A High Performance Miniature Loop Heat Pipe

This work presents the results of an experimental High Performance Miniature Loop Heat Pipe. The evaporator utilizes a wick structure with the non-inverted meniscus evaporation concept, which allows using high thermal conductivity materials for the evaporator case and capillary wick structure, and hence will further reduce the thermal resistance between the evaporator elements. The heat fluxes at the evaporator can therefore be significantly higher than that of a LHP using inverted meniscus evaporation approach.

Tests were conducted in the Material and Thermal Laboratory at the Canadian Space Agency. The evaporator heat input cross-section area was 2.4 cm². When water is used as the working liquid the heat transfer rate has reached values as high as 215W, corresponding to a heat flux density of 90W/cm² (temperature drop between heat source and LHP evaporator was ∼7°C). Working temperature oscillations (with amplitude ∼2-10°C) were observed for steady state regimes of LHP operation.