Development and Application of a Passive Variable Conductance Loop Thermosyphon

Moon exploration and using it as a platform for further exploration missions in the solar system brings unique electrical, electronic, and thermal challenges. Large quantities of electronic devices and power generation systems will be deployed to the Moon. Rejecting the large amounts of waste heat from such devices (e.g., ~kWs from Polymer Electrolyte Membrane Fuel Cells “PEMFC”) in an environment with significant temperature swings while keeping the devices’ temperature within an optimal range requires novel concepts. In order to address this unique challenge, Advanced Cooling Technologies Inc. (ACT) developed a novel passive Variable Conductance Loop Thermosyphon (VCLTS) that can passively remove large amounts of heat and maintain the evaporator (heat source) temperature within a required range regardless of the significant swings in the sink temperature. Key thermal performance results as well as different configurations of the VCLTS are presented.