喷油泵各缸喷油量不均匀度对发动机燃烧及排放的影响

Investigation on the Effects of Variation of Average Injection Quantity Between Cylinders of Fuel Pump on Combustion and Emission in a Diesel Engine

采取一种新的控制小齿条位置时各缸循环喷油量不均匀度的喷油泵标定方法,得到了标定点、怠速点和小齿条位置的各缸喷油量不均匀度大幅度改善的喷油泵,并研究了该喷油泵对发动机燃烧及排放的影响.研究结果表明,喷油泵的各缸喷油量不均匀度改善后,发动机缸内最大压力和最大压力升高率明显降低,发动机的NOx排放显著降低,PM排放略微提高.适当提前发动机喷油提前角,发动机的排放可以达到欧Ⅱ水平.

A new fuel pump calibration method was proposed, in which variation of average injection quantity between cylinders was strictly controlled when the pump rack position was smaller. Based on this new method, a fuel pump was calibrated to get smaller variations of average injection quantity between cylinders at rated power mode, idle speed mode and smaller pump rack position. The effects of this fuel pump on combustion and emission in a diesel engine was investigated. The results show that, after variation of average injection quantity between cylinders are controlled, cylinder maximum pressure and maximum pressure increase rate become lower; engine NOx, emission improves obviously; PM emission has a little deterioration. The engine emission can meet Euro II emission regulation with appropriate advancement of engine fuel injection timing.