A heat exchanger, such as for example, a condenser coil constructed as a fin and microchannel tube is fluidly connected with a volume constructed and configured to store refrigerant in certain operations, such as for example during a pump down operation. The volume is fluidly connected to a fluid port of the heat exchanger, where the fluid port is an inlet (in the cooling mode) to the heat exchanger, such as the high side condensing section of the heat exchanger. The volume receives refrigerant exiting the heat exchanger from the fluid port in a mode other than a cooling mode, e.g., a pump down operation.

A refrigeration apparatus (1) includes a heat-source-side unit (10) using a refrigerant that works in a supercritical region. The heat-source-side unit (10) includes a compression element (20) configured to compress the refrigerant, a heat-source-side heat exchanger (24), an expansion valve (26) provided downstream of the heat-source-side heat exchanger (24), a receiver (25) provided downstream of the expansion valve (26), and a control unit (101). The control unit (101) performs a first operation for evaluating the amount of the refrigerant based on a high-pressure-side pressure, on a first condition that the internal pressure of the receiver (25) be equal to or less than a supercritical pressure.

A pressure fluid handling system includes a closed pressure fluid circuit. The pressure fluid circuit includes, connected in series, a compressor and a pressure sink and a primary pressure fluid route from the compressor to the pressure sink and a secondary pressure fluid route from the pressure sink to the compressor. The pressure fluid handling system further includes a pressure fluid accumulator connected to the pressure fluid circuit via a first pressure fluid accumulator conduit. The first pressure fluid accumulator conduit includes a pump configured to pump pressure fluid from the pressure fluid circuit to the pressure fluid accumulator to lower the pressure levels in the pressure fluid circuit, and in that the pressure fluid handling system includes a controllable component for returning the pressure fluid from the pressure fluid accumulator to the pressure fluid circuit to increase the pressure levels in the pressure fluid circuit.

A refrigeration apparatus includes a refrigerant circuit including: a compressor, a radiator, an expansion mechanism, and an evaporator. The refrigerant circuit encloses a refrigerant that contains a fluorinated hydrocarbon that causes a disproportionation reaction. The refrigerant circuit further includes: a discharged refrigerant recovery receiver that is connected to a path between a discharge side of the compressor and a gas side of the radiator through a discharged refrigerant branch pipe; and a discharged refrigerant relief mechanism that is disposed in the discharged refrigerant branch pipe and that connects the discharge side of the compressor with the discharged refrigerant recovery receiver when the refrigerant on the discharge side of the compressor satisfies a predetermined condition. The predetermined condition includes at least one of a first condition under which the refrigerant does not yet cause the disproportionation reaction and a second condition under which the refrigerant causes the disproportionation reaction.

A refrigerator cooling system, comprising a pipe forming a loop and, sequentially provided on the pipe, a compressor, a condenser, a refrigerant amount regulator, a capillary tube, and an evaporator. The refrigerant amount regulator comprises a storage device and an adjustor provided within the storage device. The storage device is provided therein with a storage cavity for holding a refrigerant. The storage device is provided with an opening for the storage cavity to be in communication with the pipe. The adjustor comprises a sealer used for opening or closing the opening.

A multi-air conditioner for heating/cooling operations, including at least one indoor unit for heating/cooling operations including an indoor heat exchanger; and an outdoor unit for heating/cooling operations including a compressor, an outdoor heat exchanger, and a switching unit configured to be disposed in a discharge side of the compressor to switch a flow of refrigerant. The outdoor unit includes a receiver that selectively stores refrigerant or oil according to a cooling or heating operation mode and provides the stored refrigerant or oil to the compressor. Accordingly, in the accumulator of the multi-air conditioner using the receiver, the receiver which is not used in the heating mode may be converted and used for oil storage, thereby preventing oil burnout without adding structure.

A heat pump device comprises a refrigerant circuit in which a compressor, a first indoor heat exchanger, an electric expansion valve, and a heat source-side heat exchanger are connected in a loop, a second indoor heat exchanger arranged between the compressor and the electric expansion valve and configured to store refrigerant during positive cycle defrost operation, an electromagnetic valve arranged between the second indoor heat exchanger and the electric expansion valve and configured to adjust an amount of refrigerant stored in the second indoor heat exchanger during the positive cycle defrost operation, and a control device that controls the compressor and the electric expansion valve.

A refrigeration apparatus (1) includes a heat-source-side unit (10) using a refrigerant that works in a supercritical region. The heat-source-side unit (10) includes a compression element (20) configured to compress the refrigerant, a heat-source-side heat exchanger (24), an expansion valve (26) provided downstream of the heat-source-side heat exchanger (24), a receiver (25) provided downstream of the expansion valve (26), and a control unit (101). The control unit (101) performs a first operation for evaluating the amount of the refrigerant based on a high-pressure-side pressure, on a first condition that the internal pressure of the receiver (25) be equal to or less than a supercritical pressure.

A multi-type air conditioner is provided that includes an outdoor unit having a liquid pipe through which a liquid refrigerant flows, and a gas pipe through which a gas refrigerant flows; a plurality of indoor units including a first indoor unit and a second indoor unit each connected to the liquid pipe and the gas pipe to circulate a refrigerant; a gas pipe connecting tube connecting the gas pipe and the plurality of indoor units so that a gas refrigerant flows therethrough; and a liquid pipe connecting tube connecting the liquid pipe and the plurality of indoor units so that a liquid refrigerant flows therethrough.

A refrigeration system has a main refrigeration circuit including a compression stage, a condensing stage, and an evaporation stage, a refrigerant circulating between the compression stage, the condensing stage and the evaporation stage in a refrigeration cycle. An integrated transfer system is in closeable and openable fluid communication with the main refrigeration circuit, the transfer system including a receiver. Valves are operable to selectively open the fluid communication between the main refrigeration circuit and the transfer system. A motive force source displaces refrigerant from the main refrigeration circuit to the transfer system.