THE EFFECTIVENESS OF CYCLES, USED FOR HELIUM LIQUEFACTION,
Abstract
A comparative theoretical study is presented of various cycles used for the liquefaction of helium. Following the design and construction of a reliable piston refrigeration unit for helium such cycles became important in practice. Consequently, the author discusses a cycle using liquid nitrogen and a cascade piston unit without outside coolants. The usefulness of the nitrogen-cooled cycle depends on the cost and availability of liquid nitrogen since its consumption is quite high (0.8 liters of nitrogen for each liter of liquid helium, not including auxiliary needs from helium Dewar bottles, etc.). The cascade cycle unit seems to be much more promising (liquid nitrogen is used here only as an auxiliary coolant), and a good efficiency is found even with a two-piston unit; a three piston unit improves the efficiency by 20-40%. The hydrogen-cooled pistonless devices are 1.5 times less efficient than the other two devices. However, the hydrogen-cooled devices will most probably remain widely used wherever liquid hydrogen is already used for other purposes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 29, 1968
- Accession Number
- AD0681692
Entities
People
- I. B. Danilov
Organizations
- National Air and Space Intelligence Center