Vibration-Enhanced Heat Transfer Analysis and Improvement of Spiral Elastic Tube Heat Exchanger

Abstract

Using the fluid–solid coupling approach in fluid-induced vibration studies, the effect of flow-induced vibration on a heat exchanger is investigated. This paper analyzes the impact of flow parameters for shell fluid on heat transfer characteristics enhanced by the vibration of a spiral elastic tube bundle (SETB). Improvement schemes for heat exchangers are also proposed, and they are studied and compared. The results show that there is a positive correlation between the inlet velocity and the heat transfer coefficient of the SETB heat exchanger. As the inlet velocity rises to 0.9 from 0.3 m/s, the Nusselt number of the hollow SETB heat exchanger under vibration conditions is increased by 153.10, 45.55, and 26.73% sequentially. The vibration generated by impacting the elastic element during fluid flow can improve the Nusselt number effectively. As the flow velocity increases to 0.9 from 0.3 m/s, the flow-induced vibration enhances the Nusselt number of the hollow SETB heat exchanger by 2.13, 1.53, 1.05, and 0.89%. When the inlet flow velocity of fluid is in the range of 0.3–0.9 m/s, under the same flow velocity, same pressure drops, and same pumping power conditions, the performance of the improved heat exchanger is greater than that of the SETB heat exchanger before the structural improvement.