加氢裂化装置换热管泄漏分析

Analysis of Leaking of Heat Exchanger Tubes in Hydrocracking Unit

介绍了加氢裂化装置热高分气/冷低分油换热器E1006爆管情况,结合该换热器管壳层工作条件,利用宏观形貌分析、材质及力学性能分析、强度计算及涡流检测等方法对爆管位置样品进行了分析研究。结果表明:换热管外壁结垢引发的垢下腐蚀是导致换热管束爆管泄漏的主要原因。并通过对腐蚀机理的分析,确立了爆管失效的主要部位和可能存在的风险区,及时采取了有针对性的预防性堵管措施,大大缩短了检修周期,避免了材质的盲目升级,已连续安全运行近两年,节省投资费用近百万,保证了装置安稳长周期运行。

The rupture of tubes of heat exchanger E1006 of hot HP gas/cold LP oil heat exchanger in the hydrocracking unit is introduced. The ruptured samples are analyzed and studied based upon the operating conditions of the shell side and tube side of the heat exchanger by macro - morphology analysis, metallurgy and mechanical performance analysis, strength calculation and eddy current testing. The results show that the under - deposit corrosion caused by the fouling on the external wall of heat exchanger tubes is the culprit of rupture and leaking of＂ tubes. The analysis of corrosion mechanisms has confirmed the main locations of tube rupture and possible risk area. The timely and effective preventive tube blocking measures taken have greatly shortened the mainteuance cycle and minimized the material upgrading. The heat exchangers have been operating safely and stably for 2 years, and about one million Yuan （RMB） of investment has been saved.