Simulation of two-phase refrigerant separation in horizontal T-junction

Abstract

This paper describes a 3D numerical simulation to model the two-phase separation of refrigerants in a horizontal run-type T-junction. The computations are based on the Eulerian method with the k-ε turbulence model. Compared with data from existing experiments and phenomenological models, the average deviation of the established model is less than 5% when the liquid mass flow rate ratio is in the range 0.2–0.6. The effect of multiple parameters on phase separation is investigated using the validated model. The results show that the inlet qualities (0.3–0.7), saturation temperatures (279.15–284.15 K), and working fluids of R22 and R134a have little influence on the phase separation at the T-junction, whereas the gas mass flow rate ratio increases with the increase in inlet mass flux (100–500 kg m−2 s−1). Furthermore, it is found that two symmetric recirculation regions occur directly after the junction at the entrance to the branch.