中文摘要：

在一台增压中冷电控单体泵的四缸柴油机上采用柴油/甲醇双燃料（DMDF）燃烧方式进行台架实验,研究了甲醇替代率和不同后处理装置对有害气体、烟度和微粒排放特性的影响。结果表明：在排气管加装柴油机氧化催化转化器（DOC）耦合微粒催化转化器（POC）可以大幅降低双燃料燃烧产生的THC和CO,基本可以实现零排放;与催化前相比,微粒的总数量浓度和总质量浓度均有大幅度降低,平均降幅分别为91.7%和88.1%;烟度排放得到改善,平均降幅为21.9%;同时,该后处理装置对DMDF发动机的NO_x排放无明显影响。与之不同,双DOC耦合的后处理装置对THC和CO的催化效率略优于DOC＋POC,但在大部分工况下会导致NO_x和烟度排放的同时增加。

英文摘要：

This study was performed on a four-cylinder diesel engine with a turbocharged intercooled electronic unit pump. The bench test was conducted in the engine,which was modified for diesel/methanol dual fuel（ DMDF） operation. The effects of the substitution ratio of methanol as well as different posttreatment combinations on the emissions of harmful gas,smoke,and particulate matter were investigated. Results show significantly reduced emissions of total hydrocarbon（ THC） and CO,reaching almost zero emissions,when a combination of a diesel oxidation catalyst（ DOC） and particulate oxidation catalyst（ POC） are installed in the exhaust pipe. Compared to a pure diesel engine,both the total number and mass concentration of particulate matter are significantly reduced after installing DOC and POC,with average reductions of 91. 7% and 88. 1%,respectively. In addition,the combination of posttreatments can further reduce smoke emissions by an average of 21. 9%. However,NO_x emissions are not obviously affected. Meanwhile,the efficiency of a double DOC on the reduction of THC and CO emissions is slightly higher than that of the combination of DOC and POC,but double DOC leads to increases in both NO_x and smoke emissions in most conditions at the same time.