Heat Transfer Testing of Enhanced Finned-Tube Bundles Using the Single-Blow Technique

A single-blow test facility has been developed at the INEEL for pressure-drop and heat transfer performance testing of heat exchanger finned-tube bundles. Initial testing in the facility has been aimed at evaluating several enhanced heat transfer geometries to be used with individually finned tubes in which winglet vortex generators have been punched into the fin surfaces at specific locations. The winglets interact with the air flow to create longitudinal vortices that enhance fin-surface heat transfer performance with minimal increase in pressure drop. Results of two initial studies indicate heat transfer enhancement levels of 20–30% across the tested Reynolds number range (100–3000), with an increase in pressure drop of only 4–12%, over the same range.