柴油机后处理DOC+DPF性能试验研究

Experimental Study of Performance of DOC and DPF on Diesel Engine

在一台非道路国四用高压共轨柴油机上,利用试验台架研究了柴油机后处理柴油氧化催化器(diesel oxidtation catalyst,DOC)、柴油颗粒过滤器(diesel particulate filter,DPF)在不同温度条件下内部的化学特性。结果表明,在一定温度条件下,DOC对未燃HC、CO具有较高的转化效率,对NO的催化氧化效率随温度升高先升后降;同时,催化剂和NO2有助于降低炭烟燃烧所需的化学活化能,提高炭烟燃烧速率。研究结果对深入理解柴油机后处理DOC+DPF的工作过程具有重要的指导作用。

On a ChinaⅣnon-road high-pressure rail diesel engine,the chemical characteristic of DOC(diesel oxidation catalyst)and DPF(diesel particulate filter)in different temperatures is investigated on test bed.The test results show that DOC has a higher conversion efficiency on unburned HC and CO,and catalytic oxidation rate of NO x increases at first and then decreases with the increasing of temperature.At the same time,catalyst and NO x contribute to reduce the chemical activation energy for soot combustion and increase soot combustion rate.The research result can provide a significant guidance for understanding deeply the working process of DOC and DPF on diesel engine.