사다리꼴 미세유로의 대류비등 2상유동：1부-압력강하 특성

Abstract

Characteristics of two-phase pressure drop 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. Pressure drops in convective boiling of Refrigerant 113 were measured in the range of inlet pressure 105～195 kPa, mass velocity 150～920 kg/m^2s, and heat flux 10～100 kW/m^2. The total pressure drop generally increased with increasing mass velocity and/or heat flux. Two-phase frictional pressure drop across the microchannels increased rapidly with exit quality and showed bigger gradient at higher mass velocity. A critical review of correlations in the literature suggested that existing correlations were not able to match the experimental results obtained for two-phase pressure drop associated with convective boiling in microchannels. A new correlation suitable for predicting two-phase friction multiplier was developed based on the separated flow model and showed good agreement with the experimental data.