An ejector refrigeration circuit comprises a high pressure ejector circuit comprising in the direction of flow of a circulating refrigerant: a heat rejecting heat exchanger/gas cooler having an inlet side and an outlet side; at least two variable ejectors (6, 7) with different capacities connected in parallel, each of the variable ejectors comprising a primary high pressure input port, a secondary low pressure input port and an output port; wherein the primary high pressure input ports of the at least two variable ejectors are fluidly connected to the outlet side of the heat rejecting heat exchanger/gas cooler; a receiver, having an inlet, a liquid outlet, and a gas outlet, wherein the inlet is fluidly connected to the output ports of the at least two variable ejectors; at least one compressor having an inlet side and an outlet side.

An apparatus includes a separator tank, a heat exchanger, a compressor-less heat separator, and a fluid cooler. The separator tank separates a first refrigerant into a vapor component and a liquid component. The heat exchanger is exposed to a load. The heat exchanger uses the liquid component of the first refrigerant to remove heat from a space proximate the load. The space includes at least one of a refrigeration unit and walk-in cooler or freezer. The compressor-less heat separator extracts heat from the vapor component of the first refrigerant and uses electrical power to move the heat to a second refrigerant. The fluid cooler removes heat from the second refrigerant.

A method for controlling a valve arrangement (12), e.g. in the form of a three way valve, in a vapor compression system (1) is disclosed, the vapor 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 vapor 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 vapor 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).

A non-condensable gas purge system is configured to be used in a chiller system that uses a low pressure refrigerant in a loop refrigeration circuit. The non-condensable gas purge system includes a purge tank and a purge heat exchanger coil arranged inside the purge tank. The purge tank has a tank inlet for receiving the low pressure refrigerant from a condenser of the refrigeration circuit, a tank outlet for returning the low pressure refrigerant to an evaporator of the refrigeration circuit, and a purge outlet for purging non-condensable gas from the purge tank to the ambient atmosphere. The purge heat exchanger coil is fluidly connected to the loop refrigeration circuit such that the low pressure refrigerant contained in the loop of the chiller system can pass through the purge heat exchanger coil. Refrigerant in the purge tank is condensed by the heat exchanger coil while non-condensable gases remain gaseous.

An apparatus includes a separator tank, a heat exchanger, a compressor-less heat separator, and a fluid cooler. The separator tank separates a first refrigerant into a vapor component and a liquid component. The heat exchanger is exposed to a load. The heat exchanger uses the liquid component of the first refrigerant to remove heat from a space proximate the load. The space includes at least one of a refrigeration unit and walk-in cooler or freezer. The compressor-less heat separator extracts heat from the vapor component of the first refrigerant and uses electrical power to move the heat to a second refrigerant. The fluid cooler removes heat from the second refrigerant.

An ejector refrigeration circuit (1) comprises a high pressure ejector circuit (3) comprising in the direction of flow of a circulating refrigerant: a heat rejecting heat exchanger/gas cooler (4) having an inlet side (4a) and an outlet side (4b); at least two variable ejectors (6, 7) with different capacities connected in parallel, each of the variable ejectors (6, 7) comprising a primary high pressure input port (6a, 7a), a secondary low pressure input port (6b, 7b) and an output port (6c, 7c); wherein the primary high pressure input ports (6a, 7a) of the at least two variable ejectors (6, 7) are fluidly connected to the outlet side (4b) of the heat rejecting heat exchanger/gas cooler (4); a receiver (8), having an inlet (8a), a liquid outlet (8c), and a gas outlet (8b), wherein the inlet (8a) is fluidly connected to the output ports (6c, 7c) of the at least two variable ejectors (6, 7); at least one compressor (2a, 2b, 2c) having an inlet side (21a, 21 b, 21c) and an outlet side (22a, 22b, 22c), the inlet side (21a, 21 b, 21c) of the at least one compressor (2a, 2b, 2c) being fluidly connected to the gas outlet (8b) of the receiver (8), and the outlet side (22a, 22b, 22c) of the at least one compressor (2a, 2b, 2c) being fluidly connected to the inlet side (4a) of the heat rejecting heat exchanger/gas cooler (4). The ejector refrigeration circuit (1) further comprises a refrigerating evaporator flowpath (5) comprising in the direction of flow of the circulating refrigerant: at least one refrigeration expansion device (10) having an inlet side (10a), fluidly connected to the liquid outlet (8c) of the receiver (8), and an outlet side (7b); at least one refrigeration evaporator (12) fluidly connected between the outlet side (10b) of the at least one refrigeration expansion device (10) and the secondary low pressure input ports (6b, 7b) of the at least two variable ejectors (6, 7).

A flash tank economizer includes a sensor for sensing a condition indicative of pressure in the flash tank, and when that pressure is found to equal or exceed the critical pressure of the particular refrigerant being used, a controller responsively closes a valve in the economizer vapor line to shut off the economizer. A sensor is also provided to sense the pressure at the compressor mid-stage, and if that pressure is found to exceed the pressure in the flash tank, the controller causes the flow control device to function so as to prevent the flow of refrigerant from the compressor mid-stage to the flash tank. Provision is also made for selectively draining refrigerant from the flash tank to reduce the pressure therein from a supercritical to a subcritical condition.

A refrigeration and air-conditioning apparatus rapidly varies the pressure or the temperature inside a liquid reserve container to identify a liquid level position inside the liquid reserve container on the basis of the surface temperature of the liquid reserve container.