Miniature Loop Heat Pipe with Temperature Control

Loop Heat Pipe (LHP) and Capillary Pumped Loop (CPL) are high performance heat transport devices using capillary forces to circulate the working fluid in a closed loop. Each has its own operational advantages and disadvantages. LHPs have tremendous pumping pressures due to the use of metal wicks. They can start up at any time under almost any condition. CPLs, on the other hand, require a lengthy pre-conditioning period before they commence the loop operation. However, CPLs provide tight temperature control for the heat source which is a desirable characteristic of a spacecraft thermal control system (TCS). In addition, the ability of the CPLs to acquire heat from multiple heat sources and share the heat among them allows the design of the spacecraft TCS to be simpler and lightweight. An advanced concept of LHP (A-LHP) combines a LHP and CPL into one loop. The LHP/CPL hybrid loop inherits all operational attributes of the LHP and yet does not show any disadvantages associated with either a LHP or CPL. A miniature version of the A-LHP can be used effectively in next generation spacecraft.