催化型颗粒捕集器的净化性能及劣化规律

基于车载排放测试系统(PEMS),测试并分析了25、20、10 g·ft~(-3)(1 ft3=0.028 3 m3)3种不同贵金属负载量催化型颗粒捕集器(CDPF)对公交车尾气的净化性能及劣化规律.结果表明:25 g·ft~(-3)贵金属负载量CDPF对公交车一氧化碳(CO)、总碳氢(THC)、颗粒数量(PN)及颗粒质量(PM)的净化性能最优.CDPF对CO、THC、PN及PM的净化效率随使用里程的增加呈对数下降趋势,25 g·ft~(-3)贵金属负载量CDPF净化效率下降趋势最为缓慢,其抗劣化性能最优.使用5万公里后,25 g·ft~(-3)贵金属负载量CDPF对CO和THC的净化效率仍分别高达74%和70%,对PN及PM的净化效率保持在90%以上.贵金属负载量对CDPF的NOx净化效率影响不显著,其随使用里程的劣化现象不明显.从兼顾成本-性能的角度考虑,20 g·ft~(-3)贵金属负载量CDPF为最佳选择.

Purification Performance and Deterioration Rule of Catalyzed Diesel Particulate Filter

The purification performance and deterioration rule of catalyzed diesel particulate filter (CDPF) with different precious metal loads (25, 20, 10 g?ft-3) on the exhaust emissions of bus was studied and analyzed based on portable emission measurement system(PEMS). The results show that the more the precious metal load on CDPF, the better the purification performance on CO, total hydrocarbon (THC), PN (particle number) and PM (particle mass) is. With the increase of the use time, the purification efficiency of CDPF decreases in the form of logarithmic and the more the precious metal load, the slower the purification efficiency decrease is. After using for 50 thousand kilometers, CDPF with 25 g?ft-3 precious metal load can still keep purification efficiency about 74% and 70% for CO and THC respectively, and more than 90% for PN and PM. The precious metal loads and using mileage has no effects on the NOx emission of buses. CDPF with 20 g?ft-3 precious metal load is the best choice considering both the cost and the performance.