火花点火对缸内直喷汽油机HCCI燃烧的影响

实现汽油机均质混合气压燃(HCCI)的难点是着火控制。在缸内直喷汽油机上实现了HCCI燃烧，研究了火花点火对HCCI燃烧特性的影响。结果表明，HCCI燃烧方式较火花点火(SI)火焰传播燃烧方式放热速率快，热效率高，NOx大幅度降低。在HCCI临界状态时，火花点火有助于提高燃烧稳定性，抑制失火和爆燃，降低循环波动；当火花点火时缸内温度远超过临界着火温度时，火花点火对HCCI燃烧影响不大。火花点火在SI／HCCI燃烧模式切换工况时，能提高瞬态过渡平顺性。

Effects of Spark Ignition on HCCI Combustion in Gasoline Direct-Injection Engines

The difficulty in Homogeneous Charge Compression Ignition(HCCI)combustion is its controllability in ignition.The effects of spark ignition on the HCCI combustion were investigated in a gasoline direct-injection(GDI)engine.The results show that engine thermal efficiency and heat release rate of HCCI combustion is higher than those of spark ignition(SI)homogeneous mixture combustion,accompanying with a remarkable reduction in NO_x.At the critical temperature,utilization of spark ignition was found to improve the stability of HCCI combustion,reduce misfire and knocking as well as cycle-by-cycle variation. However,little influence from spark ignition on HCCI combustion would present when the temperature is much higher than critical temperature.Spark ignition is beneficial to the smooth transition between the combustion modes for SI/HCCI hybrid engine.