基于耐久老化测试过程催化器储氧量变化规律的车辆排放控制方法研究

Research on Vehicle Emission Control Method Based on The Variation Law of Oxygen Storage in Catalytic Converter During Durability Aging Test

为满足GB18352.6国六第二阶段排放法规中排放污染物控制装置20万公里耐久性试验要求,对国六B实际行驶污染物排放(Real Drive Emission, RDE)项目整车耐久试验中的催化器状态变化及世界轻型汽车测试循环工况(World Light Vehicle Test Cycle, WLTC)试验中的排放物变化趋势进行分析,结合催化器老化及排放恶化机理,研究了一种针对耐久老化催化器的排放控制方法。基于分析研究及排放试验结果,得出结论:催化器老化后排放物恶化的一个原因为催化器内部活性成分持续不断地下降,另一个原因为储氧量的降低导致催化器最佳催化转化窗口发生微小变化。通过调整发动机软件标定以针对性地优化转化窗口,验证发现经过优化后的催化器主要气态排放物的排放水平显著降低。

In order to meet the requirements of the 200000 km durability test of emission pollutant control devices in GB18352. 6 national VI phase II emission regulations, the change of catalyst state in the vehicle durability test of the national VI B real drive emission(RDE) project and the change trend of emissions in the world light vehicle test cycle(WLTC) test are analyzed. Combined with the aging and emission deterioration mechanism of catalyst, an emission control method for durable aging catalyst is studied. Based on the analysis and emission test results, it is concluded that the deterioration of emissions after the aging of the catalyst is due to the continuous decline of active components in the catalyst on the one hand, and the decrease of oxygen storage on the other hand, which leads to the slight change of the optimal catalytic conversion window of the catalyst. By adjusting the engine software calibration to optimize the conversion window, the emission level of the main gaseous emissions of the optimized catalyst is significantly reduced.