重型柴油机NO_x尿素SCR混合器的设计与试验研究  

Design and Experiment of Mixer in NO_x Urea-Selective Catalyst Reduction System for Heavy Duty Diesel Engine

作　　者：赵彦光[1] 胡静[1] 陈镇[2] 帅石金[1] 肖建华[1] 王建昕[1] 

机构地区：[1]清华大学汽车安全与节能国家重点实验室,北京100084 [2]杭州银轮科技有限公司,杭州310013

出　　处：《内燃机工程》2012年第1期32-37,43,共7页Chinese Internal Combustion Engine Engineering

摘　　要：设计了2种紧凑型混合器,分别为带4个叶片的混合器1和带4组叶片对(8个叶片)的混合器2。试验用U型管和傅里叶变换红外光谱仪研究了混合器对压力损失和NOx转化效率的影响。试验结果表明:排气流量、排气管管径对压力损失影响较大,而温度对压力损失影响较小;混合器2的压力损失比混合器1的小;混合器使NOx转化效率最大提高约10%;混合器安装在喷嘴后端比安装在喷嘴前端时的NOx转化效率高;无混合器时外径63mm排气管对应的NOx转化效率比外径76mm排气管对应的NOx转化效率提高约8%。Two compact mixers separately with four blades （No. 1 mixer） and four couples （eight blades total） of blades （No. 2 mixer） were designed. Pressure loss and NO~ conversion ratio were studied using U tube and Fourier transform infrared （FTIR） spectroscopy. The experiment results show that exhaust gas mass flow and exhaust pipe diameter have significant effect on the pressure loss while gas tem- perature has slight influence; the pressure loss caused by No. 1 mixer is larger than No. 2 mixer; both two mixers can improve the NO~ conversion efficiency at most about 10% ; the mixer mounted downstream of the injector has better mixing effect than that mounted upstream; in the case of no mixer, the 63 mm outer diam- eter exhaust pipe gets higher NOx conversion efficiency than that of 76 mm outer diameter by about 80//00.

关 键 词：内燃机 重型柴油机 尿素选择催化还原 混合器 氮氧化物 压力损失 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]