An apparatus includes a flash tank, a medium temperature low side heat exchanger, a low temperature low side heat exchanger, a first compressor, a second compressor, and an ejector. The flash tank stores a refrigerant. The medium temperature low side heat exchanger uses the refrigerant from the flash tank to cool a space proximate the medium temperature low side heat exchanger to a first temperature. The low temperature low side heat exchanger uses the refrigerant from the flash tank to cool a space proximate the low temperature low side heat exchanger to a second temperature that is lower than the first temperature. The first compressor compresses the refrigerant from the low temperature low side heat exchanger. The second compressor compresses the refrigerant from the medium temperature low side heat exchanger. The ejector directs a mixture of the refrigerant from the first compressor and the refrigerant from the second compressor to the low temperature low side heat exchanger during a defrost cycle. The mixture defrosts the low temperature low side heat exchanger. The flash tank receives the mixture.

A two-stage refrigeration apparatus (500) includes a first cycle (510) and a second cycle (520). The first cycle (510) includes a first compressor (511), a first condenser (512), a first expansion mechanism (513), and a first evaporator (514) that are arranged in such a manner as to be connected to the first cycle. A first refrigerant circulates through the first cycle. The second cycle (520) includes a second downstream-side condenser (523) and a second evaporator (527) that are arranged in such a manner as to be connected to the second cycle. A second refrigerant circulates through the second cycle. The first evaporator (514) and the second downstream-side condenser (523) constitute a cascade condenser (531). In the cascade condenser (531), heat is exchanged between the first refrigerant and the second refrigerant. At least one of the first refrigerant and the second refrigerant is a refrigerant mixture containing at least 1,2-difluoroethylene (FO-1132(E)).

A cooling system may include a cooling pump, a cooling source, a thermal energy storage, a mixing valve, a recharge valve, a recharge pump. The mixing valve may be in fluid communication with a thermal load. A first input of the mixing valve may be in fluid communication with the thermal energy storage. A second input of the mixing valve may be in fluid communication with the recharge pump. Operation of the recharge pump may cause heated cooling fluid output from the thermal load to bypass the cooling pump and flow to the second input of the mixing valve. The recharge valve may be in fluid communication with the thermal energy storage and the cooling pump. The recharge valve may regulate a recharge fluid flow comprising cooling fluid received from the thermal energy storage.

A refrigeration cycle apparatus is provided with a refrigerant circuit, a refrigerant tank circuit, and a degassing pipe. The refrigerant circuit is configured by connecting a compressor, a flow path switching apparatus, a first heat exchanger, a decompressing apparatus, and a second heat exchanger. The refrigerant tank circuit is connected to the first and second heat exchangers in parallel with the decompressing apparatus. The degassing pipe has a first end and a second end. The flow path switching apparatus is configured to switch a flow of refrigerant discharged from the compressor to any of the first and second heat exchangers. The refrigerant tank circuit contains a refrigerant tank. The degassing pipe has the first end connected to the refrigerant tank and has the second end connected to at least any of the refrigerant circuit and the refrigerant tank circuit.

A control unit is configured to set a rotation speed of a compressor to be lower than that in a defrosting operation and set an opening degree of a pressure reducing device to be equal to or greater than that in the defrosting operation during a first control time after completion of the defrosting operation, stop the compressor and set the opening degree of the pressure reducing device to be less than that in the first control time during a second control time after lapse of the first control time, and control a refrigerant circuit switching device to resume a heating operation after lapse of the second control time.

A refrigeration cycle apparatus includes an outdoor unit including a compressor, a first heat exchanger, and a first expansion valve, an indoor unit including a second expansion valve and a second heat exchanger, and a first pipe and a second pipe connected between the outdoor unit and the indoor unit. In a cooling operation, refrigerant delivered from the compressor sequentially passes through the first heat exchanger, the first expansion valve, the first pipe, the second expansion valve, the second heat exchanger, and the second pipe and returns to the compressor, and in the cooling operation, the first expansion valve converts refrigerant from a liquid-phase state to a two-phase state and sends two-phase refrigerant to the first pipe.

An apparatus includes a flash tank, a load, a first compressor, a coil, a first pipe, and a second compressor. The flash tank stores a refrigerant. The load uses the refrigerant from the flash tank to cool a space proximate the load. The first compressor compresses the refrigerant from the load. The coil within the flash tank receives the refrigerant from the first compressor such that the received refrigerant is within the coil. The refrigerant stored within the flash tank cools the refrigerant within the coil. The first pipe is within the flash tank. The first pipe directs the refrigerant from within the coil out of the flash tank. The second compressor compresses the refrigerant directed out of the flash tank.

An apparatus includes a high side heat exchanger, a subcooler heat exchanger, a flash tank, a load, and a compressor. The high side heat exchanger removes heat from a refrigerant. The subcooler heat exchanger receives the refrigerant. The flash tank stores the refrigerant. During a first mode of operation, the load uses the refrigerant to cool a space proximate the load and the compressor compresses the refrigerant. During a second mode of operation, the subcooler heat exchanger receives the refrigerant from the flash tank, transfers heat from the refrigerant from the high side heat exchanger to the refrigerant from the flash tank and directs the refrigerant from the flash tank to the compressor. During the second mode of operation, the compressor compresses the refrigerant from the subcooler heat exchanger and directs the compressed refrigerant to the load to defrost the load.

A liquid slug reduction and charge compensator device for use in air conditioning and heat pump systems includes a housing having a cavity. The housing includes an inlet port providing an entry path into the cavity and an outlet port providing an exit path from the cavity. The housing further includes a liquid line port providing a refrigerant pathway into and out of the cavity. The liquid slug reduction and charge compensator device further comprises a flash tube extending through the cavity and providing a passageway through the cavity such that a hot gas refrigerant that enters the cavity through the inlet port causes a liquid refrigerant that enters the flash tube to evaporate.

The present disclosure provides an accumulating/receiving device for a heat pump system. The accumulating/receiving device includes a body, an inlet, a first outlet, and a second outlet. The body defines therein a space. The body is disposed downstream of an outside heat exchanger. The inlet is connected to the outside heat exchanger through a first conduit. The first outlet is connected to an inside heat exchanger through a second conduit. The second outlet is connected, through a bypass conduit, to a third conduit. A liquid of the refrigerant flows out of the body through the first outlet in a cooling mode. A vapor of the refrigerant flows out of the body through the second outlet in a heating mode.