摘要
换流阀内水冷系统中均压电极表面发生的结垢问题会引发冷却水路阻塞、漏水和散热失灵等故障,甚至导致直流闭锁事故,危及高压直流输电系统的安全可靠运行。本文通过模拟腐蚀和结垢试验确定了冷却水中致垢离子带电特性的决定性因素;依据热力学理论对不同条件下内冷水中致垢离子的存在形态进行了计算分析。结果表明:金属散热器腐蚀是冷却水中致垢离子产生的根源,但致垢离子在冷却水中扩散和迁移阶段的带电特性并不由腐蚀反应所决定,而是完全取决于冷却水环境的pH值;在弱酸性冷却水环境下,致垢离子绝大多数以正电性铝配离子的形态存在,而在弱碱性冷却水环境下,致垢离子几乎全部以负电性铝配离子形态存在。
The deposition problem on grading electrodes in the inner cooling system of HVDC converter valves will cause water pipe blockage,leakage and heat loss failure,even DC blocking accident,endangering the safe and reliable operation of HVDC system.In this paper,simulated corrosion and deposition experiments are conducted to determine the decisive factor which influence the charged property of sediment-forming ions.The existence form of sediment-forming ions in cooling water under different conditions is calculated based on thermodynamic theory.The results show that the corrosion of the metal heat sink is the root of sediment-forming ions,but the existence form of the sediment-forming ions in the cooling water is determined by the pH of the cooling water during the migration,instead of being determined by the original corrosion reaction.In weakly acidic environment,most of the sediment-forming ions exist in the form of positive aluminum complex ions,while in weakly alkaline environment,the sediment-forming ions almost all exist in the form of negative aluminum complex ions.
作者
卢世才
李道豫
王行飞
邱志远
刘学忠
LU Shicai;LI Daoyu;WANG Xingfei;QIU Zhiyuan;LIU Xuezhong(Guiyang Bureau,CSG EHV Power Transmission Company,Guiyang 550081,China)
出处
《南方电网技术》
CSCD
北大核心
2021年第8期64-70,共7页
Southern Power System Technology
基金
中国南方电网超高压输电公司科技项目(阀冷系统内冷水极性与非极性物质的检测、去除技术的研究)(CGYKJXM20180394)。
关键词
高压直流输电
内冷却系统
均压电极
结垢
high voltage direct current power transmission
inner cooling system
grading electrode
deposition
