01

183

Simultaneous atmosphere and temperature cycling of three-way automotive exhaust catalysts  

Energy Technology Data Exchange (ETDEWEB)

As an attempt to simulate real operating conditions of automotive converters, a laboratory bench has been designed and ageing procedures determined to reproduce simultaneous chemical and thermal modifications encountered by catalysts in the exhaust line. Characterization of commercial samples after ageing according to different temperature cycles evidences formation of both platinum/rhodium alloys and cubic perovskite-type compound, CeAlO{sub 3}. Simultaneously with the formation of cerium aluminate, a thermal stabilization of catalysts is observed, in terms of mean noble metal particles size and concentration of rhodium in alloyed phases. An interpretation based on the crystallographic adaptation of alumina, cerium aluminate and ceria is proposed. 5 figs., 1 tab., 18 refs.

Humbert, S.; Colin, A.; Monceaux, L.; Courtine, P. [Dept. de Genie Chimique, Univ. de Technologie de Compiegne, Compiegne (France); Oudet, F. [Service d`Analyse Physico-Chimique, Univ. de Technologie de Compiegne (France)

1995-12-31

184

Low-temperature gas from marine shales  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Thermal cracking of kerogens and bitumens is widely accepted as the major source of natural gas (thermal gas. Decomposition is believed to occur at high temperatures, between 100 and 200°C in the subsurface and generally above 300°C in the laboratory. Although there are examples of gas deposits possibly generated at lower temperatures, and reports of gas generation over long periods of time at 100°C, robust gas generation below 100°C under ordinary laboratory conditions is unprecedented. Here we report gas generation under anoxic helium flow at temperatures 300° below thermal cracking temperatures. Gas is generated discontinuously, in distinct aperiodic episodes of near equal intensity. In one three-hour episode at 50°C, six percent of the hydrocarbons (kerogen & bitumen in a Mississippian marine shale decomposed to gas (C1–C5. The same shale generated 72% less gas with helium flow containing 10 ppm O2 and the two gases were compositionally distinct. In sequential isothermal heating cycles (~1 hour, nearly five times more gas was generated at 50°C (57.4 ?g C1–C5/g rock than at 350°C by thermal cracking (12 ?g C1–C5/g rock. The position that natural gas forms only at high temperatures over geologic time is based largely on pyrolysis experiments under oxic conditions and temperatures where low-temperature gas generation could be suppressed. Our results indicate two paths to gas, a high-temperature thermal path, and a low-temperature catalytic path proceeding 300° below the thermal path. It redefines the time-temperature dimensions of gas habitats and opens the possibility of gas generation at subsurface temperatures previously thought impossible.

Jarvie Daniel M

2009-02-01

185

High temperature gas cooled reactor  

International Nuclear Information System (INIS)

Purpose: To provide a pebble bed type high temperature gas cooled reactor adapted for use of plutonium fuel. Constitution: A fuel sphere filled in a reactor core consists of a central fuel region and an outside graphite moderator region. The fuel region further consists of an inside fuel region made of graphite as base material and coating fuel particles of plutonium oxide in slight amount added thereto, and an outside thin layer fuel region formed outside the inside fuel region with coating fule particles of plutonium oxide in large quantity added thereto. Since the fuel region is thus formed in no uniformity, neutron absorption amount by plutonium 240 is reduced so that the amount of generated neutron in the entire reactor exceeds the absorption amount to enable use of plutonium fuel. (Kamimura, M.)

186

Combined use of high efficiency liquid and capillary gas chromatography for the determination of polycyclic aromatic hydrocarbons in automotive exhaust condensates and other hydrocarbon mixtures  

Energy Technology Data Exchange (ETDEWEB)

High efficiency liquid and capillary gas chromatography are used in combination to examine and determine the polycyclic aromatic hydrocarbons present in automotive exhaust condensates from gasoline engines, finished gasolines, and catalytic reformates. The effect of adsorbed water and column temperature on liquid adsorption columns is discussed. The equilibrium conditions can readily be reached and maintained on Waters Porasil T by operating the chromatograph at a column temperature of 51.5/sup 0/C. The problems associated with the gas chromatography of polycyclic aromatic hydrocarbons are also discussed. Adsorption problems can be reduced by using glass capillary columns, but sample recovery is incomplete. The method is suited to determination of benzo(a)pyrene and benzo(a)anthracene. Each determination can be completed in 3-4 hr, which represents a substantial time saving over previous methods.

Doran, T.; McTaggart, N.G.

1974-11-01

187

On exhaust emissions from petrol-fuelled passenger cars at low ambient temperatures  

Energy Technology Data Exchange (ETDEWEB)

The study at hand deals with regulated and unregulated exhaust emissions from petrol-fuelled cars at low ambient temperatures with present-day or near-future exhaust after treatment systems. The subject has been investigated at VTT over a decade and this report compiles data from various sub-studies carried out between the years 1993 - 1997. Each one of them viewed different aspects of the phenomenon, like determining the low-temperature response of today`s new cars employing three-way catalytic converters or assessing the long-term durability and the influence of vehicle mileage upon the low-temperature emissions performance. Within these studies, together more than 120 cars of model years from 1990 to 1997 have been tested. Most of them were normal, in-service vehicles with total mileages differing between only a few thousand kilometres for new cars up to 80,000 km or even more for the in-use vehicles. Both the US FTP75 and the European test cycle have been employed, and the ambient temperatures ranged from the baseline (+22 deg C) down to +- O deg C, -7 deg C and in some cases even to -20 deg C. The studies attested that new cars having today`s advanced emissions control systems produced fairly low levels of emissions when tested in conditions designated in the regulations that are the basis of the current new-vehicle certification. However, this performance was not necessarily attained at ambient temperatures that were below the normative range. Fairly widespread response was recorded, and cars having almost equal emissions output at baseline could produce largely deviating outcomes in low-temperature conditions. On average, CO and HC emissions increased by a factor of five to 10, depending on the ambient temperature and vehicle type. However, emissions of NO{sub x} were largely unaffected. Apart from these regulated emissions, many unregulated species were also determined, either by using traditional sampling and chromatography methods or on-line, employing the latest FTIR technology. Overall, the levels of these emissions were also mostly elevated at subnormal temperatures. Total vehicle mileage seemed not to affect cold-start emissions (CO and HC) at low temperatures. Nor did the overall durability of the emission control system appear to be worse in cold-climate conditions typical for Finland. The deterioration of the emissions performance in the tested vehicles either closely followed the average trend defined by the normal, assigned deterioration factors or was even lesser. The conclusions of this report underline the necessity of a separate low-temperature test in order to really effectively curb real-world emissions. Standards at normal temperature are no more effective alone, but need to be accompanied with additional requirements for good performance also in conditions closer to the everyday use, which comprises many cold-starts even in low ambient temperature conditions. (orig.) 75 refs.

Laurikko, J. [VTT Energy, Espoo (Finland). Energy Use

1998-11-01

188

Study of an exhaust gas recirculation equipped micro gas turbine supplied with bio-fuels  

International Nuclear Information System (INIS)

The authors discuss in this paper some aspects related to the employment of liquid and gaseous bio-fuels in a micro-gas turbine. Besides the purpose of checking the effectiveness of methods for supplying the micro-turbine with fuels from renewable sources, the attention is focused on the need of controlling the pollutant emission. To this aim, several solutions are experienced and numerically tested. For the liquid fuel supply, a new shape and location of the main fuel injector is combined with a modified position of the pilot injector. In the case of the biogas fuelling, an external EGR option is considered as activated. Both methods aim at the reduction of the thermal and prompt NO formation by approaching the flameless combustion concept. -- Highlights: • External and internal EGR concepts applied to NOx control from micro gas turbines. • For gaseous fuels: internal EGR is obtained by a proper location of the pilot injector. • For liquid fuels: replacing the original radial injectors with a pressure swirl atomizer. • We apply a CFD based method, after validation with experimental data. • Blends of bio-fuels with fossil fuels promise noticeable benefits

189

New high-performance gas flow equalizing metal supports for exhaust gas catalysts  

Energy Technology Data Exchange (ETDEWEB)

Based on the theory of catalysis and in the light of the all-important exchange of substances, the existing type of catalyst metal supports has been redesigned. The new metal supports vary from their predecessors by largely split and slotted honeycomb passages. Thus the gas flow is cutted and divided again and again. In this way, thin boundary layers and turbulence are generated on the catalytically active support surfaces, with resultant intense exchange of substances between the core stream and the surface contacting zone. The increase in catalytic performance thus obtained makes it now possible to lower the specific number of cells from 400 to 200 per sq. in. Along with this goes a 27% saving of support material with a consequent reduction of cost. On the other hand, this new specific performance may be put to work by reducing the total support volume.

Nonnenmann, M.

1989-04-01

190

COMBINED IMPACT OF BIODIESEL (MENO AND EXHAUST GAS RECIRCULATION ON NOX EMISSIONS IN DI DIESEL ENGINES  

Directory of Open Access Journals (Sweden)

Full Text Available The steep rises in the prices of the petroleum fuels and the concern for the environment have forced the researchers to find alternative renewable fuels which are called bio-fuels. The objective of this work is to find the optimum EGR and biodiesel blend matrix for the better performance and optimum emission reduction in a DI diesel engine. The bio fuel used in the experimentation is derived from the Neem oil. A twin-cylinder, air-cooled, constant speed direct injection diesel engine is used for experiments. HC, NOx, CO, and smoke of the exhaust gas are measured. Various engine performance parameters such as thermal efficiency, and brake specific fuel consumption are calculated from the acquired data. As the percentage of bio diesel increased in diesel and bio fuel blend the NOx emission increased. In order to reduce the emission from bio diesel EGR is used. Application of EGR with biodiesel blends resulted in reductions in NOx emissions without any significant penalty in smoke emissions. The results reveal that the Blend 100 (100 % bio fuel produces maximum NOx emission (300 ppm. With 25% volume flow rate of EGR with the same B100 bio diesel, the NOx emission is reduced approximately 300 ppm to 100 ppm

B. Jothithirumal

2012-09-01

191

Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace  

Energy Technology Data Exchange (ETDEWEB)

Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in the laboratory setting using a variable flow duct of the same dimensions (8-inch diameter, schedule 40) as that in the field and was loaded with similar particulate (less than 10 {mu}m in diameter) of lake bed soil typically used in the vitrification process. The flow from the furnace was assumed to be straight flow. To reproduce this effect a flow straightener was installed in the device. An isokinetic sampling train was designed to include the plasma torch, with microwave power input operating at 2.45 GHz, to match local freestream velocities between 800 and 2400 ft/sec. The isokinetic sampling system worked as planned and the plasma torch had no difficulty operating at the required flowrates. Simulation of the particulate suspension was also successful. Steady particle feeds were maintained over long periods of time and the plasma diagnostic responded as expected.

Pollack, B.R.

1996-05-01

192

Formaldehyde in the exhaust gas of biogas engine plants and natural gas cogeneration plants; Formaldehyd im Abgas von Biogasmotoranlagen und Erdgas-Blockheizkraftwerken  

Energy Technology Data Exchange (ETDEWEB)

The pricing regulations of the Renewable Energy Law EEG 2009 enabled the operation of biogas facilities within the agricultural range. The emissions of formaldehyde in the exhaust gas are regarded with respect to the future limiting values with biogas combustion engine plants.

Ebertsch, Gerald [Bayerisches Landesamt fuer Umwelt, Augsburg (Germany); Fiedler, Alexander [Regierung von Oberbayern, Muenchen (Germany)

2010-07-01

193

Reduction of the exhaust gas emissions during warm up by improving the mixture preparation of spark-ignition engines  

International Nuclear Information System (INIS)

During warm-up the engine emits the highest concentration of exhaust gas emissions. An improvement of the atomization behaviour of the injected fuel should lead to a good mixture preparation in the manifold and combustion chamber and further to lower exhaust gas emissions during warm up. During these investigations it was found out that the build-up of fuel film in the manifold of cold spark-ignition engines can not be prevented. But by injecting the fuel at the open inlet valve it is possible to reduce the fuel film. The injection of extremely finely atomized fuel at the open inlet valve leads to a better mixture preparation with smaller fuel dropplets in the manifold and combustion chamber. This again leads, during warm-up of the spark ignition engine, to a reduction of the HC emissions of 30% and the CO emissions of 50%. (author)

194

A laboratory test unit for exhausted gas cleaning by electron beam and combined electron beam-microwave irradiation  

International Nuclear Information System (INIS)

At the electron accelerator laboratory, NILPR, Bucharest developed a small laboratory test unit (max. gas flow rate = 1 Nm3/h) for exhaust gas cleaning by means of electron beam and combined electron beam microwave irradiation. The aim of these methods is to obtain the concomitant removal of the NOx and SO2 by precipitation with ammonia. Several parameters such as residence time and dose, reaction temperature, argon and NH3 concentration, etc. were investigated. The removal efficiencies were: only for electron beam irradiation 63-80% for SO2 and 0-63% for NOx; for combined electron beam-microwave treatment 68-95% for SO2 and 0-70% for NOx. Also, the presence of a small concentration of argon in the irradiated gaseous mixture increases the SO2 removal efficiency (between 5% and 10%) for both electron beam and electron beam-microwave treatment. As electron beams generator was used the Linear Accelerator ALID-7 (5.5 MeV, 670 W). The microwave applicator consists of a power-controlled generator with a 2.45 GHz magnetron of 850 W maximum output power, a launcher to fit to waveguide WR430, a dual directional coupler and a three stub tuner for impedance matching. Our tests also demonstrated that the combined method electron beam-microwave irradiation, due to the additional use of microwave energy, leads to the decrease of the electron beam average power from 30% to 50%, at the eam average power from 30% to 50%, at the same removal efficiency. (orig.)

195

Experimental clean combustor program, phase 1. [aircraft exhaust/gas analysis - gas turbine engines  

Science.gov (United States)

A program of screening three low emission combustors for conventional takeoff and landing, by testing and analyzing thirty-two configurations is presented. Configurations were tested that met the emission goals at idle operating conditions for carbon monoxide and for unburned hydrocarbons (emission index values of 20 and 4, respectively). Configurations were also tested that met a smoke number goal of 15 at sea-level take-off conditions. None of the configurations met the goal for oxides of nitrogen emissions at sea-level take-off conditions. The best configurations demonstrated oxide of nitrogen emission levels that were approximately 61 percent lower than those produced by the JT9D-7 engine, but these levels were still approximately 24 percent above the goal of an emission index level of 10. Additional combustor performance characteristics, including lean blowout, exit temperature pattern factor and radial profile, pressure loss, altitude stability, and altitude relight characteristics were documented. The results indicate the need for significant improvement in the altitude stability and relight characteristics. In addition to the basic program for current aircraft engine combustors, seventeen combustor configurations were evaluated for advanced supersonic technology applications. The configurations were tested at cruise conditions, and a conceptual design was evolved.

Roberts, R.; Peduzzi, A.; Vitti, G. E.

1975-01-01

196

Analysis of the state and size of silver on alumina in effective removal of NOx from oxygen rich exhaust gas.  

Czech Academy of Sciences Publication Activity Database

Ro?. 6, ?. 4 (2006), s. 1076-1083. ISSN 1533-4880 R&D Projects: GA AV ?R 1ET400400413 Grant ostatní: European Union(XE) GR5D-CT 2001-00595 Institutional research plan: CEZ:AV0Z40400503 Keywords : silver * exhaust gas * removal of NOx Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.194, year: 2006

Arve, K.; Klingstedt, F.; Eränen, K.; Murzin, D. Yu.; ?apek, Libor; D?de?ek, Ji?í; Sobalík, Zden?k; Wichterlová, Blanka; Svennerberg, K.; Wallenberg, L. R.; Bovin, J.-O.

2006-01-01

197

Influence of an Optimized Thermoelectric Generator on the Back Pressure of the Subsequent Exhaust Gas System of a Vehicle  

Science.gov (United States)

Numerous research projects in automotive engineering focus on the industrialization of the thermoelectric generator (TEG). The development and the implementation of thermoelectric systems into the vehicle environment are commonly supported by virtual design activities. In this paper a customized simulation architecture is presented that includes almost all vehicle parts which are influenced by the TEG (overall system simulation) but is nevertheless capable of real-time use. Moreover, an optimized planar TEG with minimum nominal power output of about 580 W and pressure loss at nominal conditions of 10 mbar, synthesized using the overall system simulation, and the overall system simulation itself are used to answer a generally neglected question: What influence does the position of a TEG have on the back pressure of the subsequent exhaust gas system of the vehicle? It is found that the influence of the TEG on the muffler is low, but the catalytic converter is strongly influenced. It is shown that the TEG can reduce the back pressure of an exhaust gas system so much that its overall back pressure is less than the back pressure of a standard exhaust gas system.

Kühn, Roland; Koeppen, Olaf; Kitte, Jens

2014-06-01

198

Robust control of speed and temperature in a power plant gas turbine.  

Science.gov (United States)

In this paper, an H(?) robust controller has been designed for an identified model of MONTAZER GHAEM power plant gas turbine (GE9001E). In design phase, a linear model (ARX model) which is obtained using real data has been applied. Since the turbine has been used in a combined cycle power plant, its speed and also the exhaust gas temperature should be adjusted simultaneously by controlling fuel signals and compressor inlet guide vane (IGV) position. Considering the limitations on the system inputs, the aim of the control is to maintain the turbine speed and the exhaust gas temperature within desired interval under uncertainties and load demand disturbances. Simulation results of applying the proposed robust controller on the nonlinear model of the system (NARX model), fairly fulfilled the predefined aims. Simulations also show the improvement in the performance compared to MPC and PID controllers for the same conditions. PMID:22062324

Najimi, Ebrahim; Ramezani, Mohammad Hossein

2012-03-01

199

Gas-particle partitioning of primary organic aerosol emissions: (1) Gasoline vehicle exhaust  

Science.gov (United States)

The gas-particle partitioning of the primary organic aerosol (POA) emissions from fifty-one light-duty gasoline vehicles (model years 1987-2012) was investigated at the California Air Resources Board Haagen-Smit Laboratory. Each vehicle was operated over the cold-start unified cycle on a chassis dynamometer and its emissions were sampled using a constant volume sampler. Four independent yet complementary approaches were used to investigate POA gas-particle partitioning: sampling artifact correction of quartz filter data, dilution from the constant volume sampler into a portable environmental chamber, heating in a thermodenuder, and thermal desorption/gas chromatography/mass spectrometry analysis of quartz filter samples. This combination of techniques allowed gas-particle partitioning measurements to be made across a wide range of atmospherically relevant conditions - temperatures of 25-100 °C and organic aerosol concentrations of <1-600 ?g m-3. The gas-particle partitioning of the POA emissions varied continuously over this entire range of conditions and essentially none of the POA should be considered non-volatile. Furthermore, for most vehicles, the low levels of dilution used in the constant volume sampler created particle mass concentrations that were greater than a factor of 10 or higher than typical ambient levels. This resulted in large and systematic partitioning biases in the POA emission factors compared to more dilute atmospheric conditions, as the POA emission rates may be over-estimated by nearly a factor of four due to gas-particle partitioning at higher particle mass concentrations. A volatility distribution was derived to quantitatively describe the measured gas-particle partitioning data using absorptive partitioning theory. Although the POA emission factors varied by more than two orders of magnitude across the test fleet, the vehicle-to-vehicle differences in gas-particle partitioning were modest. Therefore, a single volatility distribution can be used to quantitatively describe the gas-particle partitioning of the entire test fleet. This distribution is designed to be applied to quartz filter POA emission factors in order to update emissions inventories for use in chemical transport models.

May, Andrew A.; Presto, Albert A.; Hennigan, Christopher J.; Nguyen, Ngoc T.; Gordon, Timothy D.; Robinson, Allen L.

2013-10-01

200

Estimation of exhaust gas aerodynamic force on the variable geometry turbocharger actuator: 1D flow model approach  

International Nuclear Information System (INIS)

Highlights: • Estimation of aerodynamic force on variable turbine geometry vanes and actuator. • Method based on exhaust gas flow modeling. • Simulation tool for integration of aerodynamic force in automotive simulation software. - Abstract: This paper provides a reliable tool for simulating the effects of exhaust gas flow through the variable turbine geometry section of a variable geometry turbocharger (VGT), on flow control mechanism. The main objective is to estimate the resistive aerodynamic force exerted by the flow upon the variable geometry vanes and the controlling actuator, in order to improve the control of vane angles. To achieve this, a 1D model of the exhaust flow is developed using Navier–Stokes equations. As the flow characteristics depend upon the volute geometry, impeller blade force and the existing viscous friction, the related source terms (losses) are also included in the model. In order to guarantee stability, an implicit numerical solver has been developed for the resolution of the Navier–Stokes problem. The resulting simulation tool has been validated through comparison with experimentally obtained values of turbine inlet pressure and the aerodynamic force as measured at the actuator shaft. The simulator shows good compliance with experimental results

201

Helium gas turbine plant with high temperature gas cooled reactor  

International Nuclear Information System (INIS)

Dreams of the Nuclear Gas Turbine was broken about 10 years ago after long term R and D in Europe and U.S. since 1960's, while HTGR'S penetration to the nuclear power market was failed in mid 1970's. In later 1980's, Modular High Temperature Gas Cooled Reactor became one of the most promising 'Passively and Inherently Safe' concept for next decades, and an appeal to call back the Closed Cycle Gas Turbine was risen by Prof. L.M. Lidsky of MIT-NPI. Supported by GCRA, ESEERCO and US-DOE, the first 'International Workshop on the Closed-Cycle Gas-Turbine Modular High Temperature Gas-Cooled Reactor' was held at MIT in June 17-19, 1991, and since then various activities are going on. Looking back the past experiences and summarizing the present status, the writer describes a revival of the Nuclear Gas Turbine. (author)

202

MEGAS - multi-electrode gas sensor system. Micromechanical high-temperature sensor system on a Si basis for measurements of nitrogen monoxide concentrations in motor car exhaust. Final report; MEGAS - Multi-Elektroden-Gassensorsystem. Mikromechanisches Hochtemperatur-Sensorsystem aus Silizium-Basis zur Ermittlung von Stickstoffmonoxid-Konzentrationen im Kfz-Abgas. Abschlussbericht  

Energy Technology Data Exchange (ETDEWEB)

The IMSAS is working on an actively heated Si substrate with interdigital structures fo working temperatures up to 550 C and for aggressive working media. The following tasks were achieved: Gas sensor design; Process development and optimisation; Processing of the Si substrate; Optimisation of the sensor substrate. The following problems were encountered: Minimisation of intrinsic stress of the stratified packages; Optimisation of the adhesive strength; Development of a stable sensor heating up to 550 C; Development and optimisation of structuring methods; Combination of thin film and thick film technologies. Resistive gas sensors with titanium-tungsten mixed oxides must be heated to 500 C for fast and sensitive response to a NO atmosphere. The gas sensitivity is strongly temperature-dependent, i.e. gas sensor temperature contro is required. In the case of diesel engine catalytic converters, ambient temperatures are high and vary with the mode of operation and operating time. The sensor temperature must be at least as high as the maximum ambient temperature and must be kept stable at this level. (orig.) [German] Am IMSAS liegt der Schwerpunkt im Bereich der Entwicklung eines aktiv beheizten Siliziumsubstrates mit Interdigitalstrukturen, das Arbeitstemperaturen bis zu 550 C und aggressiven Umgebungsbedingungen standhaelt. Die Arbeitspakete lassen sich grob zusammenfassen: - Designerstellung des Gassensors - Prozessentwicklung und -optimierung - Prozessierung des Siliziumsubstrates - Optimierung des Sensorsubstrates. Aus diesen Schwerpunkten ergeben sich Schwierigkeiten, die im Projektverlauf geloest werden muessen: - Minimierung des intrinsischen Stresses der Schichtpakete - Optimierung der Haftfestigkeit der Schichten/Schichtpakete - Entwicklung einer stabilen Sensorheizung bis 550 C - Entwicklung und Optimierung der Strukturierungsmethoden - Kombination von Duenn- und Dickschichttechnik (Si-Technologie und Siebdruck). Resistive Gassensoren mit Titan-Wolfram-Mischoxiden muessen waehrend ihres Betriebs auf ca. 500 C geheizt werden, um schnell und empfindlich eine NO-Atmosphaere ansprechen zu koennen. Die Gassensitivitaet ist stark von der Temperatur abhaengig. Aus diesem Grunde muss die Temperatur des Gassensors geregelt werden. Im Anwendungsfall Dieselkatalysator sind erhoehte Umgebungstemperaturen vorhanden, diese variieren je nach Betriebsdauer und Lastfall. Die Sensortemperatur muss deshalb mindestens so hoch sein, wie die maximale Temperatur der Umgebung und dabei stabil gehalten werden. (orig.)

Junge, S.

2002-07-01

203

Effect of ejector dilutors on measurements of automotive exhaust gas aerosol size distributions  

International Nuclear Information System (INIS)

Ejector dilutors have long been used for automotive exhaust particle sampling, as they can offer a low-cost option for stable dilution. In an ejector dilutor, pressurized air expanding in the periphery of a nozzle draws in and mixes with an exhaust sample which is then led to analytical equipment. The combination of processes involved may lead to particle losses which can affect the measurement. This study examines the losses of diesel exhaust particles of different characteristics (nucleation mode, non-volatile accumulation mode, internally and externally mixed accumulation mode) when these are sampled through an ejector dilutor. A scanning mobility particle sizer (SMPS), an electrical low-pressure impactor and a diffusion charger were used as analytical equipment to characterize losses with different instruments. Particle losses were found negligible for all practical applications of diesel exhaust aerosol sampling. Also, the sampling outlet and the operating pressure of the ejector dilutor were found to have a non-measurable effect on the distribution shape. Some variation of the labile nucleation mode particles was attributed to evaporation within the SMPS rather than an ejector effect, and this was confirmed by sampling solid NaCl particles in the same size range. The study further confirms the usability of ejector dilutors for exhaust particle sampling and dilution

204

Shock propagation in the exhaust gas handling system of the proposed large altitude rocket cell: methods and preliminary analysis  

Energy Technology Data Exchange (ETDEWEB)

Numerical predictions are to be performed of the shock pressures that would result from the detonation of 100,000 lbm TNT. The initial phase of the project was to develop the methodology for analyzing the problem, develop a preliminary conceptual design to use in initial simulations, and estimate over-pressures, inside the conceptual facility, resulting from the propellant detonation. This report discusses the methods of analysis used to study the problem of the detonation of the propellant, and the propagation of the shock wave inside the exhaust gas processing system, and presents preliminary results. The KOVEC computer code was used to simulate the detonation of 100,000 lbm TNT and develop a boundary prescription for use in the gas dynamics code GASP which models the propagation of the shock wave through the LARC exhaust gas processing system. Results are presented showing the effect of cross-sectional area changes and variations in the initial pressure in the gas processing system on the shock wave peak pressure and propagation speed.

Sutton, S.B.; Pierce, R.E.

1984-10-04

205

Effects of Gas Velocity and Temperature on Nitric Oxide Conversion in Simulated Catalytic Converter  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Gaseous emissions from gasoline engine such as carbon monoxide, unburned hydrocarbon and nitrogen oxides were usually reduced in three-way catalytic converter simultaneously around theoretical fuel and air combustion. Engine speed and load and other parameters were varied over a wide range of operating conditions, resulting in different exhaust gas composition and condition intake into catalytic converter. This work was studied the conversion of Nitric Oxide (NO in exhaust gas catalytic converter affected by gas velocity and inlet temperature using numerical modeling. Approach: The simulation was based on a one-dimensional time-dependent model within a single monolith channel of the converter. Upon certain assumptions, the study was considered heterogeneous combustion reaction between gas and solid phases based on lumped kinetic reactions. In this study, constants and variables used for mass and heat transfers were dependent on gas or solid phase temperature and mole fraction. Finite difference scheme incorporated with the generated computer code was established for solving species and energy balances within gas and solid phases. Results: The NO conversion was increased with transient period in initial and reached steady state at different values. The lower inlet gas temperature was resulted in lesser NO conversion at the same inlet NO concentration and gas velocity. The light-off temperatures were up to 520 K and a sudden rise in NO conversion was from 550-605 K and decreasing onwards, generating working temperature window. NO conversion increased throughout the catalyst bed from the inlet and the conversion decreased as the gas velocity increased. Conclusion/Recommendations: Gas space velocity and gas temperature intake to the converter affected the NO conversion over the time and the axial distance from the catalyst bed inlet. The numerical results have summarily demonstrated a good approximation compared to experimental data provided in the literature. Further investigation of such effects on other gaseous components is recommended for future work.

Sathaporn Chuepeng

2012-01-01

206

Temperature Modulation of a Catalytic Gas Sensor  

Directory of Open Access Journals (Sweden)

Full Text Available The use of catalytic gas sensors usually offers low selectivity, only based on their different sensitivities for various gases due to their different heats of reaction. Furthermore, the identification of the gas present is not possible, which leads to possible misinterpretation of the sensor signals. The use of micro-machined catalytic gas sensors offers great advantages regarding the response time, which allows advanced analysis of the sensor response. By using temperature modulation, additional information about the gas characteristics can be measured and drift effects caused by material shifting or environmental temperature changes can be avoided. In this work a miniaturized catalytic gas sensor which offers a very short response time (<150 ms was developed. Operation with modulated temperature allows analysis of the signal spectrum with advanced information content, based on the Arrhenius approach. Therefore, a high-precise electronic device was developed, since theory shows that harmonics induced by the electronics must be avoided to generate a comprehensible signal.

Eike Brauns

2014-10-01

207

Temperature modulation of a catalytic gas sensor.  

Science.gov (United States)

The use of catalytic gas sensors usually offers low selectivity, only based on their different sensitivities for various gases due to their different heats of reaction. Furthermore, the identification of the gas present is not possible, which leads to possible misinterpretation of the sensor signals. The use of micro-machined catalytic gas sensors offers great advantages regarding the response time, which allows advanced analysis of the sensor response. By using temperature modulation, additional information about the gas characteristics can be measured and drift effects caused by material shifting or environmental temperature changes can be avoided. In this work a miniaturized catalytic gas sensor which offers a very short response time (temperature allows analysis of the signal spectrum with advanced information content, based on the Arrhenius approach. Therefore, a high-precise electronic device was developed, since theory shows that harmonics induced by the electronics must be avoided to generate a comprehensible signal. PMID:25356643

Brauns, Eike; Morsbach, Eva; Kunz, Sebastian; Baeumer, Marcus; Lang, Walter

2014-01-01

208

Catalysts, systems and methods to reduce NOX in an exhaust gas stream  

Energy Technology Data Exchange (ETDEWEB)

Catalysts, systems and methods are described to reduce NO.sub.x emissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having an SCR catalyst comprising silver tungstate on an alumina support. The emissions treatment system may be used for the treatment of exhaust streams from diesel engines and lean burn gasoline engines. An emissions treatment system may further comprise an injection device operative to dispense a hydrocarbon reducing agent upstream of the catalyst.

Castellano, Christopher R. (Ringoes, NJ); Moini, Ahmad (Princeton, NJ); Koermer, Gerald S. (Basking Ridge, NJ); Furbeck, Howard (Hamilton, NJ)

2010-07-20

209

The Temperature Distribution in Turbulent Interstellar Gas  

OpenAIRE

We discuss the temperature distribution in a two-dimensional, thermally unstable numerical simulation of the warm and cold gas in the Galactic disk, including the magnetic field, self-gravity, the Coriolis force, stellar energy injection and a realistic cooling function. We find that ~50% of the turbulent gas mass has temperatures in what would be the thermally unstable range if thermal instability were to be considered alone. This appears to be a consequence of there being ...

Gazol, A.; Vazquez-semadeni, E.; Sanchez-salcedo, F. J.; Scalo, J.

2001-01-01

210

Temperature programmable microfabricated gas chromatography column  

Science.gov (United States)

A temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by the integration of a resistive heating element and temperature sensing on the microfabricated column. Additionally, means are provided to thermally isolate the heated column from their surroundings. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

Manginell, Ronald P.; Frye-Mason, Gregory C.

2003-12-23

211

Palladium based catalysts for exhaust aftertreatment of natural gas powered vehicles and biofuel combustion  

International Nuclear Information System (INIS)

Hydrothermally aged (1000/850C, 12/16h) Pd-Ce-supported alumina catalysts with high and low Ce content were prepared and tested in conversion of gas mixtures simulating the emissions from natural gas (NG) driven vehicles and biofuel combustion. The test procedure contained lean and rich light-off activity tests, stationary and oscillating lambda sweeps, space velocity tests as well as runs with sulphur poisoning. The catalysts exhibited high conversion of the model pollutants. In the oscillating lambda sweep experiments, the Pd-Ce/Al2O3 with high Ce loading showed high activities in conversion of CH4 and CO at lean ? values up to 1.04. Ageing under the reactants flow as well as hydrothermal treatment of the catalysts resulted in improved catalytic activities in terms of light-off temperatures of the model pollutants. This activation was believed to be a result of both Cl-release from the surface as well as restructuring of the Pd-particles. Interaction of Pd-Ce or Al-Ce induced at high temperature was also believed to affect the activation. Addition of 5ppm of SO2 into the gas mixture of simulated emissions from biofuel combustion raised the T50% of CH4 by approximately 100C. SO2-TPD experiments were used to correlate the catalytic activity to S-poisoning. The catalysts were characterised by H2-adsorption, XPS, FTIR, SO2-/NO-/O2-TPD, XRD, XRF and N22-TPD, XRD, XRF and N2-physisorption

212

Effect of ambient temperature on the performance of micro gas turbine with cogeneration system in cold region  

International Nuclear Information System (INIS)

A small-scale prime mover especially micro gas turbine is a key factor in order to widespread the utilization of biogas. It is well known that a performance of large-scale gas turbine is greatly affected by its inlet air temperature. However, the effect of the inlet air temperature on the performance of small-scale gas turbine (micro gas turbine) is not widely reported. The purpose of the present study is to investigate the effect of the inlet air temperature on the performance of a micro gas turbine (MGT) with cogeneration system (CGS) arrangement. An analysis model of the MGT-CGS was set up on the basis of experimental results obtained in a previous study and a manufacturer standard data, and it was analysed under a various ambient temperature condition in a cold region. The results show that when ambient temperature increased, electrical efficiency ?ele of the MGT decreased but exhaust heat recovery ?ehr increased. It was also found that when ambient temperature increased, exhaust heat to mass flow rate Qexe/me and exhaust heat recovery to mass flow rate Qehr/me increased, with maximum ratios of 259 kJ/kg and 200 kJ/kg, respectively were found in summer peak. Furthermore, it was also found that the exhaust heat to power ratio Qexe/Pe had a similar characteristic with exhaust heat recovery to power ratio Qehr/Pe. Qexe/Pe and Qehrub>exe/Pe and Qehr/Pe increased with the increase of ambient temperature. Moreover, although different values of total energy efficiency, fuel energy saving and CO2 reduction for every temperature condition were found comparing with a two conventional system that were considered, the MGT-CGS could annually reduce 30,000-80,000 m3/y of fuel consumption and 35-94 t-CO2/y of CO2 emissions. - Research highlights: ? Micro gas turbine cogeneration system (MGT-CGS) has higher electrical efficiency and lower exhaust heat recovery efficiency under cold condition. ? MGT-CGS has lower exhaust heat and exhaust heat recovery to power ratio under cold condition. ? The performance of MGT-CGS depends on heat and electrical demands of applied facilities, and it can decide the necessity of inlet precooling. ? MGT-CGS is very efficient on total energy efficiency, fuel saving and CO2 reduction.

213

Noble gas impurity balance and exhaust model for DIII-D and JET  

International Nuclear Information System (INIS)

Experiments to study the exhaust of noble gases (helium, neon) with cryopumping in DIII-D Advanced Divertor Program (ADP) configuration and in JET (Mk1 configuration) found significant differences in the global exhaust rate of helium, while efficient neon exhaust was observed in both machines. An attempt to better understand the basic processes governing the exhaust of noble gases in ELMy H-mode with cryopumping has been undertaken. Since divertor geometries investigated in the DIII-D and in the JET cases have significant differences, a comparative modeling study has been undertaken using the MIST core impurity transport code and the b2.5 time-independent divertor transport code. Photodiode measurements are used to determine ELM frequency, and charge-exchange recombination (CER) measurements are compared with the MIST ELM model to evaluate transport coefficients in the core plasma. A significant reduction in the anomalous diffusivities is found for the non-ELM component of radial transport without the need for a pinch velocity, and the model provides a more coherent description than the conventional ELM-averaged approach. Sensitivity to boundary conditions has been studied through establishment of a database of divertor enrichment cases using b2.5

214

The impact of using biodiesel/marine gas oil blends on exhaust emissions from a stationary diesel engine.  

Science.gov (United States)

The purpose of this work was to investigate the impact of marine gas oil (MGO)/biodiesel blends on the exhaust emissions and fuel consumption in a single cylinder, stationary, diesel engine. Three different origins of biodiesel were used as the blending feedstock with the reference MGO, at proportions of 5 and 10% by volume. Methyl esters were examined according to the automotive FAME standard EN 14214. The baseline MGO and biodiesel blends were examined according to ISO 8217:2005 specifications for the DMA category. Independently of the biodiesel used, a decrease of PM, HC, CO and CO(2) emissions was observed. Emissions of NO(x) were also lower with respect to MGO. This reduction in NO(x) may be attributed to some physicochemical properties of the fuels applied, such as the higher cetane number and the lower volatility of methyl esters. Reductions in PM for biodiesel blends were lower in the exhaust than those of the reference fuel which was attributed to the oxygen content and the near absence of sulphur and aromatics compounds in biodiesel. However, a slight increase in fuel consumption was observed for the biodiesel blends that may be tolerated due to the exhaust emissions benefits. Brake thermal efficiency was also determined. Unregulated emissions were characterized by determining the soluble organic fraction content of the particulate matter. PMID:18988104

Karavalakis, G; Tzirakis, E; Mattheou, L; Stournas, S; Zannikos, F; Karonis, D

2008-12-01

215

DEVELOPMENT AND TESTING OF AN AMMONIA REMOVAL UNIT FROM THE EXHAUST GAS OF A MANURE DRYING SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available The storage and handling of animal wastes is one of the main sources of ammonia gas emissions. Ammonia gas has a distinct, unpleasant odor and can become detrimental to the health of humans and animals at high concentrations. Ammonia emissions are of particular concern in manure drying systems, where large losses of nitrogen, in the form of ammonia can cause air quality concerns. The aim of this study was to develop an ammonia removal system for a poultry manure drying system. The thin layer drying of poultry manure in 1-3 cm thick layers resulted in effective sterilization; with the removal of 99.44-99.56% of total bacterial count, 88.51-93.705 of yeast and mold cells, 99.13-99.565 of E.coli cells, and complete removal of Salmonellae. The drying of poultry manure resulted in a large loss of nitrogen, through ammonia loss in the exhaust gasses. The use of a water scrubber resulted in a 75-99% removal of ammonia gas from the exhaust gases. The absorption of ammonia into the scrubberâ??s water resulted in an increase in pH, which subsequently fell as the drying process finished, and ammonia emission decreased. The heated air drying of poultry manure, with the use of an ammonia removal system proved effective in reducing the odor intensity and offensiveness of the poultry manure drying process, resulting in increased air quality. While producing a high value product.

A. E. Ghaly

2013-01-01

216

High temperature gas-cooled reactor  

Energy Technology Data Exchange (ETDEWEB)

As fuel of high temperature gas-cooled reactor is ceramic covered particles, non-active helium gas is used for coolant, and graphite stable even at super high temperature in helium gas is used for its structural materials, the reactor is superior in its safety and has a characteristic capable of being higher at exit temperature of the coolant than those of LWR and sodium cooled FBR. As about 30 years ago a large scale reactor of 3000 MWt class using a pressure vessel of pre-stressed concrete had been investigated, in 1980s a 350 MWt modular type steam power generation plant reappeared, and at present, modular type gas turbine power generation plant is a developing target. Here were described on technical consistency, safety, nuclear fuel cycle, economy, and future scope of the high temperature gas reactor gas turbine power generation plants, according to the results of a trusting research 'high temperature power generation system (1)' from the Ministry of Science and Technology, to JAERI by using the Electric Source Special Accounting Budget performed from 1996 to 200 fiscal years. (G.K.)

Muto, Yasushi; Kunitomi, Kazuhiko [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

2001-10-01

217

High temperature gas-cooled reactor  

International Nuclear Information System (INIS)

As fuel of high temperature gas-cooled reactor is ceramic covered particles, non-active helium gas is used for coolant, and graphite stable even at super high temperature in helium gas is used for its structural materials, the reactor is superior in its safety and has a characteristic capable of being higher at exit temperature of the coolant than those of LWR and sodium cooled FBR. As about 30 years ago a large scale reactor of 3000 MWt class using a pressure vessel of pre-stressed concrete had been investigated, in 1980s a 350 MWt modular type steam power generation plant reappeared, and at present, modular type gas turbine power generation plant is a developing target. Here were described on technical consistency, safety, nuclear fuel cycle, economy, and future scope of the high temperature gas reactor gas turbine power generation plants, according to the results of a trusting research 'high temperature power generation system (1)' from the Ministry of Science and Technology, to JAERI by using the Electric Source Special Accounting Budget performed from 1996 to 200 fiscal years. (G.K.)

218

Temperature dependence of the MDT gas gain  

CERN Document Server

This note describes the measurements taken in the Gamma Irradiation Facility (GIF) in the X5 test beam area at CERN to investigate the temperature dependence of the MDT drift gas (Ar/CO2 - 90:10). Spectra were taken with an Americium-241 source during the aging studies. We analysed the effects of temperature changes on the pulse height spectrum.

Gaudio, G; Treichel, M

1999-01-01

219

Noble Gas Temperature Proxy for Climate Change  

Science.gov (United States)

Noble gases in groundwater appear to offer a practical approach for quantitatively determining past surface air temperatures over recharge areas for any watershed. The noble gas temperature (NGT) proxy should then permit a paleothermometry of a region over time. This terrestria...

220

Method to manufacture a support matrix for a catalytic reactor for cleaning the exhaust gas of internal combustion engines of motor cars  

Energy Technology Data Exchange (ETDEWEB)

The support matrix of a catalytic reactor for cleaning the exhaust gas of motor car internal combustion engines is made of sheet steel resistant to high temperatures and is coated with catalyst, where the sheet steel can be smooth or corrugated and is arranged in alternate layers. The purpose of the invention is to provide a simple, adaptable soldering process which can be used for different shapes of matrices. According to the invention, the problem is solved by having degreased or pickled smooth or corrugated steel sheets in alternate layers and applying the solder in strips in the direction of the corrugations of the corrugated sheet steel or at right angles to them. By heating the matrix, the layers are soldered together. It is better that the steel sheets have solder applied to them from storage vessels filled with liquid solder via wetting rollers before assembling the steel sheets forming the matrix.

Nonnenmann, M.; Oltmanns, H.; Hohhaeusel, M.

1979-06-19

221

Medium temperature carbon dioxide gas turbine reactors  

International Nuclear Information System (INIS)

Carbon dioxide (CO2) partial pre-cooling and partial condensation gas turbine cycles attain comparable cycle efficiencies of 46 to 48% at medium temperature of 650degC with a typical helium (He) gas turbine cycle of PBMR (45.3%) at 900degC. This higher efficiency is ascribed to: reduced compression work around the critical point of CO2 and in the liquid phase (only available in the partial condensation cycle); and consideration of variation in CO2 specific heat at constant pressure, Cp, with temperature and pressure into cycle configuration. Compared to He cycles, the CO2 cycle gas turbomachinery weight is about one-fifth while recuperator size is comparable. Considering these results, power generation cost per unit electricity is evaluated to be lower for the CO2 cycle than in the He cycle. At medium temperature of 650degC, corrosion resistance of materials and reliability of components in CO2 have been proven during extensive operation in AGRs. Lowering temperature to 650degC provides flexibility in choosing materials and eases maintenance through the lower diffusion leak rate of fission products from coated particle fuel. The proposed medium temperature CO2 gas turbine reactors are expected to be alternative solutions to current high temperature He gas turbine reactors. (author)

222

Influence of steam injection through exhaust heat recovery on the design performance of solid oxide fuel cell . gas turbine hybrid systems  

International Nuclear Information System (INIS)

This study analyzed the influence of steam injection on the performance of hybrid systems combining a solid oxide fuel cell and a gas turbine. Two different configurations (pressurized system and ambient pressure system) were examined and the effects of injecting steam, generated by recovering heat from the exhaust gas, on system performances were compared. Performance variations according to the design of different turbine inlet temperatures were examined. Two representative gas turbine pressure ratios were used. Without steam injection, the pressurized system generally exhibits higher system efficiency than the ambient pressure system. The steam injection augments gas turbine power, thus increasing the power capacity of the hybrid system. The power boost effect due to the steam injection is generally greater in the relatively higher pressure ratio design in both the pressurized and ambient pressure systems. The effect of the steam injection on system efficiency varies depending on system configurations and design conditions. The pressurized system hardly takes advantage of the steam injection in terms of system efficiency. On the other hand, the steam injection contributes to the efficiency improvement of the ambient pressure system in some design conditions. In particular, a higher pressure ratio provides a better chance of efficiency increase due to the steam injection

223

Response to 'Comment on 'Experimental observation of carbon dioxide reduction in exhaust gas from hydrocarbon fuel burning'' [Phys. Plasmas 17, 014701 (2010)  

International Nuclear Information System (INIS)

A high-voltage cathode initiates an electron emission, resulting in a reduction in the carbon dioxide concentration in exhaust gas from the burning of hydrocarbon fuel. Assuming that the observed carbon dioxide reduction is originated from the molecular decomposition, the energy needed for the endothermic reaction of this carbon dioxide reduction may stem primarily from the internal energy reduction in the exhaust gas in accordance of the first law of the thermodynamics. An oxygen increase due to the reduction in carbon dioxide in a discharge gas was observed in real time.

224

Finite-temperature trapped dipolar Bose gas  

OpenAIRE

We develop a finite temperature Hartree theory for the trapped dipolar Bose gas. We use this theory to study thermal effects on the mechanical stability of the system and density oscillating condensate states. We present results for the stability phase diagram as a function of temperature and aspect ratio. In oblate traps above the critical temperature for condensation we find that the Hartree theory predicts significant stability enhancement over the semiclassical result. B...

Bisset, R. N.; Baillie, D.; Blakie, P. B.

2012-01-01

225

Quantification of diesel exhaust gas phase organics by a thermal desorption proton transfer reaction mass spectrometer  

Science.gov (United States)

A new approach was developed to measure the total abundance of long chain alkanes (C12 and above) in urban air using thermal desorption with a proton transfer reaction mass spectrometer (PTR-MS). These species are emitted in diesel exhaust and may be important precursors to secondary organic aerosol production in urban areas. Long chain alkanes undergo dissociative proton transfer reactions forming a series of fragment ions with formula CnH2n+1. The yield of the fragment ions is a function of drift conditions. At a drift field strength of 80 Townsends, the most abundant ion fragments from C10 to C16 n-alkanes were m/z 57, 71 and 85. The PTR-MS is insensitive to n-alkanes less than C8 but displays an increasing sensitivity for larger alkanes. Higher drift field strengths yield greater normalized sensitivity implying that the proton affinity of the long chain n-alkanes is less than H2O. Analysis of diesel fuel shows the mass spectrum was dominated by alkanes (CnH2n+1), monocyclic aromatics, and an ion group with formula CnH2n-1 (m/z 97, 111, 125, 139). The PTR-MS was deployed in Sacramento, CA during the Carbonaceous Aerosols and Radiative Effects Study field experiment in June 2010. The ratio of the m/z 97 to 85 ion intensities in ambient air matched that found in diesel fuel. Total diesel exhaust alkane concentrations calculated from the measured abundance of m/z 85 ranged from the method detection limit of ~1 ?g m-3 to 100 ?g m-3 in several air pollution episodes. The total diesel exhaust alkane concentration determined by this method was on average a factor of 10 greater than the sum of alkylbenzenes associated with spark ignition vehicle exhaust.

Erickson, M. H.; Wallace, H. W.; Jobson, B. T.

2012-02-01

226

Improving engine efficiency by extracting laser energy from hot exhaust gas  

International Nuclear Information System (INIS)

We show that it is possible to improve the efficiency of a classical Otto-cycle heat engine by adding a high-Q microwave cavity and a laser system that can extract coherent laser energy from thermally excited 'exhaust' atoms. This improvement does not violate the second law of thermodynamics, i.e., we show that a combined high-Q microwave cavity and a laser system does not improve the efficiency of a classical Carnot-cycle heat engine

227

Catalysts to reduce NO.sub.x in an exhaust gas stream and methods of preparation  

Energy Technology Data Exchange (ETDEWEB)

Catalysts, systems and methods are described to reduce NO.sub.x emissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having a catalyst comprising silver on a particulate alumina support, the silver having a diameter of less than about 20 nm. Methods of manufacturing catalysts are described in which ionic silver is impregnated on particulate hydroxylated alumina particles.

Koermer, Gerald S. (Basking Ridge, NJ); Moini, Ahmad (Princeton, NJ); Furbeck, Howard (Hamilton, NJ); Castellano, Christopher R. (Ringoes, NJ)

2012-05-08

228

Catalysts to reduce NO.sub.x in an exhaust gas stream and methods of preparation  

Energy Technology Data Exchange (ETDEWEB)

Catalysts, systems and methods are described to reduce NO.sub.x emissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having a catalyst comprising silver and a platinum group metal on a particulate alumina support, the atomic fraction of the platinum group metal being less than or equal to about 0.25. Methods of manufacturing catalysts are described in which silver is impregnated on alumina particles.

Castellano, Christopher R. (Ringoes, NJ); Moini, Ahmad (Princeton, NJ); Koermer, Gerald S. (Basking Ridge, NJ); Furbeck, Howard (Hamilton, NJ); Schmieg, Steven J. (Troy, MI); Blint, Richard J. (Shelby Township, MI)

2011-05-17

229

Emission characteristics of iso-propanol/gasoline blends in a spark-ignition engine combined with exhaust gas re-circulation  

Directory of Open Access Journals (Sweden)

Full Text Available Experiments were carried out in a spark-ignition engine fueled with iso-propanol/gasoline blends. Emission characteristics of this engine were investigated experimentally, including gaseous emissions (HC, CO, NOx and particulate matter emission in term of number and size distributions. The effects of different iso-propanol percentages, loads and exhaust gas recirculation rates on emissions were analyzed. Results show that the introduction of exhaust gas recirculation reduces the NOx emission and NOx emission gives the highest value at full load condition. HC and CO emissions present inconspicuous variations at all the loads except the load of 10%. Additionally, HC emission shows a sharp increase for pure propanol when the exhaust gas recirculation rate is up to 5%, while little variation is observed at lager exhaust gas recirculation rates. Moreover, the particulate matter number concentration increases monotonically with the increase of load and the decrease of exhaust gas recirculation rate. There exists a critical spark timing that produces the highest particulate matter number concentration at all the blending ratios.

Gong Jing

2014-01-01

230

Exhaust Gas Recirculation Cooler Fouling in Diesel Applications: Fundamental Studies Deposit Properties and Microstructure  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on the results of experimental efforts aimed at improving the understanding of the mechanisms and conditions at play in the fouling of EGR coolers. An experimental apparatus was constructed to utilize simplified surrogate heat exchanger tubes in lieu of full-size heat exchangers. The use of these surrogate tubes allowed removal of the tubes after exposure to engine exhaust for study of the deposit layer and its properties. The exhaust used for fouling the surrogate tubes was produced using a modern medium-duty diesel engine fueled with both ultra-low sulfur diesel and biodiesel blends. At long exposure times, no significant difference in the fouling rate was observed between fuel types and HC levels. Surface coatings for the tubes were also evaluated to determine their impact on deposit growth. No surface treatment or coating produced a reduction in the fouling rate or any evidence of deposit removal. In addition, microstructural analysis of the fouling layers was performed using optical and electron microscopy in order to better understand the deposition mechanism. The experimental results are consistent with thermophoretic deposition for deposit formation, and van der Waals attraction between the deposit surface and exhaust-borne particulate.

Storey, John Morse [ORNL; Sluder, Scott [ORNL; Lance, Michael J [ORNL; Styles, Dan [Ford Motor Company; Simko, Steve [Ford Motor Company

2013-01-01

231

Dynamic exhaust gas measurements with a laser mass spectrometer; Dynamische Abgasmessungen mit einem Laser-Massenspektrometer  

Energy Technology Data Exchange (ETDEWEB)

The optimization of the instationary engine operation will be one of the main efforts to reduce the emission of pollutants from combustion engines. The reported measurement system, developed by Bruker-Franzen Analytik GmbH, Dornier GmbH and the TU Muenchen, meets the requirements of the dynamic exhaust analysis, i.e. the measurement of the individual exhaust compounds with combustion cycle resolution. The system consists of a mass spectrometer combined with a laser ion source and a special inlet probe. Results at a motor test stand how the time-resolved concentration of representative exhaust compounds at instationary engine operation such as sudden change of speed and load, misfirings and engine control effects. (orig.) [Deutsch] Zur Verminderung der Schadstoffemissionen von Verbrennungsmotoren kann die Optimierung des instationaeren Motorbetriebes einen wichtigen Beitrag leisten. Das vorgestellte Messsystem ermoeglicht prinzipiell die dazu erforderliche Analyse der individuellen Abgasinhaltsstoffe mit Arbeitsspiel-Aufloesung. Es besteht im wesentlichen aus einem Massenspektrometer mit einer Laser-Ionenquelle und einem speziellen Probennahme- und Einlasssystem. Anwendungen am Motorpruefstand zeigen den zeitaufgeloesten Konzentrationsverlauf von repraesentativen Abgaskomponenten bei instationaeren Betriebsweisen, zum Beispiel bei Last- und Drehzahlwechsel, Zuendaussetzern und Regeleffekten. Das beschriebene Messsystem wurde in einem Verbundprojekt von Bruker-Franzen Analytik GmbH, Dornier GmbH sowie der Technischen Universitaet Muenchen entwickelt. (orig.)

Frey, R.; Nagel, H.; Franzen, J.; Betzold, H.; Ulke, W.; Boesl, U.

1995-10-01

232

Identification of nitroaromatics in diesel exhaust particulate using gas chromatography/negative ion chemical ionization mass spectrometry and other techniques  

Energy Technology Data Exchange (ETDEWEB)

A series of nitroaromatic compounds were identified in diesel exhaust particulate extract. Isomers of nitroanthracene (and/or nitrophenanthrene) and nitropyrene (and/or nitrofluoranthene) were unequivocally identified. Alkyl homologues of nitroanthracene through C/sub 3/-alkyl-nitroanthracene were tentatively identified. In addition, a C/sub 18/H/sub 11/NO/sub 2/ isomer was tentatively identified. The nitro-substituted polynuclear aromatic hydrocarbons (PAHs) were found in two fractions of diesel exhaust particulate extract collected from a low-pressure liquid chromatography (LPLC) column. One of the two fractions containing nitroaromatic constitutents accounted for a large percentage of the mutagenicity of the crude particulate extract. Initial identification were made by using high-resolution gas chromatography/electron impact mass spectrometry/computer (GC/EIMS) and negative ion chemical ionization mass specrometry/computer (GC/NICIMS). These identifications were confirmed by direct probe high-resolution mass spectrometry (HRMS) and gas chromatography/Fourier transform infrared spectrometry (GC/FT IR). The relative merit of each analytical technique for the determination of nitroaromatics is discussed with emphasis on the usefulness of GC/NICIMS as a means of analyzing for nitro-substituted PAHs.

Newton, D.L. (Research Triangle Inst., NC); Erickson, M.D.; Tomer, K.B.; Pellizzari, E.D.; Gentry, P.

1982-04-01

233

Potassium promoted iron oxide catalysts for simultaneous catalytic removal of nitrogen oxides and soot from diesel exhaust gas  

International Nuclear Information System (INIS)

This paper deals with the preparation and modification of iron oxide catalysts with different alkali metals. Among the prepared catalysts, Fe1.9K0.1O3 proved to be the most promising catalyst for the simultaneous removal of NOx and soot from diesel engines exhaust and was selected for the rest of investigations. The present study has shown that long-time treatment leads to a decline in the activity, and remains constant after at least 20 TPR experiments. This shows that the used catalysts still possess considerable activity. On the other hand long-time treatment causes a significant enhancement of N2 selectivity, and the formation of by-product N2O was not observed. This alteration of catalytic performance is likely due to agglomeration of the promoter potassium being present at surface. Catalytic performance of the used Fe1.9K0.1O3 catalyst was also carried out in a more realistic diesel exhaust gas with two different types of feed gas compositions. This study confirms that Fe1.9K0.1O3 is a suitable catalyst for simultaneous removal of soot and NOx between 350 and 480C. It is assumed that (CO) intermediates, formed by catalytic reaction of NOx and oxygen with soot surface, play an important role in NOx-soot conversion

234

The High Temperature Gas-Cooled Reactor  

International Nuclear Information System (INIS)

The key element in the deployment, performance, and safety of the High-Temperature Gas-Cooled Reactor (HTGR) is the utilization of proven high integrity microsphere fuel particles with their ceramic coatings which form a containment system which places primary emphasis on retention of fission products in the fuel. The basic particles can be embodied in a variety of different fuel element types, core sizes and geometries, and with a reactor outlet gas temperature capability up to 10000C, the gas-cooled reactor offers opportunities, unmatched by any other reactor type, for a wide spectrum of applications including electrical power generation, process heat supply, and propulsion. This paper highlights the versatility of the gas-cooled reactor for projected applications which will become paramount in the 21st century

235

Helium turbine power generation in high temperature gas reactor  

International Nuclear Information System (INIS)

This paper presents studies on the helium turbine power generator and important components in the indirect cycle of high temperature helium cooled reactor with multi-purpose use of exhaust thermal energy from the turbine. The features of this paper are, firstly the reliable estimation of adiabatic efficiencies of turbine and compressor, secondly the introduction of heat transfer enhancement by use of the surface radiative heat flux from the thin metal plates installed in the hot helium and between the heat transfer coil rows of IHX and RHX, thirdly the use of turbine exhaust heat to produce fresh water from seawater for domestic, agricultural and marine fields, forthly a proposal of plutonium oxide fuel without a slight possibility of diversion of plutonium for nuclear weapon production and finally the investigation of GT-HTGR of large output such as 500 MWe. The study of performance of GT-HTGR reduces the result that for the reactor of 450 MWt the optimum thermal efficiency is about 43% when the turbine expansion ratio is 3.9 for the turbine efficiency of 0.92 and compressor efficiency of 0.88 and the helium temperature at the compressor inlet is 45degC. The produced amount of fresh water is about 8640 ton/day. It is made clear that about 90% of the reactor thermal output is totally used for the electric power generation in the turbine and for the multi-puposed utilization of the heat from the turbine exhaust gas and compressed helium cooling seawater. The GT-Large HTGR is realized by the separation of the pressure and temperature boundaries of the pressure vessel, the increase of burning density of the fuel by 1.4 times, the extention of the nuclear core diameter and length by 1.2 times, respectively, and the enhancement of the heat flux along the nuclear fuel compact surface by 1.5 times by providing riblets with the peak in the flow direction. (J.P.N.)

236

Temperature Effect on the Radiation-Corrective Gas Temperature Measurement  

International Nuclear Information System (INIS)

When a thermocouple is placed in a gas flow stream, there are two sources of the bias error in gas temperature measurement, including the radiation on the thermocouple and the conduction through the sheath tube as shown in Figure 1. Especially, the radiation error is inherent due to a relatively large radiation heat transfer from a thermocouple surface to its surroundings. Two thermocouples with unequal diameters are relatively simpler than the other radiation correction methods. Kim et al. has investigated the gas temperature measurement methodology and device to correct the radiation bias effect at a very high temperature condition. In previous experiments, the method had the good applicability on the heating chamber, which had enough immersion length to neglect the conduction effect through the sheath tube. In the case of the pipe, the conduction effect through the sheath tube resulted in the overestimation of the measured temperatures between two thermocouples. In this study, the method was experimentally estimated at a higher gas temperature and larger mass flow rate than those of the previous experiments

237

Amperometric NOx-sensor for Combustion Exhaust Gas Control. Studies on transport properties and catalytic activity of oxygen permeable ceramic membranes  

International Nuclear Information System (INIS)

The aim of the research described in this thesis is the development of a mixed conducting oxide layer, which can be used as an oxygen permselective membrane in an amperometric NOx sensor. The sensor will be used in exhaust gas systems. The exhaust gas-producing engine will run in the lean mix mode. The preparation of this sensor is carried out using screen-printing technology, in which the different layers of the sensor are applied successively. Hereafter, a co-firing step is applied in which all layers are sintered together. This co-firing step imposes several demands on the selection of materials. The design specifications of the sensor further include requirements concerning the operating temperature, measurement range and overall stability. The operating temperature of the sensor varies between 700 and 850C, enabling measurement of NOx concentrations between 50 and 1200 ppm with a measurement accuracy of 10 ppm. Concerning the stability of the sensor, it must withstand the exhaust gas atmosphere containing, amongst others, smoke, acids, abrasive particles and sulphur. Because of the chosen lean-mix engine concept, in which the fuel/air mixture switches continuously between lean (excess oxygen) and fat (excess fuel) mixtures, the sensor must withstand alternately oxidising and reducing atmospheres. Besides, it should be resistant to thermal shock and show no cross-sensitivity of NOx with other exhaust gas constituents like oxygen and hydrocarbons. The response timeoxygen and hydrocarbons. The response time should be short, typically less than 500 ms. Because of the application in combustion engines of cars, the operational lifetime should be longer than 10 years. Demands on the mixed conducting oxide layer include the following ones. The layer should show minimal catalytic activity towards NOx-reduction. The oxygen permeability must be larger than 6.22 10-8 mol/cm2s at a layer thickness between 3-50 ?m. Since the mixed conducting oxide layer is coated on the YSZ electrolyte embodiment, the two materials must be co-firable and, hence, match in thermal, chemical and mechanical behaviour. A number of studies on different mixed oxygen ion/electron conducting materials is described in this thesis. Emphasis is put on the demands of the targeted sensor application, in which these materials are used as mixed conducting dense ceramic membranes. In Chapter 2, a series of perovskite materials is studied. The general composition is ABO3-? (A = Gd, Pr, Y; B = Mn, Cr, Fe), being partially doped with Ca2+ and Sr2+ on the A-site to create mobile oxygen vacancies. The main focus of the work presented is on the measurement of catalytic activities towards NOx and the ionic conductivities of the selected materials. In Chapter 3, the preparation and characterisation of a material with the overall composition of Gd0.7Ca0.3CoOx is described. Dual phase composite membranes are the subject of investigations presented in Chapters 4-7. The main advantage of these type of materials is that their properties can be tailored to meet the demands imposed by the sensor design. Emphasis is on the preparation of the materials, characterisation by SEM-EDX, XRD, catalytic activity and measurement of ionic/electronic conductivities. In Chapter 4, dual phase composites of composition Gd0.7Ca0.3CoOx/Ce0.8Gd0.2O2- are studied. Composites ZrO2/In2O3 and ZrO2/ITO are subject to the investigations reported in Chapters 5 and 6, respectively. Finally, in Chapter 7, composite Au/YSZ and Au/Ce0.8Gd0.2O2- membranes are studied. Finally, in Chapter 8 a summary of the results is given together with recommendations for future research

238

78 FR 63017 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...  

Science.gov (United States)

...Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate...amending the emission standards for turbine engine powered airplanes to incorporate...EPA also proposed adopting the gas turbine engine test procedures of...

2013-10-23

239

Design of thermoelectric generators operating on exhaust gas from marine diesel engines  

Directory of Open Access Journals (Sweden)

Full Text Available The design of thermoelectric generator (TEG, forming the exhaust system of the vessel, is offered in the paper. Thermal calculation of the TEG for the ves-sel engine, Ro-8 6VDS48/42-AL2, with the capacity of 2 650 kW is given. Values of output parameters of the TEG are comparable with output values of the pa-rameters of existing analogues. The thermoelectric generator with the received parameters can be used on a vessel as an additional source of the direct current electric power.

Khalykov Kamil Rafaelevich

2010-04-01

240

Quantification of diesel exhaust gas phase organics by a thermal desorption proton transfer reaction mass spectrometer  

Directory of Open Access Journals (Sweden)

Full Text Available A new approach was developed to measure the total abundance of long chain alkanes (C12 and above in urban air using thermal desorption with a proton transfer reaction mass spectrometer (PTR-MS. These species are emitted in diesel exhaust and may be important precursors to secondary organic aerosol production in urban areas. Long chain alkanes undergo dissociative proton transfer reactions forming a series of fragment ions with formula CnH2n+1. The yield of the fragment ions is a function of drift conditions. At a drift field strength of 80 Townsends, the most abundant ion fragments from C10 to C16 n-alkanes were m/z 57, 71 and 85. The PTR-MS is insensitive to n-alkanes less than C8 but displays an increasing sensitivity for larger alkanes. Higher drift field strengths yield greater normalized sensitivity implying that the proton affinity of the long chain n-alkanes is less than H2O. Analysis of diesel fuel shows the mass spectrum was dominated by alkanes (CnH2n+1, monocyclic aromatics, and an ion group with formula CnH2n?1 (m/z 97, 111, 125, 139. The PTR-MS was deployed in Sacramento, CA during the Carbonaceous Aerosols and Radiative Effects Study field experiment in June 2010. The ratio of the m/z 97 to 85 ion intensities in ambient air matched that found in diesel fuel. Total diesel exhaust alkane concentrations calculated from the measured abundance of m/z 85 ranged from the method detection limit of ~1 ?g m?3 to 100 ?g m?3 in several air pollution episodes. The total diesel exhaust alkane concentration determined by this method was on average a factor of 10 greater than the sum of alkylbenzenes associated with spark ignition vehicle exhaust.

M. H. Erickson

2012-02-01

241

Time resolved trace analysis of exhaust gas by means of laser mass spectrometry  

Energy Technology Data Exchange (ETDEWEB)

The large number of components and their very different and rapidly varying concentrations complicates the analysis of exhaust gases of combustion engines. Here, a new analytical technique, based on the combination of resonance enhanced multiphoton ionization, performed by pulsed tunable lasers, and time of flight mass spectrometry is presented. It allows the simultaneous detection of several trace components with concentrations ranging from 1 ppm up to several percent with a quantitative accuracy better than 10%. Time resolution of 10 ms could be achieved with this system. A preliminary list of substances detectable by this technique contains 25 substances; some of them belong to the strongest compounds inducing ozone formation. (orig.)

Weickhardt, C. [Inst. fuer Physikalische und Theoretische Chemie, Technische Univ. Muenchen, Garching (Germany); Boesl, U. [Inst. fuer Physikalische und Theoretische Chemie, Technische Univ. Muenchen, Garching (Germany)

1993-12-01

242

An experimental investigation on engine performance and emissions of a single cylinder diesel engine using hydrogen as inducted fuel and diesel as injected fuel with exhaust gas recirculation  

Energy Technology Data Exchange (ETDEWEB)

Fast depletion of fossil fuels is demanding an urgent need to carry out research work to find out the viable alternative fuels for meeting sustainable energy demand with minimum environmental impact. In the future, our energy systems will need to be renewable and sustainable, efficient and cost-effective, convenient and safe. The technology for producing hydrogen from a variety of resources, including renewable, is evolving and that will make hydrogen energy system as cost-effective. Hydrogen safety concerns are not the cause for fear but they simply are different than those we are accustomed to with gasoline, diesel and other fossil fuels. For the time being full substitution of diesel with hydrogen is not convenient but use of hydrogen in a diesel engine in dual fuel mode is possible. So Hydrogen has been proposed as the perfect fuel for this future energy system. The experiment is conducted using diesel-hydrogen blend. A timed manifold induction system which is electronically controlled has been developed to deliver hydrogen on to the intake manifold. The solenoid valve is activated by the new technique of taking signal from the rocker arm of the engine instead of cam actuation mechanism. In the present investigation hydrogen-enriched air has been used in a diesel engine with hydrogen flow rate at 0.15 kg/h. As diesel is substituted and hydrogen is inducted, the NO{sub x} emission is increased. In order to reduce NO{sub x} emission an EGR system has been developed. In the EGR system a lightweight EGR cooler has been used instead of bulky heat exchanger. In this experiment performance parameters such as brake thermal efficiency, volumetric efficiency, BSEC are determined and emissions such as oxides of nitrogen, carbon dioxide, carbon monoxide, hydrocarbon, smoke and exhaust gas temperature are measured. Dual fuel operation with hydrogen induction coupled with exhaust gas recirculation results in lowered emission level and improved performance level compared to the case of neat diesel operation. (author)

Bose, Probir Kumar; Maji, Dines [Department of Mechanical Engineering, Jadavpur University, Heat Power Laboratory, Kolkata 32, West Bengal (India)

2009-06-15

243

Noble gas exhaust with a strongly baffled divertor in ASDEX-Upgrade  

Science.gov (United States)

Since spring of 1997 ASDEX Upgrade has operated with the new divertor II (LYRA), which is characterised by vertical target plates, tight baffling towards the main chamber, and a dome baffle in the private flux region. The main goal of this divertor modification was to increase the divertor density (of the plasma and of the neutrals) for a given plasma density, whereas the neutral density in the main chamber should be similar or even lower. Pumping occurs now from the private flux region which is linked to the pump chamber by finite conductance below the outer target. A cryo pump (about 100 m 3/s) has been installed in the outer divertor chamber in addition to the turbo pumps. This divertor scheme is very similar to the one planned for ITER. First experiments with the new divertor indicate that the compression of helium, CHe (the ratio of neutral He density in the divertor to the He density at the plasma edge) is much higher in the new divertor, while the neon exhaust efficiency has decreased. The cryo pump can strongly enhance the scrape-off layer flow of deuterium (by a factor of about 3), resulting in a small improvement of the He exhaust rate.

Bosch, H.-S.; Ullrich, W.; Bard, A.; Coster, D.; Haas, G.; Kallenbach, A.; Neuhauser, J.; Schneider, R.; ASDEX Upgrade Team

244

Exhaust Gas Analysis and Parametric Study of Ethanol Blended Gasoline Fuel in Spark Ignition Engine  

Directory of Open Access Journals (Sweden)

Full Text Available It is well known that the future availability of energy resources, as well as the need for reducing CO2 emissions from the fuels used has increased the need for the utilization of regenerative fuels. This research is done taking commercial gasoline as reference which is originally blended with 5% ethanol. Hence 5%, 10%, 15%, 20% ethanol blended with Gasoline initially was tested in SI engines. Physical properties relevant to the fuel were determined for the four blends of gasoline. A four cylinder, four stroke, varying rpm, Petrol (MPFI engine was tested on blends containing 5%,10%,15%,20% ethanol and performance characteristics, and exhaust emissions were evaluated. Even though higher blends can replace gasoline in a SI engine, results showed that there is a reduction in exhaust gases, such as HC, O2, CO, CO2 and increase in Brake Thermal Efficiency on blending. Hence we can conclude from the result that using 10% ethanol blend is most effective and we can utilize it for further use in SI engines with little constraint on material used to sustain little increase in pressure.

Jitendra kumar

2013-07-01

245

Sensitive detection of NO in exhaust gas with a frequency-modulated, distributed-feedback, quantum-cascade laser  

Science.gov (United States)

Measurements of NO concentrations at sub-ppm levels in vehicle exhaust are needed for emission certification of future ultra-low emission vehicles. We demonstrate a laser-based system that can measure NO at a few ppb in exhaust gas. A distributed-feedback quantum cascade laser operating cw at 90 K is frequency modulated at f = 1 kHz and locked to the center of a transition at ~ 1921 cm-1 in the fundamental band of NO. Part of the beam is passed through a reference cell with 0.5% NO/N2 and then onto a detector whose demodulated signal at 1f is fed back to control the laser frequency. The rest of the beam passes through a long-pass (100 m) cell and onto a detector whose demodulated signal at 2f directly measures the NO concentration. Doppler broadening, pressure broadening, and unresolved ? doubling combine to yield a pressure for optimum sensitivity of 100 Torr and a modulation amplitude of ~ 750 MHz. The rms error (1?) in the 2f signal corresponds to an uncertainty of ± 1 ppb, but systematic errors associated with adsorption and desorption of NO on the cell walls and plumbing can greatly exceed this random error.

Weber, W. H.; Remillard, J. T.; Uy, D.; Gmachl, C.; Capasso, F.; Hutchinson, A. L.; Sivco, D. L.; Baillargeon, J. N.; Cho, A. Y.

2001-03-01

246

Argon/UF6 plasma exhaust gas reconstitution experiments using preheated fluorine and on-line diagnostics. [fissioning uranium plasma core reactor design  

Science.gov (United States)

The feasibility of employing a flowing, high-temperature, pure fluorine/UF6 regeneration system to efficiently convert a large fraction of the effluent plasma exhaust back to pure UF6 was demonstrated. The custom built T.O.F. mass spectrometer sampling system permitted on-line measurements of the UF6 concentration at different locations in the exhaust system. Negligible amounts ( 100 ppm) of UF6 were detected in the axial bypass exhaust duct and the exhaust ducts downstream of the cryogenic trap system used to collect the UF6, thus verifying the overall system efficiency over a range of operating conditions. Use of a porous Monel duct as part of the exhaust duct system, including provision for injection of pure fluorine, provided a viable technique to eliminate uranium compound residue on the inside surface of the exhaust ducts. Typical uranium compound mass deposition per unit area of duct was 2 micron g/sq cm. This porous duct technique is directly applicable to future uranium compound transfer exhaust systems. Throughout these experiments, additional basic data on the corrosion aspects of hot, pressurized UF6/fluorine were also accumulated.

Roman, W. C.

1979-01-01

247

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

Science.gov (United States)

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.

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

2012-06-01

248

The study of heat transfer for nanofluid with carbon nano particle in an exhaust gas recirculation (EGR) cooler  

Science.gov (United States)

A carbon nanofluid was adapted to examine the characteristics of its cooling performance in an exhaust gas recirculation (EGR) cooler, compared with that of the usual working fluid water. After steady state, the heat transfer rate of water became nearly constant; however, that of the nanofluid showed a slight increase, suggesting that something happened to the nanofluid. The result shows that the cooling performance of the carbon nanofluid was a little better than that of water; however, its performance data improved with time while those of water were stable. It shows that assembly of the carbon nanoparticles changed with its circulation through the EGR cooler and the shape of the particle assembly depended on the dispersion method employed.

Kim, Seongsoo; Chung, Hanshik; Jeong, Hyomin; Lee, Byungho; Ochirkhuyag, Bayanjargal; Lee, Jehyun; Choi, Heekyu

2013-07-01

249

The Use of Exhaust Gas Recirculation to Optimize Fuel Economy and Minimize Emission in Engines Operating on E85 Fuel  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes activities conducted for the project “The Use of Exhaust Gas Recirculation to Optimized Fuel Economy and Minimize Emissions in Engines Operating on E85 Fuel” under COOPERATIVE AGREEMENT NUMBER DE-FC26-07NT43271, which are as outlined in the STATEMENT OF PROJECT OBJECTIVES (SOPO) dated March 2007 and in the supplemental SOPO dated October 2010. The project objective was to develop and demonstrate an internal combustion engine that is optimized for E85 (85% ethanol and 15% gasoline) fuel operation to achieve substantially improved fuel economy while operating with E85 fuel and that is also production viable in the near- to medium-term. The key engine technology selected for research and development was turbocharging, which is known to improve fuel economy thru downsizing and is in particular capable of exploiting ethanol fuel’s characteristics of high octane number and high latent heat of vaporization. The engine further integrated synergistic efficiency improving technologies of cooled exhaust gas recirculation (EGR), direct fuel injection and dual continuously variable intake and exhaust cam phasers. On the vehicle level, fuel economy was furthered thru powertrain system optimization by mating a state-of-the-art six-speed automatic transmission to the engine. In order to achieve the project’s objective of near- to medium-term production viability, it was essential to develop the engine to be flex-fuel capable of operating with fuels ranging from E0 (0% ethanol and 100% gasoline) to E85 and to use three-way type of catalyst technology for exhaust aftertreatment. Within these scopes, various technologies were developed through systems approach to focus on ways to help accelerate catalyst light-off. Significant amount of development took place during the course of the project within General Motors, LLC. Many prototype flex-fuel engines were designed, built and developed with various hardware configurations selected to achieve the project goals. Several flex-fuel demonstration vehicles were designed and built for carrying out calibration development and final testing to quantify the technology merits. Based on the extensive test results collected from dynamometer and vehicle testing, the fuel economy benefits of cooled EGR from the intended level of turbocharger technology were quantified. When combined with turbo downsizing, the FE benefits are considered large enough for E0 fuel as well as for E85 fuel to warrant further development of the technology beyond the current proof-of-concept level to a level that can meet production driveability quality and durability requirements in order to meet customers’ expectations. Cold-start cart test results from the emissions segment of the project were positive, confirming the assumption of faster thermal response of turbo exhaust system for emissions reductions for both E0 and E85 fuels. Vehicle emissions test results directionally correlated to the cold-start cart findings. The limited number of test runs did demonstrate the potentials of meeting stringent emission standards, however, they did not comprehend the factors such as hardware variability and long-term durability, 3 which are essential for mass production to satisfy customers’ expectations. It is therefore recommended, moving forward, durability concerns over turbocharger, EGR system and aftertreatment system, which would likely impact production viability, should be addressed. The data moreover suggested that further FE increase is likely with turbocharger technology advancement.

Wu, Ko-Jen

2011-12-31

250

Study on Thermal Conductivity Gas Sensor Constant Temperature Detection Method  

Directory of Open Access Journals (Sweden)

Full Text Available The thermal conductivity gas sensor can detect gas concentration that measure the thermal conductivity coefficient of the measured gas different from the background gas.This paper analyzes the theory of thermal conductivity gas sensor and method of measurement,proposes thermal conductivity gas sensor constant temperature detection method,and experimentally validate the feasibility of ambient temperature compensation. Experimental results show that the method effectively reduces the effect of ambient temperature on measuring accuracy.

Xi-bo Ding

2013-11-01

251

Measurements of the relative intensity of ship exhaust gas as a function of distance to infrared sensors  

Science.gov (United States)

We present results from infrared imaging experiments, performed under hot and humid conditions at Chesapeake Bay, Maryland, USA in the summer of 2006. Specifically, the objective was to study the intensity of the exhaust gases from a ship at different distances. In particular there is an interest to quantify the intensity decrease of the plume with distance and correlate this with simulations of atmospheric transmission. For this purpose the ship ran a predetermined course making broad-side passes at predetermined distances from the shore-based IR camera as part of the course. The distances were 1.6, 2.4, 3.2, 4, 6, and 8 km. The cameras are sensitive in the 3 - 5 ?m and 8 - 12 ?m wavelength ranges. Digital recordings were made during the ship broad-side passes. It is challenging to identify gas cloud pixels against a background because the pixels are not necessarily clustered. We present a statistical method to identify the gas cloud pixels, calculate their average intensity, and determine the contrast between the gas pixels and the background pixels as a function of distance. The contrast versus distance data are then compared with simulations using standard atmospheric transmission software.

van Rheenen, Arthur D.; Brendhagen, Erik; Heen, Lars Trygve; Madsen, Eirik Blix; Fonnum, Helge; Steenfeldt-Foss, Pål; Wikan, Kjell; Almklov, Bernt

2007-10-01

252

Equilibrium molecular dynamics and mean first passage time analysis of the separation of exhaust gases at high temperatures by silica nanoporous membranes  

International Nuclear Information System (INIS)

An investigation of mechanisms associated with the high selectivity of a gas mixture at high temperatures by silica nanoporous membranes has been conducted in the framework of equilibrium classical molecular dynamic simulations and formalism of fractional diffusion equation on a sample of a gas mixture of exhaust gases. The important feature is the quite realistic modeling of the silica nanoporous membranes based on the use of an analytic bond order potential and the conception of dangling bonds. The last two were successfully employed to model the realistic silica chemical vapor deposition process (Burlakov et al 2001 Phys. Rev. Lett. 86 3052). The dependence of the selective properties on temperature, density (voidage volume) and morphology has been investigated. The selectivity at a low temperature (673?K) is found to be more efficient than at a high temperature (873?K). When only Lennard-Jones interaction between a gas and a solid is included the selectivity is found to be changed at the low temperature (673?K) from 1.2?:?1 for a density of 50% to 1.03?:?1 for a density of 80%. Including an additional electrostatic interaction increases the selectivity from 1.79?:?1 for a density of 50% to 2.26?:?1 for a density of 80%. At the high temperature (873?K) when only Lennard-Jones potential is included the selectivity is found to be changed from 1.21?:?1 for a density of 50% to 1.13?:?1 for a density of 80%. With an additional electrostatic force the selectivity is found to be the same for all densities at around 1.43?:?1. The conclusion is that the most efficient conditions for the selective membrane are a temperature of 673?K and a high density. Under these conditions the mean first passage times for species O2 and N2 are almost the same and much less than for species CO2. The methodology developed is general. This paper is based on the author's PhD thesis

253

Device for the removal of sulfur dioxide from exhaust gas by pulsed energization of free electrons  

International Nuclear Information System (INIS)

The performance of a new device using pulsed streamer corona for the removal of sulfur dioxide from humid air has been evaluated. The pulsed streamer corona produced free electrons which enhance gas-phase chemical reactions, and convert SO2 to sulfuric acid mist. The SO2 removal efficiency was compared with that of the electron-beam flue-gas treatment process. The comparison demonstrates the advantage of the novel device

254

IAEA high temperature gas cooled reactor activities  

International Nuclear Information System (INIS)

IAEA activities on high temperature gas cooled reactors are conducted with the review and support of Member States, primarily through the International Working Group on Gas Cooled Reactors (IWGGCR). This paper summarises the results of the IAEA gas cooled reactor project activities in recent years along with ongoing current activities through a review of Co-ordinated Research Projects (CRPs), meetings and other international efforts. A series of three recently completed CRPs have addressed the key areas of reactor physics for LEU fuel, retention of fission products, and removal of post shutdown decay heat through passive heat transport mechanisms. These activities along with other completed and ongoing supporting CRPs and meetings are summarised with reference to detailed documentation of the results. (author)

255

Operational experience with an innovative 190 kW CHP unit with gas engine and exhaust gas recirculation; Erfahrungsbericht ueber die Erprobung eines innovativen 190 kW Gasmotor-BHKW mit integrierter Abgasrueckfuehrung  

Energy Technology Data Exchange (ETDEWEB)

In February 2003 a CHP unit of the type TBG 926 EGR started operation at RWE Rhein-Ruhr AG in Duisburg. This installation represents one of the first of this type in Germany. Until December 2005 the unit reached more than 14 500 hours of successful operating and testing. The unit was built by a company called Menag Energie AG from Switzerland. The electrical and thermal output is supposed to be 190 and 256 kW at a hot water temperature of 85 C. During the test run it was possible to confirm the performance data and specially the low emissions proposed by the manufacturer. The following article will describe the innovative design using the exhaust gas recirculation. Furthermore it shows the results of the test run and gives estimation about the usability of this innovative CHP system. (orig.)

Dietze, U. [T.B.E. - Technische Beratung Energie GmbH, Duisburg (Germany)

2006-02-15

256

Inhalation of diesel engine exhaust affects spermatogenesis in growing male rats; Diesel enigne hai gas bakuro ni yoru seicho yusei rat no seishi keisei eno eiky  

Energy Technology Data Exchange (ETDEWEB)

The paper investigated effects of the exposure of diesel engine exhaust on internal secretion function of genital organs of rats being in growth. Exposure tests were divided into a group of exposing rats to total exhaust gas (TG), a group of exposing rats to particulate-free exhaust gas (PFG), and a group of exposing rats to clean air (comparison group). The tests were carried out for 6 hours/day, for 5 days/week, and for 3 months from the birth. As to the weight at the time of finishing tests, there were no significant differences in weights of testicle and epididymis in each group. About the concentration of male/female sex hormones in serum, the values were significantly higher in TG and PFG groups than the comparison group. The follide stimulating hormone significantly decreased in both exposure groups as compared with the comparison group. The luteinizing hormone significantly decreased in TG group as compared with the comparison group and PFG group. Further, the sperm productivity and testicle hyaluronidase activity significantly decreased in both exhaust exposure groups as compared with the comparison group. It is indicated that the diesel engine exhaust stimulates the secretion of adrenal cortical hormone, reduces emission of gonadotropic hormone, and controls the spermatogenesis of rats. (NEDO)

Kawai, A. [Japan Automobile Research Institute Inc., Tsukuba (Japan)

2000-04-01

257

Control of PCDDs/PCDFs, PCBs and PAHs emissions in exhaust of landfill gas fed engines  

Energy Technology Data Exchange (ETDEWEB)

Wallonia in Belgium, like many countries around the world, planned to reduce amounts of waste generated by human activity and stored in landfills. Since they experienced a couple of crisis situations in the past, both with former and presently used landfill sites, authorities launched a demanding landfill monitoring program which covers now 9 out of the 10 major sites. Biogas produced in these landfills are collected and eliminated in two different ways. Either simply burned in a flare, or, when the methane grade and flow are high enough, the biogas can be burned in electricity producing engines. This later use represents an energy recovery from the waste. In the context of difficulty for landfill sites to be accepted by the public (the well-known NIMBY phenomenon), the question has been raised whether combustion of the biogas did not entail production of dioxins and other polyaromatic compounds. For the exhaust gases of engines operated with biogas, a check on the presence of dioxins and associated organic pollutants, composed of three different runs or days of sampling for each of 5 landfill sites was performed upon demand of responsible authorities.

Idczak, F.; Dengis, P.; Duchateau, P.; Petitjean, S. [ISSeP, Liege (Belgium)

2004-09-15

258

Low-temperature gas from marine shales: wet gas to dry gas over experimental time  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Marine shales exhibit unusual behavior at low temperatures under anoxic gas flow. They generate catalytic gas 300° below thermal cracking temperatures, discontinuously in aperiodic episodes, and lose these properties on exposure to trace amounts of oxygen. Here we report a surprising reversal in hydrocarbon generation. Heavy hydrocarbons are formed before light hydrocarbons resulting in wet gas at the onset of generation grading to dryer gas over time. The effect is moderate under gas flow and substantial in closed reactions. In sequential closed reactions at 100°C, gas from a Cretaceous Mowry shale progresses from predominately heavy hydrocarbons (66% C5, 2% C1 to predominantly light hydrocarbons (56% C1, 8% C5, the opposite of that expected from desorption of preexisting hydrocarbons. Differences in catalyst substrate composition explain these dynamics. Gas flow should carry heavier hydrocarbons to catalytic sites, in contrast to static conditions where catalytic sites are limited to in-place hydrocarbons. In-place hydrocarbons and their products should become lighter with conversion thus generating lighter hydrocarbon over time, consistent with our experimental results. We recognize the similarities between low-temperature gas generation reported here and the natural progression of wet gas to dry gas over geologic time. There is now substantial evidence for natural catalytic activity in source rocks. Natural gas at thermodynamic equilibrium and the results reported here add to that evidence. Natural catalysis provides a plausible and unique explanation for the origin and evolution of gas in sedimentary basins.

Jarvie Daniel M

2009-11-01

259

Low-temperature gas from marine shales: wet gas to dry gas over experimental time.  

Science.gov (United States)

Marine shales exhibit unusual behavior at low temperatures under anoxic gas flow. They generate catalytic gas 300 degrees below thermal cracking temperatures, discontinuously in aperiodic episodes, and lose these properties on exposure to trace amounts of oxygen. Here we report a surprising reversal in hydrocarbon generation. Heavy hydrocarbons are formed before light hydrocarbons resulting in wet gas at the onset of generation grading to dryer gas over time. The effect is moderate under gas flow and substantial in closed reactions. In sequential closed reactions at 100 degrees C, gas from a Cretaceous Mowry shale progresses from predominately heavy hydrocarbons (66% C5, 2% C1) to predominantly light hydrocarbons (56% C1, 8% C5), the opposite of that expected from desorption of preexisting hydrocarbons. Differences in catalyst substrate composition explain these dynamics. Gas flow should carry heavier hydrocarbons to catalytic sites, in contrast to static conditions where catalytic sites are limited to in-place hydrocarbons. In-place hydrocarbons and their products should become lighter with conversion thus generating lighter hydrocarbon over time, consistent with our experimental results. We recognize the similarities between low-temperature gas generation reported here and the natural progression of wet gas to dry gas over geologic time. There is now substantial evidence for natural catalytic activity in source rocks. Natural gas at thermodynamic equilibrium and the results reported here add to that evidence. Natural catalysis provides a plausible and unique explanation for the origin and evolution of gas in sedimentary basins. PMID:19900271

Mango, Frank D; Jarvie, Daniel M

2009-01-01

260

Modelling diesel engines with a variable-geometry turbocharger and exhaust gas recirculation by optimization of model parameters for capturing non-linear system dynamics  

OpenAIRE

A mean-value model of a diesel engine with a variable-geometry turbocharger (VGT) and exhaust gas recirculation (EGR) is developed, parameterized, and validated. The intended model applications are system analysis, simulation, and development of model-based control systems. The goal is to construct a model that describes the gas flow dynamics including the dynamics in the manifold pressures, turbocharger, EGR, and actuators with few states in order to obtain short simulation times. An investi...

Wahlstro?m, Johan; Eriksson, Lars

2011-01-01

261

Analysis of separation characteristics of low temperature distillation system in fuel supply and exhaust system for nuclear fusion reactors  

International Nuclear Information System (INIS)

The most promising method for the hydrogen isotope separation in the fuel supply and exhaust system for nuclear fusion reactors is low temperature distillation method. In order to establish the design and operation methods for low temperature distillation towers, it is necessary to perform the experimental research and theoretical analysis for long period. The author has studied on the analysis model of low temperature distillation towers. The problem of low temperature distillation is that the experimental data of high accuracy are difficult to obtain because of many restrictions on the measurement. Accordingly, the analysis depends on the estimation by computer aid. In hydrogen isotopic separation, it is important to estimate accurately the amount of components existing in very small amount in output flow. The latent heat of evaporation is different according to the components. The decay of tritium generates heat. Hydrogen isotope system deviates from the law of Raoult. The effect of the three factors on the steady characteristics of a tower was examined, and the deviation from the law of Raoult affected most. (Kako, I.)

262

High temperature gas-cooled reactor: gas turbine application study  

Energy Technology Data Exchange (ETDEWEB)

The high-temperature capability of the High-Temperature Gas-Cooled Reactor (HTGR) is a distinguishing characteristic which has long been recognized as significant both within the US and within foreign nuclear energy programs. This high-temperature capability of the HTGR concept leads to increased efficiency in conventional applications and, in addition, makes possible a number of unique applications in both electrical generation and industrial process heat. In particular, coupling the HTGR nuclear heat source to the Brayton (gas turbine) Cycle offers significant potential benefits to operating utilities. This HTGR-GT Application Study documents the effort to evaluate the appropriateness of the HTGR-GT as an HTGR Lead Project. The scope of this effort included evaluation of the HTGR-GT technology, evaluation of potential HTGR-GT markets, assessment of the economics of commercial HTGR-GT plants, and evaluation of the program and expenditures necessary to establish HTGR-GT technology through the completion of the Lead Project.

1980-12-01

263

High temperature gas-cooled reactor: gas turbine application study  

International Nuclear Information System (INIS)

The high-temperature capability of the High-Temperature Gas-Cooled Reactor (HTGR) is a distinguishing characteristic which has long been recognized as significant both within the US and within foreign nuclear energy programs. This high-temperature capability of the HTGR concept leads to increased efficiency in conventional applications and, in addition, makes possible a number of unique applications in both electrical generation and industrial process heat. In particular, coupling the HTGR nuclear heat source to the Brayton (gas turbine) Cycle offers significant potential benefits to operating utilities. This HTGR-GT Application Study documents the effort to evaluate the appropriateness of the HTGR-GT as an HTGR Lead Project. The scope of this effort included evaluation of the HTGR-GT technology, evaluation of potential HTGR-GT markets, assessment of the economics of commercial HTGR-GT plants, and evaluation of the program and expenditures necessary to establish HTGR-GT technology through the completion of the Lead Project

264

77 FR 76842 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...  

Science.gov (United States)

...Clarifying the appropriate value of fuel flow to be used at each LTO test point. ...2012: Gaseous Emission Standards for Supersonic Engines...systems. (d) Test engines must reach a steady operating temperature before the...

2012-12-31

265

Fuel-air mixing apparatus for reducing gas turbine combustor exhaust emissions  

Science.gov (United States)

A fuel-air mixer for use in a combustion chamber of a gas turbine engine is provided. The fuel air mixing apparatus comprises an annular fuel injector having a plurality of discrete plain jet orifices, a first swirler wherein the first swirler is located upstream from the fuel injector and a second swirler wherein the second swirler is located downstream from the fuel injector. The plurality of discrete plain jet orifices are situated between the highly swirling airstreams generated by the two radial swirlers. The distributed injection of the fuel between two highly swirling airstreams results in rapid and effective mixing to the desired fuel-air ratio and prevents the formation of local hot spots in the combustor primary zone. A combustor and a gas turbine engine comprising the fuel-air mixer of the present invention are also provided as well as a method using the fuel-air mixer of the present invention.

Zupanc, Frank J. (Inventor); Yankowich, Paul R. (Inventor)

2006-01-01

266

Regeneration of mercury-charged adsorbents from exhaust gas purification; Regenerierung quecksilberbeladener Adsorbenzien aus der Abgasreinigung  

Energy Technology Data Exchange (ETDEWEB)

The regeneration of mercury-loaded zeolites is an essential step towards avoiding residual products from flue gas cleaning. A further advantage is that problems are not shifted from the atmospheric pollution path to water pollution or the production of solid wastes. (orig.) [Deutsch] Die Regenerierung quecksilberbeladener Zeolithe ist ein wesentlicher Schritt zur Vermeidung von Reststoffen bei der Abgasreinigung. Auch werden Probleme nicht vom Luftbad auf einen anderen Emissionspfad, z.B. Abwasser oder feste Abfaelle, verlagert. (orig.)

Petzoldt, O. [Lurgi Bamag GmbH, Butzbach (Germany); Gebert, U. [Nordische Quecksilber-Rueckgewinnung GmbH und Co., Luebeck (Germany)

1995-02-01

267

Bimodular high temperature planar oxygen gas sensor  

Directory of Open Access Journals (Sweden)

Full Text Available A bimodular planar O2 sensor was fabricated using NiO nanoparticles (NPs thin film coated yttria-stabilized zirconia (YSZ substrate. The thin film was prepared by radio frequency (r.f. magnetron sputtering of NiO on YSZ substrate, followed by high temperature sintering. The surface morphology of NiO nanoparticles film was characterized by atomic force microscopy (AFM and scanning electron microscopy (SEM. X-ray diffraction (XRD patterns of NiO NPs thin film before and after high temperature O2 sensing demonstrated that the sensing material possesses a good chemical and structure stability. The oxygen detection experiments were performed at 500 °C, 600 °C and 800 °C using the as-prepared bimodular O2 sensor under both potentiometric and resistance modules. For the potentiometric module, a linear relationship between electromotive force (EMF output of the sensor and the logarithm of O2 concentration was observed at each operating temperature, following the Nernst law. For the resistance module, the logarithm of electrical conductivity was proportional to the logarithm of oxygen concentration at each operating temperature, in good agreement with literature report. In addition, this bimodular sensor shows sensitive, reproducible and reversible response to oxygen under both sensing modules. Integration of two sensing modules into one sensor could greatly enrich the information output and would open a new venue in the development of high temperature gas sensors.

YuLei

2014-08-01

268

Bimodular high temperature planar oxygen gas sensor.  

Science.gov (United States)

A bimodular planar O2 sensor was fabricated using NiO nanoparticles (NPs) thin film coated yttria-stabilized zirconia (YSZ) substrate. The thin film was prepared by radio frequency (r.f.) magnetron sputtering of NiO on YSZ substrate, followed by high temperature sintering. The surface morphology of NiO NPs film was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). X-ray diffraction (XRD) patterns of NiO NPs thin film before and after high temperature O2 sensing demonstrated that the sensing material possesses a good chemical and structure stability. The oxygen detection experiments were performed at 500, 600, and 800°C using the as-prepared bimodular O2 sensor under both potentiometric and resistance modules. For the potentiometric module, a linear relationship between electromotive force (EMF) output of the sensor and the logarithm of O2 concentration was observed at each operating temperature, following the Nernst law. For the resistance module, the logarithm of electrical conductivity was proportional to the logarithm of oxygen concentration at each operating temperature, in good agreement with literature report. In addition, this bimodular sensor shows sensitive, reproducible and reversible response to oxygen under both sensing modules. Integration of two sensing modules into one sensor could greatly enrich the information output and would open a new venue in the development of high temperature gas sensors. PMID:25191652

Sun, Xiangcheng; Liu, Yixin; Gao, Haiyong; Gao, Pu-Xian; Lei, Yu

2014-01-01

269

An integrated exhaust gas analysis system with self-contained data processing and automatic calibration  

Science.gov (United States)

An integrated gas analysis system designed to operate in automatic, semiautomatic, and manual modes from a remote control panel is described. The system measures the carbon monoxide, oxygen, water vapor, total hydrocarbons, carbon dioxide, and oxides of nitrogen. A pull through design provides increased reliability and eliminates the need for manual flow rate adjustment and pressure correction. The system contains two microprocessors to range the analyzers, calibrate the system, process the raw data to units of concentration, and provides information to the facility research computer and to the operator through terminal and the control panels. After initial setup, the system operates for several hours without significant operator attention.

Anderson, R. C.; Summers, R. L.

1981-01-01

270

Gas-Alloy Interactions at Elevated Temperatures  

Energy Technology Data Exchange (ETDEWEB)

The understanding of the stability of metals and alloys against oxidation and other detrimental reactions, to the catalysis of important chemical reactions and the minimization of defects associated with processing and synthesis have one thing in common: At the most fundamental level, all these scientific/engineering problems involve interactions between metals and alloys (in the solid or liquid state) and gaseous atmospheres at elevated temperatures. In this special issue, we have collected a series of articles that illustrate the application of different theoretical, computational, and experimental techniques to investigate gas-alloy interactions.

Arroyave, Raymundo; Gao, Michael

2012-12-01

271

Radiation safety system for He gas evaporated from a cryostat for electron irradiation at cryogenic temperature, 1  

International Nuclear Information System (INIS)

For research of high energy radiation effects of some materials as superconductors at cryogenic temperature, a cryostat was constructed. In the cryostat, the samples immersed in liquid He are irradiated by electrons and X-rays of about 30 MeV from a linear accelerator. The irradiated samples and the surrounding materials can be activated and some part of the radioisotopes may contaminate the evaporated He gas. The contamination interferes reuse of He gas. In this paper, possibility of the activation was estimated and the contamination of the He gas was experimentally confirmed. A radiation safety system was installed in association with the cryostat. The system monitors radiation dose in the He gas evaporated from the cryostat in real time, and exhausts the contaminated He gas and transports only the clean He gas to a gas holder for the reuse. (author)

272

Purex canyon exhaust fan bearing temperature monitoring system doric 245 datalogger programming  

International Nuclear Information System (INIS)

A micro-processor based datalogger is used to monitor, display, and log seventeen RTD temperature channels. Five bearings are monitored for each of the three electric motor-fan assemblies and two bearings are monitored on the steam turbine unit. Several alarms per data channel (a High alarm at 236 degrees and a High High alarm at 246 degrees F) will alert the operation's staff to increasing abnormal bearing temperatures. This procedure is cross-referenced to the manufacturers manual. All programming steps will have the following footnote: Mpg x-xx. The Mpg refers to the Manual page, with x as the section number and xx as the page number in that section. When more information is needed, such as pictures or details, then the manual section and page number is provided

273

The Analysis of Exhaust Gas Thermal Energy Recovery Through a TEG Generator in City Traffic Conditions Reproduced on a Dynamic Engine Test Bed  

Science.gov (United States)

We present an analysis of thermal energy recovery through a proprietary thermoelectric generator (TEG) in an actual vehicle driving cycle reproduced on a dynamic engine test bed. The tests were performed on a 1.3-L 66-kW diesel engine. The TEG was fitted in the vehicle exhaust system. In order to assess the thermal energy losses in the exhaust system, advanced portable emission measurement system research tools were used, such as Semtech DS by Sensors. Aside from the exhaust emissions, the said analyzer measures the exhaust mass flow and exhaust temperature, vehicle driving parameters and reads and records the engine parameters. The difficulty related to the energy recovery measurements under actual traffic conditions, particularly when passenger vehicles and TEGs are used, spurred the authors to develop a proprietary method of transposing the actual driving cycle as a function V = f(t) onto the engine test bed, opn which the driving profile, previously recorded in the city traffic, was reproduced. The length of the cycle was 12.6 km. Along with the motion parameters, the authors reproduced the parameters of the vehicle and its transmission. The adopted methodology enabled high repeatability of the research trials while still ensuring engine dynamic states occurring in the city traffic.

Merkisz, Jerzy; Fuc, Pawel; Lijewski, Piotr; Ziolkowski, Andrzej; Wojciechowski, Krzysztof T.

2014-12-01

274

Low temperature heat source for power generation: Exhaustive analysis of a carbon dioxide transcritical power cycle  

International Nuclear Information System (INIS)

The main results of a theoretical work on the use of a low temperature heat source for power generation through a carbon dioxide transcritical power cycle are reported in this paper. The procedure for analyzing the behaviour of the proposed cycle consisted in modifying the input pressure to the turbine from 66 bar, maintained constant each evaluated temperature (60 oC, 90 oC, 120 oC and 150 oC) until the net work was approximately zero. As a result, the maximum exergy efficiency was 50%, while the energy efficiencies obtained were 9.8%, 7.3%, 4.9% and 2.4% and the net specific work was 18.2 kJ/kg, 12.8 kJ/kg, 7.8 kJ/kg and 3.5 kJ/kg, respectively. Furthermore, the effect of the addition of an internal heat exchanger, which obviously supposed an increase in the efficiency, was analyzed. The analysis of the proposed system shows the viability of implementing this type of process as an energy alternative and/or strengthener of non-conventional energy sources in non-provided zones, or for increasing the energy efficiency in the industry. -- Highlights: ? Energy and exergy analysis of a carbon dioxide transcritical power cycle is reported. ? The effect of the inlet temperature to the turbine is evaluated. ? Conditions of maximum efficiency and maximum net work are compared. ? The inclusion of an IHX is also analysed.

275

Laser-induced breakdown spectroscopy of alkali metals in high-temperature gas  

Science.gov (United States)

Laser-induced breakdown spectroscopy (LIBS) measurements of alkali in the high-temperature exhaust of a glass furnace show an attenuation of the Na and K LIBS signals that correlates with the stoichiometry of the bath gas surrounding the spark. The results are explained as being due to (1) a strong increase in the concentration of atomic Na and K, resulting in neutral line signal absorption by these atoms, and to (2) a change of phase of the major Na- and K-containing species from an aerosol to a gaseous phase when the gas mixture becomes fuel rich, resulting in a reduced LIBS emission intensity. LIBS sampling at lower temperatures, or in a consistently oxidizing environment, or both are suggested strategies for circumventing these difficulties.

Molina, Alejandro; Walsh, Peter M.; Shaddix, Christopher R.; Sickafoose, Shane M.; Blevins, Linda G.

2006-06-01

276

Laser-induced breakdown spectroscopy of alkali metals in high-temperature gas  

International Nuclear Information System (INIS)

Laser-induced breakdown spectroscopy (LIBS) measurements of alkali in the high-temperature exhaust of a glass furnace show an attenuation of the Na and K LIBS signals that correlates with the stoichiometry of the bath gas surrounding the spark. The results are explained as being due to (1) a strong increase in the concentration of atomic Na and K, resulting in neutral line signal absorption by these atoms, and to (2) a change of phase of the major Na- and K-containing species from an aerosol to a gaseous phase when the gas mixture becomes fuel rich, resulting in a reduced LIBSemission intensity. LIBS sampling at lower temperatures, or in a consistently oxidizing environment, or both are suggested strategies for circumventing these difficulties

277

Tokamak fusion reactor exhaust  

International Nuclear Information System (INIS)

This report presents a compilation of papers dealing with reactor exhaust which were produced as part of the TIGER Tokamak Installation for Generating Electricity study at Culham. The papers are entitled: (1) Exhaust impurity control and refuelling. (2) Consideration of the physical problems of a self-consistent exhaust and divertor system for a long burn Tokamak. (3) Possible bundle divertors for INTOR and TIGER. (4) Consideration of various magnetic divertor configurations for INTOR and TIGER. (5) A appraisal of divertor experiments. (6) Hybrid divertors on INTOR. (7) Refuelling and the scrape-off layer of INTOR. (8) Simple modelling of the scrape-off layer. (9) Power flow in the scrape-off layer. (10) A model of particle transport within the scrape-off plasma and divertor. (11) Controlled recirculation of exhaust gas from the divertor into the scrape-off plasma. (U.K.)

278

Additives for rapeseed oil fuel. Influence on the exhaust gas emissions  

Energy Technology Data Exchange (ETDEWEB)

In contrast to fossil diesel fuel, the use of additives is not common in rapeseed oil fuel. In a preceding research project the efficacy of several additives, that are commercially available for the use in fossil diesel or FAME, has been investigated for rapeseed oil fuel in the lab. Four additives could be identified, which have a significant influence on the ignition delay or the low temperature flow behaviour of rapeseed oil fuel. To investigate whether there are negative effects of the additives on other fuel-related properties in practical use, a test series on an agricultural tractor capable of running on vegetable oils has been conducted. Attention is focused on the operating parameters like power, torque or fuel consumption as well as on regulated emissions (CO, HC, particulate matter or NOx) and non-regulated emissions like polycyclic aromatic hydrocarbons. Additionally, the influence of the additives on the storage stability of rapeseed oil fuel is investigated in long term studies. No negative influence of the additives on the regulated emissions could be seen in the experiments, the data of the non-regulated emissions is still being analysed. This paper will focus on the emissions testing; results of the long term studies will be given in the presentation. (orig.)

Kastl, Johannes; Remmele, Edgar; Thuneke, Klaus [Technologie- und Foerderzentrum, Straubing (Germany)

2013-06-01

279

Electrochemical high-temperature gas sensors  

Science.gov (United States)

Combustion produced common air pollutant, NOx associates with greenhouse effects. Its high temperature detection is essential for protection of nature. Component-integration capable high-temperature sensors enable the control of combustion products. The requirements are quantitative detection of total NOx and high selectivity at temperatures above 500°C. This study reports various approaches to detect NO and NO2 selectively under lean and humid conditions at temperatures from 300°C to 800°C. All tested electrochemical sensors were fabricated in planar design to enable componentintegration. We suggest first an impedance-metric gas sensor for total NOx-detection consisting of NiO- or NiCr2O4-SE and PYSZ-electrolyte. The electrolyte-layer is about 200?m thickness and constructed of quasi-single crystalline columns. The sensing-electrode (SE) is magnetron sputtered thin-layers of NiO or NiCr2O4. Sensor sensitivity for detection of total NOx has been measured by applying impedance analysis. The cross-sensitivity to other emission gases such as CO, CO2, CH4 and oxygen (5 vol.%) has been determined under 0-1000ppm NO. Sensor maintains its high sensitivity at temperatures up to 550°C and 600°C, depending on the sensing-electrode. NiO-SE yields better selectivity to NO in the presence of oxygen and have shorter response times comparing to NiCr2O4-SE. For higher temperature NO2-sensing capability, a resistive DC-sensor having Al-doped TiO2-sensing layers has been employed. Sensor-sensitivity towards NO2 and cross-sensitivity to CO has been determined in the presence of H2O at temperatures 600°C and 800°C. NO2 concentrations varying from 25 to 100ppm and CO concentrations from 25 to 75ppm can be detected. By nano-tubular structuring of TiO2, NO2 sensitivity of the sensor was increased.

Saruhan, B.; Stranzenbach, M.; Yüce, A.; Gönüllü, Y.

2012-06-01

280

Development of high temperature metallic melting processes related to detritiation of exhausted control rods  

Energy Technology Data Exchange (ETDEWEB)

A rather critical problem to be faced in developing a safe strategy for the management of tritiated solid wastes is dealing with the outgassing property of tritium. Releases of tritium under elemental or oxide form may occur from waste items at different temperatures and rates depending upon the nature of tritium bonds into the waste matrix as well as on its `contamination history`. Apart from the commercial value of tritium, its release from waste packages anyhow represents a risk of tritium exposure that cannot be accepted by skippers, by store and disposal site operators as well as by the general public. Consequently it is mandatory to carry out the detritiation of such wastes before their packaging and storage or disposal. In the boron carbide control rods from the Lingen BWR after about three years of operation, tritium generated by neutron reaction was essentially retained in the B{sub 4}C matrix. The objectives of the study are to demonstrate the feasibility of two processes aimed at reducing to the maximum practicable extent the level of tritium contamination in such waste management are facilitated.

Dworschak, H.; Mannone, F.; Modica, G. [Commission of the European Communities, Ispra (Italy). Joint Research Centre; Nannicini, R. [Anima Unione Costruttori di Caldareria, Milan (Italy)

1994-05-01

281

Determination of benzene in exhaust gas from biofuels. Final report; Bestimmung von Benzol im Abgas von Biokraftstoffen. Abschlussbericht  

Energy Technology Data Exchange (ETDEWEB)

With the advance of environmental legislation and practices oriented towards sustainability renewable energy resources are becoming increasingly important. Use of replenishable raw materials helps preserve fossil resources. In the fuel sector the most widely used replenishable materials are rape methyl ester (RME) and ethyl tertiary butyl ether (ETBE). The purpose of the present project on the ''Determination of benzene in exhaust gas from biofuels'' was to generate orienting data on the potential health relevance of mixtures of fossil and renewable fuel intended for use in spark ignition and diesel engines. This included a determination of benzene emissions and the mutagenicity of particles. Beyond the applied-for scope of research measurements were also performed on the test engine's toluene, ethyl benzene and xylene emissions as well as on the smoke spot number and nitrogen oxide (NO{sub x}) and hydrocarbon (HC) emissions of the diesel engine. [German] Regenerative Energien gewinnen durch die Umweltgesetzgebungen und das Streben nach einer nachhaltigen Entwicklung zunehmend an Bedeutung. Durch die Verwendung nachwachsender Rohstoffe koennen die fossilen Ressourcen geschont werden. Im Kraftstoffsektor sind hier hauptsaechlich Rapsoelmethylester (RME) und optional Ethyltertiaerbutylether (ETBE) zu nennen. Um fuer Diesel- und Ottomotoren insbesondere mit Blick auf Kraftstoffgemische aus fossilen und regenerativen Komponenten orientierende Daten ueber eine potenzielle Gesundheitsrelevanz zu generieren, wurde das Projekt 'Bestimmung von Benzol im Abgas von Biokraftstoffen' durchgefuehrt. Neben der Benzolemission wurde die Mutagenitaet der Partikeln ermittelt. Ueber den beantragten Untersuchungsrahmen hinaus wurden die Tuluol-, Ethylbenzol-, und Xylolemissionen der eingesetzten Motoren, sowie die Russzahl (RZ) und die Stickoxid- (NO{sub x}) und Kohlenwasserstoffemissionen (HC) des Dieselmotors bestimmt. (orig.)

Dutz, M.; Buenger, J.; Gnuschke, H.; Halboth, H.; Gruedl, P.; Krahl, J.

2001-10-01

282

Hydrogen production from biomass pyrolysis gas via high temperature steam reforming process  

International Nuclear Information System (INIS)

Full text: The aim of this work has been undertaken as part of the design of continuous hydrogen production using the high temperature steam reforming process. The steady-state test condition was carried out using syngas from biomass pyrolysis, whilst operating at high temperatures between 600 and 1200 degree Celsius. The main reformer operating parameters (e.g. temperature, resident time and steam to biomass ratio (S/B)) have been examined in order to optimize the performance of the reformer. The operating temperature is a key factor in determining the extent to which hydrogen production is increased at higher temperatures (900 -1200 degree Celsius) whilst maintaining the same as resident time and S/B ratio. The effects of exhaust gas composition on heating value were also investigated. The steam reforming process produced methane (CH4) and ethylene (C2H4) between 600 to 800 degree Celsius and enhanced production ethane (C2H6) at 700 degree Celsius. However carbon monoxide (CO) emission was slightly increased for higher temperatures all conditions. The results show that the use of biomass pyrolysis gas can produce higher hydrogen production from high temperature steam reforming. In addition the increasing reformer efficiency needs to be optimized for different operating conditions. (author)

283

Controlling exhaust gas recirculation  

Science.gov (United States)

In controlling an engine, an amount of an intake charge provided, during operation of the engine, to a combustion chamber of the engine is determined. The intake charge includes an air component, a fuel component and a diluent component. An amount of the air component of the intake charge is determined. An amount of the diluent component of the intake charge is determined utilizing the amount of the intake charge, the amount of the air component and, in some instances, the amount of the fuel component. An amount of a diluent supplied to the intake charge is adjusted based at least in part on the determined amount of diluent component of the intake charge.

Zurlo, James Richard (Madison, WI); Konkle, Kevin Paul (West Bend, WI); May, Andrew (Milwaukee, WI)

2012-01-31

284

On the influence of solid rocket propellant exhaust gas on the stratospheric chemistry: Investigations using a three-dimensional photochemical circulation model  

International Nuclear Information System (INIS)

The work investigated in how far large orbital rockets (e.g., space shuttle, Titan IV or, in the future, Ariane V), which emit their exhaust gas directly into the atmosphere, are cumbersome to the global atmosphere and especially the stratosphere. In particular, it investigated in how far existing chemical steady-states are influenced entailing damage to the ozone layer. With the aid of a photochemical 3-D model which comprises the most important ozone-relevant reactions and calculates the distribution of 20 trace gases for any time-step, precise statements regarding the global effect could be made. Besides the horizontal distribution of the exhaust gases, particular attention was paid to their vertical distribution and to the impact on O3 concentration and individual groups of trace substances. (orig./KW)

285

Matrix for a catalytic reactor for cleaning the exhaust gas of internal combustion engines. Matrix fuer einen katalytischen Reaktor zur Abgasreinigung bei Brennkraftmaschinen  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the invention is to create the matrix of a ctalytic reactor for cleaning the exhaust gas of internal combustion engines while retaining their good mechanical stability so that greatly turbulent flow is produced in the matrix ducts, and the length of the matrix can therefore be reduced. The design features of the invention, made clear by several schematic diagrams, include one of 2 steel sheets in contact with one another, is divided into narrow strips on top of each other in the direction of flow of the exhaust gases. The rays have different corrugations; the corrugation of tape or strips in contact are at an angle and opposed (10 patent claims). (HWJ).

Nonnenmann, M.

1985-09-26

286

XCIII. A Low-Cost Temperature Programmer for Gas Chromatography  

Science.gov (United States)

Describes the construction and operation of a temperature programmer; it can be built for less than $100 and can be used with any gas chromatograph that uses a variable resistor to control oven temperature. (MLH)

Gallaher, T. N.; And Others

1977-01-01

287

Heat pump cycle by hydrogen-absorbing alloys to assist high-temperature gas-cooled reactor in producing hydrogen  

International Nuclear Information System (INIS)

A chemical heat pump system using two hydrogen-absorbing alloys is proposed to utilise heat exhausted from a high-temperature source such as a high-temperature gas-cooled reactor (HTGR), more efficiently. The heat pump system is designed to produce H2 based on the S-I cycle more efficiently. The overall system proposed here consists of HTGR, He gas turbines, chemical heat pumps and reaction vessels corresponding to the three-step decomposition reactions comprised in the S-I process. A fundamental research is experimentally performed on heat generation in a single bed packed with a hydrogen-absorbing alloy that may work at the H2 production temperature. The hydrogen-absorbing alloy of Zr(V1-xFex)2 is selected as a material that has a proper plateau pressure for the heat pump system operated between the input and output temperatures of HTGR and reaction vessels of the S-I cycle. Temperature jump due to heat generated when the alloy absorbs H2 proves that the alloy-H2 system can heat up the exhaust gas even at 600 deg. C without any external mechanical force. (authors)

288

High-temperature Gas Reactor (HTGR)  

Science.gov (United States)

General Atomics (GA) has over 35 years experience in prismatic block High-temperature Gas Reactor (HTGR) technology design. During this period, the design has recently involved into a modular have been performed to demonstrate its versatility. This versatility is directly related to refractory TRISO coated - particle fuel that can contain any type of fuel. This paper summarized GA's fuel cycle studies individually and compares each based upon its cycle sustainability, proliferation-resistance capabilities, and other performance data against pressurized water reactor (PWR) fuel cycle data. Fuel cycle studies LEU-NV;commercial HEU-Th;commercial LEU-Th;weapons-grade plutonium consumption; and burning of LWR waste including plutonium and minor actinides in the MHR. results show that all commercial MHR options, with the exception of HEU-TH, are more sustainable than a PWR fuel cycle. With LEU-NV being the most sustainable commercial options. In addition, all commercial MHR options out perform the PWR with regards to its proliferation-resistance, with thorium fuel cycle having the best proliferation-resistance characteristics.

Abedi, Sajad

2011-06-01

289

Black carbon from ships: a review of the effects of ship speed, fuel quality and exhaust gas scrubbing  

Directory of Open Access Journals (Sweden)

Full Text Available The International Maritime Organization (IMO has moved to address the health and climate impact of the emissions from the combustion of low-quality residual fuels within the commercial shipping industry. Fuel sulfur content (FS limits and an efficiency design index for future ships are examples of such IMO actions. The impacts of black carbon (BC emissions from shipping are now under review by the IMO, with a particular focus on the potential impacts of future Arctic shipping.

Recognizing that associating impacts with BC emissions requires both ambient and onboard observations, we provide recommendations for the measurement of BC. We also evaluate current insights regarding the effect of ship speed (engine load, fuel quality and exhaust gas scrubbing on BC emissions from ships. Observations demonstrate that BC emission factors (EFBC increases 3 to 6 times at very low engine loads (<25% compared to EFBC at 85–100% load; absolute BC emissions (per nautical mile of travel also increase up to 100% depending on engine load, even with reduced load fuel savings. If fleets were required to operate at lower maximum engine loads, presumably associated with reduced speeds, then engines could be re-tuned, which would reduce BC emissions.

Ships operating in the Arctic are likely running at highly variable engine loads (25–100% depending on ice conditions and ice breaking requirements. The ships operating at low load may be emitting up to 50% more BC than they would at their rated load. Such variable load conditions make it difficult to assess the likely emissions rate of BC.

Current fuel sulfur regulations have the effect of reducing EFBC by an average of 30% and potentially up to 80% regardless of engine load; a removal rate similar to that of scrubbers.

Uncertainties among current observations demonstrate there is a need for more information on (a the impact of fuel quality on EFBC using robust measurement methods and (b the efficacy of scrubbers for the removal of particulate matter by size and composition.

D. A. Lack

2012-01-01

290

Measured gas and particle temperatures in VTT's entrained flow reactor  

DEFF Research Database (Denmark)

Particle and gas temperature measurements were carried out in experiments on VTTs entrained flow reactor with 5% and 10% oxygen using Fourier transform infrared emission spectroscopy (FTIR). Particle temperature measurements were performed on polish coal,bark, wood, straw particles, and bark and wood particles treated with additive. A two-color technique with subtraction of the background light was used to estimate particle temperatures during experiments. A transmission-emission technique was used tomeasure the gas temperature in the reactor tube. Gas temperature measurements were in good agreement with thermocouple readings. Gas lines and bands from CO, CO2 and H2O can be observed in the spectra. CO was only observed at the first measuring port (100ms) with the strongest CO-signal seen during experiments with straw particles. Variations in gas concentration (CO2 and H2O) and the signal from solid particles reflects variations in particle feeding rates during the experiments.

Clausen, SØnnik; SØrensen, L.H.

2006-01-01

291

In situ gas temperature measurements by UV-absorption spectroscopy  

DEFF Research Database (Denmark)

The absorption spectrum of the NO A(2)Sigma(+) <- X(2)Pi gamma-system can be used for in situ evaluation of gas temperature. Experiments were performed with a newly developed atmospheric-pressure high-temperature flow gas cell at highly uniform and stable gas temperatures over a 0.533 m path in the range from 23 degrees C to 1,500 degrees C. The gas temperature was evaluated (1) from the analysis of the structure of selected NO high-resolution gamma-absorption bands and (2) from the analysis of vibrational distribution in the NO gamma-absorption system in the (211-238) nm spectral range. The accuracy of both methods is discussed. Validation of the classical Lambert-Beer law has been demonstrated at NO concentrations up to 500 ppm and gas temperatures up to 1,500 degrees C over an optical absorption path length of 0.533 m.

Fateev, Alexander; Clausen, SØnnik

2009-01-01

292

HPF HIGH PRESSURE FACILITY GAS ANALYSIS SYSTEM IN BASEMENT / HIGH TEMPERATURE GAS FACILITY IN THE E  

Science.gov (United States)

HPF HIGH PRESSURE FACILITY GAS ANALYSIS SYSTEM IN BASEMENT / HIGH TEMPERATURE GAS FACILITY IN THE ENGINE RESEARCH BUILDING ERB TEST CELL CE-13 / AUTOMATIC SCAN VALUE SYSTEM ON THE SECOND FLOOR OF THE INSTRUMENT RESEARCH LABORATORY IRL

1980-01-01

293

Catalysts for lean burn engine exhaust abatement  

Science.gov (United States)

The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

Ott, Kevin C.; Clark, Noline C.; Paffett, Mark T.

2006-08-01

294

Swirl and blade wakes in the interaction between gas turbines and exhaust diffusers investigated by endoscopic particle image velocimetry  

Energy Technology Data Exchange (ETDEWEB)

Exhaust diffusers studied in this thesis are installed behind the last turbine stage of gas turbines, including those used in combined cycle power plants. Extensive research made in recent years proved that effects caused by an upstream turbine need to be taken into account when designing efficient diffusers. Under certain conditions these effects can stabilize the boundary layer in diffusers and prevent separation. In this research the impact of multiple parameters, such as tip leakage flow, swirl, and rotating blade wakes, on the performance of a diffuser is studied. Experiments were conducted using a diffuser test rig with a rotating bladed wheel as a turbine effect generator and with an additional tip leakage flow insert. The major advantages of this test rig are modularity and easy variation of the main parameters. To capture the complexity and understand the physics of diffuser flow, and to clarify the phenomenon of the flow stabilisation, the 2D endoscopic laser optical measurement technique Partide Image Velocimetry (PIV) was adopted to the closed ''rotating'' diffuser test rig. Intensity and distribution of vortices in the blade tip area are decisive for diffuser performance. Large vortices in the annular diffuser inlet behind the blade tips interact with the boundary layer in diffusers. At design point these vortices are very early suppressed by the main flow. For the operating point with a low value of the flow coefficient (negative swirl), vortices are ab out two tim es stronger than for design point and the boundary layer is destabilized. V mtices develop in the direction contrary to swirl in the main flow and just cause flow destabilization. Coherent back flow zones are induced and reduction of diffuser performance occurs. For the operating point with positive swirl (for a high flow coefficient value), these vortices are also strong but do not counteract the main flow because they develop in the same direction with the swirl in the main flow. Pressure recovery in the annular diffuser is even high er than for design point because vortices energize the boundary layer and the turbulence level in the core flow is very high. Turbulent energy is better transported to the peripheral zones of the channel by the swirled flow. A small positive swirl angle in the inlet flow (behind the rotating bladed wheel in experiments) has a stabilizing effect on the diffuser, while negative swirl decreases its performance. This occurs due to change in the development of vertical structures downstream of the rotor blade tip area. The tip leakage flow from the last turbine stage positively affects pressure recovery in the diffuser energizing the boundary layer. Comparison of results for different diffuser test rig configurations with results from a more gas turbine-like test rig with a similar diffuser and a scaled turbine stage model and for higher Mach numbers showed similar pressure recovery trends, verifying the results.

Opilat, Victor

2011-10-21

295

Tailoring the structural and microstructural properties of nanosized tantalum oxide for high temperature electrochemical gas sensors.  

Science.gov (United States)

Ta2O5 nanopowders to be used as sensing electrodes in high temperature electrochemical gas sensors for hydrocarbons detection were synthesized using a sol-gel method and their structural and microstructural properties were investigated. The as-synthesized powders were heated at different temperatures in the range 250-1000 degrees C and characterized by TG-DTA, XRD, SEM, TEM and FT-IR. This investigation allowed to identify the correct thermal treatments to achieve the microstructural, textural and functional stability of materials working at high temperature, preserving their nano-metric grain size. Planar sensors fabricated by using Ta2O5 powders treated at 750 degrees C showed promising results for the selective detection of propylene at high temperature (700 degrees C). The good stability of the sensing response after gas exposure at high temperature was correlated to the stable microstructure the electrodes. Thus, Ta2O5 powders seems good candidate as sensing electrode for sensors for automotive exhausts monitoring. PMID:19916469

Bonavita, Anna; Di Bartolomeo, Elisabetta; Chevallier, Laure; D'Ottavi, Cadia; Licoccia, Silvia; Traversa, Enrico

2009-07-01

296

Characterization of particulate lead in vehicle exhaust - experimental techniques  

Energy Technology Data Exchange (ETDEWEB)

Experimental techniques and equipment required to provide representative samples of particulate matter from the exhaust of vehicles are considered. A system capable of sampling the exhaust from a vehicle under realistic operating conditions has been constructed. The vehicle is operated on a chasses dynamometer and controlled by magnetic tapes recorded on the road. The exhaust is diluted with air in a mixing tunnel and a near-proportional sample obtained using the variable dilution principle. During each run a number of samples are collected simultaneously to confirm the measurements made with different instruments, as well as to provide a mass balance. The sampling system can be used with a variety of instruments to characterize particulate matter emitted in the exhaust in terms of particle size, particle size distribution, physical structure, and composition. An exhaust filter has been developed to withstand exhaust gas temperatures, and is connected directly to the vehicle tail pipe. This filter has been shown to quantitatively collect exhaust lead compounds and thus provide the means to investigate the effect of vehicle characteristics and driving conditions on lead emissions. 13 references, 16 figures, 4 tables.

Habibi, K.

1970-03-01

297

Gas temperature determination in neon and helium afterglows  

International Nuclear Information System (INIS)

In this work we determined the gas temperature of neon and helium afterglow plasma using the frequencies of standing waves which are produced during the breakdown of a high voltage pulsed discharge. The temperature does not decay and may be considered constant within the observed afterglow periods. The mean gas temperature values obtained in neon and helium afterglow were in good agreement with the values obtained for the similar discharge conditions using microwave methods. (authors)

298

Effect of cooling the recirculated exhaust gases on diesel engine emissions  

International Nuclear Information System (INIS)

Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Spiral fin exhaust pipes were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The gases examined in this study were oxides of nitrogen (NOx), carbon dioxide (CO2) and carbon monoxide (CO). In addition, O2 concentration in the exhaust was measured. The two designs adopted in this study were exhaust pipes with solid and hollow fins around them. The first type uses air flow around the fins to cool the exhaust gases. The second type consists of hollow fins around the exhaust pipe to allow cooling water to flow in the hollow passage. Different combinations and arrangements of the solid and hollow fins exhaust pipes were used. It was found that decreasing the temperature of the EGR resulted in reductions in the oxides of nitrogen (NOx) and carbon dioxide (CO2) but increased the carbon monoxide (CO) in the exhaust gases. In addition, the oxygen (O2) concentration in the exhaust was decreased. As a general trend, the percentages of reduction in the NOx gas concentrations were lower than the percentages of increase in the CO emissions as a result of cooling the EGR of a Diesel engine by a heat exchanger. Using water as a cooling meeat exchanger. Using water as a cooling medium decreased the exhaust gases temperature and the amount of pollutants more than did air as a cooling medium. In a separate series of tests, increasing the cooled EGR ratios decreased the exhaust NOx but increased the particulate matter concentrations in the exhaust gases

299

Novel High Gas-Temperature Calibration System Demonstrated  

Science.gov (United States)

Accurate measurement of high gas temperatures, typically above 1300 K, has always presented challenges to researchers. Thermocouples often perturb the local gas flow and temperature field; they provide indirect information; and at high temperatures, they require large corrections so that actual gas temperatures can be determined. The physical and chemical stability of thermocouples to withstand the thermal loads and reactive environments prevailing at high temperatures naturally limits their life and maximum use temperature. Optical systems have their own drawbacks since accurate results depend on well-characterized emissivity, optical thickness, and gas composition information. These properties are rarely well known, especially in high-temperature, chemically reacting environments. In addition, optical systems usually require independent calibrations, which often involve the use of thermocouples, and hence, suffer from their aforementioned limitations. A new technique developed by researchers at the NASA Glenn Research Center at Lewis Field exploits an abrupt increase in the emittance of optically thin materials at their unique melting temperatures for a direct determination of gas temperature. Pure metallic-oxide fibers, varying in diameter from 60 to 400 mm, have been used in measurements over a temperature range of 2050 to 2700 K. The accuracy and reproducibility of the technique is estimated to be 15 K: that is, within the uncertainty in the melting points of the materials. Other fiber materials with different, but unique, melting points could be used to extend the technique over a larger temperature range.

Gokoglu, Suleyman A.; Schultz, Donald

2000-01-01

300

Experimental study of heat transfer coefficient in exhaust pipe  

Energy Technology Data Exchange (ETDEWEB)

Exhaust gas from spark-ignition engines are one of the main sources of atmospheric pollution, especially in urban areas where traffic is dense. In order to comply with increasingly restrictive standards, the automobile industry must develop cleaning devices such as catalytic converters and particle filters. This experimental study examined the influence of a flow's intermittent character on the heat transfer coefficient within a bent exhaust pipe. A device was developed to estimate the heat transfer coefficient on the right channel or the bent portion of the exhaust line in a periodic intermittent flowing regime, as well as in a steady regime. The goal was to build a database of coefficient and augmentation factors (CAF) for the simulation of heat transfer in a variety of basic geometries found in spark-ignition engine exhaust lines. Parietal heat flux and wall temperature were estimated from temperature measurements using the Beck inverse algorithm. Estimates of gas temperature were derived by Tagawa's method, using temperature measurements in the intermittent gas flow with a two thermocouples probe. The results showed that intermittency intensifies heat transfer in the straight pipe as well as in the bent pipe. The augmentation factor within the straight pipe depends on the frequency. Peak intensification depends on the mechanical frequency of resonance on the tube. The augmentation factor for the bent pipe was found to be lower than in the straight pipe, and did not depend on the frequency. 22 refs., 7 figs.

Bourouga, B.; Bouloc, F. [Nantes Univ., Nantes (France). LTN/UMR; Anthoine, P. [Renault, Rueil Malmaison (France). Direction de la Mecanique

2010-07-01

301

Thermoelectric generators incorporating phase-change materials for waste heat recovery from engine exhaust  

Science.gov (United States)

Thermoelectric devices, intended for placement in the exhaust of a hydrocarbon fuelled combustion device and particularly suited for use in the exhaust gas stream of an internal combustion engine propelling a vehicle, are described. Exhaust gas passing through the device is in thermal communication with one side of a thermoelectric module while the other side of the thermoelectric module is in thermal communication with a lower temperature environment. The heat extracted from the exhaust gasses is converted to electrical energy by the thermoelectric module. The performance of the generator is enhanced by thermally coupling the hot and cold junctions of the thermoelectric modules to phase-change materials which transform at a temperature compatible with the preferred operating temperatures of the thermoelectric modules. In a second embodiment, a plurality of thermoelectric modules, each with a preferred operating temperature and each with a uniquely-matched phase-change material may be used to compensate for the progressive lowering of the exhaust gas temperature as it traverses the length of the exhaust pipe.

Meisner, Gregory P; Yang, Jihui

2014-02-11

302

On maximum temperatures achievable by metal-gas interaction  

International Nuclear Information System (INIS)

Thermodynamic analysis methods are used to evaluate temperatures of Mg, Ba, B, Al, Ti, Zr metals interaction with oxygen at p=const. It is shown that at metal-gas interaction under normal conditions maximum adiabatic temperature value is Tad approximately 4500 K(Zr). Real temperatures due to heat losses are much lower. The calculations carried out of maximum metal-oxygen interaction temperatures showed that they are lower than combustion temperatures of gas-phase reactions and their values are limited by dissociation of products

303

Method for high temperature mercury capture from gas streams  

Science.gov (United States)

A process to facilitate mercury extraction from high temperature flue/fuel gas via the use of metal sorbents which capture mercury at ambient and high temperatures. The spent sorbents can be regenerated after exposure to mercury. The metal sorbents can be used as pure metals (or combinations of metals) or dispersed on an inert support to increase surface area per gram of metal sorbent. Iridium and ruthenium are effective for mercury removal from flue and smelter gases. Palladium and platinum are effective for mercury removal from fuel gas (syngas). An iridium-platinum alloy is suitable for metal capture in many industrial effluent gas streams including highly corrosive gas streams.

Granite, Evan J. (Wexford, PA); Pennline, Henry W. (Bethel Park, PA)

2006-04-25

304

A Precise Calibration Technique for Measuring High Gas Temperatures  

Science.gov (United States)

A technique was developed for direct measurement of gas temperatures in the range of 2050 K 2700 K with improved accuracy and reproducibility. The technique utilized the low-emittance of certain fibrous materials, and the uncertainty of the technique was United by the uncertainty in the melting points of the materials, i.e., +/-15 K. The materials were pure, thin, metal-oxide fibers whose diameters varied from 60 microns to 400 microns in the experiments. The sharp increase in the emittance of the fibers upon melting was utilized as indication of reaching a known gas temperature. The accuracy of the technique was confirmed by both calculated low emittance values of transparent fibers, of order 0.01, up to a few degrees below their melting point and by the fiber-diameter independence of the results. This melting-point temperature was approached by increments not larger than 4 K, which was accomplished by controlled increases of reactant flow rates in hydrogen-air and/or hydrogen-oxygen flames. As examples of the applications of the technique, the gas-temperature measurements were used: (a) for assessing the uncertainty in inferring gas temperatures from thermocouple measurements, and (b) for calibrating an IR camera to measure gas temperatures. The technique offers an excellent calibration reference for other gas-temperature measurement methods to improve their accuracy and reliably extending their temperature range of applicability.

Gokoglu, Suleyman A.; Schultz, Donald F.

2000-01-01

305

Application of modern online instrumentation for chemical analysis of gas and particulate phases of exhaust at the European Commission heavy-duty vehicle emission laboratory.  

Science.gov (United States)

The European Commission recently established a novel test facility for heavy-duty vehicles to enhance more sustainable transport. The facility enables the study of energy efficiency of various fuels/scenarios as well as the chemical composition of evolved exhaust emissions. Sophisticated instrumentation for real-time analysis of the gas and particulate phases of exhaust has been implemented. Thereby, gas-phase characterization was carried out by a Fourier transform infrared spectrometer (FT-IR; carbonyls, nitrogen-containing species, small hydrocarbons) and a resonance-enhanced multiphoton ionization time-of-flight mass spectrometer (REMPI-TOFMS; monocyclic and polycyclic aromatic hydrocarbons). For analysis of the particulate phase, a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS; organic matter, chloride, nitrate), a condensation particle counter (CPC; particle number), and a multiangle absorption photometer (MAAP; black carbon) were applied. In this paper, the first application of the new facility in combination with the described instruments is presented, whereby a medium-size truck was investigated by applying different driving cycles. The goal was simultaneous chemical characterization of a great variety of gaseous compounds and particulate matter in exhaust on a real-time basis. The time-resolved data allowed new approaches to view the results; for example, emission factors were normalized to time-resolved consumption of fuel and were related to emission factors evolved during high speeds. Compounds could be identified that followed the fuel consumption, others showed very different behavior. In particular, engine cold start, engine ignition (unburned fuel), and high-speed events resulted in unique emission patterns. PMID:21126058

Adam, T W; Chirico, R; Clairotte, M; Elsasser, M; Manfredi, U; Martini, G; Sklorz, M; Streibel, T; Heringa, M F; Decarlo, P F; Baltensperger, U; De Santi, G; Krasenbrink, A; Zimmermann, R; Prevot, A S H; Astorga, C

2011-01-01

306

Isomer distribution of nitrotriphenylenes in airborne particles, diesel exhaust particles, and the products of gas-phase radical-initiated nitration of triphenylene  

Science.gov (United States)

The formation of mutagenic nitro-polycyclic aromatic hydrocarbons (NPAHs) 1- and 2-nitrotriphenylene (1- and 2-NTP) via gas-phase OH or NO 3 radical-initiated reactions of triphenylene was demonstrated for the first time using a flow reaction system. In contrast with the results of conventional electrophilic nitration, 2-NTP was formed in larger yield than 1-NTP, but this is consistent with the mechanism proposed for gas-phase radical-initiated nitration of PAH. In diesel exhaust particle (DEP) samples, both 1- and 2-NTP were identified and their concentrations determined, as well as 1-nitropyrene (1-NP), which is a representative combustion-derived NPAH: the mean concentrations of 1-NTP, 2-NTP, and 1-NP were 4.7, 1.9, and 32 pmol mg DEP-1, respectively. The mean 2-NTP/1-NTP, 1-NTP/1-NP, and 2-NTP/1-NP ratios in samples of airborne particles collected in a residential area in Osaka, Japan, were>1.55,<0.25, and 0.37, respectively; these values are much higher than those of the DEP samples. This finding indicates that there is another source for airborne NTPs, especially 2-NTP, apart from diesel exhaust. These results strongly suggest that airborne NTPs originate from atmospheric processes such as radical-initiated reactions of triphenylene, and this has a significant influence on the atmospheric occurrence of NTPs.

Kameda, Takayuki; Inazu, Koji; Hisamatsu, Yoshiharu; Takenaka, Norimichi; Bandow, Hiroshi

307

Simultaneous conversion of nitrogen oxides and soot into nitrogen and carbon dioxide over iron containing oxide catalysts in diesel exhaust gas  

International Nuclear Information System (INIS)

This paper deals with the simultaneous catalytic conversion of NOx and soot into N2 and CO2 in diesel exhaust gas. Several iron containing oxide catalysts were partially modified by the alkali metal potassium and were used for NOx-soot reaction in a model exhaust gas. Fe1.9K0.1O3 has shown highest catalytic performance for N2 formation in the so far investigated catalysts. Further studies have shown that Fe1.9K0.1O3 was deactivated in a substantial way after about 20 TPR experiments due to the agglomeration of the promoter potassium. Experiments carried out over the aged Fe1.9K0.1O3 catalyst have shown that NOx-soot reaction was suppressed at higher O2 concentration, since O2-soot conversion was kinetically favored. In contrast to that, the catalytic activity was increased in presence of NO2 and H2O. Mechanistic examinations suggest that (CO) intermediates, formed at the soot surface, are the reactive sites in the NOx-soot reaction. Higher catalytic performance in presence of NO2 could be explained by the enhanced formation of these (CO) species. Moreover, nitrate species formed at the catalyst surface might also play an important role in NOx-soot conversion

308

New processes for the reduction and capture of mercury emissions in the exhaust gas treatment; Neue Verfahren zur Minderung und Erfassung von Quecksilber-Emissionen in der Abgasbehandlung  

Energy Technology Data Exchange (ETDEWEB)

The highly volatile heavy metal mercury is deemed to be very toxic. There exist a lot of natural as well as anthropogenic sources for the pollution of the environment with mercury such as the coal-fired power generation, the electrolytic production of chlorine, the cement burning including the release of mercury from the cement raw meal, the waste incineration and the artisanal production of gold by amalgamation with liquid mercury. The authors of the contribution under consideration report on new procedures for the reduction and capture of mercury emissions in the exhaust gas treatment. The bromine supported precipitation of mercury in the exhaust gas treatment is an efficient and economic process which takes account of the future requirements of lower limit values for mercury. Simultaneously, a new measurement technique for a continuous capture of mercury with new standards on detection sensitivity, accuracy and reliability in connection with a more simple and cost-effective maintenance is developed. The bromine supported precipitation as well as the continuous capture of mercury are trendsetters and are actually the best available technologies for the reduction of mercury emissions.

Boness, Michael [Sick Maihak GmbH, Meersburg (Germany); Kanefke, Rico [Currenta GmbH und Co. OHG, Leverkusen (Germany). Sonderabfallverbrennung Leverkusen; Vosteen, Bernhard W. [Vosteen Consulting GmbH, Koeln (Germany)

2013-03-01

309

Temperature detection in a gas turbine  

Science.gov (United States)

A temperature detector includes a first metal and a second metal different from the first metal. The first metal includes a plurality of wires and the second metal includes a wire. The plurality of wires of the first metal are connected to the wire of the second metal in parallel junctions. Another temperature detector includes a plurality of resistance temperature detectors. The plurality of resistance temperature detectors are connected at a plurality of junctions. A method of detecting a temperature change of a component of a turbine includes providing a temperature detector include ing a first metal and a second metal different from the first metal connected to each other at a plurality of junctions in contact with the component; and detecting any voltage change at any junction.

Lacy, Benjamin; Kraemer, Gilbert; Stevenson, Christian

2012-12-18

310

Simulation Study for Divertor Geometry and Gas Puffing to Handle Huge Exhaust Power in HL-2M with SOLPS5.0  

International Nuclear Information System (INIS)

One of the critical issues to be solved for HL-2M is the power exhaust. Divertor target plate geometry strongly influences the plasma profiles by controlling the neutral recycling pattern, which in turn has a strong effect on the symmetry and stability of the divertor plasma and finally on the whole edge region. The numerical simulation SOLPS5.0 package is used to design and explore the divertor target plates for HL-2M. We start with the choice of a proper target plate geometry, which has a smaller incidence angle in the permissible space, and then discuss the method of gas puffing to reduce the heat flux density on the target and the effects of gas puffing on the divertor plasma performance.

311

Effects of inlet distortion on gas turbine combustion chamber exit temperature profiles  

Science.gov (United States)

Damage to a nozzle guide vane or blade, caused by non-uniform temperature distributions at the combustion chamber exit, is deleterious to turbine performance and can lead to expensive and time consuming overhaul and repair. A test rig was designed and constructed for the Allison 250-C20B combustion chamber to investigate the effects of inlet air distortion on the combustion chamber's exit temperature fields. The rig made use of the engine's diffuser tubes, combustion case, combustion liner, and first stage nozzle guide vane shield. Rig operating conditions simulated engine cruise conditions, matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either side. An even distribution of inlet air to the combustion chamber did not create a uniform temperature profile and varying the inlet distribution of air exacerbated the profile's non-uniformity. The design of the combustion liner promoted the formation of an oval-shaped toroidal vortex inside the chamber, creating localized hot and cool sections separated by 90° that appeared in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most mass flow rate and decreasing the temperature of the hot section on the opposite side. Keywords: Allison 250, Combustion, Dual-Entry, Exit Temperature Profile, Gas Turbine, Pattern Factor, Reverse Flow.

Maqsood, Omar Shahzada

312

Nitrogen charge temperature prediction in a gas lift valve  

Scientific Electronic Library Online (English)

Full Text Available The operation of a class of retrievable gas-lift valves (GLV) is controlled by the axial movement of a bellows. One force acting on the bellows is due to the pressure exerted by the nitrogen gas contained in the GLV dome. It depends on the nitrogen temperature, which is influenced by both the produc [...] tion fluid and the injection gas temperatures in the well. This work investigated this dependence for a GLV installed in a side pocket mandrel tube. Three independent procedures were used for this purpose, comprising a compact thermal model, an experimental investigation with a thermal mockup and a numerical analysis. From these, a correlation for the nitrogen temperature was proposed, based on the local production fluid and injection gas temperatures, and on their convective coefficients with the mandrel tube surfaces.

Marcelo M., Ganzarolli; Carlos A. C., Altemani.

2010-03-01

313

Fuel arrangement for high temperature gas cooled reactor  

International Nuclear Information System (INIS)

Disclosed is a fuel arrangement for a high temperature gas cooled reactor including fuel assemblies with separate directly cooled fissile and fertile fuel elements removably inserted in an elongated moderator block also having a passageway for control elements

314

Pion gas viscosity at low temperature and density  

OpenAIRE

By using Chiral Perturbation Theory and the Uehling-Uhlenbeck equation we compute the viscosity of a pion gas, in the low temperature and low density regime, in terms of the temperature, and the pion fugacity. The viscosity turns out to be proportional to the squared root of the temperature over the pion mass. Next to leading corrections are proportional to the temperature over the pion mass to the 3/2.

Dobado Gonza?lez, Antonio; Santalla Arribas, Silvia Noemi?

2001-01-01

315

Verification of tritium gas purity by means of low-temperature gas chromatography  

International Nuclear Information System (INIS)

A gas chromatography method has been developed for quantitative determination of hydrogen isotopes and their compounds by means of gas chromatography on aluminium oxide at temperatures below -150 grad.C. For the separation process a modified gas chromatograph of CHROMATRON 18.3 type has been used with a specially made low temperature (-100 grad.C. - 180 grad.C.) thermostat. The modified device can be applied for preparative separations also, e.g. for tritium recuperation from mixtures with hydrogen

316

High frequency gas temperature and surface heat flux measurements  

OpenAIRE

Further improvements of the thermal efficiency of gas turbine cycle are closely coupled to the increase of turbine inlet temperature. This requires intensive and efficient cooling of the blades. In this perspective, experimental investigations of the gas temperature and heat transfer distribution around the airfoil are of primary importance. The present work aims at the development of two measurement techniques based on applications of the thin film sensors: the two-layer gauge for the wall h...

Iliopoulou, Vasiliki

2005-01-01

317

GC/MS Gas Separator Operates At Lower Temperatures  

Science.gov (United States)

Experiments show palladium/silver tube used to separate hydrogen carrier gas from gases being analyzed in gas-chromatography/mass-spectrometry (GC/MS) system functions satisfactorily at temperatures as low as 70 to 100 degrees C. Less power consumed, and catalytic hydrogenation of compounds being analyzed diminished. Because separation efficiency high even at lower temperatures, gas load on vacuum pump of mass spectrometer kept low, permitting use of smaller pump. These features facilitate development of relatively small, lightweight, portable GC/MS system for such uses as measuring concentrations of pollutants in field.

Sinha, Mahadeva P.; Gutnikov, George

1991-01-01

318

Development history of the gas turbine modular high temperature reactor  

International Nuclear Information System (INIS)

The development of the high temperature gas cooled reactor (HTGR) as an environmentally agreeable and efficient power source to support the generation of electricity and achieve a broad range of high temperature industrial applications has been an evolutionary process spanning over four decades. This process has included ongoing major development in both the HTGR as a nuclear energy source and associated power conversion systems from the steam cycle to the gas turbine. This paper follows the development process progressively through individual plant designs from early research of the 1950s to the present focus on the gas turbine modular HTGR. (author)

319

Effect of the factors of combustion chamber on the performance and exhaust emissions in a natural gas fueled spark ignition engine; Hibana tenkashiki tennen gas engine no doryoku seino narabini haiki tokusei ni oyobosu nenshoshitsu inshi no eikyo  

Energy Technology Data Exchange (ETDEWEB)

An experimental study was made on a natural gas fueled spark ignition engine to improve its thermal efficiency and exhaust emissions by the lean burn operation. A multi-cylinder engine was used to obtain the data for practical application. Investigated were the effects of the throat area of the orifice which separated a prechamber from a main chamber, the position of ignition spark in the prechamber and the compression ratio on the thermal efficiency, the exhaust emissions and the lean limit of stable operation. The results showed that a small throat area resulted in low emissions of NOx, low thermal efficiency and narrow lean limit. The spark ignition at the center of prechamber or near the throat was preferable to the top of prechamber in terms of the thermal efficiency. Higher compression ratio resulted in shorter combustion duration, higher thermal efficiency and extended lean limit. 7 refs., 15 figs., 1 tab.

Kataoka, K. [Okayama University of Science, Okayama (Japan); Atsumi, Y. [University of Osaka Prefecture, Osaka (Japan); Segawa, D.; Kadota, T. [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering; Fukano, Y. [Osaka Gas Co. Ltd., Tokyo (Japan)

1998-05-25

320

Removal of Pb(II), Cd(II), Cu(II), and Zn(II) by hematite nanoparticles: effect of sorbent concentration, pH, temperature, and exhaustion.  

Science.gov (United States)

Nanoparticles offer the potential to improve environmental treatment technologies due to their unique properties. Adsorption of metal ions (Pb(II), Cd(II), Cu(II), Zn(II)) to nanohematite was examined as a function of sorbent concentration, pH, temperature, and exhaustion. Adsorption experiments were conducted with 0.05, 0.1, and 0.5 g/L nanoparticles in a pH 8 solution and in spiked San Antonio tap water. The adsorption data showed the ability of nanohematite to remove Pb, Cd, Cu, and Zn species from solution with adsorption increasing as the nanoparticle concentration increased. At 0.5 g/L nanohematite, 100 % Pb species adsorbed, 94 % Cd species adsorbed, 89 % Cu species adsorbed and 100 % Zn species adsorbed. Adsorption kinetics for all metals tested was described by a pseudo second-order rate equation with lead having the fastest rate of adsorption. The effect of temperature on adsorption showed that Pb(II), Cu(II), and Cd(II) underwent an endothermic reaction, while Zn(II) underwent an exothermic reaction. The nanoparticles were able to simultaneously remove multiple metals species (Zn, Cd, Pb, and Cu) from both a pH 8 solution and spiked San Antonio tap water. Exhaustion experiments showed that at pH 8, exhaustion did not occur for the nanoparticles but adsorption does decrease for Cd, Cu, and Zn species but not Pb species. The strong adsorption coupled with the ability to simultaneously remove multiple metal ions offers a potential remediation method for the removal of metals from water. PMID:22645012

Shipley, Heather J; Engates, Karen E; Grover, Valerie A

2013-03-01

321

Gas analysis system for the Eight Foot High Temperature Tunnel  

Science.gov (United States)

This paper describes the development of a gas collection and analysis system that is to be installed in the Eight-Foot High Temperature Tunnel (8' HTT) at NASA's Langley Research Center. This system will be used to analyze the test gas medium that results after burning a methane-air mixture to achieve the proper tunnel test parameters. The system consists of a sampling rake, a gas sample storage array, and a gas chromatographic system. Gas samples will be analyzed after each run to assure that proper combustion takes place in the tunnel resulting in a correctly balanced composition of the test gas medium. The proper ratio of gas species is critically necessary in order for the proper operation and testing of scramjet engines in the tunnel. After a variety of methane-air burn conditions have been analyzed, additional oxygen will be introduced into the combusted gas and the enriched test gas medium analyzed. The pre/post enrichment sets of data will be compared to verify that the gas species of the test gas medium is correctly balanced for testing of air-breathing engines.

Leighty, Bradley D.; Davis, Patricia P.; Upchurch, Billy T.; Puster, Richard L.

1992-01-01

322

Finite temperature excitations of a trapped Bose gas  

CERN Document Server

We present a detailed study of the temperature dependence of the condensate and noncondensate density profiles of a Bose-condensed gas in a parabolic trap. These quantitites are calculated self-consistently using the Hartree-Fock-Bogoliubov equations within the Popov approximation. Below the Bose-Einstein transition the excitation frequencies have a realtively weak temperature dependence even though the condensate is strongly depleted. As the condensate density goes to zero through the transition, the excitation frequencies are strongly affected and approach the frequencies of a noninteracting gas in the high temperature limit.

Hutchinson, D; Griffin, A

1996-01-01

323

Modern gas-based temperature and pressure measurements  

CERN Document Server

This 2nd edition volume of Modern Gas-Based Temperature and Pressure Measurements follows the first publication in 1992. It collects a much larger set of information, reference data, and bibliography in temperature and pressure metrology of gaseous substances, including the physical-chemical issues related to gaseous substances. The book provides solutions to practical applications where gases are used in different thermodynamic conditions. Modern Gas-Based Temperature and Pressure Measurements, 2nd edition is the only comprehensive survey of methods for pressure measurement in gaseous media used in the medium-to-low pressure range closely connected with thermometry. It assembles current information on thermometry and manometry that involve the use of gaseous substances which are likely to be valid methods for the future. As such, it is an important resource for the researcher. This edition is updated through the very latest scientific and technical developments of gas-based temperature and pressure measurem...

Pavese, Franco

2013-01-01

324

Exhausting Science  

Science.gov (United States)

The fume hood: You know what it is, but have you ever used it? And if a safety issue arose, would you know what to do? Unfortunately, fume hoods are frequently included in a science room just for show. Little thought is often given to how they should be used or maintained. It is important for science teachers to understand and regularly inspect fume hoods in their classrooms and laboratories. In this article, the author discusses a few considerations for design, inspection, use, and maintenance of fume hoods in a science lab and classroom. Read on for an "exhaustive" look at this safety device!

Douglas Mandt

2009-01-01

325

A comparative study of the elemental composition of the exhaust emissions of cars powered by liquefied petroleum gas and unleaded petrol  

Science.gov (United States)

Elements emitted from the exhausts of new Ford Falcon Forte cars powered by unleaded petrol (ULP) and liquefied petroleum gas (LPG) were measured on a chassis dynamometer. The measurements were carried out in February, June and August 2001, and at two steady state driving conditions (60 and 80 km h -1). Thirty seven elements were quantified in the exhaust samples by inductively coupled plasma mass spectrometry (ICPMS). The total emission factors of the elements from the exhausts of ULP cars were higher than those of LPG cars at both engine speeds even though high variability in the exhaust emissions from different cars was noted. The effect of the operating conditions such as mileage of the cars, engine speed, fuel and lubricating oil compositions on the emissions was studied. To investigate the effects of these conditions, multivariate data analysis methods were employed including exploratory principal component analysis (PCA), and the multi-criteria decision making methods (MCDM), preference ranking organization method for enrichment evaluation (PROMETHEE) and geometrical analysis for interactive aid (GAIA), for ranking the cars on the basis of the emission factors of the elements. PCA biplot of the complete data matrix showed a clear discrimination of the February, June and August emission test results. In addition, (i) platinum group elements (PGE) emissions were separated from each other in the three different clusters viz. Pt with February, Pd with June and Rh with August; (ii) the motor oil related elements, Zn and P, were particularly associated with the June and August tests (these vectors were also grouped with V, Al and Cu); and (iii) highest emissions of most major elements were associated with the August test after the cars have recorded their highest mileage. Extensive analysis with the aid of the MCDM ranking methods demonstrated clearly that cars powered by LPG outperform those powered by ULP. In general, cars tested in June perform better than those tested in August, which suggested that mileage was the key criterion of car performance on the basis of elemental emission factors.

Lim, McKenzie C. H.; Ayoko, Godwin A.; Morawska, Lidia; Ristovski, Zoran D.; Jayaratne, E. Rohan; Kokot, Serge

326

The Influence of Mixing in High Temperature Gas Phase Reactions  

DEFF Research Database (Denmark)

The objective of this thesis is to describe the mixing in high temperature gas phase reactions.The Selective Non-Catalytic Reduction of NOx (referred as the SNR process) using NH3 as reductant was chosen as reaction system. This in-furnace denitrification process is made at around 1200 - 1300 K by injection of NH3 with carrier gas into the flue gas. NH3 can react with NO and form N2, but a competing reaction path is the oxidation of NH3 to NO.The SNR process is briefly described and it is shown by chemical kinetic modelling that OH radicals under the present conditions will initiate the reaction of NH3 by formation of NH2 and NH radicals.Mixing in reacting gas phase systems is described by an empirical mixing model (the droplet diffusion model). The mixing process is separated into macro- and micromixing. The macromixing is assumed to be ideal while the micromixing is modelled by molecular diffusion. The SNR process is simulated using the mixing model and an empirical kinetic model based on laboratory experiments.A bench scale reactor set-up has been built using a natural gas burner to provide the main reaction gas. The set-up has been used to perform an experimental investigation of the mixing in the SNR process using injection of NH3 with carrier gas into the flue gas in crossflow by a quartz nozzle.Experiments were made with variation in NH3 flow, carrier gas flow, carrier gas composition (O2 concentration) and reactor temperature. Natural gas has been used as an addition to the injected gas as well.The effects of the NH3 flow and natural gas addition were as expected from earlier studies in laboratory reactors and pilot plants.The experiments indicates that the SNR process was only dependenton the O2 concentration in the flue gas without any effect due to variation of the O2 concentrations in the injected gas between 0 - 20 vol%.Using a nozzle with a diameter of 1.9 mm the reduction of NO is dependent on the carrier gas flow for temperatures above 1200 K (1100 K when natural gas is added).It is shown that this effect can not be described by macromixing using a simple reactor model. The difference in the NO outlet concentration for varied carrier gas flow seems to have a maximum at 1350 K and is then decreasing for higher temperatures. This is in good agreement with an analysis of the micromixing effects.The mixing effect observed in the experiments can be described by the momentum ratio between the injected jet and the flue gas in crossflow both for the 1.0 mm and 1.9 mm nozzle, indicating that for momentum ratios above 30 there is no further improvement of the mixing. For decreasing momentum ratios below 30 the NO outlet concentration is increasing for temperatures above 1200 K. For temperatures below 1200 K the NO outlet concentration is unaffected because of lower reaction rates.The droplet diffusion model is used to model the experimental results and it can describe the influence of the carrier gas flow with a successful result.

Østberg, Martin

1996-01-01

327

Design and development of gas turbine high temperature reactor 300  

International Nuclear Information System (INIS)

JAERI (Japan Atomic Energy Research Institute) has been designing a Japan's original gas turbine high temperature reactor, GTHTR300 (Gas Turbine High Temperature Reactor 300). The greatly simplified design based on salient features of the HTGR (High Temperature Gas-cooled reactor) with a closed helium gas turbine enables the GTHTR300 a high efficient and economically competitive reactor to be deployed in early 2010s. Also, the GTHTR300 fully taking advantage of various experiences accumulated in design, construction and operation of the HTTR (High Temperature Engineering Test Reactor) and fossil gas turbine systems reduces technological development concerning a reactor system and electric generation system. Original features of this system are core design with two-year refueling interval, conventional steel material usage for a reactor pressure vessel, innovative plant flow scheme and horizontally installed gas turbine unit. Due to these salient features, the capital cost of the GTHTR300 is less than a target cost of 200 thousands Yen/kWe, and the electric generation cost is close to a target cost of 4 Yen/kWh. This paper describes the original design features focusing on reactor core design, fuel design, in-core structure design and reactor pressure vessel design except PCU design. Also, R and D for developing the power conversion unit is briefly described. The present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japane, Sports, Science and Technology of Japan. (author)

328

Utilisation of CO2, fixation of nitrogen and exhaust gas cleaning in electric discharge with electrode catalysis  

International Nuclear Information System (INIS)

The method reported here provides a contribution to CO2 utilisation, nitrogen fixation and combustion exhaust cleaning using synergetic effect of electric discharge with heterogeneous catalysis on electrodes. The efficiency of CO2 removal is about 40-65%. The process of CO2 removal is always accompanied by NOx, VOC, SX and other component removal and is connected with O2 formation. The final product of process is powder with fractal microstructure, low specific weight, water insoluble suitable for use as nitrogen containing fertilizer. The main component (95%) of solid product is amorphous condensate of amino acids with about 5% of metal organic compound with catalytic properties. The condensate has character of statistical proteinoid. Its creation seems to play important role during formation of life in pre-biotic Earth

329

Bimodular high temperature planar oxygen gas sensor  

OpenAIRE

A bimodular planar O2 sensor was fabricated using NiO nanoparticles (NPs) thin film coated yttria-stabilized zirconia (YSZ) substrate. The thin film was prepared by radio frequency (r.f.) magnetron sputtering of NiO on YSZ substrate, followed by high temperature sintering. The surface morphology of NiO nanoparticles film was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). X-ray diffraction (XRD) patterns of NiO NPs thin film before and after high tempera...

YuLei; HaiyongGao; PuxianGao

2014-01-01

330

On The Gas Temperature of Molecular Cloud Cores  

CERN Document Server

We investigate the uncertainties affecting the temperature profiles of dense cores of interstellar clouds. In regions shielded from external ultraviolet radiation, the problem is reduced to the balance between cosmic ray heating, line cooling, and the coupling between gas and dust. We show that variations in the gas phase abundances, the grain size distribution, and the velocity field can each change the predicted core temperatures by one or two degrees. We emphasize the role of non-local radiative transfer effects that often are not taken into account, for example, when modelling the core chemistry. These include the radiative coupling between regions of different temperature and the enhanced line cooling near the cloud surface. The uncertainty of the temperature profiles does not necessarily translate to a significant error in the column density derived from observations. However, depletion processes are very temperature sensitive and a two degree difference can mean that a given molecule no longer traces t...

Juvela, M

2011-01-01

331

Titanium dioxide thin films for high temperature gas sensors  

International Nuclear Information System (INIS)

Titanium dioxide (TiO2) thin film gas sensors were fabricated via the sol-gel method from a starting solution of titanium isopropoxide dissolved in methoxyethanol. Spin coating was used to deposit the sol on electroded aluminum oxide (Al2O3) substrates forming a film 1 ?m thick. The influence of crystallization temperature and operating temperature on crystalline phase, grain size, electronic conduction activation energy, and gas sensing response toward carbon monoxide (CO) and methane (CH4) was studied. Pure anatase phase was found with crystallization temperatures up to 800 oC, however, rutile began to form by 900 oC. Grain size increased with increasing calcination temperature. Activation energy was dependent on crystallite size and phase. Sensing response toward CO and CH4 was dependent on both calcination and operating temperatures. Films crystallized at 650 oC and operated at 450 oC showed the best selectivity toward CO.

332

Role of average speed in N?O exhaust emissions as greenhouse gas in a huge urban zone (MVMZ): would we need a cold sun?  

Science.gov (United States)

Nowadays, the drastic pollution problems, some of them related with greenhouse gas emissions, have promoted important attempts to face and diminish the global warming effects on the Mexico Valley Metropolitan Zone (MVMZ) as well as on the huge urban zones around the world. To reduce the exhaust gas emissions, many efforts have been carried out to reformulate fuels and design new catalytic converters; however, it is well known that other variables such as socio-economic and transport structure factors also play an important role around this problem. The present study analyzes the roles played by several commonly-used three-way catalytic converters (TWC) and the average traffic speed in the emission of N(2)O as greenhouse gas. According to this study, by increasing the average traffic flow and avoiding constant decelerations (frequent stops) during common trips, remarkable environmental and economic benefits could be obtained due to the diminution of N(2)O and other contaminant emissions such as ammonia (NH(3)) and even CO(2) with the concomitant reduced fossil fuel consumption. The actions mentioned above could be highly viable to diminish, in general, the global warming effects and contamination problems. PMID:22245865

Castillo, S; Mac-Beath, I; Mejia, I; Camposeco, R; Bazan, G; Morán-Pineda, M; Carrera, R; Gómez, R

2012-05-15

333

Exhaust Manifold Design – FEA Approach  

Directory of Open Access Journals (Sweden)

Full Text Available The Exhaust manifold in the engines is an important component which has a considerable effect on the performance of the I.C engine. The exhaust manifold operates under high temperature and pressure conditions. Their design usually has to be performed by trial and error through many experiments and analyses. Therefore, an automated design optimization would reduce technical, schedule, and cost risks for new engine developments. This paper deals with the various factors that are to be considered in the design of the exhaust manifold. It tries to explain the effect of various factors during the Finite Element Analysis.

Gopaal

2014-11-01

334

Finite temperature stability of a trapped dipolar Bose gas  

OpenAIRE

We calculate the stability diagram for a trapped normal Bose gas with dipole-dipole interactions. Our study characterizes the roles of trap geometry, temperature, and short-ranged interactions on the stability. We predict a robust double instability feature in oblate trapping geometries arising from the interplay of thermal gas saturation and the anisotropy of the interaction. Our results are relevant to current experiments with polar molecules and will be useful in developi...

Bisset, R. N.; Baillie, D.; Blakie, P. B.

2011-01-01

335

Gravitational collapse of a magnetized fermion gas with finite temperature  

CERN Document Server

We examine the dynamics of a self--gravitating magnetized electron gas at finite temperature near the collapsing singularity of a Bianchi-I spacetime. Considering a general and appropriate and physically motivated initial conditions, we transform Einstein--Maxwell field equations into a complete and self--consistent dynamical system amenable for numerical work. The resulting numerical solutions reveal the gas collapsing into both, isotropic ("point-like") and anisotropic ("cigar-like") singularities, depending on the initial intensity of the magnetic field. We provide a thorough study of the near collapse behavior and interplay of all relevant state and kinematic variables: temperature, expansion scalar, shear scalar, magnetic field, magnetization and energy density. A significant qualitative difference in the behavior of the gas emerges in the temperature range $\\hbox{T} sim10^{4}\\hbox{K}$ and $\\hbox{T}\\sim 10^{7}\\hbox{K}$.

Gaspar, I Delgado; Sussman, Roberto A; Rey, A Ulacia

2013-01-01

336

Extracting the shear viscosity of a high temperature hadron gas  

CERN Document Server

Quark-Gluon plasmas produced in relativistic heavy-ion collisions quickly expand and cool, entering a phase consisting of multiple interacting hadronic resonances just below the QCD deconfinement temperature. The transport properties of this hot hadron gas are poorly understood, yet they play an important role in our ability to infer transport properties of the quark-gluon plasma, because experimental measurements integrate over the whole system evolution. Assuming that the hot hadron gas can be modeled by a hadron cascade code based on kinetic theory assuming binary interactions, the shear viscosity over entropy ratio of a hot hadron gas for temperatures in between 120 MeV and 170 MeV is extracted. Furthermore, we present estimates for a second order transport coefficient, the shear viscous relaxation time at a temperature of 165 MeV.

Romatschke, Paul

2014-01-01

337

Gravitational collapse of a magnetized fermion gas with finite temperature  

Energy Technology Data Exchange (ETDEWEB)

We examine the dynamics of a self-gravitating magnetized fermion gas at finite temperature near the collapsing singularity of a Bianchi-I spacetime. Considering a general set of appropriate and physically motivated initial conditions, we transform Einstein-Maxwell field equations into a complete and self-consistent dynamical system amenable for numerical work. The resulting numerical solutions reveal the gas collapsing into both, isotropic (''point-like'') and anisotropic (''cigar-like''), singularities, depending on the initial intensity of the magnetic field. We provide a thorough study of the near collapse behavior and interplay of all relevant state and kinematic variables: temperature, expansion scalar, shear scalar, magnetic field, magnetization, and energy density. A significant qualitative difference in the behavior of the gas emerges in the temperature range T/m{sub f} {proportional_to} 10{sup -6} and T/m{sub f} {proportional_to} 10{sup -3}. (orig.)

Delgado Gaspar, I. [Instituto de Geofisica y Astronomia (IGA), La Habana (Cuba); Perez Martinez, A. [Instituto de Cibernetica, Matematica y Fisica (ICIMAF), La Habana (Cuba); Sussman, Roberto A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (ICN-UNAM), Mexico (Mexico); Ulacia Rey, A. [Instituto de Cibernetica, Matematica y Fisica (ICIMAF), La Habana (Cuba); Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (ICN-UNAM), Mexico (Mexico)

2013-07-15

338

High-temperature oxidation of graphite rods with temperature control by combustion gas recycle  

International Nuclear Information System (INIS)

The combustion of graphite (fuel blocks) is of fundamental importance in the fuel reprocessing scheme for the High-Temperature Gas-Cooled Reactor (HTGR). A study was made to evaluate a chunk-type burner for possible application in this reprocessing step. The combustion gases were recycled to allow operation at higher burn rates without an increase in graphite temperature. Graphite rods of two diameters were oxidized with makeup oxygen and recycled stack gases at various gas flow rates in an insulated reactor. Results of this study indicate a strong dependence of oxygen transfer on gas flow rate with little effect resulting from changes in graphite temperature. High carbon monoxide concentrations in the exit gas were not a problem except at oxygen concentrations below approx. 5%. Stable operation of a recycle controlled burner was achieved, avoiding the temperature excursions common in previous graphite burners

339

High temperature gas reactor and energy pipeline system  

International Nuclear Information System (INIS)

A study was made of the following aspects of the High Temperature Gas Reactor (HTGR) Closed Loop Chemical Energy Pipeline (CEP) concept: pipeline transmission and storage system design, pipeline and storage system cost, methane reformer interface, and system safety and environmental aspects. This paper focuses on the pipeline and storage system concepts. Pipeline size, compressor power, and storage facility requirements were developed for four different types of pipeline systems to obtain system cost estimates. Each pipeline system includes a synthesis-gas pipeline from the reformer to the methanator, a methane-rich gas pipeline from the methanator to the reformer, a water return line from the methanator to the reformer, and storage for the synthesis gas, methane-rich gas and water

340

High-temperature electron localization in dense He gas  

International Nuclear Information System (INIS)

We report accurate measurements of the mobility of excess electrons in high-density helium gas in extended ranges of temperature [(26?T?77) K] and density [(0.05?N?10.0) atoms nm-3]. The aim is the investigation of the combined effect of temperature and density on the formation and dynamics of localized electron states. The main result of the experiment is that the formation of localized states essentially depends on the relative balance of fluid dilation energy, repulsive electron-atom interaction energy, and thermal energy. As a consequence, the onset of localization depends on the medium disorder through gas temperature and density. The transition from delocalized to localized states shifts to larger densities as temperature is increased. This behavior can be understood in terms of a simple model of electron self-trapping in a spherically symmetric square well

341

Problems of unsteady temperature measurements in a pulsating flow of gas  

International Nuclear Information System (INIS)

Unsteady flow temperature is one of the most difficult and complex flow parameters to measure. Main problems concern insufficient dynamic properties of applied sensors and an interpretation of recorded signals, composed of static and dynamic temperatures. An attempt is made to solve these two problems in the case of measurements conducted in a pulsating flow of gas in the 0–200 Hz range of frequencies, which corresponds to real conditions found in exhaust pipes of modern diesel engines. As far as sensor dynamics is concerned, an analysis of requirements related to the thermometer was made, showing that there was no possibility of assuring such a high frequency band within existing solutions. Therefore, a method of double-channel correction of sensor dynamics was proposed and experimentally tested. The results correspond well with the calculations made by means of the proposed model of sensor dynamics. In the case of interpretation of the measured temperature signal, a method for distinguishing its two components was proposed. This decomposition considerably helps with a correct interpretation of unsteady flow phenomena in pipes

342

Effects of piston design and inlet gas flow on the performance and exhaust emissions in a natural gas fueled spark ignition engine; Hibana tenkashiki tennen gas engine no doryoku seino narabini haiki tokusei ni oyobosu piston keijo oyobi kyuki ryudo no eikyo  

Energy Technology Data Exchange (ETDEWEB)

An experimental study was made on a natural gas fueled spark ignition engine to improve its thermal efficiency and exhaust emissions by the lean burn operation. A multi-cylinder engine was tested for purposes of practical application. Investigated were the effects of the piston design and the gas motion induced by a shrouded inlet valve on the combustion process, the thermal efficiency, exhaust emissions and the lean limit of stable operation. It was found that a bowl-in-piston resulted in higher thermal efficiency and extended lean limit as compared with a fiat piston. A shrouded inlet valve generally resulted in shorter duration of combustion, lower NO{sub x} emissions and lower thermal efficiency than a conventional valve. When a shrouded inlet valve was set so as to direct the mixture flow toward the prechamber throat, the lean limit was extended with low exhaust emissions and relatively high thermal efficiency. (author)

Kataoka, K. [Okayama University of Science, Okayama (Japan); Atsumik, Y. [Universityof Osaka Prefecture, Osaka (Japan); Segawa, D.; Kadota, T. [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering; Fukano, Y. [Osaka Gas Co. Ltd., Osaka (Japan)

1999-04-25

343

Microstructural Characterization of Low Temperature Gas Nitrided Martensitic Stainless Steel  

DEFF Research Database (Denmark)

The present work presents microstructural investigations of the surface zone of low temperature gas nitrided precipitation hardening martensitic stainless steel AISI 630. Grazing incidence X-ray diffraction was applied to investigate the present phases after successive removal of very thin sections of the sample surface. The development of epsilon nitride, expanded austenite and expanded martensite resulted from the low temperature nitriding treatments. The microstructural features, hardness and phase composition are discussed with emphasis on the influence of nitriding duration and nitriding potential.

Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin

2015-01-01

344

Finite Temperature Momentum Distribution of a Trapped Fermi Gas  

OpenAIRE

We present measurements of the temperature-dependent momentum distribution of a trapped Fermi gas consisting of $^{40}$K in the BCS-BEC crossover regime. Accompanying theoretical results based upon a simple mean-field ground state are compared to the experimental data. Non-monotonic effects associated with temperature, $T$, arise from the competition between thermal broadening and a narrowing of the distribution induced by the decrease in the excitation gap $\\Delta(T)$ with ...

Chen, Qijin; Regal, C. A.; Jin, D. S.; Levin, K.

2006-01-01

345

Emission of carcinogenic components with automobile exhausts.  

OpenAIRE

Different sampling methods for mutagenic polynuclear aromatic hydrocarbons (PAH) are described. These methods involve either direct sampling of raw exhausts which prior to filtering are cooled in a condenser, or filter sampling of exhausts diluted in a tunnel. The relevance of gas-phase PAHs of samples from diluted exhausts is discussed; methods used are either adsorbents (XAD-2) or cryogenic condensation. The emission of benzo(a)pyrene and certain other PAHs is reported from vehicles using d...

Stenberg, U.; Alsberg, T.; Westerholm, R.

1983-01-01

346

New materials in high temperature gas-cooled reactors  

International Nuclear Information System (INIS)

One of the most characteristic properties required for the materials used for high temperature gas-cooled reactor structures is to withstand very high temperature unlike LWRs and FBRs. Generally, the highest temperature of the coolant in high temperature gas-cooled reactors is higher than 700 degC, and since helium is used as the coolant, minute amount of the impurities contained in it have the possibility to restrict the service life of structures. Also the use of coated particle fuel is one feature. Most of the core are constructed with graphite material, and it is also the feature for the safety of these reactors. In order to heighten the safety and economical efficiency of high temperature gas-cooled reactors further hereafter, the extension of fuel life, the improvement of the endurance of piping and heat exchangers, the extension of fuel block and reflector life, the simplification and the reduction of size of structures by the improvemnet of heat insulation, and the improvement of structural safety are conceivable. The materials for control rod cladding tubes, heat exchangers, high temperature piping, fuel cladding, moderators, reflectors and heat insulators are described. (Kako, I.)

347

Discussion of the effects of recirculating exhaust air on performance and efficiency of a typical microturbine  

International Nuclear Information System (INIS)

This paper reports on a specific phenomenon, noticed during steam injection experiments on a microturbine. During the considered experiments, measurements indicated an unsteady inlet air temperature of the compressor, resulting in unstable operation of the microturbine. Non-continuous exhaust air recirculation was a possible explanation for the observed behaviour of the microturbine. The aim of this paper is to investigate and demonstrate the effects of exhaust recirculation on a microgasturbine. Depending on wind direction, exhaust air re-entered the engine, resulting in changing inlet conditions which affects the operating regime of the microturbine. For this paper, a series of experiments were performed in the wind tunnel. These series of experiments allowed investigation of the effect of the wind direction on flue gasses flow. Next to the experiments, steady-state simulations of exhaust recirculation were performed in order to study the effect of exhaust recirculation on thermodynamic performance of the microturbine. Dynamic simulations of the non-continuous recirculation revealed the effects of frequency and amplitude on average performance and stability. Results from simulations supported the important impact of exhaust recirculation. Wind tunnel tests demonstrated the influence of the wind direction on recirculation and revealed the necessity to heighten the stack, thus preventing exhaust recirculation. -- Highlights: ? Unstable operation of a T100 microturbine during steam injection tests was noticed, caused by exhaust gas recirculation. ? Wind tunnel tests were performed to study the effect of the wind direction on the recirculation process. ? Steady-state simulations to investigate the effect of exhaust gas recirculation on thermodynamic performance. ? Dynamic simulations to reveal effects of frequency and amplitude on average performance and stability. ? Wind tunnel tests revealed the necessity to heighten the stack to prevent exhaust recirculation.

348

The effects of strong temperature anisotropy on the kinetic structure of collisionless slow shocks and reconnection exhausts. I. Particle-in-cell simulations  

International Nuclear Information System (INIS)

A 2-D Riemann problem is designed to study the development and dynamics of the slow shocks that are thought to form at the boundaries of reconnection exhausts. Simulations are carried out for varying ratios of normal magnetic field to the transverse upstream magnetic field (i.e., propagation angle with respect to the upstream magnetic field). When the angle is sufficiently oblique, the simulations reveal a large firehose-sense (P||>Pperpendicular) temperature anisotropy in the downstream region, accompanied by a transition from a coplanar slow shock to a non-coplanar rotational mode. In the downstream region the firehose stability parameter ?=1-?0(P||-Pperpendicular)/B2 tends to plateau at 0.25. This balance arises from the competition between counterstreaming ions, which drive ? down, and the scattering due to ion inertial scale waves, which are driven unstable by the downstream rotational wave. At very oblique propagating angles, 2-D turbulence also develops in the downstream region.

349

THE FLUIDIZED BED DRYING AT OSCILLATING GAS TEMPERATURE  

OpenAIRE

The fluidized bed drying of granular materials at oscillating gas temperature have been investigated theoretically and experimentally. The model of the diffusion in the sphere was solved analitically and proved experimentally. The parameters ? and ? were proven to have essential influence on thermal energy saving. The energy saving of the oscillating system is up to a few per cent.

Maria G?owacka; Jerzy Malczewski

1985-01-01

350

Technology of high temperature combustion of sanitary landfill gas  

Energy Technology Data Exchange (ETDEWEB)

Methane produced in residential waste dumps can be used thermally. However, necessary prerequisites are often lacking. In this case, the gas should be at least collected and flared; but in order to prevent dioxin formation, high temperature combustion should be selected. The authors describe associated problems and solutions. Special emphasis should be placed on combustion chamber lining, burner technology, safety technology and control technology.

Roediger, M.; Glomm, H.

1988-05-01

351

Gas counter for low temperature Conversion Electron Mössbauer Spectroscopy experiments  

International Nuclear Information System (INIS)

The operation of a gas counter, designed for Conversion Electron Mössbauer Spectroscopy measurement at low temperature, has been investigated. The experimental setup is described and tested with two pure gases, He and Ne, and two mixtures, He-5%CH4 and He-5%N2. The impacts on the counter performances of the applied voltage, the gas composition and pressure as well as the gas renewing are investigated between 41 K and 300 K. This investigation is made using 119Sn Mössbauer source and metallic tin absorber. The appropriate operating conditions of the present counter have been established for temperatures down to 41 K for both pure gases, and 61 and 85 K for He-5%N2 and He-5%CH4 respectively.

352

Gas counter for low temperature Conversion Electron Moessbauer Spectroscopy experiments  

Energy Technology Data Exchange (ETDEWEB)

The operation of a gas counter, designed for Conversion Electron Moessbauer Spectroscopy measurement at low temperature, has been investigated. The experimental setup is described and tested with two pure gases, He and Ne, and two mixtures, He-5%CH{sub 4} and He-5%N{sub 2}. The impacts on the counter performances of the applied voltage, the gas composition and pressure as well as the gas renewing are investigated between 41 K and 300 K. This investigation is made using {sup 119}Sn Moessbauer source and metallic tin absorber. The appropriate operating conditions of the present counter have been established for temperatures down to 41 K for both pure gases, and 61 and 85 K for He-5%N{sub 2} and He-5%CH{sub 4} respectively.

Sougrati, Moulay Tahar; Jean, Malick; Jouen, Samuel, E-mail: samuel.jouen@univ-rouen.fr; Vaudolon, Charly; Hannoyer, Beatrice [Universite de Rouen, Groupe de Physique des Materiaux (France)

2012-05-15

353

A review of helium gas turbine technology for high-temperature gas-cooled reactors  

International Nuclear Information System (INIS)

Current High-Temperature Gas-cooled Reactors (HTGRs) are based on a closed brayton cycle with helium gas as the working fluid. Thermodynamic performance of the axial-flow helium gas turbines is of critical concern as it considerably affects the overall cycle efficiency. Helium gas turbines pose some design challenges compared to steam or air turbomachinery because of the physical properties of helium and the uniqueness of the operating conditions at high pressure with low pressure ratio. This report present a review of the helium Brayton cycle experiences in Germany and in Japan. The design and availability of helium gas turbines for HTGR are also presented in this study. We have developed a new throughflow calculation code to calculate the design-point performance of helium gas turbines. Use of the method has been illustrated by applying it to the GTHTR300 reference

354

Electron density and temperature of gas-temperature-dependent cryoplasma jet  

International Nuclear Information System (INIS)

A microsize cryoplasma jet was developed and analyzed at plasma gas temperatures ranging from room temperature down to 5 K. Experimental results obtained from optical emission spectroscopy and current-voltage measurements indicate that the average electron density and electron temperature of the cryoplasma jet depend on the gas temperature. In particular, the electron temperature in the cryoplasma starts to decrease rapidly near 60 K from about 13 eV at 60 K to 2 eV at 5 K, while the electron density increases from about 109 to approximately 1012 cm-3 from room temperature to 5 K. This phenomenon induces an increase in the Coulomb interaction between electrons, which can be explained by the virial equation of state.

355

A mechanism for fission gas release from high temperature fuel  

International Nuclear Information System (INIS)

Substantial gas release is observed from columnar grain and hot equi-axed fuel. Here we demonstrate that close agreement with experimentally observed releases is obtained using the gas release model SINGAR which is based on the thermal resolution of gas atoms from intragranular bubbles. This model has already been shown to predict satisfactorily the observed releases for a diverse range of experimental conditions which include (out-of-pile) rapid heating to the fuel melting temperature, out-of-pile isothermal anneals and in-pile isothermal anneals. The current paper further extends the range for which SINGAR gives satisfactory predictions and adds important support to the use of SINGAR for gas analysis. (orig.)

356

Determining noncondensible gas fractions at elevated temperatures and pressures using wet and dry bulb temperature measurements  

International Nuclear Information System (INIS)

The work reported in this note was undertaken to provide a method of determining the noncondensible gas fractions in a steam-gas mixture such as might be found in large reactor safety experiment like LOFT. In essence, the method used involves measuring the wet and dry bulb temperatures and using an algorithm, in place of the psychometric chart, to determine the partial pressure of the noncondensible gas in the mixture. In accomplishing this, the authors did the following: (1) extended the use of wet and dry-bulb temperature readings to determine mixture composition up to a temperature of 589 K and a pressure of 4.13 x 106 Pa. (2) developed an algorithm to reduce the data (3) found which materials would survive those temperatures

357

Low temperature catalytic combustion of natural gas - hydrogen - air mixtures  

Energy Technology Data Exchange (ETDEWEB)

The low temperature catalytic combustion of natural gas - air mixtures would allow the development of no-NO{sub x} burners for heating and power applications. Using commercially available catalysts, the room temperature ignition of methane-propane-air mixtures has been shown in laboratory reactors with combustion efficiencies over 95% and maximum temperatures less than 700{sup o}C. After a 500 hour stability test, severe deactivation of both methane and propane oxidation functions was observed. In cooperation with industrial partners, scaleup to 3 kW is being investigated together with startup dynamics and catalyst stability. (author) 3 figs., 3 refs.

Newson, E.; Roth, F. von; Hottinger, P.; Truong, T.B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

358

Grain surface temperature in noble gas discharges: Refined analytical model  

International Nuclear Information System (INIS)

A model of grain surface temperature in a low-pressure weakly ionized complex plasma is refined by taking into account the effect of rare ion-neutral collisions in the vicinity of the grain. These collisions enhance plasma collection by the grain and can result in a considerable increase of the grain temperature. It is shown that the collision enhanced plasma collection model yields generally better agreement with the results of existing experiments. The effect of the temperature difference between the grain surface and the surrounding gas on the grain-grain interaction potential is also briefly discussed

359

Simulation of fission gas release during temperature transients  

International Nuclear Information System (INIS)

Paper discusses the release of fission gases Xe and Kr as a diffusion process. It takes into account gas generation due to fission, gas precipitation in bubbles within the grains, diffusion of gas towards the grain boundaries, formation of grain boundary bubbles, its saturation and subsequent gas release, resolution of the gas contained into both types of bubbles and grain growth. Temperature profile calculations have allowed to evaluate the gas distribution in fuel pellet and in each grain. Analytical and numerical methods are used. Several experiments are simulated with the code and a good agreement between the measured Paper discusses the release of fission gases Xe and Kr as a diffusion process. It takes into and calculated results has been obtained. The influence of the initial grain size and density on fission gas release has been evaluated. It has been found that larger grain size and lower density both yield lower release, but density variation has a minor effect on the release. (author). 10 refs, 4 figs

360

Engine Cylinder Temperature Control  

Science.gov (United States)

A method and apparatus for controlling a temperature in a combustion cylinder in an internal combustion engine. The cylinder is fluidly connected to an intake manifold and an exhaust manifold. The method and apparatus includes increasing a back pressure associated with the exhaust manifold to a level sufficient to maintain a desired quantity of residual exhaust gas in the cylinder, and varying operation of an intake valve located between the intake manifold and the cylinder to an open duration sufficient to maintain a desired quantity of fresh air from the intake manifold to the cylinder, wherein controlling the quantities of residual exhaust gas and fresh air are performed to maintain the temperature in the cylinder at a desired level.

Kilkenny, Jonathan Patrick (Peoria, IL); Duffy, Kevin Patrick (Metamora, IL)

2005-09-27

361

Numerical simulation of wall temperature on gas pipeline due to radiation of natural gas during combustion  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents one of the possible hazardous situations during transportation of gas through the international pipeline. It describes the case when at high-pressure gas pipeline, due to mechanical or chemical effect, cracks and a gas leakage appears and the gas is somehow triggered to burn. As a consequence of heat impingement on the pipe surface, change of material properties (decreasing of strength at high temperatures will occur. In order to avoid greater rapture a reasonable pressure relief rate needs to be applied. Standards in this particular domain of depressurizing procedure are not so exact (DIN EN ISO 23251; API 521. This paper was a part of the project to make initial contribution in defining the appropriate procedure of gas operator behaving during the rare gas leakage and burning situations on pipeline network. The main part of the work consists of two calculations. The first is the numerical simulation of heat radiation of combustible gas, which affects the pipeline, done in the FLUENT software. The second is the implementation of obtained results as a boundary condition in an additional calculation of time resolved wall temperature of the pipe under consideration this temperature depending on the incident flux as well as a number of other heat flow rates, using the Matlab. Simulations were done with the help of the “E.ON Ruhrgas AG” in Essen.

Ili? Marko N.

2012-01-01

362

Helium usage in large, high temperature-gas cooled reactors  

International Nuclear Information System (INIS)

There are several advantages in using a gas in general, and helium in particular as a coolant for nuclear reactors. A gas coolant permits high operating temperatures at moderate pressures resulting in an optimization of pressure, temperature and flow-rate. Gaseous coolants restrict the possibility of a complete loss of coolant accident since they do not change phase. Helium is chemically inert, noncorrosive, absorbs essentially zero neutrinos, makes no contribution to the reactivity of the system, has a low pumping power index, and a high cooling efficiency index. In addition to being used as a coolant for High-Temperature Gas-Cooled Reactors, helium is also utilized for various other purposes. Helium is used to actuate the Reserve Shutdown System of the HTGR thereby introducing negative reactivity as a backup for the reactor scram system. The helium purification system is regenerated by purging with helium. The adsorber columns of the Radioactive Gas Recovery System are purged with helium. Helium is also used to purge and cool the fuel-handling equipment during refueling. (U.S.)

363

Finite-temperature stability of a trapped dipolar Bose gas  

International Nuclear Information System (INIS)

We calculate the stability diagram for a trapped normal Bose gas with dipole-dipole interactions. Our study characterizes the roles of trap geometry, temperature, and short-range interactions on the stability. We predict a robust double instability feature in oblate trapping geometries arising from the interplay of thermal gas saturation and the anisotropy of the interaction. Our results are relevant to current experiments with polar molecules and will be useful in developing strategies to obtain a polar molecule Bose-Einstein condensate.

364

Gas temperature, electron density and electron temperature measurement in a microwave excited microplasma  

International Nuclear Information System (INIS)

Gas temperature, electron density and electron temperature of a microwave excited microplasma are measured by optical emission spectroscopy. This microplasma is generated in the small gap of a microstrip split-ring resonator in argon at near atmospheric pressure. When less than 100 ppm of water is present in the plasma, the gas temperature can be obtained from the rotational temperature of the hydroxyl molecule (A 2?+, v = 0) and the electron density can be measured by the Stark broadening of the hydrogen Balmer ? line. According to a collisional-radiative model, the electron temperature can be estimated from the measured excitation temperature of argon 4p and 5p levels. It is found that the values of these parameters (gas temperature, electron density and temperature) increase when the gap width of the resonator is reduced. However, when the microwave power increases, these parameters, especially the electron density, do not vary significantly. Discussions on this phenomenon, being very different from that in the low-pressure bounded discharges, are provided

365

Gas temperature, electron density and electron temperature measurement in a microwave excited microplasma  

Energy Technology Data Exchange (ETDEWEB)

Gas temperature, electron density and electron temperature of a microwave excited microplasma are measured by optical emission spectroscopy. This microplasma is generated in the small gap of a microstrip split-ring resonator in argon at near atmospheric pressure. When less than 100 ppm of water is present in the plasma, the gas temperature can be obtained from the rotational temperature of the hydroxyl molecule (A {sup 2}{sigma}{sup +}, v = 0) and the electron density can be measured by the Stark broadening of the hydrogen Balmer {beta} line. According to a collisional-radiative model, the electron temperature can be estimated from the measured excitation temperature of argon 4p and 5p levels. It is found that the values of these parameters (gas temperature, electron density and temperature) increase when the gap width of the resonator is reduced. However, when the microwave power increases, these parameters, especially the electron density, do not vary significantly. Discussions on this phenomenon, being very different from that in the low-pressure bounded discharges, are provided.

Zhu Ximing; Chen Wencong; Pu Yikang [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)], E-mail: puyikang@tsinghua.edu.cn

2008-05-21

366

40 CFR 86.1309-90 - Exhaust gas sampling system; Otto-cycle and non-petroleum-fueled engines.  

Science.gov (United States)

...For 1990 through 1994 model year methanol-fueled...the principles of fluid dynamics associated with...For 1990 through 1994 model year methanol-fueled...5.6 °C) of the average operating temperature...during the test. (The average operating...

2010-07-01

367

Feasibility study on different gas turbine cycles for high temperature gas-cooled reactor  

International Nuclear Information System (INIS)

There is growing global interest in modular High Temperature Gas-cooled Reactor (HTGR), due to its attractive features of enhanced safety. Meanwhile, the gas turbine cycle (Brayton cycle) appears to be the best near-term power conversion method for maximizing the economic potential of modular HTGR. Therefore the modular HTGR coupled with the gas turbine cycle is considered as one of the leading candidate concepts for future nuclear power deployment. In this paper, several typical gas turbine cycles for modular HTGRs are investigated theoretically, including close direct cycle (using helium as the working fluid), closed indirect cycle (using helium or nitrogen) and open indirect cycle (using air). Key factors affecting the efficiency of a cycle include the turbine inlet temperature, compressor and turbine adiabatic efficiencies, recuperator effectiveness and cycle fractional pressure loss. These parameters and their effects on the cycle performance are examined in detail. Each cycle is analyzed and optimized from the thermodynamic point of view and its turbocompressor, one of the most important components for the cycle, is aerodynamically designed. As a result, the closed direct cycle using helium as the working fluid is an ideal cycle for the modular HTGR gas turbine cycle; however it is not easy to be realized based on current technology. And the closed indirect cycle using helium or nitrogen is a practical one now; it can realize the gas turbine cycle method and makalize the gas turbine cycle method and make the technical bases for the future direct cycle. (author)

368

Design and instrumentation of an automotive heat pump system using ambient air, engine coolant and exhaust gas as a heat source  

International Nuclear Information System (INIS)

Because the amount of waste heat used for comfort heating of the passenger compartment in motor vehicles decreases continuously as a result of the increasing engine efficiencies originating from recent developments in internal combustion engine technology, it is estimated that heat requirement of the passenger compartment in vehicles using future generation diesel engines will not be met by the waste heat taken from the engine coolant. The automotive heat pump (AHP) system can heat the passenger compartment individually, or it can support the present heating system of the vehicle. The AHP system can also be employed in electric vehicles, which do not have waste heat, as well as vehicles driven by a fuel cell. The authors of this paper observed that such an AHP system using ambient air as a heat source could not meet the heat requirement of the compartment when ambient temperature was extremely low. The reason is the decrease in the amount of heat taken from the ambient air as a result of low evaporating temperatures. Furthermore, the moisture condensed from air freezed on the evaporator surface, thus blocking the air flow through it. This problem can be solved by using the heat of engine coolant or exhaust gases. In this case, the AHP system can have a higher heating capacity and reuse waste heat. (author)

369

Full-scale altitude engine test of a turbofan exhaust-gas-forced mixer to reduce thrust specific fuel consumption  

Science.gov (United States)

The specific fuel consumption of a low-bypass-ratio, confluent-flow, turbofan engine was measured with and without a mixer installed. Tests were conducted for flight Mach numbers from 0.3 to 1.4 and altitudes from 10,670 to 14,630 meters (35,000 to 48,000 ft) for core-stream-to-fan-stream temperature ratios of 2.0 and 2.5 and mixing-length-to-diameter ratios of 0.95 and 1.74. For these test conditions, the reduction in specific fuel consumption varied from 2.5 percent to 4.0 percent. Pressure loss measurements as well as temperature and pressure surveys at the mixer inlet, the mixer exit, and the nozzle inlet were made.

Cullom, R. R.; Johnson, R. L.

1977-01-01

370

CO{sub 2}-fertilization via exhaust gas treatment of reciprocating gas engines: developments and experiences; Fertilisation au CO{sub 2} par traitement des gaz provenant de moteurs a gaz alternatifs: developpement et experience  

Energy Technology Data Exchange (ETDEWEB)

The Dutch climate is such that greenhouses are used to produce vegetables, flowers and other plants. To heat the greenhouse, boilers and combined heat and power systems (CHP) are used. CHP has a better fuel utilisation than a boiler because of the simultaneously production of heat and power. In a greenhouse, CO{sub 2} has to be added to compensate the CO{sub 2} consumed by the plants to grow. Higher CO{sub 2} concentration than ambient are being used to increase plant growth and yield. The use of 'clean' flue gas from boilers was common practice but nowadays flue gas of engines can be used after cleaning. Exhaust gas cleaning systems (EGC) based on a Selective Reduction Catalyst and an Oxidation Catalyst make this possible. This paper describes the principle of these EGCs, gives insight into the important parameters which determine the required cleanliness and discusses the research results of Gasunie Research on this topic. It is found that different catalyst makes have their own specific behaviour depending on the monolith and active material and the how the catalyst is manufactured, mechanical mixed or impregnated. The use of CHP gives a high fuel utilisation and, in combination with EGC, increased crop yields. This results in an even more efficient use of the primary fuel, natural gas. (authors)

Bekker, M.; Hoving, K.; Klimstra, J.; Top, H. [N.V. Nederlandse Gasunie (Netherlands)

2000-07-01

371

IAEA high temperature gas-cooled reactor activities  

International Nuclear Information System (INIS)

The IAEA activities on high temperature gas-cooled reactors are conducted with the review and support of the Member states, primarily through the International Working Group on Gas-Cooled Reactors (IWG-GCR). This paper summarises the results of the IAEA gas-cooled reactor project activities in recent years along with ongoing current activities through a review of Co-ordinated Research Projects (CRPs), meetings and other international efforts. A series of three recently completed CRPs have addressed the key areas of reactor physics for LEU fuel, retention of fission products and removal of post shutdown decay heat through passive heat transport mechanisms. These activities along with other completed and ongoing supporting CRPs and meetings are summarised with reference to detailed documentation of the results. (authors)

372

The effect of high temperatures on tropical forest gas exchange.  

Science.gov (United States)

Further research is required to understand the sensitivity of tropical forest to climate warming. Previous research has shown that tropical forest photosynthesis decreases and respiration increases at high leaf temperatures and that tree growth is reduced in years with higher average air temperatures (Clark et al 2003). Models indicate that the climate related destruction of the Amazon forest will amplify global warming by 1.5¢ª C, resulting in a mean temperature increase of 5.5¢ª C, as compared with 4¢ª C without this carbon cycle feedback (Cox et al 2000). These studies demonstrate the importance of temperature on tropical forest gas exchange. At the LBA Tapajos km 83 site we determined what controls tropical leaf temperature and how temperature affects photosynthesis and respiration. Sunlit leaves were substantially warmer than air temperatures and this had a negative effect on photosynthesis and stomatal conductance. We used eddy flux data to compare intervals of 10 minute cloudy periods followed by 20 minute sunny periods to see if similar trends could be seen at both the leaf and canopy level. The longer the sunny interval the warmer the canopy became and canopy conductance and CO2 exchange declined correspondingly. As the canopy warmed u* increased which increased turbulence and kept the canopy temperature from rising more. Long light intervals can cause heat stress in tropical forests but due to the very cloudy nature of the tropics such intervals are rare. However, if the tropics become both warmer and less cloudy such heat stress will increase.

Doughty, C. E.; Goulden, M.; Miller, S.; Da Rocha, H.

2006-12-01

373

Simple and sensitive method for determination of nitrated polycyclic aromatic hydrocarbons in diesel exhaust particles by gas chromatography-negative ion chemical ionisation tandem mass spectrometry.  

Science.gov (United States)

An extremely simple and sensitive method was developed for determination of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs; mono-nitro-PAHs and dinitropyrenes) in diesel exhaust particles (DEPs) by gas chromatography-negative ion chemical ionisation tandem mass spectrometry (GC/NCI/MS/MS). We used two types of column in GC/NCI/MS/MS analysis. A polar column was used for determination of mono-nitro-PAHs, and a non-polar column was used for determination of dinitropyrenes and mono-nitro-PAHs except nitrofluoranthenes. The proposed method requires no clean-up procedure. The limits of detection ranged from 0.01 to 0.09 pg for all compounds tested. The applicability of the method to DEP samples was validated using diesel particulate standard reference materials (SRMs). Although DEPs contain complex matrices, all compounds could be detected easily in SRM2975 (diesel particulate matter) and SRM1975 (diesel particulate extract) without a clean-up procedure. The RSDs were less than 5% for all compounds examined. The quantitative results for SRMs exhibited good agreement with the available data in the literature. These results indicate that the proposed GC/NCI/MS/MS method is useful for determination of nitro-PAHs in DEP samples. PMID:17619018

Kawanaka, Youhei; Sakamoto, Kazuhiko; Wang, Ning; Yun, Sun-Ja

2007-09-01

374

Power Conversion Study for High Temperature Gas-Cooled Reactors  

International Nuclear Information System (INIS)

The Idaho National Laboratory (INL) is investigating a Brayton cycle efficiency improvement on a high temperature gas-cooled reactor (HTGR) as part of Generation-IV nuclear engineering research initiative. There are some technical issues to be resolved before the selection of the final design of the high temperature gas cooled reactor, called as a Next Generation Nuclear Plant (NGNP), which is supposed to be built at the INEEL by year 2017. The technical issues are the selection of the working fluid, direct vs. indirect cycle, power cycle type, the optimized design in terms of a number of intercoolers, and others. In this paper, we investigated a number of working fluids for the power conversion loop, direct versus indirect cycle, the effect of intercoolers, and other thermal hydraulics issues. However, in this paper, we present part of the results we have obtained. HYSYS computer code was used along with a computer model developed using Visual Basic computer language

375

Gas diffusion and temperature dependence of bubble nucleation during irradiation  

DEFF Research Database (Denmark)

The continuous production of gases at relatively high rates under fusion irradiation conditions may enhance the nucleation of cavities. This can cause dimensional changes and could induce embrittlement arising from gas accumulation on grain boundaries. Computer calculations have been made of the diatomic nucleation of helium bubbles, assuming helium to diffuse substitutionally, with radiation-enhanced diffusion at lower temperatures. The calculated temperature dependence of the bubble density shows excellent agreement with that observed in 600 MeV proton irradiations, including a reduction in activation energy below Tm/2. The coalescence of diatomic nuclei due to Brownian motion markedly improves the agreement and also provides a well-defined terminal density. Bubble nucleation by this mechanism is sufficiently fast to inhibit any appreciable initial loss of gas to grain boundaries during the nucleation period, provided that incubation effects do not occur.

Foreman, A. J. E.; Singh, Bachu Narain

1986-01-01

376

High temperature gas cooled reactor steam-methane reformer design  

International Nuclear Information System (INIS)

The concept of the long distance transportation of process heat energy from a High Temperature Gas Cooled Reactor (HTGR) heat source, based on the steam-methane reforming reaction, is being evaluated by the Department of Energy as an energy source/application for use early in the 21st century. This paper summaries the design of a helium heated steam reformer utilized in conjunction with an intermediate loop, 850/degree/C reactor outlet temperature, HTGR process heat plant concept. This paper also discusses various design considerations leading to the mechanical design features, the thermochemical performance, the materials selection and the structural design analysis. 12 refs

377

Gas temperature and electron temperature measurements by emission spectroscopy for an atmospheric microplasma  

International Nuclear Information System (INIS)

A microplasma suitable for material processing at atmospheric pressure in argon and argon-oxygen mixtures is being studied here. The microplasma is ignited by a high voltage dc pulse and sustained by low power (1-5 W) at 450 MHz. the mechanisms responsible for sustaining the microplasma require a more detailed analysis, which will be the subject of further study. Here it is shown that the microplasma is in nonequilibrium and appears to be in glow mode. The effect of power and oxygen content is also analyzed in terms of gas temperature and electron temperature. Both the gas temperature and the electron temperature have been determined by spectral emission and for the latter a very simple method has been used based on a collisional-radiative model. It is observed that power coupling is affected by a combination of factors and that prediction and control of the energy flow are not always straightforward even for simple argon plasmas. Varying gas content concentration has shown that oxygen creates a preferential energy channel towards increasing the gas temperature. Overall the results have shown that combined multiple diagnostics are necessary to understand plasma characteristics and that spectral emission can represent a valuable tool for tailoring microplasma to specific processing requirements

378

Properties of super alloys for high temperature gas cooled reactor  

International Nuclear Information System (INIS)

The existing data on the properties at high temperature in helium gas of iron base super alloys. Incoloy-800, -802 and -807, nickel base super alloys, Hastelloy-X, Inconel-600, -617 and -625, and a casting alloy HK-40 were collectively evaluated from the viewpoint of the selection of material for HTGRs. These properties include corrosion resistance, strength and toughness, weldability, tube making, formability, radioactivation, etc. Creep strength was specially studied, taking into consideration the data on the creep characteristics in the actual helium gas atmosphere. The necessity of further long run creep data is suggested. Hastelloy-X has completely stable corrosion resistance at high temperature in helium gas. Incoloy 800 and 807 and Inconel 617 are not preferable in view of corrosion resistance. The creep strength of Inconel 617 extraporated to 1,000 deg C for 100,000 hours in air was the greatest rupture strength of 0.6 kg/mm2 in all above alloys. However, its strength in helium gas began to fall during a relatively short time, so that its creep strength must be re-evaluated in the use for long time. The radioactivation and separation of oxide film in primary construction materials came into question, Inconel 617 and Incoloy 807 showed high induced radioactivity intensity. Generally speaking, in case of nickel base alloys such as Hastelloy-X, oxide film is difficult to break away. (Iwakiri, K.)

379

A highly efficient six-stroke internal combustion engine cycle with water injection for in-cylinder exhaust heat recovery  

International Nuclear Information System (INIS)

A concept adding two strokes to the Otto or Diesel engine cycle to increase fuel efficiency is presented here. It can be thought of as a four-stroke Otto or Diesel cycle followed by a two-stroke heat recovery steam cycle. A partial exhaust event coupled with water injection adds an additional power stroke. Waste heat from two sources is effectively converted into usable work: engine coolant and exhaust gas. An ideal thermodynamics model of the exhaust gas compression, water injection and expansion was used to investigate this modification. By changing the exhaust valve closing timing during the exhaust stroke, the optimum amount of exhaust can be recompressed, maximizing the net mean effective pressure of the steam expansion stroke (MEPsteam). The valve closing timing for maximum MEPsteam is limited by either 1 bar or the dew point temperature of the expansion gas/moisture mixture when the exhaust valve opens. The range of MEPsteam calculated for the geometry of a conventional gasoline engine and is from 0.75 to 2.5 bars. Typical combustion mean effective pressures (MEPcombustion) of naturally aspirated gasoline engines are up to 10 bar, thus this concept has the potential to significantly increase the engine efficiency and fuel economy.

380

Determination of gas temperature in the plasmatron channel according to the known distribution of electronic temperature  

OpenAIRE

An analytical method to calculate the temperature distribution of heavy particles in the channel of the plasma torch on the known distribution of the electronic temperature has been proposed. The results can be useful for a number of model calculations in determining the most effective conditions of gas blowing through the plasma torch with the purpose of heating the heavy component. This approach allows us to understand full details about the heating of co...

Gerasimov Alexander V.; Kirpichnikov Alexander P.; Rachevsky Leonid A.

2013-01-01

381

High temperature reformation of aluminum and chlorine compounds behind the Mach disk of a solid-fuel rocket exhaust  

Science.gov (United States)

Chemical reactions expected to occur among the constituents of solid-fuel rocket engine effluents in the hot region behind a Mach disk are analyzed theoretically. With the use of a rocket plume model that assumes the flow to be separated in the base region, and a chemical reaction scheme that includes evaporation of alumina and the associated reactions of 17 gas species, the reformation of the effluent is calculated. It is shown that AlClO and AlOH are produced in exchange for a corresponding reduction in the amounts of HCl and Al2O3. For the case of the space shuttle booster engines, up to 2% of the original mass of the rocket fuel can possibly be converted to these two new species and deposited in the atmosphere between the altitudes of 10 and 40 km. No adverse effects on the atmospheric environment are anticipated with the addition of these two new species.

Park, C.

1976-01-01

382

Combustion Noise and Pollutants Prediction for Injection Pattern and Exhaust Gas Recirculation Tuning in an Automotive Common-Rail Diesel Engine  

Directory of Open Access Journals (Sweden)

Full Text Available In the last years, emissions standards for internal combustion engines are becoming more and more restrictive, particularly for NOx and soot emissions from Diesel engines. In order to comply with these requirements, OEMs have to face with innovative combustion concepts and/or sophisticate after-treatment devices. In both cases, the role of the Engine Management System (EMS is increasingly essential, following the large number of actuators and sensors introduced and the need to meet customer expectations on performance and comfort. On the other hand, the large number of control variables to be tuned imposes a massive recourse to the experimental testing which is poorly sustainable in terms of time and money. In order to reduce the experimental effort and the time to market, the application of simulation models for EMS calibration has become fundamental. Predictive models, validated against a limited amount of experimental data, allow performing detailed analysis on the influence of engine control variables on pollutants, comfort and performance. In this paper, a simulation analysis on the impact of injection pattern and Exhaust Gas Recirculation (EGR rate on fuel consumption, combustion noise, NO and soot emissions is presented for an automotive Common-Rail Diesel engine. Simulations are accomplished by means of a quasi-dimensional multi-zone model of in-cylinder processes. Furthermore a methodology for in-cylinder pressure processing is presented to estimate combustion noise contribution to radiated noise. Model validation is carried out by comparing simulated in-cylinder pressure traces and exhaust emissions with experimental data measured at the test bench in steady-state conditions. Effects of control variables on engine performance, noise and pollutants are analyzed by imposing significant deviation of EGR rate and injection pattern (i.e. rail pressure, start-of-injection, number of injections. The results evidence that quasi-dimensional in-cylinder models can be effective in supporting the engine control design toward the optimal tuning of EMS with significant saving of time and money.

Arsie Ivan

2015-01-01

383

Chemical analysis and ozone formation potential of exhaust from dual-fuel (liquefied petroleum gas/gasoline) light duty vehicles  

Science.gov (United States)

Measures must be undertaken to lower the transport sector's contribution to anthropogenic emissions. Vehicles powered by liquefied petroleum gas (LPG) are an option due to their reduced emissions of air pollutants compared to engines with conventional fuels. In the present study, ten different dual-fuel LPG/gasoline light duty vehicles were tested, which all complied with European emission level legislation EURO-4. Tests with LPG and gasoline were performed on a chassis dynamometer by applying the New European Driving Cycle (NEDC) and emission factors and ozone formation potentials of both kinds of fuels were compared. The components investigated comprised regulated compounds, CO 2, volatile hydrocarbons and carbonyls. On-line analysis of aromatic species was carried out by resonance-enhanced multiphoton ionization-time-of-flight mass spectrometry (REMPI-TOFMS). We demonstrate that utilization of LPG can entail some environmental benefits by reducing emissions. However, for dual-fuel LPG/gasoline vehicles running on LPG the benefits are less than expected. The main reason is that dual-fuel vehicles usually start the engine up on gasoline even when LPG is selected as fuel. This cold-start phase is crucial for the quality of the emissions. Moreover, we demonstrate an influence on the chemical composition of emissions of vehicle performance, fuel and the evaporative emission system of the vehicles.

Adam, T. W.; Astorga, C.; Clairotte, M.; Duane, M.; Elsasser, M.; Krasenbrink, A.; Larsen, B. R.; Manfredi, U.; Martini, G.; Montero, L.; Sklorz, M.; Zimmermann, R.; Perujo, A.

2011-06-01

384

Exhaust gas emissions from various automotive fuels for light-duty vehicles. Effects on health, environment and energy utilization  

International Nuclear Information System (INIS)

The main aim of the investigation has been to assess the effects on health and environment from various alternative fuels for light-duty vehicles. Effects that can be identified and quantified, such as acidification, ozone formation, cancer risk and climate change, have been of primary interest but other effects, such as respiratory diseases, have also been investigated. Data have been collected through literature surveys for subsequent calculation of the mentioned effects in different time-frames. Corrections have been used to take into consideration the influence of climate, ageing and driving pattern. Emissions generated in fuel production have also been accounted for. The most significant and important differences between the fuels have been found for effects as ozone formation cancer risk and particulate emissions. Alternative fuels, such as methanol and methane (natural gas and biogas), significantly decrease the ozone formation in comparison to petrol, while ethanol, methanol and methane are advantageous concerning cancer risk. The particulate emissions are considerably higher for diesel engines fuelled by diesel oil and RME in comparison to the other fuels. In the future, the importance of acid emissions in the fuel production will increase since the NOx and SOx emissions will decrease from the vehicles. The emissions of climate gases could be significantly reduced by using non-fossil fuels but the efficiency of the drive train is also of importance. The technical development potential for further emission reductions is considerable for all fuels but the advantage for the best fuel options will remain in the future

385

40 CFR 1065.330 - Exhaust-flow calibration.  

Science.gov (United States)

...a calibration subsonic venturi or ultrasonic flow meter and simulate exhaust temperatures by incorporating...between the calibration meter and the exhaust-flow meter. If you can demonstrate that the flow meter to be calibrated is insensitive to...

2010-07-01

386

Roles of catalytic oxidation in control of vehicle exhaust emissions  

International Nuclear Information System (INIS)

Catalytic oxidation was initially associated with the early development of catalysis and it subsequently became a part of many industrial processes, so it is not surprising it was used to remove hydrocarbons and CO when it became necessary to control these emissions from cars. Later NOx was reduced in a process involving reduction over a Pt/Rh catalyst followed by air injection in front of a Pt-based oxidation catalyst. If over-reduction of NO to NH3 took place, or if H2S was produced, it was important these undesirable species were converted to NOx and SOx in the catalytic oxidation stage. When exhaust gas composition could be kept stoichiometric hydrocarbons, CO and NOx were simultaneously converted over a single Pt/Rh three-way catalyst (TWC). With modern TWCs car tailpipe emissions can be exceptionally low. NO is not catalytically dissociated to O2 and N2 in the presence of O2, it can only be reduced to N2. Its control from lean-burn gasoline engines involves catalytic oxidation to NO2 and thence nitrate that is stored and periodically reduced to N2 by exhaust gas enrichment. This method is being modified for diesel engines. These engines produce soot, and filtration is being introduced to remove it. The exhaust temperature of heavy-duty diesels is sufficient (250-400oC) for NO to be catalytically oxidised to NO2 over an upstream platinum catalyst that smover an upstream platinum catalyst that smoothly oxidises soot in the filter. The exhaust gas temperature of passenger car diesels is too low for this to take place all of the time, so trapped soot is periodically burnt in O2 above 550oC. Catalytic oxidation of higher than normal amounts of hydrocarbon and CO over an upstream catalyst is used to give sufficient temperature for soot combustion with O2 to take place. (author)

387

Exhaust detritiation system for JET  

International Nuclear Information System (INIS)

If the torus or other tritium containment is breached for maintenance or accidentally, the Exhaust Detritiation System (EDS) prevents the escape of tritium to the Torus Hall, and elsewhere, by maintaining the breached system al slightly sub-atmospheric pressure. The exhaust gas from the breached system is detritiated and discharged through the stack. The system includes catalytic recombiners for the oxidation of tritiated compounds, and molicular sieve driers for the recovery of water vapour. Provision for internal recirculation of the gas allows a fast start-up of torus detritiation operations (within to minutes) and processing of feed gas at a variable rate. An isotopic swamping technique is used, as required, to displace HTO from molecular sieve during the drier regeneration cycle. All major operations are controlled by a programmable control system. (author). 4 refs.; 5 figs.; 2 tabs

388

Corrosion of Alloy 617 in high-temperature gas environments  

International Nuclear Information System (INIS)

High-temperature gas-cooled reactors (HTGRs) with helium gas as the primary coolant have been considered as one type of the Generation IV nuclear power reactor systems. Several nickel-based superalloys, including Alloy 617, are potential structural materials to serve as pressure boundary components, such as the intermediate heat exchanger (IHX) in an HTGR. Impurities in a helium coolant, such as H2O and O2, can interact with structural materials at working temperatures of >900 °C, leading to serious degradation on these materials. In addition, defects in IHX surface coatings would allow these species to reach and interact with the external surfaces of these components, leading to similar or even more serious degradation. In this study we investigated the oxidation behavior of Alloy 617 in high-temperature, gaseous environments with various levels of O2 and H2O. A series of general corrosion tests were conducted at test temperatures of 650 °C, 750 °C, 850 °C and 950 °C under various coolant compositions of dry air, 1% O2, 10% relative humidity (RH), and 50% RH. Preliminary results showed that the surface morphologies of the Alloy 617 samples exhibited distinct evidence of intergranular corrosion. Compact chromium oxide layers were observed on the sample surfaces. The oxidation mechanisms of this alloy in the designated environments are discussed

389

Design of indirect gas turbine cycle for a modular high temperature gas cooled reactor  

International Nuclear Information System (INIS)

This paper describes a design of the indirect gas turbine cycle for the 200MWt pebble bed MHTGR. In the design, the helium out of the Intermediate Heat eXchanger (IHX) is extracted to a small RPV cooling system. The gas flows through a small RPV recuperator and is cooled down, then it is used to cool the RPV. The whole primary circuit is integrated in a pressure vessel. The core inlet/outlet temperatures are 550 deg. C/900 deg. C, which can supply a gas heat source of 500 deg. C/850 deg. C in the secondary side. The heat source could be used to drive a nitrogen gas turbine cycle and a plant busbar electricity generation efficiency of about 48% is estimated. The thermodynamic calculation, preliminary design of the system components, and the important accident analysis are described in this paper. (author). 5 refs, 3 figs, 4 tabs

390

CHARACTERIZING TRANSITION TEMPERATURE GAS IN THE GALACTIC CORONA  

International Nuclear Information System (INIS)

We present a study of the properties of the transition temperature (T ? 105 K) gas in the Milky Way corona, based on the measurements of O VI, N V, C IV, Si IV, and Fe III absorption lines seen in the far-ultraviolet spectra of 58 sight lines to extragalactic targets, obtained with the Far-Ultraviolet Spectroscopic Explorer and the Space Telescope Imaging Spectrograph. In many sight lines the Galactic absorption profiles show multiple components, which are analyzed separately. We find that the highly ionized atoms are distributed irregularly in a layer with a scale height of about 3 kpc, which rotates along with the gas in the disk, without an obvious gradient in the rotation velocity away from the Galactic plane. Within this layer the gas has randomly oriented velocities with a dispersion of 40-60 km s–1. On average the integrated column densities are log N(O VI) = 14.3, log N(N V) = 13.5, log N(C IV) = 14.2, log N(Si IV) = 13.6, and log N(Fe III) = 14.2, with a dispersion of just 0.2 dex in each case. In sight lines around the Galactic center and Galactic north pole, all column densities are enhanced by a factor ?2, while at intermediate latitudes in the southern sky there is a deficit in N(O VI) of about a factor of two, but no deficit for the other ions. We compare the column densities and ionic ratios to a series of theoretical predictions: collisional ionization equilibrium, shock ionization, conductive interfaces, turbulent mixing, ttive interfaces, turbulent mixing, thick disk supernovae, static non-equilibrium ionization (NIE) radiative cooling, and an NIE radiative cooling model in which the gas flows through the cooling zone. None of these models can fully reproduce the data, but it is clear that NIE radiative cooling is important in generating the transition temperature gas.

391

Factors influencing the effectiveness of air injection in reducing exhaust emissions  

Energy Technology Data Exchange (ETDEWEB)

Factors influencing the effectiveness of exhaust port air injection in oxidizing the hydrocarbons and carbon monoxide in engine exhaust gas have been investigated in order to establish guidelines for the engineering of vehicle emission control systems. Single-cylinder engine and vehicle studies have demonstrated that the temperature, composition, and residence time of the exhaust gas-air mixture are basic factors determining both the effectiveness of air injection and the type of oxidation process which occurs in the exhaust system. Both luminous and nonluminous oxidation have been observed. These basic factors are affected by such variables as: engine spark timing and air-fuel ratio, insulation and size of exhaust manifolds, injection air temperature and airflow rate, and the warmup characteristics of the air injection system. The warmup characteristics can be influenced particularly by spark timing and exhaust manifold design. By optimizing the operating and design variables, it has been possible to greatly enhance the effectiveness of air injection in reducing hydrocarbon emissions. For example, with an experimental system, a composite hydrocarbon emission of 27 ppM has been measured on a vehicle tested in accordance with the California Motor Vehicle Exhaust Emission Test Procedure. On the other hand, for the same system, the carbon monoxide emission was 0.76%. Increasing the effectiveness of air injection in reducing carbon monoxide emission has proved to be most difficult. Although these experimental systems may not be amenable to product engineering, they do illustrate the potential of air injection for reducing exhaust hydrocarbon and carbon monoxide emissions.

Brownson, D.A.; Stebar, R.F.

392

Temperature effects in a Fermi gas with population imbalance  

International Nuclear Information System (INIS)

We investigate temperature effects in a Fermi gas with imbalanced spin populations. From the general expression of the thermal gap equation we find, in weak coupling limit, an analytical expression for the transition temperature Tc as a function of various possibilities of chemical potential and mass asymmetries between the two particle species. For a range of asymmetry between certain specific values, this equation always has two solutions for Tc, which has been interpreted as a reentrant phenomena or a pairing induced by a temperature effect. We show that the lower Tc is never related to a stable solution. The same results are obtained in the strong coupling limit. The thermodynamical potential is carefully analyzed to avoid consideration of the unstable solutions. We also obtain the tricritical points for the chemical potential and mass imbalanced cases, and beyond these points we properly minimize the thermodynamic potential to find the stable and metastable first-order transition lines

393

Stabilization of high-temperature noble gas matrices  

International Nuclear Information System (INIS)

Previously matrix isolation studies of vibrational energy relaxation and matrix dynamics using high-resolution infrared absorption have been limited to those molecules that were sufficiently soluble in noble gas liquids at cryogenic temperatures. A simple method is described here that can extend the useful temperature range while employing conventional matrix preparation techniques. A less volatile nonabsorbing overcoat is condensed onto the matrix which has been prepared using conventional pulse or continuous deposition methods. Use of the method has been limited to using pure Xe as an overcoat on Ar or Kr matrices and has performed satisfactorily for temperatures up to 600K. The nu3 region for SF6 in an Ar/SF6+10,000 matrix both before and after annealing is shown as an example of use of the method. Studies carried out on CH3F, CD3F, and Ni(CO)4 in Ar matrix are discussed briefly

394

High-Temperature Gas Sensor Array (Electronic Nose) Demonstrated  

Science.gov (United States)

The ability to measure emissions from aeronautic engines and in commercial applications such as automotive emission control and chemical process monitoring is a necessary first step if one is going to actively control those emissions. One single sensor will not give all the information necessary to determine the chemical composition of a high-temperature, harsh environment. Rather, an array of gas sensor arrays--in effect, a high-temperature electronic "nose"--is necessary to characterize the chemical constituents of a diverse, high-temperature environment, such as an emissions stream. The signals produced by this nose could be analyzed to determine the constituents of the emission stream. Although commercial electronic noses for near-room temperature applications exist, they often depend significantly on lower temperature materials or only one sensor type. A separate development effort necessary for a high-temperature electronic nose is being undertaken by the NASA Glenn Research Center, Case Western Reserve University, Ohio State University, and Makel Engineering, Inc. The sensors are specially designed for hightemperature environments. A first-generation high-temperature electronic nose has been demonstrated on a modified automotive engine. This nose sensor array was composed of sensors designed for hightemperature environments fabricated using microelectromechanical-systems- (MEMS-) based technology. The array included a tin-oxide-based sensor doped for nitrogen oxide (NOx) sensitivity, a SiC-based hydrocarbon (CxHy) sensor, and an oxygen sensor (O2). These sensors operate on different principles--resistor, diode, and electrochemical cell, respectively--and each sensor has very different responses to the individual gases in the environment. A picture showing the sensor head for the array is shown in the photograph on the left and the sensors installed in the engine are shown in the photograph on the right. Electronics are interfaced with the sensors for temperature control and signal conditioning, and packaging designed for high temperatures is necessary for the array to survive the engine environment.

Hunter, Gary W.

2002-01-01

395

Challenges on the way to noble gas temperatures on speleothems  

Science.gov (United States)

In the last years, speleothems gained importance as a paleoclimate archive. Nonetheless, so far no proxy in speleothems has really gained acceptance as a commonly used paleotemperature indicator. Application of the noble gas thermometer to speleothem fluid inclusions promises in principle the determination of absolute paleotemperatures. Kluge et al. (2008) and Scheidegger et al. (2010) showed that the precise measurement of noble gas concentrations on fluid inclusions is possible in general. Unfortunately, the extraction and measurement technique presented by Kluge et al. (2008) allowed the determination of reasonable noble gas temperatures (NGTs) only for some samples. Some of the problems which occurred as well as some (possible) solutions will be presented. A general problem for the application of the noble gas thermometer on speleothems is the presence of air-filled inclusions in the speleothem. Noble gases released from them mask the temperature signal of the noble gases dissolved in the water-filled inclusions. In order to reduce the air/water volume ratio, a stepwise extraction technique has been developed successfully. However, often the different extraction steps on one sample lead to temperatures that do not agree well with each other. Samples of the stalagmite H12 from Hoti Cave in Oman showed an excess in neon. A similar neon excess was found by Scheidegger et al. (2010) but for a larger number of samples. They suggest that helium and neon can be situated in voids between the atoms forming the carbonate lattice. However, a sample of stalagmite H12 showed neon excess in the very first extraction step, which is not expected for a matrix related component. The NGTs reported by Kluge et al. (2008) seemed to be 2 to 3 °C too low compared to independent temperature reconstructions. In order to investigate this offset and the overall accuracy of the extraction and measurement technique, tiny amounts of air-equilibrated water (AEW) were measured as test samples. In a first test with these so-called ?AEWs the heavier noble gases (Ar, Kr, Xe) seemed to be underestimated, while a second measurement run did not show this offset. Overall, these tests demonstrated the good reproducibility of better than 5% for the noble gas concentrations.

Marx, T.; Aeschbach-Hertig, W.

2012-04-01

396

Design study on gas turbine high temperature reactor (GTHTR300)  

International Nuclear Information System (INIS)

Japan Atomic Energy Research Institute (JAERI) has been conducting the design study of an original design concept of gas turbine high temperature reactor, the GTHTR300 (Gas Turbine High Temperature Reactor 300). The GTHTR300 is a greatly simplified HTGR-GT plant that leads to substantially reduced technical and cost requirements for earlier technology deployment. Also, it is expected to be an efficient and economically competitive reactor in 2010s due to newly proposed design features such as core design with two-year refueling interval, conventional steel material usage for a reactor pressure vessel, innovative plant flow scheme and horizontally installed gas turbine unit. This paper describes the original design features focusing on reactor core design, fuel design, in-core structure design and reactor pressure vessel design. In addition, a preliminary cost evaluation proved that the capital cost of the GTHTR300 is less than a target cost of 200 thousands Yen/kWe. The present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

397

The effects of strong temperature anisotropy on the kinetic structure of collisionless slow shocks and reconnection exhausts. Part I: PIC simulations  

CERN Document Server

A 2-D Riemann problem is designed to study the development and dynamics of the slow shocks that are thought to form at the boundaries of reconnection exhausts. Simulations are carried out for varying ratios of normal magnetic field to the transverse upstream magnetic field (i.e., propagation angle with respect to the upstream magnetic field). When the angle is sufficiently oblique, the simulations reveal a large firehose-sense (P_parallel>P_perpendicular) temperature anisotropy in the downstream region, accompanied by a transition from a coplanar slow shock to a non-coplanar rotational mode. In the downstream region the firehose stability parameter epsilon=1-mu_0(P_parallel-P_perpendicular)/ B^2 tends to lock in to 0.25. This balance arises from the competition between counterstreaming ions, which drives epsilon down, and the scattering due to ion inertial scale waves, which are driven unstable by the downstream rotational wave. At very oblique propagating angles, 2-D turbulence also develops in the downstrea...

Liu, Yi-Hsin; Swisdak, M

2011-01-01

398

The effects of strong temperature anisotropy on the kinetic structure of collisionless slow shocks and reconnection exhausts. II. Theory  

International Nuclear Information System (INIS)

Simulations of collisionless oblique propagating slow shocks have revealed the existence of a transition associated with a critical temperature anisotropy ? = 1 - ?0(P|| - Pperpendicular)/B2 = 0.25 (Y.-H. Liu, J. F. Drake, and M. Swisdak, Phys. Plasmas 18, 062110 (2011)). An explanation for this phenomenon is proposed here based on anisotropic fluid theory, in particular, the anisotropic derivative nonlinear-Schroedinger-Burgers equation, with an intuitive model of the energy closure for the downstream counter-streaming ions. The anisotropy value of 0.25 is significant because it is closely related to the degeneracy point of the slow and intermediate modes and corresponds to the lower bound of the coplanar to non-coplanar transition that occurs inside a compound slow shock (SS)/rotational discontinuity (RD) wave. This work implies that it is a pair of compound SS/RD waves that bound the outflows in magnetic reconnection, instead of a pair of switch-off slow shocks as in Petschek's model. This fact might explain the rareness of in-situ observations of Petschek-reconnection-associated switch-off slow shocks.

399

High temperature friction and seizure in gas cooled nuclear reactors  

International Nuclear Information System (INIS)

One of the most delicate problems encountered in the gas cooled nuclear reactors is the friction without lubrication in a dry and hot (8000C /14720F) helium atmosphere even at very small velocity. The research and development programs are described together with special tribometers that operate at mode than 10000C (18320F) in dry helium. The most interesting test conditions and results are given for gas nitrited steels and for strongly alloyed Ni-Cr steels coated with chromium carbide by plasma sprayed. The effects of parameters live velocity, travelled distance, contact pressure, roughness, temperature and prolonged stops under charge are described together with the effects of negative phenomena like attachment and chattering

400

Evaluation of high-temperature alloys for helium gas turbines  

International Nuclear Information System (INIS)

Because of the high thermal and mechanical stresses in components of a helium turbine coupled directly to a high-temperature reactor and the stringent nuclear safety requirements, an extensive materials development program has been undertaken. The candidate alloys for turbine blades and hot ducts (nickel and molybdenum-base alloys) and for rotors (1% CrMoV and 12% chromium steels) have been tested under the expected service conditions. The results of creep/rupture, fatigue, and fracture mechanics tests on turbine blade and rotor materials are presented. The gas/metal reactions that occur in the simulated reactor coolant gas and the decontamination behavior of components are also discussed. In addition the development of a molybdenum-base alloy for turbine blading is reported

401

New high temperature gas flow cell developed at ISIS  

International Nuclear Information System (INIS)

A flow-through quartz gas cell, together with a gas flow control and monitoring system, has been designed and constructed at ISIS. This equipment allows neutron powder diffraction data to be collected on samples at temperatures up to around 1300 K when exposed to user chosen mixtures of O2, Ar, CO2, and CO. By exploiting the sensitivity of neutrons to the presence of light atoms such as oxygen, it is possible to probe the crystal structure of oxide materials as a function of oxygen partial pressures down to log10p(O2) of about -20. The resultant structural information can then be correlated with the bulk properties of the materials, whose research and technological interests lie in fields such as energy production, storage materials, catalysis, and earth science.

402

Brayton Cycle for High-Temperature Gas-Cooled Reactors  

International Nuclear Information System (INIS)

This paper describes research on improving the Brayton cycle efficiency for a high-temperature gas-cooled reactor (HTGR). In this study, we are investigating the efficiency of an indirect helium Brayton cycle for the power conversion side of an HTGR power plant. A reference case based on a 250-MW(thermal) pebble bed HTGR was developed using helium gas as a working fluid in both the primary and power conversion sides. The commercial computer code HYSYS was used for process optimization. A numerical model using the Visual-Basic (V-B) computer language was also developed to assist in the evaluation of the Brayton cycle efficiency. Results from both the HYSYS simulation and the V-B model were compared with Japanese calculations based on the 300-MW(electric) Gas Turbine High-Temperature Reactor (GTHTR) that was developed by the Japan Atomic Energy Research Institute. After benchmarking our models, parametric investigations were performed to see the effect of important parameters on the cycle efficiency. We also investigated single-shaft versus multiple-shaft arrangements for the turbomachinery. The results from this study are applicable to other reactor concepts such as fast gas-cooled reactors, supercritical water reactors, and others.The ultimate goal of this study is to use other fluids such as supercritical carbon dioxide for the HTGR power conversion loop in order to improve the cycle efficiency over that of the helium Brayton cycle. This study is in progress, and the cycle. This study is in progress, and the results will be published in a subsequent paper

403

Brayton Cycle for High Temperature Gas-Cooled Reactors  

International Nuclear Information System (INIS)

This paper describes research on improving the Brayton cycle efficiency for a high-temperature gas-cooled reactor (HTGR). In this study, we are investigating the efficiency of an indirect helium Brayton cycle for the power conversion side of an HTGR power plant. A reference case based on a 250-MW(thermal) pebble bed HTGR was developed using helium gas as a working fluid in both the primary and power conversion sides. The commercial computer code HYSYS was used for process optimization. A numerical model using the Visual-Basic (V-B) computer language was also developed to assist in the evaluation of the Brayton cycle efficiency. Results from both the HYSYS simulation and the V-B model were compared with Japanese calculations based on the 300-MW(electric) Gas Turbine High-Temperature Reactor (GTHTR) that was developed by the Japan Atomic Energy Research Institute. After benchmarking our models, parametric investigations were performed to see the effect of important parameters on the cycle efficiency. We also investigated single-shaft versus multiple-shaft arrangements for the turbomachinery. The results from this study are applicable to other reactor concepts such as fast gas-cooled reactors, supercritical water reactors, and others. The ultimate goal of this study is to use other fluids such as supercritical carbon dioxide for the HTGR power conversion loop in order to improve the cycle efficiency over that of the helium Brayton cycle. This study is in progress, and thn cycle. This study is in progress, and the results will be published in a subsequent paper

404

Raman-scattering gas temperature measurements in particle-laden flows  

International Nuclear Information System (INIS)

The feasibility of making time-averaged Raman-scattering temperature measurements in highly luminous flows has been investigated in tests on the Sandia Atmospheric Combustor Exhaust Simulator facility (ACES). In these experiments the diluted exhaust stream from a methane-burning combustor was seeded with 5 ?m diameter fly ash particles. Tests were run at temperatures ranging from 900 to 14500K at particle densities up to 6000 particles/cm3. Measurements were made using a pulsed argon-ion probe laser and a gated detection system for enhancement of signal-to-background ratio. Scans of the Stokes Q-branch vibrational Raman spectrum of nitrogen were fit by calculated spectra in order to determine temperature. The Raman-scattered signal was small but measurable in all cases. There was no apparent laser-induced interference from either fluorescence or particle incandescence. Good agreement between Raman-scattering temperature measurements and radiation-corrected thermocouple mearurements was obtained

405

The determination of regulated and some unregulated exhaust gas components from ethanol blended diesel fuels in comparison with neat diesel and ethanol fuel  

International Nuclear Information System (INIS)

Investigations that have been carried out at Luleaa University of Technology (LTU) show how exhaust gas emissions and engine performance are affected by the composition of the fuels. The fuels that have been tested and compared are two different ethanol blended diesel fuels, 'neat' diesel fuels and neat ethanol fuels. Two different, heavy-duty engines were used for the investigations; one for the neat ethanol fuels and the other for the ethanol blended diesel fuels and neat diesel fuels. The investigation also includes some tests with two oxidizing catalysts. Results from the investigation show that none of the fuels produce emissions exceeding the values of the 13-mode test (ECE R-49, 1997). Lowest HC-emission levels were found for the two 'neat' ethanol fuels although the difference between the HC-emissions can be considered negligible for the studied fuels. An effective reduction in the hydrocarbon emissions was achieved by using a catalyst. The investigation also shows that the NOx emissions were much lower for the neat ethanol fuels than for the other fuels. Even if the CO emissions from the two ethanol fuels were approximately three times higher than for the other investigated fuels the use of a catalyst equalize the CO emissions from the studied fuels. The formaldehyde and acetaldehyde emissions were clearly higher for the neat ethanol fuels than for the other investigated fuels. However, by using a catalyst the formaldehyde emission from the ethanolthe formaldehyde emission from the ethanol fuels could be decreased. Unfortunately, the use of a catalyst also resulted in an increase in the emission of acetaldehyde from the ethanol fuelled engine 10 refs, 11 figs, 5 tabs, 6 appendixes

406

Gas-controlled heat-pipes for accurate temperature measurements  

International Nuclear Information System (INIS)

Several gas-controlled heatpipes are operating at IMGC for primary temperature measurements from 100 to 962 deg. C. One consists of a stainless steel heat-pipe with a single thermometer well and uses 7N-pure mercury as working fluid; another is made in Inconel with six thermometer wells and uses 3N5-pure sodium as working fluid. Both heat-pipes are connected in parallel to the same accurate helium pressure control system made at IMGC. These heatpipes realize a very uniform and stable temperature zone, adequate for measurement at the millikelvin level with platinum resistance thermometers. The paper describes the two heat-pipes and their thermal characteristics, such as the temperature uniformity along the thermometer wells and their temperature response to a pressure change. For the study on the capillary structure, the heating system and the working fluids, heat-pipes in Pyrex glass with a conical connection for their opening and with three thermometer wells have been made. Some results, using pure water and a 3MTM speciality fluid for heat transfer applications, showed that a stability and uniformity of a few millikelvin can be obtained for short-term periods (about 10-15 min) without any pressure control, around the boiling temperature

407

Catalytic removal of methane and NO{sub x} in lean-burn natural-gas engine exhaust; Elimination par catalyse du methane et des NO{sub x} dans les echappements de moteur au gaz naturel a basse combustion  

Energy Technology Data Exchange (ETDEWEB)

We have developed a new catalytic system to reduce the emissions of hydrocarbons, carbon monoxide (CO), and nitrogen oxides (NO{sub x}) contained in the exhaust gases from a lean-burn natural-gas engine. Catalytic oxidation of unburned hydrocarbons and CO in the exhaust has been studied for noble metals supported on alumina. (1) A low-loading catalyst comprising platinum supported on alumina (Pt/alumina) was efficient for the oxidation of CO and hydrocarbons without methane. The CO conversions were maintained at more than 98 % for 20,000 hours over the Pt/alumina. (2) A catalyst comprising platinum and palladium supported on alumina (Pt-Pd/alumina) exhibited higher levels of oxidation of hydrocarbons (including methane) than a catalyst comprising only palladium supported on alumina (Pd/alumina). Its oxidation also lasted longer. The combined effects of the platinum and palladium metals achieved high sulfur dioxide resistance. Increasing the palladium content in the Pt-Pd/alumina catalyst increased the level of oxidation and extended the lifetime of the catalyst. (3) A catalyst comprising silver supported on alumina (Ag/alumina) was effective at reducing the amount of NO{sub X} by using the unburned hydrocarbons in the exhaust gas. The NO{sub x} conversions over Ag/alumina were maintained at more than 30 % for 3,500 hours. We describe a total clean-up system consisting of a Ag/alumina catalyst and a Pt-Pd/alumina catalyst in series on the exhaust gas stream. (authors)

Yamamoto, H.; Satokawa, S.; Yahagi, M.; Yamaseki, K.; Hoshi, F.; Uchida, H.; Yokota, H. [Tokyo Gas Co., Ltd. (Japan)

2000-07-01

408

Thorium fueled high temperature gas cooled reactors. An assessment  

International Nuclear Information System (INIS)

The use of thorium as a fertile fuel for the High Temperature Gas Cooled Reactor (HTR) instead of uranium has been reviewed. It has been concluded that the use of thorium might be beneficial to reduce the actinide waste production. To achieve a real advancement, the uranium of the spent fuel has to be recycled and the requested make-up fissile material for the fresh fuel has to be used in the form of highly-enriched uranium. A self-sustaining fuel cycle may be possible in the HTR of large core size, but this could reduce the inherent safety features of the design. (orig.)

409

Power Conversion Study for High Temperature Gas-Cooled Reactors  

Energy Technology Data Exchange (ETDEWEB)

The Idaho National Laboratory (INL) is investigating a Brayton cycle efficiency improvement on a high temperature gas-cooled reactor (HTGR) as part of Generation-IV nuclear engineering research initiative. There are some technical issues to be resolved before the selection of the final design of the high temperature gascooled reactor, called as a Next Generation Nuclear Plant (NGNP), which is supposed to be built at the INEEL by year 2017. The technical issues are the selection of the working fluid, direct vs. indirect cycle, power cycle type, the optimized design in terms of a number of intercoolers, and others. In this paper, we investigated a number of working fluids for the power conversion loop, direct versus indirect cycle, the effect of intercoolers, and other thermal hydraulics issues. However, in this paper, we present part of the results we have obtained. HYSYS computer code was used along with a computer model developed using Visual Basic computer language.

Chang Oh; Richard Moore; Robert Barner

2005-05-01

410

A study of silver behavior in Gas-turbine High Temperature Gas-cooled Reactor  

Energy Technology Data Exchange (ETDEWEB)

A Gas-turbine High Temperature Gas-cooled Reactor (GT-HTGR) is one of the promising reactor systems of future HTGRs. In the design of GT-HTGR, behavior of fission products, especially of silver, is considered to be important from the view point of maintenance of gas-turbine. A study of silver behavior in the GT-HTGR was carried out based on current knowledge. The purposes of this study were to determine an importance of the silver problem quantitatively, countermeasures to the problem and items of future research and development which will be needed. In this study, inventory, fractional release from fuel, plateout in the primary circuit and radiation dose were evaluated, respectively. Based on this study, it is predicted that gamma-ray from plateout silver in gas-turbine system contributes about a half of total radiation dose after reactor shutdown. In future, more detail data for silver release from fuel, plateout behavior, etc. using the High Temperature Engineering Test Reactor (HTTR), for example, will be needed to carry out reasonable design. (author).

Sawa, Kazuhiro; Tanaka, Toshiyuki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

1995-11-01

411

Gas-discharge flowing counter for high-temperature gas radiochromatography  

International Nuclear Information System (INIS)

An improved design of a gas-discharge flowing counter for high-temperature gas radiochromatography of compounds labelled with radioisotopes is described. The counter is designed for an operating temperature of u.o to 230 deg C. The counting characteristics of the device at t=200 deg C while using Ar and He as carrier and CO2, CH4, and C3H8 as quenching gases are given. The optimum ratio between the carrier and the quenching gas is 1:1. The sensitivity of the gas-discharge counter was determined at 220 deg C when proportioning a sample of tritium-labelled isobutanol and of palmitic acid labelled with radiocarbon. The sensitivity threshold of the counter for isobutanol was 3.5 x 10-9 Ci, and for palmitic acid 1x10-9 Ci. The counter is used to advantage for determining the radiochemical purity of fatty acids, amino acids, and other high-boiling compounds labelled with tritium, carbon-14 and sulphur-35

412

Numerical modeling of exhaust smoke dispersion for a generic frigate and comparisons with experiments  

Science.gov (United States)

The exhaust smoke dispersion for a generic frigate is investigated numerically through the numerical solution of the governing fluid flow, energy, species and turbulence equations. The main objective of this work is to obtain the effects of the yaw angle, velocity ratio and buoyancy on the dispersion of the exhaust smoke. The numerical method is based on the fully conserved control-volume representation of the fully elliptic Navier-Stokes equations. Turbulence is modeled using a two-equation ( k- ?) model. The flow visualization tests using a 1/100 scale model of the frigate in the wind tunnel were also carried out to determine the exhaust plume path and to validate the computational results. The results show that down wash phenomena occurs for the yaw angles between ? =10° and 20°. The results with different exhaust gas temperatures show that the buoyancy effect increases with the increasing of the exhaust gas temperature. However, its effect on the plume rise is less significant in comparison with its momentum. A good agreement between the predictions and experiment results is obtained.

Ergin, Selma; Dobrucal?, Erinç

2014-06-01

413

High temperature phase equilibria in a solar-composition gas  

International Nuclear Information System (INIS)

Using recent additions to thermochemical data on minerals and information on their solid solution behavior, new equilibrium phase diagrams have been computed in a system of solar gas composition (Si, Al, Mg, Ca, Fe, Ni, Ti, Na, K, C, H, O, S, N) in the pressure and temperature ranges of 1 to 10-6 bar and 1153 to 1773 K respectively. These calculations show that Fe-Ni alloy condenses before all silicates included here (except melilite) down to a pressure of 2 x 10-4 bar below which plagioclase and clinopyroxene condense first. Orthopyroxene condenses next followed by ilmenite. Pressure-temperature variation of the chemical composition of melilite, clinopyroxene, orthopyroxene, metal alloy and plagioclase may be used for cosmothermometry and cosmobarometry for equilibrium assemblages. The major transition from the refractory oxides and melilite (the meteorite 'inclusion assemblage') to an assemblage of Fe-Ni alloy, olivine, plagioclase and pyroxenes ('planet-forming') takes place within a narrow interval of pressure and temperature. Small fluctuations of either pressure or temperature across this narrow region result in drastic changes in types and modes of minerals, which may explain the wide mineralogical varieties of meteorites. (author)