尿素SCR-NO_x催化器流动、还原剂喷雾及表面化学反应三维数值模拟

3D Modeling of Flow,Spray of Reductant and Surface Chemical Reaction in Diesel Urea SCR-NO_x Catalytic Converter

采用计算流体动力学(CFD)耦合化学反应动力学的方法,建立了尿素水溶液喷射、热解以及催化剂表面化学反应整个尾气后处理过程的柴油机SCR-NOx催化器三维数值模型,在验证还原剂喷雾模型的基础上,对一实际柴油机SCR-NOx全尺寸催化器进行了全过程的三维数值模拟,给出了催化器的流场、温度场和浓度场的分布规律,并研究不同发动机负荷下催化器性能的变化,数值模拟计算的结果与发动机台架试验结果取得了较好的吻合。研究结果对指导柴油机SCR催化器的设计有参考价值。

With the aid of CFD(Computational Fluid Dynamic) coupled with chemical reaction dynamics,a three-dimensional modeling was made on a full-sized diesel SCR-NOx catalytic converter system by considering the injection and evaporation of the urea water solution,the subsequent thermal decomposition into ammonia and the surface catalytic reactions in the monolith.The catalyst performances under different loads were also investigated based on the validation of the spray injection model,and the simulated results giv...