利用SCR技术降低柴油机NOx的试验研究

设计了尿素水溶液还原添加装置,并使用这套装置在发动机台架上进行了稀燃NOx选择催化还原（SCR）催化剂的性能评价试验,最后分析了SCR技术目前存在的问题。试验结果表明：在30000h^-1空速、排气温度为340～420℃范围的条件下,该催化剂的NOx转化率维持在90%以上,而在低温和高温下的转化率较低;随着尿素水溶液添加量的增加,催化剂NOx转化率提高,但同时会增加CO排放;当空速为50000h^-1时,催化剂性能略有所下降。

Experimental Research on Reducing NOx Emission of Diesel Engine with SCR Technology

In this paper,the urea water solution reduction adding device was designed and used in a diesel engine test bench to conduct the performance evaluation test on lean-burn NOx SCR catalyst.Finally,the problems of the popularization of SCR was put forward.The result indicates that under the conditions of a space velocity(SV) of 30,000h-1,and an exhaust temperature between 340℃ and 420℃,the conversion efficiency of NOx was above 90%,while at either lower or higher temperature the conversion efficiency became lower.Increasing the quantity of the urea water solution resulted in better conversion efficiency of NOx,but at the same time brought about the rise of CO emission.And the performance of the catalyst would deteriorate slightly when SV was 50,000h-1.