芳烃装置高位水冷器腐蚀问题分析

Corrosion Analysis on Watercooler of Aromatics Unit

对某石化分公司芳烃装置换热器运行和检修情况进行分析,发现该装置的高位循环水冷却换热器(水冷器)腐蚀泄漏问题严重。剖析了水冷器垢下腐蚀的机理,研究了腐蚀与循环水流速、温度的关系。分析结果表明:由于追求循环水较高的浓缩倍数致使水中盐含量升高,部分金属盐饱和析出形成污垢,污垢粘附在水冷器壁面引起垢下腐蚀;冷却塔填料结垢后破碎导致水冷器入口堵塞,降低水的流速,进一步加剧腐蚀,导致水冷器泄漏。减轻此类腐蚀的主要措施是工艺设备改造,提高水的流速,改善水质,加强水冷器的操作及检修管理。该文对存在类似问题的相关装置有一定借鉴意义。

Severe corrosion and leakage problems were found in watercooler by analyzing operation and heat exchanger of aromatics unit in Jilin petrochemical company. Under-deposit corrosion of watercooler relationships between corrosion and circulating water velocity, temperature were studied. The results showed that high concentration of circulating water resulted in high salt content, then dirt formed by saturated precipitation of metal salts in water, which caused under-deposit adhere to the wall of watercooler; breakage of cooling tower after scaling resulted in inlet clogging ofwatercooler,which reduced water flow,further intensified the corrosion and leakage of watercooler. Corrective measures weresuggested accordingly, such as technological transformation, increase of water velocity, improvement of water quality,reinforcement of operation and maintenance management of watercooler, which have reference significance for devices with similar problems.