US 12,169,082 B2
Air-conditioning apparatus
Hiroki Washiyama, Tokyo (JP); Yuji Motomura, Tokyo (JP); and Koji Furuya, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 18/000,308
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Aug. 3, 2020, PCT No. PCT/JP2020/029685
§ 371(c)(1), (2) Date Nov. 30, 2022,
PCT Pub. No. WO2022/029845, PCT Pub. Date Feb. 10, 2022.
Prior Publication US 2023/0194131 A1, Jun. 22, 2023
Int. Cl. F25B 1/00 (2006.01); F25B 13/00 (2006.01); F25B 41/31 (2021.01); F25B 49/00 (2006.01)
CPC F25B 13/00 (2013.01) [F25B 41/31 (2021.01); F25B 49/00 (2013.01); F25B 2313/02741 (2013.01); F25B 2700/19 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An air-conditioning apparatus comprising:
a refrigerant cycle circuit in which a compressor, a first refrigerant flow switching device, a heat-source-side heat exchanger, a plurality of expansion devices, a plurality of heat-medium heat exchangers, and a plurality of second refrigerant flow switching devices are connected by a refrigerant pipe, the refrigerant cycle circuit being configured to cause heat-source-side refrigerant to circulate through the refrigerant pipe; and
a heat-medium cycle circuit in which the heat-medium heat exchangers, a pump, and a plurality of load-side heat exchangers are connected by a heat medium pipe, the heat-medium cycle circuit being configured to cause a heat medium to circulate through the heat medium pipe,
wherein each of the heat-medium heat exchangers is configured to cause heat exchange to be performed between the heat-source-side refrigerant and the heat medium,
the air-conditioning apparatus further comprising:
a low-pressure-side pressure sensor configured to detect a pressure of the heat-source-side refrigerant that flows into the compressor and output the pressure as a first detection value;
a high-pressure-side pressure sensor configured to detect a pressure of the heat-source-side refrigerant discharged from the compressor and output the pressure as a second detection value; and
a controller configured to control opening degrees of the expansion devices,
the air-conditioning apparatus having a heating operation mode and a cooling operation mode as operation modes,
wherein the first refrigerant flow switching device is configured to switch a flow of the heat-source-side refrigerant between the flow of the heat-source-side refrigerant in the heating operation mode and the flow of the heat-source-side refrigerant in the cooling operation mode,
wherein each of the second refrigerant flow switching devices is configured to switch the flow of the heat-source-side refrigerant, according to switching of the operation mode of the air-conditioning apparatus, such that an associated one of the heat-medium heat exchangers operates as a condenser or an evaporator,
wherein each of the expansion devices is provided in association with an associated one of the heat-medium heat exchangers and located upstream of the associated heat-medium heat exchanger in a flow direction of the heat-source-side refrigerant when the associated heat-medium heat exchanger operates as an evaporator,
wherein each of the second refrigerant flow switching devices is provided in association with an associated one of the heat-medium heat exchangers and located downstream of the associated heat-medium heat exchanger in the flow direction of the heat-source-side refrigerant when the heat-medium heat exchanger operates as an evaporator,
wherein the controller is configured to determine, when switching the operation mode of the air-conditioning apparatus, whether a ratio of the first detection value to the second detection value is higher than a first threshold or not,
wherein the controller is configured to perform, when the ratio is higher than the first threshold, control to cause one of the second refrigerant flow switching devices to perform a switching operation, the one of the second refrigerant flow switching devices being required to perform the switching operation, according to switching of the operation mode of the air-conditioning apparatus,
wherein the controller is configured to adjust, when the ratio is less than or equal to the first threshold, an opening degree of one of the expansion devices that is connected to the second refrigerant flow switching device required to perform the switching operation, such that the opening degree of the one of the expansion devices is less than a second threshold, and perform control to cause the second refrigerant flow switching device to perform the switching operation.