进气前处理实现柴油机超低排放的途径  

Ultra-Low Emission of the Diesel Engine by Intake Pretreatment

作　　者：姚春德[1] 刘军恒[1] 魏立江[1] 夏琦[1] 李方成 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]天津雷沃动力股份公司,天津300402

出　　处：《燃烧科学与技术》2012年第1期1-7,共7页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(50876075);教育部博士点基金资助项目(200800560040)

摘　　要：在一台电控高压共轨发动机上采用进气歧管喷射掺水乙醇(水的体积分数为30%)的方式并应用柴油/乙醇组合燃烧(DECC)方法,对其开展进气前处理的研究.研究发现,与燃用纯柴油的原机相比,采用喷乙醇的进气前处理方式,能够大量减少氮氧化合物(NOx)排放和一氧化氮(NO)排放,二氧化氮(NO2)排放仅在低负荷时有所增加,到中高负荷时即大幅度减少至与原机相近;同时排气烟度得到了改善;进气喷乙醇的方法会引起碳氢化合物(HC)和一氧化碳(CO)的排放增加,但是这可以通过在排气管上安装氧化催化转化器(DOC)得到解决,其催化效率在96%以上.对采用进气喷乙醇方法的非常规排放的检测表明,甲醛和乙醛排放高过原机,但是经过DOC催化处理,消除率在91%以上.此外,进气喷醇的前处理方法可以在中高负荷时明显减少有效燃油消耗,显著提高有效热效率.Diesel/ethanol compound combustion （DECC） was investigated, in which ethanol blended with water （30% volume fraction of water in the blend） was injected into the intake port to fumigate mixture as pretreatment. The testing results showed that the intake pretreatment of ethanol injected into intake port could remarkably reduce nitrogen ox- ides （NOx）, nitric oxide （NO）and smoke emissions simultaneously. Nitrogen dioxide （NO2） emissions decreased at high engine load but increased at low load. Unburned hydrocarbons （HC）and carbon monoxide （CO）emissions in- creased, but they could be eliminated by means of diesel oxidation catalytic converter （DOC）, the catalytic effi- ciency of DOC was more than 96%. The emissions of formaldehyde and acetaldehyde increased in general, however, they both could be reduced by more than 91% with DOC, approximately to the level of baseline engine. Experimental results also indicated that, with intake injected ethanol pretreatment, the brake thermal efficiency of engine could be improved obviously and the fuel economy increased.

关 键 词：共轨柴油机 组合燃烧 前处理 排放 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]