不同后处理装置对柴油车排放特性的影响——基于行驶里程的后处理装置对柴油公交车气态物排放特性的影响

Gaseous emission characteristics of diesel bus equipped with different after-treatments based on driving distance

三辆柴油公交车分别安装柴油机氧化催化器(DOC),催化型颗粒捕集器(CDPF)与DOC+CDPF三种后处理装置,采用便携式排放测试系统PEMS进行测试,研究整车THC,CO与NO_x等气态物排放性能随行驶里程的变化规律.研究结果表明:对于加装了DOC的公交车,行驶里程达到8万km时DOC性能劣化,应进行保养,此前CO,THC与NO_x的平均转化效率分别为78%,43%和27%;CDPF有效工作时间短,需要定期进行高温保养,周期应为1万km左右,加装CDPF的公交车CO,THC与NO_x平均转化效率分别为74%,16%与15%;DOC+CDPF在行驶里程达12万km时才出现性能劣化现象,此前加装该后处理装置后的公交车CO,THC与NO_x平均转化效率分别为87%,76%与21%.DOC+CDPF的连续再生效果可有效延长后处理装置的工作寿命.

In the long-term test, gaseous emission characteristics of 3diesel-buses equipped with DOC, CDPF and DOC＋CDPF were periodically tested with PEMS to analyze the performance deterioration of different after-treatments while the driving distance increases. Results showed that the operating lifetime of DOC was around 80,000km. Its average reduction rates of CO, THC and NOx were respectively 78%, 43% and 27% before performance deterioration. The operating lifetime of CDPF was comparatively short, so periodic maintenance with high temperature was necessary, and the maintenance period should be around 10,000km. Its average reduction rates of CO, THC and NOx were respectively 74%, 16% and 15% before performance deterioration. The operating lifetime of DOC＋CDPF was around 120000km. Its average reduction rates of CO, THC and NOx were respectively 87%, 76% and 21% before performance deterioration. The lifetime of after-treatment can be extended effectively by the the continuous regeneration of DOC＋CDPF.