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Factors Influencing the Effectiveness of Air Injection in Reducing Exhaust Emissions
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1965 by SAE International in United States
Annotation ability available
Event: Mid-Year Meeting
Factors influencing the effectiveness of exhaust port air injection in oxidizing the hydrocarbons and carbon monoxide in engine exhaust gas have been investigated in order to establish guidelines for the engineering of vehicle emission control systems. Single-cylinder engine and vehicle studies have demonstrated that the temperature, composition, and residence time of the exhaust gas-air mixture are basic factors determining both the effectiveness of air injection and the type of oxidation process which occurs in the exhaust system. Both luminous and nonluminous oxidation have been observed. These basic factors are affected by such variables as: engine spark timing and air-fuel ratio, insulation and size of exhaust manifolds, injection air temperature and airflow rate, and the warmup characteristics of the air injection system. The warmup characteristics can be influenced particularly by spark timing and exhaust manifold design.
By optimizing the operating and design variables, it has been possible to greatly enhance the effectiveness of air injection in reducing hydrocarbon emissions. For example, with an experimental system, a composite hydrocarbon emission of 27 ppm has been measured on a vehicle tested in accordance with the California Motor Vehicle Exhaust Emission Test Procedure. On the other hand, for the same system, the carbon monoxide emission was 0.76%. Increasing the effectiveness of air injection in reducing carbon monoxide emission has proved to be most difficult.
Although these experimental systems may not be amenable to product engineering, they do illustrate the potential of air injection for reducing exhaust hydrocarbon and carbon monoxide emissions.
CitationBrownson, D. and Stebar, R., "Factors Influencing the Effectiveness of Air Injection in Reducing Exhaust Emissions," SAE Technical Paper 650526, 1965, https://doi.org/10.4271/650526.
- Brownson, D. A. Johnson, R. S. and Candelise, A. “A Progress Report on ManAirOx-Manfold Air Oxidation of Exhaust Gas.” SAE paper 486N presented March 12, 1962.
- “California Standards for Ambient Air Quality and Motor Vehicle Exhaust.” State of California, Dept. of Public Health, December 4, 1959.
- “Revision of California Standards for Ambient Air Quality and Motor Vehicle Exhaust.” State of California, Dept. of Public Health, Adopted October 23, 1964.
- “Test Procedure for Vehicle Exhaust Emissions.” California Motor Vehicle Pollution Control Board, 2nd Draft, May 19, 1961.
- Cornelius W. and Caplan, J. D. “Improved System for Control and Measurement of Air Consumption of Single-Cylinder Engines.” SAE Quarterly Transactions, Vol. 6, October, 1952, pp. 666–676.
- D’Alleva B. A. and Lovell, W. G. “Relation of Exhaust Gas Composition to Air-Fuel Ratio.” SAE Journal (Transactions), Vol. 38 (1936) pp. 90–98, 116.
- Jackson, M. W. Wiese, W. M. and Wentworth, J. T. “The Influence of Air-Fuel Ratio, Spark Timing and Combustion Chamber Deposits on Exhaust Hydrocarbon Emissions.” Vehicle Emissions, SAE Technical Progress Series, Vol. 6 (1964) pp. 175–191.
- Hagen D. F. and Holiday, G. W. “The Effects of Engine Operating and Design Variables on Exhaust Emissions.” Vehicle Emissions, SAE Technical Progress Series, Vol. 6 (1964) pp. 299–314.
- Chandler, J. M. Smith, A. M. and Struck, J. H. “Development of the Concept of Non-Flame Exhaust Gas Reactors,” Vehicle Emissions, SAE Technical Progress Series, Vol. 6 (1964), pp. 299–314.
- “The Effect of Spark Timing on Exhaust Hydrocarbon Content During Idle and Deceleration,” Automobile Manufacturers Association, Status Report No. 1 of the Engine and Vehicle Modification Task Group, Vehicle Combustion Products Committee, February, 1964.
- Rounds, F. G. Bennett, P. A. and Nebel, G. J. “Some Effects of Engine-Fuel Variables on Exhaust-Gas Hydrocarbon Content.” SAE Transactions, Vol. 63, (1955).
- Yu, T. C. “Fuel Distribution Studies - A New Look at an Old Problem.” SAE Transactions, Vol. 71 (1963) pp. 596–613.