点火能量对157FMI汽油机缸内直喷燃烧性能影响研究

Research on the effect of ignition energy on the combustion performance of 157FMI gasoline direct-injection engine

以157FMI汽油机由进气道喷射改为缸内直喷过程中的技改关键技术之点火能量为切入点,以火花塞关于气缸轴线对称的位置为喷油器喷射点,90°CA BTDC开始喷油,喷油持续期为20°CA,分别选取点火能量30,40,50,60和70 mJ展开点火能量对其燃烧特性的影响研究。结果表明:当点火能量由30 mJ增加至70 mJ时,缸内温度、压力、放热率、累积放热量等有所增加,点火能量对缸内燃烧的影响主要体现在火焰生成阶段,在其他参数一定的条件下,缸内温度分布和NO分布基本不受影响。

Taking the ignition energy of key technology of technical transformation in the process of 157 FMI engine from port fuel injection to gasoline direct injection as the starting point,and the symmetrical position of the spark plug about the cylinder axis as the injection point,90℃A BTDC started to inject fuel,the fuel injection duration was 20℃A,and the ignition energy of 30,40,50,60 and 70 mJ was respectively selected to study the effect of ignition energy on its combustion characteristics.The results show that the temperature,pressures,heat releasing rate,the quantity of cumulative heat releasing in the cylinder and other factors will increase along with the ignition energy went up from 30 mJ to 70 mJ.The effect of ignition energy on the combustion in the cylinder was mainly reflected in the flame generation stage,and when other parameters were given,the temperature distribution and NO distribution in the cylinder would be not affected.