通过研究NEDC循环工况下整车的瞬态排放情况,分析研究减速断油及怠速停机过程中,氧浓度及温度的变化对整车排放性能的影响。试验结果表明,减速断油过程中,由于没有燃油喷射,新鲜空气被直接排入排气管,造成排气管内氧浓度的增加,并且,减速断油及怠速停机会造成排气管及催化器温度的降低,造成催化器转化率的下降,使发动机再次起动后排放恶化。 By studying the transient emissions of the vehicle under the NEDC cycle, the effects of oxygen concentration and temperature on the emission performance of the vehicle were analyzed and studied during the decelerating and stopping of oil depressurization and idle stoppage. The test results show that during the process of decelerating oil break-off, fresh air is directly discharged into the exhaust pipe due to no fuel injection, resulting in an increase of oxygen concentration in the exhaust pipe. Moreover, decelerating oil breakage and idling stoppages can cause the exhaust pipe and the catalyst Lower temperature, resulting in the catalyst conversion rate of decline, so that the engine start again after the discharge deteriorated.