氢发动机SCR催化器的NO_(x)转化效率模拟  

NO_(x) Conversion Efficiency Simulation of SCR Catalytic Converter for a Hydrogen Engine

作　　者：胡雨馨 张帆[1] 裴毅强[1] 蒋中锋 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)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]中自环保科技股份有限公司,成都611731

出　　处：《柴油机》2024年第1期15-21,共7页Diesel Engine

基　　金：重庆市技术创新与应用发展重点项目(cstc2020jscx-dxwtBX0024)。

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NO_(x)的催化还原过程。结果表明:入口O2体积分数对NO_(x)催化还原有抑制作用,但入口H2O体积分数对NO_(x)转化效率没有明显影响;当温度为250~400℃时,线性温升工况NO_(x)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NO_(x)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NO_(x)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。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 NO_(x) in hydrogen engine exhaust by SCR catalytic converter was analyzed.The results show that:The inlet O2 volume fraction has an inhibitory effect on NO_(x) catalytic reduction,but the inlet H2O volume fraction has no significant effect on NO_(x) conversion efficiency;When the temperature is between 250‒400℃,the NO_(x) conversion efficiency under linear temperature rise conditions is higher than that under steady-state conditions by 98%;The exhaust temperature and original NO_(x) 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 NO_(x) conversion is relatively small,because under high temperature conditions,the increased NH3 tends to react with O2.

关 键 词：氢发动机 SCR 化学反应动力学 NO_(x)转化 氨氮比 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]