淡水低电导介质中凝汽器阴极保护防腐蚀研究

Corrosion Prevention Technique for Cathodic Protection (CP) for Condensers in Freshwater Low Conductive Medium

对淡水低电导介质中火电厂凝汽器的电化学保护防腐蚀技术进行了研究。根据阴极保护技术的原理和实践，先在实验室进行了有关电化学试验，然后在模拟实验台上研究凝汽器阴极保护的方式和保护参数的范围，最后在12MW机组上进行了现场试验并采用了磁饱和式自动恒电位仪和铂铌辅助阳极。试验结果表明：淡水低电导介质中凝汽器阴极保护宜采用外加电流式；保护电位范围为+0.40～+0.10V（Zn），保护电流为1．0～2．5A；合理的电极定位和适当的电位调整是保护系统运行的关键。研究表明，在淡水低电导介质中进行凝汽器阴极保护防腐蚀是可行的。

Corrosion prevention technique for electrochemical protection for condensers infreshwater low conductive medium is investigated in thermal power plants. Based on the principleand practice of cathodic protection (CP), electrochemical experiments were first made in alaboratory, then cathodic protection mode of condensers are studied on a simulated test stand andlastly onsite testing is conducted on a 12 MW units with the adoption of magnetic saturated auto-potentiometer and platinum--niobium auxiliary anode. The test results demonstrate that thecathodic protection for condensers should be taken with the current applied. The protectivepotential ranges from +0. 40 to +0. 10 V (Zn) with protective current from 1. 0 to 2. 5 A.Rational electrode position and appropriate potential regulation is the key to the protection ofsystem operation. From the results of these researches it is verified that CP is a powerfultechnique for condensers preventing from corrosion in freshwater low conductive medium.