# US 11,906,226 B2 · Dual compressor heat pump > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,226 B2 - Document ID: US11906226B2 - Status: Granted - Kind: B2 - Application number: 17/044,009 - Filed: 2019-03-14 - Published: 2021-02-04 - Granted: 2024-02-20 - Earliest claimed: 2018-04-16 - Assignees: Carrier Corporation - Applicants: Carrier Corporation - Inventors: Jeremy Wallet-Laïly; Ahmad M. Mahmoud; Parmesh Verma - Web page: https://patentgrep.com/patent/US11906226B2 ## CPC - F25B 9/006: {the refrigerant containing more than one component (F25B9/004 takes precedence)} - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 31/00: Compressor arrangements - F25B 41/24: Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part - F25B 49/02: for compression type machines, plants or systems - F25B 49/022: {Compressor control arrangements} - F25B 2313/003: Indoor unit with water as a heat sink or heat source - F25B 2313/004: Outdoor unit with water as a heat sink or heat source - F25B 2313/027: characterised by the reversing means - F25B 2400/075: with parallel compressors - F25B 2600/2513: Expansion valves - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A vapor compression system (20; 120; 220; 320) has: first (22A; 122A; 222A) and second (22B; 122B; 222B) compressors; first (40) and second (46) heat exchangers; and one or more expansion devices (52; 52A, 52B). Means (32A, 32B; 32A, 32B, 126A, 126B; 32A, 32B, 232A, 232B) are provided for switching the system between operation in first and second modes using the respective first and second compressors. In the first mode: the first compressor compresses refrigerant; the compressed refrigerant is cooled in the first heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; and the expanded refrigerant absorbs heat in the second heat exchanger. In the second mode: the second compressor compresses refrigerant; the compressed refrigerant is cooled in the second heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; and the expanded refrigerant absorbs heat in the first heat exchanger. ## Claims ### Claim 1 A vapor compression system (20; 120; 220) comprising: a first compressor (22A; 122A; 222A); a second compressor (22B; 122B; 222B); a first heat exchanger (40); a second heat exchanger (46); one or more expansion devices (52); and means (32A, 32B; 32A, 32B, 126A, 126B; 32A, 32B, 232A, 232B) for switching the system between operation in: a first mode wherein: the first compressor compresses refrigerant; the compressed refrigerant is cooled in the first heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; the expanded refrigerant absorbs heat in the second heat exchanger and returns to the first compressor; and the second compressor is offline; and a second mode wherein: the second compressor compresses refrigerant; the compressed refrigerant is cooled in the second heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; the expanded refrigerant absorbs heat in the first heat exchanger and returns to the second compressor; and the first compressor is offline, wherein: the first compressor has a suction line (28A); the first compressor has a discharge line (30A); the second compressor has a suction line (28B); the second compressor has a discharge line (30B); the first compressor suction line (28A) and second compressor discharge line merge at a first junction (34); and the first compressor discharge line and second compressor suction line merge at a second junction (36). ### Claim 2 (depends on 1) The system of claim 1 wherein: the first compressor and the second compressor share an inverter (125). ### Claim 3 (depends on 2) The system of claim 2 wherein: the first compressor and the second compressor share a motor (228). ### Claim 4 (depends on 3) The system of claim 3 wherein: the first compressor and the second compressor are respectively coupled to the motor by a first clutch (232A) and a second clutch (232B). ### Claim 5 (depends on 1) The system of claim 1 wherein: the first heat exchanger is an outdoor heat exchanger; and the second heat exchanger is an indoor heat exchanger. ### Claim 6 (depends on 5) The system of claim 5 wherein: the first heat exchanger is a refrigerant-air heat exchanger; and the second heat exchanger is a refrigerant-liquid heat exchanger. ### Claim 7 (depends on 1) The system of claim 1 wherein: the first compressor and the second compressor are the only compressors. ### Claim 8 (depends on 5) The system of claim 5 wherein: the second compressor has a pressure ratio at least 1.25 times a pressure ratio of the first compressor. ### Claim 9 (depends on 5) The system of claim 5 wherein: the first compressor is a scroll compressor; and the second compressor is a screw compressor or a centrifugal compressor. ### Claim 10 (depends on 5) The system of claim 5 wherein: the first compressor and the second compressor are both screw compressors; or the first compressor and the second compressor are both centrifugal compressors. ### Claim 11 (depends on 5) The system of claim 5 wherein: the first mode is a cooling mode and the second mode is a heating mode; and in the heating mode, refrigerant flow proceeds in a reverse direction through ports of the first and second heat exchangers and the at least one expansion device relative to the cooling mode. ### Claim 12 (depends on 1) The system of claim 1 wherein: the system is a chiller. ### Claim 13 (depends on 1) A method for using the system of claim 1, the method comprising: running the system in the first mode; and running the system in the second mode. ### Claim 14 (depends on 13) The method of claim 13 wherein: the first mode is a cooling mode and the second mode is a heating mode; and in the heating mode, refrigerant flow proceeds in a reverse direction through ports of the first and second heat exchangers and the at least one expansion device relative to the cooling mode. ### Claim 15 A method for operating a vapor compression system (20; 120; 220), the vapor compression system comprising: a first compressor (22A; 122A; 222A); a second compressor (22B; 122B; 222B); a first heat exchanger (40); a second heat exchanger (46); and one or more expansion devices (52); the method comprising: running the system in a first mode wherein: the first compressor compresses refrigerant; the compressed refrigerant is cooled in the first heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; the expanded refrigerant absorbs heat in the second heat exchanger and returns to the first compressor; and the second compressor is offline; and running the system in a second mode wherein: the second compressor compresses refrigerant; the compressed refrigerant is cooled in the second heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; the expanded refrigerant absorbs heat in the first heat exchanger and returns to the second compressor; and the first compressor is offline, wherein: the first compressor has a suction flowpath merging with a discharge flowpath of the second compressor at a first junction (34); the first compressor has a discharge flowpath merging with a suction flowpath of the second compressor at a second junction (36); a first control valve (32A) is along the first compressor discharge flowpath; and a second control valve (32B) is along the second compressor discharge flowpath; in the first mode, the first control valve is open and the second control valve is closed; and in the second mode, the first control valve is closed and the second control valve is open. ### Claim 16 (depends on 15) The method of claim 15 wherein: the first mode is a cooling mode and the second mode is a heating mode. ### Claim 17 (depends on 15) The method of claim 15 wherein: switching between the first mode and the second mode comprises switching a single inverter between powering the first compressor and the second compressor; and said switching between the first mode and the second mode does not involve use of a four-way reversing valve. ### Claim 18 (depends on 15) The system of claim 15 wherein: relative to the first mode, flow through the one or more expansion devices (52) in the second mode is in a reverse direction. ### Claim 19 A vapor compression system (20; 120; 220) comprising: a first compressor (22A; 122A; 222A); a second compressor (22B; 122B; 222B); a first heat exchanger (40); a second heat exchanger (46); one or more expansion devices (52); and means (32A, 32B; 32A, 32B, 126A, 126B; 32A, 32B, 232A, 232B) for switching the system between operation in: a first mode wherein: the first compressor compresses refrigerant; the compressed refrigerant is cooled in the first heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; the expanded refrigerant absorbs heat in the second heat exchanger and returns to the first compressor; and the second compressor is offline; and a second mode wherein: the second compressor compresses refrigerant; the compressed refrigerant is cooled in the second heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; the expanded refrigerant absorbs heat in the first heat exchanger and returns to the second compressor; and the first compressor is offline, wherein: the first compressor has a suction flowpath merging with a discharge flowpath of the second compressor at a first junction (34); the first compressor has a discharge flowpath merging with a suction flowpath of the second compressor at a second junction (36); a first control valve (32A) is along the first compressor discharge flowpath; and a second control valve (32B) is along the second compressor discharge flowpath. ### Claim 20 (depends on 18) The method of claim 18 wherein: the first mode is a cooling mode and the second mode is a heating mode.