推迟供油提前角对生物柴油发动机燃烧和排放性能的影响

Effect of Retarding Injection Timing on Combustion and Emissions Characteristics of Biodiesel Engine

在直喷式增压柴油机上进行了供油提前角对生物柴油发动机动力性、经济性和排放性能影响的研究。试验结果表明:与柴油相比,推迟供油提前角后生物柴油的动力性下降,燃油经济性恶化,NO_x和烟度排放均有不同程度的降低。推迟供油提前角对生物柴油的喷油压力和滞燃期影响不大,但喷油始点和燃烧始点均迟于柴油。与柴油相比,推迟供油提前角后最高气缸压力下降,放热峰值出现时刻提前,指示热效率降低。燃烧始点与NO_x排放的相关性最大,喷油始点和放热峰值出现时刻也与NO_x排放呈弱相关性。

The effects of the injection timing on power output, fuel consumption and emission were investigated on a turbocharged DI injection diesel engine fueled with biodiesel and diesel. The results indicate that comparing with the diesel engine, retarding injection timing for the biodiesel engine the NOx and smoke emissions decrease, the power output and fuel consumption deteriorate, the fuel injection pressure and ignition delay are about the same , the start of injection and combustion are later, the max. cylinder pressure and the indicated thermal efficiency decrease and the max. heat release rate timing advances. Further analysis show that there is a good correlation between the combustion start and NOx emission, and the injection start and the timing of the max. heat release rate show a weak correlation to NOx emission.