Investigation on Flow Condensation of Refrigerant in Annulus of Smooth and Enhanced Tube-in-Tube Heat Exchanger
An experimental investigation of R22 and R410A condensation outside the 1EHT and herringbone tubes have been published online at:
http://link.springer.com/article/10.1007/s00231-018-2406-3
The herringbone tube has a fin root diameter of 11.43 mm, a helical angle of 21.3 °, 48 fins with a fin height of 0.262 mm and an apex angle of 36 °; the 1EHT tube has an inner diameter of 11.5 mm with a dimple enhancement; while the smooth tube has an inner diameter of 11.43 mm; and all the tubes have an outer diameter of 12.7 mm. Experiments were performed for a constant saturation temperature of 45°C; with a constant inlet vapor quality of 0.8 and a constant outlet vapor quality of 0.1; for a mass flux ranging from 5 kg/(m2 s) to 250 kg/(m2 s).
