The disclosed technology includes a heat pump having a thermal energy storage (TES) material. The heat pump can include a first heat exchanger to exchange heat between ambient air and refrigerant, a second heat exchanger to exchange heat between the refrigerant and air supplied to a climate-controlled space, and a third heat exchanger to exchange heat between the TES material and the refrigerant in a first fluid path and the refrigerant in a second fluid path. The heat pump can include a first compressor to circulate refrigerant to the first, second, and third heat exchangers and a second compressor to circulate refrigerant to the second and third heat exchangers. The first compressor can facilitate heat exchange between the ambient air and the TES material and the second compressor can facilitate heat exchange between the TES material and the air supplied to the climate-controlled space.

The disclosed technology includes systems and methods for a heat pump water heater. The disclosed technology can include a heat pump water heater system having an evaporator, a condenser, a vapor injection line, a compressor, and a multi-fluid heat exchanger. The vapor injection line can include an expansion valve to transition refrigerant received from the condenser at a first pressure to a second pressure. The compressor can be configured to circulate refrigerant through the condenser, the multi-fluid heat exchanger, the vapor injection line, and the evaporator. The multi-fluid heat exchanger can be configured to receive refrigerant at a first pressure from the condenser, refrigerant at a second pressure from the vapor injection line, and water. The multi-fluid heat exchanger can further facilitate heat transfer between the refrigerants at the first and second pressures and the water to preheat the water before the water is passed through the condenser.

The disclosed technology includes systems and methods for a heat pump water heater. The disclosed technology can include a heat pump water heater system having an evaporator, a condenser, a vapor injection line, a compressor, and a multi-fluid heat exchanger. The vapor injection line can include an expansion valve to transition refrigerant received from the condenser at a first pressure to a second pressure. The compressor can be configured to circulate refrigerant through the condenser, the multi-fluid heat exchanger, the vapor injection line, and the evaporator. The multi-fluid heat exchanger can be configured to receive refrigerant at a first pressure from the condenser, refrigerant at a second pressure from the vapor injection line, and water. The multi-fluid heat exchanger can further facilitate heat transfer between the refrigerants at the first and second pressures and the water to preheat the water before the water is passed through the condenser.

An integrated system floods an air conditioning low side heat exchanger such that the air conditioning low side heat exchanger does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger. As a result, both liquid and vapor refrigerant leave the air conditioning low side heat exchanger. The system includes an additional receiver that stores the refrigerant leaving the air conditioning low side heat exchanger. To prevent the liquid refrigerant in the receiver from overflowing, the liquid refrigerant in the receiver is used in a refrigeration system when the level of liquid refrigerant in the receiver exceeds a threshold (e.g., as detected by a sensor in the receiver).

An integrated system floods an air conditioning low side heat exchanger such that the air conditioning low side heat exchanger does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger. As a result, both liquid and vapor refrigerant leave the air conditioning low side heat exchanger. The system includes an additional receiver that stores the refrigerant leaving the air conditioning low side heat exchanger. To prevent the liquid refrigerant in the receiver from overflowing, the liquid refrigerant in the receiver is used in a refrigeration system when the level of liquid refrigerant in the receiver exceeds a threshold (e.g., as detected by a sensor in the receiver).

A system includes a flash tank, a first load, a second load, a first compressor, a second compressor, a first valve, and a second valve. The flash tank stores a refrigerant. The first and second loads use the refrigerant to cool first and second spaces. The first compressor compresses the refrigerant from the first load during a first mode of operation and a flash gas from the flash tank during a second mode of operation. The second compressor compresses a mixture of the refrigerant from the first and second loads during the first mode of operation. The first valve directs the flash gas from the flash tank to the first compressor during the second mode of operation. The second valve directs the compressed flash gas from the first compressor to the first load during the second mode of operation to defrost the first load.

A system includes a flash tank, a first load, a second load, a first compressor, a second compressor, a first valve, and a second valve. The flash tank stores a refrigerant. The first and second loads use the refrigerant to cool first and second spaces. The first compressor compresses the refrigerant from the first load during a first mode of operation and a flash gas from the flash tank during a second mode of operation. The second compressor compresses a mixture of the refrigerant from the first and second loads during the first mode of operation. The first valve directs the flash gas from the flash tank to the first compressor during the second mode of operation. The second valve directs the compressed flash gas from the first compressor to the first load during the second mode of operation to defrost the first load.

A cooling apparatus includes a compressor, a first flow path and a second flow path branched from a branch point, a condenser disposed downstream of the branch point in the first flow path, a first decompressor disposed downstream of the condenser, a plurality of evaporators disposed downstream of the first decompressor and connected in series, a second decompressor disposed downstream of the branch point in the second flow path, a detection unit, and a control unit. The second flow path includes a hot-gas flow path configured to connect an outlet of the second decompressor and a meeting point with the first flow path. The control unit controls a degree of opening of the second decompressor depending on the temperature detected by the first temperature-detection unit and controls a degree of opening of the first decompressor depending on the temperature and/or the pressure detected by the detection unit.

A cooling apparatus includes a compressor, a first flow path and a second flow path branched from a branch point, a condenser disposed downstream of the branch point in the first flow path, a first decompressor disposed downstream of the condenser, a plurality of evaporators disposed downstream of the first decompressor and connected in series, a second decompressor disposed downstream of the branch point in the second flow path, a detection unit, and a control unit. The second flow path includes a hot-gas flow path configured to connect an outlet of the second decompressor and a meeting point with the first flow path. The control unit controls a degree of opening of the second decompressor depending on the temperature detected by the first temperature-detection unit and controls a degree of opening of the first decompressor depending on the temperature and/or the pressure detected by the detection unit.

A cooling system includes a distribution system and a cooling unit. The distribution system is configured to circulate a distribution system refrigerant. The distribution system includes a distribution system pump, a main cooler, a distribution system input conduit, and a distribution system output conduit. The main cooler is configured to receive the distribution system refrigerant from the distribution system pump. The distribution system input conduit is configured to receive the distribution system refrigerant from the main cooler. The distribution system output conduit is configured to receive the distribution system refrigerant from the distribution system input conduit and to provide the distribution system refrigerant to the distribution system pump. The cooling unit is configured to circulate a cooling unit refrigerant. The cooling unit includes a cooling unit pump, an upstream receiver, a condenser, a downstream receiver, and an evaporator. The upstream receiver is configured to receive the cooling unit refrigerant.