高含CO_2储气库集输管道腐蚀防护研究

以某储气库工程为背景,结合CO2的腐蚀机理及影响因素对该工程工况条件下的集输管线的腐蚀情况进行了深入分析,结果表明:集输管线在0.81 MPa的CO2分压作用下将发生严重的腐蚀破坏,运行温度位于中温区,腐蚀产物膜的耐蚀性差,腐蚀特征以点蚀为主,同时介质流速及Cl-离子的存在进一步加剧了CO2对集输管线的腐蚀。结合腐蚀情况及实际工况条件,比选了几种针对性的腐蚀控制措施,根据最终的经济比选结果及优缺点比较,推荐集输管线选择经济、安全的316L+L450Q形式的复合钢管,后期的试验结果表明:在本工程工况条件下复合钢管的母材及环焊缝焊接接头具备良好的耐蚀性能及力学性能,满足本工程的运行要求。

Research on the Corrosion Protection of Gathering Pipeline in gas Storage Containing High Concentration CO2

Taking a certain gas storage project as the background, combined with CO2 corrosion mechanism and influencing factors, corrosion situation of gathering pipeline under the operating condition of this project was analyzed. The analysis results show that：there will be a severe corrosion in the gathering pipeline under the action of a 0.81 MPa CO2 partial pressure; Due to the medium operating temperature, the corrosion product film shows poor corrosion resistance, and main corrosion characteristic is pitting corrosion. At the same time, the flow rate and chlorine ion can aggravate the corrosion of the gathering pipeline. According to the corrosion situation and the operating condition, several control measures were compared. The comparison result shows that：the composite pipe of 316L＋L450Q is the best choice. The experimental results has proved that：the base metal and welding joint of the 316L＋L450Q composite both have good corrosion resistance and mechanical properties under the project operating condition.