Orthohydrogen-parahydrogen conversion is the largest effective phase-change of any material at cryogenic temperatures from an energy or entropy standpoint. More information on ortho-para conversion is here. The Cryocatalysis Hydrogen Experiment Facility (CHEF) was designed in 2011 to control the ortho-parahydrogen conversion of condensed hydrogen through careful material selection and catalyst implementation. The cryostat itself was retrofitted from WSU faculty members using it for plasma research.
With a total liquid hydrogen capacity approaching 5 liters, CHEF has been the most heavily utilized cryogenic system in the first decade of the HYPER lab. Read the stories below about the individual projects and research highlights CHEF has enabled.
An up to 40% increase in cooling capacity of hydrogen boil-off can be realized when equilibrium parahydrogen-orthohydrogen conversion occurs at 50K. This equates to more energy extraction per mass of boil-off and enables longer-duration liquid hydrogen storage. Such mass savings are advantageous when considering use of the most high-performance chemical and nuclear rocket propellant today in liquid hydrogen. Experimentally grounded Computational Fluid Dynamics (CFD) models can further identify flow optimization strategies able to minimize entropy generation in the core flow. The parahydrogen-orthohydrogen conversion in the outer flow enables entropy generation absorption to further improve performance. Tools such as CHEF provide the ability to sample the effects of Heisenberg Vortex Tube (HVT) optimization through fully calibrated temperature, parahydrogen-orthohydrogen composition, and mass flowrate measurement of both outlets. Software tools such as OpenFOAM can then be used with the experimental data to understand the fundamental physics of high Mach number reactive swirling flow.
The National Aeronautics and Space Administration (NASA)
An initial WSU faculty seed grant to begin testing devices for liquid hydrogen fueled drones garnered initial attention for our research. With little reserves left from the lab’s startup package, Ron (Matt) Bliesner had the monumental task of transforming an old cryostat utilized for plasma research into one capable of handling cryogenic liquid hydrogen. The United Launch Alliance (ULA) heard about the capability and provided our first external research grant to the lab to show that parahydrogen-orthohydrogen conversion was a reversible reaction that could be used to enhance Thermal Vapor Shielding (TVS) systems for reducing cryogenic boil-off.
The United Launch Alliance (ULA)