A refrigeration system includes a rotary pressure exchanger fluidly coupled to a low pressure branch and a high pressure branch. The rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure branch, to receive the refrigerant at low pressure from the low pressure branch, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger includes the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger includes the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor.

A refrigeration cycle device is configured to be selectively switchable between an air-cooling first refrigerant circuit that causes refrigerant to flow out of a liquid-phase refrigerant outlet of a gas-liquid separator, and an air-heating second refrigerant circuit that causes the refrigerant to flow out of a gas-phase refrigerant outlet of the gas-liquid separator. In the refrigeration cycle device, an oil separator is disposed in a refrigerant passage that leads from a heat dissipation device to a first expansion valve. Thus, when the first refrigerant circuit is configured in the refrigeration cycle device, the refrigerant passing through the oil separator is in a single gas phase or in an almost gas phase, so that oil can be easily separated from the refrigerant. Furthermore, when the refrigerant circulates through the first refrigerant circuit, oil can be retained at a position other than the gas-liquid separator.

A method for controlling a valve arrangement (12), e.g. in the form of a three way valve, in a vapour compression system (1) is disclosed, the vapour compression system (1) comprising an ejector (6). The valve arrangement (12) is arranged to supply refrigerant to a compressor unit (2) from the gaseous outlet (11) of a receiver (7) and/or from the outlet of an evaporator (9). The vapour compression system (1) may be operated in a first mode of operation (summer mode) or in a second mode of operation (winter mode). When operated in the second mode of operation, it is determined whether or not conditions for operating the vapour compression system (1) in the first mode of operation are prevailing. If this is the case, the valve arrangement (12) is actively switched to the first mode of operation by closing a first inlet (13) towards the evaporator (7) and fully opening a second inlet (14) towards the receiver (7).

The present disclosure relates to the technical field of heat pumps, in particular to an air source CO.sub.2 heat pump system for preventing an evaporator from frosting by using heat of a heat regenerator. The air source CO.sub.2 heat pump system mainly includes an air source heat pump system, a regenerative heat exchange tank and a cooling pump. Through the regenerative heat exchange tank, on the one hand, the temperature drop of regenerative heat of the system is further increased and throttling loss is reduced; on the other hand, the heat generated by the regenerative temperature drop is configured for heat storage used for defrosting, and configured for overheating temperature rise.

A sensor assembly is shown for sensing a crossing of the critical point in a system utilising a working fluid in a transcritical cycle passing through the critical point. A first broadband acoustic sensor is located upstream of a component and a second broadband acoustic sensor is located downstream of the component, each of which are arranged to detect high-frequency and low-frequency sounds caused by the crossing of the critical point. A flow regulation device regulates flow of working fluid through the component in response to the output of one or both of the first broadband acoustic sensor and the second broadband acoustic sensor, thereby adjusting the location of the crossing of the critical point.

A refrigeration cycle apparatus including a heat source side heat exchanger including a first heat exchanger and a second heat exchanger connected in parallel; an air-sending device that supplies air, which is an object to be heat exchanged in the first heat exchanger and the second heat exchanger, in a variable manner; solenoid valves that each opens and closes a refrigerant passage of the first heat exchanger and the second heat exchanger; a third refrigerant circuit that is parallelly connected to the first heat exchanger and the second heat exchanger; and a flow control valve that controls the flow rate of the refrigerant flowing in the third refrigerant circuit. The refrigeration cycle apparatus can improve continuity of control of a heat exchange capacity of a heat source side heat exchanger.

A method for controlling a vapour compression system (1), the vapour compression system (1) comprising a compressor unit (2) comprising one or more compressors (10, 11, 13), is disclosed. At least one of the compressors (11, 13) of the compressor unit (2) is connectable to a gaseous outlet (9) of a receiver (5), and at least one of the compressors (10, 13) of the compressor unit (2) is connectable to an outlet of an evaporator (7). A parameter of the vapour compression system (1) is measured, an enthalpy of refrigerant leaving the heat rejecting heat exchanger (3) being derivable from the measured parameter. A setpoint value for a pressure inside the receiver (5) is calculated, based on the measured parameter, and the compressor unit (2) is operated in accordance with the calculated setpoint value, and in order to obtain a pressure inside the receiver (5) which is equal to the calculated setpoint value. The vapour compression system (1) is operated in an energy efficient manner over a wide range of ambient temperatures.

A refrigeration system includes a refrigeration circuit and a coolant circuit separate from the refrigeration circuit. The refrigerant circuit includes a gas cooler/condenser, a receiver, and an evaporator. The coolant circuit includes a heat exchanger configured to transfer heat from a refrigerant circulating within the refrigeration circuit into a coolant circulating within the coolant circuit, a heat sink configured to remove heat from the coolant circulating within the coolant circuit, and a magnetocaloric conditioning unit configured to transfer heat from the coolant within a first fluid conduit of the coolant circuit into the coolant within a second fluid conduit of the coolant circuit. The first fluid conduit connects an outlet of the heat exchanger to an inlet of the heat sink, whereas the second fluid conduit connects an outlet of the heat sink to an inlet of the heat exchanger.

A cooling system includes a compressor configured to pressurize carbon dioxide to form pressurized carbon dioxide, a mixer configured to generate mixed refrigerant in which the pressurized carbon dioxide and solvent in a liquid state, a depressurization apparatus provided downstream from the mixer and configured to depressurize the mixed refrigerant, a separator configured to separate carbon dioxide in a gas state from the mixed refrigerant, a heat exchanger configured to exchange heat between the mixed refrigerant cooled through depressurization and a fluid to be cooled, and a second heat exchanger configured to cool the carbon dioxide or the mixed refrigerant using vaporized carbon dioxide or the mixed refrigerant.

A refrigeration system is described that includes a compression device configured to increase a pressure of a refrigerant. The refrigeration system further includes a first heat exchanger configured to reject heat from the refrigerant and reduce a temperature of the refrigerant. The refrigeration system further includes a storage device configured to store the refrigerant at a supercritical state. The refrigeration system further includes an expansion device configured to reduce the pressure of the refrigerant. The refrigeration system further includes a second heat exchanger configured to absorb heat into the refrigerant and increase the temperature of the refrigerant. The refrigeration system further includes a controller configured to release the refrigerant from the storage device to the expansion device to provide cooling capacity to the refrigeration system.