关键词: 泡沫铜, 流动沸腾, 流动换热, 孔隙率, 孔密度

Abstract:

Using the deionized-water as the working fluid, both single-phase and two-phase heat dissipation systems for copper foams were designed. For low Re number, the copper foam sample with 80% porosity and 90PPI presented the maximum heat transfer coefficient, while for large Re number, the copper foam sample with 80% porosity and 45PPI outweighed. The copper foam sample could show six times larger than the bare channel in heat transfer coefficient, but consume more pump power. For the two-phase heat transfer, experiments found that low porosity samples (70%~80%) could effectively reduce the wall superheat and enhance boiling heat transfer. Porosity plays a more important role than pore density. Larger pore density would be helpful to provide more nucleation site density and larger capillary force. The samples with 90PPI have better heat transfer performance in flow boiling process.

Key words: copper foam, flow boiling, convective heat transfer, porosity, pore density