铜纤维多孔表面孔结构对池沸腾换热性能的影响

The influence of Cu fiber porous surface structure on boiling heat transfer

摘要:

本文分别以30 μm、50 μm、100 μm和160 μm四种直径的紫铜纤维毡与紫铜基板构成的多孔材料为研究对象，针对紫铜纤维毡孔隙度分别为90%、80%和75%下，四种直径的纤维多孔材料池沸腾换热性能进行了检测，并与紫铜基板池沸腾换热性能进行对比。研究结果表明：紫铜纤维多孔材料具有良好的强化池沸腾换热性能，当过热度ΔT <20oC时，紫铜纤维多孔材料换热性能是紫铜基板换热性能的2~5倍；当紫铜纤维毡孔隙度为90%时，多孔材料的换热性能随着纤维直径的减小而增强；当纤维直径为160μm时，多孔材料的换热性能随着纤维毡孔隙度的减小而增强。紫铜纤维多孔材料池沸腾换热性能受多孔材料内部汽化核心数目、汽泡溢出阻力和毛细吸力等多种因素的影响。因此，在不同的工作条件下，纤维多孔材料具有不同的最佳孔结构参数。

Abstract:

In this paper, the pool boiling heat transfer performances of copper fiber porous materials which were composited with four different fiber diameters (i.e 30μm, 50μm, 100μm and 160μm) and copper plane plate were investigated under the atmospheric pressure. The experiment results show that the heat transfer performances of the copper fiber porous materials with the porosity of 90%, 80% and 75% are much better than that of the Cu plane plate when the superheat is below 20oC. The heat transfer performance of the copper fiber porous materials is enhanced as decreasing the fiber diameter when the porosity of copper fiber felt was 90%. When the fiber diameter is 160μm, the heat transfer performance is enhanced as decreasing porosity of copper fiber felt. There are many factors which can affect the pool boiling heat transfer, such as the number of active evaporation core, the resistance of bubble overflow and the fiber capillary attraction, and so on. Then, there should be different optimal pore structures under different working conditions.