论文部分内容阅读
在油滴蒸发准维燃烧模型的基础上,考虑燃油喷雾、蒸发、空气卷吸及传热的影响,结合生成NOx的化学动力学机理,建立直喷式柴油机的燃烧及NOx计算模型 实测直喷式柴油机多种转速负荷特性的NOx排放,得出柴油机运行范围内的NOx排放特性,并与模拟计算结果进行对比分析,两者变化较吻合 柴油机在低速大负荷时由于最高燃烧压力较大,温度较高,燃气在高温下停留时间较长,NOx排放浓度较大 供油提前角增加时,着火始点提前,最高燃烧压力及温度增加,NOx排放浓度也增加
Considering the effects of fuel spray, evaporation, air entrainment and heat transfer, combined with the chemical kinetic mechanism of NOx formation, the combustion and NOx calculation models of direct injection diesel engine are established based on the model of quasi-dimensional combustion of oil droplets. Diesel engines with various speed load characteristics of NOx emissions, diesel engine operating range within the NOx emission characteristics and compared with the simulation results, the two changes are more consistent with low-speed large-load diesel engine due to the maximum combustion pressure is large, the temperature When the fuel gas stays in the high temperature for a long time and the NOx emission concentration increases, the fuel injection advance angle increases, the ignition start point advances, the maximum combustion pressure and temperature increase, and the NOx emission concentration also increases