某增压型汽油机催化转化器分析

Analysis of a Turbocharged Type Gasoline Engine Catalytic Converter

在增压型汽油机的开发过程中,需要评估其催化器入口处的气流分布均匀性是否能够满足均匀性的评价标准。利用CFD软件,通过对某增压型汽油机催化器进行稳态分析,计算得到载体入口处的气流速度均匀性系数、氧传感器表面速度分布、总压分布等。结果表明:考虑涡轮机出口的旋流和废气旁通阀结构,得到的结果更准确;载体入口处的气流速度均匀性系数满足评价标准;氧传感器位于废气主流区,其布置位置合理;催化器的总压分布合理,压力损失在正常范围内。

The uniformity of the air flow at the catalyst entrance needs to be evaluated whether it is satisfied the standard during the devel opment process of the turbocharged gasoline engine. The steady state analysis for catalytic converter of the turbocharged gasoline engine was made by using CFD software. The coefficient of the air uniformity at the catalyst entrance and the surface velocity distribution of the oxygen sensor and the total pressure distribution were obtained by calculation. The results show that： the obtained results are more accurate when considering the swirl of the turbine at exit and the exhaust gas bypass valve structure; the coefficient of the air flow uniformity at the catalyst entrance meets the evaluation standard; the oxygen sensor is located at the mainstream area of exhaust, which layout is reasonable; the total pressure distribution of the catalytic converter is reasonable, and the pressure loss is within the normal range.