Enhancement of the critical heat flux in saturated pool boiling using honeycomb porous media

Enhancement of the critical heat flux in pool boiling by the attachment of a honeycomb-structured porous plate on a heated surface is investigated experimentally using water under saturated boiling conditions. As the height of the honeycomb porous plate on the heated surface decreases, the CHF increases to 2.5 MW/m2, which is approximately 2.5 times that of a plain surface (1.0 MW/m2). Automatic liquid supply due to capillary action and reduction of the flow resistance for vapor escape due to the separation of liquid and vapor flow paths by the honeycomb-structure are verified to play an important role in the enhancement of the CHF. A simplified one-dimensional model for the capillary suction limit, in which the pressure drops due to liquid and vapor flow in the honeycomb porous plate balances the capillary force, is applied to predict the CHF. The calculated results are compared with the measured results.