A comparison of the flow characteristics of refrigerants flowing through adiabatic capillary tubes

This paper presents theoretical comparison of the flow characteristics of many pairs of refrigerants flowing through adiabatic capillary tubes. The two-phase flow model developed was based on homogeneous flow assumption. Two-phase friction factor was determined from Colebrook correlation. The viscosity model was also based on the recommendations from the previous literature. For all pairs, numerical results showed that the traditional refrigerants consistently gave lower pressure drops for both single-phase and two-phase flow than the environmentally acceptable alternative refrigerants which resulted in longer tube lengths.