摘要
为探究高压输电线路因意外断线垂落故障对森林地表植被放电击穿引发恶性山火行为的特性及其影响因素,通过自主设计模拟高压输电线路断线垂落(钢棒电极)引火实验平台,在不同距离间隙下,分别对肾蕨碎块、雪松松针碎块、杨木屑以及四种含水率桉树叶碎块进行垂落导线放电引火模拟实验。结果表明:垂落导线与地表植被间存在间隙时放电引火阶段可总结为“两期两点”(放电诱导期、间隙击穿点、电弧诱导期、故障切除点),在相接触时则不存在故障切除点;不同植被被放电引燃可能性大小排序为:雪松松针>桉树叶≈杨木屑>肾蕨;随着桉树叶含水率不断增加,垂落导线放电仍可将其引燃且所需击穿电压逐渐降低;对于不同植被,在适宜距离和含水率条件下,一旦被引燃将会产生持续火焰,促进导线与植被间形成流注通道进而加剧放电,进一步促进植被燃烧,直至可能诱发一场山火。
In order to explore the characteristics and typical influential factors of fierce wildfires developed from ignition of typical forest vegetation materials via accidental faults inducing discharge breakdown processes of simulated broken and fallen segments of high voltage transmission lines(steel bar electrodes),a platform of such case was self designed to perform simulation experiments.Corresponding discharge and ignition experiments of simulated broken and fallen power lines were carried out on eucalyptus leaves,tuber fern chips,cedar pine needles and poplar chips under different gaps.Results show that the discharge inducing ignition stages can be summarized as"two phases and two points"(discharge induction period,gap breakdown point,arc induction period and fault removal point)when there is a proper gap between the simulated broken and fallen lines and the vegetation surfaces.There is no fault removal point in case of direct contacts.The possibility of ignition of the above four vegetation materials by the discharges is as follows:cedar pine needles>eucalyptus leaves≈poplar chips>tuber fernchips.With increasing water contents,eucalyptus leaves can still be ignited and the breakdown voltages required for discharge inducing ignition gradually decrease.For different forest ground vegetation types,under proper gaps and moisture contents,once they are ignited by the discharges between simulated broken and fallen lines and the vegetation materials,ignition and sustained flames will be produced,the formations of streamer channels will be promoted and the discharges and burning processes will be further aggravated until a wildfire is possibly triggered.
作者
周恺
张睿哲
赵耀鹏
尤飞
ZHOU Kai;ZHANG Rui-zhe;ZHAO Yao-peng;YOU Fei(State Grid Beijing Electric Power Research Institute,Beijing 100072,China;College of Safety Science and Engineering,Nanjing Tech University,Jiangsu Nanjing 211816,China;Institute of Fire Science and Engineering,Nanjing Tech University,Jiangsu Nanjing 211816,China)
出处
《消防科学与技术》
CAS
北大核心
2022年第6期827-832,共6页
Fire Science and Technology
基金
国网北京市电力公司科技项目(520223200068)
国家自然科学基金项目(51376089)。
关键词
输电线路
断线垂落故障
森林植被
山火
引燃
击穿电压
流注
放电
transmission line
fault of broken and fallen line
forest vegetation
wildfire
ignition
breakdown voltage
streamer
discharge
