加热炉及发动机台架老化对钒基SCR催化剂性能的影响

Effects of Aging of Heating Furnace and Diesel Engine Bench on Vanadium-Based SCR Catalyst

为适应国V排放标准的要求,探索钒基SCR催化剂耐久性的考核评价方法。在发动机台架上测试发动机台架老化和电加热炉老化2种方式下催化剂的劣化率。结果表明,从稳态单点转化效率看,相比台架老化,炉体老化方式转化效率的下降量低,但对于钒基SCR催化剂在重型柴油机ESC循环时的排放2种老化方式未见明显差异,炉体老化方式可以节省资源,这对国V标准下考核钒基SCR催化剂耐久性时采用炉体老化方式具有一定参考意义。钒基SCR催化剂低温区对于热老化更加敏感,劣化率较高温区的高,在标定后处理策略时应考虑低温劣化情况,防止在应用过程中氨泄漏超标。

Through bench test the catalyst degradation rate of the two forms-the aging on engine bench and the aging in electric heating furnace was examinzd. The test results show,according to the conversion efficiency result of the steady single point,the conversion efficiencydeclining of heating furnace aging is lower than engine bench,yet it is not obvious for the vanadium SCR catalyst in the ESC cycle emission of heavy-duty diesel engine,compared with the aging of engine bench,it has certain reference significance to examine the durability of vanadium SCR catalyst by the method of furnace body＇s aging under the China V standard,it can also save resource. Vanadium SCR catalyst is very sensitive to thermal aging in low temperature zone,and the degradation rate is higher than high temperature zone. The low temperature degradation should be considered when standardizing after treatment strategy to prevent the risk of ammonia leakage in application.