预喷射对柴油机排放影响的试验分析

Experimental Study on the Influence of Pilot-injection on Diesel Engine Emissions

为研究预喷射对柴油机排放性能的影响,在某电控高压共轨柴油机试验台架上,进行了单次喷射及预喷射对柴油机排放和经济性影响的试验。结果表明:采用预喷射可以降低缸内燃烧温度,进而减少NO_x排放量,而预喷油量增加,会增加碳烟、NO_x排放量及燃油消耗率;主预喷间隔角增加可以降低碳烟量,对NO_x排放量和燃油消耗率影响不大。与单次喷射相比,预喷射使碳烟及NO_x排放量都有所降低,燃油消耗率有所增加。采用合理的预喷射参数可以实现碳烟、NO_x排放量与燃油经济性的折中优化。

To study the influence of pilot-injection on diesel engine exhaust emissions performance, experimental study was carried out on an electronic contfol common rail diesel engine to investigate the influence of single-injection and pilot-injection on emissions and fuel economy. Test result shows that pilot-injection can reduce the highest cylinder temperalure, which leads to reduce NOx emission; with the increase of pilot-injection fuel quantity, carbon smoke, NOx and fuel consumption rate are increased; the main pre spray interval angle can effectively reduce the amount of carbon smoke, but little influence on NOx and specific fuel consumption. Compared with the single injection that pilot-injection reduce the carbon smoke and NOx,but fuel consumption rate are increased. The reasonable pilot injection parameters can achieve compromise of carbon smoke aud NOx.