某330MW机组烟气脱硝系统超低排放性能诊断与分析  

Diagnosis and Analysis on Ultra-low Emission Performance of Flue Gas Denitrification System for a 330 MW unit

作　　者：苗永旗 刘海秋 周凯[1] 庄柯[1] 吴碧君[1] 金定强[1] MIAO Yongqi;LIU Haiqiu;ZHOU Kai;ZHUANG Ke;WU Bijun;JIN Dingqiang(Guodian Environmental Protection Research Institute,State Environmental Protection Key Laboratory of Atmospheric Physical Modeling and Control of Air Pollution,Nanjing 210031,China)

机构地区：[1]国电环境保护研究院,国家环境保护大气物理模拟与污染控制重点实验室,江苏南京210031

出　　处：《中国电力》2018年第4期124-129,共6页Electric Power

基　　金：国家重点研发计划“大气污染成因与控制技术研究”重点专项资助项目(No.2016YFC0208102)。

摘　　要：超低排放改造后,一些电厂NO_x排放未达到预期目标。为解决此类问题,以某330 MW超低排放机组为例,对运行了15 500 h的烟气脱硝装置进行现场勘查、运行资料收集,并对运行催化剂进行取样检测,逐一排查NO_x超标排放的原因。研究结果表明:SCR脱硝系统设计裕量低,催化剂主活性成分V_2O_5含量偏低,催化剂微孔数与活性点位数减少导致脱硝效率下降,加之反应器入口NO_x浓度偏高、负荷变化频繁、喷氨响应不及时,造成SCR脱硝装置出口NO_x浓度超过50 mg/m^3。建议加强锅炉优化运行,尽量避免入口NO_x浓度大幅度波动,提高喷氨响应速度,并应新增1层催化剂,将现有2层催化剂进行再生,以确保NO_x排放浓度稳定达标。The anticipated target of NOx emission control have not been reached in some power plants after the ultra-low emission retrofit project.To solve this problem,taking a 330 MW ultra-low emission unit as an example,onsite investigation was conducted and the operation data of a 15 500 h flue gas denitrification unit was collected.The operating catalyst was also sampled and tested.Besides,the causes of excessive NOx emission were investigated individually.The research results show that the decline of denitrification efficiency is attributed to low design margin of SCR denitrification,low content of main active component V2O5 as well as the decrease of catalyst micropore number and active point number.In addition,the high NOx concentration at the inlet of the reactor,the frequent load changes,and untimely ammonia spray response cause the NOx emission at the outlet to exceed 50 mg/m3.In order to ensure that stable emission standards are met,it is suggested that the optimal operation of the boiler should be strengthened to avoid the large fluctuation of NOx concentration and improve the response speed of ammonia injection.One extra layer of catalysts is also advised and the existing two layers of catalyst should be regenerated.

关 键 词：燃煤电厂 烟气脱硝 SCR脱硝装置 蜂窝催化剂 运行诊断 

分 类 号：X51[环境科学与工程—环境工程] TM621.9[电气工程—电力系统及自动化]