사다리꼴 미세유로의 대류비등 2상유동：2부-열전달 특성

Abstract

Characteristics of flow boiling heat transfer in microchannels were investigated experimentally. The microchannels consisted of 9 parallel trapezoidal channels with each channel having 205 μm of bottom width, 800 μm of depth, 3.6˚ of sidewall angle, and 7 cm of length. Tests were performed with R113 over a mass velocity range of 150～920 kg/m^2s, heat flux of 10～100 kW/m^2 and inlet pressures of 105～195 kPa. Flow boiling heat transfer coefficient in microchannels was found to be dominated by heat-flux. However the effect of mass velocity was not significant. Contrary to macrochannel trends, the heat transfer coefficient was shown to decrease with increasing thermodynamic equilibrium quality. A new correlation suitable for predicting flow boiling heat transfer coefficient was developed based on the laminar single-phase heat transfer coefficient and the nucleate boiling dominant equation. Comparison with the experimental data showed good agreement.