Two-phase flow pressure drop of R1234YF and R134A in a mini-channel multiport tube

Zusammenfassung

The use of micro- and mini-channels in heat exchanger has increased in recent decades. They contribute to increasing efficiency and compactness of heat exchangers and, also, to reduce refrigerant charge. The aim of this study is to experimentally determine single- and two-phase pressure drop in mini-channels with the new low GWP refrigerant R1234yf and compare it with the values provided by some of the correlations encountered in the existing literature.Two installations for the study of condensation and boiling processes have been constructed at Technical University of Cartagena. The more relevant results of two-phase pressure drop are presented in this paper. R1234yf was measured flowing through an aluminium square multiport tube with a hydraulic diameter of 1.17 mm and compared with R134a. The influence of saturation temperature (or pressure), flow velocity, and vapour quality in pressure drop have been studied. The values considered for these variables are: saturation pressure corresponding to 30, 35, 40, 45, and 50°C; flow velocities from 350 to 945 kg/(s·m2); vapour quality from 0.05 to 0.9.The paper presents a comparison between the obtained measured results in a multiport minichannel tube with the more extended and validated pressure drop correlations.