Pool boiling of Novec-649 on minichannels filled with copper foam

Abstract

The article describes the experimental investigation of pool boiling heat transfer on minichannels with filling in the form of porous structure (copper foam). The results were compared with the data for a smooth surface and the minichannels without additional fillings. Tests were carried out for the boiling liquid Novec-649. Surfaces partially filled with porous structure were formed by inserting pieces of copper foam into the minichannels of 5 mm in depth and 1 mm width. Minichannels completely filled with copper foam formed the surface of MCC-F. The measurements were made with an increase in heat flux. The heat transfer coefficient obtained was four times higher than for the smooth surface. Additional foam fillings increased the heat transfer coefficient and reduced superheat for heat fluxes less than 100 kW/m2. Visualisation was made using a high-speed camera which allowed to determine the diameters of the growing bubble.