螺纹锁紧环式换热器内漏分析

Analysis of internal leakage of in thread ring block heat exchanger

针对胜利油田桩西精细化工有限责任公司12 kt稳定轻烃加工装置螺纹锁紧环换热器E-106的内漏问题,对螺纹锁紧环的结构特点及内漏原因进行了探讨,螺纹锁紧环换热器内漏的原因主要有:管程与壳程之间密封垫片损坏,换热管与管板焊口处存在缺陷或裂纹,管束存在腐蚀穿孔现象,管板壳程侧密封面存在缺陷,内部螺栓预紧力不够,由于设备长期处于高温高压状态运行,内部螺栓和管板垫片都有可能出现应力松弛,蠕变造成密封性能下降。通过分析并结合实际情况,发现稳定轻烃加工装置换热器E-106内漏的主要原因是管壳程垫片及管板密封面的损坏才导致换热器内漏。提出了发生内漏换热器E-106的修复方法,并总结了螺纹锁紧环式换热器安装使用过程中需要注意的事项。

The internal leaking problem of thread ring block heat exchangers E - 106 in a 12,000 TPY light hydrocarbon processing unit of Zhuangxi Chemical Co. , Ltd. of Shengli Oilfield was discussed, and the construction characteristics and leaking causes of thread ring block heat exchangers were analyzed. The main culprits of internal leakage were： damages of the seal between tube sheet and shell, existence of defects or cracks in welded joints of heat exchange tube and tube sheet, corrosion perforation in tube bundles, defects in seal surface of tube sheet and insufficient pre -tightening force on internal bolts. Under the long - term operation at high temperature and high pressure, the internal bolts and gasket of tube sheet would become loose and creep, which would reduce the sealing performance. The analysis found that the main causes of internal leakage of heat exchanger E - 106 were the damages to the sealing surface of the tube sheet and shell gasket. The repairing method of thread ring block heat exchangers E - 106 with internal leakage was recommended, and precautions in the process of installation and operation of thread ring block heat exchangers were summarized.