摘要
基于三效催化转化器内部化学反应机理以及化学动力学模型,使用大型通用计算流体力学软件FLUENT进行数值仿真。建立转化器圆形与方形2种单孔道三维模型,通过数值模拟得到尾气各组分的质量分布、组分转化率随孔道长度的变化关系以及不同流速下各组分的转化率。研究结果表明:催化转化器单孔道内的催化化学反应主要发生在中前端,后端转化率很低,且圆形孔道各组分的转化率高于方形孔道。2种孔道内CH4、CO的转化率先上升而后保持不变,H2的转化率先上升后下降。气流速度越高,各组分的转化率越低,催化转化器载体边缘处组分的转化率高于中心处。
Based on chemical mechanism and chemical kinetics model in catalytic converter, using computational fluid dynamics software, such as FLUENT, can help conduct numerical simulation. Firstly, establish two 3D single span way models. And then, obtain mass distribution of exhaust components, the relationship between the conversion efficiency of exhaust components and the channel length, and the conversion efficiency of exhaust components in different flow velocity. The results show that the structure of channel has an influence on the conversion efficiency of exhaust, the rate of conversion of exhaust components of circular tunnel is higher than square channel＇ s one, and the chemical reactions mainly occur in pre-medial single span way. The conversion efficiency of methane and carbon monoxide increases in front of channel, then levels off in end of channel. However, the conversion efficiency of hydrogen keeps down in end of channel. High flow velocity weakens the conversion efficiency of exhaust components in different flow velocity. The study can provide a beneficial reference basis for analyzing the performance of TWC .
出处
《山东交通学院学报》
CAS
2016年第1期16-20,共5页
Journal of Shandong Jiaotong University
