Boiling heat transfer in narrow channels with offset strip fins: Application to electronic chipsets cooling

An experimental study on saturated flow boiling heat transfer of HFE-7100 in vertical rectangular channels with offset strip fins is presented. The experiments have been carried out at atmospheric pressure, over a wide range of vapour quality and heat fluxes up to 1.8 Â 105 W/m2. The local boiling heat transfer coefficient has been obtained from experiments and analysed by means of Chen superposition method. Some correlations for convective boiling and nucleate boiling heat transfer coefficients have been considered. A good agreement has been found with Feldman et al. [3] correlation for convective boiling heat transfer and Kim and Sohn [8] correlations for nucleate boiling heat transfer. A closed circuit for electronic chipsets cooling, with the same evaporator as that studied in the first part of the paper, has been studied. Thermal performances of this system have been measured and electronic chipsets cooling compared with those of a circuit with the same components but no internal fins in the evaporator. The results have shown that for high heat loads the inner geometry of evaporator does not influence the two- phase heat transfer. For low heat loads, offset strip fins evaporator gives better performances than no fins evaporator.