| Three-way catalytic conversion of vehicle is the mainstream technology in exhaust emission control at present. It's a crucial matching product of the whole vehicle exhaust system. With increasingly strict emissions regulations, its performance is required more and more highly. The structure of the catalytic converter is also more complex, and effect performance clearly so that the traditional design concepts have been unable to meet this need. This subject is in this background, relying on domestic leading enterprises product catalytic converters - WUXI WEIFU LIDA CATALYTIC CONVERTER CO.,LTD to carry out the analysis of internal flow characteristics by advanced simulation to provide guidance to the structural design of catalytic converters work.Based on the fully understand of vehicle exhaust emission control and technology in after-treatment at home and abroad, combined with actual products development, the following aspects are conducted.(1) Studied on the catalytic converter flow characteristics, this paper simplified the theoretical of fluid dynamics reasonably and established the mathematical model and parameter calculation model for the specific problem. Provide theoretical support for use of CFD software reliability. The simulation results show that, calculation process has high convergence and accuracy.(2) Through the traditional three-way catalytic converter steady-analysis and 0-20s transient-analysis, this paper found out the main factors of the impacts on the flow characteristics and accumulated boundary conditions and parameter setting suited for catalytic converter. The results show that, the analysis result has high reliability and universality. Then for the catalytic converters assembly BrillianceAuto 2.0T engine, put forward three kinds of structures, and successfully resolved the problem of durability test caused by the unreasonable design.(3) Using the latest technology that coupled 1D-3D simulation, this paper carried out FOTON 486 manifold-type catalytic converter flow calculation, analyzed affect of manifold catalytic converter to the entire engine intake and exhaust system, modified the optimized model by the analysis results and design requirements, and carried out the experiment on engine test bench. The tests indicate that: Optimization model has greatly improved the flow characteristics of exhaust gas, transformation efficiency, velocity uniformity and shorten light-off time. Meanwhile, the performance of engine is also improved.Research results have been successfully applied in the actual production, provide basis and direction for the manifold catalytic converter design, and also provide reference for other similar products development. |
