滨海电厂常以天然海水作冷却水,其碳钢水室和钛管凝汽器在实施阴极保护过程中,要求钢电位应低于-0.85V(vs.SCE),电位过正则碳钢保护不足,而钛的电位则须高于-0.75V(vs.SCE),电位过负则易使钛管发生氢脆损伤.研究牺牲阳极阴极保护,需先得出两种金属在阴极保护过程中的电位分布.本文在设计室建立碳钢水室钛管模型,根据该实验体系阴极保护过程的(稳态极化和恒电流极化)测定获得两种金属有效的边界条件,用有限元(FEM)计算在一个牺牲阳极阴极保护状态得到三维电位分布.计算结果和测量结果基本一致,为优化阴极保护设计提供了理论依据.

When condensers with carbon steel waterbox and titanium tube structure were protected by SACP in an ocean beach power plant,while seawater were used to be cooling water,carbon steel was under-protected and Titanium was over-protected,because their protective potential are less than-0.85V(vs.SCE) and more than-0.75V(vs.SCE) separately.In order to optimize the SACP design,potential distribution of two materials must be obtained during the SACP process.In the lab,carbon steel waterbox and Titanium tube model(Q235-Ti model) were set up.A series of electrochemical techniques(steady polarization,galvanostatic charge technique)were used to obtain reasonable boundary condition and surface form of two materials during the SACP process.The experiments were carried out to validate 3-D potential distribution under one anode SACP condition by finite element method(FEM).The calculation results were consistent with measuring results.The results can be used to provide a theoretical foundation to design an optimal cathodic protection.