某天然气管道杂散电流干扰对阴极保护效果的影响研究

Stray Current Interference on the Cathodic Protection Effect of a Natural Gas Pipeline

某天然气管道阴极保护率不能达到阴极保护标准的要求,提高管段电位后,阴极保护电位仍然不稳定。为了确定影响原因,对管道周边杂散电流干扰源进行了排查与分析。通过对管道进行24 h杂散电流检测,发现影响阴极保护电位波动的主要原因是受到较强的动态直流杂散电流干扰。为了减少直流杂散电流对管道的影响,采用排流器+锌带方法对受到干扰的管道进行排流。排流后,再次对管道的阴极保护系统进行了密间隔电位法(CIPS)检测。结果表明,该排流方法能有效减少杂散电流的干扰,使管道阴极保护系统合格率符合标准要求。

The cathodic protection rate of a natural gas pipeline was unable to meet the protection standard for a long time.After raising the potential of the pipe section,the cathodic protection potential was still unstable.In order to find out the causes of the impact,stray currents interference sources near the pipeline were investigated and analyzed.Through 24 hours stray current detection on the pipeline,it was found that the main reason for the fluctuation of the cathodic protection potential was the strong dynamic DC stray current interference.In order to reduce the impact of DC stray currents on the pipeline,the cathodic protection system of the disturbed pipeline was subjected to drainage measures by means of“a drafter+zinc strip”.After the adoption of drainage measures,CIPS testing was carried out on the cathodic protection system of the pipeline.The results showed that after the adoption of the above measures,the interference of stray currents could be effectively reduced and the qualification rate of the cathodic protection system of the pipeline met the standard requirements.