汽车三效催化转化器劣化机理分析与仿真研究

Deterioration Mechanism Analysis and Simulation Research on Automobile Three-Way Catalytic Converter

在三效催化转化器特性的研究中,为解决发动机台架实验的断油劣化、周期长、成本高等缺点,并为开发高效长寿低排放的汽车TWC,缩短开发周期,节省开发费用,提出在分析TWC劣化机理的基础上,运用数值仿真技术,建立了包含劣化过程化学反应、储放氧反应、催化剂颗粒直径、反应速率、烧结速率及转化率的TWC劣化特性数学模型,对影响TWC的劣化的排气温度场、浓度场及表征劣化性能的Pt颗粒直径、失活因子及转化效率等参数进行了仿真与分析。研究表明可为预测TWC劣化特性的变化,提高TWC抗劣化性能与制定TWC抗劣化对策提供依据,具有很大的实际应用价值。

In order to develop highly efficient, longevous and low - emission automotive TWC, shorten development cycles and save development costs, in this paper, the TWC deterioration characteristic mathematical model was built by using numerical simulation techniques, which includs the deterioration process chemical reaction, oxygen storage and release reaction, the diameter of the catalyst particles, the reaction rate, the sintering rate and conversion efficiency. The exhaust temperature field and concentration field were simulated and analyzed, which affects the TWC deterioration and the parameters characterizing the deterioration, such as the Pt particle diameter, the inactivation factor and conversion efficiency. The research conclusions have great practice and application value in predicting de- terioration characteristics changes, improving anti - degradation performance and formulating anti - deterioration measure of the TWC.