BFe30-1-1铜镍海水冷却器管侧泄漏原因分析

An analysis of the leakage problem on the tube side of a BFe30-1-1 cupronickel seawater cooler

渤海某浮式生产储油装置工艺系统BFe30-1-1铜镍海水冷却器在使用过程中发生了管侧泄漏问题。从材质、焊接性能、海水水质、运行状况及腐蚀机理等方面,系统地分析了冷却器发生管侧泄漏的原因,并提出了预防措施。海水点蚀和冲刷腐蚀的共同作用是导致冷却器换热管管端及焊缝区域腐蚀的主要原因,管侧大量海生物随机堵塞换热管所产生的不稳定液体强力冲击是导致浮头密封面失效的主要原因。建议采用TA2等耐腐蚀和耐冲刷材料的换热管,采用复层开槽的胀焊结构连接换热管与管板,并根据实际运行情况灵活控制冷却器管束的清洗周期,密切监视冷却器海水侧的压降变化,合理调节电解铀装置开度。

The leakage problem happened at the tube side of a BFe30-1-1 seawater cooler during tis operation on a FPSO in Bohai sea.The causes of the leakage have been analyzed systematically from the factors of materials,welding performance,seawater quality,operating conditions and corrosion mechanism,etc.and the prevention measures have been presented.It is found that the corrosion of the cooler heat exchange tubes and weld zone is caused mainly by the combined action of seawater pit corrosion and scouring,and the failure of the floating-head sealing face is caused mainly by the unstable liquid shock resulting from the random clogging of great quantity of marine organisms in heat exchange tubes.It is recommended to use heat exchange tubes made by corrosion and scouring resistant material,such as TA2,etc.,and to adopt the double-layer slotted expansion welding to connect the heat exchange tubes and tube plates.Moreover,a flexible washing cycle of cooler tube banks should be used depending on actual operating conditions and the pressure-drop changes at the seawater side of the cooler should be monitored closely,thereby to regulate the openness of the electrolysis uranium device rationally.