Conveners
C1OrA - JT & Reverse Brayton Coolers (Non-Aerospace)
- Mark Zagarola (Creare LLC)
- Marcel ter Brake (University of Twente)
At the University of Twente, a vibration-free hydrogen-based sorption cooler is under development for cooling optical detectors in future scientific space missions. Depending on the operating pressures in the system, the cooler can be used can be used as stand-alone or as a precooling stage for a helium cooler establishing 4 K. In an earlier ESA project, a hydrogen-based sorption cooler was...
As observed in the earlier studies, helium is more efficient than neon as a refrigerant in a reverse Brayton cryocooler (RBC) from the thermodynamic point of view. However, the lower molecular weight of helium leads to higher refrigerant inventory as compared to neon. Thus helium is suitable to realize the high thermodynamic efficiency of RBC whereas neon is suitable for the compactness of the...
The performance of a Joule Thomson (JT) cryocooler can be improved by introducing an ejector into the JT cooling cycle. The function of the ejector is to lift the pressure of the gas leaving the evaporator to a higher level, thus reducing the cold-end temperature and/or the input power of the compressor. In this paper, the performance of an ejector operating with nitrogen gas is investigated...
Several precooled JT cryocoolers (JTC) working at 4 K have been developed for space missions. Although these cryocoolers are qualified with high reliability and long life time, their efficiencies are relatively low which is worth further research.
A JT cryocooler has an intrinsic limitation on its cooling power. The intrinsic limitation is that the JTC will be warmed up continuously when the...
