柴油机微粒捕集器灰分分布对其压降的影响评价

Evaluation of influence of ash distribution on diesel particulate filter pressure drop

通过建立灰分分布对柴油机微粒捕集器(DPF)压降影响的评价函数,分析了孔道壁面厚度、孔道直径、灰分量、碳烟量以及孔道壁面、灰分滤饼层、碳烟滤饼层渗透率等变量不同时,灰分分布对DPF压降的影响。研究结果表明:灰分滤饼层渗透率相对于孔道壁面、碳烟滤饼层渗透率的大小决定了DPF压降随灰分分布变化的趋势;当孔道壁面与灰分滤饼层的渗透率比值A=0.1、孔道壁面与碳烟滤饼层的渗透率比值S=2时,灰分分布于进口孔道壁面DPF压降小;当A=10、S=2时,灰分分布于进口孔道末端DPF压降小;孔道壁面厚度、孔道直径、灰分量、碳烟量能够改变灰分分布对DPF压降影响的程度;评价函数能够有效评价灰分分布对DPF压降的影响,也为不同情况下应用不同的DPF再生方式提供了参考。

An evaluation function was established to analyze the influence of ash distribution on Diesel Particulate Filter （DPF） pressure drop. The variables in this function include the channel diameter, channel wall thickness, ash mass and the soot. Results show that the relative magnitude of ash, wall and soot permeability decides the trend of DPF pressure drop changing with the ash distribution. When the ratio of wall and ash permeability A= 0.1 and the ratio of wall and soot permeability S= 2, the evaluation function is positive, and the DPF pressure drop is lower when ash locating on the wall of the inlet channel than the ash locating at the rear of the inlet channel, and passive regeneration is adopted. When A = 10 and S = 2, the tendency reverses, and active regeneration is taken. Wall thickness, channel diameter, ash mass and soot mass affect the extent of the influence of ash distribution on DPF pressure drop.