国Ⅴ柴油机SCR系统结构对尿素结晶影响研究

摘要

For the urea crystallization in SCR system of China Ⅴ commercial diesel vehicle ,a series of structure optimization schemes were put forward by using the methods of CFD simulation and bench test .The improved structure ameliorated the flow distribution and flow uniformity as well as urea vapor uniformity .Therefore ,the crystallization risk of SCR system was e-liminated and it could run normally .In addition ,the influences of flow distribution and system structure on urea crystallization were studied by comparing simulation results with bench test data .%针对某国 Ⅴ 商用柴油车SCR系统中出现的结晶问题,综合应用CFD模拟和台架试验进行分析研究,提出一系列结构优化和改进方案,改善了SCR前流场状态以及流体的流动均匀性和尿素均匀性,基本消除了排气系统在实际工况下的结晶风险,提高了全系统的抗结晶能力,保证了SCR系统的正常运行.通过对模拟结果和台架试验数据的比对分析,研究了流场分布以及混合器结构对结晶形成产生的影响.