尿素喷嘴对SCR系统喷射雾化影响仿真研究

Simulation Study on the Influence of Urea Nozzle on Spray Atomization of SCR System

为了提高尿素选择性催化还原技术(selective catalytic reduction,SCR)系统对柴油机尾气中的氮氧化物(NOx)的转化效率,通过使用软件模拟仿真改变尿素水溶液喷嘴的安装位置、数量、安装方向的方法,研究尿素喷嘴参数对系统性能的影响。结果表明:随着喷嘴和尾气进口之间距离的增大,NH3的均匀性系数和平均质量分数均逐渐地减小;随着喷嘴数目的增加、喷射方向与尾气流动方向夹角的增加,载体前端NH3分布均匀性均呈现先增大后减小的趋势。

In order to improve the conversion efficiency of the urea selective catalytic reduction(SCR)system to the nitrogen oxides(NOx)in the exhaust gas of the diesel engine,by using software simulation to change the installation position,number and direction of urea water solution nozzle,the influence of urea nozzle parameters on system performance was studied.The results show that with the increase of the distance between the nozzle and the exhaust gas inlet,the uniformity coefficient and the average mass fraction of NH3 gradually decrease;with the increase of the number of nozzles,the angle between the injection direction and the exhaust gas flow direction increases,the carrier The uniformity of NH3 distribution at the front end shows a trend of first increasing and then decreasing.