# US 11,112,140 B2 · Air conditioning apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,112,140 B2
- Document ID: US11112140B2
- Status: Granted
- Kind: B2
- Application number: 16/639,651
- Filed: 2017-09-07
- Published: 2020-06-04
- Granted: 2021-09-07
- Earliest claimed: 2017-09-07
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Yusuke Shimazu
- Web page: https://patentgrep.com/patent/US11112140B2

## CPC

- F24F 11/49: ensuring correct operation, e.g. by trial operation or configuration checks
- F24F 1/0059: characterised by heat exchangers
- F24F 1/32: for connecting the separate outdoor units to indoor units
- F24F 11/75: for maintaining constant air flow rate or air velocity
- F24F 11/84: using valves
- F24F 11/86: by controlling compressors within refrigeration or heat pump circuits
- F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02)
- F25B 40/02: Subcoolers
- F25B 40/06: Superheaters
- F25B 49/02: for compression type machines, plants or systems
- F24F 2110/40: Pressure, e.g. wind pressure
- F25B 41/42: Arrangements for diverging or converging flows, e.g. branch lines or junctions
- F25B 2313/0233: in parallel arrangements
- F25B 2313/02741: using one four-way valve
- F25B 2400/0409: for evaporators
- F25B 2400/0417: for subcoolers
- F25B 2400/0419: for superheaters
- F25B 2400/054: between the suction tube of the compressor and another part of the cycle
- F25B 2400/13: Economisers
- F25B 2600/2501: Bypass valves
- F25B 2600/2519: On-off valves
- F25B 2700/13: Mass flow of refrigerants
- F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02)
- F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS

## Abstract

An air conditioning apparatus includes: a supercooling heat exchanger configured to supercool refrigerant flowing in a first flow path between an outdoor heat exchanger and an expansion valve; a flow path switching valve configured to switch a flow path between an indoor heat exchanger and a compressor to one of a second flow path that does not extend through the supercooling heat exchanger and a third flow path that extends through the supercooling heat exchanger; a bypass circuit that is branched from the first flow path and extends through the supercooling heat exchanger; and a bypass regulating valve provided in the bypass circuit; and a controller. In a cooling operation, when a load is not low, the controller selects the second flow path and opens the bypass regulating valve, whereas when the load is low, the controller selects the third flow path and closes the bypass regulating valve.

## Claims

### Claim 1

An air conditioning apparatus comprising:
an outdoor unit including a compressor and an outdoor heat exchanger;
at least one indoor unit including an expansion valve and an indoor heat exchanger; and
a main circuit configured to circulate refrigerant through the compressor, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger, wherein
the main circuit includes a first flow path between the outdoor heat exchanger and the expansion valve,
the air conditioning apparatus further comprising a supercooling heat exchanger configured to supercool the refrigerant flowing in the first flow path, wherein
as a flow path between the indoor heat exchanger and the compressor, the main circuit includes a second flow path that does not extend through the supercooling heat exchanger, and a third flow path that extends through the supercooling heat exchanger,
the air conditioning apparatus further comprising:
a flow path switching valve configured to switch, to one of the second flow path and the third flow path, the flow path between the indoor heat exchanger and the compressor;
a bypass circuit that is branched from the first flow path, that extends through the supercooling heat exchanger, and that is joined to the main circuit;
a bypass regulating valve provided in the bypass circuit; and
a controller configured to control the flow path switching valve and the bypass regulating valve, wherein
in a cooling operation,
when a parameter correlated with a flow rate of the refrigerant in the main circuit indicates that the flow rate of the refrigerant is more than a reference value, the controller is configured to control the flow path switching valve to switch, to the second flow path, the flow path between the indoor heat exchanger and the compressor, and open the bypass regulating valve, and
when the parameter indicates that the flow rate of the refrigerant is less than the reference value, the controller is configured to control the flow path switching valve to switch, to the third flow path, the flow path between the indoor heat exchanger and the compressor, and close the bypass regulating valve.

### Claim 2 (depends on 1)

The air conditioning apparatus according to claim 1, wherein
the compressor is provided with a suction hole configured to suction the refrigerant, and a discharge hole configured to discharge the refrigerant,
the main circuit includes
a first pipe configured to communicate with the indoor heat exchanger,
a second pipe configured not to extend through the supercooling heat exchanger, and
a third pipe configured to extend through the supercooling heat exchanger and communicate with the suction hole,
the outdoor unit further includes a four-way valve configured to communicate the second pipe with the suction hole and communicate the outdoor heat exchanger with the discharge hole in the cooling operation, and configured to communicate the second pipe with the discharge hole and communicate the outdoor heat exchanger with the suction hole in a heating operation,
the four-way valve is driven by a differential pressure between the suction hole and the discharge hole,
the flow path switching valve is configured to communicate the first pipe with one of the second pipe and the third pipe and close the other of the second pipe and the third pipe,
the second flow path is formed by communicating the first pipe with the second pipe,
the third flow path is formed by communicating the first pipe with the third pipe, and
the controller is configured to control the flow path switching valve to communicate the first pipe with the third pipe and then communicate the first pipe with the second pipe, when switching from the cooling operation to the heating operation.

### Claim 3 (depends on 1)

The air conditioning apparatus according to claim 1, wherein the parameter is an operation frequency of the compressor.

### Claim 4 (depends on 3)

The air conditioning apparatus according to claim 3, wherein
the compressor is provided with a suction hole configured to suction the refrigerant, and a discharge hole configured to discharge the refrigerant,
the main circuit includes
a first pipe configured to communicate with the indoor heat exchanger,
a second pipe configured not to extend through the supercooling heat exchanger, and
a third pipe configured to extend through the supercooling heat exchanger and communicate with the suction hole,
the outdoor unit further includes a four-way valve configured to communicate the second pipe with the suction hole and communicate the outdoor heat exchanger with the discharge hole in the cooling operation, and configured to communicate the second pipe with the discharge hole and communicate the outdoor heat exchanger with the suction hole in a heating operation,
the four-way valve is driven by a differential pressure between the suction hole and the discharge hole,
the flow path switching valve is configured to communicate the first pipe with one of the second pipe and the third pipe and close the other of the second pipe and the third pipe,
the second flow path is formed by communicating the first pipe with the second pipe,
the third flow path is formed by communicating the first pipe with the third pipe, and
the controller is configured to control the flow path switching valve to communicate the first pipe with the third pipe and then communicate the first pipe with the second pipe, when switching from the cooling operation to the heating operation.

### Claim 5 (depends on 1)

The air conditioning apparatus according to claim 1, wherein
the at least one indoor unit includes a plurality of indoor units, and
the parameter is the number of indoor units that are being operating among the plurality of indoor units.

### Claim 6 (depends on 5)

The air conditioning apparatus according to claim 5, wherein
the compressor is provided with a suction hole configured to suction the refrigerant, and a discharge hole configured to discharge the refrigerant,
the main circuit includes
a first pipe configured to communicate with the indoor heat exchanger,
a second pipe configured not to extend through the supercooling heat exchanger, and
a third pipe configured to extend through the supercooling heat exchanger and communicate with the suction hole,
the outdoor unit further includes a four-way valve configured to communicate the second pipe with the suction hole and communicate the outdoor heat exchanger with the discharge hole in the cooling operation, and configured to communicate the second pipe with the discharge hole and communicate the outdoor heat exchanger with the suction hole in a heating operation,
the four-way valve is driven by a differential pressure between the suction hole and the discharge hole,
the flow path switching valve is configured to communicate the first pipe with one of the second pipe and the third pipe and close the other of the second pipe and the third pipe,
the second flow path is formed by communicating the first pipe with the second pipe,
the third flow path is formed by communicating the first pipe with the third pipe, and
the controller is configured to control the flow path switching valve to communicate the first pipe with the third pipe and then communicate the first pipe with the second pipe, when switching from the cooling operation to the heating operation.