高压直流输电换流阀内冷水水质控制指标研究  

Study on Quality Control Index of Inner Cooling Water of HVDC Converter Valve

作　　者：赵文亮 闫爱军 付纪华 丁德 郭季璞 姜丹 

机构地区：[1]国网陕西省电力公司电力科学研究院,陕西西安710054 [2]国网陕西省电力公司检修公司,陕西西安710075

出　　处：《陕西电力》2014年第8期76-81,共6页Shanxi Electric Power

摘　　要：探讨了目前高压直流输电换流阀内冷水水质控制指标现状,研究了换流阀内冷水电导率、pH值、二氧化碳含量、氯离子含量、含氧量等水质指标控制原理,通过理论计算估算出内冷水电导率在0.5 μs/cm时某±500 kV直流换流站因泄露电流单极每年产生Al（OH）3沉淀物约为2.5 kg,每天产生的氧气约4.1 g,证明电导率对散热器腐蚀及内冷水中含氧量有重要影响,溶解氧也应作为常规监督指标,控制含氧量＜100 μg/L;通过水质理论计算及参考金属铝的防腐技术认为密闭运行系统中内冷水的pH值应控制在6.0～8.3,开放且溶入二氧化碳的系统中内冷水的pH值应控制在6.1～8.3,开放运行系统中内冷水中溶入二氧化碳含量应＜88 μg/L;分析认为内冷水氯离子能加速铝腐蚀,也应作为内冷水水质监督指标,通过理论计算提出内冷水中氯离子应控制＜36 μg/L.This paper discusses the status of quality control index of inner cooling water of HVDC converter valve,and studies water quality control indexes such as conductivity,pH value,carbon dioxide content,chloride ion content and oxygen content.Based on the theoretical calculation,when the conductivity of inner cooling water is 0.5 μs/cm,a single compartment of ± 500 kV DC converter station would generate 2.5 kg of Al（OH）3 precipitate per year and 4.1g of oxygen daily due to the leaking current,which has proved that the conductivity has important impact on the corrosion of heat sink and the oxygen content of the inner cooling water.Therefore,dissolved oxygen should also be used as a routine supervision index and controlled below 100 μg/L.According to the theoretical calculation of water quality,referring to anti-corrosion process of metal aluminum,the pH value of the water in closed system should be controlled at 6.0～8.3,the pH value of the water in open system with the carbon dioxide content should be controlled at 6.1～8.3,and the content of dissolved carbon dioxide in the inner water of open operation system should be less than 88 μg/L.The content of chloride ions would accelerate the corrosion of aluminum,hence it should also be used as a supervision index of the inner cooling water,and the content of chloride ions in the inner cooling water should be controlled below 36 μg/L based on the theoretical calculation.

关 键 词：高压直流输电 内冷水 电导率 pH值 溶解氧 氯离子 二氧化碳 

分 类 号：TM721.1[电气工程—电力系统及自动化]