| Title |
Convective Boiling Two-phase Flow in Trapezoidal Microchannels：Part 2-Heat Transfer Characteristics |
| Authors |
김병주(Byong Joo Kim) ; 김건일(Geonil Kim) |
| Keywords |
유동비등 열전달 ; 미세유로 ; 건도 ; 비등 수 ; 마티넬리 변수 Flow boiling heat transfer ; Microchannels ; Quality ; Boiling number ; Martinelli parameter |
| 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 m of bottom width, 800 m of depth, 3.6o of sidewall angle, and 7 cm of length. Tests were performed with R113 over a mass velocity range of 150～920 kg/m2s, heat flux of 10～100 kW/m2 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. |