Experimental Assessment of Heat Transfer Correlations for a Small-Scale Evaporative Condenser

Abstract

This work presents an experimental analysis of a small-scale evaporative condenser, performed on a calorimetric test facility, where heat transfer coefficients are measured and compared to some well-known correlations from the literature. The external flow of air and spray water ranged from 2.2 kg/min to 8.7 kg/min and 4.8 kg/min to 15.0 kg/min, respectively, keeping an average air to water ratio of approximately 1:2, followed by condensation temperatures ranging from 26 to 36°C. The flow pattern map is first determined, followed by the identification of the transition regions based on the void fraction concept. The overall heat transfer coefficient for the condensation zone calculated after the experimental data acquired in the present research was compared to six literature correlations, and the one developed by Tovaras, Bykov, and Gogolin in 1984 provided the better agreement. Local and mean values of the refrigerant heat transfer coefficients did not vary significantly for both single-phase superheated vapor and subcooling liquid. Results are still particular to the evaporative condenser assessed in the present work, and full-scale analysis must be performed in order to build more general correlations.