Abstract:

Metal porous media which enables the gas and liquid separation is adopted to enhance heat transfer. Due to the different mechanical behavior between gas and liquid in the porous wall, the gas-liquid two-phase can be separated along the porous media insert, where gas cannot enter the porous wall and the liquid is free to flow in the center. Thus, the gas can flow along the tube wall and the liquid flow in the center of the tube, leading to a high heat transfer performance. Capillary force of the porous media has an important influence on the enhancement performance. In this paper, a novel capillary force testing method is used to test the capillary force of the metal porous media inserts. It is found that the capillary force of the porous media is associated with the powder material, particle size and the filling of the porosity. The particle shape is the most important factor affecting the capillary force and then the particle size, while the porosity is the weakest one.

Key words: capillary force, sintering, porous media, heat transfer, infrared thermograph

摘要：

气液分离强化传热多孔结构，由于气体、液体在多孔壁面有着不同的力学行为，使得气液两相在多孔壁面发生分离，气体不能进入多孔壁面结构，液体则能自由进入，从而形成气体始终沿管壁运动，液体则在管中心流动这一高效传热流态。多孔壁面的毛细力对气液分离有着重要的影响。采用一种新颖的毛细力测试方法——红外热像测试法测试了多孔强化结构的毛细力。研究发现，多孔结构的毛细力与使用的粉末材料形状、颗粒尺寸及填充孔隙率有关。其中对毛细力影响最大的是粉末颗粒形状，颗粒尺寸次之，孔隙率最弱。

关键词: 毛细力, 烧结, 多孔介质, 传热, 红外热像