A mathematical model of an adiabatic helical capillary tube used for R1234yf and R600a refrigerants

Abstract

This paper presents a mathematical model to simulate the effect of the coiling diameter, subcooling degree and internal diameter on the characteristics flow of the refrigerants R1234yf and R600a, flowing through an adiabatic helical capillary tube. The homogeneous flow model was developed in the two-phase region based on the fundamentals of conservation of mass, momentum and fluid energy in the capillary tube. To validate this model, a comparison with numerical data on helical capillary tubes obtained by previous investigators has been made. It was reported that the coiling diameter, the inner diameter and inlet temperature of the capillary tube significantly influence on the pressure drop and quality and temperature distribution of the refrigerants R1234yf and R600a flowing inside the adiabatic helical tube. To validate this model, a comparison with numerical data on helical capillary tubes obtained by previous investigators has been made. Finally, the outcomes obtained from the present model exhibit satisfactory agreement with the available numerical data of helical capillary tubes.