Prediction of condensation characteristics of alternatives to R-502 insideair-refrigerant enhanced surface tubing

In this paper, an experimental study on the heat transfer characteristics o f two-phase flow condensation of alternative azeotropic refrigerant mixture s to R-502, on air/refrigerant horizontal enhanced surface tubing, is prese nted. The condensation data indicated that the heat transfer coefficient on the blend R-408A has the highest heat transfer rate among the blends under investigation. The condensation data also showed that R-502 and R-407B hav e similar heat transfer rates when plotted against the refrigerant mass flo w rate. It also can be observed that, as the mass flux increases, heat tran sfer coefficient increases. Correlations were proposed to predict the heat transfer characteristics such as average heat transfer coefficients, as wel l as pressure drops of alternatives to R-502; such as R507, R404A, R407B an d R408A in two-phase flow condensation inside enhanced surface tubing. In a ddition, proposed correlations were found to fairly. predict the two-phase flow brat transfer condensation data. (C) 1999 Elsevier Science Ltd. All ri ghts reserved.