Critical Heat Loads in Boiling Heat Transfer from Porous Studs to FLUORINERT Liquid.

Abstract

The device considered in this paper is a porous stud having a net of microchannels, designed to enhance boiling heat transfer from the electronic component at the stud base to the pool of FC-72. The two-step approach was taken to clarify the effects of geometrical parameters on the critical heat load on the porous stud. In the first step, the attention was focused on the burn-out condition in a confined space, using a pair of thermal chips to simulate the geometry of microchannels. The data were obtained by changing the microchannel gap in a range of 0.1∼5mm; and based on these data, the correlation was derived for the critical heat flux vs. the microchannel size. In the second step, the heat conduction analysis was performed assuming the critical state at the stud base and using the experimentally determined correlations of boiling heat transfer for the rest of the stud zone. Finally, it is shown that there exist optimum sizes of microchannels that maximize the alowable heat load within a certain set of geometrical constraints.