脉动热管的传热极限特性

Characteristics of Heat Transfer Limit in Pulsating Heat Pipe

以蒸馏水和丙酮为工质,对多种工况下脉动热管的传热极限进行了实验研究.在分析脉动热管加热段和冷却段温度变化的基础上,归纳出了整体干涸型和局部干涸型2种传热极限的表现形式;分析了其产生机理:干涸导致传热极限的产生,再湿润引起传热极限表现形式不同.研究还发现,传热极限随着倾角、充液率的增加而增大;在倾角为0°时,热管工质为水时的传热极限低于工质为丙酮时的传热极限,在60°时,前者的传热极限却高于后者.

The pulsating heat pipe （PHP） filled with working fluids of distilled water and acetone was experimentally investigated. The characteristics of heat transfer limit of the PHP were analyzed on the basis of experimental data in multi-operating conditions. Based on the temperature oscillations of heating section and cooling section, the heat transfer limit of the PHP was classified into two models： the whole dryout and the local dryout. The mechanism was analyzed： dryout leads to the heat transfer limit, and the rewetting induces different manifestation of heat transfer limit. The results also show that the heat transfer limit of the PHP increases with the increasing of the inclination angle and the filling rate; when the inclination angle is 0°, its heat transfer limit for water as working fluid is lower than that for acetone, while the opposite result is found when the inclination angle is 60°.