TWC贵金属含量偏差对发动机排放的影响研究

Study on Influence of TWC Noble Metal Content Deviation on Engine Emission

由于制造工艺的影响,TWC(三元催化器)贵金属含量存在偏差,为探究贵金属偏差对发动机排放的影响,定制贵金属比例不变,含量相对设计值偏差-15%,-10%,-5%,10%四种偏差件,并通过台架试验进行对比。试验结果表明:-15%~+10%的偏差范围内,发动机排放满足国六法规要求。±10%的偏差范围内,NO_(X)排放余量为54%,NH_(3)为21%,CH_(4)为68%,NMHC(非甲烷碳氢)为81%,CO为91%,-15%偏差件由于贵金属含量下降,储氧量下降,起燃温度上升,排放变差,NO_(X)余量下降至17%。

Due to the influence of manufacturing process,TWC(three-way catalyst)has deviation of noble metal content.In order to explore the influence of noble metal deviation on engine emissions,TWC was specially customized.The proportion of noble metal remained unchanged,and the noble metal content deviated from the design value by-15%,-10%,-5%and 10%,and the bench comparison test is carried out.The test results show that the engine emissions meet the requirements of the sixth stage regulations of China within the deviation range of-15%~+10%.Within the deviation range of±10%,the emission allowance of NO_(X) is 54%,NH_(3) is 21%,CH_(4) is 68%,NMHC(non-methane hydrocarbon)is 81%,CO is 91%,-15%deviation parts due to the decrease of noble metal content,the rise of ignition temperature,the decrease of oxygen storage,the emission becomes worse,and the NO_(X) allowance decreases to 17%.