Abstract: The production operation cycle of the gas-desalted water heat exchanger in a hydrogen production unit is required to be 4 years, but leakage occurred before the actual tube bundle had been operated for 4 years. This resulted in an unplanned shutdown of the unit and affected the long, safe, and stable operation of the related hydrogenation unit, and also caused a certain amount of economic loss. Shortly after the standby tube bundle replaced the leaky tube bundle and was restored to service, the standby bundle leaked again. In order to solve the above leakage problem and eliminate the hidden dangers, the leaky tube bundle was tested and analyzed, and the equipment and operation of similar hydrogen units were investigated. Finally, a modification plan was formulated in which the material of the tube bundle was kept unchanged, and only the structure and manufacture of the tube bundle were optimized and improved, together with the improvement of the process operation and control. The reformed tube bundle has been in good condition after being put into operation, and the problem of tube bundle leakage has been solved. The above modification plan can provide reference for similar devices and equipment with similar problems in engineering practice.

Key words: heat exchanger, stress corrosion cracking/SCC, vibration, tube bundle modification