残余废气系数对缸内直喷发动机热-功转换过程影响研究

Study on the Effect of Residual Exhaust Coefficient on the Heat-to-Work Conversion Process of Direct Injected Cylinder Engines

为研究残余废气系数对缸内直喷发动机热-功转换过程影响,基于一台1.5L的缸内直喷发动机进行试验。试验工况为:n=1700r/min,BMEP=10bar、n=2200r/min,BMEP=10bar、n=3000r/min,BMEP=10bar;研究结果表明:适当的残余废气系数可提前CA50位置、PCP位置,延长燃烧持续期,增加COVIMEP,但均可提高发动机的热效率,与高转速工况相比,低转速工况热效率改善效果更为明显。

In order to study the influence of residual exhaust gas coefficient on the heat-to-work conversion process of a direct-injection cylinder engine,based on a 1.5L direct-injection cylinder engine Conduct the test.The test conditions are:n=1700r/min,BMEP=10bar,n=2200r/min.BMEP=10bar,n=3000r/min,BMEP=10bar;the results of the study showed that the appropriate The residual exhaust gas factor can advance the CA50,PCP position,increase the combustion duration,COVIMEP,but can enhance the Engine thermal efficiency,Compared with the high speed condition,the thermal efficiency improvement is more obvious in the low speed condition.