Experimental and computational investigation of the thermal performance of a vertical tube evaporative condenser

In the last few years, intense efforts have been devoted to the application of evaporative condensers in small residential refrigeration systems. In this work, a vertical tube evaporative condenser was designed to replace the finned tube-type air-cooled condenser in a commercially available household central air conditioner. Experimental and computational studies were conducted to investigate the thermal performance of the vertical tube evaporative condenser in the refrigeration system. The experimental results show that the COP (Coefficient of Performance) of the system increased by approximately 30%. Experimental correlations were developed from the experimental results for the proportion of wetted area and the water film heat transfer coefficient. The proportion of wetted area is a function of the water film Reynolds number and airflow Reynolds number, whereas the film heat transfer coefficient is a function of the water film Reynolds number and the Prandtl number. Moreover, a numerical model was presented to predict the thermal performance of the condenser, which provides insights into the intrinsic links between the operating condition and the relative heat transfer characteristics.