柴油机恒转矩增转速瞬态工况的烟度及燃烧特性分析

Effect of Combustion Parameters on Diesel Engine Smoke Opacity under Constant Torque and Increasing Speed Transient Operating Conditions

采用自行设计的瞬态工况控制及测量系统对增压中冷柴油机进行了恒转矩增转速瞬态工况下发动机的空燃比、消光烟度及示功图参数的测试,并与稳态数据进行了对比。试验结果表明:在瞬态工况下,发动机的外部参数及燃烧过程参数与稳态过程存在很大的差异,其差异程度随工况瞬变性加剧而增加。随转速增加率的上升空燃比减小,燃烧持续期延长,扩散燃烧比增加,导致排气烟度上升。

Airfuel ratio, smoke opacity and incylinder pressure of a turbocharged and aftercooled diesel engine under constant torque and increasing speed transient operating conditions were tested by the homemade control and measurement system. After compared with data gained under steady operating conditions, the conclusions can be drawn that with the rise of speed increasing rate, airfuel ratio decreases rapidly, combustion duration is prolonged and above all diffusion combustion rate reduces. All the factors mentioned above make diesel engine smoke opacity increased with the speed increasing rate.