US20240337401A1 - Ventilation apparatus, air conditioning system, and ventilation system - Google Patents

Ventilation apparatus, air conditioning system, and ventilation system Download PDF

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Publication number
US20240337401A1
US20240337401A1 US18/743,804 US202418743804A US2024337401A1 US 20240337401 A1 US20240337401 A1 US 20240337401A1 US 202418743804 A US202418743804 A US 202418743804A US 2024337401 A1 US2024337401 A1 US 2024337401A1
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United States
Prior art keywords
heat exchanger
air
unit
temperature
refrigerant
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Pending
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US18/743,804
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English (en)
Inventor
Takashi Takahashi
Tsunahiro Odo
Shota TSURUZONO
Nobuki Matsui
Takuya Hanada
Naotoshi Fujita
Yoshiki YAMANOI
Yuta IYOSHI
Kumiko Saeki
Takeru Miyazaki
Toshiyuki Maeda
Tetsuya Okamoto
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Daikin Industries Ltd
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Daikin Industries Ltd
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Assigned to DAIKIN INDUSTRIES, LTD. reassignment DAIKIN INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HANADA, TAKUYA, MATSUI, NOBUKI, FUJITA, Naotoshi, IYOSHI, Yuta, MAEDA, TOSHIYUKI, MIYAZAKI, Takeru, ODO, TSUNAHIRO, OKAMOTO, TETSUYA, SAEKI, KUMIKO, TAKAHASHI, TAKASHI, TSURUZONO, Shota, YAMANOI, Yoshiki
Publication of US20240337401A1 publication Critical patent/US20240337401A1/en
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    • 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
    • F24F11/41—Defrosting; Preventing freezing
    • F24F11/43—Defrosting; Preventing freezing of indoor units
    • 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
    • F24F11/41—Defrosting; Preventing freezing
    • 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
    • F24F11/81—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the air supply to heat-exchangers or bypass channels
    • 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
    • F24F12/00—Use of energy recovery systems in air conditioning, ventilation or screening
    • F24F12/001—Use of energy recovery systems in air conditioning, ventilation or screening with heat-exchange between supplied and exhausted air
    • F24F12/002—Use of energy recovery systems in air conditioning, ventilation or screening with heat-exchange between supplied and exhausted air using an intermediate heat-transfer fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/10—Temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/10—Temperature
    • F24F2110/12—Temperature of the outside air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2140/00—Control inputs relating to system states
    • F24F2140/20—Heat-exchange fluid temperature

Definitions

  • the present disclosure relates to a ventilation apparatus, an air conditioning system, a ventilation method, and a ventilation system.
  • the present disclosure provides a ventilation apparatus including
  • FIG. 1 is a diagram illustrating a configuration example of a ventilation apparatus and an air conditioner according to the first embodiment
  • FIG. 2 is a flowchart illustrating the control of frost prevention performed by the exhaust unit of the ventilation apparatus according to the first embodiment
  • FIG. 3 is a diagram illustrating a configuration example of the ventilation apparatus and the air conditioner according to the modified example 3 of the first embodiment
  • FIG. 4 is a diagram illustrating a configuration example of the ventilation apparatus and the air conditioner according to the second embodiment
  • FIG. 5 is a diagram illustrating a refrigerant circuit according to the modified example 1 of the second embodiment
  • FIG. 6 is a diagram illustrating a configuration example of a ventilation apparatus, an air conditioner, and an upper-level control device according to the third embodiment
  • FIG. 7 is a sequence diagram illustrating a flow of processing performed between the upper-level control device, the ventilation apparatus, and the air conditioner when defrosting operation of the air conditioner according to the third embodiment is started;
  • FIG. 8 is a sequence diagram illustrating a flow of processing performed between the upper-level control device, the compressor unit, and the exhaust unit group when there is a possibility of defrosting in each exhaust unit in the exhaust unit group according to the fourth embodiment;
  • FIG. 9 is a diagram illustrating an arrangement of the device group including the upper-level control device according to the seventh embodiment.
  • FIG. 10 is a diagram illustrating an arrangement of a device group including an upper-level control device according to an eighth embodiment
  • FIG. 11 illustrates a refrigerant circuit according to the eleventh embodiment
  • FIG. 12 illustrates a refrigerant circuit according to a modified example of the eleventh embodiment
  • FIG. 13 is a flowchart illustrating a processing procedure of the upper-level control device according to the twelfth embodiment
  • FIG. 14 illustrates a schematic configuration of a ventilation system according to an embodiment
  • FIG. 15 is a control block diagram of a ventilation system according to an embodiment of the present invention.
  • FIG. 16 is a flow diagram illustrating the operation of a ventilation system according to an embodiment
  • FIG. 17 is a schematic configuration diagram of a ventilation system according to a thirteenth embodiment.
  • FIG. 18 is a schematic configuration diagram of a ventilation system according to a fourteenth embodiment.
  • FIG. 19 is a schematic configuration diagram illustrating a state of installation of a ventilation system according to fourteenth and fifteenth embodiments in a building;
  • FIG. 20 is a schematic configuration diagram of a ventilation system according to a fifteenth embodiment
  • FIG. 21 is a schematic configuration diagram of a ventilation system according to a sixteenth embodiment.
  • FIG. 22 is a schematic configuration diagram of a ventilation system according to a seventeenth embodiment.
  • FIG. 23 is a schematic configuration diagram of a ventilation system according to a eighteenth embodiment.
  • FIG. 1 is a diagram illustrating a configuration example of a ventilation apparatus and an air conditioner according to the first embodiment.
  • an air conditioning system includes a ventilation apparatus 1 and an air conditioner 2 for air conditioning an indoor space.
  • the indoor space is not limited to the living room space R 11 and the ceiling space R 12 , and may be a space inside a building, for example, a space under the floor.
  • the living room space R 11 is, for example, a living room inside an office or a house.
  • the ceiling space R 12 is an adjacent space above the living room space R 11 .
  • the ceiling space R 12 exists above the living room space R 11 , and, therefore, warm air tends to be collected in the ceiling space R 12 .
  • the air conditioner 2 includes an outdoor unit 70 and two air conditioning indoor units 81 and 82 (air conditioning indoor devices).
  • the number of air conditioning indoor units is not limited to two units, but may be one unit or three units or more.
  • the air conditioner 2 performs a vapor compression type refrigeration cycle to cool and heat the living room space R 11 .
  • the air conditioner 2 according to the present embodiment can both cool and heat the living room space R 11 .
  • the present embodiment is not limited to an air conditioner capable of both cooling and heating, and may be a device capable of only cooling, for example.
  • connection pipe F 5 includes a liquid refrigerant connection pipe and a gas refrigerant connection pipe (not illustrated). Accordingly, a refrigerant circuit in which a refrigerant circulates between the outdoor unit 70 and the two air conditioning indoor units 81 and 82 is formed. When refrigerant circulates in the refrigerant circuit, a vapor compression type refrigeration cycle is performed in the air conditioner 2 .
  • the outdoor unit 70 is arranged outdoors.
  • the outdoor unit 70 is provided with a heat exchanger, and the air in which the heat is exchanged with the refrigerant flowing through the heat exchanger is discharged outdoors.
  • the air conditioning indoor units 81 and 82 are provided with a heat exchanger, and the air conditioning indoor units 81 and 82 exchange the heat in the air with the refrigerant flowing through the heat exchanger, and blow the heat exchanged air into the living room space R 11 .
  • the air conditioning indoor units 81 and 82 are ceiling-installed types installed on the ceiling of the living room space R 11 .
  • the air conditioning indoor units 81 and 82 of the present embodiment are ceiling-embedded type air conditioning indoor units, and air in which heat has been exchanged is blown out from ventilation ports 93 A and 93 B.
  • the air conditioning indoor units 81 and 82 are not limited to the ceiling-embedded type, and may be a ceiling-suspended type.
  • the air conditioning indoor units 81 and 82 may be other than the ceiling installed type, such as a wall mounted type or a floor mounted type.
  • the ventilation apparatus 1 includes the exhaust unit 10 , the air supply unit 20 , a compressor unit 50 , refrigerant circuits F 1 , F 2 , F 3 , and F 4 , an air supply flow path P 1 , and a return air flow path P 2 .
  • the ventilation apparatus 1 supplies the air taken in from outdoors to the living room space R 11 and exhausts the air taken in from the indoor space (including the living room space R 11 ) to the outside. Thus, the ventilation apparatus 1 implements the replacement of the air in the living room space R 11 .
  • the ventilation apparatus 1 exchanges heat between the exhaust unit 10 and the air supply unit 20 to reduce the temperature difference between the temperature of the air taken in from the outside and the temperature of the living room space R 11 .
  • the air supply flow path P 1 (an example of the first air flow path) is a flow path for supplying air taken in from the outside to the living room space R 11 from the ventilation port 92 after passing through the air supply unit 20 having the first heat exchanger 22 .
  • the present embodiment will describe an example in which the ventilation port 92 is provided on the ceiling, the position at which the ventilation port 92 is provided is not particularly limited.
  • the return air flow path P 2 (an example of the second air flow path) is a flow path for exhausting air (return air) taken in from the ventilation port 91 of the living room space R 11 to the outside after passing through the exhaust unit 10 having the second heat exchanger 12 .
  • the present embodiment will describe an example in which the ventilation port 91 is provided on the ceiling, the position at which the ventilation port 91 is provided is not particularly limited.
  • the air intake destination is branched into two in order to allow air intake from a plurality of rooms.
  • Each of the air intake destinations is referred to as a first return air branch path P 2 A (an example of a second air flow path) and a second return air branch path P 2 B (an example of the third air flow path).
  • the first return air branch path P 2 A (an example of the second air flow path) is an air flow path provided for exhausting air taken in from the living room space R 11 to the outside after passing through the exhaust unit 10 including the second heat exchanger 12 .
  • the first return air branch path P 2 A takes in air from the ventilation port 91 provided on the ceiling of the living room space R 11 .
  • the ventilation port may be provided in another place such as under the floor or on a wall.
  • the second return air branch path (an example of the third air flow path) P 2 B is an air flow path provided for exhausting air taken in from the ceiling space R 12 to the outside after passing through the exhaust unit 10 having the second heat exchanger 12 .
  • An example is described in which the space that is the air intake destination of the second return air branch path P 2 B is the ceiling space R 12 , which is a different space from that of the first return air branch path P 2 A.
  • the space that is the air intake destination is not limited to the ceiling space R 12 , and may be an underfloor space.
  • the air intake destination of the second return air branch path P 2 B may be a space different from the living room space R 11 .
  • An opening/closing damper 40 is provided at the tip of the second return air branch path.
  • the opening/closing damper 40 is usually closed. Then, the opening/closing damper 40 (an example of a first guide) can adjust the air volume taken in from the ceiling space R 12 by controlling from the control unit 13 provided in the exhaust unit 10 through the signal line S 2 .
  • the refrigerant circuits F 1 , F 2 , F 3 , and F 4 are circuits in which the compressor unit 50 , the first heat exchanger 22 of the air supply unit 20 , and the second heat exchanger 12 of the exhaust unit 10 are connected by refrigerant pipe, and the refrigerant flows in these refrigerant circuits.
  • the control unit 52 of the compressor unit 50 , the control unit 23 of the air supply unit 20 , and the control unit 13 of the exhaust unit 10 are connected by a signal line S 1 indicated by a dotted line in FIG. 1 .
  • a signal line S 1 indicated by a dotted line in FIG. 1 .
  • information can be transmitted and received between the control unit 52 of the compressor unit 50 , the control unit 23 of the air supply unit 20 , and the control unit 13 of the exhaust unit 10 .
  • the processing by the control units 13 , 23 , and 52 described below may be implemented by a CPU (not illustrated) reading a program, or by a hardware connection. The same applies to the control unit and the upper-level control device described in the following embodiments.
  • the compressor unit 50 is provided with a driving motor 51 and a control unit 52 , and controls circulation of the refrigerant in the refrigerant circuits F 1 , F 2 , F 3 , and F 4 by compressing any one of the refrigerants in the refrigerant circuits F 1 , F 2 , F 3 , and F 4 .
  • the compressor unit 50 compresses the refrigerant in the refrigerant circuit F 2 to circulate the refrigerant in the refrigerant circuits F 1 , F 2 , F 3 , and F 4 .
  • the driving motor 51 is a motor for rotating (driving) the compressor for compressing the refrigerant.
  • the control unit 52 controls the configuration in the compressor unit 50 .
  • the control unit 52 outputs an instruction for rotating (driving) the compressor to the driving motor 51 .
  • the air supply unit 20 includes a fan 21 , a first heat exchanger 22 , a control unit 23 , and a temperature detecting unit 24 , and takes in the outside air (OA), and supplies air (SA) to the living room space R 11 .
  • the fan 21 functions to supply air (SA) to the living room space R 11 from the outside air (OA) that is taken in.
  • the first heat exchanger 22 functions as a condenser or an evaporator.
  • the temperature detecting unit 24 detects the outdoor temperature, the surface temperature of the first heat exchanger 22 and the temperature of the refrigerant flowing through the first heat exchanger 22 .
  • the control unit 23 controls the configuration inside the air supply unit 20 .
  • the control unit 23 performs various kinds of control according to the detection result by a temperature detecting unit 14 .
  • the control unit 23 adjusts the function of the first heat exchanger 22 as a condenser or an evaporator according to the detection result by the temperature detecting unit 24 .
  • the exhaust unit 10 is provided with a fan 11 , a second heat exchanger 12 , a control unit 13 , and a temperature detecting unit 14 , takes in return air (RA) of the living room space R 11 , and exhausts (EA) the taken in air to the outside.
  • RA return air
  • EA exhausts
  • the fan 11 functions to exhaust (EA) the return air (RA) taken in from the living room space R 11 to the outside.
  • the second heat exchanger 12 functions as a condenser or an evaporator.
  • the temperature detecting unit 14 detects the indoor air temperature, the surface temperature of the second heat exchanger 12 , and the temperature of the refrigerant flowing through the second heat exchanger 12 . Further, the indoor air temperature to be detected includes, for example, the temperature of air in the living room space R 11 and the temperature of air in the ceiling space R 12 through the sensor unit (not illustrated).
  • the control unit 13 controls the configuration of the inside of the exhaust unit 10 .
  • the control unit 13 performs various kinds of control according to the detection result by the temperature detecting unit 14 .
  • the control unit 13 adjusts the function of the second heat exchanger 12 as a condenser or an evaporator according to the detection result of the temperature detecting unit 14 .
  • control unit 13 can adjust the air volume taken in from the ceiling space R 12 by controlling the opening/closing damper 40 based on the detection result by the temperature detecting unit 14 .
  • a process performed by the ventilation apparatus 1 when the air temperature is low will be described.
  • the ventilation apparatus 1 warms the outside air (OA) taken in from the outside in the air supply unit 20 , then supplies the air (SA) to the living room space R 11 , and cools the return air (RA) taken in from the living room space R 11 in the exhaust unit 10 , then exhausts the air (EA) to the outside. That is, the first heat exchanger 22 in the air supply unit 20 functions as a condenser, and the second heat exchanger 12 in the exhaust unit 10 functions as an evaporator.
  • control is performed to avoid freezing (frosting) of the second heat exchanger 12 , or to prevent frost from growing if frost are formed.
  • the control to prevent frost at least one or more of the control to avoid frost and the control to prevent frost from growing if frost is formed are referred to as the control to prevent frost.
  • the control unit 13 of the exhaust unit 10 determines whether the second heat exchanger 12 satisfies a predetermined reference indicating the possibility of frosting (freezing) from the detection result by the temperature detecting unit 14 .
  • the predetermined reference indicating the possibility that the second heat exchanger 12 will frost (freeze) may be, for example, a reference for determining whether the outdoor air temperature detected by the temperature detecting unit 14 is 0 degrees or less. Further, the present embodiment does not limit the predetermined reference to whether the outdoor air temperature is 0 degrees or less, but may be a reference for determining whether the outdoor air temperature is the minimum operating temperature of the second heat exchanger 12 .
  • the predetermined reference may not be a reference based on the air temperature of the outside air. For example, whether the surface temperature of the second heat exchanger 12 is less than or equal to the predetermined temperature (e.g., 0 degrees) may be used as the determination reference. As another example, whether the temperature of the refrigerant flowing through the second heat exchanger 12 is less than or equal to the predetermined temperature (e.g., 0 degrees) may be used as the determination reference. In the following description, an example of the predetermined reference is also provided, but any reference may be used as long as the reference indicates the possibility of frosting (freezing) of the second heat exchanger 12 . For example, as described in the embodiment to be described later, the reference may be used to determine whether the low pressure of the refrigerant circuits F 1 , F 2 , F 3 , and F 4 has fallen below the predetermined pressure threshold.
  • the present embodiment indicates an example of the information to be acquired, and the information to be acquired may be information that enables determining whether the predetermined reference is satisfied.
  • the information to be acquired may be information that enables determining whether the predetermined reference is satisfied.
  • the predetermined reference may be satisfied by combining these pieces of information.
  • An example of the information to be acquired is also illustrated in the following embodiments and modified examples, and any kind of information may be used as long as the information can be used to determine whether the predetermined reference is satisfied.
  • the control unit 13 of the exhaust unit 10 determines that the predetermined reference is satisfied, the control unit controls the opening/closing damper 40 so that the air present in the ceiling space R 12 is guided to the second heat exchanger 12 through the second return air branch path P 2 B as a control to prevent frosting in the second heat exchanger 12 . That is, warm air is gathered in the ceiling space R 12 because the ceiling space R 12 exists above the living room space R 11 . Therefore, when there is a possibility of frosting in the second heat exchanger 12 , the opening/closing damper 40 is controlled to be opened. By this control, the air mixed with the warm air existing in the ceiling space R 12 and the air existing in the living room space R 11 is guided to the second heat exchanger 12 .
  • the control unit 13 controls the warm air in the ceiling space R 12 to flow to the second heat exchanger 12 .
  • frosting in the second heat exchanger 12 can be prevented.
  • FIG. 2 is a flowchart illustrating the control of preventing frosting performed by the exhaust unit 10 of the ventilation apparatus 1 according to the present embodiment.
  • the control unit 13 of the exhaust unit 10 acquires the temperature of the outside air from the temperature detecting unit 14 (S 1201 ).
  • control unit 13 of the exhaust unit 10 determines whether a predetermined reference indicating the possibility of freezing of the second heat exchanger 12 is satisfied (S 1202 ).
  • control unit 13 of the exhaust unit 10 determines that the predetermined reference is not satisfied (S 1202 : NO)
  • the control unit 13 ends the process without performing any particular processing.
  • control unit 13 of the exhaust unit 10 determines that the predetermined reference is satisfied (S 1202 : YES)
  • the control unit 13 acquires, from the temperature detecting unit 14 , the temperature of the air in the ceiling space R 12 and the temperature of the air taken in from the living room space R 11 (S 1203 ).
  • the control unit 13 of the exhaust unit 10 determines whether the temperature of the air in the ceiling space R 12 is higher than the temperature of the air in the living room space R 11 (S 1204 ). When the control unit 13 determines that the temperature of the air in the ceiling space R 12 is lower than the temperature of the air in the living room space R 11 (S 1204 : NO), the control unit ends the process without performing control on the opening/closing damper 40 . When the control on the opening/closing damper 40 is not performed, the control to prevent frosting described in the following embodiments and modified examples may be performed.
  • control unit 13 determines that the temperature of the air in the ceiling space R 12 is higher than the temperature of the air in the living room space R 11 (S 1204 : YES)
  • the control unit performs control to open the opening/closing damper 40 (S 1205 ).
  • the air in the ceiling space R 12 where the air is warmer than the living room space R 11 is guided to the second heat exchanger 12 .
  • the temperature of the air flowing into the second heat exchanger 12 rises, and, therefore, the temperature of the refrigerant flowing through the second heat exchanger 12 can rise.
  • the possibility of frosting in the second heat exchanger 12 can be reduced.
  • the control for raising the temperature of the air flowing through the second heat exchanger 12 a method for reducing the possibility of frosting in the second heat exchanger 12 by guiding the air in the ceiling space R 12 to the second heat exchanger 12 has been described.
  • the control method for raising the temperature of the air flowing through the second heat exchanger 12 is not limited to the method for guiding the air in the ceiling space R 12 to the second heat exchanger 12 , and other methods may be used. Therefore, in the modified example 1 of the first embodiment, the air conditioner 2 is controlled to raise the temperature (room temperature) of the air in the living room space R 11 .
  • control unit 13 of the exhaust unit 10 and the control unit 71 of the outdoor unit 70 are connected by a signal line.
  • the control unit 71 of the outdoor unit 70 can output a control signal to the control unit 13 of the exhaust unit 10 .
  • control unit 13 of the exhaust unit 10 and the control unit 71 of the outdoor unit 70 by means of a signal line.
  • the mode in which information can be transmitted and received is not limited to an example in which information can be transmitted and received by means of a signal line; control signals may be transmitted and received via an upper-level control device (not illustrated), or control signals may be transmitted and received via a cloud or a server connected via a public network.
  • the control unit 13 of the exhaust unit 10 detects whether a predetermined reference indicating the possibility of freezing of the second heat exchanger 12 is satisfied while the second heat exchanger 12 functions as an evaporator.
  • the control unit 71 of the outdoor unit 70 of the air conditioner 2 outputs a control signal for raising the temperature currently set in the living room space R 11 .
  • the temperature of the air flowing through the second heat exchanger 12 rises by raising the air temperature in the living room space R 11 , and, therefore, the temperature of the refrigerant flowing through the second heat exchanger 12 can be raised.
  • the control unit 13 As an example of the control for raising the temperature of the refrigerant flowing through the second heat exchanger 12 , the control unit 13 according to the present modified example outputs to the control unit 71 a control signal for raising the temperature currently set in the living room space R 11 . Accordingly, the room temperature of the living room space R 11 is raised, and, therefore, warm air flows into the second heat exchanger 12 , and the temperature of the refrigerant flowing through the second heat exchanger 12 is raised to prevent frosting in the second heat exchanger 12 .
  • the present modified example an example of outputting a control signal for raising the temperature currently set in the living room space R 11 to the control unit 71 of the outdoor unit 70 of the air conditioner 2 has been described.
  • the present modified example does not limit the control signal output to the control unit 71 of the outdoor unit 70 of the air conditioner 2 to a control signal for raising the temperature currently set in the living room space R 11 , but the control signal may be a control signal for raising the temperature of the refrigerant flowing through the second heat exchanger 12 .
  • the control unit 13 may output a control signal for increasing the air volume in order to circulate the air in the living room space R 11 .
  • the first embodiment and modified example described above are not limited to using the method described above. Therefore, in the modified example 2 of the first embodiment, a method for controlling the fan 11 in order to prevent frosting will be described.
  • the control unit 13 of the exhaust unit 10 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied while the second heat exchanger 12 functions as an evaporator.
  • the control unit 13 controls the fan 11 (an example of a second ventilation device) to increase the air volume flowing to the second heat exchanger 12 in comparison with before the predetermined reference is satisfied in order to raise the temperature of the refrigerant flowing through the second heat exchanger 12 when it is determined that the predetermined reference is satisfied.
  • the fan 11 an example of a second ventilation device
  • the control unit 13 As an example of the control to raise the temperature of the refrigerant flowing through the second heat exchanger 12 , the control unit 13 according to the present modified example outputs a control signal to the fan 11 (an example of a second ventilation device) to increase the air volume flowing to the second heat exchanger 12 in comparison with before the predetermined reference is satisfied. Accordingly, the amount of warm air flowing to the second heat exchanger 12 increases, and, therefore, the temperature of the refrigerant can be raised to prevent frosting in the second heat exchanger 12 .
  • control unit 13 may output a control signal to increase the air volume of the fan 21 , to the control unit 23 of the air supply unit 20 .
  • the first embodiment and the modified example described above are not limited to using the method described above. Therefore, in the modified example 3 of the first embodiment, a method for providing a bypass flow path for direct air flow between the air supply unit and the exhaust unit will be described.
  • FIG. 3 is a diagram illustrating a configuration example of a ventilation apparatus and an air conditioner according to the modified example 3 of the first embodiment.
  • a ventilation apparatus 1 A and an air conditioner 2 are provided for air conditioning an indoor space.
  • the same reference numerals are assigned to the same configuration as in the first embodiment, and descriptions thereof will be omitted.
  • a bypass flow path P 102 is provided between the air supply unit 20 and the exhaust unit 110 .
  • the bypass flow path P 102 includes a first bypass partial flow path P 102 A further towards the air supply unit 20 than the air supply flow path P 101 , a third bypass partial flow path P 102 C further towards the exhaust unit 110 than the return flow path P 103 , and a second bypass partial flow path P 102 B connecting the first bypass partial flow path P 102 A and the third bypass partial flow path P 102 C.
  • An opening/closing damper 140 is provided on the second bypass partial flow path P 102 B.
  • the opening/closing damper 140 is usually closed.
  • the opening/closing damper 140 (an example of the second guide) can guide air warmed by the air supply unit 20 directly to the exhaust unit 110 by control from the control unit 113 provided in the exhaust unit 110 through the signal line S 2 .
  • the air supply unit 20 After taking in outside air (OA), the air supply unit 20 usually supplies air (SA) to the living room space R 11 through the first bypass partial flow path P 102 A and the air supply flow path P 101 .
  • SA air
  • the exhaust unit 110 includes the fan 11 , the second heat exchanger 12 , a control unit 113 , and the temperature detecting unit 14 , and takes in return air (RA) of the living room space R 11 through the return flow path P 103 and the third bypass partial flow path P 102 C, and exhausts (EA) the air to the outside.
  • RA return air
  • EA exhausts
  • the control unit 113 of the exhaust unit 110 detects whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied, while the second heat exchanger 12 functions as an evaporator.
  • control unit 13 determines that the predetermined reference is satisfied, the control unit 13 performs control to open the opening/closing damper 140 in order to raise the temperature of the refrigerant flowing through the second heat exchanger 12 .
  • control unit 113 performs control to open the opening/closing damper 140 so as to guide air through the bypass flow path P 102 to the second heat exchanger 12 . Accordingly, the air warmed in the exhaust unit 110 can flow directly to the second heat exchanger 12 , thereby preventing frosting in the second heat exchanger 12 .
  • FIG. 4 is a diagram illustrating a configuration example of a ventilation apparatus and an air conditioner according to the second embodiment.
  • a ventilation apparatus 1 B and an air conditioner 2 are provided for air conditioning an indoor space.
  • the same reference numerals are assigned to the configurations similar to those of the first embodiment, and descriptions thereof will be omitted.
  • the control unit 52 of the compressor unit 50 , the control unit 23 of the first air supply unit 220 A, the control unit 23 of the second air supply unit 220 B, and the control unit 213 of the exhaust unit 210 are connected by a signal line S 201 indicated by a dotted line.
  • a signal line S 201 indicated by a dotted line.
  • the ventilation apparatus 1 B includes an exhaust unit 210 , a first air supply unit 220 A, a second air supply unit 220 B, a compressor unit 50 , refrigerant circuits F 1 , F 2 , F 3 , and F 4 , a first air supply flow path P 201 , a second air supply flow path P 202 , and a return air flow path P 203 .
  • the first air supply flow path P 201 (an example of the first air flow path) supplies air taken in from the outdoors to the living room space R 11 from the ventilation port 92 A after passing through the first air supply unit 220 A having the first heat exchanger 22 .
  • the second air supply flow path P 202 (an example of the first air flow path) supplies air taken in from the outside to the living room space R 11 from the ventilation port 92 B after passing through the second air supply unit 220 B having the first heat exchanger 22 .
  • the return air flow path P 203 (an example of the second air flow path) exhausts air taken in from the indoor space to the outside after passing through the exhaust unit 210 having the second heat exchanger 12 .
  • the first air supply unit 220 A and the second air supply unit 220 B are provided with a fan 21 , a first heat exchanger 22 , a control unit 23 , and a temperature detecting unit 24 , and take in outside air (OA) and supply air (SA) to the living room space R 11 .
  • OA outside air
  • SA supply air
  • the exhaust unit 210 is provided with the fan 11 , the second heat exchanger 12 , a control unit 213 , and the temperature detecting unit 14 , and takes in return air (RA) of the living room space R 11 and exhausts air (EA) to the outside.
  • RA return air
  • EA exhausts air
  • the control unit 213 of the exhaust unit 210 controls the configuration of the inside of the exhaust unit 210 .
  • the control unit 213 outputs a control signal to the control unit 52 of the compressor unit 50 according to the detection result of the temperature detecting unit 14 .
  • the processing performed by the ventilation apparatus 1 B when the air temperature is low will be described below.
  • the first heat exchanger 22 of the first air supply unit 220 A and the second air supply unit 220 B functions as a condenser
  • the second heat exchanger 12 in the exhaust unit 210 functions as an evaporator.
  • the second heat exchanger 12 functions as an evaporator, the temperature of the refrigerant flowing through the second heat exchanger 12 becomes low, and, therefore, the second heat exchanger 12 may be frosted. Therefore, in the present embodiment, control is performed to prevent frosting in the second heat exchanger 12 .
  • the control unit 213 of the exhaust unit 210 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the detection result by the temperature detecting unit 14 .
  • the predetermined reference indicating the possibility of frosting in the second heat exchanger 12 may be, for example, a reference for determining whether the temperature of the refrigerant detected by the temperature detecting unit 14 is 0 degrees or less.
  • the present embodiment does not limit the predetermined reference to a reference based on the temperature of the refrigerant, but may be a reference for determining whether the pressure of the refrigerant is less than or equal to the predetermined pressure.
  • the predetermined reference may not be based on the temperature or pressure of the refrigerant.
  • the reference may be based on the temperature of the outside air or the surface temperature of the second heat exchanger 12 .
  • the control unit 213 of the exhaust unit 210 outputs a control signal for reducing the rotational speed of the compressor compared to before satisfying the predetermined reference, to the control unit 52 of the compressor unit 50 as a control for preventing frosting in the second heat exchanger 12 when the predetermined reference is determined to be satisfied.
  • the control unit 52 of the compressor unit 50 When the control signal is received, the control unit 52 of the compressor unit 50 outputs a control signal for reducing the rotational speed of the compressor as compared to before the predetermined reference is satisfied, to the driving motor 51 for driving the compressor. Accordingly, the rotational speed of the compressor is reduced. Accordingly, the pressure of the refrigerant flowing through the refrigerant circuits F 1 , F 2 , F 3 , and F 4 is reduced, and, therefore, the temperature (evaporation temperature) of the refrigerant flowing through the second heat exchanger 12 can be increased.
  • the control unit 213 As an example of the control for raising the temperature of the refrigerant flowing through the second heat exchanger 12 , the control unit 213 according to the present embodiment outputs a control signal for lowering the rotational speed of the compressor compared to before the predetermined reference is satisfied, to the control unit 52 of the compressor unit 50 . Thus, frosting in the second heat exchanger 12 can be prevented.
  • the second embodiment an example of raising the temperature (evaporation temperature) of the refrigerant flowing through the second heat exchanger 12 by lowering the rotational speed of the compressor has been described.
  • the method of raising the temperature (evaporation temperature) of the refrigerant flowing through the second heat exchanger 12 is not limited to the method of lowering the rotational speed of the compressor. Therefore, in the modified example 1, an example of providing a bypass flow path (an example of a bypass pipe) in the refrigerant circuit will be described.
  • two air supply units and one exhaust unit are provided.
  • FIG. 5 is a diagram illustrating a refrigerant circuit according to the modified example 1 of the second embodiment.
  • the flow of refrigerant when the second heat exchanger 12 of the exhaust unit 310 functions as an evaporator is illustrated. Note that the same reference numerals are assigned to the configuration similar to the above-described embodiment, and the description thereof will be omitted.
  • the air supply units 320 A and 320 B, the exhaust unit 310 , and the compressor unit 350 are provided.
  • the air supply units 320 A and 320 B include the fan 21 , the first heat exchanger 22 , the control unit 23 , the temperature detecting unit 24 , a driving motor 25 , and an electric valve 26 .
  • the driving motor 25 controls the air volume of the fan 21 by the control unit 23 .
  • the electric valve 26 functions as an expansion valve for decompressing the refrigerant, and switches whether the refrigerant is to be decompressed based on the control of the control unit 23 .
  • the electric valve 26 functions to reduce pressure when the first heat exchanger 22 functions as an evaporator and not to reduce pressure when the first heat exchanger 22 functions as a condenser.
  • the exhaust unit 310 includes the fan 11 , the second heat exchanger 12 , a control unit 313 , the temperature detecting unit 14 , a driving motor 15 , and an electric valve 16 .
  • the control unit 313 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the detection result by the temperature detecting unit 14 .
  • the predetermined reference is the same as that in the second embodiment, and the description thereof is omitted.
  • control unit 313 of the exhaust unit 310 determines that the predetermined reference is satisfied, the control unit 313 outputs, to the control unit 352 of the compressor unit 350 , a control signal for causing the refrigerant to flow into the bypass flow path F 6 , as a control for preventing frosting in the second heat exchanger 12 .
  • the driving motor 15 controls the air volume of the fan 11 by the control unit 313 .
  • the electric valve 16 functions as an expansion valve for decompressing the refrigerant, and switches whether the refrigerant is to be decompressed based on the control by the control unit 313 .
  • the electric valve 16 functions to reduce pressure when the second heat exchanger 12 functions as an evaporator and not to reduce pressure when the second heat exchanger 12 functions as a condenser.
  • the compressor unit 350 is provided with a driving motor 51 , a control unit 352 , a compressor 53 , a four-way valve 54 , an electric valve 55 , and a bypass electric valve 56 .
  • the compressor 53 compresses the refrigerant flowing through the refrigerant circuit.
  • the driving motor 51 is an actuator for driving the compressor 53 .
  • the driving motor 51 according to the present embodiment drives the compressor 53 at a rotational speed controlled by the control unit 352 .
  • the control unit 352 controls the configuration inside the compressor unit 350 .
  • the control unit 352 controls the following driving motor 51 and the four-way valve 54 .
  • the four-way valve 54 functions as a valve for switching the outflow destination of the refrigerant compressed by the compressor 53 from the refrigerant circuit F 1 and the refrigerant circuit F 4 .
  • the four-way valve 54 is switched so that the refrigerant compressed by the compressor 53 flows into the refrigerant circuit F 1 based on the control of the control unit 352 .
  • the electric valve 55 functions as a valve for controlling the opening and closing of the refrigerant circuit according to the control from the control unit 352 .
  • the electric valve 55 is in a closed state in which the refrigerant does not flow.
  • a bypass flow path F 6 is provided to allow the refrigerant compressed by the compressor 53 to flow directly to the second heat exchanger 12 in order to raise the temperature of the refrigerant flowing through the second heat exchanger 12 .
  • the bypass flow path F 6 is provided as a flow path for the refrigerant to bypass between the point between the compressor 53 and the four-way valve 54 , and the refrigerant circuit F 3 . That is, while the second heat exchanger 12 functions as an evaporator, the bypass flow path F 6 functions as a pipe for passing the refrigerant to the second heat exchanger 12 without going through the first heat exchanger 22 .
  • the bypass electric valve 56 functions as a valve for switching whether the refrigerant flows to the bypass flow path F 6 according to the control from the control unit 352 .
  • control unit 313 of the exhaust unit 310 first outputs a control signal for passing the refrigerant to the bypass flow path F 6 , to the control unit 352 of the compressor unit 350 , when it is determined that a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied.
  • control unit 352 of the compressor unit 350 controls the bypass electric valve 56 to be opened.
  • the refrigerant compressed by the compressor 53 flows through the bypass flow path F 6 into the second heat exchanger 12 .
  • frosting in the second heat exchanger 12 can be prevented.
  • the electric valve 16 functions as a valve part for decompressing the refrigerant of the high-pressure liquid flowing out from the first heat exchanger 22 in order to facilitate the evaporation of the refrigerant according to the control of the control unit 313 .
  • the opening of the electric valve 16 decreases, the pressure is reduced, and the temperature of the refrigerant decreases. That is, as the opening of the electric valve 16 increases, the temperature of the refrigerant increases.
  • control unit 313 determines that the predetermined reference has been satisfied, the control unit performs control to increase the opening degree of the electric valve 16 (an example of the second valve part) as compared with before the predetermined reference has been satisfied, as a control to prevent frosting in the second heat exchanger 12 .
  • the above-described embodiments and modified examples an example of determining whether the control unit in the exhaust unit satisfies a predetermined reference and performing control based on the determination result has been described.
  • the above-described embodiment and modified example are not limited to a method in which the control unit in the exhaust unit performs control.
  • the upper-level control device provided on an upper level of the air conditioner and the ventilation apparatus may perform the control.
  • an upper-level control device 400 is provided for performing the cooperation between the ventilation apparatus 1 C and the air conditioner 2 C.
  • the air conditioner 2 C includes an outdoor unit 470 and two air conditioning indoor units 81 and 82 .
  • the number of air conditioning indoor units is not limited to two units, but may be one unit or three units or more.
  • the outdoor unit 470 includes a control unit 471 together with a heat exchanger (not illustrated).
  • the control unit 471 controls the entire air conditioner 2 C.
  • the control unit 471 also transmits and receives information to and from the upper-level control device 400 .
  • the control unit 471 performs various kinds of control according to the control signal from the upper-level control device 400 .
  • the ventilation apparatus 1 C includes a first exhaust unit 410 A, a second exhaust unit 410 B, a first air supply unit 420 A, a second air supply unit 420 B, a compressor unit 450 , refrigerant circuits F 401 , F 402 , F 403 , and F 404 , a first air supply flow path P 401 , a second air supply flow path P 402 , a first return air flow path P 403 , and a second return air flow path P 404 .
  • the first air supply flow path P 401 supplies air taken in from outside to the living room space R 11 from the ventilation port 92 A after passing through the first air supply unit 420 A having the first heat exchanger 22 .
  • the second air supply flow path P 402 supplies air taken in from outside to the living room space R 11 from the ventilation port 92 B after passing through the second air supply unit 420 B having the first heat exchanger 22 .
  • the first return air flow path P 403 exhausts air (return air) taken in from the ventilation port 91 A of the indoor space to the outside after passing through the first exhaust unit 410 A having the second heat exchanger 12 .
  • the second return air flow path P 404 exhausts air (return air) taken in from the ventilation port 91 B of the indoor space to the outside after passing through the second exhaust unit 410 B having the second heat exchanger 12 .
  • the refrigerant circuits F 401 , F 402 , F 403 , and F 404 are circuits that connect the compressor unit 450 , the first heat exchanger 22 of the first air supply unit 420 A and the second air supply unit 420 B, and the second heat exchanger 12 of the first exhaust unit 410 and the second exhaust unit 410 B by a refrigerant pipe, and allow the refrigerant to flow inside.
  • the control unit 452 of the compressor unit 450 , the control unit 423 A of the first air supply unit 420 A, the control unit 423 B of the second air supply unit 420 B, the control unit 413 A of the first exhaust unit 410 A, and the control unit 413 B of the second exhaust unit 410 B are connected by a signal line S 401 indicated by a dotted line.
  • a signal line S 401 indicated by a dotted line.
  • the control unit 452 of the compressor unit 450 transmits the status of the ventilation apparatus 1 C received from the control unit 423 A, the control unit 423 B, the control unit 413 A, and the control unit 413 B to the upper-level control device 400 . Accordingly, the upper-level control device 400 can implement control according to the status of the ventilation apparatus 1 C.
  • the first air supply unit 420 A is provided with the fan 21 , the first heat exchanger 22 , the control unit 423 A, and the temperature detecting unit 24 , takes in outside air (OA), and supplies air (SA) from the ventilation port 92 A to the living room space R 11 .
  • the second air supply unit 420 B is provided with the fan 21 , the first heat exchanger 22 , the control unit 423 B, and the temperature detecting unit 24 , takes in outside air (OA), and supplies air (SA) from the ventilation port 92 B to the living room space R 11 .
  • the control unit 423 A and the control unit 423 B control the configuration in each air supply unit. Further, the control unit 423 A and the control unit 423 B transmit the detection result by the temperature detecting unit 24 or the like in each air supply unit to the control unit 452 of the compressor unit 450 .
  • the control unit 452 of the compressor unit 450 recognizes the current status from the detection result and transmits the recognition result to the upper-level control device 400 .
  • the upper-level control device 400 can recognize the status of the first air supply unit 420 A and the second air supply unit 420 B.
  • the first exhaust unit 410 A is provided with the fan 11 (an example of a second ventilation device), the second heat exchanger 12 , a control unit 413 A, and the temperature detecting unit 14 , and takes in return air (RA) from a ventilation port 91 B of the living room space R 11 and exhausts (EA) the air to the outside.
  • the fan 11 an example of a second ventilation device
  • the second heat exchanger 12 takes in return air (RA) from a ventilation port 91 B of the living room space R 11 and exhausts (EA) the air to the outside.
  • the second exhaust unit 410 B is provided with the fan 11 (an example of a second ventilation device), the second heat exchanger 12 , a control unit 413 B, and the temperature detecting unit 14 , and takes in return air (RA) from a ventilation port 91 A of the living room space R 11 and exhausts (EA) the air to the outside.
  • the control unit 413 A and the control unit 413 B control the configuration in each exhaust unit. Further, the control unit 413 A and the control unit 413 B transmit the detection result by the temperature detecting unit 14 or the like in each exhaust unit to the control unit 452 of the compressor unit 450 .
  • the control unit 452 of the compressor unit 450 recognizes the current status from the detection result and transmits the recognition result to the upper-level control device 400 .
  • the upper-level control device 400 can recognize the status of the first exhaust unit 410 A and the second exhaust unit 410 B.
  • the upper-level control device 400 performs various kinds of control to coordinate the operation of the ventilation apparatus 1 C with the operation of the air conditioner 2 C.
  • the upper-level control device 400 receives the status of the air conditioner 2 C from the control unit 471 of the outdoor unit 470 and receives the status of the ventilation apparatus 1 C from the control unit 452 of the compressor unit 450 .
  • the upper-level control device 400 performs various kinds of control according to the status of the air conditioner 2 C and the status of the ventilation apparatus 1 C.
  • the upper-level control device 400 when the upper-level control device 400 recognizes that the air conditioner 2 C is performing a defrosting operation based on the information received from the control unit 471 of the outdoor unit 470 , the upper-level control device 400 performs control to improve the heating performance of the ventilation apparatus 1 C.
  • the air conditioner 2 C when the air conditioner 2 C performs a defrosting operation, the air conditioner 2 C does not function as a heater, and, therefore, the temperature in the living room space R 11 may decrease.
  • the air supply temperature of the first air supply unit 420 A and the second air supply unit 420 B is increased to compensate for the decrease in the function of the air conditioner 2 C when the air conditioner 2 C performs a defrosting operation, the temperature of the refrigerant flowing to the second heat exchanger 12 of the first exhaust unit 410 A and the second exhaust unit 410 B connected by the refrigerant circuits F 401 , F 402 , F 403 , and F 404 decreases. In this case, the possibility of frosting in the second heat exchanger 12 of the first exhaust unit 410 A and the second exhaust unit 410 B is increased.
  • the upper-level control device 400 recognizes that the air conditioner 2 C is performing a defrosting operation, the upper-level control device 400 increases the air volume of the air supply and exhaust air of the ventilation apparatus 1 C, thereby improving the heating performance and preventing a decrease in temperature in the living room space R 11 .
  • FIG. 7 is a sequence diagram illustrating the flow of processing performed between the upper-level control device 400 , the ventilation apparatus 1 C, and the air conditioner 2 C when the defrosting operation of the air conditioner 2 C according to the present embodiment is started.
  • the control unit 471 in the outdoor unit 470 of the air conditioner 2 C transmits a signal indicating that the defrosting operation is to be performed to the upper-level control device 400 (S 1701 ).
  • the upper-level control device 400 determines that the air volume of the ventilation apparatus 1 C is to be controlled to rise in order to compensate for the decrease of function caused by the defrosting operation (S 1702 ).
  • the upper-level control device 400 transmits a control signal to instruct an increase in air volume of the exhaust unit group (the first exhaust unit 410 A and the second exhaust unit 410 B) to the control unit 452 of the compressor unit 450 (S 1703 ).
  • control unit 452 of the compressor unit 450 transmits a control signal to instruct an increase in air volume to each of the control units 413 A and 413 B of the exhaust unit group (the first exhaust unit 410 A and the second exhaust unit 410 B) (S 1704 ).
  • control units 413 A and 413 B of the exhaust unit group control the fan 11 (an example of the second ventilation device) to increase the air volume flowing to the second heat exchanger 12 (increase in air volume) as compared with before the air conditioner 2 C performs defrosting operation (S 1705 ).
  • the upper-level control device 400 transmits a control signal to instruct the air volume increase of the air supply unit group (the first air supply unit 420 A and the second air supply unit 420 B), to the control unit 452 of the compressor unit 450 (S 1706 ).
  • the control unit 452 of the compressor unit 450 transmits a control signal to instruct the air volume increase to the control units 423 A and 423 B of the air supply unit group (the first air supply unit 420 A and the second air supply unit 420 B) (S 1707 ).
  • control units 423 A and 423 B of the air supply unit group control the fan 21 (an example of the first ventilation device) to increase the air volume flowing to the first heat exchanger 22 (air volume increase) compared with before the air conditioner 2 C performs defrosting operation (S 1708 ).
  • the heating performance of the ventilation apparatus 1 C is increased by increasing the air supply/exhaust volume without increasing the air supply temperature of the ventilation apparatus 1 C, thereby preventing a decrease in the room temperature of the living room space R 11 .
  • the possibility of frosting in the second heat exchanger 12 due to a decrease in the evaporation temperature can be reduced by preventing an increase in the air supply temperature of the ventilation apparatus 1 C.
  • the upper-level control device 400 can reduce the possibility of frosting in the second heat exchanger 12 , thereby increasing the heating performance and preventing a decrease in the room temperature, by increasing the air supply/exhaust volume of the ventilation apparatus 1 C in order to compensate for the decrease in performance caused by the frosting operation of the air conditioner 2 C.
  • the upper-level control device 400 according to the present embodiment can perform various kinds of control other than the above-mentioned cooperative control.
  • the upper-level control device 400 may determine whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied, when the temperature of the outside air is received from the control unit 413 A or the control unit 413 B of the exhaust unit group through the control unit 452 of the compressor unit 450 and satisfies a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 . Then, when the upper-level control device 400 determines that the predetermined reference is satisfied, the upper-level control device 400 may perform control to prevent frosting in the second heat exchanger 12 . As a control for preventing frosting in the second heat exchanger 12 , for example, the upper-level control device 400 may transmit a control signal for increasing the current set temperature of the heater to the control unit 471 of the outdoor unit 470 .
  • the configuration of the upper-level control device 400 illustrated in the present embodiment may also be included as a configuration of the ventilation apparatus. That is, the processing performed by the upper-level control device 400 may be a function of the ventilation apparatus. The same shall apply to the following embodiments.
  • the upper-level control device 400 makes an adjustment so as not to implement control for simultaneously preventing frosting in the second heat exchangers 12 of the plurality of exhaust units 410 .
  • the control of preventing frosting in the ventilation apparatus 1 C controls to increase the air volume flowing to the second heat exchangers 12 .
  • the control to increase the air volume flowing to the second heat exchangers 12 is simultaneously performed by a plurality of exhaust units 410 A and 410 B, the pressure in the living room space R 11 may become negative pressure.
  • the defrosting control is performed by increasing the air volume in one of the plurality of exhaust units 410 A and 410 B, and the air volume is decreased in the other one of the plurality of exhaust units 410 A and 410 B. That is, in the present embodiment, the defrosting control operation is performed preferentially in one of the plurality of exhaust units 410 A and 410 B. Furthermore, the upper-level control device 400 prevents the negative pressure of the living room space R 11 by adjusting to maintain the total air volume to be discharged.
  • FIG. 8 is a sequence diagram illustrating the flow of processing performed between the upper-level control device 400 , the compressor unit 450 , and the exhaust unit group when there is a possibility of frosting in each of the exhaust units in the exhaust unit group according to the present embodiment.
  • control unit 413 A of the first exhaust unit 410 A acquires the temperature of the outside air from the temperature detecting unit 14 (S 1801 ).
  • control unit 413 A reports the detected temperature of the outside air to the control unit 452 of the compressor unit 450 (S 1802 ).
  • the control unit 413 B of the second exhaust unit 410 B acquires the temperature of the outside air from the temperature detecting unit 14 (S 1811 ).
  • the control unit 413 B reports the detected temperature of the outside air to the control unit 452 of the compressor unit 450 (S 1812 ).
  • the control unit 452 of the compressor unit 450 determines, based on the detected outside air temperatures received from the control unit 413 A of the first exhaust unit 410 A and the control unit 413 B of the second exhaust unit 410 B, whether the second heat exchanger 12 of the first exhaust unit 410 A and the second exhaust unit 410 B satisfies a predetermined reference indicating the possibility of frosting (S 1821 ). In the example illustrated in FIG. 8 , it is determined that each of the second heat exchangers 12 of the first exhaust unit 410 A and the second exhaust unit 410 B satisfies the predetermined reference.
  • the predetermined reference is the same as in the above-described embodiment, and, therefore, the description thereof will be omitted.
  • the control unit 452 of the compressor unit 450 reports, to the upper-level control device 400 , the determination result indicating the possibility of frosting (S 1822 ).
  • the upper-level control device 400 determines the order in which frost prevention is controlled for the first exhaust unit 410 A and the second exhaust unit 410 B based on the received determination result (S 1831 ). Any method may be used to determine the order. For example, the frost prevention may be controlled so that the frost prevention is carried out first when there is a high probability of frosting, or the order may be determined according to the priority order previously assigned to the first exhaust unit 410 A and the second exhaust unit 410 B. The example illustrated in FIG. 8 is an example in which it has been determined to prevent frosting in the order of the first exhaust unit 410 A and the second exhaust unit 410 B.
  • the upper-level control device 400 transmits a signal indicating an instruction to increase the air volume of the first exhaust unit 410 A to the control unit 452 of the compressor unit 450 (S 1832 ).
  • the control unit 452 of the compressor unit 450 transmits a signal indicating an instruction to increase the air volume to the control unit 413 A of the first exhaust unit 410 A (S 1823 ).
  • control unit 413 A of the first exhaust unit 410 A controls the fan 11 to increase the air volume flowing to the second heat exchanger 12 (increase the air volume) compared with before the temperature detection at S 1801 (S 1803 ).
  • the upper-level control unit 400 After increasing the air volume flowing to the second heat exchanger 12 by the control described above, the upper-level control unit 400 transmits a signal indicating an instruction to decrease the air volume of the second exhaust unit 410 B to the control unit 452 of the compressor unit 450 after a predetermined time (a predetermined time for preventing frosting) has elapsed (S 1833 ).
  • control unit 452 of the compressor unit 450 transmits a signal indicating an instruction of air volume reduction to the control unit 413 B of the second exhaust unit 410 B (S 1824 ).
  • control unit 413 B of the second exhaust unit 410 B controls the fan 11 to reduce the air volume flowing to the second heat exchanger 12 (air volume reduction) compared with before temperature detection at S 1811 (S 1813 ).
  • the air volume of the first exhaust unit 410 A is increased and the air volume of the second exhaust unit 410 B is decreased to maintain the total air volume discharged. Thereafter, the upper-level control device 400 switches the exhaust unit for which frosting prevention is to be performed.
  • the upper-level control device 400 transmits a signal indicating an instruction for reducing the air volume of the first exhaust unit 410 A to the control unit 452 of the compressor unit 450 (S 1834 ).
  • the control unit 452 of the compressor unit 450 transmits a signal indicating an instruction for reducing the air volume to the control unit 413 A of the first exhaust unit 410 A (S 1825 ).
  • control unit 413 A of the first exhaust unit 410 A controls the fan 11 to reduce the air volume flowing to the second heat exchanger 12 (air volume reduction) as compared with before temperature detection was performed in S 1801 (S 1804 ).
  • the upper-level control device 400 transmits a signal indicating an instruction to increase the air volume of the second exhaust unit 410 B to the control unit 452 of the compressor unit 450 (S 1835 ).
  • the control unit 452 of the compressor unit 450 transmits a signal indicating an instruction to increase the air volume to the control unit 413 B of the second exhaust unit 410 B (S 1826 ).
  • control unit 413 B of the second exhaust unit 410 B controls the fan 11 to increase the air volume flowing to the second heat exchanger 12 (increase the air volume) compared with before the temperature detection at S 1811 (S 1814 ).
  • control unit 452 of the compressor unit 450 and the upper-level control device 400 control the fan 11 associated with any one of the plurality of second heat exchangers 12 to increase the air volume flowing to the second heat exchanger 12 compared with before the predetermined reference is satisfied when it is determined that the predetermined reference has been satisfied while the plurality of second heat exchangers 12 are functioning as evaporators. Accordingly, the amount of (warm) air flowing into any one of the second heat exchangers 12 increases, and, therefore, frosting can be prevented.
  • the upper-level control unit 400 controls the fan 11 associated with one of the plurality of the second heat exchangers 12 to increase the air volume
  • the upper-level control unit 400 controls the fan 11 associated with the other one of the plurality of the second heat exchangers 12 to decrease the air volume flowing to the second heat exchanger 12 compared to before the predetermined reference is satisfied. Accordingly, the air volume discharged from the group of a plurality of exhaust unit can be maintained, thereby avoiding a situation where the pressure in the living room space R 11 becomes negative pressure.
  • the fourth embodiment an example of making an adjustment to maintain the air volume discharged from a group of a plurality of exhaust units when controlling frosting has been described.
  • the method of avoiding negative pressure is not limited to a method of making an adjustment to maintain the air volume discharged from a group of a plurality of exhaust units.
  • the fifth embodiment a case in which the air volume taken in from the outside by the air supply unit group is increased when the air volume exhausted from the exhaust unit group is increased will be described.
  • the configuration of the present embodiment is similar to that of the fourth embodiment.
  • control unit 452 of the compressor unit 450 of the present embodiment determines whether the second heat exchanger 12 of the first exhaust unit 410 A and the second exhaust unit 410 B satisfies the predetermined reference indicating the possibility of frosting based on the received outside air temperature.
  • the upper-level control device 400 instructs the exhaust unit to increase the air volume.
  • the method of the instruction is the same as that of the fourth embodiment, and the description thereof is omitted.
  • the upper-level control device 400 determines that each of the first exhaust unit 410 A and the second exhaust unit 410 B satisfies the predetermined reference, the upper-level control device 400 determines the order in which frost prevention is to be performed for the first exhaust unit 410 A and the second exhaust unit 410 B. The upper-level control device 400 then instructs each of the first exhaust unit 410 A and the second exhaust unit 410 B to increase the air volume according to the order.
  • the upper-level control device 400 instructs one or more of the first air supply unit 420 A and the second air supply unit 420 B to increase the air volume, instead of instructing the decrease of the air volume as described in the fourth embodiment.
  • the upper-level control device 400 gives an instruction to increase the air volume to one or more of the control unit 423 A of the first air supply unit 420 A and the control unit 423 B of the second air supply unit 420 B to increase the air volume through the control unit 452 of the compressor unit 450 .
  • the target for instructing the increase of the air volume may be any one of the first air supply unit 420 A and the second air supply unit 420 B, or may be each of the first air supply unit 420 A and the second air supply unit 420 B.
  • the upper-level control device 400 makes an adjustment such that the air volume discharged by the first exhaust unit 410 A and the second exhaust unit 410 B and the air volume taken in by the first air supply unit 420 A and the second air supply unit 420 B are the same.
  • the upper-level control device 400 controls the fan 21 included in the air supply unit group to increase the air volume flowing to the first heat exchanger 22 compared with before the predetermined reference is satisfied based on the increased air volume when the fan 11 associated with any one of the plurality of second heat exchangers 12 included in the exhaust unit group is controlled to increase the air volume flowing to the second heat exchanger 12 .
  • the air volume to be taken in and the air volume to be exhausted are substantially the same, and, therefore, it is possible to prevent the pressure in the living room space R 11 from becoming negative pressure.
  • the method for controlling frosting is not limited to the above-described embodiment, and other methods may be used. Therefore, in the sixth embodiment, an example will be described in which the operation of the compressor of the compressor unit is stopped, and the frosting control is performed by passing air through the second heat exchanger 12 .
  • the configuration of the present embodiment may be any configuration, and a configuration may have the upper-level control device 400 as illustrated in FIG. 6 of the third embodiment.
  • a configuration may have the upper-level control device 400 as illustrated in FIG. 6 of the third embodiment.
  • two exhaust units and two air supply units are provided, but one exhaust unit and one air supply unit may be provided.
  • the number of exhaust units and air supply units may be any number.
  • the control unit 413 A of the first exhaust unit 410 A and the control unit 413 B of the second exhaust unit 410 B obtain the surface temperature of the second heat exchanger 12 from the temperature detecting unit 14 .
  • the control unit 413 A and the control unit 413 B of the second exhaust unit 410 B transmit the detected surface temperature of the second heat exchanger 12 to the control unit 452 of the compressor unit 450 .
  • the control unit 452 of the compressor unit 450 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied.
  • the predetermined reference indicating the possibility of frosting in the second heat exchanger 12 may be, for example, a reference for determining whether the surface temperature of the second heat exchanger 12 is zero degrees or less.
  • the predetermined reference may be any reference indicating the possibility of frosting in the second heat exchanger 12 .
  • the predetermined reference may be a reference such as that of the above-described embodiment, for example, a reference based on the temperature or pressure of the refrigerant.
  • the control unit 452 of the compressor unit 450 reports, to the upper-level control unit 400 , a determination result indicating the possibility of frosting in the second heat exchanger 12 .
  • the upper-level control unit 400 transmits a control signal instructing to stop the compressor to the control unit 452 of the compressor unit 450 . Accordingly, the control unit 452 of the compressor unit 450 performs control to stop the compressor.
  • the upper-level control device 400 Based on the determination result, the upper-level control device 400 outputs a control signal so as to continue to control the fan 11 to pass the air to the second heat exchanger 12 , through the control unit 452 of the compressor unit 450 , to the control unit 413 A of the first exhaust unit 410 A and the control unit 413 B of the second exhaust unit 410 B. Further, the upper-level control device 400 may perform control of increasing the air volume of the fan 11 as in the fourth embodiment.
  • the temperature of the surface of the second heat exchanger 12 can be increased to prevent frosting in the second heat exchanger 12 .
  • the upper-level control device 400 controls one compressor unit 450 .
  • the number of compressor units controlled by the upper-level control device 400 is not limited to one. Therefore, in the seventh embodiment, an example in which the upper-level control device 400 controls three compressor units will be described.
  • FIG. 9 is a diagram illustrating an arrangement of a group of devices including the upper-level control device 500 according to the seventh embodiment.
  • the example illustrated in FIG. 9 includes at least living room spaces R 501 , R 502 , R 503 , lavatory rooms R 511 , R 512 , and a pipe shaft R 521 .
  • the lavatory rooms R 511 , R 512 are provided with ventilation ports 595 A, 595 B, respectively.
  • the air conditioner 2 D includes three outdoor units 571 , 572 , and 573 and eight air conditioning indoor units 581 , 582 , 583 , 584 , 585 , 586 , 587 , and 588 .
  • the three outdoor units 571 to 573 and the eight air conditioning indoor units 581 to 588 are connected by a connection pipe (not illustrated).
  • the three outdoor units 571 to 573 are connected to the upper-level control device 500 by a signal line.
  • the three outdoor units 571 to 573 can perform air conditioning control according to the control of the upper-level control device 500 .
  • the first ventilation apparatus 1 D_ 1 is a ventilation apparatus provided in the living room space R 501 and includes a first compressor unit 550 A, a first air supply unit 520 A, and a first exhaust unit 510 A.
  • the first air supply unit 520 A supplies air (SA) from the ventilation port 592 A.
  • the first exhaust unit 510 A returns air (RA) from the ventilation port 591 A.
  • the first compressor unit 550 A, the first air supply unit 520 A, and the first exhaust unit 510 A are connected by a connection pipe F 501 .
  • the connection pipe F 501 includes a plurality of refrigerant connection pipes. Thereby, the refrigerant can be circulated between the first compressor unit 550 A, the first air supply unit 520 A, and the first exhaust unit 510 A.
  • the first compressor unit 550 A, the first air supply unit 520 A, and the first exhaust unit 510 A are connected by a signal line (not illustrated). This enables transmission and reception of information between the units.
  • the configuration inside the first compressor unit 550 A, the first air supply unit 520 A, and the first exhaust unit 510 A is the same as that of the compressor unit 450 A, the first air supply unit 420 A, and the first exhaust unit 410 A illustrated in FIG. 6 , and the description thereof will be omitted.
  • the second ventilation apparatus 1 D 2 is a ventilation apparatus provided in the living room space R 502 and includes a second compressor unit 550 B, a second air supply unit 520 B, and a second exhaust unit 510 B.
  • the second air supply unit 520 B supplies air (SA) from the ventilation port 592 B.
  • the second exhaust unit 510 B returns air (RA) from the ventilation port 591 B.
  • the second compressor unit 550 B, the second air supply unit 520 B, and the second exhaust unit 510 B are connected by a connection pipe F 502 .
  • the connection pipe F 502 includes a plurality of refrigerant connection pipes. Thus, the refrigerant can be circulated between the second compressor unit 550 B, the second air supply unit 520 B, and the second exhaust unit 510 B.
  • the second compressor unit 550 B, the second air supply unit 520 B, and the second exhaust unit 510 B are connected by a signal line (not illustrated). This enables transmission and reception of information between the units.
  • the configuration inside the second compressor unit 550 B, the second air supply unit 520 B, and the second exhaust unit 510 B is the same as that of the compressor unit 450 A, the first air supply unit 420 A, and the first exhaust unit 410 A illustrated in FIG. 6 , and descriptions thereof will be omitted.
  • the third ventilation apparatus 1 D_ 3 is a ventilation apparatus provided in the living room space R 503 and includes a third compressor unit 550 C, a third air supply unit 520 C, and a third exhaust unit 510 C.
  • the third air supply unit 520 C supplies air (SA) from the ventilation port 592 C.
  • the third exhaust unit 510 C returns air (RA) from the ventilation port 591 C.
  • the third compressor unit 550 C, the third air supply unit 520 C, and the third exhaust unit 510 C are connected by a connection pipe F 503 .
  • the connection pipe F 503 includes a plurality of refrigerant connection pipes. Thus, the refrigerant can be circulated between the third compressor unit 550 C, the third air supply unit 520 C, and the third exhaust unit 510 C.
  • the third compressor unit 550 C, the third air supply unit 520 C, and the third exhaust unit 510 C are connected by a signal line (not illustrated). This enables transmission and reception of information between the units.
  • the configuration inside the third compressor unit 550 C, the third air supply unit 520 C, and the third exhaust unit 510 C is the same as that of the compressor unit 450 A, the first air supply unit 420 A, and the first exhaust unit 410 A illustrated in FIG. 6 , and the description thereof will be omitted.
  • the present embodiment includes a plurality of combinations of a compressor unit, an air supply unit, an exhaust unit, and a connection pipe.
  • the first compressor unit 550 A, the second compressor unit 550 B, and the third compressor unit 550 C are arranged on the pipe shaft R 521 .
  • the upper-level control device 500 is connected to the first compressor unit 550 A, the second compressor unit 550 B, and the third compressor unit 550 C by a signal line. Accordingly, the upper-level control device 500 can recognize the state of each apparatus of the first ventilation apparatus 1 D_ 1 to the third ventilation apparatus 1 D_ 3 and control each apparatus.
  • the control unit (not illustrated) of the first compressor unit 550 A to the third compressor unit 550 C receives the surface temperature of the second heat exchanger 12 from each of the first exhaust units 510 A to the third exhaust unit 510 C.
  • the control unit of the first compressor unit 550 A to the third compressor unit 550 C of the present embodiment determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the surface temperature of the second heat exchanger 12 .
  • the predetermined reference is the same as in the above-described embodiment, and, therefore, the description thereof will be omitted.
  • the control units of the first compressor unit 550 A to the third compressor unit 550 C report, to the upper-level control device 500 , the determination result indicating whether the predetermined reference is satisfied.
  • the upper-level control device 500 determines from the determination result that there are a plurality of compressor units (for example, the first compressor unit 550 A to the third compressor unit 550 C) connected to the second heat exchanger 12 satisfying a predetermined reference by a connection pipe, the upper-level control device 500 outputs a control signal for stopping the compressor to the plurality of compressor units (for example, the first compressor unit 550 A to the third compressor unit 550 C) in a predetermined order as a control for preventing frosting in the second heat exchanger 12 .
  • the predetermined order may be any order, such as an ascending order according to surface temperature, or may be based on a preset priority order of compressor units.
  • the upper-level control device 500 maintains control of the fan 11 corresponding to the second heat exchanger 12 that satisfies the predetermined reference to pass air from the living room spaces R 501 to R 503 to the second heat exchanger 12 . Accordingly, the temperature of the refrigerant flowing through the second heat exchanger 12 can be increased.
  • the frosting in the second heat exchanger 12 can be prevented by stopping the refrigerant flowing to the second heat exchanger 12 and maintaining the air flowing to the second heat exchanger 12 .
  • the upper-level control device 500 stops a plurality of compressor units in a predetermined order has been described.
  • the eighth embodiment an example in which a plurality of air supply units and a plurality of exhaust units are connected to one compressor will be described.
  • FIG. 10 is a diagram illustrating an arrangement of a group of devices including an upper-level control device 600 according to the eighth embodiment.
  • FIG. 10 configurations similar to those of the above-described embodiments are assigned the same reference numerals, and descriptions thereof will be omitted.
  • the compressor unit 650 is connected to the first air supply unit 520 A and the first exhaust unit 510 A through the connection pipe F 601 , connected to the second air supply unit 520 B and the second exhaust unit 510 B through the connection pipe F 602 , and connected to the third air supply unit 520 C and the third exhaust unit 510 C through the connection pipe F 603 . Accordingly, the refrigerant circulates through the units connected by the connection pipes F 601 , F 602 , and F 603 .
  • the compressor unit 650 , the first air supply unit 520 A to the third air supply unit 520 C, and the first exhaust unit 510 A to the third exhaust unit 510 C are connected by a signal line (not illustrated), and, therefore, information can be transmitted and received between the units.
  • the upper-level control device 600 and the compressor unit 650 are also connected by a signal line, and, therefore, information can be transmitted and received therebetween.
  • the first air supply unit 520 A, the second air supply unit 520 B, and the third air supply unit 520 C are provided with the electric valve 26 (an example of the first valve part) as illustrated in FIG. 5 .
  • the first exhaust unit 510 A, the second exhaust unit 510 B, and the third exhaust unit 510 C are provided with the electric valve 16 (an example of the first valve part) as illustrated in FIG. 5 .
  • the electric valve 16 functions as a valve to adjust the opening of the flow path to the second heat exchanger 12 (to adjust the pressure of the refrigerant).
  • the upper-level control device 600 can individually stop and control the inflow of refrigerant by controlling the electric valve 16 to be in a closed state.
  • the control unit (not illustrated) of the compressor unit 650 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the surface temperature of the second heat exchanger 12 .
  • the predetermined reference is the same as that of the above-described embodiment, and a description thereof is omitted.
  • the control unit 652 (not illustrated) of the compressor unit 650 reports, to the upper-level control device 600 , the determination result.
  • the upper-level control device 600 when the upper-level control device 600 recognizes, based on the determination result, that there are a plurality of second heat exchangers 12 that satisfy the predetermined reference, the upper-level control device 600 outputs, in a predetermined order, a control signal for closing the electric valve 16 to a plurality of exhaust units (for example, the first exhaust unit 510 A to the third exhaust unit 510 C) including the second heat exchanger 12 that satisfy the predetermined reference, as a control for preventing frosting in the second heat exchanger 12 .
  • the predetermined order may be any order, such as an ascending order according to surface temperature, or may be based on a preset priority order of compressor units.
  • the upper-level control device 500 also maintains control of the fan 11 corresponding to the second heat exchanger 12 that satisfies the predetermined reference, to pass air from the living room spaces R 501 to R 503 to the second heat exchanger 12 .
  • the refrigerant flowing to the second heat exchanger 12 is stopped and the air flowing to the second heat exchanger 12 is maintained, so that frosting can be prevented.
  • a method other than the above-described embodiment may be used to prevent frosting in the second heat exchanger 12 . Therefore, in the ninth embodiment, an example of performing adjustment between the air supply amount and the exhaust amount will be described.
  • the configuration of the ninth embodiment may be any configuration of the above-described embodiment, for example, the configuration illustrated in FIG. 6 . Therefore, in the present embodiment, a case with the configuration illustrated in FIG. 6 will be described.
  • the control unit 452 of the compressor unit 450 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the surface temperature of the second heat exchanger 12 .
  • the predetermined reference is the same as that of the above-described embodiment, and a description thereof is omitted.
  • the control unit 452 of the compressor unit 450 reports, to the upper-level control device 400 , the determination result.
  • the upper-level control device 400 recognizes that there are a plurality of second heat exchangers 12 that meet the predetermined reference, the upper-level control device 400 outputs a control signal for controlling the fans 11 and 21 such that the total air volume supplied by the fan 11 (an example of the second ventilation device) of the exhaust unit group (for example, the first exhaust unit 410 A and the second exhaust unit 410 B) is greater than the total air volume exhausted by the fan 21 (an example of the first ventilation device) of the air supply unit group (for example, the first supply air unit 420 A and the second supply air unit 420 B), as a control for preventing frosting in the second heat exchanger 12 .
  • frosting prevention can be implemented by preventing the condensing ability of the air supply unit group and raising the evaporation temperature of the second heat exchanger 12 of the exhaust unit group, by making the air volume of the exhausted air larger than the air volume of the supplied air.
  • a method other than the above-described embodiment may be used to prevent frosting in the second heat exchanger 12 . Therefore, in the tenth embodiment, an example of adjusting the temperature of air after passing through the first heat exchanger 22 will be described.
  • the configuration of the tenth embodiment may be any configuration of the above-described embodiment, and may be, for example, the configuration illustrated in FIG. 6 . Therefore, in the present embodiment, a case with the configuration illustrated in FIG. 6 will be described.
  • the control unit 452 of the compressor unit 450 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the surface temperature of the second heat exchanger 12 while the second heat exchanger 12 functions as an evaporator.
  • the predetermined reference is the same as that of the above embodiment, and, therefore, the description thereof is omitted.
  • the control unit 452 of the compressor unit 450 reports, to the upper-level control device 400 , the determination result.
  • the upper-level control device 400 when the upper-level control device 400 recognizes that there are a plurality of second heat exchangers 12 that satisfy a predetermined reference, the upper-level control device 400 outputs a control signal that causes the temperature of the air after passing through the first heat exchanger 22 to become lower than the temperature set to the air conditioner 2 C provided in the living room space R 11 , to the first heat exchanger of the air supply unit group (for example, the first supply air unit 420 A and the second supply air unit 420 B), as the control for preventing frosting in the second heat exchangers 12 .
  • the temperature set in the air conditioner 2 C is acquired from the control unit 471 of the outdoor unit 470 .
  • the temperature of the air after passing through the first heat exchanger 22 of the air supply unit group becomes lower than the indoor set temperature. Accordingly, the compressor of the compressor unit 450 is operated at a low rotational speed, and, therefore, the decrease in the evaporation temperature of the second heat exchanger 12 can be prevented.
  • a method other than the above-described embodiment may be used to prevent frosting in the second heat exchanger 12 . Therefore, in the eleventh embodiment, an example of adjusting the pressure of the refrigerant by an electric valve (an example of the third valve part) provided downstream of the exhaust unit will be described.
  • the configuration of the eleventh embodiment may be any configuration of the above-described embodiment, for example, the configuration illustrated in FIG. 6 . Therefore, in the present embodiment, a case with the configuration illustrated in FIG. 6 will be described.
  • FIG. 11 is a diagram illustrating a refrigerant circuit according to the eleventh embodiment.
  • a flow of refrigerant when the second heat exchanger 12 of the exhaust units 410 A and 410 B functions as an evaporator is illustrated.
  • the same reference numerals are assigned to the configuration similar to that of the above-described embodiment, and the description thereof is omitted.
  • the control unit 452 of the compressor unit 450 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the surface temperature of the second heat exchanger 12 while the second heat exchanger 12 functions as an evaporator. Note that the predetermined reference is the same as in the above-described embodiment, and the description thereof is omitted.
  • the control unit 452 of the compressor unit 450 reports, to the upper-level control device 400 , the determination result.
  • the upper-level control device 400 when the upper-level control device 400 recognizes the existence of the second heat exchanger 12 that satisfies the predetermined reference, the upper-level control device 400 outputs a control signal to throttle the electric valve (the electric valve 601 or the electric valve 602 ) compared with before the predetermined reference is satisfied, to the control unit (the control unit 413 A or the control unit 413 B) of the exhaust unit (for example, the first exhaust unit 410 A or the second exhaust unit 410 B) that includes the second heat exchanger 12 .
  • the pressure of refrigerant flowing through the second heat exchanger 12 that exists upstream from the expansion valve (the expansion valve 161 or the expansion valve 162 ) can be increased. Accordingly, the evaporation temperature of refrigerant flowing through the second heat exchanger 12 can be increased. Therefore, frosting in the second heat exchanger 12 can be prevented.
  • bypass flow path F 6 is illustrated in FIG. 11 , in the present embodiment, the bypass flow path F 6 may or may not be combined with the control using the bypass flow path F 6 illustrated in the above embodiment.
  • an example of preventing frosting using a method of throttling the electric valves 601 and 602 downstream from the second heat exchanger 12 has been described.
  • a case in which an exhaust unit 730 of an outdoor unit is further provided in a refrigerant circuit to control the exhaust unit 730 will be described.
  • FIG. 12 is a diagram illustrating a refrigerant circuit according to a modified example of the eleventh embodiment.
  • an exhaust unit 730 is further provided in the refrigerant circuit illustrated in FIG. 11 . Except for the exhaust unit 730 , the configuration is similar to that of the eleventh embodiment, and descriptions thereof will be omitted.
  • the exhaust unit 730 includes the fan 11 , a third heat exchanger 732 , a control unit 733 , the temperature detecting unit 14 , a driving motor 15 , and an electric valve 16 .
  • the exhaust unit 730 functions as an outdoor unit. That is, the exhaust unit 730 is provided on a flow path (an example of the fourth air flow path) for exhausting, to the outdoors, the air in which heat exchange has been performed between the outdoor air and a refrigerant flowing through the third heat exchanger 732 .
  • the control unit 452 of the compressor unit 450 determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the surface temperature of the second heat exchanger 12 .
  • the predetermined reference is the same as that of the above-described embodiment, and a description thereof is omitted.
  • the control unit 452 of the compressor unit 450 reports, to the upper-level control device 400 , the determination result.
  • the upper-level control device 400 when the upper-level control device 400 recognizes that there is the second heat exchanger 12 that satisfies a predetermined reference, the upper-level control device 400 performs the same control as in the eleventh embodiment, and performs control such that the third heat exchanger 732 of the exhaust unit 730 performs heat exchange at a lower evaporation temperature than the second heat exchanger 12 .
  • the flow of refrigerant through the third heat exchanger 732 of the exhaust unit 730 is connected to the flow of refrigerant through the second heat exchanger 12 of the exhaust units 410 A and 410 B. Therefore, the evaporation temperature of the second heat exchanger 12 can be increased by lowering the evaporation temperature of the third heat exchanger 732 . Thus, frosting in the second heat exchanger 12 can be prevented.
  • the method of sharing the processing between the control unit 452 of the compressor unit 450 and the upper-level control device 500 has been described, the method is not limited to the method of sharing the processing between the control unit 452 of the compressor unit 450 and the upper-level control device 500 , and the determination and control of other devices may be performed by either of the control unit 452 of the compressor unit 450 or the upper-level control device 500 . Furthermore, the method is not limited to processing by the control unit 452 of the compressor unit 450 and the upper-level control device 500 , but it is possible to perform processing of the above-described embodiment on a server for centralized management or in the cloud.
  • a method other than the above-described embodiment may be used to prevent frosting in the second heat exchanger 12 . Therefore, in the twelfth embodiment, an example of switching the control in consideration of power consumption will be described.
  • the control unit 452 of the compressor unit 450 of the present embodiment determines whether a predetermined reference indicating the possibility of frosting in the second heat exchanger 12 is satisfied based on the surface temperature of the second heat exchanger 12 .
  • the control unit 452 of the compressor unit 450 reports, to the upper-level control device 400 , the determination result.
  • the predetermined reference may be based on the temperature of the refrigerant or the pressure of the refrigerant flowing through the second heat exchanger 12 , or the predetermined reference may be the same as in the above-described embodiment.
  • FIG. 13 is a flowchart illustrating the processing procedure of the upper-level control device 400 according to the present embodiment.
  • control unit 452 of the compressor unit 450 receives the detection result of the second heat exchanger 12 from each exhaust unit in the exhaust unit group (S 2101 ).
  • the detection result is the temperature or the pressure of the refrigerant flowing through the second heat exchanger 12 .
  • the control unit 452 of the compressor unit 450 determines whether the predetermined reference is satisfied based on the detection result (S 2102 ). For example, as the predetermined reference indicating the possibility of frosting in the second heat exchanger 12 , the reference is whether the detected (evaporation) temperature of the refrigerant is lower than a predetermined temperature t, or whether the detected (evaporation) pressure of the refrigerant is lower than a predetermined pressure p. If it is determined that the predetermined reference is not satisfied (NO in S 2102 ), the process is performed again from S 2101 .
  • the predetermined temperature t and pressure p are values determined according to the embodiment as the reference of whether there is a possibility of frosting, and explanations thereof are omitted. It is considered that the determination is made every predetermined time (for example, x minutes).
  • control unit 452 of the compressor unit 450 determines that the predetermined reference is satisfied (YES in S 2102 )
  • the control unit 452 reports, to the upper-level control device 400 , the determination result.
  • the upper-level control device 400 controls the temperature of the refrigerant flowing through the second heat exchanger 12 to prevent frosting, and calculates the power consumption E 1 for maintaining the current temperature of the living room space R 11 and the like (S 2103 ).
  • the upper-level control device 400 performs a defrosting operation, and calculates the power consumption E 2 for maintaining the current temperature of the living room space R 11 and the like (S 2104 ).
  • the upper-level control device 500 stores in advance the power consumption calculation model set in advance for calculating the power consumption E 1 and the power consumption E 2 .
  • the upper-level control device 500 inputs input information (for example, room/outside air temperature, air volume of fans 11 and 21 , pressure of refrigerant, rotational speed of the compressor, etc.: an example of the status of the living room space) into the power consumption calculation model to calculate power consumption.
  • input information for example, room/outside air temperature, air volume of fans 11 and 21 , pressure of refrigerant, rotational speed of the compressor, etc.: an example of the status of the living room space
  • the power consumption calculation method is not limited to the method of using the calculation model, and other methods may be used.
  • the upper-level control device 400 determines whether the power consumption E 1 is lower than the power consumption E 2 (S 2105 ). When the upper-level control device 400 determines that the power consumption E 1 is lower than the power consumption E 2 (YES in S 2105 ), the upper-level control device 400 outputs a control signal to prevent frosting to the exhaust unit group (S 2106 ). Note that the method for preventing frosting may be the process illustrated in the above-described embodiment, and the description thereof will be omitted. Thereafter, the upper-level control device 500 performs the process from step S 2101 again.
  • the upper-level control device 400 outputs a control signal to the exhaust unit group for allowing frosting, and executing the defrosting operation after determining that frosting has occurred according to the detection result (S 2107 ).
  • the defrosting operation method may be any method, regardless of whether the method is known, and the description thereof will be omitted.
  • the upper-level control device 400 receives the detection result of the second heat exchanger 12 from each exhaust unit in the exhaust unit group via the control unit 452 of the compressor unit 450 (S 2108 ).
  • the detection result is the temperature or the pressure of the refrigerant flowing through the second heat exchanger 12 .
  • the upper-level control device 400 determines whether a defrosting end reference is satisfied (S 2109 ). For example, as the defrosting end reference of the second heat exchanger 12 , the reference is whether the detected (evaporation) temperature of the refrigerant is higher than a predetermined temperature t+ ⁇ , or whether the detected (evaporation) pressure of the refrigerant is lower than a predetermined pressure p+ ⁇ . As for the defrosting end reference, any reference may be used as long as the completion of the defrosting can be determined by the reference.
  • the variables a and B are positive numbers determined according to the embodiment, and descriptions thereof are omitted. It is determined whether the defrosting end reference is satisfied (S 2109 ). If it is determined that the defrosting end reference is not satisfied (NO in S 2109 ), the process is performed again from S 2108 . It is considered that the determination is made every predetermined time (for example, y minutes).
  • the upper-level control device 400 determines that the defrosting end reference is satisfied based on the detection result (YES in S 2109 ), the upper-level control device outputs a control signal for ending the defrosting operation to the exhaust unit group (S 2110 ) and ends the process. Thereafter, the upper-level control device 400 performs processing from step S 2101 again.
  • the upper-level control device 400 can perform control to cause the temperature of the second heat exchanger 12 to become a temperature at which frosting in the second heat exchanger 12 does not occur when it is determined that the predetermined reference is satisfied, by controlling the temperature of the refrigerant flowing to the second heat exchanger 12 such that the temperature of the second heat exchanger 12 becomes a temperature at which frosting in the second heat exchanger 12 does not occur or by controlling the operation to defrost the second heat exchanger 12 after frosting occurs on the second heat exchanger 12 , based on the power consumption required when the temperature of the refrigerant flowing through the second heat exchanger 12 is controlled or the power consumption required for the operation for defrosting the second heat exchanger 12 after frosting occurs on the second heat exchanger 12 .
  • power consumption can be prevented when preventing frosting in the exhaust unit group or when performing defrosting.
  • the air supply unit is a casing (an example of the first casing) that houses at least a part of the first heat exchanger 22 and the air flow path (an example of the first air flow path)
  • the exhaust unit is a casing (an example of the second casing) that houses at least a part of the second heat exchanger 12 and the air flow path (an example of the second air flow path), so that the units are separated by casings.
  • the exhaust unit and the air supply unit can be arranged at positions away from each other.
  • the degree of freedom of arrangement of the ventilation apparatus capable of recovering heat can be increased compared with the conventional technology.
  • the above-described embodiments and modified examples are not limited to the example where the casings of the air supply unit and the exhaust unit are separated, and the air supply unit and the exhaust unit may be integrated. That is, when the first heat exchanger 22 and the second heat exchanger 12 are connected by a refrigerant circuit, and the fan 21 corresponding to the first heat exchanger 22 and the fan corresponding to the second heat exchanger 12 are provided, the air volume adjustment and the temperature adjustment of the refrigerant as described in the above-described embodiments and modified examples may be applied. As described above, the method illustrated in the above-described embodiments and modified examples may be applied when the air supply unit and the exhaust unit are integrated.
  • the air conditioning system by starting the compressor and using the first heat exchanger of the air supply unit as the condenser and using the second heat exchanger of the exhaust unit as the evaporator, the heat of the exhaust air (indoor air) can be recovered to the refrigerant in the refrigerant circuit while the indoor air can be ventilated.
  • the heat of the exhaust air indoor air
  • frosting occurs in the second heat exchanger when the temperature of the exhaust air (indoor air) is lower than a predetermined value, and the low pressure of the refrigerant circuit is lowered. In this case, it becomes difficult to cause the started compressor to operate continuously.
  • a ventilation system with a refrigerant circuit enables reliable continuous operation of the compressor when a heat exchanger is used as an evaporator.
  • FIG. 14 is a schematic configuration diagram of the ventilation system of the present disclosure.
  • FIG. 15 is a control block diagram of the ventilation system of the present disclosure.
  • a ventilation system 1 E according to the thirteenth embodiment is referred to as the thirteenth ventilation system 1 F
  • a ventilation system 1 E according to the fourteenth embodiment is referred to as the fourteenth ventilation system 1 G
  • a ventilation system 1 E according to the fifteenth embodiment is referred to as the fifteenth ventilation system 1 H
  • a ventilation system 1 E according to the sixteenth embodiment is referred to as the sixteenth ventilation system 1 I
  • a ventilation system 1 E according to the seventeenth embodiment see FIG.
  • ventilation system 1 J a ventilation system 1 E according to the eighteenth embodiment (see FIG. 23 ) is referred to as the eighteenth ventilation system 1 K.
  • ventilation system 1 E the common configuration among the thirteenth to eighteenth ventilation systems 1 F to 1 K is described.
  • the ventilation system 1 E illustrated in FIG. 14 is an embodiment of the ventilation apparatus of the present disclosure and is installed in a building, such as a factory, to implement ventilation of a target space in the building.
  • the ventilation system 1 E includes an air supply unit 1020 , an exhaust unit 1030 , a compressor unit 1040 , and a refrigerant circuit 1050 .
  • the air supply unit 1020 includes a first casing 1021 , an air supply fan 1022 , and a first heat exchanger 1023 .
  • the first casing 1021 of the present embodiment is a cube-shaped box body composed of panel members having thermal insulation properties, and an intake port 1024 and a blowout port 1025 are formed on the side surfaces.
  • the air supply fan 1022 and the first heat exchanger 1023 are arranged in the first casing 1021 .
  • the air supply unit 1020 takes the air (outside air OA) of the outdoor (hereinafter referred to as outdoors 1000 S 2 , see FIGS.
  • the ventilation system 1 E has an air supply flow path P 1001 (an example of the first air flow path) for supplying the taken in outside air OA from the blowout port 1025 to the indoors 1000 S 1 through the first casing 1021 .
  • the first heat exchanger 1023 configures a refrigerant circuit 1050 which will be described later.
  • the first heat exchanger 1023 is a crossfin tube type or a microchannel type heat exchanger, and is used to cause the refrigerant flowing in the first heat exchanger 1023 to perform heat exchange with the air (outside air OA) of the outdoors 1000 S 2 .
  • the air supply unit 1020 includes an air supply temperature sensor 1026 and an outside air temperature sensor 1027 .
  • the air supply temperature sensor 1026 is arranged in the air flow that has passed through the first heat exchanger 1023 in the first casing 1021 , and detects the temperature T 1 (hereinafter referred to as the blowout air temperature T 1 ) of the air supply SA.
  • the outside air temperature sensor 1027 is arranged in the air flow before passing through the first heat exchanger 1023 in the first casing 1021 , and detects the temperature T 2 (hereinafter referred to as the outside air temperature T 2 ) of the outside air OA.
  • the air supply unit 1020 includes a first heat exchange temperature sensor 1055 and a first refrigerant temperature sensor 1056 .
  • the first heat exchange temperature sensor 1055 detects the temperature Tb 1 of the first heat exchanger 1023 (that is, the refrigerant in the first heat exchanger 1023 ).
  • the first refrigerant temperature sensor 1056 detects the temperature Ta 2 of the refrigerant after passing through the first heat exchanger 1023 (outlet).
  • the first heat exchange temperature sensor 1055 may be a pressure sensor for detecting the pressure in the first heat exchanger 1023 , and in this case, the refrigerant temperature in the first heat exchanger 1023 is converted from the detected pressure value.
  • the exhaust unit 1030 includes a second casing 1031 , an exhaust fan 1032 , and a second heat exchanger 1033 .
  • the second casing 1031 of the present embodiment is a cube-shaped box body composed of panel members having thermal insulation properties, and an intake port 1034 and a blowout port 1035 are formed on the side surfaces.
  • the exhaust fan 1032 and the second heat exchanger 1033 are arranged in the second casing 1031 .
  • the exhaust unit 1030 takes the air (return air RA) of the indoors 1000 S 1 into the second casing 1031 , causes the taken in air to exchange heat with the refrigerant in the second heat exchanger 1033 , and then releases the air (exhaust air EA) from the blowout port 1035 to the outdoors 1000 S 2 .
  • the ventilation system 1 E has a return air flow path P 1002 (an example of the second air flow path) for releasing the air (return air RA) of the indoors 1000 S 1 from the blowout port 1035 to the outdoors 1000 S 2 through the second casing 1031 .
  • the second heat exchanger 1033 constitutes a refrigerant circuit 1050 which will be described later.
  • the second heat exchanger 1033 is a crossfin tube type or a microchannel type heat exchanger and is used for heat exchange of a refrigerant flowing in the second heat exchanger 1033 with air (return air RA) of the indoors 1000 S 1 .
  • the exhaust unit 1030 includes a return air temperature sensor 1036 .
  • the return air temperature sensor 1036 is arranged in the air flow before passing through the second heat exchanger 1033 in the second casing 1031 , and detects the temperature T 3 of the air flowing into the second heat exchanger 1033 .
  • this temperature T 3 is referred to as the intake air temperature T 3 .
  • the intake air temperature T 3 in the case where only the air taken in from the indoors 1000 S 1 passes through the second heat exchanger 1033 is the temperature of the air in the indoors 1000 S 1 .
  • the temperature in the indoors 1000 S 1 may be detected by a sensor (not illustrated) provided in the indoors 1000 S 1 .
  • the exhaust unit 1030 includes a second heat exchanger temperature sensor 1057 and a second refrigerant temperature sensor 1058 .
  • the second heat exchanger temperature sensor 1057 detects the temperature Tb 2 (that is, the refrigerant in the second heat exchanger 1033 ) of the second heat exchanger 1033 .
  • the second refrigerant temperature sensor 1058 detects the temperature Tb 3 of the refrigerant after passing through the second heat exchanger 1033 (outlet).
  • the second heat exchange temperature sensor 1057 may be a pressure sensor for detecting the pressure in the second heat exchanger 1033 , and in this case, the refrigerant temperature in the first heat exchanger 1023 is converted from the pressure detection value.
  • the compressor unit 1040 includes a third casing 1041 , a compressor 1042 , a four-way switching valve 1043 , and an expansion valve 1044 .
  • the compressor unit 1040 of the present embodiment includes a third casing 1041 , but the third casing 1041 may be omitted.
  • the compressor 1042 and the four-way switch valve 1043 are preferably housed in the first casing 1021 of the air supply unit 1020 or the second casing 1031 of the exhaust unit 1030 .
  • the ventilation system 1 E of the present embodiment houses the expansion valve 1044 in the compressor unit 1040
  • the expansion valve 1044 may be housed in the first casing 1021 of the air supply unit 1020 or the second casing 1031 of the exhaust unit 1030 .
  • the compressor unit 1040 includes a low pressure sensor 1052 , a discharge pressure sensor 1053 , and a discharge temperature sensor 1054 .
  • the low pressure sensor 1052 detects the pressure PL of the refrigerant taken into the compressor 1042 . In the following description, this pressure PL is also referred to as the low pressure PL.
  • the discharge pressure sensor 1053 detects the pressure PH of the refrigerant discharged from the compressor 1042 . In the following description, this pressure PH is also referred to as the high-pressure pressure PH.
  • the discharge temperature sensor 1054 detects the temperature Ta 1 of the refrigerant discharged from the compressor 1042 .
  • the compressor 1042 takes in the low pressure gaseous refrigerant and discharges the high-pressure gaseous refrigerant.
  • the compressor 1042 includes a motor that can adjust the operating speed by inverter control.
  • the compressor 1042 is a variable capacity type (variable performance type) that can change the capacity (performance) by inverter control of the motor.
  • the compressor 1042 may be a constant capacity type.
  • the compressor 1042 used in the ventilation system 1 E of the present disclosure may be configured by connecting two or more compressors in parallel.
  • the four-way switch valve 1043 inverts the flow of refrigerant in the refrigerant pipe and supplies refrigerant discharged from the compressor 1042 to one of the first heat exchanger 1023 and the second heat exchanger 1033 .
  • the ventilation system 1 E can switch between a cooling operation mode (hereinafter also referred to as the first operation mode M 1 ) for cooling the outside air OA and a heating operation mode (hereinafter also referred to as the second operation mode M 2 ) for heating the outside air OA.
  • the expansion valve 1044 is composed of an electric valve capable of adjusting the flow rate and pressure of the refrigerant. In the ventilation system 1 E, the opening degree of the expansion valve 1044 is controlled to adjust the pressure of the refrigerant supplied to the first heat exchanger 1023 or the second heat exchanger 1033 .
  • the refrigerant circuit 1050 includes a compressor 1042 , a four-way switching valve 1043 , an expansion valve 1044 , a first heat exchanger 1023 , a second heat exchanger 1033 , and a refrigerant pipe 1051 (a liquid pipe 1051 L and a gas pipe 1051 G) connecting these elements.
  • the refrigerant circuit 1050 circulates the refrigerant between the first heat exchanger 1023 and the second heat exchanger 1033 .
  • the four-way switch valve 1043 is held in the state illustrated by a solid line in FIG. 14 .
  • the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1042 flows into the second heat exchanger 1033 of the exhaust unit 1030 through the four-way switch valve 1043 .
  • the second heat exchanger 1033 functions as a condenser, and the refrigerant flowing through the second heat exchanger 1033 is condensed and liquefied by heat exchange with the return air RA by the operation of the exhaust fan 1032 .
  • the liquefied refrigerant is decompressed by the expansion valve 1044 and flows into the first heat exchanger 1023 .
  • the first heat exchanger 1023 functions as an evaporator, and in the first heat exchanger 1023 , the refrigerant evaporates by exchanging heat with the outside air OA.
  • the outside air OA cooled by the evaporation of the refrigerant is supplied to the indoors 1000 S 1 as the supply air SA by the air supply fan 1022 .
  • the refrigerant evaporated in the first heat exchanger 1023 returns to the compressor unit 1040 through the refrigerant pipe 1051 (the gas pipe 1051 G) and is taken into the compressor 1042 through the four-way switch valve 1043 .
  • the four-way switch valve 1043 is held in the state indicated by a dashed line in FIG. 14 .
  • the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1042 passes through the four-way switch valve 1043 and flows into the first heat exchanger 1023 of the air supply unit 1020 .
  • the first heat exchanger 1023 functions as a condenser, and in the first heat exchanger 1023 , the refrigerant is condensed and liquefied by exchanging heat with the outside air OA.
  • the outside air OA heated by the condensation of the refrigerant is supplied to the indoors 1000 S 1 by an air supply fan 1022 .
  • the refrigerant liquefied in the first heat exchanger 1023 passes through the refrigerant pipe 1051 (liquid pipe 1051 L) to the compressor unit 1040 , is decompressed to a predetermined low pressure by an expansion valve 1044 , and flows into the second heat exchanger 1033 .
  • the second heat exchanger 1033 functions as an evaporator, and in the second heat exchanger 1033 , the refrigerant evaporates by exchanging heat with the return air RA.
  • the refrigerant evaporated and vaporized in the second heat exchanger 1033 is taken into the compressor 1042 through the four-way switch valve 1043 .
  • FIG. 15 is a control block diagram of the ventilation system 1 E.
  • the ventilation system 1 E has a control unit 1018 .
  • the control unit 1018 is a device for controlling the operation of the ventilation system 1 E, and is composed of, for example, a microcomputer equipped with a processor such as a CPU, and a memory such as a RAM, a ROM, etc.
  • the control unit 1018 may be implemented as hardware using an LSI, an ASIC, an FPGA, or the like.
  • the control unit 1018 performs a predetermined function by the processor executing a program installed in the memory.
  • the control unit 1018 is connected to an air supply fan 1022 , an exhaust fan 1032 , a compressor 1042 , a four-way switching valve 1043 , and an expansion valve 1044 .
  • the control unit 1018 is connected to an air supply temperature sensor 1026 , an outside air temperature sensor 1027 , a return air temperature sensor 1036 , a low pressure sensor 1052 , a discharge pressure sensor 1053 , an discharge temperature sensor 1054 , a first heat exchange temperature sensor 1055 , a first refrigerant temperature sensor 1056 , a second heat exchange temperature sensor 1057 , and a second refrigerant temperature sensor 1058 .
  • the control unit 1018 controls the operation of the air supply fan 1022 , the exhaust fan 1032 , the compressor 1042 , the four-way switching valve 1043 , the expansion valve 1044 , and the low pressure raising means 1080 based on the detected values of the sensors.
  • the control unit 1018 calculates the saturation temperature TS of the second heat exchanger 1033 functioning as an evaporator based on the detected value (high-pressure pressure PH) of the discharge pressure sensor 1053 .
  • the control unit 1018 obtains the low pressure PL of the refrigerant circuit 1050 from the detected value of the low pressure sensor 1052 .
  • the control unit 1018 obtains the evaporation temperature TE of the second heat exchanger 1033 from the detected value (temperature Tb 2 ) of the second heat exchange temperature sensor 1057 .
  • the control unit 1018 obtains the evaporation temperature TE of the second heat exchanger 1033 from the acquired low pressure PL.
  • the ventilation system 1 E of the present disclosure has a first operation mode M 1 and a second operation mode M 2 as operation modes selectable by the user.
  • the control unit 1018 switches the four-way switch valve 1043 so that the first heat exchanger 1023 can be used as an evaporator and the second heat exchanger 1033 can be used as a condenser.
  • the control unit 1018 switches the four-way switch valve 1043 so that the first heat exchanger 1023 can be used as a condenser and the second heat exchanger 1033 can be used as an evaporator.
  • “when the user selects the second operation mode M 2 and starts the operation of the ventilation system 1 E” includes a case where the switching of the four-way switch valve 1043 has already been completed and a case where the switching of the four-way switch valve 1043 has not yet been completed.
  • the control unit 1018 may execute low pressure raising control (first control).
  • the operation mode of the ventilation system 1 E when the control unit 1018 executes low pressure raising control is referred to as low pressure raising mode M 3 .
  • the control unit 1018 starts the compressor 1042 and detects the low pressure PL of the refrigerant circuit 1050 or the evaporation temperature TE of the second heat exchanger 1033 .
  • the control unit 1018 determines that the low pressure PL or the evaporation temperature TE has fallen below the threshold (in this description, referred to as the first threshold) set for each of these values, the operation mode of the ventilation system 1 E is switched to the low pressure raising mode M 3 , and the low pressure raising control is executed.
  • the control unit 1018 does not determine that the low pressure PL or the evaporation temperature TE has fallen below the first threshold, the operation mode of the ventilation system 1 E is not switched to the low pressure raising mode M 3 (the low pressure raising control is not executed).
  • the ventilation system 1 E having the refrigerant circuit 1050 can recover the heat of the exhaust air EA to the refrigerant in the refrigerant circuit 1050 by using the first heat exchanger 1023 as a condenser and the second heat exchanger 1033 as an evaporator.
  • the ventilation system 1 E in this case, when the temperature of the exhaust air EA becomes low, frosting may occur in the second heat exchanger 1033 , and in this case, the low pressure PL of the refrigerant circuit 1050 decreases, making it difficult to continue the operation of the compressor 1042 .
  • the control unit 1018 selects the low pressure raising mode M 3 to enable the continued operation of the compressor 1042 .
  • continuous operation of the compressor here means that the operation can be continued without reaching a state where the operation cannot be continued (must be stopped) due to a decrease in the low pressure of the refrigerant circuit or the like after the start of the compressor.
  • the control unit 1018 stores a first threshold X for determining whether the conditions under which the second operation mode M 2 can operate are satisfied.
  • a pressure threshold X 1 which is the first threshold X for the low pressure PL of the refrigerant circuit 1050
  • a refrigerant temperature threshold X 2 which is the first threshold X for the evaporation temperature TE of the second heat exchanger 1033
  • an indoor temperature threshold X 3 which is the first threshold X for the intake air temperature T 3 which is the temperature of the air in the indoors 1000 S 1
  • an outside air temperature threshold X 4 which is the first threshold X for the outside air temperature T 2 which is the temperature of the air in the outdoors 1000 S 2 , are stored.
  • control unit 1018 of the present embodiment stores the pressure threshold X 1 , the refrigerant temperature threshold X 2 , the indoor temperature threshold X 3 , and the outdoor temperature threshold X 4 as the first threshold X
  • the ventilation system 1 E of the present disclosure may store any one of the respective thresholds X 1 to X 4 in the control unit 1018 .
  • the control unit 1018 stores a second threshold Y for determining whether conditions enabling operation by the second operation mode M 2 are satisfied when the control unit 1018 executes low pressure raising control (that is, when ventilation system 1 E is operated in low pressure raising mode M 3 ).
  • a pressure threshold Y 1 which is the second threshold Y for the low pressure PL of the refrigerant circuit 1050
  • a saturation temperature threshold Y 2 which is the second threshold Y for the saturation temperature TS of the second heat exchanger 1033
  • an air temperature threshold Y 3 which is the second threshold Y for the intake air temperature T 3 of the second heat exchanger 1033 are stored.
  • control unit 1018 of the present embodiment stores the pressure threshold Y 1 , the saturation temperature threshold Y 2 , and the air temperature threshold Y 3 as the second threshold Y
  • the ventilation system 1 E of the present disclosure may store at least one of the pressure threshold Y 1 , the saturation temperature threshold Y 2 , or the air temperature threshold Y 3 in the control unit 1018 .
  • control unit 1018 controls the operation at the start of operation according to the flow illustrated in FIG. 16 .
  • the control unit 1018 first determines whether the operation has been started upon selecting the second operation mode M 2 (S 2501 ). If, in step S 2501 , the control unit 1018 determines that the operation has been started upon selecting the second operation mode M 2 (YES), the next step (S 2502 ) is executed. If, in step S 2501 , the control unit 1018 determines that the operation has not been started upon selecting the second operation mode M 2 (NO), the control unit 1018 ends the control at the start of operation. In step S 2502 , the control unit 1018 starts the compressor 1042 and proceeds to the next step (S 2503 ).
  • step S 2503 the control unit 1018 makes a determination with respect to the low pressure PL of the refrigerant circuit 1050 .
  • step S 2503 when the control unit 1018 determines that the low pressure PL is not below the first threshold X (pressure threshold X 1 ) for the low pressure PL (NO), the next step S 2504 is executed.
  • step S 2503 when the control unit 1018 determines that the low pressure PL is below the first threshold X (pressure threshold X 1 ) (YES), the next step S 2507 is executed.
  • step S 2504 the control unit 1018 makes a determination with respect to the evaporation temperature TE of the second heat exchanger 1033 .
  • step S 2504 when the control unit 1018 determines that the evaporation temperature TE is not lower than the first threshold X (refrigerant temperature threshold X 2 ) for the evaporation temperature TE (NO), the next step S 2505 is executed.
  • step S 2504 when the control unit 1018 determines that the evaporation temperature TE is lower than the first threshold X (refrigerant temperature threshold X 2 ) (YES), the next step S 2507 is executed.
  • step S 2505 the control unit 1018 makes a determination with respect to the intake air temperature T 3 , which is the air temperature of the indoors 1000 S 1 .
  • step S 2505 when the control unit 1018 determines that the intake air temperature T 3 is not lower than the first threshold X (indoor temperature threshold X 3 ) for the intake air temperature T 3 (NO), the next step S 2506 is executed.
  • step S 2505 when the control unit 1018 determines that the intake air temperature T 3 is lower than the first threshold X (indoor temperature threshold X 3 ) (YES), the next step S 2507 is executed.
  • step S 2506 the control unit 1018 makes a determination with respect to the outside air temperature T 2 , which is the air temperature of the outdoors 1000 S 2 .
  • step S 2506 when the control unit 1018 determines that the outside air temperature T 2 is not lower than the first threshold X (outside air temperature threshold X 4 ) for the outside air temperature T 2 (NO), the next step S 2512 is executed.
  • step S 2506 when the control unit 1018 determines that the outside air temperature T 2 is lower than the first threshold X (outside air temperature threshold X 4 ) (YES), the next step S 2507 is executed.
  • step S 2507 the control unit 1018 executes low pressure raising control. Specifically, in step S 2507 , the control unit 1018 switches the operation mode of the ventilation system 1 E to a low pressure raising mode M 3 to operate the ventilation system 1 E. When the control unit 1018 executes low pressure raising control, the ventilation system 1 E uses the low pressure raising means 1080 , which will be described later. The control unit 1018 executes a further step (S 2508 ) after starting execution of the low pressure raising control.
  • step (S 2508 ) the control unit 1018 makes a determination with respect to the low pressure PL of the refrigerant circuit 1050 during execution of the low pressure raising control.
  • step S 2508 if the control unit 1018 determines that the low pressure PL does not exceed the second threshold Y (pressure threshold Y 1 ) for the low pressure PL (NO), step S 2509 is executed.
  • step S 2508 if the control unit 1018 determines that the low pressure PL exceeds the pressure threshold Y 1 (YES), step S 2511 is executed.
  • step S 2509 the control unit 1018 makes a determination with respect to the saturation temperature TS of the second heat exchanger 1033 . If it is determined in step S 2509 that the saturation temperature TS does not exceed the second threshold Y (saturation temperature threshold Y 2 ) for the saturation temperature TS (NO), step S 2510 is executed. If it is determined in step S 2509 that the saturation temperature TS exceeds the saturation temperature threshold Y 2 (YES), step S 2511 is executed.
  • step S 2510 the control unit 1018 makes a determination with respect to the intake air temperature T 3 of the second heat exchanger 1033 .
  • the control unit 1018 executes step S 2511 .
  • step S 2511 the control unit 1018 ends the low pressure raising control. After ending the low pressure raising control, the control unit 1018 executes step S 2512 .
  • step S 2512 the control unit 1018 switches the operation mode of the ventilation system 1 E to the second operation mode M 2 to operate the ventilation system 1 E. Accordingly, the control unit 1018 ends the operation control at the start of the operation (flow illustrated in FIG. 16 ).
  • the determination conditions in each step (S 2508 ) to (S 2510 ) are conditions for determining whether the compressor 1042 can be reliably continuously operated in the second operation mode M 2 . That is, if any of the conditions are satisfied in the steps (S 2508 ) to (S 2510 ), conditions are satisfied to ensure continuous operation of the compressor 1042 in the second operation mode M 2 .
  • the ventilation system 1 E can satisfy conditions to ensure continuous operation of the compressor 1042 .
  • the ventilation system 1 E can ensure continuous operation of the compressor 1042 by starting operation in the second operation mode M 2 after satisfying conditions to ensure continuous operation of the compressor 1042 .
  • whether to proceed to the step (S 2507 ) is determined based on the determination with respect to the low pressure PL in the step (S 2503 ), the determination with respect to the evaporation temperature TE in the step (S 2504 ), the determination with respect to the intake air temperature T 3 in the step (S 2505 ), and the determination with respect to the outside air temperature T 2 in the step (S 2506 ); however, whether to proceed to the step (S 2507 ) may be determined based on only one of the steps (S 2503 ) to (S 2506 ).
  • whether to proceed to the step (S 2511 ) is determined based on the determination with respect to the low pressure PL in the step (S 2508 ), the determination with respect to the saturation temperature TS in the step (S 2509 ), and the determination with respect to the intake air temperature T 3 in the step (S 2510 ); however, whether to proceed to the step (S 2511 ) may be determined based on only one of the steps (S 2508 ) to (S 2510 ).
  • the ventilation system 1 E of the present disclosure includes a low pressure raising means 1080 .
  • the thirteenth to eighteenth ventilation systems 1 F to 1 K described below have different configurations of the low pressure raising means 1080 .
  • the low pressure raising means 1080 is used during execution of the above-described low pressure raising control (see FIG. 16 ).
  • the common parts of the thirteenth to eighteenth ventilation systems 1 F to 1 K are denoted by the same reference numerals, and with respect to the parts denoted by the same reference numerals, repetitive descriptions will be omitted.
  • FIG. 17 illustrates a thirteenth ventilation system 1 F according to a thirteenth embodiment of the ventilation system 1 E of the present disclosure.
  • the thirteenth ventilation system 1 F illustrated in FIG. 17 includes an air supply unit 1020 , an exhaust unit 1030 , and a compressor unit 1040 .
  • the air supply unit 1020 , the exhaust unit 1030 , and the compressor unit 1040 are integrally configured.
  • the thirteenth ventilation system 1 F described in the present embodiment includes the air supply unit 1020 , the exhaust unit 1030 , and the compressor unit 1040 configured integrally, in the ventilation system 1 E of the present disclosure, air supply unit 1020 (the first heat exchanger 1023 and the air supply fan 1022 ), the exhaust unit 1030 (the second heat exchanger 1033 and the exhaust fan 1032 ), and the compressor unit 1040 (the compressor 1042 ) may be arranged separately.
  • the thirteenth ventilation system 1 F may be arranged outdoors 1000 S 2 , for example.
  • the blowout port 1025 of the air supply unit 1020 and the intake port 1034 of the exhaust unit 1030 are directly attached to the outer wall surface of the building 1000 B.
  • the present embodiment illustrates a case where the thirteenth ventilation system 1 F is arranged in the outdoors 1000 S 2
  • the thirteenth ventilation system 1 F may be arranged entirely or partially in the indoors 1000 S 1 .
  • the thirteenth ventilation system 1 F includes an air conditioner 1081 which is the first low pressure raising means 1080 .
  • the air conditioner 1081 includes a refrigerant circuit 1081 d including an indoor unit 1081 a , an outdoor unit 1081 b , and a refrigerant pipe 1081 c.
  • the air conditioner 1081 is installed in a building 1000 B to implement air conditioning of the air conditioning target space (indoors 1000 S 1 ).
  • the air conditioner 1081 heats and cools the air conditioning target space by performing a steam compression type refrigeration cycle operation.
  • the system of the air conditioner as the low pressure raising means 1080 is not limited to this, and may be an air conditioner which implements air conditioning of the target space by, for example, cold and hot water supplied from a heat source device.
  • the indoor unit 1081 a is arranged indoors 1000 S 1 and the outdoor unit 1081 b is arranged outdoors 1000 S 2 .
  • the indoor unit 1081 a and the outdoor unit 1081 b are connected by a refrigerant pipe 1081 c .
  • the air conditioner 1081 has a refrigerant circuit 1081 d for air conditioning.
  • the refrigerant circuit 1081 d for air conditioning includes a compressor, a four-way switching valve, an outdoor heat exchanger, an expansion valve, an indoor heat exchanger, and the like (none of which are illustrated).
  • the refrigerant circuit 1081 d for air conditioning circulates the refrigerant between the indoor unit 1081 a and the outdoor unit 1081 b through the refrigerant pipe 1081 c .
  • the refrigerant circuit 1081 d for air conditioning is separated from the refrigerant circuit 1050 of the thirteenth ventilation system 1 F and constitutes an independent circuit.
  • the air conditioner 1081 detects the temperature of the indoors 1000 S 1 .
  • the temperature of the indoors 1000 S 1 is increased by operating the air conditioner 1081 when the low pressure raising control is executed.
  • the control unit 1018 determines that the temperature of the air in the indoors 1000 S 1 detected by the air conditioner 1081 exceeds the second threshold Y (air temperature threshold Y 3 for intake air temperature T 3 ) (see FIG. 15 )
  • the operation of the exhaust fan 1032 is started.
  • this causes the second heat exchanger 1033 to take in air having a temperature higher than the air temperature threshold Y 3 for the intake air temperature T 3 .
  • the frosting in the second heat exchanger 1033 is prevented by operating the air conditioner 1081 .
  • the intake air temperature T 3 of the second heat exchanger 1033 functioning as an evaporator can be increased by the air conditioner 1081 , thereby preventing the frosting in the second heat exchanger 1033 and preventing the lowering of the low pressure PL of the refrigerant circuit 1050 .
  • the control unit 1018 may forcibly start the air conditioner 1081 .
  • the control unit 1018 may provide information urging the user to start the air conditioner 1081 and the user may start the air conditioner 1081 .
  • the exhaust fan 1032 may be operated to measure the intake air temperature T 3 after a predetermined time, and the control unit 1018 may start the air conditioner 1081 based on the measured value.
  • control unit 1018 may be configured to detect the operation state of the air conditioner 1081 , and when the control unit 1018 detects that the air conditioner 1081 is in operation when the second operation mode M 2 is selected and the air conditioner 1081 is started, the control unit 1018 may execute low pressure raising control.
  • control unit 1018 may stop the air conditioner 1081 , or the control unit 1018 may continue the operation of the air conditioner 1081 .
  • FIG. 18 is a schematic configuration diagram of a ventilation system according to a fourteenth embodiment of the present disclosure.
  • FIG. 19 is a schematic configuration diagram illustrating a state of installation of a ventilation system according to the fourteenth embodiment of the present disclosure in a building.
  • the fourteenth ventilation system 1 G illustrated in FIGS. 18 and 19 is a fourteenth embodiment of the ventilation system 1 E of the present disclosure.
  • the fourteenth ventilation system 1 G differs from the thirteenth ventilation system 1 F in that the fourteenth ventilation system 1 G includes a second low pressure raising means 1082 which is a second low pressure raising means 1080 .
  • the fourteenth ventilation system 1 G includes a second low pressure raising means 1082 .
  • the second low pressure raising means 1082 includes a bypass pipe 1082 a and a valve 1082 b .
  • the valve 1082 b is, for example, a motor-driven valve, a solenoid valve, or the like.
  • the bypass pipe 1082 a bypasses the discharge pipe 1045 of the compressor 1042 and the liquid pipe 1051 L.
  • the bypass pipe 1082 a can supply high temperature and high pressure gaseous refrigerant discharged from the compressor 1042 to the second heat exchanger 1033 through the liquid pipe 1051 L.
  • the valve 1082 b can switch the flow of refrigerant in the bypass pipe 1082 a .
  • valve 1082 b When the valve 1082 b is opened, the gaseous refrigerant can flow into the bypass pipe 1082 a , and when the valve 1082 b is closed, the flow of the gaseous refrigerant in the bypass pipe 1082 a can be stopped.
  • the fourteenth ventilation system 1 G raises the temperature of the refrigerant flowing through the second heat exchanger 1033 by supplying the gaseous refrigerant to the second heat exchanger 1033 through the bypass pipe 1082 a with the valve 1082 b open, thereby preventing frosting in the second heat exchanger 1033 .
  • the saturation temperature TS at the outlet of the second heat exchanger 1033 functioning as an evaporator can be increased by the second low pressure raising means 1082 , thereby preventing frosting in the second heat exchanger 1033 and preventing lowering of the low pressure PL of the refrigerant circuit 1050 .
  • control unit 1018 closes the valve 1082 b to end the low pressure raising control.
  • FIG. 20 is a schematic configuration diagram of a ventilation system according to a fifteenth embodiment of the present disclosure.
  • the fifteenth ventilation system 1 H illustrated in FIGS. 19 and 20 is a fifteenth embodiment of the ventilation system 1 E of the present disclosure.
  • the fifteenth ventilation system 1 H differs from the thirteenth and fourteenth ventilation systems 1 F and 1 G in that the fifteenth ventilation system 1 H includes a third low pressure raising means 1083 , which is a third low pressure raising means 1080 .
  • the fifteenth ventilation system 1 H includes a third low pressure raising means 1083 .
  • the third low pressure raising means 1083 includes a bypass duct 1083 a and a damper 1083 b .
  • the bypass duct 1083 a is formed in the third casing 1041 and communicates with the discharge side of the first casing 1021 and the intake side of the second casing.
  • the bypass duct 1083 a can supply a part of the air flow (air supply SA) generated by the air supply unit 1020 to the intake side of the exhaust fan 1032 in the exhaust unit 1030 .
  • the damper 1083 b includes a valve and an opening/closing mechanism for opening/closing the flow of the air supply SA in the bypass duct 1083 a . When the damper 1083 b is opened, the supply air SA can flow in the bypass duct 1083 a , and when the damper 1083 b is closed, the flow of the supply air SA in the bypass duct 1083 a can be stopped.
  • the control unit 1018 determines that the blowout air temperature T 1 detected by the supply air temperature sensor 1026 exceeds the second threshold Y (air temperature threshold Y 3 for the intake air temperature T 3 ) (see FIG. 15 ) (see FIG. 15 ).
  • the damper 1083 b is opened.
  • the fifteenth ventilation system 1 H can raise the intake air temperature T 3 of the second heat exchanger 1033 by supplying the supply air SA to the intake side of the second heat exchanger 1033 through the bypass duct 1083 a while the damper 1083 b is opened.
  • control unit 1018 closes the damper 1083 b to end the low pressure raising control.
  • the air supply unit 1020 , the exhaust unit 1030 , and the compressor unit 1040 are arranged in the space (hereinafter referred to as a ceiling space R 2 ) behind the ceiling of the room R 1 , which is the space to be ventilated in the indoors 1000 S 1 .
  • a ceiling space R 2 the space behind the ceiling of the room R 1 , which is the space to be ventilated in the indoors 1000 S 1 .
  • the present embodiment illustrates the case where the sixteenth ventilation system 1 I is arranged in the indoors 1000 S 1
  • the sixteenth ventilation system 1 I may be arranged entirely or partially in the outdoors 1000 S 2 .
  • the other end of the first air supply duct 1028 a is connected to the air supply unit 1020 .
  • the second air supply duct 1028 b connects the air supply unit 1020 to the indoors 1000 S 1 .
  • the second air supply duct 1028 b has a blowout port 1028 d as one end, and the blowout port 1028 d is connected to an opening on the ceiling surface of the indoors 1000 S 1 to communicate with the indoors 1000 S 1 .
  • the other end of the second air supply duct 1028 b is connected to the air supply unit 1020 .
  • the exhaust unit 1030 forms a part of the exhaust air flow path 1038 .
  • the exhaust air flow path 1038 is an air flow path communicating with the indoors 1000 S 1 and the outdoors 1000 S 2 .
  • the exhaust air flow path 1038 includes a first exhaust duct 1038 a , a second exhaust duct 1038 b , and an exhaust unit 1030 .
  • the first exhaust duct 1038 a connects the outdoors 1000 S 2 and the exhaust unit 1030 .
  • the first exhaust duct 1038 a has an exhaust port 1038 c at one end, and the exhaust port 1038 c is connected to an opening in the outer wall of the building 1000 B and communicates with the outdoors 1000 S 2 .
  • the other end of the first exhaust duct 1038 a is connected to the exhaust unit 1030 .
  • the second exhaust duct 1038 b connects the exhaust unit 1030 to the indoors 1000 S 1 .
  • the second exhaust duct 1038 b has an intake port 1038 d at one end, and the intake port 1038 d is connected to an opening on the ceiling surface of the indoors 1000 S 1 to communicate with the indoors 1000 S 1 .
  • the other end of the second exhaust duct 1038 b is connected to the exhaust unit 1030 .
  • the sixteenth ventilation system 1 I includes a fourth low pressure raising means 1084 .
  • the fourth low pressure raising means 1084 includes a bypass duct 1084 a and a damper 1084 b .
  • the bypass duct 1084 a communicates with the second air supply duct 1028 b connected to the blowout side of the air supply unit 1020 and the second exhaust duct 1038 b connected to the intake side of the exhaust unit 1030 .
  • the bypass duct 1084 a can supply a part of the air flow (supply air SA) generated by the air supply unit 1020 to the intake side of the exhaust fan 1032 in the exhaust unit 1030 .
  • the damper 1084 b includes a valve and an opening/closing mechanism for opening/closing the flow of the supply air SA in the bypass duct 1084 a .
  • the damper 1084 b is opened, the supply air SA can flow in the bypass duct 1084 a , and when the damper 1084 b is closed, the flow of the supply air SA in the bypass duct 1084 a can be stopped.
  • the damper 1084 b is opened.
  • the sixteenth ventilation system 1 I can raise the intake air temperature T 3 of the second heat exchanger 1033 by supplying the supply air SA to the intake side of the second heat exchanger 1033 through the bypass duct 1084 a while the damper 1084 b is opened.
  • the intake air temperature T 3 of the second heat exchanger 1033 functioning as an evaporator can be raised by the fourth low pressure raising means 1084 , thereby preventing frosting in the second heat exchanger 1033 and preventing lowering of the low pressure PL of the refrigerant circuit 1050 .
  • the fifth low pressure raising means 1085 includes an intake duct 1085 a , a damper 1085 b , and a ceiling space temperature sensor 1085 c .
  • the intake duct 1085 a is connected to the second exhaust duct 1038 b and is opened in the ceiling space R 2 so that air in the ceiling space R 2 can be taken into the exhaust unit 1030 by driving the exhaust fan 1032 .
  • air in the ceiling space R 2 taken into the exhaust unit 1030 can be passed into the second heat exchanger 1033 .
  • the damper 1085 b is a valve for opening and closing the air flow in the intake duct 1085 a . When the damper 1085 b is opened, the air in the ceiling space R 2 can be taken into the intake duct 1085 a , and when the damper 1085 b is closed, the air flow in the intake duct 1085 a can be stopped.
  • the ceiling space temperature sensor 1085 c is connected to the control unit 1018 .
  • the ceiling space temperature sensor 1085 c can detect the temperature of the air in the ceiling space R 2 .
  • the damper 1085 b is opened and the air in the ceiling space R 2 is passed to the second heat exchanger 1033 through the intake duct 1085 a.
  • control unit 1018 closes the damper 1085 b , thereby ending the low pressure raising control.
  • FIG. 23 is a schematic configuration diagram of a ventilation system according to an eighteenth embodiment of the present disclosure.
  • the eighteenth ventilation system 1 K illustrated in FIG. 23 is a eighteenth embodiment of the ventilation system 1 E of the present disclosure.
  • the configuration of the low pressure raising means 1080 of the eighteenth ventilation system 1 K is different from those of the sixteenth and seventeenth ventilation systems 1 I and 1 J.
  • the eighteenth ventilation system 1 K includes a sixth low pressure raising means 1086 which is a sixth low pressure raising means 1080 .
  • the sixth low pressure raising means 1086 includes a louver 1086 a which is turnably arranged around a rotation axis and a mechanism (not illustrated) for turning the louver 1086 a .
  • the louver 1086 a is arranged in the vicinity of the blowout port 1028 d in the indoors 1000 S 1 .
  • the louver 1086 a is turnably configured between a housing position 1000 P 1 which does not change the blowout direction of the supply air SA blown out from the blowout port 1028 d , and an operating position 1000 P 2 which changes the blowout direction of the supply air SA blown out from the blowout port 1028 d.
  • the louver 1086 a is rotated from the housing position 1000 P 1 to the operating position 1000 P 2 .
  • the blowout direction of the air supply SA blown out from the blowout port 1028 d is changed by hitting the louver 1086 a and flows toward the intake port 1038 d .
  • the intake air temperature T 3 of the second heat exchanger 1033 is increased by actively taking in the air supply SA having a higher temperature than that of the indoor air 1000 S 1 through the intake port 1038 d .
  • the intake air temperature T 3 of the second heat exchanger 1033 functioning as an evaporator can be increased by the sixth low pressure raising means 1086 , whereby frosting in the second heat exchanger 1033 can be prevented and lowering of the low pressure PL of the refrigerant circuit 1050 can be prevented.
  • control unit 1018 changes the turning position of the louver 1086 a from the operating position 1000 P 2 to the housing position 1000 P 1 , thereby ending the low pressure raising control.
  • the ventilation system 1 E illustrated in the above embodiment includes the compressor 1042 , the first heat exchanger 1023 , and the second heat exchanger 1033 connected by the refrigerant pipe 1051 , the refrigerant circuit 1050 through which refrigerant flows, the air supply fan 1022 for supplying air from the outdoors 1000 S 2 to the indoors 1000 S 1 through the first heat exchanger 1023 , the exhaust fan 1032 for exhausting air from the indoors 1000 S 1 to the outdoors 1000 S 2 through the second heat exchanger 1033 , and the control unit 1018 .
  • the control unit 1018 starts the compressor 1042 , and when it is determined that the low pressure PL of the refrigerant circuit 1050 , or the evaporation temperature TE of the second heat exchanger 1033 , or the temperature of the indoors 1000 S 1 (intake air temperature T 3 ), or the temperature of the outdoors 1000 S 2 (outside air temperature T 2 ) has fallen below the first threshold X for the low pressure PL of the refrigerant circuit 1050 , or the evaporation temperature TE of the second heat exchanger 1033 , or the intake air temperature T 3 , or the outside air temperature T 2 , the control unit performs low pressure raising control to raise the low pressure PL of the refrigerant circuit 1050 .
  • the compressor 1042 can be reliably continuously operated.
  • the refrigerant circuit 1050 has the bypass pipe 1082 a connecting the discharge pipe 1045 of the compressor 1042 and the second heat exchanger 1033 or the liquid pipe 1051 L connected to the second heat exchanger 1033 , and the valve 1082 b provided in the bypass pipe 1082 a .
  • the control unit 1018 opens the valve 1082 b in the low pressure raising control (first control).
  • the gas refrigerant of high temperature and high pressure can be supplied to the second heat exchanger 1033 in the low pressure raising control.
  • frosting in the second heat exchanger 1033 can be prevented.
  • the control unit 1018 closes the valve 1082 b when the control unit 1018 determines that the low pressure PL of the refrigerant circuit 1050 , the saturation temperature TS of the second heat exchanger 1033 , or the intake air temperature T 3 of the exhaust fan 1032 exceeds the second threshold Y for the low pressure PL of the refrigerant circuit 1050 , the saturation temperature TS of the second heat exchanger 1033 , or the intake air temperature T 3 of the second heat exchanger 1033 .
  • the low pressure raising control can be ended.
  • control unit 1018 causes the second heat exchanger 1033 to take in air at a temperature higher than the second threshold Y (air temperature threshold Y 3 ) for the intake air temperature T 3 in the low pressure raising mode M 3 for performing the low pressure raising control.
  • control unit 1018 adjusts the blowout direction of the air supply fan 1022 so as to guide the air blown out from the air supply fan 1022 to the intake side of the exhaust fan 1032 in the low pressure raising mode M 3 for performing the low pressure raising control.
  • air having a temperature higher than the second threshold Y (air temperature threshold Y 3 ) for the intake air temperature T 3 can flow into the second heat exchanger 1033 during the execution of the low pressure raising control.
  • an air conditioner 1081 for air conditioning the indoors 1000 S 1 is further provided, and the control unit 1018 drives the exhaust fan 1032 when the air temperature of the indoors 1000 S 1 becomes higher than the second threshold Y (air temperature threshold Y 3 ) by the air conditioner 1081 in the low pressure raising mode M 3 for performing the low pressure raising control.
  • air having a higher temperature than the second threshold Y (air temperature threshold Y 3 ) for the intake air temperature T 3 can flow into the second heat exchanger 1033 during the execution of the low pressure raising control.
  • the above-described embodiments and modified examples by performing the above-described control, it is possible to prevent frosting (for example, with respect to the second heat exchanger) and to continue the ventilation operation by supplying air to an indoor space and exhausting air to the outdoors without stopping.
  • the prevention of frosting is not limited to avoiding frosting, but means controlling such that frost does not grow even if frosting occurs.
  • a ventilation apparatus or ventilation system according to an embodiment and a modified example it is possible to maintain the comfort of a living room space by controlling frosting and continuing the ventilation operation.
  • the number of air supply units and exhaust units described in the above-described embodiments and the modified examples is indicated as an example.
  • the number of air supply units and the number of exhaust units may be determined according to the living room space.
  • the number of air supply units may be one or more
  • the number of exhaust units may be one or more.
  • the control unit illustrated in the above-described embodiments and the modified examples is described as an embodiment, and may be included in any device.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Conditioning Control Device (AREA)
US18/743,804 2021-12-17 2024-06-14 Ventilation apparatus, air conditioning system, and ventilation system Pending US20240337401A1 (en)

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JP2021205609 2021-12-17
JP2021-205609 2021-12-17
JP2021-204798 2021-12-17
JP2021204798 2021-12-17
PCT/JP2022/036876 WO2023112428A1 (ja) 2021-12-17 2022-09-30 換気装置、空調システム、換気方法、及び換気システム

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US20240011655A1 (en) * 2022-07-11 2024-01-11 Rheem Manufacturing Company Enhanced heat pump defrost without use of auxiliary heat

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KR102728188B1 (ko) * 2024-09-20 2024-11-11 주식회사 에코이엔지 외부정보 연동 개별환기장치의 제어방법 및 환기시스템

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Publication number Priority date Publication date Assignee Title
US20240011655A1 (en) * 2022-07-11 2024-01-11 Rheem Manufacturing Company Enhanced heat pump defrost without use of auxiliary heat

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