在全寿命期内, 铺管船水下结构腐蚀防护状态处于动态过程。因此, 依据实际情况设计腐蚀防护方案十分必要。采用数值模拟计算方法预报腐蚀防护状态, 并通过缩比模型试验验证了此方法的准确性。在此基础上设计了两种腐蚀防护方案: “单纯外加电流阴极保护”和“外加电流+牺牲阳极辅助的联合阴极保护”。并通过数值模拟计算预报了两种方案下的腐蚀防护状态。经过对比发现, 使用“外加电流+牺牲阳极辅助的联合阴极保护”时, 表面电位分布更均匀, 阳极屏面积及电源功率都有较明显的减小, 水下结构处于更为良好的腐蚀防护状态。

Corrosion protection status of the pipe laying vessel underwater structure is under a dynamic process in the lifecycle. Thus, it is necessary to design the corrosion protection program according to the practical situation. In this paper, numerical simulation method was used to predict the corrosion protection status and the accuracy of the method was evaluated by the scale model test. Then two cathodic protection plans were considered, which were “impressed current cathodic protection” and “sacrificial anode and impressed current joint cathodic protection”. The corrosion protection status was predicted by the numerical simulation for these two protection plans. After comparison it was found that the application of “sacrificial anode and impressed current joint cathodic protection” enhanced the uniformity of potential distribution. The area of the anode shield and the power of two DC electrical sources were reduced by a large margin. All the submerged structures were in good protection.