基于外加电流阴极保护法的FPSO保护方案

FPSO Protection Scheme Based on Impressed Current Cathodic Protection(ICCP)

目的确定目标FPSO主船体结构全寿命期下外加电流阴极保护系统中的最优参数。方法采用计算机软件数值模拟的方法,建立目标FPSO主船体结构外加电流阴极保护模型,研究外加电流阴极保护系统中辅助阳极位置、数量以及输出电流对目标FPSO保护状态的影响。结果分别在距离目标FPSO船尾57、127、191、267 m,吃水深度为5.3、5.7、5.7、5.2 m处的左、右两舷侧上对称布置共8个辅助阳极,各个辅助阳极初期释放电流分别为7、6、6、6A,外加电流阴极保护系统输出总电流以34.6A/a线性增加,可使得全寿命期下目标FPSO主船体结构水下部分处于完全保护状态。结论采用计算机软件数值模拟计算可以快速得到外加电流阴极保护系统参数与目标FPSO保护状态之间的关系,进而可得到阴极保护最优参数,这为后续在目标FPSO上使用外加电流阴极保护系统确立最优参数提供了理论依据。

This paper is to determine the optimal parameters of impressed current cathodic protection system under the whole life cycle of the main hull structure of the target FPSO.The impressed current cathodic protection model of the main hull structure of the target FPSO is established by numerical simulation with computer software,and the influence of the position,quantity and output current of the auxiliary anodes in the impressed current cathodic protection system on the protection state of the target FPSO is studied.Eight auxiliary anodes are symmetrically arranged on the left and right sides at 57,127,191 and 267m from the aft of the target FPSO and the intake depth is 5.3,5.7,5.7 and 5.2 m respectively.The initial release current of each auxiliary anode is 7,6,6 and 6 A respectively.The total output current of the impressed current cathodic protection system increases linearly at 34.6 A per year,which makes the underwater part of the main hull structure of the target FPSO in a fully protected state during its whole life.The relationship between the parameters of the impressed current cathodic protection system and the protection status of the target FPSO can be quickly obtained by numerical simulation with computer software,and then the optimal parameters of the cathodic protection can be obtained,which provides a theoretical basis for the subsequent use of the impressed current cathodic protection system on the target FPSO to establish the optimal parameters.