非对称微通道平板脉动热管的变工况实验研究

Experimental Study of Non-Symmetry Micro Channel Flat Plate Pulsating Heat Pipe Under Variable Conditions

为解决小型化电子器件的高效散热和脉动热管难于水平运行的问题,文中设计了非对称微通道平板脉动热管(NCPHP)并搭建了其传热性能实验平台。在非对称通道的结构设计下,通过控制不同倾角、充液率和冷却水温度的方法,探究了NCPHP的运行特性。结果表明:在30%及50%充液率下,NCPHP的热阻对倾角的变化较为敏感,30%充液率下NCPHP发生了烧干现象,50%充液率下NCPHP可以在倾角为-5°和0°时达到较低的热阻值,分别为0.622和0.545 K/W;NCPHP的最小热阻值出现在60°倾角和50%充液率条件下,为0.415 K/W;在-5°倾角和50%充液率下,加热功率达到40 W时,NCPHP的蒸发段温度出现短时间内持续升高的现象,而加热功率为50 W时此现象消失并转变为平稳波动的脉动特性;不同冷却水温度对稳态阶段NCPHP蒸发段平均温差的影响,随着加热功率的升高而降低;50%充液率下,NCPHP蒸发段温差从30 W时的5.1℃下降到60 W时的4.2℃;较低的冷却水温度能够延缓30%充液率下NCPHP烧干现象的发生。

In order to solve the problem of efficient heat dissipation of miniaturized electronic devices and the difficulty of horizontal operation of pulsating heat pipe,this study designed a non-symmetry micro-channel flat plate pulsating heat pipe(NCPHP)and built an experimental platform for its heat transfer performance.By controlling different incline angles,filling rate and cooling water temperature,the operation characteristics of NCPHP were investigated under the structure design of non-symmetry channel.The results show that the thermal resistance of NCPHP is sensitive to the change of incline angle at 30%and 50%filling rate,and the dry-out phenomenon of NCPHP is observed at 30%filling rate.At 50%filling rate,the thermal resistance of NCPHP can be as low as 0.622 and 0.545 K/W when incline angle is−5°and 0°,respectively.The minimum thermal resistance of NCPHP was 0.415 K/W when the incline angle is 60°and the filling rate is 50%.When the incline angle is−5°and the liquid filling rate is 50%,and the heating power reaches 40 W,the temperature in the evaporation section of NCPHP continues to rise in a short time,but this phenomenon disappears and changes into a stable and fluctuating characteristic when the heating power reaches 50 W.The influence of cooling water temperature on the average temperature difference in the evaporation section of NCPHP decreases with the increase of heating power.At 50%liquid filling rate,the temperature difference of NCPHP evaporation section decreases from 5.1℃at 30 W to 4.2℃at 60 W.Lower cooling water temperature can delay the dry-out phenomenon of 30%liquid filling rate.