Experimental Investigation of Heat Transfer and Flow Characteristics in Different Inlet Subcooled Flow Boiling in Microchannel

Abstract

The current experimental study considered the heat transfer and pressure drop for subcooled flow boiling of deionized water in a microchannel heat sink. The heat sink consisted of a single microchannel, 300μm wide and 300μm in height with a hydraulic diameter of 300μm. The heat sink was formed of oxygen-free cooper with 72mm length and 12mm width. Experimental operation conditions spanned the heat flux 78-800 kW/m2, mass flux 1700 and 2100kg/m2.s and at 21, 31 K subcooled inlet temperature. Boiling heat transfer coefficient was measured and compared with existing correlations. Also, the experimental pressure drop was measured and compared with micro scale pressure drop correlations. The results show that higher mass flux leads to a higher boiling heat transfer coefficient and the dominant mechanism is convective boiling. Also, the experimental pressure drop decreases with increasing heat flux in a single phase region, while it increases in a two-phase region. The heat transfer coefficient increase with increasing the inlet subcooled. When compared the experimental results in the experimental condition range, it was found that an existing correlation provides satisfactory prediction of heat transfer coefficient and pressure drop.