Heat Transfer Characteristic of Spherical Heat Pipe to Cool LED Device

Abstract

Heat transfer of a spherical heat pipe the surface of which penetrates visual light was measured to examine the possibility of LED lamp cooling. Uniform surface temperature was observed, which proved that the heat pipe functions. Using bare surface and the surface covered with aluminum foil, heat transfers by radiation and convection were separated. When base plate temperature was 80 °C, 8.1 W was removed. 5.5 W and 2.6 W were transferred by radiation and convection, respectively. This shows the possibility to cool LED lamps. Heat transfers by convection and radiation were almost the same as that of an existing correlation of natural convection or the thermal radiation law.