柴油机尿素SCR反应特性的试验研究  

Experimental Study on Reaction Characteristics of Urea-SCR System for Diesel Engine

作　　者：唐炜[1] 蔡忆昔[1] 王军[1] 李超[1] 王兴华[1] 

机构地区：[1]江苏大学汽车与交通工程学院,江苏镇江212013

出　　处：《车用发动机》2016年第1期63-67,共5页Vehicle Engine

基　　金：国家自然科学基金(51306074);江苏高校优势学科建设工程资助项目(PAPD);江苏大学高级专业人才科研启动基金项目(10JDG051)

摘　　要：利用可独立控制尿素喷射量的SCR系统,通过柴油机台架试验,研究了钒基催化剂温度和空速对SCR催化还原反应NOx转化效率和反应速率的影响,以及尿素喷嘴安装位置对转化效率的影响。结果表明:NOx转化率随着氨氮比(NH3与NOx物质的量之比)的升高而逐渐升高,由于尿素水解和热解不完全等因素,氨氮比上升到2时NOx转化率才可达到最大;NOx转化率随着催化剂温度升高而升高,到400℃时基本趋于稳定,NOx转化率随空速升高略有下降;SCR反应速率随温度的升高而升高,随空速的变化不明显;相同氨氮比时,尿素喷嘴与催化剂的距离增加,有利于NOx转化率的升高。The influences of vanadium-based catalyst temperature and space velocity on NOxconversion efficiency and reaction rate and the influences of nozzle position on NOxconversion efficiency were investigated on engine test bench through the SCR system which could control the urea injection quantity independently.The results show that NOxconversion efficiency increases with the increase of NH3/NOxratio and reaches the peak when the ratio increases to 2due to urea incomplete hydrolysis and pyrolysis.NOxconversion efficiency increases with the increase of catalyst temperature and reaches the peak at 400℃,but decreases slightly with the increase of space velocity.The SCR reaction rate increases with the increase of temperature,but dose not change obviously with the increase of space velocity.For the same NH3/NOxratio,the larger distance between urea nozzle and catalyst is beneficial to improve NOxconversion efficiency.

关 键 词：柴油机 选择性催化还原 转化率 反应速率 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]