Abstract: The mathematical model of cathodic protection potential distribution with impressed current on the exterior of metal storage tank bottom is established and calculated by using Comsol multiphysics software. The effects of the numbers and layout of cathodic confluence points depth of auxiliary anode, soil resistivity, and the influence of polarization characteristic on protection potential distribution of tank bottom were studied. The results showed that, with other conditions unchanged, the way of setting confluence points on the center of tank bottom and more points confluence would produce better results of cathodic protection. But due to potential drop of tank bottom with little difference, and considering economic feasibility factors. Singlepoint confluence at the edges was proposed. Moreover, the smaller the soil resistivity was, the deeper the depth of auxiliary anode was. The tank bottom is not easy to be corroded and polarized. It is better for cathodic protection effect of tank bottom.

Key words: Metal storage tank, Cathodic protection, Impressed current, Comsol multiphysics, Numerical simulation

摘要： 利用ComsolMultiphysics软件建立了金属储罐底板外加电流法阴极保护电位分布的仿真模型。通过数值模拟方法,研究了阴极汇流点数量、汇流点布置情况、辅助阳极埋设深度、土壤电阻率以及电极的极化特性等因素对保护电位分布规律和阴极保护效果的影响。结果表明,在其他条件不变的情况下,罐底中心设置汇流点和多点汇流的方式,罐底板的阴极保护效果更好,但由于罐底板整体电位降差别不大,考虑到经济可行性因素,建议采用边缘处单点汇流的方式;此外,土壤电阻率越小,阳极埋深越深,罐底板越不容易受到腐蚀,罐底板越易于极化,储罐底板的阴极保护效果越好。

关键词: 金属储罐, 阴极保护, 外加电流, ComsolMultiphysics, 数值模拟