Particle collection characteristic in wet electrostatic precipitator under charged water drop atomization
TENG Chen-zi, LI Jian
Key Laboratory of Beijing on Regional Air Pollution Control, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China
A plate-type wet electrostatic precipitator was designed and built to research the particle capture characteristic under atomization of charged water drop. The effects of electric field intensity, residence time, dust concentration, and liquid flow rate on removal efficiency were acquired. Results showed that particle grade penetration ratio with charged droplets was higher than the dry ESP. As the electric field intensity increased, reduction of penetration ratio and outlet concentration firstly increased and then decreased with the division of 3.5kV/cm, at which the outlet PM0.5, PM1 and PM2.5 decreased by 28.7%, 28.0% and 27.1% respectively. Longer residence time resulted in higher removal efficiency under the same applied voltage, the penetration ratio for PM0.5, PM1 and PM2.5 reduced by 50.2%, 49.3% and 48.5% when the residence time increased from 2.14s to 4.04s at 4kV/cm. Particle collision and agglomeration could be reinforced as the increase of dust concentration, thus the removal efficiency increased correspondingly. While the electron density was insufficient for particle charge, further enhancement of dust density led to decrease of removal efficiency. Improving the water flow rate was benefit for particle charge, agglomeration, and increase of removal efficiency. Compared with the traditional wet electrostatic precipitator (WESP), adoption of charged dropletscould largely reduce the water consumption and keepthe collection efficiency at relatively high level.
滕辰姊, 李坚. 液滴荷电雾化湿式电除尘器颗粒捕集特性研究[J]. 中国环境科学, 2020, 40(6): 2389-2397.
TENG Chen-zi, LI Jian. Particle collection characteristic in wet electrostatic precipitator under charged water drop atomization. CHINA ENVIRONMENTAL SCIENCECE, 2020, 40(6): 2389-2397.
Yang Z D, Zheng C H, Liu S J, et al.A combined wet electrostatic precipitator for efficiently eliminating fine particle penetration [J].Fuel Processing Technology, 2018,180:122-129.
[2]
国家能源局.能源发展“十三五”规划[R/OL].http://www.ndrc.gov.cn/zcfb/zcfbghwb/01701/t20170117_835296.html, 2016. National Energy Administration.The 13th five-year plan for energy development [R/OL].http://www.ndrc.gov.cn/zcfb/zcfbghwb/01701/t20170117_835296.html, 2016.
[3]
环境保护部.全面实施燃煤电厂超低排放和节能改造工作方案[EB/OL].http://www.mee.gov.cn/gkml/hbb/bwj/201512/t20151215319170.htm, 2015. Ministry of Ecology and Environment of the PRC.Fully Implementing the Work Program of Ultra-Low Emission and Energy Conservation Renovation of Coal-fired Power Plants [EB/OL].http://www.mee.gov.cn/gkml/hbb/bwj/201512/t20151215_319319.htm, 2015.
[4]
DB37/664-2019火电厂大气污染物排放标准[S]. DB37/664-2019 Emission standard of air pollutants for thermal power plants [S].
[5]
DB12/810-2018火电厂大气污染物排放标准[S]. DB12/810-2018 Emission standard of air pollutants for thermal power plants [S].
[6]
刘含笑,姚宇平,郦建国,等.电除尘技术发展面临的挑战解析[J].中国环保产业, 2018,2:18-22. Liu H X, Yao Y P, Li J G, et al.Challenge Resolution Faced by Electrostatic Precipitation TechnicalDevelopment [J].China Environmental Protection Industry, 2018,2:18-22.
[7]
安连锁,王金平,郦建国,等.中国燃煤电厂电除尘技术发展及应用综述[J].中国电力, 2018,51(4):115-123. An L S, Wang J P, Li J G, et al.Development and application overview of electrostatic precipitation technology for coal-fired Power Plant in China [J].Electric Power, 2018,51(4):115-123.
[8]
中国电力企业联合会.2017年度火电厂环保产业登记信息[EB/OL].http://www.cec.org.cn/huanbao/jienenghbfenhui/fenhuidongtai/fenhuixinwen/2018-04-24/179910.html, 2018. China Electricity Council.Environmental protection industry registration information of thermal power plant in 2017[EB/OL].http://www.cec.org.cn/huanbao/jienenghbfenhui/fenhuidongtai/fenhuixinwen/2018-04-24/179910.html, 2018.
[9]
Chang Q Y, Zheng C H, Yang Z D, et al.Electric agglomeration modes of coal-fired fly-ash particles with water droplet humidification [J].Fuel, 2017,200:134-145.
[10]
Su L P, Du Q, Wang Y D, et al.Purification characteristics of fine particulate matter treated by a self-flushing wet electrostatic precipitator equipped with a flexible electrode [J].Journal of the Air & Waste Management Association, 2018,68(7):725-736.
[11]
You C F, Wang X H, Liu R L, et al.Simultaneous effects of electrostatic field and thermophoresis on inhalable particulate matter removal [J].Powder Technology, 2010,202:95-100.
[12]
Wang X H, You C F.Effects of thermophoresis, vapor, and water film on particle removal of electrostatic precipitator [J].Journal of Aerosol Science, 2013,63:1-9.
[13]
Chen T M, Tsai C J, Yan S Y, et al.An efficient wet electrostatic precipitator for removing nanoparticles, submicron and micron-sized particles [J].Separation and Purification Technology, 2014,136:27-35.
[14]
Xu C Y, Chang J C, Meng Z, et al.Wetting properties and performance test of modified rigid collector in wet electrostatic precipitators [J].Journal of the Air & Waste Management Association, 2016,66(10): 1019-1030.
[15]
Wang X, Chang J C, Xu C Y, et al.Collection and charging characteristics of particles in an electrostatic precipitator with a wet membrane collecting electrode [J].Journal of Electrostatics, 2016, 83:28-34.
[16]
Yang Z D, Zheng C H, Chang Q Y, et al.Fine particle migration and collection in a wet electrostatic precipitator [J].Journal of the Air & Waste Management Association, 2017,67(4):498-506.
[17]
甘晨浩,郑成航,杨正大,等.蜂窝湿式静电除尘脱除燃煤细颗粒物实验研究[J].环境科学学报, 2016,36(7):2369-2374. Gan C H, Zheng C H, Yang, Z D, et al.Experimental study of honeycomb experimental-scale wet electrostatic precipitator removing coal-fired fine particulate matter [J].Acta Scientiae Circumstantiae, 2016,36(7):2369-2374.
[18]
甘晨浩.蜂窝湿式静电脱除燃煤细颗粒物实验研究[D].杭州:中国计量学院, 2016. Gan C H.Experimental study of coal-fired fine particulate matter by honeycomb WESP [D].Hangzhou:China Jiliang University, 2016.
[19]
Hang R P A, Borra J P, Brunner D J, et al.The evolution of electro-hydrodynamic sprays produced in the cone-jet mode, a physical model [J].Journal of Electrostatics, 1999,47:143-170.
[20]
李庆,孙晓荣,李海凤,等.高压负电晕放电雾化实验分析[J].高电压技术, 2010,36(6):1520-1524. Li Q, Sun X R, Li H F, et al.Experimental analysis on electrostatic atomization of negative high-voltage corona discharge [J].High Voltage Engineering, 2010,36(6):1520-1524.
[21]
Lear C W, Krieve W F, Cohen E.Charged droplet scrubbing for fine particle control [J].Journal of the Air Pollution Control Association, 1975,25(2):184-189.
[22]
李庆,肖振雷,丁倩,等.雾化水电极用于微细粉尘收集的实验研究[J].高电压技术, 2011,37(10):2506-2511. Li Q, Xiao Z L, Ding Q, et al.Experimental study on the fine dust collection of the spray electrode [J].High Voltage Engineering, 2011, 37(10):2506-2511.
[23]
Jaworek A, Balachandran W, Lackowski M, et al.Multi-nozzle electrospray system for gas cleaning processes [J].Journal of Electrostatics, 2006,64:194-202.
[24]
Tepper G, Kessick R, et al.A study of ionization and collection efficiencies in electrospray-based electrostatic precipitators [J].Aerosol Science, 2008,39:609-617.
[25]
Kim J H, Lee H S, Kim H H, et al.Electrospray with electrostatic precipitator enhances fine particles collection efficiency [J].Journal of Electrostatics, 2010,68:305-310.
[26]
朱唯卓,沈之旸,严佩,等.高温烟气中颗粒静电脱除特性的实验研究[J].中国环境科学, 2016,36(4):1009-1016. Zhu W Z, Shen Z Y, Yan P, et al.Experimental investigation on particle collection performance of electrostatic precipitator at high temperatures [J].China Environmental Science, 2016,36(4):1009-1016.
[27]
Nouri H, Zouzou N, Moreau E, et al.Effect of relative humidity on current-voltage characteristics of an electrostatic precipitator [J].Journal of Electrostatics, 2012,70:20-24.
[28]
Du Q, Su L P, Dong H M, et al.The experimental study of a water-saving wet electrostatic precipitator for removing fine particles [J].Journal of Electrostatics, 2016,81:42-47.
[29]
沈之旸,郑成航,刘昕涛,等.高温烟气静电除尘中试试验研究[J].中国环境科学, 2018,38(5):1637-1645. Shen Z Y, Zheng C H, Liu X T, et al.Pilot-scale experimental investigation on particle electrostatic removal in high-temperature flue gas [J].China Environmental Science, 2018,38(5):1637-1645.
[30]
马广大.除尘器性能计算[M].北京:中国环境科学出版社, 1990. Ma G D.Calculation for performance of precipitator [M].Beijing: China Environmental Science Press, 1990.
[31]
中国环境保护产业协会电除尘委员会.燃煤电厂烟气超低排放技术[M].北京:中国电力出版社, 2015. China Association of Environmental Protection Industry.Technology of flue gas ultra-low emission for coal-fired power plant [M].Beijing: China Electric Power Press, 2015.
[32]
马春元,常景彩,崔琳,等.新型电极湿式静电除尘技术研究[M].北京:科学出版社, 2018. Ma C Y, Chang J C, Cui L, et al.Study on wet electrostatic precipitation technology with novel electrodes [M].Beijing: Science Press, 2018.
[33]
周文俊.荷电水雾除尘机理和规律的研究[D].武汉:武汉水利电力学院, 1990. Zhou W J.Study of Charged Droplets Mechanism and Laws of Precipitation [D].Wuhan, Wuhan University of Hydraulic and Electrical Engineering, 1990.
[34]
张军,何宏舟.电场作用下液滴动力学特性及应用[M].北京:化学工业出版社, 2018. Zhang J, He H Z.Droplet dynamics under electric field action and its application [M].Beijing: Chemical Industry Press, 2018.
[35]
Lin G Y, Tsai C J, Chen S C, et al.An efficient single-stage wet electrostatic precipitator for fine and nanosized particle control [J].Aerosol Sci.Technol., 2010,44:38-45.
[36]
王晓华.静电场中水对颗粒物脱除增强机理与过程[D].北京:清华大学, 2013. Wang X H.Enhancement mechanism and process of water on particle removal in electrostatic field [D].Beijing:Tsinghua University, 2013.
[37]
万益.湿式静电除尘水膜均布及颗粒物强化脱除研究[D].杭州:浙江大学, 2014. Wan Y.Study on uniformity of water film and enhancement of fine particles removal in WESP [D].Hangzhou: Zhejiang University, 2014.