依据NACE-SP0176-2007规范, 在外加电流阴极保护系统中, 辅助阳极与结构物表面的距离不小于1.5 m, 否则需要采用屏蔽层以防止过保护。在导管架外加电流阴极保护系统中, 辅助阳极与导管架结构表面之间的距离是一个重要的参数, 对阳极屏的使用与否有直接影响, 也间接对阴极保护系统的造价和运行方案产生影响。通过阴极保护数值模拟计算技术, 改变辅助阳极与导管架之间的距离, 得到在无阳极屏蔽层并且不发生过保护的前提下, 辅助阳极可以释放的最大电流, 并通过实海试验予以了验证。数值模拟与试验结果均表明, 针对辅助阳极与结构表面之间的不同距离条件控制辅助阳极的最大释放电流, 不仅可以避免使用阳极屏蔽层带来一系列工程问题, 而且能够为导管架外加电流阴极保护系统的优化设计提供重要依据。

According to NACE-SP0176-2007, impressed current anodes should be located usually in a minimum distance of 1.5 m from any structure member, or anode shields should be used in case of overprotection. During the impressed current corrosion design of a jacket, the design distance between the anode and the structure is an important parameter, and has a direct effect on whether to use the anode shields or not. It also brings indirect effects on the manufacturing cost and the operating scheme. With the methods of numerical simulation, the design distance between the anode and the nearest structure was changed to get the maximum current without the anode shields. The numerical simulation and experiment showed that the method could not only avoid a range of engineering problems with the use of anode shields, but also provide an important reference for optimizing the design of the jacket corrosion protection system.