自然吸气二甲醚发动机排气再循环NO_x满足国Ⅳ、Ⅴ排放标准的研究  

Investigation of Dimethyl Ether Engine NO_x Reduction to China Ⅳ and Ⅴ Regulation by Exhaust Gas Recirculation

作　　者：盛新堂 黄瑾[2] 王小荣[2] 王辉[2] 王鹏飞[2] 刘圣华[2] 

机构地区：[1]江苏女神汽车集团,江苏江都225200 [2]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2013年第7期18-22,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51176151);国家高技术研究发展计划资助项目(2012AA111721)

摘　　要：为实现常规机械供油系统发动机装备的非道路车辆和低速载货汽车的排放达到国Ⅳ、Ⅴ排放标准的要求,通过采用增大喷油泵柱塞直径、喷油器喷孔数和直径来增加燃料循环供给量的方法,将一台自然吸气2102QB柴油机改装成二甲醚燃料发动机,并在优化的二甲醚供给正时下,研究了排气再循环(EGR)对二甲醚发动机的动力、经济和排放特性的影响。结果表明,二甲醚发动机运行受EGR的影响小,即使在化学计量比下工作,仍能保持较高的动力性和经济性,大幅降低发动机的NOx生成和排放。同时,针对ESC13工况不同的NOx比排放,建立了二甲醚发动机的NOx排放满足国Ⅳ、Ⅴ排放要求的EGR率策略,当NOx达到国Ⅳ、Ⅴ排放标准时,采用EGR率策略的二甲醚发动机的HC排放增加不多,CO排放比未采用EGR率策略时分别增加了1倍和2倍。该结果可为二甲醚发动机燃烧理论及实现清洁燃烧方法的研究提供参考。Dimethyl ether（DME）can be used as alternative fuel of diesel.DME contains high oxygen and is smoke free,which creates an easy way for the off-road vehicles and low speed trucks to meet China Ⅳ and Ⅴ Standard whose engines equipped with the conventional mechanical fuel injection system.In this paper,a 2102QB diesel engine was retrofitted to run on DME by enlarging its plunge diameter and nozzle flow area to increase cyclic DME fuel quantity.The effects of exhaust gas recirculation（EGR）on the DME engine power,fuel economy,and emissions were investigated,as well as the optimization of DME fuel delivery advance angle.The results indicate that EGR has minor effects on DME engine performances.Even under stoichiometric air fuel ratio condition,the DME engine power and fuel economy are less deteriorated,while NOx emission is reduced significantly.Based on the experimental data,the specific NOx emission was calculated and then it was used to set the rate of EGR under the ESC13 operating conditions.At the mean time,HC and CO emission were evaluated.DME engine gives out a little more HC,while CO increases to two or three times when the DME engine NOx emission meets the regulations of China 4 and 5.The investigation proved DME engine clean combustion theory and provided a way to achieve low emissions of DME engines.

关 键 词：二甲醚 发动机 排气再循环 排放 国Ⅳ排放标准 国Ⅴ排放标准 

分 类 号：TK411.2[动力工程及工程热物理—动力机械及工程]