WO2017068902A1 - Air conditioning system - Google Patents

Air conditioning system Download PDF

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Publication number
WO2017068902A1
WO2017068902A1 PCT/JP2016/077763 JP2016077763W WO2017068902A1 WO 2017068902 A1 WO2017068902 A1 WO 2017068902A1 JP 2016077763 W JP2016077763 W JP 2016077763W WO 2017068902 A1 WO2017068902 A1 WO 2017068902A1
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WO
WIPO (PCT)
Prior art keywords
way switching
switching valve
outdoor unit
pressure
heating cycle
Prior art date
Application number
PCT/JP2016/077763
Other languages
French (fr)
Japanese (ja)
Inventor
隆博 加藤
Original Assignee
三菱重工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱重工業株式会社 filed Critical 三菱重工業株式会社
Priority to ES16857220T priority Critical patent/ES2732660T3/en
Priority to EP16857220.4A priority patent/EP3315877B1/en
Priority to CN201680043745.3A priority patent/CN107850352A/en
Publication of WO2017068902A1 publication Critical patent/WO2017068902A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • 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
    • F24F11/89—Arrangement or mounting of control or safety devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/025—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units
    • F25B2313/0253—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units in parallel arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
    • F25B2313/02741—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using one four-way valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
    • F25B2313/02792—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using reversing valve changing the refrigerant flow direction due to pressure differences of the refrigerant and not by external actuation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2507—Flow-diverting valves

Definitions

  • the present invention relates to an air conditioning system in which a plurality of outdoor units including a compressor, a four-way switching valve, and an outdoor heat exchanger are connected in parallel to a refrigeration cycle.
  • a conventional air conditioning system in an air conditioning system in which a plurality of compressors are installed in an outdoor unit, if any one of the compressors fails or a plurality of outdoor units are used for one refrigeration cycle
  • the air conditioning system can be operated by operating a normal compressor or outdoor unit in order to avoid a situation where the air conditioning system will be completely stopped. Air conditioning systems with continuous backup operation functions are provided.
  • the position of the four-way switching valve is set to the cooling cycle position or the heating cycle in order to make the operation mode of the outdoor units the same during backup operation.
  • the four-way selector valve can be switched by operating the remaining compressors even if some of them are broken.
  • the compressor of the outdoor unit cannot be operated, and thus the four-way selector valve may not be synchronized.
  • the slide valve body is slid so that a predetermined value (normally 0, although depending on the product specifications of the four-way switching valve). It is necessary to ensure a high and low pressure difference of 3 MPa) or more. However, in the outdoor unit where the compressor is broken, the high / low pressure difference cannot be secured, so the four-way switching valve cannot be switched synchronously to the heating cycle position, and as a result, the system cannot be operated. was there.
  • JP-A-6-341742 Patent No. 3203096
  • Patent Document 1 since the system disclosed in Patent Document 1 has to stop the operation of the system once an abnormality occurs, for example, when the cooling operation is performed in the cooling cycle, when the operation is switched to the heating operation, the failure is caused as it is.
  • the four-way switching valve of the outdoor unit cannot be switched from the cooling cycle position to the heating cycle position, and the system must be stopped once, and how to synchronize the direction of the four-way switching valve of each outdoor unit. It did not disclose a specific method or means for the above.
  • the present invention has been made in view of such circumstances, and even when a compressor of any one of a plurality of outdoor units connected in parallel fails, the four-way switching valve is reliably synchronized.
  • the purpose is to provide an air conditioning system capable of backup operation.
  • an air conditioning system includes a single refrigeration cycle configured by connecting refrigerant circuits on an indoor unit side and an outdoor unit side by a refrigerant liquid pipe and a refrigerant gas pipe, at least one compressor, A four-way switching valve and an outdoor heat exchanger for switching the refrigeration cycle to either a cooling or heating cycle, and a plurality of the outdoor units connected in parallel to the refrigeration cycle, and the plurality of outdoor units
  • a backup operation control unit configured to continue the air conditioning operation by performing a backup operation of another normal outdoor unit when the compressor of a certain outdoor unit breaks down, the backup operation control unit comprising: In the backup operation, when the four-way switching valve is operated by switching from the cooling cycle position to the heating cycle position, The four-way switching valve of the unit is once operated in the cooling cycle position, the low-pressure pressure of the failed outdoor unit is lowered, the operating differential pressure of the four-way switching valve of the failed outdoor unit is secured, and
  • the air conditioning system when a compressor of a certain outdoor unit among a plurality of outdoor units breaks down, the air conditioning system includes a backup operation control unit that continues the air conditioning operation by performing a backup operation of another normal outdoor unit.
  • the backup operation control unit during the backup operation, when the four-way switching valve is switched from the cooling cycle position to the heating cycle position, the four-way switching valve of the normal outdoor unit is once operated as the cooling cycle position, resulting in a failure.
  • Reduce the low pressure of the outdoor unit secure the differential pressure of the four-way switching valve of the failed outdoor unit, switch the four-way switching valve to the heating cycle position, and then switch the four-way switching valve of the normal outdoor unit to the heating cycle position.
  • the four-way selector valve synchronization control unit is operated to synchronize the four-way selector valve and operate in the heating cycle, backup operation
  • the four-way switching valve of the malfunctioning outdoor unit is switched from the cooling cycle position to the heating cycle position to ensure a working differential pressure.
  • Backup operation can be performed in synchronization with the cycle position. Therefore, the failure outdoor unit that occurs when the four-way switching valve of the failed outdoor unit cannot ensure the operation differential pressure necessary for switching from the cooling cycle position to the heating cycle position, and the four-way switching valve cannot be switched synchronously to the heating cycle position. This eliminates problems such as the application of high-pressure refrigerant gas to the low-pressure path and the total stop of the air-conditioning system, and the normal outdoor unit can be reliably operated for backup operation.
  • the four-way switching valve synchronization control unit is configured such that when the rotational speed of the compressor on the normal outdoor unit side reaches a predetermined rotational speed, The four-way switching valve is configured to output a switching command to the heating cycle position.
  • the four-way switching valve synchronization control unit outputs a switching command to the heating cycle position to the four-way switching valve of the failed outdoor unit when the compressor rotation speed on the normal outdoor unit side reaches a predetermined rotation speed. Because it is configured, it is necessary to switch the four-way selector valve to the heating cycle position because the low pressure of the failed outdoor unit decreases due to the compressor rotation speed on the normal outdoor unit side reaching the predetermined rotation speed Assuming that a sufficient differential pressure is secured, a switching command is output, and the four-way switching valve of the failed outdoor unit can be switched to the heating cycle position. Therefore, without making a hardware change to the current system, only the software change is required, and during backup operation, the four-way selector valve of the failed outdoor unit is reliably switched from the cooling cycle position to the heating cycle position and synchronized. Can be backed up.
  • the air conditioning system of the present invention is the above air conditioning system, wherein the four-way switching valve synchronization control unit is configured such that when the detected value of the low pressure on the failure outdoor unit side falls below a predetermined value, the failure outdoor unit The four-way switching valve is configured to output a switching command to the heating cycle position.
  • the four-way switching valve synchronization control unit outputs a switching command to the heating cycle position to the four-way switching valve of the failed outdoor unit when the detected value of the low pressure on the failed outdoor unit side falls below a predetermined value. Therefore, when the detected value of the low-pressure pressure on the failure outdoor unit side falls below a predetermined value, the low pressure on the failure outdoor unit decreases, and the four-way selector valve is switched to the heating cycle position. Assuming that the necessary differential pressure is secured, a switching command is output, and the four-way switching valve of the failed outdoor unit can be switched to the heating cycle position. Therefore, without making a hardware change to the current system, only the software change is required, and during backup operation, the four-way selector valve of the failed outdoor unit is reliably switched from the cooling cycle position to the heating cycle position and synchronized. Can be backed up.
  • the air conditioning system of the present invention is the above air conditioning system, wherein the four-way switching valve synchronization control unit is configured such that when the difference between the detected values of the high pressure and low pressure on the failed outdoor unit side is a predetermined value or more, A switching command to the heating cycle position is output to the four-way switching valve of the failed outdoor unit.
  • the four-way switching valve synchronization control unit moves the four-way switching valve of the failed outdoor unit to the heating cycle position. Since the difference between the detected values of the high pressure and low pressure on the failed outdoor unit side is equal to or greater than a predetermined value, the low pressure of the failed outdoor unit is reduced. Assuming that the differential pressure necessary to switch the four-way switching valve to the heating cycle position is secured, a switching command is output, and the four-way switching valve of the failed outdoor unit can be switched to the heating cycle position. Therefore, without making a hardware change to the current system, only the software change is required, and during backup operation, the four-way selector valve of the failed outdoor unit is reliably switched from the cooling cycle position to the heating cycle position and synchronized. Can be backed up.
  • the low-pressure paths between the four-way switching valves of the plurality of outdoor units and the compressor are connected to each other via low-pressure communication pipes. It is characterized by that.
  • the four-way switching valves of the failed outdoor unit are cooled during the backup operation.
  • the low pressure pressure should be quickly reduced via the low pressure communication pipe Can do. Therefore, the reliability and certainty at the time of switching of the four-way switching valve can be improved, and the time required for switching can be shortened.
  • the air conditioning system of the present invention is characterized in that, in the above air conditioning system, the low pressure communication pipe is an oil equalizing pipe or a pressure equalizing pipe connecting the low pressure paths of the compressors of the plurality of outdoor units.
  • the low-pressure communication pipes are oil equalizing pipes or pressure equalizing pipes connecting the low-pressure paths of the compressors of the plurality of outdoor units
  • a plurality of units are used in an air conditioning system including a plurality of outdoor units.
  • the outdoor unit compressors or their low-pressure paths are connected by an oil equalizing pipe or a pressure equalizing pipe.
  • the oil equalizing pipe or the pressure equalizing pipe is also used as a low-pressure communication pipe.
  • the low-pressure pressure on the failed outdoor unit side can be reduced via the oil equalizing pipe or the pressure equalizing pipe, and the four-way switching valve of the failed outdoor unit can be switched to the heating cycle position for synchronization. Therefore, the existing oil equalizing pipe or pressure equalizing pipe can be used, and the four-way switching valve of the failed outdoor unit can be switched synchronously reliably without cost increase.
  • an air conditioning system includes a single refrigeration cycle configured by connecting refrigerant circuits on an indoor unit side and an outdoor unit side with a refrigerant liquid pipe and a refrigerant gas pipe, at least one compressor, A four-way switching valve and an outdoor heat exchanger for switching the refrigeration cycle to either a cooling or heating cycle, and a plurality of the outdoor units connected in parallel to the refrigeration cycle, and the plurality of outdoor units
  • a backup operation control unit configured to continue the air-conditioning operation by performing a backup operation of another normal outdoor unit when the compressor of a certain outdoor unit breaks down, the plurality of outdoor units
  • the discharge pipe between the compressor and the four-way switching valve is provided with a high-pressure bypass circuit including an electromagnetic valve that connects the discharge pipes to each other, In the backup operation control unit, during the backup operation, when the four-way switching valve is operated by switching from the cooling cycle position to the heating cycle position, the electromagnetic valve provided in the high-pressure bypass circuit is opened, and the failure outdoor unit The four-way switching valve is switched to the heating
  • the air conditioning system when a compressor of a certain outdoor unit among a plurality of outdoor units breaks down, the air conditioning system includes a backup operation control unit that continues the air conditioning operation by performing a backup operation of another normal outdoor unit.
  • the discharge pipe between the compressors of the plurality of outdoor units and the four-way switching valve is provided with a high-pressure bypass circuit having an electromagnetic valve for connecting the discharge pipes to each other, and the backup operation control unit has a backup operation.
  • the four-way switch Since the four-way switching valve synchronization control unit is operated to synchronize with each other and operate in the heating cycle, the four-way switch is used during backup operation When switching the valve from the cooling cycle position to the heating cycle position, the high-pressure refrigerant gas discharged from the normal outdoor unit is applied to the discharge pipe of the failed outdoor unit, and the four-way selector valve of the failed outdoor unit is operated reliably. It is possible to switch from the cooling cycle position to the heating cycle position while ensuring the differential pressure, and to perform the backup operation in synchronization with the heating cycle position.
  • the failure outdoor unit that occurs when the four-way switching valve of the failed outdoor unit cannot ensure the operation differential pressure necessary for switching from the cooling cycle position to the heating cycle position, and the four-way switching valve cannot be switched synchronously to the heating cycle position.
  • the four-way switching valve of the failed outdoor unit ensures the operation differential pressure to ensure the cooling cycle position. Because it is possible to switch to the heating cycle position and perform backup operation in synchronization with the heating cycle position, the operating differential pressure required for switching the failed outdoor unit's four-way switching valve from the cooling cycle position to the heating cycle position cannot be secured. This eliminates problems such as the application of high-pressure refrigerant gas to the low-pressure path of the failed outdoor unit and the total shutdown of the air-conditioning system caused by the fact that the four-way switching valve cannot be switched synchronously to the heating cycle position. Can be backed up.
  • FIG. 5 is a refrigerant circuit diagram when the four-way switching valve of the failed outdoor unit cannot be switched synchronously to the heating cycle position when performing backup operation of the system.
  • FIG. 4 is a refrigerant circuit diagram in a state in which the four-way switching valve on the failed outdoor unit side is synchronously switched to the heating cycle position when performing backup operation of the air conditioning system.
  • FIG. 6 is a refrigerant circuit diagram after the four-way switching valve on the failed outdoor unit side has been normally synchronously switched from the state of FIG. 5. It is a flowchart figure which shows an example of switching control of the four-way switching valve at the time of backup operation of the said air conditioning system. It is a flowchart figure which shows the other example of switching control of the four-way switching valve at the time of backup operation of the said air conditioning system. It is a refrigerant circuit figure of the air-conditioning system concerning a 2nd embodiment of the present invention.
  • FIG. 1 shows a refrigerant circuit diagram in a state where the air conditioning system according to the present embodiment is operated in a cooling cycle.
  • FIG. 2 is a configuration diagram of a four-way switching valve incorporated in the refrigerant circuit. Shows a refrigerant circuit diagram of the system operating in a heating cycle.
  • the air conditioning system 1 of the present embodiment connects a plurality of outdoor units 2A and 2B and a plurality of indoor units 3A and 3B in parallel with each other via a so-called transition refrigerant liquid pipe 4 and refrigerant gas pipe 5. And it is set as the system which comprised one refrigerating cycle 6.
  • FIG. 1 shows a refrigerant circuit diagram in a state where the air conditioning system according to the present embodiment is operated in a cooling cycle.
  • FIG. 2 is a configuration diagram of a four-way switching valve incorporated in the refrigerant circuit. Shows a refrigerant circuit diagram of the system operating in a heating cycle.
  • the plurality of outdoor units 2A and 2B include a compressor 10, an oil separator 11, a check valve 12, a four-way switching valve 13, an outdoor heat exchanger 14, a heating expansion valve (EEVH) 15, a receiver 16, and a liquid side operation.
  • the outdoor refrigerant circuit 21 is configured by connecting the valve 17, the gas side operation valve 18, the accumulator 19 and the like through a refrigerant pipe 20 in a known manner, and an electromagnetic wave is provided between the compressor 10 and the oil separator 11.
  • An oil return circuit 24 including a valve 22 and a cupilary tube 23 is connected, and is connected in parallel to the refrigeration cycle 6 via the refrigerant liquid pipes 4A and 4B and the refrigerant gas pipes 5A and 5B. Yes.
  • a high pressure sensor 25 is provided in the refrigerant discharge pipe 20 ⁇ / b> A from the compressor 10 to the four-way switching valve 13 in the outdoor refrigerant circuit 21, and a low pressure pressure is provided in the refrigerant suction pipe 20 ⁇ / b> B from the four-way switching valve 13 to the compressor 10.
  • a sensor 26 is provided. Further, between the compressors 10 of the outdoor units 2A and 2B, an oil equalizing pipe 27 for equalizing the oil level of the oil filled in each compressor 10 is connected via an operation valve 28. .
  • the oil equalizing pipe 27 or a pressure equalizing pipe provided in parallel therewith connects the low pressure paths (refrigerant suction pipes 20B) between the four-way switching valves 13 and the compressors 10 of the plurality of outdoor units 2A and 2B to each other. It has a function as a low-pressure communication pipe that equalizes the low pressure of the path.
  • the compressor 10 here is a low-pressure housing type compressor in which the inside of the housing has a low-pressure refrigerant atmosphere. Further, the four-way switching valve 13 incorporated in the outdoor refrigerant circuit 21 of each of the outdoor units 2A and 2B is for switching the refrigeration cycle 6 between the cooling cycle shown in FIG. 1 and the heating cycle shown in FIG. Yes, it has the following configuration.
  • the four-way switching valve 13 includes a valve main body 30, and is provided with a high-pressure port 31 connected to the refrigerant discharge pipe 20 ⁇ / b> A from the compressor 10 on one side wall surface of the valve main body 30.
  • a first port 33 and a second port 34 to which the refrigerant gas pipe 20D connected to the heat exchanger 14 is connected are provided. Further, in the internal flow path 35 of the valve main body 30, on the valve seat portion on the other side wall surface.
  • the slide valve body 36 that is in sliding contact is built in.
  • the slide valve body 36 is provided with a switching channel 37 for communicating the low pressure port 32 with either the first port 33 or the second port 34 on the sliding contact surface side, and a pair of pistons 38 at both ends. 39 are coupled to each other, and a pair of left and right first pilot chambers 40 and second pilot chambers 41 defined by the pistons 38 and 39 from the internal flow path 35 are formed. Note that the refrigerant gas slightly leaks between the internal flow path 35 in the valve body 30 and the first pilot chamber 40 and the second pilot chamber 41 due to a minute gap between the valve body 30 and the pistons 38 and 39. It is like that.
  • the four-way switching valve 13 is provided with a pilot valve 42 for switching the communication state between the first pilot chamber 40 and the second pilot chamber 41 and the low pressure port 32, and the pressure difference between the high pressure and the low pressure is controlled by the first pilot chamber.
  • Chamber 40 and second pilot chamber 41 and by sliding the slide valve body 36 together with the pistons 38 and 39 in the valve body 30 by the pressure difference, the high pressure port 31, the low pressure port 32, the first port 33 and The communication state with the second port 34 can be switched.
  • the pilot valve 42 includes a valve main body 43, an electromagnetic coil 44 installed on one end side of the valve main body 43, a plunger 45 that is attracted by exciting the electromagnetic coil 44, and the electromagnetic coil 44 in a non-excited state.
  • a spring 46 that pushes out the plunger 45 and a valve body 47 that switches one of the first pilot chamber 40 and the second pilot chamber 41 to the low-pressure port 32 in response to the operation of the plunger 45 are provided. Yes.
  • the plurality of indoor units 3A and 3B have an indoor side refrigerant circuit 52 including an indoor heat exchanger 50 and a cooling expansion valve (EEVC) 51, and include refrigerant liquid pipes 4A and 4B and refrigerant gas pipes 5A, It is connected in parallel to the refrigeration cycle 6 via 5B.
  • EEVC cooling expansion valve
  • the four-way switching valve 13 When the air conditioning system 1 is operated in a cooling cycle, the four-way switching valve 13 is not energized with the pilot valve 42 and the electromagnetic coil 44 is not excited. Therefore, as shown in FIG.
  • the valve body 47 When the valve body 47 is pushed out, the first pilot chamber 40 is in communication with the low pressure port 32. Therefore, when the compressor 10 is driven and a high pressure is applied to the internal flow path 35 from the refrigerant discharge pipe 20 ⁇ / b> A via the high pressure port 31, the slide valve body is caused by the high / low pressure difference between the first pilot chamber 40 and the internal flow path 35. 36 is in the cooling cycle position shown in FIG. 2, and the high pressure port 31 and the second port 34, and the low pressure port 32 and the first port 33 are in communication with each other.
  • the refrigerant discharged from the compressor 10 to the refrigerant discharge pipe 20A is, as shown by solid line arrows in FIG. 1, the oil separator 11, the check valve 12, the four-way switching valve 13, the outdoor heat exchanger 14, and the heating Expansion valve (EEVH) 15, receiver 16, liquid side operation valve 17, refrigerant liquid pipes 4, 4A, 4B, cooling expansion valve (EEVC) 51, indoor heat exchanger 50, refrigerant gas pipes 5, 5A, 5B, gas It circulates in the cooling cycle returning to the compressor 10 through the side operation valve 18, the four-way switching valve 13, the refrigerant suction pipe 20 ⁇ / b> B and the accumulator 19.
  • EEVH Heating Expansion valve
  • EEVC cooling expansion valve
  • the refrigerant condensed and liquefied by the outdoor heat exchanger 14 is adiabatically expanded by the cooling expansion valve (EEVC) 51 and absorbs heat from the air heat exchanged by the indoor heat exchanger 50 to be evaporated and gasified. Used for indoor cooling.
  • the thick line portion in the refrigeration cycle 6 shown in FIG. 1 indicates the high pressure side, and the thin line portion indicates the low pressure side.
  • the four-way switching valve 13 is energized to the pilot valve 42 and the electromagnetic coil 44 is excited, so that the plunger 45 and the valve body 47 resist the spring 46.
  • the second pilot chamber 41 is in communication with the low pressure port 32 by being attracted to the electromagnetic coil 44 side. Therefore, when the compressor 10 is driven and a high pressure is applied to the internal flow path 35 from the refrigerant discharge pipe 20 ⁇ / b> A via the high pressure port 31, the slide valve body is caused by the high / low pressure difference between the second pilot chamber 41 and the internal flow path 35. 36 slides and moves from the left side position shown in FIG. 2 to the right side position to be in the heating cycle position, and the high pressure port 31 and the first port 33 and the low pressure port 32 and the second port 34 are in communication with each other. .
  • the refrigerant discharged from the compressor 10 to the refrigerant discharge pipe 20A by the switching of the four-way switching valve 13 to the heating cycle position is the oil separator 11, the check valve 12, and the four-way switching valve as shown by solid line arrows in FIG. 13, gas side operation valve 18, refrigerant gas pipes 5, 5A, 5B, indoor heat exchanger 50, cooling expansion valve (EEVC) 51, refrigerant liquid pipes 4, 4A, 4B, refrigerant liquid pipes 4, 4A, 4B, It circulates in the heating cycle which returns to the compressor 10 through the receiver 16, the heating expansion valve (EEVH) 15, the outdoor heat exchanger 14, the four-way switching valve 13, the refrigerant suction pipe 20B, and the accumulator 19.
  • EEVC cooling expansion valve
  • the refrigerant condensed and liquefied by radiating heat to the air heat-exchanged by the indoor heat exchanger 50 is adiabatically expanded by the heating expansion valve (EEVH) 15 and evaporated by the outdoor heat exchanger 14. Therefore, it is used for indoor heating.
  • the thick line part in the refrigerating cycle 6 shown in FIG. 3 is a high voltage
  • the outdoor controllers 60A and 60B and the indoor controller correspond to the operation command from the remote controller or the like, and the rotation speed of the compressor 10, the four-way switching valve 13 Switching, the opening degree of the cooling expansion valve (EEVC) 51 and the heating expansion valve (EEVH) 15, the rotational speeds of indoor fans and outdoor fans (not shown), and the like are appropriately controlled. .
  • the outdoor controllers 60A and 60B not only control the number of operating units of the plurality of outdoor units 2A and 2B according to the air conditioning load, but also the compressor 10 of any of the outdoor units 2A and 2B breaks down.
  • the backup operation control units 61A and 61B that operate the normal outdoor units 2A and 2B and continue the air conditioning operation are provided.
  • the backup operation control units 61A and 61B include the four-way switching valve 13 of the malfunctioning outdoor units 2A and 2B when the four-way switching valve 13 is switched from the cooling cycle position to the heating cycle position during the backup operation.
  • the four-way switching valve synchronization control units 62A and 62B for switching to the heating cycle position in a reliable manner.
  • the normal four-way switching valve 13 of the outdoor unit 2A is once set as the cooling cycle position.
  • the normal four-way switching valve 13 of the outdoor unit 2A is once set as the cooling cycle position.
  • the failure outdoor unit 2B since the compressor 10 has failed, a predetermined value required when switching the four-way switching valve 13 from the cooling cycle position to the heating cycle position (the product specification of the four-way switching valve 13 may be different).
  • the failure outdoor unit 2B is not possible.
  • the four-way switching valve 13 cannot be switched to the heating cycle position synchronously, and as shown in FIG. 4, as shown in FIG. 4, the refrigerant flows into the low-pressure suction path from the four-way switching valve 13 of the malfunctioning outdoor unit 2 B to the compressor 10.
  • the four-way switching valve synchronization control units 62A and 62B are for solving this problem.
  • FIG. 6 shows a state in which the four-way switching valve 13 of the failed outdoor unit 2B is synchronized with the same heating cycle position as that of the normal four-way switching valve 13 of the outdoor unit 2A. Is the heating cycle position, it is possible to prevent the high-pressure refrigerant gas from being applied to the low-pressure suction path (refrigerant suction pipe 20B) from the four-way switching valve 13 to the compressor 10.
  • FIGS. 7 and 8 are flowcharts showing the control functions of the above-described four-way switching valve synchronization control units 62A and 62B.
  • an operable unit (outdoor A control function for synchronously switching the four-way switching valve 13 of the failed outdoor unit 2B from the cooling cycle position to the heating cycle position by the operation of the unit 2A) will be specifically described with reference to FIGS.
  • FIG. 7 is a flowchart for the cases (2) and (3).
  • the process proceeds to step S2 and normal operation is possible.
  • a heating operation command by backup operation is output to the outdoor unit 2A.
  • the normal outdoor unit 2A is first operated with the four-way switching valve 13 in the cooling cycle position in which the high pressure port 31 and the second port 34 and the low pressure port 32 and the first port 33 are communicated.
  • step S4 the process proceeds to step S4, where, as in (2) or (3) above, whether the detected value by the low pressure sensor 26 is equal to or less than a predetermined value, or the detected values of the high pressure sensor 25 and the low pressure sensor 26. It is determined whether or not the difference (high pressure-low pressure) is equal to or greater than a predetermined value. If YES is determined, the process proceeds to step S5, and a switching command is output to the four-way switching valve 13 of the failed outdoor unit 2B. Accordingly, the process proceeds to step S6, where the low-pressure pressure of the four-way switching valve 13 of the failed outdoor unit 2B is reduced, and an operating differential pressure for moving the slide valve body 36 from the cooling cycle position to the heating cycle position is secured as described above. Therefore, even when the compressor 10 is stopped, it can be switched to the heating cycle position.
  • step S7 a switching command is output with respect to the four-way selector valve 13 of the normal outdoor unit 2A currently operated as a cooling cycle position, and the normal outdoor unit 2A is switched to the heating cycle position in step S8. It operates by a heating cycle and can start backup heating operation as Step S9.
  • FIG. 8 shows a flowchart for the case (1).
  • step S14 steps other than determining whether the rotational speed of the compressor 10 of the normal outdoor unit 2A operating in the cooling cycle has reached a predetermined rotational speed, that is, steps S11 to S11.
  • Step S13 and steps S15 to S19 are the same as steps S1 to S3 and steps S5 to S9 described with reference to FIG.
  • the following operational effects are obtained.
  • the outdoor unit 2A or 2B in this case, the outdoor unit 2B
  • the backup operation control units 61A and 61B continue the air conditioning operation by operating the normal outdoor unit 2A.
  • the four-way switching valve 13 of the failed outdoor unit 2B is maintained as it is in the cooling cycle position or the heating cycle position.
  • the normal four-way switching valve 13 of the outdoor unit 2A may be set to the cooling cycle position or the heating cycle position, and the backup operation may be performed by synchronizing the positions of the four-way switching valves 13 of the outdoor units 2A and 2B.
  • the four-way switching valve 13 must be switched to the cooling cycle position or the heating cycle position during the backup operation, and in this case, the four-way switching valve 13 of the normal outdoor unit 2A ensures an operating differential pressure. Since it can be switched to the heating cycle position as usual, the four-way switching valve 13 of the failure outdoor unit 2B has a compressor 10 failure and ensures a high-low pressure difference (for example, 0.3 MPa) of a predetermined value or more. In some cases, the four-way switching valve 13 cannot be synchronized with the heating cycle position.
  • the four-way switching valve synchronization controllers 62A and 62B once operate the four-way switching valve 13 of the normal outdoor unit 2A as the cooling cycle position to reduce the low pressure of the normal outdoor unit 2A.
  • the failure outdoor unit 2B side By reducing the low pressure on the failure outdoor unit 2B side through the refrigerant gas pipe 5B, it is determined that a pressure difference of 3 MPa or more is secured in any of the above (1) to (3), and the failure outdoor By issuing a switching command to the heating cycle position to the four-way switching valve 13 of the unit 2B, switching the four-way switching valve 13 to the heating cycle position, and then switching the four-way switching valve 13 of the normal outdoor unit 2A to the heating cycle position.
  • the four-way switching valve 13 of each outdoor unit 2A, 2B can be synchronized with the heating cycle position.
  • the four-way switching valve 13 of the malfunctioning outdoor unit 2B cannot be ensured to have an operating differential pressure required for switching from the cooling cycle position to the heating cycle position, and the four-way switching valve 13 cannot be switched synchronously to the heating cycle position.
  • the problems such as the application of the high-pressure refrigerant gas to the low-pressure path of the failed outdoor unit 2B and the total stop of the air conditioning system can be solved, and the normal outdoor unit 2A can be reliably operated to execute the backup operation.
  • the low pressure paths (refrigerant suction pipes 20B) between the four-way switching valves 13 of the plurality of outdoor units 2A and 2B and the compressor 10 are connected to each other via low pressure communication pipes such as an oil equalizing pipe 27 or a pressure equalizing pipe.
  • low pressure communication pipes such as an oil equalizing pipe 27 or a pressure equalizing pipe.
  • a high-pressure bypass circuit 70 having an electromagnetic valve 71 is provided between the refrigerant discharge pipes 20A of the plurality of outdoor units 2A and 2B, and the electromagnetic valve 71 is switched in four directions, compared to the first embodiment described above.
  • the difference is that the valve synchronization control units 63A and 63B perform opening / closing control. Since other points are the same as those in the first embodiment, the description thereof will be omitted.
  • the high pressure bypass circuit 70 provided with the electromagnetic valve 71 between the refrigerant discharge pipes 20A of the plurality of outdoor units 2A, 2B via the operation valve 72 for pipe connection. Connected by. Then, a certain outdoor unit in the plurality of outdoor units 2A and 2B, for example, the compressor 10 of the outdoor unit 2B breaks down, and another normal outdoor unit such as the outdoor unit 2A is operated by the backup operation control units 61A and 61B.
  • the four-way switching valve synchronization controller 73A that opens the electromagnetic valve 71 of the high-pressure bypass circuit 70 is opened. , 73B.
  • two electromagnetic valves 71 are provided in the high pressure bypass circuit 70. This is because the plurality of outdoor units 2A and 2B have a common configuration. Of course, it is also possible to have a configuration in which one electromagnetic valve 71 is provided.
  • the high pressure is supplied via the four-way switching valve synchronization control units 73A and 73B.
  • the electromagnetic valve 71 of the bypass circuit 70 By opening the electromagnetic valve 71 of the bypass circuit 70, the high-pressure refrigerant gas discharged from the normal outdoor unit 2A is applied to the refrigerant discharge pipe 20A of the failed outdoor unit 2B, and the four-way switching valve 13 of the failed outdoor unit 2B is turned on.
  • a differential pressure (high / low pressure difference) necessary for switching from the cooling cycle position to the heating cycle position can be secured, and the four-way switching valve 13 can be switched to the heating cycle position and synchronized. Therefore, according to this embodiment, the same effect as that of the first embodiment can be expected.
  • this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably.
  • a backup operation is performed for the operable unit (for example, the outdoor unit 2A) to perform air conditioning operation.
  • the four-way switching valve 13 of the failed outdoor unit 2B is synchronously switched from the cooling cycle position to the heating cycle position, but the outdoor unit 2A during the backup operation is defrosted during the backup heating operation.
  • the four-way switching valve 13 In order to perform the operation or the oil return operation, the four-way switching valve 13 needs to be synchronously switched when the operation is switched to the cooling cycle, and when the operation is completed and the operation is returned to the backup heating operation. It goes without saying that the present invention can be similarly applied to such a case.

Abstract

An air conditioning system (1) provided with backup operation control units (61A, 61B) that, when a compressor (10) of a particular outdoor unit among a plurality of outdoor units (2A, 2B) has malfunctioned, carries out a backup operation for the normal outdoor unit, wherein the backup operation control units (61A, 61B) are provided with four-way-switching-valve synchronization control units (62A, 62B) such that when the four-way switching valves (13) are operated during the backup operation by being switched from an air-cooling position to an air-warming position, the four-way switching valve (13) in the normal-functioning outdoor unit is operated so as to be temporarily placed in the air-cooling position, the low pressure of the malfunctioning outdoor unit is reduced, the four-way switching valve (13) in the malfunctioning outdoor unit is switched to the air-warming position with the actuating pressure differential of the four-way switching valve (13) being ensured, the four-way switching valve (13) in the normal-functioning outdoor unit is then switched to the air-warming position, and the four-way switching valves (13) are synchronized.

Description

空調システムAir conditioning system
　本発明は、冷凍サイクルに対して、圧縮機、四方切換弁および室外熱交換器を備えた複数台の室外ユニットが並列に接続されている空調システムに関するものである。 The present invention relates to an air conditioning system in which a plurality of outdoor units including a compressor, a four-way switching valve, and an outdoor heat exchanger are connected in parallel to a refrigeration cycle.
　従来の空調システムにおいて、室外ユニットに複数台の圧縮機が搭載されている空調システムでは、圧縮機の中の任意の１台が故障した場合、あるいは１系統の冷凍サイクルに対して複数台の室外ユニットが並列に接続されている空調システムでは、任意の室外ユニットの圧縮機が故障した場合、空調システムが全停止に至る事態を避けるため、正常な圧縮機あるいは室外ユニットを運転して空調運転を継続するバックアップ運転機能を備えた空調システムが提供されている。 In a conventional air conditioning system, in an air conditioning system in which a plurality of compressors are installed in an outdoor unit, if any one of the compressors fails or a plurality of outdoor units are used for one refrigeration cycle In an air conditioning system in which units are connected in parallel, if a compressor of any outdoor unit fails, the air conditioning system can be operated by operating a normal compressor or outdoor unit in order to avoid a situation where the air conditioning system will be completely stopped. Air conditioning systems with continuous backup operation functions are provided.
　かかる空調システムの中、複数台の室外ユニットが並列に接続されている空調システムでは、バックアップ運転時、室外ユニット同士の運転モードを同一にすべく、四方切換弁の位置を冷房サイクル位置または暖房サイクル位置に同期させる必要がある。この際、室外ユニットに複数台の圧縮機が搭載されている場合、その一部が故障しても、残りの圧縮機を運転することにより四方切換弁を切換えることができるが、室外ユニットの搭載圧縮機が１台の場合もしくは搭載圧縮機の全てが故障した場合、その室外ユニットの圧縮機が運転できないことから、四方切換弁を同期させることができない場合がある。 Among such air conditioning systems, in an air conditioning system in which a plurality of outdoor units are connected in parallel, the position of the four-way switching valve is set to the cooling cycle position or the heating cycle in order to make the operation mode of the outdoor units the same during backup operation. Must be synchronized to position. At this time, if multiple compressors are installed in the outdoor unit, the four-way selector valve can be switched by operating the remaining compressors even if some of them are broken. When the number of compressors is one or when all of the on-board compressors fail, the compressor of the outdoor unit cannot be operated, and thus the four-way selector valve may not be synchronized.
　つまり、四方切換弁を無通電状態の冷房サイクル位置から通電状態の暖房サイクル位置の切換えるには、スライド弁体をスライドさせるため、所定値（四方切換弁の製品仕様にもよるが、通常、０．３ＭＰａ）以上の高低圧差を確保する必要がある。しかし、圧縮機が故障している室外ユニットでは、その高低圧差を確保することができないため、四方切換弁を暖房サイクル位置に同期切換えすることができず、その結果としてシステムの運転ができなくなる場合があった。 That is, in order to switch the four-way switching valve from the non-energized cooling cycle position to the energized heating cycle position, the slide valve body is slid so that a predetermined value (normally 0, although depending on the product specifications of the four-way switching valve). It is necessary to ensure a high and low pressure difference of 3 MPa) or more. However, in the outdoor unit where the compressor is broken, the high / low pressure difference cannot be secured, so the four-way switching valve cannot be switched synchronously to the heating cycle position, and as a result, the system cannot be operated. was there.
　これは、正常な室外ユニットの四方切換弁を暖房サイクル位置とし、暖房サイクルで運転できたとしても、圧縮機が故障している室外ユニット側の四方切換弁は、暖房サイクル位置に切換えることができないため、冷房サイクル位置のままとなる。この場合、故障室外ユニット側の四方切換弁から圧縮機に至る低圧系の吸入経路に、正常室外ユニットを運転することにより発生した高圧が冷媒ガス管を介して印加されることになり、かかる事態を防止すべく、空調システムの運転を禁止するようにしているためである。 This is because, even if the normal four-way switching valve of the outdoor unit is set to the heating cycle position and the operation can be performed in the heating cycle, the four-way switching valve on the outdoor unit side where the compressor is broken cannot be switched to the heating cycle position. Therefore, the cooling cycle position remains. In this case, the high pressure generated by operating the normal outdoor unit is applied via the refrigerant gas pipe to the low pressure system suction path from the four-way switching valve on the failed outdoor unit side to the compressor. This is because the operation of the air conditioning system is prohibited in order to prevent this.
　上記の如く、圧縮機故障等の異常発生時、四方切換弁の方向が室外ユニット間で異なる状態となり、そのまま運転を継続したとき、高圧冷媒と低圧冷媒とがショートして高圧カットによりシステムが停止される。これの繰り返しにより室外ユニットがダメージを受ける等の問題を解決するため、異常発生時、システムの運転をいったん停止し、各室外ユニットの四方切換弁の方向を同一方向に合わせて同期させた後、システムを再起動する制御手段を備えたものが、特許文献１に示されている。 As described above, when an abnormality such as a compressor failure occurs, the direction of the four-way switching valve is different between outdoor units. When the operation is continued as it is, the high-pressure refrigerant and the low-pressure refrigerant are short-circuited and the system stops due to the high-pressure cut. Is done. In order to solve problems such as damage to the outdoor unit due to repetition of this, when an abnormality occurs, the system operation is temporarily stopped and the direction of the four-way switching valve of each outdoor unit is synchronized in the same direction, Japanese Patent Application Laid-Open No. H10-228667 discloses a control means for restarting the system.
特開平６－３４１７４２号（特許第３２０３０９６号）公報JP-A-6-341742 (Patent No. 3203096)
　しかしながら、上記特許文献１に示すものは、異常発生時、システムの運転をいったん停止しなければならないため、例えば、冷房サイクルで冷房運転しているときに、暖房運転に切換える際にも、そのまま故障室外ユニットの四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えることができず、いったんシステムを停止しなければならないものであり、しかも、各室外ユニットの四方切換弁の方向を如何にして同期させるのかについての具体的方法、手段を開示するものではなかった。 However, since the system disclosed in Patent Document 1 has to stop the operation of the system once an abnormality occurs, for example, when the cooling operation is performed in the cooling cycle, when the operation is switched to the heating operation, the failure is caused as it is. The four-way switching valve of the outdoor unit cannot be switched from the cooling cycle position to the heating cycle position, and the system must be stopped once, and how to synchronize the direction of the four-way switching valve of each outdoor unit. It did not disclose a specific method or means for the above.
　本発明は、このような事情に鑑みてなされたものであって、並列に接続された複数台の室外ユニットのいずれかのユニットの圧縮機が故障した場合でも、確実に四方切換弁を同期させてバックアップ運転ができる空調システムを提供することを目的とする。 The present invention has been made in view of such circumstances, and even when a compressor of any one of a plurality of outdoor units connected in parallel fails, the four-way switching valve is reliably synchronized. The purpose is to provide an air conditioning system capable of backup operation.
　上記した課題を解決するために、本発明の空調システムは、以下の手段を採用する。
　すなわち、本発明にかかる空調システムは、室内ユニット側および室外ユニット側の冷媒回路を冷媒液管、冷媒ガス管により接続して構成される１系統の冷凍サイクルと、少なくとも１台の圧縮機、前記冷凍サイクルを冷房または暖房サイクルのいずれかに切換える四方切換弁および室外熱交換器を備え、前記冷凍サイクルに対して並列に接続される複数台の前記室外ユニットと、前記複数台の室外ユニット中の或る室外ユニットの前記圧縮機が故障した時、他の正常な室外ユニットをバックアップ運転して空調運転を継続するバックアップ運転制御部と、を備えた空調システムであって、前記バックアップ運転制御部は、バックアップ運転時、前記四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際に、前記正常室外ユニットの前記四方切換弁をいったん冷房サイクル位置として運転し、前記故障室外ユニットの低圧圧力を低下させ、前記故障室外ユニットの前記四方切換弁の作動差圧を確保して該四方切換弁を暖房サイクル位置に切換えた後、前記正常室外ユニットの前記四方切換弁を暖房サイクル位置に切換え、前記四方切換弁を同期させて暖房サイクルで運転する四方切換弁同期制御部を備えていることを特徴とする。 In order to solve the above problems, the air conditioning system of the present invention employs the following means.
That is, an air conditioning system according to the present invention includes a single refrigeration cycle configured by connecting refrigerant circuits on an indoor unit side and an outdoor unit side by a refrigerant liquid pipe and a refrigerant gas pipe, at least one compressor, A four-way switching valve and an outdoor heat exchanger for switching the refrigeration cycle to either a cooling or heating cycle, and a plurality of the outdoor units connected in parallel to the refrigeration cycle, and the plurality of outdoor units A backup operation control unit configured to continue the air conditioning operation by performing a backup operation of another normal outdoor unit when the compressor of a certain outdoor unit breaks down, the backup operation control unit comprising: In the backup operation, when the four-way switching valve is operated by switching from the cooling cycle position to the heating cycle position, The four-way switching valve of the unit is once operated in the cooling cycle position, the low-pressure pressure of the failed outdoor unit is lowered, the operating differential pressure of the four-way switching valve of the failed outdoor unit is secured, and the four-way switching valve is heated. After switching to a position, the four-way switching valve of the normal outdoor unit is switched to a heating cycle position, and a four-way switching valve synchronization control unit that operates in a heating cycle by synchronizing the four-way switching valve is provided. .
　本発明によれば、複数台の室外ユニット中の或る室外ユニットの圧縮機が故障した時、他の正常な室外ユニットをバックアップ運転して空調運転を継続するバックアップ運転制御部を備えた空調システムにあって、バックアップ運転制御部に、バックアップ運転時、四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際に、正常室外ユニットの四方切換弁をいったん冷房サイクル位置として運転し、故障室外ユニットの低圧圧力を低下させ、故障室外ユニットの四方切換弁の作動差圧を確保して当該四方切換弁を暖房サイクル位置に切換えた後、正常室外ユニットの四方切換弁を暖房サイクル位置に切換え、四方切換弁を同期させて暖房サイクルで運転する四方切換弁同期制御部を設けているため、バックアップ運転時、四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際にも、故障室外ユニットの四方切換弁を、確実に作動差圧を確保して冷房サイクル位置から暖房サイクル位置に切換え、暖房サイクル位置に同期させてバックアップ運転することができる。従って、故障室外ユニットの四方切換弁を冷房サイクル位置から暖房サイクル位置への切換えに必要な作動差圧を確保できず、その四方切換弁を暖房サイクル位置に同期切換えできないことによって発生する故障室外ユニットの低圧経路への高圧冷媒ガスの印加や空調システムの全停止等の問題を解消し、確実に正常室外ユニットを運転してバックアップ運転することができる。 According to the present invention, when a compressor of a certain outdoor unit among a plurality of outdoor units breaks down, the air conditioning system includes a backup operation control unit that continues the air conditioning operation by performing a backup operation of another normal outdoor unit. In the backup operation control unit, during the backup operation, when the four-way switching valve is switched from the cooling cycle position to the heating cycle position, the four-way switching valve of the normal outdoor unit is once operated as the cooling cycle position, resulting in a failure. Reduce the low pressure of the outdoor unit, secure the differential pressure of the four-way switching valve of the failed outdoor unit, switch the four-way switching valve to the heating cycle position, and then switch the four-way switching valve of the normal outdoor unit to the heating cycle position. Because the four-way selector valve synchronization control unit is operated to synchronize the four-way selector valve and operate in the heating cycle, backup operation When switching the four-way switching valve from the cooling cycle position to the heating cycle position, the four-way switching valve of the malfunctioning outdoor unit is switched from the cooling cycle position to the heating cycle position to ensure a working differential pressure. Backup operation can be performed in synchronization with the cycle position. Therefore, the failure outdoor unit that occurs when the four-way switching valve of the failed outdoor unit cannot ensure the operation differential pressure necessary for switching from the cooling cycle position to the heating cycle position, and the four-way switching valve cannot be switched synchronously to the heating cycle position. This eliminates problems such as the application of high-pressure refrigerant gas to the low-pressure path and the total stop of the air-conditioning system, and the normal outdoor unit can be reliably operated for backup operation.
　さらに、本発明の空調システムは、上記の空調システムにおいて、前記四方切換弁同期制御部は、前記正常室外ユニット側の前記圧縮機の回転数が所定回転数に達したとき、前記故障室外ユニットの前記四方切換弁に暖房サイクル位置への切換指令を出力する構成とされていることを特徴とする。 Furthermore, in the air conditioning system according to the present invention, in the above air conditioning system, the four-way switching valve synchronization control unit is configured such that when the rotational speed of the compressor on the normal outdoor unit side reaches a predetermined rotational speed, The four-way switching valve is configured to output a switching command to the heating cycle position.
　本発明によれば、四方切換弁同期制御部が、正常室外ユニット側の圧縮機回転数が所定回転数に達したとき、故障室外ユニットの四方切換弁に暖房サイクル位置への切換え指令を出力する構成とされているため、正常室外ユニット側の圧縮機回転数が所定回転数に達したことを以って、故障室外ユニットの低圧が低下し、四方切換弁を暖房サイクル位置に切換えるのに必要な差圧が確保されていると見做して切換指令を出力し、故障室外ユニットの四方切換弁を暖房サイクル位置に切換えることができる。従って、現行システムに対してハード的な変更を施すことなく、ソフト面の変更のみで、バックアップ運転時、故障室外ユニットの四方切換弁を、確実に冷房サイクル位置から暖房サイクル位置に切換えて同期させ、バックアップ運転することができる。 According to the present invention, the four-way switching valve synchronization control unit outputs a switching command to the heating cycle position to the four-way switching valve of the failed outdoor unit when the compressor rotation speed on the normal outdoor unit side reaches a predetermined rotation speed. Because it is configured, it is necessary to switch the four-way selector valve to the heating cycle position because the low pressure of the failed outdoor unit decreases due to the compressor rotation speed on the normal outdoor unit side reaching the predetermined rotation speed Assuming that a sufficient differential pressure is secured, a switching command is output, and the four-way switching valve of the failed outdoor unit can be switched to the heating cycle position. Therefore, without making a hardware change to the current system, only the software change is required, and during backup operation, the four-way selector valve of the failed outdoor unit is reliably switched from the cooling cycle position to the heating cycle position and synchronized. Can be backed up.
　また、本発明の空調システムは、上記の空調システムにおいて、前記四方切換弁同期制御部は、前記故障室外ユニット側の低圧圧力の検出値が所定値以下に低下したとき、前記故障室外ユニットの前記四方切換弁に暖房サイクル位置への切換指令を出力する構成とされていることを特徴とする。 Further, the air conditioning system of the present invention is the above air conditioning system, wherein the four-way switching valve synchronization control unit is configured such that when the detected value of the low pressure on the failure outdoor unit side falls below a predetermined value, the failure outdoor unit The four-way switching valve is configured to output a switching command to the heating cycle position.
　本発明によれば、四方切換弁同期制御部が、故障室外ユニット側の低圧圧力の検出値が所定値以下に低下したとき、故障室外ユニットの四方切換弁に暖房サイクル位置への切換指令を出力する構成とされているため、故障室外ユニット側の低圧圧力の検出値が所定値以下に低下したことを以って、故障室外ユニットの低圧が低下し、四方切換弁を暖房サイクル位置に切換えるのに必要な差圧が確保されていると見做して切換指令を出力し、故障室外ユニットの四方切換弁を暖房サイクル位置に切換えることができる。従って、現行システムに対してハード的な変更を施すことなく、ソフト面の変更のみで、バックアップ運転時、故障室外ユニットの四方切換弁を、確実に冷房サイクル位置から暖房サイクル位置に切換えて同期させ、バックアップ運転することができる。 According to the present invention, the four-way switching valve synchronization control unit outputs a switching command to the heating cycle position to the four-way switching valve of the failed outdoor unit when the detected value of the low pressure on the failed outdoor unit side falls below a predetermined value. Therefore, when the detected value of the low-pressure pressure on the failure outdoor unit side falls below a predetermined value, the low pressure on the failure outdoor unit decreases, and the four-way selector valve is switched to the heating cycle position. Assuming that the necessary differential pressure is secured, a switching command is output, and the four-way switching valve of the failed outdoor unit can be switched to the heating cycle position. Therefore, without making a hardware change to the current system, only the software change is required, and during backup operation, the four-way selector valve of the failed outdoor unit is reliably switched from the cooling cycle position to the heating cycle position and synchronized. Can be backed up.
　さらに、本発明の空調システムは、上記の空調システムにおいて、前記四方切換弁同期制御部は、前記故障室外ユニット側の高圧圧力および低圧圧力の検出値の差が所定値以上になったとき、前記故障室外ユニットの前記四方切換弁に暖房サイクル位置への切換指令を出力する構成とされていることを特徴とする。 Furthermore, the air conditioning system of the present invention is the above air conditioning system, wherein the four-way switching valve synchronization control unit is configured such that when the difference between the detected values of the high pressure and low pressure on the failed outdoor unit side is a predetermined value or more, A switching command to the heating cycle position is output to the four-way switching valve of the failed outdoor unit.
　本発明によれば、四方切換弁同期制御部が、故障室外ユニット側の高圧圧力および低圧圧力の検出値の差が所定値以上になったとき、故障室外ユニットの四方切換弁に暖房サイクル位置への切換指令を出力する構成とされているため、故障室外ユニット側の高圧圧力および低圧圧力の検出値の差が所定値以上になったことを以って、故障室外ユニットの低圧が低下し、四方切換弁を暖房サイクル位置に切換えるのに必要な差圧が確保されていると見做して切換指令を出力し、故障室外ユニットの四方切換弁を暖房サイクル位置に切換えることができる。従って、現行システムに対してハード的な変更を施すことなく、ソフト面の変更のみで、バックアップ運転時、故障室外ユニットの四方切換弁を、確実に冷房サイクル位置から暖房サイクル位置に切換えて同期させ、バックアップ運転することができる。 According to the present invention, when the difference between the detected values of the high pressure and low pressure on the failed outdoor unit side is equal to or greater than a predetermined value, the four-way switching valve synchronization control unit moves the four-way switching valve of the failed outdoor unit to the heating cycle position. Since the difference between the detected values of the high pressure and low pressure on the failed outdoor unit side is equal to or greater than a predetermined value, the low pressure of the failed outdoor unit is reduced. Assuming that the differential pressure necessary to switch the four-way switching valve to the heating cycle position is secured, a switching command is output, and the four-way switching valve of the failed outdoor unit can be switched to the heating cycle position. Therefore, without making a hardware change to the current system, only the software change is required, and during backup operation, the four-way selector valve of the failed outdoor unit is reliably switched from the cooling cycle position to the heating cycle position and synchronized. Can be backed up.
　さらに、本発明の空調システムは、上述のいずれかの空調システムにおいて、前記複数台の室外ユニットの前記四方切換弁と前記圧縮機間の低圧経路が、互いに低圧連通管を介して接続されていることを特徴とする。 Furthermore, in the air conditioning system of the present invention, in any one of the above-described air conditioning systems, the low-pressure paths between the four-way switching valves of the plurality of outdoor units and the compressor are connected to each other via low-pressure communication pipes. It is characterized by that.
　本発明によれば、複数台の室外ユニットの四方切換弁と圧縮機間の低圧経路が、互いに低圧連通管を介して接続されているため、バックアップ運転時、故障室外ユニットの四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて同期する際に、正常室外ユニットを冷房サイクルで運転して故障室外ユニット側の低圧圧力を低下する時、低圧連通管を介して速やかに低圧圧力を低下させることができる。従って、四方切換弁の切換時の信頼性、確実性を高めることができるとともに、切換えに要する時間を短縮化することができる。 According to the present invention, since the low-pressure paths between the four-way switching valves of the plurality of outdoor units and the compressor are connected to each other via the low-pressure communication pipe, the four-way switching valves of the failed outdoor unit are cooled during the backup operation. When switching from the cycle position to the heating cycle position and synchronizing, when operating the normal outdoor unit in the cooling cycle to reduce the low pressure pressure on the failed outdoor unit side, the low pressure pressure should be quickly reduced via the low pressure communication pipe Can do. Therefore, the reliability and certainty at the time of switching of the four-way switching valve can be improved, and the time required for switching can be shortened.
　さらに、本発明の空調システムは、上記の空調システムにおいて、前記低圧連通管は、前記複数台の室外ユニットの前記圧縮機の低圧経路同士を接続する均油管または均圧管とされていることを特徴とする。 Furthermore, the air conditioning system of the present invention is characterized in that, in the above air conditioning system, the low pressure communication pipe is an oil equalizing pipe or a pressure equalizing pipe connecting the low pressure paths of the compressors of the plurality of outdoor units. And
　本発明によれば、低圧連通管が、複数台の室外ユニットの圧縮機の低圧経路同士を接続する均油管または均圧管とされているため、複数台の室外ユニットを備えた空調システムでは複数台の室外ユニットの圧縮機同士あるいはその低圧経路同士を均油管または均圧管で接続している場合が多く、かかるケースでは、その均油管または均圧管を低圧連通管として兼用化し、バックアップ運転時、該均油管または均圧管を介して故障室外ユニット側の低圧圧力を低下させ、故障室外ユニットの四方切換弁を暖房サイクル位置に切換えて同期させることができる。従って、既存の均油管または均圧管を利用し、コストアップを避けて確実に故障室外ユニットの四方切換弁を同期切換えすることができる。 According to the present invention, since the low-pressure communication pipes are oil equalizing pipes or pressure equalizing pipes connecting the low-pressure paths of the compressors of the plurality of outdoor units, a plurality of units are used in an air conditioning system including a plurality of outdoor units. In many cases, the outdoor unit compressors or their low-pressure paths are connected by an oil equalizing pipe or a pressure equalizing pipe.In such a case, the oil equalizing pipe or the pressure equalizing pipe is also used as a low-pressure communication pipe. The low-pressure pressure on the failed outdoor unit side can be reduced via the oil equalizing pipe or the pressure equalizing pipe, and the four-way switching valve of the failed outdoor unit can be switched to the heating cycle position for synchronization. Therefore, the existing oil equalizing pipe or pressure equalizing pipe can be used, and the four-way switching valve of the failed outdoor unit can be switched synchronously reliably without cost increase.
　また、本発明にかかる空調システムは、室内ユニット側および室外ユニット側の冷媒回路を冷媒液管、冷媒ガス管により接続して構成される１系統の冷凍サイクルと、少なくとも１台の圧縮機、前記冷凍サイクルを冷房または暖房サイクルのいずれかに切換える四方切換弁および室外熱交換器を備え、前記冷凍サイクルに対して並列に接続される複数台の前記室外ユニットと、前記複数台の室外ユニット中の或る室外ユニットの前記圧縮機が故障した時、他の正常な室外ユニットをバックアップ運転して空調運転を継続するバックアップ運転制御部と、を備えた空調システムであって、前記複数台の室外ユニットの前記圧縮機と前記四方切換弁間の吐出配管に、該吐出配管同士を連通接続する電磁弁を備えた高圧バイパス回路を設け、前記バックアップ運転制御部に、バックアップ運転時、前記四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際、前記高圧バイパス回路に設けられている前記電磁弁を開として前記故障室外ユニットの前記四方切換弁を暖房サイクル位置に切換え、前記四方切換弁同士を同期させて暖房サイクルで運転する四方切換弁同期制御部を設けたことを特徴とする。 In addition, an air conditioning system according to the present invention includes a single refrigeration cycle configured by connecting refrigerant circuits on an indoor unit side and an outdoor unit side with a refrigerant liquid pipe and a refrigerant gas pipe, at least one compressor, A four-way switching valve and an outdoor heat exchanger for switching the refrigeration cycle to either a cooling or heating cycle, and a plurality of the outdoor units connected in parallel to the refrigeration cycle, and the plurality of outdoor units A backup operation control unit configured to continue the air-conditioning operation by performing a backup operation of another normal outdoor unit when the compressor of a certain outdoor unit breaks down, the plurality of outdoor units The discharge pipe between the compressor and the four-way switching valve is provided with a high-pressure bypass circuit including an electromagnetic valve that connects the discharge pipes to each other, In the backup operation control unit, during the backup operation, when the four-way switching valve is operated by switching from the cooling cycle position to the heating cycle position, the electromagnetic valve provided in the high-pressure bypass circuit is opened, and the failure outdoor unit The four-way switching valve is switched to the heating cycle position, and a four-way switching valve synchronization control unit that operates in the heating cycle by synchronizing the four-way switching valves is provided.
　本発明によれば、複数台の室外ユニット中の或る室外ユニットの圧縮機が故障した時、他の正常な室外ユニットをバックアップ運転して空調運転を継続するバックアップ運転制御部を備えた空調システムにあって、複数台の室外ユニットの圧縮機と四方切換弁間の吐出配管に、該吐出配管同士を連通接続する電磁弁を備えた高圧バイパス回路を設けるとともに、バックアップ運転制御部に、バックアップ運転時、四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際、高圧バイパス回路に設けられている電磁弁を開として障室外ユニットの四方切換弁を暖房サイクル位置に切換え、四方切換弁同士を同期させて暖房サイクルで運転する四方切換弁同期制御部を設けた構成としているため、バックアップ運転時、四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際に、故障室外ユニットの吐出配管に正常室外ユニットから吐出された高圧冷媒ガスを印加し、故障室外ユニットの四方切換弁を、確実に作動差圧を確保して冷房サイクル位置から暖房サイクル位置に切換え、暖房サイクル位置に同期させてバックアップ運転することができる。従って、故障室外ユニットの四方切換弁を冷房サイクル位置から暖房サイクル位置への切換えに必要な作動差圧を確保できず、その四方切換弁を暖房サイクル位置に同期切換えできないことによって発生する故障室外ユニットの低圧経路への高圧冷媒ガスの印加や空調システムの全停止等の問題を解消し、確実に正常室外ユニットを運転してバックアップ運転することができる。 According to the present invention, when a compressor of a certain outdoor unit among a plurality of outdoor units breaks down, the air conditioning system includes a backup operation control unit that continues the air conditioning operation by performing a backup operation of another normal outdoor unit. In addition, the discharge pipe between the compressors of the plurality of outdoor units and the four-way switching valve is provided with a high-pressure bypass circuit having an electromagnetic valve for connecting the discharge pipes to each other, and the backup operation control unit has a backup operation. When the four-way switching valve is operated by switching from the cooling cycle position to the heating cycle position, the four-way switching valve of the outdoor unit is switched to the heating cycle position by opening the solenoid valve provided in the high-pressure bypass circuit. Since the four-way switching valve synchronization control unit is operated to synchronize with each other and operate in the heating cycle, the four-way switch is used during backup operation When switching the valve from the cooling cycle position to the heating cycle position, the high-pressure refrigerant gas discharged from the normal outdoor unit is applied to the discharge pipe of the failed outdoor unit, and the four-way selector valve of the failed outdoor unit is operated reliably. It is possible to switch from the cooling cycle position to the heating cycle position while ensuring the differential pressure, and to perform the backup operation in synchronization with the heating cycle position. Therefore, the failure outdoor unit that occurs when the four-way switching valve of the failed outdoor unit cannot ensure the operation differential pressure necessary for switching from the cooling cycle position to the heating cycle position, and the four-way switching valve cannot be switched synchronously to the heating cycle position. This eliminates problems such as the application of high-pressure refrigerant gas to the low-pressure path and the total stop of the air-conditioning system, and the normal outdoor unit can be reliably operated for backup operation.
　本発明によると、バックアップ運転時、四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際にも、故障室外ユニットの四方切換弁を、確実に作動差圧を確保して冷房サイクル位置から暖房サイクル位置に切換え、暖房サイクル位置に同期させてバックアップ運転することができるため、故障室外ユニットの四方切換弁を冷房サイクル位置から暖房サイクル位置への切換えに必要な作動差圧を確保できず、その四方切換弁を暖房サイクル位置に同期切換えできないことによって発生する故障室外ユニットの低圧経路への高圧冷媒ガスの印加や空調システムの全停止等の問題を解消し、確実に正常室外ユニットを運転してバックアップ運転することができる。 According to the present invention, during the backup operation, even when the four-way switching valve is operated by switching from the cooling cycle position to the heating cycle position, the four-way switching valve of the failed outdoor unit ensures the operation differential pressure to ensure the cooling cycle position. Because it is possible to switch to the heating cycle position and perform backup operation in synchronization with the heating cycle position, the operating differential pressure required for switching the failed outdoor unit's four-way switching valve from the cooling cycle position to the heating cycle position cannot be secured. This eliminates problems such as the application of high-pressure refrigerant gas to the low-pressure path of the failed outdoor unit and the total shutdown of the air-conditioning system caused by the fact that the four-way switching valve cannot be switched synchronously to the heating cycle position. Can be backed up.
本発明の第１実施形態に係る空調システムを冷房サイクルで運転している状態の冷媒回路図である。It is a refrigerant circuit figure of the state which is operating the air-conditioning system concerning a 1st embodiment of the present invention by a cooling cycle. 上記システムの冷媒回路に組込まれる四方切換弁の構成図である。It is a block diagram of the four-way selector valve integrated in the refrigerant circuit of the said system. 上記システムを暖房サイクルで運転している状態の冷媒回路図である。It is a refrigerant circuit figure of the state which is driving | operating the said system by a heating cycle. 上記システムをバックアップ運転する際、故障室外ユニットの四方切換弁を暖房サイクル位置に同期切換えできなかった場合の冷媒回路図である。FIG. 5 is a refrigerant circuit diagram when the four-way switching valve of the failed outdoor unit cannot be switched synchronously to the heating cycle position when performing backup operation of the system. 上記空調システムをバックアップ運転する際、故障室外ユニット側の四方切換弁を暖房サイクル位置に同期切換えしている状態の冷媒回路図である。FIG. 4 is a refrigerant circuit diagram in a state in which the four-way switching valve on the failed outdoor unit side is synchronously switched to the heating cycle position when performing backup operation of the air conditioning system. 図５の状態から故障室外ユニット側の四方切換弁を正常に同期切換えした後の冷媒回路図である。FIG. 6 is a refrigerant circuit diagram after the four-way switching valve on the failed outdoor unit side has been normally synchronously switched from the state of FIG. 5. 上記空調システムのバックアップ運転時における四方切換弁の切換え制御の一例を示すフローチャート図である。It is a flowchart figure which shows an example of switching control of the four-way switching valve at the time of backup operation of the said air conditioning system. 上記空調システムのバックアップ運転時における四方切換弁の切換え制御の他の例を示すフローチャート図である。It is a flowchart figure which shows the other example of switching control of the four-way switching valve at the time of backup operation of the said air conditioning system. 本発明の第２実施形態に係る空調システムの冷媒回路図である。It is a refrigerant circuit figure of the air-conditioning system concerning a 2nd embodiment of the present invention.
　以下に、本発明にかかる実施形態について、図面を参照して説明する。
［第１実施形態］
　以下、本発明の第１実施形態について、図１ないし図８を用いて説明する。
　図１には、本実施形態に係る空調システムを冷房サイクルで運転している状態の冷媒回路図が示され、図２には、その冷媒回路に組込まれる四方切換弁の構成図、図３には、該システムを暖房サイクルで運転している状態の冷媒回路図が示されている。
　本実施形態の空調システム１は、複数台の室外ユニット２Ａ，２Ｂと、複数台の室内ユニット３Ａ，３Ｂとを、いわゆる渡り冷媒液管４および冷媒ガス管５を介して各々を互いに並列に接続し、１系統の冷凍サイクル６を構成したシステムとされている。 Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a refrigerant circuit diagram in a state where the air conditioning system according to the present embodiment is operated in a cooling cycle. FIG. 2 is a configuration diagram of a four-way switching valve incorporated in the refrigerant circuit. Shows a refrigerant circuit diagram of the system operating in a heating cycle.
The air conditioning system 1 of the present embodiment connects a plurality of outdoor units 2A and 2B and a plurality of indoor units 3A and 3B in parallel with each other via a so-called transition refrigerant liquid pipe 4 and refrigerant gas pipe 5. And it is set as the system which comprised one refrigerating cycle 6. FIG.
　複数台の室外ユニット２Ａ，２Ｂは、圧縮機１０、油分離器１１、逆止弁１２、四方切換弁１３、室外熱交換器１４、暖房用膨張弁（ＥＥＶＨ）１５、レシーバ１６、液側操作弁１７、ガス側操作弁１８およびアキュームレータ１９等を、冷媒配管２０を介して公知の如く接続することにより室外側冷媒回路２１を構成するとともに、圧縮機１０と油分離器１１との間に電磁弁２２およびキュピラリチューブ２３を備えた油戻し回路２４を接続した構成とされており、冷媒液管４Ａ，４Ｂおよび冷媒ガス管５Ａ，５Ｂを介して冷凍サイクル６に対して並列に接続されている。 The plurality of outdoor units 2A and 2B include a compressor 10, an oil separator 11, a check valve 12, a four-way switching valve 13, an outdoor heat exchanger 14, a heating expansion valve (EEVH) 15, a receiver 16, and a liquid side operation. The outdoor refrigerant circuit 21 is configured by connecting the valve 17, the gas side operation valve 18, the accumulator 19 and the like through a refrigerant pipe 20 in a known manner, and an electromagnetic wave is provided between the compressor 10 and the oil separator 11. An oil return circuit 24 including a valve 22 and a cupilary tube 23 is connected, and is connected in parallel to the refrigeration cycle 6 via the refrigerant liquid pipes 4A and 4B and the refrigerant gas pipes 5A and 5B. Yes.
　室外側冷媒回路２１における圧縮機１０から四方切換弁１３に至る冷媒吐出配管２０Ａには、高圧圧力センサ２５が設けられ、四方切換弁１３から圧縮機１０に至る冷媒吸入配管２０Ｂには、低圧圧力センサ２６が設けられている。また、各室外ユニット２Ａ，２Ｂの圧縮機１０間には、各圧縮機１０に充填されている油の油面レベルを均一化するための均油管２７が操作弁２８を介して接続されている。この均油管２７あるいはそれと平行して設けられる均圧管等は、複数台の室外ユニット２Ａ，２Ｂの四方切換弁１３と圧縮機１０間の低圧経路（冷媒吸入配管２０Ｂ）同士を互いに接続し、低圧経路の低圧を均圧化する低圧連通管としての機能を有するものとされている。 A high pressure sensor 25 is provided in the refrigerant discharge pipe 20 </ b> A from the compressor 10 to the four-way switching valve 13 in the outdoor refrigerant circuit 21, and a low pressure pressure is provided in the refrigerant suction pipe 20 </ b> B from the four-way switching valve 13 to the compressor 10. A sensor 26 is provided. Further, between the compressors 10 of the outdoor units 2A and 2B, an oil equalizing pipe 27 for equalizing the oil level of the oil filled in each compressor 10 is connected via an operation valve 28. . The oil equalizing pipe 27 or a pressure equalizing pipe provided in parallel therewith connects the low pressure paths (refrigerant suction pipes 20B) between the four-way switching valves 13 and the compressors 10 of the plurality of outdoor units 2A and 2B to each other. It has a function as a low-pressure communication pipe that equalizes the low pressure of the path.
　なお、ここでの圧縮機１０は、ハウジング内が低圧冷媒雰囲気とされる低圧ハウジングタイプの圧縮機とされている。
　さらに、各室外ユニット２Ａ，２Ｂの室外側冷媒回路２１に組込まれている四方切換弁１３は、冷凍サイクル６を図１に示す冷房サイクルと、図３に示す暖房サイクルとに切換えるためのものであり、以下の構成を備えている。 The compressor 10 here is a low-pressure housing type compressor in which the inside of the housing has a low-pressure refrigerant atmosphere.
Further, the four-way switching valve 13 incorporated in the outdoor refrigerant circuit 21 of each of the outdoor units 2A and 2B is for switching the refrigeration cycle 6 between the cooling cycle shown in FIG. 1 and the heating cycle shown in FIG. Yes, it has the following configuration.
　四方切換弁１３は、図２に示されるように、弁本体３０を備え、その弁本体３０一側壁面に圧縮機１０からの冷媒吐出配管２０Ａが接続される高圧ポート３１が設けられ、他側壁面の弁座部に圧縮機１０への冷媒吸入配管２０Ｂが接続される低圧ポート３２と、その低圧ポート３２を挟んでその両側に、後述する室内熱交換器５０に連なる冷媒ガス管２０Ｃおよび室外熱交換器１４に連なる冷媒ガス管２０Ｄが接続される第１ポート３３および第２ポート３４とが設けられ、更に、弁本体３０の内部流路３５内に、他側壁面の弁座部上を摺接するスライド弁体３６が内蔵された構成とされている。 As shown in FIG. 2, the four-way switching valve 13 includes a valve main body 30, and is provided with a high-pressure port 31 connected to the refrigerant discharge pipe 20 </ b> A from the compressor 10 on one side wall surface of the valve main body 30. A low pressure port 32 to which a refrigerant suction pipe 20B to the compressor 10 is connected to a valve seat portion on the wall surface, and a refrigerant gas pipe 20C connected to an indoor heat exchanger 50 (described later) and an outdoor side on both sides of the low pressure port 32 A first port 33 and a second port 34 to which the refrigerant gas pipe 20D connected to the heat exchanger 14 is connected are provided. Further, in the internal flow path 35 of the valve main body 30, on the valve seat portion on the other side wall surface. The slide valve body 36 that is in sliding contact is built in.
　また、上記スライド弁体３６には、摺接面側に低圧ポート３２を第１ポート３３または第２ポート３４のいずれかに連通する切換流路３７が設けられるとともに、両端部に一対のピストン３８，３９が結合されており、そのピストン３８，３９により内部流路３５から区画された左右一対の第１パイロット室４０および第２パイロット室４１が形成されている。なお、弁本体３０内の内部流路３５と第１パイロット室４０および第２パイロット室４１との間は、弁本体３０とピストン３８および３９との間の微小隙間により冷媒ガスが微小漏れされるようになっている。 Further, the slide valve body 36 is provided with a switching channel 37 for communicating the low pressure port 32 with either the first port 33 or the second port 34 on the sliding contact surface side, and a pair of pistons 38 at both ends. 39 are coupled to each other, and a pair of left and right first pilot chambers 40 and second pilot chambers 41 defined by the pistons 38 and 39 from the internal flow path 35 are formed. Note that the refrigerant gas slightly leaks between the internal flow path 35 in the valve body 30 and the first pilot chamber 40 and the second pilot chamber 41 due to a minute gap between the valve body 30 and the pistons 38 and 39. It is like that.
　更に、四方切換弁１３には、第１パイロット室４０および第２パイロット室４１と低圧ポート３２との連通状態を切換えるためのパイロット弁４２が具備されており、高低圧の圧力差を第１パイロット室４０および第２パイロット室４１に与え、その圧力差でスライド弁体３６をピストン３８，３９と共に弁本体３０内を摺動させることにより、高圧ポート３１および低圧ポート３２と、第１ポート３３および第２ポート３４との間の連通状態が切換えられるようになっている。 Further, the four-way switching valve 13 is provided with a pilot valve 42 for switching the communication state between the first pilot chamber 40 and the second pilot chamber 41 and the low pressure port 32, and the pressure difference between the high pressure and the low pressure is controlled by the first pilot chamber. Chamber 40 and second pilot chamber 41, and by sliding the slide valve body 36 together with the pistons 38 and 39 in the valve body 30 by the pressure difference, the high pressure port 31, the low pressure port 32, the first port 33 and The communication state with the second port 34 can be switched.
　上記パイロット弁４２は、弁本体４３と、弁本体４３の一端側に設置されている電磁コイル４４と、電磁コイル４４を励磁することにより吸引されるプランジャ４５と、電磁コイル４４が無励磁状態のとき、プランジャ４５を押し出すバネ４６と、プランジャ４５の動作に応動して第１パイロット室４０または第２パイロット室４１の一方を低圧ポート３２に切換え連通させる弁体４７とを備えた構成とされている。 The pilot valve 42 includes a valve main body 43, an electromagnetic coil 44 installed on one end side of the valve main body 43, a plunger 45 that is attracted by exciting the electromagnetic coil 44, and the electromagnetic coil 44 in a non-excited state. In this case, a spring 46 that pushes out the plunger 45 and a valve body 47 that switches one of the first pilot chamber 40 and the second pilot chamber 41 to the low-pressure port 32 in response to the operation of the plunger 45 are provided. Yes.
　一方、複数台の室内ユニット３Ａ，３Ｂは、室内熱交換器５０および冷房用膨張弁（ＥＥＶＣ）５１を備えた室内側冷媒回路５２を有し、冷媒液管４Ａ，４Ｂおよび冷媒ガス管５Ａ，５Ｂを介して冷凍サイクル６に並列に接続されている。 On the other hand, the plurality of indoor units 3A and 3B have an indoor side refrigerant circuit 52 including an indoor heat exchanger 50 and a cooling expansion valve (EEVC) 51, and include refrigerant liquid pipes 4A and 4B and refrigerant gas pipes 5A, It is connected in parallel to the refrigeration cycle 6 via 5B.
　上記空調システム１を冷房サイクルで運転する際、四方切換弁１３は、パイロット弁４２が無通電で電磁コイル４４が無励磁の状態とされるため、図２に示すように、バネ４６によりプランジャ４５および弁体４７が押し出されることにより、第１パイロット室４０が低圧ポート３２に連通された状態となる。このため、圧縮機１０が駆動され、冷媒吐出配管２０Ａから高圧ポート３１を経て内部流路３５に高圧が印加されると、第１パイロット室４０と内部流路３５との高低圧差でスライド弁体３６は、図２に示す冷房サイクル位置とされ、高圧ポート３１と第２ポート３４、低圧ポート３２と第１ポート３３をそれぞれ連通する状態となる。 When the air conditioning system 1 is operated in a cooling cycle, the four-way switching valve 13 is not energized with the pilot valve 42 and the electromagnetic coil 44 is not excited. Therefore, as shown in FIG. When the valve body 47 is pushed out, the first pilot chamber 40 is in communication with the low pressure port 32. Therefore, when the compressor 10 is driven and a high pressure is applied to the internal flow path 35 from the refrigerant discharge pipe 20 </ b> A via the high pressure port 31, the slide valve body is caused by the high / low pressure difference between the first pilot chamber 40 and the internal flow path 35. 36 is in the cooling cycle position shown in FIG. 2, and the high pressure port 31 and the second port 34, and the low pressure port 32 and the first port 33 are in communication with each other.
　これによって、圧縮機１０から冷媒吐出配管２０Ａに吐出された冷媒は、図１に実線矢印で示す通り、油分離器１１、逆止弁１２、四方切換弁１３、室外熱交換器１４、暖房用膨張弁（ＥＥＶＨ）１５、レシーバ１６、液側操作弁１７、冷媒液管４，４Ａ，４Ｂ、冷房用膨張弁（ＥＥＶＣ）５１、室内熱交換器５０、冷媒ガス管５，５Ａ，５Ｂ、ガス側操作弁１８、四方切換弁１３、冷媒吸入配管２０Ｂおよびアキュームレータ１９を経て圧縮機１０に戻る冷房サイクル内を循環する。 As a result, the refrigerant discharged from the compressor 10 to the refrigerant discharge pipe 20A is, as shown by solid line arrows in FIG. 1, the oil separator 11, the check valve 12, the four-way switching valve 13, the outdoor heat exchanger 14, and the heating Expansion valve (EEVH) 15, receiver 16, liquid side operation valve 17, refrigerant liquid pipes 4, 4A, 4B, cooling expansion valve (EEVC) 51, indoor heat exchanger 50, refrigerant gas pipes 5, 5A, 5B, gas It circulates in the cooling cycle returning to the compressor 10 through the side operation valve 18, the four-way switching valve 13, the refrigerant suction pipe 20 </ b> B and the accumulator 19.
　この間、室外熱交換器１４で凝縮液化された冷媒は、冷房用膨張弁（ＥＥＶＣ）５１で断熱膨張され、室内熱交換器５０で熱交換される空気から吸熱して蒸発ガス化されることにより、室内の冷房等に供される。なお、この冷房サイクルにおいて、図１に示す冷凍サイクル６中の太線部分が高圧側、細線部分が低圧側であることを示している。 During this time, the refrigerant condensed and liquefied by the outdoor heat exchanger 14 is adiabatically expanded by the cooling expansion valve (EEVC) 51 and absorbs heat from the air heat exchanged by the indoor heat exchanger 50 to be evaporated and gasified. Used for indoor cooling. In this cooling cycle, the thick line portion in the refrigeration cycle 6 shown in FIG. 1 indicates the high pressure side, and the thin line portion indicates the low pressure side.
　一方、空調システム１を暖房サイクルで運転する際、四方切換弁１３は、パイロット弁４２に通電され、電磁コイル４４が励磁された状態とされるため、プランジャ４５および弁体４７がバネ４６に抗して電磁コイル４４側に吸引されることにより、第２パイロット室４１が低圧ポート３２に連通された状態となる。このため、圧縮機１０が駆動され、冷媒吐出配管２０Ａから高圧ポート３１を経て内部流路３５に高圧が印加されると、第２パイロット室４１と内部流路３５との高低圧差でスライド弁体３６は、図２に示した左側位置から右側位置に摺動・移動して暖房サイクル位置とされ、高圧ポート３１と第１ポート３３、低圧ポート３２と第２ポート３４をそれぞれ連通する状態となる。 On the other hand, when the air conditioning system 1 is operated in the heating cycle, the four-way switching valve 13 is energized to the pilot valve 42 and the electromagnetic coil 44 is excited, so that the plunger 45 and the valve body 47 resist the spring 46. As a result, the second pilot chamber 41 is in communication with the low pressure port 32 by being attracted to the electromagnetic coil 44 side. Therefore, when the compressor 10 is driven and a high pressure is applied to the internal flow path 35 from the refrigerant discharge pipe 20 </ b> A via the high pressure port 31, the slide valve body is caused by the high / low pressure difference between the second pilot chamber 41 and the internal flow path 35. 36 slides and moves from the left side position shown in FIG. 2 to the right side position to be in the heating cycle position, and the high pressure port 31 and the first port 33 and the low pressure port 32 and the second port 34 are in communication with each other. .
　四方切換弁１３の暖房サイクル位置への切換えにより、圧縮機１０から冷媒吐出配管２０Ａに吐出された冷媒は、図３に実線矢印で示す通り、油分離器１１、逆止弁１２、四方切換弁１３、ガス側操作弁１８、冷媒ガス管５，５Ａ，５Ｂ、室内熱交換器５０、冷房用膨張弁（ＥＥＶＣ）５１、冷媒液管４，４Ａ，４Ｂ、冷媒液管４，４Ａ，４Ｂ、レシーバ１６、暖房用膨張弁（ＥＥＶＨ）１５、室外熱交換器１４、四方切換弁１３、冷媒吸入配管２０Ｂ、アキュームレータ１９を経て圧縮機１０に戻る暖房サイクル内を循環する。 The refrigerant discharged from the compressor 10 to the refrigerant discharge pipe 20A by the switching of the four-way switching valve 13 to the heating cycle position is the oil separator 11, the check valve 12, and the four-way switching valve as shown by solid line arrows in FIG. 13, gas side operation valve 18, refrigerant gas pipes 5, 5A, 5B, indoor heat exchanger 50, cooling expansion valve (EEVC) 51, refrigerant liquid pipes 4, 4A, 4B, refrigerant liquid pipes 4, 4A, 4B, It circulates in the heating cycle which returns to the compressor 10 through the receiver 16, the heating expansion valve (EEVH) 15, the outdoor heat exchanger 14, the four-way switching valve 13, the refrigerant suction pipe 20B, and the accumulator 19.
　この間、室内熱交換器５０で熱交換される空気に放熱することにより凝縮液化された冷媒は、暖房用膨張弁（ＥＥＶＨ）１５で断熱膨張され、室外熱交換器１４で蒸発ガス化されることにより、室内の暖房等に供される。なお、この暖房サイクルにおいて、図３に示す冷凍サイクル６中の太線部分が高圧側、細線部分が低圧側であることを示している。 During this time, the refrigerant condensed and liquefied by radiating heat to the air heat-exchanged by the indoor heat exchanger 50 is adiabatically expanded by the heating expansion valve (EEVH) 15 and evaporated by the outdoor heat exchanger 14. Therefore, it is used for indoor heating. In addition, in this heating cycle, it has shown that the thick line part in the refrigerating cycle 6 shown in FIG. 3 is a high voltage | pressure side, and a thin line part is a low voltage | pressure side.
　上記空調システム１の冷房サイクルあるいは暖房サイクルでの運転は、リモコン等からの運転指令に対応して室外コントローラ６０Ａ，６０Ｂおよび室内コントローラ（図示省略）が、圧縮機１０の回転数、四方切換弁１３の切換え、冷房用膨張弁（ＥＥＶＣ）５１および暖房用膨張弁（ＥＥＶＨ）１５の開度、図示省略の室内ファンおよび室外ファンの回転数等を適宜制御することにより実行されるようになっている。 In the cooling cycle or the heating cycle of the air conditioning system 1, the outdoor controllers 60A and 60B and the indoor controller (not shown) correspond to the operation command from the remote controller or the like, and the rotation speed of the compressor 10, the four-way switching valve 13 Switching, the opening degree of the cooling expansion valve (EEVC) 51 and the heating expansion valve (EEVH) 15, the rotational speeds of indoor fans and outdoor fans (not shown), and the like are appropriately controlled. .
　また、上記室外コントローラ６０Ａ，６０Ｂは、空調負荷に応じて複数台の室外ユニット２Ａ，２Ｂの運転台数をコントロールするだけでなく、その室外ユニット２Ａ，２Ｂのいずれかの圧縮機１０が故障する等により運転できなくなった場合でも、空調システム１が全停止に至る事態を回避すべく、正常な室外ユニット２Ａ，２Ｂを運転して空調運転を継続するバックアップ運転制御部６１Ａ，６１Ｂを備えている。 The outdoor controllers 60A and 60B not only control the number of operating units of the plurality of outdoor units 2A and 2B according to the air conditioning load, but also the compressor 10 of any of the outdoor units 2A and 2B breaks down. In order to avoid a situation in which the air conditioning system 1 is completely stopped even if the air conditioning system 1 cannot be operated due to the operation, the backup operation control units 61A and 61B that operate the normal outdoor units 2A and 2B and continue the air conditioning operation are provided.
　更に、上記バックアップ運転制御部６１Ａ，６１Ｂには、バックアップ運転時、四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換えて運転する際に、故障中の室外ユニット２Ａ，２Ｂの四方切換弁１３を確実に同期して暖房サイクル位置に切換えるための四方切換弁同期制御部６２Ａ，６２Ｂが設けられている。 Further, the backup operation control units 61A and 61B include the four-way switching valve 13 of the malfunctioning outdoor units 2A and 2B when the four-way switching valve 13 is switched from the cooling cycle position to the heating cycle position during the backup operation. Are provided with four-way switching valve synchronization control units 62A and 62B for switching to the heating cycle position in a reliable manner.
　この四方切換弁同期制御部６２Ａ，６２Ｂは、バックアップ運転時、四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換える際、例えば、正常な室外ユニット２Ａの四方切換弁１３をいったん冷房サイクル位置として運転し、故障室外ユニット２Ｂの低圧側圧力を低下させて、故障室外ユニット２Ｂの四方切換弁１３を作動するための差圧を確保し、当該四方切換弁１３を暖房サイクル位置に切換えた後、正常室外ユニット２Ａの四方切換弁１３を暖房サイクル位置に切換えることにより、各室外ユニット２Ａ，２Ｂの四方切換弁１３を暖房サイクル位置に同期させる制御機能を備えたものである。 When the four- way switching valve 62A, 62B switches the four-way switching valve 13 from the cooling cycle position to the heating cycle position during the backup operation, for example, the normal four-way switching valve 13 of the outdoor unit 2A is once set as the cooling cycle position. After operating, lowering the low pressure side pressure of the malfunctioning outdoor unit 2B, ensuring a differential pressure for operating the four-way switching valve 13 of the malfunctioning outdoor unit 2B, and switching the four-way switching valve 13 to the heating cycle position, By switching the four-way switching valve 13 of the normal outdoor unit 2A to the heating cycle position, a control function for synchronizing the four-way switching valve 13 of each outdoor unit 2A, 2B to the heating cycle position is provided.
　つまり、故障室外ユニット２Ｂでは、圧縮機１０が故障しているため、四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換えるときに必要な所定値（四方切換弁１３の製品仕様に異なる場合もあるが、一般に、０．３ＭＰａ程度）以上の差圧を確保できないことから、正常な室外ユニット２Ａの四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換えてバックアップ運転する際、故障室外ユニット２Ｂの四方切換弁１３を同期して暖房サイクル位置に切換えることができず、図４に示すように、故障室外ユニット２Ｂの四方切換弁１３から圧縮機１０に至る低圧系の吸入経路に対し、冷媒ガス管５Ｂを経て正常室外ユニット２Ａから吐出された高圧冷媒ガスが印加される等の問題が発生する。四方切換弁同期制御部６２Ａ，６２Ｂは、この問題を解消するためのものである。 That is, in the failed outdoor unit 2B, since the compressor 10 has failed, a predetermined value required when switching the four-way switching valve 13 from the cooling cycle position to the heating cycle position (the product specification of the four-way switching valve 13 may be different). However, when the backup operation is performed by switching the normal four-way switching valve 13 of the outdoor unit 2A from the cooling cycle position to the heating cycle position, the failure outdoor unit 2B is not possible. The four-way switching valve 13 cannot be switched to the heating cycle position synchronously, and as shown in FIG. 4, as shown in FIG. 4, the refrigerant flows into the low-pressure suction path from the four-way switching valve 13 of the malfunctioning outdoor unit 2 B to the compressor 10. There arises a problem that the high-pressure refrigerant gas discharged from the normal outdoor unit 2A through the gas pipe 5B is applied. The four-way switching valve synchronization control units 62A and 62B are for solving this problem.
　四方切換弁同期制御部６２Ａ，６２Ｂは、上記の如く、例えば正常な室外ユニット２Ａの四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換えてバックアップ運転する時、図５に示すように、正常室外ユニット２Ａの四方切換弁１３をいったん冷房サイクル位置として運転される。この際、故障室外ユニット２Ｂの四方切換弁１３は無通電で冷房サイクル位置となるため、正常室外ユニット２Ａが運転されると、冷媒ガス管５Ｂを介して故障室外ユニット２Ｂの四方切換弁１３から圧縮機１０に至る吸入経路（冷媒吸入配管２０Ｂ）の低圧が低下され、これによって、四方切換弁１３を切換えるために必要な０．３ＭＰａ以上の差圧が確保されることになる。 As shown in FIG. 5, when the four-way switching valve synchronization control units 62A and 62B perform the backup operation by switching the normal four-way switching valve 13 of the outdoor unit 2A from the cooling cycle position to the heating cycle position as described above, for example, The four-way switching valve 13 of the outdoor unit 2A is once operated in the cooling cycle position. At this time, since the four-way switching valve 13 of the failed outdoor unit 2B is not energized and is in the cooling cycle position, when the normal outdoor unit 2A is operated, the four-way switching valve 13 of the failed outdoor unit 2B is operated via the refrigerant gas pipe 5B. The low pressure in the suction path (refrigerant suction pipe 20B) leading to the compressor 10 is lowered, and thereby a differential pressure of 0.3 MPa or more necessary for switching the four-way switching valve 13 is secured.
　そして、下記（１）ないし（３）のいずれかにより、０．３ＭＰａ以上の差圧が確保されたと判断し、故障室外ユニット２Ｂの四方切換弁１３に暖房サイクル位置への切換え指令を出力して四方切換弁１３を暖房サイクル位置に切換えるようにしたものである。
　（１）正常室外ユニット２Ａを冷房サイクルで運転し、その圧縮機１０の回転数が所定回転数に達したとき、故障室外ユニット２Ｂ側の低圧が所定値以下に低下し、所定値（０．３ＭＰａ）以上の差圧が確保されたと判定して故障室外ユニット２Ｂに四方切換弁１３の切換指令を出力する。 Then, it is determined that a differential pressure of 0.3 MPa or more has been secured by any of the following (1) to (3), and a switching command to the heating cycle position is output to the four-way switching valve 13 of the failed outdoor unit 2B. The four-way switching valve 13 is switched to the heating cycle position.
(1) When the normal outdoor unit 2A is operated in the cooling cycle and the rotational speed of the compressor 10 reaches a predetermined rotational speed, the low pressure on the failure outdoor unit 2B side decreases to a predetermined value or less, and the predetermined value (0. It is determined that a differential pressure of 3 MPa or more is secured, and a switching command for the four-way switching valve 13 is output to the failure outdoor unit 2B.
　（２）正常室外ユニット２Ａを冷房サイクルで運転し、故障室外ユニット２Ｂ側の低圧圧力センサ２６により低圧が所定値以下に低下したことが検知されたとき、所定値（０．３ＭＰａ）以上の差圧が確保されたと判定して故障室外ユニット２Ｂに四方切換弁１３の切換指令を出力する。
　（３）正常室外ユニット２Ａを冷房サイクルで運転し、故障室外ユニット２Ｂ側の高圧圧力センサ２５と低圧圧力センサ２６による検出値の差（高圧－低圧）が所定値以上であることが検知されたとき、所定値（０．３ＭＰａ）以上の差圧が確保されたと判定して故障室外ユニット２Ｂに四方切換弁１３の切換指令を出力する。 (2) When the normal outdoor unit 2A is operated in a cooling cycle, and the low pressure sensor 26 on the failed outdoor unit 2B side detects that the low pressure has dropped below a predetermined value, a difference of a predetermined value (0.3 MPa) or more It is determined that the pressure has been secured, and a switching command for the four-way switching valve 13 is output to the failed outdoor unit 2B.
(3) The normal outdoor unit 2A is operated in the cooling cycle, and it is detected that the difference (high pressure-low pressure) detected by the high pressure sensor 25 and the low pressure sensor 26 on the failure outdoor unit 2B side is equal to or greater than a predetermined value. When it is determined that a differential pressure equal to or greater than a predetermined value (0.3 MPa) has been secured, a switching command for the four-way switching valve 13 is output to the failed outdoor unit 2B.
　その後、正常な室外ユニット２Ａの四方切換弁１３を暖房サイクル位置に切換えることにより、正常室外ユニット２Ａおよび故障室外ユニット２Ｂの四方切換弁１３を暖房サイクル位置に同期させるようにしたものである。図６は、故障室外ユニット２Ｂの四方切換弁１３を正常な室外ユニット２Ａの四方切換弁１３と同じ暖房サイクル位置に同期させて状態を示したものであり、故障室外ユニット２Ｂの四方切換弁１３が暖房サイクル位置とされているため、四方切換弁１３から圧縮機１０に至る低圧系の吸入経路（冷媒吸入配管２０Ｂ）に高圧冷媒ガスが印加されるのを防ぐことができる。 Thereafter, the four-way switching valve 13 of the normal outdoor unit 2A is switched to the heating cycle position so that the four-way switching valve 13 of the normal outdoor unit 2A and the failed outdoor unit 2B is synchronized with the heating cycle position. FIG. 6 shows a state in which the four-way switching valve 13 of the failed outdoor unit 2B is synchronized with the same heating cycle position as that of the normal four-way switching valve 13 of the outdoor unit 2A. Is the heating cycle position, it is possible to prevent the high-pressure refrigerant gas from being applied to the low-pressure suction path (refrigerant suction pipe 20B) from the four-way switching valve 13 to the compressor 10.
　図７および図８は、上記した四方切換弁同期制御部６２Ａ，６２Ｂの制御機能を示すフローチャート図である。以下に、複数台の室外ユニット２Ａ，２Ｂを並列に接続した空調システム１において、或る室外ユニット（室外ユニット２Ｂ）が圧縮機１０の故障により運転不可となった時、運転可能なユニット（室外ユニット２Ａ）の運転により、故障室外ユニット２Ｂの四方切換弁１３を冷房サイクル位置から暖房サイクル位置に同期切換えする制御機能について、図７および図８に基づいて具体的に説明する。 7 and 8 are flowcharts showing the control functions of the above-described four-way switching valve synchronization control units 62A and 62B. Hereinafter, in the air conditioning system 1 in which a plurality of outdoor units 2A and 2B are connected in parallel, when a certain outdoor unit (outdoor unit 2B) becomes inoperable due to a failure of the compressor 10, an operable unit (outdoor A control function for synchronously switching the four-way switching valve 13 of the failed outdoor unit 2B from the cooling cycle position to the heating cycle position by the operation of the unit 2A) will be specifically described with reference to FIGS.
　図７は、上記（２），（３）の場合のフローチャート図であり、ステップＳ１において故障室外ユニット２Ｂが圧縮機１０の故障等により運転不可状態になると、ステップＳ２に進み、運転可能な正常室外ユニット２Ａにバックアップ運転による暖房運転指令が出力される。この場合、ステップＳ３において正常室外ユニット２Ａが、まず四方切換弁１３を高圧ポート３１と第２ポート３４、低圧ポート３２と第１ポート３３を連通した冷房サイクル位置として運転される。 FIG. 7 is a flowchart for the cases (2) and (3). When the failed outdoor unit 2B becomes inoperable due to a failure of the compressor 10 or the like in step S1, the process proceeds to step S2 and normal operation is possible. A heating operation command by backup operation is output to the outdoor unit 2A. In this case, in step S3, the normal outdoor unit 2A is first operated with the four-way switching valve 13 in the cooling cycle position in which the high pressure port 31 and the second port 34 and the low pressure port 32 and the first port 33 are communicated.
　この状態でステップＳ４に進み、ここで上記（２）または（３）のように、低圧圧力センサ２６による検出値が所定値以下か否か、もしくは高圧圧力センサ２５と低圧圧力センサ２６の検出値の差（高圧－低圧）が所定値以上か否かが判定され、ＹＥＳと判定された場合、ステップＳ５に進み、故障室外ユニット２Ｂの四方切換弁１３に対して切換指令が出力される。これによってステップＳ６に進み、ここで故障室外ユニット２Ｂの四方切換弁１３は、低圧圧力が低下され、上記の通りスライド弁体３６を冷房サイクル位置から暖房サイクル位置に移動する作動差圧が確保されていることから、圧縮機１０が停止中であっても、暖房サイクル位置に切換えることができる。 In this state, the process proceeds to step S4, where, as in (2) or (3) above, whether the detected value by the low pressure sensor 26 is equal to or less than a predetermined value, or the detected values of the high pressure sensor 25 and the low pressure sensor 26. It is determined whether or not the difference (high pressure-low pressure) is equal to or greater than a predetermined value. If YES is determined, the process proceeds to step S5, and a switching command is output to the four-way switching valve 13 of the failed outdoor unit 2B. Accordingly, the process proceeds to step S6, where the low-pressure pressure of the four-way switching valve 13 of the failed outdoor unit 2B is reduced, and an operating differential pressure for moving the slide valve body 36 from the cooling cycle position to the heating cycle position is secured as described above. Therefore, even when the compressor 10 is stopped, it can be switched to the heating cycle position.
　その後、ステップＳ７に進み、冷房サイクル位置として運転されている正常室外ユニット２Ａの四方切換弁１３に対して、切換指令を出力し、ステップＳ８で暖房サイクル位置に切換えることにより、正常室外ユニット２Ａを暖房サイクルで運転し、ステップＳ９の通りバックアップ暖房運転を開始することができる。 Then, it progresses to step S7, a switching command is output with respect to the four-way selector valve 13 of the normal outdoor unit 2A currently operated as a cooling cycle position, and the normal outdoor unit 2A is switched to the heating cycle position in step S8. It operates by a heating cycle and can start backup heating operation as Step S9.
　一方、上記（１）の場合のフローチャート図が図８に示されている。
　この場合、上記の通り、故障室外ユニット２Ｂ側の低圧が所定値以下に低下し、四方切換弁１３の切換えに必要な０．３ＭＰａ以上の差圧が確保されているか否かを、図８に示すステップＳ１４の通り、冷房サイクルで運転している正常室外ユニット２Ａの圧縮機１０の回転数が所定回転数に達したか否かで判定するようにしている以外のステップ、即ちステップＳ１１～ステップＳ１３およびステップＳ１５～ステップＳ１９については、図７に基づいて説明した各ステップＳ１～ステップＳ３およびステップＳ５～ステップＳ９と同様であるので説明は省略する。 On the other hand, FIG. 8 shows a flowchart for the case (1).
In this case, as described above, whether or not the low pressure on the failure outdoor unit 2B side is reduced to a predetermined value or less and a differential pressure of 0.3 MPa or more necessary for switching the four-way switching valve 13 is ensured in FIG. As shown in step S14, steps other than determining whether the rotational speed of the compressor 10 of the normal outdoor unit 2A operating in the cooling cycle has reached a predetermined rotational speed, that is, steps S11 to S11. Step S13 and steps S15 to S19 are the same as steps S1 to S3 and steps S5 to S9 described with reference to FIG.
　斯くして、本実施形態によれば、以下の作用効果を奏する。
　上記した空調システム１において、複数台の室外ユニット２Ａ，２Ｂのいずれか一方または双方を運転することにより空調運転を行っているとき、運転中の室外ユニット２Ａまたは２Ｂ（ここでは、室外ユニット２Ｂとする。）の圧縮機１０が故障して運転することができなくなった場合、バックアップ運転制御部６１Ａ，６１Ｂは、正常な室外ユニット２Ａを運転することにより空調運転を継続する。 Thus, according to the present embodiment, the following operational effects are obtained.
In the air conditioning system 1 described above, when the air conditioning operation is performed by operating one or both of the plurality of outdoor units 2A and 2B, the outdoor unit 2A or 2B (in this case, the outdoor unit 2B When the compressor 10 in the above state fails and cannot be operated, the backup operation control units 61A and 61B continue the air conditioning operation by operating the normal outdoor unit 2A.
　この際、冷房サイクルまたは暖房サイクルで運転していて、冷房モードまたは暖房モードを継続してバックアップ運転する場合、故障室外ユニット２Ｂの四方切換弁１３をそのまま冷房サイクル位置または暖房サイクル位置に維持した状態で正常な室外ユニット２Ａの四方切換弁１３を冷房サイクル位置または暖房サイクル位置とし、各々の室外ユニット２Ａ，２Ｂの四方切換弁１３の位置を同期させてバックアップ運転すればよい。 In this case, when operating in the cooling cycle or the heating cycle and continuing the backup operation in the cooling mode or the heating mode, the four-way switching valve 13 of the failed outdoor unit 2B is maintained as it is in the cooling cycle position or the heating cycle position. The normal four-way switching valve 13 of the outdoor unit 2A may be set to the cooling cycle position or the heating cycle position, and the backup operation may be performed by synchronizing the positions of the four-way switching valves 13 of the outdoor units 2A and 2B.
　しかし、バックアップ運転時、四方切換弁１３を冷房サイクル位置または暖房サイクル位置に切換えて運転しなければならないケースがあり、この場合、正常な室外ユニット２Ａの四方切換弁１３は、作動差圧を確保できることから通常とおり暖房サイクル位置に切換えることができるが、故障室外ユニット２Ｂの四方切換弁１３は、圧縮機１０が故障しており、所定値以上の高低圧差（例えば、０．３ＭＰａ）を確保することができず、四方切換弁１３を暖房サイクル位置に同期させることができないケースが生じる。 However, there are cases where the four-way switching valve 13 must be switched to the cooling cycle position or the heating cycle position during the backup operation, and in this case, the four-way switching valve 13 of the normal outdoor unit 2A ensures an operating differential pressure. Since it can be switched to the heating cycle position as usual, the four-way switching valve 13 of the failure outdoor unit 2B has a compressor 10 failure and ensures a high-low pressure difference (for example, 0.3 MPa) of a predetermined value or more. In some cases, the four-way switching valve 13 cannot be synchronized with the heating cycle position.
　しかるに、本実施形態によれば、かかるケースでも四方切換弁同期制御部６２Ａ，６２Ｂにより、いったん正常な室外ユニット２Ａの四方切換弁１３を冷房サイクル位置として運転し、正常な室外ユニット２Ａの低圧を低下させ、同時に冷媒ガス管５Ｂを介して故障室外ユニット２Ｂ側の低圧を低下させることにより、上記（１）ないし（３）のいずれかで３ＭＰａ以上の圧力差を確保したと判定し、故障室外ユニット２Ｂの四方切換弁１３に暖房サイクル位置への切換指令を出して、当該四方切換弁１３を暖房サイクル位置に切換えた後、正常室外ユニット２Ａの四方切換弁１３を暖房サイクル位置に切換えることによって、各室外ユニット２Ａ，２Ｂの四方切換弁１３を暖房サイクル位置に同期させることができる。 However, according to the present embodiment, even in such a case, the four-way switching valve synchronization controllers 62A and 62B once operate the four-way switching valve 13 of the normal outdoor unit 2A as the cooling cycle position to reduce the low pressure of the normal outdoor unit 2A. At the same time, by reducing the low pressure on the failure outdoor unit 2B side through the refrigerant gas pipe 5B, it is determined that a pressure difference of 3 MPa or more is secured in any of the above (1) to (3), and the failure outdoor By issuing a switching command to the heating cycle position to the four-way switching valve 13 of the unit 2B, switching the four-way switching valve 13 to the heating cycle position, and then switching the four-way switching valve 13 of the normal outdoor unit 2A to the heating cycle position. The four-way switching valve 13 of each outdoor unit 2A, 2B can be synchronized with the heating cycle position.
　従って、故障室外ユニット２Ｂの四方切換弁１３を冷房サイクル位置から暖房サイクル位置への切換えに必要な作動差圧を確保できず、その四方切換弁１３を暖房サイクル位置に同期切換えできないことにより発生する、故障室外ユニット２Ｂの低圧経路への高圧冷媒ガスの印加や空調システムの全停止等の問題を解消し、確実に正常室外ユニット２Ａを運転してバックアップ運転を実行することができる。 Therefore, the four-way switching valve 13 of the malfunctioning outdoor unit 2B cannot be ensured to have an operating differential pressure required for switching from the cooling cycle position to the heating cycle position, and the four-way switching valve 13 cannot be switched synchronously to the heating cycle position. The problems such as the application of the high-pressure refrigerant gas to the low-pressure path of the failed outdoor unit 2B and the total stop of the air conditioning system can be solved, and the normal outdoor unit 2A can be reliably operated to execute the backup operation.
　また、バックアップ運転時、上記（１）ないし（３）のいずれかで、四方切換弁１３の切換えに必要な所定値（０．３ＭＰａ）以上の圧力差が確保し得たと判定できるため、故障室外ユニット２Ｂの四方切換弁１３を圧縮機１０が故障で運転不可の場合でも、確実に作動差圧を確保して四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換えることができる。しかも、このような四方切換弁１３の切換えを、現行システムに対してハード的な変更を施すことなく、ソフト面の変更で対応できるため、コストアップを抑制することができる。なお、上記（１）ないし（３）は、（１），（２），（３）の順でより信頼性を高めることができる。 In addition, during backup operation, it can be determined in any of the above (1) to (3) that a pressure difference equal to or greater than a predetermined value (0.3 MPa) necessary for switching the four-way switching valve 13 can be secured. Even when the compressor 10 is out of order and the operation cannot be performed on the four-way switching valve 13 of the unit 2B, the four-way switching valve 13 can be switched from the cooling cycle position to the heating cycle position with a reliable operation differential pressure. In addition, since the switching of the four-way switching valve 13 can be handled by a change in software without applying a hardware change to the current system, an increase in cost can be suppressed. Note that (1) to (3) can improve the reliability in the order of (1), (2), and (3).
　さらに、本実施形態では、複数台の室外ユニット２Ａ，２Ｂの四方切換弁１３と圧縮機１０間の低圧経路（冷媒吸入配管２０Ｂ）同士を、均油管２７あるいは均圧管等の低圧連通管を介して連通接続した構成としているため、上記の如く、正常室外ユニット２Ａを運転して故障室外ユニット２Ｂの低圧圧力を低下させる際、速やかに故障室外ユニット２Ｂ側の低圧を低下させることができ、四方切換弁１３の切換時の信頼性、確実性を高めることができるとともに、切換えに要する時間を短縮化することができる。 Further, in the present embodiment, the low pressure paths (refrigerant suction pipes 20B) between the four-way switching valves 13 of the plurality of outdoor units 2A and 2B and the compressor 10 are connected to each other via low pressure communication pipes such as an oil equalizing pipe 27 or a pressure equalizing pipe. As described above, when the normal outdoor unit 2A is operated and the low pressure of the failed outdoor unit 2B is reduced as described above, the low pressure on the failed outdoor unit 2B side can be quickly reduced. The reliability and certainty at the time of switching of the switching valve 13 can be improved, and the time required for switching can be shortened.
［第２実施形態］
　次に、本発明の第２実施形態について、図９を用いて説明する。
　本実施形態は、上記した第１実施形態に対して、複数台の室外ユニット２Ａ，２Ｂの冷媒吐出配管２０Ａ間に電磁弁７１を備えた高圧バイパス回路７０を設け、その電磁弁７１を四方切換弁同期制御部６３Ａ，６３Ｂで開閉制御するようにしている点が異なる。その他の点については、上記した第１実施形態と同様であるので説明は省略する。 [Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
In the present embodiment, a high-pressure bypass circuit 70 having an electromagnetic valve 71 is provided between the refrigerant discharge pipes 20A of the plurality of outdoor units 2A and 2B, and the electromagnetic valve 71 is switched in four directions, compared to the first embodiment described above. The difference is that the valve synchronization control units 63A and 63B perform opening / closing control. Since other points are the same as those in the first embodiment, the description thereof will be omitted.
　つまり、本実施形態では、図９に示すように、複数台の室外ユニット２Ａ，２Ｂの冷媒吐出配管２０Ａ同士を、配管接続用の操作弁７２を介して電磁弁７１を備えた高圧バイパス回路７０によって接続している。そして、複数台の室外ユニット２Ａ，２Ｂ中の或る室外ユニット、例えば室外ユニット２Ｂの圧縮機１０が故障し、バックアップ運転制御部６１Ａ，６１Ｂにより他の正常な室外ユニット、例えば室外ユニット２Ａを運転してバックアップ運転する時、故障室外ユニット２Ｂの四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換えて同期する際、高圧バイパス回路７０の電磁弁７１を開とする四方切換弁同期制御部７３Ａ，７３Ｂを設けた構成としている。 That is, in this embodiment, as shown in FIG. 9, the high pressure bypass circuit 70 provided with the electromagnetic valve 71 between the refrigerant discharge pipes 20A of the plurality of outdoor units 2A, 2B via the operation valve 72 for pipe connection. Connected by. Then, a certain outdoor unit in the plurality of outdoor units 2A and 2B, for example, the compressor 10 of the outdoor unit 2B breaks down, and another normal outdoor unit such as the outdoor unit 2A is operated by the backup operation control units 61A and 61B. During the backup operation, when the four-way switching valve 13 of the failed outdoor unit 2B is switched from the cooling cycle position to the heating cycle position and synchronized, the four-way switching valve synchronization controller 73A that opens the electromagnetic valve 71 of the high-pressure bypass circuit 70 is opened. , 73B.
　なお、上記したものでは、高圧バイパス回路７０中に電磁弁７１が２個設けられることになるが、これは複数台の室外ユニット２Ａ，２Ｂを共通構成とするためであり、高圧バイパス回路７０中に電磁弁７１を１個設けた構成としてもよいことはもちろんである。 In the above, two electromagnetic valves 71 are provided in the high pressure bypass circuit 70. This is because the plurality of outdoor units 2A and 2B have a common configuration. Of course, it is also possible to have a configuration in which one electromagnetic valve 71 is provided.
　このような構成とすることにより、バックアップ運転時、故障室外ユニット２Ｂの四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換えて同期する際、四方切換弁同期制御部７３Ａ，７３Ｂを介して高圧バイパス回路７０の電磁弁７１を開とすることによって、正常な室外ユニット２Ａから吐出された高圧冷媒ガスを故障室外ユニット２Ｂの冷媒吐出配管２０Ａに印加し、故障室外ユニット２Ｂの四方切換弁１３を冷房サイクル位置から暖房サイクル位置に切換えるのに必要な差圧（高低圧差）を確保し、当該四方切換弁１３を暖房サイクル位置に切換えて同期させることができる。従って、かかる実施形態によっても、第１実施形態と同様の効果を期待することができる。 With such a configuration, during the backup operation, when the four-way switching valve 13 of the failed outdoor unit 2B is switched from the cooling cycle position to the heating cycle position and synchronized, the high pressure is supplied via the four-way switching valve synchronization control units 73A and 73B. By opening the electromagnetic valve 71 of the bypass circuit 70, the high-pressure refrigerant gas discharged from the normal outdoor unit 2A is applied to the refrigerant discharge pipe 20A of the failed outdoor unit 2B, and the four-way switching valve 13 of the failed outdoor unit 2B is turned on. A differential pressure (high / low pressure difference) necessary for switching from the cooling cycle position to the heating cycle position can be secured, and the four-way switching valve 13 can be switched to the heating cycle position and synchronized. Therefore, according to this embodiment, the same effect as that of the first embodiment can be expected.
　なお、本発明は、上記実施形態にかかる発明に限定されるものではなく、その要旨を逸脱しない範囲において、適宜変形が可能である。例えば、上記実施形態では、或る室外ユニット（例えば、室外ユニット２Ｂ）が圧縮機１０の故障により運転不可となった時、運転可能なユニット（例えば、室外ユニット２Ａ）をバックアップ運転して空調運転を継続する際、故障室外ユニット２Ｂの四方切換弁１３を冷房サイクル位置から暖房サイクル位置に同期切換えする場合の例について説明したが、バックアップ暖房運転中に、バックアップ運転中の室外ユニット２Ａを除霜運転あるいは油戻し運転するため、冷房サイクルに切換えて運転し、その運転が終了後、バックアップ暖房運転に復帰する際にも、同様に四方切換弁１３の同期切換えが必要である。本発明は、かかる場合にも同様に適用できることは云うまでもない。 In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above-described embodiment, when a certain outdoor unit (for example, the outdoor unit 2B) cannot be operated due to a failure of the compressor 10, a backup operation is performed for the operable unit (for example, the outdoor unit 2A) to perform air conditioning operation. Has been described for the case where the four-way switching valve 13 of the failed outdoor unit 2B is synchronously switched from the cooling cycle position to the heating cycle position, but the outdoor unit 2A during the backup operation is defrosted during the backup heating operation. In order to perform the operation or the oil return operation, the four-way switching valve 13 needs to be synchronously switched when the operation is switched to the cooling cycle, and when the operation is completed and the operation is returned to the backup heating operation. It goes without saying that the present invention can be similarly applied to such a case.
　また、上記実施形態では、複数台の室外ユニット２Ａ，２Ｂにそれぞれ圧縮機１０を１台搭載した例について説明したが、各ユニット２Ａ，２Ｂに圧縮機１０が複数台並列に接続されて搭載されている室外ユニット２Ａ，２Ｂにおいて、各々の室外ユニット２Ａ，２Ｂに搭載されている圧縮機１０が全て故障して、その室外ユニット２Ａ，２Ｂが運転不可になった場合等にも、同様に適用できることはもちろんである。 In the above embodiment, an example in which one compressor 10 is mounted on each of the plurality of outdoor units 2A and 2B has been described. However, a plurality of compressors 10 are connected and mounted on each unit 2A and 2B in parallel. The same applies to the case where the compressor 10 mounted in each outdoor unit 2A, 2B fails and the outdoor units 2A, 2B become inoperable. Of course you can.
１　空調システム
２Ａ，２Ｂ　室外ユニット
３Ａ，３Ｂ　室内ユニット
４，４Ａ，４Ｂ　冷媒液管
５，５Ａ，５Ｂ　冷媒ガス管
６　冷凍サイクル
１０　圧縮機
１３　四方切換弁
１４　室外熱交換器
２０Ａ　冷媒吐出配管
２０Ｂ　冷媒吸入配管（低圧経路）
２１　室外側冷媒回路
２５　高圧圧力センサ
２６　低圧圧力センサ
２７　均油管（低圧連通管）
５２　室内側冷媒回路
６０Ａ，６０Ｂ　室外コントローラ
６１Ａ，６１Ｂ　バックアップ運転制御部
６２Ａ，６２Ｂ，６３Ａ，６３Ｂ　四方切換弁同期制御部
７０　高圧バイパス回路
７１　電磁弁 DESCRIPTION OF SYMBOLS 1 Air conditioning system 2A, 2B Outdoor unit 3A, 3B Indoor unit 4, 4A, 4B Refrigerant liquid pipe 5, 5A, 5B Refrigerant gas pipe 6 Refrigeration cycle 10 Compressor 13 Four-way switching valve 14 Outdoor heat exchanger 20A Refrigerant discharge piping 20B Refrigerant Suction piping (low pressure path)
21 Outdoor refrigerant circuit 25 High pressure sensor 26 Low pressure sensor 27 Oil leveling pipe (low pressure communication pipe)
52 Indoor- side refrigerant circuits 60A, 60B Outdoor controllers 61A, 61B Backup operation control units 62A, 62B, 63A, 63B Four-way switching valve synchronization control unit 70 High-pressure bypass circuit 71 Solenoid valve

Claims (7)

  1. 　室内ユニット側および室外ユニット側の冷媒回路を冷媒液管、冷媒ガス管により接続して構成される１系統の冷凍サイクルと、
    　少なくとも１台の圧縮機、前記冷凍サイクルを冷房または暖房サイクルのいずれかに切換える四方切換弁および室外熱交換器を備え、前記冷凍サイクルに対して並列に接続される複数台の前記室外ユニットと、
    　前記複数台の室外ユニット中の或る室外ユニットの前記圧縮機が故障した時、他の正常な室外ユニットをバックアップ運転して空調運転を継続するバックアップ運転制御部と、を備えた空調システムであって、
    　前記バックアップ運転制御部は、バックアップ運転時、前記四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際に、前記正常室外ユニットの前記四方切換弁をいったん冷房サイクル位置として運転し、前記故障室外ユニットの低圧圧力を低下させ、前記故障室外ユニットの前記四方切換弁の作動差圧を確保して該四方切換弁を暖房サイクル位置に切換えた後、前記正常室外ユニットの前記四方切換弁を暖房サイクル位置に切換え、前記四方切換弁を同期させて暖房サイクルで運転する四方切換弁同期制御部を備えていることを特徴とする空調システム。     A refrigeration cycle of one system configured by connecting refrigerant circuits on the indoor unit side and the outdoor unit side by a refrigerant liquid pipe and a refrigerant gas pipe;
    At least one compressor, a four-way switching valve for switching the refrigeration cycle to either a cooling or heating cycle, and an outdoor heat exchanger, and a plurality of the outdoor units connected in parallel to the refrigeration cycle;
    A backup operation control unit configured to continue the air-conditioning operation by performing a backup operation of another normal outdoor unit when the compressor of a certain outdoor unit in the plurality of outdoor units breaks down. And
    The backup operation control unit, during the backup operation, when operating the four-way switching valve from the cooling cycle position to the heating cycle position, the four-way switching valve of the normal outdoor unit is once operated as the cooling cycle position, After reducing the low pressure of the malfunctioning outdoor unit, ensuring the operating differential pressure of the four-way switching valve of the malfunctioning outdoor unit and switching the four-way switching valve to the heating cycle position, the four-way switching valve of the normal outdoor unit is An air conditioning system comprising a four-way switching valve synchronization control unit that switches to a heating cycle position and synchronizes the four-way switching valve to operate in a heating cycle.
  2. 　前記四方切換弁同期制御部は、前記正常室外ユニット側の前記圧縮機の回転数が所定回転数に達したとき、前記故障室外ユニットの前記四方切換弁に暖房サイクル位置への切換指令を出力する構成とされていることを特徴とする請求項１に記載の空調システム。 The four-way switching valve synchronization control unit outputs a switching command to the heating cycle position to the four-way switching valve of the failed outdoor unit when the rotation speed of the compressor on the normal outdoor unit side reaches a predetermined rotation speed. The air conditioning system according to claim 1, wherein the air conditioning system is configured.
  3. 　前記四方切換弁同期制御部は、前記故障室外ユニット側の低圧圧力の検出値が所定値以下に低下したとき、前記故障室外ユニットの前記四方切換弁に暖房サイクル位置への切換指令を出力する構成とされていることを特徴とする請求項１に記載の空調システム。 The four-way switching valve synchronization control unit is configured to output a switching command to the heating cycle position to the four-way switching valve of the failed outdoor unit when the detected value of the low pressure on the failed outdoor unit side falls below a predetermined value. The air conditioning system according to claim 1, wherein:
  4. 　前記四方切換弁同期制御部は、前記故障室外ユニット側の高圧圧力および低圧圧力の検出値の差が所定値以上になったとき、前記故障室外ユニットの前記四方切換弁に暖房サイクル位置への切換指令を出力する構成とされていることを特徴とする請求項１に記載の空調システム。 The four-way switching valve synchronization controller switches the heating outdoor unit to the heating cycle position when the difference between the detected values of the high pressure and low pressure on the failed outdoor unit becomes a predetermined value or more. The air conditioning system according to claim 1, wherein the air conditioning system is configured to output a command.
  5. 　前記複数台の室外ユニットの前記四方切換弁と前記圧縮機間の低圧経路が、互いに低圧連通管を介して接続されていることを特徴とする請求項１ないし４のいずれかに記載の空調システム。 5. The air conditioning system according to claim 1, wherein low-pressure paths between the four-way switching valves of the plurality of outdoor units and the compressor are connected to each other via low-pressure communication pipes. .
  6. 　前記低圧連通管は、前記複数台の室外ユニットの前記圧縮機の低圧経路同士を接続する均油管または均圧管とされていることを特徴とする請求項５に記載の空調システム。 The air conditioning system according to claim 5, wherein the low-pressure communication pipe is an oil equalizing pipe or a pressure equalizing pipe that connects the low-pressure paths of the compressors of the plurality of outdoor units.
  7. 　室内ユニット側および室外ユニット側の冷媒回路を冷媒液管、冷媒ガス管により接続して構成される１系統の冷凍サイクルと、
    　少なくとも１台の圧縮機、前記冷凍サイクルを冷房または暖房サイクルのいずれかに切換える四方切換弁および室外熱交換器を備え、前記冷凍サイクルに対して並列に接続される複数台の前記室外ユニットと、
    　前記複数台の室外ユニット中の或る室外ユニットの前記圧縮機が故障した時、他の正常な室外ユニットをバックアップ運転して空調運転を継続するバックアップ運転制御部と、を備えた空調システムであって、
    　前記複数台の室外ユニットの前記圧縮機と前記四方切換弁間の吐出配管に、該吐出配管同士を連通接続する電磁弁を備えた高圧バイパス回路を設け、
    　前記バックアップ運転制御部に、バックアップ運転時、前記四方切換弁を冷房サイクル位置から暖房サイクル位置に切換えて運転する際、前記高圧バイパス回路に設けられている前記電磁弁を開として前記故障室外ユニットの前記四方切換弁を暖房サイクル位置に切換え、前記四方切換弁同士を同期させて暖房サイクルで運転する四方切換弁同期制御部を設けたことを特徴とする空調システム。     A refrigeration cycle of one system configured by connecting refrigerant circuits on the indoor unit side and the outdoor unit side by a refrigerant liquid pipe and a refrigerant gas pipe;
    At least one compressor, a four-way switching valve for switching the refrigeration cycle to either a cooling or heating cycle, and an outdoor heat exchanger, and a plurality of the outdoor units connected in parallel to the refrigeration cycle;
    A backup operation control unit configured to continue the air-conditioning operation by performing a backup operation of another normal outdoor unit when the compressor of a certain outdoor unit in the plurality of outdoor units breaks down. And
    The discharge pipe between the compressor of the plurality of outdoor units and the four-way switching valve is provided with a high-pressure bypass circuit including an electromagnetic valve that connects the discharge pipes to each other,
    In the backup operation control unit, during the backup operation, when the four-way switching valve is operated by switching from the cooling cycle position to the heating cycle position, the electromagnetic valve provided in the high-pressure bypass circuit is opened to open the failure outdoor unit. An air conditioning system comprising a four-way switching valve synchronization control unit that switches the four-way switching valve to a heating cycle position and synchronizes the four-way switching valves to operate in a heating cycle.
PCT/JP2016/077763 2015-10-22 2016-09-21 Air conditioning system WO2017068902A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
ES16857220T ES2732660T3 (en) 2015-10-22 2016-09-21 Air conditioning system
EP16857220.4A EP3315877B1 (en) 2015-10-22 2016-09-21 Air conditioning system
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EP3315877A4 (en) 2018-06-20
JP2017078561A (en) 2017-04-27
EP3315877B1 (en) 2019-06-05

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