40 MW链条炉SNCR-SCR脱硝技术中还原剂均布性优化研究  

Optimization of uniform distribution of reducing agent on the hybrid SNCR-SCR denox technology in a 40 MW industrial chaingrate boiler

作　　者：贾玉杰 曾亚军 王志 王夫美[1] 沈伯雄[1] 胡晓晓 JIA Yujie;ZENG Yajun;WANG Zhi;WANG Fumei;SHEN Boxiong;HU Xiaoxiao(School of Energy and Environmental Engineering,Hebei University of Technology,Tianjin 300401,China;Tai'an Ecological Environment Protection Centre,Tai'an,Shandong 271000,China)

机构地区：[1]河北工业大学能源与环境工程学院,天津300401 [2]泰安市生态环境保护控制中心,山东泰安271000

出　　处：《河北工业大学学报》2023年第5期39-48,共10页Journal of Hebei University of Technology

基　　金：河北省自然科学基金(E2022202188);河北省教育厅重点项目(ZD2019065);国家自然科学基金联合项目(U20A20302)。

摘　　要：为优化SNCR-SCR(Selective Non-Catalytic Reduction-Selective Catalytic Reduction,SNCR-SCR)联合脱硝过程中还原剂的分布并满足工业锅炉日趋严格的NOx排放要求,本研究基于计算流体力学(Computational Fluid Dynamics,CFD),对一台40 MW链条炉中的SNCR-SCR联合脱硝过程进行模拟。结果显示:SNCR脱硝系统喷枪高度设置在计算域上锅炉1.2 m处,侧墙设置4支喷枪时,炉内还原剂分布较均匀;SNCR-SCR联合脱硝系统位于炉顶处竖直安装2支补氨喷枪,喷枪间距为0.81 m时补充还原剂与烟气混合程度较好;在补氨喷枪氨氮摩尔比(NSR)小于1.0时增大氨氮比可大幅提高SNCR-SCR脱硝效率,脱硝效率可达83.33%,氨逃逸为3.1 mg/m3;增大氨氮比(>1.0)对提高脱硝效率作用不大,相反会大幅增大氨逃逸。In order to optimize the distribution of reducing agent in the process of Selective Non-Catalytic Reduction-Selective Catalytic Reduction(SNCR-SCR)combined DeNOx and meet the increasingly strict NOx emission requirements of industrial boilers,this study is based on Computational Fluid Dynamics(CFD)simulations of a combined SNCR-SCR DeNOx process in a 40 MW chain-grate boiler.The results show that the height of the spray gun of the SNCR DeNOx system is set at 1.2 m of the boiler in the calculation domain,and when 4 spray guns are installed on the side wall,the reducing agent distribution in the boiler is more uniform.The SNCR-SCR combined DeNOx system is located on the top of the boiler.Two ammonia supplement spray guns are installed vertically.When the spray gun spacing is 0.81 m,the mixing degree of supplementary reducing agent and flue gas is better;when the NSR of the ammonia supplement spray gun is less than 1.0,the ammonia nitrogen ratio can be increased,and thus can significantly improve the DeNOx efficiency of SNCR-SCR;the DeNOx efficiency can reach 83.33%,and the ammonia escape is 3.1 mg/m3.So increasing the ammonianitrogen ratio(>1.0)has little effect on improving the DeNOx efficiency;on the contrary,it will greatly increase the ammonia escape.

关 键 词：氮氧化物 数值模拟 工业链条炉 SNCR-SCR联合脱硝 

分 类 号：X701.7[环境科学与工程—环境工程]