摘要
通过建立喷射系统CFD三维仿真模型,研究了柴油机SCR系统在空气辅助雾化条件下尿素喷射的喷雾速度流场、雾化粒径、喷雾形态和贯穿距等变化规律,并通过试验对模型进行了验证;根据喷射模型对SCR系统的喷孔直径等结构参数进行了优化设计,通过发动机ESC,ETC试验对还原剂雾化性能进行试验验证。试验结果表明:采用改进后的柴油机空气辅助喷射还原剂供给系统后,柴油机NOx排放和NH3泄漏等指标均满足国Ⅴ阶段排放法规要求,验证了所采用的喷雾特性仿真优化设计方法有效可行。
By establishing three-dimensional CFD simulation model of injection system,the variation laws of spray velocity flow field,atomization particle size,spray shape and penetration distance for the urea injection in the SCR system of diesel engine under air-assisted atomization conditions were studied.The structural parameters such as orifice diameter of SCR system were optimized according to the injection model.The atomization performance of reductant was verified by the ESC and ETC tests.The test results show that NO x emission and NH 3 leakage of diesel engine meet the ChinaⅤ-stage emission regulations after using the improved supply system of air-assisted injecting reductant,which proves that the simulation and optimization method of spray characteristics is effective and feasible.
作者
刘磊
邓成林
LIU Lei;DENG Chenglin(State Key Laboratory of Automotive Safety and Energy,Tsinghua University,Beijing 100084,China;Institute of Logistics Science and Technology,Beijing 100071,China)
出处
《车用发动机》
北大核心
2018年第5期8-13,共6页
Vehicle Engine
