燃烧室抛光技术对汽油机经济性影响的研究OA北大核心CSTPCD

An experimental study of the interaction between combustion phase,combustion duration and average indicated thermal efficiency of a single-cylinder gasoline engine before and after combustion chamber wall polishing was carried out.The results show that when the single-cylinder gasoline engine operates at stoichiometric air-fuel ratio,low load and low pressure ratios,the heat transfer loss of the polished combustion chamber wall is reduced and the economic performance is improved,and the average indicated thermal efficiency increases from 40.8%to 42.2%.With the increase of load and compression ratios,the knock effect caused by the reduction of heat transfer loss of the polished combustion chamber wall is enhanced,the combustion phase is delayed and the combustion duration is prolonged,and finally the average indicated thermal efficiency decreases.When the gasoline engine operates in the lean combustion mode,the average indicated thermal efficiency increases greatly,and the maximum thermal efficiency exceeds 45%.When the gasoline engine enters into the knock area and operates at a load of 10.5 bar,the heat transfer loss after wall polishing is reduced and the knock effect is enhanced,resulting in the overall decrease of the average indicated thermal efficiency compared with that before wall polishing.