An experimental study on the working characteristics of a methane-charged cryogenic loop heat pipe

Methane-charged cryogenic loop heat pipe can realize efficient cryogenic heat transport at the temperature range of 90-190 K, which exhibits great application potential in the thermal control of future space infrared exploration system. In this work, an extensive experimental study on the supercritical startup and heat transport characteristics of a methane-charged cryogenic loop heat pipe integrated with a pulse tube cryocooler was conducted, where the effects of the auxiliary heat load applied to the secondary evaporator and was investigated. Experimental results showed that the CLHP could successfully realize the supercritical startup with an auxiliary heat load of 1.5 W. The CLHP could reach a heat transport capability of 7.5W over a distance of 0.6m corresponding to an optimum charged pressure of the working fluid. And there exists a minimum auxiliary heat load for the cryogenic loop heat pipe with primary heat load of 1W at some charged pressure. Furthermore, the mechanisms responsible for these phenomena mentioned above have been analysed and discussed qualitatively, providing a better understanding from the theoretical aspect.