Enhanced pool boiling of dielectric and highly wetting liquids - a review on enhancement mechanisms

Direct cooling with inert and hazards free dielectric liquids may well become the method of choice for thermal management of future electronic systems. Owing to the efficiency of phase-change process and the ease of natural circulation, pool boiling is of great interest for this application. The present review consolidates a large number of pool boiling experimental data for dielectric and other highly wetting liquids subject to engineered surfaces with elaborating the related augmentation mechanisms. Potential micro/nano engineered surfaces are categorized into one-dimensional (either CHF or HTC enhancing) and two-dimensional (both CHF and HTC) enhancement surfaces. The enhancement mechanisms along with the bubble dynamics of these enhanced surfaces are discussed briefly. Furthermore, a general classification of electronics coolants (dielectric, non-dielectric, and nanofluids) along with their thermophysical properties is made; especially the problems associated with the dielectric liquids are discussed. Finally, the potential mechanisms for higher HTCs and CHFs are identified.