Abstract: A refrigeration cycle apparatus includes a main circuit and a bypass circuit. The main circuit includes: a compressor; a first condenser; a first refrigerant-to-refrigerant heat exchanger; a first expansion device; a first branching portion; a first evaporator; a third branching; and a fourth branching portion. The bypass includes: a second expansion device; the first refrigerant-to-refrigerant heat exchanger; and a second branching portion. The second branching portion includes a liquid outflow pipe and a gas outflow pipe. The liquid outflow pipe defines one outlet for the refrigerant and is located below the gas outflow pipe. The gas outflow pipe defines another outlet for the refrigerant and is located above the liquid outflow pipe. The one outlet of the second branching portion communicates with the third branching portion. The other outlet of the second branching portion communicates with the fourth branching portion.

Abstract: An air conditioning apparatus includes a plurality of third heat exchangers and flow rate control valves. In a heating mode, a controller opens a flow rate control valve corresponding to a heat exchanger that is being requested to perform air conditioning of the plurality of third heat exchangers, and closes a flow rate control valve corresponding to a heat exchanger that is not being requested to perform air conditioning of the plurality of third heat exchangers. In a defrosting mode, when a temperature of a second heat medium is lower than a first determination temperature, the controller opens a flow rate control valve corresponding to at least one of the heat exchangers that are not being requested to perform air conditioning. The at least one of the heat exchangers is assigned a higher priority than a remaining heat exchanger that is not being requested to perform air conditioning.

Abstract: A refrigeration cycle device with a main circuit, a bypass circuit and a supercooling heat exchanger further includes: a controller to control an opening degree of the bypass expansion valve; a first sensor to detect a temperature at the refrigerant inflow side of the evaporator; and a second sensor to detect a pressure of the non-azeotropic mixed refrigerant flowing from the evaporator, wherein the controller controls the opening degree of the bypass expansion valve using temperatures of the evaporator, that is, the temperature at the refrigerant inflow side and a saturated gas temperature of the non-azeotropic mixed refrigerant calculated from the pressure so as to adjust a flow rate of the non-azeotropic mixed refrigerant flowing into the evaporator, to eliminate the temperature difference in the evaporator for suppressing uneven frost formation on the evaporator, and thus to prevent heat exchange performance from degrading.

Abstract: An air-conditioning apparatus includes a primary-side circuit in which a compressor, a first flow switching device, an outdoor heat exchanger, a second flow switching device, a first expansion device, and a relay heat exchanger are connected by pipes and in which refrigerant circulates; a secondary-side circuit in which the relay heat exchanger, a pump, a plurality of indoor heat exchangers, and heat medium flow control devices are connected by pipes and in which a heat medium circulates; and a controller configured to control the first and second flow switching devices such that in cooling and heating operations, the refrigerant and a heat-source-side fluid flow through the outdoor heat exchanger in opposite directions and the refrigerant flows through the relay heat exchanger in a constant direction. The pump is installed such that the heat medium, the refrigerant flow, and air for an air-conditioning target space flow in particular directions.

Abstract: An air-conditioning apparatus includes: a heat-source-side device that heats or cools a heat medium; a pump that sucks and transfers the heat medium; use-side heat exchangers; a heat medium circuit; flow rate control devices; indoor-side pressure sensors; a pump inlet-side pressure sensor and/or a pump outlet-side pressure sensor; a flow rate detection device that detects a pump flow rate; and a controller that performs a first operation in which the flow rate control devices are individually opened or closed and data regarding a flow passage resistance at a path related to each of the heat exchangers is obtained, and a second operation in which heat is supplied to indoor air, and calculates calculate flow rates of the heat medium that flows through the heat exchangers in the second operation, from pump flow rates and pressures detected by the pressure sensors in the first and second operations.

Abstract: A relay includes a first relay unit and a second relay unit provided between an outdoor unit and an indoor unit to allow refrigerant to circulate between the first relay unit and the outdoor unit and between the second relay unit and the outdoor unit, and a heat medium circuit connecting the first relay unit and the second relay unit to the indoor unit to allow a heat medium to circulate through the heat medium circuit. The second relay unit is installed above or on a top of the first relay unit.

Abstract: An air conditioning apparatus includes: a second heat exchanger; a plurality of third heat exchangers; and a plurality of flow rate control valves. In a defrosting mode, when a heat exchanger that is not being requested to perform air conditioning includes a first device having a set temperature lower than or equal to a current room temperature and a second device which is set so as not to perform air conditioning, a controller is configured to control a first flow rate control valve corresponding to the first device and a second flow rate control valve corresponding to the second device such that a degree of opening of the first flow rate control valve is higher than or equal to a degree of opening of the second flow rate control valve.

Abstract: An air-conditioning apparatus includes outdoor units each including a compressor and outdoor heat exchanger, refrigerant flowing through the outdoor units; an indoor unit including an indoor heat exchanger, a heat medium flowing through the indoor unit; relay devices to which the outdoor units are connected, and to which the indoor unit is connected, each relay device includes a heat medium heat exchanger that exchanges heat between the refrigerant and the heat medium; and a controller. The controller controls action of the outdoor units, the indoor unit, and the relay devices. The controller determines necessity for a defrosting operation; responsive the defrosting operation being necessary, compares an indoor unit total load with an outdoor unit total capacity; and controls an operating frequency of the compressor of an outdoor unit other than the outdoor unit on which the defrosting operation is to be performed to increase the outdoor unit total capacity.

Abstract: An air-conditioning apparatus includes: a heat medium circulation circuit including: a heat medium device, a heat medium pipe, a pump, a heat medium detection unit, and a controller that includes a count unit to count an air-conditioning operation time and count a pump operation time based on heat medium detection information of the heat medium detection unit, a storage unit storing a set air-conditioning time and a set pump time, a comparison unit to compare the air-conditioning operation time with the set air-conditioning time and compare the pump operation time with the set pump time, and a device control unit to control driving of the pump so that the pump operation time reaches or exceeds the set pump time when the air-conditioning operation time is longer than or equal to the set air-conditioning time and the pump operation time is shorter than the set pump time.

Abstract: An air-conditioning apparatus includes an outdoor unit, multiple indoor units, and an intermediate unit. The indoor units each include a flow control device and an indoor controller. The intermediate unit includes an intermediate heat exchanger, a circulation device, and an intermediate controller. When at least one indoor unit starts operating, the intermediate controller determines whether a flow rate of a heat medium flowing into the intermediate heat exchanger is greater than or equal to a minimum flow rate. In response to determining that the flow rate is less than the minimum flow rate, the intermediate controller transmits an open instruction signal, representing an instruction to increase the opening degree of the flow control device, to the indoor controller of the indoor unit that is in a non-operation state. The indoor controller increases the opening degree of the flow control device in response to the received open instruction signal.

Abstract: An air-conditioning apparatus according to the present disclosure includes a heat medium circulation circuit, a heat-source-side device, and a voltage drop device. In the heat medium circulation circuit, a pump, an indoor heat exchanger, and a flow control device are connected by pipes to circulate the heat medium. The pump sends a heat medium that contains water or brine and transfers heat. The indoor heat exchanger causes heat exchange to be performed between the heat medium and an indoor air in an air-conditioned space. The flow control device controls a flow rate of the heat medium in the indoor heat exchanger. The heat-source-side device heats or cools the heat medium before the heat medium is sent to the indoor heat exchanger. The voltage drop device reduces a voltage that is applied to the pump based on a value of a current that is supplied to the pump, in association with a flow rate of the heat medium in the heat medium circulation circuit.

Abstract: An air-conditioning apparatus includes a low-pressure-side pressure sensor that detects the pressure of heat-source-side refrigerant that flows into a compressor and outputs it as a first detection value and a high-pressure-side pressure sensor that detects the pressure of heat-source-side refrigerant discharged from the compressor and outputs it as a second detection value. When switching the operation mode of the apparatus, a controller determines whether the ratio of the first detection value to the second detection value is higher than a first threshold. When the ratio is higher than the threshold, the controller causes a second refrigerant flow switching device to perform a switching operation. When the ratio is less than or equal to the threshold, the controller makes an adjustment such that an opening degree of an expansion device is less than a second threshold, and then causes the second refrigerant flow switching device to perform the switching operation.

Abstract: An air-conditioning system comprising: a heat source side unit; a use side unit; a relay unit; a refrigerant circuit; a water circuit; a controller configured to operate in a trial operation mode, and configured to operate in a normal operation mode; a first setting unit; a second setting unit; and a third setting unit, wherein the controller is configured to invalidate an error that occurs in the water circuit when the trial operation mode is set, a target for the trial operation in the trial operation mode is set to the refrigerant circuit, and invalidation of an error is set to be active, and invalidate an error that occurs in the refrigerant circuit when the trial operation mode is set, a target for the trial operation in the trial operation mode is set to the water circuit, and invalidation of an error is set to be active.

Abstract: A relay unit includes: a heat medium heat exchanger; a casing; a first refrigerant pipe connection port connected to one of two refrigerant pipes through which refrigerant circulates between the heat medium heat exchanger and the heat source side unit; a second refrigerant pipe connection port connected to an other of the refrigerant pipes; a first heat medium pipe connection port connected to one of two heat medium pipes through which a heat medium circulates between the heat medium heat exchanger and the load side unit; and a second heat medium pipe connection port connected to an other of the heat medium pipes. The first refrigerant pipe connection port, the second refrigerant pipe connection port, the first heat medium pipe connection port, and the second heat medium pipe connection port are provided on a top surface of the casing and face in a direction opposite to a direction of gravity.

Abstract: When a refrigerant leakage sensor detects a leakage of refrigerant from a refrigeration cycle apparatus having an indoor unit and an outdoor unit, a refrigerant recovery operation is started. In the refrigerant recovery operation, refrigerant is recovered in an accumulator and afterward a pump down operation is performed. In recovery of refrigerant in the accumulator, refrigerant in a liquid phase is accumulated in the accumulator as a result of circulation of refrigerant by operating a compressor in the state where a liquid shut-off valve and a gas shut-off valve are opened. After recovery of refrigerant in the accumulator is ended, the refrigerant in a liquid phase is accumulated in an outdoor heat exchanger by the pump down operation for operating the compressor in the state where the liquid shut-off valve is closed.

Abstract: A heat medium relay device includes: a valve block provided in a third space, and including a plurality of valves to allow a secondary heat medium subjected to the heat exchange at a first heat exchanger and a secondary heat medium subjected to the heat exchange at a second heat exchanger to flow to at least one indoor unit, the valve block being lighter in weight than each of the first heat exchanger, a first pump, the second heat exchanger, and a second pump.

Abstract: The heat-medium cycle circuit includes a discharge mechanism including a discharge valve, the discharge mechanism being configured to, when the discharge valve is open, discharge air present inside the heat-medium cycle circuit to the outside of the heat-medium cycle circuit. The air-conditioning apparatus is configured to execute an air discharge operation mode in which the air present inside the heat-medium cycle circuit is discharged to the outside of the heat-medium cycle circuit. The air discharge operation mode includes a first operation mode, and a second operation mode performed after the first operation mode. The first operation mode is an operation mode in which, with the discharge valve being closed, an operation similar to a cooling operation is performed. The second operation mode is an operation mode in which, with the discharge valve being open, an operation similar to a heating operation is performed.

Abstract: An air-conditioning apparatus includes: a heat-medium transfer device including a pump provided to transfer a heat medium that contains water or brine and transfers heat; a plurality of indoor units each of which includes an indoor heat exchanger provided to cause heat exchange to be performed between indoor air and the heat medium, and a flow control valve provided to adjust a flow rate of the heat medium that flows through the indoor heat exchanger, the plurality of indoor units being connected to the heat-medium transfer device by respective heat medium pipes; and a controller provided to control an opening degree of the flow control valve.

Abstract: When heating is being performed, and a temperature detected by a temperature sensor is lower than a first determination value, a controller opens the flow rate control valve corresponding to a heat exchanger, of the third heat exchangers, to which a request for air conditioning has not been made, and closes the flow rate control valve corresponding to a heat exchanger, of the third heat exchangers, to which the request for air conditioning has been made. When heating is being performed, and the temperature detected by the temperature sensor is higher than a second determination value, the controller opens the flow rate control valve corresponding to the heat exchanger to which the request for air conditioning has been made, and closes the flow rate control valve corresponding to the heat exchanger to which the request for air conditioning has not been made.

Abstract: An air-conditioning apparatus includes: a heat source-side system having an intermediate heat exchanger that causes heat exchange to be performed between a heat source-side heat medium and a use-side heat medium, causes the heat source-side heat medium to receive or transfer heat, and causes the use-side heat medium to undergo a phase change; and a use-side cycle circuit formed of pipes connecting, to one another, the intermediate heat exchanger, a pump that sucks and delivers the use-side heat medium in a liquid state, a use-side heat exchanger that heats or cools air in an air-conditioning target space due to heat exchange causing a change in phase of the use-side heat medium, and a pressure-reducing device that reduces a pressure of the use-side heat medium that passes through the use-side heat exchanger, the use-side cycle circuit causing the use-side heat medium to circulate through the use-side cycle circuit.