# US 12,215,897 B2 · Air conditioning apparatus and outdoor unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,897 B2 - Document ID: US12215897B2 - Status: Granted - Kind: B2 - Application number: 17/614,235 - Filed: 2019-07-22 - Published: 2022-07-07 - Granted: 2025-02-04 - Earliest claimed: 2019-07-22 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Hiroaki Makino; Hirotaka Ishida - Web page: https://patentgrep.com/patent/US12215897B2 ## CPC - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 25/005: {using primary and secondary systems} - F25B 39/028: {having distributing means} - F25B 40/02: Subcoolers - 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 2313/004: Outdoor unit with water as a heat sink or heat source - F25B 2313/006: two pipes connecting the outdoor side to the indoor side with multiple indoor units - F25B 2313/02741: using one four-way valve - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract In an air conditioning apparatus, heat exchange is conducted between refrigerant passing through a first high-temperature-side flow path and refrigerant passing through a first low-temperature-side flow path of a cooler, and between refrigerant passing through a second high-temperature-side flow path and refrigerant passing through a second low-temperature-side flow path of the cooler. A switching device switches between first/second refrigerant circuits. In the first circuit, an inlet of the first high-temperature-side flow path is formed downstream of the first low-temperature-side flow path with respect to an outlet of the first high-temperature-side flow path, and in the second refrigerant circuit, an inlet of the second high-temperature-side flow path is formed downstream of the second low-temperature-side flow path with respect to an outlet of the second high-temperature-side flow path. ## Claims ### Claim 1 An air conditioning apparatus comprising: a compressor that compresses a refrigerant; a pressure-reducing valve that reduces a pressure of the refrigerant; a heat source-side heat exchanger that makes heat exchange to be conducted between the refrigerant and a heat source-side heat medium; a load-side heat exchanger that makes heat exchange to be conducted between the refrigerant and a load-side heat medium; first and second refrigerant-to-refrigerant heat exchangers that cool the refrigerant; a flow path switching valve that switches a refrigerant circuit in which the refrigerant circulates; and a refrigerant piping that connects the compressor, the pressure-reducing valve, the heat source-side heat exchanger, the load-side heat exchanger, the first and second refrigerant-to-refrigerant heat exchangers, and the flow path switching valve, wherein a high-temperature-side flow path and a low-temperature-side flow path are formed in the first and second refrigerant-to-refrigerant heat exchangers, the high-temperature-side flow path includes a first high-temperature-side flow path and a second high-temperature-side flow path, the low-temperature-side flow path includes a first low-temperature-side flow path and a second low-temperature-side flow path, heat exchange is conducted between the refrigerant passing through the first high-temperature-side flow path and the refrigerant passing through the first low-temperature-side flow path, and heat exchange is conducted between the refrigerant passing through the second high-temperature-side flow path and the refrigerant passing through the second low-temperature-side flow path, the flow path switching valve switches between a first flow direction in which the refrigerant circulates in order of the compressor, the heat source-side heat exchanger, the first high-temperature-side flow path, the pressure-reducing valve, the load-side heat exchanger, the first low-temperature-side flow path, and the compressor, and a second flow direction in which the refrigerant circulates in order of the compressor, the load-side heat exchanger, the second high-temperature-side flow path, the pressure-reducing valve, the heat source-side heat exchanger, the second low-temperature-side flow path, and the compressor, wherein in the first flow direction, an inlet port of the first high-temperature-side flow path is formed at a place located downstream of the refrigerant flowing through the first low-temperature-side flow path with respect to an outlet port of the first high-temperature-side flow path, and in the second flow direction, an inlet port of the second high-temperature-side flow path is formed at a place located downstream of the refrigerant flowing through the second low-temperature-side flow path with respect to an outlet port of the second high-temperature-side flow path. ### Claim 2 (depends on 1) The air conditioning apparatus according to claim 1, wherein the refrigerant flowing from the heat source-side heat exchanger to the first high-temperature-side flow path in the first flow direction is in a gas-liquid two-phase state, and the refrigerant flowing from the load-side heat exchanger to the second high-temperature-side flow path in the second flow direction is in a gas-liquid two-phase state. ### Claim 3 (depends on 1) The air conditioning apparatus according to claim 1, wherein the refrigerant flowing from the first high-temperature-side flow path to the pressure-reducing valve in the first flow direction is in a liquid state, and the refrigerant flowing from the second high-temperature-side flow path to the pressure-reducing valve in the second flow direction is in a liquid state. ### Claim 4 (depends on 1) The air conditioning apparatus according to claim 1, wherein in the first flow direction, the refrigerant circulates in order of the compressor, the heat source-side heat exchanger, the first high-temperature-side flow path, the pressure-reducing valve, the second high-temperature-side flow path, the load-side heat exchanger, the first low-temperature-side flow path and the second low-temperature-side flow path, and the compressor, and in the second flow direction, the refrigerant circulates in order of the compressor, the load-side heat exchanger, the second high-temperature-side flow path, the pressure-reducing valve, the first high-temperature-side flow path, the heat source-side heat exchanger, the first low-temperature-side flow path and the second low-temperature-side flow path, and the compressor. ### Claim 5 (depends on 1) The air conditioning apparatus according to claim 1, wherein in the first flow direction, a flow direction of the refrigerant flowing through the first high-temperature-side flow path is opposite to a flow direction of the refrigerant flowing through the first low-temperature-side flow path, and in the second flow direction, a flow direction of the refrigerant flowing through the second high-temperature-side flow path is opposite to a flow direction of the refrigerant flowing through the second low-temperature-side flow path. ### Claim 6 (depends on 1) The air conditioning apparatus according to claim 1, wherein the first and second refrigerant-to-refrigerant heat exchangers include a first piping forming the low-temperature-side flow path and a second piping forming the high-temperature-side flow path, the second piping being spirally wound around the first piping. ### Claim 7 (depends on 1) The air conditioning apparatus according to claim 1, wherein the refrigerant is a flammable refrigerant. ### Claim 8 (depends on 1) The air conditioning apparatus according to claim 1, wherein the refrigerant is R290. ### Claim 9 (depends on 5) The air conditioning apparatus according to claim 5, wherein a chiller oil of the compressor is polyalkylene glycol. ### Claim 10 An outdoor unit comprising: a compressor that compresses a refrigerant; a pressure-reducing valve that reduces a pressure of the refrigerant; a heat source-side heat exchanger that makes heat exchange to be conducted between the refrigerant and a heat source-side heat medium; first and second refrigerant-to-refrigerant heat exchangers that cool the refrigerant; a flow path switching valve that switches a refrigerant circuit in which the refrigerant circulates; a refrigerant piping that connects the compressor, the pressure-reducing valve, the heat source-side heat exchanger, the first and second refrigerant-to-refrigerant heat exchangers, and the flow path switching valve; a first piping connection portion connected to one end portion of a load-side heat exchanger flow path via a piping, the load-side heat exchanger flow path being formed in a load-side heat exchanger that makes heat exchange to be conducted between the refrigerant and a load-side heat medium; and a second piping connection portion connected to the other end portion of the load-side heat exchanger flow path via a piping, wherein a high-temperature-side flow path and a low-temperature-side flow path are formed in the first and second refrigerant-to-refrigerant heat exchangers, the high-temperature-side flow path includes a first high-temperature-side flow path and a second high-temperature-side flow path, the low-temperature-side flow path includes a first low-temperature-side flow path and a second low-temperature-side flow path, heat exchange is conducted between the refrigerant passing through the first high-temperature-side flow path and the refrigerant passing through the first low-temperature-side flow path, and heat exchange is conducted between the refrigerant passing through the second high-temperature-side flow path and the refrigerant passing through the second low-temperature-side flow path, wherein the flow path switching valve switches between a first flow direction and a second flow direction, the first flow direction that flows the refrigerant in order of the compressor, the heat source-side heat exchanger, the first high-temperature-side flow path, the pressure-reducing valve, and the first piping connection portion, the second piping connection portion, and the first low-temperature-side flow path, and the second flow direction that flows the refrigerant in order of the second piping connection portion, the first piping connection portion, the second high-temperature-side flow path, the pressure-reducing valve, the heat source-side heat exchanger, the second low-temperature-side flow path, and the compressor, wherein in the first flow direction, an inlet port of the first high-temperature-side flow path is formed at a place located downstream of an outlet port of the first high-temperature-side flow path with respect to the refrigerant flowing through the first low-temperature-side flow path, and in the second flow direction, an inlet port of the second high-temperature-side flow path is formed at a place located downstream of an outlet port of the second high-temperature-side flow path with respect to the refrigerant flowing through the second low-temperature-side flow path.