Enhancement of Saturation Boiling of PF-5060 on Microporous Surface

Abstract

Pool boiling experiments were conducted to investigate the saturation boiling of PF-5060 dielectric liquid on micro porous copper surface. The micro porous surface is deposited on a copper coated silicon wafer diced to a size of 40 mm × 68 mm. Reference experiments were performed using a bare silicon wafer of the same size. Experiments are also performed using deionized water that was degassed prior to the experiment. The experimental results show that there is ∼48% enhancement of heat flux in nucleate boiling regime on the micro porous copper surface, compared to that on a bare surface for pool boiling of PF-5060. The measurement uncertainty for heat flux in these experiments is estimated to be ∼15%. The enhanced surface area provided by the micro porous copper surface as well as the reduction in the magnitude of the Taylor instability wavelength on a copper surface, increase in the nucleation site density on the porous surface, capillary replenishment of the dry out regions and the increase in transient heat transfer from the porous surface — are postulated to be the enhancement mechanisms for the observed augmentation in heat flux values.