Experimental measurements and theoretical prediction for the volumetric heat transfer coefficient of a three-phase direct contact condenser

The volumetric heat transfer coefficient of a three-phase direct contact heat transfer condenser has been investigated analytically and experimentally. The experiments were carried out utilising a column of 70 cm in total height and 4 cm inner diameter. The active column height throughout the experiments was taken to be equal to 48 cm. Vapour pentane with three different initial temperatures (40 degrees C, 43.5 degrees C and 47.5 degrees C) was used as a dispersed phase, while tap water at a constant temperature 19 degrees C was used as a continuous phase. The variation of the volumetric heat transfer coefficient along the height of the column was measured experimentally and predicted analytically. The effects of the initial dispersed phase temperature, the dispersed mass flow rate and the continuous mass flow rate on the volumetric heat transfer coefficient were tested. The results indicate that the volumetric heat transfer coefficient decreases upon moving up the column, while it increases with an increase in the mass flow rate of either the dispersed phase or the continuous phase. No considerable impact of the dispersed initial temperature on the volumetric heat transfer coefficient was observed under the experimental conditions considered here. Finally, an excellent agreement was achieved between the analytical model and the experimental results. (C) 2015 Elsevier Ltd. All rights reserved.