乙烯装置TS-212粗苯反应换热器腐蚀失效分析与防护措施

Corrosion Failure Analysis and Protective Measures of Ethylene Unit TS-212 Crude Benzol Reaction Heat Exchanger

某乙烯装置TS-212粗苯反应换热器发生腐蚀泄漏,采取X射线衍射、能谱分析、扫描电镜等检测手段,对该管束进行了失效分析,结果表明,TS-212发生的腐蚀主要是由CO2+H2O腐蚀体系所引起的,而系统中存在的O2更加剧了这种腐蚀。另外,腐蚀速率受CO2分压、流速、温度、保护膜和溶液成分等诸多因素的影响,尤其是壳程湍流引发空泡腐蚀产生的冲刷和冲击作用加剧了腐蚀破坏作用。据此结论提出了系统的防治措施。

X-ray diffraction （XRD）, energy-dispersive spectroscopy （EDS） and scanning electronic microscopy （SEM） were used to analyze the corrosion and leakage reason of the ethylene unit TS-212 crude benzol reaction heat exchanger. The results show that the CO2 ＋ H2O corrosion system resulted in the corrosion failure of TS-212 heat exchanger, and O2 existing in this system accelerated the corrosion process. Factors such as partial pressure of CO2, velocity of flow, temperature, protective film, solution composition and so on affected the corrosive rate. A series of protective measures were proposed according to the above results of corrosion analysis.