平板回路型脉动热管启动阶段传热特性的试验研究

An experimental study on operating performance of flat-plate closed-loop pulsating heat pipe in start-up period

笔者搭建了平板回路型脉动热管可视化实验台对其启动特性进行试验研究。根据蒸发段与冷凝段之间的温差随时间的变化,将平板回路型脉动热管工作过程划分为启动、过渡和稳定工作3个阶段。试验结果表明:启动阶段传递的热量是显热;随着热负荷的增大,平板回路型脉动热管的启动时间逐渐缩短;最佳充灌率在50%左右,最佳倾斜角在50°~70°之间。工质的热物性对启动时间也有影响,λ越大,ρc越小,(d P/d T)sat越大,启动时间越短。

An experimental study on operating performance of a flat-plate closed loop pulsating heat pipe(FCLPHP)in start-up period was carried out.According to the change of temperature difference between evaporating section and condensing section with time,the working process of the FCLPHP could be divided into three periods:the start-up period,the transitional period and the stable working period.In the start-up period,heat exchanged is sensible heat.The influence of various operating parameters on the start-up time was investigated in detail.The experimental results show that the start-up time increases with the decrease of heat load,there is an optimal filling ratio 50%,and a best tilt angle existed between 50°and 70°.The greater the thermal diffusivity and the(dP/dT)sat,the shorter the start-up time is.