汽车尾气催化转化器内流动均匀性对起燃特性的影响  

Influence of gas flow uniformity on catalyst light-off characteristics in automotive catalytic converter

作　　者：王栋[1] 王维城[1] 王晓亮[1] 吴晓敏[1] 王建昕[2] 

机构地区：[1]清华大学热能工程系,北京100084 [2]清华大学汽车工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2003年第6期782-785,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(50076021)

摘　　要：为了优化汽车尾气催化转化器设计,研究其中流动均匀性与催化剂起燃特性的关系。建立了冷启动过程催化剂载体温度场变化的数学模型。使用计算流体力学软件分析流动均匀性对载体温度场和催化剂转化效率的影响。实验中,通过改变载体端面形状,改变催化器内流动均匀性,并在发动机实验台上测试流动均匀性对起燃特性和催化剂转化效率的影响。计算和实验结果都显示:提高催化器内流动均匀性将明显延缓催化剂的起燃过程,从而增加起燃过程中尾气中污染物的排放。The relationship between the gas flow uniformity and catalyst lightoff characteristics is very important for the optimization of automotive catalytic converters. A mathematical model was developed to analyze the influence of gas flow uniformity on the temperature field in a monolith catalyst and on the catalyst conversion efficiency during warmup. Monolith catalysts with different configurations were used in experimental tests to generate different gas flow distributions distubations. The catalysts were installed in a catalytic converter in an engine test bench to measure the overall catalyst conversion efficiency. The simulation and the experimental results showed that although the improved gas flow uniformity increased the catalytic converter lifetime, it also retarded the catalyst lightoff time and reduced the overall conversion efficiency during warmup.

关 键 词：汽车尾气催化转化器 流动均匀性 起燃特性 催化剂 温度场 尾气排放 

分 类 号：U464.134.4[机械工程—车辆工程]