GDI发动机二次喷射策略对油耗和排放影响的试验研究

Experimental study on fuel consumption and emission of a GDI Engine with Twice Injection Strategy

通过改变某款GDI汽油发动机二次喷射策略,在2800rpm,13.5bar工况下研究了二次喷射比例和喷油时刻对油耗、排放的影响。试验结果表明:适当的二次喷射策略有利于优化发动机经济性和排放;二次喷射的比例和喷油时刻影响混合气的形成,可燃混合气形成的优劣程度直接影响燃烧和排放中炭烟生成,可通过优化策略控制CO和HC排放;二次喷射影响缸内温度,温度升高NOx排放增大。

By changing the second injection strategy of a GDI gasoline engine,we studied the effects of second injection fraction and injection timing on fuel consumption and emission at 2800rpm 13.5bar.The results show that proper second injection strategy is beneficial to optimize engine economy and emission;The proportion of second injection and injection timing influence the formation of the mixture,the superiority of the forming of combustible mixture directly influences the combustion and emissions of carbon smoke generated,the CO and HC emissions can be controlled by optimizing strategy;The second injection affects the internal temperature of the cylinder,as the temperature rises,NOx emissions increase.