常减压蒸馏装置常顶系统的腐蚀与防护

随着加工原油劣质化程度的加重和开工周期的延长,设备的腐蚀必呈加剧趋势。中国石化上海石化股份有限公司8 Mt/a常减压蒸馏装置2005年2月投产至今,常顶系统的设备和管线出现了不同程度的腐蚀,常压塔上层塔盘、塔顶空冷器、塔顶油气管线均曾因腐蚀而失效。从原油性质、工艺防腐、材质使用情况等方面分析了腐蚀的主要原因,并试图通过及时调整"一脱三注"、改变空冷器管束内衬形式、使用复合搪瓷管件、运用在线监检技术等手段的来减缓设备管线的腐蚀,同时强调加强工艺防腐、提高材质等级、重视原油混配和开展监检测等工作的重要性。

Discussion over Corrosion and Protection of Overhead System of Atmospheric-vacuum Distillation Unit

Due to the aggravating degradation of the crude oil and the extension of the operation cycle, the corrosion of equipment in oil refineries is becoming increasingly serious. Different degrees of corrosion have occurred in the equipment and pipelines of overhead system since the 8.0 MM TPY atmospheric - vacuum distillation unit of Sinopec Shanghai Petrochemical Co. ,Ltd was put into operation in February, 2005. All of upper atmospheric tower trays, the overhead air cooler and the overhead oil and gas pipelines failed because of corrosion. The main causes of corrosion were analyzed in respect of crude oil properties, process corrosion prevention, material selection, etc. Various measures were tried to alleviate the corrosion of pipelines, including adjusting the techniques of ＂one removal and three injections＂ , improving the internal lining of the air cooler tubes, applying composite enamel fittings and adopting the on - line monitoring techniques, etc. In addition, strengthening the anti - corrosion performance of the process, upgrading materials and improving crude oil blending and strengthening corrosion detection are recommended to protect the unit from corrosion.