Abstract: An air-conditioning management system includes: an air conditioning apparatus configured to carry out a refrigerant recovery operation of recovering a refrigerant from a refrigerant circuit that connects an outdoor unit and an indoor unit and sending the recovered refrigerant to each recovery unit of the outdoor unit; and a control unit configured to make a determination whether all the recovered refrigerant is sendable to each recovery unit before a start of the refrigerant recovery operation by the air conditioning apparatus, and to output, when determining that all the recovered refrigerant is not sendable to each recovery unit, a command for notifying the determination.

Abstract: A ventilation system 1 includes: a refrigerant circuit 60; an air supply fan 22 that draws outdoor air into an indoor space through a first heat exchanger 12 of the refrigerant circuit 60; an exhaust fan 42 that exhausts indoor air to an outdoor space through a second heat exchanger 32 of the refrigerant circuit 60; a temperature sensor 24 for detecting a blow-out temperature TS of the air supply fan 22; a monitoring sensor 80 for detecting indoor state information CT; and a control unit CU that adjusts indoor ventilation rate. The types of control modes performed by the control unit CU include a first mode and a second mode described below. First mode: A control mode having higher weighting on the state information CT, among the state information CT and the blow-out temperature TS that are usable for adjusting the indoor ventilation rate.

Abstract: A cascade unit is a cascade unit of a refrigeration system including a first circuit, a second circuit, and a cascade heat exchanger. The first circuit includes a first connecting portion that connects a first pipe and a second pipe extending from the cascade heat exchanger, of the first pipe and the second pipe connecting a first heat exchanger and the cascade heat exchanger), to the first pipe and the second pipe extending from the first heat exchanger inside or outside a cascade casing. The second circuit includes a second connecting portion that connects a liquid pipe and gas pipes extending from the cascade heat exchanger, among the liquid pipe and the gas pipes connecting second heat exchangers and the cascade heat exchanger, to the liquid pipe and the gas pipes extending from the second heat exchangers inside or outside the cascade casing.

Abstract: Provided are a refrigerant vessel and a refrigeration cycle apparatus capable of suppressing accumulation of a refrigerating machine oil inside. A secondary-side receiver reserves a refrigerant in a secondary-side refrigerant circuit in which a refrigerant and a refrigerating machine oil circulate, the secondary-side receiver including a vessel body, a first refrigerant pipe connected to the vessel body, and a second refrigerant pipe connected to the vessel body, in which the refrigerating machine oil is incompatible with the refrigerant and has a higher density than the refrigerant, and the second refrigerant pipe extends downward from a bottom part of the vessel body.

Abstract: A cascade unit and a refrigeration cycle apparatus are capable of cooling an electric component. The cascade unit of the refrigeration cycle apparatus includes a primary-side refrigerant circuit that includes a primary-side heat exchanger and in which a primary-side refrigerant flows, a secondary-side refrigerant circuit that includes a secondary-side compressor and a utilization-side heat exchanger and in which a secondary-side refrigerant flows, and a cascade heat exchanger that causes the primary-side refrigerant and the secondary-side refrigerant to exchange heat with each other, the cascade unit including the secondary-side compressor, the cascade heat exchanger, a first electric component, a second electric component, a third electric component, and an electric component fan, and a cascade casing that accommodates the secondary-side compressor, the first electric component, and the electric component fan.

Abstract: A safety valve includes a secondary-side refrigerant circuit that includes a secondary-side receiver that reserves a refrigerant, a flow path switching portion that includes a first connecting portion, a second connecting portion, and a third connecting portion connected to the secondary-side receiver, the flow path switching portion (96) that switches between a first state in which the third connecting portion communicates with the first connecting portion and a second state in which the third connecting portion communicates with the second connecting portion, and a safety valve that includes a safety valve connecting portion connected to the first connecting portion or the second connecting portion, and releases the refrigerant to outside when a refrigerant pressure in the secondary-side receiver satisfies a predetermined condition, in which at least the safety valve connecting portion is made of stainless steel.

Abstract: A cascade unit and a refrigeration cycle apparatus are capable of cooling an electric component. A cascade unit of a refrigeration cycle apparatus includes a primary-side refrigerant circuit that includes a primary-side heat exchanger and through which a primary-side refrigerant flows, a secondary-side refrigerant circuit that includes a secondary-side compressor and a utilization-side heat exchanger and through which a secondary-side refrigerant flows, and a cascade heat exchanger that exchanges heat between the primary-side refrigerant and the secondary-side refrigerant, the cascade unit including the secondary-side compressor, the cascade heat exchanger, a first electric component that drives the secondary-side compressor, a first cooling portion that cools the first electric component with the secondary-side refrigerant flowing through the secondary-side refrigerant circuit, a cascade casing that accommodates the secondary-side compressor, the first electric component, and the first cooling portion.

Abstract: A ventilator includes: a refrigerant circuit through which a refrigerant flows and that includes a compressor, a first heat exchanger, and a second heat exchanger that are connected by a refrigerant pipe; an air supply fan that supplies air from an outdoor space to an indoor space through the first heat exchanger; a first casing that accommodates the first heat exchanger and the air supply fan; an exhaust fan that exhausts air from the indoor space to the outdoor space through the second heat exchanger; a second casing that accommodates the second heat exchanger and the exhaust fan; and a third casing that accommodates the compressor. The first casing is separable from the second casing. The third casing is separable from the first casing and the second casing.

Abstract: A ventilator includes: a refrigerant circuit through which a refrigerant flows and that includes a compressor, first heat exchangers, and a second heat exchanger that are connected by a refrigerant pipe; air supply fans that supply air from an outdoor space to indoor spaces through the first heat exchangers; an exhaust fan that exhausts air from the indoor spaces to the outdoor space through the second heat exchanger; an exhaust-side casing that accommodates the exhaust fan; air supply-side casings that accommodate the air supply fans; and air supply units that accommodate the first heat exchangers and the air supply fans in the air supply-side casings. The exhaust-side casing is separated from the air supply-side casings. The exhaust fan and the exhaust-side casing are disposed in the outdoor space. The air supply units individually supply the air from the outdoor space to the indoor spaces.

Abstract: A primary refrigerant circuit allows circulation of a primary refrigerant, the primary refrigerant circuit including a primary compressor, a cascade heat exchanger, a primary receiver, and a primary heat exchanger. A secondary refrigerant circuit allows circulation of a secondary refrigerant, the secondary refrigerant circuit including a secondary compressor, the cascade heat exchanger, and a utilization heat exchanger; a primary casing accommodating the primary compressor; and a heat source casing accommodating the secondary compressor. The receiver is provided outside the primary casing.

Abstract: A primary refrigerant circuit allows circulation of a primary refrigerant and includes a primary compressor, a cascade heat exchanger, and a primary heat exchanger. A secondary refrigerant circuit allows circulation of a secondary refrigerant and includes a secondary compressor, the cascade heat exchanger, and a utilization heat exchanger. The primary refrigerant circuit includes a first connecting pipe, a primary first connection pipe, and a liquid connecting pipe connecting the cascade heat exchanger and the primary heat exchanger, a primary suction flow path of the primary compressor, a primary subcooling circuit connecting the liquid connecting pipe and the primary suction flow path, and a primary subcooling expansion valve provided in the primary subcooling circuit.

Abstract: A primary refrigerant circuit allows circulation of a primary refrigerant and includes a primary compressor, a cascade heat exchanger, a primary heat exchanger, and a primary switching mechanism. A secondary refrigerant circuit allows circulation of a secondary refrigerant and includes a secondary compressor, the cascade heat exchanger, a utilization heat exchanger, and a secondary switching mechanism. The secondary refrigerant circuit includes a bypass flow path connecting a portion between the utilization heat exchanger and the cascade heat exchanger and a suction flow path of the secondary compressor, and a bypass expansion valve provided on the bypass flow path. Executed is defrosting operation of circulating the primary refrigerant in the order of the primary compressor, the primary heat exchanger, and the cascade heat exchanger, and circulating the second refrigerant in the order of the secondary compressor, the cascade heat exchanger, and the bypass flow path.

Abstract: A primary refrigerant circuit allows circulation of a primary refrigerant and includes a primary compressor, a cascade heat exchanger, a primary heat exchanger, and a primary switching mechanism. A secondary refrigerant circuit allows circulation of a secondary refrigerant and includes a secondary compressor, the cascade heat exchanger, and a utilization heat exchanger; and an indoor fan configured to supply air to exchange heat with the secondary refrigerant flowing in the utilization heat exchanger When a defrosting condition is satisfied during normal operation, the primary refrigerant circulates in the order of the primary compressor, the primary heat exchanger, and the cascade heat exchanger after the indoor fan is stopped and the secondary compressor is operated.

Abstract: A refrigeration cycle system includes: a heat source circuit including a secondary-side compressor, a cascade heat exchanger, a secondary-side switching mechanism, and a suction flow path; a plurality of utilization circuits respectively including utilization-side heat exchanger; a first communication pipe; a second communication pipe; a third communication pipe; a connection path; and a first on-off valve. The first communication pipe and the first heat source pipe connect the plurality of utilization-side heat exchangers and the secondary-side switching mechanism. The second communication pipe and the second heat source pipe connect the plurality of utilization-side heat exchangers and suction flow path. The third communication pipe, the fourth heat source pipe, and the fifth heat source pipe connect the plurality of utilization-side heat exchangers and the cascade heat exchanger. The connection path connects the first communication pipe and the second communication pipe.

Abstract: A refrigeration cycle apparatus includes a primary-side refrigerant circuit in which a first refrigerant circulates and a secondary-side refrigerant circuit in which a second refrigerant circulates. The primary-side refrigerant circuit includes a primary-side compressor, a primary-side flow path of a cascade heat exchanger, a primary-side heat exchanger, and a primary-side switching mechanism.

Abstract: A refrigeration cycle system includes a first cycle and a second cycle. The first cycle is connected with a first compressor, a cascade heat exchanger, a first expansion unit, and a first heat exchanger, and includes a first flow path that connects the first compressor to the cascade heat exchanger, a second flow path that connects the cascade heat exchanger to the first expansion unit, a third flow path that connects the first heat exchanger to the first compressor, and a bypass flow path that connects at least one of the first flow path and the second flow path to the third flow path. The second cycle includes the cascade heat exchanger. In a case of using the cascade heat exchanger as a radiator of the first cycle and a heat sink of the second cycle, the first compressor of the first cycle is started after a flow of a heat medium generates in the cascade heat exchanger in the second cycle.

Abstract: A valve opening circuit mounted on a heat pump device having a valve on a refrigerant circuit includes a DC electric path to which a DC voltage generated from an AC voltage for normal use is applied, a valve drive circuit that opens and closes the valve by using the DC voltage of the DC electric path, a control unit that acquires a control power source voltage based on the DC voltage of the DC electric path and controls the valve drive circuit, and a power feed port connected to the DC electric path and connectable to a DC power source line provided from outside for emergency. The control unit causes the valve drive circuit to open the valve when the AC voltage is lost and the DC voltage is fed from the DC power source line to the power feed port.

Abstract: An outdoor unit 3 of an air conditioner 1 includes an outdoor control unit 31 having a first control mode and a second control mode different from each other as control modes of a refrigerant recovery operation for recovering a refrigerant of a refrigerant circuit 9. A flow rate of the refrigerant in the refrigerant circuit 9 in the first control mode is larger than a flow rate of the refrigerant in the refrigerant circuit 9 in the second control mode.

Abstract: An air-conditioning management system includes: an air conditioning apparatus configured to carry out a refrigerant recovery operation of recovering a refrigerant from a refrigerant circuit that connects an outdoor unit and an indoor unit and sending the recovered refrigerant to each recovery unit of the outdoor unit; and a control unit configured to make a determination whether all the recovered refrigerant is sendable to each recovery unit before a start of the refrigerant recovery operation by the air conditioning apparatus, and to output, when determining that all the recovered refrigerant is not sendable to each recovery unit, a command for notifying the determination.

Abstract: An air conditioning apparatus is an air conditioning apparatus dedicated to cooling and includes a first circuit and a second circuit. The first circuit has an outdoor heat exchanger that cools a first refrigerant by outdoor air. In the second circuit, a first heat transfer medium that is cooled by exchanging heat with the first refrigerant that flows in the first circuit flows. The first refrigerant is a HFO refrigerant having a critical temperature higher than that of R32.