摘要
针对穿管铜导线过电流故障熔化痕迹难以识别的问题,利用电气故障模拟及痕迹制备实验装置,实验模拟了4~7倍额定电流I e下穿管铜导线过电流故障,划分了过电流故障传热特征阶段,分析了电流对碳烟析出、熔断时间、熔痕体积和熔痕数量的影响,探究了过电流故障熔痕金相组织特征。研究发现:“累积期”电流增大碳烟析出增加,熔断时间减小。穿管铜导线发生熔断电流至少5.5 I e,在5.5~7I e时产生了电弧熔痕、迸溅熔珠及结痂痕;随着电流增大,电弧熔痕和迸溅熔珠的体积逐渐增大,结痂痕的体积逐渐减小;迸溅熔珠和结痂痕数量逐渐增加。电弧熔痕的金相组织为树枝晶和胞状晶,迸溅熔珠和结痂痕金相组织只有胞状晶,熔痕与本体之间无明显过渡区,熔痕内部存在孔洞。实验结果表明穿管铜导线过电流故障与未穿管铜导线过电流故障痕迹特征存在差别。研究结论为火灾事故调查中识别与鉴定穿管铜导线过电流故障痕迹提供参考依据。
It is difficult to identify the traces of cellular copper conductor melting under overcurrent fault.In this paper,the experimental device of electrical fault simulation and trace preparation was used to simulate the cellular copper conductor under overcurrent fault at different current from 4 to 7 I e,and the characteristic stages for heat process of overcurrent fault were divided.Besides,the effects of different current on the smoke separation,melting time,volume and number of melt traces were analyzed,and the metallographic structure of melt trace was studied.The study found that in the“accumulated period”,as the current increased,the amount of smoke separation increased,but the melting time decreased.The fusing current of cellular copper conductor is at least 5.5 I e.When the current was 5.5~7 I e,the cellular copper conductor would produce arc beads,hot particles and globules.As the current increased,the volume of arc beads and hot particles gradually increased,the volume of globules gradually decreased,and the quantity of hot particle and globules increased.The metallographic structure of arc beads is dendritic crystal and cellular crystal,and the metallographic structure of hot particles and globules is cellular crystal.There is no obvious transition zone between the melt trace and the body,and there are some holes in the melt trace.The experimental results show that there are differences between the trace characteristics of cellular copper conductor and non-cellular copper conductor under overcurrent fault.The conclusion of this study can provide a reference for identifying the melt trace of cellular copper conductor under overcurrent fault.
作者
陈晓坤
徐学岩
李阳
王伟峰
白磊
王刘兵
王博
CHEN Xiao-kun;XU Xue-yan;LI Yang;WANG Wei-feng;BAI Lei;WANG Liu-bing;WANG Bo(College of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054.China;Department of Fire Protection Engineering,Chinese People’s Police University,Langfang 065000,China)
出处
《西安科技大学学报》
CAS
北大核心
2020年第3期393-399,共7页
Journal of Xi’an University of Science and Technology
基金
国家重点研发计划(2018YFC0807900)
陕西省创新能力支撑计划(2018PT-33)
陕西省重点研发计划(2017ZDCXL-GY-01-02-03,2017ZDXM-SF-092)
西安科技大学校级教育教学改革与研究项目(JG18018)。
关键词
火灾调查
过电流故障
穿管
熔痕
显微分析
fire investigation
overcurrent
tube
melt trace
microscopic analysis
