Cryogenic Loop Heat Pipes as Flexible Thermal Links for Cryocoolers

Loop heat pipes with flexible transport lines are needed in some cryogenic applications as thermal links between cryocoolers and the cooled components for a variety of reasons such as vibration isolation, increased thermal transport distance, thermal diode function, multiple components, etc. This paper presents an innovative configuration of a cryogenic loop heat pipe designed to operate in the temperature range between 70 K and 140 K. The experimental data obtained for the loop heat with oxygen as a working fluid show that it reliably and predictably started in multiple tests and operated with the heat load range at the main evaporator from 0.5 W to 9 W with the main evaporator elevated up to 5 cm versus the condenser.