New evaporator structure for micro loop heat pipes

A loop heat pipe (LHP) is a heat transfer device whose operation principle is based on the evaporation and 'condensation of the working fluid, and it uses capillary forces to achieve fluid circulation. In this study, a new flat evaporator structure and micro-LHP with an evaporator thickness of 3 mm and a one-way transport length of 200 mm are proposed. The micro-LHP with a wick made of a porous polytetrafluoroethylene (PTFE) is designed, fabricated, and tested. In addition, a three-dimensional mathematical model is developed for the flat evaporator of the micro-LHP while taking into account the peculiarities of the evaporator configuration and specific characteristics of a one-side heat load supply. The results confirm the stable operation of the micro-LHP for the target heat load amount up to a maximum heat load of 11 W. The calculated results obtained from the mathematical model are compared with experimental data, and good agreement is observed between the predicted and measured temperature distributions across the micro-LHP. (C) 2016 Elsevier Ltd. All rights reserved.