细水雾对空气球–球短间隙工频击穿特性的影响
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摘要
细水雾是一种新兴的高效灭火技术,但其绝缘性能一直缺乏研究。火灾消防用细水雾的雾滴直径为50～400μm,介于雾霾颗粒(<10μm)与降雨雨滴(>1 mm)之间。为此研究细水雾雾滴直径、雾滴间距与球隙工频击穿场强的关系。试验获得了细水雾雾滴直径与击穿场强的变化关系。研究表明,对于1.5 cm及以下的球隙,火灾消防用细水雾的击穿场强较空气更低,雾滴直径是影响细水雾击穿场强的主要原因。细水雾添加剂显著提升细水雾的灭火效率,因此研究了KCl、氟碳表面活性剂FC-1470等典型添加剂对细水雾球–球短间隙工频击穿特性的影响。研究表明强电解质细水雾添加剂KCl显著降低纯水细水雾短球隙击穿场强,降低幅度达24.8%,弱电解质细水雾添加剂FC-1470对纯水细水雾短球隙击穿场强的影响相对较小,降低幅度只有7.5%。研究结果对细水雾在高电压火灾带电灭火的安全应用具有一定的指导意义。
Water mist is a new kind of high efficient fire extinguishing technology. But its insulation performance has been lack of research. The diameters of water mist droplets are between 50 μm and 400 μm, which are larger than that of fog particles(diameter is less than 10 μm), but smaller than that of rain drops(diameter is larger than 1 mm). The influence of droplet size and distance between the droplets of water mist on the AC breakdown voltage of sphere-sphere short air gap were studied. The result shows that at a gap distance smaller than 1.5 cm, the breakdown field strength of water mist is lower than that of air, and the diameter of water mist is the main reason affecting the breakdown field strength of water mist. Water mist additives can improve the fire suppression efficiency of water mist. Thus, the influence of representative water mist additive KCl and fluorocarbon surfactants FC-1470 on the AC breakdown voltage were investigated.The results showed that, for the sphere-sphere short air gap whose size under the 1.5 cm and below, both the droplet diameter size and the distance between the droplets of water mist influenced the AC breakdown field strength. However, the former had more effect. In addition, the addition of strong electrolyte water mist additive KCl largely decreased the short air gap breakdown field strength of water mist(24.8%), and however, the addition of weak electrolyte water mist additive FC–1470 decreased the short air gap breakdown field strength of water mist at a relatively small degree(7.5%). This work studied the safety of water mist under the environment of high voltage to provide the theoretical basis for putting out electric power fires.
Water mist is a new kind of high efficient fire extinguishing technology. But its insulation performance has been lack of research. The diameters of water mist droplets are between 50 μm and 400 μm, which are larger than that of fog particles(diameter is less than 10 μm), but smaller than that of rain drops(diameter is larger than 1 mm). The influence of droplet size and distance between the droplets of water mist on the AC breakdown voltage of sphere-sphere short air gap were studied. The result shows that at a gap distance smaller than 1.5 cm, the breakdown field strength of water mist is lower than that of air, and the diameter of water mist is the main reason affecting the breakdown field strength of water mist. Water mist additives can improve the fire suppression efficiency of water mist. Thus, the influence of representative water mist additive KCl and fluorocarbon surfactants FC-1470 on the AC breakdown voltage were investigated.The results showed that, for the sphere-sphere short air gap whose size under the 1.5 cm and below, both the droplet diameter size and the distance between the droplets of water mist influenced the AC breakdown field strength. However, the former had more effect. In addition, the addition of strong electrolyte water mist additive KCl largely decreased the short air gap breakdown field strength of water mist(24.8%), and however, the addition of weak electrolyte water mist additive FC–1470 decreased the short air gap breakdown field strength of water mist at a relatively small degree(7.5%). This work studied the safety of water mist under the environment of high voltage to provide the theoretical basis for putting out electric power fires.
引文
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[5]刘宝奎.对变压器装设水喷雾自动灭火装置的看法[J].广东电力,2005,18(9):57-62.LIU Baokui.Opinion of installing automatic fire sprinklers on transformers[J].Guangdong Electric Power,2005,18(9):57-62.
[6]NISTIR IR 5514 Protection of data processing equipment with fine water sprays[S].Gaithersburg,USA:National Institute of Standards and Technology,1994.
[7]HILLS A T,SIMPSON T,SMITH D P.Water mist fire protection systems for telecommunication switch geat and other electronic facilities[C]∥Proceedings:Water Mist Fire Suppression Workshop.Atlantic City,USA:Federal Aviation Administration,1993:123-144.
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[9]DENG H,HE Z,MA J,XU Y,et al.Initiation and propagation of discharge in liquid droplets:effect of droplet sizes[J].IEEE Transactions on Plasma Science,2010,38(12):3282-3288.
[10]康钧,李佩,王生富,等.盐雾对“棒-板”间隙交直流击穿电压的影响[J].高电压技术,2015,41(6):1989-1994.KANG Jun,LI Pei,WANG Shengfu,et al.Influence of salt spray on AC/DC breakdown voltage of rod-plane gap[J].High Voltage Engineering,2015,41(6):1989-1994.
[11]耿江海,钟正,刘云鹏,等.高电导率雾对悬式瓷质绝缘子交流闪络特性的影响[J].高电压技术,2017,43(9):2976-2982.GENG Jiaghai,ZHONG Zheng,LIU Yunpeng,et al.Influence of high conductivity fog on AC flashover characteristics of suspension porcelain insulator[J].High Voltage Engineering,2017,43(9):2976-2982.
[12]刘琴,李瑶琴,谢梁,等.盐雾环境下清洁和染污绝缘子交流耐压特性[J].高电压技术,2018,44(9):2828-2834.LIU Qin,LI Yaoqin,XIE Liang,et al.AC withstand characteristics of clean and polluted insulators in salt-fog[J].High Voltage Engineering,2018,44(9):2828-2834.
[13]蒋兴良,周龙武,袁耀,等.降雨对短空气间隙直流放电的影响分析[J].高电压技术,2015,41(7):2350-2355.JIANG Xingliang,ZHOU Longwu,YUAN Yao,et al.Analysis on DCdischarge performance of short air gap under rain conditions[J].High Voltage Engineering,2015,41(7):2350-2355.
[14]叶齐政,顾温国,齐军,等.运动水滴在尖-板式直流电场中的放电研究[J].高电压技术,1999,25(4):7-9.YE Qizheng,GU Wenguo,QI Jun,et al.Research on the DC discharge in needle-to-plane air gaps containing moving water drops[J].High Voltage Engineering,1999,25(4):7-9.
[15]齐军,叶齐政,顾温国,等.运动水滴在球-球直流电场中的放电研究[J].高压电器,2000,43(2):12-14.QI Jun,YE Qizheng,GU Wenguo,et al.Study on the DC discharge of moving water drops in sphere-sphere gap[J].High Voltage Apparatus,2000,43(2):12-14.
[16]Standard on water mist fire protection systems:NFPA 750-2015[S],2015.
[17]鲁非.微米级液滴气液两相体击穿特性研究[D].武汉:华中科技大学,2006:28-46.LU Fei.Research on the breakdown characteristics of the two-phase mixture of gas and micron water droplets[D].Wuhan,China:Huazhong University of Science and Technology,2006:28-46.
[18]鲁非,叶齐政,李劲,等.球-球电极气液两相体直流击穿现象的研究[J].高压电器,2005,41(4):268-278.LU Fei,YE Qizheng,LI Jin,et al.Breakdown characteristics of the two-phase mixture of gas and liquid in a sphere-sphere DC gap[J].High Voltage Apparatus,2005,41(4):268-278.
[19]邓鹤鸣,何正浩,许宇航,等.水滴大小对放电开始和发展过程的影响[J].中国电机工程学报,2010,30(28):120-125.DENG Heming,HE Zhenghao,XU Yuhang,et al.Influence of water droplet szes on the intiation and growth of discharge[J].Proceedings of the CSEE,2010,30(28):120-125.
[20]BABAEVA N YU,KUSHNER M J.Effect of inhomogeneities on streamer propagation I:intersection with isolated bubbles and particles[J].Plasma Sources Science and Technology,2009,18(3):035009.1-035009.15.
[21]VAN VELDHUIZEN E M,RUTGERS W R.Pulsed positive corona streamer propagation and branching[J].Journal of Physics D:Applied Physics,2002,35(17):2169-2179.
[22]YE Q,LI J,XIE Z.Analytical model of the breakdown mechanism in a two-phase mixture[J].Journal of Physics D:Applied Physics,2004,37(24):3373-3382.
[23]蒋兴良,刘伟,奚思建,等.降雨对“棒-板”短空气间隙正极性直流放电特性的影响[J].高电压技术,2011,37(2):261-267.JIANG Xingliang,LIU Wei,XI Sijian,et al.Influence of rain on positive DC Discharge characteristic of rod-plane short air gap[J].High Voltage Engineering,2011,37(2):261-267.
[24]YE Q Z,LI J,ZHANG J C.A dipole-enhanced approximation for a dielectric mixture[J].Journal of Electrostatics,2004(61):99-106.
[25]姚文俊,何正浩,邓鹤鸣,等.直流电压下两相体放电的粒径效应[J].中国电机工程学报,2012,32(13):144-151.YAO Wenjun,HE Zhenghao,DENG Heming,et al.Effects of macroparticle sizes on two-phase mixture discharge under DC voltage[J].Proceedings of the CSEE,2012,32(13):144-151.
[26]杨长河.气水混合两相体放电现象及机制的理论与试验研究[D].武汉:华中科技大学,2005.YANG Changhe.Theoretical and experimental study on the phenomena/mechanism of discharge in air water two phase mixture[D].Wuhan,China:Huazhong University of Science and Technology,2005.
[27]GRIGOR’EV A I,SHIRY’AEVA S O.The mechanism of corona discharge from a water droplet[J].Journal of Engineering Physics,1991,60(4):481-488.
[2]LU J Z,CHEN B H,WU C P,et al.A multi-additive suppressant agent-based low-flow and long-distance firefighting approach for suppressing wildfires near electrical transmission lines[J].Journal of Fire Sciences,2016,34(5):398-415.
[3]陆佳政,周特军,吴传平,等.某省级电网220 kV及以上输电线路故障统计与分析[J].高电压技术,2016,42(1):200-207.LU Jiazheng,ZHOU Tejun,WU Chuanping,et al.Fault statistics and analysis of 220 k V and above power transmission line in province-level power grid[J].High Voltage Engineering,2016,42(1):200-207.
[4]黄乐,舒双焰.南方电网2010年第一季度线路山火跳闸情况分析[J].广东电力,2011,24(3):95-97.HUANG Le,SHU Shuangyan.Analysis on fault trips caused by forest fire in CSG in the first quarter of year 2010[J].Guangdong Electric Power,2011,24(3):95-97.
[5]刘宝奎.对变压器装设水喷雾自动灭火装置的看法[J].广东电力,2005,18(9):57-62.LIU Baokui.Opinion of installing automatic fire sprinklers on transformers[J].Guangdong Electric Power,2005,18(9):57-62.
[6]NISTIR IR 5514 Protection of data processing equipment with fine water sprays[S].Gaithersburg,USA:National Institute of Standards and Technology,1994.
[7]HILLS A T,SIMPSON T,SMITH D P.Water mist fire protection systems for telecommunication switch geat and other electronic facilities[C]∥Proceedings:Water Mist Fire Suppression Workshop.Atlantic City,USA:Federal Aviation Administration,1993:123-144.
[8]MAWHINNEY J R,ENG P.Finding of experiments using water mist for fire suppression in an electronic equipment room[C]∥Halon Options Technical Working Conference.Albuquerque,USA:[s.n.],1996:15-25.
[9]DENG H,HE Z,MA J,XU Y,et al.Initiation and propagation of discharge in liquid droplets:effect of droplet sizes[J].IEEE Transactions on Plasma Science,2010,38(12):3282-3288.
[10]康钧,李佩,王生富,等.盐雾对“棒-板”间隙交直流击穿电压的影响[J].高电压技术,2015,41(6):1989-1994.KANG Jun,LI Pei,WANG Shengfu,et al.Influence of salt spray on AC/DC breakdown voltage of rod-plane gap[J].High Voltage Engineering,2015,41(6):1989-1994.
[11]耿江海,钟正,刘云鹏,等.高电导率雾对悬式瓷质绝缘子交流闪络特性的影响[J].高电压技术,2017,43(9):2976-2982.GENG Jiaghai,ZHONG Zheng,LIU Yunpeng,et al.Influence of high conductivity fog on AC flashover characteristics of suspension porcelain insulator[J].High Voltage Engineering,2017,43(9):2976-2982.
[12]刘琴,李瑶琴,谢梁,等.盐雾环境下清洁和染污绝缘子交流耐压特性[J].高电压技术,2018,44(9):2828-2834.LIU Qin,LI Yaoqin,XIE Liang,et al.AC withstand characteristics of clean and polluted insulators in salt-fog[J].High Voltage Engineering,2018,44(9):2828-2834.
[13]蒋兴良,周龙武,袁耀,等.降雨对短空气间隙直流放电的影响分析[J].高电压技术,2015,41(7):2350-2355.JIANG Xingliang,ZHOU Longwu,YUAN Yao,et al.Analysis on DCdischarge performance of short air gap under rain conditions[J].High Voltage Engineering,2015,41(7):2350-2355.
[14]叶齐政,顾温国,齐军,等.运动水滴在尖-板式直流电场中的放电研究[J].高电压技术,1999,25(4):7-9.YE Qizheng,GU Wenguo,QI Jun,et al.Research on the DC discharge in needle-to-plane air gaps containing moving water drops[J].High Voltage Engineering,1999,25(4):7-9.
[15]齐军,叶齐政,顾温国,等.运动水滴在球-球直流电场中的放电研究[J].高压电器,2000,43(2):12-14.QI Jun,YE Qizheng,GU Wenguo,et al.Study on the DC discharge of moving water drops in sphere-sphere gap[J].High Voltage Apparatus,2000,43(2):12-14.
[16]Standard on water mist fire protection systems:NFPA 750-2015[S],2015.
[17]鲁非.微米级液滴气液两相体击穿特性研究[D].武汉:华中科技大学,2006:28-46.LU Fei.Research on the breakdown characteristics of the two-phase mixture of gas and micron water droplets[D].Wuhan,China:Huazhong University of Science and Technology,2006:28-46.
[18]鲁非,叶齐政,李劲,等.球-球电极气液两相体直流击穿现象的研究[J].高压电器,2005,41(4):268-278.LU Fei,YE Qizheng,LI Jin,et al.Breakdown characteristics of the two-phase mixture of gas and liquid in a sphere-sphere DC gap[J].High Voltage Apparatus,2005,41(4):268-278.
[19]邓鹤鸣,何正浩,许宇航,等.水滴大小对放电开始和发展过程的影响[J].中国电机工程学报,2010,30(28):120-125.DENG Heming,HE Zhenghao,XU Yuhang,et al.Influence of water droplet szes on the intiation and growth of discharge[J].Proceedings of the CSEE,2010,30(28):120-125.
[20]BABAEVA N YU,KUSHNER M J.Effect of inhomogeneities on streamer propagation I:intersection with isolated bubbles and particles[J].Plasma Sources Science and Technology,2009,18(3):035009.1-035009.15.
[21]VAN VELDHUIZEN E M,RUTGERS W R.Pulsed positive corona streamer propagation and branching[J].Journal of Physics D:Applied Physics,2002,35(17):2169-2179.
[22]YE Q,LI J,XIE Z.Analytical model of the breakdown mechanism in a two-phase mixture[J].Journal of Physics D:Applied Physics,2004,37(24):3373-3382.
[23]蒋兴良,刘伟,奚思建,等.降雨对“棒-板”短空气间隙正极性直流放电特性的影响[J].高电压技术,2011,37(2):261-267.JIANG Xingliang,LIU Wei,XI Sijian,et al.Influence of rain on positive DC Discharge characteristic of rod-plane short air gap[J].High Voltage Engineering,2011,37(2):261-267.
[24]YE Q Z,LI J,ZHANG J C.A dipole-enhanced approximation for a dielectric mixture[J].Journal of Electrostatics,2004(61):99-106.
[25]姚文俊,何正浩,邓鹤鸣,等.直流电压下两相体放电的粒径效应[J].中国电机工程学报,2012,32(13):144-151.YAO Wenjun,HE Zhenghao,DENG Heming,et al.Effects of macroparticle sizes on two-phase mixture discharge under DC voltage[J].Proceedings of the CSEE,2012,32(13):144-151.
[26]杨长河.气水混合两相体放电现象及机制的理论与试验研究[D].武汉:华中科技大学,2005.YANG Changhe.Theoretical and experimental study on the phenomena/mechanism of discharge in air water two phase mixture[D].Wuhan,China:Huazhong University of Science and Technology,2005.
[27]GRIGOR’EV A I,SHIRY’AEVA S O.The mechanism of corona discharge from a water droplet[J].Journal of Engineering Physics,1991,60(4):481-488.