某天然气管道交流杂散电流腐蚀监测与防控

Monitoring and prevention of AC stray current corrosion in a natural gas pipeline

  • 摘要: 某长输天然气埋地钢质管道与高速铁路、高压输电线路并行,并多次交叉,空间电磁环境复杂,交流杂散电流干扰突出,显著加剧埋地钢质管道的电化学腐蚀风险,亟须量化腐蚀干扰强度并制定针对性的腐蚀防护策略。采用数据记录仪对管道交流电流密度进行连续监测,以评估交流电流对埋地钢质管道的腐蚀风险。针对高腐蚀风险区段,设计并实施了“固态去耦合器+ 深井接地体”组合排流措施,对比治理前后数据,验证了该策略在抑制交流腐蚀方面的有效性。监测到高风险点交流电流密度峰值高达566.84 A/m2,为《埋地钢质管道交流干扰防护技术标准》(GB/T 50698—2020)安全阈值(100 A/m2)的5.7倍;治理后各测试位点交流腐蚀电流密度平均值降至30 A/m2以内,满足标准要求。“固态去耦合器+深井接地极”组合排流措施可有效抑制强交流杂散电流干扰,实现管道防腐的目标。

     

    Abstract: A long-distance buried steel natural gas pipeline runs parallel to and intersects high-speed railways and high-voltage power lines multiple times, creating a complex electromagnetic environment with severe AC stray current interference. This significantly raises the risk of electrochemical corrosion, making it urgent to quantify corrosion interference intensity and develop targeted protection strategies. In this study, data loggers were employed to continuously monitor the AC current density of the pipeline to assess the corrosion risk induced by AC current in the buried steel pipeline. For segments identified with high corrosion risk, a combined drainage system of "solid-state decouplers + deep-well grounding electrodes" was designed and implemented. The effectiveness of this strategy in mitigating AC corrosion was confirmed by comparing monitoring data before and after remediation. The peak AC current density at high-risk monitoring points reached 566.84 A/m2, 5.7 times the 100 A/m2 safety threshold specified in"Standard for AC interference mitigation of buried steel pipelines" (GB/T 50698—2020). After remediation, the average AC corrosion current density at all test posts dropped below 30 A/m2, fully meeting the standard requirements. The combined drainage system of"solid-state decouplers + deep-well grounding electrodes"effectively suppresses severe AC stray current interference, achieving pipeline corrosion protection.

     

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