| 摘要:建立一维选择性催化还原（selective catalytic reduction，SCR）催化器模型，采用稳态、瞬态小样试验标定SCR化学反应动力学机理，并分析SCR催化器对氢发动机排气中NOx的催化还原过程。结果表明：入口O2体积分数对NOx催化还原有抑制作用，但入口H2O体积分数对NOx转化效率没有明显影响；当温度为250~400 ℃时，线性温升工况NOx转化效率高于稳态工况且超过98%；氢发动机排气温度和原排NOx体积分数随功率增大而增大，当功率大于60 kW且氨氮比等于1时，SCR催化器转化效率小于95%；增加氨氮比对NOx转化效率的提高作用较小，这是由于在高温条件下增加的NH3倾向与O2反应。 |
| 关键词: 氢发动机 SCR 化学反应动力学 NOx转化 氨氮比 |
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| NOx Conversion Efficiency Simulation of SCR Catalytic Converter for a Hydrogen Engine |
| HU Yuxin,ZHANG Fan,PEI Yiqiang,JIANG Zhongfeng |
| State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China;Sinocat Environmental Technology Co., Ltd., Chengdu 611731, China |
| Abstract:The one-dimensional SCR catalytic converter model was established，and the kinetic mechanism of SCR chemical reaction was calibrated by steady and transient sample experiments.The catalytic reduction process of NOx in hydrogen engine exhaust by SCR catalytic converter was analyzed.The results show that：The inlet O2 volume fraction has an inhibitory effect on NOx catalytic reduction，but the inlet H2O volume fraction has no significant effect on NOx conversion efficiency；When the temperature is between 250?400 ℃，the NOx conversion efficiency under linear temperature rise conditions is higher than that under steady-state conditions by 98%；The exhaust temperature and original NOx volume fraction of hydrogen engines increase with increasing power；When the power is bigger than 60 kW and the ammonia nitrogen ratio is equal to 1，the conversion efficiency of the SCR catalyst is less than 95%；The effect of increasing the ammonia nitrogen ratio on improving the efficiency of NOx conversion is relatively small，because under high temperature conditions，the increased NH3 tends to react with O2. |
| Key words: hydrogen engine SCR chemical reaction kinetics NOx conversion ammonia nitrogen ratio |
