摩托车催化转化器及整车瞬态工况排放的数值模拟

Numerical Simulation of Catalytic Converter and Motorcycle Emission under the UDC Condition

以建设牌125ml摩托车上所使用的三效催化转化器为研究对象,利用CES08A催化器活性评价测试仪对催化剂小样的空燃比特性和氧平衡系数为0.97、1和1.03时的起燃温度特性进行试验测试。空燃比特性结果显示该催化剂对CO的转化效率较高,都保持在90% 以上。起燃温度特性结果显示氧平衡系数对CO的起燃温度影响不大。通过对催化剂反应机理的研究,建立了催化反应模型,对其进行数值求解,模拟结果与试验值吻合较好,验证了模型的正确性。在底盘测功机上对整车在循环工况下的排放进行了定容采样测试,并利用Boost软件建立发动机循环仿真模型,对整车在瞬态工况下的排放进行数值模拟。

This paper focuses on the catalytic convertor of JS 125 ml motorcycle. Using the CES08A test equipment of catalytic converter activity, the catalyst sample＇s characteristics of air-fuel ratio and light-off temperature with the oxygen balance factor of 0.97,1 and 1.03 were experimented. The results of air-fuel ratio characteristics show a high conversion rate of CO , which maintains above 90%. The results of light- off temperature characteristics show that the balance factor has a little effect on CO. A model of catalytic chemical reaction was set up based on the research of catalytic reaction mechanism. The results from numerical calculations meet the experimental data very well. With the method of CVS, the motorcycle emissions on Driving Cycles were tested on the chassis dynamometer, while the motorcycle emissions under the UDC condition were simulated by the cycle simulation model established by using Boost software.