燃用高沾污性煤质锅炉SCR脱硝流场优化
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摘要
某2×300 MW机组选择性催化还原(SCR)烟气脱硝装置,自2013年运行以来,一直存在喷氨格栅、水平烟道和导流板等位置积灰严重,氨逃逸量明显超标,空气预热器差压高等问题。通过计算流体动力学(CFD)流场校核分析产生问题的原因,最终确定优化方案为:更换防积灰能力强、混合特性好的花瓣型喷氨格栅,优化导流板布置,并加大导流板和烟道壁面处流速以减轻积灰。优化后,喷氨格栅分区可调性能明显好转,SCR脱硝装置出口NOx质量浓度分布更为均匀,氨逃逸量显著降低,运行8个月后停炉检修时发现喷氨格栅、烟道和导流板异常堵灰的情况得到了根本解决。
Since the SCR device of a 2×300 MW unit was put into service in 2013, there has been serious problems such as ash deposition in the location of ammonia injection grid, horizontal flue gas duct and deflector. Meanwhile, the ammonia slip concentration obviously exceeded the standard value, resulting in a high differential pressure of the air preheater. To solve these problems, the flow field was checked through computational fluid dynamics(CFD) to find out the reason. The final optimization scheme is: replacing the original ammonia injection grid(AIG) by the petal type one better anti-fouling ability and mixing characteristics, optimizing the deflectors, and increasing the velocity near the guide plate and flue duct wall to alleviate ash accumulation. After the modification, the adjustable performance of the ammonia-spraying grille zoning was improved obviously, the distribution of nitrogen oxide concentration at outlet of the SCR denitrification system was more uniform, and the ammonia escape amount was significantly reduced. The abnormal ash blockage in the ammonia-spraying grille, flue and guide plate was solve when the furnace was shut down after 8 months' operation.
Since the SCR device of a 2×300 MW unit was put into service in 2013, there has been serious problems such as ash deposition in the location of ammonia injection grid, horizontal flue gas duct and deflector. Meanwhile, the ammonia slip concentration obviously exceeded the standard value, resulting in a high differential pressure of the air preheater. To solve these problems, the flow field was checked through computational fluid dynamics(CFD) to find out the reason. The final optimization scheme is: replacing the original ammonia injection grid(AIG) by the petal type one better anti-fouling ability and mixing characteristics, optimizing the deflectors, and increasing the velocity near the guide plate and flue duct wall to alleviate ash accumulation. After the modification, the adjustable performance of the ammonia-spraying grille zoning was improved obviously, the distribution of nitrogen oxide concentration at outlet of the SCR denitrification system was more uniform, and the ammonia escape amount was significantly reduced. The abnormal ash blockage in the ammonia-spraying grille, flue and guide plate was solve when the furnace was shut down after 8 months' operation.
引文
[1]中国电力企业联合会.中电联发布2014年度火电厂环保产业信息[P/OL].(2015-05-07)[2017-9-23].http://www.cec.org.cn/huanbao/jienenghbfenhui/fenhuidongtai/fenhuixinwen/2015-05-12/137681.html.China Electric Power Enterprise Association.CICreleases 2014 annual information on environmental protection industry of thermal power plants[P/OL].(2015-05-07)[2017-9-23].http://www.cec.org.cn/huan bao/jienenghbfenhui/fenhuidongtai/fenhuixinwen/2015-05-12/137681.html.
[2]中华人民共和国环境保护部.关于印发《全面实施燃煤电厂超低排放和节能改造工作方案》的通知[EB/OL][2015-12-11].http://www.zhb.gov.cn/gkml/hbb/bwj/201512/t20151215_319170.htm.The Ministry of Environmental Protection of the People’s Republic of China.Notice on the issue of“fully implementing the program of work on ultra-low emission and energy conservation reform of coal-fired power plants”[EB/OL][2015-12-11].http://www.zhb.gov.cn/gkml/hbb/bwj/201512/t20151215_319170.htm.
[3]张洁,张扬.燃煤电站SCR烟气脱硝工程技术关键问题研究[J].电力科技与环保,2011,27(2):38-41.ZHANG Jie,ZHANG Yang.Study on key technical issues of SCR denitrication from coal-fired boiler flue gas[J].Electric Power Technology and Environmental Protection,2011,27(2):38-41.
[4]林伟杰,牛国平,白少林,等.火电厂烟气污染物超低排放技术[M].北京:中国电力出版社,2015:91-92.LIN Weijie,NIU Guoping,BAI Shaolin,et al.Ultra low emission technology of flue gas pollutants in thermal power plants[M].Beijing:China Electric Power Press,2015:91-92.
[5]尤良洲.燃煤机组SCR装置运行现状调查及存在问题分析[J].电力科技与环保,2015,31(6):36-38.YOU Liangzhou.Survey on operation condition and in existing problems of SCR facilities in coal-fired units[J],Electric Power Technology and Environmental Protection2016,31(6):36-38.
[6]方文沐,杜惠敏,李天荣,等.燃料分析技术问答[M].北京:中国电力出版社,2005:306-308.FANG Wenmu,DU Huimin,LI Tianrong,et al.Fuel analysis technology question and answer[M].Beijing:China Electric Power Press,2005:306-308.
[7]姚伟,何红光,刘家利.煤灰沾污性能判别试验研究[J].热力发电,2010,39(3):65-69.YAO Wei,HE Hongguang,LIU Jiali.Test on distinguishing contamination properties of coal ash[J].Thermal Power Generation,2010,39(3):65-69.
[8]乐长义.燃煤的燃烧性结渣性和积灰性评价技术[J].华东电力,1985(15):6-18.LE Changyi.Coal combustion of slagging and fouling evaluation technology[J].East China Electric Power,1985(15):6-18.
[9]王林.燃煤飞灰沉积特性的实验研究[D].哈尔滨:哈尔滨工业大学,2015:1-2.WANG Lin.Experimental study on characteristics of coal ash deposition[D].Harbin:Harbin Institute of Technology,2015:1-2.
[10]樊建人,周大冬,岑可法.煤灰粒子冲击管束的碰撞和磨损研究[J].工程热物理学报,1989,10(4):452-455.FAN Jianren,ZHOU Dadong,CEN Kefa.An investigation of tube banks erosion by coal ash impaction[J].Journal of Engineering Thermophysics,1989,10(4):452-455.
[11]安敬学,王磊,秦淇.SCR脱硝系统催化剂磨损机理分析与治理[J].热力发电,2015,44(12):119-125.AN Jingxue,WANG Lei,QIN Qi.Mechanism research on catalyst attrition in SCR denitration system and the treatment[J].Thermal Power Generation,2015,44(12):119-125.
[12]王震.我国煤炭市场形势分析及对策建议[J].煤炭经济研究,2017,37(3):43-46.WANG Zhen.Analyzed the situation of coal market and countermeasure proposals[J].Coal Economic Research,2017,37(3):43-46.
[13]董陈,乔海勇,牛国平.某600 MW机组SCR烟气脱硝装置优化设计[J].热力发电,2014,43(12):99-104.DONG Chen,QIAO Haiyong,NIU Guoping.Optimization design of SCR flue gas denitration equipment for a600MW unit[J].Thermal Power Generation,2014,43(12):99-104.
[14]牛国平,董陈,王晓冰,等.一种局部涡流和整体旋流相结合的花瓣型喷氨格栅:201210394099.9[P].2013-04-03.NIU Guoping,DONG Chen,WANG Xiaobing,et al.Apetal-shaped ammonia-spraying grid combining local eddy current with integral eddy current:201210394099.9[P].2013-04-03.
[15]舒凯,南蛟,曹帅锋.北方联合电力有限责任公司包头第三热电厂2号机组脱硝喷氨优化调整试验报告[R].西安:热工研究院有限公司,2017:11-12.SHU Kai,NAN Jiao,CAO Shuaifeng.Experimental report on optimization and adjustment of SCR for No.2unit of Baotou third thermal power plant[R].Xi’an:Xi’an Thermal Power Research Institute Co.,Ltd.,2017:11-12.
[16]谭增强,杨世极,宋晓磊.北方联合电力有限责任公司包头第三热电厂1号机组脱硝喷氨优化调整试验报告[R].西安:西安热工研究院有限公司,2017:20-21.TAN Zengqiang,YANG Shiji,SONG Xiaolei.Experimental report on optimization and adjustment of SCR for No.1unit of Baotou third thermal power plant[R].Xi’an:Xi’an Thermal Power Research Institute Co.,Ltd.,2017:20-21.
[2]中华人民共和国环境保护部.关于印发《全面实施燃煤电厂超低排放和节能改造工作方案》的通知[EB/OL][2015-12-11].http://www.zhb.gov.cn/gkml/hbb/bwj/201512/t20151215_319170.htm.The Ministry of Environmental Protection of the People’s Republic of China.Notice on the issue of“fully implementing the program of work on ultra-low emission and energy conservation reform of coal-fired power plants”[EB/OL][2015-12-11].http://www.zhb.gov.cn/gkml/hbb/bwj/201512/t20151215_319170.htm.
[3]张洁,张扬.燃煤电站SCR烟气脱硝工程技术关键问题研究[J].电力科技与环保,2011,27(2):38-41.ZHANG Jie,ZHANG Yang.Study on key technical issues of SCR denitrication from coal-fired boiler flue gas[J].Electric Power Technology and Environmental Protection,2011,27(2):38-41.
[4]林伟杰,牛国平,白少林,等.火电厂烟气污染物超低排放技术[M].北京:中国电力出版社,2015:91-92.LIN Weijie,NIU Guoping,BAI Shaolin,et al.Ultra low emission technology of flue gas pollutants in thermal power plants[M].Beijing:China Electric Power Press,2015:91-92.
[5]尤良洲.燃煤机组SCR装置运行现状调查及存在问题分析[J].电力科技与环保,2015,31(6):36-38.YOU Liangzhou.Survey on operation condition and in existing problems of SCR facilities in coal-fired units[J],Electric Power Technology and Environmental Protection2016,31(6):36-38.
[6]方文沐,杜惠敏,李天荣,等.燃料分析技术问答[M].北京:中国电力出版社,2005:306-308.FANG Wenmu,DU Huimin,LI Tianrong,et al.Fuel analysis technology question and answer[M].Beijing:China Electric Power Press,2005:306-308.
[7]姚伟,何红光,刘家利.煤灰沾污性能判别试验研究[J].热力发电,2010,39(3):65-69.YAO Wei,HE Hongguang,LIU Jiali.Test on distinguishing contamination properties of coal ash[J].Thermal Power Generation,2010,39(3):65-69.
[8]乐长义.燃煤的燃烧性结渣性和积灰性评价技术[J].华东电力,1985(15):6-18.LE Changyi.Coal combustion of slagging and fouling evaluation technology[J].East China Electric Power,1985(15):6-18.
[9]王林.燃煤飞灰沉积特性的实验研究[D].哈尔滨:哈尔滨工业大学,2015:1-2.WANG Lin.Experimental study on characteristics of coal ash deposition[D].Harbin:Harbin Institute of Technology,2015:1-2.
[10]樊建人,周大冬,岑可法.煤灰粒子冲击管束的碰撞和磨损研究[J].工程热物理学报,1989,10(4):452-455.FAN Jianren,ZHOU Dadong,CEN Kefa.An investigation of tube banks erosion by coal ash impaction[J].Journal of Engineering Thermophysics,1989,10(4):452-455.
[11]安敬学,王磊,秦淇.SCR脱硝系统催化剂磨损机理分析与治理[J].热力发电,2015,44(12):119-125.AN Jingxue,WANG Lei,QIN Qi.Mechanism research on catalyst attrition in SCR denitration system and the treatment[J].Thermal Power Generation,2015,44(12):119-125.
[12]王震.我国煤炭市场形势分析及对策建议[J].煤炭经济研究,2017,37(3):43-46.WANG Zhen.Analyzed the situation of coal market and countermeasure proposals[J].Coal Economic Research,2017,37(3):43-46.
[13]董陈,乔海勇,牛国平.某600 MW机组SCR烟气脱硝装置优化设计[J].热力发电,2014,43(12):99-104.DONG Chen,QIAO Haiyong,NIU Guoping.Optimization design of SCR flue gas denitration equipment for a600MW unit[J].Thermal Power Generation,2014,43(12):99-104.
[14]牛国平,董陈,王晓冰,等.一种局部涡流和整体旋流相结合的花瓣型喷氨格栅:201210394099.9[P].2013-04-03.NIU Guoping,DONG Chen,WANG Xiaobing,et al.Apetal-shaped ammonia-spraying grid combining local eddy current with integral eddy current:201210394099.9[P].2013-04-03.
[15]舒凯,南蛟,曹帅锋.北方联合电力有限责任公司包头第三热电厂2号机组脱硝喷氨优化调整试验报告[R].西安:热工研究院有限公司,2017:11-12.SHU Kai,NAN Jiao,CAO Shuaifeng.Experimental report on optimization and adjustment of SCR for No.2unit of Baotou third thermal power plant[R].Xi’an:Xi’an Thermal Power Research Institute Co.,Ltd.,2017:11-12.
[16]谭增强,杨世极,宋晓磊.北方联合电力有限责任公司包头第三热电厂1号机组脱硝喷氨优化调整试验报告[R].西安:西安热工研究院有限公司,2017:20-21.TAN Zengqiang,YANG Shiji,SONG Xiaolei.Experimental report on optimization and adjustment of SCR for No.1unit of Baotou third thermal power plant[R].Xi’an:Xi’an Thermal Power Research Institute Co.,Ltd.,2017:20-21.