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Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine

Description: The performance of a single-cylinder, direct-injection diesel engine was measured with intake oxygen levels of up to 35% and fuel water contents of up to 20%. Because a previous study indicated that the use of a less-expensive fuel would be more economical, two series of tests with No. 4 diesel fuel and No. 2 diesel fuel were conducted. To control the emissions of nitrogen oxides (NO{sub x}), water was introduced into the combustion process in the form of water-emulsified fuel, or the fuel injection timing was retarded. In the first series of tests, compressed oxygen was used; in the second series of tests, a hollow-tube membrane was used. Steady-state engine performance and emissions data were obtained. Test results indicated a large increase in engine power density, a slight improvement in thermal efficiency, and significant reductions in smoke and particulate-matter emissions. Although NO{sub x} emissions increased, they could be controlled by introducing water and retarding the injection timing. The results further indicated that thermal efficiency is slightly increased when moderately water-emulsified fuels are used, because a greater portion of the fuel energy is released earlier in the combustion process. Oxygen-enriched air reduced the ignition delay and caused the heat-release rate and cumulative heat-release rates to change measurably. Even at higher oxygen levels, NO{sub x} emissions decreased rapidly when the timing was retarded, and the amount of smoke and the level of particulate-matter emissions did not significantly increase. The single-cylinder engine tests confirmed the results of an earlier technical assessment and further indicated a need for a low-pressure-drop membrane specifically designed for oxygen enrichment. Extension data set indexed separately. 14 refs.
Date: November 1, 1991
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L. & Marciniak, T.J.
Partner: UNT Libraries Government Documents Department

Evaluation of oxygen-enrichment system for alternative fuel vehicles

Description: This report presents results on the reduction in exhaust emissions achieved by using oxygen-enriched intake air on a flexible fuel vehicle (FFV) that used Indolene and M85 as test fuels. The standard federal test procedure (FTP) and the US Environmental Protection Agency`s (EPA`s) off-cycle (REP05) test were followed. The report also provides a review of literature on the oxygen membrane device and design considerations. It presents information on the sources and contributions of cold-phase emissions to the overall exhaust emissions from light-duty vehicles (LDVs) and on the various emission standards and present-day control technologies under consideration. The effects of oxygen-enriched intake air on FTP and off-cycle emissions are discussed on the basis of test results. Conclusions are drawn from the results and discussion, and different approaches for the practical application of this technology in LDVs are recommended.
Date: December 1, 1995
Creator: Poola, R.B.; Sekar, R.R. & Ng, H.K.
Partner: UNT Libraries Government Documents Department

Application of oxygen-enriched combustion for locomotive diesel engines. Phase 1

Description: A thermodynamic simulation is used to study the effects of oxygen-enriched intake air on the performance and nitrogen oxide (NO) emissions of a locomotive diesel engine. The parasitic power of the air separation membrane required to supply the oxygen-enriched air is also estimated. For a given constraint on peak cylinder pressure, the gross and net power outputs of an engine operating under different levels of oxygen enrichment are compared with those obtained when a high-boost turbocharged engine is used. A 4% increase in peak cylinder pressure can result in an increase in net engine power of approximately 13% when intake air with an oxygen content of 28% by volume is used and fuel injection timing is retarded by 4 degrees. When the engine is turbocharged to a higher inlet boost, the same increase in peak cylinder pressure improves power by only 4%. If part of the significantly higher exhaust enthalpies available as a result of oxygen enrichment are recovered, the power requirements of the air separator membrane can be met, resulting in substantial net power improvements. Oxygen enrichment reduces particulate and visible smoke emissions but increases NO emissions. However, a combination of retarded fuel injection timing and post-treatment of exhaust gases may be adequate to meet the locomotive diesel engine NO{sub x} standards. Exhaust gas after-treatment and heat recovery would be required to realize the full potential of oxygen enrichment. Economic analysis shows that oxygen-enrichment technology is economically feasible and provides high returns on investment. The study also indicates the strong influence of membrane parasitic requirements and exhaust energy recovery on economic benefits. To obtain an economic advantage while using a membrane with higher parasitic power requirements, it is necessary to recover a part of the exhaust energy.
Date: September 1, 1996
Creator: Poola, R.B.; Sekar, R.R. & Assanis, D.N.
Partner: UNT Libraries Government Documents Department

Using monatomic nitrogen induced by a pulsed arc to remove nitrogen oxides from a gas stream

Description: The effectiveness of monatomic nitrogen, induced by a pulsed electric arc, in reducing nitric oxide (NO) and nitrogen dioxide (NO{sub 2}) was studied. The goal for this research is the reduction of nitrogen oxides (NO{sub x}) from automobile emissions by this alternative technique, which can be cost-effective (to be demonstrated in the near future) and has the potential to reduce NO{sub x} in exhaust containing up to 10% oxygen. The initial tests with 100, 500, and 1,000 ppm NO in pure nitrogen have shown that a greater than 50% reduction of NO/NO{sub x} is readily achievable. Different flow rates of the monatomic nitrogen and the gas stream were tested. The flow rate of the monatomic nitrogen did not have a significant effect on the reduction efficiency, unlike the flow rate of the gas stream. The cross-sectional flow area of the gas stream was varied in order to assess whether the proximity of the gas stream to the arc would affect NO/NO{sub x} reduction. Results of the tests revealed that the smallest cross-sectional area gave the best reduction, but it also had the greatest chance of contacting the arc. The composition of the gas stream was also varied to elucidate the effects of NO{sub 2} and O{sub 2} on the NO/NO{sub x} reduction efficiency. When NO{sub 2} and O{sub 2} are present in the gas stream, both gases lower the reduction efficiency significantly by creating more NO or NO{sub 2}. Experiments are continuing to improve the reduction efficiency. The electrical power, a function of pulse frequency, voltage, and current, was treated as a key parameter in the investigation. The power consumption of the high-voltage pulser apparatus for a 100-kW engine was estimated to be 3 kW.
Date: December 1, 1995
Creator: Ng, H.K.; Novick, V.J. & Sekar, R.R.
Partner: UNT Libraries Government Documents Department

Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine

Description: This report contains the data gathered from tests conducted on a single-cylinder diesel engine to study the benefits and problems of oxygen-enriched diesel combustion and the use of water-emulsified and low-grade diesel fuels. This research, funded by the Office of Industrial Technologies (OIT) in the United States Department of Energy, is being conducted in support of the Industrial Cogeneration Program. The report is made up of two volumes. Volume 1 contains the description of the experiments, selected data points, discussion of trends, and conclusions and recommendations; Volume 2 contains the data sets. With the two-volume approach, readers can find information at the desired level of detail, depending on individual interest or need.
Date: November 1, 1991
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L. & Marciniak, T.J.
Partner: UNT Libraries Government Documents Department

Utilizing intake-air oxygen-enrichment technology to reduce cold- phase emissions

Description: Oxygen-enriched combustion is a proven, serious considered technique to reduce exhaust hydrocarbons (HC) and carbon monoxide (CO) emissions from automotive gasoline engines. This paper presents the cold-phase emissions reduction results of using oxygen-enriched intake air containing about 23% and 25% oxygen (by volume) in a vehicle powered by a spark-ignition (SI) engine. Both engineout and converter-out emissions data were collected by following the standard federal test procedure (FTP). Converter-out emissions data were also obtained employing the US Environmental Protection Agency`s (EPA`s) ``Off-Cycle`` test. Test results indicate that the engine-out CO emissions during the cold phase (bag 1) were reduced by about 46 and 50%, and HC by about 33 and 43%, using nominal 23 and 25% oxygen-enriched air compared to ambient air (21% oxygen by volume), respectively. However, the corresponding oxides of nitrogen (NO{sub x}) emissions were increased by about 56 and 79%, respectively. Time-resolved emissions data indicate that both HC and CO emissions were reduced considerably during the initial 127 s of the cold-phase FTP, without any increase in NO, emissions in the first 25 s. Hydrocarbon speciation results indicate that all major toxic pollutants, including ozone-forming specific reactivity factors, such as maximum incremental reactivity (NUR) and maximum ozone incremental reactivity (MOIR), were reduced considerably with oxygen-enrichment. Based on these results, it seems that using oxygen-enriched intake air during the cold-phase FTP could potentially reduce HC and CO emissions sufficiently to meet future emissions standards. Off-cycle, converter-out, weighted-average emissions results show that both HC and CO emissions were reduced by about 60 to 75% with 23 or 25% oxygen-enrichment, but the accompanying NO{sub x}, emissions were much higher than those with the ambient air.
Date: December 31, 1995
Creator: Poola, R.B.; Ng, H.K.; Sekar, R.R.; Baudino, J.H. & Colucci, C.P.
Partner: UNT Libraries Government Documents Department

Removal of nitrogen oxides from a gas stream by using monatomic nitrogen induced by a pulsed arc

Description: The effectiveness of N atoms, nitrogen, induced by a pulsed electric arc, in reducing nitric oxide (NO) and nitrogen dioxide (NO{sub 2}) was studied. Goal is reduction of nitrogen oxides (NO{sub x}) from automobile emissions by this alternative technique, which can be cost-effective and has the potential to reduce NO{sub x} in exhaust containing up to 10% oxygen. Initial tests with 100, 500, and 1,000 ppM NO in pure nitrogen have shown that a greater than 50% reduction of NO/NO{sub x} is readily achievable. At an NO concentration of 100 ppM, a greater than 90% NO/NO{sub x} reduction was recorded. Different flow rates of the monatomic nitrogen and the gas stream were tested. The flow rate of the monatomic nitrogen did not have a significant effect on the reduction efficiency, unlike the flow rate of the gas stream. The cross-sectional flow area of the gas stream was varied in order to assess whether the proximity of the gas stream to the arc would affect NO/NO{sub x} reduction. Results of the tests revealed that the smallest cross-sectional area had the best reduction, but also the highest chance of contacting the arc. The composition of the gas stream was also varied to elucidate the effects of N0{sub 2} and 0{sub 2} on the NO/NO{sub x} reduction efficiency. When N0{sub 2} and 0{sub 2} are present in the gas stream, both gases lower the reduction efficiency significantly by creating more NO or N0{sub 2}. Experiments are continuing to improve the reduction efficiency. The electrical power, a function of pulse frequency, voltage, and current, was treated as a key parameter in the investigation. The power consumption of the high-voltage purser apparatus for a 100-kW engine was estimated to be 3 kW.
Date: January 1, 1995
Creator: Ng, H.K.; Novick, V.J.; Sekar, R.R.; Pierucci, K.A. & Geise, M.F.
Partner: UNT Libraries Government Documents Department

Diesel cogeneration plant using oxygen enriched air and emulsified fuels

Description: The investigation of oxygen-enriched combustion of alternative fuels in diesel engines at Argonne National Laboratory (ANL) is based on information gathered from two previous Department of Energy programs. The first was the slow-speed diesel engine program which used fuels such as coal-water slurry and coal derived liquid fuels in a slow speed diesel engine. The second was the development of membrane oxygen separation equipment. The results of these programs indicated that using the new membrane oxygen enrichment technology with medium- and high-speed diesel engines would do two things. First, oxygen enrichment could reduce some emissions from stationary diesel engines, particularly smoke, particulates and hydrocarbons while significantly increasing power output. The second, was that it might be possible to use less expensive liquid fuels such as No. 4, No. 6 and residual oil emulsified with water in medium- to high-speed diesel engines. The water would (1) help to eliminate the undesirable increase in nitrogen oxide production when enriched oxygen is used, and (2) by reducing the viscosity of the heavier liquid fuels, make them easier to use in smaller industrial cogeneration applications. This program consists of four steps: preliminary feasibility study, exploratory experiments, system development, and demonstration and commercialization of an industrial cogeneration system. 3 refs., 13 figs.
Date: January 1, 1990
Creator: Marciniak, T.J.; Cole, R.L.; Sekar, R.R.; Stodolsky, F. (Argonne National Lab., IL (USA)) & Eustis, J.N. (USDOE, Washington, DC (USA))
Partner: UNT Libraries Government Documents Department

Simulation studies of diesel engine performance with oxygen enriched air and water emulsified fuels

Description: A computer simulation code of a turbocharged, turbocompound diesel engine was modified to study the effects of using oxygen-enriched combustion air and water-emulsified diesel fuels. Oxygen levels of 21 percent to 40 percent by volume in the combustion air were studied. Water content in the fuel was varied from 0 percent to 50 percent mass. Simulation studies and a review and analysis of previous work in this area led to the following conclusions about expected engine performance and emissions: the power density of the engine is significantly increased by oxygen enrichment. Ignition delay and particulate emissions are reduced. Combustion temperatures and No{sub x} emissions are increased with oxygen enrichment but could be brought back to the base levels by introducing water in the fuel. The peak cylinder pressure which increases with the power output level might result in mechanical problems with engine components. Oxygen enrichment also provides an opportunity to use cheaper fuel such as No. 6 diesel fuel. Overall, the adverse effects of oxygen enrichment could be countered by the addition of water and it appears that an optimum combination of water content, oxygen level, and base diesel fuel quality may exist. This could yield improved performance and emissions characteristics compared to a state-of-the-art diesel engine. 9 refs., 8 figs.
Date: January 1, 1990
Creator: Assanis, D.N.; Baker, D. (Illinois Univ., Urbana, IL (USA)); Sekar, R.R.; Siambekos, C.T.; Cole, R.L. & Marciniak, T.J. (Argonne National Lab., IL (USA))
Partner: UNT Libraries Government Documents Department

Diesel engine experiments with oxygen enrichment, water addition and lower-grade fuel

Description: The concept of oxygen enriched air applied to reciprocating engines is getting renewed attention in the context of the progress made in the enrichment methods and the tougher emissions regulations imposed on diesel and gasoline engines. An experimental project was completed in which a direct injection diesel engine was tested with intake oxygen levels of 21% -- 35%. Since an earlier study indicated that it is necessary to use a cheaper fuel to make the concept economically attractive, a less refined fuel was included in the test series. Since a major objection to the use of oxygen enriched combustion air had been the increase in NO{sub x} emissions, a method must be found to reduce NO{sub x}. Introduction of water into the engine combustion process was included in the tests for this purpose. Fuel emulsification with water was the means used here even though other methods could also be used. The teat data indicated a large increase in engine power density, slight improvement in thermal efficiency, significant reductions in smoke and particulate emissions and NO{sub x} emissions controllable with the addition of water. 15 refs., 10 figs., 2 tabs.
Date: January 1, 1990
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. (Argonne National Lab., IL (USA)) & Schaus, J.E. (Autoresearch Labs., Inc. (USA))
Partner: UNT Libraries Government Documents Department

Oxygen-enriched diesel engine performance: A comparison of analytical and experimental results

Description: Use of oxygen-enriched combustion air in diesel engines can lead to significant improvements in power density, as well as reductions in particulate emissions, but at the expense of higher NO{sub x} emissions. Oxygen enrichment would also lead to lower ignition delays and the opportunity to burn lower grade fuels. Analytical and experimental studies are being conducted in parallel to establish the optimal combination of oxygen level and diesel fuel properties. In this paper, cylinder pressure data acquired on a single-cylinder engine are used to generate heat release rates for operation under various oxygen contents. These derived heat release rates are in turn used to improve the combustion correlation -- and thus the prediction capability -- of the simulation code. It is shown that simulated and measured cylinder pressures and other performance parameters are in good agreement. The improved simulation can provide sufficiently accurate predictions of trends and magnitudes to be useful in parametric studies assessing the effects of oxygen enrichment and water injection on diesel engine performance. Measured ignition delays, NO{sub x} emissions, and particulate emissions are also compared with previously published data. The measured ignition delays are slightly lower than previously reported. Particulate emissions measured in this series of tests are significantly lower than previously reported. 14 refs., 10 figs., 1 tab.
Date: January 1, 1990
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. (Argonne National Lab., IL (USA)); Assanis, D.N. (Illinois Univ., Urbana, IL (USA)) & Schaus, J.E. (Autoresearch Labs., Inc., Chicago, IL (USA))
Partner: UNT Libraries Government Documents Department