柴油机尿素SCR后处理系统排放特性试验研究  

Study on Emission Characteristics of Urea-SCR Aftertreatment System of Diesel Engine

作　　者：姜磊[1] 葛蕴珊[1] 李璞[1] 刘志华[1] 

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《内燃机工程》2010年第5期30-35,共6页Chinese Internal Combustion Engine Engineering

摘　　要：影响尿素SCR后处理系统性能的因素很多,如喷嘴形式、喷射位置、辅助空气、催化剂性能等。通过发动机台架试验,对影响尿素SCR性能的因素进行了研究。结论如下:喷嘴形式和喷射方向对尿素的雾化和空间分布有很大影响;喷嘴距离催化剂越远转化效率越高;本系统采用0.2 MPa的辅助空气压力较为理想;NOx的转化效率随着催化剂温度的升高而提高;催化剂温度越低其储氨能力越强;SCR催化剂对NO与NO2的比例、HC和CO的浓度有影响。The performance of urea-SCR aftertreatment system is affected by many factors,such as spray type,position of injection,air-blast system and characteristics of catalyst,etc.The study of urea-SCR system performance made on engine test bench reveals that spray type and direction of injection have a great influence on urea solution atomization and spatial distribution;distance between the spray nozzle and the catalyst the greater,the conversion efficiency the better;for the urea-SCR system used here,air-blast pressure of 0.2 MPa is suitable;NOx conversion efficiency increases with catalyst temperature rising;the catalyst temperature the lower,its storing ammonia capacity the greater;and the SCR may affect ratio of NO and NO2 and concentration of HC and CO.

关 键 词：内燃机 尿素 氮氧化物 选择性催化还原 转化率 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]