摘要
为满足国Ⅵ排放标准,提出并开发了双级尿素(urea)选择性催化还原(selective catalytic reduction system, SCR)系统及控制策略,并针对该系统在柴油机上的NOx排放特性及对柴油颗粒捕集器(DPF)被动再生的影响进行了台架验证。结果表明:冷态国际统一瞬态循环(WHTC)双级urea-SCR系统NOx转化效率达到89.2%,比单级urea-SCR系统提高了5.4%,冷起动NOx排放显著降低;热态WHTC双级urea-SCR系统NOx转化效率达到99.3%,比单级urea-SCR系统提高了3.0%;对双级urea-SCR系统尿素喷射量采用闭环控制策略,热态WHTC下DPF平衡点碳载量仅比单级urea-SCR系统提高了0.2 g/L,DPF被动再生效果几乎未受影响。
A two-stage urea-selective catalytic reduction(SCR) system and a related control strategy were developed as an alternative solution to fulfilling the China Ⅵ emissions regulation. Experiments were proceeded to validate the developed system performance in converting NOx and to investigate the influence of the new system on diesel particulate filter(DPF) passive regeneration. The results show that during the world harmonized transient cycle(WHTC) the efficiency of converting NOx by the new system reaches up to 89.2% at cold start and up to 99.3% at hot start, 5.4% and 3.0% respectively higher than those of the conventional system. The total WHTC emissions are lower than those of the China Ⅵ emissions regulation, which indicates the new system has the potential to satisfy the further emissions legislation. When a closed-loop control is adopted for the urea injection, the two-stage urea-SCR system has only 0.2 g/L higher soot loading than the conversional system at DPF balance point under WHTC cycle, exerting very limit influence on the DPF passive regeneration performance.
作者
韩峰
王晓华
王意宝
HAN Feng;WANG Xiaohua;WANG Yibao(Engine Research and Development Center ,WEICHAI Power Co. ,Ltd. ,Weifang 261061,China)
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2019年第3期41-45,55,共6页
Chinese Internal Combustion Engine Engineering
关键词
双级尿素
选择性催化还原系统
国Ⅵ排放
闭环控制
国际统一瞬态循环(WHTC)
被动再生
two-stage urea-selective catalytic reduction system
China Ⅵ missions regulation
closed-loop control
world harmonized transient cycle(WHTC)
passive regeneration
