SCR催化转化器内流场数值模拟与结构优化设计

Numerical Simulation of Internal Flows Field and Optimal Design of SCR Catalytic Converter

在ANSYS软件中建立了SCR催化转化器的三维模型和有限元模型,对其内流场进行了三维稳态数值模拟。结果表明该催化转化器载体入口处速度分布不均匀,且其压力损失较大。在此基础上,研究了载体直径、载体长度对催化转化器内部流动特性的影响,分析了载体入口处的速度分布和催化转化器压力损失的变化规律,并基于响应面法对其结构进行了优化设计,从而使载体入口处速度分布更均匀,催化转化器的压力损失下降了12.6%,排气背压的降低,有利于提高发动机的性能。

A three-dimensional model and finite element model of the SCR catalytic converter were es- tablished by using ANSYS software. The Three-dimensional numerical simulation of the steady flow in the catalytic converter was performed. The results show that the velocity distribution in the entrance of substrate is non-uniform and the pressure loss of the catalytic converter is larger. On this base, the ef- fects of the structure parameters, such as the diameter and the length of substrate on the internal flow field of catalytic converter were researched. The velocity distribution in the entrance of substrate and the pressure loss variation laws of catalytic converter were analyzed. The structure of catalytic converter was optimized based on response surface method. Thus, the velocity distribution in the entrance of sub- strate is more uniform. The pressure loss of catalytic converter is decreased by 12.6%. The reducing of back pressure benefits to improve the performance of engine.