关键词: 汽车工程, 汽油发动机, 富氧燃烧, 燃烧特性, 排放特性

Abstract: Oxygen-enriched combustion is realized on a gasoline engine by controlling the different intake oxygen volume fraction. The characteristics of combustion and emission of a gasoline engine in the idling condition are studied by controlling the oxygen volume fraction at 21. 1%，22. 6%，25. 5% O2 . The research results show that with the increment of oxygen volume fraction in idling condition，the in-cylinder pressure and combustion heat release rate increase obviously; the time when the angle of peak appears advances and cumulative heat release increases sharply. As the intake oxygen density increases， the cycle-to-cycle variation decreases，and the combustion stability of the gasoline engine is improved; meanwhile，fuel consumptions are almost invariable. Realizing oxygen-enriched combustion in idling condition，the emission of THC and CO reduces largely and emission of NO2 increases，but the increment is at a low level.

Key words: automobileengineering, gasolineengine, oxygen-enrichedcombustion, combustionperformance, emissionperformanc