# US 11,906,207 B2 · Refrigeration apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,207 B2 - Document ID: US11906207B2 - Status: Granted - Kind: B2 - Application number: 16/913,589 - Filed: 2020-06-26 - Published: 2020-10-15 - Granted: 2024-02-20 - Earliest claimed: 2017-12-18 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Eiji Kumakura; Takuro Yamada; Atsushi Yoshimi; Ikuhiro Iwata; Mitsushi Itano; Daisuke Karube; Yuuki Yotsumoto; Kazuhiro Takahashi; Tatsuya Takakuwa; Yuzo Komatsu; Shun Ohkubo - Web page: https://patentgrep.com/patent/US11906207B2 ## CPC - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - C09K 5/045: {containing only fluorine as halogen} - F25B 5/04: arranged in series - F25B 31/004: {oil recirculating arrangements} - C09K 2205/126: Unsaturated fluorinated hydrocarbons - C09K 2205/22: All components of a mixture being fluoro compounds - C09K 2205/40: Replacement mixtures - 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 25/005: {using primary and secondary systems} - F25B 2313/003: Indoor unit with water as a heat sink or heat source - F25B 2313/0233: in parallel arrangements - F25B 2313/0311: Pressure sensors near the expansion valve - F25B 2313/0314: Temperature sensors near the indoor heat exchanger - F25B 2313/0315: Temperature sensors near the outdoor heat exchanger - F25B 2400/053: between the storage receiver and another part of the system - F25B 2400/054: between the suction tube of the compressor and another part of the cycle - F25B 2400/06: Several compression cycles arranged in parallel - F25B 2400/07: Details of compressors or related parts - F25B 2400/121: using R1234 - F25B 2400/13: Economisers - 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 - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE ## Abstract A two-stage refrigeration apparatus (500) includes a first cycle (510) and a second cycle (520). The first cycle (510) includes a first compressor (511), a first condenser (512), a first expansion mechanism (513), and a first evaporator (514) that are arranged in such a manner as to be connected to the first cycle. A first refrigerant circulates through the first cycle. The second cycle (520) includes a second downstream-side condenser (523) and a second evaporator (527) that are arranged in such a manner as to be connected to the second cycle. A second refrigerant circulates through the second cycle. The first evaporator (514) and the second downstream-side condenser (523) constitute a cascade condenser (531). In the cascade condenser (531), heat is exchanged between the first refrigerant and the second refrigerant. At least one of the first refrigerant and the second refrigerant is a refrigerant mixture containing at least 1,2-difluoroethylene (HFO-1132(E)). ## Claims ### Claim 1 A refrigeration apparatus comprising: a first cycle including a first compressor, a first radiator, a first expansion mechanism, and a first heat absorber that are arranged in such a manner as to be connected to the first cycle, a first refrigerant circulating through the first cycle; and a second cycle including a second compressor, a second radiator, a second expansion mechanism, and a second heat absorber that are arranged in such a manner as to be connected to the second cycle, a second refrigerant circulating through the second cycle, wherein the first heat absorber and the second radiator constitute a heat exchanger in which heat is exchanged between the first refrigerant flowing through the first heat absorber and the second refrigerant flowing through the second radiator, and at least one of the first refrigerant and the second refrigerant is a refrigerant mixture comprising trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoro-1-propene (R1234yf), when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant mixture is respectively represented by x, y and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments ON, NU, and UO that connect the following 3 points: point O (22.6, 36.8, 40.6), point N (27.7, 18.2, 54.1), and point U (3.9, 36.7, 59.4), or on these line segments; the line segment ON is represented by coordinates (0.0072 y2−0.6701y+37.512, y, −0.0072 y2−0.3299y+62.488); the line segment NU is represented by coordinates (0.0083 y2−1.7403y+56.635, y, −0.0083y2+0.7403y+43.365); and the line segment UO is a straight line. ### Claim 2 (depends on 1) The refrigeration apparatus according to claim 1, wherein the second cycle further includes a second compressor and a second expansion mechanism that are arranged in such a manner as to be connected to the second cycle, the first refrigerant flowing through the first radiator of the first cycle releases heat into outside air, the first refrigerant is the refrigerant mixture, and the second refrigerant is carbon dioxide. ### Claim 3 (depends on 1) The refrigeration apparatus according to claim 1, wherein the second cycle further includes a second compressor and a second expansion mechanism that are arranged in such a manner as to be connected to the second cycle, the first refrigerant flowing through the first radiator of the first cycle releases heat into outside air, the first refrigerant is the refrigerant mixture, and the second refrigerant is the refrigerant mixture. ### Claim 4 (depends on 1) The refrigeration apparatus according to claim 1, wherein the second cycle further includes a second compressor and a second expansion mechanism that are arranged in such a manner as to be connected to the second cycle, the first refrigerant flowing through the first radiator of the first cycle releases heat into outside air, the first refrigerant is R32, and the second refrigerant is the refrigerant mixture. ### Claim 5 (depends on 1) The refrigeration apparatus according to claim 1, wherein the first refrigerant flowing through the first radiator of the first cycle (RC) releases heat into outside air, the first refrigerant is the refrigerant mixture, and the second refrigerant is a liquid medium.