Two-phase split of refrigerants at a T-junction

The present study experimentally investigated the two-phase flow split of refrigerants at a T-junction. As geometric parameters, the direction of the inlet or branch tube and the tube diameter ratio of branch to inlet tube were chosen. As inlet flow parameters, the inlet mass flux and quality were varied from 100 to 700 kg m−2 s−1 and from 0.1 to 0.9, respectively, for the condition of distribution header of a multi-pass evaporator in the general refrigeration system. All experiments were performed for R-22, R-134a, and R-410A. The measured data were compared with the values predicted by the models developed for air–water or steam–water mixture in the literature. We propose a modified model for application to the reduced T-junction and vertical orientation of tubes. Among the geometric parameters, the branch tube direction showed the largest sensitivity to the mass flow rate ratio for the gas phase, while the inlet quality showed the largest sensitivity to the mass flow rate ratio among the inlet flow parameters.