AUGMENTATION OF R-113 IN-TUBE EVAPORATION WITH MICRO-FIN TUBES.

One of the most effective techniques for augmenting in-tube evaporation heat transfer in refrigeration and air conditioning systems is to use internally finned tubes. In this study, the effects of several geometrical parameters of micro-finned tubes were experimentally investigated for single-phase and evaporation heat transfer. Specifically, the geometrical parameters studied were peak shape, valley shape, fin height, number of fins, and spiral angle. Commercial refrigeration and air-conditioning tubes with 3/8 in (9. 52 mm) od were tested using refrigerant R-113 in a 39 in (1. 0 m) long test section. The mass velocity range was varied from 145,000 lbm/hr multiplied by (times) ft**2 (197 kg/s multiplied by (times) m**2) to 440,000 1bm/hr multiplied by (times) ft**2 (594 kg/s multiplied by (times) m**2) while the average quality over the test section varied from 0. 15 to 0. 85. The system pressure was maintained at about 35 psi (241 kPa).

AUGMENTATION OF R-113 IN-TUBE EVAPORATION WITH MICRO-FIN TUBES. Conference Paper