Parameters Optimization of Fin-and-Tube Heat Exchanger with a Novel Vortex Generator Fin by Taguchi Method

Abstract

In this study, the effects of various vortex generator configurations on the heat transfer and flow friction characteristics are investigated by numerical method. Compared with common-flow-down configuration, the Nusselt numbers of common-flow-up configuration increase by 2.7–2.9% in the range of studied Reynolds number, while the friction factors reduce by 7.8–10.0%. A comparative study of the effects of location of axial dimension, location of spanwise dimension, attack angle, and length and height of vortex generator on fin performance is conducted. The results show that the intensity of heat transfer can be greatly increased with decreasing the location and attack angle of vortex generator, and with increasing height of vortex generator, accompanying with the increase of pressure drop. The Nusselt number and friction factors first increase and then decrease with increasing length of vortex generator. The parameters of the vortex generator fin-and-tube heat exchanger are optimized by the Taguchi method. Sixteen kinds of models are made by compounding levels on each factor, and the heat transfer and flow friction characteristics of each model are analyzed. The results allow us to quantitatively estimate the various parameters affecting heat exchanger performance, and the main factors for optimal design of a heat exchanger are selected. The two optimal conditions are acquired, and the reproducibility of the results is verified by two analytical results.