An experimental study of heat transfer on a tube bank under frost formation conditions

Abstract

An experimental study of heat and mass transfer on a tube bank under frost formation conditions was conducted using a closed-loop wind tunnel. The tube bank was exposed to a controlled environment; surface temperature from −14∘C to −8∘C, relative humidity from 50% to 90%, air dry bulb temperature from 1 °C to 11 °C, average air velocity from 0.3 ms−1 to 1.0 ms−1, and Reynolds number from 518 to 1719. The results showed a non-uniform frost growth due to the air stream characteristics. When the Reynolds number increases a more uniform pattern becomes noticeable. The frost growth is more uniform on the last tube than on the first one, due to the aerodynamic differences. Sensible heat transfer has a greater impact on the total heat transfer, compared to latent heat transfer effect. The higher the frost layer growth the lower the frost deposition rate on the tubes.