废气进口位置对汽油机性能和NOx排放影响的研究

为同时兼顾排放性、经济性和动力性,提高汽油机废气再循环率,提出改变EGR进气方式,将EGR废气通过管路直接通到进气门处的方案。在一台四气门汽油机上对进气门处单侧通废气与中央通废气的方式进行了对比试验。试验结果表明,与中央进气方式的EGR相比,单侧EGR进气方式在降低同样NOx的排放的情况下,具有更高的燃油经济性、动力性和EGR率。另外,单侧EGR不必降低EGR进气温度,即能获得较较好的发动机性能。

EFFECT OF EGR JET POSITION ON GASOLINE PERFORMANCE AND NOx EMISSION

In order to reduce NOx emission from gasoline engine by exhaust gas recycled (EGR) and take account of fuel economy and power output, a new pattern of EGR entering cylinder is proposed, which is to force EGR injected into intake port by side of one port close to the intake valve. The tests were conducted on a gasoline engine with 4 valves and with pent-roof combustion chamber. The testing results showed that the new pattern of EGR could reduce almost the same amount of NOx emissions compared with the pattern o EGR jet located at the middle of the two intake ports, but also could improve engine fuel economy and increase power output as well as EGR ratio slightly more than that the conventional pattern of EGR could. Meanwhile, the new pattern of EGR could improve comprehensive engine performance without using cooled EGR.