进气门早关对汽油机进气过程及燃烧性能的影响  

Effect of early intake valve closing on intake process and combustion performance of SI engine

作　　者：谢宗法[1,2] 付文超 魏枫展 常英杰[1,2] 孙婷婷 张开宇[1,2] XIE Zong-fa;FU Wen-chao;WEI Feng-zhan;CHANG Ying-jie;SUN Ting-ting;ZHANG Kai-yu(School of Mechanical Engineering,Shandong University,Jinan 250061,China;Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education,Shandong University,Jinan 250061,China)

机构地区：[1]山东大学机械工程学院,济南250061 [2]山东大学高效洁净机械制造教育部重点实验室,济南250061

出　　处：《吉林大学学报（工学版）》2020年第3期850-858,共9页Journal of Jilin University:Engineering and Technology Edition

基　　金：山东省重点研发计划项目(2019JZZY010914);“十三五”国家重点研发计划项目(2017YFB0103405).

摘　　要：介绍了一种全可变液压气门机构(FHVVS),该机构采用进气门早关(EIVC)的方式取代节气门,实现无节气门汽油机负荷调节。研究发现:虽然进气门早关使中、小负荷工况下的泵气损失得到大幅度降低,但无节气门汽油机进气管压力的提高降低了残余废气倒流量,使油气混合不良、燃烧性能恶化,导致进气道喷射式汽油机的指示热效率明显降低。为改善燃烧性能,介绍了一种在气门小升程时能产生强烈进气涡流的螺旋气门。试验结果表明:螺旋气门显著改善了进气道喷射式无节气门汽油机的燃烧性能并提高了燃油经济性,使中、小负荷工况下的燃油消耗率比节气门汽油机降低了7.2%~12.5%。A fully hydraulic variable valve system(FHVVS)is described in this paper,which replaces the conventional throttle valve with the mode of early intake valve closing(EIVC)to control the load of an unthrottled SI engine.It is found that the pumping losses of an unthrottled SI engine at low and medium loads are significantly reduced,however,the amount of residual exhaust flowing back into the intake port is greatly reduced due to the increase in the intake port pressure,causing poor fuel-air mixing and deterioration of combustion performance,which results in a significant decrease in indicated thermal efficiency of the port fuel injection(PFI)SI engine.To improve the combustion performance of the unthrottled SI engine,a new helical valve is proposed which is capable of generating a strong intake swirl at small intake valve lift.The experiment results demonstrate that the helical valve significantly improves the combustion performance and fuel economy of the PFI unthrottled SI engine. Compared with the throttledSI engine,the brake specific fuel consumption of the unthrottled SI engine at low to medium load isreduced by 7.2% to 12.5%.

关 键 词：动力机械工程 全可变液压气门机构 进气门早关 泵气损失 进气涡流 燃油消耗率 

分 类 号：TK411.2[动力工程及工程热物理—动力机械及工程]