海泥介质全埋管线阴极保护设计验证和优化

Verification and Optimization of Cathodic Protection Design of Fully Buried Pipeline in Submarine Mud

针对海泥中全埋设钢制管线服役周期长达50 a的要求,采用淡海水和海泥作为测试介质,进行电化学试验,筛选和优化了铝合金阳极,并将其用于21 km海底管线牺牲阳极阴极保护方案的优化设计中。结果表明:在淡海水中,与DNV标准组分铝合金阳极的电化学性能比,优选组分铝合金阳极的电化学性能差别不大,但是在海泥中,优选铝合金阳极具有更加优异的电化学性能,其电位更负、电容量更高、溶解更均匀。在阴极保护方案设计中,优选铝合金阳极的用量比标准铝合金阳极的用量减少了25%,大大提高了阴极保护方案的经济性。

Aluminum alloy anode was screened and optimized by electrochemical test in brackish water and sea mud as testing mediums, aiming at the requirement of 50 years service period of steel pipelines buried in sea mud. And the optimized anode was used in the optimal design of sacrificial anode cathodic protection scheme for a 21 km subsea pipeline. The results show that the electrochemical performance of the preferred component aluminum alloy anode had little difference compared with that of DNV standard component aluminum alloy anode in the brackish water. But in the sea mud, the preferred aluminum alloy anode had better electrochemical performance, showing more negative potential, higher capacitance and more uniform dissolution, compared with the standard aluminum alloy. In the design of cathodic protection scheme, the consumption of preferred aluminum alloy anode was 25% less than that of standard aluminum alloy anode, which greatly improved the economy of cathodic protection scheme.