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Sample records for combustion exhaust streams

  1. Material and system for catalytic reduction of nitrogen oxide in an exhaust stream of a combustion process

    DOEpatents

    Gardner, Timothy J.; Lott, Stephen E.; Lockwood, Steven J.; McLaughlin, Linda I.

    1998-01-01

    A catalytic material of activated hydrous metal oxide doped with platinum, palladium, or a combination of these, and optionally containing an alkali or alkaline earth metal, that is effective for NO.sub.X reduction in an oxidizing exhaust stream from a combustion process is disclosed. A device for reduction of nitrogen oxides in an exhaust stream, particularly an automotive exhaust stream, the device having a substrate coated with the activated noble-metal doped hydrous metal oxide of the invention is also provided.

  2. Development of All-Solid-State Sensors for Measurement of Nitric Oxide and Ammonia Concentrations by Optical Absorption in Particle-Laden Combustion Exhaust Streams

    SciTech Connect

    Jerald A. Caton; Kalyan Annamalai; Robert P. Lucht

    2006-12-31

    An all-solid-state continuous-wave (cw) laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule has been developed and demonstrated. For the NO sensor, 250 nW of tunable cw ultraviolet radiation is produced by sum-frequency-mixing of 532-nm radiation from a diode-pumped Nd:YAG laser and tunable 395-nm radiation from an external cavity diode laser (ECDL). The sum-frequency-mixing process occurs in a beta-barium borate crystal. The nitric oxide absorption measurements are performed by tuning the ECDL and scanning the sum-frequency-mixed radiation over strong nitric oxide absorption lines near 226 nm. In Year 1 of the research, the nitric oxide sensor was used for measurements in the exhaust of a coal-fired laboratory combustion facility. The Texas A&M University boiler burner facility is a 30 kW (100,000 Btu/hr) downward-fired furnace with a steel shell encasing ceramic insulation. Measurements of nitric oxide concentration in the exhaust stream were performed after modification of the facility for laser based NOx diagnostics. The diode-laser-based ultraviolet absorption measurements were successful even when the beam was severely attenuated by particulate in the exhaust stream and window fouling. Single-laser-sweep measurements were demonstrated with an effective time resolution of 100 msec, limited at this time by the scan rate of our mechanically tuned ECDL system. In Year 2, the Toptica ECDL in the original system was replaced with a Sacher Lasers ECDL. The mode-hop-free tuning range and tuning rate of the Toptica ECDL were 25 GHz and a few Hz, respectively. The mode-hop-free tuning range and tuning rate of the Sacher Lasers ECDL were 90 GHz and a few hundred Hz, respectively. The Sacher Lasers ECDL thus allows us to scan over the entire NO absorption line and to determine the absorption baseline with increased accuracy and precision. The increased tuning rate is an advantage in that data can be acquired much more rapidly and the

  3. Development of All-Solid-State Sensors for Measurement of Nitric Oxide and Ammonia Concentrations by Optical Absorption in Particle-Laden Combustion Exhaust Streams

    SciTech Connect

    Jerald A. Caton; Kalyan Annamalai; Robert P. Lucht

    2005-09-30

    An all-solid-state continuous-wave (cw) laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule has been developed and demonstrated. For the NO sensor, 250 nW of tunable cw ultraviolet radiation is produced by sum-frequency-mixing of 532-nm radiation from a diode-pumped Nd:YAG laser and tunable 395-nm radiation from an external cavity diode laser (ECDL). The sum-frequency-mixing process occurs in a beta-barium borate crystal. The nitric oxide absorption measurements are performed by tuning the ECDL and scanning the sum-frequency-mixed radiation over strong nitric oxide absorption lines near 226 nm. In Year 1 of the research, the nitric oxide sensor was used for measurements in the exhaust of a coal-fired laboratory combustion facility. The Texas A&M University boiler burner facility is a 30 kW (100,000 Btu/hr) downward-fired furnace with a steel shell encasing ceramic insulation. Measurements of nitric oxide concentration in the exhaust stream were performed after modification of the facility for laser based NOx diagnostics. The diode-laser-based ultraviolet absorption measurements were successful even when the beam was severely attenuated by particulate in the exhaust stream and window fouling. Single-laser-sweep measurements were demonstrated with an effective time resolution of 100 msec, limited at this time by the scan rate of our mechanically tuned ECDL system. In Year 2, the Toptica ECDL in the original system was replaced with a Sacher Lasers ECDL. The mode-hop-free tuning range and tuning rate of the Toptica ECDL were 25 GHz and a few Hz, respectively. The mode-hop-free tuning range and tuning rate of the Sacher Lasers ECDL were 90 GHz and a few hundred Hz, respectively. The Sacher Lasers ECDL thus allows us to scan over the entire NO absorption line and to determine the absorption baseline with increased accuracy and precision. The increased tuning rate is an advantage in that data can be acquired much more rapidly and the

  4. DEVELOPMENT OF ALL-SOLID-STATE SENSORS FOR MEASUREMENT OF NITRIC OXIDE AND AMMONIA CONCENTRATIONS BY OPTICAL ABSORPTION IN PARTICLE-LADEN COMBUSTION EXHAUST STREAMS

    SciTech Connect

    Jerald A. Caton; Kalyan Annamalai; Robert P. Lucht

    2004-09-30

    An all-solid-state continuous-wave (cw) laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule has been developed and demonstrated. For the NO sensor, 250 nW of tunable cw ultraviolet radiation is produced by sum-frequency-mixing of 532-nm radiation from a diode-pumped Nd:YAG laser and tunable 395-nm radiation from an external cavity diode laser (ECDL). The sum-frequency-mixing process occurs in a beta-barium borate crystal. The nitric oxide absorption measurements are performed by tuning the ECDL and scanning the sum-frequency-mixed radiation over strong nitric oxide absorption lines near 226 nm. In Year 1 of the research, the nitric oxide sensor was used for measurements in the exhaust of a coal-fired laboratory combustion facility. The Texas A&M University boiler burner facility is a 30 kW (100,000 Btu/hr) downward-fired furnace with a steel shell encasing ceramic insulation. Measurements of nitric oxide concentration in the exhaust stream were performed after modification of the facility for laser based NOx diagnostics. The diode-laser-based ultraviolet absorption measurements were successful even when the beam was severely attenuated by particulate in the exhaust stream and window fouling. Single-laser-sweep measurements were demonstrated with an effective time resolution of 100 msec, limited at this time by the scan rate of our mechanically tuned ECDL system. In Year 2 described in this progress report, the Toptica ECDL in the original system was replaced with a Sacher Lasers ECDL. The mode-hop-free tuning range and tuning rate of the Toptica ECDL were 25 GHz and a few Hz, respectively. The mode-hop-free tuning range and tuning rate of the Sacher Lasers ECDL were 90 GHz and a few hundred Hz, respectively. The Sacher Lasers ECDL thus allows us to scan over the entire NO absorption line and to determine the absorption baseline with increased accuracy and precision. The increased tuning rate is an advantage in that data can be

  5. Two phase exhaust for internal combustion engine

    SciTech Connect

    Vuk, Carl T.

    2011-11-29

    An internal combustion engine having a reciprocating multi cylinder internal combustion engine with multiple valves. At least a pair of exhaust valves are provided and each supply a separate power extraction device. The first exhaust valves connect to a power turbine used to provide additional power to the engine either mechanically or electrically. The flow path from these exhaust valves is smaller in area and volume than a second flow path which is used to deliver products of combustion to a turbocharger turbine. The timing of the exhaust valve events is controlled to produce a higher grade of energy to the power turbine and enhance the ability to extract power from the combustion process.

  6. Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

    DOEpatents

    Wijmans Johannes G.; Merkel, Timothy C.; Baker, Richard W.

    2012-05-15

    A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

  7. Exhaust Nozzle for a Multitube Detonative Combustion Engine

    NASA Technical Reports Server (NTRS)

    Bratkovich, Thomas E.; Williams, Kevin E.; Bussing, Thomas R. A.; Lidstone, Gary L.; Hinkey, John B.

    2004-01-01

    expansion of the pulsed combustion gases from the multiple combustion tubes into a common exhaust stream, in such a manner as to enhance performance in two ways: (1) It reduces the cyclic variations of pressure at the outlets of the combustion tubes so as to keep the pressure approximately constant near the optimum level needed for filling the tubes, regardless of atmospheric pressure at the altitude of operation; and (2) It maximizes the transfer of momentum from the exhaust gas to the engine, thereby maximizing thrust. The figure depicts a typical engine equipped with a nozzle according to the invention. The nozzle includes an interface section comprising multiple intake ports that couple the outlets of the combustion tubes to a common plenum. Proceeding from its upstream to its downstream end, the interface section tapers to a larger cross-sectional area for flow. This taper fosters expansion of the exhaust gases flowing from the outlets of the combustion tubes and contributes to the desired equalization of exhaust combustion pressure. The cross-sectional area for flow in the common plenum is greater than, or at least equal to, the combined cross-sectional flow areas of the combustor tubes. In the common plenum, the exhaust streams from the individual combustion tubes mix to form a single compound subsonic exhaust stream. Downstream of the common plenum is the throat that tapers to a smaller flow cross section. In this throat, the exhaust gases become compressed to form a compound sonic gas stream. Downstream of the throat is an expansion section, which typically has a bell or a conical shape. (The expansion section can be truncated or even eliminated in the case of an air-breathing engine.) After entering the expansion section, the exhaust gases expand rapidly from compound sonic to compound supersonic speeds and are then vented to the environment. The basic invention admits of numerous variations. For example, the combustion tubes can be arranged around the central

  8. Internal combustion engine with an exhaust gas turbocharger

    SciTech Connect

    Hiereth, H.; Withalm, G.

    1981-06-09

    An internal combustion engine with an exhaust-gas turbocharger, particularly a mixture-compressing internal combustion engine, is disclosed in which a bleeder valve is provided which during the operation of the internal combustion engine in the partial load range conducts the exhaust gases in bypassing relationship to the turbine of the exhaust gas turbocharger.

  9. Exhaust gas recirculation system for an internal combustion engine

    DOEpatents

    Wu, Ko-Jen

    2013-05-21

    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.

  10. Exhaust system for an internal combustion engine, burn-off unit and methods therefor

    SciTech Connect

    Frankenberg, A.A.; Scott, D.R.

    1984-05-22

    An exhaust system is disclosed for an internal combustion engine which burns a hydrocarbon fuel mixture and which produces a carbonaceous particle carrying exhaust gas stream that passes through a filter of the system that retains at least part of the particles therein, the system having a burn-off unit for periodically burning the retained particles in the filter to tend to periodically clean the filter of the retained particles thereof. The burn-off unit is adapted to raise the temperature of the exhaust gas stream intermediate the engine and the filter to raise the temperature of the filter to particle burning temperature thereof, the burn-off unit injecting and burning a certain amount of the hydrocarbon fuel mixture in the exhaust gas stream intermediate the engine and the filter to raise the temperature of the exhaust gas stream intermediate the engine and the filter. The fuel mixture is injected into the exhaust gas stream by an aspirating unit of the burn-off unit, and the temperature of the exhaust gas stream is raised by an electrical heater and a catalyst bed in which the injected fuel mixture is to burn.

  11. Removal of sulfur compounds from combustion product exhaust

    DOEpatents

    Cheng, Dah Y.

    1982-01-01

    A method and device are disclosed for removing sulfur containing contaminents from a combustion product exhaust. The removal process is carried out in two stages wherein the combustion product exhaust is dissolved in water, the water being then heated to drive off the sulfur containing contaminents. The sulfur containing gases are then resolublized in a cold water trap to form a concentrated solution which can then be used as a commercial product.

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

    DOEpatents

    Castellano, Christopher R.; Moini, Ahmad; Koermer, Gerald S.; Furbeck, Howard

    2010-07-20

    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.

  13. Exhaust system for an internal combustion engine

    SciTech Connect

    Ikenoya, Y.; Otani, J.

    1982-10-19

    An exhaust system for an engine of a motorcycle is disclosed having catalytic and silencing mufflers arranged in adjacent side -by-side series flow relationship, the catalytic muffler extending rearwardly of the motorcycle, and, adjacent its rear end, being interconnected with the silencing muffler, the silencing muffler including plural expansion chambers which are interconnected in flow reversal relationship for gases to be exhausted rearwardly of the motorcycle.

  14. Mutagenicity and carcinogenicity of car exhausts and coal combustion emissions

    SciTech Connect

    Holmberg, B.; Ahlbourg, U.

    1983-01-01

    Car exhausts and coal combustion emissions may cause a spectrum of health effects, varying from annoyance reactions, to bronchitis, to cancer in the respiratory organs and possibly also other organs. Deaths in cardiovascular diseases in particularly sensitive individuals have furthermore, under certain circumstances, been associated with ambient air pollution. The objective of the meeting was to examine the relevance of short-term and long-term biological tests for mutagenicity and carcinogenicity to the assessment of human carcinogenic risk that may arise from exposure to air pollution from motor vehicle exhausts and coal combustion products. (135 refs.)

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

    DOEpatents

    Castellano, Christopher R.; Moini, Ahmad; Koermer, Gerald S.; Furbeck, Howard; Schmieg, Steven J.; Blint, Richard J.

    2011-05-17

    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.

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

    DOEpatents

    Koermer, Gerald S.; Moini, Ahmad; Furbeck, Howard; Castellano, Christopher R.

    2012-05-08

    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.

  17. Exhaust gas recirculation method for internal combustion engines

    SciTech Connect

    Kawanabe, T.; Kimura, K.; Asakura, M.; Shiina, T.

    1988-07-19

    This patent describes a method of controlling exhaust gas recirculation in an internal combustion engine having an exhaust passage, an intake passage, an exhaust gas recirculating passage communicating the exhaust passage with the intake passage, and exhaust gas recirculating valve; and a transmission having a shift lever. The valve opening of the exhaust gas recirculating valve is controlled in response to operating conditions of the engine so as to regulate the amount of exhaust gas recirculation to values appropriate to the operating conditions of the engine. The method comprising the steps of (1) determining whether or not the engine is in at least one of a predetermined accelerating condition and a predetermined decelerating condition; (2) varying the valve opening of the exhaust gas recirculating valve by a predetermined value when the engine is determined to be in at least one of the predetermined accelerating condition and the predetermined decelerating condition; (3) detecting a position of the shift lever of the transmission; and (4) correcting the predetermined value in accordance with the detected position of the shift lever so as to increase the valve opening of the exhaust gas recirculating valve as the shift lever of the transmission is set to a higher speed position.

  18. On the thermodynamics of waste heat recovery from internal combustion engine exhaust gas

    NASA Astrophysics Data System (ADS)

    Meisner, G. P.

    2013-03-01

    The ideal internal combustion (IC) engine (Otto Cycle) efficiency ηIC = 1-(1/r)(γ - 1) is only a function of engine compression ratio r =Vmax/Vmin and exhaust gas specific heat ratio γ = cP/cV. Typically r = 8, γ = 1.4, and ηIC = 56%. Unlike the Carnot Cycle where ηCarnot = 1-(TC/TH) for a heat engine operating between hot and cold heat reservoirs at TH and TC, respectively, ηIC is not a function of the exhaust gas temperature. Instead, the exhaust gas temperature depends only on the intake gas temperature (ambient), r, γ, cV, and the combustion energy. The ejected exhaust gas heat is thermally decoupled from the IC engine and conveyed via the exhaust system (manifold, pipe, muffler, etc.) to ambient, and the exhaust system is simply a heat engine that does no useful work. The maximum fraction of fuel energy that can be extracted from the exhaust gas stream as useful work is (1-ηIC) × ηCarnot = 32% for TH = 850 K (exhaust) and TC = 370 K (coolant). This waste heat can be recovered using a heat engine such as a thermoelectric generator (TEG) with ηTEG> 0 in the exhaust system. A combined IC engine and TEG system can generate net useful work from the exhaust gas waste heat with efficiency ηWH = (1-ηIC) × ηCarnot ×ηTEG , and this will increase the overall fuel efficiency of the total system. Recent improvements in TEGs yield ηTEG values approaching 15% giving a potential total waste heat conversion efficiency of ηWH = 4.6%, which translates into a fuel economy improvement approaching 5%. This work is supported by the US DOE under DE-EE0005432.

  19. Lightweight Exhaust Manifold and Exhaust Pipe Ducting for Internal Combustion Engines

    NASA Technical Reports Server (NTRS)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1999-01-01

    An improved exhaust system for an internal combustion gasoline-and/or diesel-fueled engine includes an engine exhaust manifold which has been fabricated from carbon- carbon composite materials in operative association with an exhaust pipe ducting which has been fabricated from carbon-carbon composite materials. When compared to conventional steel. cast iron. or ceramic-lined iron paris. the use of carbon-carbon composite exhaust-gas manifolds and exhaust pipe ducting reduces the overall weight of the engine. which allows for improved acceleration and fuel efficiency: permits operation at higher temperatures without a loss of strength: reduces the "through-the wall" heat loss, which increases engine cycle and turbocharger efficiency and ensures faster "light-off" of catalytic converters: and, with an optional thermal reactor, reduces emission of major pollutants, i.e. hydrocarbons and carbon monoxide.

  20. Exhaust recycle to carburetor of an internal combustion engine

    SciTech Connect

    Johnson, C.R.

    1984-03-20

    A hot slipstream from the exhaust of an internal combustion engine is used directly, that is without valving it, to heat and vaporize fuel as it is sprayed from the fuel nozzle of a carburetor having a booster venturi above the throttle plate, provided the ratio of the volume of slipstream to the volume of exhaust gases is self-regulated within narrow limits at all times during the engine's operation, in accordance with the physical considerations governing gas flow. The main jets of a conventional carburetor may be changed to provide decreased flow of gasoline by about 10% to give better mileage without sacrificing performance of the engine, and without adversely affecting the exhaust emissions which are otherwise controlled by a conventional emission control system.

  1. Premixed turbulent combustion to opposed streams

    SciTech Connect

    Kostiuk, L.W.; Cheng, R.K.

    1992-03-01

    Premixed turbulent combustion in opposed streams has been studied experimentally by the use of two component laser doppler aneomometry. This flow geometry is part of a class of stagnating flows used to study turbulent combustion in recent years. It does not involve any surface near the flames because of the flow symmetry thus circumventing many of the effects of flame surface interaction. The mean non-reacting flow is found to be self-similar for all the conditions studied in this and the stagnation plate configuration. A homogeneous region of plane straining is produced in the vicinity of the stagnation and there is a strong interaction between the turbulence in the flow and the mean straining which can increase the rms velocity as the flow stagnates. The reacting flow fields are found to be symmetric about the free stagnation point. The traverses of mean axial velocity in the stagnation streamlines for reaction flows are not dramatically different from the non-reaction flows. These results differ from turbulent combustion experiments where the flow is stagnated by a flat plate. The extinction limits was studied for propane:air mixtures. 11 refs.

  2. Catalyst for treatment of exhaust gases from internal combustion engines

    SciTech Connect

    Blanchard, G.; Brunelle, J.P.; Prigent, M.

    1984-01-17

    The exhaust gases from internal combustion engines are catalytically oxidized/reduced, to remove CO, unburned hydrocarbons and NO /SUB x/ therefrom, utilizing an improved stable and long-lived catalyst which comprises (1) a support substrate, e.g., a monolithic or particulate support, and (2) an active phase deposited thereon, said active phase (2) comprising (i) cerium, (ii) iron, (iii) at least one of the metals gallium and/or yttrium, (iv) at least one of the metals platinum and/or palladium, and (v) at least one of the metals iridium and/or rhodium.

  3. Low NOx combustion using cogenerated oxygen and nitrogen streams

    DOEpatents

    Kobayashi, Hisashi; Bool, Lawrence E.; Snyder, William J.

    2009-02-03

    Combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.

  4. Combustion chamber and thermal vapor stream producing apparatus and method

    DOEpatents

    Sperry, John S.; Krajicek, Richard W.; Cradeur, Robert R.

    1978-01-01

    A new and improved method and apparatus for burning a hydrocarbon fuel for producing a high pressure thermal vapor stream comprising steam and combustion gases for injecting into a subterranean formation for the recovery of liquefiable minerals therefrom, wherein a high pressure combustion chamber having multiple refractory lined combustion zones of varying diameters is provided for burning a hydrocarbon fuel and pressurized air in predetermined ratios injected into the chamber for producing hot combustion gases essentially free of oxidizing components and solid carbonaceous particles. The combustion zones are formed by zones of increasing diameters up a final zone of decreasing diameter to provide expansion zones which cause turbulence through controlled thorough mixing of the air and fuel to facilitate complete combustion. The high pressure air and fuel is injected into the first of the multiple zones where ignition occurs with a portion of the air injected at or near the point of ignition to further provide turbulence and more complete combustion.

  5. Removal of particulate matter from combustion gas streams

    SciTech Connect

    Krigmont, H.V.; Coe, E.L. Jr.

    1991-01-29

    This patent describes an apparatus for removing particulate matter from a combustion gas stream that is passed through an electrostatic precipitator having precipitating elements therein. It comprises: first means for selectively injecting a controllably variable amount of a conditioning agent into a combustion gas stream at a location prior to the entry of the combustion gas into an electrostatic precipitator; second means for establishing the duty cycle of the power provided to a precipitating element in the electrostatic precipitator; third means for measuring the relative particulate content of the combustion gas stream after it leaves the electrostatic precipitator; and fourth means for controlling the first means and the second means in response to the measurement derived from the third means.

  6. Exhaust pipe arrangement for a turbocharged multi-cylinder internal combustion engine having catalytic converters

    SciTech Connect

    Gauffres, U.J.

    1984-04-24

    An exhaust pipe arrangement for internal combustion engines is disclosed which includes an exhaust gas turbocharger, a bypass conduit for circumventing the turbocharger, a blow off valve, a starter catalyst disposed in an exhaust pipe, an oxygen sensor, and a main catalyst connected downstream of the turbocharger, starter catalyst, and oxygen sensor. To reduce the exhaust gas counterpressure and relieve the load on the starter catalyst at the same time, the starter catalyst is arranged upstream of a junction of the bypass conduit entering into the exhaust pipe.

  7. Combustion of dense streams of coal particles

    SciTech Connect

    Annamalai, K.

    1992-01-01

    Ignition of the high volatile isolated coal particles in vitiated environment seems to occur heterogeneously at the leading edge of the particle. Volatiles are observed to be ejected upward as jets in the direction of the convective flow but only after heterogeneous ignition. The volatiles burn in the gas phase homogeneously and form a wake flame; a black inner zone (unburned volatile) is formed (see Fig.A.3 for many common characteristics of isolated flames).Intermittent volatile ignition and combustion are observed to occur during the combustion process for a few of the isolated particle combustion experiments on high volatile non-swelling coal. The medium volatile coal particles ignite faster than the high volatile coal; but the intermittent ignition is not observed. The low volatile isolated coal particles combust in shorter time. The isolated char particles ignite at the surface of the particle heterogeneously with little volatile ejected, yet are not sufficient to form a volatile flame, resulting in a subsequent heterogeneous combustion. A group flame is formed for the two-particle arrays at closer interparticle spacing (Fig.A.4). Also, intermittent ignition does not occur for the high volatile particles when the two particles are at farther distances which suggests that radiation interaction between the particles might be occurring. However this conclusion is purely speculative. The char arrays experience heterogeneous ignition at the leading edge; combustion proceeds heterogeneously.

  8. Side branch absorber for exhaust manifold of two-stroke internal combustion engine

    SciTech Connect

    Harris, Ralph E.; Broerman, III, Eugene L.; Bourn, Gary D.

    2011-01-11

    A method of improving scavenging operation of a two-stroke internal combustion engine. The exhaust pressure of the engine is analyzed to determine if there is a pulsation frequency. Acoustic modeling is used to design an absorber. An appropriately designed side branch absorber may be attached to the exhaust manifold.

  9. A flow calorimeter for determining combustion efficiency from residual enthalpy of exhaust gases

    NASA Technical Reports Server (NTRS)

    Evans, Albert; Hibbard, Robert R

    1954-01-01

    A flow calorimeter for determining the combustion efficiency of turbojet and ram-jet combustors from measurement of the residual enthalpy of combustion of the exhaust gas is described. Briefly, the calorimeter catalytically oxidizes the combustible constituents of exhaust-gas samples, and the resultant temperature rise is measured. This temperature rise is related to the residual enthalpy of combustion of the sample by previous calibration of the calorimeter. Combustion efficiency can be calculated from a knowledge of the residual enthalpy of the exhaust gas and the combustor input enthalpy. An accuracy of +-0.2 Btu per cubic foot was obtained with prepared fuel-air mixtures, and the combustion efficiencies of single turbojet combustors measured by both the flow-calorimeter and heat-balance methods compared within 3 percentage units. Flow calorimetry appears to be a suitable method for determining combustion efficiencies at high combustor temperatures where ordinary thermocouples cannot be used. The method is fundamentally more accurate than heat-balance methods at high combustion efficiencies and can be used to verify near-100-percent efficiency data.

  10. Exhaust emissions reduction for intermittent combustion aircraft engines

    NASA Technical Reports Server (NTRS)

    Rezy, B. J.; Stuckas, K. J.; Tucker, J. R.; Meyers, J. E.

    1982-01-01

    Three concepts which, to an aircraft piston engine, provide reductions in exhaust emissions of hydrocarbons and carbon monoxide while simultaneously improving fuel economy. The three chosen concepts, (1) an improved fuel injection system, (2) an improved cooling cylinder head, and (3) exhaust air injection, when combined, show a synergistic relationship in achieving these goals. In addition, the benefits of variable ignition timing were explored and both dynamometer and flight testing of the final engine configuration were accomplished.

  11. Relation of Hydrogen and Methane to Carbon Monoxide in Exhaust Gases from Internal-Combustion Engines

    NASA Technical Reports Server (NTRS)

    Gerrish, Harold C; Tessmann, Arthur M

    1935-01-01

    The relation of hydrogen and methane to carbon monoxide in the exhaust gases from internal-combustion engines operating on standard-grade aviation gasoline, fighting-grade aviation gasoline, hydrogenated safety fuel, laboratory diesel fuel, and auto diesel fuel was determined by analysis of the exhaust gases. Two liquid-cooled single-cylinder spark-ignition, one 9-cylinder radial air-cooled spark-ignition, and two liquid-cooled single-cylinder compression-ignition engines were used.

  12. Velocity and temperature characteristics of two-stream, coplanar jet exhaust plumes

    NASA Technical Reports Server (NTRS)

    Von Glahn, U.; Goodykoontz, J.; Wasserbauer, C.

    1984-01-01

    The subsonic jet exhaust velocity and temperature characteristics of model scale, two stream coplanar nozzles were obtained experimentally. The data obtained included the effects of fan to primary stream velocity and temperature ratios on the jet axial and radial flow characteristics. Empirical parameters were developed to correlate the measured data. The resultant equations were shown to be extensions of a previously published single stream jet velocity and temperature correlation.

  13. The effect of EGR ratio on a spray combustion and emission[Exhaust Gas Recirculation

    SciTech Connect

    Ogawa, Hirokatsu; Ogiwara, Goro; Arai, Masataka

    1998-07-01

    It was widely known that preheating of primary air and EGR were effective to reduce NOx emission in a combustion system. Then the authors proposed the effective system of the external EGR for a spray combustion system such as a gas turbine combustor. In this paper, they tried to obtain various combustion characteristic related to the EGR effect. The EFR ratio was defined by the O{sub 2} concentrations of the EGR gas and the total inlet gas to which EGR gas was added. The combustion characteristics at 0% to 20% of the EGR ratio were measured to investigate the effect of the external EGR. The total inlet gas was the mixture, in which a fresh air was mixed with a hot burned gas recirculated externally. The O{sub 2} concentration in the total inlet gas decreased from 21% to 19%. The temperature of the total inlet gas increased from room temperature to about 110 C. The results showed that the combustion characteristics were improved by the EGR. At a high level of the EGR ratio, hot EGR gas promoted to vaporize the kerosene spray. This kerosene vapor and combustion air formed a homogeneous mixture gas which stabilized high intensity flame. It resulted flame stabilization in wide range of the EGR. Flame which was filled up fully in the combustion chamber was non-luminous flame like a gaseous fuel combustion. Also, the level of NO concentration in the exhaust gas was reduced. IN the flame of high EGR ratio, hot spots which caused NO formation in the flame were highly reduced. And the residence time in the combustion chamber was also reduced, because of the average sectional velocity increased with an increase of the recirculating gas flow in the system. So the maximum values of NO concentration in the combustion chamber were reduced in all cases of experimental conditions with EGR. The level of NO concentration in the exhaust gas was suppressed to about 60% compared with no EGR combustion states.

  14. Exhaust gas diverter for divided volute turbocharger of internal combustion engine

    SciTech Connect

    Jain, A.; Meistrick, Z.S.; Pitzi, V.J.

    1992-09-15

    This patent describes a divided volute turbocharger diverter disposed between the exhaust manifold of an internal combustion engine and the turbine of the turbocharger, it comprises: first and second volute passageways; an interconnection passageway interconnecting the first and second volute passageways; an a diverter member disposed in only the first of the first and second volute passageways.

  15. Dynamic instabilities in spark-ignited combustion engines with high exhaust gas recirculation

    NASA Astrophysics Data System (ADS)

    Daw, C. Stuart; Finney, Charles E. A.

    2011-04-01

    We propose a cycle-resolved dynamic model for combustion instabilities in spark-ignition engines operating with high levels of exhaust gas recirculation (EGR). We account for the complex combustion response to cycle-to-cycle feedback by utilizing a global probability distribution that describes the pre-spark state of in-cylinder fuel mixing. The proposed model does a good job of simulating combustion instabilities observed in both lean-fueling engine experiments and in experiments where nitrogen dilution is used to simulate some of the combustion inhibition of EGR. When used to simulate high internal EGR operation, the model exhibits a range of global bifurcations and chaos that appear to be very robust. We use the model to show that it should be possible to reduce high EGR combustion instabilities by switching from internal to external EGR.

  16. Exhaust emission reduction for intermittent combustion aircraft engines

    NASA Technical Reports Server (NTRS)

    Moffett, R. N.

    1979-01-01

    Three concepts for optimizing the performance, increasing the fuel economy, and reducing exhaust emission of the piston aircraft engine were investigated. High energy-multiple spark discharge and spark plug tip penetration, ultrasonic fuel vaporization, and variable valve timing were evaluated individually. Ultrasonic fuel vaporization did not demonstrate sufficient improvement in distribution to offset the performance loss caused by the additional manifold restriction. High energy ignition and revised spark plug tip location provided no change in performance or emissions. Variable valve timing provided some performance benefit; however, even greater performance improvement was obtained through induction system tuning which could be accomplished with far less complexity.

  17. Combustion control system adding a liquid, exhaust gases, and PCV gases

    SciTech Connect

    Lindberg, J.E.

    1980-01-15

    A combustion control system is disclosed that adds a fluid and heat energy to the air-fuel mixture of the induction system of an internal combustion engine in response to engine need to improve combustion, to increase power, to improve efficiency, and to reduce emissions. The system incorporates fluidic control mechanisms which provide the control functions without any moving parts. The system incorporates one or more variable impedance flow control mechanisms, each of which produces an impedance to flow through the control mechanism which varies in a controlled relationship to the pressure differential across the control mechanism. In one embodiment, the main variable impedance control mechanism is a vortex chamber. The outlet of the vortex chamber is connected to the positive crankcase ventilation (PCV) inlet to intake manifold downstream of the butterfly valve. The vortex chamber has inputs for supplying air, the liquid, exhaust gases, and PCV gases for mixing within the vortex chamber. The incoming liquid, air, exhaust gases, and PCV gases are transmitted into the main vortex chamber by input constructions which, in themselves, provide for controlled regulation of both the relative proportions and total amounts of the incoming liquid and gases. In a specific embodiment, the input constructions include a liquid-exhaust gas acceleration chamber for mixing liquid with exhaust gases and a PCV-exhaust gas vortex chamber for mixing exhaust gases with PCV gases and air and swirl producing devices for causing controlled choking of the inlets of one or more of the vortex chambers. The system also incorporates a variable impedance syphon break in the line connecting the liquid source with the liquid-exhaust gas acceleration chamber.

  18. Combustion-derived nanoparticulate induces the adverse vascular effects of diesel exhaust inhalation

    PubMed Central

    Mills, Nicholas L.; Miller, Mark R.; Lucking, Andrew J.; Beveridge, Jon; Flint, Laura; Boere, A. John F.; Fokkens, Paul H.; Boon, Nicholas A.; Sandstrom, Thomas; Blomberg, Anders; Duffin, Rodger; Donaldson, Ken; Hadoke, Patrick W.F.; Cassee, Flemming R.; Newby, David E.

    2011-01-01

    Aim Exposure to road traffic and air pollution may be a trigger of acute myocardial infarction, but the individual pollutants responsible for this effect have not been established. We assess the role of combustion-derived-nanoparticles in mediating the adverse cardiovascular effects of air pollution. Methods and results To determine the in vivo effects of inhalation of diesel exhaust components, 16 healthy volunteers were exposed to (i) dilute diesel exhaust, (ii) pure carbon nanoparticulate, (iii) filtered diesel exhaust, or (iv) filtered air, in a randomized double blind cross-over study. Following each exposure, forearm blood flow was measured during intra-brachial bradykinin, acetylcholine, sodium nitroprusside, and verapamil infusions. Compared with filtered air, inhalation of diesel exhaust increased systolic blood pressure (145 ± 4 vs. 133 ± 3 mmHg, P< 0.05) and attenuated vasodilatation to bradykinin (P= 0.005), acetylcholine (P= 0.008), and sodium nitroprusside (P< 0.001). Exposure to pure carbon nanoparticulate or filtered exhaust had no effect on endothelium-dependent or -independent vasodilatation. To determine the direct vascular effects of nanoparticulate, isolated rat aortic rings (n= 6–9 per group) were assessed in vitro by wire myography and exposed to diesel exhaust particulate, pure carbon nanoparticulate and vehicle. Compared with vehicle, diesel exhaust particulate (but not pure carbon nanoparticulate) attenuated both acetylcholine (P< 0.001) and sodium-nitroprusside (P= 0.019)-induced vasorelaxation. These effects were partially attributable to both soluble and insoluble components of the particulate. Conclusion Combustion-derived nanoparticulate appears to predominately mediate the adverse vascular effects of diesel exhaust inhalation. This provides a rationale for testing environmental health interventions targeted at reducing traffic-derived particulate emissions. PMID:21753226

  19. Catalytic converters for exhaust emission control of commercial equipment powered by internal combustion engines.

    PubMed Central

    Cohn, J G

    1975-01-01

    The development of PTX, monolithic catalytic exhaust purifiers, is outlined, and their first use for exhaust emissions control of commercial equipment is described. The main use of PTX converters is on forklift trucks. The purification achievable with PTX-equipped fork-lift trucks under various operational conditions is discussed, and examples from the field are given. During more than ten years of operation, no adverse health effects have been reported, and PTX-equipped internal combustion engines appear safe for use in confined areas. PMID:50933

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    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.

  1. In-stream measurements of combustion during Mach 5 to 7 tests of the Hypersonic Research Engine (HRE)

    NASA Technical Reports Server (NTRS)

    Lezberg, Erwin A.; Metzler, Allen J.; Pack, William D.

    1993-01-01

    Results of in-stream combustion measurements taken during Mach 5 to 7 true simulation testing of the Hypersonic Research Engine/Aerothermodynamic Integration Model (HRE/AIM) are presented. These results, the instrumentation techniques, and configuration changes to the engine installation that were required to test this model are described. In test runs at facility Mach numbers of 5 to 7, an exhaust instrumentation ring which formed an extension of the engine exhaust nozzle shroud provided diagnostic measurements at 10 circumferential locations in the HRE combustor exit plane. The measurements included static and pitot pressures using conventional conical probes, combustion gas temperatures from cooled-gas pyrometer probes, and species concentration from analysis of combustion gas samples. Results showed considerable circumferential variation, indicating that efficiency losses were due to nonuniform fuel distribution or incomplete mixing. Results using the Mach 7 facility nozzle but with Mach 6 temperature simulation, 1590 to 1670 K, showed indications of incomplete combustion. Nitric oxide measurements at the combustor exit peaked at 2000 ppmv for stoichiometric combustion at Mach 6.

  2. Experimental Investigation of Active Noise Controller for Internal Combustion Engine Exhaust System

    NASA Astrophysics Data System (ADS)

    Wu, Jian-Da; Chen, Chih-Keng; Lee, Chun-Ying; Lee, Tian-Hua

    2002-10-01

    Two active noise control (ANC) algorithms for internal combustion engine exhaust systems are developed and their performances are compared in various experiments. The first controller is based on the filtered-x least mean square (FXLMS) algorithm with feedback neutralization, while the second is a fixed controller with a gain-scheduled active control technique for broadband attenuation with thermal effects. Both control algorithms are implemented on a digital signal processing (DSP) platform. Experiments are carried out to evaluate the attenuation performance of the proposed active noise control systems for an engine exhaust system. The results of the experiments indicate that both the adaptive controller and the gain-scheduled controller effectively suppress the noise of engine exhaust systems. The experimental comparison and analysis of the proposed controllers are also described.

  3. Dynamic instabilities in spark-ignited combustion engines with high exhaust gas recirculation

    SciTech Connect

    Daw, C Stuart; FINNEY, Charles E A

    2011-01-01

    We propose a cycle-resolved dynamic model for combustion instabilities in spark-ignition engines operating with high levels of exhaust gas recirculation (EGR). High EGR is important for increasing fuel efficiency and implementing advanced low-emission combustion modes such as homogenous charge compression ignition (HCCI). We account for the complex combustion response to cycle-to-cycle feedback by utilizing a global probability distribution that describes the pre-spark state of in-cylinder fuel mixing. The proposed model does a good job of simulating combustion instabilities observed in both lean-fueling engine experiments and in experiments where nitrogen dilution is used to simulate some of the combustion inhibition of EGR. When used to simulate high internal EGR operation, the model exhibits a range of global bifurcations and chaos that appear to be very robust. We use the model to show that it should be possible to reduce high EGR combustion instabilities by switching from internal to external EGR. We also explain why it might be helpful to deliberately stratify the fuel in the pre-spark gas mixture. It might be possible to extend the simple approach used in this model to other chemical reaction systems with spatial inhomogeneity.

  4. Recombination of Hydrogen-Air Combustion Products in an Exhaust Nozzle

    NASA Technical Reports Server (NTRS)

    Lezberg, Erwin A.; Lancashire, Richard B.

    1961-01-01

    Thrust losses due to the inability of dissociated combustion gases to recombine in exhaust nozzles are of primary interest for evaluating the performance of hypersonic ramjets. Some results for the expansion of hydrogen-air combustion products are described. Combustion air was preheated up to 33000 R to simulate high-Mach-number flight conditions. Static-temperature measurements using the line reversal method and wall static pressures were used to indicate the state of the gas during expansion. Results indicated substantial departure from the shifting equilibrium curve beginning slightly downstream of the nozzle throat at stagnation pressures of 1.7 and 3.6 atmospheres. The results are compared with an approximate method for determining a freezing point using an overall rate equation for the oxidation of hydrogen.

  5. Method of and apparatus for removing sulfur oxides from exhaust gases formed by combustion

    SciTech Connect

    Voeste, T.

    1981-01-27

    A process is described for removing sulfur oxides from exhaust gas formed by combustion particularly exhaust gas from an electricity generating power plant. The exhaust gas flows through a reaction zone which operates like a spray dryer. A purifying liquor consisting of an aqueous solution of sodium carbonate and/or sodium bicarbonate is sprayed into the reaction zone, in which the heat content of the exhaust gases causes virtually all of the water content of the purifying liquor to be evaporated. The exhaust gas is subsequently passed through a filter. Anhydrous solids are withdrawn from the reaction zone and the filter and contain at least 75% of sodium sulfite, sodium sulfate and sodium chloride and are processed to form sodium carbonate. To that end the solids are dissolved and sulfite is oxidized to form sulfate so that a solution that contains sodium sulfate and sodium chloride is formed. The sulfate is separated from that solution and the remaining solution is used in the recovery of sodium carbonate by the solvay process.

  6. SiO2/TiO2 Composite for Removing Hg from Combustion Exhaust

    NASA Technical Reports Server (NTRS)

    Mazyck, David; Londeree, Danielle; Wu, Chang-Yu; Powers, Kevin; Pitoniak, Erik

    2008-01-01

    Pellets made of a high-surface-area composite of silica and titania have shown promise as means of removing elemental mercury from flue gases. With further technical development and commercialization, this material could become economically attractive as a more effective, less-expensive alternative to activated carbons for removing mercury from exhaust streams of coal-burning power plants, which are the sources of more than 90 percent of all anthropogenic airborne mercury.

  7. Impact of the injection dose of exhaust gases, on work parameters of combustion engine

    NASA Astrophysics Data System (ADS)

    Marek, W.; Śliwiński, K.

    2016-09-01

    This article is another one from the series in which were presented research results indicated the possible areas of application of the pneumatic injection using hot combustion gases proposed by Professor Jarnuszkiewicz. This publication present the results of the control system of exhaust gas recirculation. The main aim of this research was to determine the effect of exhaust gas recirculation to the operating parameters of the internal combustion engine on the basis of laboratory measurements. All measurements were performed at a constant engine speed. These conditions correspond to the operation of the motor operating an electrical generator. The study was conducted on the four-stroke two-cylinder engine with spark ignition. The study were specifically tested on the air injection system and therefore the selection of the rotational speed was not bound, as in conventional versions of operating parameters of the electrical machine. During the measurement there were applied criterion which used power control corresponding to the requirements of load power, at minimal values of engine speed. Recirculation value determined by the following recurrent position control valve of the injection doses inflator gas for pneumatic injection system. They were studied and recorded, the impact of dose of gases recirculation to the operating and ecological engine parameters such as power, torque, specific fuel consumption, efficiency, air fuel ratio, exhaust gas temperature and nitrogen oxides and hydrocarbons.

  8. NOx reduction in combustion with concentrated coal streams and oxygen injection

    DOEpatents

    Kobayashi, Hisashi; Bool, III, Lawrence E.; Snyder, William J.

    2004-03-02

    NOx formation in the combustion of solid hydrocarbonaceous fuel such as coal is reduced by obtaining, from the incoming feed stream of fuel solids and air, a stream having a ratio of fuel solids to air that is higher than that of the feed steam, and injecting the thus obtained stream and a small amount of oxygen to a burner where the fuel solids are combusted.

  9. The washout of combustion-generated hydrogen chloride. [rocket exhaust raindrop scavenging quantification

    NASA Technical Reports Server (NTRS)

    Fenton, D. L.; Purcell, R. Y.; Hrdina, D.; Knutson, E. O.

    1980-01-01

    The coefficient for the washout from a rocket exhaust cloud of HCl generated by the combustion of an ammonium perchlorate-based solid rocket propellant such as that to be used for the Space Shuttle Booster is determined. A mathematical model of HCl scavenging by rain is developed taking into account rain droplet size, fall velocity and concentration under various rain conditions, partitioning of exhaust HCl between liquid and gaseous phases, the tendency of HCl to promote water vapor condensation and the concentration and size of droplets within the exhaust cloud. The washout coefficient is calculated as a function of total cloud water content, total HCl content at 100% relative humidity, condensation nuclei concentration and rain intensity. The model predictions are compared with experimental results obtained in scavenging tests with solid rocket exhaust and raindrops of different sizes, and the large reduction in washout coefficient at high relative humidities predicted by the model is not observed. A washout coefficient equal to 0.0000512 times the -0.176 power of the mass concentration of HCl times the 0.773 power of the rainfall intensity is obtained from the experimental data.

  10. Apparatus for measuring rotor exhaust gas bulk temperature in a combustion turbine and method therefore

    SciTech Connect

    Allen, J.M.

    1993-07-13

    Apparatus is described for measuring rotor exhaust gas bulk total temperature in a combustion turbine which includes first and last stages of rotating turbine blades comprising: optical pyrometer means for measuring the circumferentially total gas averaged temperature relative to said last stage turbine blades at a plurality of common radial points from the turbine hub to tip where said optical pyrometer means includes a single optical pyrometer having a line of sight along with means for rotating such pyrometer around an axis of rotation, with the pyrometer being tilted from said axis so that the line of sight of said pyrometer rotates around said axis thereby providing a radial traverse of said last stage turbine blades; means for calculating said rotor exhaust bulk total temperature relative to said last stage blades by flow weight averaging said measured temperatures of said radial points.

  11. The effect of exhaust gas recirculation on the combustion noise level of an indirect injection diesel engine

    SciTech Connect

    Bowen, C.E.; Reader, G.T.; Potter, I.J.

    1997-12-31

    A pollutant that has not yet received as much public or regulatory attention as gaseous or solid particulate emissions is engine generated noise. Excessive levels of noise can, however, be as harmful to human health and the environment as noxious gases. In a well-designed engine, mechanical noise can be kept to a minimum but the combustion process itself still generates noise, combustion noise. Thus, if the combustion process is modified for exhaust emission control it can be expected that the level of noise generated by combustion will also be affected, albeit not necessarily adversely. As exhaust gas recirculation (EGR) is becoming an essential technology for NOx emission control in diesel engines, and, as this technique modifies the combustion process, it is important that the effects of using EGR on noise generation be identified.

  12. Development of All-Solid-State Sensors for Measurement of Nitric Oxide and Ammonia Concentrations by Optical Absorption in Particle-Laden Combusion Exhaust Streams

    SciTech Connect

    Jerald A. Caton; Kalyan Annamalai

    2003-09-24

    An all-solid-state continuous-wave (cw) laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule has been developed and demonstrated. For the NO sensor, 250 nW of tunable cw ultraviolet radiation is produced by sum-frequency-mixing of 532-nm radiation from a diode-pumped Nd:YAG laser and tunable 395-nm radiation from an external cavity diode laser (ECDL). The sum-frequency-mixing process occurs in a beta-barium borate crystal. The nitric oxide absorption measurements are performed by tuning the ECDL and scanning the sum-frequency-mixed radiation over strong nitric oxide absorption lines near 226 nm. The nitric oxide sensor has been used for measurements in the exhaust of a coal-fired laboratory combustion facility. The Texas A&M University boiler burner facility is a 30 kW (100,000 Btu/hr) downward-fired furnace with a steel shell encasing ceramic insulation. Measurements of nitric oxide concentration in the exhaust stream were performed after modification of the facility for laser based NOx diagnostics. The diode-laser-based sensor measurements showed good agreement with the results from physical probe sampling of the combustion exhaust. The diode-laser-based ultraviolet absorption measurements were successful even when the beam was severely attenuated by particulate in the exhaust stream and window fouling. Single-laser-sweep measurements were demonstrated with an effective time resolution of 100 msec, limited at this time by the scan rate of our mechanically tuned ECDL system. Future planned modifications will lead to even faster response times at sensitivity levels at or below 1 ppm.

  13. Development of an Organic Rankine Cycle system for exhaust energy recovery in internal combustion engines

    NASA Astrophysics Data System (ADS)

    Cipollone, Roberto; Bianchi, Giuseppe; Gualtieri, Angelo; Di Battista, Davide; Mauriello, Marco; Fatigati, Fabio

    2015-11-01

    Road transportation is currently one of the most influencing sectors for global energy consumptions and CO2 emissions. Nevertheless, more than one third of the fuel energy supplied to internal combustion engines is still rejected to the environment as thermal waste at the exhaust. Therefore, a greater fuel economy might be achieved recovering the energy from exhaust gases and converting it into useful power on board. In the current research activity, an ORC-based energy recovery system was developed and coupled with a diesel engine. The innovative feature of the recovery power unit relies upon the usage of sliding vane rotary machines as pump and expander. After a preliminary exhaust gas mapping, which allowed to assess the magnitude of the thermal power to be recovered, a thermodynamic analysis was carried out to design the ORC system and the sliding vane machines using R236fa as working fluid. An experimental campaign was eventually performed at different operating regimes according to the ESC procedure and investigated the recovery potential of the power unit at design and off-design conditions. Mechanical power recovered ranged from 0.7 kW up to 1.9 kW, with an overall cycle efficiency from 3.8% up to 4.8% respectively. These results candidate sliding vane machines as efficient and reliable devices for waste heat recovery applications.

  14. Determination of Combustion Product Radicals in a Hydrocarbon Fueled Rocket Exhaust Plume

    NASA Technical Reports Server (NTRS)

    Langford, Lester A.; Allgood, Daniel C.; Junell, Justin C.

    2007-01-01

    The identification of metallic effluent materials in a rocket engine exhaust plume indicates the health of the engine. Since 1989, emission spectroscopy of the plume of the Space Shuttle Main Engine (SSME) has been used for ground testing at NASA's Stennis Space Center (SSC). This technique allows the identification and quantification of alloys from the metallic elements observed in the plume. With the prospect of hydrocarbon-fueled rocket engines, such as Rocket Propellant 1 (RP-1) or methane (CH4) fueled engines being considered for use in future space flight systems, the contributions of intermediate or final combustion products resulting from the hydrocarbon fuels are of great interest. The effect of several diatomic molecular radicals, such as Carbon Dioxide , Carbon Monoxide, Molecular Carbon, Methylene Radical, Cyanide or Cyano Radical, and Nitric Oxide, needs to be identified and the effects of their band systems on the spectral region from 300 nm to 850 nm determined. Hydrocarbon-fueled rocket engines will play a prominent role in future space exploration programs. Although hydrogen fuel provides for higher engine performance, hydrocarbon fuels are denser, safer to handle, and less costly. For hydrocarbon-fueled engines using RP-1 or CH4 , the plume is different from a hydrogen fueled engine due to the presence of several other species, such as CO2, C2, CO, CH, CN, and NO, in the exhaust plume, in addition to the standard H2O and OH. These species occur as intermediate or final combustion products or as a result of mixing of the hot plume with the atmosphere. Exhaust plume emission spectroscopy has emerged as a comprehensive non-intrusive sensing technology which can be applied to a wide variety of engine performance conditions with a high degree of sensitivity and specificity. Stennis Space Center researchers have been in the forefront of advancing experimental techniques and developing theoretical approaches in order to bring this technology to a more

  15. Optical backscatter probe for sensing particulate in a combustion gas stream

    SciTech Connect

    Parks, James E; Partridge, William P

    2013-05-28

    A system for sensing particulate in a combustion gas stream is disclosed. The system transmits light into a combustion gas stream, and thereafter detects a portion of the transmitted light as scattered light in an amount corresponding to the amount of particulates in the emissions. Purge gas may be supplied adjacent the light supply and the detector to reduce particles in the emissions from coating or otherwise compromising the transmission of light into the emissions and recovery of scattered light from the emissions.

  16. Combustion Model of Supersonic Rocket Exhausts in an Entrained Flow Enclosure

    NASA Technical Reports Server (NTRS)

    Vu, Bruce T.; Oliveira, Justin

    2011-01-01

    This paper describes the Computational Fluid Dynamics (CFD) model developed to simulate the supersonic rocket exhaust in an entrained flow cylinder. The model can be used to study the plume-induced environment due to static firing tests of the Taurus-II launch vehicle. The finite-rate chemistry is used to model the combustion process involving rocket propellant (RP-1) and liquid oxidizer (LOX). A similar chemical reacting model is also used to simulate the mixing of rocket plume and ambient air. The model provides detailed information on the gas concentration and other flow parameters within the enclosed region, thus allowing different operating scenarios to be examined in an efficient manner. It is shown that the real gas influence is significant and yields better agreement with the theory.

  17. Combustion Model of Supersonic Rocket Exhausts in an Entrained Flow Enclosure

    NASA Technical Reports Server (NTRS)

    Vu, Bruce; Oliveira, Justin

    2011-01-01

    This paper describes the Computation Fluid Dynamics (CFD) model developed to simulate the supersonic rocket exhaust in an entrained flow cylinder. The model can be used to study the plume-induced environment due to static firing test of the Taurus II launch vehicle. The finite rate chemistry is used to model the combustion process involving rocket propellant (RP 1) and liquid oxidizer (LOX). A similar chemical reacting model is also used to simulate the mixing of rocket plume and ambient air. The model provides detailed information on the gas concentration and other flow parameters within the enclosed region thus allowing different operating scenarios to be examined in an efficient manner. It is shown that the real gas influence is significant and yields better agreement with the theory.

  18. Fuel-Specific Effect of Exhaust Gas Residuals on HCCI Combustion: A Modeling Study

    SciTech Connect

    Szybist, James P

    2008-01-01

    A modeling study was performed to investigate fuel-specific effects of exhaust gas recirculation (EGR) components on homogeneous charge compression ignition (HCCI) combustion at conditions relevant to the negative valve overlap (NVO) strategy using CHEMKIN-PRO. Four single-component fuels with well-established kinetic models were chosen: n-heptane, iso-octane, ethanol, and toluene. These fuels were chosen because they span a wide range of fuel chemistries, and produce a wide compositions range of complete stoichiometric products (CSP). The simulated engine conditions combined a typical spark ignition engine compression ratio (11.34) and high intake charge temperatures (500-550 K) that are relevant to NVO HCCI. It was found that over the conditions investigated, all the fuels had overlapping start of combustion (SOC) phasing, despite the wide range in octane number (RON = 0 to 120). The effect of the EGR components CO2 and H2O was to suppress the compression temperature because of their higher heat capacities, which retarded SOC. For a concentration of O2 higher than the stoichiometric amount, or excess O2, there was an effect of advancing SOC for n-heptane, iso-octane, and toluene, but SOC for ethanol was not advanced. Low temperature heat release (LTHR) for n-heptane was also found to be highly dependent on excess O2, and mild endothermic reaction was observed for cases when excess O2 was not present.

  19. Combustion of dense streams of coal particles. Final report, August 29, 1990--February 28, 1994

    SciTech Connect

    Annamalai, K.; Gopalakrishnan, C.; Du, X.

    1994-05-01

    The USA consumes almost 94 quads of energy (1 quad = 10{sup 15} BTU or 1.05 {times} 10{sup 15} KJ). The utilities account for about 30 quads of fossil energy where coal is predominantly used as energy source. The coal is ground to finer size and fired into the boiler as dense suspension. Under dense conditions, the particles burn at slower rate due to deficient oxygen within the interparticle spacing. Thus interactions exist amongst the particles for dense clouds. While the earlier literature dealt with combustion processes of isolated particles, the recent research focusses upon the interactive combustion. The interactive combustion studies include arrays consisting of a finite number of particles, and streams and clouds of a large number of particles. Particularly stream combustion models assume cylindrical geometry and predict the ignition and combustion characteristics. The models show that the ignition starts homogeneously for dense streams of coal particles and the ignition time show a minimum as the stream denseness is increased, and during combustion, there appears to be an inner flame within the stream and an outer flame outside the stream for a short period of time. The present experimental investigation is an attempt to verify the model predictions. The set-up consists of a flat flame burner for producing hot vitiated gases, a locally fluidizing feeder system for feeding coal particles, a particle collection probe for collecting particles and an image processing system for analyzing the flame structure. The particles are introduced as a stream into the hot gases and subsequently they ignite and burn. The ash % of fired and collected particles are determined and used to estimate the gasification efficiency or burnt fraction. The parametric studies include gas temperature, oxygen % in gases, residence time, and A:F ratio of the stream.

  20. A Highly Efficient Six-Stroke Internal Combustion Engine Cycle with Water Injection for In-Cylinder Exhaust Heat Recovery

    SciTech Connect

    Conklin, Jim; Szybist, James P

    2010-01-01

    A concept is presented here that adds two additional strokes to the four-stroke Otto or Diesel cycle that has the potential to increase fuel efficiency of the basic cycle. The engine cycle can be thought of as a 4 stroke Otto or Diesel cycle followed by a 2-stroke heat recovery steam cycle. Early exhaust valve closing during the exhaust stroke coupled with water injection are employed to add an additional power stroke at the end of the conventional four-stroke Otto or Diesel cycle. An ideal thermodynamics model of the exhaust gas compression, water injection at top center, and expansion was used to investigate this modification that effectively recovers waste heat from both the engine coolant and combustion exhaust gas. Thus, this concept recovers energy from two waste heat sources of current engine designs and converts heat normally discarded to useable power and work. This concept has the potential of a substantial increase in fuel efficiency over existing conventional internal combustion engines, and under appropriate injected water conditions, increase the fuel efficiency without incurring a decrease in power density. By changing the exhaust valve closing angle during the exhaust stroke, the ideal amount of exhaust can be recompressed for the amount of water injected, thereby minimizing the work input and maximizing the mean effective pressure of the steam expansion stroke (MEPsteam). The value of this exhaust valve closing for maximum MEPsteam depends on the limiting conditions of either one bar or the dew point temperature of the expansion gas/moisture mixture when the exhaust valve opens to discard the spent gas mixture in the sixth stroke. The range of MEPsteam calculated for the geometry of a conventional gasoline spark-ignited internal combustion engine and for plausible water injection parameters 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

  1. Observations of airglow during injections of exhaust streams of ``Progress'' orbital maneuvering subsystem

    NASA Astrophysics Data System (ADS)

    Beletsky, Alexandr; Mikhalev, Alexander; Khakhinov, Vitaly; Lebedev, Valentin

    Observations of airglow during injections of exhaust streams of “Progress” orbital maneuvering subsystem A. Mikhalev, V. Khakhinov, A. Beletsky, V. Lebedev Institute of Solar-Terrestrial Physics of Siberian Branch of Russian Academy of Sciences (ISTP SB RAS) 664033, Lermontov str. 126a, p/o Box 291, Irkutsk, Russia ABSTRACT The effect of increasing the intensity of airglow emissions associated with spacecraft engines exhaust to the atmosphere is well-known. We carried out the "Radar-Progress" active space experiment for studying the ionosphere on April 17 2013. The exhaust products of orbital maneuvering subsystem engines of transport spacecraft “Progress” were used as a source of ionosphere disturbances. The engines run from 13:24:37 to 13:24:46 UT. The "Progress" orbit altitude was 412 km. We carried out observations of nightglow in the several spectral lines. The all-sky camera was used for obtaining spatial distribution of the 630 nm emission intensity. An increase in the emission intensity in the area of "Progress" track was observed after starting the engines. According to preliminary estimates, the rate of the glow expansion at the orbit altitude during first 60 seconds after the start was ~ 7 km/c along the orbit and ~ 3.5 km/s across the orbit. The observed glow area reached the largest size of ~ 350 km along the orbit and ~ 250 km across the orbit 120-150 s after start. The study has been supported by the grant 13-05-00456-a and 13-02-00957-a of the Russian Foundation for Basic Research and RF President Grant of Public Support for RF Leading Scientific Schools (NSh-2942.2014.5).

  2. Comparison of the toxicity of diesel exhaust produced by bio- and fossil diesel combustion in human lung cells in vitro

    NASA Astrophysics Data System (ADS)

    Steiner, Sandro; Czerwinski, Jan; Comte, Pierre; Popovicheva, Olga; Kireeva, Elena; Müller, Loretta; Heeb, Norbert; Mayer, Andreas; Fink, Alke; Rothen-Rutishauser, Barbara

    2013-12-01

    Alternative fuels are increasingly combusted in diesel- and gasoline engines and the contribution of such exhausts to the overall air pollution is on the rise. Recent findings on the possible adverse effects of biodiesel exhaust are contradictive, at least partly resulting from the various fuel qualities, engine types and different operation conditions that were tested. However, most of the studies are biased by undesired interactions between the exhaust samples and biological culture media. We here report how complete, freshly produced exhausts from fossil diesel (B0), from a blend of 20% rapeseed-methyl ester (RME) and 80% fossil diesel (B20) and from pure rapeseed methyl ester (B100) affect a complex 3D cellular model of the human airway epithelium in vitro by exposing the cells at the air-liquid interface. The induction of pro-apoptotic and necrotic cell death, cellular morphology, oxidative stress, and pro-inflammatory responses were assessed. Compared to B0 exhaust, B20 exhaust decreased oxidative stress and pro-inflammatory responses, whereas B100 exhaust, depending on exposure duration, decreased oxidative stress but increased pro-inflammatory responses. The effects are only very weak and given the compared to fossil diesel higher ecological sustainability of biodiesel, it appears that - at least RME - can be considered a valuable alternative to pure fossil diesel.

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

    NASA Astrophysics Data System (ADS)

    Afiq, Mohd; Azuhairi, Mohd; Jazair, Wira

    2010-06-01

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

  4. Apparatus for controlling the flow of exhaust gas in an internal combustion engine with a turbocharger and a catalytic converter

    SciTech Connect

    Iwamoto, K.; Omata, K.

    1984-03-20

    An apparatus for controlling the flow of the exhaust gas in an internal combustion engine including a turbocharger, a catalytic converter in an exhaust duct, and a throttle valve in an intake duct, wherein the apparatus comprises a bypass passage bypassing a turbine of the turbocharger, a waste gate valve which controls the amount of the exhaust gas passing therethrough, an actuator for actuating the waste gate valve which has first and second pressure chambers separated from one another, and a switching valve which selectively connects the second pressure chamber to the atmosphere or to the intake vacuum area, the first pressure chamber being connected to the delivery pressure area of the turbocharger by means of a conduit which is connected to an atmospheric pressure area via a restriction.

  5. WOOD PRODUCTS IN THE WASTE STREAM: CHARACTERIZATION AND COMBUSTION EMISSIONS - VOLUME 2. APPENDICES

    EPA Science Inventory

    The report gives results of a study of technical, public policy, and regulatory issues that affect the processing and combustion of waste wood for fuel. (NOTE: Waste wood is wood that is separated from a solid-waste stream, processed into a uniform-sized product, and reused for o...

  6. WOOD PRODUCTS IN THE WASTE STREAM: CHARACTERIZATION AND COMBUSTION EMISSIONS - VOLUME 1. TECHNICAL REPORT

    EPA Science Inventory

    The report gives results of a study of technical, public policy, and regulatory issues that affect the processing and combustion of waste wood for fuel. (NOTE: Waste wood is wood that is separated from a solid-waste stream, processed into a uniform-sized product, and reused for o...

  7. Simultaneous film and convection cooling of a plate inserted in the exhaust stream of a gas turbine combustor

    NASA Technical Reports Server (NTRS)

    Marek, C. J.; Juhasz, A. J.

    1973-01-01

    Data were obtained on a parallel-flow film- and convection-cooled test section placed in the exhaust stream of a rectangular-sector combustor. The combustor was operated at atmospheric pressure and at exhaust temperatures of 589 and 1033 K (600 and 1400 F). The cooling air was at ambient pressure and temperature. Test results indicate that it is better to use combined film and convection cooling rather than either film or convection cooling alone for a fixed total coolant flow. An optimum ratio of film to convection cooling flow rates was determined for the particular geometry tested. The experimental results compared well with calculated results.

  8. Method for simultaneously removing SO.sub.2 and NO.sub.X pollutants from exhaust of a combustion system

    DOEpatents

    Levendis, Yiannis A.; Wise, Donald L.

    1994-05-17

    A method is disclosed for removing pollutants from the exhaust of combustion systems burning fuels containing substantial amounts of sulfur and nitrogen. An exemplary method of the invention involves the formation and reaction of a sorbent comprising calcium magnesium acetate (CMA). The CMA is either dry-sprayed (in the form of a fine powder) or wet-sprayed in an aqueous solution in a high temperature environment such as a combustion chamber. The latter technique is feasible since CMA is a uniquely water-soluble form of calcium and magnesium. When the dispersed particles of CMA are heated to a high temperature, fine calcium and magnesium oxide particles, which are hollow with thin and highly porous walls are formed, affording optimum external and internal accessibility for reacting with toxic gaseous emissions such as SO.sub.2. Further, the combustion of the organic acetate portion of the sorbent results in the conversion of NO.sub.x to N.sub.2.

  9. Metal particle emissions in the exhaust stream of diesel engines: an electron microscope study.

    PubMed

    Liati, Anthi; Schreiber, Daniel; Dimopoulos Eggenschwiler, Panayotis; Arroyo Rojas Dasilva, Yadira

    2013-12-17

    Scanning electron microscopy and transmission electron microscopy were applied to investigate the morphology, mode of occurrence and chemical composition of metal particles (diesel ash) in the exhaust stream of a small truck outfitted with a typical after-treatment system (a diesel oxidation catalyst (DOC) and a downstream diesel particulate filter (DPF)). Ash consists of Ca-Zn-P-Mg-S-Na-Al-K-phases (lube-oil related), Fe, Cr, Ni, Sn, Pb, Sn (engine wear), and Pd (DOC coating). Soot agglomerates of variable sizes (<0.5-5 μm) are abundant upstream of the DPF and are ash-free or contain notably little attached ash. Post-DPF soot agglomerates are very few, typically large (>1-5 μm, exceptionally 13 μm), rarely <0.5 μm, and contain abundant ash carried mostly from inside the DPF. The ash that reaches the atmosphere also occurs as separate aggregates ca. 0.2-2 μm in size consisting of sintered primary phases, ca. 20-400 nm large. Insoluble particles of these sizes may harm the respiratory and cardiovascular systems. The DPF probably promotes breakout of large soot agglomerates (mostly ash-bearing) by favoring sintering. Noble metals detached from the DOC coating may reach the ambient air. Finally, very few agglomerates of Fe-oxide nanoparticles form newly from engine wear and escape into the atmosphere. PMID:24274188

  10. Metal particle emissions in the exhaust stream of diesel engines: an electron microscope study.

    PubMed

    Liati, Anthi; Schreiber, Daniel; Dimopoulos Eggenschwiler, Panayotis; Arroyo Rojas Dasilva, Yadira

    2013-12-17

    Scanning electron microscopy and transmission electron microscopy were applied to investigate the morphology, mode of occurrence and chemical composition of metal particles (diesel ash) in the exhaust stream of a small truck outfitted with a typical after-treatment system (a diesel oxidation catalyst (DOC) and a downstream diesel particulate filter (DPF)). Ash consists of Ca-Zn-P-Mg-S-Na-Al-K-phases (lube-oil related), Fe, Cr, Ni, Sn, Pb, Sn (engine wear), and Pd (DOC coating). Soot agglomerates of variable sizes (<0.5-5 μm) are abundant upstream of the DPF and are ash-free or contain notably little attached ash. Post-DPF soot agglomerates are very few, typically large (>1-5 μm, exceptionally 13 μm), rarely <0.5 μm, and contain abundant ash carried mostly from inside the DPF. The ash that reaches the atmosphere also occurs as separate aggregates ca. 0.2-2 μm in size consisting of sintered primary phases, ca. 20-400 nm large. Insoluble particles of these sizes may harm the respiratory and cardiovascular systems. The DPF probably promotes breakout of large soot agglomerates (mostly ash-bearing) by favoring sintering. Noble metals detached from the DOC coating may reach the ambient air. Finally, very few agglomerates of Fe-oxide nanoparticles form newly from engine wear and escape into the atmosphere.

  11. Drive cycle simulation of high efficiency combustions on fuel economy and exhaust properties in light-duty vehicles

    SciTech Connect

    Gao, Zhiming; Curran, Scott J.; Parks, James E.; Smith, David E.; Wagner, Robert M.; Daw, C. Stuart; Edwards, K. Dean; Thomas, John F.

    2015-04-06

    We present fuel economy and engine-out emissions for light-duty (LD) conventional and hybrid vehicles powered by conventional and high-efficiency combustion engines. Engine technologies include port fuel-injected (PFI), direct gasoline injection (GDI), reactivity controlled compression ignition (RCCI) and conventional diesel combustion (CDC). In the case of RCCI, the engine utilized CDC combustion at speed/load points not feasible with RCCI. The results, without emissions considered, show that the best fuel economies can be achieved with CDC/RCCI, with CDC/RCCI, CDC-only, and lean GDI all surpassing PFI fuel economy significantly. In all cases, hybridization significantly improved fuel economy. The engine-out hydrocarbon (HC), carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter (PM) emissions varied remarkably with combustion mode. The simulated engine-out CO and HC emissions from RCCI are significantly higher than CDC, but RCCI makes less NOx and PM emissions. Hybridization can improve lean GDI and RCCI cases by increasing time percentage for these more fuel efficient modes. Moreover, hybridization can dramatically decreases the lean GDI and RCCI engine out emissions. Importantly, lean GDI and RCCI combustion modes decrease exhaust temperatures, especially for RCCI, which limits aftertreatment performance to control tailpipe emissions. Overall, the combination of engine and hybrid drivetrain selected greatly affects the emissions challenges required to meet emission regulations.

  12. Drive cycle simulation of high efficiency combustions on fuel economy and exhaust properties in light-duty vehicles

    DOE PAGES

    Gao, Zhiming; Curran, Scott J.; Parks, James E.; Smith, David E.; Wagner, Robert M.; Daw, C. Stuart; Edwards, K. Dean; Thomas, John F.

    2015-04-06

    We present fuel economy and engine-out emissions for light-duty (LD) conventional and hybrid vehicles powered by conventional and high-efficiency combustion engines. Engine technologies include port fuel-injected (PFI), direct gasoline injection (GDI), reactivity controlled compression ignition (RCCI) and conventional diesel combustion (CDC). In the case of RCCI, the engine utilized CDC combustion at speed/load points not feasible with RCCI. The results, without emissions considered, show that the best fuel economies can be achieved with CDC/RCCI, with CDC/RCCI, CDC-only, and lean GDI all surpassing PFI fuel economy significantly. In all cases, hybridization significantly improved fuel economy. The engine-out hydrocarbon (HC), carbon monoxidemore » (CO), nitrogen oxides (NOx), and particulate matter (PM) emissions varied remarkably with combustion mode. The simulated engine-out CO and HC emissions from RCCI are significantly higher than CDC, but RCCI makes less NOx and PM emissions. Hybridization can improve lean GDI and RCCI cases by increasing time percentage for these more fuel efficient modes. Moreover, hybridization can dramatically decreases the lean GDI and RCCI engine out emissions. Importantly, lean GDI and RCCI combustion modes decrease exhaust temperatures, especially for RCCI, which limits aftertreatment performance to control tailpipe emissions. Overall, the combination of engine and hybrid drivetrain selected greatly affects the emissions challenges required to meet emission regulations.« less

  13. Two stroke engine exhaust emissions separator

    DOEpatents

    Turner, Terry D.; Wilding, Bruce M.; McKellar, Michael G.; Raterman, Kevin T.

    2003-04-22

    A separator for substantially resolving at least one component of a process stream, such as from the exhaust of an internal combustion engine. The separator includes a body defining a chamber therein. A nozzle housing is located proximate the chamber. An exhaust inlet is in communication with the nozzle housing and the chamber. A nozzle assembly is positioned in the nozzle housing and includes a nozzle moveable within and relative to the nozzle housing. The nozzle includes at least one passage formed therethrough such that a process stream entering the exhaust inlet connection passes through the passage formed in the nozzle and imparts a substantially rotational flow to the process stream as it enters the chamber. A positioning member is configured to position the nozzle relative to the nozzle housing in response to changes in process stream pressure thereby adjusting flowrate of said process stream entering into the chamber.

  14. Two stroke engine exhaust emissions separator

    DOEpatents

    Turner, Terry D.; Wilding, Bruce M.; McKellar, Michael G.; Raterman, Kevin T.

    2002-01-01

    A separator for substantially resolving at least one component of a process stream, such as from the exhaust of an internal combustion engine. The separator includes a body defining a chamber therein. A nozzle housing is located proximate the chamber. An exhaust inlet is in communication with the nozzle housing and the chamber. A nozzle assembly is positioned in the nozzle housing and includes a nozzle moveable within and relative to the nozzle housing. The nozzle includes at least one passage formed therethrough such that a process stream entering the exhaust inlet connection passes through the passage formed in the nozzle, which imparts a substantially rotational flow to the process stream as it enters the chamber. A positioning member is configured to position the nozzle relative to the nozzle housing in response to changes in process stream pressure to adjust flowrate of said process stream entering into the chamber.

  15. Coherent Anti-Stokes Raman Spectroscopy (cars) Gas Temperature Measurements in a Monodisperse Combusting Droplet Stream.

    NASA Astrophysics Data System (ADS)

    Zhu, Junyong

    1991-06-01

    This dissertation describes a coherent anti-Stokes Raman spectroscopy (CARS) instrument for spatially and temporally resolved non-intrusive temperature measurements in combustion environments. It presents a detailed description of the CARS system development and standard procedures to perform CARS gas temperature measurements,and procedures to analyze the CARS spectra for temperature determination. The dissertation also applies the CARS apparatus developed to a single monodisperse methanol droplet stream flame to demonstrate synchronous CARS temperature measurements. The measurements correlate the temperature field with the droplet position and give the local characteristics of the combusting droplet stream thermal field. These measurements are not possible with conventional thermal probes due to the perturbation caused by the probes and the poor temporal and spatial resolution. These CARS measurements are the first known non-intrusive characterization of the local temperature field near burning droplets. The experiments use a 50 μm diameter nozzle vibrated by a piezoelectric crystal to generate a monodisperse droplet stream with a droplet diameter of about 150 μm and droplet-to-droplet spacing of 10 droplet diameters. A frequency divider divides the crystal vibration frequency of 10 kHz 1000 times to synchronize the CARS laser firing (~ 10 Hz) with the droplet generation process. The results show that there is a small thermal wake behind each droplet in the stream. The temperature profile measured radially outward from the droplet has a local minimum near the droplet surface, rises to a maximum at about 7 droplet diameters away, and then falls to room temperature at a radial distance of 15 mm (100 droplet diameters). The temperature profile measured between two adjacent droplets on the stream axis is nearly flat, suggesting that individual flames do not surround each droplet. The local effects due to the presence of droplets completely disappear about 15 droplet

  16. Combustion of dense streams of coal particles. Quarterly progress report No. 12, May 29, 1993--August 28, 1993

    SciTech Connect

    Annamalai, K.

    1993-09-20

    Research continued on coal stream combustion. This report presents the results obtained from the gasification efficiency experiments by varying the (i) air fuel ratio of the coal cloud (ii) reaction zone height (residence time) and (iii) oxygen concentration. A brief discussion on the divergence of coal stream is presented.

  17. Combustion method for simultaneous control of nitrogen oxides and products of incomplete combustion

    SciTech Connect

    Ho, Min-Da.

    1993-05-25

    A method is described for combusting material with controlled generation of both nitrogen oxides and products of incomplete combustion comprising: (A) combusting material in a first combustion zone to produce gaseous exhaust containing products of incomplete combustion and products of complete combustion; (B) passing the gaseous exhaust from the first combustion zone into a second combustion zone having a width and an axial direction; (C) injecting through a lance with an orientation substantially parallel to said axial direction at least one stream of oxidant, without fuel, having a diameter less than 1/100 of the width of the second combustion zone and having an oxygen concentration of at least 30% into the second combustion zone at a high velocity of at least 300 feet per second; (D) aspirating products of incomplete combustion into the high velocity oxidant; (E) combusting products of incomplete combustion aspirated into the high velocity oxidant with high velocity oxidant within the second combustion zone to carry out a stable combustion by the mixing of the aspirated products of incomplete combustion with the high velocity oxidant; and (F) spreading out the combustion reaction by aspiration of products of complete combustion into the oxidant, said products of complete combustion also serving as a heat sink, to inhibit NO[sub x] formation.

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

  19. Air pollution from aircraft. [jet exhaust - aircraft fuels/combustion efficiency

    NASA Technical Reports Server (NTRS)

    Heywood, J. B.; Chigier, N. A.

    1975-01-01

    A model which predicts nitric oxide and carbon monoxide emissions from a swirl can modular combustor is discussed. A detailed analysis of the turbulent fuel-air mixing process in the swirl can module wake region is reviewed. Hot wire anemometry was employed, and gas sampling analysis of fuel combustion emissions were performed.

  20. Mobile Source Air Toxics (MSATs) from High Efficiency Clean Combustion: Catalytic Exhaust Treatment Effects

    SciTech Connect

    Storey, John Morse; Lewis Sr, Samuel Arthur; Parks, II, James E; Barone, Teresa L; Prikhodko, Vitaly Y

    2008-01-01

    High Efficiency Clean Combustion (HECC) strategies such as homogenous charge compression ignition (HCCI) and pre-mixed charge compression ignition (PCCI) offer much promise for the reduction of NOx and PM from diesel engines. While delivering low PM and low NOx, these combustion modes often produce much higher levels of CO and HC than conventional diesel combustion modes. In addition, partially oxygenated species such as formaldehyde (an MSAT) and other aldehydes increase with HECC modes. The higher levels of CO and HCs have the potential to compromise the performance of the catalytic aftertreatment, specifically at low load operating points. As HECC strategies become incorporated into vehicle calibrations, manufacturers need to avoid producing MSATs in higher quantities than found in conventional combustion modes. This paper describes research on two different HECC strategies, HCCI and PCCI. Engine-out data for several MSAT species (formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, xylenes, naphthalene, PAHs, diesel PM) as well as other HC species are presented and compared when possible with conventional operation. In addition, catalyst-out values were measured to assess the destruction of individual MSATs over the catalyst. At low engine loads, MSATs were higher and catalyst performance was poorer. Particle sizing results identify large differences between PM from conventional and HECC operation.

  1. Predictive Acoustic Modelling Applied to the Control of Intake/exhaust Noise of Internal Combustion Engines

    NASA Astrophysics Data System (ADS)

    Davies, P. O. A. L.; Harrison, M. F.

    1997-05-01

    The application of validated acoustic models to intake/exhaust system acoustic design is described with reference to a sequence of specific practical examples. These include large turbocharged diesel generating sets, truck engines and high performance petrol engines. The discussion includes a comparison of frequency domain, time domain and hybrid modelling approaches to design methodology. The calculation of sound emission from open terminations is summarized in an appendix.

  2. Application of fault tree approach for the causation mechanism of urban haze in Beijing--Considering the risk events related with exhausts of coal combustion.

    PubMed

    Huang, Weiqing; Fan, Hongbo; Qiu, Yongfu; Cheng, Zhiyu; Qian, Yu

    2016-02-15

    Haze weather has become a serious environmental pollution problem which occurs in many Chinese cities. One of the most critical factors for the formation of haze weather is the exhausts of coal combustion, thus it is meaningful to figure out the causation mechanism between urban haze and the exhausts of coal combustion. Based on above considerations, the fault tree analysis (FAT) approach was employed for the causation mechanism of urban haze in Beijing by considering the risk events related with the exhausts of coal combustion for the first time. Using this approach, firstly the fault tree of the urban haze causation system connecting with coal combustion exhausts was established; consequently the risk events were discussed and identified; then, the minimal cut sets were successfully determined using Boolean algebra; finally, the structure, probability and critical importance degree analysis of the risk events were completed for the qualitative and quantitative assessment. The study results proved that the FTA was an effective and simple tool for the causation mechanism analysis and risk management of urban haze in China. PMID:26493345

  3. Application of fault tree approach for the causation mechanism of urban haze in Beijing--Considering the risk events related with exhausts of coal combustion.

    PubMed

    Huang, Weiqing; Fan, Hongbo; Qiu, Yongfu; Cheng, Zhiyu; Qian, Yu

    2016-02-15

    Haze weather has become a serious environmental pollution problem which occurs in many Chinese cities. One of the most critical factors for the formation of haze weather is the exhausts of coal combustion, thus it is meaningful to figure out the causation mechanism between urban haze and the exhausts of coal combustion. Based on above considerations, the fault tree analysis (FAT) approach was employed for the causation mechanism of urban haze in Beijing by considering the risk events related with the exhausts of coal combustion for the first time. Using this approach, firstly the fault tree of the urban haze causation system connecting with coal combustion exhausts was established; consequently the risk events were discussed and identified; then, the minimal cut sets were successfully determined using Boolean algebra; finally, the structure, probability and critical importance degree analysis of the risk events were completed for the qualitative and quantitative assessment. The study results proved that the FTA was an effective and simple tool for the causation mechanism analysis and risk management of urban haze in China.

  4. Fast spatially resolved exhaust gas recirculation (EGR) distribution measurements in an internal combustion engine using absorption spectroscopy.

    PubMed

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2015-09-01

    Exhaust gas recirculation (EGR) in internal combustion engines is an effective method of reducing NOx emissions while improving efficiency. However, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder non-uniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. A sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. The study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz. PMID:26253286

  5. Condensation of water vapor and carbon dioxide in the jet exhausts of rocket engines: 1. Heterogeneous condensation of combustion products

    NASA Astrophysics Data System (ADS)

    Platov, Yu. V.; Semenov, A. I.; Filippov, B. V.

    2014-01-01

    Condensation of water vapor and carbon dioxide in the jet exhausts of rocket engines during last stages of Proton, Molniya, and Start launchers operating in the upper atmospheric with different types of fuels is considered. Particle heating is taken into account with emission of latent heat of condensation and energy loss due to radiation and heat exchange with combustion products. Using the solution of the heat balance and condensed particle mass equations, the temporal change in the temperature and thickness of the condensate layer is obtained. Practically, no condensation of water vapor and carbon dioxide in the jet exhaust of a Start launcher occurs. In plumes of Proton and Molniya launchers, the condensation of water vapor and carbon dioxide can start at distances of 120-170 m and 450-650 m from the engine nozzle, respectively. In the course of condensation, the thickness of the "water" layer on particles can exceed 100 Å, and the thickness of carbon dioxide can exceed 60 Å.

  6. Fast spatially resolved exhaust gas recirculation (EGR) distribution measurements in an internal combustion engine using absorption spectroscopy.

    PubMed

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2015-09-01

    Exhaust gas recirculation (EGR) in internal combustion engines is an effective method of reducing NOx emissions while improving efficiency. However, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder non-uniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. A sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. The study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.

  7. Fast Spatially Resolved Exhaust Gas Recirculation (EGR) Distribution Measurements in an Internal Combustion Engine Using Absorption Spectroscopy

    DOE PAGES

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E.; Perfetto, Anthony; Geckler, Sam; Partridge, William P.

    2015-09-01

    One effective method of reducing NOx emissions while improving efficiency is exhaust gas recirculation (EGR) in internal combustion engines. But, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder nonuniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. Furthermore, a sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in themore » intake manifold. Our study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.« less

  8. Fast Spatially Resolved Exhaust Gas Recirculation (EGR) Distribution Measurements in an Internal Combustion Engine Using Absorption Spectroscopy

    SciTech Connect

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E.; Perfetto, Anthony; Geckler, Sam; Partridge, William P.

    2015-09-01

    One effective method of reducing NOx emissions while improving efficiency is exhaust gas recirculation (EGR) in internal combustion engines. But, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder nonuniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. Furthermore, a sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. Our study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.

  9. A Study of the Theoretical Potential of Thermochemical Exhaust Heat Recuperation for Internal Combustion Engines

    SciTech Connect

    Chakravarthy, Veerathu K; Daw, C Stuart; Pihl, Josh A; Conklin, Jim

    2010-01-01

    We present a detailed thermodynamic analysis of thermochemical recuperation (TCR) applied to an idealized internal combustion engine with single-stage work extraction. Results for several different fuels are included. For a stoichiometric mixture of methanol and air, TCR can increase the estimated ideal engine Second Law efficiency by about 3% for constant pressure reforming and over 5% for constant volume reforming. For ethanol and isooctane the estimated Second Law efficiency increases for constant volume reforming are 9% and 11%, respectively. The Second Law efficiency improvements from TCR result primarily from the higher intrinsic exergy of the reformed fuel and pressure boost associated with gas mole increase. Reduced combustion irreversibility may also yield benefits for future implementations of combined cycle work extraction.

  10. A Study of the Theoretical Potential of Thermochemical Exhaust Heat Recuperation in Internal Combustion Engines

    SciTech Connect

    Daw, C Stuart; Pihl, Josh A; Chakravarthy, Veerathu K; Conklin, Jim

    2010-01-01

    A detailed thermodynamic analysis of thermochemical recuperation (TCR) applied to an idealized internal combustion engine with single-stage work extraction is presented. Results for several different fuels are included. For a stoichiometric mixture of methanol and air, TCR can increase the estimated ideal engine second law efficiency by about 3% for constant pressure reforming and over 5% for constant volume reforming. For ethanol and isooctane, the estimated second law efficiency increases for constant volume reforming are 9 and 11%, respectively. The second law efficiency improvements from TCR result primarily from the higher intrinsic exergy of the reformed fuel and pressure boost associated with the gas mole increase. Reduced combustion irreversibility may also yield benefits for future implementations of combined cycle work extraction.

  11. Carbonyl compounds in dining areas, kitchens and exhaust streams in restaurants with varying cooking methods in Kaohsiung, Taiwan.

    PubMed

    Cheng, Jen-Hsuan; Lee, Yi-Shiun; Chen, Kang-Shin

    2016-03-01

    Eighteen carbonyl species in C1-C10 were measured in the dining areas, kitchens and exhaust streams of six different restaurant types in Kaohsiung, southern Taiwan. Measured results in the dining areas show that Japanese barbecue (45.06ppb) had the highest total carbonyl concentrations (sum of 18 compounds), followed by Chinese hotpot (38.21ppb), Chinese stir-frying (8.99ppb), Western fast-food (8.22ppb), Chinese-Western mixed style (7.38ppb), and Chinese buffet (3.08ppb), due to their different arrangements for dining and cooking spaces and different cooking methods. On average, low carbon-containing species (C1-C4), e.g., formaldehyde, acetaldehyde, acetone and butyraldehyde were dominant and contributed 55.01%-94.52% of total carbonyls in the dining areas of all restaurants. Meanwhile, Chinese-Western mixed restaurants (45.48ppb) had high total carbonyl concentrations in kitchens mainly because of its small kitchen and poor ventilation. However, high carbon-containing species (C5-C10) such as hexaldehyde, heptaldehyde and nonanaldehyde (16.62%-77.00% of total carbonyls) contributed comparatively with low carbon-containing compounds (23.01%-83.39% of total carbonyls) in kitchens. Furthermore, Chinese stir-frying (132.10ppb), Japanese barbecue (125.62ppb), Western fast-food (122.67ppb), and Chinese buffet (119.96ppb) were the four restaurant types with the highest total carbonyl concentrations in exhaust streams, indicating that stir-frying and grilling are inclined to produce polluted gases. Health risk assessments indicate that Chinese hotpot and Japanese barbecue exceeded the limits of cancer risk (10(-6)) and hazard index (=1), mainly due to high concentrations of formaldehyde. The other four restaurants were below both limits. PMID:26969068

  12. Conductometric Sensor for Soot Mass Flow Detection in Exhausts of Internal Combustion Engines.

    PubMed

    Feulner, Markus; Hagen, Gunter; Müller, Andreas; Schott, Andreas; Zöllner, Christian; Brüggemann, Dieter; Moos, Ralf

    2015-01-01

    Soot sensors are required for on-board diagnostics (OBD) of automotive diesel particulate filters (DPF) to detect filter failures. Widely used for this purpose are conductometric sensors, measuring an electrical current or resistance between two electrodes. Soot particles deposit on the electrodes, which leads to an increase in current or decrease in resistance. If installed upstream of a DPF, the "engine-out" soot emissions can also be determined directly by soot sensors. Sensors were characterized in diesel engine real exhausts under varying operation conditions and with two different kinds of diesel fuel. The sensor signal was correlated to the actual soot mass and particle number, measured with an SMPS. Sensor data and soot analytics (SMPS) agreed very well, an impressing linear correlation in a double logarithmic representation was found. This behavior was even independent of the used engine settings or of the biodiesel content. PMID:26580621

  13. Conductometric Sensor for Soot Mass Flow Detection in Exhausts of Internal Combustion Engines

    PubMed Central

    Feulner, Markus; Hagen, Gunter; Müller, Andreas; Schott, Andreas; Zöllner, Christian; Brüggemann, Dieter; Moos, Ralf

    2015-01-01

    Soot sensors are required for on-board diagnostics (OBD) of automotive diesel particulate filters (DPF) to detect filter failures. Widely used for this purpose are conductometric sensors, measuring an electrical current or resistance between two electrodes. Soot particles deposit on the electrodes, which leads to an increase in current or decrease in resistance. If installed upstream of a DPF, the “engine-out” soot emissions can also be determined directly by soot sensors. Sensors were characterized in diesel engine real exhausts under varying operation conditions and with two different kinds of diesel fuel. The sensor signal was correlated to the actual soot mass and particle number, measured with an SMPS. Sensor data and soot analytics (SMPS) agreed very well, an impressing linear correlation in a double logarithmic representation was found. This behavior was even independent of the used engine settings or of the biodiesel content. PMID:26580621

  14. Conductometric Sensor for Soot Mass Flow Detection in Exhausts of Internal Combustion Engines.

    PubMed

    Feulner, Markus; Hagen, Gunter; Müller, Andreas; Schott, Andreas; Zöllner, Christian; Brüggemann, Dieter; Moos, Ralf

    2015-11-13

    Soot sensors are required for on-board diagnostics (OBD) of automotive diesel particulate filters (DPF) to detect filter failures. Widely used for this purpose are conductometric sensors, measuring an electrical current or resistance between two electrodes. Soot particles deposit on the electrodes, which leads to an increase in current or decrease in resistance. If installed upstream of a DPF, the "engine-out" soot emissions can also be determined directly by soot sensors. Sensors were characterized in diesel engine real exhausts under varying operation conditions and with two different kinds of diesel fuel. The sensor signal was correlated to the actual soot mass and particle number, measured with an SMPS. Sensor data and soot analytics (SMPS) agreed very well, an impressing linear correlation in a double logarithmic representation was found. This behavior was even independent of the used engine settings or of the biodiesel content.

  15. Investigation of the Influence of Convective Mach Number on Compressible Plane Jet Exhausting into Parallel Streams

    NASA Astrophysics Data System (ADS)

    Datta, Abanti; Sinhamahapatra, Kalyan Prasad

    2016-08-01

    The effects of convective Mach number on plane jets with parallel co-flow streams are investigated in the present study. Two-dimensional viscous compressible plane jet issuing to co-flowing parallel streams is numerically simulated using higher order spatial and temporal integration schemes. To remove mesh induced non-uniformities explicit tridiagonal spatial filter is applied. The mean flow field and turbulence statistics are captured from the simulated results using time-average over streamwise direction. The captured mean velocity profiles in appropriate non-dimensional form exhibit self-similar behaviour and do not change considerably with convective Mach number. The streamwise mean excess velocity profiles collapse very well with previous experimental data. The turbulent intensity profiles and Reynolds shear stress profiles do not show self-similar characteristic and increase slowly in farther downstream. The two-dimensional simulation is found capable of capturing correct jet spreading and decay.

  16. Device for use in a furnace exhaust stream for thermoelectric generation

    SciTech Connect

    Polcyn, Adam D.

    2013-06-11

    A device for generating voltage or electrical current includes an inner elongated member mounted in an outer elongated member, and a plurality of thermoelectric modules mounted in the space between the inner and the outer members. The outer and/or inner elongated members each include a plurality of passages to move a temperature altering medium through the members so that the device can be used in high temperature environments, e.g. the exhaust system of an oxygen fired glass melting furnace. The modules are designed to include a biasing member and/or other arrangements to compensate for differences in thermal expansion between the first and the second members. In this manner, the modules remain in contact with the first and second members. The voltage generated by the modules can be used to power electrical loads.

  17. System and method for selective catalytic reduction of nitrogen oxides in combustion exhaust gases

    DOEpatents

    Sobolevskiy, Anatoly; Rossin, Joseph A

    2014-04-08

    A multi-stage selective catalytic reduction (SCR) unit (32) provides efficient reduction of NOx and other pollutants from about 50-550.degree. C. in a power plant (19). Hydrogen (24) and ammonia (29) are variably supplied to the SCR unit depending on temperature. An upstream portion (34) of the SCR unit catalyzes NOx+NH.sub.3 reactions above about 200.degree. C. A downstream portion (36) catalyzes NOx+H.sub.2 reactions below about 260.degree. C., and catalyzes oxidation of NH.sub.3, CO, and VOCs with oxygen in the exhaust above about 200.degree. C., efficiently removing NOx and other pollutants over a range of conditions with low slippage of NH.sub.3. An ammonia synthesis unit (28) may be connected to the SCR unit to provide NH.sub.3 as needed, avoiding transport and storage of ammonia or urea at the site. A carbonaceous gasification plant (18) on site may supply hydrogen and nitrogen to the ammonia synthesis unit, and hydrogen to the SCR unit.

  18. Some Effects of Exposure to Exhaust-gas Streams on Emittance and Thermoelectric Power of Bare-wire Platinum Rhodium - Platinum Thermocouples

    NASA Technical Reports Server (NTRS)

    Glawe, George E; Shepard, Charles E

    1954-01-01

    Thermocouples were exposed to exhaust gases from the combustion of propane, 72-octane gasoline, and JP-4 fuel. Exposure increased the emissivity of the thermocouple wire, which increased its radiation error. Two methods are presented for determining the emittance of the wires. The emissivity of a clean platinum rhodium-platinum thermocouple was approximately 0.2 in the temperature range investigated, while the emittance of an exposed thermocouple coated with exhaust residue was about 0.5. The exposure caused negligible change in the thermoelectric power of the thermocouples.

  19. Conversion of the exhaust emission results obtained from combustion engines of heavy-duty vehicles

    NASA Astrophysics Data System (ADS)

    Merkisz, J.; Pielecha, J.

    2016-09-01

    The use of internal combustion engines as the drive for heavy-duty vehicles forces these engines to be tested on an engine dynamometer. Thus, these engines operate under forced conditions, which are significantly different from their actual application. To assess the ecology of such vehicles (or more accurately the engine alone) the emission of pollution per unit of work done by the engine must be determined. However, obtaining the results of unit emissions (expressed in grams of the compound per a unit of performed work) does not give the grounds for determining the mass of pollutants on a given stretch of the road travelled by the vehicle. Therefore, there is a need to change the emission value expressed in units referenced to the engine work into a value of road emissions. The paper presents a methodology of determining pollutant emissions of heavy-duty road vehicles on the basis of the unit emissions, as well as additional parameters determined on the basis of the algorithm presented in the article. A solution was obtained that can be used not only for heavy-duty vehicles, but was also extended to allow use for buses.

  20. Rat inhalation test with particles from biomass combustion and biomass co-firing exhaust

    NASA Astrophysics Data System (ADS)

    Bellmann, B.; Creutzenberg, O.; Ernst, H.; Muhle, H.

    2009-02-01

    The health effects of 6 different fly ash samples from biomass combustion plants (bark, wood chips, waste wood, and straw), and co-firing plants (coal, co-firing of coal and sawdust) were investigated in a 28-day nose-only inhalation study with Wistar WU rats. Respirable fractions of carbon black (Printex 90) and of titanium dioxide (Bayertitan T) were used as reference materials for positive and negative controls. The exposure was done 6 hours per day, 5 days per week at an aerosol concentration of 16 mg/m3. The MMAD of all fly ash samples and reference materials in the inhalation unit were in the range from 1.5 to 3 μm. The investigations focused predominantly on the analysis of inflammatory effects in the lungs of rats using bronchoalveolar lavage (BAL) and histopathology. Different parameters (percentage of polymorphonuclear neutrophils (PMN), interleukin-8 and interstitial inflammatory cell infiltration in the lung tissue) indicating inflammatory effects in the lung, showed a statistically significant increase in the groups exposed to carbon black (positive control), C1 (coal) and C1+BM4 (co-firing of coal and sawdust) fly ashes. Additionally, for the same groups a statistically significant increase of cell proliferation in the lung epithelium was detected. No significant effects were detected in the animal groups exposed to BM1 (bark), BM2 (wood chips), BM3 (waste wood), BM6 (straw) or titanium dioxide.

  1. Stationary, gaseous-fueled, internal combustion engine, air-fuel ratio control for application of three-way catalysts for exhaust emission reduction

    SciTech Connect

    Engman, T.J.

    1983-01-01

    Exhaust emissions reduction has become very important to operators and manufacturers of stationary internal combustion engines. Many applications require the maximum reductions that only three-way nonselective catalysts can provide. Air-Fuel Ratio is an important variable that must be controlled to maintain efficient catalytic activity. Design considerations and operating results are presented for an Air-Fuel Ratio control system for application of catalytic converters to industrial, natural gas fueled engines.

  2. A diffusion-kinetic model for pulverized-coal combustion and heat-and-mass transfer in a gas stream

    SciTech Connect

    E.A. Boiko; S.V. Pachkovskii

    2008-12-15

    A diffusion-kinetic model for pulverized-coal combustion and heat-and-mass transfer in a gas stream is proposed, and the results of numerical simulation of the burnout dynamics of Kansk-Achinsk coals in the pulverized state at different treatment conditions and different model parameters are presented. The mathematical model describes the dynamics of thermochemical conversion of solid organic fuels with allowance for complex physicochemical phenomena of heat-and-mass exchange between coal particles and the gaseous environment.

  3. Studies on the influence of combustion exhaust gases and the products of their reaction with ammonia on the living organism. I. The influence on DNA, RNA and soluble proteins in the liver of guinea pig.

    PubMed

    Stanosek, J; Lewandowska-Tokarz, A; Ludyga, K; Pietras, A; Kula, B

    1981-01-01

    The paper presents the behaviour of DNA, RNA and soluble proteins in whole homogenate as well as the nuclear, mitochondrial and postmitochondrial liver fractions in guinea pigs exposed to combustion exhaust gases and the products of their reaction with ammonia. A decrease of RNA level was found in the liver of animals exposed to combustion exhaust gases together with a decrease of soluble proteins in all the studied fractions. On the other hand, in the group of animals subjected to the action of neutralization products of combustion gases by ammonia, the studied components were increased. This increase may be the result of the simultaneous action of industrial noise.

  4. Spatial and taxonomic variation in trace element bioaccumulation in two herbivores from a coal combustion waste contaminated stream.

    PubMed

    Fletcher, Dean E; Lindell, Angela H; Stillings, Garrett K; Mills, Gary L; Blas, Susan A; Vaun McArthur, J

    2014-03-01

    Dissimilarities in habitat use, feeding habits, life histories, and physiology can result in syntopic aquatic taxa of similar trophic position bioaccumulating trace elements in vastly different patterns. We compared bioaccumulation in a clam, Corbicula fluminea and mayfly nymph Maccaffertium modestum from a coal combustion waste contaminated stream. Collection sites differed in distance to contaminant sources, incision, floodplain activity, and sources of flood event water and organic matter. Contaminants variably accumulated in both sediment and biofilm. Bioaccumulation differed between species and sites with C. fluminea accumulating higher concentrations of Hg, Cs, Sr, Se, As, Be, and Cu, but M. modestum higher Pb and V. Stable isotope analyses suggested both spatial and taxonomic differences in resource use with greater variability and overlap between species in the more physically disturbed site. The complex but essential interactions between organismal biology, divergence in resource use, and bioaccumulation as related to stream habitat requires further studies essential to understand impacts of metal pollution on stream systems.

  5. Pitot pressure measurements in flow fields behind circular-arc nozzles with exhaust jets at subsonic free-stream Mach numbers. [langley 16 foot transonic tunnel

    NASA Technical Reports Server (NTRS)

    Mason, M. L.; Putnam, L. E.

    1979-01-01

    The flow field behind a circular arc nozzle with exhaust jet was studied at subsonic free stream Mach numbers. A conical probe was used to measure the pitot pressure in the jet and free stream regions. Pressure data were recorded for two nozzle configurations at nozzle pressure ratios of 2.0, 2.9, and 5.0. At each set of test conditions, the probe was traversed from the jet center line into the free stream region at seven data acquisition stations. The survey began at the nozzle exit and extended downstream at intervals. The pitot pressure data may be applied to the evaluation of computational flow field models, as illustrated by a comparison of the flow field data with results of inviscid jet plume theory.

  6. Combusting vegetable oils in diesel engines: the impact of unsaturated fatty acids on particle emissions and mutagenic effects of the exhaust.

    PubMed

    Bünger, Jürgen; Bünger, Jörn F; Krahl, Jürgen; Munack, Axel; Schröder, Olaf; Brüning, Thomas; Hallier, Ernst; Westphal, Götz A

    2016-06-01

    High particle emissions and strong mutagenic effects were observed after combustion of vegetable oil in diesel engines. This study tested the hypothesis that these results are affected by the amount of unsaturated or polyunsaturated fatty acids of vegetable oils. Four different vegetable oils (coconut oil, CO; linseed oil, LO; palm tree oil, PO; and rapeseed oil, RO) and common diesel fuel (DF) were combusted in a heavy-duty diesel engine. The exhausts were investigated for particle emissions and mutagenic effects in direct comparison with emissions of DF. The engine was operated using the European Stationary Cycle. Particle masses were measured gravimetrically while mutagenicity was determined using the bacterial reverse mutation assay with tester strains TA98 and TA100. Combustion of LO caused the largest amount of total particulate matter (TPM). In comparison with DF, it particularly raised the soluble organic fraction (SOF). RO presented second highest TPM and SOF, followed by CO and PO, which were scarcely above DF. RO revealed the highest number of mutations of the vegetable oils closely followed by LO. PO was less mutagenic, but still induced stronger effects than DF. While TPM and SOF were strongly correlated with the content of polyunsaturated fatty acids in the vegetable oils, mutagenicity had a significant correlation with the amount of total unsaturated fatty acids. This study supports the hypothesis that numbers of double bounds in unsaturated fatty acids of vegetable oils combusted in diesel engines influence the amount of emitted particles and the mutagenicity of the exhaust. Further investigations have to elucidate the causal relationship.

  7. Combusting vegetable oils in diesel engines: the impact of unsaturated fatty acids on particle emissions and mutagenic effects of the exhaust.

    PubMed

    Bünger, Jürgen; Bünger, Jörn F; Krahl, Jürgen; Munack, Axel; Schröder, Olaf; Brüning, Thomas; Hallier, Ernst; Westphal, Götz A

    2016-06-01

    High particle emissions and strong mutagenic effects were observed after combustion of vegetable oil in diesel engines. This study tested the hypothesis that these results are affected by the amount of unsaturated or polyunsaturated fatty acids of vegetable oils. Four different vegetable oils (coconut oil, CO; linseed oil, LO; palm tree oil, PO; and rapeseed oil, RO) and common diesel fuel (DF) were combusted in a heavy-duty diesel engine. The exhausts were investigated for particle emissions and mutagenic effects in direct comparison with emissions of DF. The engine was operated using the European Stationary Cycle. Particle masses were measured gravimetrically while mutagenicity was determined using the bacterial reverse mutation assay with tester strains TA98 and TA100. Combustion of LO caused the largest amount of total particulate matter (TPM). In comparison with DF, it particularly raised the soluble organic fraction (SOF). RO presented second highest TPM and SOF, followed by CO and PO, which were scarcely above DF. RO revealed the highest number of mutations of the vegetable oils closely followed by LO. PO was less mutagenic, but still induced stronger effects than DF. While TPM and SOF were strongly correlated with the content of polyunsaturated fatty acids in the vegetable oils, mutagenicity had a significant correlation with the amount of total unsaturated fatty acids. This study supports the hypothesis that numbers of double bounds in unsaturated fatty acids of vegetable oils combusted in diesel engines influence the amount of emitted particles and the mutagenicity of the exhaust. Further investigations have to elucidate the causal relationship. PMID:26126632

  8. Determination of total iodine in nutritional and biological samples by ICP-MS following their combustion within an oxygen stream.

    PubMed

    Gélinas, Y; Krushevska, A; Barnes, R M

    1998-03-01

    A mineralization and determination method for total iodine in nutritional and biological samples is described. Combustion of the sample in an oxygen stream is followed by collection of the combustion products in a 5% water-soluble tertiary amine solution. Iodine is determined by inductively coupled plasma mass spectrometry. The accuracy and precision of the quantitative iodine analysis using standard addition is better than +/- 10%. A semi-quantitative analysis of four standard reference materials is evaluated. Owing to the presence of low-level iodine contaminant in the blank solution, the determination limit of the method is +/- 10 micrograms kg-1. Good agreement with certified iodine values is obtained for six reference materials. The use of the tertiary amine matrix solution permits the simultaneous determination of iodine and other trace metals of biological and toxicological importance, including Mn, Co, Ni, Cu, Zn, Rb, Cd, and Pb.

  9. Carbonaceous material obtained from exhausted coffee by an aqueous solution combustion process and used for cobalt (II) and cadmium (II) sorption.

    PubMed

    Serrano-Gómez, J; López-González, H; Olguín, M T; Bulbulian, S

    2015-06-01

    New carbonaceous materials were obtained using a fast aqueous solution combustion process from mixtures of exhausted coffee, ammonium nitrate (oxidizer) and urea (fuel) heated at 600, 700, 800 or 900 °C. The resulting powders were effective adsorbents for removing Co(II) and Cd(II) from aqueous solutions. Exhausted coffee was also calcined at different temperatures and compared. The products were characterized, and the obtained carbons had BET specific surface areas of 114.27-390.85 m(2)/g and pore diameters of 4.19 to 2.44 nm when the temperature was increased from 600 to 800 °C. Cobalt and cadmium adsorption by the carbonaceous materials was correlated with the maximum adsorption capacities and specific surface areas of the materials. The method reported here is advantageous because it only required 5 min of reaction to improve the textural properties of carbon obtained from exhausted coffee, which play an important role in the material's cobalt and cadmium adsorption capacities. PMID:25841193

  10. Carbonaceous material obtained from exhausted coffee by an aqueous solution combustion process and used for cobalt (II) and cadmium (II) sorption.

    PubMed

    Serrano-Gómez, J; López-González, H; Olguín, M T; Bulbulian, S

    2015-06-01

    New carbonaceous materials were obtained using a fast aqueous solution combustion process from mixtures of exhausted coffee, ammonium nitrate (oxidizer) and urea (fuel) heated at 600, 700, 800 or 900 °C. The resulting powders were effective adsorbents for removing Co(II) and Cd(II) from aqueous solutions. Exhausted coffee was also calcined at different temperatures and compared. The products were characterized, and the obtained carbons had BET specific surface areas of 114.27-390.85 m(2)/g and pore diameters of 4.19 to 2.44 nm when the temperature was increased from 600 to 800 °C. Cobalt and cadmium adsorption by the carbonaceous materials was correlated with the maximum adsorption capacities and specific surface areas of the materials. The method reported here is advantageous because it only required 5 min of reaction to improve the textural properties of carbon obtained from exhausted coffee, which play an important role in the material's cobalt and cadmium adsorption capacities.

  11. Use of aromatic salts for simultaneously removing SO.sub.2 and NO.sub.x pollutants from exhaust of a combustion system

    DOEpatents

    Levendis, Yiannis A.; Wise, Donald L.

    1994-10-04

    A method is disclosed for removing pollutants from the exhaust of combustion systems burning fuels containing substantial amounts of sulfur and nitrogen. An exemplary method of the invention involves the formation and reaction of a sorbent comprising calcium benzoate. The calcium benzoate is either dry-sprayed (in the form of a fine powder) or wet-sprayed in an aqueous solution in a high temperature environment such as a combustion chamber. The latter technique is feasible since calcium benzoate is a water-soluble form of calcium. When the dispersed particles of calcium benzoate are heated to a high temperature, the organic benzoate burns off and fine calcium oxide particles are formed. These particles are cenospheric (hollow) and have thin and highly porous walls, thus, affording optimum external and internal accessibility for reacting with toxic gaseous emissions such as SO.sub.2. Further, the combustion of the organic benzoate portion of the sorbent results in the conversion of NO.sub.x to N.sub.2.

  12. Effect of varying the combustion parameters on the emissions of carbon monoxide and nitrogen oxides in the exhaust gases from propane-fueled vehicles.

    PubMed

    Roberge, B

    2000-05-01

    Propane-fueled forklifts are one source of carbon monoxide (CO) contamination of workplace air. The previous study carried out by the Quebec Occupational Health and Safety Research Institute dealt with worker exposure to CO during forklift use in buildings. It recommends that exhaust gas emissions be kept below a 1 percent concentration. However, this control has not produced a significant reduction in worker exposure to CO, when factors (ventilation, type of work tasks, and management of vehicle fleet) specific to companies are taken into account. Consequently, a reduction in CO emissions below the threshold of 0.3 percent should be considered. The experience acquired with propane-fueled ice resurfacers can be used to determine the effect of combustion parameters on exhaust gas emissions. It is known that a reduction in CO emissions from ice resurfacers resulted in the appearance of nitrogen oxides (NOx) and eventually in nitrogen dioxide (NO2) poisoning. Few publications present NOx results in relation to the CO measured in the exhaust gases of propane-fueled vehicles. The objective of this study is to define the level to which CO emissions can be reduced without increasing NOx concentrations. This real-situation study quantified the CO, NO, and NOx in the exhaust gases of a fleet of propane-fueled forklifts in relation to the mixture ratio. The results show the impact of the motor speed and mixture ratio on the CO, NO, and NO2 concentrations. They confirm an increase in NOx concentrations when CO concentrations are reduced. They also show that proper maintenance of forklifts combined with optimal adjustments can reduce CO and NOx emissions. The study proposes a compromise between CO and NOx emissions by taking into account worker health and safety as well as vehicle performance. Monitoring must be done to control air quality in work areas and worker exposure to CO and NO2. A forklift preventive maintenance program and general building ventilation are the favored

  13. Numerical Investigation of Hydrogen and Kerosene Combustion in Supersonic Air Streams

    NASA Technical Reports Server (NTRS)

    Taha, A. A.; Tiwari, S. N.; Mohieldin, T. O.

    1999-01-01

    The effect of mixing schemes on the combustion of both gaseous hydrogen and liquid kerosene is investigated. Injecting pilot gaseous hydrogen parallel to the supersonic incoming air tends to maintain the stabilization of the main liquid kerosene, which is normally injected. Also the maximum kerosene equivalence ratio that can maintain stable flame can be increased by increasing the pilot energy level. The wedge flame holding contributes to an increased kerosene combustion efficiency by the generation of shock-jet interaction.

  14. Combustion

    NASA Technical Reports Server (NTRS)

    Bulzan, Dan

    2007-01-01

    An overview of the emissions related research being conducted as part of the Fundamental Aeronautics Subsonics Fixed Wing Project is presented. The overview includes project metrics, milestones, and descriptions of major research areas. The overview also includes information on some of the emissions research being conducted under NASA Research Announcements. Objective: Development of comprehensive detailed and reduced kinetic mechanisms of jet fuels for chemically-reacting flow modeling. Scientific Challenges: 1) Developing experimental facilities capable of handling higher hydrocarbons and providing benchmark combustion data. 2) Determining and understanding ignition and combustion characteristics, such as laminar flame speeds, extinction stretch rates, and autoignition delays, of jet fuels and hydrocarbons relevant to jet surrogates. 3) Developing comprehensive kinetic models for jet fuels.

  15. Characterization and single-stage denitrification anaerobic digestion of spent stream from the hydrolysis-fermentation-combustion process

    NASA Astrophysics Data System (ADS)

    Singh, Ramnik

    The demand for ethanol as an oxygenate and octane booster in automobile fuel is growing. A number of processes are being investigated for conversion of biomass to ethanol. The Hydrolysis-Fermentation-Combustion (HFC) process for fuel ethanol production developed at the University of California Forest Products Laboratory, Richmond, California is at the stage of technology transfer following over two decades of research and development. This study addresses the technology to be used in treatment of spent streams to be discharged from this process. The treatment design combines a single stage denitrification and anaerobic digestion (SSDAD) for the biological treatment of a representative stream from this process. A typical spent stream contained a wide range of soluble organic materials including: unfermented sugars, components of the feedstocks solubilized in the hydrolysis, acid degradation products of carbohydrates, cleavage products of lignin, water-soluble extractives and phenolics, terpenes and other unfermented organic material, and nitrate ion from the nitric acid used as a catalyst in the hydrolysis reaction. Three sets of experiments were conducted in laboratory scale anaerobic digesters. Commonly available anaerobic sludge from local sewage treatment plants was used as a starter seed and was successfully acclimated to the high nitrate substrate leading to enrichment of denitrifiers. Necessary nutrients and trace elements were identified and supplied to satisfy the obligatory requirements of different groups of bacterial groups present. A major finding was the unique role of ammonium hydroxide in controlling pH leading to steady-state operation of the digester. At steady state operation the reduction in COD was 65%, the nitrate reduction was 88% and the nitrite reduction was 100%. Nitrate was reduced to safe nitrogen gas without buildup of any intermediate products. Organic material was converted to useful methane gas and carbon dioxide. The SSDAD system was

  16. Exhaust system with emissions storage device and plasma reactor

    DOEpatents

    Hoard, John W.

    1998-01-01

    An exhaust system for a combustion system, comprising a storage device for collecting NO.sub.x, hydrocarbon, or particulate emissions, or mixture of these emissions, and a plasma reactor for destroying the collected emissions is described. After the emission is collected in by the storage device for a period of time, the emission is then destroyed in a non-thermal plasma generated by the plasma reactor. With respect to the direction of flow of the exhaust stream, the storage device must be located before the terminus of the plasma reactor, and it may be located wholly before, overlap with, or be contained within the plasma reactor.

  17. Characterization of rocket propellant combustion products: Description of sampling and analysis methods for rocket exhaust characterization studies

    SciTech Connect

    Jenkins, R.A.

    1990-06-07

    A systematic approach has been developed and experimentally validated for the sampling and chemical characterization of the rocket motor exhaust generated from the firing of scaled down test motors at the US Army's Signature Characterization Facility (ASCF) at Redstone Arsenal in Huntsville, Alabama. The overall strategy was to sample and analyze major exhaust constituents in near real time, while performing off-site analyses of samples collected for the determination of trace constituents of the particulate and vapor phases. Initial interference studies were performed using atmospheric pressure burns of 1 g quantities of propellants in small chambers at Oak Ridge National Laboratory. Carbon monoxide and carbon dioxide were determined using non-dispersive infrared instrumentation. Hydrogen cyanide, hydrogen chloride, and ammonia determinations were made using ion selective electrode technology. Oxides of nitrogen were determined using chemiluminescence instrumentation. Airborne particulate mass concentration was determined using infrared forward scattering measurements and a tapered element oscillating microbalance, as well as conventional gravimetry. Particulate phase metals were determined by collection on Teflon membrane filters, followed by inductively coupled plasma and atomic absorption analysis. Particulate phase polynuclear aromatic hydrocarbons (PAH) and nitro-PAH were collected using high volume sampling on a two stage filter. Target species were extracted, and quantified by gas chromatography/mass spectrometry (GC/MS). Vapor phase species were collected on multi-sorbent resin traps, and subjected to thermal desorption GC/MS for analysis. 11 refs., 1 fig., 1 tab.

  18. An experimental and computational study of moderately underexpanded rocket exhaust plumes in a co-flowing hypersonic free stream

    SciTech Connect

    Morris, N.; Buttsworth, D.; Jones, T.; Brescianini, C. |

    1995-09-01

    Rocket plume exhaust structures are aerodynamically and thermochemically very complex and the prediction of plume properties such as temperature, velocity, pressure, chemical species concentrations and turbulence properties is a formidable task as there are no definitive models for viscous and chemical effects. Contemporary computational techniques are still in their infancy and cannot yet reliably predict plume properties. Only through validation of computer codes using experimental data, can computational models be developed to the point where they can be confidently used as design and predictive tools. The motivation for this study was to acquire well defined data for rocket plumes at low altitude hypersonic flight conditions so that the above issues could be investigated.

  19. Review of the state-of-the-art of exhaust particulate filter technology in internal combustion engines.

    PubMed

    Guan, Bin; Zhan, Reggie; Lin, He; Huang, Zhen

    2015-05-01

    The increasingly stringent emission regulations, such as US 2010, Tier 2 Bin 5 and beyond, off-road Tier 4 final, and Euro V/5 for particulate matter (PM) reduction applications, will mandate the use of the diesel particulate filters (DPFs) technology, which is proven to be the only way that can effectively control the particulate emissions. This paper covers a comprehensive overview of the state-of-the-art DPF technologies, including the advanced filter substrate materials, the novel catalyst formulations, the highly sophisticated regeneration control strategies, the DPF uncontrolled regenerations and their control methodologies, the DPF soot loading prediction, and the soot sensor for the PM on-board diagnostics (OBD) legislations. Furthermore, the progress of the highly optimized hybrid approaches, which involves the integration of diesel oxidation catalyst (DOC) + (DPF, NOx reduction catalyst), the selective catalytic reduction (SCR) catalyst coated on DPF, as well as DPF in the high-pressure exhaust gas recirculation (EGR) loop systems, is well discussed. Besides, the impacts of the quality of fuel and lubricant on the DPF performance and the maintenance and retrofit of DPF are fully elaborated. Meanwhile, the high efficiency gasoline particulate filter (GPF) technology is being required to effectively reduce the PM and particulate number (PN) emissions from the gasoline direct injection (GDI) engines to comply with the future increasingly stricter emissions regulations.

  20. Review of the state-of-the-art of exhaust particulate filter technology in internal combustion engines.

    PubMed

    Guan, Bin; Zhan, Reggie; Lin, He; Huang, Zhen

    2015-05-01

    The increasingly stringent emission regulations, such as US 2010, Tier 2 Bin 5 and beyond, off-road Tier 4 final, and Euro V/5 for particulate matter (PM) reduction applications, will mandate the use of the diesel particulate filters (DPFs) technology, which is proven to be the only way that can effectively control the particulate emissions. This paper covers a comprehensive overview of the state-of-the-art DPF technologies, including the advanced filter substrate materials, the novel catalyst formulations, the highly sophisticated regeneration control strategies, the DPF uncontrolled regenerations and their control methodologies, the DPF soot loading prediction, and the soot sensor for the PM on-board diagnostics (OBD) legislations. Furthermore, the progress of the highly optimized hybrid approaches, which involves the integration of diesel oxidation catalyst (DOC) + (DPF, NOx reduction catalyst), the selective catalytic reduction (SCR) catalyst coated on DPF, as well as DPF in the high-pressure exhaust gas recirculation (EGR) loop systems, is well discussed. Besides, the impacts of the quality of fuel and lubricant on the DPF performance and the maintenance and retrofit of DPF are fully elaborated. Meanwhile, the high efficiency gasoline particulate filter (GPF) technology is being required to effectively reduce the PM and particulate number (PN) emissions from the gasoline direct injection (GDI) engines to comply with the future increasingly stricter emissions regulations. PMID:25743879

  1. Mixing Characteristics Downstream of Core Region of High-Temperature Axisymmetric Jets Exhausting Into Transonic and Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Huff, Ronald G.; Abdalla, Kaleel L.

    1960-01-01

    A series of rocket motors with varying exit to throat area ratios was tested in the 8- by 6-foot wind tunnel to determine the effects of mixing on jet diameter and temperature decay at large distances (x/d > 30) from the nozzle exit. An approximate method to account for effects of the initial expansion was evolved. It was determined that the combustion efficiency has an important effect on jet spreading, since the unburned products can burn downstream of the nozzle. The data showed considerable scatter; however, mixing rates were, in general, lower than those observed for subsonic jets. Data for angles of attack of 5 and 10 deg are also presented, giving the respective centerline shift and temperature decay as a function of axial distance.

  2. Exhaust purification with on-board ammonia production

    DOEpatents

    Robel, Wade J.; Driscoll, James Joshua; Coleman, Gerald N.

    2008-05-13

    A system of ammonia production for a selective catalytic reduction system is provided. The system 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 may be converted into ammonia.

  3. Exhaust purification with on-board ammonia production

    DOEpatents

    Robel, Wade J.; Driscoll, James Joshua; Coleman, Gerald N.

    2010-10-12

    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.

  4. 46 CFR 169.609 - Exhaust systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Electrical Internal Combustion Engine Installations § 169.609 Exhaust systems. Engine exhaust installations... separate from the engine cooling system, a suitable warning device must be provided to indicate a...

  5. Inferring temperature uniformity from gas composition measurements in a hydrogen combustion-heated hypersonic flow stream

    SciTech Connect

    Olstad, S.J.

    1995-08-01

    The application of a method for determining the temperature of an oxygen-replenished air stream heated to 2600 K by a hydrogen burner is reviewed and discussed. The purpose of the measurements is to determine the spatial uniformity of the temperature in the core flow of a ramjet test facility. The technique involves sampling the product gases at the exit of the test section nozzle to infer the makeup of the reactant gases entering the burner. Knowing also the temperature of the inlet gases and assuming the flow is at chemical equilibrium, the adiabatic flame temperature is determined using an industry accepted chemical equilibrium computer code. Local temperature depressions are estimated from heat loss calculations. A description of the method, hardware and procedures is presented, along with local heat loss estimates and uncertainty assessments. The uncertainty of the method is estimated at {+-}31 K, and the spatial uniformity was measured within {+-}35 K.

  6. Nitration of polynuclear aromatic hydrocarbons in coal combustors and exhaust streams: Final report, September 1, 1991--September 30, 1994

    SciTech Connect

    Yu, L.; Cho, S.; Hildemann, L.; Niksa, S.

    1995-02-01

    The objectives of this three-year project were to (1) identify the conditions which promote the nitration of PAH during primary combustion, reburning, hot gas cleanup, and particulate removal; and (2) investigate the potential relationship between NOx abatement and PAH nitration. Meeting the objectives of this program involved two broad tasks: (1) Preparing the polynuclear aromatic hydrocarbons (PAH) under closely monitored pulverized fuel (p. f.) firing conditions; and, (2) analyzing the PAH samples to monitor extents of nitration, ring number distribution, etc. A novel coal flow reactor burning actual coal products that operates over the domains of heating rates, temperatures, fuel-equivalence ratios, and residence times in utility boilers was used to generate the coal tar samples. The distribution of products obtained from primary, secondary, and oxidative pyrolysis of two coal types, Pittsburgh No. 8 and Dietz, were analyzed, with emphasis on the nitrogen-containing species generated. The coal tax samples collected from the coal flow reactor were fractionated based on their size and polarity using gravity flow column chromatography. After examining how the sample fractionation depended on the coal type and pyrolysis conditions, the relatively nonpolar fraction was further analyzed via high performance liquid chromatography, to characterize the ring number distribution of the polycyclic aromatic compounds (PAC) present. Finally, gas chromatographic techniques were utilized to measure the amount of nitrogen-containing PAC present, and to investigate how much of these nitrogen-containing species consist of nitro-PAH.

  7. Variation in trace-element accumulation in predatory fishes from a stream contaminated by coal combustion waste.

    PubMed

    Fletcher, Dean E; Lindell, Angela H; Stillings, Garrett K; Mills, Gary L; Blas, Susan A; McArthur, J Vaun

    2014-04-01

    Extensive and critical evaluation can be required to assess contaminant bioaccumulation in large predatory fishes. Species differences in habitat use, resource use, and trophic level, often influenced by body form, can result in diverging contaminant bioaccumulation patterns. Moreover, the broad size ranges inherent with large-bodied fish provide opportunity for trophic and habitat shifts within species that can further influence contaminant exposure. We compared contaminant bioaccumulation in four fish species, as well as two herbivorous invertebrates, from a coal combustion waste contaminated stream. Muscle, liver, and gonad tissue were analyzed from fish stratified across the broadest size ranges available. Effects of trophic position (δ (15)N), carbon sources (δ (13)C), and body size varied among and within species. Mercury and cesium concentrations were lowest in the invertebrates and increased with trophic level both among and within fish species. Other elements, such as vanadium, cadmium, barium, nickel, and lead, had greater levels in herbivorous invertebrates than in fish muscle. Sequestration by the fish livers averted accumulation in muscle. Consequently, fish liver tissue appeared to be a more sensitive indicator of bioavailability, but exceptions existed. Despite liver sequestration, within fishes, muscle concentrations of many elements still tended to increase by trophic level. Notable variation within some species was observed. These results illustrate the utility of stable isotope data in exploring differences of bioaccumulation within taxa. Our analyses suggest a need for further evaluation of the underlying sources of this variability to better understand contaminant bioaccumulation in large predatory fishes.

  8. Exhaust gas recirculation system

    SciTech Connect

    Minoura, M.; Yorioka, K.

    1980-11-18

    An exhaust gas recirculation system for cleaning exhaust gas from an internal combustion engine is provided in which a variable constriction is provided between an intake pipe and a pressure control valve in operative connection to a throttle valve in the carburetor and the pressure differential across said variable constriction is maintained constant to keep off any influence of the exhaust gas pressure while the ratio of the exhaust gas flow rate to the air intake into the engine is varied in correspondence to the intake pipe negative pressure. This exhaust gas recirculation system can be adapted to a fuel injection type intake system as well as other intake systems provided with an air valve for regulating air intake or having no venturi constriction such as employed in an su type carburetor.

  9. A technique for monitoring SO2 in combustion exhausts: Use of a non-Nernstian sensing element in combination with an upstream catalytic filter

    SciTech Connect

    West, David L; Montgomery, Fred C; Armstrong, Timothy R.

    2009-01-01

    Detection of sulfur dioxide (SO2) at high temperature (600 750 oC) in the presence of some interferents found in typical combustion exhausts (oxides of nitrogen (NO2 and NO, "NOx"), CO2, CO, and hydrocarbon (C3H6)) is described. The detection scheme involves use of a catalytic filter in front of a non-Nernstian sensing element. The catalytic filter was a Ni:Cr powder bed operating at 850 oC and the sensing elements were pairs of platinum (Pt) and oxide (Ba-promoted copper chromite ((Ba,Cu)xCryOz) and Sr-modified lanthanum ferrite (LSF)) electrodes on yttria-stabilized zirconia. The Ni:Cr powder bed was capable of reducing the sensing element response to NOx, CO, and C3H6, but the presence of NOx (100 ppm by volume) still interfered with the SO2 response of the Pt-(Ba,Cu)xCryOz sensing element at 600 oC, causing approximately a 7 mV (20%) reduction in the response to 120 ppm SO2 and a response equivalent to about 20 ppm SO2 in the in the absence of SO2. The Pt-LSF sensing element, operated at 750 oC, did not suffer from this NOx interference but at the cost of a reduced SO2 response magnitude (120 ppm SO2 yielded ~10 mV, in contrast to ~30 mV for the Pt-(Ba,Cu)xCryOz sensing element). The powder bed and Pt-LSF sensing element were operated continuously over approximately 350 hours, and the response to SO2 drifted downward by about 7%, with most of this change occurring during the initial 100 hours of operation.

  10. Treatment of power utilities exhaust

    SciTech Connect

    Koermer, Gerald

    2012-05-15

    Provided is a process for treating nitrogen oxide-containing exhaust produced by a stationary combustion source by the catalytic reduction of nitrogen oxide in the presence of a reductant comprising hydrogen, followed by ammonia selective catalytic reduction to further reduce the nitrogen oxide level in the exhaust.

  11. Toxicological and chemical characterization of the process stream materials and gas combustion products of an experimental low-Btu coal gasifier

    SciTech Connect

    Benson, J.M.; Hanson, R.L.; Royer, R.E.; Clark, C.R.; Henderson, R.F.

    1984-04-01

    The process gas stream of an experimental pressurized McDowell-Wellman stirred-bed low-Btu coal gasifier, and combustion products of the clean gas were characterized as to their mutagenic properties and chemical composition. Samples of aerosol droplets condensed from the gas were obtained at selected positions along the process stream using a condenser train. Mutagenicity was assessed using the Ames Salmonella mammalian microsome mutagenicity assay (TA98, with and without rat liver S9). All materials required metabolic activation to be mutagenic. Droplets condensed from gas had a specific mugtagenicity of 6.7 reverants/..mu..g (50,000 revertants/liter of raw gas). Methylnaphthalene, phenanthrene, chrysene, and nitrogen-containing compounds were positively identified in a highly mutagenic fraction of raw gas condensate. While gas cleanup by the humidifier-tar trap system and Venturi scrubber led to only a small reduction in specific mutagenicity of the cooled process stream material (4.1 revertants/..mu..g), a significant overall reduction in mutagenicity was achieved (to 2200 reverants/liter) due to a substantial reduction in the concentration of material in the gas. By the end of gas cleanup, gas condensates had no detectable mutagenic activity. Condensates of combustion product gas, which contained several polycyclic aromatic compounds, had a specific mutagenicity of 1.1 revertants/..mu..g (4.0 revertants/liter). Results indicate that the process stream material is potentially toxic and that care should be taken to limit exposure of workers to the aerosolized tars emitted in fugitive emissions. Health risks to general population resulting from exposure to gas combustion products are expected to be minimal. 28 references.

  12. A candidate reference method for quantification of low concentrations of plasmid DNA by exhaustive counting of single DNA molecules in a flow stream

    NASA Astrophysics Data System (ADS)

    Yoo, Hee-Bong; Oh, Donggeun; Song, Jae Yong; Kawaharasaki, Mamoru; Hwang, Jeeseong; Yang, In Chul; Park, Sang-Ryoul

    2014-10-01

    This work demonstrates accurate measurement of the amount of substance concentration of low concentration plasmid DNA by counting individual DNA molecules using a high-sensitivity flow cytometric setup. Plasmid DNA is a widely used form of DNA, and its quantity often needs to be accurately determined. This work establishes a reference analytical method for direct quantification of low concentration plasmid DNA prepared as reference standards for polymerase chain reaction-based DNA quantification. The model plasmid DNA pBR322 (4361 bp) was stained with a fluorescent dye and was detected in a flow stream in a micro-fluidic channel with laser-induced fluorescence detection, for which the DNA flow was electro-hydrodynamically focused at the centre of the channel. 200 to 8000 DNA molecules in a ˜1 µL sample volume were counted within 2 min in an ‘exhaustive counting’ manner, which facilitated quantitation without calibration. The sample volume was measured and validated from the close agreement of the results of two independent measurement methods, gravimetric determination of water filling the capillary and graphical estimation of actual cross sectional area of the capillary tubing with the image of calibrated scanning electron microscopy. Within the given concentration range, an excellent measurement linearity (R2 = 0.999) was achieved with appropriate data processing for the correction of the events of double molecules (detection of double molecules opposed to single molecule detection assumed, which occurs due to their coincidental passing of the detection zone). The validity of the proposed method was confirmed from the close agreement with the results of quantitation of enzymatically released nucleotides using capillary electrophoresis.

  13. Combustion of dense streams of coal particles. Quarterly progress report No. 9, August 29, 1992--November 28, 1992

    SciTech Connect

    Annamalai, K.

    1992-12-31

    Ignition of the high volatile isolated coal particles in vitiated environment seems to occur heterogeneously at the leading edge of the particle. Volatiles are observed to be ejected upward as jets in the direction of the convective flow but only after heterogeneous ignition. The volatiles burn in the gas phase homogeneously and form a wake flame; a black inner zone (unburned volatile) is formed (see Fig.A.3 for many common characteristics of isolated flames).Intermittent volatile ignition and combustion are observed to occur during the combustion process for a few of the isolated particle combustion experiments on high volatile non-swelling coal. The medium volatile coal particles ignite faster than the high volatile coal; but the intermittent ignition is not observed. The low volatile isolated coal particles combust in shorter time. The isolated char particles ignite at the surface of the particle heterogeneously with little volatile ejected, yet are not sufficient to form a volatile flame, resulting in a subsequent heterogeneous combustion. A group flame is formed for the two-particle arrays at closer interparticle spacing (Fig.A.4). Also, intermittent ignition does not occur for the high volatile particles when the two particles are at farther distances which suggests that radiation interaction between the particles might be occurring. However this conclusion is purely speculative. The char arrays experience heterogeneous ignition at the leading edge; combustion proceeds heterogeneously.

  14. Factors and Trends Affecting the Identification of a Reliable Biomarker for Diesel Exhaust Exposure

    PubMed Central

    2014-01-01

    The monitoring of human exposures to diesel exhaust continues to be a vexing problem for specialists seeking information on the potential health effects of this ubiquitous combustion product. Exposure biomarkers have yielded a potential solution to this problem by providing a direct measure of an individual's contact with key components in the exhaust stream. Spurred by the advent of new, highly sensitive, analytical methods capable of detecting substances at very low levels, there have been numerous attempts at identifying a stable and specific biomarker. Despite these new techniques, there is currently no foolproof method for unambiguously separating diesel exhaust exposures from those arising from other combustion sources. Diesel exhaust is a highly complex mixture of solid, liquid, and gaseous components whose exact composition can be affected by many variables, including engine technology, fuel composition, operating conditions, and photochemical aging. These factors together with those related to exposure methodology, epidemiological necessity, and regulatory reform can have a decided impact on the success or failure of future research aimed at identifying a suitable biomarker of exposure. The objective of this review is to examine existing information on exposure biomarkers for diesel exhaust and to identify those factors and trends that have had an impact on the successful identification of metrics for both occupational and community settings. The information will provide interested parties with a template for more thoroughly understanding those factors affecting diesel exhaust emissions and for identifying those substances and research approaches holding the greatest promise for future success. PMID:25170242

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

    SciTech Connect

    Meisner, Gregory P; Yang, Jihui

    2014-02-11

    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.

  16. Nonequilibrium hydrogen combustion in one- and two-phase supersonic flow

    SciTech Connect

    Chang, H.T.; Hourng, L.W.; Chien, L.C.

    1997-05-01

    A time-splitting method for the numerical simulation of stiff nonequilibrium combustion problem was developed. The algorithm has been applied to simulate the shock-induced combustion and to investigate a supersonic one-and two-phase flowfield. The results are physically reasonable and demonstrate that the presence of particles has a dramatic effect on the nozzle flowfield and the thrust. Supersonic combustion usually happens in high speed flying aerodynamic problems, such as supersonic combustion ramjet (scramjet) engine for hypersonic airbreathing vehicles. Particularly for the scramjet engine, due to short residence time in the combustion chamber, it still contains incomplete combustion fuel as it enters the nozzle. For solid propellant rocket motors, the exhaust stream contains particles of aluminum oxide. In these two-phase nozzle flows, transfer of momentum and heat between gas particles often result in a decrease of nozzle efficiency.

  17. Staged combustion with piston engine and turbine engine supercharger

    DOEpatents

    Fischer, Larry E.; Anderson, Brian L.; O'Brien, Kevin C.

    2011-11-01

    A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

  18. Staged combustion with piston engine and turbine engine supercharger

    DOEpatents

    Fischer, Larry E.; Anderson, Brian L.; O'Brien, Kevin C.

    2006-05-09

    A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

  19. The effect of fuel and sorbent properties on their partitioning between the flyash and bottom ash streams in fluidized bed combustion

    NASA Astrophysics Data System (ADS)

    Rozelle, Peter Lawrence

    2000-10-01

    The fluidized bed combustion process has been employed successfully in several applications, among which steam raising is notable. The use of circulating fluidized bed (CFB) combustion for steam and power generation offers a competitive alternative both in the United States and worldwide, yet there remain technical issues, which if addressed, can improve the competitive position of CFB boiler technology, and improve the operating economics of existing plants. Prominent among these technical issues are the performance of limestones and dolostones as sorbents for emissions control, and the ability of a plant's ash handling system to respond to changes in the fuel or sorbent used by the plant. Study of the effects of fuel and sorbent properties on the partitioning of their resultant bed particles between the ash streams, during the fluidized bed combustion process, has been carried out. This work used results from sorbent tests in a commercial CFB boiler and experimentation with laboratory fluid bed reactors. Sorbents varying in petrographic properties were used in the boiler tests as well as the laboratory testing. Fuels tested had varying distributions of ash content by specific gravity, and ranged in composite ash content from 25 to 49 wt%. Sorbent petrographic properties, described by a characteristic crystallite size, influenced the partitioning of calcium to the flyash and bottom ash streams of the boiler. Under the boiler conditions used for the sorbent tests, sorbent petrographic properties significantly influenced the sorbent consumption rate required by the boiler to maintain air quality compliance. Testing of a range of fuels was carried out in a laboratory fluid bed combustor. Ashing of different specific gravity fractions of the coarse fuel particles revealed a trend where higher specific gravity fractions of the fuel yielded coarse ash particles. A trend was found between increased presence of high ash content particles in a fuel, and increased

  20. Decomposition of nitric oxide in a hot nitrogen stream to synthesize air for hypersonic wind tunnel combustion testing

    NASA Technical Reports Server (NTRS)

    Zumdieck, J. F.; Zlatarich, S. A.

    1974-01-01

    A clean source of high enthalpy air was obtained from the exothermic decomposition of nitric oxide in the presence of strongly heated nitrogen. A nitric oxide jet was introduced into a confined coaxial nitrogen stream. Measurements were made of the extent of mixing and reaction. Experimental results are compared with one- and two-dimensional chemical kinetics computations. Both analyses predict much lower reactivity than was observed experimentally. Inlet nitrogen temperatures above 2400 K were sufficient to produce experimentally a completely reacted gas stream of synthetic air.

  1. Exhaust gas recirculator

    SciTech Connect

    Suda, K.

    1983-01-04

    An exhaust gas recirculator for an internal combustion engine having an exhaust pipe, an intake manifold and a carburetor throttle valve. The exhaust gas recirculator comprises an egr passage which makes the exhaust pipe communicate with the intake manifold, an egr controlling valve and an egr valve respectively arranged in the upper and lower portions of the egr passage. The egr valve operates in association with the carburetor throttle valve for metering the flow of egr gas. The egr controlling valve is separated by a diaphragm into an egr gas chamber communicating with the egr passage between the egr controlling valve and the egr valve and a negative pressure chamber communicating with the intake manifold. The negative pressure chamber contains a compression spring, and the diaphragm is connected with a valve member through a rod upon which is disposed a stopper to serve as a different seal in place of the valve member to close off the exhaust gas passage, which valve member and stopper are constructed to be opened and closed by pressure difference between the egr gas chamber and the negative pressure chamber and by elastic force of the compression spring. The egr controlling valve functions to control the pressure difference around the egr valve to be constant.

  2. Characterization of rocket propellant combustion products. Chemical characterization and computer modeling of the exhaust products from four propellant formulations: Final report, September 23, 1987--April 1, 1990

    SciTech Connect

    Jenkins, R.A.; Nestor, C.W.; Thompson, C.V.; Gayle, T.M.; Ma, C.Y.; Tomkins, B.A.; Moody, R.L.

    1991-12-09

    The overall objective of the work described in this report is four-fold: to (a) develop a standardized and experimentally validated approach to the sampling and chemical and physical characterization of the exhaust products of scaled-down rocket launch motors fired under experimentally controlled conditions at the Army`s Signature Characterization Facility (ASCF) at Redstone Arsenal in Huntsville, Alabama; (b) determine the composition of the exhaust produces; (c) assess the accuracy of a selected existing computer model for predicting the composition of major and minor chemical species; (d) recommended alternations to both the sampling and analysis strategy and the computer model in order to achieve greater congruence between chemical measurements and computer prediction. 34 refs., 2 figs., 35 tabs.

  3. Vehicle exhaust gas chemical sensors using acoustic wave resonators

    SciTech Connect

    Cernosek, R.W.; Small, J.H.; Sawyer, P.S.; Bigbie, J.R.; Anderson, M.T.

    1998-03-01

    Under Sandia`s Laboratory Directed Research and Development (LDRD) program, novel acoustic wave-based sensors were explored for detecting gaseous chemical species in vehicle exhaust streams. The need exists for on-line, real-time monitors to continuously analyze the toxic exhaust gases -- nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HC) -- for determining catalytic converter efficiency, documenting compliance to emission regulations, and optimizing engine performance through feedback control. In this project, the authors adapted existing acoustic wave chemical sensor technology to the high temperature environment and investigated new robust sensor materials for improving gas detection sensitivity and selectivity. This report describes one new sensor that has potential use as an exhaust stream residual hydrocarbon monitor. The sensor consists of a thickness shear mode (TSM) quartz resonator coated with a thin mesoporous silica layer ion-exchanged with palladium ions. When operated at temperatures above 300 C, the high surface area film catalyzes the combustion of the hydrocarbon vapors in the presence of oxygen. The sensor acts as a calorimeter as the exothermic reaction slightly increases the temperature, stressing the sensor surface, and producing a measurable deviation in the resonator frequency. Sensitivities as high as 0.44 (ppm-{Delta}f) and (ppm-gas) have been measured for propylene gas, with minimum detectable signals of < 50 ppm of propylene at 500 C.

  4. Injection, atomization, ignition and combustion of liquid fuels in high-speed air streams. Annual scientific report 1 December 81-31 December 82

    SciTech Connect

    Schetz, J.A.

    1983-01-01

    A simulation approach to studying hot flow subsonic cross-stream fuel injection problems in a less complex and costly cold flow facility was developed. A typical ramjet combustion chamber fuel injection problem was posed where ambient temperature fuel (Kerosene) is injected into a hot airstream. This case was transformed through two new similarity parameters involving injection and freestream properties to a simulated case where a chilled injectant is injected into an ambient temperature airstream. Experiments for the simulated case using chilled Freon-12 injected into the Va. Tech 23 x 23 cm. blow-down wind tunnel at a freestream Mach number of 0.44 were run. The freestream stagnation pressure and temperature were held at 2.5 atm. and 300 degrees K respectively. Results showed a clear picture of the mechanisms of jet decomposition in the presence of rapid vaporization. Immediately after injection a vapor cloud was formed in the jet plume, which dissipated downstream leaving droplets on the order of 8 to 10 microns in diameter for the conditions examined. This represents a substantial reduction compared to baseline tests run at the same conditions with water which had little vaporization. The desirability of using slurry fuels for aerospace application has long been recognized, but the problems of slurry combustion have delayed their use. The present work is an experimental and numerical investigation into the break-up and droplet formation of laminar slurry jets issuing into quiescent air.

  5. Exhaust Gas Modeling Effects on Hypersonic Powered Simulation at Mach 10

    NASA Technical Reports Server (NTRS)

    Tatum, Kenneth E.; Huebner, Lawrence D.

    1995-01-01

    A numerical study was performed to investigate the accuracy and validity of cold-gas simulation of actual hot scramjet exhaust within a Mach 10 free stream over a representative single-stage-to-orbit airbreathing configuration. In particular, exhausts of various noncombusting chemistry models were studied to characterize their effects on the vehicle aftbody performance and the plume flow field definition. Two approximations of the hot scramjet combustion products were utilized to determine the requirement for expensive, multi-species numerical modeling, and to establish a baseline for the validation of cold-gas simulation. Cold-gas simulation at Mach 10 is shown to be a viable technique using an appropriate thermally perfect gas mixture for reproducing hot scramjet exhaust effects.

  6. Heat regenerative external combustion engine

    NASA Astrophysics Data System (ADS)

    Duva, Anthony W.

    1993-10-01

    A heat regenerative external combustion engine is disclosed. The engine includes fuel inlet means which extends along the exhaust passage and/or combustion chamber in order to preheat the fuel, To provide for preheating by gases in both the combustion chamber and the exhaust passage, the combustion chamber is arranged annularly around the drive shaft and between the cylinders. This configuration also is advantageous in that it reduces the noise of combustion. The engine of the invention is particularly well-suited for use in a torpedo.

  7. Controlled human exposures to diesel exhaust

    EPA Science Inventory

    Diesel exhaust (DE) is a complex mixture of gaseous and particulate compounds resulting from an incomplete combustion of diesel fuel. Controlled human exposures to DE and diesel exhaust particles (DEP) have contributed to understanding health effects. Such exposure studies of h...

  8. 49 CFR 393.83 - Exhaust systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... combustible part of the motor vehicle. (b) No exhaust system shall discharge to the atmosphere at a location... gasoline engine shall discharge to the atmosphere at or within 6 inches forward of the rearmost part of the bus. (d) The exhaust system of a bus using fuels other than gasoline shall discharge to the...

  9. 49 CFR 393.83 - Exhaust systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... combustible part of the motor vehicle. (b) No exhaust system shall discharge to the atmosphere at a location... gasoline engine shall discharge to the atmosphere at or within 6 inches forward of the rearmost part of the bus. (d) The exhaust system of a bus using fuels other than gasoline shall discharge to the...

  10. Exhaust after-treatment system with in-cylinder addition of unburnt hydrocarbons

    DOEpatents

    Coleman, Gerald N.; Kesse, Mary L.

    2007-10-30

    Certain exhaust after-treatment devices, at least periodically, require the addition of unburnt hydrocarbons in order to create reductant-rich exhaust conditions. The present disclosure adds unburnt hydrocarbons to exhaust from at least one combustion chamber by positioning, at least partially within a combustion chamber, a mixed-mode fuel injector operable to inject fuel into the combustion chamber in a first spray pattern with a small average angle relative to a centerline of the combustion chamber and a second spray pattern with a large average angle relative to the centerline of the combustion chamber. An amount of fuel is injected in the first spray pattern into a non-combustible environment within the at least one combustion chamber during at least one of an expansion stroke and exhaust stroke. The exhaust with the unburnt amount of fuel is moved into an exhaust passage via an exhaust valve.

  11. Quantification of benzene, toluene, ethylbenzene and o-xylene in internal combustion engine exhaust with time-weighted average solid phase microextraction and gas chromatography mass spectrometry.

    PubMed

    Baimatova, Nassiba; Koziel, Jacek A; Kenessov, Bulat

    2015-05-11

    A new and simple method for benzene, toluene, ethylbenzene and o-xylene (BTEX) quantification in vehicle exhaust was developed based on diffusion-controlled extraction onto a retracted solid-phase microextraction (SPME) fiber coating. The rationale was to develop a method based on existing and proven SPME technology that is feasible for field adaptation in developing countries. Passive sampling with SPME fiber retracted into the needle extracted nearly two orders of magnitude less mass (n) compared with exposed fiber (outside of needle) and sampling was in a time weighted-averaging (TWA) mode. Both the sampling time (t) and fiber retraction depth (Z) were adjusted to quantify a wider range of Cgas. Extraction and quantification is conducted in a non-equilibrium mode. Effects of Cgas, t, Z and T were tested. In addition, contribution of n extracted by metallic surfaces of needle assembly without SPME coating was studied. Effects of sample storage time on n loss was studied. Retracted TWA-SPME extractions followed the theoretical model. Extracted n of BTEX was proportional to Cgas, t, Dg, T and inversely proportional to Z. Method detection limits were 1.8, 2.7, 2.1 and 5.2 mg m(-3) (0.51, 0.83, 0.66 and 1.62 ppm) for BTEX, respectively. The contribution of extraction onto metallic surfaces was reproducible and influenced by Cgas and t and less so by T and by the Z. The new method was applied to measure BTEX in the exhaust gas of a Ford Crown Victoria 1995 and compared with a whole gas and direct injection method. PMID:25911428

  12. Quantification of benzene, toluene, ethylbenzene and o-xylene in internal combustion engine exhaust with time-weighted average solid phase microextraction and gas chromatography mass spectrometry.

    PubMed

    Baimatova, Nassiba; Koziel, Jacek A; Kenessov, Bulat

    2015-05-11

    A new and simple method for benzene, toluene, ethylbenzene and o-xylene (BTEX) quantification in vehicle exhaust was developed based on diffusion-controlled extraction onto a retracted solid-phase microextraction (SPME) fiber coating. The rationale was to develop a method based on existing and proven SPME technology that is feasible for field adaptation in developing countries. Passive sampling with SPME fiber retracted into the needle extracted nearly two orders of magnitude less mass (n) compared with exposed fiber (outside of needle) and sampling was in a time weighted-averaging (TWA) mode. Both the sampling time (t) and fiber retraction depth (Z) were adjusted to quantify a wider range of Cgas. Extraction and quantification is conducted in a non-equilibrium mode. Effects of Cgas, t, Z and T were tested. In addition, contribution of n extracted by metallic surfaces of needle assembly without SPME coating was studied. Effects of sample storage time on n loss was studied. Retracted TWA-SPME extractions followed the theoretical model. Extracted n of BTEX was proportional to Cgas, t, Dg, T and inversely proportional to Z. Method detection limits were 1.8, 2.7, 2.1 and 5.2 mg m(-3) (0.51, 0.83, 0.66 and 1.62 ppm) for BTEX, respectively. The contribution of extraction onto metallic surfaces was reproducible and influenced by Cgas and t and less so by T and by the Z. The new method was applied to measure BTEX in the exhaust gas of a Ford Crown Victoria 1995 and compared with a whole gas and direct injection method.

  13. Pulse combusted acoustic agglomeration apparatus and process

    DOEpatents

    Mansour, Momtaz N.

    1993-01-01

    An improved apparatus and process for removal of particulates entrained in a gas stream are provided. The removal process employs a pulse combustor to provide an acoustic pressure wave to acoustically enhance bimodal agglomeration of particulates which may be collected and removed using a conventional separation apparatus. A particulate having a size different from the size of the particulate in the gas stream to be cleaned is introduced into the system to effectuate the bimodal process. The apparatus may be employed as a direct fired system for improved operation of gas-operated equipment such as a gas turbine, or may, alternatively, be employed as an add-on subsystem for combustion exhaust clean-up. Additionally, the added particulate may be a sorbent for effecting sorption of other contaminants such as sulfur. Various other particulates for contaminant removal may also be introduced into the system as exemplified by alkali-gettering agents.

  14. Combustion modeling in internal combustion engines

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  15. Device for controlling supercharging pressure of an exhaust gas turbocharger

    SciTech Connect

    Iwasa, Y.

    1988-04-12

    A supercharge pressure control apparatus is described comprising: a turbocharger having an exhaust turbine rotated by exhaust gas flow of an internal combustion engine and a compressor rotated by the exhaust gas flow toward the turbine and having a valve member disposed in the turbine.

  16. 46 CFR 119.430 - Engine exhaust pipe installation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., combustible material. (2) Be provided with noncombustible hangers and blocks for support. (h) An exhaust pipe... 46 Shipping 4 2014-10-01 2014-10-01 false Engine exhaust pipe installation. 119.430 Section 119... INSTALLATION Specific Machinery Requirements § 119.430 Engine exhaust pipe installation. (a) The design of...

  17. 46 CFR 119.430 - Engine exhaust pipe installation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... panting, and is double clamped where practicable. (f) Where an exhaust pipe passes through a watertight... stresses resulting from the expansion of the exhaust piping. (g) A dry exhaust pipe must: (1) If it passes through a combustible bulkhead or partition, be kept clear of, and suitably insulated or shielded...

  18. Flow characteristics of various swirl-can module designs. [exhaust flow simulation, flow characteristics, and combustion efficiency of jet engine fuels

    NASA Technical Reports Server (NTRS)

    Mularz, E. J.

    1975-01-01

    Flow measurements were performed on each of six swirl-can combustor module designs under simulated combustor operating conditions to find the design which exhibited a small recirculation zone, intense air mixing, and good fuel distribution in its wake. Conditions that are favorable for producing low oxides of nitrogen emissions and high combustion efficiency were investigated. The recirculation zone, the turbulence intensity and the fuel distribution pattern are obtained in the wake region of the center module of a three module array. The most promising swirl-can module design incorporates two air swirlers which discharge air in opposite directions (contraswirl), mixes the fuel and air upstream of the inner swirler, and has a flow area blockage of 64.3% for the three module array.

  19. Abating exhaust noises in jet engines

    NASA Technical Reports Server (NTRS)

    Schwartz, I. R. (Inventor)

    1974-01-01

    A noise abating improvement for jet engines including turbojets, turbofans, turboprops, ramjets, scramjets, and hybrid jets is introduced. A provision is made for an apparatus in the primary and/or secondary flow streams of the engines; the apparatus imparts to the exhaust gases a component rotation or swirl about the engine's longitudinal axis. The rotary component in the exhaust gases causes a substantial suppression of sound energy build up normally produced by an axial flow exhaust system.

  20. Programmed combustion steam generator

    SciTech Connect

    Wagner, W.R.

    1984-08-14

    The present invention provides a steam generator which comprises rocket-type multielement injector head and a small diameter, highly elongated, cylindrical combustion chamber whose walls are formed from a plurality of longitudinally adjoined water tubes. The multielement injector head injects an array of associating streams of fuel and oxidizer into the combustion chamber under sufficient pressure to maintain a combustion pressure in the range of 25-150 psia whereupon the narrowness of the combustion chamber serves to constrict the resultant combustion gases to thereby promote radiant and convective heat transfer from the flame of combustion through the walls of the combustion chamber into the water passing through the water tubes. By such arrangement the production of nitrogen oxides in the combustion chamber is avoided.

  1. Studies on the influence of combustion exhaust gases and the products of their reaction with ammonia on the living organism. II. The influence on aspartate aminotransferase (AspAT) and alanine aminotransferase (AiAt) activities in the liver of guinea pig.

    PubMed

    Lewandowska-Tokarz, A; Stanosek, J; Ludyga, K; Kochanski, L

    1981-01-01

    The behaviour of aspartate aminotransferase (AspAT) an alanine aminotransferase (AIAT) in the whole homogenate and subcellular liver fractions of guinea pigs exposed to combustion exhaust gases and the neutralization products of these gases is presented in this paper. In the liver of animals exposed to the chronic action of combustion exhaust gases a decrease of both enzyme activities in the whole homogenate as well as in the subcellular fractions could be noted. Statistically significant changes are shown by AspAT. In the group of animals subjected to the action of neutralization products an increase of AIAT activity was observed. The activity of AspAT still shows a decrease, but less distinct in comparison with group I. An exception here is the mitochondrial fraction in which the AspAT activity is distinctly increased.

  2. Advanced combustion technologies for gas turbine power plants

    SciTech Connect

    Vandsburger, U.; Roe, L.A.; Desu, S.B.

    1995-12-31

    Objectives are to develop actuators for enhancing the mixing between gas streams, increase combustion stability, and develop hgih-temperature materials for actuators and sensors in combustors. Turbulent kinetic energy maps of an excited jet with co-flow in a cavity with a partially closed exhaust end are given with and without a longitudinal or a transverse acoustic field. Dielectric constants and piezoelectric coefficients were determined for Sr{sub 2}(Nb{sub x}Ta{sub 1-x}){sub 2}O{sub 7} ceramics.

  3. Homogeneous catalysts in hypersonic combustion

    SciTech Connect

    Harradine, D.M.; Lyman, J.L.; Oldenborg, R.C.; Pack, R.T.; Schott, G.L.

    1989-01-01

    Density and residence time both become unfavorably small for efficient combustion of hydrogen fuel in ramjet propulsion in air at high altitude and hypersonic speed. Raising the density and increasing the transit time of the air through the engine necessitates stronger contraction of the air flow area. This enhances the kinetic and thermodynamic tendency of H/sub 2/O to form completely, accompanied only by N/sub 2/ and any excess H/sub 2/(or O/sub 2/). The by-products to be avoided are the energetically expensive fragment species H and/or O atoms and OH radicals, and residual (2H/sub 2/ plus O/sub 2/). However, excessive area contraction raises air temperature and consequent combustion-product temperature by adiabatic compression. This counteracts and ultimately overwhelms the thermodynamic benefit by which higher density favors the triatomic product, H/sub 2/O, over its monatomic and diatomic alternatives. For static pressures in the neighborhood of 1 atm, static temperature must be kept or brought below ca. 2400 K for acceptable stability of H/sub 2/O. Another measure, whose requisite chemistry we address here, is to extract propulsive work from the combustion products early in the expansion. The objective is to lower the static temperature of the combustion stream enough for H/sub 2/O to become adequately stable before the exhaust flow is massively expanded and its composition ''frozen.'' We proceed to address this mechanism and its kinetics, and then examine prospects for enhancing its rate by homogeneous catalysts. 9 refs.

  4. Evaluation of pilot-scale pulse-corona-induced plasma device to remove NO{sub x} from combustion exhausts from a subscale combustor and from a hush house at Nellis AFB, Nevada. Final report, August 1994--January 1997

    SciTech Connect

    Haythornthwaite, S.M.; Durham, M.D.; Anderson, G.L.; Rugg, D.E.

    1997-05-01

    Jet engine test cells (JETCs) are used to test-fire new, installed, and reworked jet engines. Because JETCs have been classified as stationary sources of pollutant emissions, they are subject to possible regulation under Title 1 of the Clean Air Act (CAA) as amended in 1990. In Phase 1 of the Small Business Innovation Research (SBIR) program, a novel NOx-control approach utilizing pulsed-corona-induced plasma successfully showed 90% removal of NOx in the laboratory. The objective of Phase 2 was to reproduce the laboratory-scale results in a pilot-scale system. The technology was successfully demonstrated at pilot scale in the field, on a slipstream of JETC flue gas at Nellis Air Force Base. Based on the field data, cost projections were made for a system to treat the full JETC exhaust. The technology efficiently converted NO into ONO, and a wet scrubber was required to achieve the treatment goal of 50-percent removal and destruction of NOx. The plasma simultaneously removes hydrocarbons from the flue gas stream. This project demonstrated that pulse-corona-induced plasma technology is scalable to practical industrial dimensions.

  5. Pressure Loads Produced on a Flat-Plate Wing By Rocket Jets Exhausting in a Spanwise Direction Below the Wing and Perpendicular to a Free-Stream Flow of Mach Number 2.0

    NASA Technical Reports Server (NTRS)

    Falanga, Ralph A.; Janos, Joseph J.

    1961-01-01

    An investigation at a Reynolds number per foot of 14.4 x 10(exp 6) was made to determine the pressure loads produced on a flat-plate wing by rocket jets exhausting in a spanwise direction beneath the wing and perpendicular to a free-stream flow of Mach number 2.0. The ranges of the variables involved were (1) nozzle types - one sonic (jet Mach number of 1.00), two supersonic (jet Mach numbers of 1.74 and 3.04),. and one two-dimensional supersonic (jet Mach number of 1.71); (2) vertical nozzle positions beneath the wing of 4, 8 and 12 nozzle-throat diameters; and (3) ratios of rocket-chamber total pressure to free- stream static pressure from 0 to 130. The incremental normal force due to jet interference on the wing varied from one to two times the rocket thrust and generally decreased as the pressure ratio increased. The chordwise coordinate of the incremental-normal-force center of pressure remained upstream of the nozzle center line for the nozzle positions and pressure ratios of the investigation. The chordwise coordinate approached zero as the jet vertical distance beneath the wing increased. In the spanwise direction there was little change due to varying rocket-jet position and pressure ratio. Some boundary-layer flow separation on the wing was observed for the rocket jets close to the wing and at the higher pressure ratios. The magnitude of the chordwise and spanwise pressure distributions due to jet interference was greatest for rocket jets close to the wing and decreased as the jet was displaced farther from the wing. The design procedure for the rockets used is given in the appendix.

  6. Apparatus for totally recycling engine exhaust gas

    SciTech Connect

    Suzuki, N.

    1986-05-13

    A method is described of burning fuel in the combustion chamber of an engine using an apparatus of the type which comprises an electrostatic precipitator connected to the exhaust manifold of the engine; a dissociation chamber connected to the electrostatic precipitator and to the intake manifold of the engine and including a dissociated gas control reservoir connected to the dissociation chamber and to the engine intake manifold; and a cyclone drum connected to the electrostatic precipitator for removing particles from the exhaust gases in the electrostatic precipitator. The method consists of: dissociating the molecules of the exhaust gas from the engine in the dissociation chamber into monomolecules by subjecting the exhaust gas to the effects of a corona discharge in the dissociation chamber; removing carbon and other particulate matter from the exhaust in the electrostatic precipitator and cyclone drum to dedust the exhaust gas; and igniting a mixture of fuel and the dedusted exhaust gas in the combustion chamber of the engine, whereby fuel is initially oxidized solely by an oxygen component of the dissociated exhaust gas.

  7. Emissions from combustion engines and their control

    SciTech Connect

    Patterson, D.J.; Henein, N.A.

    1981-01-01

    This standard text for the automotive industry explains in detail the fundamentals of emission formation and control for gasoline and diesel engines. These concepts can be applied to other combustion systems, such as gas turbines and stationary power plants. Topics of discussion include: combustion in homogeneous mixtures; effect of design and operating variables on gasoline engine exhaust emissions; hydrocarbon evaporation emissions; diesel engine combustion emissions and controls; emission instrumentation; and automotive exhaust emission testing. 200 references, 197 figures.

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

    NASA Astrophysics Data System (ADS)

    El-Asrag, Hossam A.; Ju, Yiguang

    2013-04-01

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

  9. Municipal solid waste combustion: Fuel testing and characterization

    SciTech Connect

    Bushnell, D.J.; Canova, J.H.; Dadkhah-Nikoo, A.

    1990-10-01

    The objective of this study is to screen and characterize potential biomass fuels from waste streams. This will be accomplished by determining the types of pollutants produced while burning selected municipal waste, i.e., commercial mixed waste paper residential (curbside) mixed waste paper, and refuse derived fuel. These materials will be fired alone and in combination with wood, equal parts by weight. The data from these experiments could be utilized to size pollution control equipment required to meet emission standards. This document provides detailed descriptions of the testing methods and evaluation procedures used in the combustion testing and characterization project. The fuel samples will be examined thoroughly from the raw form to the exhaust emissions produced during the combustion test of a densified sample.

  10. Measurements of Aged Aircraft Exhaust in the ACCENT Mission

    NASA Technical Reports Server (NTRS)

    Friedl, R.; Ross, A.

    2000-01-01

    The Atmospheric Chemistry of Combustion Emissions Near the Tropopause (ACCENT) mission is a multi-agency sponsored effort to evaluate the roles of aircraft and rocket exhaust in perturbing ozone chemistry and modifying aerosols and clouds.

  11. Pulse combusted acoustic agglomeration apparatus and process

    DOEpatents

    Mansour, Momtaz N.; Chandran, Ravi

    1994-01-01

    An improved apparatus and process for removal of particulates entrained in a gas stream are provided. The removal process employs a pulse combustor to provide an acoustic pressure wave to acoustically enhance agglomeration of particulates which may be collected and removed using a conventional separation apparatus. The apparatus may be employed as a direct fired system for improved operation of gas-operated equipment such as a gas turbine, or may, alternatively, be employed as an add-on subsystem for combustion exhaust clean-up. Additionally, added particulates may include a sorbent for effecting sorption of other contaminants such as sulfur. Various other particulates for contaminant removal may also be introduced into the system as exemplified by alkali-gettering agents.

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

    DOEpatents

    Duffy, Kevin P.; Kieser, Andrew J.; Rodman, Anthony; Liechty, Michael P.; Hergart, Carl-Anders; Hardy, William L.

    2008-05-27

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

  13. Flame blowout and pollutant emissions in vitiated combustion of conventional and bio-derived fuels

    NASA Astrophysics Data System (ADS)

    Singh, Bhupinder

    The widening gap between the demand and supply of fossil fuels has catalyzed the exploration of alternative sources of energy. Interest in the power, water extraction and refrigeration (PoWER) cycle, proposed by the University of Florida, as well as the desirability of using biofuels in distributed generation systems, has motivated the exploration of biofuel vitiated combustion. The PoWER cycle is a novel engine cycle concept that utilizes vitiation of the air stream with externally-cooled recirculated exhaust gases at an intermediate pressure in a semi-closed cycle (SCC) loop, lowering the overall temperature of combustion. It has several advantages including fuel flexibility, reduced air flow, lower flame temperature, compactness, high efficiency at full and part load, and low emissions. Since the core engine air stream is vitiated with the externally cooled exhaust gas recirculation (EGR) stream, there is an inherent reduction in the combustion stability for a PoWER engine. The effect of EGR flow and temperature on combustion blowout stability and emissions during vitiated biofuel combustion has been characterized. The vitiated combustion performance of biofuels methyl butanoate, dimethyl ether, and ethanol have been compared with n-heptane, and varying compositions of syngas with methane fuel. In addition, at high levels of EGR a sharp reduction in the flame luminosity has been observed in our experimental tests, indicating the onset of flameless combustion. This drop in luminosity may be a result of inhibition of processes leading to the formation of radiative soot particles. One of the objectives of this study is finding the effect of EGR on soot formation, with the ultimate objective of being able to predict the boundaries of flameless combustion. Detailed chemical kinetic simulations were performed using a constant-pressure continuously stirred tank reactor (CSTR) network model developed using the Cantera combustion code, implemented in C++. Results have

  14. Removal of particulates from diesel engine exhaust gas

    SciTech Connect

    Wade, W.R.

    1983-09-20

    A method and apparatus is disclosed for periodically oxidizing particulate matter trapped in and on an exhaust gas purifying device used in conjunction with a diesel engine. Fuel normally delivered to selected combustion chambers is diverted to a fuel burning device associated with the purifying device. The diversion deactivates the combustion process in the selected chambers. The diverted fuel is then burned by the burning device to increase the exhaust gas temperature flowing through the purifying device and effect oxidation of collected particles.

  15. 46 CFR 108.123 - Isolation of combustible material.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Isolation of combustible material. 108.123 Section 108... combustible material. Each internal combustion engine exhaust, boiler and galley uptake, and similar heat source must be separated or insulated from combustible materials....

  16. 46 CFR 108.123 - Isolation of combustible material.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Isolation of combustible material. 108.123 Section 108... combustible material. Each internal combustion engine exhaust, boiler and galley uptake, and similar heat source must be separated or insulated from combustible materials....

  17. Implications of Low Particulate Matter Emissions on System Fuel Efficiency for High Efficiency Clean Combustion

    SciTech Connect

    Parks, II, James E; Prikhodko, Vitaly Y

    2009-01-01

    Advanced diesel combustion regimes such as High Efficiency Clean Combustion (HECC) offer the benefits of reduced engine out NOX and particulate matter (PM) emissions. Lower PM emissions during advanced combustion reduce the demand on diesel particulate filters (DPFs) and can, thereby, reduce the fuel penalty associated with DPF regeneration. In this study, a SiC DPF was loaded and regenerated on a 1.7-liter 4-cylinder diesel engine operated in conventional and advanced combustion modes at different speed and load conditions. A diesel oxidation catalyst (DOC) and a lean NOX trap (LNT) were also installed in the exhaust stream. Five steady-state speed and load conditions were weighted to estimate Federal Test Procedure (FTP) fuel efficiency. The DPF was loaded using lean-rich cycling with frequencies that resulted in similar levels of NOX emissions downstream of the LNT. The pressure drop across the DPF was measured at a standard point (1500 rpm, 5.0 bar) before and after loading, and a P rise rate was determined for comparison between conventional and advanced combustion modes. Higher PM emissions in conventional combustion resulted in a higher rate of backpressure rise across the DPF at all of the load points leading to more frequent DPF regenerations and higher fuel penalty. The fuel penalty during conventional combustion was 4.2% compared with 3.1% for a mixture of conventional and advanced modes.

  18. 49 CFR 229.43 - Exhaust and battery gases.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Exhaust and battery gases. 229.43 Section 229.43 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... § 229.43 Exhaust and battery gases. (a) Products of combustion shall be released entirely outside...

  19. 49 CFR 229.43 - Exhaust and battery gases.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Exhaust and battery gases. 229.43 Section 229.43 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... § 229.43 Exhaust and battery gases. (a) Products of combustion shall be released entirely outside...

  20. 49 CFR 229.43 - Exhaust and battery gases.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Exhaust and battery gases. 229.43 Section 229.43 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... § 229.43 Exhaust and battery gases. (a) Products of combustion shall be released entirely outside...

  1. 49 CFR 229.43 - Exhaust and battery gases.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Exhaust and battery gases. 229.43 Section 229.43 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... § 229.43 Exhaust and battery gases. (a) Products of combustion shall be released entirely outside...

  2. 49 CFR 229.43 - Exhaust and battery gases.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Exhaust and battery gases. 229.43 Section 229.43... § 229.43 Exhaust and battery gases. (a) Products of combustion shall be released entirely outside the... conditions. (b) Battery containers shall be vented and batteries kept from gassing excessively....

  3. Combustion Chemistry Diagnostics for Cleaner Processes.

    PubMed

    Kohse-Höinghaus, Katharina

    2016-09-12

    Climate change, environmental problems, urban pollution, and the dependence on fossil fuels demand cleaner, renewable energy strategies. However, they also ask for urgent advances in combustion science to reduce emissions. For alternative fuels and new combustion regimes, crucial information about the chemical reactions from fuel to exhaust remains lacking. Understanding such relations between combustion process, fuel, and emissions needs reliable experimental data from a wide range of conditions to provide a firm basis for predictive modeling of practical combustion processes.

  4. Combustion Chemistry Diagnostics for Cleaner Processes.

    PubMed

    Kohse-Höinghaus, Katharina

    2016-09-12

    Climate change, environmental problems, urban pollution, and the dependence on fossil fuels demand cleaner, renewable energy strategies. However, they also ask for urgent advances in combustion science to reduce emissions. For alternative fuels and new combustion regimes, crucial information about the chemical reactions from fuel to exhaust remains lacking. Understanding such relations between combustion process, fuel, and emissions needs reliable experimental data from a wide range of conditions to provide a firm basis for predictive modeling of practical combustion processes. PMID:27440049

  5. Flameless Combustion for Gas Turbines

    NASA Astrophysics Data System (ADS)

    Gutmark, Ephraim; Li, Guoqiang; Overman, Nick; Cornwell, Michael; Stankovic, Dragan; Fuchs, Laszlo; Milosavljevic, Vladimir

    2006-11-01

    An experimental study of a novel flameless combustor for gas turbine engines is presented. Flameless combustion is characterized by distributed flame and even temperature distribution for high preheat air temperature and large amount of recirculating low oxygen exhaust gases. Extremely low emissions of NOx, CO, and UHC are reported. Measurements of the flame chemiluminescence, CO and NOx emissions, acoustic pressure, temperature and velocity fields as a function of the preheat temperature, inlet air mass flow rate, exhaust nozzle contraction ratio, and combustor chamber diameter are described. The data indicate that larger pressure drop promotes flameless combustion and low NOx emissions at the same flame temperature. High preheated temperature and flow rates also help in forming stable combustion and therefore are favorable for flameless combustion.

  6. Prediction of transient exhaust soot for a turbocharged diesel engine

    SciTech Connect

    Xiaoping, B.; Shu, H.

    1995-12-31

    A generalized computer model for prediction of transient exhaust soot and response of turbocharged diesel engines is developed. It includes detailed thermodynamic and dynamic processes. This model utilizes a multi-zone combustion submodel that emphasizes simple and economical calculations for combustion behavior and zonal soot, so overall transient exhaust soot can be predicted. This model is applied to a turbocharged diesel engine. The steady state exhaust soot and performance are calculated and validated, and on the basis, the exhaust soot and response under three classes of transient operating conditions are predicted. The parametric study is carried out by using this model. The effects of valve overlap period, exhaust manifold volume, turbocharger inertia and ambient pressure are predicted. Applications of this model have proved that it is a convenient analytical tool in the study for turbocharged diesel engines. 18 refs., 14 figs., 2 tabs.

  7. Apparatus for photocatalytic destruction of internal combustion engine emissions during cold start

    DOEpatents

    Janata, Jiri; McVay, Gary L.; Peden, Charles H.; Exarhos, Gregory J.

    1998-01-01

    A method and apparatus for the destruction of emissions from an internal combustion engine wherein a substrate coated with TiO.sub.2 is exposed to a light source in the exhaust system of an internal combustion engine thereby catalyzing oxidation/reduction reactions between gaseous hydrocarbons, carbon monoxide, nitrogen oxides and oxygen in the exhaust of the internal combustion engine.

  8. Determination of sulfur trioxide in engine exhaust.

    PubMed

    Arnold, D R

    1975-04-01

    Sulfur trioxide in the exhaust gas of an internal combustion engine is removed and concentrated by absorption in a solution of 80% isopropyl alcohol, which quantitatively absorbs it and inhibits the oxidation of any sulfur dioxide which may be absorbed. The absorbed sulfur trioxide (sulfuric acid) is determined by an absorption titration by using barium chloride as the titrant and thorin as the indicator. The sulfur dioxide content of the exhaust is measured continuously by means of a DuPont Model 411 ultraviolet photoanalyzer.

  9. Determination of sulfur trioxide in engine exhaust.

    PubMed Central

    Arnold, D R

    1975-01-01

    Sulfur trioxide in the exhaust gas of an internal combustion engine is removed and concentrated by absorption in a solution of 80% isopropyl alcohol, which quantitatively absorbs it and inhibits the oxidation of any sulfur dioxide which may be absorbed. The absorbed sulfur trioxide (sulfuric acid) is determined by an absorption titration by using barium chloride as the titrant and thorin as the indicator. The sulfur dioxide content of the exhaust is measured continuously by means of a DuPont Model 411 ultraviolet photoanalyzer. PMID:50930

  10. Collection and analysis of organic acids in exhaust gas. Comparison of different methods

    NASA Astrophysics Data System (ADS)

    Zervas, E.; Montagne, X.; Lahaye, J.

    This paper reports the development of a specific method to identify organic acids in exhaust gases. The organic acids are collected in two impingers containing liquids (pure water or Na 2CO 3 1% aqueous solution) and four cartridges containing solids (silica, fluorisil, alumina B and alumina N). Once collected, the acids are eluted of the solids by a hot water stream. These traps performances, in terms of organic acids collection and elution efficiency, are evaluated and compared. Two sources are used to produce the gas flow containing organic acids: one generates a flow whose concentration is known and stable, the other produces organic acids among other combustion products. For eluted solutions analysis, two methods are used: isocratic ionic chromatography/conductivity detection and GC/FID. Their efficiency in separating 10 aliphatic acids are compared. Their characteristics such as detection limits, detection linearity, repeatability and possible interferences with other components found in exhaust gases are determined. The stability of the organic acids solutions is also studied. Lastly, the use of these methods is illustrated by the analysis of the gas-phase organic acids exhausted by a spark ignition and by a diesel engine.

  11. Heat Exhaustion, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Heat Exhaustion, First Aid A A A Heat exhaustion signs and symptoms ... specific to the other stages of heat illness. First Aid Guide Use a combination of the following measures ...

  12. E-Alerts: Combustion, engines, and propellants (reciprocation and rotating combustion engines). E-mail newsletter

    SciTech Connect

    1999-04-01

    Design, performance, and testing of reciprocating and rotating engines of various configurations for all types of propulsion. Includes internal and external combustion engines; engine exhaust systems; engine air systems components; engine structures; stirling and diesel engines.

  13. Apparatus and method to inject a reductant into an exhaust gas feedstream

    DOEpatents

    Viola, Michael B.

    2009-09-22

    An exhaust aftertreatment system for an internal combustion engine is provided including an apparatus and method to inject a reductant into the exhaust gas feedstream. Included is a fuel metering device adapted to inject reductant into the exhaust gas feedstream and a controllable pressure regulating device. A control module is operatively connected to the reductant metering device and the controllable pressure regulating device, and, adapted to effect flow of reductant into the exhaust gas feedstream over a controllable flow range.

  14. Assessment of Literature Related to Combustion Appliance Venting Systems

    SciTech Connect

    Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

    2015-02-01

    In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

  15. Handbook of infrared radiation from combustion gases

    NASA Technical Reports Server (NTRS)

    Ludwig, C. B.; Malkmus, W.; Reardon, J. E.; Thomson, J. A. L.; Goulard, R. (Editor)

    1973-01-01

    The treatment of radiant emission and absorption by combustion gases are discussed. Typical applications include: (1) rocket combustion chambers and exhausts, (2) turbojet engines and exhausts, and (3) industrial furnaces. Some mention is made of radiant heat transfer problems in planetary atmospheres, in stellar atmospheres, and in reentry plasmas. Particular consideration is given to the temperature range from 500K to 3000K and the pressure range from 0.001 atmosphere to 30 atmospheres. Strong emphasis is given to the combustion products of hydrocarbon fuels with oxygen, specifically to carbon dioxide, water vapor, and carbon monoxide. In addition, species such as HF, HC1, CN, OH, and NO are treated.

  16. High speed exhaust gas recirculation valve

    DOEpatents

    Fensom, Rod; Kidder, David J.

    2005-01-18

    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.

  17. Interrelation of exhaust-gas constituents

    NASA Technical Reports Server (NTRS)

    Gerrish, Harold C; Voss, Fred

    1938-01-01

    This report presents the results of an investigation conducted to determine the interrelation of the constituents of the exhaust gases of internal-combustion engines and the effect of engine performance on these relations. Six single-cylinder, liquid-cooled tests engines and one 9-cylinder radial air-cooled engine were tested. Various types of combustion chambers were used and the engines were operated at compression ratios from 5.1 to 7.0 using spark ignition and from 13.5 to 15.6 using compression ignition. The investigation covered a range of engine speeds from 1,500 to 2,100 r.p.m. The fuels used were two grades of aviation gasoline, auto diesel fuel, and laboratory diesel fuel. Power, friction, and fuel-consumption data were obtained from the single-cylinder engines at the same time that the exhaust-gas samples were collected.

  18. Compounded turbocharged rotary internal combustion engine fueled with natural gas

    SciTech Connect

    Jenkins, P.E.

    1992-10-15

    This patent describes a compounded engine. It comprises: a first Wankel engine having a housing with a trochoidal inner surface containing a generally triangular shaped rotor, the engine containing a fuel supply system suitable for operating the engine with natural gas as a fuel; a turbocharge compressing air for combustion by the engine, the turbocharger being driven by the exhaust gases which exit from the engine; a combustion chamber in fluid communication with the exhaust from the engine after that exhaust has passed through the turbocharger, the chamber having an ignition device suitable for igniting hydrocarbons in the engine exhaust, whereby the engine timing, and the air and fuel mixture of the engine are controlled so that when the engine exhaust reaches the combustion chamber the exhaust contains a sufficient amount of oxygen and hydrocarbons to enable ignition and combustion of the engine exhaust in the combustion chamber without the addition of fuel or air, and whereby the engine operating conditions are controlled to vary the performance of the secondary combustor; and a controllable ignition device to ignite the exhaust gases in the combustion chamber at predetermined times.

  19. Secondary combustion device for woodburning stove

    SciTech Connect

    Craver, R.D.

    1989-08-08

    This patent describes in a wood burning stove including an exhaust flue opening, a combustion chamber for primary combustion having an access door, a support for wood to be burned and a primary air inlet means for supplying air to support primary combustion of the wood to produce flue gases containing combustible particulate material, plenum means for directing the flue gases in a direction from the combustion chamber to the flue opening in a preselected path, and secondary combustion means for burning the particulate material in the flue gases before flue gases through the exhaust flue opening. The improvement comprising: the combustion chamber having a flue gas exit opening extending laterally across the top of the combustion chamber and communicating the combustion chamber with the plenum means, an elongated manifold extending laterally across and above the combustion chamber substantially coextensively with the flue gas exit opening, a number of air opening spaced longitudinally along the manifold and facing opposite the direction of the flue gases closely adjacent the flue gas exit opening, and an air inlet means for supplying ambient, secondary combustion air to the manifold for counterflow thereof from the openings into the path of the flue gases in a plurality of distinct jets.

  20. Integrated exhaust gas recirculation and charge cooling system

    SciTech Connect

    Wu, Ko-Jen

    2013-12-10

    An intake system for an internal combustion engine comprises an exhaust driven turbocharger configured to deliver compressed intake charge, comprising exhaust gas from the exhaust system and ambient air, through an intake charge conduit and to cylinders of the internal combustion engine. An intake charge cooler is in fluid communication with the intake charge conduit. A cooling system, independent of the cooling system for the internal combustion engine, is in fluid communication with the intake charge cooler through a cooling system conduit. A coolant pump delivers a low temperature cooling medium from the cooling system to and through the intake charge cooler for the transfer of heat from the compressed intake charge thereto. A low temperature cooler receives the heated cooling medium through the cooling system conduit for the transfer or heat therefrom.

  1. Non-thermal plasma for exhaust gases treatment

    NASA Astrophysics Data System (ADS)

    Alva R., Elvia; Pacheco P., Marquidia; Gómez B., Fernando; Pacheco P., Joel; Colín C., Arturo; Sánchez-Mendieta, Víctor; Valdivia B., Ricardo; Santana D., Alfredo; Huertas C., José; Frías P., Hilda

    2015-09-01

    This article describes a study on a non-thermal plasma device to treat exhaust gases in an internal combustion engine. Several tests using a plasma device to treat exhaust gases are conducted on a Honda GX200-196 cm3 engine at different rotational speeds. A plasma reactor could be efficient in degrading nitrogen oxides and particulate matter. Monoxide and carbon dioxide treatment is minimal. However, achieving 1%-3% degradation may be interesting to reduce the emission of greenhouse gases.

  2. Low-pressure-ratio regenerative exhaust-heated gas turbine

    SciTech Connect

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

    1991-01-01

    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.

  3. Exhaust purification with on-board ammonia production

    DOEpatents

    Robel, Wade J.; Driscoll, James J.; Coleman, Gerald N.; Knox, Kevin J.

    2009-06-30

    A power source is provided for use with selective catalytic reduction systems for exhaust-gas purification. The power source includes a first cylinder group with a first air-intake passage and a first exhaust passage, and a second cylinder group with a second air-intake passage and a second exhaust passage. The second air-intake passage is fluidly isolated from the first air-intake passage. A fuel-supply device may be configured to supply fuel into the first exhaust passage, and a catalyst may be disposed downstream of the fuel-supply device to convert at least a portion of the exhaust stream in the first exhaust passage into ammonia.

  4. Ice nucleus activity measurements of solid rocket motor exhaust particles

    NASA Technical Reports Server (NTRS)

    Keller, V. W. (Compiler)

    1986-01-01

    The ice Nucleus activity of exhaust particles generated from combustion of Space Shuttle propellant in small rocket motors has been measured. The activity at -20 C was substantially lower than that of aerosols generated by unpressurized combustion of propellant samples in previous studies. The activity decays rapidly with time and is decreased further in the presence of moist air. These tests corroborate the low effectivity ice nucleus measurement results obtained in the exhaust ground cloud of the Space Shuttle. Such low ice nucleus activity implies that Space Shuttle induced inadvertent weather modification via an ice phase process is extremely unlikely.

  5. Energy saving exhaust siphon

    SciTech Connect

    Baldwin, N.B.

    1982-04-06

    A device is disclosed for attachment to the tailpipe of an exhaust system comprising a body portion placed around the tailpipe, but spaced apart from the tailpipe, in a manner that air may easily flow between the body portion and the tailpipe when the vehicle is moving in a forward direction, a narrowing portion operative to compress the air flow, and an exhaust discharge portion operative for the exhaust from the tailpipe and the air to be discharged therethrough.

  6. Exhaust gas purification device

    SciTech Connect

    Fujiwara, H.; Hibi, T.; Sayo, S.; Sugiura, Y.; Ueda, K.

    1980-02-19

    The exhaust gas purification device includes an exhaust manifold , a purification cylinder connected with the exhaust manifold through a first honey-comb shaped catalyst, and a second honeycomb shaped catalyst positioned at the rear portion of the purification cylinder. Each catalyst is supported by steel wool rings including coarse and dense portions of steel wool. The purification device further includes a secondary air supplying arrangement.

  7. Exhaust gas purifying device

    SciTech Connect

    Sakurai, S.; Hamada, S.

    1985-04-23

    An exhaust gas purifying device for use with a diesel engine comprising a filter block disposed in an engine exhaust passage for collecting exhaust gas particulates, and a heater for incinerating the collected exhaust gas particulates. The filter block has parallel channels defined therein and separated from one another by porous partition walls, some of the channels being closed at their inlet ends with blind plugs while the other channels are closed at their outlet ends with blind plugs. The heater is supported by the blind plugs.

  8. Hydrocarbon Fouling of SCR during PCCI combustion

    SciTech Connect

    Prikhodko, Vitaly Y; Pihl, Josh A; Lewis Sr, Samuel Arthur; Parks, II, James E

    2012-01-01

    The combination of advanced combustion with advanced selective catalytic reduction (SCR) catalyst formulations was studied in the work presented here to determine the impact of the unique hydrocarbon (HC) emissions from premixed charge compression ignition (PCCI) combustion on SCR performance. Catalyst core samples cut from full size commercial Fe- and Cu-zeolite SCR catalysts were exposed to a slipstream of raw engine exhaust from a 1.9-liter 4-cylinder diesel engine operating in conventional and PCCI combustion modes. The zeolites which form the basis of these catalysts are different with the Cu-based catalyst made on a chabazite zeolite which las smaller pore structures relative to the Fe-based catalyst. Subsequent to exposure, bench flow reactor characterization of performance and hydrocarbon release and oxidation enabled evaluation of overall impacts from the engine exhaust. The Fe-zeolite NOX conversion efficiency was significantly degraded, especially at low temperatures (<250 C), after the catalyst was exposed to the raw engine exhaust. The degradation of the Fe-zeolite performance was similar for both combustion modes. The Cu-zeolite showed better tolerance to HC fouling at low temperatures compared to the Fe-zeolite but PCCI exhaust had a more significant impact than the exhaust from conventional combustion on the NOX conversion efficiency. Furthermore, chemical analysis of the hydrocarbons trapped on the SCR cores was conducted to better determine chemistry specific effects.

  9. Performance of Installed Cooking Exhaust Devices

    SciTech Connect

    Singer, Brett C.; Delp, William W.; Apte, Michael G.; Price, Philip N.

    2011-11-01

    The performance metrics of airflow, sound, and combustion product capture efficiency (CE) were measured for a convenience sample of fifteen cooking exhaust devices, as installed in residences. Results were analyzed to quantify the impact of various device- and installation-dependent parameters on CE. Measured maximum airflows were 70% or lower than values noted on product literature for 10 of the devices. Above-the-cooktop devices with flat bottom surfaces (no capture hood) – including exhaust fan/microwave combination appliances – were found to have much lower CE at similar flow rates, compared to devices with capture hoods. For almost all exhaust devices and especially for rear-mounted downdraft exhaust and microwaves, CE was substantially higher for back compared with front burner use. Flow rate, and the extent to which the exhaust device extends over the burners that are in use, also had a large effect on CE. A flow rate of 95 liters per second (200 cubic feet per minute) was necessary, but not sufficient, to attain capture efficiency in excess of 75% for the front burners. A-weighted sound levels in kitchens exceeded 57 dB when operating at the highest fan setting for all 14 devices evaluated for sound performance.

  10. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, Clark W.; Landrum, D. Brian; Spetman, David

    1997-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ambient air for successful operation in the ramjet and scramjet modes. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane. The modeling basis was centered on using convective Mach Number as the similarity parameter to establish correlation between subscale, cold flow tests and full scale, hot firing modes. This parameter has been used successfully to correlate supersonic shear layer growth rates. The experiment design includes hot (600 R) air as the rocket exhaust simulant and hot (760 R) carbon dioxide as the turbine exhaust gas simulant. The combination of gases and their elevated temperatures was required to achieve a convective Mach Number which matched the fall scale item design conditions. The carbon dioxide is seeded with Acetone to permit tracing of the mixing processes through Laser Induced Fluorescence (LIF) techniques. The experiment and its design will be discussed in detail. Both the rocket and turbine exhaust duct nozzles are of unique (square and rectangular) shape and the turbine exhaust e)dt intersects the rocket nozzle wall upstream of the exit. Cold flow testing with the individual nozzles has been conducted to ascertain their behavior in comparison to conventional flow theory. These data are presented.

  11. Catalysts For Lean Burn Engine Exhaust Abatement

    DOEpatents

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

    2004-04-06

    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.

  12. Catalysts for lean burn engine exhaust abatement

    DOEpatents

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

    2003-01-01

    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.

  13. Catalysts for lean burn engine exhaust abatement

    DOEpatents

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

    2006-08-01

    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.

  14. Fuel-cell engine stream conditioning system

    DOEpatents

    DuBose, Ronald Arthur

    2002-01-01

    A stream conditioning system for a fuel cell gas management system or fuel cell engine. The stream conditioning system manages species potential in at least one fuel cell reactant stream. A species transfer device is located in the path of at least one reactant stream of a fuel cell's inlet or outlet, which transfer device conditions that stream to improve the efficiency of the fuel cell. The species transfer device incorporates an exchange media and a sorbent. The fuel cell gas management system can include a cathode loop with the stream conditioning system transferring latent and sensible heat from an exhaust stream to the cathode inlet stream of the fuel cell; an anode humidity retention system for maintaining the total enthalpy of the anode stream exiting the fuel cell related to the total enthalpy of the anode inlet stream; and a cooling water management system having segregated deionized water and cooling water loops interconnected by means of a brazed plate heat exchanger.

  15. Pilot-scale conversion of lime-treated wheat straw into bioethanol: quality assessment of bioethanol and valorization of side streams by anaerobic digestion and combustion

    PubMed Central

    Maas, Ronald HW; Bakker, Robert R; Boersma, Arjen R; Bisschops, Iemke; Pels, Jan R; de Jong, Ed; Weusthuis, Ruud A; Reith, Hans

    2008-01-01

    Introduction The limited availability of fossil fuel sources, worldwide rising energy demands and anticipated climate changes attributed to an increase of greenhouse gasses are important driving forces for finding alternative energy sources. One approach to meeting the increasing energy demands and reduction of greenhouse gas emissions is by large-scale substitution of petrochemically derived transport fuels by the use of carbon dioxide-neutral biofuels, such as ethanol derived from lignocellulosic material. Results This paper describes an integrated pilot-scale process where lime-treated wheat straw with a high dry-matter content (around 35% by weight) is converted to ethanol via simultaneous saccharification and fermentation by commercial hydrolytic enzymes and bakers' yeast (Saccharomyces cerevisiae). After 53 hours of incubation, an ethanol concentration of 21.4 g/liter was detected, corresponding to a 48% glucan-to-ethanol conversion of the theoretical maximum. The xylan fraction remained mostly in the soluble oligomeric form (52%) in the fermentation broth, probably due to the inability of this yeast to convert pentoses. A preliminary assessment of the distilled ethanol quality showed that it meets transportation ethanol fuel specifications. The distillation residue, which contained non-hydrolysable and non-fermentable (in)organic compounds, was divided into a liquid and solid fraction. The liquid fraction served as substrate for the production of biogas (methane), whereas the solid fraction functioned as fuel for thermal conversion (combustion), yielding thermal energy, which can be used for heat and power generation. Conclusion Based on the achieved experimental values, 16.7 kg of pretreated wheat straw could be converted to 1.7 kg of ethanol, 1.1 kg of methane, 4.1 kg of carbon dioxide, around 3.4 kg of compost and 6.6 kg of lignin-rich residue. The higher heating value of the lignin-rich residue was 13.4 MJ thermal energy per kilogram (dry basis). PMID

  16. Exhaust pressure pulsation observation from turbocharger instantaneous speed measurement

    NASA Astrophysics Data System (ADS)

    Macián, V.; Luján, J. M.; Bermúdez, V.; Guardiola, C.

    2004-06-01

    In internal combustion engines, instantaneous exhaust pressure measurements are difficult to perform in a production environment. The high temperature of the exhaust manifold and its pulsating character make its application to exhaust gas recirculation control algorithms impossible. In this paper an alternative method for estimating the exhaust pressure pulsation is presented. A numerical model is built which enables the exhaust pressure pulses to be predicted from instantaneous turbocharger speed measurements. Although the model is data based, a theoretical description of the process is also provided. This combined approach makes it possible to export the model for different engine operating points. Also, compressor contribution in the turbocharger speed pulsation is discussed extensively. The compressor contribution is initially neglected, and effects of this simplified approach are analysed.

  17. Removal of nitric oxide from exhaust gas with cyanuric acid--

    SciTech Connect

    Siebers, D.L. . Combustion Research Faclity); Caton, J.A. . Dept. of Mechanical Engineering)

    1990-01-01

    Addition of gaseous isocyanic acid (HNCO) to the exhaust of combustion systems or chemical process is proposed as a method for reducing nitric oxide (NO) emissions. The HNCO selectively reduces NO in the exhaust through a multistep chemical reaction mechanism. This article presents an experimental investigation of the proposed NO reduction process using cyanuric acid as the source of HNCO. At elevated temperature cyanuric acid decomposes and forms HNCO. The effects of temperature, exhaust gas composition, cyanuric acid concentration (i.e., HNCO concentration), and surfaces were examined. The experiments were conducted in an electrically heated quartz flow reactor using either exhaust from a diesel engine or simulated exhaust gas. The results demonstrate that gas phase NO reduction approaching 100% can be obtained.

  18. Engine valve actuation for combustion enhancement

    DOEpatents

    Reitz, Rolf Deneys; Rutland, Christopher J.; Jhavar, Rahul

    2008-03-04

    A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-strokes combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

  19. Engine Valve Actuation For Combustion Enhancement

    DOEpatents

    Reitz, Rolf Deneys; Rutland, Christopher J.; Jhavar, Rahul

    2004-05-18

    A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

  20. Detection of combustion formed nanoparticles.

    PubMed

    Sgro, L A; Basile, G; Barone, A C; D'Anna, A; Minutolo, P; Borghese, A; D'Alessio, A

    2003-06-01

    UV-visible extinction and scattering and two extra situ sampling techniques: atomic force microscopy (AFM) and differential mobility analysis (DMA) are used to follow the evolution of the particles formed in flames. These particle sizing techniques were chosen because of their sensitivity to detect inception particles, which have diameters, d<5 nm, too small to be observed with typical particle measurement instrumentation. The size of the particles determined by AFM and DMA compares well with the size determined by in situ optical measurements, indicating that the interpretation of the UV-visible optical signal is quite good, and strongly showing the presence of d=2-4 nm particles. UV-visible extinction measurements are also used to determine the concentration of d=2-4 nm particles at the exhausts of practical combustion systems. A numerical model, able to reproduce the experimentally observed low coagulation rate of nanoparticles with respect to soot particles, is used to investigate the operating conditions in the combustion chamber and exhaust system for which 2-4 nm particles survive the exhaust or grow to larger sizes. Combustion generated nanoparticles are suspected to affect human and environmental health because of their affinity for water, small size, low rate of coagulation, and large surface area/weight ratio. The ability to isolate nanoparticles from soot particles in hydrosols collected from combustion may be useful for future analysis by a variety of techniques and toxicological assays.

  1. Duplex tab exhaust nozzle

    NASA Technical Reports Server (NTRS)

    Gutmark, Ephraim Jeff (Inventor); Martens, Steven (nmn) (Inventor)

    2012-01-01

    An exhaust nozzle includes a conical duct terminating in an annular outlet. A row of vortex generating duplex tabs are mounted in the outlet. The tabs have compound radial and circumferential aft inclination inside the outlet for generating streamwise vortices for attenuating exhaust noise while reducing performance loss.

  2. Advanced engine management of individual cylinders for control of exhaust species

    DOEpatents

    Graves, Ronald L [Knoxville, TN; West, Brian H [Knoxville, TN; Huff, Shean P [Knoxville, TN; Parks, II, James E

    2008-12-30

    A method and system controls engine-out exhaust species of a combustion engine having a plurality of cylinders. The method typically includes various combinations of steps such as controlling combustion parameters in individual cylinders, grouping the individual cylinders into a lean set and a rich set of one or more cylinders, combusting the lean set in a lean combustion parameter condition having a lean air:fuel equivalence ratio, combusting the rich set in a rich combustion parameter condition having a rich air:fuel equivalence ratio, and adjusting the lean set and the rich set of one or more cylinders to generate net-lean combustion. The exhaust species may have elevated concentrations of hydrogen and oxygen.

  3. Combustion noise

    NASA Technical Reports Server (NTRS)

    Strahle, W. C.

    1977-01-01

    A review of the subject of combustion generated noise is presented. Combustion noise is an important noise source in industrial furnaces and process heaters, turbopropulsion and gas turbine systems, flaring operations, Diesel engines, and rocket engines. The state-of-the-art in combustion noise importance, understanding, prediction and scaling is presented for these systems. The fundamentals and available theories of combustion noise are given. Controversies in the field are discussed and recommendations for future research are made.

  4. Free-flight Performance of 16-inch-diameter Supersonic Ram-jet Units III : Four Units Designed for Combustion-chamber-inlet Mach Number of 0.245 at Free-stream Mach Number of 1.8 (units D-1, D-2, D-3, and D-4)

    NASA Technical Reports Server (NTRS)

    Disher, John H; Rabinowitz, Leonard

    1950-01-01

    Performance of four 16-inch-diameter ram-jet units was determined at free-stream Mach numbers of 0.49 to 1.78 over range of gas total-temperature ratios of 1.0 to 6.1. Time histories of each flight and data on thrust, drag, diffuser efficiency, and combustion are presented. A maximum thrust coefficient of 0.88 and a maximum net acceleration of 5.13 g's were observed for the four units.

  5. Combustion engine system

    NASA Technical Reports Server (NTRS)

    Houseman, John (Inventor); Voecks, Gerald E. (Inventor)

    1986-01-01

    A flow through catalytic reactor which selectively catalytically decomposes methanol into a soot free hydrogen rich product gas utilizing engine exhaust at temperatures of 200 to 650 C to provide the heat for vaporizing and decomposing the methanol is described. The reactor is combined with either a spark ignited or compression ignited internal combustion engine or a gas turbine to provide a combustion engine system. The system may be fueled entirely by the hydrogen rich gas produced in the methanol decomposition reactor or the system may be operated on mixed fuels for transient power gain and for cold start of the engine system. The reactor includes a decomposition zone formed by a plurality of elongated cylinders which contain a body of vapor permeable, methanol decomposition catalyst preferably a shift catalyst such as copper-zinc.

  6. 40 CFR 86.1310-2007 - Exhaust gas sampling and analytical system for gaseous emissions from heavy-duty diesel-fueled...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... system must provide sufficient secondary dilution air to maintain the double-diluted exhaust stream at a... subtracted from the values measured in the diluted exhaust stream. In the case of primary dilution air, the... stream and the transfer tube wall should be minimized). Double-wall, thin-wall, air-gap insulated, or...

  7. 40 CFR 86.1310-2007 - Exhaust gas sampling and analytical system for gaseous emissions from heavy-duty diesel-fueled...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... system must provide sufficient secondary dilution air to maintain the double-diluted exhaust stream at a... subtracted from the values measured in the diluted exhaust stream. In the case of primary dilution air, the... stream and the transfer tube wall should be minimized). Double-wall, thin-wall, air-gap insulated, or...

  8. Chemistry and the Internal Combustion Engine II: Pollution Problems.

    ERIC Educational Resources Information Center

    Hunt, C. B.

    1979-01-01

    Discusses pollution problems which arise from the use of internal combustion (IC) engines in the United Kingdom (UK). The IC engine exhaust emissions, controlling IC engine pollution in the UK, and some future developments are also included. (HM)

  9. Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion

    SciTech Connect

    Choudhuri, Ahsan

    2013-09-30

    Oxy-fuel combustion has been used previously in a wide range of industrial applications. Oxy- combustion is carried out by burning a hydrocarbon fuel with oxygen instead of air. Flames burning in this configuration achieve higher flame temperatures which present opportunities for significant efficiency improvements and direct capture of CO2 from the exhaust stream. In an effort to better understand and characterize the fundamental flame characteristics of oxy-fuel combustion this research presents the experimental measurements of flame stability of various oxyfuel flames. Effects of H2 concentration, fuel composition, exhaust gas recirculation ratio, firing inputs, and burner diameters on the flame stability of these fuels are discussed. Effects of exhaust gas recirculation i.e. CO2 and H2O (steam) acting as diluents on burner operability are also presented. The roles of firing input on flame stability are then analyzed. For this study it was observed that many oxy-flames did not stabilize without exhaust gas recirculation due to their higher burning velocities. In addition, the stability regime of all compositions was observed to decrease as the burner diameter increased. A flashback model is also presented, using the critical velocity gradient gF) values for CH4-O2-CO2 flames. The second part of the study focuses on the experimental measurements of the flow field characteristics of premixed CH4/21%O2/79%N2 and CH4/38%O2/72%CO2 mixtures at constant firing input of 7.5 kW, constant, equivalence ratio of 0.8, constant swirl number of 0.92 and constant Reynolds Numbers. These measurements were taken in a swirl stabilized combustor at atmospheric pressure. The flow field visualization using Particle Imaging Velocimetry (PIV) technique is implemented to make a better understanding of the turbulence characteristics of

  10. Municipal Solid Waste Combustion : Fuel Testing and Characterization : Task 1 Report, May 30, 1990-October 1, 1990.

    SciTech Connect

    Bushnell, Dwight J.; Canova, Joseph H.; Dadkhah-Nikoo, Abbas.

    1990-10-01

    The objective of this study is to screen and characterize potential biomass fuels from waste streams. This will be accomplished by determining the types of pollutants produced while burning selected municipal waste, i.e., commercial mixed waste paper residential (curbside) mixed waste paper, and refuse derived fuel. These materials will be fired alone and in combination with wood, equal parts by weight. The data from these experiments could be utilized to size pollution control equipment required to meet emission standards. This document provides detailed descriptions of the testing methods and evaluation procedures used in the combustion testing and characterization project. The fuel samples will be examined thoroughly from the raw form to the exhaust emissions produced during the combustion test of a densified sample.

  11. Methods of separating particulate residue streams

    DOEpatents

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, J. Richard

    2011-04-05

    A particulate residue separator and a method for separating a particulate residue stream may include an air plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams that are formed by the harvesting device and that travel, at least in part, along the air plenum and in a direction of the second, exhaust end; and a baffle assembly that is located in partially occluding relation relative to the air plenum and that substantially separates the first and second particulate residue air streams.

  12. A Review of Major Non-Power-Related Carbon Dioxide Stream Compositions

    SciTech Connect

    Last, George V.; Schmick, Mary T.

    2015-07-01

    A critical component in the assessment of long-term risk from geologic sequestration of carbon dioxide (CO2) is the ability to predict mineralogical and geochemical changes within storage reservoirs as a result of rock-brine-CO2 reactions. Impurities and/or other constituents in CO2 source streams selected for sequestration can affect both the chemical and physical (e.g., density, viscosity, interfacial tension) properties of CO2 in the deep subsurface. The nature and concentrations of these impurities are a function of both the industrial source(s) of CO2, as well as the carbon capture technology used to extract the CO2 and produce a concentrated stream for subsurface injection and geologic sequestration. This article reviews the relative concentrations of CO2 and other constituents in exhaust gases from major non-energy-related industrial sources of CO2. Assuming that carbon capture technology would remove most of the incondensable gases N2, O2, and Ar, leaving SO2 and NOx as the main impurities, the authors then summarize the relative proportions of the remaining impurities assumed to be present in CO2 source streams that could be targeted for geologic sequestration. The summary is presented relative to five potential sources of CO2: 1) Flue Gas with Flue Gas Desulfurization, 2) Combustion Stack from Coke Production, 3) Portland Cement Kilns, 4) Natural Gas Combustion, and 5) Lime Production.

  13. Manifold intake arrangement for internal combustion engines

    SciTech Connect

    Heath, K.E.

    1988-09-27

    This patent describes an internal combustion engine, comprising: a combustion chamber having a piston disposed therein; a pressure chamber; a first intake valve means for providing selective communication between the pressure chamber and the combustion chamber; a second valve means for providing selective communication between the pressure chamber and a fuel and air mixture supply; exhaust valve means for providing selective communication between the combustion chamber and the atmosphere, the exhaust valve means opening during the exhaust stroke of the piston and allowing spent gases to be expelled therethrough and closing at the end of the exhaust stroke; an intake control means connected to the first valve means for opening the first valve means during the intake stroke of the piston after the exhaust valve means is closed and maintaining the first valve open during an initial portion of the compression stroke for pressurizing the pressure chamber during the initial portion of the compression stroke and for closing the first valve means during the remaining portion of the compression stroke; wherein the second valve means opens during the intake stroke of the piston a period of time after the opening of the first valve means and closes during the compression stroke of the piston.

  14. Test Would Quantify Combustion Oxygen From Different Sources

    NASA Technical Reports Server (NTRS)

    Tapphorn, Ralph M.

    1993-01-01

    Proposed isotope-enrichment scheme enables determination of contributions of dual sources of oxygen for combustion. Liquid oxygen or other artificial stream enriched with O(18) to about 1 percent by weight. Combustion products analyzed by mass spectrometer to measure relative abundances of H2O(18) and H2O(16). From relative abundances of water products measured, one computes relative contribution of oxygen extracted from stream compared to other source of oxygen in combustion process. Used to determine contributions of natural oxygen in air and liquid oxygen supplied in separate stream mixed with air or sent directly into combustion chamber.

  15. Atmospheric scavenging exhaust

    NASA Technical Reports Server (NTRS)

    Fenton, D. L.; Purcell, R. Y.

    1977-01-01

    Solid propellant rocket exhaust was directly utilized to ascertain raindrop scavenging rates for hydrogen chloride. The airborne HCl concentration varied from 0.2 to 10.0 ppm and the raindrop sizes tested included 0.55 mm, 1.1 mm, and 3.0 mm. Two chambers were used to conduct the experiments. A large, rigid walled, spherical chamber stored the exhaust constituents while the smaller chamber housing all the experiments was charged as required with rocket exhaust HCl. Surface uptake experiments demonstrated an HCl concentration dependence for distilled water. Sea water and brackish water HCl uptake was below the detection limit of the chlorine-ion analysis technique employed. Plant life HCl uptake experiments were limited to corn and soybeans. Plant age effectively correlated the HCl uptake data. Metallic corrosion was not significant for single 20 minute exposures to the exhaust HCl under varying relative humidity.

  16. Real-time analysis of aromatics in combustion engine exhaust by resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS): a robust tool for chassis dynamometer testing.

    PubMed

    Adam, T W; Clairotte, M; Streibel, T; Elsasser, M; Pommeres, A; Manfredi, U; Carriero, M; Martini, G; Sklorz, M; Krasenbrink, A; Astorga, C; Zimmermann, R

    2012-07-01

    Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS) is a robust method for real-time analysis of monocyclic and polycyclic aromatic hydrocarbons in complex emissions. A mobile system has been developed which enables direct analysis on site. In this paper, we utilize a multicomponent calibration scheme based on the analytes' photo-ionisation cross-sections relative to a calibrated species. This allows semi-quantification of a great number of components by only calibrating one compound of choice, here toluene. The cross-sections were determined by injecting nebulised solutions of aromatic compounds into the TOF-MS ion source with the help of a HPLC pump. Then, REMPI-TOF-MS was implemented at various chassis dynamometers and test cells and the exhaust of the following vehicles and engines investigated: a compression ignition light-duty (LD) passenger car, a compression ignition LD van, two spark ignition LD passenger cars, 2 two-stroke mopeds, and a two-stroke engine of a string gas trimmer. The quantitative time profiles of benzene are shown. The results indicate that two-stroke engines are a significant source for toxic and cancerogenic compounds. Air pollution and health effects caused by gardening equipment might still be underestimated.

  17. Sandia Combustion Research Program: Annual report, 1986

    SciTech Connect

    Not Available

    1986-01-01

    This report presents research results of the past year, divided thematically into some ten categories. Publications and presentations arising from this work are included in the appendix. Our highlighted accomplishment of the year is the announcement of the discovery and demonstration of the RAPRENOx process. This new mechanism for the elimination of nitrogen oxides from essentially all kinds of combustion exhausts shows promise for commercialization, and may eventually make a significant contribution to our nation's ability to control smog and acid rain. The sections of this volume describe the facility's laser and computer system, laser diagnostics of flames, combustion chemistry, reacting flows, liquid and solid propellant combustion, mathematical models of combustion, high-temperature material interfaces, studies of engine/furnace combustion, coal combustion, and the means of encouraging technology transfer. 182 refs., 170 figs., 12 tabs.

  18. A hybrid 2-zone/WAVE engine combustion model for simulating combustion instabilities during dilute operation

    SciTech Connect

    Edwards, Kevin Dean; Wagner, Robert M; Chakravarthy, Veerathu K; Daw, C Stuart; Green Jr, Johney Boyd

    2006-01-01

    Internal combustion engines are operated under conditions of high exhaust gas recirculation (EGR) to reduce NO x emissions and promote enhanced combustion modes such as HCCI. However, high EGR under certain conditions also promotes nonlinear feedback between cycles, leading to the development of combustion instabilities and cyclic variability. We employ a two-zone phenomenological combustion model to simulate the onset of combustion instabilities under highly dilute conditions and to illustrate the impact of these instabilities on emissions and fuel efficiency. The two-zone in-cylinder combustion model is coupled to a WAVE engine-simulation code through a Simulink interface, allowing rapid simulation of several hundred successive engine cycles with many external engine parametric effects included. We demonstrate how this hybrid model can be used to study strategies for adaptive feedback control to reduce cyclic combustion instabilities and, thus, preserve fuel efficiency and reduce emissions.

  19. Evaluation of the Migrating Combustion Chamber (MCC) engine

    NASA Astrophysics Data System (ADS)

    Miller, K. M.; Morar, Dorin

    1993-01-01

    The Belvoir Research, Development and Engineering Center (BRDEC) tested three Migrating Combustion Chamber (MCC) engines built by Engine Research Associates (ERA) for Natick RD and E Center. The MCC concept attempts to provide a lightweight, quiet engine having a cool exhaust gas stream. The cool exhaust is attained by capturing additional energy from expansion beyond that achievable in conventional engines by the use of gas porting to multiple expansion chambers; this provides a more efficient engine operation than is otherwise attainable for the configuration. The testing included determining the engine torque-speed-power characteristics and the Brake Specific Fuel Consumption (BSFC) under a variety of load conditions. Startability and operability were concerns; starting under normal ambient conditions was difficult. All testing was performed using a 10:1 fuel/oil mixture of low lead gasoline with AMZOIL synthetic lubricating oil for two-stroke engines. The maximum power achieved was 0.25 horsepower at 4,400 rpm. The peak torque observed was 69 oz.-in. at 3,200 rpm. It was not possible to make noise and vibration measurements during the testing cycle, but they appeared to be low. The MCC engines tested had relatively short lives, operating for less than 25 hours. Performance and durability improvements are necessary before this MCC design can be considered as a viable alternative to commercially available two-cycle engines.

  20. Measuring Combustion Advance in Solid Propellants

    NASA Technical Reports Server (NTRS)

    Yang, L. C.

    1986-01-01

    Set of gauges on solid-propellant rocket motor with electrically insulating case measures advance of combustion front and local erosion rates of propellant and insulation. Data furnished by gauges aid in motor design, failure analysis, and performance prediction. Technique useful in determining propellant uniformity and electrical properties of exhaust plum. Gauges used both in flight and on ground. Foilgauge technique also useful in basic research on pulsed plasmas or combustion of solids.

  1. Analysis on fuel economy improvement and exhaust emission reduction in a two-stroke engine by using an exhaust valve

    SciTech Connect

    Asai, Masahiro; Kurosaki, Takaharu; Okada, Kazunori

    1995-12-31

    A timing controlled auto-ignition name ``AR combustion`` could improve irregular combustion in the part load operation of conventional two-stroke engines. Their previous papers have suggested its idea and the drastic improvements in fuel consumption and HC emission proven through a bench experiments. This time, form a concept that improvements of a two-stroke engine should be done maintaining its original advantages, an AR combustion engine was developed by using a simple exhaust valve and maintaining engine`s original power output. This engine was mounted on a motorcycle and experimented in the ``Dakar rally``. As the results, good fuel economies exceeding a four-stroke rally model, excellent driveability and durability were proven, because of the improvement in the combustion and engine`s potential for the downsizing. The AR combustion engine, consequently, has good prospects for the practical use.

  2. Computational Combustion

    SciTech Connect

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

    2004-08-26

    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  3. Odor intensity and characterization studies of exhaust from a turbojet engine combustor

    NASA Technical Reports Server (NTRS)

    Butze, H. F.; Kendall, D. A.

    1973-01-01

    Sensory odor tests of the exhaust from a turbojet combustor operating at simulated idle conditions were made by a human panel sniffing diluted exhaust gas. Simultaneously, samples of undiluted exhaust gas were collected on adsorbent substrates, subsequently removed by solvent flushing, and analyzed chemically by liquid chromatographic methods. The concentrations of the principal malodorous species, the aromatic (unburned fuel-related) and the oxygenated (partially burned fuel) fractions, as determined chromatographically, correlated well with the intensity of the odor as determined by sniffing. Odor intensity increased as combustion efficiency decreased. Combustor modifications which increased combustion efficiency decreased odor intensity.

  4. Simulating Combustion

    NASA Astrophysics Data System (ADS)

    Merker, G.; Schwarz, C.; Stiesch, G.; Otto, F.

    The content spans from simple thermodynamics of the combustion engine to complex models for the description of the air/fuel mixture, ignition, combustion and pollutant formation considering the engine periphery of petrol and diesel engines. Thus the emphasis of the book is on the simulation models and how they are applicable for the development of modern combustion engines. Computers can be used as the engineers testbench following the rules and recommendations described here.

  5. Diesel exhaust-gas purification system

    SciTech Connect

    Doherty, B.J.

    1982-07-01

    The design of a diesel exhaust gas purification system is presented. It will provide 2000 scfm of dry, anerobic gas (essentially nitrogen) for use in air drilling operations where drill pipe corrosion is a problem, such as geothermal applications. The system is operable in the field and may be transported via highways. It will operate at ambient temperatures up to 110/sup 0/F and requires no water - diesel fuel is used to combust excess oxygen and to generate electricity for the system. Gas production costs, including capital amortization, operations, fuel and maintenance (for reasonable utilization) are about $1.50/1000 scf.

  6. Apparatus for photocatalytic destruction of internal combustion engine emissions during cold start

    DOEpatents

    Janata, J.; McVay, G.L.; Peden, C.H.; Exarhos, G.J.

    1998-07-14

    A method and apparatus are disclosed for the destruction of emissions from an internal combustion engine wherein a substrate coated with TiO{sub 2} is exposed to a light source in the exhaust system of an internal combustion engine thereby catalyzing oxidation/reduction reactions between gaseous hydrocarbons, carbon monoxide, nitrogen oxides and oxygen in the exhaust of the internal combustion engine. 4 figs.

  7. Fluidic systems may improve combustion in automotive engines

    NASA Technical Reports Server (NTRS)

    Mangion, C.

    1972-01-01

    Application of fluidic devices to reduce generation of noxious exhausts from internal combustion engines is discussed. Operation of fluidic system to provide bypass of fuel air mixture into heated loop to provide more complete combustion is explanined. Advantage lies in no moving parts required for fluidic by-pass action.

  8. Influence of increased exhaust gas recirculation ratio on the thermodynamic processes in CI DI engine

    NASA Astrophysics Data System (ADS)

    Pielecha, I.; Skowron, M.; Bueschke, W.; Cieślik, W.; Wisłocki, K.

    2016-09-01

    The aim of the conducted research was the thermodynamic identification of combustion process involving up to 50-60% recirculated exhaust gasses in compression ignition engine. The values of the respective indicators obtained for the high share of exhaust gasses in the cylinder were compared to the values obtained in the engine working without EGR. The research was conducted on the single-cylinder AVL 5804 engine equipped with recirculated gas cooling system. The conditions of combustion process were determined using indicators of engine operation and measurements of fast-varying cylinder pressure. The evaluation of the influence of different share of exhaust gases in the cylinder on the combustion course and heat release was conducted. As a result of the conducted research the possibility of utilizing the high share of exhaust gasses (50-60%) with simultaneous ecological benefits, not only in relation to nitrogen oxides, was demonstrated.

  9. Combustion of droplets and sprays

    NASA Astrophysics Data System (ADS)

    Eigenbrod, Christian; Sattelmayer, Thomas; Bäßler, Stefan; Mauss, Fabian; Meisl, Jürgen; Oomens, Bas; Rackwitz, Leif; Tait, Nigel; Angelberger, Christian; Eilts, Peter; Magnusson, Ingemar; Lauvergne, Romain; Tatschl, Reinhard

    2005-10-01

    The combustion of liquid hydrocarbon fuels in internal combustion engines and gas turbines for energy production and aircraft propulsion is intrinsically tied to the formation of pollutants. Apart from aiming for the highest combustion efficiencies in order to lower the operational costs and the emission of CO2, the reduction of poisonous and environmentally harmful exhaust constituents is a challenging task for scientists and engineers. The most prominent pollutants are soot, identified to trigger respiratory diseases and cancer, and nitric oxides such as NO and NO2, which promote the formation of ozone affecting the cardiovascular system when released in the lower atmosphere. Soot and nitric oxides are greenhouse pollutants in the upper atmosphere. Even though only 2-3% of the anthropogenic emission of nitric oxides are contributed by aircraft, it is the only emission at high altitudes. Unfortunately, it has the greatest impact on climate there and it does not matter whether the fuels are fossil or, in the future, biomass.

  10. System and method for cooling a combustion gas charge

    DOEpatents

    Massey, Mary Cecelia; Boberg, Thomas Earl

    2010-05-25

    The present invention relates to a system and method for cooling a combustion gas charge prior. The combustion gas charge may include compressed intake air, exhaust gas, or a mixture thereof. An evaporator is provided that may then receive a relatively high temperature combustion gas charge and discharge at a relatively lower temperature. The evaporator may be configured to operate with refrigeration cycle components and/or to receive a fluid below atmospheric pressure as the phase-change cooling medium.

  11. Stabilization Of Combustion Of Sprayed Fuel

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.; Jan, Darrell L.

    1995-01-01

    Several modifications of nozzle spraying liquid propellant into combustion chamber proposed to stabilize combustion. Proposed changes in design of nozzle alter flow field in combustion chamber, according to fluid-mechanical principles, in such way as to suppress oscillations. Various alternative nozzle configurations include bluff or toroidal body to generate turbulence. Other features helping to suppress oscillations include down-stream recirculation zones, baffles, and damping cavities. Similar modifications help to suppress oscillations in industrial combustion chambers and in commercial and domestic oil-burning furnaces.

  12. Nonequilibrium combustion effects in supersonic streams

    NASA Technical Reports Server (NTRS)

    Jensen, R. M.; Bryce, C. A.; Reese, B. A.

    1972-01-01

    This research program is a theoretical and experimental investigation of the effect of nonequilibrium conditions upon the performance of combustors employing supersonic flows. Calculations and experiments are made regarding the effects on the ignition of hydrogen of the nonequilibrium species (free radicals, atoms, water vapor, etc.) obtained using vitiated air. Results of this investigation show that the nonequilibrium free-radical content from a supersonic vitiated air source will cause early ignition of the hydrogen. An analysis of heated air expended from a high temperature source to test section conditions also indicates that there is sufficient free radical content in the incoming flow to cause early ignition. Water vapor, an inherent contaminant in the generation of vitiated air, was found to reduce the ignition delay period under the experimental conditions considered.

  13. Combustion of dense streams of coal particles

    SciTech Connect

    Annamalai, K.

    1991-01-01

    The main objective of our work is to obtain a specific velocity of the resulting flame and to maintain this flame consistent throughout the experiment. To optimize our work, theoretical study has been conducted relating the flow rate of the premixed gas (gas + air), stoichiometric coal mass flow rate, interparticle distance of the coal particles, number of particles and the max. coal mass flow rate needed to maintain a specific velocity. Runs were made for velocities of 1.5, 2.0, 2.5, and 3.0 m/s.

  14. Energy and mass flow computation in biomass computation in biomass combustion systems

    SciTech Connect

    Payne, F.A.

    1984-09-01

    A computational technique which utilizes biomass ultimate analysis, gross heat of combustion from a bomb calorimeter, and moisture content was developed for balancing an empirical chemical equation and calculating the combustion temperature and exhaust composition. A single equation for relating the net heat of combustion of a biomass to moisture content was developed. A sample calculation is presented. 7 references.

  15. Using Laser-Induced Incandescence To Measure Soot in Exhaust

    NASA Technical Reports Server (NTRS)

    Bachalo, William D.; Sankar, Subramanian V.

    2005-01-01

    An instrumentation system exploits laser-induced incandescence (LII) to measure the concentration of soot particles in an exhaust stream from an engine, furnace, or industrial process that burns hydrocarbon fuel. In comparison with LII soot-concentration-measuring systems, this system is more complex and more capable.

  16. Exhaust bypass flow control for exhaust heat recovery

    SciTech Connect

    Reynolds, Michael G.

    2015-09-22

    An exhaust system for an engine comprises an exhaust heat recovery apparatus configured to receive exhaust gas from the engine and comprises a first flow passage in fluid communication with the exhaust gas and a second flow passage in fluid communication with the exhaust gas. A heat exchanger/energy recovery unit is disposed in the second flow passage and has a working fluid circulating therethrough for exchange of heat from the exhaust gas to the working fluid. A control valve is disposed downstream of the first and the second flow passages in a low temperature region of the exhaust heat recovery apparatus to direct exhaust gas through the first flow passage or the second flow passage.

  17. Diesel exhaust exposures in port workers.

    PubMed

    Debia, Maximilien; Neesham-Grenon, Eve; Mudaheranwa, Oliver C; Ragettli, Martina S

    2016-07-01

    Exposure to diesel engine exhaust has been linked to increased cancer risk and cardiopulmonary diseases. Diesel exhaust is a complex mixture of chemical substances, including a particulate fraction mainly composed of ultrafine particles, resulting from the incomplete combustion of fuel. Diesel trucks are known to be an important source of diesel-related air pollution, and areas with heavy truck traffic are associated with higher air pollution levels and increased public health problems. Several indicators have been proposed as surrogates for estimating exposures to diesel exhaust but very few studies have focused specifically on monitoring the ultrafine fraction through the measurement of particle number concentrations. The aim of this study is to assess occupational exposures of gate controllers at the port of Montreal, Canada, to diesel engine emissions from container trucks by measuring several surrogates through a multimetric approach which includes the assessment of both mass and number concentrations and the use of direct reading devices. A 10-day measurement campaign was carried out at two terminal checkpoints at the port of Montreal. Respirable elemental and organic carbon, PM1, PM2.5, PMresp (PM4), PM10, PMtot (inhalable fraction), particle number concentrations, particle size distributions, and gas concentrations (NO2, NO, CO) were monitored. Gate controllers were exposed to concentrations of contaminants associated with diesel engine exhaust (elemental carbon GM = 1.6 µg/m(3); GSD = 1.6) well below recommended occupational exposure limits. Average daily particle number concentrations ranged from 16,544-67,314 particles/cm³ (GM = 32,710 particles/cm³; GSD = 1.6). Significant Pearson correlation coefficients were found between daily elemental carbon, PM fractions and particle number concentrations, as well as between total carbon, PM fractions and particle number concentrations. Significant correlation coefficients were found between particle number

  18. Diesel exhaust exposures in port workers.

    PubMed

    Debia, Maximilien; Neesham-Grenon, Eve; Mudaheranwa, Oliver C; Ragettli, Martina S

    2016-07-01

    Exposure to diesel engine exhaust has been linked to increased cancer risk and cardiopulmonary diseases. Diesel exhaust is a complex mixture of chemical substances, including a particulate fraction mainly composed of ultrafine particles, resulting from the incomplete combustion of fuel. Diesel trucks are known to be an important source of diesel-related air pollution, and areas with heavy truck traffic are associated with higher air pollution levels and increased public health problems. Several indicators have been proposed as surrogates for estimating exposures to diesel exhaust but very few studies have focused specifically on monitoring the ultrafine fraction through the measurement of particle number concentrations. The aim of this study is to assess occupational exposures of gate controllers at the port of Montreal, Canada, to diesel engine emissions from container trucks by measuring several surrogates through a multimetric approach which includes the assessment of both mass and number concentrations and the use of direct reading devices. A 10-day measurement campaign was carried out at two terminal checkpoints at the port of Montreal. Respirable elemental and organic carbon, PM1, PM2.5, PMresp (PM4), PM10, PMtot (inhalable fraction), particle number concentrations, particle size distributions, and gas concentrations (NO2, NO, CO) were monitored. Gate controllers were exposed to concentrations of contaminants associated with diesel engine exhaust (elemental carbon GM = 1.6 µg/m(3); GSD = 1.6) well below recommended occupational exposure limits. Average daily particle number concentrations ranged from 16,544-67,314 particles/cm³ (GM = 32,710 particles/cm³; GSD = 1.6). Significant Pearson correlation coefficients were found between daily elemental carbon, PM fractions and particle number concentrations, as well as between total carbon, PM fractions and particle number concentrations. Significant correlation coefficients were found between particle number

  19. Diesel engine exhaust

    Integrated Risk Information System (IRIS)

    Diesel engine exhaust ; CASRN N.A . Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  20. Hybrid Exhaust Component

    NASA Technical Reports Server (NTRS)

    Pelletier, Gerard D. (Inventor); Logan, Charles P. (Inventor); McEnerney, Bryan William (Inventor); Haynes, Jeffrey D. (Inventor)

    2015-01-01

    An exhaust includes a wall that has a first composite material having a first coefficient of thermal expansion and a second composite material having a second coefficient of the thermal expansion that is less than the first coefficient of thermal expansion.

  1. Evaluation of carcinogenic hazard of diesel engine exhaust needs to consider revolutionary changes in diesel technology.

    PubMed

    McClellan, Roger O; Hesterberg, Thomas W; Wall, John C

    2012-07-01

    Diesel engines, a special type of internal combustion engine, use heat of compression, rather than electric spark, to ignite hydrocarbon fuels injected into the combustion chamber. Diesel engines have high thermal efficiency and thus, high fuel efficiency. They are widely used in commerce prompting continuous improvement in diesel engines and fuels. Concern for health effects from exposure to diesel exhaust arose in the mid-1900s and stimulated development of emissions regulations and research to improve the technology and characterize potential health hazards. This included epidemiological, controlled human exposure, laboratory animal and mechanistic studies to evaluate potential hazards of whole diesel exhaust. The International Agency for Research on Cancer (1989) classified whole diesel exhaust as - "probably carcinogenic to humans". This classification stimulated even more stringent regulations for particulate matter that required further technological developments. These included improved engine control, improved fuel injection system, enhanced exhaust cooling, use of ultra low sulfur fuel, wall-flow high-efficiency exhaust particulate filters, exhaust catalysts, and crankcase ventilation filtration. The composition of New Technology Diesel Exhaust (NTDE) is qualitatively different and the concentrations of particulate constituents are more than 90% lower than for Traditional Diesel Exhaust (TDE). We recommend that future reviews of carcinogenic hazards of diesel exhaust evaluate NTDE separately from TDE. PMID:22561182

  2. Evaluation of carcinogenic hazard of diesel engine exhaust needs to consider revolutionary changes in diesel technology.

    PubMed

    McClellan, Roger O; Hesterberg, Thomas W; Wall, John C

    2012-07-01

    Diesel engines, a special type of internal combustion engine, use heat of compression, rather than electric spark, to ignite hydrocarbon fuels injected into the combustion chamber. Diesel engines have high thermal efficiency and thus, high fuel efficiency. They are widely used in commerce prompting continuous improvement in diesel engines and fuels. Concern for health effects from exposure to diesel exhaust arose in the mid-1900s and stimulated development of emissions regulations and research to improve the technology and characterize potential health hazards. This included epidemiological, controlled human exposure, laboratory animal and mechanistic studies to evaluate potential hazards of whole diesel exhaust. The International Agency for Research on Cancer (1989) classified whole diesel exhaust as - "probably carcinogenic to humans". This classification stimulated even more stringent regulations for particulate matter that required further technological developments. These included improved engine control, improved fuel injection system, enhanced exhaust cooling, use of ultra low sulfur fuel, wall-flow high-efficiency exhaust particulate filters, exhaust catalysts, and crankcase ventilation filtration. The composition of New Technology Diesel Exhaust (NTDE) is qualitatively different and the concentrations of particulate constituents are more than 90% lower than for Traditional Diesel Exhaust (TDE). We recommend that future reviews of carcinogenic hazards of diesel exhaust evaluate NTDE separately from TDE.

  3. Test-methods on the test-bench: a comparison of complete exhaust and exhaust particle extracts for genotoxicity/mutagenicity assessment.

    PubMed

    Steiner, Sandro; Heeb, Norbert V; Czerwinski, Jan; Comte, Pierre; Mayer, Andreas; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

    2014-05-01

    With the growing number of new exhaust after-treatment systems, fuels and fuel additives for internal combustion engines, efficient and reliable methods for detecting exhaust genotoxicity and mutagenicity are needed to avoid the widespread application of technologies with undesirable effects toward public health. In a commonly used approach, organic extracts of particulates rather than complete exhaust is used for genotoxicity/mutagenicity assessment, which may reduce the reliability of the results. In the present study, we assessed the mutagenicity and the genotoxicity of complete diesel exhaust compared to an organic exhaust particle extract from the same diesel exhaust in a bacterial and a eukaryotic system, that is, a complex human lung cell model. Both, complete exhaust and organic extract were found to act mutagenic/genotoxic, but the amplitudes of the effects differed considerably. Furthermore, our data indicate that the nature of the mutagenicity may not be identical for complete exhaust and particle extracts. Because in addition, differences between the responses of the different biological systems were found, we suggest that a comprehensive assessment of exhaust toxicity is preferably performed with complete exhaust and with biological systems representative for the organisms and organs of interest (i.e., human lungs) and not only with the Ames test. PMID:24697289

  4. Aeroacoustics of Three-Stream Jets

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda S.

    2012-01-01

    Results from acoustic measurements of noise radiated from a heated, three-stream, co-annular exhaust system operated at subsonic conditions are presented. The experiments were conducted for a range of core, bypass, and tertiary stream temperatures and pressures. The nozzle system had a fan-to-core area ratio of 2.92 and a tertiary-to-core area ratio of 0.96. The impact of introducing a third stream on the radiated noise for third-stream velocities below that of the bypass stream was to reduce high frequency noise levels at broadside and peak jet-noise angles. Mid-frequency noise radiation at aft observation angles was impacted by the conditions of the third stream. The core velocity had the greatest impact on peak noise levels and the bypass-to-core mass flow ratio had a slight impact on levels in the peak jet-noise direction. The third-stream jet conditions had no impact on peak noise levels. Introduction of a third jet stream in the presence of a simulated forward-flight stream limits the impact of the third stream on radiated noise. For equivalent ideal thrust conditions, two-stream and three-stream jets can produce similar acoustic spectra although high-frequency noise levels tend to be lower for the three-stream jet.

  5. Combustion physics

    NASA Astrophysics Data System (ADS)

    Jones, A. R.

    1985-11-01

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

  6. Partially integrated exhaust manifold

    SciTech Connect

    Hayman, Alan W; Baker, Rodney E

    2015-01-20

    A partially integrated manifold assembly is disclosed which improves performance, reduces cost and provides efficient packaging of engine components. The partially integrated manifold assembly includes a first leg extending from a first port and terminating at a mounting flange for an exhaust gas control valve. Multiple additional legs (depending on the total number of cylinders) are integrally formed with the cylinder head assembly and extend from the ports of the associated cylinder and terminate at an exit port flange. These additional legs are longer than the first leg such that the exit port flange is spaced apart from the mounting flange. This configuration provides increased packaging space adjacent the first leg for any valving that may be required to control the direction and destination of exhaust flow in recirculation to an EGR valve or downstream to a catalytic converter.

  7. Mutagenicity of diesel exhaust particle extracts: influence of driving cycle and environmental temperature.

    PubMed

    Clark, C R; Dutcher, J S; Brooks, A L; McClellan, R O; Marshall, W F; Naman, T M

    1982-01-01

    General Motors and Volkswagen diesel passenger cars (1980 and 1981 model year) were operated on a climate controlled chassis dynomometer and the particulate portion of the exhaust was collected on high volume filters. Dichloromethane extracts of the exhaust particles (soot) collected while the cars were operated under simulated highway, urban and congested urban driving cycles were assayed for mutagenicity in Salmonella strains TA-98 and TA-100. Driving pattern did not significantly influence the mutagenic potency of the exhaust particle extracts or estimates of the amount of mutagenicity emitted from the exhaust despite large differences in particle emission rates and extractable fraction of the particles. Mutagenicity of extracts of exhaust particles collected while the vehicles were operated at test chamber temperatures of 25, 50, 75 and 100 degrees F were also very similar. The results suggest that driving pattern and environmental temperature do not significantly alter the emission of genotoxic combustion products from the exhaust. PMID:6193022

  8. Mutagenicity of diesel exhaust particle extracts: influence of driving cycle and environmental temperature.

    PubMed

    Clark, C R; Dutcher, J S; Brooks, A L; McClellan, R O; Marshall, W F; Naman, T M

    1982-01-01

    General Motors and Volkswagen diesel passenger cars (1980 and 1981 model year) were operated on a climate controlled chassis dynomometer and the particulate portion of the exhaust was collected on high volume filters. Dichloromethane extracts of the exhaust particles (soot) collected while the cars were operated under simulated highway, urban and congested urban driving cycles were assayed for mutagenicity in Salmonella strains TA-98 and TA-100. Driving pattern did not significantly influence the mutagenic potency of the exhaust particle extracts or estimates of the amount of mutagenicity emitted from the exhaust despite large differences in particle emission rates and extractable fraction of the particles. Mutagenicity of extracts of exhaust particles collected while the vehicles were operated at test chamber temperatures of 25, 50, 75 and 100 degrees F were also very similar. The results suggest that driving pattern and environmental temperature do not significantly alter the emission of genotoxic combustion products from the exhaust.

  9. Combustion mode switching with a turbocharged/supercharged engine

    SciTech Connect

    Mond, Alan; Jiang, Li

    2015-09-22

    A method for switching between low- and high-dilution combustion modes in an internal combustion engine having an intake passage with an exhaust-driven turbocharger, a crankshaft-driven positive displacement supercharger downstream of the turbocharger and having variable boost controllable with a supercharger bypass valve, and a throttle valve downstream of the supercharger. The current combustion mode and mass air flow are determined. A switch to the target combustion mode is commanded when an operating condition falls within a range of predetermined operating conditions. A target mass air flow to achieve a target air-fuel ratio corresponding to the current operating condition and the target combustion mode is determined. The degree of opening of the supercharger bypass valve and the throttle valve are controlled to achieve the target mass air flow. The amount of residual exhaust gas is manipulated.

  10. Horizontally opposed internal combustion engine

    SciTech Connect

    Honkanen, E.G.

    1992-07-28

    This patent describes a internal combustion engine. It comprises a base plate coincident with a horizontal plane and generally symmetrical with respect to a central longitudinal axis coincident with a vertical plane extending between fore and aft ends of the base plate, a main power crankshaft suspended below the base plate and extending parallel with the central longitudinal axis, a plurality of open-ended piston cylinders disposed below the base plate arranged in axially aligned pairs, a pair of auxiliary crankshafts detachably journaled below the base plate on opposite sides of the vertical plane; a connecting rod assembly pivotally interconnecting the pair of auxiliary crankshafts with the main power crankshaft; a piston assembly in each of the cylinders operatively connected with the associated auxiliary crankshaft and including a piston having a head, a wrist-pin and a connecting rod connecting the wrist-pin of each piston with the associated auxiliary crankshaft; a fuel induction assembly for admitting a combustible fuel mixture into the cylinders between the opposed heads of the pistons in a controlled sequence correlated to the receding movement of the pistons in the cylinders in a fuel intake stroke; means for igniting the fuel mixture compressed between the juxtaposed heads of the pistons; means for exhausting from the cylinders the products of combustion of the fuel mixture in correlation to the movement of the pistons in an exhaust stroke; and means including an oil pan enclosing the auxiliary crankshafts.

  11. Parasitic load control system for exhaust temperature control

    DOEpatents

    Strauser, Aaron D.; Coleman, Gerald N.; Coldren, Dana R.

    2009-04-28

    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.

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

    DOEpatents

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

    2014-05-13

    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.

  13. Diesel emission reduction using internal exhaust gas recirculation

    SciTech Connect

    He, Xin; Durrett, Russell P.

    2012-01-24

    A method for controlling combustion in a direct-injection diesel engine includes monitoring a crankshaft rotational position of a cylinder of the engine, monitoring an engine load, determining an intake stroke within the cylinder based upon the crankshaft rotational position, and when the engine load is less than a threshold engine load, opening an exhaust valve for the cylinder during a portion of the intake stroke.

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

    DOEpatents

    McMillian, Michael H.

    1992-01-01

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

  15. Fundamental studies of spray combustion

    SciTech Connect

    Li, S.C.; Libby, P.A.; Williams, F.A.

    1997-12-31

    Our research on spray combustion involves both experiment and theory and addresses the characteristics of individual droplets and of sprays in a variety of flows: laminar and turbulent, opposed and impinging. Currently our focus concerns water and fuel sprays in two stage laminar flames, i.e., flames arising, for example from a stream of fuel and oxidizer flowing opposite to an air stream carrying a water spray. Our interest in these flames is motivated by the goals of reducing pollutant emissions and extending the range of stable spray combustion. There remains considerable research to be carried out in order to achieve these goals. Thus far our research on the characteristics of sprays in turbulent flows has been limited to nonreacting jets impinging on a plate but this work will be extended to opposed flows with and without a flame. In the following we discuss details of these studies and our plans for future work.

  16. The toxicity of diesel exhaust: implications for primary care.

    PubMed

    Krivoshto, Irina N; Richards, John R; Albertson, Timothy E; Derlet, Robert W

    2008-01-01

    Diesel fuel and the products of its combustion represent one of the toxins most commonly encountered by people living in both urban and rural areas of the world. As nations become more heavily populated, there will be increasing reliance on diesel fuel to power mass transportation and commercial vehicles, as well as heavy machinery involved in construction, farming, and mining. The majority of patients who present to urban primary care clinics and emergency departments will have had significant chronic exposure to diesel exhaust because most use and/or live near busy streets and highways. Furthermore, those who operate or work or live near diesel-powered machinery will have even more toxic exposure. Primary care physicians should be aware of the acute and chronic deleterious clinical effects of diesel exhaust. In this article we review the toxicity and myriad health problems associated with diesel exhaust.

  17. Biofuels combustion.

    PubMed

    Westbrook, Charles K

    2013-01-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  18. Bubble Combustion

    NASA Technical Reports Server (NTRS)

    Corrigan, Jackie

    2004-01-01

    A method of energy production that is capable of low pollutant emissions is fundamental to one of the four pillars of NASA s Aeronautics Blueprint: Revolutionary Vehicles. Bubble combustion, a new engine technology currently being developed at Glenn Research Center promises to provide low emissions combustion in support of NASA s vision under the Emissions Element because it generates power, while minimizing the production of carbon dioxide (CO2) and nitrous oxides (NOx), both known to be Greenhouse gases. and allows the use of alternative fuels such as corn oil, low-grade fuels, and even used motor oil. Bubble combustion is analogous to the inverse of spray combustion: the difference between bubble and spray combustion is that spray combustion is spraying a liquid in to a gas to form droplets, whereas bubble combustion involves injecting a gas into a liquid to form gaseous bubbles. In bubble combustion, the process for the ignition of the bubbles takes place on a time scale of less than a nanosecond and begins with acoustic waves perturbing each bubble. This perturbation causes the local pressure to drop below the vapor pressure of the liquid thus producing cavitation in which the bubble diameter grows, and upon reversal of the oscillating pressure field, the bubble then collapses rapidly with the aid of the high surface tension forces acting on the wall of the bubble. The rapid and violent collapse causes the temperatures inside the bubbles to soar as a result of adiabatic heating. As the temperatures rise, the gaseous contents of the bubble ignite with the bubble itself serving as its own combustion chamber. After ignition, this is the time in the bubble s life cycle where power is generated, and CO2, and NOx among other species, are produced. However, the pollutants CO2 and NOx are absorbed into the surrounding liquid. The importance of bubble combustion is that it generates power using a simple and compact device. We conducted a parametric study using CAVCHEM

  19. Biofuels combustion*

    DOE PAGES

    Westbrook, Charles K.

    2013-01-04

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acidsmore » and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.« less

  20. Biofuels combustion*

    SciTech Connect

    Westbrook, Charles K.

    2013-01-04

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.

  1. Biofuels Combustion

    NASA Astrophysics Data System (ADS)

    Westbrook, Charles K.

    2013-04-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  2. Stream Processors

    NASA Astrophysics Data System (ADS)

    Erez, Mattan; Dally, William J.

    Stream processors, like other multi core architectures partition their functional units and storage into multiple processing elements. In contrast to typical architectures, which contain symmetric general-purpose cores and a cache hierarchy, stream processors have a significantly leaner design. Stream processors are specifically designed for the stream execution model, in which applications have large amounts of explicit parallel computation, structured and predictable control, and memory accesses that can be performed at a coarse granularity. Applications in the streaming model are expressed in a gather-compute-scatter form, yielding programs with explicit control over transferring data to and from on-chip memory. Relying on these characteristics, which are common to many media processing and scientific computing applications, stream architectures redefine the boundary between software and hardware responsibilities with software bearing much of the complexity required to manage concurrency, locality, and latency tolerance. Thus, stream processors have minimal control consisting of fetching medium- and coarse-grained instructions and executing them directly on the many ALUs. Moreover, the on-chip storage hierarchy of stream processors is under explicit software control, as is all communication, eliminating the need for complex reactive hardware mechanisms.

  3. 500 CFM portable exhauster temperature and humidity analysis

    SciTech Connect

    BIELICKI, B.E.

    1999-05-20

    500 cfm portable exhausters will be utilized on single shell tanks involved in saltwell pumping. This will be done, in part, to remove flammable gases from the tank vapor space. The exhaust filter train, fan, stack, and associated instrumentation and equipment are mounted on a portable skid. The design analysis and basis for the skid system design are documented in reference 1. A pumped drainage collection system is being added to the existing portable exhausters. Additional equipment and instrumentation are also being added to the exhausters, including a vacuum pump cabinet and a generic effluent monitoring system (GEMS). The GEMS will provide sampling and monitoring capabilities. The purpose of this analysis is three fold. First, to determine the maximum saltwell tank vapor space temperature. Second, to determine an allowable exhauster inlet air temperature increase to ensure the humidity is less than 70%. Third, to assess potential adverse temperature effects to the continuous air monitor (CAM) sample head. The results of this analysis will be used to ensure that air stream temperatures in the portable exhausters are increased sufficiently to prevent condensation from forming on either the pre or HEPA filters without adversely effecting the CAM.

  4. IODIDE AEROSOL SORBENTS FOR MERCURY CAPTURE IN COMBUSTION EXHAUSTS

    EPA Science Inventory

    Several sorbent processes are being studied for their feasibility for mercury capture. Mercury is different from the other heavy metals as it is not as chemically reactive (due to a filled outer electronic shell), thus making it difficult for sorbents to chemically trap it (a). ...

  5. THRSTER: A THRee-STream Ejector Ramjet Analysis and Design Tool

    NASA Technical Reports Server (NTRS)

    Chue, R. S.; Sabean, J.; Tyll, J.; Bakos, R. J.

    2000-01-01

    An engineering tool for analyzing ejectors in rocket based combined cycle (RBCC) engines has been developed. A key technology for multi-cycle RBCC propulsion systems is the ejector which functions as the compression stage of the ejector ramjet cycle. The THRee STream Ejector Ramjet analysis tool was developed to analyze the complex aerothermodynamic and combustion processes that occur in this device. The formulated model consists of three quasi-one-dimensional streams, one each for the ejector primary flow, the secondary flow, and the mixed region. The model space marches through the mixer, combustor, and nozzle to evaluate the solution along the engine. In its present form, the model is intended for an analysis mode in which the diffusion rates of the primary and secondary into the mixed stream are stipulated. The model offers the ability to analyze the highly two-dimensional ejector flowfield while still benefits from the simplicity and speed of an engineering tool. To validate the developed code, wall static pressure measurements from the Penn-State and NASA-ART RBCC experiments were used to compare with the results generated by the code. The calculated solutions were generally found to have satisfactory agreement with the pressure measurements along the engines, although further modeling effort may be required when a strong shock train is formed at the rocket exhaust. The range of parameters in which the code would generate valid results are presented and discussed.

  6. THRSTER: A Three-Stream Ejector Ramjet Analysis and Design Tool

    NASA Technical Reports Server (NTRS)

    Chue, R. S.; Sabean, J.; Tyll, J.; Bakos, R. J.; Komar, D. R. (Technical Monitor)

    2000-01-01

    An engineering tool for analyzing ejectors in rocket based combined cycle (RBCC) engines has been developed. A key technology for multi-cycle RBCC propulsion systems is the ejector which functions as the compression stage of the ejector ramjet cycle. The THRee STream Ejector Ramjet analysis tool was developed to analyze the complex aerothermodynamic and combustion processes that occur in this device. The formulated model consists of three quasi-one-dimensional streams, one each for the ejector primary flow, the secondary flow, and the mixed region. The model space marches through the mixer, combustor, and nozzle to evaluate the solution along the engine. In its present form, the model is intended for an analysis mode in which the diffusion rates of the primary and secondary into the mixed stream are stipulated. The model offers the ability to analyze the highly two-dimensional ejector flowfield while still benefits from the simplicity and speed of an engineering tool. To validate the developed code, wall static pressure measurements from the Penn-State and NASA-ART RBCC experiments were used to compare with the results generated by the code. The calculated solutions were generally found to have satisfactory agreement with the pressure measurements along the engines, although further modeling effort may be required when a strong shock train is formed at the rocket exhaust. The range of parameters in which the code would generate valid results are presented and discussed.

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

    SciTech Connect

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

    1991-01-01

    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.

  8. Turbulent combustion

    SciTech Connect

    Talbot, L.; Cheng, R.K.

    1993-12-01

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  9. Emissions, combustion dynamics, and control of a multiple swirl combustor

    NASA Astrophysics Data System (ADS)

    Li, Guoqiang

    To achieve single digit NOx emission from gas turbine combustors and prevent the combustion dynamics encountered in Lean Premixed Combustion, it is essential to understand the correlations among emission characteristics, combustion dynamics, and dynamics and characteristics of swirling flow field. The focus of this dissertation is to investigate the emission characteristics and combustion dynamics of multiple swirl dump combustors either in premixing or non-premixed combustion (e.g. Lean Direct Injection), and correlate these combustion characteristics (emissions, combustion instability and lean flammability) to the fluids dynamics (flow structures and its evolution). This study covers measurement of velocity flow field, temperature field, and combustion under effects of various parameters, including inlet flow Reynolds number, inlet air temperature, swirl configurations, downstream exhaust nozzle contraction ratios, length of mixing tube. These parameters are tested in both liquid and gaseous fuel combustions. Knowledge obtained through this comprehensive study is applied to passive and active controls for improving gas turbine combustion performance in the aid of novel sensor and actuator technologies. Emissions and combustion characteristics are shown closely related to the shape and size of central recirculation zone (CRZ), the mean and turbulence velocity and strain rate, and dynamics of large vortical structures. The passive controls, mostly geometry factors, affect the combustion characteristics and emissions through their influences on flow fields, and consequently temperature and radical fields. Air assist, which is used to adjust the momentum of fuel spray, is effective in reducing NOx and depress combustion oscillation without hurting LBO. Fuel distribution/split is also one important factor for achieving low NOx emission and control of combustion dynamics. The dynamics of combustion, including flame oscillations close to LBO and acoustic combustion

  10. OPTIONS FOR ABATING GREENHOUSE GASES FROM EXHAUST STREAMS.

    SciTech Connect

    FTHENAKIS,V.

    2001-12-01

    This report examines different alternatives for replacing, treating, and recycling greenhouse gases. It is concluded that treatment (abatement) is the only viable short-term option. Three options for abatement that were tested for use in semiconductor facilities are reviewed, and their performance and costs compared. This study shows that effective abatement options are available to the photovoltaic (PV) industry, at reasonable cost.

  11. Method and apparatus for producing thermal vapor stream

    DOEpatents

    Cradeur, Robert R.; Sperry, John S.; Krajicek, Richard W.

    1979-01-01

    Method and apparatus for producing a thermal vapor stream for injecting into a subterranean formation for the recovery of liquefiable minerals therefrom, including a pressure vessel containing a high pressure combustion chamber for producing a heating gas for introduction into a heating gas injector. The heating gas injector is partly immersed in a steam generating section of the pressure vessel such that the heating gas is passed through the steam generating section to produce steam and combustion products which are directed between the pressure vessel and the combustion chamber for simultaneously cooling of the combustion chamber by further heating of the steam and combustion gases.

  12. Gas stream cleanup

    SciTech Connect

    Bossart, S.J.; Cicero, D.C.; Zeh, C.M.; Bedick, R.C.

    1990-08-01

    This report describes the current status and recent accomplishments of gas stream cleanup (GSCU) projects sponsored by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The primary goal of the Gas Stream Cleanup Program is to develop contaminant control strategies that meet environmental regulations and protect equipment in advanced coal conversion systems. Contaminant control systems are being developed for integration into seven advanced coal conversion processes: Pressurized fludized-bed combustion (PFBC), Direct coal-fueled turbine (DCFT), Intergrated gasification combined-cycle (IGCC), Gasification/molten carbonate fuel cell (MCFC), Gasification/solid oxide fuel cell (SOFC), Coal-fueled diesel (CFD), and Mild gasification (MG). These advanced coal conversion systems present a significant challenge for development of contaminant control systems because they generate multi-contaminant gas streams at high-pressures and high temperatures. Each of the seven advanced coal conversion systems incorporates distinct contaminant control strategies because each has different contaminant tolerance limits and operating conditions. 59 refs., 17 figs., 5 tabs.

  13. Non-exhaust PM emissions from electric vehicles

    NASA Astrophysics Data System (ADS)

    Timmers, Victor R. J. H.; Achten, Peter A. J.

    2016-06-01

    Particulate matter (PM) exposure has been linked to adverse health effects by numerous studies. Therefore, governments have been heavily incentivising the market to switch to electric passenger cars in order to reduce air pollution. However, this literature review suggests that electric vehicles may not reduce levels of PM as much as expected, because of their relatively high weight. By analysing the existing literature on non-exhaust emissions of different vehicle categories, this review found that there is a positive relationship between weight and non-exhaust PM emission factors. In addition, electric vehicles (EVs) were found to be 24% heavier than equivalent internal combustion engine vehicles (ICEVs). As a result, total PM10 emissions from EVs were found to be equal to those of modern ICEVs. PM2.5 emissions were only 1-3% lower for EVs compared to modern ICEVs. Therefore, it could be concluded that the increased popularity of electric vehicles will likely not have a great effect on PM levels. Non-exhaust emissions already account for over 90% of PM10 and 85% of PM2.5 emissions from traffic. These proportions will continue to increase as exhaust standards improve and average vehicle weight increases. Future policy should consequently focus on setting standards for non-exhaust emissions and encouraging weight reduction of all vehicles to significantly reduce PM emissions from traffic.

  14. A laboratory scale supersonic combustive flow system

    SciTech Connect

    Sams, E.C.; Zerkle, D.K.; Fry, H.A.; Wantuck, P.J.

    1995-02-01

    A laboratory scale supersonic flow system [Combustive Flow System (CFS)] which utilizes the gaseous products of methane-air and/or liquid fuel-air combustion has been assembled to provide a propulsion type exhaust flow field for various applications. Such applications include providing a testbed for the study of planar two-dimensional nozzle flow fields with chemistry, three-dimensional flow field mixing near the exit of rectangular nozzles, benchmarking the predictive capability of various computational fluid dynamic codes, and the development and testing of advanced diagnostic techniques. This paper will provide a detailed description of the flow system and data related to its operation.

  15. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 19 equivalent rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  16. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 10 rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  17. Free-radicals aided combustion with scramjet applications

    NASA Technical Reports Server (NTRS)

    Yang, Yongsheng; Kumar, Ramohalli

    1992-01-01

    Theoretical and experimental investigations aimed at altering 'nature-prescribed' combustion rates in hydrogen/hydrocarbon reactions with (enriched) air are presented. The intent is to anchor flame zones in supersonic streams, and to ensure proper and controllable complete combustion in scramjets. The diagnostics are nonintrusive through IR thermograms and acoustic emissions in the control and free-radicals altered flame zones.

  18. DEMONSTRATION BULLETIN: THE PYRETRON OXYGEN BURNER, AMERICAN COMBUSTION TECHNOLOGIES, INC.

    EPA Science Inventory

    The Pyretron is a burner which is designed to allow for the injection of oxygen into the combustion air stream for the purpose of increasing the efficiency of a hazardous waste incinerator. The SITE demonstration of the Pyretron took place at the U.S. EPA's Combustion Re...

  19. Total diesel exhaust particulate length measurements using a modified household smoke alarm ionization chamber.

    PubMed

    Vojtisek-Lom, Michal

    2011-02-01

    To evaluate the effectiveness of various means to combat the negative health effects of ultrafine particles emitted by internal combustion engines, a reliable, low-cost instrument for dynamic measurements of the exhaust emissions of ultrafine particulate matter (PM) is needed. In this study, an ordinary ionization-type building smoke detector was modified to serve as a measuring ionization chamber and utilized for dynamic measurements of PM emissions from diesel engines. When used with diluted exhaust, the readings show an excellent correlation with total particulate length. The instrument worked well with raw and diluted exhaust and with varying emission levels and is well suitable for on-board use.

  20. Total diesel exhaust particulate length measurements using a modified household smoke alarm ionization chamber.

    PubMed

    Vojtisek-Lom, Michal

    2011-02-01

    To evaluate the effectiveness of various means to combat the negative health effects of ultrafine particles emitted by internal combustion engines, a reliable, low-cost instrument for dynamic measurements of the exhaust emissions of ultrafine particulate matter (PM) is needed. In this study, an ordinary ionization-type building smoke detector was modified to serve as a measuring ionization chamber and utilized for dynamic measurements of PM emissions from diesel engines. When used with diluted exhaust, the readings show an excellent correlation with total particulate length. The instrument worked well with raw and diluted exhaust and with varying emission levels and is well suitable for on-board use. PMID:21387930

  1. Regenerative combustion device

    DOEpatents

    West, Phillip B.

    2004-03-16

    A regenerative combustion device having a combustion zone, and chemicals contained within the combustion zone, such as water, having a first equilibrium state, and a second combustible state. Means for transforming the chemicals from the first equilibrium state to the second combustible state, such as electrodes, are disposed within the chemicals. An igniter, such as a spark plug or similar device, is disposed within the combustion zone for igniting combustion of the chemicals in the second combustible state. The combustion products are contained within the combustion zone, and the chemicals are selected such that the combustion products naturally chemically revert into the chemicals in the first equilibrium state following combustion. The combustion device may thus be repeatedly reused, requiring only a brief wait after each ignition to allow the regeneration of combustible gasses within the head space.

  2. Variable area exhaust nozzle

    NASA Technical Reports Server (NTRS)

    Johnston, E. A. (Inventor)

    1979-01-01

    An exhaust nozzle for a gas turbine engine comprises a number of arcuate flaps pivotally connected to the trailing edge of a cylindrical casing which houses the engine. Seals disposed within the flaps are spring biased and extensible beyond the side edges of the flaps. The seals of adjacent flaps are maintained in sealing engagement with each other when the flaps are adjusted between positions defining minimum nozzle flow area and the cruise position. Extensible, spring biased seals are also disposed within the flaps adjacent to a supporting pylon to thereby engage the pylon in a sealing arrangement. The flaps are hinged to the casing at the central portion of the flaps' leading edges and are connected to actuators at opposed outer portions of the leading edges to thereby maximize the mechanical advantage in the actuation of the flaps.

  3. Advanced Combustion

    SciTech Connect

    Holcomb, Gordon R.

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  4. Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

    DOEpatents

    Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

    2008-11-25

    A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

  5. Automotive Fuel and Exhaust Systems.

    ERIC Educational Resources Information Center

    Irby, James F.; And Others

    Materials are provided for a 14-hour course designed to introduce the automotive mechanic to the basic operations of automotive fuel and exhaust systems incorporated on military vehicles. The four study units cover characteristics of fuels, gasoline fuel system, diesel fuel systems, and exhaust system. Each study unit begins with a general…

  6. Internal combustion engine

    SciTech Connect

    Evans, H.G.; Speer, S.

    1991-12-31

    This patent describes improvement in a 2-cycle, diesel cycle internal combustion engine comprising a single in-line engine block, internal wall surfaces defining at least one cylinder within the engine block, the central longitudinal axis of each cylinder being within a common plane extending longitudinally of the engine block, the axially extending internal wall surface of each cylinder being closed at one end and having at least one air intake port therethrough, a piston axially and reciprocally movable within each cylinder over a permitted stroke distance, so as to alternately cover and expose each air intake port for a finite time period; an exhaust port at the closed end of the cylinder above the piston, and a mechanically operated valve for opening and closing such exhaust port located immediately adjacent such port, a substantially rigid connecting rod pivotably connected at one end of each piston, and a crankshaft, rotatably connected to the second end of each connecting rod, such that the crankshaft is caused to rotate connecting means between the piston and the connecting rod. The improvement comprises the diameter of the cylinder is greater than the permitted stroke distance of the piston within the cylinder, and the axis of the crankshaft is parallel to and laterally offset from the common plane by a distance sufficient to form an angle alpha between the connecting rod and the axis of the cylinder, when the piston is at top-dead center, of at least about 12 degrees, such that the time during which each air intake port is exposed is increased when the direction of crankshaft rotation is opposite to the direction of the crankshaft offset from the common plane.

  7. Variable stream control engine concept for advanced supersonic aircraft: Features and benefits

    NASA Technical Reports Server (NTRS)

    Howlett, R. A.

    1976-01-01

    The Variable Stream Control Engine is studied for advanced supersonic cruise aircraft. Significant environmental and performance improvements relative to first generation supersonic turbojet engines are cited. Two separate flow streams, each with independent burner and nozzle systems are incorporated within the engine. By unique control of the exhaust temperatures and velocities in two coannular streams, significant reduction in jet noise is obtained.

  8. Selected results from combustion research at the Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Jones, R. E.

    1981-01-01

    Combustion research at Lewis is organized to provide a balanced program responsive to national needs and the gas turbine industry. The results of this research is a technology base that assists the gas turbine engine manufacturers in developing new and improved combustion systems for advanced civil and military engines with significant improvements in performance, durability, fuel flexibility and control of exhaust emissions. Research efforts consist of fundamentals and modeling, and applied component and combustor research.

  9. Elimination of abnormal combustion in a hydrogen-fueled engine

    SciTech Connect

    Swain, M.R.; Swain, M.N.

    1995-11-01

    This report covers the design, construction, and testing of a dedicated hydrogen-fueled engine. Both part-load and full-load data were taken under laboratory conditions. The engine design included a billet aluminum single combustion chamber cylinder-head with one intake valve, two sodium coiled exhaust valves, and two spark plugs. The cylinder-head design also included drilled cooling passages. The fuel-delivery system employed two modified Siemens electrically actuated fuel injectors, The exhaust system included two separate headers, one for each exhaust port. The piston/ring combination was designed specifically for hydrogen operation.

  10. Combustion powered thermophotovoltaic emitter system

    SciTech Connect

    McHenry, R.S.

    1995-07-01

    The US Naval Academy (USNA) has recently completed an engineering design project for a high temperature thermophotovoltaic (TPV) photon emitter. The final apparatus was to be portable, completely self contained, and was to incorporate cycle efficiency optimization such as exhaust stream recuperation. Through computer modeling and prototype experimentation, a methane fueled emitter system was designed from structural ceramic materials to fulfill the high temperature requirements necessary for high system efficiency. This paper outlines the engineering design process, discusses obstacles and solutions encountered, and presents the final design.

  11. Swirling base injection for supersonic combustion ramjets.

    NASA Technical Reports Server (NTRS)

    Povinelli, L. A.; Ehlers, R. C.

    1972-01-01

    Experimental evaluation of the swirling base injection proposed by Swithenbank and Chigier (1969) for application in supersonic combustion ramjets or scramjets. This concept of accelerated mixing in supersonic streams through swirl was tested, but the results indicate that swirl does not produce any enhancement of mixing.

  12. Controlling exhaust gas recirculation

    DOEpatents

    Zurlo, James Richard; Konkle, Kevin Paul; May, Andrew

    2012-01-31

    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.

  13. Biodiesel exhaust-induced cytotoxicity and proinflammatory mediator production in human airway epithelial cells.

    PubMed

    Mullins, Benjamin J; Kicic, Anthony; Ling, Kak-Ming; Mead-Hunter, Ryan; Larcombe, Alexander N

    2016-01-01

    Increasing use of biodiesel has prompted research into the potential health effects of biodiesel exhaust exposure. Few studies directly compare the health consequences of mineral diesel, biodiesel, or blend exhaust exposures. Here, we exposed human epithelial cell cultures to diluted exhaust generated by the combustion of Australian ultralow-sulfur-diesel (ULSD), unprocessed canola oil, 100% canola biodiesel (B100), and a blend of 20% canola biodiesel mixed with 80% ULSD. The physicochemical characteristics of the exhaust were assessed and we compared cellular viability, apoptosis, and levels of interleukin (IL)-6, IL-8, and Regulated on Activation, Normal T cell Expressed and Secreted (RANTES) in exposed cultured cells. Different fuel types produced significantly different amounts of exhaust gases and different particle characteristics. All exposures resulted in significant apoptosis and loss of viability when compared with control, with an increasing proportion of biodiesel being correlated with a decrease in viability. In most cases, exposure to exhaust resulted in an increase in mediator production, with the greatest increases most often in response to B100. Exposure to pure canola oil (PCO) exhaust did not increase mediator production, but resulted in a significant decrease in IL-8 and RANTES in some cases. Our results show that canola biodiesel exhaust exposure elicits inflammation and reduces viability of human epithelial cell cultures in vitro when compared with ULSD exhaust exposure. This may be related to an increase in particle surface area and number in B100 exhaust when compared with ULSD exhaust. Exposure to PCO exhaust elicited the greatest loss of cellular viability, but virtually no inflammatory response, likely due to an overall increase in average particle size.

  14. Holey graphene frameworks for highly selective post-combustion carbon capture

    NASA Astrophysics Data System (ADS)

    Chowdhury, Shamik; Balasubramanian, Rajasekhar

    2016-02-01

    Atmospheric CO2 concentrations continue to rise rapidly in response to increased combustion of fossil fuels, contributing to global climate change. In order to mitigate the effects of global warming, development of new materials for cost-effective and energy-efficient CO2 capture is critically important. Graphene-based porous materials are an emerging class of solid adsorbents for selectively removing CO2 from flue gases. Herein, we report a simple and scalable approach to produce three-dimensional holey graphene frameworks with tunable porosity and pore geometry, and demonstrate their application as high-performance CO2 adsorbents. These holey graphene macrostructures exhibit a significantly improved specific surface area and pore volume compared to their pristine counterparts, and can be effectively used in post-combustion CO2 adsorption systems because of their intrinsic hydrophobicity together with good gravimetric storage capacities, rapid removal capabilities, superior cycling stabilities, and moderate initial isosteric heats. In addition, an exceptionally high CO2 over N2 selectivity can be achieved under conditions relevant to capture from the dry exhaust gas stream of a coal burning power plant, suggesting the possibility of recovering highly pure CO2 for long-term sequestration and/or utilization for downstream applications.

  15. Multifunctional (NOx/CO/O2) Solid-State Sensors For Coal Combustion Control

    SciTech Connect

    Eric D. Wachsman

    2006-12-31

    Solid-state sensors were developed for coal combustion control and the understanding of sensing mechanisms was advanced. Several semiconducting metal oxides (p-type and n-type) were used to fabricate sensor electrodes. The adsorption/desorption characteristics and catalytic activities of these materials were measured with Temperature Programmed Desorption (TPD) and Temperature Programmed Reaction (TPR) experiments. The sensitivity, selectivity, and response time of these sensors were measured for steps of NO, NO{sub 2}, CO, CO{sub 2}, O{sub 2}, and H{sub 2}O vapor in simple N{sub 2}-balanced and multi-component, simulated combustion-exhaust streams. The role of electrode microstructure and fabrication parameters on sensing performance was investigated. Proof for the proposed sensing mechanism, Differential Electrode Equilibria, was demonstrated by relating the sensing behavior (sensitivities and cross-sensitivities) of the various electrode materials to their gas adsorption/desorption behaviors and catalytic activities. A multifunctional sensor array consisting of three sensing electrodes and an integrated heater and temperature sensors was fabricated with tape-casting and screen-printing and its NO{sub x} sensing performance was measured. The multifunctional sensor demonstrated it was possible to measure NO{sub 2} independent of NO by locally heating one of the sensing electrodes. The sensor technology was licensed to Fuel FX International, Inc. Fuel FX has obtained investor funding and is developing prototype sensors as a first step in their commercialization strategy for this technology.

  16. Holey graphene frameworks for highly selective post-combustion carbon capture

    PubMed Central

    Chowdhury, Shamik; Balasubramanian, Rajasekhar

    2016-01-01

    Atmospheric CO2 concentrations continue to rise rapidly in response to increased combustion of fossil fuels, contributing to global climate change. In order to mitigate the effects of global warming, development of new materials for cost-effective and energy-efficient CO2 capture is critically important. Graphene-based porous materials are an emerging class of solid adsorbents for selectively removing CO2 from flue gases. Herein, we report a simple and scalable approach to produce three-dimensional holey graphene frameworks with tunable porosity and pore geometry, and demonstrate their application as high-performance CO2 adsorbents. These holey graphene macrostructures exhibit a significantly improved specific surface area and pore volume compared to their pristine counterparts, and can be effectively used in post-combustion CO2 adsorption systems because of their intrinsic hydrophobicity together with good gravimetric storage capacities, rapid removal capabilities, superior cycling stabilities, and moderate initial isosteric heats. In addition, an exceptionally high CO2 over N2 selectivity can be achieved under conditions relevant to capture from the dry exhaust gas stream of a coal burning power plant, suggesting the possibility of recovering highly pure CO2 for long-term sequestration and/or utilization for downstream applications. PMID:26879393

  17. Holey graphene frameworks for highly selective post-combustion carbon capture.

    PubMed

    Chowdhury, Shamik; Balasubramanian, Rajasekhar

    2016-02-16

    Atmospheric CO2 concentrations continue to rise rapidly in response to increased combustion of fossil fuels, contributing to global climate change. In order to mitigate the effects of global warming, development of new materials for cost-effective and energy-efficient CO2 capture is critically important. Graphene-based porous materials are an emerging class of solid adsorbents for selectively removing CO2 from flue gases. Herein, we report a simple and scalable approach to produce three-dimensional holey graphene frameworks with tunable porosity and pore geometry, and demonstrate their application as high-performance CO2 adsorbents. These holey graphene macrostructures exhibit a significantly improved specific surface area and pore volume compared to their pristine counterparts, and can be effectively used in post-combustion CO2 adsorption systems because of their intrinsic hydrophobicity together with good gravimetric storage capacities, rapid removal capabilities, superior cycling stabilities, and moderate initial isosteric heats. In addition, an exceptionally high CO2 over N2 selectivity can be achieved under conditions relevant to capture from the dry exhaust gas stream of a coal burning power plant, suggesting the possibility of recovering highly pure CO2 for long-term sequestration and/or utilization for downstream applications.

  18. Holey graphene frameworks for highly selective post-combustion carbon capture.

    PubMed

    Chowdhury, Shamik; Balasubramanian, Rajasekhar

    2016-01-01

    Atmospheric CO2 concentrations continue to rise rapidly in response to increased combustion of fossil fuels, contributing to global climate change. In order to mitigate the effects of global warming, development of new materials for cost-effective and energy-efficient CO2 capture is critically important. Graphene-based porous materials are an emerging class of solid adsorbents for selectively removing CO2 from flue gases. Herein, we report a simple and scalable approach to produce three-dimensional holey graphene frameworks with tunable porosity and pore geometry, and demonstrate their application as high-performance CO2 adsorbents. These holey graphene macrostructures exhibit a significantly improved specific surface area and pore volume compared to their pristine counterparts, and can be effectively used in post-combustion CO2 adsorption systems because of their intrinsic hydrophobicity together with good gravimetric storage capacities, rapid removal capabilities, superior cycling stabilities, and moderate initial isosteric heats. In addition, an exceptionally high CO2 over N2 selectivity can be achieved under conditions relevant to capture from the dry exhaust gas stream of a coal burning power plant, suggesting the possibility of recovering highly pure CO2 for long-term sequestration and/or utilization for downstream applications. PMID:26879393

  19. EXHAUST MAIN PERSONNEL EXPOSURE CALCULATION

    SciTech Connect

    S. Su

    1999-09-29

    The purpose of this activity is to identify and determine potential radiation hazards in the service exhaust main due to a waste package leakage from an emplacement drift. This work supports the subsurface ventilation system design for the EDA II, which consists of an accessible service exhaust main for personnel, and an exhaust main for hot air flow. The objective is to provide the necessary radiation exposure calculations to determine if the service exhaust main is accessible following a waste package leak. This work includes the following items responsive to the stated purpose and objective: Calculate the limiting transient radiation exposure of personnel in the service exhaust main due to the passage of airborne radioactive material through the ventilation raise and connecting horizontal raise to the exhaust main in the event of a leaking waste package Calculate the potential exposures to maintenance workers in the service exhaust main from residual radioactive material deposited inside of the ventilation raise and connecting horizontal raise This calculation is limited to external radiation only, since the airborne and contamination sources will be contained in the ventilation raise and connecting horizontal raise.

  20. Integrated self-cleaning window assembly for optical transmission in combustion environments

    DOEpatents

    Kass, Michael D [Oak Ridge, TN

    2007-07-24

    An integrated window design for optical transmission in combustion environments is described. The invention consists of an integrated optical window design that prevents and removes the accumulation of carbon-based particulate matter and gaseous hydrocarbons through a combination of heat and catalysis. These windows will enable established optical technologies to be applied to combustion environments and their exhaust systems.

  1. Stream Studies.

    ERIC Educational Resources Information Center

    Hamilton City Board of Education (Ontario).

    This manual provides teachers with some knowledge of ecological study methods and techniques used in collecting data when plants and animals are studied in the field. Most activities deal with the interrelatedness of plant and animal life to the structure and characteristics of a stream and pond. Also included in this unit plan designed for the…

  2. Stream Studies.

    ERIC Educational Resources Information Center

    Stein, Scott

    1997-01-01

    Outlines a science curriculum reform effort aimed at enabling students to collect original data concerning an environmental parameter such as water quality on a yearly basis. Students track the overall health of the stream by analyzing both biotic and abiotic factors. (DDR)

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

    DOEpatents

    Dutart, Charles H.; Choi, Cathy Y.

    2003-01-01

    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.

  4. DNA adducts induced by in vitro activation of diesel and biodiesel exhaust extracts

    EPA Science Inventory

    The abstract reports the results of studies assessing the relative DNA damage potential of extracts of exhaust particles resulting from the combustion of petroleum diesel, biodiesel, and petroleum diesel-biodiesel blends. Results indicate that the commercially available B20 petr...

  5. 40 CFR 1045.245 - How do I determine deterioration factors from exhaust durability testing?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the engine only in the laboratory. (3) In the case of dual-fuel or flexible-fuel engines, you may accumulate service hours on a single emission-data engine using the type or mixture of fuel expected to have the highest combustion and exhaust temperatures. For dual-fuel engines, you must measure emissions...

  6. A time-resolved measurement technique for particulate number density in diesel exhaust using a fast-response flame ionization detector

    NASA Astrophysics Data System (ADS)

    Sun, J. H.; Chan, S. H.

    1997-03-01

    The fast-response flame ionization detector (FRFID) has been used widely to measure, in real time, the concentration of unburnt hydrocarbons in internal combustion engines. In this study, a FRFID is modified to measure, simultaneously, the concentration of the gaseous hydrocarbons and the number density of soot particulates present in the exhaust of a turbocharged Dl diesel engine. The system is also capable of differentiating the hydrocarbon fraction of the particulates from that of gaseous hydrocarbons, hence providing information for deducing the amount of gaseous hydrocarbon that is adsorbed by or condensed onto the surface of the particulates. Another unmodified FRFID, with a particulate collector placed immediately upstream of it, is used to determine the total particulate matter in terms of mass concentration. Experimental results show that the particulate number density measured by the modified FRFID is correlated well with the mass concentration determined by the filtration method under various engine operating conditions. The hydrocarbon fraction of the particulates shows a similar trend to the gaseous hydrocarbon present in the raw exhaust gas stream under various steady-speed engine test runs. A transient engine load acceptance test concludes the usability of this modified FRFID to measure, on a time-resolved basis, the particulate number densities with trends similar to those of generally known smoke opacities.

  7. Modeling the internal combustion engine

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.; Mcbride, B. J.

    1985-01-01

    A flexible and computationally economical model of the internal combustion engine was developed for use on large digital computer systems. It is based on a system of ordinary differential equations for cylinder-averaged properties. The computer program is capable of multicycle calculations, with some parameters varying from cycle to cycle, and has restart capabilities. It can accommodate a broad spectrum of reactants, permits changes in physical properties, and offers a wide selection of alternative modeling functions without any reprogramming. It readily adapts to the amount of information available in a particular case because the model is in fact a hierarchy of five models. The models range from a simple model requiring only thermodynamic properties to a complex model demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. Among its many features the model includes heat transfer, valve timing, supercharging, motoring, finite burning rates, cycle-to-cycle variations in air-fuel ratio, humid air, residual and recirculated exhaust gas, and full combustion kinetics.

  8. Westinghouse introduces 401 combustion turbine

    SciTech Connect

    McNeely, M.

    1996-12-01

    With the introduction of its new 401 combustion turbine, Westinghouse has developed a mid-sized engine nominally rated at 80 MW that fulfills a power category between its 251B12 at 49 MW and the 501D5 at 107 MW. The new 401 is scheduled to ship in mid-1998, with commercial operation slated for late-1998. The origin of the 401 engine is a scaled down version of the 501G, itself a very high efficiency combustion turbine. Designed for reliability and ease of maintenance, the 401 shares the same features that have been well-proven though experience in other Westinghouse combustion turbine models, including a two-bearing rotor; horizontally split casings; cold-end generator drive; axial exhaust; access to critical hot parts without cover lift; and all flow path components removable without rotor lift. Capable of operation in both simple and combined cycle, the 401 can operate on conventional fuels, as well as on coal-derived low heat value gas produced in an integrated gasification combined cycle power plant. 3 figs., 1 tab.

  9. Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

    DOEpatents

    Walker, Richard J.

    1986-01-01

    A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

  10. The Fluids and Combustion Facility Combustion Integrated Rack and The Multi-User Droplet Combustion Apparatus: Microgravity Combustion Science Using A Modular Multi-User Hardware

    NASA Astrophysics Data System (ADS)

    O'Malley, T. F.; Myhre, C. A.

    2002-01-01

    The Fluids and Combustion Facility (FCF) is a multi-rack payload planned for the International Space Station that will enable the study of fluid physics and combustion science in a microgravity environment. The Combustion Integrated Rack (CIR) is one of two International Standard Payload Racks of the FCF and is being designed primarily to support combustion science experiments. It is currently in the Flight Unit Build phase. The Multi-user Droplet Combustion Apparatus (MDCA) is a multi-user facility designed to accommodate four different droplet combustion science experiments and is the first payload for CIR. MDCA is currently in the Engineering Model build phase. Launch of the CIR and MDCA is planned for 2004. The CIR will function independently until the later launch of the Fluids Integrated Rack component of the FCF. This paper provides an overview of the capabilities and the development status of the CIR and MDCA. The CIR will contain the hardware and software required to support combustion experiments in space. It will contain an optics bench, combustion chamber, fuel oxidizer and management assembly, exhaust vent system, diagnostic cameras, power, environment control system, command and data management system, and a passive rack isolation system. Additional hardware will be installed in the chamber and on the optics bench that is customized for each science investigation. The chamber insert may provide the sample holder, small ignition source, and small diagnostics such as thermocouples and radiometers. The combustion experiments that may be conducted in the FCF include, but are not limited to, the study of laminar flames, reaction kinetics, droplet and spray combustion, flame spread, fire and fire suppressants, condensed phase organic fuel combustion, turbulent combustion, soot and polycyclic aromatic hydrocarbons, and materials synthesis. It is expected that the facility will provide most of the hardware, with a small amount of unique hardware developed for

  11. Ship exhaust gas plume cooling

    NASA Astrophysics Data System (ADS)

    Schleijpen, H. M. A.; Neele, Filip P.

    2004-08-01

    The exhaust gas plume is an important and sometimes dominating contributor to the infrared signature of ships. Suppression of the infrared ship signatures has been studied by TNO for the Royal Netherlands Navy over considerable time. This study deals with the suppression effects, which can be achieved using a spray of cold water in the inner parts of the exhaust system. The effects are compared with the effect of cooling with air. A typical frigate size diesel engine serves as an example for gas flow, composition and temperature of the plume. The infrared emission of the cooled an un-cooled exhaust gases is calculated. Both the spectral behaviour and the integrated values over typical bands are discussed. Apart from the signature also some advantages of water exhaust gas cooling for the ship design are discussed.

  12. Biodiesel exhaust: the need for a systematic approach to health effects research.

    PubMed

    Larcombe, Alexander N; Kicic, Anthony; Mullins, Benjamin J; Knothe, Gerhard

    2015-10-01

    Biodiesel is a generic term for fuel that can be made from virtually any plant or animal oil via transesterification of triglycerides with an alcohol (and usually a catalyst). Biodiesel has received considerable scientific attention in recent years, as it is a renewable resource that is directly able to replace mineral diesel in many engines. Additionally, some countries have mandated a minimum biodiesel content in all diesel fuel sold on environmental grounds. When combusted, biodiesel produces exhaust emissions containing particulate matter, adsorbed chemicals and a range of gases. In many cases, absolute amounts of these pollutants are lower in biodiesel exhaust compared with mineral diesel exhaust, leading to speculation that biodiesel exhaust may be less harmful to health. Additionally, engine performance studies show that the concentrations of these pollutants vary significantly depending on the renewable oil used to make the biodiesel and the ratio of biodiesel to mineral diesel in the fuel mix. Given the strategic and legislative push towards the use of biodiesel in many countries, a concerning possibility is that certain biodiesels may produce exhaust emissions that are more harmful to health than others. This variation suggests that a comprehensive, systematic and comparative approach to assessing the potential for a range of different biodiesel exhausts to affect health is urgently required. Such an assessment could inform biodiesel production priorities, drive research and development into new exhaust treatment technologies, and ultimately minimize the health impacts of biodiesel exhaust exposure.

  13. Biodiesel exhaust: the need for a systematic approach to health effects research.

    PubMed

    Larcombe, Alexander N; Kicic, Anthony; Mullins, Benjamin J; Knothe, Gerhard

    2015-10-01

    Biodiesel is a generic term for fuel that can be made from virtually any plant or animal oil via transesterification of triglycerides with an alcohol (and usually a catalyst). Biodiesel has received considerable scientific attention in recent years, as it is a renewable resource that is directly able to replace mineral diesel in many engines. Additionally, some countries have mandated a minimum biodiesel content in all diesel fuel sold on environmental grounds. When combusted, biodiesel produces exhaust emissions containing particulate matter, adsorbed chemicals and a range of gases. In many cases, absolute amounts of these pollutants are lower in biodiesel exhaust compared with mineral diesel exhaust, leading to speculation that biodiesel exhaust may be less harmful to health. Additionally, engine performance studies show that the concentrations of these pollutants vary significantly depending on the renewable oil used to make the biodiesel and the ratio of biodiesel to mineral diesel in the fuel mix. Given the strategic and legislative push towards the use of biodiesel in many countries, a concerning possibility is that certain biodiesels may produce exhaust emissions that are more harmful to health than others. This variation suggests that a comprehensive, systematic and comparative approach to assessing the potential for a range of different biodiesel exhausts to affect health is urgently required. Such an assessment could inform biodiesel production priorities, drive research and development into new exhaust treatment technologies, and ultimately minimize the health impacts of biodiesel exhaust exposure. PMID:26179557

  14. Turbocharged two-stroke internal combustion engine with four-stroke capability

    SciTech Connect

    Burrahm, R.W.

    1990-03-13

    This patent describes, in a turbocharged two-stroke internal combustion engine without crankcase scavenging and having means for operating the exhaust valves in accordance with either two-stroke or four-stroke operation, a means for enabling the intake of combustible gas into cylinders of the engine during four-stroke operation through a port in each cylinder from a combustible gas source. It comprises: a valve mounted on each port responsive to pressure within the cylinder.

  15. Laser-induced incandescence measurements of particles in aeroengine exhausts

    NASA Astrophysics Data System (ADS)

    Black, John D.

    1999-09-01

    Laser Induced Incandescence (LII) has been demonstrated as a non-intrusive technique for measurement of particle concentration in the exhausts of aero-engines on sea level test beds as part of a European Union collaborative program (AEROJET) aimed at replacing gas sampling rakes behind development engines with non-intrusive instrumentation. Currently emissions of CO, NOx, unburned hydrocarbon, and smoke from aero-engines must be shown to be less than internationally specified limits. Measurements are made on development engines on sea level test beds by applying a number of standard analytical methods to extracted exhaust gas samples. The hardware required for exhaust gas sampling is heavy and complex and is expensive to build and install. As a result, only the minimum number of emissions tests are conducted during an engine development program, and emissions data is only available to combustion engineers late in the program. Hence, there is a need for more versatile and less costly non-intrusive measurement techniques. Molecular species can be measured using Fourier Transform Infrared (FTIR) spectroscopy, while LII is a promising smoke measuring technique. The development of an LII system specifically designed for exhaust applications is described.

  16. The hydrocarbon composition of exhaust emitted from gasoline fuelled vehicles

    NASA Astrophysics Data System (ADS)

    Nelson, P. F.; Quigley, S. M.

    The non-methane hydrocarbon (NMHC) compositions of the exhausts from 67 vehicles in 'on the road' condition and driven through an urban driving cycle on a chassis dynamometer, have been determined. The major components were ethylene (11.2% w/w of NMHC), toluene (10.2%), acetylene (8.7%), m, p-Xylenes(6.5%), benzene (5.0%), propylene (5.0%) and i-pentane(4.8%). These compounds have also been reported as significant components in the exhausts from two similar populations of American vehicles. The NMHC compositions were found to be insensitive to the mass emission rates of hydrocarbons from the vehicles, except for the combustion-derived olefins, ethylene and propylene, which were affected by engine modifications introduced to satisfy emission control requirements. A close relationship was found between petrol composition and exhaust composition but this did not correspond simply to emissions of unburnt petrol. The aromatics are enriched relative to the alkanes in exhaust when compared with their proportions in the petrol.

  17. Real-time exhaust gas modular flowmeter and emissions reporting system for mobile apparatus

    NASA Technical Reports Server (NTRS)

    Breton, Leo Alphonse Gerard (Inventor)

    2002-01-01

    A real-time emissions reporting system includes an instrument module adapted to be detachably connected to the exhaust pipe of a combustion engine to provide for flow of exhaust gas therethrough. The instrument module includes a differential pressure probe which allows for determination of flow rate of the exhaust gas and a gas sampling tube for continuously feeding a sample of the exhaust gas to a gas analyzer or a mounting location for a non-sampling gas analyzer. In addition to the module, the emissions reporting system also includes an elastomeric boot for detachably connecting the module to the exhaust pipe of the combustion engine, a gas analyzer for receiving and analyzing gases sampled within the module and a computer for calculating pollutant mass flow rates based on concentrations detected by the gas analyzer and the detected flowrate of the exhaust gas. The system may also include a particulate matter detector with a second gas sampling tube feeding same mounted within the instrument module.

  18. Exhaust gas emissions of a vortex breakdown stabilized combustor

    NASA Technical Reports Server (NTRS)

    Yetter, R. A.; Gouldin, F. C.

    1976-01-01

    Exhaust gas emission data are described for a swirl stabilized continuous combustor. The combustor consists of confined concentric jets with premixed fuel and air in the inner jet and air in the outer jet. Swirl may be induced in both inner and outer jets with the sense of rotation in the same or opposite directions (co-swirl and counter-swirl). The combustor limits NO emissions by lean operation without sacrificing CO and unburned hydrocarbon emission performance, when commercial-grade methane and air fired at one atmosphere without preheat are used. Relative swirl direction and magnitude are found to have significant effects on exhaust gas concentrations, exit temperatures, and combustor efficiencies. Counter-swirl gives a large recirculation zone, a short luminous combustion zone, and large slip velocities in the interjet shear layer. For maximum counter-swirl conditions, the efficiency is low.

  19. Combustion chemistry

    SciTech Connect

    Brown, N.J.

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  20. [Passive detection of aeroengine exhaust based on Fourier transform infrared system].

    PubMed

    Li, Shao-cheng; Zuo, Hong-fu; Xia, Qing

    2008-10-01

    Since the composition and concentration of aeroengine exhaust can reflect the combustion efficiency, they can provide the basis for condition based maintenance, and also the basis for the analysis of environment pollution caused by aeroengine exhaust. So the importance of aeroengine exhaust detection is evident. Up to now, the measurement of aeroengine exhaust is based on sampling analysis which is not convenient and can't meet the detection requirements when an aeroplane is flying-off or flying in the sky. Hence, new methods of exhaust detection must be studied. The passive measurement technology based on Fourier transform infrared spectroscopy (FTIR) was applied to the measurement of aeroengine exhaust in the present paper. At first, the principle of passive measurement based on FTIR was introduced in detail. On this basis, a model algorithm for gas concentration calculation was deduced based on the principle of infrared transmission. Then the feasibility of aeroengine exhaust measurement based on passive FTIR was analyzed, and the passive measurement method of aeroengine exhaust based on FTIR was given. In the end, an experiment of aeroengine exhaust passive measurement was carried out by a FTIR with the type of Tensor 27 produced by BRUKER. Good quality spectra of the exhaust and the background were measured. Based on the model algo rithm of passive measurement, the absorbance spectra of CO and NO were obtained respectively, and the concentrations of CO and NO were figured out. To check up the veracity of this method, a comparison was made with another apparatus. There were only little differences between the results of the two experiments, showing that the passive measurement technology based on FTIR could meet the requirements of aeroengine exhaust detection.

  1. Diagnostics of combustion process based on flame images analysis and genetic programming

    NASA Astrophysics Data System (ADS)

    Tanaś, J.; Kotyra, A.; Shegebaeva, Jibek

    2015-09-01

    One of the means of assessing the state of combustion process is analyzing data obtained from flame images. Flame images can be used as a source of information of combustion process input parameters such as air flow, fuel expense or fumes temperature. These parameters are crucial for stable and effective combustion. Considering complexity of combustion process and large number of fluctuating variables, genetic programming is an approach that seems most appropriate. Several video streams of co-combusting biomass and coal were recorded at the rate of 150 frames per second with 800x800 resolution. Different image and combustion parameters were processed to determine dependencies between them.

  2. Mitigating the effect of siloxanes on internal combustion engines using landfill gasses

    SciTech Connect

    Besmann, Theodore M

    2015-01-06

    A waste gas combustion method that includes providing a combustible fuel source, in which the combustible fuel source is composed of at least methane and siloxane gas. A sodium source or magnesium source is mixed with the combustible fuel source. Combustion of the siloxane gas of the combustible fuel source produces a silicon containing product. The sodium source or magnesium source reacts with the silicon containing product to provide a sodium containing glass or sodium containing silicate, or a magnesium containing silicate. By producing the sodium containing glass or sodium containing silicate, or the magnesium containing silicate, or magnesium source for precipitating particulate silica instead of hard coating, the method may reduce or eliminate the formation of silica deposits within the combustion chamber and the exhaust components of the internal combustion engine.

  3. Mitigating the effect of siloxanes on internal combustion engines using landfill gasses

    SciTech Connect

    Besmann, Theodore M

    2014-01-21

    A waste gas combustion method that includes providing a combustible fuel source, in which the combustible fuel source is composed of at least methane and siloxane gas. A sodium source or magnesium source is mixed with the combustible fuel source. Combustion of the siloxane gas of the combustible fuel source produces a silicon containing product. The sodium source or magnesium source reacts with the silicon containing product to provide a sodium containing glass or sodium containing silicate, or a magnesium containing silicate. By producing the sodium containing glass or sodium containing silicate, or the magnesium containing silicate, or magnesium source for precipitating particulate silica instead of hard coating, the method may reduce or eliminate the formation of silica deposits within the combustion chamber and the exhaust components of the internal combustion engine.

  4. Noise Prediction Module for Offset Stream Nozzles

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda S.

    2011-01-01

    A Modern Design of Experiments (MDOE) analysis of data acquired for an offset stream technology was presented. The data acquisition and concept development were funded under a Supersonics NRA NNX07AC62A awarded to Dimitri Papamoschou at University of California, Irvine. The technology involved the introduction of airfoils in the fan stream of a bypass ratio (BPR) two nozzle system operated at transonic exhaust speeds. The vanes deflected the fan stream relative to the core stream and resulted in reduced sideline noise for polar angles in the peak jet noise direction. Noise prediction models were developed for a range of vane configurations. The models interface with an existing ANOPP module and can be used or future system level studies.

  5. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    SciTech Connect

    Jost O.L. Wendt

    2003-06-02

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process.

  6. Revolutionary systems for catalytic combustion and diesel catalytic particulate traps.

    SciTech Connect

    Stuecker, John Nicholas; Witze, Peter O.; Ferrizz, Robert Matthew; Cesarano, Joseph, III; Miller, James Edward

    2004-12-01

    This report is a summary of an LDRD project completed for the development of materials and structures conducive to advancing the state of the art for catalyst supports and diesel particulate traps. An ancillary development for bio-medical bone scaffolding was also realized. Traditionally, a low-pressure drop catalyst support, such as a ceramic honeycomb monolith, is used for catalytic reactions that require high flow rates of gases at high-temperatures. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. ''Robocasting'' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low-pressure drops. These alternative 3-dimensional geometries may also provide a foundation for the development of self-regenerating supports capable of trapping and combusting soot particles from a diesel engine exhaust stream. This report describes the structures developed and characterizes the improved catalytic performance that can result. The results show that, relative to honeycomb monolith supports, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a trade-off between enhanced mass transfer and increased pressure drop, which can be optimized depending on the particular demands of a given application. Practical applications include the combustion of natural gas for power generation, production of syngas, and hydrogen reforming reactions. The robocast lattice structures also show practicality for diesel particulate trapping. Preliminary results for trapping efficiency are reported as well as the development of electrically resistive lattices that can regenerate the structure by combusting the

  7. On-board ammonia generation and exhaust after treatment system using same

    DOEpatents

    Driscoll, Josh; Robel, Wade J.; Brown, Cory A.; Urven, Jr., Roger L.

    2010-03-30

    Often NOx selective catalysts that use ammonia to reduce NOx within exhaust to a harmless gas require on-board storage of ammonia which can be hazardous and inconvenient. In order to generate ammonia in exhaust, the present disclosure increases a NOx concentration in exhaust from at least one combustion chamber, at least in part, by injecting fuel in a predetermined increased NOx generation sequence that includes a first injection during non-auto ignition conditions and a second injection during auto ignition conditions. At least a portion of the NOx is converted to ammonia by passing at least a portion of the exhaust with the increased NOx concentration over an ammonia-producing catalyst.

  8. Oxy-fuel combustion with integrated pollution control

    DOEpatents

    Patrick, Brian R.; Ochs, Thomas Lilburn; Summers, Cathy Ann; Oryshchyn, Danylo B.; Turner, Paul Chandler

    2012-01-03

    An oxygen fueled integrated pollutant removal and combustion system includes a combustion system and an integrated pollutant removal system. The combustion system includes a furnace having at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases. The flue gas stream is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds. The integrated pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid to produce a pollutant-laden liquid stream and a stripped flue gas stream and at least one compressor for receiving and compressing the stripped flue gas stream.

  9. Coal combustion science

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

    1990-11-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 91 refs., 40 figs., 9 tabs.

  10. Combustion Fundamentals Research

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Increased emphasis is placed on fundamental and generic research at Lewis Research Center with less systems development efforts. This is especially true in combustion research, where the study of combustion fundamentals has grown significantly in order to better address the perceived long term technical needs of the aerospace industry. The main thrusts for this combustion fundamentals program area are as follows: analytical models of combustion processes, model verification experiments, fundamental combustion experiments, and advanced numeric techniques.

  11. The efficiency of combustion turbines with constant-pressure combustion

    NASA Technical Reports Server (NTRS)

    Piening, Werner

    1941-01-01

    Of the two fundamental cycles employed in combustion turbines, namely, the explosion (or constant-volume) cycle and the constant-pressure cycle, the latter is considered more in detail and its efficiency is derived with the aid of the cycle diagrams for the several cases with adiabatic and isothermal compression and expansion strokes and with and without utilization of the exhaust heat. Account is also taken of the separate efficiencies of the turbine and compressor and of the pressure losses and heat transfer in the piping. The results show that without the utilization of the exhaust heat the efficiencies for the two cases of adiabatic and isothermal compression is offset by the increase in the heat supplied. It may be seen from the curves that it is necessary to attain separate efficiencies of at least 80 percent in order for useful results to be obtained. There is further shown the considerable effect on the efficiency of pressure losses in piping or heat exchangers.

  12. The toxicity of particles from combustion processes

    SciTech Connect

    Henderson, R.F.; Mauderly, J.L.

    1991-12-31

    The pulmonary toxicity of inhaled particles will depend on their size, solubility and inherent toxicity. Many combustion-derived particles, such as soot and fly ash, are of a respirable size and, being poorly soluble, are retained for prolonged periods in the lung. The acute toxicity of fly ash from coal combustion was compared to that of a known toxic particle, alpha-quartz, by exposures of rats to 35 mg/m{sup 3} of each type of particle for 7 hr/day, 5 days/wk for 4 wk. The acute pulmonary toxicity was measured by analysis of bronchoalveolar lavage fluid. One year after the exposures, fibrosis with granulomas was observed in the quartz-exposed rats, while little or no fibrosis developed in the fly-ash-exposed rats. The toxicity of soot from diesel exhaust was determined by chronic (30 mo) exposures of rats, 7 hr/day, 5 days/wk to exhaust containing 0.35, 3.5 or 7.0 mg/m{sup 3} soot. The two higher exposures caused persistent pulmonary inflammation, fibrosis and neoplasmas. Rats exposed to the lowest concentration demonstrated no toxic responses and there was no life shortening caused by any exposure. Ongoing comparative studies indicate that pure carbon black particles cause responses similar to those caused by diesel exhaust, indicating that much of the toxicity induced by the diesel soot results from the presence of the large lung burdens of carbonaceous particles.

  13. The toxicity of particles from combustion processes

    SciTech Connect

    Henderson, R.F.; Mauderly, J.L.

    1991-01-01

    The pulmonary toxicity of inhaled particles will depend on their size, solubility and inherent toxicity. Many combustion-derived particles, such as soot and fly ash, are of a respirable size and, being poorly soluble, are retained for prolonged periods in the lung. The acute toxicity of fly ash from coal combustion was compared to that of a known toxic particle, alpha-quartz, by exposures of rats to 35 mg/m{sup 3} of each type of particle for 7 hr/day, 5 days/wk for 4 wk. The acute pulmonary toxicity was measured by analysis of bronchoalveolar lavage fluid. One year after the exposures, fibrosis with granulomas was observed in the quartz-exposed rats, while little or no fibrosis developed in the fly-ash-exposed rats. The toxicity of soot from diesel exhaust was determined by chronic (30 mo) exposures of rats, 7 hr/day, 5 days/wk to exhaust containing 0.35, 3.5 or 7.0 mg/m{sup 3} soot. The two higher exposures caused persistent pulmonary inflammation, fibrosis and neoplasmas. Rats exposed to the lowest concentration demonstrated no toxic responses and there was no life shortening caused by any exposure. Ongoing comparative studies indicate that pure carbon black particles cause responses similar to those caused by diesel exhaust, indicating that much of the toxicity induced by the diesel soot results from the presence of the large lung burdens of carbonaceous particles.

  14. Compression ratio effect on methane HCCI combustion

    SciTech Connect

    Aceves, S. M.; Pitz, W.; Smith, J. R.; Westbrook, C.

    1998-09-29

    We have used the HCT (Hydrodynamics, Chemistry and Transport) chemical kinetics code to simulate HCCI (homogeneous charge compression ignition) combustion of methane-air mixtures. HCT is applied to explore the ignition timing, bum duration, NOx production, gross indicated efficiency and gross IMEP of a supercharged engine (3 atm. Intake pressure) with 14:1, 16:l and 18:1 compression ratios at 1200 rpm. HCT has been modified to incorporate the effect of heat transfer and to calculate the temperature that results from mixing the recycled exhaust with the fresh mixture. This study uses a single control volume reaction zone that varies as a function of crank angle. The ignition process is controlled by adjusting the intake equivalence ratio and the residual gas trapping (RGT). RGT is internal exhaust gas recirculation which recycles both thermal energy and combustion product species. Adjustment of equivalence ratio and RGT is accomplished by varying the timing of the exhaust valve closure in either 2-stroke or 4-stroke engines. Inlet manifold temperature is held constant at 300 K. Results show that, for each compression ratio, there is a range of operational conditions that show promise of achieving the control necessary to vary power output while keeping indicated efficiency above 50% and NOx levels below 100 ppm. HCT results are also compared with a set of recent experimental data for natural gas.

  15. Combustion Safety Simplified Test Protocol Field Study

    SciTech Connect

    Brand, L; Cautley, D.; Bohac, D.; Francisco, P.; Shen, L.; Gloss, S.

    2015-11-05

    "9Combustions safety is an important step in the process of upgrading homes for energy efficiency. There are several approaches used by field practitioners, but researchers have indicated that the test procedures in use are complex to implement and provide too many false positives. Field failures often mean that the house is not upgraded until after remediation or not at all, if not include in the program. In this report the PARR and NorthernSTAR DOE Building America Teams provide a simplified test procedure that is easier to implement and should produce fewer false positives. A survey of state weatherization agencies on combustion safety issues, details of a field data collection instrumentation package, summary of data collected over seven months, data analysis and results are included. The project provides several key results. State weatherization agencies do not generally track combustion safety failures, the data from those that do suggest that there is little actual evidence that combustion safety failures due to spillage from non-dryer exhaust are common and that only a very small number of homes are subject to the failures. The project team collected field data on 11 houses in 2015. Of these homes, two houses that demonstrated prolonged and excessive spillage were also the only two with venting systems out of compliance with the National Fuel Gas Code. The remaining homes experienced spillage that only occasionally extended beyond the first minute of operation. Combustion zone depressurization, outdoor temperature, and operation of individual fans all provide statistically significant predictors of spillage.

  16. Internal combustion engine without connecting rods

    SciTech Connect

    Adams, L.M.

    1989-05-09

    This patent describes a reciprocating, multicylinder, internal combustion engine having an axially rotating power output crankshaft, the combination of: (a) combustion chambers in side-by-side parallel arrangement, each chamber containing first means to admit a combustible fuel/air mixture and to exhaust the fumes of combustion; (b) a separate cylinder having an open end and a closed end forming part of each combustion chamber and a piston working independently in each cylinder and arranged to travel toward the closed end to compress the mixture and be driven in a power stroke toward the open end as a result of the burning of the mixture; (c) a carrier member and means to attach the member to a pair of adjacent pistons for interconnecting them to reciprocate in unison in their respective cylinders; and, (d) a guide member, pivotally attached to an offset throw formed in the output crankshaft connected to the carrier member in sliding engagement therewith to convert the reciprocating motion of the pistons into rotary motion of the crankshaft through motion in a plane lying transverse to the axis of the crankshaft.

  17. Internal combustion engine without connecting rods

    SciTech Connect

    Adams, L.M.

    1989-03-21

    This patent describes a reciprocating, multicylinder, internal combustion engine having an axially rotating power output crankshaft, the combination of: (a) a plurality of combustion chambers in side-by-side parallel arrangement, each chamber containing first means to admit a combustible fuel/air mixture and to exhaust the fumes of combustion; (b) a separate cylinder having an open end and a closed end forming apart of each combustion chamber and a piston working independently in each cylinder and arranged to travel toward the closed end to compress the mixture and be driven in a power stroke toward the open end as a result of the burning of the mixture; (c) a carrier member and means to attach the member in fixed relationship to a pair of adjacent pistons for interconnecting them to reciprocate in unison their respective cylinders; (d) means for absorbing side thrust developed during the rotation of the crankshaft; and, (e) a guide member, pivotally attached to an offset throw formed in the output crankshaft, connected to the carrier member in sliding engagement therewith to convert the reciprocating motion of the pistons into rotary motion of the crankshaft through motion in a plane lying transverse to the axis of the crankshaft.

  18. Concepts for reducing exhaust emissions and fuel consumption of the aircraft piston engine

    NASA Technical Reports Server (NTRS)

    Rezy, B. J.; Stuckas, K. J.; Tucker, J. R.; Meyers, J. E.

    1979-01-01

    A study was made to reduce exhaust emissions and fuel consumption of a general aviation aircraft piston engine by applying known technology. Fourteen promising concepts such as stratified charge combustion chambers, cooling cylinder head improvements, and ignition system changes were evaluated for emission reduction and cost effectiveness. A combination of three concepts, improved fuel injection system, improved cylinder head with exhaust port liners and exhaust air injection was projected as the most cost effective and safe means of meeting the EPA standards for CO, HC and NO. The fuel economy improvement of 4.6% over a typical single engine aircraft flight profile does not though justify the added cost of the three concepts, and significant reductions in fuel consumption must be applied to the cruise mode where most of the fuel is used. The use of exhaust air injection in combination with exhaust port liners reduces exhaust valve stem temperatures which can result in longer valve guide life. The use of exhaust port liners alone can reduce engine cooling air requirements by 11% which is the equivalent of a 1.5% increase in propulsive power. The EPA standards for CO, HC and NO can be met in the IO-520 engine using air injection alone or the Simmonds improved fuel injection system.

  19. Measuring soot particles from automotive exhaust emissions

    NASA Astrophysics Data System (ADS)

    Andres, Hanspeter; Lüönd, Felix; Schlatter, Jürg; Auderset, Kevin; Jordan-Gerkens, Anke; Nowak, Andreas; Ebert, Volker; Buhr, Egbert; Klein, Tobias; Tuch, Thomas; Wiedensohler, Alfred; Mamakos, Athanasios; Riccobono, Francesco; Discher, Kai; Högström, Richard; Yli-Ojanperä, Jaakko; Quincey, Paul

    2014-08-01

    The European Metrology Research Programme participating countries and the European Union jointly fund a three year project to address the need of the automotive industry for a metrological sound base for exhaust measurements. The collaborative work on particle emissions involves five European National Metrology Institutes, the Tampere University of Technology, the Joint Research Centre for Energy and Transport and the Leibniz Institute for Tropospheric Research. On one hand, a particle number and size standard for soot particles is aimed for. Eventually this will allow the partners to provide accurate and comparable calibrations of measurement instruments for the type approval of Euro 5b and Euro 6 vehicles. Calibration aerosols of combustion particles, silver and graphite proof partially suitable. Yet, a consensus choice together with instrument manufactures is pending as the aerosol choice considerably affects the number concentration measurement. Furthermore, the consortium issued consistent requirements for novel measuring instruments foreseen to replace today's opacimeters in regulatory periodic emission controls of soot and compared them with European legislative requirements. Four partners are conducting a metrological validation of prototype measurement instruments. The novel instruments base on light scattering, electrical, ionisation chamber and diffusion charging sensors and will be tested at low and high particle concentrations. Results shall allow manufacturers to further improve their instruments to comply with legal requirements.

  20. Control logic for exhaust gas driven turbocharger

    SciTech Connect

    Adeff, G.A.

    1991-12-31

    This patent describes a method of controlling an exhaust gas driven turbocharger supplying charge air for an internal combustion engine powering vehicle, the turbocharger being adjustable from a normal mode to a power mode in which the charge air available to the engine during vehicle acceleration is increased over that available when the turbocharger is in the normal mode, the vehicle including engine power control means switchable by the vehicle operator from a normal mode to a power mode so that the vehicle operator may selectively elect either the normal mode or the power mode, comprising the steps of measuring the speed of the vehicle, permitting the vehicle operator to elect either the power mode or the normal mode for a subsequent vehicle acceleration, and then adjusting the turbocharger to the power mode when the speed of the vehicle is less than a predetermined reference speed and the vehicle operator has elected to power mode to increase the charge air available to the engine and thereby increasing engine power on a subsequent acceleration of the vehicle.

  1. Indirect combustion noise of auxiliary power units

    NASA Astrophysics Data System (ADS)

    Tam, Christopher K. W.; Parrish, Sarah A.; Xu, Jun; Schuster, Bill

    2013-08-01

    Recent advances in noise suppression technology have significantly reduced jet and fan noise from commercial jet engines. This leads many investigators in the aeroacoustics community to suggest that core noise could well be the next aircraft noise barrier. Core noise consists of turbine noise and combustion noise. There is direct combustion noise generated by the combustion processes, and there is indirect combustion noise generated by the passage of combustion hot spots, or entropy waves, through constrictions in an engine. The present work focuses on indirect combustion noise. Indirect combustion noise has now been found in laboratory experiments. The primary objective of this work is to investigate whether indirect combustion noise is also generated in jet and other engines. In a jet engine, there are numerous noise sources. This makes the identification of indirect combustion noise a formidable task. Here, our effort concentrates exclusively on auxiliary power units (APUs). This choice is motivated by the fact that APUs are relatively simple engines with only a few noise sources. It is, therefore, expected that the chance of success is higher. Accordingly, a theoretical model study of the generation of indirect combustion noise in an Auxiliary Power Unit (APU) is carried out. The cross-sectional areas of an APU from the combustor to the turbine exit are scaled off to form an equivalent nozzle. A principal function of a turbine in an APU is to extract mechanical energy from the flow stream through the exertion of a resistive force. Therefore, the turbine is modeled by adding a negative body force to the momentum equation. This model is used to predict the ranges of frequencies over which there is a high probability for indirect combustion noise generation. Experimental spectra of internal pressure fluctuations and far-field noise of an RE220 APU are examined to identify anomalous peaks. These peaks are possible indirection combustion noise. In the case of the

  2. Combustion 2000

    SciTech Connect

    2000-06-30

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench Scale Activities

  3. Combustion 2000

    SciTech Connect

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  4. Condensation of water vapor and carbon dioxide in the jet exhausts of rocket engines: 1. Model calculation of the physical conditions in a jet exhaust

    NASA Astrophysics Data System (ADS)

    Platov, Yu. V.; Alpatov, V. V.; Klyushnikov, V. Yu.

    2014-01-01

    Model calculations have been performed for the temperature and pressure of combustion products in the jet exhaust of rocket engines of last stages of Proton, Molniya, and Start launchers operating in the upper atmosphere at altitudes above 120 km. It has been shown that the condensation of water vapor and carbon dioxide can begin at distances of 100-150 and 450-650 m away from the engine nozzle, respectively.

  5. Damage of natural stone tablets exposed to exhaust gas under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Farkas, Orsolya; Szabados, György; Török, Ákos

    2016-04-01

    Natural stone tablets were exposed to exhaust gas under laboratory conditions to assess urban stone damage. Cylindrical test specimens (3 cm in diameter) were made from travertine, non-porous limestone, porous limestone, rhyolite tuff, sandstone, andesite, granite and marble. The samples were exposed to exhaust gas that was generated from diesel engine combustion (engine type: RÁBA D10 UTSLL 160, EURO II). The operating condition of the internal combustion engine was: 1300 r/m (app 50%). The exhaust gas was diverted into a pipe system where the samples were placed perpendicular to main flow for 1, 2, 4, 8 and 10 hours, respectively. The exhaust emission was measured by using AVL particulate measurement technology; filter paper method (AVL 415). The stone samples were documented and selective parameters were measured prior to and after exhaust gas exposure. Density, volume, ultrasonic pulse velocity, mineral composition and penetration depth of emission related particulate matter were recorded. The first results indicate that after 10 hours of exposure significant amount of particulate matter deposited on the stone surface independently from the surface properties and porosity. The black soot particles uniformly covered all types of stones, making hard to differentiate the specimens.

  6. Automotive Fuel and Exhaust Systems.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide mechanics with an understanding of the construction, operation, malfunction, diagnosis, maintenance, and repair of the fuel and exhaust systems used in automobiles. The course contains five study units covering fundamentals of gasoline engine fuel…

  7. Thermoelectric exhaust-gas energy recovery: An integrated approach

    NASA Astrophysics Data System (ADS)

    Powell, A. V.; Kaltzoglou, A.; Vaqueiro, P.; Min, G.; Garcia-Cañadas, J.; Stobart, R. K.; Li, J.; Dong, G.; Wijewardane, A.

    2012-06-01

    Here we describe the first results from an interdisciplinary project that seeks to develop a skutterudite-based thermoelectric (TE) energy recovery system for a vehicle exhaust stream. Filled skutterudites have been prepared and characterised and their thermal stability evaluated. Thermoelements fabricated from these skutterudites have been used to evaluate the compatibility of materials required for the construction of TE modules. The results of modelling studies for the optimization of heat exchanger design and the creation of a component in the loop test facility are also described.

  8. Combustion Sensors: Gas Turbine Applications

    NASA Technical Reports Server (NTRS)

    Human, Mel

    2002-01-01

    This report documents efforts to survey the current research directions in sensor technology for gas turbine systems. The work is driven by the current and future requirements on system performance and optimization. Accurate real time measurements of velocities, pressure, temperatures, and species concentrations will be required for objectives such as combustion instability attenuation, pollutant reduction, engine health management, exhaust profile control via active control, etc. Changing combustor conditions - engine aging, flow path slagging, or rapid maneuvering - will require adaptive responses; the effectiveness of such will be only as good as the dynamic information available for processing. All of these issues point toward the importance of continued sensor development. For adequate control of the combustion process, sensor data must include information about the above mentioned quantities along with equivalence ratios and radical concentrations, and also include both temporal and spatial velocity resolution. Ultimately these devices must transfer from the laboratory to field installations, and thus must become low weight and cost, reliable and maintainable. A primary conclusion from this study is that the optics-based sensor science will be the primary diagnostic in future gas turbine technologies.

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

    DOEpatents

    Schmieg, Steven J.; Blint, Richard J.; Den, Ling; Viola, Michael B.; Lee, Jong-Hwan

    2011-08-30

    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.

  10. Weight Penalty Incurred in Thermoelectric Recovery of Automobile Exhaust Heat

    NASA Astrophysics Data System (ADS)

    Rowe, D. M.; Smith, J.; Thomas, G.; Min, G.

    2011-05-01

    Thermoelectric recovery of automobile waste exhaust heat has been identified as having potential for reducing fuel consumption and environmentally unfriendly emissions. Around 35% of combustion energy is discharged as heat through the exhaust system, at temperatures which depend upon the engine's operation and range from 800°C to 900°C at the outlet port to less than 50°C at the tail-pipe. Beneficial reduction in fuel consumption of 5% to 10% is widely quoted in the literature. However, comparison between claims is difficult due to nonuniformity of driving conditions. In this paper the available waste exhaust heat energy produced by a 1.5 L family car when undergoing the new European drive cycle was measured and the potential thermoelectric output estimated. The work required to power the vehicle through the drive cycle was also determined and used to evaluate key parameters. This enabled an estimate to be made of the engine efficiency and additional work required by the engine to meet the load of a thermoelectric generating system. It is concluded that incorporating a thermoelectric generator would attract a penalty of around 12 W/kg. Employing thermoelectric modules fabricated from low-density material such as magnesium silicide would considerably reduce the generator weight penalty.

  11. Hydrocarbon emissions speciation in diesel and biodiesel exhausts

    NASA Astrophysics Data System (ADS)

    Payri, Francisco; Bermúdez, Vicente R.; Tormos, Bernardo; Linares, Waldemar G.

    Diesel engine emissions are composed of a long list of organic compounds, ranging from C 2 to C 12+, and coming from the hydrocarbons partially oxidized in combustion or produced by pyrolisis. Many of these are considered as ozone precursors in the atmosphere, since they can interact with nitrogen oxides to produce ozone under atmospheric conditions in the presence of sunlight. In addition to problematic ozone production, Brookes, P., and Duncan, M. [1971. Carcinogenic hydrocarbons and human cells in culture. Nature.] and Heywood, J. [1988. Internal Combustion Engine Fundamentals.Mc Graw-Hill, ISBN 0-07-1000499-8.] determined that the polycyclic aromatic hydrocarbons present in exhaust gases are dangerous to human health, being highly carcinogenic. The aim of this study was to identify by means of gas chromatography the amount of each hydrocarbon species present in the exhaust gases of diesel engines operating with different biodiesel blends. The levels of reactive and non-reactive hydrocarbons present in diesel engine exhaust gases powered by different biodiesel fuel blends were also analyzed. Detailed speciation revealed a drastic change in the nature and quantity of semi-volatile compounds when biodiesel fuels are employed, the most affected being the aromatic compounds. Both aromatic and oxygenated aromatic compounds were found in biodiesel exhaust. Finally, the conservation of species for off-side analysis and the possible influence of engine operating conditions on the chemical characterization of the semi-volatile compound phase are discussed. The use of oxygenated fuel blends shows a reduction in the Engine-Out emissions of total hydrocarbons. But the potential of the hydrocarbon emissions is more dependent on the compositions of these hydrocarbons in the Engine-Out, to the quantity; a large percent of hydrocarbons existing in the exhaust, when biodiesel blends are used, are partially burned hydrocarbons, and are interesting as they have the maximum

  12. High Efficiency, Clean Combustion

    SciTech Connect

    Donald Stanton

    2010-03-31

    challenges to reduce oil consumption and greenhouse gases, meet stringent emissions regulations, provide customer value, and improve safety. The HECC program successfully reduced engine fuel consumption and greenhouse gases while providing greater customer valve. The US EPA 2010 emissions standard poses a significant challenge for developing clean diesel powertrains that meet the DoE Vehicle Technologies Multi-Year Program Plan (MYPP) for fuel efficiency improvement while remaining affordable. Along with exhaust emissions, an emphasis on heavy duty vehicle fuel efficiency is being driven by increased energy costs as well as the potential regulation of greenhouse gases. An important element of the success of meeting emissions while significantly improving efficiency is leveraging Cummins component technologies such as fuel injection equipment, aftertreatment, turbomahcinery, electronic controls, and combustion systems. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 55% peak brake thermal efficiency for the engine plus aftertreatment system. The first step in developing high efficiency clean products has been supported by the DoE co-sponsored HECC program. The objectives of the HECC program are: (1) To design and develop advanced diesel engine architectures capable of achieving US EPA 2010 emission regulations while improving the brake thermal efficiency by 10% compared to the baseline (a state of the art 2007 production diesel engine). (2) To design and develop components and subsystems (fuel systems, air handling, controls, etc) to enable construction and development of multi-cylinder engines. (3) To perform an assessment of the commercial viability of the newly developed engine technology. (4) To specify fuel properties conducive to improvements in emissions, reliability, and fuel efficiency for engines using high

  13. Sulfur dioxide removal from gas streams

    SciTech Connect

    Urban, P.; Ginger, E.A.

    1986-11-11

    A process is described for removal of sulfur dioxide pollutant gas from gas stream which comprises contacting the gas stream with pretreated shale in the form of an aqueous solution of aluminum sulfate including from about 0.1 to about 2.0% by weight of the pretreated shale. The pretreatment of the shale comprises the heating of the shale in the presence of a gas unable to support combustion at a temperature in a range of from about 340/sup 0/C. to about 480/sup 0/C.

  14. Fundamentals of Gas Turbine combustion

    NASA Technical Reports Server (NTRS)

    Gerstein, M.

    1979-01-01

    Combustion problems and research recommendations are discussed in the areas of atomization and vaporization, combustion chemistry, combustion dynamics, and combustion modelling. The recommendations considered of highest priority in these areas are presented.

  15. Engine Would Recover Exhaust Energy More Efficiently

    NASA Technical Reports Server (NTRS)

    Dimpelfeld, Philip M.

    1993-01-01

    Exhaust energy used for supercharging and extra shaft power. Flow of exhaust apportioned by waste gate to meet demand of turbocharger, and portion not fed to turbocharger sent to power-recovery turbine. Expected to increase fuel efficiency.

  16. Ignition/combustion processes

    NASA Technical Reports Server (NTRS)

    Pryor, D. E.

    1985-01-01

    The overall objectives for this initial technology are to generate an advanced, comprehensive combustion analytical code, and to verify the combustion flow dynamic predictions from this model with hot test experimental data.

  17. Internal combustion engine with multiple combustion chambers

    SciTech Connect

    Gruenwald, D.J.

    1992-05-26

    This patent describes a two-cycle compression ignition engine. It comprises one cylinder, a reciprocable piston moveable in the cylinder, a piston connecting rod, a crankshaft for operation of the piston connecting rod, a cylinder head enclosing the cylinder, the upper surface of the piston and the enclosing surface of the cylinder head defining a cylinder clearance volume, a first combustion chamber and a second combustion chamber located in the cylinder head. This patent describes improvement in means for isolating the combustion process for one full 360{degrees} rotation of the crankshaft; wherein the combustion chambers alternatively provide for expansion of combustion products in the respective chambers into the cylinder volume near top dead center upon each revolution of the crankshaft.

  18. Maximal combustion temperature estimation

    NASA Astrophysics Data System (ADS)

    Golodova, E.; Shchepakina, E.

    2006-12-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models.

  19. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    DOEpatents

    Wijmans, Johannes G.; Merkel, Timothy C; Baker, Richard W.

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

  20. Stagnation pressure probe. [for measuring pressure of supersonic gas streams

    NASA Technical Reports Server (NTRS)

    Goodyer, M. J. (Inventor)

    1974-01-01

    A method and apparatus for measuring the stagnation pressure of supersonic velocity gas streams without the generation of shock waves which interfere with such measurements are given. The technique is insensitive to the type of gas and Mach number and is therefore particularly useful in the study of jet engine exhausts.

  1. EGR control device for internal combustion engine

    SciTech Connect

    Nishida, M.; Inoue, N.; Asayama, Y.; Suzuki, H.

    1988-12-13

    This patent describes an EGR control device for an internal combustion engine comprising an EGR control valve installed in EGR passageway communicating with an exhaust system and an intake system of an internal combustion engine, an oxygen sensor for detecting the oxygen content of the intake air installed in the downstream of the opening of the EGR passageway in the intake system, a pressure sensor for detecting the atmospheric pressure in the oxygen sensor, and EGR control means for computing a first quantity corresponding to a target EGR rate, correcting the output signal of the oxygen sensor using the output signal of the pressure sensor, and opening or shutting the EGR control valve in proportion to the deviation of the second quantity thus corrected from the first quantity in order to set the operating condition of the engine in conformity with a predetermined target EGR.

  2. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize... balance of fuel, intake air, and exhaust according to § 1065.655 to verify exhaust system integrity....

  3. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize... balance of fuel, intake air, and exhaust according to § 1065.655 to verify exhaust system integrity....

  4. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize... balance of fuel, intake air, and exhaust according to § 1065.655 to verify exhaust system integrity....

  5. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize..., intake air, and exhaust according to § 1065.655 to verify exhaust system integrity. (f)...

  6. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize... balance of fuel, intake air, and exhaust according to § 1065.655 to verify exhaust system integrity....

  7. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  8. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  9. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  10. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  11. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  12. Probe samples components of rocket engine exhaust

    NASA Technical Reports Server (NTRS)

    Schumacher, P. E.

    1965-01-01

    Water-cooled, cantilevered probe samples the exhaust plume of rocket engines to recover particles for examination. The probe withstands the stresses of a rocket exhaust plume environment for a sufficient period to obtain a useful sample of the exhaust components.

  13. Jet engine exhaust emissions of high altitude commercial aircraft projected to 1990

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Ingebo, R. D.

    1974-01-01

    Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high-altitude cruise conditions are presented. The forecasts are based on:(1) current knowledge of emission characteristics of combustors and augmentors; (2) the status of combustion research in emission reduction technology; and (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft fueled by either JP fuel, liquefied natural gas, or hydrogen. Results are presented for cruise conditions in terms of both an emission index (g constituent/kg fuel) and an emission rate (g constituent/hr).

  14. Combustion and flow modelling applied to the OMV VTE

    NASA Technical Reports Server (NTRS)

    Larosiliere, Louis M.; Jeng, San-Mou

    1990-01-01

    A predictive tool for hypergolic bipropellant spray combustion and flow evolution in the OMV VTE (orbital maneuvering vehicle variable thrust engine) is described. It encompasses a computational technique for the gas phase governing equations, a discrete particle method for liquid bipropellant sprays, and constitutive models for combustion chemistry, interphase exchanges, and unlike impinging liquid hypergolic stream interactions. Emphasis is placed on the phenomenological modelling of the hypergolic liquid bipropellant gasification processes. An application to the OMV VTE combustion chamber is given in order to show some of the capabilities and inadequacies of this tool.

  15. Lab-scale Lidar Sensing of Diesel Engines Exhausts

    NASA Technical Reports Server (NTRS)

    Borghese, A.

    1992-01-01

    Combustion technology and its environmental concerns are being considered with increasing attention, not only for global-scale effects, but also for toxicological implications, particularly in the lift conditions of traffic-congested areas and industrial sites. Majority combustion by-products (CO, NO(sub x)) and unburned hydrocarbons (HC), are already subject to increasingly severe regulations; however other, non-regulated minority species, mainly soot and heavy aromatic molecules, involve higher health risks, as they are suspected to be agents of serious pathologies and even mutagenic effects. This is but one of the reasons why much research work is being carried out worldwide on the physical properties of these substances. Correspondingly, the need arises to detect their presence in urban environments, with as high a sensitivity as is required by their low concentrations, proper time- and space-resolutions, and 'real-time' capabilities. Lidar techniques are excellent candidates to this purpose, although severe constraints limit their applicability, eye-safety problems and aerosol Mie scattering uncertainties above all. At CNR's Istituto Motori in Napels, a Lidar-like diagnostic system is being developed, aimed primarily at monitoring the dynamic behavior of internal combustion engines, particularly diesel exhausts, and at exploring the feasibility of a so-called 'Downtown Lidar'.

  16. Exhaust emission control and diagnostics

    DOEpatents

    Mazur, Christopher John; Upadhyay, Devesh

    2006-11-14

    A diesel engine emission control system uses an upstream oxidation catalyst and a downstream SCR catalyst to reduce NOx in a lean exhaust gas environment. The engine and upstream oxidation catalyst are configured to provide approximately a 1:1 ratio of NO to NO2 entering the downstream catalyst. In this way, the downstream catalyst is insensitive to sulfur contamination, and also has improved overall catalyst NOx conversion efficiency. Degradation of the system is determined when the ratio provided is no longer near the desired 1:1 ratio. This condition is detected using measurements of engine operating conditions such as from a NOx sensor located downstream of the catalysts. Finally, control action to adjust an injected amount of reductant in the exhaust gas based on the actual NO to NO2 ratio upstream of the SCR catalyst and downstream of the oxidation catalyst.

  17. Experimental exposure to diesel exhaust increases arterial stiffness in man

    PubMed Central

    Lundbäck, Magnus; Mills, Nicholas L; Lucking, Andrew; Barath, Stefan; Donaldson, Ken; Newby, David E; Sandström, Thomas; Blomberg, Anders

    2009-01-01

    Introduction Exposure to air pollution is associated with increased cardiovascular morbidity, although the underlying mechanisms are unclear. Vascular dysfunction reduces arterial compliance and increases central arterial pressure and left ventricular after-load. We determined the effect of diesel exhaust exposure on arterial compliance using a validated non-invasive measure of arterial stiffness. Methods In a double-blind randomized fashion, 12 healthy volunteers were exposed to diesel exhaust (approximately 350 μg/m3) or filtered air for one hour during moderate exercise. Arterial stiffness was measured using applanation tonometry at the radial artery for pulse wave analysis (PWA), as well as at the femoral and carotid arteries for pulse wave velocity (PWV). PWA was performed 10, 20 and 30 min, and carotid-femoral PWV 40 min, post-exposure. Augmentation pressure (AP), augmentation index (AIx) and time to wave reflection (Tr) were calculated. Results Blood pressure, AP and AIx were generally low reflecting compliant arteries. In comparison to filtered air, diesel exhaust exposure induced an increase in AP of 2.5 mmHg (p = 0.02) and in AIx of 7.8% (p = 0.01), along with a 16 ms reduction in Tr (p = 0.03), 10 minutes post-exposure. Conclusion Acute exposure to diesel exhaust is associated with an immediate and transient increase in arterial stiffness. This may, in part, explain the increased risk for cardiovascular disease associated with air pollution exposure. If our findings are confirmed in larger cohorts of susceptible populations, this simple non-invasive method of assessing arterial stiffness may become a useful technique in measuring the impact of real world exposures to combustion derived-air pollution. PMID:19284640

  18. Efficient gas-separation process to upgrade dilute methane stream for use as fuel

    DOEpatents

    Wijmans, Johannes G.; Merkel, Timothy C.; Lin, Haiqing; Thompson, Scott; Daniels, Ramin

    2012-03-06

    A membrane-based gas separation process for treating gas streams that contain methane in low concentrations. The invention involves flowing the stream to be treated across the feed side of a membrane and flowing a sweep gas stream, usually air, across the permeate side. Carbon dioxide permeates the membrane preferentially and is picked up in the sweep air stream on the permeate side; oxygen permeates in the other direction and is picked up in the methane-containing stream. The resulting residue stream is enriched in methane as well as oxygen and has an EMC value enabling it to be either flared or combusted by mixing with ordinary air.

  19. An Extended Combustion Model for the Aircraft Turbojet Engine

    NASA Astrophysics Data System (ADS)

    Rotaru, Constantin; Andres-Mihăilă, Mihai; Matei, Pericle Gabriel

    2014-08-01

    The paper consists in modelling and simulation of the combustion in a turbojet engine in order to find optimal characteristics of the burning process and the optimal shape of combustion chambers. The main focus of this paper is to find a new configuration of the aircraft engine combustion chambers, namely an engine with two main combustion chambers, one on the same position like in classical configuration, between compressor and turbine and the other, placed behind the turbine but not performing the role of the afterburning. This constructive solution could allow a lower engine rotational speed, a lower temperature in front of the first stage of the turbine and the possibility to increase the turbine pressure ratio by extracting the flow stream after turbine in the inner nozzle. Also, a higher thermodynamic cycle efficiency and thrust in comparison to traditional constant-pressure combustion gas turbine engines could be obtained.

  20. Pulmonary function in workers exposed to diesel exhausts: The effect of control measures

    SciTech Connect

    Ulfvarson, U.; Alexandersson, R.; Dahlqvist, M.; Ekholm, U.; Bergstroem, B. )

    1991-01-01

    To assess the protective effect of exhausts pipe filters or respirators on pulmonary function, 15 workers in a tunnel construction site, truck and loading machine drivers, rock workers, and others were studied. The total and respirable dust, combustible matter in respirable dust, carbon monoxide, nitrogen monoxide and nitrogen dioxide were measured for each subject during entire work shifts. The effect of the exposure on the lung function variables was measured by dynamic spirometry, carbon monoxide single breath technique, and nitrogen single breath wash-out. The exhaust pipe filtering had a protective effect, directly discernible in the drivers on vital capacity and FEV1.0 and for the whole group on FEV% and TLco. The dust respirators had no effect, probably because of the difficulties in correctly using personal protection under the circumstances in the tunnel. In the absence of a true exposure assessment, control measures for diesel exhausts can be tested by medical effect studies. Catalytic particle filters of diesel exhausts are one method of rendering the emissions less irritant, although they will not remove irritant gases. An indicator of diesel exhaust exposure should include the particle fraction of the diesel exhausts, but a discrimination between different sources of organic dust must be possible.

  1. Denitrification mechanism in combustion of biocoal briquettes.

    PubMed

    Kim, Heejoon; Li, Tianji

    2005-02-15

    Pulp black liquor (PBL), an industrial waste from paper production, has been previously shown to be an effective binder and denitrification agent for coal briquettes. This study investigated the denitrification mechanism of PBL in both the volatile combustion and char combustion stages of coal briquettes. X-ray diffraction and ion chromatography were used to analyze the residual ashes of combustion. The exhaust gas was analyzed by a flue gas analysis system and a Q-mass spectrometry system. The denitrification mechanism of PBL in the volatile combustion stage was found to result from the emission of NH3. The denitrification of PBL in the char combustion stage was associated with the NaOH contained in PBL. The direct reaction of NaOH with NO gas was examined, and some interesting phenomena were observed. Pure carbon or pure NaOH showed only limited reaction with NO. However, the mixture of NaOH and carbon (NaOH + C) significantly enhanced the reaction. This mixture increased the NO removal up to 100%. Subsequently, denitrification lasted for a long time period, with about 25% of NO removal. The pyrolysis characteristic of NaNO3, a compound resulting from denitrification, was also affected by the presence of carbon. In the presence of carbon, the NOx emission resulting from the pyrolysis of NaNO3 was reduced by a factor of 6. Since the denitrification phenomena appeared only in the absence of oxygen, a model of oxygen distribution in a burning coal briquette was employed to explain the reactions occurring in real combustion of coal briquettes.

  2. Denitrification mechanism in combustion of biocoal briquettes.

    PubMed

    Kim, Heejoon; Li, Tianji

    2005-02-15

    Pulp black liquor (PBL), an industrial waste from paper production, has been previously shown to be an effective binder and denitrification agent for coal briquettes. This study investigated the denitrification mechanism of PBL in both the volatile combustion and char combustion stages of coal briquettes. X-ray diffraction and ion chromatography were used to analyze the residual ashes of combustion. The exhaust gas was analyzed by a flue gas analysis system and a Q-mass spectrometry system. The denitrification mechanism of PBL in the volatile combustion stage was found to result from the emission of NH3. The denitrification of PBL in the char combustion stage was associated with the NaOH contained in PBL. The direct reaction of NaOH with NO gas was examined, and some interesting phenomena were observed. Pure carbon or pure NaOH showed only limited reaction with NO. However, the mixture of NaOH and carbon (NaOH + C) significantly enhanced the reaction. This mixture increased the NO removal up to 100%. Subsequently, denitrification lasted for a long time period, with about 25% of NO removal. The pyrolysis characteristic of NaNO3, a compound resulting from denitrification, was also affected by the presence of carbon. In the presence of carbon, the NOx emission resulting from the pyrolysis of NaNO3 was reduced by a factor of 6. Since the denitrification phenomena appeared only in the absence of oxygen, a model of oxygen distribution in a burning coal briquette was employed to explain the reactions occurring in real combustion of coal briquettes. PMID:15773493

  3. Space shuttle exhaust cloud properties

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Keller, V. W.

    1983-01-01

    A data base describing the properties of the exhaust cloud produced by the launch of the Space Transportation System and the acidic fallout observed after each of the first four launches was assembled from a series of ground and aircraft based measurements made during the launches of STS 2, 3, and 4. Additional data were obtained from ground-based measurements during firings of the 6.4 percent model of the Solid Rocket Booster at the Marshall Center. Analysis indicates that the acidic fallout is produced by atomization of the deluge water spray by the rocket exhaust on the pad followed by rapid scavening of hydrogen chloride gas aluminum oxide particles from the Solid Rocket Boosters. The atomized spray is carried aloft by updrafts created by the hot exhaust and deposited down wind. Aircraft measurements in the STS-3 ground cloud showed an insignificant number of ice nuclei. Although no measurements were made in the column cloud, the possibility of inadvertent weather modification caused by the interaction of ice nuclei with natural clouds appears remote.

  4. Exhaust gas recirculation control system

    SciTech Connect

    Yamada, K.

    1981-02-03

    An E.G.R. control system includes a pressure modulator operative to modulate the magnitude of the port vacuum as applied to a diaphragm type actuator of an E.G.R. valve. The modulator comprises a housing and a diaphragm assembly disposed in the housing and consisting of a pair of diaphragms and a member connecting the diaphragms so that they are deformed simultaneously. The diaphragm assembly divides the interior of the housing into first, second and third chambers which are communicated with the engine carburetor venturi, vented to the atmosphere and communicated with the E.G.R. passage between the E.G.R. valve and a fixed restriction in the E.G.R. passage upstream of the E.G.R. valve, respectively, so that the diaphragm assembly is moved in response to variation in the venturi vacuum and also in response to variation in the exhaust gas pressure in the E.G.R. passage between the restriction and the E.G.R. valve. A valve member is mounted on the diaphragm assembly for movement therewith to control the flow of the atmospheric air from the second chamber into the E.G.R. valve actuator so that the port vacuum as applied to the E.G.R. valve actuator is modulated. The controlled flow of the recirculated exhaust gases through the E.G.R. passage from the exhaust pipe into the intake pipe is in proportion to the intake air flow.

  5. Forecast of jet engine exhaust emissions for future high altitude commercial aircraft

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Ingebo, R. D.

    1974-01-01

    Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are presented. The forecasts are based on: (1) current knowledge of emission characteristics of combustors and augmentors; (2) the current status of combustion research in emission reduction technology; (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft. Results are presented for cruise conditions in terms of an emission index, g pollutant/kg fuel. Two sets of engine exhaust emission predictions are presented: the first, based on an independent NASA study and the second, based on the consensus of an ad hoc committee composed of industry, university, and government representatives. The consensus forecasts are in general agreement with the NASA forecasts.

  6. 40 CFR 600.112-08 - Exhaust sample analysis.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy and Carbon-Related Exhaust Emission Test Procedures § 600.112-08 Exhaust sample analysis. The exhaust sample analysis must...

  7. Correlates of work exhaustion for medical technologists.

    PubMed

    Blau, Gary; Tatum, Donna Surges; Ward-Cook, Kory

    2003-01-01

    In a sample of 196 medical technologists followed over a 4-year period, this study investigated if work-related demand and resource variables were related to subsequent work exhaustion. As hypothesized, increased levels of perceived work interference with family and task load and lower organizational support were related to higher subsequent work exhaustion. Distributive justice, as an intervening variable, had direct and partially mediating effects on work exhaustion. Distributive justice partially mediated the effects of work interfering with family and organizational support on work exhaustion. Distributive justice also mediated the impact of procedural justice on work exhaustion. Study limitations and future research issues are discussed. PMID:14526896

  8. Hydrogen cyanide exhaust emissions from in-use motor vehicles.

    PubMed

    Baum, Marc M; Moss, John A; Pastel, Stephen H; Poskrebyshev, Gregory A

    2007-02-01

    Motor vehicle exhaust emissions are known to contain hydrogen cyanide (HCN), but emission rate data are scarce and, in the case of idling vehicles, date back over 20 years. For the first time, vehicular HCN exhaust emissions from a modern, in-use fleet at idle have been measured. The 14 tested light duty motor vehicles were operating at idle as these conditions are associated with the highest risk exposure scenarios (i.e., enclosed spaces). Vehicular HCN was detected in 89% of the sampled exhaust streams and did not correlate with instantaneous air-fuel-ratio or with any single, coemitted pollutant. However, a moderate correlation between HCN emissions and the product of carbon monoxide and nitric oxide emissions was observed under cold-start conditions. Fleet average, cold-start, undiluted HCN emissions were 105 +/- 97 ppbV (maximum: 278 ppbV), whereas corresponding emissions from vehicles operating under stabilized conditions were 79 +/- 71 ppbV (maximum: 245 ppbV); mean idle fleet HCN emission rates were 39 +/- 35 and 21 +/- 18 microg-min(-1) for cold-start and stabilized vehicles, respectively. The significance of these results is discussed in terms of HCN emissions inventories in the South Coast Air Basin of California and of health risks due to exposure to vehicular HCN.

  9. Combustion Enhancement in Scramjet-Operation of a RBCC Engine

    NASA Astrophysics Data System (ADS)

    Sadatake Tomioka, By; Ryohei Kobayashi; Murakami, Atsuo; Shuichi Ueda; Komuro, Tomoyuki; Katsuhiro Itoh, And

    Combination of a scramjet (supersonic combustion ramjet) flow-pass with embedded rocket engines (the combined system termed as Rocket Based Combined Cycle engine) are expected to be the most effective propulsion system for Booster stage of space launch vehicles. At hypersonic regime, it will be operated at rather high rocket engine output for final acceleration with some Isp gains due to air-breathing effects. In this regime, attaining thrust at this high-speed regime becomes very difficult, so that parallel injection of the fuel for scramjet combustion is favorable as the momentum of the injection can contribute to the thrust production. Thus, embedded rocket chamber was supposed to the operated as fuel rich gas generator at very high output. This configuration was tested at simulated flight Mach number of 7-11 at High Enthalpy Shock Tunnel (HIEST) with detonation tube as the source of the simulated rocket exhaust. However, combustion of the residual fuel in the rocket exhaust with airflow could not be attained. Direct-connect combustor tests were performed to evaluate effectiveness of a combustion enhancement technique termed auxiliary injection, i.e., a portion of fuel to be directly injected into airflow to provide ignition source for the residual fuel. Results of both the engine model tests at HIEST and the direct-connect tests are summarized and presented, and modification to the engine model for combustion enhancement was proposed.

  10. Turbocharged engine exhaust gas recirculation system

    SciTech Connect

    Stachowicz, R.W.

    1984-01-24

    Improved exhaust gas recirculation systems for turbocharged gas engines that include an exhaust pipe, a turbocharger connected thereto, and a carburetor connected with a source of gas for the engine. The recirculation system includes an air conduit extending from the turbocharger compressor discharge to a venturi, an exhaust gas conduit that extends from a connection with the exhaust pipe between the engine and the turbocharger to the venturi, a second air conduit that extends from the exhaust pipe to a connection with the first air conduit, and control valves located in the exhaust gas conduit and in the second air conduit. The valves are closed when the engine is being started or idling at no load and open when a load is imposed or when engine rpm's are increased. No pumps, blowers, etc. are needed because the system operates on a differential in pressure created within the system to cause the exhaust gas recirculation.

  11. Evaluation of catalytic combustion of actual coal-derived gas

    NASA Astrophysics Data System (ADS)

    Blanton, J. C.; Shisler, R. A.

    1982-02-01

    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  12. Evaluation of catalytic combustion of actual coal-derived gas

    NASA Technical Reports Server (NTRS)

    Blanton, J. C.; Shisler, R. A.

    1982-01-01

    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  13. Opportunities in pulse combustion

    SciTech Connect

    Brenchley, D.L.; Bomelburg, H.J.

    1985-10-01

    In most pulse combustors, the combustion occurs near the closed end of a tube where inlet valves operate in phase with the pressure amplitude variations. Thus, within the combustion zone, both the temperature and the pressure oscillate around a mean value. However, the development of practical applications of pulse combustion has been hampered because effective design requires the right combination of the combustor's dimensions, valve characteristics, fuel/oxidizer combination, and flow pattern. Pulse combustion has several additional advantages for energy conversion efficiency, including high combustion and thermal efficiency, high combustion intensity, and high convective heat transfer rates. Also, pulse combustion can be self-aspirating, generating a pressure boost without using a blower. This allows the use of a compact heat exchanger that may include a condensing section and may obviate the need for a chimney. In the last decade, these features have revived interest in pulse combustion research and development, which has resulted in the development of a pulse combustion air heater by Lennox, and a pulse combustion hydronic unit by Hydrotherm, Inc. To appraise this potential for energy savings, a systematic study was conducted of the many past and present attempts to use pulse combustion for practical purposes. The authors recommended areas where pulse combustion technology could possibly be applied in the future and identified areas in which additional R and D would be necessary. Many of the results of the study project derived from a special workshop on pulse combustion. This document highlights the main points of the study report, with particular emphasis on pulse combustion application in chemical engineering.

  14. Simulation and experiment for oxygen-enriched combustion engine using liquid oxygen to solidify CO2

    NASA Astrophysics Data System (ADS)

    Liu, Yongfeng; Jia, Xiaoshe; Pei, Pucheng; Lu, Yong; Yi, Li; Shi, Yan

    2016-01-01

    For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation (EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.

  15. Thief carbon catalyst for oxidation of mercury in effluent stream

    DOEpatents

    Granite, Evan J.; Pennline, Henry W.

    2011-12-06

    A catalyst for the oxidation of heavy metal contaminants, especially mercury (Hg), in an effluent stream is presented. The catalyst facilitates removal of mercury through the oxidation of elemental Hg into mercury (II) moieties. The active component of the catalyst is partially combusted coal, or "Thief" carbon, which can be pre-treated with a halogen. An untreated Thief carbon catalyst can be self-promoting in the presence of an effluent gas streams entrained with a halogen.

  16. Method for destroying hazardous organics and other combustible materials in a subcritical/supercritical reactor

    DOEpatents

    Janikowski, Stuart K.

    2000-01-01

    A waste destruction method using a reactor vessel to combust and destroy organic and combustible waste, including the steps of introducing a supply of waste into the reactor vessel, introducing a supply of an oxidant into the reactor vessel to mix with the waste forming a waste and oxidant mixture, introducing a supply of water into the reactor vessel to mix with the waste and oxidant mixture forming a waste, water and oxidant mixture, reciprocatingly compressing the waste, water and oxidant mixture forming a compressed mixture, igniting the compressed mixture forming a exhaust gas, and venting the exhaust gas into the surrounding atmosphere.

  17. An assessment of consistence of exhaust gas emission test results obtained under controlled NEDC conditions

    NASA Astrophysics Data System (ADS)

    Balawender, K.; Jaworski, A.; Kuszewski, H.; Lejda, K.; Ustrzycki, A.

    2016-09-01

    Measurements concerning emissions of pollutants contained in automobile combustion engine exhaust gases is of primary importance in view of their harmful impact on the natural environment. This paper presents results of tests aimed at determining exhaust gas pollutant emissions from a passenger car engine obtained under repeatable conditions on a chassis dynamometer. The test set-up was installed in a controlled climate chamber allowing to maintain the temperature conditions within the range from -20°C to +30°C. The analysis covered emissions of such components as CO, CO2, NOx, CH4, THC, and NMHC. The purpose of the study was to assess repeatability of results obtained in a number of tests performed as per NEDC test plan. The study is an introductory stage of a wider research project concerning the effect of climate conditions and fuel type on emission of pollutants contained in exhaust gases generated by automotive vehicles.

  18. Oxygen Smelting of Copper Concentrate With Exhaust SO2 Gas Recycling

    NASA Astrophysics Data System (ADS)

    Yazawa, Akira; Tozawa, Kazuteru

    1982-03-01

    In the conventional copper smelting process, the concentrate is usually oxidized by air, and heat is supplied by the combustion of fuel. Considerable dust and heat losses, due to the large quantity of exhaust gas, are inevitable. The use of oxygen greatly decreases such losses, but the copper matte grade is limited to around 50% to keep the furnace temperature at an optimum level. An oxygen smelting process, with exhaust SO2 recycling, is proposed based upon material and heat balance calculations. When 60% Cu matte is produced, the participating amounts of heat and gas are around 62% and 28% (14% if final gas is considered) of those of the conventional process. A considerable decrease in capital and operating costs can be expected when considering a new smelter. Because a small volume of high-strength SO2 exhaust gas is produced, this process has large flexibility with respect to sulfur by-products and offers a major advantage in environmentally sensitive locations.

  19. Real Time Diagnostics of Jet Engine Exhaust Plumes Using a Chirped QC Laser Spectrometer

    NASA Astrophysics Data System (ADS)

    Hay, K. G.; Duxbury, G.; Langford, N.

    2010-06-01

    Quantitative measurements of real-time variations of the chemical composition of a jet engine exhaust plume is demonstrated using a 4.86 μmn intra-pulse quantum cascade laser spectrometer. The measurements of the gas turbine exhaust were carried out in collaboration with John Black and Mark Johnson at Rolls Royce. The recording of five sets of averaged spectra a second has allowed us to follow the build up of the combustion products within the exhaust, and to demonstrate the large variation of the integrated absorption of these absorption lines with temperature. The absorption cross sections of the lines of both carbon monoxide and water increase with temperature, whereas those of the three main absorption lines of carbon dioxide decrease. At the steady state limit the absorption lines of carbon dioxide are barely visible, and the spectrum is dominated by absorption lines of carbon monoxide and water.

  20. The characteristics of performance and exhaust emissions of a diesel engine using a biodiesel with antioxidants.

    PubMed

    Ryu, Kyunghyun

    2010-01-01

    The aim of this study is to investigate the effects of antioxidants on the oxidation stability of biodiesel fuel, the engine performance and the exhaust emissions of a diesel engine. Biodiesel fuel used in the study was derived from soybean oil. The results show that the efficiency of antioxidants is in the order TBHQ>PrG>BHA>BHT>alpha-tocopherol. The oxidative stability of biodiesel fuel attained the 6-h quality standard with 100 ppm TBHQ and with 300 ppm PrG in biodiesel fuel. Combustion characteristics and exhaust emissions in diesel engine were not influenced by the addition of antioxidants in biodiesel fuel. The BSFC of biodiesel fuel with antioxidants decreased more than that of biodiesel fuel without antioxidants, but no trends were observed according to the type or amount of antioxidant. Antioxidants had few effects on the exhaust emissions of a diesel engine running on biodiesel. PMID:19525107

  1. The characteristics of performance and exhaust emissions of a diesel engine using a biodiesel with antioxidants.

    PubMed

    Ryu, Kyunghyun

    2010-01-01

    The aim of this study is to investigate the effects of antioxidants on the oxidation stability of biodiesel fuel, the engine performance and the exhaust emissions of a diesel engine. Biodiesel fuel used in the study was derived from soybean oil. The results show that the efficiency of antioxidants is in the order TBHQ>PrG>BHA>BHT>alpha-tocopherol. The oxidative stability of biodiesel fuel attained the 6-h quality standard with 100 ppm TBHQ and with 300 ppm PrG in biodiesel fuel. Combustion characteristics and exhaust emissions in diesel engine were not influenced by the addition of antioxidants in biodiesel fuel. The BSFC of biodiesel fuel with antioxidants decreased more than that of biodiesel fuel without antioxidants, but no trends were observed according to the type or amount of antioxidant. Antioxidants had few effects on the exhaust emissions of a diesel engine running on biodiesel.

  2. Application of hybrid evolutionary algorithms to low exhaust emission diesel engine design

    NASA Astrophysics Data System (ADS)

    Jeong, S.; Obayashi, S.; Minemura, Y.

    2008-01-01

    A hybrid evolutionary algorithm, consisting of a genetic algorithm (GA) and particle swarm optimization (PSO), is proposed. Generally, GAs maintain diverse solutions of good quality in multi-objective problems, while PSO shows fast convergence to the optimum solution. By coupling these algorithms, GA will compensate for the low diversity of PSO, while PSO will compensate for the high computational costs of GA. The hybrid algorithm was validated using standard test functions. The results showed that the hybrid algorithm has better performance than either a pure GA or pure PSO. The method was applied to an engineering design problem—the geometry of diesel engine combustion chamber reducing exhaust emissions such as NOx, soot and CO was optimized. The results demonstrated the usefulness of the present method to this engineering design problem. To identify the relation between exhaust emissions and combustion chamber geometry, data mining was performed with a self-organising map (SOM). The results indicate that the volume near the lower central part of the combustion chamber has a large effect on exhaust emissions and the optimum chamber geometry will vary depending on fuel injection angle.

  3. Combustion analysis and its optimization in two-stroke engines

    SciTech Connect

    Ishibe, Noriaki; Ohira, Tetsuya

    1995-12-31

    The purpose of this study is to show cycle-to-cycle combustion variation in transient conditions of quick throttle opening and to control the combustion fluctuation and improve acceleration in a two-stroke motorcycle engine. Two phases of engine operation were focused on: the low-load condition before quick throttle opening, and the transient condition after quick throttle opening. The time-series variation of the heat release rate based on the in-cylinder pressure, the engine-speed and the exhaust pressure variation were measured simultaneously, in an engine with a new multiple-timing-ignition-system, and in an engine with a modified exhaust port. Stable ignition performance and fast burning velocity were the keys to attaining smooth acceleration.

  4. Tritium uptake by fish in a small stream. [Largemouth Bass

    SciTech Connect

    Eaton, D.; Murphy, C.E. Jr.

    1992-09-17

    The tritium concentration in the water from freeze drying and the water from combustion of the dry tissue was measured in fish (largemouth bass), stream macrophytes, and streamside vegetation at five sampling locations in Four Mile Branch on the Savannah River Site (SRS). Four Mile Branch has elevated tritium concentration, largely from migration of water through the soil from adjacent seepage basins that received industrial wastewater containing tritium. The stream water and the vegetation, through the food chain, are thought to be the two sources of tritium reaching the fish. Comparision of the tritium activity of the freeze-dried water from fish flesh and of the sources of tritium, indicates that the fish flesh approaches a steady-state concentration with the stream water. The freeze-dry water from the vegetation is also at a lower specific activity than the stream water. The water of combustion from the vegetation is also at a lower specific activity than stream water. The water of combustion from the fish flesh is somewhat higher in specific activity than the stream water or the water in the fish. The distribution of tritium among the components of this system can be explain in terms of the turnover of water and organic hydrogen in the components.

  5. Tritium uptake by fish in a small stream. Revision 1

    SciTech Connect

    Eaton, D.; Murphy, C.E. Jr.

    1992-09-17

    The tritium concentration in the water from freeze drying and the water from combustion of the dry tissue was measured in fish (largemouth bass), stream macrophytes, and streamside vegetation at five sampling locations in Four Mile Branch on the Savannah River Site (SRS). Four Mile Branch has elevated tritium concentration, largely from migration of water through the soil from adjacent seepage basins that received industrial wastewater containing tritium. The stream water and the vegetation, through the food chain, are thought to be the two sources of tritium reaching the fish. Comparision of the tritium activity of the freeze-dried water from fish flesh and of the sources of tritium, indicates that the fish flesh approaches a steady-state concentration with the stream water. The freeze-dry water from the vegetation is also at a lower specific activity than the stream water. The water of combustion from the vegetation is also at a lower specific activity than stream water. The water of combustion from the fish flesh is somewhat higher in specific activity than the stream water or the water in the fish. The distribution of tritium among the components of this system can be explain in terms of the turnover of water and organic hydrogen in the components.

  6. Boiler using combustible fluid

    DOEpatents

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  7. Catalytic combustion over hexaaluminates

    SciTech Connect

    Ramesh, K.S.; Kingsley, J.J.; Hubler, T.L.; McCready, D.E.; Cox, J.L.

    1997-12-31

    Combustion is the oldest and most extensively used process for the production of light, heat, and energy utilization. Mankind has sought to control combustion since prehistoric times to more effectively utilize the combustible material, control the products of combustion, and harness the energy released during combustion. Catalysts provide the means to control the reactions of combustion beyond what can be achieved in the homogeneous gas phase (1). Catalysts also enable operation outside the range of flammability limits and control atmospheric pollutants of combustion, mainly NO{sub x}, carbon monoxide, and particles of incomplete combustion (soot). The major technical difficulty that has hindered widespread application of catalytic combustion devices is their poor performance, particularly durability of their ceramic substrates and catalytically active phases in the high temperature environment. Catalytic combustion of hydrocarbons over metals and metal oxide catalysts has been explored extensively. Recent reviews of materials for high temperature catalytic combustion have been provided by Marcus et al. (2) and Trim (3). Hexaaluminates which show good thermal stability above 1200{degrees}C are one class of metal oxides receiving consideration for application in high temperature combustion devices. Matsuda et al. (4) have developed thermally stable La-hexaaluminates with the same layer structure as Ba-hexaaluminate and have investigated their catalytic application. Machida et al. (5-7) have investigated the catalytic properties of a number of hexaaluminates of BaMAl{sub 11}O{sub 19-{alpha}}(M=Cr, Mn,Fe,Co,Ni). Here we report the synthesis, properties and catalytic combustion of some new hexaaluminates.

  8. Enhancement of automotive exhaust heat recovery by thermoelectric devices

    SciTech Connect

    Ibrahim, Essam; Szybist, James P; Parks, II, James E

    2010-01-01

    In an effort to improve automobile fuel economy, an experimental study is undertaken to explore practical aspects of implementing thermoelectric devices for exhaust gas energy recovery. A highly instrumented apparatus consisting of a hot (exhaust gas) and a cold (coolant liquid) side rectangular ducts enclosing the thermoelectric elements has been built. Measurements of thermoelectric voltage output and flow and surface temperatures were acquired and analyzed to investigate the power generation and heat transfer properties of the apparatus. Effects of inserting aluminum wool packing material inside the hot side duct on augmentation of heat transfer from the gas stream to duct walls were studied. Data were collected for both the unpacked and packed cases to allow for detection of packing influence on flow and surface temperatures. Effects of gas and coolant inlet temperatures as well as gas flow rate on the thermoelectric power output were examined. The results indicate that thermoelectric power production is increased at higher gas inlet temperature or flow rate. However, thermoelectric power generation decreases with a higher coolant temperature as a consequence of the reduced hot-cold side temperature differential. For the hot-side duct, a large temperature gradient exists between the gas and solid surface temperature due to poor heat transfer through the gaseous medium. Adding the packing material inside the exhaust duct enhanced heat transfer and hence raised hot-side duct surface temperatures and thermoelectric power compared to the unpacked duct, particularly where the gas-to-surface temperature differential is highest. Therefore it is recommended that packing of exhaust duct becomes common practice in thermoelectric waste energy harvesting applications.

  9. Tunable Diode Laser Sensor for Monitoring and Control of Harsh Combustion Environments

    SciTech Connect

    VonDrasek, William; Melsio-Pubill, Anna

    2006-05-30

    This work represents the collaborative effort between American Air Liquide and Physical Sciences, Inc. for developing a sensor based on near-IR tunable diode lasers (TDL). The multi-species capability of the sensor for simultaneous monitoring of CO, O2, and H2O concentration as well as gas temperature is ideal for in-situ monitoring on industrial furnaces. The chemical species targeted are fundamental for controlling the combustion space for improved energy efficiency, reduced pollutants, and improved product quality, when coupling the measurement to a combustion control system. Several add-on modules developed provide flexibility in the system configuration for handling different process monitoring applications. For example, the on-Demand Power Control system for the 1.5 ?m laser is used for high particle density exhaust streams where laser transmission is problematic. For long-distance signal collection a fiber optic communication system is used to reduce noise pick-up. Finally, hardened modules to withstand high ambient temperatures, immune to EMF interference, protection from flying debris, and interfaced with pathlength control laser beam shielding probes were developed specifically for EAF process monitoring. Demonstration of these different system configurations was conducted on Charter Steel's reheat furnace, Imco Recycling, Inc. (now Aleris International, Inc.) aluminum reverberatory furnace, and Gerdau Ameristeel's EAF. Measurements on the reheat furnace demonstrated zone monitoring with the measurement performed close to the steel billet. Results from the aluminum furnace showed the benefit of measuring in-situ near the bath. In this case, low-level furnace optimization was performed and demonstrated 5% fuel savings. Monitoring tests on the EAF off-gas demonstrated the level of industrialization of the sensor to survive the harsh EAF environment. Long-term testing on the EAF has been on-going for over 6 months with essentially zero maintenance

  10. Oil combustion and childhood cancers

    PubMed Central

    Knox, E

    2005-01-01

    Study objectives: To identify specific toxic atmospheric emissions and their industrial sources in Great Britain. To link them with each other and with the birth addresses of children dying from cancer. To identify specific causal agents and sources. Design: Birth and death addresses of children dying from cancer were linked to emissions hotspots for specific chemicals: and to related source installations. Among those who moved house, distances from each address to the nearest hazard were compared. Relative excesses of close-to-hazard birth addresses showed high prenatal or early postnatal risks. Relative risks for individual and for combined exposures were measured. Setting and subjects: Atmospheric emissions hotspots (UK, 2001) published as maps on the internet, were converted to coordinates. Industrial sites were identified through trade directories and map inspections. Child cancer addresses for 1955–80 births were extracted from an earlier inquiry and their postcodes converted to map references. Main results: There were excess relative risks (RR) within 0.3 km of hotspots for carbon monoxide, PM10 particles, nitrogen oxides, 1,3-butadiene, benzene, dioxins, benzo(a)pyrene, and volatiles; and within 1.0 km of bus stations, hospitals, heavy transport centres, railways, and oil installations. Some excesses were attributable to mutual confounding, but 1,3-butadiene and carbon monoxide, mainly derived from engine exhausts, were powerful independent predictors. They were strongly reinforced when associated with bus stations, hospitals, railways, oil installations, and industrial transport centres; RR = 12.6 for joint <0.5 km exposure to bus stations and 1,3-butadiene. Conclusions: Childhood cancers are strongly determined by prenatal or early postnatal exposures to oil based combustion gases, especially from engine exhausts. 1,3-butadiene, a known carcinogen, may be directly causal. PMID:16100313

  11. Exhaust gas clean up process

    DOEpatents

    Walker, R.J.

    1988-06-16

    A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

  12. Exhaust gas clean up process

    DOEpatents

    Walker, Richard J.

    1989-01-01

    A method of cleaning an exhaust gas containing particulates, SO.sub.2 and NO.sub.x includes prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO.sub.x and SO.sub.2, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO.sub.x is removed as N.sub.2 or nitrogen-sulfonate ions and the oxides of sulfur are removed as a vaulable sulfate salt.

  13. Method for removal of nitrogen oxides from stationary combustion sources

    NASA Technical Reports Server (NTRS)

    Cooper, Charles D. (Inventor); Clausen, III, Christian A. (Inventor); Collins, Michelle M. (Inventor)

    2004-01-01

    A method for removing NO.sub.X from gas streams emanating from stationary combustion sources and manufacturing plants utilizes the injection of hydrogen peroxide into the gas stream for rapid gas-phase oxidation of NO to NO.sub.2 and water-soluble nitrogen acids HNO.sub.2 and HNO.sub.3. The nitrogen acids may be removed from the oxidized gas stream by wet scrubbing or by contact with a particulate alkaline material to form a nitrite/nitrate salt.

  14. Combustible radioactive waste treatment by incineration and chemical digestion

    SciTech Connect

    Stretz, L.A.; Crippen, M.D.; Allen, C.R.

    1980-05-28

    A review is given of present and planned combustible radioactive waste treatment systems in the US. Advantages and disadvantages of various systems are considered. Design waste streams are discussed in relation to waste composition, radioactive contaminants by amount and type, and special operating problems caused by the waste.

  15. Combustion of Micropowdered Biomass

    NASA Astrophysics Data System (ADS)

    Geil, Ethan; Thorne, Robert

    2009-03-01

    Combustion of finely powdered biomass has the potential to replace heating oil, which accounts for a significant fraction of US oil consumption, in heating, cooling and local power generation applications. When ground to 30-150 micron powders and dispersed in air, wood and other biomass can undergo deflagrating combustion, as occurs with gaseous and dispersed liquid fuels. Combustion is very nearly complete, and in contrast to sugar/starch or cellulose-derived ethanol, nearly all of the available plant mass is converted to usable energy so the economics are much more promising. We are exploring the fundamental combustion science of biomass powders in this size range. In particular, we are examining how powder size, powder composition (including the fraction of volatile organics) and other parameters affect the combustion regime and the combustion products.

  16. Lump wood combustion process

    NASA Astrophysics Data System (ADS)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  17. Coal combustion products

    USGS Publications Warehouse

    Kalyoncu, R.S.; Olson, D.W.

    2001-01-01

    Coal-burning powerplants, which supply more than half of U.S. electricity, also generate coal combustion products, which can be both a resource and a disposal problem. The U.S. Geological Survey collaborates with the American Coal Ash Association in preparing its annual report on coal combustion products. This Fact Sheet answers questions about present and potential uses of coal combustion products.

  18. Numerical simulations in combustion

    NASA Technical Reports Server (NTRS)

    Chung, T. J.

    1989-01-01

    This paper reviews numerical simulations in reacting flows in general and combustion phenomena in particular. It is shown that use of implicit schemes and/or adaptive mesh strategies can improve convergence, stability, and accuracy of the solution. Difficulties increase as turbulence and multidimensions are considered, particularly when finite-rate chemistry governs the given combustion problem. Particular attention is given to the areas of solid-propellant combustion dynamics, turbulent diffusion flames, and spray droplet vaporization.

  19. Ignition and flame stabilization of a strut-jet RBCC combustor with small rocket exhaust.

    PubMed

    Hu, Jichao; Chang, Juntao; Bao, Wen

    2014-01-01

    A Rocket Based Combined Cycle combustor model is tested at a ground direct connected rig to investigate the flame holding characteristics with a small rocket exhaust using liquid kerosene. The total temperature and the Mach number of the vitiated air flow, at exit of the nozzle are 1505 K and 2.6, respectively. The rocket base is embedded in a fuel injecting strut and mounted in the center of the combustor. The wall of the combustor is flush, without any reward step or cavity, so the strut-jet is used to make sure of the flame stabilization of the second combustion. Mass flow rate of the kerosene and oxygen injected into the rocket is set to be a small value, below 10% of the total fuel when the equivalence ratio of the second combustion is 1. The experiment has generated two different kinds of rocket exhaust: fuel rich and pure oxygen. Experiment result has shown that, with a relative small total mass flow rate of the rocket, the fuel rich rocket plume is not suitable for ignition and flame stabilization, while an oxygen plume condition is suitable. Then the paper conducts a series of experiments to investigate the combustion characteristics under this oxygen pilot method and found that the flame stabilization characteristics are different at different combustion modes.

  20. Ignition and Flame Stabilization of a Strut-Jet RBCC Combustor with Small Rocket Exhaust

    PubMed Central

    2014-01-01

    A Rocket Based Combined Cycle combustor model is tested at a ground direct connected rig to investigate the flame holding characteristics with a small rocket exhaust using liquid kerosene. The total temperature and the Mach number of the vitiated air flow, at exit of the nozzle are 1505 K and 2.6, respectively. The rocket base is embedded in a fuel injecting strut and mounted in the center of the combustor. The wall of the combustor is flush, without any reward step or cavity, so the strut-jet is used to make sure of the flame stabilization of the second combustion. Mass flow rate of the kerosene and oxygen injected into the rocket is set to be a small value, below 10% of the total fuel when the equivalence ratio of the second combustion is 1. The experiment has generated two different kinds of rocket exhaust: fuel rich and pure oxygen. Experiment result has shown that, with a relative small total mass flow rate of the rocket, the fuel rich rocket plume is not suitable for ignition and flame stabilization, while an oxygen plume condition is suitable. Then the paper conducts a series of experiments to investigate the combustion characteristics under this oxygen pilot method and found that the flame stabilization characteristics are different at different combustion modes. PMID:24578655

  1. Finite-rate water condensation in combustion-heated wind tunnels

    NASA Technical Reports Server (NTRS)

    Erickson, Wayne D.; Mall, Gerald H.; Prabhu, Ramadas K.

    1988-01-01

    A quasi-one-dimensional method for computing finite rate nucleation and droplet growth of water in a supersonic expansion of combustion products is presented. Sample computations are included for the Langley 8 foot High Temperature Tunnel, but the method can also be applied to other combustion heated wind tunnels. The sample results indicate that the free stream static pressure can be in the range of 25 to 60 percent greater than that computed for isentropic nozzle flow without water condensation. The method provides a tool for examining the effects of water condensation on static state properties and velocity of the supersonic stream in combustion heated wind tunnels.

  2. Method and system for the removal of oxides of nitrogen and sulfur from combustion processes

    DOEpatents

    Walsh, John V.

    1987-12-15

    A process for removing oxide contaminants from combustion gas, and employing a solid electrolyte reactor, includes: (a) flowing the combustion gas into a zone containing a solid electrolyte and applying a voltage and at elevated temperature to thereby separate oxygen via the solid electrolyte, (b) removing oxygen from that zone in a first stream and removing hot effluent gas from that zone in a second stream, the effluent gas containing contaminant, (c) and pre-heating the combustion gas flowing to that zone by passing it in heat exchange relation with the hot effluent gas.

  3. Advanced reburning for reduction of NO sub x emissions in combustion systems

    SciTech Connect

    Seeker, W.R.; Chen, S.L.; Kramlich, J.C.

    1992-08-18

    This patent describes a process for reducing nitrogen oxides in combustion emission systems. It comprises mixing a reburning fuel with combustion emissions in a gaseous reburning zone such that the reburning zone is substantially oxygen deficient; passing the resulting mixture of reburning fuel and combustion emissions into a first burnout zone; introducing a first stream of burnout air into the first burnout zone; advancing the resulting mixture from the first burnout zone to a second burnout zone; and introducing a second stream of burnout air into the second burnout zone.

  4. Technique for atmospheric rate chemistry calculations. [of SST exhaust

    NASA Technical Reports Server (NTRS)

    Matloff, G. L.

    1976-01-01

    The possibility that predictions of atmospheric photochemistry/transport models are sensitive to uncertainties in reaction rates and other inputs stresses the need for rapid numerical integration schemes in rate photochemistry problems. Reducing the computational burden has a major merit in facilitating sensitivity studies to assess the effect of uncertainties on predicted ozone diminutions from NOx (NO + NO2) in the exhaust plume of SST engines. The paper discusses the validity of an algorithmic approach to integration of rate chemistry problems in combustion, developed by Rubel and Baronti for an approximate calculation of the production rate of the i-th chemical species involved. An analysis of two projected SST engines confirms the validity of the proposed algorithm. Because of the relative arithmetical simplicity, it may be easier to treat diffusion rate chemistry calculations using the Rubel and Baronti approximation than would be possible by other approaches.

  5. Exhaust gas measurements in a propane fueled swirl stabilized combustor

    NASA Technical Reports Server (NTRS)

    Aanad, M. S.

    1982-01-01

    Exhaust gas temperature, velocity, and composition are measured and combustor efficiencies are calculated in a lean premixed swirl stabilized laboratory combustor. The radial profiles of the data between the co- and the counter swirl cases show significant differences. Co-swirl cases show evidence of poor turbulent mixing across the combustor in comparison to the counter-swirl cases. NO sub x levels are low in the combustor but substantial amounts of CO are present. Combustion efficiencies are low and surprisingly constant with varying outer swirl in contradiction to previous results under a slightly different inner swirl condition. This difference in the efficiency trends is expected to be a result of the high sensitivity of the combustor to changes in the inner swirl. Combustor operation is found to be the same for propane and methane fuels. A mechanism is proposed to explain the combustor operation and a few important characteristics determining combustor efficiency are identified.

  6. T cell exhaustion during persistent viral infections.

    PubMed

    Kahan, Shannon M; Wherry, E John; Zajac, Allan J

    2015-05-01

    Although robust and highly effective anti-viral T cells contribute to the clearance of many acute infections, viral persistence is associated with the development of functionally inferior, exhausted, T cell responses. Exhaustion develops in a step-wise and progressive manner, ranges in severity, and can culminate in the deletion of the anti-viral T cells. This disarming of the response is consequential as it compromises viral control and potentially serves to dampen immune-mediated damage. Exhausted T cells are unable to elaborate typical anti-viral effector functions. They are characterized by the sustained upregulation of inhibitory receptors and display a gene expression profile that distinguishes them from prototypic effector and memory T cell populations. In this review we discuss the properties of exhausted T cells; the virological and immunological conditions that favor their development; the cellular and molecular signals that sustain the exhausted state; and strategies for preventing and reversing exhaustion to favor viral control.

  7. Combustion pressure sensor

    SciTech Connect

    Bettman, M.

    1986-04-29

    A combustion pressure sensor is described for mounting on an internal combustion engine so as to have access to the interior of a combustion cylinder. The sensor consists of: a first diaphragm means adjacent a combustion region for deflecting as a function of the magnitude of adjacent pressure in the combustion region, and for acting as a gas tight seal between the combustion region and an interior volume of the combustion pressure sensor means; a second diaphragm means, spaced from the first diaphragm means, for deflecting as a function of the deflection of the first diaphragm and generating a signal indicative of the deflection of the second diaphragm means; a force transmitting means located between the first diaphragm means and the second diaphragm means for transmitting movement from the first diaphragm means to the second diaphragm means, and for reducing the speed and amplitude of heat tramsmission from the first diaphragm means to the second diaphragm means; and the second diaphragm including a steel member having a portion coated with an electrically insulating glass enamel, upon which is formed a thick film piezoresistor for use as a thick film resistive strain gauge and overlapping thick film conductor terminations for use as electrically conductive contacts, the thick film piezoresistor having a baseline resistance which can be temperature compensated by resistance measurement between successive combustion firings in the interior of the combustion cylinder.

  8. Combustion Byproducts Recycling Consortium

    SciTech Connect

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  9. Tripropellant combustion process

    NASA Technical Reports Server (NTRS)

    Kmiec, T. D.; Carroll, R. G.

    1988-01-01

    The addition of small amounts of hydrogen to the combustion of LOX/hydrocarbon propellants in large rocket booster engines has the potential to enhance the system stability. Programs being conducted to evaluate the effects of hydrogen on the combustion of LOX/hydrocarbon propellants at supercritical pressures are described. Combustion instability has been a problem during the development of large hydrocarbon fueled rocket engines. At the higher combustion chamber pressures expected for the next generation of booster engines, the effect of unstable combustion could be even more destructive. The tripropellant engine cycle takes advantage of the superior cooling characteristics of hydrogen to cool the combustion chamber and a small amount of the hydrogen coolant can be used in the combustion process to enhance the system stability. Three aspects of work that will be accomplished to evaluate tripropellant combustion are described. The first is laboratory demonstration of the benefits through the evaluation of drop size, ignition delay and burning rate. The second is analytical modeling of the combustion process using the empirical relationship determined in the laboratory. The third is a subscale demonstration in which the system stability will be evaluated. The approach for each aspect is described and the analytical models that will be used are presented.

  10. Diesel engine combustion processes

    SciTech Connect

    1995-12-31

    Diesel Engine Combustion Processes guides the engineer and research technician toward engine designs which will give the ``best payoff`` in terms of emissions and fuel economy. Contents include: Three-dimensional modeling of soot and NO in a direct-injection diesel engine; Prechamber for lean burn for low NOx; Modeling and identification of a diesel combustion process with the downhill gradient search method; The droplet group micro-explosions in W/O diesel fuel emulsion sprays; Combustion process of diesel spray in high temperature air; Combustion process of diesel engines at regions with different altitude; and more.

  11. Multispectral imaging of aircraft exhaust

    NASA Astrophysics Data System (ADS)

    Berkson, Emily E.; Messinger, David W.

    2016-05-01

    Aircraft pollutants emitted during the landing-takeoff (LTO) cycle have significant effects on the local air quality surrounding airports. There are currently no inexpensive, portable, and unobtrusive sensors to quantify the amount of pollutants emitted from aircraft engines throughout the LTO cycle or to monitor the spatial-temporal extent of the exhaust plume. We seek to thoroughly characterize the unburned hydrocarbon (UHC) emissions from jet engine plumes and to design a portable imaging system to remotely quantify the emitted UHCs and temporally track the distribution of the plume. This paper shows results from the radiometric modeling of a jet engine exhaust plume and describes a prototype long-wave infrared imaging system capable of meeting the above requirements. The plume was modeled with vegetation and sky backgrounds, and filters were selected to maximize the detectivity of the plume. Initial calculations yield a look-up chart, which relates the minimum amount of emitted UHCs required to detect the presence of a plume to the noise-equivalent radiance of a system. Future work will aim to deploy the prototype imaging system at the Greater Rochester International Airport to assess the applicability of the system on a national scale. This project will help monitor the local pollution surrounding airports and allow better-informed decision-making regarding emission caps and pollution bylaws.

  12. Diesel exhaust exposure induces angiogenesis

    PubMed Central

    Xu, Xiaohua; Kherada, Nisharahmed; Hong, Xinru; Quan, Chunli; Zheng, Ling; Wang, Aixia; Wold, Loren; Lippmann, Morton; Chen, Lung Chi; Rajagopalan, Sanjay; Sun, Qinghua

    2009-01-01

    Our aim was to test the hypothesis that exposure to whole diesel exhaust (WDE) would enhance angiogenesis/vasculogenesis. Male apolipoprotein E-deficient mice, with either scaffold implantation subcutaneously or hindlimb ischemia, were exposed to either WDE (containing diesel exhaust particle [DEP] at a concentration of about 1 mg/m3) or filtered air 6 hours/day, 5 days/week in a whole body exposure chamber for 2, 5, or 8 weeks, respectively. WDE exposure significantly increased total cell counts in the scaffolds, aortic, and perivascular fat tissues. Macrophage infiltration was enhanced and CD31 expression increased in the scaffolds, which was coupled by increased α-smooth muscle actin (α-SMA) expression. WDE exposure led to increased CD31 expression, while decreasing endothelial nitric oxide synthase in the aortic wall. The vessel volume measured by micro-CT was increased in ischemic and non-ischemic hindlimbs in response to WDE exposure. DEP exposure induced capillary-like tube formation in endothelial cells in vitro, and caused capillary sprouting from aortic rings ex vivo. In addition, WDE exposure significantly increased mRNA expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF)-1α, while decreasing prolylhydroxylase (PHD) 2 expression. WDE exposure increases inflammatory cell infiltration, enhances the vessel volume/flow, and increases capillary tube formation and sprouting, thereby inducing angiogenesis and vasculogenesis. The angiogenic effects may occur through increasing HIF-1α and VEGF while decreasing PHD2 expression. PMID:19683567

  13. Stratified charge rotary engine combustion studies

    NASA Technical Reports Server (NTRS)

    Shock, H.; Hamady, F.; Somerton, C.; Stuecken, T.; Chouinard, E.; Rachal, T.; Kosterman, J.; Lambeth, M.; Olbrich, C.

    1989-01-01

    Analytical and experimental studies of the combustion process in a stratified charge rotary engine (SCRE) continue to be the subject of active research in recent years. Specifically to meet the demand for more sophisticated products, a detailed understanding of the engine system of interest is warranted. With this in mind the objective of this work is to develop an understanding of the controlling factors that affect the SCRE combustion process so that an efficient power dense rotary engine can be designed. The influence of the induction-exhaust systems and the rotor geometry are believed to have a significant effect on combustion chamber flow characteristics. In this report, emphasis is centered on Laser Doppler Velocimetry (LDV) measurements and on qualitative flow visualizations in the combustion chamber of the motored rotary engine assembly. This will provide a basic understanding of the flow process in the RCE and serve as a data base for verification of numerical simulations. Understanding fuel injection provisions is also important to the successful operation of the stratified charge rotary engine. Toward this end, flow visualizations depicting the development of high speed, high pressure fuel jets are described. Friction is an important consideration in an engine from the standpoint of lost work, durability and reliability. MSU Engine Research Laboratory efforts in accessing the frictional losses associated with the rotary engine are described. This includes work which describes losses in bearing, seal and auxillary components. Finally, a computer controlled mapping system under development is described. This system can be used to map shapes such as combustion chamber, intake manifolds or turbine blades accurately.

  14. Supersonic combustion engine and method of combustion initiation and distribution

    SciTech Connect

    Stickler, D.B.; Ballantyne, A.; Kyuman Jeong.

    1993-06-29

    A supersonic combustion ramjet engine having a combustor with a combustion zone intended to channel gas flow at relatively high speed therethrough, the engine comprising: means for substantially continuously supplying fuel into the combustion zone; and means for substantially instantaneously igniting a volume of fuel in the combustion zone for providing a spatially controlled combustion distribution, the igniting means having means for providing a diffuse discharge of energy into the volume, the volume extending across a substantially complete cross-sectional area of the combustion zone, the means for discharging energy being capable of generating free radicals within the volume of reactive fuel in the combustion zone such that fuel in the volume can initiate a controlled relatively rapid combustion of fuel in the combustion zone whereby combustion distribution in relatively high speed gas flows through the combustion zone can be initiated and controlled without dependence upon a flame holder or relatively high local static temperature in the combustion zone.

  15. Fuel flow regulator control for a diesel engine with exhaust gas driven turbocharger

    SciTech Connect

    Ludwig, G.C.

    1984-03-06

    A fuel flow regulator for an internal combustion engine having an exhaust gas turbocharger is disclosed. The fuel flow regulator responds to intake manifold pressure. Thus the fuel flow regulator increases the maximum fuel flow to the internal combustion engine from a first maximum predetermined fuel flow rate when the intake manifold pressure is at a first predetermined intake air pressure level to a second predetermined maximum fuel flow rate when the intake air manifold pressure is at a second predetermined intake air pressure level. Additionally, the fuel flow regulator decreases fuel flow to a third maximum fuel flow rate which is less than the first predetermined maximum fuel flow rate when the intake manifold pressure is greater than the second predetermined intake air pressure level. Therefore, the fuel flow regulator protects the internal combustion engine from overboost of the engine by the turbocharger and for overfueling the engine.

  16. Development of naval diesel engine duty cycles for air exhaust emission environmental impact analysis. Master's thesis

    SciTech Connect

    Markle, S.P.

    1994-05-01

    A strategy for testing naval diesel engines for exhaust emissions was developed. A survey of existing international and national standard diesel engine duty cycles was conducted. All were found to be inadequate for testing and certification of engine exhaust emissions from naval diesel powered ships. Naval ship data covering 11,500 hours of engine operation of four U.S. Navy LSD 41 Class amphibious ships was analyzed to develop a 27 point class operating profile. A procedure combining ship hull form characteristics, ship propulsion plant parameters, and ship operating profile was detailed to derive an 11-Mode duty cycle representative for testing LSD 41 Class propulsion diesel engines. A similar procedure was followed for ship service diesel engines. Comparisons with industry accepted duty cycles were conducted using exhaust emission contour plots for the Colt-Pielstick PC-4B diesel engines. Results showed the 11-Mode LSD 41 Class Duty Cycle best predicted ship propulsion engine emissions compared to the 27 point operating profile propeller curve. The procedure was applied to T-AO 187 Class with similar results. The application of civilian industry standards to measure naval diesel ship propulsion engine exhaust emissions was found to be inadequate. Engine exhaust flow chemistry post turbocharger was investigated using the SANDIA Lab computer tool CHEMKIN. Results showed oxidation and reduction reactions within exhaust gases are quenched in the exhaust stack. Since the exhaust stream in the stack is unreactive, emission sampling may be performed where most convenient. A proposed emission measurement scheme for LSD 41 Class ships was presented.

  17. Exhaust gas bypass valve control for thermoelectric generator

    DOEpatents

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

    2012-09-04

    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.

  18. Methodology development of a time-resolved in-cylinder fuel oxidation analysis: Homogeneous charge compression ignition combustion study application

    SciTech Connect

    Nowak, L.; Guibert, P.; Cavadias, S.; Dupre, S.; Momique, J.C.

    2008-08-15

    A technique was developed and applied to understand the mechanism of fuel oxidation in an internal combustion engine. This methodology determines the fuel and concentrations of various intermediates during the combustion cycle. A time-resolved measurement of a large number of species is the objective of this work and is achieved by the use of a sampling probe developed in-house. A system featuring an electromagnetically actuated sampling valve with internal N{sub 2} dilution was developed for sampling gases coming from the combustion chamber. Combustion species include O{sub 2}, CO{sub 2}, CO, NO{sub x}, fuel components, and hydrocarbons produced due to incomplete combustion of fuel. Combustion gases were collected and analyzed with the objectives of analysis by an automotive exhaust analyzer, separation by gas chromatography, and detection by flame ionization detection and mass spectrometry. The work presented was processed in a homogeneous charge compression ignition combustion mode context. (author)

  19. Lung Cancer in Railroad Workers Exposed to Diesel Exhaust

    PubMed Central

    Garshick, Eric; Laden, Francine; Hart, Jaime E.; Rosner, Bernard; Smith, Thomas J.; Dockery, Douglas W.; Speizer, Frank E.

    2004-01-01

    Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from coal-fired to diesel-powered locomotives. We obtained work histories from the U.S. Railroad Retirement Board, and ascertained mortality using Railroad Retirement Board, Social Security, and Health Care Financing Administration records. Cause of death was obtained from the National Death Index and death certificates. There were 43,593 total deaths including 4,351 lung cancer deaths. Adjusting for a healthy worker survivor effect and age, railroad workers in jobs associated with operating trains had a relative risk of lung cancer mortality of 1.40 (95% confidence interval, 1.30–1.51). Lung cancer mortality did not increase with increasing years of work in these jobs. Lung cancer mortality was elevated in jobs associated with work on trains powered by diesel locomotives. Although a contribution from exposure to coal combustion products before 1959 cannot be excluded, these results suggest that exposure to diesel exhaust contributed to lung cancer mortality in this cohort. PMID:15531439

  20. Combustion modes around hypersonic projectiles

    NASA Astrophysics Data System (ADS)

    Kamel, Michel Roger

    This work provides new experiments which detail the flow field characteristics around a blunt projectile traveling hypersonically in a reactive mixture using simultaneous planar laser-induced fluoresence and schlieren imaging, and stagnation pressure history measurements. The flow fields are generated using an expansion tube facility which accelerates a reactive mixture to supersonic speeds. The physical characteristics and the performance of the expansion tube are discussed. A blunt projectile is fixed at the exit of the tube and laser-based diagnostics are used to image the resulting combustion. Experimental results obtained here as well as results obtained from the literature suggest that for steady combustion to occur in supersonic reactive flow fields two conditions must be satisfied: (1) the post-shock induction time along the stagnation line should be much smaller than the time required for the shocked particles to reach the body; (2) the flow velocity relative to the projectile has to be larger than the mixture's Chapman-Jouget detonation velocity. For the unsteady flows, the measured frequency of oscillations decreases with increasing body diameter, mixture sensitivity, and free stream pressure. Dimensional analysis of the experimental results suggests that the dominant oscillations are due to disturbances reflecting off the cylinder body, in agreement with models proposed previously. Analogies are made between the flow fields observed in these experiments and those of 1-D pulsed detonations, and deflagration to detonation transitions. A theory for prediction of detonation initiation by blunted projectiles traveling at the Chapman-Jouget detonation speeds is modified here to be applicable to projectiles traveling at lower velocities. The modified theory is used to identify the boundaries of the different combustion modes as a function of projectile Mach number and mixture initial pressure. Results from the ballistic range experiments, computational fluid

  1. Fifteenth combustion research conference

    SciTech Connect

    1993-06-01

    The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers.

  2. ASRM combustion instability studies

    NASA Technical Reports Server (NTRS)

    Strand, L. D.

    1992-01-01

    The objectives of this task were to measure and compare the combustion response characteristics of the selected propellant formulation for the Space Shuttle Advanced Solid Rocket Motor (ASRM) with those of the current Redesigned Solid Rocket Motor (RSRM) formulation. Tests were also carried out to characterize the combustion response of the selected propellant formulation for the ASRM igniter motor.

  3. Coal Combustion Science

    SciTech Connect

    Hardesty, D.R.; Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. )

    1991-08-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

  4. Summary of synfuel characterization and combustion studies

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.

    1983-01-01

    Combustion component research studies aimed at evolving environmentally acceptable approaches for burning coal derived fuels for ground power applications were performed at the NASA Lewis Research Center under a program titled the ""Critical Research and Support Technology Program'' (CRT). The work was funded by the Department of Energy and was performed in four tasks. This report summarizes these tasks which have all been previously reported. In addition some previously unreported data from Task 4 is also presented. The first, Task 1 consisted of a literature survey aimed at determining the properties of synthetic fuels. This was followed by a computer modeling effort, Task 2, to predict the exhaust emissions resulting from burning coal liquids by various combustion techniques such as lean and rich-lean combustion. The computer predictions were then compared to the results of a flame tube rig, Task 3, in which the fuel properties were varied to simulate coal liquids. Two actual SRC 2 coal liquids were tested in this flame tube task.

  5. Regex-Stream

    SciTech Connect

    Goodall, John

    2012-09-01

    Log files are typically semi-or un-structured. To be useable, they need to be parsed into a standard, structured format. Regex-Stream facilitates parsing text files into structured data (JSON) in streams of data.

  6. Saving Our Streams.

    ERIC Educational Resources Information Center

    Firehock, Karen

    1993-01-01

    Presents an Izaak Walton League of America's Save Our Streams (SOS) program that teaches citizens how to protect streams. This organization provides activities for families, school groups, scout troops, 4-H clubs and other youth organizations. (MCO)

  7. Prioritized Contact Transport Stream

    NASA Technical Reports Server (NTRS)

    Hunt, Walter Lee, Jr. (Inventor)

    2015-01-01

    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  8. Japan's microgravity combustion science program

    NASA Technical Reports Server (NTRS)

    Sato, Junichi

    1993-01-01

    Most of energy used by us is generated by combustion of fuels. On the other hand, combustion is responsible for contamination of our living earth. Combustion, also, gives us damage to our life as fire or explosive accidents. Therefore, clean and safe combustion is now eagerly required. Knowledge of the combustion process in combustors is needed to achieve proper designs that have stable operation, high efficiency, and low emission levels. However, current understanding on combustion is far from complete. Especially, there is few useful information on practical liquid and solid particle cloud combustion. Studies on combustion process under microgravity condition will provide many informations for basic questions related to combustors.

  9. 49 CFR 393.83 - Exhaust systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... would likely result in burning, charring, or damaging the electrical wiring, the fuel supply, or any... immediately below the fuel tank or the fuel tank filler pipe. (c) The exhaust system of a bus powered by a... bus. (d) The exhaust system of a bus using fuels other than gasoline shall discharge to the...

  10. Motorcycle with closeable engine intake exhaust passages

    SciTech Connect

    Kazuta, H.; Kawai, Y.; Tsuchida, N.

    1984-03-06

    An intake and exhaust system for a compact motorcycle including a valve arrangement for closing both the intake and exhaust systems so as to preclude the excape of fuel vapors to the surrounding area when the motorcycle is not in use.

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

    SciTech Connect

    Marriott, Craig; Gonzalez, Manual; Russell, Durrett

    2011-06-30

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

  12. Low Temperature Combustion with Thermo-Chemical Recuperation to Maximize In-Use Engine Efficiency

    SciTech Connect

    Nigel N. Clark; Francisco Posada; Clinton Bedick; John Pratapas; Aleksandr Kozlov; Martin Linck; Dmitri Boulanov

    2009-03-30

    The key to overcome Low Temperature Combustion (LTC) load range limitations in reciprocating engines is based on proper control over the thermo-chemical properties of the in-cylinder charge. The studied alternative to achieve the required control of LTC is the use of two separate fuel streams to regulate timing and heat release at specific operational points, where the secondary fuel is a reformed product of the primary fuel in the tank. It is proposed in this report that the secondary fuel can be produced using exhaust heat and Thermo-Chemical Recuperation (TCR). TCR for reciprocating engines is a system that employs high efficiency recovery of sensible heat from engine exhaust gas and uses this energy to transform fuel composition. The recuperated sensible heat is returned to the engine as chemical energy. Chemical conversions are accomplished through catalytic and endothermic reactions in a specially designed reforming reactor. An equilibrium model developed by Gas Technology Institute (GTI) for heptane steam reforming was applied to estimate reformed fuel composition at different reforming temperatures. Laboratory results, at a steam/heptane mole ratio less than 2:1, confirm that low temperature reforming reactions, in the range of 550 K to 650 K, can produce 10-30% hydrogen (by volume, wet) in the product stream. Also, the effect of trading low mean effective pressure for displacement to achieve power output and energy efficiency has been explored by WVU. A zerodimensional model of LTC using heptane as fuel and a diesel Compression Ignition (CI) combustion model were employed to estimate pressure, temperature and total heat release as inputs for a mechanical and thermal loss model. The model results show that the total cooling burden on an LTC engine with lower power density and higher displacement was 14.3% lower than the diesel engine for the same amount of energy addition in the case of high load (43.57mg fuel/cycle). These preliminary modeling and

  13. Validation of scramjet exhaust simulation technique

    NASA Technical Reports Server (NTRS)

    Hopkins, H. B.; Konopka, W.; Leng, J.

    1976-01-01

    Scramjet/airframe integration design philosophy for hypersonic aircraft results in configurations having lower aft surfaces that serve as exhaust nozzles. There is a strong coupling between the exhaust plume and the aerodynamics of the vehicle, making accurate simulation of the engine exhaust mandatory. The experimental verification of the simulation procedure is described. The detonation tube simulator was used to produce an exact simulation of the scramjet exhaust for a Mach 8 flight condition. The pressure distributions produced by the exact exhaust flow were then duplicated by a cool mixture Argon and Freon 13B1. Such a substitute gas mixture validated by the detonation tube technique could be used in conventional wind tunnel tests. The results presented show the substitute gas simulation technique to be valid for shockless expansions.

  14. Low-pressure performance of annular, high-pressure (40 atm) high-temperature (2480 K) combustion system

    NASA Technical Reports Server (NTRS)

    Wear, J. D.

    1980-01-01

    Experimental tests were conducted to develop a combustion system for a 40 atmosphere pressure, 2480 K exhaust gas temperature, turbine cooling facility. The tests were conducted in an existing facility with a maximum pressure capability of 10 atmospheres and where inlet air temperatures as high as 894 K could be attained. Exhaust gas temperatures were as high as 2365 K. Combustion efficiences were about 100 percent over a fuel air ratio range of 0.016 to 0.056. Combustion efficiency decreased at leaner and richer ratios when the inlet air temperature was 589 K. Data are presented that show the effect of fuel air ratio and inlet air temperature on liner metal temperature. Isothermal system pressure loss as a function of diffuser inlet Mach number is also presented. Data included exhaust gas pattern factors; unburned hydrocarbon, carbon monoxide, and oxides of nitrogen emission index values; and smoke numbers.

  15. Jet exhaust and support interference effects on the transonic aerodynamic characteristics of a fighter model with two widely spaced engines

    NASA Technical Reports Server (NTRS)

    Compton, W. B., III

    1976-01-01

    Jet exhaust, nozzle installation, and model support interference effects on the longitudinal aerodynamic characteristics of a twin-engine fighter model were determined. Realistic jet exhaust nozzle configurations and a reference configuration with a simulated vertical-tail support were tested. Free-stream Mach number was varied from 0.6 to 1.2, and model angle of attack from 0 deg to 9 deg. The jet exhaust affected drag more than it affected lift and pitching moment. The largest effects occurred at a Mach number of 0.9 and for the afterburning mode of exhaust nozzle operation. The combined differences between the aerodynamic characteristics of the realistic and reference configurations (which were due to afterbody and nozzle contours, jet operation, and simulated reference support interference) were considerably different from those for the jet interference alone.

  16. Characterizing dilute combustion instabilities in a multi-cylinder spark-ignited engine using symbolic analysis.

    PubMed

    Daw, C S; Finney, C E A; Kaul, B C; Edwards, K D; Wagner, R M

    2015-02-13

    Spark-ignited internal combustion engines have evolved considerably in recent years in response to increasingly stringent regulations for emissions and fuel economy. One new advanced engine strategy ustilizes high levels of exhaust gas recirculation (EGR) to reduce combustion temperatures, thereby increasing thermodynamic efficiency and reducing nitrogen oxide emissions. While this strategy can be highly effective, it also poses major control and design challenges due to the large combustion oscillations that develop at sufficiently high EGR levels. Previous research has documented that combustion instabilities can propagate between successive engine cycles in individual cylinders via self-generated feedback of reactive species and thermal energy in the retained residual exhaust gases. In this work, we use symbolic analysis to characterize multi-cylinder combustion oscillations in an experimental engine operating with external EGR. At low levels of EGR, intra-cylinder oscillations are clearly visible and appear to be associated with brief, intermittent coupling among cylinders. As EGR is increased further, a point is reached where all four cylinders lock almost completely in phase and alternate simultaneously between two distinct bi-stable combustion states. From a practical perspective, it is important to understand the causes of this phenomenon and develop diagnostics that might be applied to ameliorate its effects. We demonstrate here that two approaches for symbolizing the engine combustion measurements can provide useful probes for characterizing these instabilities. PMID:25548262

  17. Characterizing dilute combustion instabilities in a multi-cylinder spark-ignited engine using symbolic analysis

    SciTech Connect

    Daw, C. Stuart; Finney, Charles E. A.; Kaul, Brian C.; Edwards, Kevin Dean; Wagner, Robert M.

    2014-12-29

    Spark-ignited internal combustion engines have evolved considerably in recent years in response to increasingly stringent regulations for emissions and fuel-economy. One new advanced engine strategy utilizes high levels of exhaust gas recirculation (EGR) to reduce combustion temperatures, thereby increasing thermodynamic efficiency and reducing nitrogen oxide emissions. While this strategy can be highly effective, it also poses major control and design challenges due to the large combustion oscillations that develop at sufficiently high EGR levels. Previous research has documented that combustion instabilities can propagate between successive engine cycles in individual cylinders via self-generated feedback of reactive species and thermal energy in the retained residual exhaust gases. In this work, we use symbolic analysis to characterize multi-cylinder combustion oscillations in an experimental engine operating with external EGR. At low levels of EGR, intra-cylinder oscillations are clearly visible and appear to be associated with brief, intermittent coupling among cylinders. As EGR is increased further, a point is reached where all four cylinders lock almost completely in phase and alternate simultaneously between two distinct bi-stable combustion states. From a practical perspective, it is important to understand the causes of this phenomenon and develop diagnostics that might be applied to ameliorate its effects. We demonstrate here that two approaches for symbolizing the engine combustion measurements can provide useful probes for characterizing these instabilities.

  18. Characterizing dilute combustion instabilities in a multi-cylinder spark-ignited engine using symbolic analysis.

    PubMed

    Daw, C S; Finney, C E A; Kaul, B C; Edwards, K D; Wagner, R M

    2015-02-13

    Spark-ignited internal combustion engines have evolved considerably in recent years in response to increasingly stringent regulations for emissions and fuel economy. One new advanced engine strategy ustilizes high levels of exhaust gas recirculation (EGR) to reduce combustion temperatures, thereby increasing thermodynamic efficiency and reducing nitrogen oxide emissions. While this strategy can be highly effective, it also poses major control and design challenges due to the large combustion oscillations that develop at sufficiently high EGR levels. Previous research has documented that combustion instabilities can propagate between successive engine cycles in individual cylinders via self-generated feedback of reactive species and thermal energy in the retained residual exhaust gases. In this work, we use symbolic analysis to characterize multi-cylinder combustion oscillations in an experimental engine operating with external EGR. At low levels of EGR, intra-cylinder oscillations are clearly visible and appear to be associated with brief, intermittent coupling among cylinders. As EGR is increased further, a point is reached where all four cylinders lock almost completely in phase and alternate simultaneously between two distinct bi-stable combustion states. From a practical perspective, it is important to understand the causes of this phenomenon and develop diagnostics that might be applied to ameliorate its effects. We demonstrate here that two approaches for symbolizing the engine combustion measurements can provide useful probes for characterizing these instabilities.

  19. Characterizing dilute combustion instabilities in a multi-cylinder spark-ignited engine using symbolic analysis

    DOE PAGES

    Daw, C. Stuart; Finney, Charles E. A.; Kaul, Brian C.; Edwards, Kevin Dean; Wagner, Robert M.

    2014-12-29

    Spark-ignited internal combustion engines have evolved considerably in recent years in response to increasingly stringent regulations for emissions and fuel-economy. One new advanced engine strategy utilizes high levels of exhaust gas recirculation (EGR) to reduce combustion temperatures, thereby increasing thermodynamic efficiency and reducing nitrogen oxide emissions. While this strategy can be highly effective, it also poses major control and design challenges due to the large combustion oscillations that develop at sufficiently high EGR levels. Previous research has documented that combustion instabilities can propagate between successive engine cycles in individual cylinders via self-generated feedback of reactive species and thermal energy inmore » the retained residual exhaust gases. In this work, we use symbolic analysis to characterize multi-cylinder combustion oscillations in an experimental engine operating with external EGR. At low levels of EGR, intra-cylinder oscillations are clearly visible and appear to be associated with brief, intermittent coupling among cylinders. As EGR is increased further, a point is reached where all four cylinders lock almost completely in phase and alternate simultaneously between two distinct bi-stable combustion states. From a practical perspective, it is important to understand the causes of this phenomenon and develop diagnostics that might be applied to ameliorate its effects. We demonstrate here that two approaches for symbolizing the engine combustion measurements can provide useful probes for characterizing these instabilities.« less

  20. Catalytic combustion with incompletely vaporized residual fuel

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.

    1981-01-01

    Catalytic combustion of fuel lean mixtures of incompletely vaporized residual fuel and air was investigated. The 7.6 cm diameter, graded cell reactor was constructed from zirconia spinel substrate and catalyzed with a noble metal catalyst. Streams of luminous particles exited the rector as a result of fuel deposition and carbonization on the substrate. Similar results were obtained with blends of No. 6 and No. 2 oil. Blends of shale residual oil and No. 2 oil resulted in stable operation. In shale oil blends the combustor performance degraded with a reduced degree of fuel vaporization. In tests performed with No. 2 oil a similar effect was observed.

  1. Meteorological assessment of SRM exhaust products' environmental impact. Final report

    SciTech Connect

    Dingle, A.N.

    1982-01-01

    The environmental impact of solid rocket motor (SRM) exhaust products discharged into the free air stream upon the launching of space vehicles that depend upon SRM boosters to obtain large thrust was assessed. The emission of Al/sub 2/O/sub 3/ to the troposphere from the SRMs in each Shuttle launch is considered. The Al/sub 2/O/sub 3/ appears as particles suitable for heterogeneous nucleation of hydrochloric acid which under frequently occurring atmospheric conditions may form a highly acidic rain capable of damaging property and crops and of impacting upon the health of human and animal populations. The cloud processes leading to the formation of acid rain and the concentration of the acid that then reaches the ground, and the atmospheric situations that lead to the production of cloud and rain at and near a launch site, and the prediction of weather conditions that may permit or prohibit a launch operation are studied.

  2. Meteorological assessment of SRM exhaust products' environmental impact

    NASA Technical Reports Server (NTRS)

    Dingle, A. N.

    1982-01-01

    The environmental impact of solid rocket motor (SRM) exhaust products discharged into the free air stream upon the launching of space vehicles that depend upon SRM boosters to obtain large thrust was assessed. The emission of Al2O3 to the troposphere from the SRMs in each Shuttle launch is considered. The Al2O3 appears as particles suitable for heterogeneous nucleation of hydrochloric acid which under frequently occurring atmospheric conditions may form a highly acidic rain capable of damaging property and crops and of impacting upon the health of human and animal populations. The cloud processes leading to the formation of acid rain and the concentration of the acid that then reaches the ground, and the atmospheric situations that lead to the production of cloud and rain at and near a launch site, and the prediction of weather conditions that may permit or prohibit a launch operation are studied.

  3. Catalytic oxidation process cleans volatile organics from exhaust

    SciTech Connect

    Haggin, J.

    1994-06-27

    Unsteady-state catalytic oxidation is the basis of a technology now becoming available in the US for removing volatile organic compounds (VOCs) from industrial exhaust streams. The technology originated in Russia and is being developed for the US market by Monsanto Enviro-Chem Systems, St. Louis. At least 149 of the 189 pollutants identified by EPA are VOCs. EPA estimates that the initial cost to industry for equipment to remove the hazardous materials will be about $350 million. The expected annual maintenance bill to treat the major pollution sources is about $182 million. Catalytic oxidizers are applicable to most, but not all, VOC removal applications. The advantages in most cases are VOC removal efficiencies of at least 99%, half the energy requirement of other systems, low operating temperatures, stable operation with variable flow rates and VOC concentrations, and low capital and operating costs.

  4. Chemical effect of entrained particles in coal conversion streams. Sixth quarterly technical progress report, November 1, 1982-January 31, 1983

    SciTech Connect

    Stinespring, C.; Yousefian, V.; Gruninger, J.; Annen, K.; Frankel, D.; Stewart, G.

    1983-01-01

    A major objective of the US Department of Energy is to increase coal utilization through the development of combustion stream cleanup technologies. Many of the existing cleanup devices as well as advanced concepts rely on heterogeneous processes (i.e., gas-solid interactions) to achieve efficient stream removal. Examples of such devices include particle injection and granular bed filters for alkali removal, limestone injection for SO/sub x/ removal in fluid bed combustors, dry injection for SO/sub x/removal in entrained combustion, and trace metal adsorption and removal on fly ash. Recent studies indicate that the successful use of turbines in combined cycle processes may depend on understanding the interaction between the gas phase alkali and particles in the combustion stream to substantially reduce turbine corrosion. This report documents progress in efforts to model the heterogeneous chemistry of coal combustion streams as well as laboratory studies to obtain critical input data for the report. 5 references, 15 figures.

  5. Non-Thermal Plasma System Development for CIDI Exhaust Aftertreatment

    SciTech Connect

    Balmer, M. Lou ); Tonkyn, Russell ); Maupin, Gary; Yoon, Steven; Kolwaite, Ana; Barlow, Stephen; Domingo, Norberto; Storey, John M.; Hoard, John Wm.; Howden, Ken

    2000-04-01

    There is a need for an efficient, durable technology to reduce NOx emissions from oxidative exhaust streams such as those produced by compression-ignition, direct injection (CIDI) diesel or lean-burn gasoline engines. A partnership formed between the DOE Office of Advanced Automotive Technology, Pacific Northwest National Laboratory, Oak Ridge National Laboratory and the USCAR Low Emission Technologies Research and Development Partnership is evaluating the effectiveness of a non-thermal plasma in conjunction with catalytic materials to mediate NOx and particulate emissions from diesel fueled light duty (CIDI) engines. Preliminary studies showed that plasma-catalyst systems could reduce up to 70% of NOx emissions at an equivalent cost of 3.5% of the input fuel in simulated diesel exhaust. These studies also showed that the type and concentration of hydrocarbon play a key role in both the plasma gas phase chemistry and the catalyst surface chemistry. More recently, plasma/catalyst systems have been evaluated for NOx reduction and particulate removal on a CIDI engine. Performance results for select plasma-catalyst systems for both simulated and actual CIDI exhaust will be presented. The effect of NOx and hydrocarbon concentration on plasma-catalyst performance will also be shown. SAE Paper SAE-2000-01-1601 {copyright} 2000 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.

  6. Combustion Characteristics of Oxy-fuel Burners for CO2 Capturing Boilers

    NASA Astrophysics Data System (ADS)

    Ahn, Joon; Kim, Hyouck Ju; Choi, Kyu Sung

    Oxy-fuel boilers have been developed to capture CO2 from the exhaust gas. A 50 kW class model burner has been developed and tested in a furnace type boiler. The burner has been scaled up to 0.5 and 3 MW class for fire-tube type boilers. The burners are commonly laid out in a coaxial type to effectively heat the combustion chamber of boilers. Burners are devised to support air and oxy-fuel combustion modes for the retrofitting scenario. FGR (flue gas recirculation) has been tried during the scale-up procedure. Oxy-fuel combustion yields stretched flame to uniformly heat the combustion chamber. It also provides the high CO2 concentration, which is over 90% in dry base. However, pure oxy-fuel combustion increases NO concentration, because of the reduced flow rate. The FGR can suppress the thermal NOx induced by the infiltration of the air.

  7. Combustion in supersonic flow

    NASA Technical Reports Server (NTRS)

    Northam, G. B.

    1985-01-01

    A workshop on combustion in supersonic flow was held in conjunction with the 21st JANNAF Combustion Meeting at Laurel, Maryland on October 3 to 4 1984. The objective of the workshop was to establish the level of current understanding of supersonic combustion. The workshop was attended by approximately fifty representatives from government laboratories, engine companies, and universities. Twenty different speakers made presentations in their area of expertise during the first day of the workshop. On the second day, the presentations were discussed, deficiencies in the current understanding defined, and a list of recommended programs generated to address these deficiencies. The agenda for the workshop is given.

  8. Gas turbine combustion instability

    SciTech Connect

    Richards, G.A.; Lee, G.T.

    1996-09-01

    Combustion oscillations are a common problem in development of LPM (lean premix) combustors. Unlike earlier, diffusion style combustors, LPM combustors are especially susceptible to oscillations because acoustic losses are smaller and operation near lean blowoff produces a greater combustion response to disturbances in reactant supply, mixing, etc. In ongoing tests at METC, five instability mechanisms have been identified in subscale and commercial scale nozzle tests. Changes to fuel nozzle geometry showed that it is possible to stabilize combustion by altering the timing of the feedback between acoustic waves and the variation in heat release.

  9. Magnetic analyses of powders from exhausted cabin air filters

    NASA Astrophysics Data System (ADS)

    Winkler, Aldo; Sagnotti, Leonardo

    2013-04-01

    The automotive cabin air filter is a pleated-paper filter placed in the outside-air intake for the car's passenger compartment. Dirty and saturated cabin air filters significantly reduce the airflow from the outside and introduce particulate matter (PM) and allergens (for example, pollen) into the cabin air stream. Magnetic measurements and analyses have been carried out on powders extracted from exhausted cabin air filters to characterize their magnetic properties and to compare them to those already reported for powders collected from disk brakes, gasoline exhaust pipes and Quercus ilex leaves. This study is also aimed at the identification and quantification of the contribution of the ultrafine fraction, superparamagnetic (SP) at room temperature, to the overall magnetic properties of these powders. This contribution was estimated by interpreting and comparing data from FORCs, isothermal remanent magnetization vs time decay curves, frequency and field dependence of the magnetic susceptibility and out-of-phase susceptibility. The magnetic properties and the distribution of the SP particles are generally homogenous and independent of the brand of the car, of the model of the filter and of its level of usage. The relatively high concentration of magnetic PM trapped in these filters poses relevant questions about the air quality inside a car.

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

    NASA Astrophysics Data System (ADS)

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

    2009-06-01

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

  11. Dry low combustion system with means for eliminating combustion noise

    DOEpatents

    Verdouw, Albert J.; Smith, Duane; McCormick, Keith; Razdan, Mohan K.

    2004-02-17

    A combustion system including a plurality of axially staged tubular premixers to control emissions and minimize combustion noise. The combustion system includes a radial inflow premixer that delivers the combustion mixture across a contoured dome into the combustion chamber. The axially staged premixers having a twist mixing apparatus to rotate the fluid flow and cause improved mixing without causing flow recirculation that could lead to pre-ignition or flashback.

  12. A comparison of sampling and analytical methods for assessing occupational exposure to diesel exhaust in a railroad work environment

    SciTech Connect

    Verma, D.K.; Shaw, L.; Julian, J.; Smolynec, K.; Wood, C.; Shaw, D.

    1999-10-01

    Methods of assessing occupational exposure to diesel exhaust were evaluated in a railroad work environment. The American Conference of Governmental Industrial Hygienists (ACGIH{reg_sign})-recommended elemental carbon and respirable combustible dust methods of sampling and analysis for assessing diesel exhaust were included in the study. A total of 215 personal and area samples were collected using both size-selective and non-size-selective samplers. The results demonstrate that the elemental carbon method is suitable for the railroad environment and the respirable combustible dust method is not. All elemental carbon concentrations measured were below the proposed ACG1H Threshold Limit Value (TLV{reg_sign}) of 0.15 mg/m{sup 3}. The concentrations of oxides of nitrogen (nitric oxide and nitrogen dioxide) were also found to be below their respective TLVs. There is no correlation between elemental carbon or respirable combustible dust and the oxides of nitrogen. The elemental carbon as fraction of total carbon is about 13%, except for onboard locomotives where it is about 24%. Comparison of elemental carbon and respirable combustible dust measurements showed consistent relationships for most sampling locations with respirable combustible dust concentrations 12 to 53 times higher than the elemental carbon levels.

  13. A comparison of sampling and analytical methods for assessing occupational exposure to diesel exhaust in a railroad work environment.

    PubMed

    Verma, D K; Shaw, L; Julian, J; Smolynec, K; Wood, C; Shaw, D

    1999-10-01

    Methods of assessing occupational exposure to diesel exhaust were evaluated in a railroad work environment. The American Conference of Governmental Industrial Hygienists (ACGIH)-recommended elemental carbon and respirable combustible dust methods of sampling and analysis for assessing diesel exhaust were included in the study. A total of 215 personal and area samples were collected using both size-selective (nylon cyclone and Marple) and non-size-selective samplers. The results demonstrate that the elemental carbon method is suitable for the railroad environment and the respirable combustible dust method is not. All elemental carbon concentrations measured were below the proposed ACGIH Threshold Limit Value (TLV) of 0.15 mg/m3. The concentrations of oxides of nitrogen (nitric oxide and nitrogen dioxide) were also found to be below their respective TLVs. There is no correlation between elemental carbon or respirable combustible dust and the oxides of nitrogen. The elemental carbon as fraction of total carbon is about 13 percent, except for onboard locomotives where it is about 24 percent. Comparison of elemental carbon and respirable combustible dust measurements showed consistent relationships for most sampling locations, with respirable combustible dust concentrations 12 to 53 times higher than the elemental carbon levels.

  14. Metal nanoparticles in diesel exhaust derived by in-cylinder melting of detached engine fragments

    NASA Astrophysics Data System (ADS)

    Liati, Anthi; Pandurangi, Sushant Sunil; Boulouchos, Konstantinos; Schreiber, Daniel; Arroyo Rojas Dasilva, Yadira

    2015-01-01

    A wide range of environmental and health effects are linked to combustion-generated pollutants related to traffic. Nanoparticles, in particular, are a major concern for humans since they can be inhaled and have potentially toxic effects. The variability and sources of combustion-related nanoparticle pollutants remain inadequately investigated. Here we report the presence of ca. 5-100 nm large Fe3O4 nanoparticles, in form of agglomerates, in diesel exhaust. The mode of occurrence of these nanoparticles, in combination with their chemical composition matching that of steel indicate that they derive by melting of engine fragments in the combustion chamber and subsequent crystallization during cooling. To evaluate this hypothesis, we applied CFD simulations of material transport in the cylinder of a diesel engine, assuming detachment of steel fragments from various sites of the cylinder. The CFD results show that fragments ≤20 μm in size dislodged from the piston surface or from the fuel nozzle interior can be indeed transported to such hot areas of the combustion chamber where they can melt. The simulation results concur with the experimental observations and point out that metal nanoparticle formation by in-cylinder melting of engine fragments can occur in diesel engines. The present study proposes a hitherto neglected formation mechanism of metal nanoparticle emissions from internal combustion engines raising possible environmental and health concerns, especially in urban areas.

  15. Sandia Combustion Research: Technical review

    SciTech Connect

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  16. NO reduction using sublimation of cyanuric acid

    SciTech Connect

    Perry, R.A.

    1990-03-13

    This patent describes a method of reducing the NO content of an exhaust gas stream generated by combustion. It comprises: contacting the exhaust gas stream generated by combustion with an amount of gaseous HNCO at a temperature effective for heat induced decomposition of HNCO. The amount and temperature being effective for resultant lowering of the NO content of the exhaust gas stream and the contacting being effected by adding gaseous HNCO directly to the exhaust gas stream.

  17. Combustion of solid waste in a pulse incinerator

    NASA Astrophysics Data System (ADS)

    Kan, Tie

    This study investigated the effects of pulsations on the combustion of simulated solid waste at high Reynolds numbers in an incinerator fed with cold or preheated combustion air. Corrugated cardboard and charcoal were chosen as waste surrogates. Combustion times and emissions of CO2, CO and NOx were measured while the samples were burned under different experimental conditions. Pulsations significantly reduced flaming combustion times in tests with and without preheated. Most of this enhancement resulted from increased heat transfer rate due to a closer attachment of the gas flame to the solid sample. Pulsations also reduced smoldering combustion time. This was caused by faster transport of oxygen to and combustion products from the sample surface. Furthermore, the smoldering combustion rate increased with increasing Sound Pressure Levels. While this effect was the strongest in laminar flows, pulsations doubled combustion rates even in a highly turbulent flow where Re = 47,000. Higher combustion rates at elevated Reynolds numbers in steady tests were caused by larger turbulent velocity fluctuations. Combustion rates were further enhanced by the addition of acoustic velocity fluctuations, which dominated the process if they were much larger than the turbulent velocity fluctuations. Below this limit, acoustic modes with velocities normal to the main flow enhanced the combustion process more significantly than those parallel to the flow. Most of this enhancement by pulsations resulted from increased species transport due to faster removal of ash layers on the burning surface by acoustic shear. Acoustic streaming was not responsible for the observed, enhanced combustion rates. Instantaneous pollutant emissions were much higher with pulsations than without. However, pulsations did not affect total amount of carbon converted into gaseous products from the sample but favored more complete combustion, i.e., less total CO emission. This was caused by a larger fraction of

  18. Experimental Investigation of Fuel-Reactivity Controlled Compression Ignition (RCCI) Combustion Mode in a Multi-Cylinder, Light-Duty Diesel Engine

    SciTech Connect

    Cho, Kukwon; Curran, Scott; Prikhodko, Vitaly Y; Sluder, Scott; Parks, II, James E; Wagner, Robert M

    2011-01-01

    An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm and an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without applying exhaust gas recirculation (EGR). However, high carbon monoxide (CO) and hydrocarbon (HC) emissions were observed. The low combustion gas temperature during the expansion and exhaust processes seemed to be the dominant source of high CO emissions in the RCCI combustion mode. The high HC emissions during the RCCI combustion mode could be due to the increased combustion quenching layer thickness as well as the -stratification at the periphery of the combustion chamber. The slightly higher brake thermal efficiency (BTE) of the RCCI combustion mode was observed than the other combustion modes, such as the conventional diesel combustion (CDC) mode, and single-fuel, premixed charge compression ignition (PCCI) combustion mode. The parametric study of the RCCI combustion mode revealed that the combustion phasing and/or the peak cylinder pressure rise rate of the RCCI combustion mode could be controlled by several physical parameters premixed ratio (rp), intake swirl intensity, and start of injection (SOI) timing of directly

  19. A method and apparatus for destroying hazardous organics and other combustible materials in a subcritical/supercritical reactor

    SciTech Connect

    Janikowski, Stuart K.

    1997-12-01

    A waste destruction method is described using a reactor vessel to combust and destroy organic and combustible waste, including the steps of introducing a supply of waste into the reactor vessel, introducing a supply of an oxidant into the reactor vessel to mix with the waste forming a waste and oxidant mixture, introducing a supply of water into the reactor vessel to mix with the waste and oxidant mixture forming a waste, water and oxidant mixture, reciprocatingly compressing the waste, water and oxidant mixture forming a compressed mixture, igniting the compressed mixture forming a exhaust gas, and venting the exhaust gas into the surrounding atmosphere.

  20. Particulate hot gas stream cleanup technical issues

    SciTech Connect

    Pontius, D.H.; Snyder, T.R.

    1999-09-30

    The analyses of hot gas stream cleanup particulate samples and descriptions of filter performance studied under this contract were designed to address problems with filter operation that have been linked to characteristics of the collected particulate matter. One objective of this work was to generate an interactive, computerized data bank of the key physical and chemical characteristics of ash and char collected from operating advanced particle filters and to relate these characteristics to the operation and performance of these filters. The interactive data bank summarizes analyses of over 160 ash and char samples from fifteen pressurized fluidized-bed combustion and gasification facilities utilizing high-temperature, high pressure barrier filters.