车用三效催化转化器劣化性能数值模拟

基于车用三效催化转化器的劣化机理,深入分析了Pt颗粒平均直径、反应频率因子等三效催化转化器主要劣化性能参数.然后将劣化性能参数与化学反应机理相结合,建立了包含劣化过程的三效催化转化器反应模型,并进行数值模拟.结果表明80 000 km劣化后,化学反应失活因子在载体前部最小,储放氧反应失活因子则在载体中部最小,而Pt颗粒平均直径在中部最大,两端均减小,并且模拟值与实验值比较吻合,从而验证了基于劣化性能的三效催化转化器反应模型的有效性.

Numerical Simulation of the Deterioration Performance of Automotive Three-Way Catalytic Converter

Based on the deterioration mechanism of the three-way catalystic converter, the main deterioration performance parameters, such as mean diameter of Pt particles and frequency factors of reaction, were analyzed in detail. Then the reaction model, including the deterioration process of three-way catalytic converter, was created by combining deterioration performance parameters with the chemical reactions mechanism. Numerical simulation was in progress then. The results have showed that, after a deterioration of 80000km, the deactivation factor of reaction was minimal in the front of the monolish, and the deactivation factor of oxygen storage and release effects was minimal in the middle of the monolish, while the mean diameter of Pt particles was maximal in the middle and decreased in the ends. The results were roughly coincident with the test results, thus the validity of the reaction model of three-way catalytic converter based on deterioration performance was verified.