# US 12,007,150 B2 · Refrigeration cycle device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,150 B2 - Document ID: US12007150B2 - Status: Granted - Kind: B2 - Application number: 17/219,395 - Filed: 2021-03-31 - Published: 2021-07-15 - Granted: 2024-06-11 - Earliest claimed: 2018-10-02 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Ikuhiro Iwata; Eiji Kumakura; Kazuhiro Furusho; Ryusuke Fujiyoshi; Hiromune Matsuoka - Web page: https://patentgrep.com/patent/US12007150B2 ## CPC - F25B 49/02: for compression type machines, plants or systems - F25B 1/10: with multi-stage compression (with cascade operation F25B7/00) - F25B 7/00: Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit (F25B9/00 takes precedence) - F25B 9/008: {the refrigerant being carbon dioxide} - F25B 40/00: Subcoolers, desuperheaters or superheaters - F25B 41/39: Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator - F25B 43/00: Arrangements for separating or purifying gases or liquids (in analysers or rectifiers F25B33/00); Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat (F25B40/00 takes precedence) - F25B 2313/0314: Temperature sensors near the indoor heat exchanger - F25B 2313/0315: Temperature sensors near the outdoor heat exchanger - F25B 2400/23: Separators - F25B 2600/2513: Expansion valves - F25B 2700/1931: Discharge pressures - F25B 2700/1933: Suction pressures - F25B 2700/21151: at the suction side of the compressor - F25B 2700/21152: at the discharge side of the compressor - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract Even if, in decompressing a refrigerant by an expansion mechanism, the temperature of the refrigerant cannot be sufficiently reduced, in order to increase the evaporation capacity of a use-side heat exchanger, a main expansion mechanism including an expansion element of a rotary or scroll type that causes power to be produced by decompressing a main refrigerant is provided at a main refrigerant circuit in which the main refrigerant circulates. Further, a sub-refrigerant circuit that differs from the main refrigerant circuit and in which a sub-refrigerant circulates is provided. A sub-use-side heat exchanger that is provided at the sub-refrigerant circuit and that functions as an evaporator of the sub-refrigerant is caused to function as a heat exchanger that cools the main refrigerant that flows between the main expansion mechanism and a main use-side heat exchanger. ## Claims ### Claim 1 A refrigeration cycle device comprising: a main refrigerant circuit having a main compressor that compresses a main refrigerant, a main heat-source-side heat exchanger that functions as a radiator of the main refrigerant, a main use-side heat exchanger that functions as an evaporator of the main refrigerant, a main expansion mechanism including an expansion element of a rotary or scroll type that causes power to be produced by decompressing the main refrigerant that flows between the main heat-source-side heat exchanger and the main use-side heat exchanger, and a main intermediate-pressure adjusting valve between the main expansion mechanism and the main use-side heat exchanger, wherein the main refrigerant circuit has a sub-use-side heat exchanger that functions as a cooler of the main refrigerant that flows between the main expansion mechanism and the main use-side heat exchanger; the refrigeration cycle device further comprising: a sub-refrigerant circuit having a sub-compressor that compresses a sub-refrigerant, a sub-heat-source-side heat exchanger that functions as a radiator of the sub-refrigerant, and the sub-use-side heat exchanger that functions as an evaporator of the sub-refrigerant and that cools the main refrigerant that flows between the main expansion mechanism and the main use-side heat exchanger; and the refrigerant cycle device further comprising a controller that controls the main intermediate-pressure adjusting valve in accordance with an input power of the sub-refrigerant circuit. ### Claim 2 (depends on 1) The refrigerant cycle device according to claim 1, wherein the controller obtains the input power of the sub-refrigerant circuit from outside air temperature or a current value of the sub-compressor. ### Claim 3 (depends on 1) The refrigeration cycle device according to claim 1, wherein the main intermediate-pressure adjusting valve is provided at a portion of the main refrigerant circuit, the portion being between the sub-use-side heat exchanger and the main use-side heat exchanger, and wherein, when the input power of the sub-refrigerant circuit increases, the controller decreases an opening degree of the main intermediate-pressure adjusting valve. ### Claim 4 (depends on 3) The refrigerant cycle device according to claim 3, wherein, when the input power of the sub-refrigerant circuit decreases, the controller unit increases the opening degree of the main intermediate-pressure adjusting valve. ### Claim 5 (depends on 1) The refrigeration cycle device according to claim 1, wherein the main refrigerant circuit has a gas-liquid separator between the main expansion mechanism and the main use-side heat exchanger, the gas-liquid separator causing the main refrigerant decompressed at the main expansion mechanism to separate gas and liquid, wherein a degassing pipe that extracts the main refrigerant in a gas state and sends the main refrigerant in the gas state toward a suction side of the main compressor is connected to the gas-liquid separator, wherein the main intermediate-pressure adjusting valve is provided at the degassing pipe, and wherein, when the input power of the sub-refrigerant circuit increases, the controller decreases an opening degree of the main intermediate-pressure adjusting valve. ### Claim 6 (depends on 5) The refrigerant cycle device according to claim 5, wherein, when the input power of the sub-refrigerant circuit decreases, the controller increases the opening degree of the main intermediate-pressure adjusting valve. ### Claim 7 (depends on 1) The refrigeration cycle device according to claim 1, wherein the main compressor includes a low-stage-side compression element of a rotary or scroll type that compresses the main refrigerant and a high-stage-side compression element of a rotary or scroll type that compresses the main refrigerant discharged from the low-stage-side compression element. ### Claim 8 (depends on 1) The refrigeration cycle device according to claim 1, wherein the main refrigerant is carbon dioxide, and wherein the sub-refrigerant is a HFC refrigerant, a HFO refrigerant, or a mixture refrigerant in which the HFC refrigerant and the HFO refrigerant are mixed, each of the HFC refrigerant, the HFO refrigerant, and the mixture refrigerant having a GWP that is 750 or less. ### Claim 9 (depends on 1) The refrigeration cycle device according to claim 1, wherein the main refrigerant is carbon dioxide, and wherein the sub-refrigerant circuit utilizes a natural refrigerant such that the sub-refrigerant circuit has a coefficient of performance that is higher than the coefficient of performance of the main refrigerant circuit using a carbon dioxide refrigerant. ### Claim 10 (depends on 2) The refrigeration cycle device according to claim 2, wherein the main intermediate-pressure adjusting valve is provided at a portion of the main refrigerant circuit, the portion being between the sub-use-side heat exchanger and the main use-side heat exchanger, and wherein, when the input power of the sub-refrigerant circuit increases, the controller decreases an opening degree of the main intermediate-pressure adjusting valve. ### Claim 11 (depends on 10) The refrigerant cycle device according to claim 10, wherein, when the input power of the sub-refrigerant circuit decreases, the control unit increases the opening degree of the main intermediate-pressure adjusting valve. ### Claim 12 (depends on 2) The refrigeration cycle device according to claim 2, wherein the main refrigerant circuit has a gas-liquid separator between the main expansion mechanism and the main use-side heat exchanger, the gas-liquid separator causing the main refrigerant decompressed at the main expansion mechanism to separate gas and liquid, wherein a degassing pipe that extracts the main refrigerant in a gas state and sends the main refrigerant in the gas state toward a suction side of the main compressor is connected to the gas-liquid separator, wherein the main intermediate-pressure adjusting valve is provided at the degassing pipe, and wherein, when the input power of the sub-refrigerant circuit increases, the controller decreases an opening degree of the main intermediate-pressure adjusting valve. ### Claim 13 (depends on 12) The refrigerant cycle device according to claim 12, wherein, when the input power of the sub-refrigerant circuit decreases, the controller increases the opening degree of the main intermediate-pressure adjusting valve. ### Claim 14 (depends on 2) The refrigeration cycle device according to claim 2, wherein the main compressor includes a low-stage-side compression element of a rotary or scroll type that compresses the main refrigerant and a high-stage-side compression element of a rotary or scroll type that compresses the main refrigerant discharged from the low-stage-side compression element. ### Claim 15 (depends on 3) The refrigeration cycle device according to claim 3, wherein the main compressor includes a low-stage-side compression element of a rotary or scroll type that compresses the main refrigerant and a high-stage-side compression element of a rotary or scroll type that compresses the main refrigerant discharged from the low-stage-side compression element. ### Claim 16 (depends on 4) The refrigeration cycle device according to claim 4, wherein the main compressor includes a low-stage-side compression element of a rotary or scroll type that compresses the main refrigerant and a high-stage-side compression element of a rotary or scroll type that compresses the main refrigerant discharged from the low-stage-side compression element. ### Claim 17 (depends on 5) The refrigeration cycle device according to claim 5, wherein the main compressor includes a low-stage-side compression element of a rotary or scroll type that compresses the main refrigerant and a high-stage-side compression element of a rotary or scroll type that compresses the main refrigerant discharged from the low-stage-side compression element. ### Claim 18 A refrigeration cycle device comprising: a main refrigerant circuit having a main compressor that compresses a main refrigerant, a main heat-source-side heat exchanger that functions as a radiator of the main refrigerant, a main use-side heat exchanger that functions as an evaporator of the main refrigerant, a main expansion mechanism including an expansion element of a rotary or scroll type that causes power to be produced by decompressing the main refrigerant that flows between the main heat-source-side heat exchanger and the main use-side heat exchanger, and a main intermediate-pressure adjusting valve between the main expansion mechanism and the main use-side heat exchanger, wherein the main refrigerant circuit has a sub-use-side heat exchanger that functions as a cooler of the main refrigerant that flows between the main expansion mechanism and the main use-side heat exchanger; the refrigeration cycle device further comprising: a sub-refrigerant circuit having a sub-compressor that compresses a sub-refrigerant, a sub-heat-source-side heat exchanger that functions as a radiator of the sub-refrigerant, and the sub-use-side heat exchanger that functions as an evaporator of the sub-refrigerant and that cools the main refrigerant that flows between the main expansion mechanism and the main use-side heat exchanger; and the refrigeration cycle device further comprising: a controller that controls the main intermediate-pressure adjusting valve, wherein the controller controls an opening degree of the main intermediate-pressure adjusting valve inversely to the outside air temperature such that as the outside air temperature rises, the main intermediate-pressure adjusting valve is further closed, and as the outside air temperature falls, the main intermediate-pressure adjusting valve is further opened. ### Claim 19 (depends on 18) The refrigeration cycle device according to claim 18, wherein the main compressor includes a low-stage-side compression element of a rotary or scroll type that compresses the main refrigerant and a high-stage-side compression element of a rotary or scroll type that compresses the main refrigerant discharged from the low-stage-side compression element.