常减压装置常压塔顶空冷腐蚀与防护研究

Corrosion&Protection of Atmospheric Overhead Air Cooler in Crude Distillation Unit

针对某公司常减压蒸馏装置常顶空冷A-102腐蚀泄漏问题,通过常顶空冷泄漏特点分析、空冷配管结构分析及空冷冷凝水分析,找出了造成常顶空冷腐蚀泄漏的原因。结果表明,常顶空冷A-102配管为非对称结构,偏流严重,导致气液相分布严重不均,使A-102/5~8处于酸性环境中遭受严重腐蚀,导致了腐蚀泄漏。同时发现,对于非对称空冷系统,简单监测常顶回流罐冷凝水并不能真正反映各空冷的腐蚀状况,并提出了在A-102/5~8入口分别加注中和缓蚀剂、注水的防腐建议及监测各片空冷出口冷凝水的监测方案。建议实施后,各片空冷出口冷凝水pH值和铁离子的合格率均高达100%,有效减缓了A-102/5~8的腐蚀泄漏,延长了常顶空冷的使用寿命。

By analyzing leakage feature of the air cooler,the structure of air cooling piping,and the condensate water of the air coolers,the corrosion cause of atmospheric overhead air cooler was analyzed.The result shows that dissymmetric structure of the air cooling piping cause deflection&distribution of atmospheric oil&gas into the air cooler,and make A-102/5~8 into severe acidic corrosion environment.So the corrosion leakage of A-102/5~8 is caused by the severe acidic corrosion environment.At the same time,the anti-corrosion suggestion of injecting water&inhibitor in A-102/5~8 respectively is proved effective in mitigating the corrosion of the atmospheric overhead air cooler.