酸性气管线的腐蚀穿孔原因  

Analysis of Corrosion and Perforation of Sour Gas Piping

作　　者：李建宏[1] 陈博[2] LI Jianhong;CHEN Bo(Pressure Vessel Inspection Department of PetroChina Dushanzi Petrochemical Company,Karamay 833699,China;Storage and Transportation United Unit of Oil Refinery of PetroChina Dushanzi Petrochemical Company,Karamay 833699,China)

机构地区：[1]中国石油独山子石化公司压力容器检验所,克拉玛依833699 [2]中国石油独山子石化公司炼油厂储运联合车间,克拉玛依833699

出　　处：《腐蚀与防护》2019年第3期230-234,共5页Corrosion & Protection

摘　　要：酸性水汽提塔顶空冷系统出口端的酸性气管线弯头因腐蚀穿孔而更换。结合管线的结构与服役情况,对失效弯头进行了宏观检查、壁厚测定、能谱检测以及冲蚀模拟计算,结果表明:酸性水汽提塔顶含有H2S、NH3以及水蒸气的混合气冷却后形成了含液滴的腐蚀性流体,进入垂直向下具有较长直管段的酸性气管线,在重力和内压作用下对弯头外拱璧处产生较大的剪切应力,在流体介质腐蚀与冲刷的耦合作用下,生成的腐蚀物保护膜不断发生破损流失,形成一种自催化加速冲蚀腐蚀的效果,最终导致该酸性气管线弯头减薄穿孔。The acid gas pipeline elbow at the outlet end of an acid water stripper top air cooling system was replaced because of corrosion perforation.Combined with the structure and service conditions of the pipeline,macroscopic inspection,wall thickness measurement,energy spectrum detection and erosion simulation calculation were performed on the failed elbow,and the failure reason was analyzed.The results show that the mixture of H2 S,NH3 and water vapor at the top of the acid water stripper cooled to form a corrosive fluid containing droplets,and entered the acid gas pipeline with a long straight pipe section vertically downward.Under the action of gravity and internal pressure,the corrosive fluid caused large shear stress on the external arch of the elbow.Under the coupling action of corrosion and erosion of the fluid medium,generated corrosion product film was continuously broken,forming an autocatalytic accelerated erosion corrosion effect,eventually leading to the thinning and perforation of the acid gas pipeline elbow.

关 键 词：酸性气管线 弯头 冲蚀 

分 类 号：TQ050.9[化学工程]