柴油机全负荷工况多次喷射策略数值分析

Numerical analysis of Multiple injection strategies of the diesel engine under high load

为了获得全负荷工况下的最优多次喷射策略,采用FIRE软件分别对采用二次、三次、四次、和五次喷射策略的缸内工作情况进行了仿真计算,分析NOx减少率和Soot减少率及压力峰值改变率,对各喷射方案进行比较得出全负荷工况下最优的多次喷射策略。仿真结果表明,相对于单次喷射,各多次喷射策略对NOx和Soot均有一定的改善效果,其中五次喷射最优喷射方案对NOx和Soot排放改善效果最好。

In order to obtain the optimal multiple injection strategy for the diesel engine under high load, a numerical simulation of the combustion process was performed for the diesel engine using the twice, triple, four and five times injection strategy under high load by means of a numerical analysis software FIRE. Compared with the results of single injection, the decrement of NOx and Soot and the peak pressure change was analysed to get the optimal injection strategy of the diesel engine under high load.The simulation results show that each multiple injection technology can reduce the NOx and Soot emissions, the injection scheme of five times injection strategy has the best effect on reducing the NOx and Soot emissions.