颗粒物氧化催化转化器对柴油机排放的影响研究

Effects of Particulate Oxidation Catalyst on Emissions Characteristic of Diesel Engines

在发动机台架上对一台装有颗粒氧化催化转化器（particulateoxidationcatalyst，POC）的重型柴油机进行了常规气态污染物和颗粒物粒径分布与成分的排放特性试验。利用废气分析仪测量POC前后柴油机的常规气态污染物，利用ELPl分析颗粒物数量粒径分布，采用聚四氟乙烯滤膜采集POC前后颗粒物，并对POC前后的颗粒物质量与成分进行分析。研究结果表明：POC对HC、Co和PM排放降低作用显著。在发动机工作范围内，POC对HC的平均转化效率为54％；在大部分工况对CO的转化效率都在85％以上；对NOx基本上没有影响；对N02和N0之间的比例影响非常大，使NO2排放增长了三倍以上；加装POC后颗粒物数量的平均降低率为49．0％，PM质量比排放量降低了45．2％～89．0％，PM中干碳烟部分减少41．7％～93．3％，SOF部分减少7．8％～97．7％。

Gaseous and PM emissions emitted from a heavy-duty diesel engine equipped with a Particulate Oxidation Catalyst （POC） converter were investigated on a test bench. The gaseous emissions were obtained by an exhaust analyzer and the particulate matter （PM） was collected by a Teflon membrane, while the exhausf composition was analyzed respectively before and after the POC converter. The results show that the POC exhibits a good performance on the emission control of HC, CO and PM. Within the engine operating range, the HC average reduction efficiency of 54 ~ and the CO reduction efficiency of more than 850/6 under most conditions are achieved. The POC has no effect on the NOx emission, while the effect of POC on the ratio of NO2 to NO is significant and the specific emission of NO2 is increased by 3 times. With the POC converter, the specific emissions of PM, soot and SOF are reduced by 45.2%-89.0%, 41.7%-93.3%, and 7.8%-97.7% respectively.