稀燃汽油机EGR耦合LNT技术对NO_x排放的影响  

Effect of EGR-LNT Coupling Technology on NO_x Emission of Lean-Burn Gasoline Engine

作　　者：刘磊[1] 李志军[1] 岳东鹏[2] 张瀛[1] 马小强[3] 

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]天津职业技术师范大学,天津300222 [3]天津大学内燃机研究所,天津300072

出　　处：《工程热物理学报》2013年第10期1978-1981,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50276042;No.50776062;No.51276128);国家"863"计划项目资助(No.2008AA06Z322);天津市自然科学基金重点项目(No.11JCZDJC23200)

摘　　要：对一台改制稀燃汽油机分别采用EGR、LNT催化器及EGR耦合LNT系统对该发动机的.NO_x排放控制效果进行对比分析。结果发现,单独采用EGR时,当EGR率超过30%以后发动机开始出现工况运转不稳的状况,并且当EGR率为15%至30%之间时,可以对NO_x的排放起到明显的降低效果;单独采用LNT催化器时,LNT催化器的NO_x转化效率可以稳定地保持在89.3%左右;采用EGR耦合LNT系统时,EGR率为10%至20%之间时,两种技术的耦合使得系统总体的NO_x排放控制效果最佳.相比于单独采用EGR和单独采用LNT,EGR耦合LNT系统具有同时实现低NO_x排放及低成本的潜力。A comparative analysis of the effect of sole EGR, sole LNT and EGR-LNT coupling system on NOx emission control is conducted in a lean-burn gasoline engine. Results show that, in the case of sole EGR, unstable operation do not occur until EGR rate is higher than 30%, and there is a significant effect of NOx reduction when EGR rate ranges between 15% and 30%. In the case of sole LNT, its NOx conversion efficiency can be stably maintained at about 89.3%. In the case of EGR-LNT coupling system, the coupling of that two technologies can make the system achieve the best effect of NOx reduction when EGR ranges between 10% and 20%. Compared with sole EGR and sole LNT, EGR-LNT coupling system has the potential to achieve both low NOx emission and low cost.

关 键 词：稀燃 EGR LNT NOx 

分 类 号：TK411.5[动力工程及工程热物理—动力机械及工程]