The Experimental Analysis of Subcooled and Saturated Flow Boiling for Dielectric Fluid FC-72 in Horizontal Microchannels
|關鍵字:||熱傳;流動沸騰;微小管道;FC--72;heat transfer;flow boiling;microchannel;FC-72|
This thesis experimentally investigated the boiling curve, heat transfer characteristics and critical heat flux of dielectric liquid FC-72 in horizontal microchannels. The experiments were carried out for mass flux at 320､425､530 and 635㎏/㎡s, and subcooled temperature at 3℃､6℃and 10℃.The resuls showed that the fluid inlet subcooled temperature has much more effects than mass flux on heat transfer characteristics in the regime of nucleate boiling. The lower subcooled temperature had the better heat transfer performance. On the contrary, in the saturated state, the measured results were far different from those in the subcooled state. The heat transfer coefficients increased with mass flux, except only at low mass flux 320 ㎏/㎡s where higher heat transfer coefficients were found. In this experiment, the critical heat flux was mainly affected by subcooled temperature, not mass flux. A modified correlation of heat transfer coefficients of subcooled flow boiling was developed,which could predict the heat transfer coefficient for this experiment within 15% band of deviation.