Analysis on Corrosion Failure of Air Cooler of Hot Low - Pressure Separator for Diesel Upgrading Unit

• Published in: Cai liao bao hu Vol. 55; no. 11; pp. 203 - 208
• Main Author: ZHANG Dongling, LIU Bingyan, YAN Zhenxing, WANG Lida, NIU Xing, HAO Anfeng, LIU Guichang
• Format: Journal Article
• Language: Chinese
• Published: Editorial Department of Materials Protection 01.11.2022
• Subjects: diesel upgrading unit|air cooler of hot low - pressure separator|dew point corrosion|failure
• ISSN: 1001-1560
• DOI: 10.16577/j.issn.1001-1560.2022.0330

The spiral heat exchange tube made by 15CrMo stainless steel suffered from obvious leakage failure during service period at the air cooler of hot low - pressure separator for diesel upgrading unit. Corrosion causes of the air cooler were investigated by analyzing the composition of substrate and corrosion products and CFD simulation analysis. Research result showed that the corrosion failure of the spiral tubes was mainly caused by the direct contact between the spiral tubes due to thermal expansion during the service period of the air cooler, and the heat conduction between heat exchange tubes occurred, which changed the temperature distribution of the wall surface, causing local supercooling of the wall surface at the contact point. Finally, the sudden cooling of high - temperature fluid in the tubes caused condensation, causing dew point corrosion failure. Based on the above corrosion cause, corresponding protective recommendations were put forward.