Laboratory Hydrogen Liquefier with Neon Refrigeration Cycle

A combined hydrogen liquefying unit was developed for laboratory studies in the 21–30 K temperature range. High-pressure neon cycle with refrigeration of a straight flow in a nitrogen bath boiling under vacuum was used. Neon refrigeration reduced the pressure in the hydrogen circuit to 1 MPa. Under the hydrogen liquefaction conditions the productivity of the complex was 18 dm 3 /h for orthohydrogen and 13 dm 3 /h for parahydrogen. The unit also liquefies neon with a flow rate of 7 dm 3 /h. An experimental prototype of the combined hydrogen-neon system was built. Russian-made diaphragm compressors were used in the compression block. The unit was designed for investigating heat insulation, structural properties of materials and phase separation processes in technologies for production of light inert gases. Liquid neon was used to simulate conditions close to the hydrogen temperature level. Preliminary tests of hydrogen equipment were therefore conducted using a relatively safe refrigerant.