基于气道喷射的汽油机全负荷工况燃油喷射控制策略研究

Research on Fuel Injection Control Strategy of Port Fuel Injection Gasoline Engine under Full-Load Conditions

通过对一台气道喷射式汽油机应用模拟仿真方法,研究了喷油器参数对混合气形成过程的影响;通过试验分析,研究了不同燃油喷射时刻对全负荷工况下动力性与排放的影响。仿真与试验结果表明:喷油器改进设计后,通过对喷油器喷雾角度、安装角度及安装位置的调整,能够形成开阀喷射所需要的均质混合气;通过对燃油喷射时刻的寻优发现,在全负荷工况,转速为1 200~5 600r/min下,存在最佳开阀喷射的喷油结束角(EOI),EOI为420°曲轴转角时,发动机动力性与闭阀喷射相比能够提升了1%~2%,且THC排放保持不变。而转速为6 000r/min时,闭阀喷射的动力性较佳。

The effect of injector parameters on the mixture preparation process was investigated by using simulation on a port fuel injection engine. To this end the effect of fuel injection timing on power and emission characteristics under full-load condition was studied by experiments. Results show that by improving the injector design, homogeneous mixture required by open-valve injection can be produced by adjusting the injector’s spray cone angle, installation angle and installation position. Through the optimization of injection timing, a best end of injection（EOI） of the best open valve injection is discovered at full load conditions and at a speed of 1 200 r/min-5 600 r/min. When the EOI is 420° ,the engine power is increased by 1% - 2% compared with that of the closed valve injection, and total hydrocarbons （THC） emissions are almost not affected. While the closed-valve injection has better power performance at the speed of 6 000 r/min.