Enhancement of the Liquefaction Rate in Small-Scale Helium Liquefiers Working Near and Above the Critical Point

Rillo, Conrado ; Gabal, Miguel ; Lozano Bernal, María Pilar (Universidad de Zaragoza) ; Sesé, Javier (Universidad de Zaragoza) ; Spagna, Stefano ; Diederichs, Jost ; Sager, Ronald ; Chialvo, Cesar ; Terry, Jeremy ; Rayner, Grant ; Warburton, Richard ; Reineman, Richard

Resumen: Low-temperature research laboratories with typical liquid-helium consumption of the order of tens of liters per day have greatly benefited from the recent development of small-scale liquefiers. In general, these liquefiers are based on Gifford-McMahon or pulse-tube closed-cycle refrigerators with a nominal cooling power ranging from 1 to 1.5Wat 4.2 K. The liquefaction rate for these cryocooler-based liquefiers depends on the pressure at which the helium is liquefied, although the final user conditions of the produced liquid helium are always atmospheric pressure and boiling temperature (e.g., 4.2 K at 100 kPa). Here, we show a systematic study on this effect, in which an enhancement in excess of 70% in liquefaction rate is found experimentally for pressures near and above the critical point of helium (220 kPa). We propose that the underlying mechanism for the liquefaction enhancement is based on the increase in cryocooler cooling power with temperature and the decrease of the helium enthalpy with pressure.

Idioma: Inglés

DOI: 10.1103/PhysRevApplied.3.051001

Año: 2015

Publicado en: Physical Review Applied 3 (2015), 051001 [5 pp]
ISSN: 2331-7019

Factor impacto JCR: 4.061 (2015)

Categ. JCR: PHYSICS, APPLIED rank: 22 / 145 = 0.152 (2015) - Q1 - T1

Factor impacto SCIMAGO: 2.345 - Physics and Astronomy (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MINECO/IPT-2012-0442-420000

Tipo y forma: Article (Published version)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)