Measurement of the cooling capacity of an RMC‐Cryosystems Model LTS 4.5‐025 closed‐cycle helium refrigerator

1991 ◽  
Vol 62 (5) ◽  
pp. 1309-1310 ◽  
Author(s):  
R. L. de Zafra ◽  
W. H. Mallison ◽  
L. K. Emmons ◽  
D. Koller
Keyword(s):  
Cooling Capacity ◽  
Closed Cycle ◽  
Helium Refrigerator

Effect of Operating Conditions on the Performance of Two-Bed Closed-Cycle Solid-Sorption Heat Pump Systems

1995 ◽  
Vol 117 (3) ◽  
pp. 181-186 ◽  
Author(s):  
W. Zheng ◽  
W. M. Worek ◽  
G. Nowakowski
Keyword(s):  
Ambient Temperature ◽  
System Performance ◽  
Cooling Capacity ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Operating Parameters ◽  
Closed Cycle ◽  
Sorption Heat ◽  
Cycling Speed ◽  
Sorption Heat Pump

The effect of two operating parameters, the regeneration temperature and the ambient temperature, on the performance of two-bed, closed-cycle solid-sorption heat pumps is investigated. The results show that increasing the regeneration temperature can improve both the COP and cooling capacity, and the effect on cooling capacity is more significant than the COP. Increasing the regeneration temperature from 180°C to 260°C, the cooling capacity increases by 50 percent and the COP improves 20 percent. When the ambient temperature drops, the system performance increases significantly. When the ambient temperature decreases by 10°C from the design point of 35°C, the COP and cooling capacity increases by 50 percent and 40 percent, respectively. Also, the bed cycling speed should be increased to achieve the optimum system performance when the regeneration temperature is higher or the ambient temperature becomes lower.

Use of a Closed Cycle Helium Refrigerator for Mössbauer Studies

1968 ◽  
Vol 39 (7) ◽  
pp. 995-997 ◽  
Author(s):  
J. W. Wiggins ◽  
J. R. Oleson ◽  
Y. K. Lee ◽  
J. C. Walker
Keyword(s):  
Closed Cycle ◽  
Mössbauer Studies ◽  
Helium Refrigerator

scholarly journals Reducing the background of ultra-low-temperature X-ray diffraction data through new methods and advanced materials

2019 ◽  
Vol 52 (2) ◽  
pp. 445-450 ◽  
Author(s):  
Charles James McMonagle ◽  
Michael Richard Probert
Keyword(s):  
Diffraction Data ◽  
Advanced Materials ◽  
Average Intensity ◽  
Closed Cycle ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Methods ◽  
Fold Reduction ◽  
Scattering Contribution ◽  
Helium Refrigerator

New methods and advanced materials that significantly reduce the background when collecting single-crystal X-ray diffraction data at ultra-low temperatures using a closed-cycle helium refrigerator are presented here. These include a magnetically controlled internal beamstop and a separate internal collimator that together completely remove the scattering contribution to the background from the beryllium vacuum chamber. Additionally, a new radiation shield made from flexible graphite significantly reduces the background and maintains excellent thermal properties. In combination these improvements have led to a sixfold reduction in the average intensity and a 15-fold reduction in peak intensity of the background observed for diffraction experiments conducted with a closed-cycle helium refrigerator. Moreover, access to ultra-low base temperatures, 2.05 K, has been maintained. The design and implementation of these methods are discussed along with a case study of vitamin C to demonstrate the effectiveness of the improvements.

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