中文摘要：

设计并搭建了以R134a为工质的微通道散热及可视化实验台。对R134a在不同饱和温度、流速、热流密度条件下流经微通道产生过冷沸腾状态时的换热性能进行了实验研究。研究了壁面过热度,质量流速对热沉换热系数和压降的影响,通过结果分析,将整得换热区域分为单相对流、过冷沸腾、饱和沸腾三个区域。并采用基于高速摄像机的可视化技术对微通道内气泡运动状态进行了分析。

英文摘要：

Experiments are conducted to investigate the subcooled boiling heat transfer and flow characteristics of R134 a in microchannel heat sink.The experiment is aimed at investgating the effects of saturation,mass flux,and subcooling degree on subcooled boiling heat transfer and flow characteristics.The influences of superheating degree and mass velocity on the boiling curve,heat transfer coefficient and pressure drop are investigated.On the basis of the analysis for the flow and heat transfer characteristics,the heat transfer coefficient curves are divided into three parts namely single phase,subcooled boiling and saturated boiling.Flow visualizations are performed by using a high-speed digital video camera to observe bubbles flow characteristics.