FLOW BOILING IN MICROCHANNEL HEATSINK WITH WATER-ALCOHOL MIXTURES

摘要

In this study, the transport properties of the binary mixtures of water-methanol, water-ethanol and water-isopropanol systems are first derived to be used in a foundational heat sink parametric study. Subsequent analytical calculations for pressure drop and thermal properties were conducted on a silicon heatsink with a base of 15 mm x 15 mm, fins of 500 μm thickness are separated by microchannels of l00μm width and height, with a heat flux of 100 W/cm2 and a mass flow rate of 500 kg/m~2-s. In our studies, the results suggest that heat transfer near azeotropic point may not be the optimum conditions. It can be seen that wall temperature, T_w, for methanol and ethanol systems are much lower compared to just pure water. For isopropanol, above x = 0.5, the T_w is above that of pure water. Water-methanol system show decreasing T_w as the alcohol fraction is increased. Comparing the pressure drop, water-methanol system also has the lowest drop among the three binary mixtures.