摘要
为了查明川气东送天然气长输管道诸多阀室及邻近管段强制电流阴极保护失效、常年处于欠保护状态的原因,以其某RTU阀室为例,建立了阀室局部阴极保护的简单物理模型,通过模型推导与现场测试验证相结合的方法,得出管道与接地网导通诱发绝缘失效是导致管道欠保护的直接原因。在查找管道绝缘失效原因并进行定位的过程中,发现了长输管道阴极保护和防雷接地系统在设计、建造、运行维护期间的诸多问题,提出管道绝缘失效整改及保护电位恢复应采取电路隔离、牺牲阳极接地极改造、区域牺牲阳极热点保护、区域强制电流阴极保护等应对措施。
To find out the causes of the impressed current cathodic protection failure in valve chambers and adjacent pipes,as well as the resulting long-term lack of protection in Sichuan-to-East long-distance natural gas transmission pipeline,a simple physical model of partial cathodic protection in valve chambers was established based on a case study of RTU valve chamber.Through the method of model deduction in combination with field test verification,it can be concluded that the insulation failure,which is caused by conduction between pipeline and grounding grid,should be the direct cause of lack of protection.During the process of finding the causes of pipeline insulation failure and positioning,many problems,existing in design,construction,operation and maintenance of cathodic protection and lightning protection grounding system for long-distance pipelines,were exposed.Countermeasures,such as circuit isolation,grounding electrode modification by sacrificial anode,regional hot spot protection by sacrificial anode,and regional cathodic protection by impressed current,have been proposed for the rectification of pipeline insulation failure and restoration of protection.
作者
李刚川
邓同军
汪恋
李气林
LI Gangchuan;DENG Tongjun;WANG Lian;LI Qilin(SINOPEC Sichuan to East Gas Pipeline Co.Ltd.;Shandong Zhongyuan Natural Gas Technical Services Co.Ltd.)
出处
《油气储运》
CAS
北大核心
2019年第12期1378-1382,共5页
Oil & Gas Storage and Transportation
关键词
长输管道
阴极保护
接地导通
绝缘失效
欠保护
long-distance pipeline
cathodic protection
grounding conduction
insulation failure
lack of protection
