柴油车尿素-SCR系统数值模拟研究  

Numerical Simulation of Urea-SCR After-Treatment System for Diesel Vehicle

作　　者：李驰宇 孙强 朱一西 王志春 LI Chiyu;SUN Qiang;ZHU Yixi;WANG Zhichun(School of Automobile and Transportation Engineering,Wuxi Institute of Technology,Wuxi 214121,China;Wuxi Xichuang Automobile Environmental Protection Company Limited,Wuxi 214161,China)

机构地区：[1]无锡职业技术学院汽车与交通工程学院,江苏无锡214121 [2]无锡锡创汽车环保有限公司,江苏无锡214161

出　　处：《汽车实用技术》2024年第19期72-76,共5页Automobile Applied Technology

基　　金：江苏省新能源汽车节能与电池安全工程研究中心项目(苏发改高技发[2022]1103号);江苏省产学研合作项目(BY2022719,BY20230730);江苏省高职院校青年教师企业实践培训项目(2023QYSJ112)。

摘　　要：为提高柴油车尿素-选择性催化还原(SCR)系统的工作性能,文章使用计算流体力学(CFD)方法对某型柴油汽车排气后处理系统进行了数值模拟,研究了不同排气温度工况下该尿素-SCR系统的内部流动及载体前端入口平面上NH3分布的均匀性、速度均匀性等参数。计算结果表明,随着排气温度的升高,SCR载体前端平面的NH3均匀性有明显提升,速度均匀性也略有增加。此外,根据文章计算结果可知,排气温度越高,喷入尿素-SCR系统的尿素溶液蒸发和热解的速率越快,进入催化器的尿素明显减少。文章数值模拟结果可为后续该型柴油机尿素-SCR后处理系统的改进优化提供思路。To improve the performance of urea-selective catalytic reduction(SCR)system of diesel vehicles,this paper adopts computational fluid dynamics(CFD)method to simulate the exhaust after-treatment system of a certain diesel vehicle.The internal flow of the Urea-SCR system and the uniformity of NH3 distribution and velocity on the front entrance plane of the carrier are studied under different exhaust temperature conditions.The results show that with the increase of exhaust temperature,the NH3 uniformity in front plane of SCR carrier is obviously improved,and the velocity uniformity is also slightly increased.In addition,according to the calculated results in this paper,the higher the exhaust temperature,the faster the evaporation and pyrolysis rate of urea solution injected into the Urea-SCR system,and the urea into the catalytic converter is significantly reduced.The numerical simulation results in this paper can provide ideas for the improvement and optimization of Urea-SCR after-treatment system of this diesel engine.

关 键 词：尾气后处理 SCR系统 排气温度 均匀性 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]