Thermal Characteristics of a Flat Evaporator Miniature Loop Heat Pipe

A miniature LHP has been designed, built and tested in order to evaluate its thermal characteristics when operating with concentrated heat loads, on an available heat dissipation area of 3 cm², using pure water as the working fluid. Tests results show that the miniature LHP presented reliable operation for the range of designed heat loads for two different condensation temperatures used. The concentrated heat flux caused the miniature LHP to present operating temperatures around 100 ºC for the highest heat load. However, even when operating at high temperature levels, the miniature LHP always showed reliable thermal behavior without indication of evaporator depriming or failure. The results point the importance of evaluating the thermal characteristics when miniaturizing LHPs, leading to potential applications for a wide range of temperatures. Specific details on the thermal characteristics of the miniature LHP will be presented in order to better evaluate the influence of the miniaturization of the set capillary evaporator/ compensation chamber on the LHP.