摘要
电力杆塔接地引下线存在较为严重的腐蚀问题,为了对比分析现行金属接地体和石墨接地体对杆塔钢引下线的腐蚀影响,理论分析了钢引下线土壤腐蚀机理并基于此建立钢引下线接地体和钢引下线-石墨接地体的土壤电化学腐蚀模型,对比分析了接地体材质、土壤孔隙度、埋深对引下线工作电极电位、局部土壤氧浓差、腐蚀电流密度等腐蚀过程参数的影响。计算结果表明:引下线腐蚀速率先随土壤湿度的增大而增大,当达到一个饱和值后,腐蚀速率反而降低;钢引下线在埋深0.31~0.41 m位置处引下线氧浓差腐蚀比埋深为0.5 m时更严重,而引下线-石墨接地体连接时,埋深越大氧浓差腐蚀越强烈;当引下线与石墨接地体连接时,引下线的局部氧还原电流密度和铁腐蚀电流密度越大,石墨接地体与引下线构成电偶腐蚀,加速了深地层引下线连接柔性石墨接地体部分的腐蚀,使连接处比地表引下线的氧浓差腐蚀更加严重。
There is a serious corrosion problem in the grounding wire of power tower.In order to compare and analyze the corrosion effect of the current metal grounding body and graphite grounding body on the steel wire of the tower,the author theoretically analyzes the soil corrosion mechanism of the steel wire and establishes the soil electrochemical corrosion model of the steel wire grounding body and the steel wire-graphite grounding body.The influence of the grounding material,soil porosity and buried depth on the working electrode potential,local soil oxygen concentration and corrosion current density of the grounding wire is compared and analyzed.The calculation results show that the corrosion rate of the down-lead first increases with the increase of soil moisture,and then decreases after reaching a saturation value.The oxygen concentration corrosion of the steel lead wire at the position of 0.31–0.41 m is more serious than that at the position of 0.5 m.When the lead wire is connected with graphite grounding body,the greater the buried depth is,the stronger the oxygen concentration corrosion is.When the lower wire is connected with the graphite grounding body,the greater the local oxygen reduction current density and i⁃ron corrosion current density of the lower wire,the galvanic corrosion between the graphite grounding body and the lower wire is formed,which accelerates the corrosion of the flexible graphite grounding body connected with the lower wire in deep strata,and makes the oxygen concentration corrosion of the connec⁃tion more serious than that of the surface lower wire.
作者
黄涛
沈文韬
谢洪平
安韵竹
杜长青
井栋
HUANG Tao;SHEN Wentao;XIE Hongping;AN Yunzhu;DU Changqing;JING Dong(State Grid Jiangsu Power Engineering Consulting Limited Company,Nanjing 210000,China;Electrical and Electronic Engineering College,Shandong University of Technology,Zibo 255000,China)
出处
《电瓷避雷器》
CAS
2024年第1期93-102,共10页
Insulators and Surge Arresters
基金
国家自然科学基金项目(编号:51807113)。
关键词
接地网
接地材料
引下线
腐蚀
孔隙度
grounding grid
grounding material
down-lead line
corrosion
porosity
作者简介
黄涛(1986-),男,博士,高级工程师,输变电工程运行与规划。E-mail:549984231@qq.com。
