车用柴油机加速工况时喷油与燃烧特性的研究

通过柴油机工作过程测量分析系统对一台直喷式车用柴油机加速时的喷油和燃烧过程进行了试验研究和计算,并计算了其加速过程中的总声压级;利用油滴蒸发准维燃烧模型对柴油机加速过程NOx 排放进行了模拟计算。研究结果表明,柴油机喷油和燃烧特性参数的综合效果对NOx排放值产生影响;柴油机加速时的燃烧噪声大于标定工况,加速工况时的NOx 排放浓度值变化较大,有时大于标定工况。

A Research on Fuel Injection and Combustion Characteristics of a Automobile Diesel Engine during Accelerating Process

The process of fuel injection and combustion is experimentally studied and calculated in a direct injection automobile diesel engine by use of the measuring and analyzing system of working process in internal combustion engine.The total sound pressure level is also calculated. NO_x emission of direct injection diesel engines is stimulatelly calculated by use of the quasi-dimensional spray combustion model during accelerating process.The research result shows that the comprehensive effect of characteristic parameter of fuel injection and combustion in a diesel engine takes an effect on NO_x Emission. The combustion noise of the accelerating process in a diesel engine is more than that of the rated working condion.The variation of NO_x concentration is considerable during accelerating process.Some of them are still more than those of the rated working condition.