南朗段埋地天然气管道杂散电流检测与治理

Stray Current Detection and Treatment for Buried Natural Gas Pipeline of Nanlang Segment

目的减小杂散电流对南朗段天然气管道的干扰,消除杂散电流腐蚀隐患。方法利用沿线阴极保护电位测试、SCM检测等技术对南朗段管道的杂散电流干扰情况进行检测,并根据检测结果实施排流设计与改造。在009—019测试桩中设计6个排流点,用固态去耦合器排流技术实施排流改造。改造完成后,对排流效果进行验证。结果检测表明,杂散电流最大干扰值达16.839 V,杂散电流密度达393A/m^2,干扰长度为8 km。杂散电流干扰来源于电气化铁路,在铁路运行时间段存在杂散电流干扰,在铁路停运时间段无杂散电流干扰。改造完成后,杂散电流干扰电压降至了4 V以下。结论该排流技术的应用有效减小了南朗段埋地管道的杂散电流干扰,使其达到了国家规定标准,消除了杂散电流腐蚀的隐患,保障了南朗段天然气管线的安全运行。杂散电流干扰的检测与排流技术可以用于消除铁路等对埋地管道杂散电流腐蚀的影响,对受到新建带电结构影响的管道的防护工作具有示范作用。

Objective To reduce the interference of stray current on natural gas pipeline of Nanlang segment,and eliminate the stray current corrosion risks. Methods Detection of stray current interference on natural gas pipeline of Nanlang segment was conducted by cathodic protection potential test and SCM detection technology. According to the test results,discharge of stray current was designed and transformed. Six discharge points were designed in the 009—019 test pile,and the drainage technology was implemented using the solid state decoupling device. After the completion of the transformation,the effectiveness of the implementation was verified. Results The detection result showed that the maximum disturbance of stray current was 16. 839 V,the stray current density was 393 A/m^2,and the interference length was 8 km. The stray current interference came from the electrified railway.There was stray current interference during the railway running time,and no stray current interference during the railway outage time. After the transformation was completed,the stray current interference voltage dropped to below 4 V. Conclusion The practical application of the drainage technology effectively reduced the stray current interference on natural gas pipeline of Nanlang segment,and the national standard was attained. The risk of the stray current corrosion was eliminated,ensuring the safety operation of natural gas pipeline of Nanlang segment. The detection and drainage technology of stray current interference could be used to eliminate the influence of railway on the stray current corrosion of the buried pipeline. and is of demonstration significance for the protection of pipelines affected by the newly built charged structure.