进气冲程增压注水对柴油发动机性能的影响

Effect of intake stroke water injection on performance of diesel turbocharged engine

采用AVL-FIRE软件,研究了YC6G系列柴油发动机在进气冲程中不同注水量下燃烧室内的燃烧过程,分析了进气注水对发动机性能的影响,以及不同注水量下发动机内部压强、温度和排放的变化情况。仿真表明:增压发动机注水对发动机气缸内部温度和压强影响不大,但进气注水仍然可以少量降低缸内温度的峰值;且进气冲程注水对尾气排放的影响十分显著。注水质量分数提高5%,Soot的生成量大约下降10%;NO x 排放则降低至不注水时的0.21%。因此,进气冲程增压注水有效地改善了柴油发动机内部的燃烧并且降低了尾气排放。

The AVL-FIRE software was used to study the effect of water injection to combustion in the YC6G series diesel engine during the intake stroke. Specifically, the influence of intake water injection on engine internal pressure, temperature, emission and ultimately performance was analyzed. Simulation results show that water injection of the supercharged engine has little effect on the average internal temperature and pressure of the engine cylinder but it can still reduce the peak temperature of the cylinder to a certain extent. The effect of water injection at the intake stroke on the exhaust emission is very significant. When the water injection mass fraction increased by 5%, soot production would decrease by approximately 10% and NO x emissions decreased to 0.21% over when water was not injected. Therefore, the intake stroke boosting water injection effectively improves the combustion inside the diesel engine and reduces exhaust emissions.