Abstract: The air preheater vibration and noise often occurs during operation in a SINOPEC refinery. FLUENT software was used to establish a mathematical model for simulating the flow field of shell side and analyzing the causes of vibration and to propose solutions. The results showed that a kamen vortex exists on the back of the air preheater tube bundle, and there are two large vortices in the bottom cavity. As soon as the vortex frequency is close to the inherent frequency of tube box, vibration and noise occur. The revamping plan was confirmed: increasing clapboard along the direction of the pipes in enamel pipe sectors, adding baffle in the bottom cavity and "well" shaped partition wall in the flue system. After revamping, the vibration and noise no longer occur.

Key words: air preheater, shell side, flow field, vibration