Falling film and spray evaporation enhancement using an applied electric field

The effect of an electric field on the falling-film evaporation of refriger ant R-134a on a vertical plate and three commercially available tubes was i nvestigated experimentally. The plate test section was 25.4 mm wide and 76. 2 mm long, and each tube test section was 19 mm in diameter and 140 mm long . Experiments were conducted in both falling film and spray evaporation mod es. The effects of various parameters such as heat flux, refrigerant flow r ate, electrode gap, and applied voltage were investigated It was Sound that in the presence of an applied electric field, the maximum enhancement in t he heat transfer coefficient for both falling film and spray evaporation mo des on a plate was nearly the same. A maximum enhancement of fourfold in th e heat transfer coefficient with the plate, 90 percent with the smooth tube , 110 percent with the Turbo BIII, and 30 percent with 19 fpi tube were obt ained The electrohydrodynamic power consumption in all cases was less than 0.12 percent of the total energy exchange rate in the test section.