This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Effect of Engine Operating Variables and Piston and Ring Parameters on Crevice Hydrocarbon Emissions
Annotation ability available
Sector:
Language:
English
Abstract
A study was performed to determine the effects of engine operating variables and piston and ring parameters on the crevice hydrocarbon emissions from a spark-ignition engine. Natural gas was used as the test fuel in an effort to isolate crevice mechanisms as the only major source of unburned hydrocarbons in the test engine's exhaust. The largest of the in-cylinder crevices, the piston ring pack crevices, were modified, both in size and accessibility, by altering the piston top land height and the number of piston rings and their end gaps. Each piston and ring configuration was subjected to a series of test sweeps of engine operating variables known to affect exhaust hydrocarbon emissions.
None of the physical crevice modifications had any significant effect on the level of the exhaust hydrocarbon emissions, although the cycle-to-cycle repeatability of these emissions, measured with a fast hydrocarbon analyzer, was found to vary between the different configurations. Exhaust hydrocarbon concentrations were minimized by engine operation at leaner than stoichiometric fuel/air equivalence ratios and, at a fixed ratio, by choosing engine operating parameters which maximized exhaust temperature.
A linear correlation between the exhaust hydrocarbon and oxygen concentrations was found at a stoichiometric fuel/air equivalence ratio. Crevice storage and release of unburned fuel/air mixture was thought to be the reason for this interrelationship.
A correlation was derived between the exhaust hydrocarbon concentration and the exhaust temperature and engine speed which provided an excellent fit to the experimental data. It was concluded that, for an engine fuelled with natural gas, at a fixed fuel/air equivalence ratio, exhaust hydrocarbon levels are primarily determined by the degree of post-combustion oxidation as dictated by the post-combustion in-cylinder temperatures andresidence times.
Recommended Content
Citation
Thompson, N. and Wallace, J., "Effect of Engine Operating Variables and Piston and Ring Parameters on Crevice Hydrocarbon Emissions," SAE Technical Paper 940480, 1994, https://doi.org/10.4271/940480.Also In
References
- Adamczyk A.A. Lavoie G.A. “Laminar Head-On Flame Quenching - A Theoretical Study” SAE Transactions 87 SAE paper 780969 1978
- Westbrook C.K. Adamczyk A.A. Lavoie G.A. “A Numerical Study of Laminar Flame Wall Quenching” Combustion and Flame 40 81 99 1981
- LoRusso, J.A. Kaiser E.W. Lavoie G.A. “In-Cylinder Measurements of Wall Layer Hydrocarbons in a Spark Ignited Engine” Combust. Sci. Technol. 33 75 112 1983
- Gatellier B. Trapy J. Herrier D. Quelin J.M. Galliot F. “Hydrocarbon Emissions of SI Engines as Influenced by Fuel Absorption-Desorption in Oil Films,” SAE paper 920095 1992
- Chappelow, C.C. III Prausnitz J.M. “Solubilities of Gases in High-boiling Hydrocarbon Solvents,” AIChE Journal 20 1097 1104 1974
- Adamczyk A.A. Kaiser E.W. Lavoie G.A. “A Combustion Bomb Study of the Hydrocarbon Emissions from Engine Crevices,” Combust. Sci. Technology 33 261 1983
- Wentworth J.T. “Piston and Ring Variables Affect Exhaust Hydrocarbon Emission,” SAE paper 680109 1968
- Wentworth J.T. “The Piston Crevice Volume Effect on Exhaust Hydrocarbon Emission Combust. Sci. Technol. 4 97 100 1971
- Haskell W.W. Legate C.E. “Exhaust Hydrocarbon Emissions from Gasoline Engines - Surface Phenomena,” SAE paper 720255 1972
- Willcock M. Tidmarsh D.H. Foss P. Bates D. “A Comparison of Hydrocarbon Emissions from Different Piston Designs in an SI Engine,” SAE paper 930714 1993
- Namazian M. Heywood J.B. “Flow in the Piston-Cylinder-Ring Crevices of a Spark-ignition Engine: Effect on Hydrocarbon Emissions, Efficiency and Power,” SAE paper 820088 1982
- Reitz R.D. Kuo T.-W. “Modeling of HC Emissions Due to Crevice Flows in Premixed-Charge Engines,” SAE paper 892085 1989
- Holt J.W. Murray E.J. “A Two Ring Piston for Gasoline Engines,” SAE paper 860248 1986
- Kuo T.-W. Sellnau M.C. Theobald M.A. Jones J.D. “Calculation of Flow in the Piston-Cylinder-Ring Crevices of a Homogeneous-Charge Engine and Comparison with Experiment ”SAE paper 890838 1989
- Tabaczynski R.J. Heywood J.B. Keck J.C. “Time-Resolved Measurements of Hydrocarbon Mass Flowrate in the Exhaust of a Spark-Ignition Engine,” SAE Transactions 81 SAE paper 720112 1972
- Ekchian A. Heywood J.B. Rife J.M. “Time Resolved Measurements of the Exhaust from a Jet Ignition Prechamber Stratified Charge Engine,” SAE Transactions 86 SAE paper 770043 1977
- Finlay I.C. Boam D.J. Bingham J.F. Clark T.A. “Fast Response FID Measurement of Unburned Hydrocarbons in the Exhaust Port of a Firing Gasoline Engine,” SAE paper 902165 1990
- Caton J.A. Heywood J.B. Mendillo J. V. “Hydrocarbon Oxidation in a Spark Ignition Engine Exhaust Port,” Combust. Sci. Technol 37 153 169 1984
- Adamczyk A.A. Kaiser E.W. Cavolowsky J.A. Lavoie G.A. “An Experimental Study of Hydrocarbon Emissions from Closed Vessel Explosions” Eighteenth Symposium (International) on Combustion The Combustion Institute 1695 1702 1981
- Caton J.A. “Comparisons of Thermocouple, Time-Averaged and Mass-Averaged Exhaust Gas Temperatures for a Spark-Ignited Engine,” SAE paper 820050 1982
- Caton J.A. Heywood J.B. “An Experimental and Analytical Study of Heat Transfer in an Engine Exhaust Port,” Int. J. of Heat and Mass Transfer 24 581 595 1981
- Mendillo J.V. Heywood J.B. “Hydrocarbon Oxidation in the Exhaust Port of a Spark Ignition Engine,” SAE paper 810019 1981
- Poulsen J.H. “Operating Parameter and Fuel Composition Effects on the Speciated Hydrocarbon Emissions from a Natural Gas Fuelled Engine,” University of Toronto 1993
- Sigworth, H.W. Jr. Myers P.S. Uyehara O.A. “The Disappearance of Ethylene, Propylene, n-Butane and I-Butane in Spark-Ignition Engine Exhaust,” SAE paper 700472 1970
- Lord H.A. Sondreal E.A. Kadlec R.H. Patterson D.J. “Reactor Studies for Exhaust Oxidation Rates,” SAE paper 730203 1973
- Bascunana J.L. Skibinski J. Weaver E.E. “Rates of Exhaust Gas-Air Reactions,” SAE paper 770639 1977
- Westbrook C.K. Dryer F.L. “Simplified Reaction Mechanisms for the Oxidation of Hydrocarbon Fuels in Flames,” Combust. Sci. Technology 27 31 43 1981
- Glassman I. Combustion Second Academic Press 1987
- Jääskeläinen H.E. private communication July 1993
- Jääskeläinen H.E. Wallace J.S. “Effect of Increasing Compression Ratio in a Light-Duty Natural gas Fueled Engine on Efficiency and Emissions,” SAE paper 932746 1993
- Heywood J.B. International Combustion Engine Fundamentals McGraw-Hill 1988