Parametric Study on Thermal-Hydraulic Characteristics of H-Type Finned Tube Heat Exchangers

In this paper, the thermal-hydraulic characteristics of H-type finned tube banks are numerically investigated on the basis of a more accurate and convenient calculation method of fin efficiency for H-type fins. Experiments are performed to validate the numerical simulations. The variations of the Nusselt number, Euler number, and comprehensive factor j/f with the Reynolds number and seven geometric parameters of H-type finned tube banks are obtained. The results indicate that the Nusselt number is proportional to the Reynolds number, the slit width, the fin thickness, and the longitudinal tube pitch; but, it is inversely proportional to the tube row number, the fin height, and the spanwise tube pitch. As the Reynolds number, the tube row number, the slit width, the fin pitch, and the spanwise tube pitch increase, the Euler number decreases. The j/f factor rises with the increase of the slit width, and there exists an optimal tube row number (n=5) at which the j/f factor is the maximum. The correlations of the heat transfer (Nusselt number) and pressure drop (Euler number) of the 10-row H-type finned tube bank, which can nearly be considered to be fully developed, are presented. The numerical results and correlations have good applicability under different fluids and show good agreement with the experimental results and correlations.