Measuring device for heat pipe

Abstract

In this study, plate type heat pipes having mesh capillaries were investigated experimentally and theoretically. A test apparatus was designed to test thermal performance of a plate type copper-water heat pipe having one or two layers of #50 or #80 mesh capillary structures with 5 to 50 W heat input. A working fluid charge volume fraction varied from 13% to 50% of the heat pipe internal space. In addition to horizontal orientation, the heat pipes were tested with the evaporator section elevated up to a 40 degree inclination angle. Temperature distribution of the heat pipe was measured, and the evaporator, adiabatic and condensation resistance of the heat pipe were calculated separately. The effects of mesh size, charge volume, and inclination angle on each thermal resistance were discussed. In general, the #80 mesh yields lower thermal resistances; and inclination angle has more significant effect on the condenser section than the evaporator section. Theoretical models were proposed to interpolate the evaporation and condensation phenomena shown by the experiments. The present model predicts the experimental data of evaporation resistance to within ±20%, and most condensation resistance data to within ±30%.