Effects of helical condenser coil designs on the heating process of the domestic refrigerator for hot water production: A numerical study

Abstract

Enhancement of heat transfer characteristics in helical condenser coils by modifying the coil shape has been reported by many researchers. While the influence of different types of condenser coil designs on the operating performance of refrigeration machines for hot water production unit is available in the literature, there exists no published numerical or experimental analysis of the impact of geometric parameter of immersed helical condenser coil on heat transfer characteristics and water velocity distribution during water heating process, which is the subject of our article. With using CFD methodology, a numerical study was carried out to present the water velocity distribution with varying coil parameters such as pipe diameter, tube pitch, and turns number. After validating the numerical model by the experimental ones, the effect of coil parameters on water velocity distribution was examined. The results confirm that by reducing the coil pitch and increasing the tube diameter, an increase of the water velocity and a higher natural convection is obtained. On the other hand, the results indicate that with reducing the turns number, the water velocity and the heat transfer coefficient is also increasing. Indeed, the average water velocity of condenser coil with N = 11 turns is higher than the other two condenser coil structures, which presents 21.34% and 63.56% higher than that of N = 13 turns and N = 15 turns, respectively. Thus, this investigation could provide some guidance to obtain the optimum condenser coil structure for water heating process.