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如果改进牺牲阳极保护系统设计,使之变得更加经济有效,那末将加速近海结构趋向非维修阴极保护系统。在给定阳极寿命和电流密度时有希望实现减少阳极重量。本论文探讨了固定近海结构现有阴极保护设计规范和实践的历史情况,并提出了新的设计方法。新的测量数据是对这些新设计方法的补充证明。研究了一种数学模式,在考虑结构极化时,使阳极电流输出的历史数据和近期数据与阳极寿命相适应。当考虑到由于极化而减少了驱动电位时,可实现节省39％材料费和减少36％的阳极重量。列举了目前使用的牺牲阳极系统和推荐的设计方法的费用比较。由于管道极化减少了驱动电位,使近海管道的寿命设计有所延长。本文还阐述了自升式钻机牺牲阳极阴极保护系统设计用的一种数学模式。它表明当调节电流密度和寿命要求使之适应在泥区(高电阻率)和水区(低电阻率)的循环工作次数时,可改善负荷并节省费用。
If sacrificial anode protection system design is to be improved to make it more cost-effective then accelerating offshore structures will tend toward non-repairing cathodic protection systems. At a given anode life and current density, it is desirable to achieve reduced anode weight. This paper explores the history of existing cathodic protection design codes and practices for fixed offshore structures and proposes new design methods. The new measurement data is a supplement to these new design methods. A mathematical model was studied that, when considering the structural polarization, matched the historical data of the anode current output with the recent data with the anode lifetime. When considering that the drive potential is reduced due to polarization, savings of 39% on material costs and an anode weight reduction of 36% can be achieved. A comparison of the cost of the currently used sacrificial anode system with the recommended design method is given. As the pipeline polarization reduces the driving potential, offshore pipeline life design has been extended. This article also describes a mathematical model used in the design of the sacrificial anode cathodic protection system for self-elevating drilling rigs. It shows that loading and cost savings can be achieved when current density and lifetime requirements are adjusted to accommodate cycles of operation in mud zones (high resistivity) and water zones (low resistivity).