即热式热水器底部加强板阴极保护系统电场数值模拟

【目的】为给即热式热水器的底部加强板添加外加电流阴极保护系统,并获得均匀的电场分布。【方法】利用有限元法对两种型号即热式热水器底部加强板,在不同辅助阳极排布方式下的阴极保护电场进行数值模拟。【结果】在与钢条垂直方向,当辅助阳极位于热水器内胆高度的4/9处时,底板电位开始达到均匀分布。在与钢条平行方向,当阳极在热水器内胆长度的11/18到13/18的范围内,底板左右两端电位分布较均匀。随着辅助阳极数量的增加,底板表面的电位分布更为均匀,但对底板的电位数值变负未有太大的影响。将求解的平面空间分层并折算成直线,以辅助阳极所在的位置为中心,阳极两边均出现电位自衰减现象。【结论】采用2个辅助阳极较为经济。阳极的最佳位置区间为一个顶点坐标固定的长方形域。可根据衰减曲线,通过调节辅助阳极的电位,使离阳极最远的两个末端的电位达到保护要求。

Numerical Simulation for Electric Field of Cathodic Protection of the Bottom Strengthening Plate of Instant Water Heater

[Objective] Aiming to design the impressed current cathodic protection system for the bottom steel plate of a constant water heater and to obtain the uniform electric field distribution.[Methods] The finite element method was used to calculate electric field from cathodic protection of the strengthening plate based on different arrangements of auxiliary anodes.[Results] When the auxiliary anodes being vertical to the steel bar were placed at 4/9 of the heater height, the potential began to be uniformly distributed. When the anode being parallel to the steel bar were placed at 11/18 to 13/18 of the heater length, the potential distribution of left and right ends was more uniform. With the increase of the number of auxiliary anodes, the potential distribution was more uniform, but little impact on the value of the steel bar was found. Converting the solving region into a straight line, the auxiliary anode was in the center of the line. There was a self-attenuating phenomenon about potential.[Conclusion] So two auxiliary anodes were enough and economic. The anodes were preferably placed in a rectangular shape with specific coordinates. According to the attenuating curve, potentials of two ends can be adjusted to meet the requirement of standard.