ZR-BV单芯铜线过电流熔断痕迹形成过程  

Melted mark formation of the ZR-BV single-core copper wire under overcurrent

作　　者：王博 李阳 司永轩 吕慧菲 荣彦超 WANG Bo;LI Yang;SI Yong-xuan;LV Hui-fei;RONG Yan-chao(China People's Police University,Hebei Langfang 065000,China;Fire Physical Evidence Appraisal Center,China People's Police University,Hebei Langfang 065000,China;Kaifeng Fire and Rescue Detachment,Henan Kaifeng 475000,China;College of Safety Science and Engineering,Xi'an University of Science and Technology,Shaanxi Xi'an 710054,China)

机构地区：[1]中国人民警察大学,河北廊坊065000 [2]中国人民警察大学火灾物证鉴定中心,河北廊坊065000 [3]开封市消防救援支队,河南开封475000 [4]西安科技大学安全科学与工程学院,陕西西安710054

出　　处：《消防科学与技术》2020年第4期561-565,共5页Fire Science and Technology

基　　金：河北省重点研发计划自筹项目“火灾现场中铝合金导线熔化痕迹鉴别技术研究”(17275611);中国人民警察大学重点实验室培育类课题“基于电气故障间转化机理的痕迹鉴别技术研究”(2019SYCXPD001)。

摘　　要：模拟聚氯乙烯绝缘阻燃(ZR-BV)单芯铜线在不同电流值时的过电流故障,借助高速摄像、视频截帧等技术,研究导线的发热过程及熔断痕迹形成过程。研究表明:导线发生过电流故障时,I≤3.5Ie,过电流导线仅出现线芯发热,绝缘热解破坏;I≥4Ie,过电流导线会发生熔断,引起绝缘层的燃烧。燃烧发生时,I<4.5Ie,导线绝缘层的燃烧仅能从熔断点蔓延至其两侧一定位置处;I≥4.5Ie,导线绝缘层的燃烧会从导线熔断点处向两侧持续蔓延,直至导线端部。导线的绝缘燃烧是结疤熔痕形成的必要条件,枝晶偏析组织是该熔痕的典型组织。在发生较大电流过电流故障时,导线会出现明火燃烧的现象。A simulation was conducted to study the heating process and the melted mark formation of the ZR-BV single-core copper wire under overcurrent.The formation process was shot by a highspeed camera and analyzed frame by frame.The result shows that,when overcurrent fault occurs,when I≤3.5Ie,overcurrent conduc⁃tors only have the phenomenon of core heating and insulation pyrol⁃ysis damage;When I≥4Ie,the overcurrent wire will ignite the insu⁃lation.There are two kinds of insulation combustion:When I<4.5Ie,the fire of the insulation burning can spread only from the breaking point to a certain point on both sides of the conductor;When I≥4.5Ie,the fire of the insulation burning can spread to the end of the wire from the breaking point on both sides and it is this insulation combustion that causes the formation of globules.Den⁃dritic crystal structure is the typical structure of globules.This study shows that there will be flame when energized conductor car⁃ries large current.

关 键 词：火灾调查 电气火灾 铜导线 过电流 发热过程 结痂熔痕 

分 类 号：X928.7[环境科学与工程—安全科学] TU998.12[建筑科学—市政工程]