【摘要】 基于热老化原理与Arrhenius方程，开发出一种通用的柴油机选择性催化还原(SCR)系统快速老化方法，并通过试验验证了快速老化与常规老化方法的等效性．结果表明：SCR系统的NO_x转化效率下降存在显著的温度差异，快速老化使SCR催化剂损坏、储NH3能力显著下降是SCR低温工作条件下劣化显著的主要原因．全球统一瞬态循环(WHTC)下NO_x排放与SCR等效耐久里程线性相关系数为0.988，用于验证等效性的常规老化样件的WHTC试验排放测量值与拟合值的误差范围为-4.12%～3.13%，证明快速老化方法具有良好等效性．基于试验数据，该型国Ⅵ柴油机在运行0.80×10~6～1.06×10~6km后超越0.46 g/(kW·h)的耐久排放限值要求，在运行3.13×10~6～3.67×10~6km后超越1.20 g/(kW·h)的车载诊断系统(OBD)限值要求．更多还原

【Abstract】 A general accelerated aging method for the selective catalytic reduction（SCR） system of diesel engines was developed based on the principle of thermal aging and Arrhenius equation,and the equivalence between accelerated aging and conventional aging methods was verified by engine tests. The test results show that a significant temperature difference appears in the deterioration of NO_x conversion efficiency of the SCR system. The constructional damage of the SCR catalyst by thermal aging and the deterioration of NH₃ storage capacity is the main reasons for the significant deterioration of SCR under low-temperature working conditions. The linear correlation coefficient between the world harmonized transient cycle（WHTC）-NO_x emission and equivalent durability mileage is 0.988,and the error range between the measured WHTC-NO_x factors and the fitted values used to verify the equivalence of conventional aging is in a range of -4.12% to 3.13%,proving that the accelerated aging method has good equivalence with the conventional aging method. Based on the test data,the tested China-Ⅵ diesel engine will exceed the durability emission limit of 0.46 g/（kW·h） after 0.80×10⁶—1.06×10⁶km and will exceed the on board diagnostics（OBD） limit of 1.20 g/（kW·h） after 3.13×10⁶—3.67×10⁶km.更多还原