Transparent cryogenic thermosiphon using N2 and CF4 mixture as the working fluid

Abstract

A mixed working fluid has a potential to widen the operation temperature range of the thermosiphon. In this study, the thermosiphon using N2 and CF4 mixture as the working fluid is fabricated and tested to verify its transient thermo hydraulic characteristic. A transparent pyrex glass tube was used for the thermosiphon itself and the vacuum chamber was also fabricated by glass to visualize the internal state of thermosiphon. Onset of condensation temperature was related to the partial pressure of CF4. Two solidifications were observed and condensate temperature range of mixed working fluid was from 160 K to 70.7 K with N2 25% composition.