阴极保护在埋地水管网上的应用

Application of Cathodic Protection on Buried Water Pipeline Networks

中国石油天然气股份有限公司大庆石化分公司炼油厂的埋地水管网始建于上世纪60年代初,目前已有近90%的埋地钢质管道的使用年限接近或超过了管道防护层的使用寿命,管道腐蚀泄漏时有发生。由于厂区埋地水管网分布广、管线错综复杂,为此采取了以外加电流阴极保护为主、镁合金牺牲阳极为辅的保护措施。共安装恒电位仪42台,采用80 m深的深井阳极地床,每井安装4组、每组含3支质量分数为50 mg的高硅铸铁阳极。阴极保护于2006年10月完工,经测试,管网保护电位在-0.85～-1.50 V,工作正常。采取阴极保护措施后,使管网腐蚀泄漏次数由87次/年降为45次/年。

The buried water pipeline networks of PetroChina Daqing Petrochemical Company was built in early 1960s. Now the protection coatings of nearly 90% of the pipelines had exceeded their service life or were near the service life, and corrosion leakages of pipeline occurred one time or another. As the buried water pipelines scatter over a large area in complicated arrangement, applied-eurrent cathodic protection has been applied and supported by magnesium alloy sacrificing anode. 42 potentiometers have been installed and 80 m deep beds have been provided. Each well has 4 groups of anodes and each group has 3 high - silicon cast ion anodes. After installation of cathodic protection system in Oct., 2006, the protection voltage of pipelines is maintained at - 0.85 - - 1.5 V, and the number of corrosion leakages have been reduced to 45 from 87 a year.