Experimental Study of the Enhancement of Condensation Heat Transfer on Downward-Facing Horizontal Surfaces

Experiments were performed to study the effects of surface geometry and porous drainage strip on the condensation heat transfer performance of downward-facing submerged and vapor space condensers to be used for the immersion cooling modules. A smooth surface and two finned surfaces with and without the porous drainage strip were tested for condensation of R-113 and methanol. For the submerged condensers, formation of vapor space under the condensing surface was observed in the low-heat.flux regime, whereas the surface was covered with rising bubbles in the high-heat-flux regime. For both the submerged and vapor space condensers, significant heat transfer enhancement over the smooth surface value was provided by the finned surfaces. For the vapor space condensers, further heat transfer enhancement was provided by use of the porous drainage strip.