某330 MW机组烟气脱硝系统超低排放性能诊断与分析
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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 NO_x 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 NO_x 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 V_2O_5 as well as the decrease of catalyst micropore number and active point number. In addition, the high NO_x concentration at the inlet of the reactor, the frequent load changes, and untimely ammonia spray response cause the NO_x emission at the outlet to exceed 50 mg/m~3.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 NO_x 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.
The anticipated target of NO_x 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 NO_x 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 V_2O_5 as well as the decrease of catalyst micropore number and active point number. In addition, the high NO_x concentration at the inlet of the reactor, the frequent load changes, and untimely ammonia spray response cause the NO_x emission at the outlet to exceed 50 mg/m~3.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 NO_x 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.
引文
[1]国家能源局.火电厂烟气脱硝催化剂检测技术规范:DL/T 1286-2013[S].2013.
[2]中华人民共和国国家质量监督检验检疫总局,国家标准化管理委员会.蜂窝式烟气脱硝催化剂:GB/T 31587-2015[S].2015.
[3]王康,朱林,刘涛,等.SCR脱硝催化剂检测与性能评价实验平台的设计与建议[J].中国电力,2016,49(7):157-161.WANG Kang,ZHU Lin,LIU Tao,et al.Design and construction of the experimental platform for SCR denitration catalyst testing and performance evaluation[J].Electric Power,2016,49(7):157-161.
[4]袁宏观,李小海,卢立新,等.某600 MW燃煤电厂SCR蜂窝式脱硝催化剂性能检测与分析[J].能源环境保护,2017,31(2):58-62.YUAN Hongguan,LI Xiaohai,LU Lixin,et al.Properties testing and analysis of honeycomb SCR De-NOx catalyst from a 600 MW coal fired power plant[J].Energy Environmental Protection,2017,31(2):58-62.
[5]LI Pan,LIU Qingya,LIU Zhenyu.Behaviors of NH4HSO4 in SCR of NO by NH3 over different cokes[J].Chemical Engineering Journal,2012,181-182(1):169-173.
[6]YOU Kunkun,MA Xiaocheng,LIU Jiantao,et al.Characteristic analysis of SCR flue gas denitrification catalyst in power plant[J].Advanced Materials Research,2012,518-523:2433-2436.
[7]武宝会,崔利.火电厂SCR烟气脱硝控制方式及其优化[J].热力发电,2013,42(10):116-119.WU Baohui,CUI Li.SCR flue gas denitrification control and optimization in thermal power plants[J].Thermal Power Generation,2013,42(10):116-119.
[8]晏敏,赵凯,朱跃.燃煤电厂运行中脱硝催化剂的性能检测评价与分析[J].中国电力,2016,49(7):168-172.YAN Min,ZHAO Kai,ZHU Yue.Performance assessment and analysis of denitration catalyst in coal-fired power plant[J].Electric Power,2016,49(7):168-172.
[9]商雪松,陈进生,赵金平,等.SCR脱硝催化剂失活及其原因研究[J].燃料化学学报,2011,39(6):465-470.SHANG Xuesong,CHEN Jinsheng,ZHAO Jinping,et al.Discussion on the deactivation of SCR denitrification catalyst and its reasons[J].Journal of Fuel Chemistry and Technology,2011,39(6):465-470.
[10]曹林岩,吴碧君.SCR烟气脱硝催化剂失活原因分析及再生方法探讨[J].电力科技与环保,2012,28(6):7-9.CAO Linyan,WU Bijun.The deactivation causes and regeneration procedures for selective catalytic reduction flue gas de-NOx catalysts[J].Electric Power Technology and Environmental Protection,2012,28(6):7-9.
[11]TANG Fushun,XU Bolian,SHI Haihua,et al.The poisoning effect of Na+and Ca2+ions doped on the V2O5/Ti O2,catalysts for selective catalytic reduction of NO by NH3[J].Applied Catalysis B:Environmental,2010,94(1/2):71-76.
[12]SHI Yajuan,SHU Hang,ZHANG Yuhua,et al.Formation and decomposition of NH4HSO4 during selective catalytic reduction of NO with NH3 over V2O5-WO3/Ti O2 catalysts[J].Fuel Processing Technology,2016,150:141-147.
[13]沈伯雄,熊丽仙,刘亭,等.纳米负载型V2O5-WO3/Ti O2催化剂碱中毒及再生研究[J].燃料化学学报,2010,38(1):85-90.SHEN Boxiong,XIONG Lixian,LIU Ting,et al.Alkali deactivation and regeneration of nano V2O5-WO3/Ti O2 catalyst[J].Journal of Fuel Chemistry and Technology,2010,38(1):85-90.
[14]陈进生,商雪松,赵金平,等.烟气脱硝催化剂的性能检测与评价[J].中国电力,2010,43(11):64-69.CHEN Jinsheng,SHANG Xuesong,ZHAO Jinping,et al.Performance determination and evaluation of denitration catalyst in flue gas[J].Electric Power,2010,43(11):64-69.
[15]LEI Zhigang,LIU Xueyi,JIA Meiru.Modeling of selective catalytic reduction(SCR)for NO removal using monolithic honeycomb catalyst[J].Energy&Fuels,2009,23(12):6146-6151.
[16]YU Jian,GUO Feng,WANG Yingli.Sulfur poisoning resistant mesoporous Mn-base catalyst for low-temperature SCR of NO with NH3[J].Applied Catalysis B:Environmental,2010,95(1/2):160-168.
[17]FORZATTI P.Present status and perspectives in de-NOx SCRcatalysis[J].Applied Catalysis A:General,2001,222(1/2):221-236.
[18]ZHENG Yuanjing,JENSEN A D,JOHNSSON J E.Laboratory investigation of selective catalytic reduction catalysts:deactivation by potassium compounds and catalyst regeneration[J].Industrial&Engineering Chemistry Research,2004,43(4):941-947.
[19]武宝会,李刚,薛大禹,等.SCR Control+脱硝控制系统研究及其在660 MW机组的应用[J].中国电力,2017,50(11):175-179,184.WU Baohui,LI Gang,XUE Dayu,et al.Study on SCR control+denitrification injection control system and its application in a 660MW unit[J].Electric Power,2017,50(11):175-179,184.
[20]DIAO Chunyan,HE Huazhong.Comparative analysis of performance for SCR De-NOx catalysts in power plant[J].Advanced Materials Research,2014,1004-1005:711-714.
[2]中华人民共和国国家质量监督检验检疫总局,国家标准化管理委员会.蜂窝式烟气脱硝催化剂:GB/T 31587-2015[S].2015.
[3]王康,朱林,刘涛,等.SCR脱硝催化剂检测与性能评价实验平台的设计与建议[J].中国电力,2016,49(7):157-161.WANG Kang,ZHU Lin,LIU Tao,et al.Design and construction of the experimental platform for SCR denitration catalyst testing and performance evaluation[J].Electric Power,2016,49(7):157-161.
[4]袁宏观,李小海,卢立新,等.某600 MW燃煤电厂SCR蜂窝式脱硝催化剂性能检测与分析[J].能源环境保护,2017,31(2):58-62.YUAN Hongguan,LI Xiaohai,LU Lixin,et al.Properties testing and analysis of honeycomb SCR De-NOx catalyst from a 600 MW coal fired power plant[J].Energy Environmental Protection,2017,31(2):58-62.
[5]LI Pan,LIU Qingya,LIU Zhenyu.Behaviors of NH4HSO4 in SCR of NO by NH3 over different cokes[J].Chemical Engineering Journal,2012,181-182(1):169-173.
[6]YOU Kunkun,MA Xiaocheng,LIU Jiantao,et al.Characteristic analysis of SCR flue gas denitrification catalyst in power plant[J].Advanced Materials Research,2012,518-523:2433-2436.
[7]武宝会,崔利.火电厂SCR烟气脱硝控制方式及其优化[J].热力发电,2013,42(10):116-119.WU Baohui,CUI Li.SCR flue gas denitrification control and optimization in thermal power plants[J].Thermal Power Generation,2013,42(10):116-119.
[8]晏敏,赵凯,朱跃.燃煤电厂运行中脱硝催化剂的性能检测评价与分析[J].中国电力,2016,49(7):168-172.YAN Min,ZHAO Kai,ZHU Yue.Performance assessment and analysis of denitration catalyst in coal-fired power plant[J].Electric Power,2016,49(7):168-172.
[9]商雪松,陈进生,赵金平,等.SCR脱硝催化剂失活及其原因研究[J].燃料化学学报,2011,39(6):465-470.SHANG Xuesong,CHEN Jinsheng,ZHAO Jinping,et al.Discussion on the deactivation of SCR denitrification catalyst and its reasons[J].Journal of Fuel Chemistry and Technology,2011,39(6):465-470.
[10]曹林岩,吴碧君.SCR烟气脱硝催化剂失活原因分析及再生方法探讨[J].电力科技与环保,2012,28(6):7-9.CAO Linyan,WU Bijun.The deactivation causes and regeneration procedures for selective catalytic reduction flue gas de-NOx catalysts[J].Electric Power Technology and Environmental Protection,2012,28(6):7-9.
[11]TANG Fushun,XU Bolian,SHI Haihua,et al.The poisoning effect of Na+and Ca2+ions doped on the V2O5/Ti O2,catalysts for selective catalytic reduction of NO by NH3[J].Applied Catalysis B:Environmental,2010,94(1/2):71-76.
[12]SHI Yajuan,SHU Hang,ZHANG Yuhua,et al.Formation and decomposition of NH4HSO4 during selective catalytic reduction of NO with NH3 over V2O5-WO3/Ti O2 catalysts[J].Fuel Processing Technology,2016,150:141-147.
[13]沈伯雄,熊丽仙,刘亭,等.纳米负载型V2O5-WO3/Ti O2催化剂碱中毒及再生研究[J].燃料化学学报,2010,38(1):85-90.SHEN Boxiong,XIONG Lixian,LIU Ting,et al.Alkali deactivation and regeneration of nano V2O5-WO3/Ti O2 catalyst[J].Journal of Fuel Chemistry and Technology,2010,38(1):85-90.
[14]陈进生,商雪松,赵金平,等.烟气脱硝催化剂的性能检测与评价[J].中国电力,2010,43(11):64-69.CHEN Jinsheng,SHANG Xuesong,ZHAO Jinping,et al.Performance determination and evaluation of denitration catalyst in flue gas[J].Electric Power,2010,43(11):64-69.
[15]LEI Zhigang,LIU Xueyi,JIA Meiru.Modeling of selective catalytic reduction(SCR)for NO removal using monolithic honeycomb catalyst[J].Energy&Fuels,2009,23(12):6146-6151.
[16]YU Jian,GUO Feng,WANG Yingli.Sulfur poisoning resistant mesoporous Mn-base catalyst for low-temperature SCR of NO with NH3[J].Applied Catalysis B:Environmental,2010,95(1/2):160-168.
[17]FORZATTI P.Present status and perspectives in de-NOx SCRcatalysis[J].Applied Catalysis A:General,2001,222(1/2):221-236.
[18]ZHENG Yuanjing,JENSEN A D,JOHNSSON J E.Laboratory investigation of selective catalytic reduction catalysts:deactivation by potassium compounds and catalyst regeneration[J].Industrial&Engineering Chemistry Research,2004,43(4):941-947.
[19]武宝会,李刚,薛大禹,等.SCR Control+脱硝控制系统研究及其在660 MW机组的应用[J].中国电力,2017,50(11):175-179,184.WU Baohui,LI Gang,XUE Dayu,et al.Study on SCR control+denitrification injection control system and its application in a 660MW unit[J].Electric Power,2017,50(11):175-179,184.
[20]DIAO Chunyan,HE Huazhong.Comparative analysis of performance for SCR De-NOx catalysts in power plant[J].Advanced Materials Research,2014,1004-1005:711-714.