凝变除湿复合烟气深度净化技术工程应用
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摘要
湿法脱硫后湿烟气排放会形成湿烟羽现象,不仅浪费水资源,产生视觉污染,同时湿烟气中的SO_3、溶解在液态水中的盐、颗粒物等在大气环境中会形成二次污染。本文提出了一种凝变除湿复合烟气深度净化技术,包括凝变湿电一体化和凝变除雾一体化两种技术路线,分别在630 MW和1000 MW燃煤机组上进行了工程应用。结果表明,凝变除湿复合烟气深度净化技术对脱硫后饱和湿烟气的除水量大于4 g·kg~(-1)·℃~(-1),在烟气温度降低1.5～5.3℃时,可回收烟气中5%～20%的水分,有效节约水资源;显著减少水汽排放,有效消除湿烟羽现象;离子浓度降低65%以上,SO_3脱除率大于75%,颗粒物脱除率为92.53%。
A moist plume forms when the flue gas emitted from wet desulfurization equipment exits into the ambient air, resulting in a waste of water resources and visual pollution. In addition, sulfur trioxide(SO_3),water with dissolved salts, and particles in the wet flue gas form secondary pollution in the surrounding atmosphere. In this study, a deep purification technology for flue gas involving phase-transition agglomeration and dehumidification(PAD) is proposed. This deep purification technology includes two technical routes: the integrated technology of phase-transition agglomeration and a wet electrostatic precipitator(PAW); and the integrated technology of phase-transition agglomeration and a mist eliminator(PAM).Industrial applications of PAW and PAM were carried out on 630 and 1000 MW coal-fired units,respectively. The results show that the average amount of recycled water obtained from wet flue gas by means of PAD is more than 4 g·(kg·℃)~(-1). Decreasing the wet flue gas temperature by 1.5-5.3 ℃ allows 5%-20% of the moisture in the flue gas to be recycled; therefore, this process could effectively save water resources and significantly reduce water vapor emissions. In addition, the moist plume is effectively eliminated. With the use of this process, the ion concentration in droplets of flue gas is decreased by more than 65%, the SO_3 removal efficiency from flue gas is greater than 75%, and the removal efficiency of particulate matter is 92.53%.
A moist plume forms when the flue gas emitted from wet desulfurization equipment exits into the ambient air, resulting in a waste of water resources and visual pollution. In addition, sulfur trioxide(SO_3),water with dissolved salts, and particles in the wet flue gas form secondary pollution in the surrounding atmosphere. In this study, a deep purification technology for flue gas involving phase-transition agglomeration and dehumidification(PAD) is proposed. This deep purification technology includes two technical routes: the integrated technology of phase-transition agglomeration and a wet electrostatic precipitator(PAW); and the integrated technology of phase-transition agglomeration and a mist eliminator(PAM).Industrial applications of PAW and PAM were carried out on 630 and 1000 MW coal-fired units,respectively. The results show that the average amount of recycled water obtained from wet flue gas by means of PAD is more than 4 g·(kg·℃)~(-1). Decreasing the wet flue gas temperature by 1.5-5.3 ℃ allows 5%-20% of the moisture in the flue gas to be recycled; therefore, this process could effectively save water resources and significantly reduce water vapor emissions. In addition, the moist plume is effectively eliminated. With the use of this process, the ion concentration in droplets of flue gas is decreased by more than 65%, the SO_3 removal efficiency from flue gas is greater than 75%, and the removal efficiency of particulate matter is 92.53%.
引文
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[12]Li WJ,Shao LY,Zhang DZ,Ro CU,Hu M,Bi X,et al.A review of single aerosol particle studies in the atmosphere of East Asia:morphology,mixing state,source,and heterogeneous reactions.J Clean Prod 2016;112:1330-49.
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[14]Xiong YY,Tan HZ.Influence of wet phase transition condensate dust removal technology on fine particle removal.Clean Coal Technol 2015;21(2):20-4.Chinese.
[15]Cao RJ,Tan HZ,Xiong YY,Mikulcic H,Vujanovic M,Wang X,et al.Improving the removal of particles and trace elements from coal-fired power plants by combining a wet phase transition agglomerator with wet electrostatic precipitator.J Clean Prod 2017;161:1459-65.
[16]Zhou S.Heat condensate recovery research and application of gas-fired boiler flue gas[dissertation].Jinan:Shandong University;2012.Chinese.
[17]Yang Z,Zheng C,Chang Q,Wan Y,Wang Y,Gao X,et al.Fine particle migration and collection in a wet electrostatic precipitator.J Air Waste Manage Assoc2017;67(4):498-506.
[2]Qiu LC.The research on stack white fume in large utility boiler burning coal.Boil Technol 2015;46(3):26-9.Chinese.
[3]Tan L,Zhao X,Liang Z,Zhang H.Analysis of the white smoke problem in waste incineration power plant.Environ Sci Technol 2014;37(120):483-5.Chinese.
[4]Nie YQ,Kuang XL,Song CH.The formation mechanism of white-smoke in spray drying tower of ceramic factory and solving measures.Environ Eng 2006;24(4):71-5.Chinese.
[5]Zhai SP,Huang LN,Zeng Y.Application of clean flue gas reheat technology in the wet desulfurization.Environ Eng 2015;33(8):52-5.Chinese.
[6]Chen WL.Technical and economic analysis of MGGH technology application in1000 MW unit.Electr Power Constr 2014;35(5):103-7.Chinese.
[7]Zhang R,Xin DD,Sun XF.Application of heat pipe on decreasing temperature of exhaust gas in power plant.Power Syst Eng 2011;27(3):23-5.Chinese.
[8]Ni YC,Zhang DP.Application of hot secondary-air heating desulfurized clean flue gas in 600 MW unit.Electr Power Sci Eng 2013;29(8):69-72.Chinese.
[9]Pan DP,Wu H,Bao JJ,Huang RT,Hu B,Zhang YP,et al.Removal effect of wet flue gas desulfurization system on fine particles and SO3acid mist from coalfired power plants.Proc CSEE 2016;36(16):4356-62.Chinese.
[10]Samuelson C.Recovery of water from boiler flue gas[dissertation].Bethlehem:Lehigh University;2008.
[11]Tian L,Han Z,Dong Y,Lv Y,Li Y,Chen X,et al.Review of water recovering technologies from flue gas in coal fired power plant.Clean Coal Technol2017;23(5):105-10.Chinese.
[12]Li WJ,Shao LY,Zhang DZ,Ro CU,Hu M,Bi X,et al.A review of single aerosol particle studies in the atmosphere of East Asia:morphology,mixing state,source,and heterogeneous reactions.J Clean Prod 2016;112:1330-49.
[13]Zhu LP,Tan HZ,Xiong YY,Hui RT,Xu Y,Zhuang K,et al.Experimental research on wet phase change condensation of fine particle in boiler flue gas.Sci Technol Eng 2015;15(1):210-5.Chinese.
[14]Xiong YY,Tan HZ.Influence of wet phase transition condensate dust removal technology on fine particle removal.Clean Coal Technol 2015;21(2):20-4.Chinese.
[15]Cao RJ,Tan HZ,Xiong YY,Mikulcic H,Vujanovic M,Wang X,et al.Improving the removal of particles and trace elements from coal-fired power plants by combining a wet phase transition agglomerator with wet electrostatic precipitator.J Clean Prod 2017;161:1459-65.
[16]Zhou S.Heat condensate recovery research and application of gas-fired boiler flue gas[dissertation].Jinan:Shandong University;2012.Chinese.
[17]Yang Z,Zheng C,Chang Q,Wan Y,Wang Y,Gao X,et al.Fine particle migration and collection in a wet electrostatic precipitator.J Air Waste Manage Assoc2017;67(4):498-506.