轻轨杂散电流对埋地煤气管线影响研究

A Survey of Effect of Stray Current of Light-rail on Buried Gas Pipelines

对沈阳市浑南新区2条埋地煤气管线上4个测试点受轻轨杂散电流影响进行了调查和研究。结果表明,轻轨电车在运行期间产生的杂散电流对附近埋地煤气管线产生严重影响。4个测试点管地电位最大正向偏移值分别为188,233,180和187 mV。过大的管地电位正向偏移致使埋地煤气管线涂层破损处金属阳极溶解反应加剧,进而导致管线腐蚀穿孔,并产生泄漏。有效的排流保护能够大大降低杂散电流对埋地煤气管线的影响,从而减缓管线的腐蚀。本文采用极性排流和负电位排流相结合的方式对埋地煤气管线进行排流保护。

A survey of the effect of stray current of light rail on two buried gas pipelines in Hunnan distric of Shenyang is carried out at four selected test sites. Results show that there exists serious effect of stray currents on the buried pipeline nearby. The maximum positive shifts of the pipe-to-ground potential reach 188, 233, 180 and 187 mV, respectively for the four test sites. The positive shifting of the potential of pipe results in the increase of the anodic dissolution of the buried pipeline steel where the coating is broken, which for long may lead to perforation and leakage of the pipeline. The polarity drainage and negative potential drainage are used to protect the pipeline from the interference of DC stray current. After the application of the drainage measures, the effect of DC stray current on the buried pipeline may effectively be eliminated.