进气参数对HCCI汽油机缸内残余废气分布的影响

在采用全可变气门机构的汽油HCCI试验机上,固定排气门升程和相位,选取了4组不同的进气门升程与相位组合,并应用Simpack软件对气体流动进行计算,同时还引入了残余废气的空间分布率和不均匀度的概念,分析了进气门相位和升程对缸内残余废气分布的影响。结果表明:改变进气门的开启定时和升程会对缸内残余废气的分布造成一定的影响,进气门开启定时对缸内残余废气不均匀度的影响比进气门开启升程对其的影响要大;进气门开启时刻越早,上止点附近残余废气不均匀度越小。

Influence of Intake Parameters on In-cylinder Residual Gas Distribution for HCCI Gasoline Engine

On HL195Q HCCI gasoline engine with a fully variable valve system,the exhaust valve lift and timing were fixed,four different combinations of intake valve lift and timing were selected and the gas flow was simulated with the Simpack software.Moreover,the concepts of spatial distribution proportion and inhomogeneity for the residual gas were introduced and the influences of intake valve lift and timing on in-cylinder residual gas distribution were analyzed.The results show that the changes of intake valve lift and timing have a certain influence on the distribution of in-cylinder residual gas.The intake valve timing has a greater effect on residual gas inhomogeneity than the intake valve lift.Earlier intake valve opening leads to lower residual gas inhomogeneity around TDC.