Investigations on the Influence Rule of Injector Characteristic Parameters on Emission Characteristics of Diesel Engine YC4F50

By researching matching tests of the injector with natural aspirated diesel engine(YC4F50) based on the result of 8-Mode Test Cycle, the effect of variety of hole number, hole diameter, umbrella spray taper angle and the landing height of oil line on discharging characteristics is analyzed. As the injection pressure is constant, the experimental results show that the umbrella spray taper Angle of 155 ° has a smaller standard variance than that of 150 °, and the even distribution degree of the oil line along the arc length to the combustion chamber in circumferential direction is better, so is the result of the 8-Mode Test Cycle; suitable enlargement of the injector can improve oil and gas mixed degree aperture, and increase the combustion efficiency, reducing PM, HC, CO emissions value; the injector with 6 holes can approach a decrease in PM, HC, CO compared with that of 5 holes, increase in NOX, and the same specific fuel consumption. Finally, the injector parameters was determined which matched the YC4F50 diesel engine, and good emission characters and economic performance were achieved.