US 5,172,554 A · Superfluid thermodynamic cycle refrigerator

Abstract

A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Claims18

Dependent claims

A refrigerator for cryogenic cooling, comprising:

a single phase working solution of liquid .sup.3 He at a predetermined initial concentration in superfluid .sup.4 He;
a bulk fluid containing superfluid .sup.4 He;
first pump means defining a first variable volume for containing said working solution, a second variable volume for containing said bulk fluid, and means for cyclically transferring said bulk fluid between said first and second variable volumes;
first superleak means connecting said first and second variable volumes to permit said bulk fluid in said second variable volume to pass therethrough and cyclically vary said concentration of .sup.3 He in said first volume for cyclically heating and cooling said working solution in said first volume;
and
at least one heat exchanger operatively connected with said first volume for thermal energy exchange with said working solution.

3 more elements

Dependencies are inferred from the claim text.

Superfluid thermodynamic cycle refrigerator

Life of this patent

Superfluid thermodynamic cycle refrigerator

Life of this patent

Abstract

Claims18