Calculated Regenerator Performance at 4 K With Helium-4 and Helium-3

Radebaugh, Ray; Huang, Yonghua; O'Gallagher, Agnes; Gary, John

doi:10.1063/1.2908551

Cited by 19 publications

(15 citation statements)

References 3 publications

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“…They obtained the temperature curves along the regenerator which were later demonstrated to be consistent with the experimental results [7]. The comparative study of He-3 and He-4 systems showed that He-3 was more like an ideal gas at low temperature, which indicated that the substitution of He-3 for He -4 helped to improve the performance of regenerator [5]. Using Regen 3.3, the influence of porosity on the losses of the regenerator was analyzed, showing that the regenerator loss decreased with the decrease of porosity [4].…”

Section: Introductionsupporting

confidence: 67%

“…Its oscillating flow characteristics play a critical role in the performance of a PTR, which has attracted extensive attention in both theoretical and experimental studies. Radebaugh et al reported a series of numerical studies on the performance and optimization of regenerators of a 4 K cryogenic system [4][5][6][7]. They used the commercial software Regen 3.2 in the simulation and design.…”

Section: Introductionmentioning

confidence: 99%

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Modeling of Heat Transfer and Oscillating Flow in the Regenerator of a Pulse Tube Cryocooler Operating at 50 Hz

et al. 2017

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Abstract:The regenerator of the pulse tube refrigerator (PTR) operates with oscillating pressure and mass flow, so a proper description of the heat transfer characteristics of the oscillating flow in the regenerator is crucial. In this paper, a one-dimensional model based on Lagrangian representation is developed to simulate the oscillating flow in the regenerator of the PTR. The continuity equation, momentum equation and energy equation are solved iteratively using the SIMPLER algorithm. The Darcy-Brinkman-Forchheimer model is used in the momentum equation, and a thermal non-equilibrium model is implemented in the energy equation. Lagrangian representation is employed to describe the thermodynamics of fluid parcels while the Eulerian representation (control volume method) is adopted for the energy equation of the solid matrix. The boundary conditions are set as the periodic flow of the sine function. The thermodynamic parameters of the gas parcels are obtained, which reveal the critical processes of the heat transfer in the regenerator under oscillating flow. The performance of the regenerator with different geometries is evaluated based on the numerical results. The present study provides insight for better understanding the physical process in the regenerator of the PTR, and the proposed model serves as a useful tool for the design and optimization of the cryogenic regenerator.

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Section: Introductionsupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Modeling of Heat Transfer and Oscillating Flow in the Regenerator of a Pulse Tube Cryocooler Operating at 50 Hz

et al. 2017

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“…Compared with the relatively matured 80 K SPTCs, the efficiency of 4 K SPTCs is still rather low (about 0.5%-1% Carnot efficiency) (Olson et al, 2006;Nast et al, 2007;Bradley et al, 2008;Radebaugh et al, 2008;Qiu et al, 2011) due to regenerator losses with both the 4 K low temperature region (van Sciver, 1986) and high operating frequencies (Tanaeva et al, 2006). At temperatures below about 15 K, the specific heat capacity of regenerator materials significantly decreases with the cube of the temperature, while the specific heat capacity of helium-4 (He-4) increases remarkably, which leads to large regenerator heat transfer loss.…”

Section: Introductionmentioning

confidence: 99%

Performance of a precooled 4 K Stirling type high frequency pulse tube cryocooler with Gd2O2S

Jiang

Gan

et al. 2014

J. Zhejiang Univ. Sci. A

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Abstract:The efficiency of 4 K Stirling type pulse tube cryocoolers (SPTCs) is rather low due to significant regenerator losses associated with the unique properties of helium around 4 K and the high operating frequencies. In this paper, regenerator performance at liquid helium temperature regions under high frequencies is investigated based on a single-stage SPTC precooled by a two-stage Gifford-McMahon type pulse tube cryocooler (GMPTC). The 4 K SPTC used a 10 K cold inertance tube as phase shifters for better phase relationship between pressure and mass flow. The effect of the operating parameters, including frequency and average pressure on the performance of the 4 K SPTC, was investigated and the first and second precooling powers provided by the GMPTC were obtained. To reduce the regenerator heat transfer losses, a multi-layer regenerator matrix, including Gd 2 O 2 S (GOS) and HoCu 2 , was used instead of a single-layer HoCu 2 around 4 K. A theoretical and experimental comparison between the two types of regenerator materials was made and the precooling requirements for a regenerator operating at high frequencies to reach liquid helium temperatures were given, which provided guidance for the design of a three-stage SPTC.

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“…Recent work with a 4 K GM-type pulse tube [2,3] and a Stirling-type pulse tube cryocooler [4] has shown that the use of 3 He instead of 4 He increased the cooling power for the same power input. Previous modeling efforts by us [5,6] have shown that the loss associated with real gas effects in the regenerator can be significantly reduced by using 3 He at a relatively low average pressure of 0.5 to 1.0 MPa instead of 4 He at the normal pressure of 1.5 to 2.5 MPa. A layered regenerator matrix of gadolinium oxysulfate (GOS) at the cold end and Er 0.5 Pr 0.5 at the warm end was found to minimize the losses in a 4 K regenerator with the warm end at 20 K [6].…”

Section: Introductionmentioning

confidence: 99%

Optimization Calculations for a 30 Hz, 4 K Regenerator With Helium-3 Working Fluid

Radebaugh¹,

Huang²,

O'Gallagher³

et al. 2010

AIP Conference Proceedings

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The NIST numerical software, REGEN3.3, which incorporates both He-4 and He-3 properties, was used to calculate the losses and second law efficiencies of 4 K regenerators operating at 30 Hz. Operating parameters, such as average pressure, pressure ratio, and warm-end temperature were varied to investigate the effect of non-ideal gas properties. Regenerator parameters such as matrix material and shape, hydraulic diameter, and regenerator geometry were varied to investigate losses due to non-ideal regenerator behavior. The results show that He-3 can increase the regenerator efficiency by a factor of at least two compared to a regenerator optimized for He-4. A layered regenerator of gadolinium oxysulfate (GOS) at the cold end and ErPr at the warm end is the best of many material combinations. A regenerator with parallel holes of about 20 % porosity showed only slight improvement over one with packed spheres. The regenerator warm-end temperature has little effect on its efficiency for temperatures below 35 K and pressures of 1.0 MPa and above. An optimized 4 K He-3 regenerator uses layered GOS and ErPr with the warm end at about 30 K and an average pressure of about 1.0 MPa. With those optimum conditions a reduced regenerator loss of 0.36 and a regenerator second law efficiency of 25 % are achieved.

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Calculated Regenerator Performance at 4 K With Helium-4 and Helium-3

Cited by 19 publications

References 3 publications

Modeling of Heat Transfer and Oscillating Flow in the Regenerator of a Pulse Tube Cryocooler Operating at 50 Hz

Modeling of Heat Transfer and Oscillating Flow in the Regenerator of a Pulse Tube Cryocooler Operating at 50 Hz

Performance of a precooled 4 K Stirling type high frequency pulse tube cryocooler with Gd2O2S

Optimization Calculations for a 30 Hz, 4 K Regenerator With Helium-3 Working Fluid

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