循环流化床床料与燃料粒径对脱硝反应的影响Influence of particle sizes of bed material and fuel on denitration reaction in circulating fluidized bed
张曜;于娟;林晨;冯帆;张忠孝;
ZHANG Yao;YU Juan;LIN Chen;FENG Fan;ZHANG Zhongxiao;School of Mechanical Engineering,Shanghai Jiao Tong University;
摘要(Abstract):
随着能源动力产业的大力发展,大气污染形势日趋严峻,控制NO_x排放的相关环保标准也日益严格。选择性非催化还原技术(SNCR)能有效降低NO_x排放,为了进一步降低循环流化床的NO_x排放,需要从源头降低NO_x生成量,有必要研究床料及燃料粒径对脱硝反应的影响规律。利用循环流化床热态试验系统探讨了反应温度、氨氮摩尔比、床料粒径配比、煤粉平均粒径对NO_x排放的影响。结果表明:氨还原剂有效还原NO_x的温度为860~950℃;不同反应温度下,氨的脱硝效率随氨氮摩尔比的增大均先增大后减小;增大细颗粒床料占比能有效减少NO_x生成量、提高脱硝效率、降低SNCR活性反应温度;其中,细颗粒占比最大的床料脱硝效率随NSR的增加不断升高,当NSR=2.0时,脱硝效率达到了最高42%,NO_x排放量降至215 mg/m~3。适当减小煤粉平均粒径,可降低NO_x生成量并促使SNCR反应在较低温度下进行。各温度下,平均粒径330μm煤粉产生的NO_x较425μm煤粉下降10~30 mg/m~3。高温下,氨还原剂的脱硝效率随燃料粒径的增大明显上升;较低温度时,氨的脱硝效率随燃料粒径的增大可能下降。910℃时,燃烧平均粒径600μm煤粉在不同NSR下,脱硝效率比燃烧425μm煤粉显著高出20%~30%; 860℃时,平均粒径425μm煤粉脱硝效率明显低于330μm煤粉。造成这一现象的主要原因是,氨的还原反应与NO_x初始浓度和反应温度有关。在不同初始浓度和温度下氨具有不同的反应选择性。确定燃料粒径后,需要匹配合适的工艺操作参数以满足NO_x排放要求。
With the vigorous development of the energy power industry,the situation of air pollution becomes increasingly severe,and the relevant environmental protection standards for NO_x emission control become increasingly strict. Selective non-catalytic reduction technology( SNCR) can effectively reduce NO_x emission,but the production of NO_x needs to be reduced from the source in order to further reduce NO_x emission in circulating fluidized bed.Therefore,the influence law of bed material and fuel particle size on denitration reaction has great research value.The effects of reaction temperature,molar ratio of ammonia to NO_x ,particle size ratio of bed material and average particle size of pulverized coal on NO_x emission were investigated by using the circulating fluidized bed thermal experiment system.The results show that the temperature range of NO_x reduction with ammonia reducing agent is 860-950 ℃ .The denitration efficiency of ammonia increases first and then decreases with the increase of NSR at different reaction temperatures. Increasing the proportion of fine particle bed material can effectively reduce the production of NO_x ,improve the denitration efficiency,and reduce the SNCR active reaction temperature.Among them,the denitrification efficiency of the bed material with the largest proportion of fine particles increases with the increase of NSR.When NSR = 2.0,the denitrification efficiency reaches the highest 42%,and the NO_x emission decreases to 215 mg/m~3.By appropriately reducing the average particle size of pulverized coal,the production of NO_x can be reduced and the SNCR reaction can be carried out at a lower temperature.At each temperature,the NO_x generated by pulverized coal with an average particle size of 330 μm decreases by 10-30 mg/m~3 compared with that of pulverized coal with an average particle size of 425 μm.At high temperature,the denitration efficiency of ammonia reducing agent increases obviously with the increase of fuel particle size.At lower temperature,the denitration efficiency of ammonia may decrease with the increase of fuel particle size.At 910 ℃,the denitration efficiency of pulverized coal with an average particle size of 600 μm is significantly 20%-30% higher than that of pulverized coal with an average particle size of 425 μm under different NSR.At860 ℃,the denitration efficiency of pulverized coal with an average particle size of 425 μm is significantly lower than that of pulverized coal with an average particle size of 330 μm.The main reason for this phenomenon is that the reduction reaction of ammonia is related to the initial concentration of NO_x and the reaction temperature.Ammonia has different reaction selectivity at different initial concentration and temperature.After determining the fuel particle size,the appropriate process operating parameters should be matched to meet the NO_x emission requirements.
关键词(KeyWords):
循环流化床;脱硝;反应温度;氨氮摩尔比;床料粒径;煤粉粒径
circulating fluidized bed;denitration;reaction temperature;molar ratio of ammonia to NO_x;bed materials size;pulverized coal particle size
基金项目(Foundation): 国家重点研发计划资助项目(2016YFB0600202)
作者(Author):
张曜;于娟;林晨;冯帆;张忠孝;
ZHANG Yao;YU Juan;LIN Chen;FENG Fan;ZHANG Zhongxiao;School of Mechanical Engineering,Shanghai Jiao Tong University;
Email:
DOI: 10.13226/j.issn.1006-6772.CFB20040501
参考文献(References):
- [1]屈卫东,周建强,杨建华,等.循环流化床锅炉SNCR脱硝系统优化及应用[J].热力发电,2014,43(1):133-136.QU Weidong,ZHOU Jianqiang,YANG Jianhua,et al.SNCR denitrification system in CFB boilers:Optimization and application[J].Thermal Power Generation,2014,43(1):133-136.
- [2]李明波,杜向前,巴换粉,等.SNCR脱硝技术在循环流化床锅炉上的应用[J].中国环保产业,2014(2):13-15.LI Mingbo,DU Qianqian,BA Huanfen,et al.Application of SNCRdenitration technology in circulating fluidized bed boiler[J].China Environmental Protection Industry,2014(2):13-15.
- [3]李秀平.SNCR烟气脱硝技术在循环流化床锅炉中的应用[J].中国资源综合利用,2015(5):51-52.LI Xiuping.Application of SNCR flue gas denitration technology in circulating fluidized bed boiler[J].China Resources Comprehensive Utilization,2015(5):51-52.
- [4]仇云霞,朱冲.一种改善SNCR窗口温度的新工艺[J].中国环保产业,2016(12):43-44.QIU Yunxia,ZHU Chong.A new technology for improvement of SNCR window temperature[J].China Environmental Protection Industry,2016(12):43-44.
- [5]王俊杰,房晶瑞,雷本喜,等.水泥窑炉SNCR反应机制及优化运行[J].水泥,2018(2):52-55.WANG Junjie,FANG Jingrui,LEI Benxi,et al.SNCR reaction mechanism and optimized operation of cement kiln[J].Cement,2018(2):52-55.
- [6]董陈,赵树春,徐宏杰,等.燃煤锅炉SNCR脱硝工艺关键技术[J].热力发电,2016,45(12):73-77,88.DONG Chen,ZHAO Shuchun,XU Hongjie,et al.Key points of SNCR denitrification technology for coal fired boilers[J].Thermal Power Generation,2016,45(12):73-77,88.
- [7]孔红.生活垃圾焚烧厂SNCR脱硝系统的自动控制[J].环境卫生工程,2018,26(3):23-25.KONG Hong.Automatic control of SNCR system in waste incineration plant[J].Environmental Sanitation Engineering,2018,26(3):23-25.
- [8]金山.选择性非催化还原(SNCR)脱硝反应影响因素的探索与研究[J].能源研究与信息,2019,35(3):142-145.JIN Shan.Exploration and research on influential factors of selective non-catalytic reduction denitrification[J].Energy Research and Information,2019,35(3):142-145.
- [9]姜金东,林晨,张曜,等.工艺操作参数对烟气SNCR脱硝性能影响的数值模拟[J].中国电机工程学报,2018,38 (2):383-389.JIANG Jindong,LIN Chen,ZHANG Yao,et al.Numerical simulation of effect of process operation parameters on flue gas denitrification performance of SNCR[J].Proceedings of the CSEE,2018,38(2):383-389.
- [10]薛现恒,邓雨生,段伦博,等.基于410 t/h Compact型流化床锅炉的SNCR影响因素探究[J].锅炉技术,2019,50(3):30-35.XUE Xianheng,DENG Yusheng,DUAN Lunbo,et al.The research of the influences of the SNCR on a 410 t/h circulating fluidized bed boiler[J].Boiler Technology,2019,50(3):30-35.
- [11]曾勇,周俊虎.循环流化床锅炉SNCR关键因素及工程应用[J].工业锅炉,2016(5):36-38.ZENG Yong,ZHOU Junhu.Key factor and engineering application of SNCR on circulating fluidized bed boiler[J].Industrial Boiler,2016(5):36-38.
- [12]任宪红,刘爱成.基于流态重构的循环流化床锅炉多污染物协同控制技术[J].工业锅炉,2013(5):59-63.REN Xianhong,LIU Aicheng.Coordination control technology on multiple pollutants of CFB boiler based on fluidization state reconstruction[J].Industrial Boiler,2013(5):59-63.
- [13]中国环境监测总站,上海市环境监测中心,湖北省环境监测中心站.河北省环境监测中心站.固定污染源烟气(SO2、NOx、颗粒物)排放连续监测技术规范:HJ 75-2017[S].北京:中国环境科学出版社,2017.China National Environmental Monitoring Center,Shanghai Environmental Monitoring Center,Hubei Environmental Monitoring Center Station,Hebei Environmental Monitoring Center Station.Specifications for continuous emissions monitoring of SO2,NOx,and particulate matter in the flue gas emitted from stationary sources:HJ 75-2017[S].Beijing:China Environmental Science Press,2017.
- [14]雷琼.燃气轮机氮氧化物排放规律及转化机制[D].郑州:郑州大学,2019.LEI Qiong.Emission characteristics and conversion mechanism of nitrogen oxide from gas turbines[D].Zhengzhou:Zhengzhou University,2019.
- [15]孙健秋,曹林涛.运行调整对循环流化床锅炉NOx排放影响分析[J].应用能源技术,2014(2):28-30.SUN Jianqiu,CAO Lintao.Analysis of the influence of the operation adjustment for NOxmission of circulating fluidized bed boiler[J].Applied Energy Technology,2014(2):28-30.
- [16]仝志辉,刘汉涛.一维火焰燃烧过程过程中SNCR脱硝试验研究[J].锅炉技术,2012,43(1):77-80.TONG Zhihui,LIU Hantao.Experimental studies on SNCR in one-dimensional furnaces[J].Boiler Technology,2012,43 (1):77-80.
- [17]林宗虎.循环流化床锅炉[M].北京:化学工业出版社,2004.LIN Zonghu.Circulating fluidized bed boiler[M].Beijing:Chemical Industry Press,2004.
- [18]王继华.SCR、SNCR和SNCR/SCR烟气脱硝技术应用及比较[J].电力科技与环保,2018,34(5):39-40.WANG Jihua.Application and comparison of SCR,SNCRand SNCR/SCR flue gas denitration technology[J].Electric Power Environmental Protection,2018,34(5):39-40.
- [19]杨石,杨海瑞,吕俊复,等.基于流态重构的低能耗循环流化床锅炉技术[J].电力技术,2010,19(2):9-16.YANG Shi,YANG Hairui,LYU Junfu,et al.The lower energy consumption (LEC) CFB technology based on state specification design theory[J].Electric Power Standardization,2010,19(2):9-16.
- [20]王秀国.循环流化床锅炉流态重构节能超低排放技术应用小结[J].中氮肥,2017(4):57-59.WANG Xiuguo.Summary of application of energy saving and ultra-low emission technology for flow pattern reconstruction of circulating fluidized bed boiler[J].Nitrogenous Fertilizer Progress,2017(4):57-59.
- [21]魏砾宏,姜秀民,张超群,等.超细化煤粉在热解条件下氮的迁移特性试验研究[J].中国电机工程学报,2006,26 (7):62-66.WEI Shihong,JIANG Xiumin,ZHANG Chaoqun,et al.A experimental investigation on nitrogen emission properties of micro-pulverized during pyrolysis[J].Proceedings of the CSEE,2006,26(7):62-66.
- [22]宋国良,吕清刚,周俊虎,等.煤粉浓度对HCN与NH3析出特性的影响[J].中国电机工程学报,2008,28(17):49-54.SONG Guoliang,LYU Qinggang,ZHOU Junhu,et al.Effect of pulverized coal concentration on emission characteristics of HCN and NH3[J].Proceedings of the CSEE,2008,28(17):49-54.
- [23]KASUYA F,GLARBORG P,JOHNSSON J E,et al.The thermal De NOxprocess:Influence of partial pressures and temperature[J].Chemical Engineering Science,1995,50(9):1455-1466.
文章评论(Comment):
|
||||||||||||||||||
|
- 循环流化床
- 脱硝
- 反应温度
- 氨氮摩尔比
- 床料粒径
- 煤粉粒径
circulating fluidized bed - denitration
- reaction temperature
- molar ratio of ammonia to NO_x
- bed materials size
- pulverized coal particle size
- 张曜
- 于娟
- 林晨
- 冯帆
- 张忠孝
ZHANG Yao- YU Juan
- LIN Chen
- FENG Fan
- ZHANG Zhongxiao
- School of Mechanical Engineering
- Shanghai Jiao Tong University
- 张曜
- 于娟
- 林晨
- 冯帆
- 张忠孝
ZHANG Yao- YU Juan
- LIN Chen
- FENG Fan
- ZHANG Zhongxiao
- School of Mechanical Engineering
- Shanghai Jiao Tong University