# US 11,994,323 B2 · Refrigerant charging method, heat source unit, and renewed 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 11,994,323 B2 - Document ID: US11994323B2 - Status: Granted - Kind: B2 - Application number: 17/280,406 - Filed: 2019-09-20 - Published: 2022-01-06 - Granted: 2024-05-28 - Earliest claimed: 2018-09-28 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Takuro Yamada; Atsushi Yoshimi; Eiji Kumakura; Ikuhiro Iwata; Shun Ohkubo - Web page: https://patentgrep.com/patent/US11994323B2 ## CPC - F25B 45/00: Arrangements for charging or discharging refrigerant - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 31/004: {oil recirculating arrangements} - F25B 41/20: Disposition of valves, e.g. of on-off valves or flow control valves (expansion valves F25B41/31) - F25B 41/30: Expansion means; Dispositions thereof - F25B 41/42: Arrangements for diverging or converging flows, e.g. branch lines or junctions - 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 49/02: for compression type machines, plants or systems - F25B 40/00: Subcoolers, desuperheaters or superheaters - F25B 41/24: Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part - F25B 43/003: {Filters} - F25B 2313/0233: in parallel arrangements - F25B 2345/001: Charging refrigerant to a cycle - F25B 2345/002: Collecting refrigerant from a cycle - F25B 2345/003: Control issues for charging or collecting refrigerant to or from a cycle - F25B 2345/007: characterised by the weighing of refrigerant or oil - F25B 2400/12: Inflammable refrigerants - F25B 2400/16: Receivers - F25B 2400/19: Pumping down refrigerant from one part of the cycle to another part of the cycle, e.g. when the cycle is changed from cooling to heating, or before a defrost cycle is started - F25B 2500/221: Preventing leaks from developing - F25B 2600/0253: with variable speed - F25B 2600/2509: Economiser valves - F25B 2600/2513: Expansion valves - Y02B 30/70: Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract There is provided a refrigerant charging method in which a foreign material and moisture are avoided from entering a heat source unit until a refrigeration cycle apparatus is configured. The refrigerant charging method is a method of charging a refrigerant to a refrigerant circuit in which a refrigeration cycle is to be performed by a circulating refrigerant, the refrigerant circuit being configured by connecting a second heat source unit and a utilization unit to each other. The refrigerant charging method includes charging a first refrigerant to the second heat source unit before connecting the second heat source unit to the utilization unit to configure the refrigerant circuit, and connecting the second heat source unit to the utilization unit and charging a second refrigerant that differs from the first refrigerant to the refrigerant circuit to obtain the circulating refrigerant that includes the second refrigerant and the first refrigerant that is charged in the second heat source unit. ## Claims ### Claim 1 A refrigerant charging method of charging a refrigerant to a refrigerant circuit in which a refrigeration cycle is to be performed by a circulating refrigerant, the refrigerant circuit being configured by connecting a heat source unit and a utilization unit to each other, the method comprising: (a) charging a first refrigerant to the heat source unit before connecting the heat source unit to the utilization unit to configure the refrigerant circuit; and (b) connecting the heat source unit to the utilization unit and additionally charging a second refrigerant that differs from the first refrigerant to the refrigerant circuit to obtain the circulating refrigerant that includes the second refrigerant and the first refrigerant that is charged in the heat source unit, wherein the second refrigerant is a refrigerant recovered from another refrigerant circuit that previously connected another heat source unit that is different from the heat source unit to the utilization unit. ### Claim 2 (depends on 1) The refrigerant charging method according to claim 1, wherein, in (a), the first refrigerant charged in the heat source unit has an absolute pressure that is more than or equal to an atmospheric pressure at 20° C. in the heat source unit. ### Claim 3 (depends on 2) The refrigerant charging method according to claim 2, wherein, in (a), the first refrigerant charged in the heat source unit has an absolute pressure that is less than 1 MPa at 35° C. in the heat source unit. ### Claim 4 (depends on 1) The refrigerant charging method according to claim 1, wherein the first refrigerant is an R32 refrigerant, and the second refrigerant includes an R410A refrigerant. ### Claim 5 (depends on 1) The refrigerant charging method according to claim 1, wherein the circulating refrigerant is non-flammable. ### Claim 6 (depends on 1) The refrigerant charging method according to claim 1, further comprising: after (a), transporting the heat source unit with the first refrigerant charged therein to a location where the heat source unit is to be connected to configure the refrigerant circuit. ### Claim 7 A refrigerant charging method of charging a refrigerant to a refrigerant circuit in which a refrigeration cycle is to be performed by a circulating refrigerant, the refrigerant circuit being configured by connecting a heat source unit and a utilization unit to each other, the method comprising: (a) charging a first refrigerant to the heat source unit before connecting the heat source unit to the utilization unit to configure the refrigerant circuit; and (b) connecting the heat source unit to the utilization unit and additionally charging a second refrigerant that differs from the first refrigerant to the refrigerant circuit to obtain the circulating refrigerant that includes the second refrigerant and the first refrigerant that is charged in the heat source unit, wherein, after (a), the method comprises transporting the heat source unit with the first refrigerant charged therein to a location where the heat source unit is to be connected to configure the refrigerant circuit, wherein, before (b) is performed, a connection pipe connected to the utilization unit and/or the heat source unit is connected to another heat source unit other than the heat source unit at the location and configures another refrigerant circuit that differs from the refrigerant circuit, and wherein, in (b), a recovered refrigerant recovered from the other refrigerant circuit is charged as the second refrigerant to the refrigerant circuit. ### Claim 8 (depends on 2) The refrigerant charging method according to claim 2, wherein the first refrigerant is an R32 refrigerant, and the second refrigerant includes an R410A refrigerant. ### Claim 9 (depends on 3) The refrigerant charging method according to claim 3, wherein the first refrigerant is an R32 refrigerant, and the second refrigerant includes an R410A refrigerant. ### Claim 10 (depends on 2) The refrigerant charging method according to claim 2, wherein the circulating refrigerant is non-flammable. ### Claim 11 (depends on 3) The refrigerant charging method according to claim 3, wherein the circulating refrigerant is non-flammable. ### Claim 12 (depends on 4) The refrigerant charging method according to claim 4, wherein the circulating refrigerant is non-flammable. ### Claim 13 (depends on 2) The refrigerant charging method according to claim 2, further comprising: after (a), transporting the heat source unit with the first refrigerant charged therein to a location where the heat source unit is to be connected to configure the refrigerant circuit. ### Claim 14 (depends on 3) The refrigerant charging method according to claim 3, further comprising: after (a), transporting the heat source unit with the first refrigerant charged therein to a location where the heat source unit is to be connected to configure the refrigerant circuit. ### Claim 15 (depends on 4) The refrigerant charging method according to claim 4, further comprising: after (a), transporting the heat source unit with the first refrigerant charged therein to a location where the heat source unit is to be connected to configure the refrigerant circuit. ### Claim 16 (depends on 5) The refrigerant charging method according to claim 5, further comprising: after (a), transporting the heat source unit with the first refrigerant charged therein to a location where the heat source unit is to be connected to configure the refrigerant circuit.