柴油机颗粒捕集器特性测试评价

Evaluation on Key Performance of Diesel Particulate Filter

为了满足柴油机颗粒物(particulate matter,PM)排放标准的要求,应用微粒捕集器(diesel particulate filter,DPF)对柴油机排放的PM进行捕集并再生。对涂覆前后DPF的压差、不同工况下的被动和主动再生速率、压降特性及极限情况下的累碳量等进行测试评价。研究结果表明:相对于白载体,涂覆后的DPF压差略为增加;在氧化催化器(diesel oxidation catalyst,DOC)作用下,DPF捕集的碳颗粒较易发生被动再生,连续再生速率随着温度升高而提高;温度为400℃时,累碳速率和被动再生速率达到动态平衡,超过600℃时发生主动再生;在降怠速情况下测试累碳量,并通过轻型车排放测试规程(world harmonized light vehicles test cycle,WLTC)进行排放试验验证,结果表明,DPF对PM和粒子数量(particle number,PN)的捕集效率满足工程目标要求。

Based on the requirements of China vehicle emission regulation for particulate matter of diesel engines,DPF is widely used and teseted.In the paper,back pressure,passive/active regenerating rate and pressure drop characteristic are tested and evaluated on the test bench.The results show that pressure of DPF coating increase at different charge;with DOC coating,passive regeneration begin at low temperature.When engine speed/torque increases,passive rate increases.At 400 degree,the capture rate and regenerate rate of soot are balanced.While up to 600 degree,active regeneration begins.Then WLTC cycle emission test on a chassis test bench is carried out.The results show that the particulate matter conversion efficiency for PM/PN meet the project objectives for practical application.