Flow-Induced Vibration in Spiral Finned Gas Tube Bundle Heat Exchangers

Abstract

In the past finned tube bundle heat exchangers were often subject of severe damages due to flow-induced vibration followed by high amounts of loss for the operator. A case of practical importance is the design of spiral finned gas tube bundle heat exchangers that still have been investigated in literature only seldom. Both acoustic resonance and fluidelastic instability can lead to tube rupture within a short period of operation. In this paper analytic calculation methods for tube Eigenfrequencies are extended to spiral finned tubes. The results are in agreement with static and vibrational experiments. Stability criteria for fluidelastic instability are derived by flow channel experiments extending Connor’s equation to the design of spiral finned tube bundles. A number of cases of damage is described. The importance of correct damping values is demonstrated. The scheme reported in this paper is able to avoid damages in spiral finned tube bundle heat exchangers due to fluidelastic instability.