Experimental investigation on flow boiling of HFE-7100 in a microchannel with pin fin array

Abstract

An experimental investigation on flow boiling heat transfer and pressure drop characteristics in a microchannel with an array of in-line circular pin fins was carried out. The tests with HFE-7100 as a working fluid were conducted at mass fluxes from 189 to 374 kg/m2∙s, inlet subcooling temperatures from 20.4 to 34.4 °C and effective heat fluxes from 17.4 to 239.3 kW/m2 near atmospheric pressure. The effects of mass flux, inlet subcooling temperature, heat flux and vapor quality were examined and analyzed. Flow visualization was also obtained during the experiments to explain the heat transfer mechanism. The boiling hysteresis was observed, which may be attributed to the low surface tension of HFE-7100. The experimental data were compared with various published data of dielectric fluorinated fluids, and many well-known correlations of pressure drop and two-phase heat transfer coefficient for pin–fin microchannels. The improved correlations of pressure drop and two-phase heat transfer were proposed, which demonstrated good predictions for both experimental data of the present and previous studies.