柴油机颗粒捕集器压力损失的研究

A Study on the Pressure Drop of Diesel Particulate Filter

建立了柴油机颗粒捕集器压力损失的数学模型,并进行了试验验证,通过模拟分析了过滤体的结构和运行参数对压力损失的影响规律。结果表明,过滤体的直径与长度的增大均对压力损失的降低有积极作用,较小过滤体的长径比可进一步降低压力损失,过滤体壁厚的增大会增加压力损失;目数的适当增大有利于降低挂烟过滤体的压力损失,但在过滤体壁较厚时,目数过大反而会增加压力损失;随着过滤体内颗粒物累积量的增加,压力损失以比直线稍快的趋势上升;排气流量与温度的提高都会增加压力损失,在排气流量较大时,排气温度对压力损失的影响更为明显,在颗粒物累积量较大时,随着排气流量增加,压力损失的增幅较大。

The mathematical model for the pressure drop of wall-flow diesel particulate filter （DPF） is established and verified by test. Through a simulation with the model, the effects of filter structural and operating parameters on exhaust back pressure （EBP） are analyzed. The results show that the increases in the diameter and length of filter have positive effects on reducing EBP, the smaller length/diameter ratio of filter can further reduce EBP while increasing the wall thickness of filter may make it rise; The reasonable increase in filter＇s channel number per unit cross section is conducive to the reduction in pressure drop of filter with particulates cumulated, but overdoing will cause reverse effects in thicker filter wall; With particulate cumulating in filter increasingly, the EBP goes up slightly more than linearly; The rises in both exhaust flow and temperature may increase EBP with the effect of exhaust temperature on EBP more obvious in higher exhaust flow, and the EBP rises as the exhaust flow increases with a higher rising rate in heavier soot deposit.