# US 11,029,042 B2 · Indoor unit for heat pump use apparatus and heat pump use apparatus including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,042 B2 - Document ID: US11029042B2 - Status: Granted - Kind: B2 - Application number: 16/319,854 - Filed: 2016-10-17 - Published: 2019-08-29 - Granted: 2021-06-08 - Earliest claimed: 2016-10-17 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Yasuhiro Suzuki; Taro Hattori; Hirokazu Minamisako; Kazutaka Suzuki - Web page: https://patentgrep.com/patent/US11029042B2 ## CPC - F24D 19/1072: {the system uses a heat pump} - F24D 11/0228: {combined with conventional heater} - F24D 17/02: using heat pumps - F25B 30/02: of the compression type - F25B 47/025: {by reversing the cycle} - F24D 2200/123: Compression type heat pumps - F25B 2339/047: Water-cooled condensers - 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 2400/121: using R1234 - F25B 2400/16: Receivers - Y02B 10/70: Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies - F24D: DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR (using steam or condensate extracted or exhausted from steam engine plants for heating purposes F01K17/02) - 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 Provided is an indoor unit for a heat pump use apparatus, the indoor unit being a part of the heat pump use apparatus including a refrigerant circuit configured to circulate refrigerant, a heat medium circuit configured to allow a heat medium to flow through the heat medium circuit, and a heat exchanger configured to exchange heat between the refrigerant and the heat medium. The indoor unit is connectable to an outdoor unit accommodating the refrigerant circuit and the heat exchanger. The indoor unit accommodates a part of the heat medium circuit. The indoor unit includes a pressure protection device connected to the heat medium circuit, and an on-off device provided to be interposed between the heat medium circuit and the pressure protection device. ## Claims ### Claim 1 An indoor unit for a heat pump use apparatus, the indoor unit being a part of the heat pump use apparatus comprising a refrigerant circuit configured to circulate refrigerant, a heat medium circuit configured to allow a heat medium to flow through the heat medium circuit, and a heat exchanger configured to exchange heat between the refrigerant and the heat medium, the indoor unit being connectable to an outdoor unit accommodating the refrigerant circuit and the heat exchanger, the indoor unit accommodating a part of the heat medium circuit, the indoor unit comprising: a pressure protection device connected to the heat medium circuit; an on-off device provided to be interposed between the heat medium circuit and the pressure protection device; and a controller configured to control the on-off device, the controller being configured to open and close the on-off device on a basis of information acquired from the outdoor unit. ### Claim 2 (depends on 1) The indoor unit for a heat pump use apparatus of claim 1, wherein the heat medium circuit includes a main circuit and a plurality of branch circuits connected to the main circuit to be branched from the main circuit, and wherein the pressure protection device is connected to the main circuit. ### Claim 3 (depends on 2) The indoor unit for a heat pump use apparatus of claim 2, further comprising: a first branching portion provided on a pipe for connecting the on-off device and the main circuit to each other; and an expansion tank connected to the first branching portion. ### Claim 4 An indoor unit for a heat pump use apparatus, the indoor unit being a part of the heat pump use apparatus comprising a refrigerant circuit configured to circulate refrigerant, a heat medium circuit configured to allow a heat medium to flow through the heat medium circuit, and a heat exchanger configured to exchange heat between the refrigerant and the heat medium, the indoor unit being connectable to an outdoor unit accommodating the refrigerant circuit and the heat exchanger, the indoor unit accommodating a part of the heat medium circuit, the indoor unit comprising: an air purge device connected to the heat medium circuit; an on-off device provided to be interposed between the heat medium circuit and the air purge device; and the controller being configured to open and close the on-off device on a basis of information acquired from the outdoor unit. ### Claim 5 (depends on 1) The indoor unit for a heat pump use apparatus of claim 1, wherein the information comprises any one of information of a name of the refrigerant, information of flammability of the refrigerant, information indicating whether or not the outdoor unit includes a pressure protection device connected to the heat medium circuit, information indicating whether or not the outdoor unit includes an air purge device connected to the heat medium circuit, and information indicating whether or not the outdoor unit includes the pressure protection device and the air purge device that are connected to the heat medium circuit. ### Claim 6 (depends on 1) The indoor unit for a heat pump use apparatus of claim 1, wherein, when the controller determines that the refrigerant is flammable refrigerant, the controller is configured to set the on-off device to a closed state. ### Claim 7 (depends on 1) The indoor unit for a heat pump use apparatus of claim 1, wherein, when the controller determines that the refrigerant is nonflammable refrigerant, the controller is configured to set the on-off device to an opened state. ### Claim 8 (depends on 1) The indoor unit for a heat pump use apparatus of claim 1, wherein, when the controller determines that the outdoor unit includes the pressure protection device connected to the heat medium circuit, the controller is configured to set the on-off device to a closed state. ### Claim 9 (depends on 1) The indoor unit for a heat pump use apparatus of claim 1, wherein, when the controller is unable to determine that the outdoor unit includes the pressure protection device connected to the heat medium circuit, the controller is configured to set the on-off device to an opened state. ### Claim 10 (depends on 1) The indoor unit for a heat pump use apparatus of claim 1, wherein, when the controller determines that the outdoor unit includes the air purge device connected to the heat medium circuit, the controller is configured to set the on-off device to a closed state. ### Claim 11 (depends on 1) The indoor unit for a heat pump use apparatus of claim 1, wherein, when the controller is unable to determine that the outdoor unit includes the air purge device connected to the heat medium circuit, the controller is configured to set the on-off device to an opened state. ### Claim 12 (depends on 1) A heat pump use apparatus, comprising: the indoor unit for a heat pump use apparatus of claim 1; and the outdoor unit. ### Claim 13 (depends on 12) The heat pump use apparatus of claim 12, wherein the outdoor unit includes at least one of the pressure protection device and the air purge device that is connected to the heat medium circuit. ### Claim 14 (depends on 4) The indoor unit for a heat pump use apparatus of claim 4, wherein the heat medium circuit includes a main circuit and a plurality of branch circuits each connected to the main circuit to be branched from the main circuit, and the air purge device is connected to the main circuit. ### Claim 15 (depends on 4) A heat pump use apparatus, comprising: the indoor unit for a heat pump of claim 4; and the outdoor unit.