A large-cooling-capacity integrated Stirling pneumatic refrigerator supported by large-stroke column springs, consisting of an active vibration absorber, a motor, a coaxial type compression-expansion piston, a compression piston column spring, an expansion piston column spring, a hot-end radiator, a cylinder wall, a housing, and a cold finger, wherein the coaxial compression-expansion piston is composed of a compression piston and an expansion piston, the expansion piston is nested in the compression piston, and the compression piston and the expansion piston share one hot-end radiator; the compression piston is driven by a motor, and the expansion piston is driven by gas force and no motor drive is required. The compression piston and the expansion piston are both supported by column springs, the column spring provides an axial restoring force for the coaxial type compression-expansion piston. The active vibration absorber is installed at the tail part of the housing.

A duct is provided and includes a tubular member having an inlet portion, an outlet portion and a central portion interposed between the inlet and outlet portions and a tributary tubular member fluidly coupled to the tubular member at the central portion. The tributary tubular member includes first and second torus sectors defining first and second apertures, respectively, through which an upstream end of the central portion extends. The second torus sector is disposed within the first torus sector to define a sectioned toroidal annulus about the first and second apertures and between an exterior surface of the second torus sector and an interior surface of the first torus sector.

A duct is provided and includes a tubular member having an inlet portion, an outlet portion and a central portion interposed between the inlet and outlet portions and a tributary tubular member fluidly coupled to the tubular member at the central portion. The tributary tubular member includes first and second torus sectors defining first and second apertures, respectively, through which an upstream end of the central portion extends. The second torus sector is disposed within the first torus sector to define a sectioned toroidal annulus about the first and second apertures and between an exterior surface of the second torus sector and an interior surface of the first torus sector.

The cryocooler includes an expander motor that operates an expander of the cryocooler, an inverter that is configured to control an operation frequency of the expander motor and is operable to drive the expander motor in the steady operation at an operation frequency lower than in the cool-down operation, a current sensor that measures a current supplied from the inverter to the expander motor, and outputs a motor current signal indicating the current; and a processor that monitors the expander motor on a basis of the motor current signal in at least the steady operation.

A gas turbine engine has a compressor section, a combustor, and a turbine section. An associated fluid is to be cooled and an associated fluid is to be heated. A transcritical vapor cycle heats the fluid to be heated, and cools the fluid to be cooled. The transcritical vapor cycle includes a gas cooler in which the fluid to be heated is heated by a refrigerant in the transcritical vapor cycle. An evaporator heat exchanger at which the fluid to be cooled is cooled by the refrigerant in the transcritical vapor cycle. A compressor upstream of the gas cooler compresses the refrigerant to a pressure above a critical point for the refrigerant. An expansion device expands the refrigerant downstream of the gas cooler, with the evaporator heat exchanger being downstream of the expansion device, and such that the refrigerant passing through the gas cooler to heat the fluid to be heated is generally above the critical point.

A gas turbine engine has a compressor section, a combustor, and a turbine section. An associated fluid is to be cooled and an associated fluid is to be heated. A transcritical vapor cycle heats the fluid to be heated, and cools the fluid to be cooled. The transcritical vapor cycle includes a gas cooler in which the fluid to be heated is heated by a refrigerant in the transcritical vapor cycle. An evaporator heat exchanger at which the fluid to be cooled is cooled by the refrigerant in the transcritical vapor cycle. A compressor upstream of the gas cooler compresses the refrigerant to a pressure above a critical point for the refrigerant. An expansion device expands the refrigerant downstream of the gas cooler, with the evaporator heat exchanger being downstream of the expansion device, and such that the refrigerant passing through the gas cooler to heat the fluid to be heated is generally above the critical point.

Various systems and methods for suppling cryogenic refrigeration to supercomputing applications such as quantum computing operations are provided. The disclosed systems and methods are flexible, efficient and scaleable to meet the cryogenic refrigeration requirements of many supercomputing applications. The disclosed systems and methods include: (i) a liquid nitrogen based integrated refrigeration system that integrates a nitrogen refrigerator with a refrigeration load circuit; (ii) a closed loop liquid nitrogen based refrigerator that provides cooling to the refrigeration load circuit via indirect heat exchange between liquid nitrogen in a nitrogen refrigerator and a separate refrigerant in a closed-loop refrigeration load circuit; and (iii) a liquid air based integrated refrigeration system that integrates an air intake system with a refrigerator and a refrigeration load circuit.

A system and method are disclosed for cooling ambient air to be supplied as combustion air to a gas turbine. The system comprises a closed coolant loop direct expansion cooling system including a compressor for compressing a suitable working fluid, an expansion device downstream from the compressor for expanding the working fluid so as to cool a cooling coil. The cooling coil is in heat exchange relation with ambient air flowing to the gas turbine for lowering the temperature of the ambient air to a lower temperature such that combustion air delivered to the gas turbine is below the ambient temperature thereby to increase the efficiency of the gas turbine. A return line is provided for returning the working fluid to the compressor.

A system and method are disclosed for cooling ambient air to be supplied as combustion air to a gas turbine. The system comprises a closed coolant loop direct expansion cooling system including a compressor for compressing a suitable working fluid, an expansion device downstream from the compressor for expanding the working fluid so as to cool a cooling coil. The cooling coil is in heat exchange relation with ambient air flowing to the gas turbine for lowering the temperature of the ambient air to a lower temperature such that combustion air delivered to the gas turbine is below the ambient temperature thereby to increase the efficiency of the gas turbine. A return line is provided for returning the working fluid to the compressor.

Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.