李兵

             （潍柴动力股份有限公司，山东 潍坊 261205）

    摘 要：运用计算流体动力学（CFD）的方法对某一柴油机Urea-SCR催化器进行了数值模拟，考虑了尿素溶液的喷射雾化、水分蒸发以及热解过程，忽略了载体内部的表面化学反应过程。通过考察载体入口处氨气分布均匀性系数，对有无混合器、不同喷射距离、不同喷孔分布形式及不同喷孔直径条件下的催化器性能进行评估对比，为催化器的进一步优化提供指导性意见。

    关键词：柴油机；排放控制；选择性催化还原；数值模拟        

    Abstract：The numerical simulation of certain diesel engine Urea-SCR catalyst is carried out using computational fluid dynamics method. The injection and atomization of Urea solution, the evaporation of water and the thermolysis of Urea are taken into account, while the surface chemical reaction in the carrier is ignored. Through the study of ammonia concentration mal-distribution index on the inlet cross-section of the carrier, the performance of the catalyst under different circumstances is evaluated and compared, which can provide some guiding suggestion for further optimization, and the different circumstances are cases with or without mixer, cases with different injection distance, cases with different types of injectors and cases with different orifice diameters.

    Key words：Diesel Engine, Emission control, selective catalytic reduction, numerical simulation