Integrated Brayton Cryocooler for LOx and LH2 Applications

NASA is in need of affordable and robust cryogenic cooling solutions for use in space applications.nbsp; In support of the Artemis program, NASA seeks innovative integrated refrigeration cycles for use in liquefaction of hydrogen and oxygen from the lunar surface. Based on initial estimates from Phase I activities, 330+ W of cooling is needed at 90 K and 130+ W of cooling is needed at 20 K to support at least 11.7 metric tons per year.nbsp; Currently, space-based cryocoolers have yet to demonstrate cooling beyond 20 W at 20. Concepts NREC (CN) is working towards the demonstration of two high-capacity helium-based reverse-Brayton cryocoolers, and plans to leverage these cryocoolers to develop a novel integrated two-stage helium system capable of supporting both oxygen and hydrogen liquefaction needs on the Moon. The proposed solution will increase the current state-of-the-art in cryogenic cooling by an order of magnitude. The two lowest TRL/MRL components derived from Phase I activities are a micro-tube recuperator with a titanium construction replacing the legacy materials, and a compressor capable of operation under lunar surface ambient conditions. The titanium micro-tube recuperators utilize a proven, underlying design; the same manufacturing method and models can easily be adapted to the changes brought upon by the change to titanium, and development risk is considered low. Lunar ambient compressor operation has the highest system risk when looking at the changes from legacy CN demonstrations. Existing turboalternator powertrain technology will be leveraged to develop a compressor powertrain that is capable of operation at the reduced ambient conditions. The capabilities of the newly developed powertrain will need to handle larger thrust loads at higher rotational speeds than what is currently found on the turboalternators. Results from this study will provide valuable input into NASArsquo;s on-going Cryogenic Fluid Management directives.