米勒循环结合可变涡轮增压优化柴油机性能的仿真与试验研究

在开发一款机车柴油机过程中,利用AVL BOOST软件对柴油机工作过程进行了仿真计算,计算了不同米勒强度和不同喷油正时条件下柴油机的性能参数。根据计算结果,排除了弱米勒的方案。针对强米勒和中米勒,开展了试验研究,通过调整喷油定时、增压压力设定、共轨喷射压力,进行了多方案试验研究,试验结果表明,强米勒方案虽然可以有效降低Nox排放,但是带来PM排放升高和涡轮前排气温度升高的问题,中米勒虽然降低Nox排放的效果弱于强米勒,但是能获得比较满意的PM排放,且涡轮前排气温度远低于强米勒,综合各方面性能参数的比较结果,在满足排放要求的前提下,中米勒为优选方案。

Simulation and Experimental Study on Miller Cycle Combined with VGT Optimization of Diesel Engine Performance

In the process of developing locomotive diesel engine , the working process of diesel engine was simulated by AVL BOOST software, and the performance parameters of diesel engine under different Miller strength and different injection timing conditions were calculated. According to the calculation results, the weak Miller scheme was excluded. Aiming at the strong Miller and the middle Miller, the experimental research was carried out. Through the adjustment of the injection timing, the boost pressure setting target and the common rail injection pressure, a multi-program test was carried out. The test results show that although the strong Miller scheme can effectively reduce the Nox emissions, it brings the problem of increased PM emissions and elevated exhaust gas temperature before the turbine. Although the effect of reducing the Nox emissions is weaker than that of the strong Miller, the middle Miller can obtain satisfactory PM emissions, and the exhaust temperature before the turbine is much lower than that of the strong Miller. Based on the comparison of various performance parameters, the middle Miller is the preferred solution under the premise of meeting the emission requirements.