Enhanced flow boiling in parallel microchannels with metallic porous coating

Three heat sinks with porous-coated parallel microchannels were fabricated by using a solid-state sintering method. The enhanced flow boiling of anhydrous ethanol in the porous-coated microchannels was systematically studied and compared to that of bare microchannels. The changes in pressure drop, flow boiling instability and flow boiling heat transfer performances caused by the introducing of porous coatings were discussed. The effect of particle size on pressure drop and heat transfer performance was also studied. The porous-coated microchannels showed significant mitigation of flow boiling instability, which was explained by the changes in bubble dynamics. Dramatic enhancement of flow boiling heat transfer in the porous-coated microchannels was obtained. The enhancement from porous coatings showed dependence on particle size and diminished with the increase of vapor quality.