# US 2018/0023818 A1 · Heat pump system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0023818 A1 - Document ID: US20180023818A1 - Status: Published application - Kind: A1 - Application number: 15/546,466 - Filed: 2015-03-19 - Published: 2018-01-25 - Earliest claimed: 2015-03-19 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Keisuke TAKAYAMA - Web page: https://patentgrep.com/patent/US20180023818A1 ## CPC - F24D 3/18: using heat pumps - F24D 11/0214: {water heating system} - F24D 19/1024: {a multiple way valve} - F24D 19/1039: {the system uses a heat pump} - F24H 1/00: Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters (steam boilers F22B) - F25B 1/10: with multi-stage compression (with cascade operation F25B7/00) - F25B 6/04: arranged in series - F25B 9/008: {the refrigerant being carbon dioxide} - F25B 30/02: of the compression type - F25B 40/00: Subcoolers, desuperheaters or superheaters - F24H 15/219: after heating - F24H 15/254: Room temperature - F24H 15/32: of switching valves (for by-passing F24H15/325) - F24H 15/335: Control of pumps, e.g. on-off control (control of compressors of heat pumps F24H15/38) - F24H 15/375: Control of heat pumps - F24H 15/395: Information to users, e.g. alarms - F24H 15/45: remotely accessible - F25B 2309/061: with cycle highest pressure above the supercritical pressure - Y02B 30/12: Hot water central heating systems using heat pumps - 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) - F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22) - 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 A heat pump system includes: a compressor for compressing refrigerant; a first heat exchanger for exchanging heat between the refrigerant compressed by the compressor and a heating medium; a second heat exchanger for exchanging heat between the refrigerant compressed by the compressor and the heating medium; a first pipe through which the refrigerant is fed from the compressor to the first heat exchanger; a second pipe through which the refrigerant returns from the first heat exchanger to the compressor; a third pipe through which the refrigerant is fed from the compressor to the second heat exchanger after returning from the first heat exchanger; and switching apparatus for switching a flow of the heating medium between a first mode and a second mode. The heating medium flows through the first heat exchanger and the second heat exchanger in series in the first mode. The heating medium flows through the first heat exchanger and the second heat exchanger in parallel in the second mode. ## Claims ### Claim 1 A heat pump system comprising: a compressor configured to compress refrigerant; a first heat exchanger configured to exchange heat between the refrigerant compressed by the compressor and a heating medium; a second heat exchanger configured to exchange heat between the refrigerant compressed by the compressor and the heating medium; a first pipe through which the refrigerant is fed from the compressor to the first heat exchanger; a second pipe through which the refrigerant returns from the first heat exchanger to the the compressor; a third pipe through which the refrigerant is fed from the compressor to the second heat exchanger after returning from the first heat exchanger; and a switching apparatus configured to switch a flow of the heating medium between a first mode and a second mode, the heating medium flowing through the first heat exchanger and the second heat exchanger in series in the first mode, the heating medium flowing through the first heat exchanger and the second heat exchanger in parallel in the second mode, wherein in the second mode, flows of the refrigerant and the heating medium in the first heat exchanger become concurrent flows and flows of the refrigerant and the heating medium in the second heat exchanger become countercurrent flows. ### Claim 2 (depends on 1) The heat pump system according to claim 1, wherein the compressor includes a compressing unit in which the refrigerant is compressed, an electric motor configured to drive the compressing unit, and a sealed container configured to house the compressing unit and the electric motor, the refrigerant compressed by the compressing unit is fed to the first heat exchanger through the first pipe without being discharged to an internal space of the sealed container, the refrigerant having passed through the second pipe is discharged to the internal space of the sealed container, and the refrigerant in the internal space of the sealed container is fed to the second heat exchanger through the third pipe. ### Claim 3 (canceled) ### Claim 4 (depends on 1) The heat pump system according to claim 1, wherein in the first mode, flows of the refrigerant and the heating medium in the first heat exchanger and the second heat exchanger become countercurrent flows. ### Claim 5 (depends on 1) The heat pump system according to claim 1, further comprising an adjuster configured to adjust a ratio between a flow rate of the heating medium in the first heat exchanger and a flow rate of the heating medium in the second heat exchanger in the second mode. ### Claim 6 (depends on 1) The heat pump system according to claim 1, wherein the switching apparatus includes a four-way valve having a first port, a second port, a third port, and a fourth port and a check valve configured to prevent a backflow, and the four-way valve is configured to switch between a first state in which the first port and the second port are communicated with each other and the third port and the fourth port are communicated with each other and a second state in which the first port and the fourth port are communicated with each other and the second port and the third port are communicated with each other. ### Claim 7 (depends on 6) The heat pump system according to claim 6, wherein the switching apparatus further includes a first passage connecting a heating medium outlet of the heat pump system with the first port, a second passage connecting a heating medium passage of the first heat exchanger with the second port, a third passage connecting a branching section, where the heating medium prior to being heated branches in the second mode, with the third port, and a fourth passage connecting a merging section, where the heating medium heated by the first heat exchanger and the heating medium heated by the second heat exchanger merge in the second mode, with the fourth port, and the check valve is configured to prevent a backflow in the fourth passage. ### Claim 8 (depends on 1) The heat pump system according to claim 1, wherein the switching apparatus includes a plurality of two-way valves configured to open and close flow paths. ### Claim 9 (depends on 1) The heat pump system according to claim 1, further comprising a controller configured to control switching between the first mode and the second mode. ### Claim 10 (depends on 9) The heat pump system according to claim 9, wherein the controller is configured to select the first mode when performing a heat accumulating operation for accumulating heat in a heat storage tank and select the second mode when performing an indoor-heating operation for feeding the heating medium to an indoor heater. ### Claim 11 A heat pump system comprising: a compressor configured to compress refrigerant; a first heat exchanger configured to exchange heat between the refrigerant compressed by the compressor and a heating medium; a second heat exchanger configured to exchange heat between the refrigerant compressed by the compressor and the heating medium; a first pipe through which the refrigerant is fed from the compressor to the first heat exchanger; a second pipe through hick the refrigerant returns from the first heat exchanger to the the compressor; a third pipe through which the refrigerant is fed from the compressor to the second heat exchanger after returning from the first heat exchanger; and a switching apparatus configured to switch a flow of the heating medium between a first mode and a second mode, the heating medium flowing through the first heat exchanger and the second heat exchanger in series in the first mode, the heating medium flowing through the first heat exchanger and the second heat exchanger in parallel in the second mode, wherein the switching apparatus includes a four-way valve having a first port, a second port, a third port, and a fourth port and a check valve configured to prevent a backflow, and the four-way valve is configured to switch between a first state in which the first port and the second port are communicated with each other and the third port and the fourth port are communicated with each other and a second state in which the first port and the fourth port are communicated with each other and the second port and the third port are communicated with each other. ### Claim 12 (depends on 11) The heat pump system according to claim 11, wherein the compressor includes a compressing unit in which the refrigerant is compressed, an electric motor configured to drive the compressing unit, and a sealed container configured to house the compressing unit and the electric motor, the refrigerant compressed by the compressing unit s fed to the first heat exchanger through the first pipe without being discharged to an internal space of the sealed container, the refrigerant having passed through the second pipe is discharged to the internal space of the sealed container, and the refrigerant in the internal space of the sealed container is fed to the second heat exchanger through the third pipe. ### Claim 13 (depends on 11) The heat pump system according to claim 11, wherein in the second mode, flows of the refrigerant and the heating medium in the first heat exchanger become concurrent flows and flows of the refrigerant and the heating medium in the second heat exchanger become countercurrent flows. ### Claim 14 (depends on 11) The heat pump system according to claim 11, wherein in the first mode, flows of the refrigerant and the heating medium in the first heat exchanger and the second heat exchanger become countercurrent flows. ### Claim 15 (depends on 11) The heat pump system according to claim 11, further comprising an adjuster configured to adjust a ratio between a flow rate of the heating medium in the first heat exchanger and a flow rate of the heating medium in the second heat exchanger in the second mode. ### Claim 16 (depends on 11) The heat pump system according to claim 11, wherein the switching apparatus further includes a first passage connecting a heating medium outlet of the heat pump system first port, a second passage connecting a heating medium passage of the first heat exchanger with the second port, a third passage connecting a branching section, where the heating medium prior to being heated branches in the second mode, with the third port, and a fourth passage connecting a merging section, where the heating medium heated by the first heat exchanger and the heating medium heated by the second heat exchanger merge in the second mode, with the fourth port, and the check valve is configured to prevent a backflow in the fourth passage. ### Claim 17 (depends on 11) The heat pump system according to claim 11, further comprising a controller configured to control switching between the first mode and the second mode. ### Claim 18 (depends on 17) The heat pump system according to claim 17, wherein the controller is configured to select the first mode when performing a heat accumulating operation for accumulating heat in a heat storage tank and select the second mode when performing an indoor heating operation for feeding the heating medium to an indoor heater.