Phase behavior, refrigeration cycle, two phase flow, non-equilibrium, enthalpy
Vapor compression refrigeration system is usually designed such that refrigerant exits a condenser at subcooled liquid state in order not to cause possible damage to expansion devices. Even in small refrigeration systems incorporating capillary tube as an expansion device, the refrigerant is supposed to be subcooled before entering the expansion device. In this study, experimental apparatus equipped with several thermocouples, pressure transducers and visualization device was constructed in order to observe the behavior of refrigerant flow at condenser outlet of a vapor compression refrigeration system. Visual observation as well as temperature and pressure readings indicate the presence of two-phase flow at highly subcooled temperature. An alternative equation was suggested to calculate the enthalpy of the two-phase refrigerant in subcooled region and verification test was conducted.