Cryogenic refrigeration

Gaseous helium is commonly used as the working fluid ia closed-cycle cryogenic refrigerators because of chemical iaertness, nearly ideal behavior at all but the lowest temperatures, high heat capacity per unit mass, low viscosity, and high thermal conductivity. 

Engine Expansion Cycle. In this process, a refrigerant fluid is compressed, optionally precooled, and expanded to a lower pressure through an expander while producing work to reduce both the enthalpy and temperature of the fluid. The expanded refrigerant fluid is warmed to provide cryogenic refrigeration. 

Loveday, P. E., Theoretical and Typical W/Q Ratio for Cryogenic Refrigeration Systems, Chem. Proc., p. 37, April 8, (1963). All rights reserved. 

G. Walker, E.R. Bingham Low-Capacity Cryogenic Refrigeration, Clarendon Press, Oxford (1994)... 

Staff Gas Processing Handbook, Gulf Publishing Co., Houston, I X, April 1990. Walker, G. and E.R. Bingham Low-Capacity Cryogenic Refrigeration, Oxford University Press. Inc.. New York, NY. 1994. 

Cryogenic refrigeration with compressors, refrigerants and eventually expanders is the common method for LNG production. Several new methods are under development. 

Turboalternators were developed in the 1960s to improve the efficiency of small cryogenic refrigeration systems. This is accomplished by converting the kinetic energy in the expanding fluid to electrical energy, which in turn is transferred outside of the system, where it can be converted to heat and dissipated to an ambient heat sink. 

Vasiliev L.L., Kulakov A.G. (2003) Heat Pipe applications in sorption refrigerators, Low Temperature and Cryogenic Refrigeration. NATO Science Series II, Vol 99, Kluwer Academic Publishers, 401- 414. 

Praseodymium 59 Pr Alloys, didymium glass (for protective goggles), yellow ceramic pigments, cryogenic refrigerant, misch metal... 

Gadolinium 64 Gd Electronic materials, high-temperature refractories, alloys, cryogenic refrigerant, thermal neutron absorber, superconductor, magnetic materials, bubble memory substrates... 

Radebaugh, R., (2003) Pulse Tube Cryocoolers, Low Temperature and Cryogenic Refrigeration, S. Kakae, et al. (eds.) Kluwer Aeademic Publishers, Dordrecht, pp. 415-434. 

Neon is primarily used in luminous tubes (vacuum electric discharge tubes), airplane beacons, helium-neon lasers, high-voltage indicators, cryogenic refrigerant, and laboratory experiments. 

These exchangers can handle gases, liquids, and two-phase applications. It has the greatest potential in cryogenic, refrigeration, gas... 

CRYOGENICS - Refrigeration which deals with producing temperatures of -157°C below zero and lower. 

In an investigation of the applicability of binary gas mixtures as cryogenic refrigerants, it is necessary to have phase data on the mixtures of interest. Since the literature showed only fragmentary data for mixtures, a test program was initiated to determine the phase boundaries for selected mixtures. 

---