PODE_n/柴油对重型柴油机燃烧与排放的试验

Experimental Study on Combustion and Emissions of PODE_n/Diesel Blends for Heavy Diesel Engine

针对一台多缸重型柴油机,围绕进气和燃油喷射系统,研究了可变截面涡轮增压器(VGT)、燃油喷射参数(燃油喷射压力、喷油器流量)对聚甲氧基二甲醚(PODE_n)/柴油混合燃料低温燃烧方式的影响.结果表明:PODE_n/柴油混合燃料可以改善燃烧,降低排放.随着负荷的增加,VGT开度逐渐增大,在进气量充足的情况下,增加VGT开度有助于改善燃油消耗率.综合排放和有效热效率的影响,B25、B50和B100对应的最佳VGT开度分别为50%,、55%,和60%,.提高燃油喷射压力可以降低排放,但过高的燃油喷射压力会导致燃油消耗率升高,B25、B50和B100工况的最佳燃油喷射压力分别为140、160和175,MPa.提高喷油器流量可以缩短燃油喷射持续期和燃烧持续期,提高扩散燃烧速率,排放和有效热效率同时得到改善.

The influence of variable geometry turbocharger(VGT)and fuel injection parameters(fuel injection pressure,injector flow)on combustion and emissions of PODEn/diesel blends fuel was researched in a multi-cylinder heavy-duty diesel engine.The results show that PODEn/diesel blends fuel can effectively improve the combustion and reduce the emissions.As the load increases,the opening of VGT increases.Under the condition of adequate inlet air quantity,raising the opening of VGT can improve the brake specific fuel consumption.In addition,the best opening of VGT is 50%,,55%,and 60%,at the load of B25,B50 and B100 respectively.Increasing the fuel injection pressure can reduce the emissions.However,too high injection pressure leads to less thermal efficiency.The best fuel injection pressure is 140,MPa,160,MPa and 175,MPa at the operating conditions of B25,B50 and B100 respectively.Besides,increasing the injector flow can reduce the fuel injection duration and the combustion duration.It can also increase the diffusion combustion rate and the break thermal efficiency,while keep low emissions.