超薄交替变径通道平板脉动热管的传热特性

Heat transfer characteristics of ultra-thin flat-plate oscillating heat pipes with dual-diameter channels

采用印刷电路工艺,设计制作了厚度为1.00 mm的铜基平板脉动热管.宽度分别为1.00和2.20 mm的通道在平板脉动热管内交替排布,宽通道底部为刻蚀有平行微槽的阵列结构.以HFE-7100为工质,在充液率为30%~50%条件下,对有、无微槽结构的交替变径通道平板脉动热管的启动和传热性能开展比较研究.研究结果表明:平板脉动热管在水平和竖直放置时均可以正常启动,且实现稳定运行,引入微槽结构可以显著改善脉动热管的启动和传热性能,降低蒸发段温度,并增强其抗重力性能;在加热功率为24 W、充液率为30%条件下,超薄脉动热管分别呈水平和竖直放置时,其等效导热系数可分别达到1241和1226 W/(m·℃),比无微槽脉动热管分别提高25.6%和18.7%,能够较好满足部分芯片器件散热冷却的需要.

The copper-based flat-plate oscillating heat pipes(FPOHPs)with thickness of 1.00 mm were designed and fabricated by printed circuit technology.The dual-diameter channels in the FPOHP with two neighboring channel widths of 1.00 and 2.20 mm were arranged,respectively.At the bottom of each wider channel,the parallel microgroove structures were respectively wet-etched.HFE-7100 was used as working fluid,and the start-up and the heat transfer performance of ultra-thin FPOHPs with/without micro grooves were compared at different filling ratios ranging from 30%to 50%.The experimental results show that the FPOHPs with/without micro grooves can start up and operate stably at both horizontal and vertical orientations,and the addition of microgroove structures can significantly enhance the FPOHP performance and lower the evaporator temperatures.The gravity independence of the FPOHP is improved after using microgroove structures.For the power input of 24 W,the effective thermal conductivities of the micro-grooved FP0HP at 30%filling ratio are respective 1241 and 1226 W/(m.℃)at horizontal and vertical orientations,which are increased by 25.6%and 18.7%as compared with those without micro grooves.The ultra-thin printed circuit FPOHP can largely meet the demand of electronic chip cooling.