柴油机运行参数对颗粒过滤器压降特性影响的试验研究

Experimental Study on the Effect of Diesel Engine Running Parameters on Particulate Filter's Pressure Drop Characters

基于排气背压的柴油机颗粒过滤器(Diesel Particulate Filter,DPF)再生时机判断是DPF后处理系统的关键。针对壁流式过滤器,采取理论与试验相结合的方法,研究了柴油机不同的排气流量、温度以及DPF加载水平对过滤器压降特性的影响规律。结果表明:压降随温度升高基本成线性增长;随流量增加基本成二次方增长;随碳烟加载量的增加而增长的趋势是曲线斜率先大、后小、再增大。随后分析了排气背压和流量、温度以及碳烟加载量之间的数学关系。研究对于准确判断车载DPF的再生时机,进一步提升DPF后处理系统性能具有一定的指导意义。

Diesel Particulate Filter （DPF） regeneration time judgment based on exhaust pressure-drop is the key to the DPF after-treatment system. In view of wall-flow filter, this paper analyzes the influence law on the pressure-drop of DPF of different exhaust flow, different exhaust temperature and different DPF loading level by means of combining theory and experiment. The results show that pressure-drop basically increases linearly with temperature rising, increases basically in a quadratic relation with the flow rising, increases with DPF loading level in a trend that the slop increases first, then reduces and increases again;then it analyzes the mathematical relationship among back pressure, exhaust flow, exhaust temperature and DPF loading level. The study has a guiding significance for accurately judging DPF regeneration time, and further promoting the DPF after-treatment system performance.