E111 Boiling Heat Transfer Characteristics in Rapid Heating for a Cold-Plate with Thermal Spray Coating

Abstract

This study deals with boiling heat transfer enhancement for a narrow channel by thermal spray coating. Aluminum powder was coated on the heating surface by vacuum plasma spraying. Wall superheats at the onset of boiling and steady condition were evaluated in flow boiling of R123 with inlet subcooling for mass fluxes of 125, 188, and 313kg/(m^2・s), inlet subcooling of 10, 15, and 20, and heat flux 62-365kW/m^2. The test channel with the channel gap of 2mm, channel width of 20mm, and heated length of 100mm was placed vertically and heated on one side by ceramic plate heaters. As the result, it was shown that the coating surface could make wall superheat at the onset of boiling lower and critical heat flux higher than a smooth surface.