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.

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.

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

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 cryogenic cooling system provided by the present disclosure can achieve extremely low temperatures, as low as 1.4 K (based on helium-4 medium) or 0.2 K (based on helium-3 medium) without the need for the consumption of liquid helium. The disclosed cooling system can also efficiently isolate intrinsic mechanical vibrations of the closed-cycle cooling system. The disclosed cooling system can achieve variable temperature regulation through the temperature feedback control system. The disclosed cooling system can be compatible with ultra-high vacuum environments for high-temperature baking.

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).

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

The invention provides a cryogenic refrigeration installation comprising an enclosure with thermally conductive trays (thermal stages) and plates. A cooling system uses a refrigerator with a helium-based cycle fluid. The cycle circuit incorporates a first storage vessel for liquefied cycle fluid. After initial tray/plate cooling, a first bypass line with an expansion member diverts some cycle fluid to this vessel. Subsequently, the main cycle fluid is cooled by heat exchange with the liquefied fluid in said first vessel before further tray/plate cooling. A key feature is a second bypass line within the enclosure, which further expands a portion of this pre-cooled cycle fluid. This expansion generates an even colder flow (e.g., 1 K to 2 K) to cool an additional tray or plate, facilitating efficient multi-temperature cryogenic cooling.