深井型直流接地极固井混凝土电阻率变化规律  

Electrical Resistivity Variation Law of Well Cementing Concrete of DC Deep Well Grounding Electrode

作　　者：蔡汉生 滕芸[2] 贾磊 郑智慧[2] 胡上茂 鲁海亮[2] 刘刚 文习山[2] CAI Hansheng;TENG Yun;JIA Lei;ZHENG Zhihui;HU Shangmao;LU Hailiang;LIU Gangl;WEN Xishan(State Key Laboratory of HVDC, Electric Power Research Institute, CSG, Guangzhou 510663, China;School of Electrical Engineering, Wuhan University, Wuhan 430072, China)

机构地区：[1]直流输电技术国家重点实验室(南方电网科学研究院),广州510663 [2]武汉大学电气工程学院,武汉430072

出　　处：《南方电网技术》2017年第9期23-29,共7页Southern Power System Technology

基　　金：南方电网重大专项项目(WY-KJXM-20150901)~~

摘　　要：深井型直流接地极(简称深井接地极)被持续施加恒定直流时,固井混凝土作为电解质会与井壁钢套管发生腐蚀电化学反应,造成混凝土电阻率的改变。为研究不同状态的混凝土在直流作用下电阻率随着通电时间的变化规律,本文按实际深井接地极工程用混凝土配比配制试样,对固结3~7 d及完全固结后的干燥、浸渍混凝土试块进行了直流实验。综合实验结果表明:固结初期混凝土电阻率变化规律符合Archie公式;固结期内、完全固结后又被水浸渍的混凝土随通电时间的增加电阻率升高;完全固结并干燥的混凝土电阻率随通电时间的增加电阻率降低。分析认为直流极化作用是导致二者趋势差异的主要原因。When constant direct current（DC） is impressed on DC deep well grounding electrode, electrochemical, corrosion reaction occurs between the well cementing concrete and the steel tube, and the well cementing concrete acts as electrolyte. The reaction leads to the electrical resistivity variation of the well cementing concrete. In order to study the electrical resistivity variation law of well ce- menting concrete in different conditions with the DC duration, experiments are carded out in this paper. According to the water cement ratio of the practical deep well grounding electrode engineering, the concrete samples are prepared. The DC experiments for concrete samples which are cured for 3 ~ 7 days and entirely cured are conducted. The results show that the concrete electrical resistivity con- forms to Archie formula at the beginning of curing period, the concrete electrical resistivity during curing period increases with the DC duration and so does the entirely cured and impregnated concrete, while the electrical resistivity of entirely cured and dried concrete de- creases with the DC duration. The analysis shows that DC polarization is the main reason leading to the difference of the two trends.

关 键 词：深井接地极 固井混凝土 固结时间 电极反应 直流极化 电阻率 

分 类 号：TM863[电气工程—高电压与绝缘技术]