管道杂散电流干扰及防腐层破损分析

Analysis of pipeline stray current interference and corrosion protection coating damage

建立管道杂散电流模型,研究杂散电流与地铁和变电所间距、土壤电阻率、地铁牵引电压以及走行轨和埋地管道间距之间的关系及其对防腐层破损管道的干扰规律。结果表明,地铁与变电所间距的减小、地铁牵引电压的减小、土壤电阻率的增大、走行轨与埋地管道间距的增大均会减少杂散电流对管道的干扰。埋地管道杂散电流随着管道防腐层破损面积的增大而增大,且变电所附近的破损点腐蚀比较严重。从防腐层破损时的管地电位分布图可以直观确定破损点的位置,从而为管道防腐层破损点定位提供新的分析手段,为钢制天然气管道潜在高危区域的判断提供理论支撑与指导,同时能够为新建管道的地段选择提供理论依据。

A pipeline stray current model was established,and the relationship between stray current and the distance between metro and substation,soil resistivity,metro traction voltage and the distance between rail and buried pipeline,as well as its interference law to pipeline with damaged anticorrosive layer was studied.The results show that the interference of the stray current on the pipeline decreases with the decrease of the distance between the metro and the substation and the traction voltage of the metro,also decreases with the increase of the soil resistivity and the distance between the rail and the buried pipeline.The stray current of buried pipelines increases as the damaged area of the pipeline coating increases,and the damaged pitting corrosion near the substation is more serious.The coating damage pipe-to-soil potential distribution can intuitively determine the location of damaged point.It provides a new positioning analysis method of pipeline anticorrosive coating damage point,and theoretical support and guidance for stray current on steel gas pipeline of potential high risk areas of judgment and as well as theoretical basis for the location selection for new pipelines.