30万t FPSO外加电流阴极保护系统设计

考虑到FPSO设计为30年不进坞,需要设计满足外板防腐要求的ICCP系统,按照规范计算经验布置艏艉两套ICCP系统,通过数值仿真软件建立三维模型后进行模拟分析,校核在作业期间ICCP系统输出的保护电流以及船体各区域保护电位值。按照数值模拟结果,对ICCP系统设计进行调整和优化,数值结果表明,简单按照规范计算得出保护电流后确定的ICCP系统,存在部分区域保护电流分布不均,出现过保护或欠保护的现象。基于规范计算结果,采用数值仿真软件进行ICCP系统设计模拟分析后,针对FPSO船体外形结构型式特点,通过艏、中、艉部区域配置不同型号辅助阳极,增大辅助阳极屏蔽层面积,能够让外板保护电流更加均匀分布,保持合理的保护电位。

Design of ICCP System for 300000 t FPSO

Considering that the FPSO will not dock for 30 years,it is necessary to design an impressed current cathodic protection(ICCP)system to meet the anti-corrosion requirements of the outer plate.According to the calculation experience,two sets of ICCP systems were arranged in the fore and aft parts.The three-dimensional model was established to assess the protection current output by the ICCP system and the protection potential value in each area of the hull during the operation.The ICCP system was adjusted and optimized according to the simulation result.The results showed that the protect current not well-distributed and the hull potential can’t meet the reasonable range based on the rule experience ICCP system design.Combined the numerical simulation,the ICCP system can output enough protect current and keep the hull in the reasonable potential through choose the different anodes and shield size for forward,middle and stern area of the hull.