随着城市化进程迅速发展,埋地天然气管道受铁路、城际轨道直流杂散电流干扰和高压输电线路交流干扰加剧。采用数据记录仪对管道进行杂散电流普查和24 h连续监测,分析了动态直流杂散电流的干扰程度和影响规律，研究、评价了交流杂散电流干扰。结果表明:管道受铁路和城际轨道杂散电流的影响,距离干扰源越近受杂散电流干扰程度越大；杂散电流在管段之间不同位置交替为流出和流入区域,受不同干扰源的交互影响，同一位置杂散电流的流入和流出特性不同；不宜采用交流电压和计算交流电流密度评价交流杂散电流干扰,应使用试片实测交流电流密度以及交流电流密度与直流电流密度的比值来评价交流腐蚀的风险。研究可为新建或在役天然气管道杂散电流干扰评价与排流防护提供参考。

With the rapid development of urbanization, buried natural gas pipelines were subject to DC stray current interference from railway and intercity rail and AC interference from high-voltage transmission lines. Stray current survey and 24-hour monitoring were carried out for pipeline using data recorder. The interference degree and influence pattern of dynamic DC stray current were analyzed, and the AC stray current interference was also studied and evaluated. The results showed that the pipeline was affected by the stray current from high-speed rail and intercity rail, and the shorter the distance from the interference source, the greater the degree of stray current interference. Stray current alternates between outflow and inflow areas at different positions between pipe sections, and the inflow and outflow characteristics of stray current at the same position were different due to the interaction of different interference sources. It is not appropriate to use AC voltage and the calculated AC current density to evaluate AC stray current interference. The AC current density measured on the test piece and the ratio of AC current density to DC current density should be used to evaluate the risk of AC corrosion. This study can provide reference for stray current interference evaluation and DC drainage protection of newly installed or existing natural gas pipelines.