微細流路を通過する冷媒気液二相流の沸騰現象の可視化と伝熱評価

抄録

In order to reduce the amount of refrigerant charged in the refrigerator and to improve energy saving, heat exchangers are required to be compact and higher performance. The heat transfer between refrigerant and evaporator has been promoted by reducing the cross-sectional area of the refrigerant flow path. The purpose of this study is to promote heat transfer of an evaporator by changing the cross-sectional shape of the mini groove. The refrigerant R134a was visualized using a high-speed camera to observe the behavior of gas and liquid two phase flow under the recessed groove, U groove and V groove flow paths respectively. Moreover, the heat transfer coefficient was estimated to evaluate the correlation between flow and heat transfer characteristics. The result of this study indicates that the recessed groove has the best heat transfer coefficient.