# US 2014/0360218 A1 · Air-conditioning apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0360218 A1 - Document ID: US20140360218A1 - Status: Published application - Kind: A1 - Application number: 14/372,092 - Filed: 2012-01-23 - Published: 2014-12-11 - Earliest claimed: 2012-01-23 - Assignees: Mitsubishi Electric Corporation - Inventors: Naofumi Takenaka; Shinichi Wakamoto; Koji Yamashita; Hiroyuki Morimoto; Takeshi Hatomura; Katsuhiro Ishimura - Web page: https://patentgrep.com/patent/US20140360218A1 ## CPC - F25B 1/10: with multi-stage compression (with cascade operation F25B7/00) - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 30/02: of the compression type - F25B 2313/005: Outdoor unit expansion valves - F25B 2313/006: two pipes connecting the outdoor side to the indoor side with multiple indoor units - F25B 2313/0233: in parallel arrangements - F25B 2313/0272: using bridge circuits of one-way valves - F25B 2313/02741: using one four-way valve - F25B 2400/13: Economisers - F25B 2600/2509: Economiser valves - F25B 2700/1931: Discharge pressures - F25B 2700/21152: at the discharge side of the compressor - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract An air-conditioning apparatus includes an outdoor-side flow rate control device (a fourth flow rate control device) that generates an intermediate pressure for injection into a compressor, and a bypass flow rate control device (a sixth flow rate control device) that is placed at a bypass pipe allowing bypassing of an outdoor heat exchanger in parallel to the outdoor-side flow rate control device and that controls the amount of heat exchange of the outdoor heat exchanger together with the outdoor-side flow rate control device. ## Claims ### Claim 1 An air-conditioning apparatus comprising: a compressor into which an intermediate-pressure refrigerant is allowed to be injected via an injection pipe in the course of compressing a refrigerant; an outdoor heat exchanger; a flow passage switching device that switches connection of the outdoor heat exchanger; an injection flow rate control device that controls a flow rate of injection into the compressor; an outdoor-side flow rate control device that generates an intermediate pressure for injection into the compressor and that is able to change a flow passage resistance in a continuous manner; a bypass flow rate control device that is placed at a bypass pipe which allows bypassing of the outdoor heat exchanger in parallel to the outdoor-side flow rate control device, that controls an amount of heat exchange of the outdoor heat exchanger, together with the outdoor-side flow rate control device, and that is able to change a flow passage resistance in a continuous manner; an indoor heat exchanger; and an indoor-side flow rate control device that adjusts a flow rate of refrigerant to the indoor heat exchanger, wherein the compressor, the outdoor heat exchanger, the flow passage switching device, the injection flow rate control device, the outdoor-side flow rate control device, and the bypass flow rate control device are provided within an outdoor unit, wherein the indoor heat exchanger and the indoor-side flow rate control device are provided within an indoor unit, and wherein the indoor unit includes a plurality of indoor units, which are connected to the outdoor unit in parallel. ### Claim 2 (depends on 1) The air-conditioning apparatus of claim 1, comprising a relay unit interposed between the outdoor unit and the indoor units, wherein the relay unit allows the indoor units to perform a cooling and heating mixed operation by switching a flow passage of the refrigerant so that cooling or heating is performed by each of the indoor units. ### Claim 3 (depends on 1) The air-conditioning apparatus of claim 1, wherein in accordance with an indoor load or an outside air temperature, switching is performed between control of the amount of heat exchange of the outdoor heat exchanger by the outdoor-side flow rate control device and the bypass flow rate control device, and control of the intermediate pressure and control of the flow rate of injection into the compressor by the outdoor-side flow rate control device, the bypass flow rate control device, and the injection flow rate control device. ### Claim 4 (depends on 3) The air-conditioning apparatus of claim 3, wherein in accordance with at least one piece of operation data out of the outside air temperature, an indoor temperature, the number of indoor units performing cooling and heating, and a pressure, a temperature, and a frequency of the compressor within the air-conditioning apparatus, switching is performed between the control of the amount of heat exchange of the outdoor heat exchanger and the control of the flow rate of injection into the compressor. ### Claim 5 (depends on 1) The air-conditioning apparatus of claim 1, wherein a direction in which the refrigerant flows within the outdoor heat exchanger is fixed in one direction, regardless of whether the outdoor heat exchanger operates as a condenser or an evaporator. ### Claim 6 (depends on 1) The air-conditioning apparatus of claim 1, wherein each of the outdoor-side flow rate control device and the bypass flow rate control device is configured to be able to change the flow passage resistance in a continuous manner, and wherein the control of the amount of heat exchange is performed by continuously changing a flow rate of the refrigerant flowing into the outdoor heat exchanger. ### Claim 7 (depends on 1) The air-conditioning apparatus of claim 1, wherein as a refrigerant for a heat source, difluoromethane or a refrigerant mixture of tetrafluoropropane and 15 mass percent or more of difluoromethane is used. ### Claim 8 (depends on 1) The air-conditioning apparatus of claim 1, wherein the control of the flow rate of injection into the compressor is performed such that a discharge temperature of the refrigerant discharged from the compressor does not exceed 110 degrees Centigrade. ### Claim 9 (depends on 2) The air-conditioning apparatus of claim 2, wherein in an operation mode in which the outdoor heat exchanger operates as an evaporator, a target value for the intermediate pressure differs between a case where none of the indoor units are performing cooling and a case where at least one indoor unit is performing cooling. ### Claim 10 (depends on 3) The air-conditioning apparatus of claim 3, wherein the outdoor-side flow rate control device and the bypass flow rate control device cooperate with each other to, based on the outside air temperature, switch between the control of the amount of heat exchange of the outdoor heat exchanger, and the control of the intermediate pressure and the control of the flow rate of injection into the compressor.