Experimental Analysis of Atypically Long Finned Oscillating Heat Pipe for Ventilation Waste Heat Recovery Application

Abstract

Oscillating heat pipes (OHP) which are constructed from a serpentine-arranged capillary tube possess a desirable aerodynamic form factor and provide for relatively high heat transfer rates via cyclic evaporation and condensation of an encapsulated working fluid with no internal wicking structure required. In last two decades, OHP has been extensively investigated for its potential application in thermal management of various applications. This study presents an experimental investigation on the heat transfer performance of an atypically long finned OHP. The heat transfer performance of the proposed OHP was analyzed and compared with a bare tube OHP with similar overall dimensions. Results show that a unit row of finned OHP filled with n-pentane with fill ratio of 70% can recover up to (400±40) W of heat from a typical waste exhaust air stream. The additional pressure drop due to fins was estimated to be (6.8±2) Pa resulting in an increase of 1–2 W of fan power consumption. The average heat recovery rate via finned OHP was found to be almost 80% more than bare tube OHP filled with same working fluid with same fill ratio.