Abstract: A refrigerant circuit (10) of a refrigeration apparatus is filled up with carbon dioxide as a refrigerant. In the refrigerant circuit (10), a first compressor (21) and a second compressor (22) are arranged in parallel. The first compressor (21) is connected to both an expander (23) and a first electric motor (31), and is driven by both of the expander (23) and the first electric motor (31). On the other hand, the second compressor (22) is connected only to a second electric motor (32), and is driven by the second electric motor (32). In addition, the refrigerant circuit (10) is provided with a bypass line (40) which bypasses the expander (23). The bypass line (40) is provided with a bypass valve (41). And, the capacity of the second compressor (22) and the valve opening of the bypass valve (41) are regulated so that the COP of the refrigeration apparatus is improved after enabling the refrigeration apparatus to operate properly in any operation conditions.

Abstract: A blade 8 is integrally fixed to a roller 7 mounted around an eccentric section 22 of a drive shaft 21. The blade 8 extend radially outwardly of the roller 7, and partitions the inside of a cylinder chamber 41 into a compression chamber X and a suction chamber Y. A protruded end portion of the blade 8 is received in a reception groove 11a of a support member 11 which is pivotally supported by a stationary member 4. A substitute fleon refrigerant is used as a working fluid in the cylinder chamber 41, and an oil adapted to the substitute fleon refrigerant is used as a lubricating oil for a compressor CP. While using the substitute fleon refrigerant, the deterioration of the oil in the compressor is prevented.

Abstract: A thermal isolation arrangement for use in a co-rotating scroll refrigerant compressor includes various thermal insulation elements adapted to minimize heat transfer between hot rotating members of the scroll fluid device and the return refrigerant to be compressed, and between hot lubricant in the compressor and the return refrigerant. The thermal isolation elements of the present invention may be used individually or collectively to minimize the preheating of the inlet refrigerant so as to maintain the density of the return refrigerant being compressed to thereby increase the total efficiency of the scroll fluid device.

Abstract: In a cryogenic refrigerator having a precooling refrigerating circuit including a cryostat for cooling and maintaining a cryogenic working apparatus which is operated at a very low temperature level, expander for expanding refrigerant gas, such as helium gas, and a J-T circuit for generating cold by Joule-Thomson expanding refrigerant gas precooled by the precooling refrigerating circuit, the present invention prevents the working vibration of the expander from unduly effecting the cryogenic working apparatus and to maintain the cryogenic working apparatus at a very low temperature level for many hours, even while the precooling refrigerating circuit is stopped, thereby enabling a stabilized operation of the cryogenic working apparatus to be performed.

Abstract: In cryogenic refrigerator provided with a cryostat having a low temperature level maintaining part for cooling and maintaining a part to be cooled at a very low temperature level and an expander which is fitted in the low temperature level maintaining part of the cryostat and generates cold in the low temperature level maintaining part by expanding refrigerant gas compressed by a compressor, vibration of the working expander is prevented from being transmitted to the part to be cooled by fixing and supporting the part to be cooled to the cryostat, separately from the expander, thereby minimizing the bad influence or vibration on a cryogenic working apparatus which is sensitive to vibration and by integrally supporting the part to be cooled and the expander to the crystat. In this way, the necessity of supporting the part to be cooled and the expander individually is eliminated and installation of the refrigerator is easy.

Abstract: In a cryogenic refrigerator having a precooling refrigerating circuit including a cryostat for cooling and maintaining a cryogenic working apparatus which is operated at a very low temperature level, an expander for expanding refrigerant gas, such as helium gas, and a J-T circuit for generating cold by Joule-Thomson expanding refrigerant gas precooled by the precooling refrigerating circuit, the present invention prevents the working vibration of the expander from unduly effecting the cryogenic working apparatus and to maintain the cryogenic working apparatus at a very low temperature level for many hours, even while the precooling refrigerating circuit is stopped thereby enabling a stabilized operation of the cryogenic working apparatus to be performed.

Abstract: A cryogenic refrigeration system for cooling specimen, wherein an expander having one or more heat stations and a cooler at a main refrigeration circuit, which has a specimen mounting unit and is cooled at a temperature lower than the heat station, are housed in first and second vacuum chambers separate from each other, and at the second vacuum chamber is provided an open-close lid which is open to enable a specimen to be taken in or out, whereby the second vacuum chamber only is broken of its vacuum so as to enable the specimen to be exchanged.

Abstract: A multi-vane type compressor formed with vane back pressure spaces having introduced thereinto a suction gas pressure in the suction and compression strokes and a discharge gas pressure in the discharge stroke. The compressor includes supply grooves for introducing the discharge gas pressure into the vane back pressure spaces, which are each split into a trailing side portion and a leading side portion. Each leading side portion for coping with the terminating stage of the discharge stroke is exposed to the discharge gas pressure via a passageway offering large resistance to the flow of fluid, to throttle the gas forced out of the vane back pressure spaces as the vanes are forced into vane grooves to thereby raise the vane back pressure. This is conducive to prevention of the jumping action of the vanes, and wear of the tips of the vanes and to minimization of vibration and noise.

Abstract: A cross-fin coil type heat exchanger wherein a multiplicity of raised fins of the louver type are formed on the major portion of the surface of a convoluted fin base plate and the area of the portion of the fin base plate reduced in heat transfer performance is minimized, to improve the heat transfer effects achieved by the fins. Means is provided to inhibit the growth of a boundary layer by the front edge effect of the raised fins and promote the conversion of a current of a heat exchange fluid. Ribs are formed in the fins remote from heat transfer tubes to further promote the conversion of the current of the heat exchange fluid into a turbulent flow and also to reinforce the fins. The raised fins of the louver type have a construction that tends itself to good draining, to avoid an increase in the resistance offered to the passage of the current of the heat exchange fluid in wet condition.

Abstract: The invention is concerned with a cooling system for cooling telecommunication equipment at an unattended microwave relay station or the like located in desert or like regions where there is a large difference between the maximum daytime temperature and minimum nighttime temperature. The cooling system includes an outdoor heat exchanger disposed outside and above a shelter accommodating the telecommunication equipment, an indoor heat exchanger disposed in the shelter and a heat storage means disposed at an intermediate level between these heat exchangers. These heat exchangers and the heat storage means are connected with one another by conduit means charged with a condenseable refrigerant, such that the refrigerant is naturally circulated in said conduit means by gravity.