G0610105 Influence of the direction of buoyancy force in the boiling with impinging flow using high-carbon alcohol aqueous solutions

Abstract

In recent years, with the technological advance of electronic device, increasing of heat emission and decreasing of surface area by downsizing have been challenging problems. Therefore, thermal efficiency and safety are more important than ever. We had applied high-carbon alcohol aqueous solution to boiling with impinging flow in mini channel to promote the boiling heat transfer. With three thermocouples which were inserted near the heat transfer surface, we calculated the heat flux and the temperature of the heat transfer surface by the temperature gradient obtained from them. The high-carbon alcohol aqueous solution realized higher dryout heat flux than others. In addition, the maximum value of CHF was found to be dependent on the concentration of the solutions. We investigated the flow velocity on the bubble and liquid interface with the numerical model which analyzed the Marangoni convection mechanism. In this model, butanol aqueous solution also indicated that the maximum value of the flow velocity existed for some concentration of the solutions. This suggested the relationship between the experiment and the numerical model in terms of maximum CHF.