US20210318041A1 - Air conditioner and flow path switching valve - Google Patents

Air conditioner and flow path switching valve Download PDF

Info

Publication number
US20210318041A1
US20210318041A1 US17/356,910 US202117356910A US2021318041A1 US 20210318041 A1 US20210318041 A1 US 20210318041A1 US 202117356910 A US202117356910 A US 202117356910A US 2021318041 A1 US2021318041 A1 US 2021318041A1
Authority
US
United States
Prior art keywords
port
flow path
refrigerant
switching valve
way switching
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
US17/356,910
Other languages
English (en)
Inventor
Shigetaka Wakisaka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daikin Industries Ltd
Original Assignee
Daikin Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries Ltd filed Critical Daikin Industries Ltd
Assigned to DAIKIN INDUSTRIES, LTD. reassignment DAIKIN INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: WAKISAKA, SHIGETAKA
Publication of US20210318041A1 publication Critical patent/US20210318041A1/en
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
    • F24F11/84—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F24F11/32—Responding to malfunctions or emergencies
    • F24F11/36—Responding to malfunctions or emergencies to leakage of heat-exchange fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/86—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling compressors within refrigeration or heat pump circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B39/00—Evaporators; Condensers
    • F25B39/02—Evaporators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
    • F25B41/24—Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/005—Arrangement or mounting of control or safety devices of safety devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
    • F25B5/02—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity arranged in parallel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/005—Outdoor unit expansion valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/006—Compression machines, plants or systems with reversible cycle not otherwise provided for two pipes connecting the outdoor side to the indoor side with multiple indoor units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0231—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units with simultaneous cooling and heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/029—Control issues
    • F25B2313/0292—Control issues related to reversing valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/22—Preventing, detecting or repairing leaks of refrigeration fluids
    • F25B2500/222—Detecting refrigerant leaks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2515—Flow valves

Definitions

  • the present disclosure relates to an air conditioner and a flow path switching valve.
  • Patent Document 1 discloses an air conditioner including an indoor unit and an outdoor unit. An electromagnetic valve and an expansion valve are connected to a refrigerant pipe that is connected to the indoor unit. If a refrigerant leakage detector detects leakage of a refrigerant in the indoor unit, the electromagnetic valve and the expansion valve are closed.
  • Patent Document 1 Japanese Unexamined Patent Publication No. 2012-13339
  • a first aspect is directed to an air conditioner including: a refrigerant circuit ( 10 a ) that includes a heat source circuit ( 20 a ) to which a compressor ( 21 ) and a heat source heat exchanger ( 22 ) are connected, and includes a utilization circuit ( 30 a ) to which a utilization heat exchanger ( 31 ) is connected, and that is configured to perform a refrigeration cycle.
  • the refrigerant circuit ( 10 a ) further includes: two refrigerant flow paths ( 41 , 42 ) connected to respective ends of the utilization circuit ( 30 a ), and two cut-off valves connected to the respective refrigerant flow paths ( 41 , 42 ).
  • At least one of the cut-off valves is configured as a flow path switching valve (V 1 , V 2 ) configured to switch a flow path so as to block the refrigerant flow paths ( 41 , 42 ) when a refrigerant leaks in the utilization circuit ( 30 a ).
  • FIG. 1 is a piping system diagram illustrating a schematic configuration of an air conditioner of an embodiment.
  • FIG. 2 is an enlarged circuit diagram of a cut-off unit, illustrating a flow of a refrigerant during a normal cooling operation.
  • FIG. 3 is an enlarged circuit diagram of a cut-off unit, illustrating a flow of the refrigerant during a normal heating operation.
  • FIG. 4 is an enlarged circuit diagram of a cut-off unit, illustrating a state in which the refrigerant leaks.
  • FIGS. 5A and 5B are enlarged circuit diagrams illustrating a cut-off unit of a second variation.
  • FIG. 5A shows a state during a normal operation.
  • FIG. 5B shows a state in which a refrigerant has leaked.
  • FIGS. 6A and 6B are enlarged circuit diagrams illustrating a cut-off unit of a third variation.
  • FIG. 6A shows a state during a normal operation.
  • FIG. 6B shows a state in which a refrigerant has leaked.
  • FIG. 7 is a piping system diagram illustrating a schematic configuration of an air conditioner of a first example according to another embodiment.
  • FIG. 8 is a piping system diagram illustrating a schematic configuration of an air conditioner of a second example according to another embodiment.
  • FIG. 9 is a table showing refrigerants used in a refrigerant circuit of the air conditioner of the embodiment, variations, and other embodiments.
  • An air conditioner ( 10 ) of this embodiment conditions air in an indoor space that is a target space.
  • the air conditioner ( 10 ) of this example is a multiple-type air conditioner and includes an outdoor unit ( 20 ) and a plurality of indoor units ( 30 ).
  • the air conditioner ( 10 ) of this example switches between cooling and heating of air in the target space.
  • the number of the indoor units ( 30 ) may be three or more.
  • the outdoor unit ( 20 ) is placed outside.
  • the outdoor unit ( 20 ) constitutes a heat source unit.
  • the outdoor unit ( 20 ) is provided with a heat source circuit ( 20 a ).
  • the indoor units ( 30 ) are placed inside.
  • the indoor units ( 30 ) each constitute a utilization unit.
  • the indoor units ( 30 ) are each provided with a utilization circuit ( 30 a ).
  • the outdoor unit ( 20 ) is connected to the indoor units ( 30 ) via connection pipes ( 11 , 15 ).
  • the air conditioner ( 10 ) includes a refrigerant circuit ( 10 a ).
  • the refrigerant circuit ( 10 a ) is filled with a refrigerant.
  • a vapor compression refrigeration cycle is performed by circulation of the refrigerant.
  • the refrigerant circuit ( 10 a ) includes a heat source circuit ( 20 a ) in the outdoor unit ( 20 ) and a plurality of utilization circuits ( 30 a ) in the respective indoor units ( 30 ).
  • the utilization circuits ( 30 a ) are connected in parallel to each other.
  • the heat source circuit ( 20 a ) is connected to the utilization circuits ( 30 a ) via connection pipes ( 11 , 15 ).
  • connection pipes include a liquid connection pipe ( 11 ) and a gas connection pipe ( 15 ).
  • the liquid connection pipe ( 11 ) includes a main liquid pipe ( 12 ) and a plurality of liquid branch pipes ( 13 ). One end of the liquid connection pipe ( 11 ) is connected to a liquid stop valve ( 25 ) of the heat source circuit ( 20 a ). One ends of the liquid branch pipes ( 13 ) are connected to the main liquid pipe ( 12 ). The other ends of the liquid branch pipes ( 13 ) are connected to the respective liquid ends (liquid-side joints) of the utilization circuits ( 30 a ).
  • the gas connection pipe ( 15 ) includes a main gas pipe ( 16 ) and a plurality of gas branch pipes ( 17 ). One end of the gas connection pipe ( 15 ) is connected to a gas stop valve ( 26 ) of the heat source circuit ( 20 a ). One ends of the gas branch pipes ( 17 ) are connected to the main gas pipe ( 16 ). The other ends of the gas branch pipes ( 17 ) are connected to the respective gas ends (gas-side joints) of the utilization circuits ( 30 a ).
  • the liquid branch pipes ( 13 ) each constitute a liquid refrigerant flow path ( 41 ) connected to the liquid end of the associated one of the utilization circuits ( 30 a ).
  • the gas branch pipes ( 17 ) each constitute a gas refrigerant flow path ( 42 ) connected to the gas end of the associated one of the utilization circuits ( 30 a ).
  • the gas refrigerant flow paths ( 42 ) each have a pipe diameter larger than the pipe diameters of the liquid refrigerant flow paths ( 41 ).
  • the gas refrigerant flow paths ( 42 ) each have an outer pipe diameter of 12.7 mm or 15.9 mm, for example.
  • the air conditioner ( 10 ) includes one outdoor unit ( 20 ).
  • the outdoor unit ( 20 ) includes a casing (not shown) that houses the heat source circuit ( 20 a ).
  • the heat source circuit ( 20 a ) connects a compressor ( 21 ), an outdoor heat exchanger ( 22 ), an outdoor four-way switching valve ( 23 ), an outdoor expansion valve ( 24 ), the gas stop valve ( 26 ), and the liquid stop valve ( 25 ).
  • the compressor ( 21 ) compresses a refrigerant sucked thereinto and discharges the compressed refrigerant.
  • the outdoor heat exchanger ( 22 ) constitutes a heat source heat exchanger that exchanges heat between the refrigerant and outdoor air.
  • An outdoor fan ( 22 a ) is provided adjacent to the outdoor heat exchanger ( 22 ).
  • the outdoor fan ( 22 a ) transfers the outdoor air passing through the outdoor heat exchanger ( 22 ).
  • the outdoor four-way switching valve ( 23 ) switches between a first state indicated by solid lines in FIG. 1 and a second state indicated by broken lines in FIG. 1 .
  • the outdoor four-way switching valve ( 23 ) in the first state makes a discharge side of the compressor ( 21 ) and a gas end of the outdoor heat exchanger ( 22 ) communicate with each other, and makes a suction side of the compressor ( 21 ) and the gas stop valve ( 26 ) communicate with each other.
  • the outdoor four-way switching valve ( 23 ) in the second state makes the discharge side of the compressor ( 21 ) and the gas stop valve ( 26 ) communicate with each other, and makes the suction side of the compressor ( 21 ) and the gas end of the outdoor heat exchanger ( 22 ) communicate with each other.
  • the outdoor expansion valve ( 24 ) is connected between the outdoor heat exchanger ( 22 ) and the liquid stop valve ( 25 ), in the heat source circuit ( 20 a ).
  • the outdoor expansion valve ( 24 ) is configured as an electronic expansion valve having an adjustable opening degree.
  • the outdoor unit ( 20 ) is provided with an outdoor controller ( 27 ).
  • the outdoor controller ( 27 ) controls components including the compressor ( 21 ), the outdoor expansion valve ( 24 ), and the outdoor fan ( 22 a ), in the outdoor unit ( 20 ).
  • the outdoor controller ( 27 ) includes a microcomputer mounted on a control board, and a memory device (specifically, a semiconductor memory) storing software for operating the microcomputer.
  • the air conditioner ( 10 ) includes a plurality of indoor units ( 30 ).
  • the indoor units ( 30 ) are of a ceiling-mounted type. That is, the indoor units ( 30 ) may each be embedded in the ceiling or suspended from the ceiling.
  • the indoor units ( 30 ) each include a casing (not shown) that houses the associated one of the utilization circuits ( 30 a ).
  • the utilization circuit ( 30 a ) connects an indoor heat exchanger ( 31 ) and an indoor expansion valve ( 32 ).
  • the indoor heat exchanger ( 31 ) constitutes a utilization heat exchanger that exchanges heat between the refrigerant and indoor air.
  • An indoor fan ( 31 a ) is provided adjacent to the indoor heat exchanger ( 31 ). The indoor fan ( 31 a ) transfers the indoor air passing through the indoor heat exchanger ( 31 ).
  • the indoor expansion valve ( 32 ) is connected between the liquid-side joint and the indoor heat exchanger ( 31 ) in the utilization circuit ( 30 a ).
  • the indoor expansion valve ( 32 ) is configured as an electronic expansion valve having an adjustable opening degree.
  • the indoor units ( 30 ) are each provided with an indoor controller ( 33 ).
  • the indoor controller ( 33 ) controls components including the indoor expansion valves ( 32 ) and the indoor fan ( 31 a ), in the indoor unit ( 30 ).
  • the indoor controller ( 33 ) includes a microcomputer mounted on a control board, and a memory device (specifically, a semiconductor memory) storing software for operating the microcomputer.
  • the indoor units ( 30 ) are each connected to a remote control ( 34 ).
  • the remote control ( 34 ) is operated to switch the operating mode and the set temperature of the associated one of the indoor units ( 30 ).
  • the indoor units ( 30 ) each include an LED light (not shown).
  • the LED light is turned on when a cut-off unit ( 50 ) is open and closed.
  • the lighting state of the LED light is different between when the valve is open and when the valve is closed.
  • a user can determine whether or not the cut-off unit ( 50 ) (strictly speaking, a flow path switching valve (V 1 , V 2 )) is open or closed by checking the lighting state of the LED light.
  • the air conditioner ( 10 ) includes refrigerant leakage detection sensors ( 35 ).
  • the refrigerant leakage detection sensors ( 35 ) are provided in the respective indoor units ( 30 ).
  • the refrigerant leakage detection sensors ( 35 ) are each disposed inside the casing of the associated one of the indoor units ( 30 ).
  • the refrigerant leakage detection sensors ( 35 ) each constitute a detection unit that detects the leakage of the refrigerant in the utilization circuit ( 30 a ) of the associated one of the indoor units ( 30 ).
  • the refrigerant leakage detection sensors ( 35 ) may each be disposed outside the casing of the indoor unit ( 30 ).
  • the air conditioner ( 10 ) includes the cut-off units ( 50 ).
  • the cut-off units ( 50 ) are each configured to block the liquid refrigerant flow path ( 41 ) and the gas refrigerant flow path ( 42 ) when the refrigerant has leaked in the associated one of the utilization circuits ( 30 a ).
  • the cut-off units ( 50 ) each include the liquid refrigerant flow path ( 41 ), the gas refrigerant flow path ( 42 ), a first flow path switching valve (V 1 ), a second flow path switching valve (V 2 ), and a high-pressure introduction circuit ( 60 ).
  • the first flow path switching valve (V 1 ) is connected to the liquid refrigerant flow path ( 41 ).
  • the first flow path switching valve (V 1 ) constitutes a cut-off valve that blocks the liquid refrigerant flow path ( 41 ).
  • the second flow path switching valve (V 2 ) is connected to the gas refrigerant flow path ( 42 ).
  • the second flow path switching valve (V 2 ) constitutes a cut-off valve that blocks the gas refrigerant flow path ( 42 ).
  • the first flow path switching valve (V 1 ) and the second flow path switching valve (V 2 ) are disposed outside the casing of the indoor unit ( 30 ).
  • the liquid refrigerant flow path ( 41 ) includes a first liquid flow path ( 41 a ) that is a first flow path and a second liquid flow path ( 41 b ) that is a second flow path.
  • the first liquid flow path ( 41 a ) is formed in a portion of the liquid refrigerant flow path ( 41 ) closer to the heat source circuit ( 20 a ).
  • the second liquid flow path ( 41 b ) is formed on the side of the utilization circuit ( 30 a ) in the liquid refrigerant flow path ( 41 ).
  • the gas refrigerant flow path ( 42 ) includes a first gas flow path ( 42 a ) that is a first flow path and a second gas flow path ( 42 b ) that is a second flow path.
  • the first gas flow path ( 42 a ) is formed in a portion of the gas refrigerant flow path ( 42 ) closer to the heat source circuit ( 20 a ).
  • the second gas flow path ( 42 b ) is formed in a portion of the gas refrigerant flow path ( 42 ) closer to the utilization circuit ( 30 a ).
  • the high-pressure introduction circuit ( 60 ) includes a liquid-side introduction path ( 61 ), a gas-side introduction path ( 62 ), and a main introduction path ( 63 ).
  • One end of the liquid-side introduction path ( 61 ) is connected to an intermediate portion of the first liquid flow path ( 41 a ).
  • the other end of the liquid-side introduction path ( 61 ) is connected to one end of the main introduction path ( 63 ).
  • One end of the gas-side introduction path ( 62 ) is connected to an intermediate portion of the first gas flow path ( 42 a ).
  • the other end of the gas-side introduction path ( 62 ) is connected to one end of the main introduction path ( 63 ).
  • the other end of the main introduction path ( 63 ) branches into a first branch introduction section ( 63 a ) and a second branch introduction section ( 63 b ).
  • the first check valve ( 64 ) allows the refrigerant to flow from the liquid-side introduction path ( 61 ) toward the main introduction path ( 63 ) and disallows the refrigerant to flow in the opposite direction.
  • the second check valve ( 65 ) allows the refrigerant to flow from the gas-side introduction path ( 62 ) toward the main introduction path ( 63 ) and disallows the refrigerant to flow in the opposite direction.
  • the first flow path switching valve (V 1 ) of this example is configured as a first four-way switching valve ( 51 ) of a differential pressure drive type.
  • the second flow path switching valve (V 2 ) of this example is configured as a second four-way switching valve ( 52 ) of a differential pressure drive type.
  • four-way switching valves ( 51 , 52 ) each include a first port (P 1 ), a second port (P 2 ), a third port (P 3 ), and a fourth port (P 4 ).
  • the first port (P 1 ) of the first four-way switching valve ( 51 ) is connected to the first liquid flow path ( 41 a ).
  • the second port (P 2 ) of the first four-way switching valve ( 51 ) is connected to the second liquid flow path ( 41 b ).
  • the third port (P 3 ) of the first four-way switching valve ( 51 ) communicates with the high-pressure introduction circuit ( 60 ).
  • the third port (P 3 ) of the first four-way switching valve ( 51 ) is connected to the first branch introduction section ( 63 a ) of the high-pressure introduction circuit ( 60 ).
  • the fourth port (P 4 ) of the first four-way switching valve ( 51 ) is closed with a first closing member ( 53 ) (see FIG. 2 ).
  • the first port (P 1 ) of the second four-way switching valve ( 52 ) is connected to the first gas flow path ( 42 a ).
  • the second port (P 2 ) of the second four-way switching valve ( 52 ) is connected to the second gas flow path ( 42 b ).
  • the third port (P 3 ) of the second four-way switching valve ( 52 ) communicates with the high-pressure introduction circuit ( 60 ).
  • the third port (P 3 ) of the second four-way switching valve ( 52 ) is connected to the second branch introduction section ( 63 b ) of the high-pressure introduction circuit ( 60 ).
  • the fourth port (P 4 ) of the second four-way switching valve ( 52 ) is closed with a second closing member ( 54 ) (see FIG. 2 ).
  • the four-way switching valves ( 51 , 52 ) are each switchable between a first state (indicated by the solid lines in FIG. 1 ) and a second state (indicated by the broken lines in FIG. 1 ).
  • first state the first port (P 1 ) communicates with the second port (P 2 )
  • the third port (P 3 ) communicates with the fourth port (P 4 ).
  • second state the first port (P 1 ) communicates with the third port (P 3 ), and the second port (P 2 ) communicates with the fourth port (P 4 ).
  • the first four-way switching valve ( 51 ) has a first low-pressure pipe ( 55 ).
  • One end of the first low-pressure pipe ( 55 ) is connected to the second port (P 2 ) of the first four-way switching valve ( 51 ).
  • the first low-pressure pipe ( 55 ) communicates with the utilization circuit ( 30 a ) via the second liquid flow path ( 41 b ).
  • the other end of the first low-pressure pipe ( 55 ) is connected to a pressure chamber inside the first four-way switching valve ( 51 ).
  • the second four-way switching valve ( 52 ) has a second low-pressure pipe ( 56 ). One end of the second low-pressure pipe ( 56 ) is connected to the second port (P 2 ) of the second four-way switching valve ( 52 ). The second low-pressure pipe ( 56 ) communicates with the utilization circuit ( 30 a ) via the second gas flow path ( 42 b ). The other end of the second low-pressure pipe ( 56 ) is connected to a pressure chamber inside the second four-way switching valve ( 52 ). In each of the four-way switching valves ( 51 , 52 ) shown in FIGS. 2 to 4 , an internal flow path for communicating the four ports (P 1 , P 2 , P 3 , P 4 ) is indicated by broken lines.
  • the cut-off unit ( 50 ) includes a control unit ( 57 ).
  • the control unit ( 57 ) includes a microcomputer mounted on a control board and a memory device (specifically, a semiconductor memory) storing software for operating the microcomputer.
  • the air conditioner ( 10 ) performs a cooling operation and a heating operation.
  • the cooling operation and the heating operation during a normal operation in which the refrigerant has not leaked will be described with reference to FIG. 1 .
  • the outdoor four-way switching valve ( 23 ) is in the first state
  • the first four-way switching valve ( 51 ) is in the first state
  • the second four-way switching valve ( 52 ) is in the first state.
  • the outdoor expansion valve ( 24 ) is open.
  • the opening degree of the indoor expansion valve ( 32 ) is controlled based on the superheat degree of the associated one of the indoor heat exchangers ( 31 ).
  • the outdoor fan ( 22 a ) and the indoor fans ( 31 a ) are actuated.
  • a first refrigeration cycle (cooling cycle) in which the refrigerant dissipates heat and is condensed in the outdoor heat exchanger ( 22 ), and the refrigerant evaporates in the indoor heat exchangers ( 31 ).
  • the refrigerant compressed in the compressor ( 21 ) dissipates heat and is condensed in the outdoor heat exchanger ( 22 ) and passes through the outdoor expansion valve ( 24 ).
  • the refrigerant flows from the main liquid pipe ( 12 ) into the liquid refrigerant flow path ( 41 ), flows through the first port (P 1 ) and the second ports (P 2 ) of the first four-way switching valve ( 51 ) in this order, and flows into the associated one of the utilization circuits ( 30 a ).
  • the utilization circuit ( 30 a ) the refrigerant is decompressed at the indoor expansion valve ( 32 ), and then evaporates in the indoor heat exchanger ( 31 ).
  • the indoor heat exchanger ( 31 ) the air is cooled by the evaporating refrigerant. The cooled air is supplied to the indoor space.
  • the refrigerant that has evaporated in the indoor heat exchanger ( 31 ) flows through the gas refrigerant flow path ( 42 ), and flows through the second port (P 2 ) and the first port (P 1 ) of the second four-way switching valve ( 52 ) in this order.
  • the flows of the refrigerant merge together in the main gas pipe ( 16 ) to be sucked into the compressor ( 21 ).
  • the outdoor four-way switching valve ( 23 ) is in the second state
  • the first four-way switching valve ( 51 ) is in the first state
  • the second four-way switching valve ( 52 ) is in the first state.
  • the opening degree of the outdoor expansion valve ( 24 ) is controlled based on the superheat degree of the refrigerant flowing out of the outdoor heat exchanger ( 22 ).
  • the opening degree of the indoor expansion valve ( 32 ) is controlled based on the subcooling degree of the refrigerant flowing out of the indoor heat exchanger ( 31 ).
  • the outdoor fan ( 22 a ) and the indoor fan ( 31 a ) are actuated.
  • a second refrigeration cycle (heating cycle) in which the refrigerant dissipates heat and is condensed in the indoor heat exchanger ( 31 ), and the refrigerant evaporates in the indoor heat exchangers ( 31 ).
  • the refrigerant that has compressed in the compressor ( 21 ) flows from the main gas pipe ( 16 ) into the gas refrigerant flow path ( 42 ), flows through the first port (P 1 ) and the second port (P 2 ) of the second four-way switching valve ( 52 ) in this order, and flows into the associated one of the utilization circuits ( 30 a ).
  • the utilization circuit ( 30 a ) the refrigerant dissipates heat and is condensed in the indoor heat exchanger ( 31 ).
  • the indoor heat exchanger ( 31 ) the air is heated by the refrigerant dissipating heat. The heated air is supplied to the indoor space.
  • the refrigerant that has dissipated heat in the indoor heat exchanger ( 31 ) flows through the liquid refrigerant flow path ( 41 ), and flows through the second port (P 2 ) and the first port (P 1 ) of the first four-way switching valve ( 51 ) in this order.
  • the flows of refrigerant merge in the main liquid pipe ( 12 ) to be decompressed in the outdoor expansion valve ( 24 ).
  • the decompressed refrigerant flows through the outdoor heat exchanger ( 22 ).
  • the refrigerant absorbs heat from the outdoor air to evaporate.
  • the evaporated refrigerant is sucked into the compressor ( 21 ).
  • the first four-way switching valve ( 51 ) and the second four-way switching valve ( 52 ) of this example are configured to be kept in the above-mentioned first state during the normal operation. Specifically, a spool valve inside each of the four-way switching valves ( 51 , 52 ) is pressed with a high-pressure refrigerant introduced from the third port (P 3 ) or an urger such as a spring to be positioned such that the first port (P 1 ) communicates with the second port (P 2 ) and the third port (P 3 ) communicates with the fourth port (P 4 ), for example (see FIGS. 2 and 3 ).
  • a valve seat of the spool valve is preferably made from a resin material with low sliding resistance.
  • the resin material may be, for example, Teflon (registered trademark).
  • the high-pressure introduction circuit ( 60 ) of this example is configured to introduce the high-pressure refrigerant into the third port (P 3 ) during both cooling operation and heating operation.
  • the high-pressure liquid refrigerant flows through the liquid refrigerant flow path ( 41 ), and the decompressed low-pressure gas refrigerant flows through the gas refrigerant flow path ( 42 ).
  • the high-pressure liquid refrigerant in the liquid-side introduction path ( 61 ) flows through the first check valve ( 64 ) in the open state and is introduced into the third port (P 3 ) of each of the four-way switching valves ( 51 , 52 ) via the main introduction path ( 63 ).
  • the second check valve ( 65 ) is basically in the closed state.
  • the high-pressure gas refrigerant flows through the gas refrigerant flow path ( 42 ), and the liquid refrigerant having a pressure slightly lower than that of the gas refrigerant flows through the liquid refrigerant flow path ( 41 ).
  • the high-pressure gas refrigerant in the gas-side introduction path ( 62 ) flows through the second check valve ( 65 ) in the open state and is introduced into the third port (P 3 ) of each of the four-way switching valves ( 51 , 52 ) via the main introduction path ( 63 ).
  • the second check valve ( 65 ) is in the closed state or open state.
  • the high-pressure refrigerant serving as a drive source of each of the four-way switching valves ( 51 , 52 ) can be reliably supplied to the third port (P 3 ).
  • the first four-way switching valve ( 51 ) and the second four-way switching valve ( 52 ) are placed in the second state (see FIG. 4 ).
  • This operation blocks the liquid refrigerant flow path ( 41 ) and the gas refrigerant flow path ( 42 ).
  • the leakage of the refrigerant in the heat source circuit ( 20 a ), the main liquid pipe ( 12 ), and the main gas pipe ( 16 ) from the utilization circuit ( 30 a ) to the indoor space may be avoided.
  • the internal pressures of the utilization circuit ( 30 a ), the liquid refrigerant flow path ( 41 ), and the gas refrigerant flow path ( 42 ) decrease.
  • the internal pressure of the first low-pressure pipe ( 55 ) decreases with the decrease in the internal pressure of the liquid refrigerant flow path ( 41 ).
  • the differential pressure between the pressure of the high-pressure refrigerant introduced from the third port (P 3 ) and the internal pressure of the first low-pressure pipe ( 55 ) causes the spool valve to move in the first four-way switching valve ( 51 ).
  • the first four-way switching valve ( 51 ) is placed in the second state in which the first port (P 1 ) and the third port (P 3 ) communicate with each other, and the second port (P 2 ) and the fourth port (P 4 ) communicate with each other, as shown in FIG. 4 .
  • the first four-way switching valve ( 51 ) blocks the liquid refrigerant flow path ( 41 ).
  • the internal pressure of the second low-pressure pipe ( 56 ) decreases with the decrease in the internal pressure of the gas refrigerant flow path ( 42 ).
  • the differential pressure between the pressure of the high-pressure refrigerant introduced from the third port (P 3 ) and the internal pressure of the second low-pressure pipe ( 56 ) causes the spool valve to move in the second four-way switching valve ( 52 ).
  • the second four-way switching valve ( 52 ) is placed in the second state in which the first port (P 1 ) and the third port (P 3 ) communicate with each other, and the second port (P 2 ) and the fourth port (P 4 ) communicate with each other, as shown in FIG. 4 .
  • the second four-way switching valve ( 52 ) blocks the liquid refrigerant flow path ( 41 ).
  • each of the four-way switching valves ( 51 , 52 ) of this embodiment uses the decrease in the internal pressure of the low-pressure pipe ( 55 , 56 ) to switch to the second state automatically when the refrigerant leaks in the utilization circuit ( 30 a ). In this way, the utilization circuit ( 30 a ) may be reliably switched to a closed circuit.
  • a pilot pipe and a pilot valve of known art may be used in switching the four-way switching valves ( 51 , 52 ) of a differential pressure drive type from the first state to the second state.
  • the refrigerant leakage detection sensor ( 35 ) detects the leakage.
  • the indoor controller ( 33 ) receives the detection signal from the refrigerant leakage detection sensor ( 35 )
  • a sign indicating the leakage is displayed on a display unit.
  • the display unit may be provided, for example, in the remote control ( 34 ) or in a decorative panel of the indoor unit ( 30 ). The display unit is switched between displaying a status indicating an abnormality due to the leakage of the refrigerant and displaying a status indicating normality because of no leakage of the refrigerant.
  • the air conditioner of the embodiment includes: a refrigerant circuit ( 10 a ) including a heat source circuit ( 20 a ) to which a compressor ( 21 ) and an outdoor heat exchanger ( 22 ) are connected, and a utilization circuit ( 30 a ) to which an indoor heat exchanger ( 31 ) is connected, and configured to perform a refrigeration cycle; an outdoor unit ( 20 ) including the heat source circuit ( 20 a ); and an indoor unit ( 30 ) provided with the utilization circuit ( 30 a ).
  • the refrigerant circuit ( 10 a ) further includes: two refrigerant flow paths ( 41 , 42 ) connected to respective ends of the utilization circuit ( 30 a ), and two cut-off valves connected to the respective refrigerant flow paths ( 41 , 42 ). At least one of the two cut-off valves is configured as a flow path switching valve (V 1 , V 2 ) configured to switch a flow path so as to block refrigerant flow paths ( 41 , 42 ) when the refrigerant leaks in the utilization circuit ( 30 a ).
  • V 1 , V 2 flow path switching valve
  • the cut-off valves of the liquid refrigerant flow path ( 41 ) and the gas refrigerant flow path ( 42 ) are configured as respective flow path switching valves (V 1 , V 2 ). Due to its structure, the flow path switching valves (V 1 , V 2 ) each have a relatively wide flow path as compared with an electromagnetic valve or an expansion valve. This allows a reduction in the pressure loss when the refrigerant passes through the flow path switching valve (V 1 , V 2 ) during the cooling operation and the heating operation. Therefore, the power consumption of the air conditioner ( 10 ) can be reduced. Switching the flow paths of the flow path switching valves (V 1 , V 2 ) enables the flow of the refrigerant to be blocked.
  • the refrigerant flow paths ( 41 , 42 ) includes respective first flow paths ( 41 a , 42 a ) formed on sides of the respective flow path switching valves (V 1 , V 2 ) closer to the heat source circuit ( 20 a ), and respective second flow paths ( 41 b , 42 b ) formed on sides of the flow path switching valves (V 1 , V 2 ) closer to the utilization circuit ( 30 a ), and the flow path switching valves (V 1 , V 2 ) are configured as respective four-way switching valves ( 51 , 52 ) each having a first port (P 1 ) connected to associated one of the first flow paths ( 41 a , 42 a ), a second port (P 2 ) connected to associated one of the second flow paths ( 41 b , 42 b ), a third port (P 3 ), and a fourth port (P 4 ).
  • the flow path switching valves (V 1 , V 2 ) are configured as the respective four-way switching valves ( 51 , 52 ). Due to its structure, the four-way switching valves ( 51 , 52 ) each have a relatively wide flow path as compared to an electromagnetic valve or an expansion valve. This allows a reduction in the pressure loss when the refrigerant passes through the flow path switching valves (V 1 , V 2 ) during the cooling operation and the heating operation. Therefore, the power consumption of the air conditioner ( 10 ) can be reduced. As described above, the four-way switching valves ( 51 , 52 ) are connected to a pipe having an outer diameter of 12.7 mm or 15.9 mm.
  • the outdoor four-way switching valve ( 23 ) of the multiple-type air conditioner ( 10 ) may be connected to a pile having the same outer diameter.
  • the same kind of valve as the outdoor four-way switching valve ( 23 ) may be used as the four-way switching valves ( 51 , 52 ). This allows a reduction in the amount of the refrigerant leaking when the valve is in the closed state, as compared to the case in which the electromagnetic valve or the expansion valve is used as the cut-off valve and is connected to the pipe having the outer diameter of 12.7 mm or 15.9 mm.
  • the refrigerant circuit ( 10 a ) further includes a high-pressure introduction circuit ( 60 ) configured to introduce a high-pressure refrigerant in the first flow paths ( 41 a , 42 a ) into the third port (P 3 ), and the four-way switching valves ( 51 , 52 ) are of a differential pressure drive type, using the high-pressure refrigerant introduced into the third port (P 3 ) as a drive source.
  • a high-pressure introduction circuit ( 60 ) configured to introduce a high-pressure refrigerant in the first flow paths ( 41 a , 42 a ) into the third port (P 3 )
  • the four-way switching valves ( 51 , 52 ) are of a differential pressure drive type, using the high-pressure refrigerant introduced into the third port (P 3 ) as a drive source.
  • the high-pressure refrigerant in the first flow paths ( 41 a , 42 a ) is introduced into the third port (P 3 ) of the four-way switching valves ( 51 , 52 ).
  • the pressure of the high-pressure refrigerant is used to switch the states of the four-way switching valves ( 51 , 52 ). This allows the refrigerant flow paths ( 41 , 42 ) to be blocked without using another drive source such as an electric motor.
  • the refrigerant circuit ( 10 a ) is configured to perform a first refrigeration cycle (cooling cycle) in which the outdoor heat exchanger ( 22 ) serves as a radiator and the indoor heat exchanger ( 31 ) serves as an evaporator, and a second refrigeration cycle (heating cycle) in which the indoor heat exchanger ( 31 ) serves as a radiator and the outdoor heat exchanger ( 22 ) serves as an evaporator, and the high-pressure introduction circuit ( 60 ) is configured to introduce the high-pressure refrigerant in the first flow path ( 41 a , 42 a ) having higher pressure out of the first flow paths ( 41 a , 42 a ) at least into the third port (P 3 ).
  • the high-pressure refrigerant can be reliably introduced into the third port (P 3 ) of the four-way switching valve ( 51 , 52 ) during both cooling operation and heating operation. This allows the four-way switching valve ( 51 , 52 ) to be reliably switched using the pressure of the high-pressure refrigerant.
  • the high-pressure introduction circuit ( 60 ) includes a liquid-side introduction path ( 61 ) for allowing the first liquid flow path ( 41 a ) of the liquid refrigerant flow path ( 41 ) and the third port (P 3 ) to communicate with each other, and a gas-side introduction path ( 62 ) for allowing the first gas flow path ( 42 a ) of the gas refrigerant flow path ( 42 ) and the third port (P 3 ) communicate with each other, the liquid-side introduction path ( 61 ) is provided with a first check valve ( 64 ) that is open during the first refrigeration cycle, and the gas-side introduction path ( 62 ) is provided with a second check valve ( 65 ) that is open during the second refrigeration cycle.
  • the first check valve ( 64 ) when the pressure in the liquid refrigerant flow path ( 41 ) increases during the first refrigeration cycle (cooling cycle), the first check valve ( 64 ) is open to introduce the high-pressure refrigerant into the third port (P 3 ).
  • the second check valve ( 65 ) is open to introduce the high-pressure refrigerant into the third port (P 3 ).
  • the four-way switching valves ( 51 , 52 ) each have the fourth port (P 4 ) in a closed state
  • the four-way switching valves ( 51 , 52 ) in the first state each make the first port (P 1 ) and the second port (P 2 ) communicate with each other
  • the third port (P 3 ) and the fourth port (P 4 ) communicate with each other
  • the four-way switching valves ( 51 , 52 ) in a second state each make the first port (P 1 ) and the third port (P 3 ) communicate with each other
  • the second port (P 2 ) and the fourth port (P 4 ) communicate with each other.
  • the four-way switching valves ( 51 , 52 ) when the four-way switching valves ( 51 , 52 ) are in the first state, the first port (P 1 ) and the second port (P 2 ) communicate with each other, and the refrigerant flow paths ( 41 , 42 ) are conductive. In this state, the cooling operation and the heating operation are performed.
  • the four-way switching valves ( 51 , 52 ) are in the second state, the second port (P 2 ) and the fourth port (P 4 ) in the closed state communicate with each other. In this state, the liquid refrigerant flow path ( 41 ) and the gas refrigerant flow path ( 42 ) are blocked, and the utilization circuit ( 30 a ) is disconnected from the refrigerant circuit ( 10 a ).
  • the four-way switching valves ( 51 , 52 ) includes respective low-pressure pipes ( 55 , 56 ) that communicate with the utilization circuit ( 30 a ), and are switched to the second state by differential pressures between the high-pressure refrigerant and internal pressures of the low-pressure pipes ( 55 , 56 ).
  • the internal pressure of the utilization circuit ( 30 a ) decreases. Accordingly, the internal pressures of the low-pressure pipes ( 55 , 56 ) decrease.
  • the four-way switching valves ( 51 , 52 ) the differential pressures between the high-pressure refrigerant and the internal pressures of the low-pressure pipes ( 55 , 56 ) increase, and the four-way switching valves ( 51 , 52 ) are switched from the first state to the second state.
  • the four-way switching valves ( 51 , 52 ) are switched to the second state automatically when the refrigerant leaks in the utilization circuit ( 30 a ).
  • the flow path switching valve (V 1 , V 2 ) is connected to at least the gas refrigerant flow path ( 42 ) out of the two refrigerant flow paths ( 41 , 42 ).
  • the pipe diameter of the gas refrigerant flow path ( 42 ) is larger than the pipe diameter of the liquid refrigerant flow path ( 41 ). Therefore, the flow path switching valve (V 1 , V 2 ) provided in the gas refrigerant flow path ( 42 ) enables effective reduction in the increase in pressure loss caused by a shield valve.
  • the first check valve ( 64 ), which is a first on-off valve, is provided in the liquid-side introduction path ( 61 ) of the high-pressure introduction circuit ( 60 ).
  • the second check valve ( 65 ), which is a second on-off valve, is provided in the gas-side introduction path ( 62 ) of the high-pressure introduction circuit ( 60 ).
  • the first on-off valve is configured as a first electromagnetic on-off valve
  • the second on-off valve is configured as a second electromagnetic on-off valve.
  • the first electromagnetic on-off valve is open during the first refrigeration cycle (cooling cycle) and is closed during the second refrigeration cycle (heating cycle).
  • the second electromagnetic on-off valve is closed during the first refrigeration cycle (cooling cycle) and is open during the second refrigeration cycle (heating cycle).
  • the high-pressure refrigerant is allowed to be reliably introduced into the third port (P 3 ) of the four-way switching valve ( 51 , 52 ) during both cooling operation and heating operation.
  • FIGS. 5A and 5B illustrate a second variation, in which the configuration of the cut-off unit ( 50 ) is different from that of the foregoing embodiment.
  • the cut-off valve of the cut-off unit ( 50 ) is configured as three-way switching valves ( 71 , 72 ).
  • the three-way switching valves ( 71 , 72 ) of this example are so-called rotary valves of an electric rotary type.
  • the first three-way switching valve ( 71 ) is connected to the liquid refrigerant flow path ( 41 ).
  • the second three-way switching valve ( 72 ) is connected to the gas refrigerant flow path ( 42 ).
  • the three-way switching valves ( 71 , 72 ) each have a first port (P 1 ), a second port (P 2 ), and a third port (P 3 ).
  • the first port (P 1 ) of the first three-way switching valve ( 71 ) is connected to the first liquid flow path ( 41 a ).
  • the second port (P 2 ) of the first three-way switching valve ( 71 ) is connected to the second liquid flow path ( 41 b ).
  • the third port (P 3 ) of the first three-way switching valve ( 71 ) is closed with a third closing member ( 83 ).
  • the first port (P 1 ) of the second three-way switching valve ( 72 ) is connected to the first gas flow path ( 42 a ).
  • the second port (P 2 ) of the second three-way switching valve ( 72 ) is connected to the second gas flow path ( 42 b ).
  • the third port (P 3 ) of the second three-way switching valve ( 72 ) is closed with a fourth closing member ( 84 ).
  • the three-way switching valves ( 71 , 72 ) each include an electric motor ( 75 ), a rotating portion ( 76 ) rotationally driven by the electric motor ( 75 ), and a case ( 78 ) housing the rotating portion ( 76 ).
  • the first port (P 1 ), the second port (P 2 ), and the third port (P 3 ) are formed in the case ( 78 ).
  • an internal flow path ( 77 ) is formed in the rotating portion ( 76 .
  • the internal flow path ( 77 ) of this example is formed to have a substantially L-shaped cross section when cut in the direction perpendicular to the axis thereof.
  • Three-way switching valves ( 71 , 72 ) are each switched between a first state in which the refrigerant flow path ( 41 , 42 ) is conductive and a second state in which the refrigerant flow path ( 41 , 42 ) is blocked.
  • the control unit ( 57 ) controls the three-way switching valves ( 71 , 72 ) into the first state.
  • the control unit ( 57 ) controls the electric motor ( 75 ) to place the three-way switching valves ( 71 , 72 ) in the first state.
  • the rotating portion ( 76 ) of each of the three-way switching valves ( 71 , 72 ) in the first state is placed at a rotational angle position at which the first port (P 1 ) and the second port (P 2 ) communicate with each other via the internal flow path ( 77 ). This allows the refrigerant to flow through the liquid refrigerant flow path ( 41 ) and the gas refrigerant flow path ( 42 ) during the cooling operation and the heating operation.
  • a signal is output from the indoor controller ( 33 ) to the control unit ( 57 ).
  • the control unit ( 57 ) when the control unit ( 57 ) receives the signal, it switches the three-way switching valves ( 71 , 72 ) to the second state.
  • the control unit ( 57 ) controls the electric motor ( 75 ) to place the three-way switching valves ( 71 , 72 ) in the second state.
  • each of the three-way switching valves ( 71 , 72 ) in the second state is placed at a rotational angle position at which the first port (P 1 ) and the third port (P 3 ) communicate with each other via the internal flow path ( 77 ).
  • This causes the second port (P 2 ) to be substantially closed when the refrigerant leaks, thereby disconnecting the utilization circuit ( 30 a ) from the refrigerant circuit ( 10 a ).
  • the flow path switching valves (V 1 , V 2 ) are of an electric rotary-type and each have a first port (P 1 ) connected to associated one of the first flow paths ( 41 a , 42 a ), a second port (P 2 ) connected to associated one of the second flow paths ( 41 b , 42 b ), a rotating portion ( 76 ) in which an internal flow path ( 77 ) is formed, and an electric motor ( 75 ) configured to rotatably drive the rotating portion ( 76 ), and the rotating portion ( 76 ) of the flow path switching valve (V 1 , V 2 ) can be placed at a rotational angle position of the first state in which the first port (P 1 ) and the second port (P 2 ) communicate with each other via the internal flow path ( 77 ), and placed at a rotational angle position of the second state in which the first port (P 1 ) and the second port (P 2 ) are closed.
  • the electric rotary-type flow path switching valves (V 1 , V 2 ) each have a relatively wide flow path as compared to an electromagnetic valve or a motor-operated valve. This allows a reduction in the pressure loss in the cut-off valve.
  • the refrigerant flow paths ( 41 , 42 ) include respective first flow paths ( 41 a , 42 a ) formed on sides of the respective flow path switching valves (V 1 , V 2 ) closer to the heat source circuit ( 20 a ), and respective second flow paths ( 41 b , 42 b ) formed on sides of the flow path switching valves (V 1 , V 2 ) closer to the utilization circuit ( 30 a ), and the flow path switching valves (V 1 , V 2 ) are configured as three-way switching valves ( 71 , 72 ) of an electric rotary type and each have a third port (P 3 ) in a closed state, and the rotating portion ( 76 ) of each of the three-way switching valves ( 71 , 72 ) in the first state is placed at a rotational angle position at which the first port (P 1 ) and the second port (P 2 ) communicate with each other via the internal flow path ( 77 ), and the rotating portion ( 76 ) of each of
  • the three-way switching valves ( 71 , 72 ) are each switchable between a state in which the refrigerant flow path ( 41 , 42 ) is conductive and a state in which the refrigerant flow path ( 41 , 42 ) is blocked.
  • the three-way switching valves ( 71 , 72 ) may each be configured such that, in the second state, the first port (P 1 ) and the closed third port (P 3 ) communicate with each other, and the second port (P 2 ) is closed with a surface of the rotating portion ( 76 ).
  • This configuration allows the refrigerant to flow through the refrigerant flow paths ( 41 , 42 ) during the cooling operation and the heating operation, and allows the utilization circuit ( 30 a ) to be disconnected from the refrigerant circuit ( 10 a ) when the refrigerant leaks.
  • FIGS. 6A and 6B illustrate a third variation, in which the configuration of the cut-off unit ( 50 ) is different from that of the foregoing embodiment.
  • the cut-off valve of the cut-off unit ( 50 ) is configured as two-way switching valves ( 81 , 82 ).
  • the two-way switching valves ( 81 , 82 ) of the present example are so-called rotary valves of an electric rotary type.
  • the first two-way switching valve ( 81 ) is connected to the liquid refrigerant flow path ( 41 ).
  • the second two-way switching valve ( 82 ) is connected to the gas refrigerant flow path ( 42 ).
  • the two-way switching valves ( 81 , 82 ) each have a first port (P 1 ) and a second port (P 2 ).
  • the first port (P 1 ) of the first two-way switching valve ( 81 ) is connected to the first liquid flow path ( 41 a ).
  • the second port (P 2 ) of the first two-way switching valve ( 81 ) is connected to the second liquid flow path ( 41 b ).
  • the first port (P 1 ) of the second two-way switching valve ( 82 ) is connected to the first gas flow path ( 42 a ).
  • the second port (P 2 ) of the second two-way switching valve ( 82 ) is connected to the second gas flow path ( 42 b ).
  • the two-way switching valves ( 81 , 82 ) each include an electric motor ( 75 ), a rotating portion ( 76 ) rotationally driven by the electric motor ( 75 ), and a case ( 78 ) housing the rotating portion ( 76 ).
  • the first port (P 1 ) and the second port (P 2 ) are formed in the case ( 78 ).
  • an internal flow path ( 77 ) is formed in the rotating portion ( 76 ).
  • the internal flow path ( 77 ) of this example is formed to have a linear cross section when cut in the direction perpendicular to the axis thereof.
  • the two-way switching valves ( 81 , 82 ) are each switched between a first state in which the refrigerant flow path ( 41 , 42 ) is conductive and a second state in which the refrigerant flow path ( 41 , 42 ) is blocked.
  • the control unit ( 57 ) controls the two-way switching valves ( 81 , 82 ) into the first state.
  • the control unit ( 57 ) controls the electric motor ( 75 ) to place the two-way switching valves ( 81 , 82 ) in the first state.
  • the rotating portion ( 76 ) of each of the two-way switching valves ( 81 , 82 ) in the first state is placed at a rotational angle position at which the first port (P 1 ) and the second port (P 2 ) communicate with each other via the internal flow path ( 77 ). This allows the refrigerant to flow through the liquid refrigerant flow path ( 41 ) and the gas refrigerant flow path ( 42 ) during the cooling operation and the heating operation.
  • a signal is output from the indoor controller ( 33 ) to the control unit ( 57 ).
  • the control unit ( 57 ) switches the two-way switching valves ( 81 , 82 ) to the second state.
  • the control unit ( 57 ) controls the electric motor ( 75 ) to place the two-way switching valves ( 81 , 82 ) in the second state.
  • the rotating portion ( 76 ) of each of the two-way switching valves ( 81 , 82 ) in the second state is placed at a rotational angle position at which the first port (P 1 ) and the second port (P 2 ) are closed with the rotating portion ( 76 ).
  • the internal flow path ( 77 ) is orthogonal to the first port (P 1 ) and the second port (P 2 ).
  • the first port (P 1 ) and the second port (P 2 ) are closed with a surface of the rotating portion ( 76 ) when the refrigerant leaks.
  • the utilization circuit ( 30 a ) is disconnected from the refrigerant circuit ( 10 a ).
  • the two-way switching valves may each be a ball valve applicable to a water pipe or the like.
  • the electric rotary-type flow path switching valve may be a four-way switching valve having four ports. In this case, two ports of the four-way switching valve are closed with a closing member, for example.
  • the four-way switching valve switches between a first state in which the first port (P 1 ) and the second port (P 2 ) communicate with each other and a state in which the second port (P 2 ) is closed.
  • a plurality of indoor units ( 30 ) may be connected in parallel to a pair of refrigerant flow paths ( 41 , 42 ).
  • a plurality of utilization circuits ( 30 a ) may be connected in parallel to the pair of the liquid refrigerant flow path ( 41 ) and the gas refrigerant flow path ( 42 ).
  • the air conditioner ( 10 ) may be configured such that the heat source circuit ( 20 a ) of one outdoor unit ( 20 ) and the utilization circuit ( 30 a ) of one indoor unit ( 30 ) are connected to each other via the liquid connection pipe ( 11 ) and the gas connection pipe ( 15 ).
  • the air conditioner ( 10 ) may be of a so-called pair type.
  • the liquid connection pipe ( 11 ) constitutes the liquid-side refrigerant flow path ( 41 ) on a liquid side
  • the gas connection pipe ( 15 ) constitutes the refrigerant flow path ( 42 ) on a gas side.
  • the indoor unit ( 30 ) is not limited to a ceiling-mounted type, and may be of another type such as a wall-mounted type or a floor-mounted type.
  • the flow path switching valves (V 1 , V 2 ) of the above-described embodiments and variations may be combined in any pattern.
  • the flow path switching valve of the present disclosure may be adopted in only one of the two refrigerant flow paths ( 41 , 42 ), and an electromagnetic valve or an expansion valve may be adopted in the other.
  • the refrigerants used in the refrigerant circuit ( 10 a ) of the air conditioner ( 10 ) of the embodiment, the variations, and the other embodiments are flammable refrigerants.
  • the flammable refrigerant includes refrigerants falling under Class 3 (highly flammable), Class 2 (less flammable), and Subclass 2L (mildly flammable) in the standards of ASHRAE34 Designation and safety classification of refrigerant in the United States or the standards of ISO817 Refrigerants- Designation and safety classification.
  • FIG. 9 shows specific examples of the refrigerants used in the embodiment and the variations. In FIG.
  • “ASHRAE Number” indicates the ASHRAE number of each refrigerant defined in ISO 817
  • “Component” indicates the ASHRAE number of each substance contained in the refrigerant
  • “mass %” indicates the concentration of each substance contained in the refrigerant by mass %
  • “Alternative” indicates the name of an alternative to the substance of the refrigerant which is often replaced by the alternative.
  • the refrigerant used in the present embodiment is R32.
  • the examples of the refrigerants shown in FIG. 9 are characterized by having a higher density than air.
  • the present disclosure is useful for an air conditioner and a flow path switching valve.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Multiple-Way Valves (AREA)
  • Air Conditioning Control Device (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
US17/356,910 2019-01-02 2021-06-24 Air conditioner and flow path switching valve Pending US20210318041A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2019008841A JP7412887B2 (ja) 2019-01-02 2019-01-02 空気調和機及び流路切換弁
JP2019-008841 2019-01-02
PCT/JP2019/045808 WO2020141582A1 (ja) 2019-01-02 2019-11-22 空気調和機及び流路切換弁

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/045808 Continuation WO2020141582A1 (ja) 2019-01-02 2019-11-22 空気調和機及び流路切換弁

Publications (1)

Publication Number Publication Date
US20210318041A1 true US20210318041A1 (en) 2021-10-14

Family

ID=71407188

Family Applications (1)

Application Number Title Priority Date Filing Date
US17/356,910 Pending US20210318041A1 (en) 2019-01-02 2021-06-24 Air conditioner and flow path switching valve

Country Status (5)

Country Link
US (1) US20210318041A1 (zh)
EP (1) EP3889515A4 (zh)
JP (1) JP7412887B2 (zh)
CN (1) CN113227663B (zh)
WO (1) WO2020141582A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220187001A1 (en) * 2020-12-11 2022-06-16 Lg Electronics Inc. Air conditioner and method for controlling air conditioner

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE1030293B1 (nl) * 2022-02-23 2023-09-18 Daikin Europe Nv Airconditioningsysteem en werkwijze voor het tot stand brengen van een besturingslogica voor de bediening van de afsluitklep

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5526649A (en) * 1993-02-26 1996-06-18 Daikin Industries, Ltd. Refrigeration apparatus
CN102213463A (zh) * 2011-05-26 2011-10-12 广东美的电器股份有限公司 使用可燃冷媒的空调器及其控制方法
WO2014083678A1 (ja) * 2012-11-30 2014-06-05 三菱電機株式会社 空気調和装置
WO2018061188A1 (ja) * 2016-09-30 2018-04-05 三菱電機株式会社 室内機及び空気調和機
WO2019146139A1 (ja) * 2018-01-26 2019-08-01 三菱電機株式会社 冷凍サイクル装置

Family Cites Families (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62141469A (ja) * 1985-12-14 1987-06-24 ダイキン工業株式会社 ヒ−トポンプ式空気調和機
JPH09264641A (ja) * 1996-03-29 1997-10-07 Matsushita Electric Ind Co Ltd 冷凍サイクル装置
JPH11182895A (ja) * 1997-12-17 1999-07-06 Mitsubishi Electric Corp 空気調和機
JP3530370B2 (ja) * 1998-01-20 2004-05-24 株式会社鷺宮製作所 冷暖房ユニットの駆動用電力供給方法及びその装置
JP4265868B2 (ja) * 2000-12-11 2009-05-20 東芝キヤリア株式会社 空気調和機
JP4141676B2 (ja) 2001-11-06 2008-08-27 三菱電機株式会社 蓄熱式空気調和装置およびその冷媒回収方法
KR20040073565A (ko) * 2002-01-15 2004-08-19 가부시끼가이샤 도시바 냉매누출을 알리는 알림장치를 구비한 냉장고
JP2003227664A (ja) 2002-02-05 2003-08-15 Mitsubishi Electric Corp 空気調和機および空気調和機の運転方法
JP2007163011A (ja) * 2005-12-13 2007-06-28 Daikin Ind Ltd 冷凍装置
JP5211894B2 (ja) * 2008-06-27 2013-06-12 ダイキン工業株式会社 空気調和機
CN102667276B (zh) * 2009-10-22 2014-03-12 大金工业株式会社 空调机
EP2570740B1 (en) * 2010-05-12 2019-02-27 Mitsubishi Electric Corporation Air conditioning apparatus
JP5517789B2 (ja) 2010-07-02 2014-06-11 日立アプライアンス株式会社 空気調和機
WO2012008148A1 (ja) * 2010-07-13 2012-01-19 ダイキン工業株式会社 冷媒流路切換ユニット
JP2012127519A (ja) * 2010-12-13 2012-07-05 Panasonic Corp 空気調和機
KR101678324B1 (ko) * 2012-08-27 2016-11-21 다이킨 고교 가부시키가이샤 냉동장치
KR20140056965A (ko) 2012-11-02 2014-05-12 엘지전자 주식회사 공기조화기 및 그 제어 방법
JP6285172B2 (ja) * 2013-12-19 2018-02-28 日立ジョンソンコントロールズ空調株式会社 空気調和機の室外機
JP6262560B2 (ja) 2014-02-18 2018-01-17 株式会社Ｎｔｔファシリティーズ 空気調和装置および空気調和装置の制御方法
JP6252332B2 (ja) * 2014-04-18 2017-12-27 ダイキン工業株式会社 冷凍装置
JP6604051B2 (ja) * 2015-06-26 2019-11-13 ダイキン工業株式会社 空気調和システム
JP7215819B2 (ja) * 2017-01-11 2023-01-31 ダイキン工業株式会社 空気調和装置及び室内ユニット

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5526649A (en) * 1993-02-26 1996-06-18 Daikin Industries, Ltd. Refrigeration apparatus
CN102213463A (zh) * 2011-05-26 2011-10-12 广东美的电器股份有限公司 使用可燃冷媒的空调器及其控制方法
WO2014083678A1 (ja) * 2012-11-30 2014-06-05 三菱電機株式会社 空気調和装置
WO2018061188A1 (ja) * 2016-09-30 2018-04-05 三菱電機株式会社 室内機及び空気調和機
WO2019146139A1 (ja) * 2018-01-26 2019-08-01 三菱電機株式会社 冷凍サイクル装置

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
CN-102213463-A English Translation (Year: 2011) *
WO-2014083678-A1 English Translation (Year: 2014) *
WO-2018061188-A1 English Translation (Year: 2018) *
WO-2019146139-A1 English Translation (Year: 2019) *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220187001A1 (en) * 2020-12-11 2022-06-16 Lg Electronics Inc. Air conditioner and method for controlling air conditioner

Also Published As

Publication number Publication date
JP2020109342A (ja) 2020-07-16
CN113227663A (zh) 2021-08-06
EP3889515A1 (en) 2021-10-06
JP7412887B2 (ja) 2024-01-15
EP3889515A4 (en) 2022-02-16
WO2020141582A1 (ja) 2020-07-09
CN113227663B (zh) 2023-05-23

Similar Documents

Publication Publication Date Title
CN107429934B (zh) 利用侧空调装置以及包括该利用侧空调装置的空调装置
AU2016238875B2 (en) Refrigeration cycle apparatus
KR101678324B1 (ko) 냉동장치
US20210131706A1 (en) Air conditioner and indoor unit
US20210318041A1 (en) Air conditioner and flow path switching valve
JP6701337B2 (ja) 空気調和装置
AU2016284145A1 (en) Air conditioning system
CN113366270B (zh) 制冷剂循环装置
CN113994151A (zh) 制冷剂循环装置
US11692725B2 (en) Air-conditioning system with refrigerant leak detection and countermeasures
CN114729768A (zh) 空调系统
US20220373205A1 (en) Air-conditioning system
CN113260822B (zh) 空调机以及断流阀
JP6906708B2 (ja) 水冷式空気調和装置
WO2023026638A1 (ja) 室外機、室内機、及び空気調和システム
WO2023026639A1 (ja) 空気調和システム
WO2020250987A1 (ja) 冷媒サイクルシステム
US11719450B2 (en) Air-conditioning system
US20240044533A1 (en) Air conditioning system, operation control method therefor, and operation control device for air conditioning system
US20220146158A1 (en) Refrigerant cycle system and method
WO2023276535A1 (ja) 空気調和システム
JP2023037822A (ja) 空気調和装置

Legal Events

Date Code Title Description
AS Assignment

Owner name: DAIKIN INDUSTRIES, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WAKISAKA, SHIGETAKA;REEL/FRAME:056661/0407

Effective date: 20210416

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE AFTER FINAL ACTION FORWARDED TO EXAMINER