【摘要】 根据汽车发动机必需消声量频率特性曲线 ,利用相关的数学模型 ,设计制造了催化净化消声器 ,分别用含有少量贵金属的稀土元素和陶瓷作催化剂和载体 .讨论了脉动补氧量、空燃比A/F、发动机工况和载体的结构形式等因素对净化效果的影响 .试验结果表明 :怠速时 ,由于 CO、HC的排放浓度较其他工况高 ,补氧十分必要 ,而且随着补氧量增加 ,CO、HC的净化转化率提高 ;在节气门开度和转速一定的情况下 ,空燃比 A/F增大时 ,CO、HC的排放浓度降低 ,同时净化率提高 ;在模拟汽车等速工况运行时 ,颗粒型载体的净化效果优于蜂窝型 ,而在怠速工况时 ,两者的净化效果基本一致 ;同种情况下 ,CO的转化率高于 HC的转化率 .更多还原

【Abstract】 A ceramic substrate catalytic converter was designed and manufactured according to the necessary noise reduction frequency characteristic for automotive engine and the relevant mathematical model, in which the rare earth elements containing some noble metals are used as catalyst. The experiments were mainly conducted to evaluate the effects of the factors including the quantity of added oxygen, air fuel ratio (A/F), working condition of engine, and catalyst substrate structure on the conversion efficiency. The experimental results show that the added oxygen is necessary especially for the idling condition of engine because of the comparatively high concentrations of carbon monoxide (CO) and hydrocarbons (HC), furthermore, the conversion efficiency increases markedly as the quantity of added oxygen increases. When the aperture of throttle gate and rotational speed of the engine keep constant, with the increase of A/F ratio, the concentrations of CO and HC decrease while the conversion efficiency increases. At the simulating constant velocity condition of automobile, the purifying effect of the converter with beaded catalyst substrate is better than that with honeycomb like catalyst substrate although their purifying effects are approximately identical at the idling condition. Under the same condition, the conversion efficiency for CO is higher than that for HC.更多还原