薄层多孔层内池沸腾时回液特性

Pool-boiling liquid backflow characteristics in thin porous coatings

多孔介质可以强化相变传热,被广泛应用到电子器件散热中。热管依靠毛细芯孔隙内沸腾和凝结形成热质快速迁移的驱动,实现高密度和高效传热。薄层多孔层内沸腾时液体回流特性研究对提高热管传热效率、热流密度及寿命意义重大。通过不同多孔介质在不同液位下的池沸腾实验,获得了薄层多孔表面在较高热流密度下沸腾时的气泡特性和沸腾曲线,并结合毛细理论分析多孔表面的回液特性。实验结果表明,高热流密度下毛细回流占主导作用,较小的有效毛细半径和较大的渗透率有利于液体回流。

Porous coatings are commonly used in electron device heat dissipation for enhancing heat transfer.Reling on working media fast movement because of boiling and condensing inside porous capillary core,heat pipe can realize high-desity and efficient heat transfer.Research on liquid backflow characteristics in thin porous coatings while boiling is significant to improve heat transfer efficient,heat dissipation flux,life.Pool-boiling experiments of different porous coatings in different liquid level were conducted to obtain bubble characteristics and boiling curve of thin porous coatings in high heat flux,and liquid backflow characteristics was analysed with the capillary theory.From the experiments results,liquid backflow mechanism in porous coatings may be understood and influential factors can be studied.Key wrods： porous coatings;pool boiling;bubble characteristics;boiling curve;liquid feedback