Condensation heat transfer coefficients of halogenated binary refrigerant mixtures on a smooth tube

Flow fields in shell-and-tube condensers: comparison of a pure refrigerant and a binary mixture

“…Belghazi et al [5,6] recorded a decrease in 30-50% in heat transfer coefficient for the mixture R23/R134a with the same explanation. Jung et al [7,8] measured heat transfer coefficients for the mixture R407C on a single smooth, horizontal tube, and found up to 50% lower heat transfer coefficients than for R22. Gabrielii and Vamling [9] studied R22 and three mixtures in a full-scale condenser, and found a decrease of up to 70% in heat transfer for the mixtures.…”

“…It is not only important to investigate the heat transfer coefficient on the first tube or the progress in a perfect, rectangular tube bundle, which has been done by many researchers experimentally [3][4][5][6][7][8], but it is also important to see what effects the gliding temperature difference and the mass transfer resistances can have on the flow field and on the condensation process in a geometry similar to that in real condensers, and vice versa. It will also be investigated whether a simple modification of the design has an influence on the rate of condensation for the mixture.…”