# US 11,441,819 B2 · Refrigeration cycle apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,819 B2 - Document ID: US11441819B2 - Status: Granted - Kind: B2 - Application number: 16/912,055 - Filed: 2020-06-25 - Published: 2020-10-15 - Granted: 2022-09-13 - Earliest claimed: 2017-12-18 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Mitsushi Itano; Daisuke Karube; Yuuki Yotsumoto; Kazuhiro Takahashi; Tatsuya Takakuwa; Yuzo Komatsu; Shun Ohkubo; Tetsushi Tsuda; Takeo Abe; Yumi Toda - Web page: https://patentgrep.com/patent/US11441819B2 ## CPC - F25B 1/00: Compression machines, plants or systems with non-reversible cycle (F25B3/00, F25B5/00, F25B6/00, F25B7/00, F25B9/00 take precedence) - C09K 5/045: {containing only fluorine as halogen} - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 43/006: {Accumulators} - C09K 2205/126: Unsaturated fluorinated hydrocarbons - C09K 2205/22: All components of a mixture being fluoro compounds - F25B 2313/0292: related to reversing valves - F25B 2313/0293: related to the indoor fan, e.g. controlling speed - F25B 2313/0294: related to the outdoor fan, e.g. controlling speed - F25B 2313/0314: Temperature sensors near the indoor heat exchanger - F25B 2313/0315: Temperature sensors near the outdoor heat exchanger - F25B 2400/121: using R1234 - F25B 2400/13: Economisers - F25B 2600/2509: Economiser valves - F25B 2600/2513: Expansion valves - F25B 2700/1931: Discharge pressures - F25B 2700/1933: Suction pressures - F25B 2700/2106: of fresh outdoor air - 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 refrigeration cycle apparatus that can improve operation efficiency when a refrigerant that contains at least 1,2-difluoroethylene is used is provided. An air conditioning apparatus 1 includes a compressor (21), an outdoor heat exchanger (23), an outdoor expansion valve (24), an indoor heat exchanger (31), and a suction injection pipe (40), and uses a refrigerant that contains at least 1,2-difluoroethylene. The suction injection pipe (40) allows a part of a refrigerant that flows toward the indoor heat exchanger (31) from the outdoor heat exchanger (23) to merge with a low-pressure refrigerant that is sucked into the compressor (21). ## Claims ### Claim 1 A refrigeration cycle apparatus comprising: a compressor that sucks a refrigerant from a suction flow path, compresses the refrigerant, and discharges a high-pressure refrigerant, the refrigerant flowing through the suction flow path being a low-pressure refrigerant; a condenser that condenses the high-pressure refrigerant discharged from the compressor; a decompressor that decompresses the high-pressure refrigerant that has exited from the condenser; an evaporator that evaporates the refrigerant decompressed at the decompressor; and an injection flow path that is at least either one of an intermediate injection flow path and a suction injection flow path, the intermediate injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with an intermediate-pressure refrigerant in the compressor, the suction injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with the low-pressure refrigerant that is sucked by the compressor wherein the refrigerant comprises trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoro-1-propene (R1234yf), wherein when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant 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 IJ, JN, NE, and EI that connect the following 4 points: point I (72.0, 0.0, 28.0), point J (48.5, 18.3, 33.2), point N (27.7, 18.2, 54.1), and point E (58.3, 0.0, 41.7), or on these line segments (excluding the points on the line segment EI; the line segment U is represented by coordinates (0.0236y2−1.7616y+72.0, y, −0.0236y2+0.7616y+28.0); the line segment NE is represented by coordinates (0.012y2-1.9003y+58.3, y, −0.012y2+0.9003y+41.7); and the line segments JN and EI are straight lines. ### Claim 2 (depends on 1) The refrigeration cycle apparatus according to claim 1, further comprising: a branching flow path that branches off from a main refrigerant flow path that connects the condenser and the evaporator to each other; an opening degree adjusting valve that is provided in the branching flow path; and an injection heat exchanger that causes the refrigerant that flows in the main refrigerant flow path and the refrigerant that flows on a downstream side with respect to the opening degree adjusting valve in the branching flow path to exchange heat, wherein the refrigerant that exits from the injection heat exchanger and flows in the branching flow path flows in the injection flow path. ### Claim 3 (depends on 1) The refrigeration cycle apparatus according to claim 1, further comprising: a refrigerant storage tank that is provided in a main refrigerant flow path that connects the condenser and the evaporator to each other, wherein a gas component of the refrigerant that accumulates in the refrigerant storage tank flows in the injection flow path. ### Claim 4 (depends on 1) The refrigeration cycle apparatus according to claim 1, wherein the compressor includes a fixed scroll and a swinging scroll, the fixed scroll including an end plate and a lap that stands spirally from the end plate, the swinging scroll forming a compression chamber (Sc) by engaging with the fixed scroll, and the refrigerant that flows in the injection flow path merges at the compression chamber. ### Claim 5 A refrigeration cycle apparatus comprising: a compressor that sucks a refrigerant from a suction flow path, compresses the refrigerant, and discharges a high-pressure refrigerant, the refrigerant flowing through the suction flow path being a low-pressure refrigerant; a condenser that condenses the high-pressure refrigerant discharged from the compressor; a decompressor that decompresses the high-pressure refrigerant that has exited from the condenser; an evaporator that evaporates the refrigerant decompressed at the decompressor; and an injection flow path that is at least either one of an intermediate injection flow path and a suction injection flow path, the intermediate injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with an intermediate-pressure refrigerant in the compressor, the suction injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with the low-pressure refrigerant that is sucked by the compressor, wherein the refrigerant comprises trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoro-1-propene (R1234yf), wherein when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant 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 MM′, M′N, NV, VG; and GM that connect the following 5 points: point M (52.6, 0.0, 47.4), point M′(39.2, 5.0, 55.8), point N (27.7, 18.2, 54.1), point V (11.0, 18.1, 70.9), and point G (39.6, 0.0, 60.4), or on these line segments (excluding the points on the line segment GM); the line segment MM′ is represented by coordinates (0.132y2−3.34y+52.6, y, −0.132y2+2.34y+47.4); the line segment MN is represented by coordinates (0.0596y2−2.2541y+48.98, y, −0.0596y2+1.2541y+51.02); the line segment VG is represented by coordinates (0.0123y2−1.8033y+39.6, y, −0.0123y2+0.8033y+60.4); and the line segments NV and GM are straight lines. ### Claim 6 (depends on 5) The refrigeration cycle apparatus according to claim 5, further comprising: a branching flow path that branches off from a main refrigerant flow path that connects the condenser and the evaporator to each other; an opening degree adjusting valve that is provided in the branching flow path; and an injection heat exchanger that causes the refrigerant that flows in the main refrigerant flow path and the refrigerant that flows on a downstream side with respect to the opening degree adjusting valve in the branching flow path to exchange heat, wherein the refrigerant that exits from the injection heat exchanger and flows in the branching flow path flows in the injection flow path. ### Claim 7 (depends on 5) The refrigeration cycle apparatus according to claim 5, further comprising: a refrigerant storage tank that is provided in a main refrigerant flow path that connects the condenser and the evaporator to each other, wherein a gas component of the refrigerant that accumulates in the refrigerant storage tank flows in the injection flow path. ### Claim 8 (depends on 5) The refrigeration cycle apparatus according to claim 5, wherein the compressor includes a fixed scroll and a swinging scroll, the fixed scroll including an end plate and a lap that stands spirally from the end plate, the swinging scroll forming a compression chamber (Sc) by engaging with the fixed scroll, and the refrigerant that flows in the injection flow path merges at the compression chamber. ### Claim 9 A refrigeration cycle apparatus comprising: a compressor that sucks a refrigerant from a suction flow path, compresses the refrigerant, and discharges a high-pressure refrigerant, the refrigerant flowing through the suction flow path being a low-pressure refrigerant; a condenser that condenses the high-pressure refrigerant discharged from the compressor; a decompressor that decompresses the high-pressure refrigerant that has exited from the condenser; an evaporator that evaporates the refrigerant decompressed at the decompressor; and an injection flow path that is at least either one of an intermediate injection flow path and a suction injection flow path, the intermediate injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with an intermediate-pressure refrigerant in the compressor, the suction injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with the low-pressure refrigerant that is sucked by the compressor, wherein the refrigerant comprises trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoro-1-propene (R1234yf), wherein when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant 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 (0.0072y2−0.6701y+37.512, y, −0.0072y2−0.3299y+62.488); the line segment NU is represented by coordinates (0.0083y2−1.7403y+56.635, y, −0.0083y2+0.7403y+43.365); and the line segment UO is a straight line. ### Claim 10 (depends on 9) The refrigeration cycle apparatus according to claim 9, further comprising: a branching flow path that branches off from a main refrigerant flow path that connects the condenser and the evaporator to each other; an opening degree adjusting valve that is provided in the branching flow path; and an injection heat exchanger that causes the refrigerant that flows in the main refrigerant flow path and the refrigerant that flows on a downstream side with respect to the opening degree adjusting valve in the branching flow path to exchange heat, wherein the refrigerant that exits from the injection heat exchanger and flows in the branching flow path flows in the injection flow path. ### Claim 11 (depends on 9) The refrigeration cycle apparatus according to claim 9, further comprising: a refrigerant storage tank that is provided in a main refrigerant flow path that connects the condenser and the evaporator to each other, wherein a gas component of the refrigerant that accumulates in the refrigerant storage tank flows in the injection flow path. ### Claim 12 (depends on 9) The refrigeration cycle apparatus according to claim 9, wherein the compressor includes a fixed scroll and a swinging scroll, the fixed scroll including an end plate and a lap that stands spirally from the end plate, the swinging scroll forming a compression chamber (Sc) by engaging with the fixed scroll, and the refrigerant that flows in the injection flow path merges at the compression chamber. ### Claim 13 A refrigeration cycle apparatus comprising: a compressor that sucks a refrigerant from a suction flow path, compresses the refrigerant, and discharges a high-pressure refrigerant, the refrigerant flowing through the suction flow path being a low-pressure refrigerant; a condenser that condenses the high-pressure refrigerant discharged from the compressor; a decompressor that decompresses the high-pressure refrigerant that has exited from the condenser; an evaporator that evaporates the refrigerant decompressed at the decompressor; and an injection flow path that is at least either one of an intermediate injection flow path and a suction injection flow path, the intermediate injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with an intermediate-pressure refrigerant in the compressor, the suction injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with the low-pressure refrigerant that is sucked by the compressor, wherein the refrigerant comprises trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoro-1-propene (R1234yf), wherein when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant 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 QR, RT, TL, LK, and KQ that connect the following 5 points: point Q (44.6, 23.0, 32.4), point R (25.5, 36.8, 37.7), point T (8.6, 51.6, 39.8), point L (28.9, 51.7, 19.4), and point K (35.6, 36.8, 27.6), or on these line segments; the line segment QR is represented by coordinates (0.0099y2−1.975y+84.765, y, −0.0099y2+0.975y+15.235); the line segment RT is represented by coordinates (0.0082y2−1.8683y+83.126, y, −0.0082y2+0.8683y+16.874); the line segment LK is represented by coordinates (0.0049y2-0.8842y+61.488, y, −0.0049y2−0.1158y+38.512); the line segment KQ is represented by coordinates (0.0095y2−1.2222y+67.676, y, −0.0095y2+0.2222y+32.324); and the line segment TL is a straight line. ### Claim 14 (depends on 13) The refrigeration cycle apparatus according to claim 13, further comprising: a branching flow path that branches off from a main refrigerant flow path that connects the condenser and the evaporator to each other; an opening degree adjusting valve that is provided in the branching flow path; and an injection heat exchanger that causes the refrigerant that flows in the main refrigerant flow path and the refrigerant that flows on a downstream side with respect to the opening degree adjusting valve in the branching flow path to exchange heat, wherein the refrigerant that exits from the injection heat exchanger and flows in the branching flow path flows in the injection flow path. ### Claim 15 (depends on 13) The refrigeration cycle apparatus according to claim 13, further comprising: a refrigerant storage tank that is provided in a main refrigerant flow path that connects the condenser and the evaporator to each other, wherein a gas component of the refrigerant that accumulates in the refrigerant storage tank flows in the injection flow path. ### Claim 16 (depends on 13) The refrigeration cycle apparatus according to claim 13, wherein the compressor includes a fixed scroll and a swinging scroll, the fixed scroll including an end plate and a lap that stands spirally from the end plate, the swinging scroll forming a compression chamber (Sc) by engaging with the fixed scroll, and the refrigerant that flows in the injection flow path merges at the compression chamber. ### Claim 17 (depends on 1) The refrigeration cycle apparatus according claim 1, A refrigeration cycle apparatus comprising: a compressor that sucks a refrigerant from a suction flow path, compresses the refrigerant, and discharges a high-pressure refrigerant, the refrigerant flowing through the suction flow path being a low-pressure refrigerant; a condenser that condenses the high-pressure refrigerant discharged from the compressor; a decompressor that decompresses the high-pressure refrigerant that has exited from the condenser; an evaporator that evaporates the refrigerant decompressed at the decompressor; and an injection flow path that is at least either one of an intermediate injection flow path and a suction injection flow path, the intermediate injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with an intermediate-pressure refrigerant in the compressor, the suction injection flow path allowing a part of the refrigerant that flows toward the evaporator from the condenser to merge with the low-pressure refrigerant that is sucked by the compressor, wherein the refrigerant comprises trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoro-1-propene (R1234yf), wherein when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant 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 PS, ST, and TP that connect the following 3 points: point P (20.5, 51.7, 27.8), point S (21.9, 39.7, 38.4), and point T (8.6, 51.6, 39.8), or on these line segments; the line segment PS is represented by coordinates (0.0064y2−0.7103y+40.1, y, −0.0064y2−0.2897y+59.9); the line segment ST is represented by coordinates (0.0082y2−1.8683y+83.126, y, −0.0082y2+0.8683y+16.874); and the line segment TP is a straight line. ### Claim 18 (depends on 17) The refrigeration cycle apparatus according to claim 17, further comprising: a branching flow path that branches off from a main refrigerant flow path that connects the condenser and the evaporator to each other; an opening degree adjusting valve that is provided in the branching flow path; and an injection heat exchanger that causes the refrigerant that flows in the main refrigerant flow path and the refrigerant that flows on a downstream side with respect to the opening degree adjusting valve in the branching flow path to exchange heat, wherein the refrigerant that exits from the injection heat exchanger and flows in the branching flow path flows in the injection flow path. ### Claim 19 (depends on 17) The refrigeration cycle apparatus according to claim 17, further comprising: a refrigerant storage tank that is provided in a main refrigerant flow path that connects the condenser and the evaporator to each other, wherein a gas component of the refrigerant that accumulates in the refrigerant storage tank flows in the injection flow path. ### Claim 20 (depends on 17) The refrigeration cycle apparatus according to claim 17, wherein the compressor includes a fixed scroll and a swinging scroll, the fixed scroll including an end plate and a lap that stands spirally from the end plate, the swinging scroll forming a compression chamber (Sc) by engaging with the fixed scroll, and the refrigerant that flows in the injection flow path merges at the compression chamber.