Accession Number : AD0681692

Title :   THE EFFECTIVENESS OF CYCLES, USED FOR HELIUM LIQUEFACTION,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Danilov,I. B.

Report Date : 29 MAY 1968

Pagination or Media Count : 20

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)

Descriptors :   (*LIQUEFIED GASES, *HELIUM), CRYOGENICS, CONDENSERS(LIQUEFIERS), NITROGEN, THERMODYNAMICS, USSR

Subject Categories : Industrial Chemistry and Chemical Processing
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE