摘要

The design concept and thermal tests under vacuum of a miniature heat switch (MHS) are presented. The MHS is based on the variable conductance vapor-modulated loop heat pipe (VMLHP) technology, in which the switch capacity is provided by a two-way pressure regulating valve installed in the vapor line. The objective of the development is to exceed the current heat switches characteristics (paraffin). The thermal test results reveal that MHS ON/OFF conductance ratio is 580, more than 5 times higher than that of the current state-of-the-art paraffin heat switches, operating with an ON conductance of 3.5 W/K and an OFF conductance of 0.006 W/K. In addition, MHS shows a precise (±1.5°C) and robust temperature control together with a functional gravity field independence and low mass (148 g). The new product combines the advantages of the thermal control based on VMLHP with the miniaturization of new developed components and it would be beneficial for small orbiting spacecrafts. Other potential applications are the thermal control of spacecraft electronic boxes, power electronic components, batteries, and highly dissipative chips on a printed circuit board.