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.

In a cryogenic refrigerator, a displacer has an internal space in which refrigerant gas flows. A cylinder houses the displacer to enable the displacer to perform reciprocating movement and forms an expansion space of the refrigerant gas between the cylinder and a bottom surface of the displacer. The displacer supplies the refrigerant gas to the expansion space during movement inside the cylinder from a bottom dead center to a top dead center. The displacer collects the refrigerant gas from the expansion space during movement inside the cylinder from the top dead center to the bottom dead center. A flow path resistance between the displacer and the expansion space is lower when the displacer is at the bottom dead center than when the displacer is at the top dead center.

A GM cryocooler includes a valve portion which defines a valve group including a first intake valve, a first exhaust valve, and a pressure equalizing valve. A valve rotor of the valve portion includes a rotor plane which is in surface contact with a stator plane of a valve stator. The valve rotor includes a high pressure flow path which is open to the rotor plane to form a portion of the first intake valve, a low pressure flow path which is open to the rotor plane to form a portion of the first exhaust valve, and a pressure equalization flow path which is open to the rotor plane to form a portion of the pressure equalizing valve, and the high pressure flow path, the low pressure flow path, and the pressure equalization flow path are circumferentially arranged around a valve rotation axis on the rotor plane.

Refrigeration device intended to extract heat from at least one member by heat exchange with a working fluid circulating in the working circuit comprising in series: a fluid compression mechanism a fluid cooling mechanism, preferably isobaric or substantially isobaric, a fluid expansion mechanism, and a fluid heating mechanism, in which device the compression mechanism is of the centrifugal compression type and consists of two compression stages arranged in series in the circuit, the device comprising two respective electric drive motors driving the two compression stages, the expansion mechanism consisting of a turbine coupled to the motor of one of the compression stages, the turbine of the expansion mechanism being coupled to the drive motor of the first compression stage.

Refrigeration device intended to extract heat from at least one member by heat exchange with a working fluid circulating in the working circuit comprising in series: a fluid compression mechanism a fluid cooling mechanism, preferably isobaric or substantially isobaric, a fluid expansion mechanism, and a fluid heating mechanism, in which device the compression mechanism is of the centrifugal compression type and consists of two compression stages arranged in series in the circuit, the device comprising two respective electric drive motors driving the two compression stages, the expansion mechanism consisting of a turbine coupled to the motor of one of the compression stages, the turbine of the expansion mechanism being coupled to the drive motor of the first compression stage.

A method for controlling a vapour compression system (1) is disclosed, the vapour compression system (1) comprising at least one compressor (2, 16), a heat rejecting heat exchanger (3), a high pressure expansion device (4, 15, 17), a receiver (5), an evaporator expansion device (6), an evaporator (7) and a gas bypass valve (8), arranged in a refrigerant path. It is registered that the gas bypass valve (8) is malfunctioning or saturated, and a pressure value for a pressure prevailing inside the receiver (5) is obtained. Finally, the vapour compression system (1) is controlled in order to control a gaseous refrigerant supply to the receiver (5) to adjust the pressure prevailing inside the receiver (5) to reach a target pressure level.

The present disclosure relates to the technical field of cryogenic cooling. In particular, the present disclosure relates to a mechanical vibration-isolated, liquid helium consumption-free cryogenic cooling device. The system according to some embodiments of the present disclosure comprises: a closed-cycle cryogenic cooling system, a helium heat exchange gas cooling and vibration isolation interface system, a cryogenic throttle valve cooling system, and a temperature feedback control system. The closed-cycle cooling system includes a cold head, a compressor, and a helium pipeline. The cryogenic throttle valve cooling system is thermally coupled to a low-temperature end of the cooling and vibration isolation interface.

Refrigeration device intended to extract heat from at least one member by heat exchange with a working fluid circulating in the working circuit comprising in series: a fluid compression mechanism a fluid cooling mechanism, preferably isobaric or substantially isobaric, a fluid expansion mechanism, and a fluid heating mechanism, in which device the compression mechanism is of the centrifugal compression type and consists of two compression stages arranged in series in the circuit, the device comprising two respective electric drive motors driving the two compression stages, the expansion mechanism consisting of a turbine coupled to the motor of one of the compression stages, the turbine of the expansion mechanism being coupled to the drive motor of the first compression stage.

A pneumatic cryocooler using a pneumatic motor for use in cryogenically cooling superconductors, which pneumatic cryocooler is capable of operation in strong magnetic fields.

A method for controlling a vapour compression system (1) is disclosed. Malfunctioning of a gas bypass valve (8) is registered. An actual opening degree of the gas bypass valve (8) is derived, and a target opening degree of the gas bypass valve (8) is derived, based on one or more control parameters of the vapour compression system (1). The actual opening degree is compared to the target opening degree, and the vapour compression system (1) is controlled based on the comparison, and in order to match a mass flow of gaseous refrigerant through the gas bypass valve (8) to the actual opening degree of the gas bypass valve (8).