A numerical study on the thermal hydraulic performance of finned elliptical tube with wet air flowing around

Abstract

Energy conservation is a key concern for countries around the world. Enhanced heat exchange is one of the important ways to save energy. The heat transfer process of wet gas is a special heat transfer process, accompanied by a mass transfer phenomenon. Improving the thermal hydraulic performance of wet gas can greatly improve the energy utilization rate. The thermal hydraulic characteristic of finned elliptical tubes with different elliptical axis ratios (0.9 to 0.5) was numerically studied under wet air conditions. Chilton & Colburn factor was chosen as assessment parameters for the thermal performance. The mass transfer effect was characterized by a dehumidifying coefficient. The flow resistance coefficient was adopted to judge the flow characteristic and the London area goodness factor was evaluated for the overall performance. The simulations indicated the superior performance of the finned elliptical tube, j factor of the finned elliptical tube was greater and the flow resistance coefficient was less than that of the finned circular tube. Comparison between different finned elliptical tubes showed that the JF factor increased with the decrease of the elliptical axis ratio. Under the same inlet conditions, the JF factor increases by approximately 50% as the elliptical axis ratio changed from 1 to 0.5.