管壳式换热器换热管的泄漏失效原因  

Failure Reason of the Tube Leakage in Shell and Tube Heat Exchanger

作　　者：张玉福 苏厚德[1,2,3] 沈溃领 黄超鹏[1,2] 余建永 赵昕 ZHANG Yufu;SU Houde;SHEN Kuiling;HUANG Chaopeng;YU Jianyong;ZHAO Xin(Shanghai Lanbin Petrochemical Equipment Co.,Ltd.,Shanghai 201518,China;Machinery Industry Shanghai Lanya Petrochemical Equipment Inspection Institute Co.,Ltd.,Shanghai 201518,China;Lanpec Technologies Limited,Lanzhou 730070,China;College of New Energy,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]上海蓝滨石化设备有限责任公司,上海201518 [2]机械工业上海蓝亚石化设备检测所有限公司,上海201518 [3]甘肃蓝科石化高新装备股份有限公司,兰州730070 [4]中国石油大学(华东)新能源学院,青岛266580

出　　处：《腐蚀与防护》2023年第1期97-101,共5页Corrosion & Protection

基　　金：2018年产业技术基础公共服务能力提升和行业质量共性技术推广项目(CMIF-ZHL-20190102-S001)。

摘　　要：某管壳式换热器在运行过程中发生了换热管泄漏现象,导致换热器失效。为防止此类事件再次发生,采用化学成分分析、微观形貌观察,腐蚀产物分析等手段对换热管失效的原因进行了全面研究。结果表明:换热管的C含量偏低,外壁出现了脱碳现象,脱碳层厚度约362μm。换热管内壁和腐蚀坑内覆盖着大量絮状腐蚀产物,其Fe、O、S、C元素含量较高,腐蚀产物主要由铁的氧化物(Fe_(3)O_(4)和Fe_(2)O_(3))、铁的硫化物(FeS和FeS2)、铁的硫酸盐[Fe_(2)(SO_(4))3]和碳酸盐(FeCO_(3))组成。认为是换热管在H2S和CO_(2)的协同作用下引起了局部腐蚀破坏,H2S破坏了换热管表面的FeCO_(3)产物膜,造成换热管局部区域形成了腐蚀电池,导致腐蚀破坏的发生。Leakage happebed on the tube in a shell-tube type heat exchanger during operation,which led to the failure of the heat exchanger.In order to prevent such event,chemical composition analysis,microscopic morphology observation and corrosion product analysis were used to comprehensively study the causes of heat exchange tube failure.The results showed that the content of C in the heat exchange tube was low,decarburization occured on the outer wall,and the thickness of decarburization layer was about 362μm.The inner wall of the heat exchange tube and the corrosion pit were covered with a large number of flocculent corrosion products,which contained high content of Fe,O,S and C elements.The corrosion products were mainly composed of iron oxides(Fe_(3)O_(4)and Fe_(2)O_(3)),iron sulfides(FeS and FeS2),iron sulfates[Fe_(2)(SO_(4))3]and carbonates(FeCO_(3)).It was consideered that,under the synergetic effect of H2S and CO_(2),localized corrosion damage happened on the heat exchange tube.H2S had damaged the FeCO_(3)product film on the surface of the heat exchange tube,resulting in the formation of corrosion cells in localized areas of the heat exchange tube,leading to corrosion damage.

关 键 词：管壳式换热器 富/贫硫甲醇 局部腐蚀 CO_(2)腐蚀 

分 类 号：TG179[金属学及工艺—金属表面处理]