Flow condensation heat transfer characteristics of R134a in multiport mini-channel by jet impingement cooling

Abstract

The flow condensation heat transfer of refrigerant R134a inside a multiport mini-channel having a hydraulic diameter of 0.63 mm is experimentally investigated in the present study by jet impingement cooling. Experiments were performed under the operating states of refrigerant vapor quality 0–1, heat flux 10–46 kW/m2, mass flux 115–290 kg/(m2·s), and saturation pressure 0.38–0.51 MPa. The effects of these factors on condensation heat transfer are quantitatively studied. The results indicate that the local heat transfer coefficient is seldom affected by the mass flux and vapor quality of the refrigerant but is closely related with heat flux and saturation pressure. The prediction accuracies of the existing correlations are assessed, and a new formula is proposed. This study on flow condensation heat transfer in a multiport mini-channel is meaningful for the investigation and design of a two-phase mini-channel condenser.