Abstract: The control section implements: a utilization cooling operation in which the thermal storage medium absorbs heat from the refrigerant and in which the refrigerant evaporates in the indoor heat exchanger, when the receiving section receives a first signal indicating a request for reduced use of power during an operation in which the room is cooled by the refrigerant evaporating in the indoor heat exchanger; and a cooling and cold thermal energy storage operation in which the refrigerant absorbs heat from the thermal storage medium and in which the refrigerant evaporates in the indoor heat exchanger, when the receiving section receives a second signal indicating a request for accelerated use of power during the operation in which the room is cooled by the refrigerant evaporating in the indoor heat exchanger.

Abstract: To avoid decline in the efficiency of a compressor at a low load, a thermal storage air conditioner has a refrigerant circuit (11) which has a compressor (22), an outdoor heat exchanger (23), and an indoor heat exchanger (72) and performs a refrigeration cycle, and a thermal storage section (60) which has a thermal storage medium and exchanges heat between the thermal storage medium and a refrigerant of the refrigerant circuit (11). The thermal storage air conditioner performs a simple cooling operation in which in the refrigerant circuit (11), the refrigerant is condensed in the outdoor heat exchanger (23) and evaporates in the indoor heat exchanger (72), and a cooling and cold thermal energy storage operation in which in the refrigerant circuit (11), the refrigerant is condensed in the outdoor heat exchanger (23) and evaporates in the indoor heat exchanger (72), and in which the thermal storage medium in the thermal storage section (60) is cooled by the refrigerant.

Abstract: To avoid decline in the efficiency of a compressor at a low load, the thermal storage air conditioner has an operation controller which, if a rotational speed of the compressor is slowed down to a predetermined lower reference value in a simple cooling operation, switches operation of the thermal storage air conditioner from the simple cooling operation to a cooling and cold thermal energy storage operation to increase the rotational speed of the compressor. During the simple cooling operation refrigerant is condensed in the outdoor heat exchanger and evaporates in the indoor heat exchanger, and during a cooling and cold thermal energy storage operation the refrigerant is condensed in the outdoor heat exchanger, evaporates in the indoor heat exchanger, and the thermal storage medium in the thermal storage section is cooled by the refrigerant.

Abstract: To avoid decline in the efficiency of a compressor at a low load, a thermal storage air conditioner has a refrigerant circuit (11) which has a compressor (22), an outdoor heat exchanger (23), and an indoor heat exchanger (72) and performs a refrigeration cycle, and a thermal storage section (60) which has a thermal storage medium and exchanges heat between the thermal storage medium and a refrigerant of the refrigerant circuit (11). The thermal storage air conditioner performs a simple cooling operation in which in the refrigerant circuit (11), the refrigerant is condensed in the outdoor heat exchanger (23) and evaporates in the indoor heat exchanger (72), and a cooling and cold thermal energy storage operation in which in the refrigerant circuit (11), the refrigerant is condensed in the outdoor heat exchanger (23) and evaporates in the indoor heat exchanger (72), and in which the thermal storage medium in the thermal storage section (60) is cooled by the refrigerant.

Abstract: To avoid decline in the efficiency of a compressor at a low load, a thermal storage air conditioner has a refrigerant circuit (11) which has a compressor (22), an outdoor heat exchanger (23), and an indoor heat exchanger (72) and performs a refrigeration cycle, and a thermal storage section (60) which has a thermal storage medium and exchanges heat between the thermal storage medium and a refrigerant of the refrigerant circuit (11). The thermal storage air conditioner performs a simple cooling operation in which in the refrigerant circuit (11), the refrigerant is condensed in the outdoor heat exchanger (23) and evaporates in the indoor heat exchanger (72), and a cooling and cold thermal energy storage operation in which in the refrigerant circuit (11), the refrigerant is condensed in the outdoor heat exchanger (23) and evaporates in the indoor heat exchanger (72), and in which the thermal storage medium in the thermal storage section (60) is cooled by the refrigerant.

Abstract: The control section implements: a utilization cooling operation in which the thermal storage medium absorbs heat from the refrigerant and in which the refrigerant evaporates in the indoor heat exchanger, when the receiving section receives a first signal indicating a request for reduced use of power during an operation in which the room is cooled by the refrigerant evaporating in the indoor heat exchanger; and a cooling and cold thermal energy storage operation in which the refrigerant absorbs heat from the thermal storage medium and in which the refrigerant evaporates in the indoor heat exchanger, when the receiving section receives a second signal indicating a request for accelerated use of power during the operation in which the room is cooled by the refrigerant evaporating in the indoor heat exchanger.

Abstract: A discharge muffler includes a muffler container. In the muffler container, refrigerating machine oil is separated from refrigerant gas containing the refrigerating machine oil, and the refrigerating machine oil is stored in a lower space. An inlet of an outlet pipe connected to the muffler container opens in the lower space.

Abstract: A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism, a second expansion mechanism, an evaporator, a first internal heat exchanger, a branch pipe a third expansion mechanism, and a second internal heat exchanger. The first internal heat exchanger causes heat to be exchanged between refrigerant that flows from the radiator to the inflow side of the first expansion mechanism, and refrigerant that flows from the evaporator to the compression mechanism. The branch pipe branches from a third refrigerant pipe for connecting the radiator and the second expansion mechanism, and merges with the second refrigerant pipe. A third expansion mechanism is provided to the branch pipe. The second internal heat exchanger causes heat to be exchanged between refrigerant that flows out from the first expansion mechanism, and refrigerant that flows out from the third expansion mechanism.

Abstract: A discharge muffler includes a muffler container. In the muffler container, refrigerating machine oil is separated from refrigerant gas containing the refrigerating machine oil, and the refrigerating machine oil is stored in a lower space. An inlet of an outlet pipe connected to the muffler container opens in the lower space.

Abstract: A refrigerant circuit (15) is provided with a low-pressure stage oil separator (26) for separating refrigerating machine oil out of refrigerant discharged from a low-pressure stage compressor (21) and returning it to the suction side of the low-pressure stage compressor (21), and a high-pressure stage oil separator (36) for separating refrigerating machine oil out of refrigerant discharged from a high-pressure stage compressor (31) and returning it to the suction side of the high-pressure stage compressor (31). The efficiency of oil separation of the low-pressure stage oil separator (26) is set lower than that of the high-pressure stage oil separator (36).

Abstract: A refrigerant circuit (11) includes an oil separator (60) configured to separate oil from high pressure refrigerant, and an oil feed circuit (70) configured to feed the oil separated in the oil separator (60) to a compression mechanism (20) so as to cool the refrigerant in the course of a compression phase of the compression mechanism (20). The oil feed circuit (70) includes a recovery mechanism (40) configured to recover energy of the oil separated in the oil separator (60). In the compression mechanism (20), the refrigerant is cooled by the oil, thereby reducing power of the compression mechanism (20). Simultaneously, in the recovery mechanism (40), power required to increase pressure of the oil in the compression mechanism (20) is recovered.

Abstract: A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism, a second expansion mechanism, an evaporator, a first internal heat exchanger, a branch pipe, a third expansion mechanism, and a second internal heat exchanger. The first internal heat exchanger causes heat to be exchanged between refrigerant that flows from the radiator to the inflow side of the first expansion mechanism, and refrigerant that flows from the evaporator to the compression mechanism. The branch pipe branches from a third refrigerant pipe for connecting the radiator and the second expansion mechanism, and merges with the second refrigerant pipe. A third expansion mechanism is provided to the branch pipe. The second internal heat exchanger causes heat to be exchanged between refrigerant that flows out from the first expansion mechanism, and refrigerant that flows out from the third expansion mechanism.

Abstract: A refrigeration system includes a refrigerant circuit including a gas-liquid separator (18) and operating in a two-stage compression and two-stage expansion refrigeration cycle. In the refrigerant circuit, intermediate-pressure gas-liquid two-phase refrigerant having flowed through an intermediate expansion valve after flowing through an outdoor heat exchanger is introduced through an inflow pipe (20) of the gas-liquid separator (18) into the vessel body (16) thereof and separated therein into liquid refrigerant and gas refrigerant. The liquid refrigerant flows out through a liquid outflow pipe (30), then flows through a main expansion valve and then through a refrigeration heat exchanger and is then sucked into a low-pressure stage compressor. The gas refrigerant flows out through a gas outflow pipe (40), is then fed to the suction side of a high-pressure stage compressor and is then sucked into the high-pressure stage compressor together with refrigerant discharged from the low-pressure stage compressor.

Abstract: A refrigeration system (10) includes: a refrigerant circuit (15) including a low-pressure stage compressor (21) variable in displacement and a high-pressure stage compressor (31) variable in displacement and operating in a two-stage compression refrigeration cycle; and a controller (100) for controlling the operation of the refrigeration system (10). The controller (100) includes a first control section (101) and a second control section (102). The first control section (101) controls the operating capacity of the low-pressure stage compressor (21) to adapt to the load of the refrigeration capacity.

Abstract: A refrigerant circuit (15) is provided with a low-pressure stage oil separator (26) for separating refrigerating machine oil out of refrigerant discharged from a low-pressure stage compressor (21) and returning it to the suction side of the low-pressure stage compressor (21), and a high-pressure stage oil separator (36) for separating refrigerating machine oil out of refrigerant discharged from a high-pressure stage compressor (31) and returning it to the suction side of the high-pressure stage compressor (31). The efficiency of oil separation of the low-pressure stage oil separator (26) is set lower than that of the high-pressure stage oil separator (36).