氨分布对柴油机并联式SCR后处理系统NOx排放的影响

刘兴龙; 王军; 王奉双; 王远景

doi:10.3969/j.issn.1001-2222.2020.03.008

车用发动机 ›› 2020, Vol. 0 ›› Issue (3) : 50-56. DOI: 10.3969/j.issn.1001-2222.2020.03.008

栏目

氨分布对柴油机并联式SCR后处理系统NO_x排放的影响

刘兴龙^1,2，王军^1,2，王奉双^1,2，王远景^1,2

作者信息 +

Influence of Ammonia Distribution on NO_x Emission of Parallel SCR Aftertreatment System for Diesel Engine

LIU Xinglong^1,2,Wang Jun^1,2,WANG Fengshuang^1,2，WANG Yuanjing^1,2

Author information +

文章历史 +

摘要

以国六并联式SCR后处理系统为研究对象，在13 L国六柴油机上，采用速度均匀性和氨分布均匀性仿真计算、两路SCR平均氨浓度分析和氨质量加权百分数仿真计算、氨分布均匀性试验、排放性能试验等方法，对两种仅混合器不同的国六并联式SCR后处理系统NO_x排放进行研究。仿真分析研究表明：两路并联的SCR后处理系统速度均匀性和氨分布均匀性计算值在0.96～0.99之间，单个SCR装置的前端面氨浓度均匀性试验测试结果也在0.98以上，但两路SCR前端面的平均氨浓度相对偏差在5%~17%之间，会导致后处理系统NO_x排放较差；氨浓度试验验证了仿真分析的正确性。排放性能试验表明，两路SCR前端面平均氨浓度偏差较大的后处理系统WHSC排放结果会恶化；可通过氨质量加权百分数相对偏差的仿真计算评估并联式SCR后处理系统催化能力，经试验对比建议计算评价标准设定为5%以内较为合理。

Abstract

Taking China Ⅵ parallel SCR aftertreatment system as the research object, NO_x emissions of two systems with different mixers were studied on a 13 L China Ⅵ diesel engine by using the calculation of velocity uniformity and ammonia uniformity, the analysis of twoway average ammonia concentration, the simulation of ammonia massweighted percentage, and the experiment of ammonia distribution uniformity and emission performance. The simulation results show that the calculated values of velocity uniformity and ammonia distribution uniformity of twoway parallel SCR aftertreatment systems are between 0.96 and 0.99, and the test results of ammonia concentration uniformity in the front end of single SCR are also beyond 0.98, but the relative deviation of average ammonia concentration in the front end of twoway SCR is between 5%-17%, which will result in poor NO_x emission of aftertreatment. The simulation is verified by ammonia concentration test. According to the emission performance test, the WHTC emission results will become worse if the average ammonia concentration deviation is large. Accordingly, the parallel SCR aftertreatment catalytic capacity can be evaluated by the relative deviation calculation of ammonia massweighted percentage and it is thought to be reasonable that the calculation evaluation standard is set within 5%.

导出引用

刘兴龙，王军，王奉双，王远景. 氨分布对柴油机并联式SCR后处理系统NO_x排放的影响[J]. 车用发动机. 2020, 0(3): 50-56 https://doi.org/10.3969/j.issn.1001-2222.2020.03.008

LIU Xinglong,Wang Jun,WANG Fengshuang，WANG Yuanjing. Influence of Ammonia Distribution on NO_x Emission of Parallel SCR Aftertreatment System for Diesel Engine[J]. Vehicle Engine. 2020, 0(3): 50-56 https://doi.org/10.3969/j.issn.1001-2222.2020.03.008