Influence of Filling Ratios on the Thermal Performance of Flat Heat Pipes

Abstract

This research investigated the effect of the filling ratio on the thermal performance of a flat heat pipes. The flat heat pipes (FHP) used in this study were made of copper and had an inner and an outer diameter of 5.4 mm and 6.0 mm, respectively. Water was used as the working fluids to fill the FHPs during the tests. The wick structure was made from copper powder sintering. The copper tube was compressed into 3.0 mm of thickness; the porosity of wick was 50 ± 5%; and the wick thickness was 0.6 mm. In this work, the four different filling ratios of working fluid were considered: 35, 45, 55 and 65%. The FHPs were set to operate in the horizontal heating mode and input heat load until FHPs cannot work. From the results, the filling ratio of 65% can transfer 50.0W of heat load and 0.013oC/W of thermal resistant.