基于恒电位法的阀冷却系统铝散热器腐蚀特性研究

Corrosion Characteristics of Aluminum Radiator for Valve Cooling System Based on Constant Potential Method

目前高压直流输电阀冷却系统普遍存在均压电极结垢问题,严重的甚至影响高压直流系统的正常运行。从均压电极结垢的源头即散热器的腐蚀出发,以安顺换流站的换流阀的内冷水系统为对象,基于电化学原理、恒电位法和测试技术,分析铝散热器的腐蚀机理,从温度、悬浮树脂浓度、水流速、溶解氧浓度和PH值5个方面讨论铝散热器腐蚀的影响因素和作用机制,得出了抑制铝散热器腐蚀的各因素最佳值,并建设性地提出了改善阀冷系统限制其腐蚀结垢的方法,为解决南方电网其他换流站内冷却水系统的腐蚀结垢提供科学依据。

At present, the problem of grading electrode scaling is common in the cooling system of HVDC converter valve, which seriously affects the normal operation of HVDC system. Based on the internal cooling water system of the converter valve of the Anshun converter station, the corrosion of the aluminum radiator which is the source of grading electrode scaling is analyzed by the electrochemical principle, the constant potential method and the testing technique. The influence factors and mechanism of corrosion of aluminum radiator are discussed from five aspects: temperature, suspension resin concentration, water flow rate, dissolved oxygen concentration and pH value. The optimum values of the factors that inhibit the corrosion of aluminum radiator are obtained. And the method of improving the corrosion and scaling of the valve cooling system is put forward constructively, in order to provide a scientific basis for solving corrosion and scaling of the other converter station cooling water system of China southern power grid.