Cooling Components with Boiling Halocarbons

One of the most effective ways to dissipate power from a surface is by direct~contact heat transfer to a boiling liquid; that is, by evaporative cooling. High flux density can be obtained at moderate temperature differentials, as much as 100 to 300 kW/m
²
at about 30 degrees with halocarbons. This liquid cooling method has been used successfully to increase the packaging density of components in electric equipment and to reduce operating temperature. Performance characteristics are described for several cooling systems in which heat-generating components are submerged by liquid dielectrics circulating in free convection. Empirical equations for estimating component-liquid heat flux are recommended, and thermal considerations in the design of packages are discussed.