Pool boiling critical heat flux in dielectric liquids and nanofluids

Abstract

With the recent advances in consumer and power electronics, efficient thermal management of high heat flux components has taken on new urgency. While its inherent advantages have made air cooling the method of choice for the vast majority of electronic systems, the relatively poor thermophysical properties of air limit its ability to meet today's more demanding thermal requirements. Therefore, researchers have continued to investigate liquid cooling techniques such as microchannel forced convection, jet impingement, and pool boiling heat transfer. Although water has superior thermal properties, concern over its dielectric strength and chemical activity have directed attention to the use of the inert and dielectric perfluorocarbons as alternative cooling fluids, with particular emphasis on harnessing boiling and evaporative heat transfer processes. Passive pool boiling with these dielectric fluids, including the effects of subcooling, pressure, length scale, mixtures, surface enhancements, and nanoadditives, has been investigated by a large number of researchers. The present study focuses on the critical heat flux for pool boiling of these dielectric liquids, representing the upper limit of the nucleate pool boiling regime, and provides a review and summary of the work reported in more than 100 archival papers by research groups from around the globe.