As NASA prepares to make manned missions into deep space, the management of cryogenic fluids will become increasingly important. Cryogenic fluids such as liquefied hydrogen, oxygen, and methane are expected to be used for chemical and nuclear propulsion, fuel cells, life support systems, cooling, refrigeration, liquefaction, and In-Situ Resource Utilization. Transfer of stored cryogenic liquids from a supply tank to an empty tank will be an important procedure during which phase change will occur. In addition, temperature fluctuations during long term storage of cryogenic fluids can result in the vaporization of these liquids. In low gravity conditions, buoyancy forces will be insufficient to separate the vapors formed from the liquids and the presence of vapor in the liquid streams will interfere with combustion in engines, and pumps, resulting in equipment damage.
In this Phase I SBIR project, we propose to demonstrate the feasibility of using a specially designed chamber to separate the vapor from the cryogenic liquid. This separator will use swirl to generate centripetal forces to force vapor out of the liquid into the central core of the vortex. The lighter vapor bubbles will separate from the cryogenic liquid to form a stable core in the center of the chamber surrounded by the liquid. The vapor can then be pumped from the system and collected for further use. The design will prevent the vaporous core from reaching the liquid exit. The liquid stream will flow out of the other end of the chamber where it can be stored or transferred.
This approach is based on our previous separator designs for removing air from water under microgravity. The resulting technology has been tested under microgravity conditions. Based on those results the application of a similar design to cryogenic fluid management is predicted to succeed.
Numerous NASA applications to be used for longterm space habitation and manned missions into deep space will require cryogenic fluids management. These include the storage and transfer of cryogenic fluids for chemical and nuclear based propulsors, life support systems formation and recovery of fluids generated in situ, etc. Longterm storage of cryogenic fluids may subject the stored fluids to boil off. Therefore, cryogenic phase separation is needed to protect pumps and equipment from bubbly flows in low gravity conditions.
The separation of vapor phases in cryogenic fluids is applicable in Magnetic Resonance Imaging equipment, superconductors, supercomputers and cryopreservation of biological samples liquefaction of natural gas and cryopreservation of pathology and biological samples. This technology could also be used in hospitals and medical research centers, as well as Department of Defense missile programs.