Optimisation de l'amplitude de l'impédance du régénérateur de cryo-refroidisseurs de Stirling à tube à pulsation fonctionnant aux températures de l'hélium liquide.

Impedance magnitude optimization of the regenerator in Stirling pulse tube cryocoolers working at liquid-helium temperatures.

Auteurs : CAO Q., QIU L. M., ZHI X. Q., et al.

Type d'article : Article

Résumé

The impedance magnitude is important for the design and operation of a Stirling pulse tube cryocooler (SPTC). However, the influence of the impedance magnitude on the SPTC working at liquid-helium temperatures is still not clear due to the complexity of refrigeration mechanisms at this temperature range. In this study, the influence of the impedance magnitude on the viscous and thermal losses has been investigated, which contributes to the overall refrigeration efficiency. Different from the previous study at liquid nitrogen temperatures, it has been found and verified experimentally that a higher impedance magnitude may result in a larger mass-flow rate accompanied with larger losses in the warmer region, hence the refrigeration efficiency is lowered. Numerical simulation is carried out in SPTCs of different geometry dimensions and working parameters, and the experimental study is carried out in a three-stage SPTC. A minimum no-load refrigeration temperature is achieved with an appropriate impedance magnitude that is determined by the combination of frequency and precooling temperature. A lowest temperature of 4.76 K is achieved at 28 Hz and a precooling temperature of 22.6 K, which is the lowest temperature ever achieved with He-4 for SPTCs. Impedance magnitude optimization is clearly an important consideration for the design of a 4 K SPTC.

Détails

  • Titre original : Impedance magnitude optimization of the regenerator in Stirling pulse tube cryocoolers working at liquid-helium temperatures.
  • Identifiant de la fiche : 30009576
  • Langues : Anglais
  • Source : Cryogenics - vol. 58
  • Date d'édition : 12/2013
  • DOI : http://dx.doi.org/10.1016/j.cryogenics.2013.09.007

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