输气管线阴极防腐保护工程初步设计.doc

输气管线阴极防腐保护工程初步设计 Preliminary design of cathodic protection project of gas-pipe line 大连理工大学毕业设计（论文）格式规范 输气管线阴极防腐保护工程初步设计 PAGE - - - PAGE I - 摘 要 金属材料在使用过程中易受环境作用随时间的延长而逐渐受到损坏或性能下降，根据发达国家的调查统计，全世界每年因腐蚀损失高于7000亿美元。由此可见金属腐蚀问题十分严重和普遍。我国输气管道材质现在大多采用的是钢管，钢质输气管在埋地运行中常常会发生一些局部腐蚀而穿孔，造成极大的经济损失，危及人民群众的生命安全，因此对输气管道采取相应的防腐措施是必须的和必要的。 阴极保护是一种公认的防腐蚀技术，其应用领域广，涉及到地下、水中及化工介质中的管道、容器、及化工设备等各个方面，尤其在埋地钢质管道方面，其防腐蚀效果和其它防腐技术相比具有无可替代的作用。 本设计在查阅了大量文献资料基础上，简述了埋地输气金属管道电化学腐蚀理论和防腐理论，对牛居—青龙台D426输气管道的外防护层和腐蚀现状进行了分析，找出了影响土壤腐蚀的各种因素。本设计具有一定的实用价值和指导意义。 本工程依据中国石油辽河油田茨榆坨采油厂提出的设计任务委托书。防腐设计严格遵守国家、行业和部门政策法规，严格执行国标及行业标准。本着“技术可行、经济合理、安全环保、以人为本”的指导思想为设计原则，在采用新技术、新设备、新材料时进行充分论证，以确保所采取的措施及方法技术上的可行性。 关键词：腐蚀；阴极保护；设计原则；设计依据 输气管线阴极防腐保护工程初步设计 - PAGE IV - Preliminary design of cathodic protection project of gas-pipe line Abstract The metal materials in their using process in vulnerability environment will be gradually damaged or decline in performance with time. Loss of more than 700 billion dollars each year due to corrosion is reported in the developed countries around the world. Obviously, metal corrosion problem is very serious and common. In China, steel is the mostly used material for natural gas pipeline. Steel natural gas pipe buried in ground often have the problem of corrosion, which can cause accident, and endanger peoples lives and safety. So it is necessary and essential to take anti-corrosion protection for the gas pipeline. Cathodic protection is a recognized as anti-corrosion technology. It is broadly applied in the protection of the media pipeline, storage containers, and chemical equipment, and other various aspects, especially in the buried steel pipeline. Many papers report the electrochemical corrosion of metals and anti-corrosion theory for the buried natural gas pipeline. We analyze the corrosion status of the Niuju-Qinglongtai natural gas pipeline and design a corrosion protective layer. It is found that a variety of factors including soil can affect corrosion. Our work has certain p