柴油车固体SCR系统运行及NO_x排放特性研究

Solid SCR System Operation and NO_x Emission Characteristics of Diesel Vehicle

利用汽车尾气实时监控平台获得了装有固体SCR系统柴油环卫车运行38天共135万条有效实时工况数据和排放数据,分析了固体SCR对柴油车NO_x排放的影响规律。研究结果表明:柴油车城市中行驶平均速度13.45 km/h,90%以上加速度点在±1.5 m/s^2范围内波动。该柴油车NO_x平均质量浓度为0.023 g/s,NO_x平均排放因子为4.17 g/km。随着速度升高,NO_x转化率逐渐升高。随着排气温度升高,NO_x转化率逐渐升高,后逐渐趋于平稳,在平均排气温度低于150℃时,NO_x平均转化率为61%,表明其能较大程度改善柴油车在排气温度低时的NO_x排放。

A total of 1.35 million effective real-time working and emission data within 38 days for diesel sanitation vehicle with solid SCR system were acquired by using the real-time monitoring platform of automobile exhaust gas.The results show that diesel vehicle runs at an average speed of 13.45 km/h and 90%of acceleration points fluctuates within±1.5 m/s^2.The average mass concentration of NOx is 0.023 g/s and its average emission factor is 4.17 g/km.The NO x conversion rate increases with the increase of vehicle velocity and increases and then becomes stable with the increase of exhaust temperature.When the average exhaust temperature is lower than 150℃,the average conversion rate of NO x is 61%.Accordingly,the solid SCR system can greatly reduce NO x emissions of diesel vehicles at low exhaust temperature.