Abstract: A displacer cryocooler including a multistage heat exchanger is modified with a phase shifting device connected between stage volumes for gas phase shifting of gas pressure in the cryocooler for improving the efficiency and temperature range of expander cryocoolers.

Abstract: A system (20) for conditioning air (30) includes conditioning circuits (26, 28). Each of the circuits (26, 28) includes a heat transfer coil (54, 60) residing in a supply section (22) of the system (20), and a heat transfer coil (56, 62) residing in a return section (24) of the system (20). A controller (50) in communication with the circuits (26, 28) determines one of a heating mode (78, 110) and a cooling mode (148, 150) for an interior space (34). The controller (50) selectively actuates the conditioning circuits (26, 28) to condition outside air (30) entering the supply section (22) to produce conditioned supply air (36) for provision into space (34) and to recover heating and cooling energy from return air (38) entering the return section (24) from the space (34) prior to its discharge from the system (20) as exhaust air (44).

Abstract: The present invention relates generally to combined power and cooling generation systems, and, more particularly, to a combined power and refrigeration cascade system (“PARCS”) that includes an electric power system (PS) that produces both electric power and medium-to-high-grade waste heat that can be used for providing the cooling and power supply needs of data centers and the like.

Abstract: A refrigerant circuit (10) operates in a refrigeration cycle in which the pressure of refrigerant discharged from a compressor (22) is at or above the critical pressure. In performing an operation in which a first indoor heat exchanger (33a) performs a heating operation and, concurrently, a second indoor heat exchanger is made inactive, an indoor expansion valve (34b) associated with the inactive indoor heat exchanger (33b) is fully closed.

Abstract: Refrigeration circuit comprising a compressor, a heat-rejecting heat exchanger an expansion valve, a receiver (3), and a further expansion valve/evaporator to provide cooling. A second heat exchanger (24) is arranged in an upper gas portion of the receiver and/or a third heat exchanger (34) is arranged in a lower liquid portion of the receiver. A better liquid/vapour separation of the refrigerant and/or sub-cooling of the liquid refrigerant are achieved.

Abstract: A dewpoint cooler comprises: two medium circuits coupled mutually via a heat-conducting wall, through which circuits two media can flow, wherein the second medium contains gas, which wall has heat-conducting protrusions; wherein the wall and the protrusions are covered with a hydrophilic coating which can absorb an evaporable liquid and relinquish it again through evaporation such that the wetted coating, and thereby also the heath-conducting surfaces and the protrusions, are cooled; a wetting unit for subjecting the secondary medium to wetting by the evaporable liquid by evaporating liquid from the coating such that the evaporated liquid entrained by the secondary medium extracts heat from the primary medium via the heath-conducting wall. The coating consists of a porous technical ceramic material, such as a mineral wool.

Abstract: A cooling system suitable for cooling food on board an aircraft is provided which includes a chiller device and a first cooling circuit which is adapted to feed cooling energy generated by the chiller device to at least one cooling station, the chiller device includes a second cooling circuit formed separately from the first cooling circuit and is thermally coupled to the first cooling circuit.

Abstract: The invention relates to a cooling system (20) for an aircraft, comprising a number of refrigeration devices (1) which produce refrigeration and transmit this refrigeration to a cooling medium, and a circuit (21), containing at least one refrigeration consumer (22), for the cooling medium, for supplying the refrigeration consumer(s) (22) with refrigeration. Each refrigeration device (1) is a modular unit coupled to the circuit (21) and having a pump (10), which conveys the cooling medium through the circuit (21).

Abstract: To defrost one barrel of a two barrel FCB dispenser, a refrigeration system defrosts the one barrel, while neither defrosting nor chilling the other barrel, for either a selected time or until a frozen beverage is drawn from the other barrel, whichever occurs first. Once the selected time or beverage draw occurs, the refrigeration system chills the other barrel until beverage within it is properly frozen, while neither defrosting nor chilling the one barrel. Once beverage in the other barrel is properly frozen, the refrigeration system resumes defrosting the one barrel, whereupon the foregoing cycle is repeated until defrost of the one barrel is complete, at which point the refrigeration system chills the one barrel to refreeze product in it. The arrangement keeps beverage in the other barrel properly frozen during defrosting of the one barrel.

Abstract: An air-conditioner having a dual-refrigerant cycle includes a primary refrigerant circuit heat-exchanged with outdoor air; a secondary refrigerant circuit heat-exchanged with indoor air to perform either a cooling operation or a heating operation; and a heat exchange unit disposed between the primary refrigerant circuit and the secondary refrigerant circuit to perform heat exchange therebetween, wherein the secondary refrigerant circuit includes a compressor for compressing a refrigerant circulating in the secondary refrigerant circuit. A condensing pressure of the primary refrigerant circuit is lowered during the hating operation and an evaporation pressure of the primary refrigerant circuit is increased to thereby enhance efficiency of the air-conditioner.

Abstract: The present invention provides a refrigeration system including a first refrigerant circuit including a first heat exchanger for transferring heat from refrigerant, a second refrigerant circuit including a second heat exchanger for transferring heat to refrigerant, and a third refrigerant circuit. The third refrigerant circuit includes a compressor, a condenser connected to the first refrigerant circuit such that heat exchange can occur between the refrigerants of the first and refrigerant circuits, an expansion device, and an evaporator connected to the second refrigerant circuit such that heat exchange can occur between the refrigerant of the second and third refrigerant circuits. The refrigerant can travel along the third refrigerant circuit in a common direction during operation in both heating and cooling modes. Refrigerant can be prevented from moving between first, second, and third refrigerant circuits during operation in heating and cooling modes.

Abstract: A refrigerated transport system includes a prioritizing algorithm to limit the maximum amount of refrigerant flow available to at least one limited cooling compartment by holding a delta T (difference between the supply air temperature and return air temperature) instead of a setpoint temperature in the at least one limited cooling compartment when the available cooling capacity is insufficient to hold a substantially constant temperature in all compartments. A method for creating multiple refrigerated compartment spaces having precision temperature control includes the steps of: prioritizing the compartments by identifying at least one priority compartment to be held at a setpoint temperature; and limiting refrigerant flow to all but the priority compartment when there is insufficient cooling capacity to maintain all compartments at their respective setpoint temperatures.

Abstract: The present invention relates to a refrigerant circuit (1), in particular for use in a liquefaction plant, the refrigerant circuit (1) at least comprising: —a refrigerator (2) having an inlet (21) for refrigerant (10) at a refrigeration pressure, and at least five outlets (22, 23, 24, 25, 26, . . . ) for evaporated refrigerant (20, 30, 40, 50, 60, . . . ) evaporated at different pressure levels, the at least five outlets (22, 23, 24, 25, 26, . . . ) being preferably intended for refrigerants evaporated at increasing pressures from the first outlet (22) to the fifth (26) and optional higher outlets; —a first compressor (3) having one or more inlets for receiving evaporated refrigerant from the refrigerator and an outlet (34) that can be connected to the inlet (21) of the refrigerator (2); and—a second compressor (4) having one or more inlets for receiving evaporated refrigerant from the refrigerator and an outlet (44) that can be connected to the inlet (21) of the refrigerator (2).

Abstract: In order that an indoor heat exchanger (41), a cold storage heat exchanger (45), and a freeze storage heat exchanger (51) may differ in their refrigerant evaporating temperature, a refrigerant circuit (1E) is provided with a suction side three way switching valve (102) capable of switching of flow paths between the heat exchangers (41, 45, 51) and a compressor (2).

Abstract: Variable speed drives are utilized in refrigerant systems to operate motors of the system components at varying speeds, typically for the purposes of capacity adjustment, efficiency enhancement, reliability improvement or power consumption limitation. However, variable speed controls are expensive. The present invention offers flexibility to utilize a variable speed drive to provide variable speed functionality between compressor and fans (or other rotating components having electric motors) within a refrigerant system depending on operational and environmental conditions and external load demands. The switching device switches the variable speed drive between component motors as indicated by a control for the refrigerant system.

Abstract: A pulse tube cryocooler used under a non-vacuum atmosphere, the pulse tube cryocooler includes a pressure wave generator configured to generate pressure wave in an operations gas; a first stage regenerator having a high temperature end connected to the pressure wave generator; a second stage regenerator having a high temperature end connected to the first stage regenerator; a first stage pulse tube having a high temperature end and a low temperature end, the high temperature end being connected to a first buffer tank, the low temperature end being connected to a low temperature end of the first stage regenerator; a second stage pulse tube having a high temperature end and a low temperature end, the high temperature end being connected to a second buffer tank, the low temperature end being connected to a low temperature end of the second stage regenerator; a first stage cooling stage provided in a position where the first stage regenerator and the first stage pulse tube are connected; and a second stage coolin

Abstract: A CO2 cooling and heating apparatus and method permit simultaneous production of high-temperature heat source and low-temperature heat source having a temperature difference therebetween. The apparatus/method uses CO2 (carbon dioxide) as a refrigerant, and has a first refrigerating cycle circuit where the refrigerant is compressed to a supercritical zone and then decompressed via an expansion device to a pressure/temperature level of the CO2 triple point or below to thereby attain evaporation. The apparatus can include multistage compressors, intermediate cooler disposed in a first refrigerant flow path between a condenser and the expansion device.

Abstract: A thermodynamic system that can approximate the Ericsson or Brayton cycles and operated in reverse or forward modes to implement a cooler or engine, respectively. The thermodynamic system includes a device for compressing a first fluid stream containing a first gas-liquid mixture having a sufficient liquid content so that compression of the gas within the first gas-liquid mixture by the compressing device is nearly isothermal, and a device for expanding a second fluid stream containing a second gas-liquid mixture having a sufficient liquid content so that expansion of the gas within the second gas-liquid mixture by the expanding device is nearly isothermal. A heat sink is in thermal communication with at least the liquid of the first gas-liquid mixture for transferring heat therefrom, and a heat source is in thermal communication with at least the liquid of the second gas-liquid mixture for transferring heat thereto.

Abstract: A refrigerator includes a Stirling refrigerating machine having a high-temperature heat radiation portion and a low-temperature heat absorption portion and for cooling a freezing compartment, and a compressor for circulating a first refrigerant through a first circulation circuit having a cooling compartment evaporator. The high-temperature heat radiation portion is in contact with a first circulation spiral portion formed in the first circulation circuit.

Abstract: A method includes operating the refrigeration system in a cooling mode wherein a space is conditioned, and also includes transferring heat from a heat-transfer circuit to a thermoelectric device to a refrigeration circuit. A method further includes operating the refrigeration system in a defrost mode of operation including transferring heat through the thermoelectric device to the heat-transfer circuit to a heat exchanger.

Abstract: A double-effect thermoelectric cooling apparatus is described. The double-effect thermoelectric cooling apparatus includes a heat-dissipating barrel, a wind guide, cooling fins, and a fan. The heat-dissipating barrel further includes a thermoelectric chip-cooling module and heat-dissipating fins disposed therein. The fan drives a part of air passing through the heat-dissipating fins to remove a heat exchanged by the thermoelectric chip-cooling module. One end of the wind guide is coupled to a heat source of an electronic device, for example, a CPU or a graphic card of a computer. Another end of the wind guide is coupled to the fan to guide another part of the air through the cooling fins reducing the temperature thereof to the heat source of the electronic device to reduce the operating temperature of the heat source.

Abstract: A thermoelectric cooling apparatus is described. The thermoelectric cooling apparatus includes a heat-dissipating barrel, a wind guide, cooling fins, and a guiding fan. The heat-dissipating barrel further includes a thermoelectric chip cooling module and heat-dissipating fins disposed therein to remove the heat exchanged by the thermoelectric chip cooling module. One end of the wind guide is coupled to a heat source of an electronic device, for example, a CPU or a graphic chip of a computer. Another end of the wind guide is coupled to the cooling fins coupled to the thermoelectric chip cooling module. The guiding fan drives air passing through the cooling fins to reduce a temperature thereof and blowing to the heat source to reduce the operating temperature thereof.

Abstract: A device for transporting heat from a cold reservoir to a warm reservoir, in which at least two cyclic processes are employed for transporting heat thereby absorbing work, of which at least one is a regenerative cyclic process, and at least one is a magnetocaloric cyclic process, wherein the regenerative cyclic process has a working fluid and a heat storage medium, is characterized in that the heat storage medium of the regenerative cyclic process comprises a magnetocaloric material for the magnetocaloric cyclic process, wherein the magnetocaloric material is in a regenerator area with a cold end and a warm end, the working fluid of the regenerative cyclic process additionally serving as a heat transfer fluid for the magnetocaloric cyclic process. This produces a compact device with low apparative expense, wherein the power density and also the efficiency of the device are increased. The device may advantageously be used for cooling a superconducting magnet configuration.

Abstract: A pulse tube refrigerator comprising a cold head, wherein the cold head comprises at least one pulse tube (6) and at least one regenerator (7); the cold head having a cold end (8) and a warm end (5), each end being provided with respective heat exchangers (12, 13); wherein refrigerant is supplied (3) to the cold head; and wherein the warm end heat exchanger (13) is provided with a secondary cooling mechanism (16, 17) to improve the efficiency of the PTR.

Abstract: Method for gas liquefaction comprising cooling a feed gas by a first refrigeration system in a first heat exchange zone and withdrawing a substantially liquefied stream therefrom, further cooling the substantially liquefied stream by indirect heat exchange with one or more work-expanded refrigerant streams in a second heat exchange zone, and withdrawing therefrom a further cooled, substantially liquefied stream. At least one of the one or more work-expanded refrigerant streams is provided by compressing one or more refrigerant gases to provide a compressed refrigerant stream, cooling all or a portion of the compressed refrigerant stream in a third heat exchange zone to provide a cooled, compressed refrigerant stream, and work expanding the cooled, compressed refrigerant stream to provide one of the one or more work-expanded refrigerant streams.

Abstract: Disclosed is an ultra-low temperature, dual-compressor (114,144), recirculating gas chilling system that includes a closed-loop mixed-refrigerant primary refrigeration system (110) in combination with a closed-loop gas secondary refrigeration loop (112). The ultra-low temperature, dual-compressor (114,144), recirculating gas chilling system disclosed is capable of providing continuous long term chilled gas and fast cooling of a high or ambient temperature object (158), such as a chuck used in processing semiconductor wafers or any such device. The gas chilling system is characterized by three modes of operation: a normal cooling mode, a bakeout mode, and a post-bake cooling mode.

Abstract: A two-stage hybrid cryocooler includes a first-stage Stirling expander having a first-stage regenerator having a first-stage-regenerator inlet and a first-stage-regenerator outlet, and a second-stage pulse tube expander. The second-stage pulse tube expander includes a second-stage regenerator having a second-stage regenerator inlet in gaseous communication with the first-stage regenerator outlet, and a second-stage regenerator outlet, and a pulse tube having a pulse-tube inlet in gaseous communication with the second-stage regenerator outlet, and a pulse-tube outlet. The second-stage regenerator and the pulse tube together provide a first gas-flow path between the first-stage regenerator and the pulse-tube outlet. A pulse tube pressure drop structure has a pulse-tube-pressure-drop inlet in gaseous communication with the pulse-tube outlet, and a pulse-tube pressure-drop outlet, and a gas volume is in gaseous communication with the pulse-tube pressure-drop outlet.

Abstract: A refrigeration system includes a first cooling system having a refrigerant in thermal communication with a heat exchanger device to provide a first cooling source. A second cooling system has a coolant in thermal communication with the heat exchanger device and a refrigeration device is configured to receive the coolant. A third cooling system is configured to provide a second cooling source to the coolant when the first cooling source is unavailable, so that a pressure of the coolant does not exceed a predetermined level when the first cooling source is unavailable.

Abstract: A system and method for maintaining the temperature of a thermal transfer fluid at a selectable level within a wide temperature range, so as to operate a process tool in a chosen mode employing at least two cascaded stages, each operating with a different fluid in a separate refrigeration cycle. By interrelating energy transfers between parts of upper and lower stages, thermal efficiency is maximized and a smooth continuum of temperature levels can be provided. The refrigerants advantageously have vaporization points below and above ambient, for upper and lower stages respectively, and employs the upper stage for a constant refrigeration capacity, controlling the final temperature with the lower stage. The system allows for a further extension of range because the thermal transfer fluid can be heated for some process tool modes as the refrigeration cycles are run at low loads.

Abstract: With the intention of reducing power consumption and noise, there is provided a binary refrigeration unit which can be started even by a compressor equipped with a small-torque and compact motor. The binary refrigeration unit is constructed in such a manner that an evaporator 4 of a high-temperature side refrigerant circuit H and a condenser 12 of a low-temperature side refrigerant circuit L are disposed side by side, a refrigerant of the low-temperature side refrigerant circuit L is cooled to be condensed at the condenser 12 by vaporization heat of a refrigerant of the high-temperature side refrigerant circuit H evaporated by the evaporator 4, the condensed refrigerant of the low-temperature side refrigerant circuit L is evaporated at an evaporator 14, and accordingly a low temperature much lower than a low temperature obtained by the evaporator 4 is obtained by the evaporator 14.

Abstract: The performance of a multi-stage inertance pulse tube cryocooler in accordance with an embodiment of the present invention may be enhanced by cooling the inertance tube of one stage placing it in thermal communication with the cool heat exchanger of a preceding stage. Cooling at least one inertance tube of a multi-stage cooler in this invention lowers the viscosity and sound speed of the gas in the inertance tube, thereby improving the cooling power for that subsequent cooling stage, and for the entire device.

Abstract: The present invention provides an oil equalizing circuit for a refrigeration system provided with a plurality of compression mechanisms, the oil equalizing circuit being capable of supplying sufficient oil to the compressors that are running during partial load operation. The refrigeration system compression mechanism is provided with the following: first, second, and third compressors; a refrigerant intake main pipe; first, second, and third intake branch pipes connected to the intake sides of the compressors; first, second, and third oil separators connected to the discharge sides of the compressors; and first, second, and third oil return pipes provided on the oil separators. The first oil return pipe is configured such that oil is delivered to the refrigerant intake main pipe due to gravity when only the first compressor is running. The second oil return pipe is configured such that oil is delivered to the refrigerant intake main pipe due to gravity when only the first and second compressors are running.

Abstract: This invention is directed to systems, apparatuses and methods for reducing the temperature of a condenser fluid, used in a condenser in an air conditioning system to cool a compressed refrigerant, without releasing fluids to the environment. These systems include a first heat exchanger for reducing the temperature of a condenser fluid using a coolant fluid, a second heat exchanger for reducing the temperature of the coolant fluid using a refrigerant and a cooling system for reducing the temperature of the refrigerant. Theses systems do not release fluids into the environment, which is common when conventional evaporative cooling towers are used to reduce the temperature of condenser fluids.

Abstract: In a tube for a heat exchanger, a plurality of passages is defined. The passages are arranged in rows parallel to a major axis of the tube cross-section and staggered. When the tube is extruded, an extrusion material can flow around dies for forming passages and easily merge between the dies. Since walls between adjacent passages can be easily formed, formability of the tube is improved.

Abstract: A pulse tube cryocooler (90) is disclosed having a second cryocooler section (94b) with a single pulse tube stage (35c), and having a first cryocooler section (94a) with a pair of pulse tube stages (35a, 35b). A first pressure oscillator (98a) is associated with the first cryocooler section (94a), while a second pressure oscillator (98b) is associated with the second cryocooler section (94b). The first cryocooler section (94a) and the second cryocooler section (94b) are fluidly isolated from each other. Therefore, the charge pressure, the pressure amplitude, oscillation frequency, and working gas in each of the first cryocooler section (94a) and the second cryocooler section (94b) may be independently selected/established.

Abstract: A ground freezing method and system which circulates refrigerated heat transfer fluid through freeze pipes in the ground at a low temperature of at least −52° C. (−62° F.) to minimize drilling for the freeze pipe installation. The heat transfer fluid is preferably aqua ammonia (ammonium hydroxide) because of its beneficial characteristics in this application. The circulating heat transfer fluid is preferably cooled by a refrigeration system that includes low and high stage cycles arranged in a cascade relationship and using ammonia or another refrigerant in the high stage refrigeration system and carbon dioxide as the refrigerant in the low stage refrigeration system.

Abstract: A refrigeration system includes a first cooling system having a refrigerant in thermal communication with a heat exchanger device to provide a first cooling source. A second cooling system has a coolant in thermal communication with the heat exchanger device and a refrigeration device is configured to receive the coolant. A third cooling system is configured to provide a second cooling source to the coolant when the first cooling source is unavailable, so that a pressure of the coolant does not exceed a predetermined level when the first cooling source is unavailable.

Abstract: Methods and apparatus for a two chamber freezer whereby both chambers can be maintained at a substantially constant ultra-low temperature, such as within the range of about −40° C. to −80° C. Short term items may be stored in and accessed by the upper door from an upper chamber while long term items may be stored in and accessed by the lower door in the lower chamber. The upper and lower chambers are thermodynamically independent of each other thereby reducing the power usage of the freezer.

Abstract: An improved torus multi-element semiconductor thermoelectric heater and chiller utilizes torus thermoelectric generator to provide high current to force heat flow. Overall efficiency of heat conversion is improved by coupling a thermoelectric generator directly to a torus heater and chiller. A thermoelectric generator exhaust heat drives a second thermoelectric generator connected to a thermoelectric heater and chiller to produce heat flow in the heater and chiller using air, gas, or liquid to convey heat into and away from the thermoelectric device.

Abstract: Disclosed is an ultra-low temperature, dual-compressor (114,144), recirculating gas chilling system that includes a closed-loop mixed-refrigerant primary refrigeration system (110) in combination with a closed-loop gas secondary refrigeration loop (112). The ultra-low temperature, dual-compressor (114,144), recirculating gas chilling system disclosed is capable of providing continuous long term chilled gas and fast cooling of a high or ambient temperature object (158), such as a chuck used in processing semiconductor wafers or any such device. The gas chilling system is characterized by three modes of operation: a normal cooling mode, a bakeout mode, and a post-bake cooling mode.

Abstract: Methods and apparatus for a two chamber freezer whereby both chambers can be maintained at a substantially constant ultra-low temperature, such as within the range of about −40° C. to −80° C. Short term items may be stored in and accessed by the upper door from an upper chamber while long term items may be stored in and accessed by the lower door in the lower chamber. The upper and lower chambers are thermodynamically independent of each other thereby reducing the power usage of the freezer.

Abstract: With the intention of reducing power consumption and noise, there is provided a binary refrigeration unit which can be started even by a compressor equipped with a small-torque and compact motor. The binary refrigeration unit is constructed in such a manner that an evaporator 4 of a high-temperature side refrigerant circuit H and a condenser 12 of a low-temperature side refrigerant circuit L are disposed side by side, a refrigerant of the low-temperature side refrigerant circuit L is cooled to be condensed at the condenser 12 by vaporization heat of a refrigerant of the high-temperature side refrigerant circuit H evaporated by the evaporator 4, the condensed refrigerant of the low-temperature side refrigerant circuit L is evaporated at an evaporator 14, and accordingly a low temperature much lower than a low temperature obtained by the evaporator 4 is obtained by the evaporator 14.

Abstract: Method for liquefying a gas which comprises cooling a feed gas stream successively through first and second temperature ranges to provide a liquefied product, wherein refrigeration for cooling the feed gas stream in the first temperature range is provided by a first vaporizing refrigerant and refrigeration for cooling the stream in the second temperature range is provided by a second vaporizing refrigerant, and further wherein the second vaporizing refrigerant provides additional refrigeration by vaporization at temperatures above a lowest temperature in the first temperature range.

Abstract: A cascade thermoelectric cooler designed to cool to cryogenic temperatures of 30 to 120 K integrates high performance\high-ZT BixSb2−xTe3 and Bi2Te3−xSe3-based super-lattice-structure thin-film thermoelectric devices with a bulk-material based thermoelectric cooler including plural cascaded cold stages with each successive cascaded cold stage able to cool to a progressively lower temperature. Each cold stage in the bulk-material thermoelectric cooler includes a heat source plate, a heat sink plate, a p-type thermoelectric, and a n-type thermoelectric. Moreover, the thin-film thermoelectric cooler can have multiple stages in which each stage contains a heat source plate, a heat sink plate, a p-type super-latticed thermoelectric element, and a n type super-latticed thermoelectric element.

Abstract: A pulse tube refrigeration system wherein the pulse tube working gas is cooled to a defined first stage temperature and is brought to a defined second stage temperature by operation of a regenerator and pulse tube, which are in flow communication through a cold heat exchanger, prior to providing refrigeration to a high temperature superconductor.

Abstract: The present invention provides a cryogenic refrigerating system for achieving ultra low temperature by sequentially obtaining low temperature through repetition of expansion and evaporation of a mixed-refrigerant in multiple stages. The refrigerating system includes a heat exchanger and a compressor between a final evaporator and a compressor. The heat exchanger causes evaporated refrigerant vapor in a suction tube for the compressor to be heated and to be drawn into the compressor, and causes the refrigerant condensed by a condenser to be supercooled. The refrigerating system includes a plurality of expansion/suction apparatuses connected with one another between the gas/liquid separator and the final evaporator.

Abstract: The cryogenic refrigeration system of the present invention includes a JT refrigerator and a pre-cooling refrigerator. The JT refrigerator includes a JT valve, which is fully opened during a clog elimination operation, and a first switching valve, which is provided along a low pressure line of a JT circuit and is closed during the clog elimination operation. The cryogenic refrigeration system includes a PL pipe for collecting a helium gas from a helium tank into a buffer tank. The PL pipe includes a second switching valve and a third switching valve, which are opened during the clog elimination operation.

Abstract: A two-stage cascade refrigerating system including a primary side refrigerant circuit, and at least one secondary side refrigerant circuit. The receiver of the primary refrigerant circuit is arranged such that a first pipe is introduced to the inside of the container such that an open of the first pipe is located at an inside upper portion of the container, and a second pipe is introduced to the inside of a container such that an open end of the second pipe is located at an inside lower portion of the container. The receiver of the secondary side refrigerant circuit(s) is reversible in refrigerant circulation and is arranged such that a first pipe and a second pipe are introduced to the inside of the container such that open ends of both pipes are located at an inside lower position of the container.

Abstract: A refrigeration system having a main refrigeration circuit having a condensing stage, wherein a first refrigerant in a high pressure gas state is condensed at least partially to a liquid state. The condensing stage has a pair of stand-alone condensing stage closed loops in heat exchange relation with the main refrigeration circuit. The stand-alone condensing stage closed loops are is in parallel one to another with a condenser of the condensing stage and each comprise comprises a second refrigerant circulating between at least a heat absorption stage, wherein the second refrigerant absorbs heat from the first refrigerant in the main refrigeration circuit so as to condense the first refrigerant to the liquid state, and a heat release stage, wherein the second refrigerant releases the absorbed heat. The condensing stage has modulating valves for selectively and quantitatively modulating the temperature of said first refrigerant and compressor head pressure.

Abstract: A method and apparatus for using a secondary refrigerant to precool and liquefy a primary refrigerant, then vaporizing and expanding the primary refrigerant to cool a cold tip of a cryosurgical instrument for ablation of biological tissue, such as cardiovascular tissue, in particular endocardiac tissue and tissue inside a cardiac blood vessel. The secondary refrigerant has a critical temperature above the critical temperature of the primary refrigerant, and a cooling temperature below the critical temperature of the primary refrigerant, thereby facilitating the use of the precooling step to provide liquid primary refrigerant in an operating room environment in which the primary refrigerant could not otherwise be provided in the liquid phase.