直流杂散电流对埋地管道的电腐蚀规律及排流措施

Electrical Corrosion Law of DC Stray Current on Buried Pipelines and Discharge Mea⁃sures

随着工业化进程的不断发展,轨道交通对埋地管道的直流杂散电流干扰愈发严重。为降低杂散电流引发的电腐蚀问题,在监测埋地管道沿线电位的基础上,分析干扰规律、干扰频率、干扰源位置对管道的影响,考察电流流入和流出的规律,并测试不同排流措施效果。结果表明:干扰规律与轨道的运营状态保持一致,干扰频率与发车时间间隔保持一致;距离干扰源越近,电位正向偏移的时间比例越大,腐蚀趋势远大于其余管段;同一位置不同时段可能互为电流流入、流出段,电流流动方向和规律随时间动态变化;排流措施中强制排流的效果最好,其次为极性排流和接地排流,阴极保护的效果较差;通过多重联合防护,除与轨道交通最近的管段外,其余管段均达到了良好的保护效果,腐蚀速率大幅降低,可减少管道更换和泄漏放空量。

With the continuous development of industrialization,the interference of DC stray current on buried pipelines by rail transit has become increasingly severe.In order to reduce the electrical corrosion problem caused by stray current,based on the monitoring of potential along the buried pipeline,the influence of interference law,interference frequency,and interference source location on the pipeline is analyzed,the current inflow and outflow law is investigated,and the effects of different discharge measures are tested.The results show that the interference law is consistent with the operating state of the rail transit,and the interference frequency is consistent with the departure time interval.The closer the distance to the interference source,the larger the time proportion of positive potential deviation,the corrosion trend is much larger than that of other pipe segments.Different time periods at the same position may be current inflow and outflow segments,and the current flow direction and law change dynamically with time.Forced discharge has the best effect,followed by polar discharge and ground discharge,while cathodic protection has a poor effect.Through multiple joint protection,except for the pipe segment closest to rail transit,the other pipe segments have achieved good protection effect,the corrosion rate is greatly reduced,and the pipeline replacement and leakage cavitation are reduced.