原油储罐内腐蚀机理与防护

为了提高原油储罐的使用寿命，对储罐内不同部位的腐蚀机理进行了分析，并对现有防腐技术现场应用效果进行了评价。结果表明：沉降罐罐底局部腐蚀最为严重，以局部点蚀、坑蚀为主，腐蚀机理主要为电化学腐蚀和微生物腐蚀；罐顶气相空间腐蚀次之，以片状腐蚀为主，腐蚀机理主要为化学腐蚀；罐壁腐蚀程度相对较轻，以均匀腐蚀为主，腐蚀机理主要为电化学腐蚀。根据研究结果提出了相关防护措施：在储罐罐底及以上5 m位置采用EEC弹性环氧复合涂层+阴极保护装置相结合的防腐工艺；通过安装负压排泥装置、研究新型低温破乳剂等技术有效延长储罐服役寿命；进一步排除储罐渗漏等安全隐患，提高站库运行安全系数。

Corrosion Mechanism and Protection of Crude Oil Storage Tank

In order to improve the service life of crude oil storage tank, the corrosion mechanism of different parts in the storage tank is analyzed, and the application effect of existing anti-corrosion technology is evaluated. The results show that the local corrosion of the bottom plate of the settling tank is the most serious, mainly local pitting corrosion and pitting corrosion, and the corrosion mechanism is mainly electrochemical corrosion and microbial corrosion. The gas space corrosion of the tank top is more serious, and the corrosion mechanism is mainly chemical corrosion. The corrosion degree of tank wall is relatively light, and the main corrosion mechanism is electrochemical corrosion. According to the research results, some protective measures are put forward. The anticorrosion process of EEC+cathodic protection device is adopted at the bottom and 5 m above the bottom. The service life of the storage tank can be effectively extended by installing negative pressure sludge discharge device and researching new low temperature demulsifier. Further eliminate storage tank leakage and other safety hazards, improve the safety factor of station operation.