摘要
冷凝器管束在运行过程中会发生腐蚀穿孔。以某石化企业的闪蒸塔顶气冷凝器作为研究对象,其中管程介质为循环水,壳程介质为闪蒸塔顶气,通过化学成分分析、宏观形貌观察、微观形貌分析、能谱分析、X射线荧光分析等方法,研究管束失效机理。结果表明:因循环水中氧含量较高,管束内壁较易发生溶解氧腐蚀。同时,由于循环水流速较低、浊度较高,管束内壁发生结垢,并促使水中微生物大量繁殖产生黏泥垢;垢层内外会存在氧浓度差腐蚀电池,管束内壁因而发生垢下腐蚀并形成垢下闭塞区;氯离子和硫离子则在闭塞区富集加速垢下腐蚀,最终造成管束局部腐蚀穿孔。为了防止管束发生腐蚀失效,需要采用耐蚀性能更好的材料,并加强循环水系统管理。
The condenser tube bundles generated corrosion perforation during operating.The flash tower top gas condenser of a petrochemical enterprise was taken as the research object,in which the tube side medium was circulating water and the shell side medium was flash tower top gas.The failure mechanism of the tube bundle was researched by chemical composition analysis,macroscopic morphology inspection,micro morphology analysis,energy diffraction spetroscope analysis(EDS)and X-ray fluorescence analysis(XRF),etc.The results show that the dissolved oxygen corrosion occurs on the inner surface of the tube bundle due to the high oxygen content in the circulating water.At the same time,fouling takes place in the tube owing to the low flow rate and high turbidity of the circulating water,which promotes a large number of microorganisms in the water to produce slime scale.There is an oxygen concentration difference corrosion cell inside and outside of the fouling layer,so the tube bundle corrodes in the inner surface and forms an occlusion area under the fouling.The chloride and sulfur ion accumulate in the occlusion area to accelerate under-deposit corrosion,and eventually lead to localized corrosion perforation of the tube bundle.It is suggested that the material with better corrosion resistance should be used,and the circulating water system management should be strengthened to prevent corrosion failure of the tube bundles.
作者
林冠堂
黄思
陈建勋
张聪
杨宁祥
LIN Guantang;HUANG Si;CHEN Jianxun;ZHANG Cong;YANG Ningxiang(Guangdong Institute of Special Equipment Inspection and Research Zhuhai Branch,Zhuhai 519002,China;School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510641,China)
出处
《重庆理工大学学报（自然科学）》
CAS
北大核心
2020年第9期152-158,共7页
Journal of Chongqing University of Technology：Natural Science
基金
国家自然科学基金项目(21878102)
广东省特种设备检测研究院科技项目(2020CY11)。
关键词
冷凝器管束
腐蚀穿孔
失效分析
耐蚀材料
condenser tube bundle
corrosion perforation
failure analysis
corrosion resistant materials
