中文摘要：

在发动机试验台上，对比研究了分子筛和钒基选择催化还原（SCR）催化器在真实柴油机排气环境下的稳态与瞬态反应特性，在此基础上进行了ETC瞬态试验，对分子筛SCR催化器还原剂的瞬态喷射策略进行了优化．结果表明：分子筛SCR催化器在250℃以下的低温区域的Nq标称转化效率明显优于钒基SCR催化器，但两者的标称转化效率在高温区域相差不大；在相同工况下，分子筛SCR催化器的瞬态氨存储能力大约为钒基SCR催化器的两倍；在ETC瞬态循环下，分子筛SCR催化器的瞬态响应速度更快，ETC瞬态循环的排放性能远远优于钒基SCR催化器；相比于钒基SCR催化器，分子筛SCR催化器在低温区域使用的氨氮比应提高0．05左右，在负荷跃迁区域应采用更小的还原剂喷射延迟．

英文摘要：

The selective catalytic reduction （SCR） response properties were investigated on zeolite based SCR（Z- SCR） catalysts and vanadium based SCR （V-SCR） catalysts on a real engine bench. The transient characteristics of the two different SCR catalysts were analyzed under the transient test cycle condition （ETC）, and the urea injection strategy of Z-SCR was optimized. The results show that the NOx conversion efficiency of Z-SCR catalyst was much higher than that of V-SCR catalyst when temperature is below 250 ℃, but when temperature is above 325 ℃, there is little difference between the two catalysts. The storage capacity of NH3 of zeolite is twice that of vanadium. The NOx conversion efficiency of zeolite is better than that of vanadium under the ETC condition, resulting from the high transient reaction rate of Z-SCR. Compared with V-SCR, the transient normal stoichiometric ratio of Z-SCR should be promoted by 0.05 when temperature is below 250 ~C, and a smaller urea injection delay should be used in the load ramp area. The NOx conversion efficiency of Z-SCR is significantly increased with the use of the optimized urea injection strategy.