Abstract: A cooling system includes a cold-accumulating refrigerator, and a cooling circuit. The cold-accumulating refrigerator includes a cold accumulator. The cooling circuit includes a heat exchanger. The heat exchanger is thermally brought into contact with a portion of the cold accumulator whose temperature is varied from a high temperature to a low temperature by a working medium flowing therein. Thus, it is possible to utilize cold produced by the working medium flowing in the cold accumulator in one cycle (e.g., from a high temperature to a low temperature, and from a low temperature to a high temperature), thereby remarkably enhancing the cooling system in terms of cooling efficiency.

Abstract: A cooling system includes a cold-accumulating refrigerator, and a cooling circuit. The cold-accumulating refrigerator includes a regenerator. The cooling circuit includes a main circuit, and a branched circuit. The main circuit includes a counterflow heat exchanger. The branched circuit is branched from an upstream portion of the main circuit, and joined to a downstream portion thereof, thereby reducing one of the flows of a refrigerant, flowing in a high-pressure-side passage and a low-pressure-side passage which are disposed in the counterflow heat exchanger, with respect to the other one of the flows. Moreover, the branched circuit includes a heat exchanger, and the heat exchanger is thermally brought into contact with a portion of the regenerator whose temperature is varied from a high temperature to a low temperature by another refrigerant flowing therein.

Abstract: A refrigeration system includes a refrigerator having a compression portion having a compression cylinder and a compression piston moving slidably in the cylinder, a first heat excahnger, a regenerator and a second heat exchanger. An expansion portion has an expansion cylinder and an expansion piston moving slidably in the cylinder. A drive device drives the compression piston via a first rod and the expansion piston via a second rod. The compression cylinder includes a first large diameter portion where the compression piston is slidably moved and a first small diameter portion where the first rod is slidably moved, and the expansion cylinder includes a second large diameter portion where the expansion piston is slidably moved and a second small diameter portion where the second rod is slidably moved.

Abstract: A refrigerating system of this invention includes at least one expansion chamber, at least one cryogenic accumulator, conduits connecting the expansion chamber and the cryogenic accumulator, and a substance to be cooled disposed between the expansion chamber and the cryogenic accumulator and in contact with one of conduits. It is a feature of this invention that a bypass conduit is disposed in parallel with one of the conduits in contact with the substance to be cooled. Thus, even when the substance to be cooled is placed away from one of the expansion chambers and one of the cryogenic accumulators, the refrigerating system of this invention can efficiently produce an extremely cold temperature of 40.degree. K. or less, and cool the substance to be cooled to a much lower temperature.