Heat transfer and flow distribution in a multichannel microcondenser working at low mass fluxes

An experimental study of convective condensation in a multichannel microcondenser cooled by air was conducted. A specific procedure was developed to determine the local boundary conditions at the external walls of the channels, using laser-induced fluorescence. An energy balance indicated the phase change mainly occurred in the annular zone developing in the entrance region of the channels. Thanks to this property, flow distribution in the channels was determined for various flow rates. Analyses of these flow distributions highlight the important role of phase distribution in the collector, and that the hydrodynamic coupling between the channels does not significantly affect the flow regime transition.