WO2009119023A1 - Freezing apparatus - Google Patents

Freezing apparatus Download PDF

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Publication number
WO2009119023A1
WO2009119023A1 PCT/JP2009/001097 JP2009001097W WO2009119023A1 WO 2009119023 A1 WO2009119023 A1 WO 2009119023A1 JP 2009001097 W JP2009001097 W JP 2009001097W WO 2009119023 A1 WO2009119023 A1 WO 2009119023A1
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WO
WIPO (PCT)
Prior art keywords
compressor
target value
control
heat exchanger
refrigerant
Prior art date
Application number
PCT/JP2009/001097
Other languages
French (fr)
Japanese (ja)
Inventor
笠原伸一
Original Assignee
ダイキン工業株式会社
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 ダイキン工業株式会社 filed Critical ダイキン工業株式会社
Priority to CN2009801105845A priority Critical patent/CN101978227A/en
Priority to EP09724056A priority patent/EP2261580A1/en
Priority to US12/922,810 priority patent/US20110011125A1/en
Publication of WO2009119023A1 publication Critical patent/WO2009119023A1/en

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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00Compression machines, plants or systems, with reversible cycle
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00Arrangement or mounting of control or safety devices
    • F25B49/02Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/005Outdoor unit expansion valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/006Compression machines, plants or systems with reversible cycle not otherwise provided for two pipes connecting the outdoor side to the indoor side with multiple indoor units
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0233Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/027Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
    • F25B2313/02741Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using one four-way valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00Problems to be solved
    • F25B2500/15Hunting, i.e. oscillation of controlled refrigeration variables reaching undesirable values
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00Control issues
    • F25B2600/02Compressor control
    • F25B2600/025Compressor control by controlling speed
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00Control issues
    • F25B2600/25Control of valves
    • F25B2600/2513Expansion valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00Sensing or detecting of parameters; Sensors therefor
    • F25B2700/19Pressures
    • F25B2700/193Pressures of the compressor
    • F25B2700/1931Discharge pressures
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00Sensing or detecting of parameters; Sensors therefor
    • F25B2700/19Pressures
    • F25B2700/193Pressures of the compressor
    • F25B2700/1933Suction pressures
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21Temperatures
    • F25B2700/2117Temperatures of an evaporator
    • F25B2700/21174Temperatures of an evaporator of the refrigerant at the inlet of the evaporator
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21Temperatures
    • F25B2700/2117Temperatures of an evaporator
    • F25B2700/21175Temperatures of an evaporator of the refrigerant at the outlet of the evaporator
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B43/00Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
    • F25B43/006Accumulators

Definitions

  • the present invention relates to a refrigeration apparatus that performs a refrigeration cycle in which the high pressure is set to a value higher than the critical pressure of the refrigerant.
  • a refrigeration apparatus that performs a refrigeration cycle by circulating a refrigerant in a refrigerant circuit is known.
  • the high pressure of the refrigeration cycle performed in the refrigerant circuit is set to a value higher than the critical pressure of the refrigerant. That is, a so-called supercritical cycle is performed in the refrigerant circuit of the refrigeration apparatus.
  • the compressor may be started and stopped to adjust the capacity of the refrigeration apparatus.
  • the capacity of the refrigeration system may be too large for the load even if the capacity of the compressor is minimized. In such a situation, the compressor is stopped. It is done.
  • the high pressure is higher than in a general refrigeration cycle.
  • the high pressure and low pressure of the refrigeration cycle reach appropriate values after starting the compressor. The power required for this increases. Nevertheless, until now, sufficient measures have not been taken to reduce the frequency of start and stop of the compressor in a refrigeration apparatus that performs a supercritical cycle.
  • the present invention has been made in view of the above points, and an object of the present invention is to improve the operating efficiency of the refrigeration apparatus by reducing the number of times the compressor is started and stopped in a refrigeration apparatus that performs a so-called supercritical cycle. .
  • the compressor (31), the expansion mechanism (34, 42, 47), the heat source side heat exchanger (33), and the use side heat exchanger (41, 46) are connected, and the high pressure is the refrigerant.
  • a refrigerant circuit (20) for performing a refrigeration cycle set to a value higher than the critical pressure, and a control means (80) for controlling the compressor (31) and the expansion mechanism (34, 42, 47) are provided.
  • the said control means (80) is capacity
  • the degree of superheat of the refrigerant from the heat source side heat exchanger (33) and the use side heat exchanger (41, 46) operating as an evaporator to the compressor (31) is the superheat degree target value.
  • the compressor (31) is stopped by the flow rate control operation for adjusting the flow rate of the refrigerant passing through the expansion mechanism (34, 42, 47) and the capacity control operation, the degree of superheat The superheat degree target value changing operation for forcibly raising the target value is performed.
  • the compressor (31), the expansion mechanism (34, 42, 47), the heat source side heat exchanger (33), and the use side heat exchanger (41, 46) are connected, and the high pressure is the refrigerant.
  • a refrigeration apparatus that operates as a gas cooler and performs at least a cooling operation in which the use side heat exchanger (41, 46) operates as an evaporator is an object.
  • the control means (80) uses the evaporation temperature of the refrigerant in the use side heat exchanger (41, 46) or the low pressure of the refrigeration cycle performed in the refrigerant circuit (20) as a control parameter.
  • the control target value changing operation for gradually decreasing the control target value after the start of the compressor (31) is performed.
  • the compressor (31), the expansion mechanism (34, 42, 47), the heat source side heat exchanger (33), and the use side heat exchanger (41, 46) are connected, and the high pressure is the refrigerant.
  • a refrigerant circuit (20) for performing a refrigeration cycle set to a value higher than the critical pressure; and a control means (80) for controlling the compressor (31), the utilization side heat exchanger (41, 46) ) Is operated as a gas cooler, and the heat source side heat exchanger (33) is a refrigeration apparatus that performs at least a heating operation that operates as an evaporator.
  • the control means (80) uses the high pressure of the refrigeration cycle performed in the refrigerant circuit (20) as a control parameter, and adjusts the capacity of the compressor (31) so that the control parameter becomes a control target value.
  • the control target value is gradually set after starting the compressor (31) so that the control target value becomes a predetermined standard target value after a predetermined time has elapsed since the start of the compressor (31). The control target value changing operation is increased.
  • the compressor (31), the expansion mechanism (34, 42, 47), the heat source side heat exchanger (33), and the use side heat exchanger (41, 46) are connected, and the high pressure is the refrigerant.
  • a refrigeration apparatus including a refrigerant circuit (20) that performs a refrigeration cycle set to a value higher than the critical pressure and a control means (80) that controls the compressor (31) is an object.
  • the control means (80) sets the command value calculated using the physical quantity and the control gain so that the physical quantity indicating the operating state of the refrigeration cycle performed in the refrigerant circuit (20) becomes a control target value. Based on this, a capacity control operation for adjusting the capacity of the compressor (31) and a gain adjustment operation for reducing the control gain as the load of the refrigeration apparatus decreases are configured.
  • the refrigeration cycle is performed by circulating the refrigerant in the refrigerant circuit (20). At that time, the pressure of the refrigerant discharged from the compressor (31) is higher than the critical pressure of the refrigerant. Further, one of the heat source side heat exchanger (33) and the use side heat exchanger (41, 46) provided in the refrigerant circuit (20) operates as a gas cooler, and the other operates as an evaporator.
  • the control means (80) performs a capacity control operation.
  • this capacity control operation the capacity of the compressor (31) is adjusted so that the predetermined physical quantity becomes the control target value.
  • the control means (80) stops the compressor (31) when the predetermined physical quantity deviates from the control target value but the capacity of the compressor (31) cannot be reduced any more.
  • the control means (80) performs the superheat degree target value changing operation and forcibly raises the superheat degree target value. Thereafter, when the operation of the compressor (31) is resumed, the control means (80) performs a flow rate control operation using the superheat degree target value raised by the superheat degree target value changing operation.
  • control means (80) expands so that the superheat degree of the refrigerant heading from the heat exchanger (33, 41, 46) operating as an evaporator to the compressor (31) becomes the superheat degree target value raised.
  • the flow rate of the refrigerant passing through the mechanism (34, 42, 47) is adjusted.
  • the expansion mechanism (34, 42, 47) is set to a state in which the flow rate of the refrigerant passing therethrough decreases as the superheat degree target value increases.
  • the higher the superheat degree target value the smaller the amount of refrigerant circulating in the refrigerant circuit (20), so the capacity of the refrigeration apparatus (10) becomes lower. That is, the lower the superheat degree target value, the lower the lower limit value of the capacity of the refrigeration apparatus (10). For this reason, even if the control means (80) had to stop the compressor (31) before raising the target superheat, the compressor (31) continued to operate after raising the target superheat. The possibility of being able to be increased.
  • the control means (80) performs a capacity control operation and a control target value changing operation during the cooling operation.
  • the control means (80) uses the refrigerant evaporation temperature in the use side heat exchanger (41, 46) or the low pressure of the refrigeration cycle performed in the refrigerant circuit (20) as a control parameter.
  • the capacity of the compressor (31) is adjusted so as to reach the control target value.
  • the control means (80) stops the compressor (31) when the capacity of the compressor (31) cannot be further reduced even though the control parameter deviates from the control target value. Thereafter, when the operation of the compressor (31) is resumed, the control means (80) performs a control target value changing operation.
  • control target value changing operation the control means (80) sets the control target value at the time when the operation of the compressor (31) is resumed to a value higher than the standard target value, and a predetermined time has elapsed from that point. In the meantime, the control target value is gradually lowered to approach the standard target value. Meanwhile, in the capacity control operation, the capacity adjustment of the compressor (31) is performed using the control target value adjusted by the control target value changing operation.
  • the compressor (31) immediately after the compressor (31) is started, the difference between the measured value of the refrigerant evaporation temperature and the low pressure of the refrigeration cycle, which are control parameters, and the standard target value is large. Therefore, if the control target value remains at the standard target value immediately after the compressor (31) is started, the capacity of the compressor (31) increases rapidly in order to bring the control parameter close to the standard target value as soon as possible. Will be allowed to. And if the cooling capacity of the refrigeration system (10) suddenly increases with the rapid capacity increase of the compressor (31), the cooling capacity will be excessive in a relatively short time after the compressor (31) is started. Thus, the compressor (31) must be stopped again.
  • control means (80) of the second invention sets the control target value to a value higher than the standard target value for a while after the compressor (31) is started. Therefore, even immediately after the compressor (31) is started, the control target value remains the standard target value in terms of the difference between the measured value of the evaporation temperature of the refrigerant and the low pressure of the refrigeration cycle and the control target value. Smaller than in some cases. As a result, the rapid increase in capacity of the compressor (31) after the start of the compressor (31) is suppressed, and the cooling capacity of the refrigeration apparatus (10) also changes gradually.
  • control means (80) makes the control target value higher than the standard target value as in the present invention, the control means (80) stops the compressor (31) if the control target value remains the standard target value. There is a high possibility that the operation of the compressor (31) can be continued even in a situation where it has been necessary to do so.
  • the control means (80) performs a capacity control operation and a control target value changing operation during the heating operation.
  • the control means (80) uses the high pressure of the refrigeration cycle performed in the refrigerant circuit (20) as a control parameter, and adjusts the capacity of the compressor (31) so that the control parameter becomes a control target value.
  • the control means (80) stops the compressor (31) when the capacity of the compressor (31) cannot be further reduced even though the control parameter deviates from the control target value. Thereafter, when the operation of the compressor (31) is resumed, the control means (80) performs a control target value changing operation.
  • control target value changing operation the control means (80) sets the control target value at the time when the operation of the compressor (31) is resumed to a value lower than the standard target value, and a predetermined time has elapsed from that point. In the meantime, the control target value is gradually raised to approach the standard target value. Meanwhile, in the capacity control operation, the capacity adjustment of the compressor (31) is performed using the control target value adjusted by the control target value changing operation.
  • the compressor (31) immediately after the compressor (31) is started, the difference between the measured value of the high pressure of the refrigeration cycle, which is a control parameter, and the standard target value is large. Therefore, if the control target value remains at the standard target value immediately after the compressor (31) is started, the capacity of the compressor (31) increases rapidly in order to bring the control parameter close to the standard target value as soon as possible. Will be allowed to. And if the heating capacity of the refrigeration system (10) increases rapidly with the sudden increase in capacity of the compressor (31), the heating capacity will be excessive in a relatively short time after the compressor (31) is started. Thus, the compressor (31) must be stopped again.
  • control means (80) of the third invention sets the control target value to a value lower than the standard target value for a while after the compressor (31) is started. Therefore, even immediately after the compressor (31) is started, the difference between the measured value of the high pressure of the refrigeration cycle, which is the control parameter, and the control target value is compared with the case where the control target value remains the standard target value. Get smaller. As a result, the rapid capacity increase of the compressor (31) after the start of the compressor (31) is suppressed, and the heating capacity of the refrigeration apparatus (10) also changes gradually. For this reason, if the control means (80) makes the control target value lower than the standard target value as in the present invention, the control means (80) stops the compressor (31) if the control target value remains the standard target value. There is a high possibility that the operation of the compressor (31) can be continued even in a situation where it has been necessary to do so.
  • the control means (80) performs the capacity control operation and the control target value changing operation.
  • this capacity control operation the capacity of the compressor (31) is adjusted so that the predetermined physical quantity becomes the control target value.
  • the control means (80) stops the compressor (31) when the predetermined physical quantity deviates from the control target value but the capacity of the compressor (31) cannot be reduced any more.
  • the control means (80) performs a gain adjustment operation, and decreases the value of the control gain used in the capacity control operation as the load on the refrigeration apparatus (10) decreases.
  • control means (80) of the fourth invention reduces the value of the control gain as the load of the refrigeration apparatus (10) decreases.
  • the command value calculated using the predetermined physical quantity and the control gain is smaller than that when the control gain is constant.
  • the control means (80) must stop the compressor (31) if the control gain remains constant. The possibility that the operation of the compressor (31) can be continued increases.
  • the capacity of the refrigeration apparatus (10) is excessive with respect to the load by increasing the superheat degree target value and lowering the lower limit value of the capacity of the refrigeration apparatus (10). This reduces the possibility of the compressor (31) stopping due to the failure.
  • the cooling capacity of the refrigeration apparatus (10) becomes excessive with respect to the load by setting the control parameter during the cooling operation to a higher value immediately after the compressor (31) is started. This reduces the possibility that the compressor (31) will stop.
  • the heating capability of the freezing apparatus (10) became excessive with respect to load by setting the control parameter in heating operation low immediately after starting of a compressor (31). This reduces the possibility that the compressor (31) will stop.
  • the control gain is set to be small, thereby causing the capacity of the refrigeration apparatus (10) to be excessive with respect to the load. This reduces the possibility of the compressor (31) stopping.
  • the compressor (31) is caused by the fact that the capacity of the refrigeration apparatus (10) is excessive with respect to the load.
  • the possibility of stopping can be reduced.
  • capacity adjustment in the refrigeration system (10) that performs the supercritical cycle with the characteristic that “the power required for the high pressure and low pressure of the refrigeration cycle to reach appropriate values after starting the compressor (31) increases” Therefore, the number of times the compressor (31) starts and stops can be reduced. Therefore, according to the present invention, the power consumed during the operation of the refrigeration apparatus (10) can be reduced by reducing the number of times the compressor (31) for adjusting the capacity is started and stopped, and the refrigeration apparatus (10) The driving efficiency can be improved.
  • FIG. 1 is a refrigerant circuit diagram illustrating a schematic configuration of the air conditioner according to the first embodiment.
  • FIG. 2 is a block diagram illustrating configurations of the main controller and the sub controller according to the first embodiment.
  • FIG. 3 is a block diagram illustrating a configuration of the main controller according to the second embodiment.
  • FIG. 4 is a block diagram illustrating a configuration of the main controller according to the third embodiment.
  • Air conditioner (refrigeration equipment) 20 Refrigerant circuit 31 Compressor 33 Outdoor heat exchanger (heat source side heat exchanger) 34 Outdoor expansion valve (expansion mechanism) 41 Indoor heat exchanger (use side heat exchanger) 42 Indoor expansion valve (expansion mechanism) 46 Indoor heat exchanger (use side heat exchanger) 47 Indoor expansion valve (expansion mechanism) 60 Main controller 70a Sub controller 70b Sub controller 80 Control means
  • Embodiment 1 of the Invention As shown in FIG. 1, the air conditioner (10) of this embodiment is provided with one outdoor unit (11) and two indoor units (12, 13).
  • the outdoor unit (11) is installed outdoors.
  • Each indoor unit (12, 13) is installed indoors.
  • the number of outdoor units (11) and indoor units (12, 13) shown here is merely an example.
  • the air conditioner (10) includes a main controller (60) and sub controllers (70a, 70b).
  • the main controller (60) and the sub-controllers (70a, 70b) constitute control means (80).
  • the outdoor circuit (30) of the outdoor unit (11) and the indoor circuit (40, 45) of each indoor unit (12, 13) are connected to the liquid side communication pipe (21) and
  • the refrigerant circuit (20) is formed by connecting with the gas side connecting pipe (22).
  • the refrigerant circuit (20) is filled with carbon dioxide (CO 2 ) as a refrigerant.
  • CO 2 carbon dioxide
  • the high pressure is set to a value higher than the critical pressure of carbon dioxide, which is a refrigerant.
  • the outdoor unit (11) accommodates one outdoor circuit (30).
  • the outdoor circuit (30) includes a compressor (31), a four-way switching valve (32), an outdoor heat exchanger (33) that is a heat source side heat exchanger, and an outdoor expansion valve (34) that is an expansion mechanism.
  • a receiver (35), a liquid side closing valve (36), and a gas side closing valve (37) are provided.
  • the outdoor unit (11) is provided with an outdoor fan (16) for sending outdoor air to the outdoor heat exchanger (33).
  • the compressor (31) has its discharge side connected to the first port of the four-way switching valve (32) and its suction side connected to the second port of the four-way switching valve (32). Yes.
  • the outdoor heat exchanger (33) has a gas side end connected to the third port of the four-way switching valve and a liquid side end connected to one end of the outdoor expansion valve (34).
  • the other end of the outdoor expansion valve (34) is connected to the liquid side closing valve (36) via the receiver (35).
  • the fourth port of the four-way switching valve (32) is connected to the gas side closing valve (37).
  • Each indoor unit (12, 13) contains one indoor circuit (40, 45).
  • Each indoor circuit (40, 45) is connected to an indoor heat exchanger (41, 46) which is a use side heat exchanger and an indoor expansion valve (42, 47) which is an expansion mechanism. .
  • the indoor heat exchanger (41, 46) and the indoor expansion valve (42, 47) are arranged in series.
  • Each indoor unit (12, 13) is provided with one indoor fan (17, 18) for sending indoor air to the indoor heat exchanger (41, 46).
  • one end of the liquid side connecting pipe (21) is connected to the liquid side closing valve (36).
  • the other end of the liquid side connecting pipe (21) is bifurcated and connected to the end of each indoor circuit (40, 45) on the indoor expansion valve (42, 47) side.
  • one end of the gas side communication pipe (22) is connected to the gas side closing valve (37).
  • the other end of the gas side connection pipe (22) is bifurcated and connected to the end of each indoor circuit (40, 45) on the indoor heat exchanger (41, 46) side. That is, in this refrigerant circuit (20), two indoor circuits (40, 45) are connected in parallel to one outdoor circuit (30).
  • the compressor (31) is a hermetic compressor in which a compression mechanism and an electric motor are accommodated in one casing.
  • Both the outdoor heat exchanger (33) and the indoor heat exchangers (41, 46) are fin-and-tube type air heat exchangers configured to exchange heat between refrigerant and air.
  • Both the outdoor expansion valve (34) and the indoor expansion valves (42, 47) are electric expansion valves with variable opening.
  • the four-way switching valve (32) includes a first state (state indicated by a solid line in FIG. 1) in which the first port and the third port communicate with each other, and the second port and the fourth port communicate with each other. The state is switched to a second state (state indicated by a broken line in FIG. 1) in which the port communicates with the fourth port and the second port communicates with the third port.
  • the outdoor unit (11) includes a high pressure sensor (51), a low pressure sensor (52), an intake temperature sensor (53), an outdoor gas side temperature sensor (54), and an outside air temperature sensor (58).
  • the high pressure sensor (51) is connected between the discharge side of the compressor (31) in the refrigerant circuit (20) and the first port of the four-way switching valve (32), and is discharged from the compressor (31). Measure the refrigerant pressure.
  • the low pressure sensor (52) is connected between the suction side of the compressor (31) and the second port of the four-way switching valve (32) in the refrigerant circuit (20), and is sucked into the compressor (31). Measure the refrigerant pressure.
  • the suction temperature sensor (53) is provided between the suction side of the compressor (31) and the second port of the four-way switching valve (32) in the refrigerant circuit (20), and is sucked into the compressor (31). Measure the temperature of the refrigerant.
  • the outdoor gas side temperature sensor (54) is provided in the vicinity of the gas side end of the outdoor heat exchanger (33) in the outdoor circuit (30), and measures the temperature of the refrigerant passing therethrough.
  • the outdoor air temperature sensor (58) measures the temperature of the outdoor air before passing through the outdoor heat exchanger (33).
  • Each indoor unit (12, 13) is provided with one indoor temperature sensor (55a, 55b), one indoor gas side temperature sensor (56, 56b), and one indoor liquid side temperature sensor (57, 57b). Yes.
  • the indoor temperature sensor (55a, 55b) measures the temperature of the indoor air before passing through the indoor heat exchanger (41, 46).
  • the indoor gas side temperature sensor (56, 56b) is located near the end of each indoor circuit (40, 45) opposite to the indoor expansion valve (42, 47) of the indoor heat exchanger (41, 46). The temperature of the refrigerant
  • the indoor liquid side temperature sensor (57, 57b) is provided in the vicinity of the end of each indoor circuit (40, 45) on the indoor expansion valve (42, 47) side of the indoor heat exchanger (41, 46), The temperature of the refrigerant passing there is measured.
  • the main controller (60) is installed in the outdoor unit (11). As shown in FIG. 2, the main controller (60) includes a low pressure target value setting unit (61), a high pressure target value setting unit (62), a compressor control unit (63), and an outdoor expansion valve control unit ( 64) and a superheat degree target value changing section (65).
  • the main controller (60) includes a high pressure sensor (51), a low pressure sensor (52), a suction temperature sensor (53), an outdoor gas side temperature sensor (54), each indoor temperature sensor (55a, 55b), and an outside The measured value of the temperature sensor (58) is input.
  • Sub-controllers (70a, 70b) are installed in each indoor unit (12, 13). As shown in FIG. 2, each sub-controller (70a, 70b) is provided with an indoor expansion valve controller (71a, 71b). The measured values of the low-pressure sensor (52) are input to the sub controllers (70a, 70b). In addition, each sub-controller (70a, 70b) measures the indoor gas side temperature sensor (56, 56b) and the indoor liquid side temperature sensor (57, 57b) installed in the same indoor unit (12, 13). A value is entered.
  • the main controller (60) and the sub-controllers (70a, 70b) control the operation of the air conditioner (10) using the measured values input from the sensors. Details of the control operation performed by the main controller (60) and the sub-controllers (70a, 70b) will be described later.
  • the air conditioner (10) of the present embodiment selectively performs a cooling operation that is a cooling operation and a heating operation that is a heating operation. Switching between the cooling operation and the heating operation is performed by operating the four-way switching valve (32).
  • ⁇ Cooling operation The operation of the air conditioner (10) during the cooling operation will be described.
  • the four-way switching valve (32) is set to the first state (the state indicated by the solid line in FIG. 1).
  • an outdoor expansion valve (34) is set to full open, and the opening degree of each indoor expansion valve (42, 47) is adjusted suitably.
  • the refrigerant circulates to perform a refrigeration cycle.
  • the outdoor heat exchanger (33) operates as a gas cooler, and each indoor heat exchanger (41, 46) operates as an evaporator.
  • the supercritical refrigerant discharged from the compressor (31) is sent to the outdoor heat exchanger (33) through the four-way switching valve (32) and dissipates heat to the outdoor air.
  • the refrigerant flowing out of the outdoor heat exchanger (33) flows into the liquid side communication pipe (21) through the outdoor expansion valve (34) and the receiver (35), and is then distributed to each indoor circuit (40, 45). Is done.
  • each indoor circuit (40, 45) is reduced in pressure when passing through the indoor expansion valve (42, 47) to become a gas-liquid two-phase state, and then indoors in the indoor heat exchanger (41, 46). It absorbs heat from the air and evaporates.
  • Each indoor unit (12, 13) supplies indoor air cooled by the indoor heat exchanger (41, 46) to the room.
  • the refrigerant that has passed through the indoor heat exchangers (41, 46) flows into the gas side communication pipe (22) and joins, and then is sucked into the compressor (31) through the four-way switching valve (32).
  • the compressor (31) compresses the sucked refrigerant and discharges it.
  • ⁇ Heating operation> The operation of the air conditioner (10) during the heating operation will be described.
  • the four-way selector valve (32) is set to the second state (the state indicated by the broken line in FIG. 1). Further, during the heating operation, the opening degrees of the outdoor expansion valve (34) and the indoor expansion valves (42, 47) are appropriately adjusted.
  • each indoor heat exchanger (41, 46) operates as a gas cooler
  • the outdoor heat exchanger (33) operates as an evaporator.
  • the supercritical refrigerant discharged from the compressor (31) flows into the gas side communication pipe (22) through the four-way switching valve (32), and then to each indoor circuit (40, 45). Distributed to.
  • the refrigerant that has flowed into the indoor circuits (40, 45) radiates heat to the indoor air by the indoor heat exchanger (41, 46).
  • Each indoor unit (12, 13) supplies indoor air heated by the indoor heat exchanger (41, 46) to the room.
  • the refrigerant flowing out of the indoor heat exchanger (41, 46) flows into the liquid side connection pipe (21) after passing through the indoor expansion valve (42, 47), and then flows into the outdoor circuit (30).
  • the refrigerant flowing into the outdoor circuit (30) is sent to the outdoor expansion valve (34) after passing through the receiver (35), and is reduced in pressure when passing through the outdoor expansion valve (34) to be in a gas-liquid two-phase state.
  • the refrigerant that has passed through the outdoor expansion valve (34) is sent to the outdoor heat exchanger (33), and absorbs heat from the outdoor air to evaporate.
  • the refrigerant flowing out of the outdoor heat exchanger (33) is sucked into the compressor (31) through the four-way switching valve (32).
  • the compressor (31) compresses the sucked refrigerant and discharges it.
  • main controller (60) and the sub-controllers (70a, 70b) control the operation of the air conditioner (10) using the measurement values input from the sensors.
  • ⁇ Cooling operation> The operation of the main controller (60) and the sub controllers (70a, 70b) during the cooling operation will be described.
  • the main controller (60) is operated by the low pressure target value setting unit (61), the compressor control unit (63), and the superheat degree target value changing unit (65). ),
  • the outdoor expansion valve control section (64) performs only the operation of keeping the opening degree of the outdoor expansion valve (34) fully open, and the high pressure target value setting section (62) is stopped.
  • each indoor expansion valve control part (71a, 71b) operates.
  • the indoor expansion valve controller (71a, 71b) of each sub controller (70a, 70b) adjusts the opening of the indoor expansion valve (42, 47) provided in the corresponding indoor unit (12, 13). That is, in the first indoor unit (12), the indoor expansion valve control unit (71a) of the sub controller (70a) has a degree of superheat of the refrigerant at the outlet of the first indoor heat exchanger (41). The opening degree of the first indoor expansion valve (42) is adjusted so as to be the target value. In the second indoor unit (13), the indoor expansion valve control unit (71b) of the sub controller (70b) has a superheat degree of the refrigerant at the outlet of the second indoor heat exchanger (46). The opening degree of the second indoor expansion valve (47) is adjusted so as to reach the target value.
  • each indoor expansion valve controller (71a, 71b) determines the detected value of the low pressure sensor (52) from the detected value of the indoor gas side temperature sensor (56, 56b) provided in the corresponding indoor unit (12, 13). By subtracting the saturation temperature of the refrigerant, the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger (41, 46) provided in the corresponding indoor unit (12, 13) is calculated. And the opening degree of the indoor expansion valve (42, 47) provided in the corresponding indoor unit (12, 13) is adjusted so that the calculated value of the superheat degree becomes the superheat degree target value.
  • the opening control of the indoor expansion valves (42, 47) by the indoor expansion valve control units (71a, 71b) is performed by general feedback control such as PID control.
  • the indoor expansion valve control unit (71a, 71b) increases the superheat degree of the refrigerant at the outlet of the indoor heat exchanger (41, 46) when the calculated superheat value is smaller than the superheat degree target value. In order to do so, the flow rate of the refrigerant passing through the indoor heat exchanger (41, 46) is reduced by reducing the opening of the indoor expansion valve (42, 47). Further, the indoor expansion valve control unit (71a, 71b) reduces the superheat degree of the refrigerant at the outlet of the indoor heat exchanger (41, 46) when the calculated value of the superheat degree is larger than the superheat degree target value.
  • the flow rate of the refrigerant passing through the indoor heat exchanger (41, 46) is increased by increasing the opening of the indoor expansion valve (42, 47).
  • the superheat degree target value is set to a constant standard value (for example, 5 ° C.) except when it is changed by the superheat degree target value changing part (65). Yes.
  • the low pressure target value setting unit (61) is configured to perform a low pressure target value setting operation.
  • the low pressure target value which is the low pressure target value of the refrigeration cycle, is set to a value corresponding to the cooling load in the indoor units (12, 13) during the cooling operation.
  • the low pressure target value setting unit (61) determines whether the indoor unit (12, 13) has sufficient or insufficient cooling capacity based on the measured value of each indoor temperature sensor (55a, 55b), the indoor set temperature during cooling, etc. Judging. If the low pressure target value setting unit (61) determines that the cooling capacity of the indoor units (12, 13) is insufficient, the low pressure target value setting unit (61) decreases the low pressure target value to increase the cooling capacity. Further, when the low pressure target value setting unit (61) determines that the cooling capacity in the indoor units (12, 13) is excessive, it raises the low pressure target value in order to decrease the cooling capacity.
  • the compressor control unit (63) is configured to perform a capacity control operation.
  • the operating capacity of the compressor (31) is adjusted so that the measured value of the low pressure sensor (52) (that is, the measured value of the low pressure of the refrigeration cycle) becomes the low pressure target value. That is, the compressor control unit (63) uses the low pressure of the refrigeration cycle as a control parameter, and adjusts the operating capacity of the compressor (31) so that the control parameter becomes the low pressure target value.
  • the compressor control unit (63) changes the frequency of the alternating current supplied to the electric motor of the compressor (31) and changes the rotational speed of the compression mechanism driven by the electric motor (31). ) Is changed.
  • the compressor control unit (63) rotates the rotation speed of the motor of the compressor (31) to reduce the low pressure of the refrigeration cycle.
  • the compressor control unit (63) rotates the motor speed of the compressor (31) to increase the low pressure of the refrigeration cycle.
  • the compressor control unit (63) rotates the motor speed of the compressor (31) to increase the low pressure of the refrigeration cycle.
  • the compressor control unit (63) uses the measured value of the low-pressure sensor (52) and a predetermined control gain to command the change amount of the AC frequency supplied to the motor of the compressor (31). Is calculated. Specifically, in the compressor control unit (63), as the difference between the measured value of the low pressure sensor (52) and the low pressure target value increases, the command value for the change amount of the AC frequency becomes larger, and the low pressure sensor (52 The smaller the difference between the measured value) and the low pressure target value, the smaller the command value for changing the AC frequency.
  • the compressor control unit (63) determines that the measured value of the low pressure sensor (52) is lower than the low pressure target value even though the frequency of the alternating current supplied to the motor of the compressor (31) has reached the lower limit value. If the low state continues for a predetermined time, it is determined that the cooling capacity is excessive with respect to the cooling load, and the compressor (31) is stopped. Furthermore, the compressor control unit (63) determines that the room needs to be cooled when the difference between the measured value of the room temperature sensor (55a, 55b) and the indoor set temperature during cooling reaches a certain level. Start the compressor (31).
  • the superheat degree target value changing unit (65) is configured to perform a superheat degree target value changing operation.
  • the superheat degree target value changing section (65) counts the number of times the compressor (31) is stopped by the compressor control section (63).
  • the superheat degree target value changing unit (65) sets the number of times the compressor is stopped by the compressor control unit (63) to a predetermined value (for example, twice) within a predetermined time (for example, within 15 minutes).
  • a predetermined value for example, twice
  • a predetermined time for example, within 15 minutes.
  • the superheat target value is forcibly increased from a standard value (for example, 5 ° C.).
  • the indoor expansion valve controller (71a, 71b) uses the superheat degree target value raised from the standard value to expand the room. Adjust the opening of the valves (42, 47).
  • the superheat degree target value changing unit (65) the upper limit of the superheat degree target value by the superheat degree target value changing operation is limited so that the temperature of the refrigerant discharged from the compressor (31) does not become too high. Value is set.
  • the main controller (60) operates the high pressure target value setting unit (62), the compressor control unit (63), the outdoor expansion valve control unit (64), and the superheat degree target value changing unit (65). And the low pressure target value setting unit (61) is suspended.
  • each indoor expansion valve control part (71a, 71b) operates.
  • the indoor expansion valve controller (71a, 71b) of each sub controller (70a, 70b) adjusts the opening of the indoor expansion valve (42, 47) provided in the corresponding indoor unit (12, 13). This point is the same as the operation during the cooling operation. However, the indoor expansion valve control units (71a, 71b) during heating operation have the detection values of the indoor liquid side temperature sensors (57, 57b) provided in the corresponding indoor units (12, 13) as the predetermined target values. The opening degree of the indoor expansion valve (42, 47) is adjusted so as to be.
  • the indoor expansion valve control unit (71a, 71b) during the heating operation is configured so that the refrigerant temperature at the outlet of the indoor heat exchanger (41, 46) operating as a gas cooler becomes a predetermined target value. Adjust the opening of (42,47).
  • the opening control of the indoor expansion valves (42, 47) by the indoor expansion valve control units (71a, 71b) is performed by general feedback control such as PID control.
  • the indoor expansion valve control unit (71a, 71b) is arranged at the outlet of the indoor heat exchanger (41, 46). In order to reduce the temperature of the refrigerant, the flow rate of the refrigerant passing through the indoor heat exchanger (41, 46) is reduced by reducing the opening of the indoor expansion valve (42, 47). Further, the indoor expansion valve control unit (71a, 71b), when the detected value of the indoor liquid side temperature sensor (57, 57b) is lower than the target value, the refrigerant at the outlet of the indoor heat exchanger (41, 46). In order to increase the temperature, the flow rate of the refrigerant passing through the indoor heat exchanger (41, 46) is increased by increasing the opening of the indoor expansion valve (42, 47).
  • the high pressure target value setting unit (62) is configured to perform a high pressure target value setting operation.
  • the high pressure target value which is the high pressure target value of the refrigeration cycle, is set to a value corresponding to the heating load in the indoor units (12, 13) during the heating operation.
  • the high-pressure target value setting unit (62) determines whether the indoor unit (12, 13) is overheated or insufficient based on the measured value of each indoor temperature sensor (55a, 55b), the indoor set temperature during heating, etc. Judging. When the high pressure target value setting unit (62) determines that the heating capacity of the indoor units (12, 13) is insufficient, the high pressure target value setting unit (62) raises the high pressure target value to increase the heating capacity. Further, when the high pressure target value setting unit (62) determines that the heating capacity in the indoor units (12, 13) is excessive, the high pressure target value setting unit (62) lowers the high pressure target value in order to decrease the heating capacity.
  • the compressor control unit (63) is configured to perform a capacity control operation.
  • the operating capacity of the compressor (31) is adjusted so that the measured value of the high pressure sensor (51) (that is, the actual measured value of the high pressure of the refrigeration cycle) becomes the high pressure target value. That is, the compressor control unit (63) uses the high pressure of the refrigeration cycle as a control parameter, and adjusts the operating capacity of the compressor (31) so that the control parameter becomes the high pressure target value.
  • the compressor control unit (63) changes the frequency of the alternating current supplied to the electric motor of the compressor (31) and changes the rotational speed of the compression mechanism driven by the electric motor (31). ) Is changed.
  • the compressor control unit (63) rotates the motor speed of the compressor (31) to increase the high pressure of the refrigeration cycle.
  • the compressor control unit (63) rotates the rotational speed of the motor of the compressor (31) to reduce the high pressure of the refrigeration cycle. To reduce the operating capacity of the compressor (31).
  • the compressor control unit (63) uses the measured value of the high pressure sensor (51) and a predetermined control gain to command the change amount of the AC frequency supplied to the motor of the compressor (31). Is calculated. Specifically, in the compressor control unit (63), as the difference between the measured value of the high pressure sensor (51) and the high pressure target value becomes larger, the command value for the change amount of the AC frequency becomes larger, and the high pressure sensor (51 The smaller the difference between the measured value and the high pressure target value, the smaller the command value for the change amount of the AC frequency.
  • the outdoor expansion valve control unit (64) is configured to perform a flow rate control operation. In this flow control operation, the degree of opening of the outdoor expansion valve (34) is adjusted so that the superheat degree of the refrigerant at the outlet of the outdoor heat exchanger (33) that operates as an evaporator during heating operation becomes the superheat degree target value. Is done. That is, the outdoor expansion valve control unit (64) controls the flow rate of the refrigerant passing through the outdoor expansion valve (34) by adjusting the opening degree of the outdoor expansion valve (34).
  • the opening degree control of the outdoor expansion valve (34) by the outdoor expansion valve control unit (64) is performed by general feedback control such as PID control.
  • the outdoor expansion valve control unit (64) subtracts the saturation temperature of the refrigerant at the detection value of the low-pressure sensor (52) from the detection value of the outdoor gas side temperature sensor (54), so that the outdoor heat exchanger (33) The degree of superheat of the refrigerant at the outlet is calculated. And the opening degree of an outdoor expansion valve (34) is adjusted so that the calculated value of this superheat degree may become a superheat degree target value. Specifically, when the calculated value of the superheat degree is smaller than the superheat degree target value, the outdoor expansion valve control unit (64) increases the superheat degree of the refrigerant at the outlet of the outdoor heat exchanger (33).
  • the flow rate of the refrigerant passing through the outdoor heat exchanger (33) is reduced by reducing the opening of the outdoor expansion valve (34).
  • the outdoor expansion valve control unit (64) when the calculated value of the superheat degree is larger than the target value of the superheat degree, increases the outdoor expansion in order to reduce the superheat degree of the refrigerant at the outlet of the outdoor heat exchanger (33).
  • the flow rate of the refrigerant passing through the outdoor heat exchanger (33) is increased by increasing the opening of the valve (34).
  • the superheat degree target value changing unit (65) is configured to perform a superheat degree target value changing operation. That is, as in the cooling operation, when the number of times the compressor is stopped by the compressor control unit (63) reaches a predetermined value within a predetermined time, the superheat degree target value changing unit (65) The degree target value is forcibly increased from a standard value (for example, 5 ° C.). After the superheat degree target value changing unit (65) forcibly raises the superheat degree target value, the outdoor expansion valve control part (64) uses the superheat degree target value raised from the standard value to set the outdoor expansion valve ( Adjust the opening in 34).
  • the superheat degree target value changing unit (65) the upper limit of the superheat degree target value by the superheat degree target value changing operation is limited so that the temperature of the refrigerant discharged from the compressor (31) does not become too high. Value is set.
  • the superheat target value changing unit (65) of the main controller (60) has an excessive capacity of the air conditioner (10), and the compressor control unit (63) stops the compressor (31).
  • the indoor expansion valve controller (71a, 71b) of the sub controller (70a, 70b) causes the degree of superheat of the refrigerant from the indoor heat exchanger (41, 46) to the compressor (31).
  • the opening degree of the indoor expansion valve (42, 47) is adjusted so that the raised superheat degree target value is obtained.
  • the outdoor expansion valve control unit (64) of the main controller (60) is used to increase the superheat degree of the refrigerant from the outdoor heat exchanger (33) to the compressor (31).
  • the opening degree of the outdoor expansion valve (34) is adjusted so as to be a value.
  • the opening degree of the indoor expansion valves (42, 47) and the outdoor expansion valve (34) decreases as the superheat degree target value increases. That is, the indoor expansion valves (42, 47) and the outdoor expansion valve (34) are in a state where the flow rate of the refrigerant passing therethrough is reduced (that is, the opening degree is set to be small).
  • the compressor (31) is caused by the capacity of the air conditioner (10) being excessive with respect to the load. Can be reduced.
  • Embodiment 2 of the Invention A second embodiment of the present invention will be described.
  • the present embodiment is obtained by changing the configuration of the main controller (60) in the air conditioner (10) of the first embodiment.
  • the main controller (60) of the present embodiment is provided with a control target value changing unit (66) instead of the superheat degree target value changing unit (65) of the first embodiment. .
  • the operations of the low pressure target value setting unit (61), the high pressure target value setting unit (62), the compressor control unit (63), and the outdoor expansion valve control unit (64) Is the same as the operation in the first embodiment.
  • the control target value changing unit (66) is configured to perform a control target value changing operation. In this control target value changing operation, the control target value changing unit (66) counts the number of times the compressor (31) is stopped by the compressor control unit (63). Then, the control target value changing unit (66) reaches the predetermined value (for example, twice) within a predetermined time (for example, within 15 minutes) the number of times the compressor has been stopped by the compressor control unit (63). Then, the control target value used in the compressor control unit (63) is forcibly changed.
  • the predetermined value for example, twice
  • a predetermined time for example, within 15 minutes
  • the control target value changing unit (66) performs an operation for forcibly changing the low pressure target value as a control target value changing operation. Specifically, when the number of times the compressor is stopped by the compressor control unit (63) reaches a predetermined number within a predetermined time, the control target value changing unit (66) causes the compressor control unit (63) to The low pressure target value to be used is raised from the standard target value which is the value determined by the low pressure target value setting unit (61). Then, when the compressor (31) is subsequently started, the compressor control unit (63) uses the low-pressure target value raised by the control target value changing unit (66), and the compressor (31) Adjust the operating capacity. Further, the compressor control unit (63) sets the value of the low pressure target value so that the low pressure target value becomes the standard target value when a predetermined time (for example, 4 minutes) has elapsed since the start of the compressor (31). Pull it down gradually.
  • a predetermined time for example, 4 minutes
  • the compressor (31) immediately after the compressor (31) is started, the difference between the measured value of the low-pressure sensor (52) and the standard target value is large. For this reason, if the low pressure target value remains the standard target value immediately after the compressor (31) is started, the compressor (31) is used to bring the measured value of the low pressure sensor (52) close to the standard target value as soon as possible. ) Is rapidly increased. And if the cooling capacity of the air conditioner (10) suddenly increases with the sudden increase in capacity of the compressor (31), the room temperature will be reduced within a relatively short time after the compressor (31) is started. The temperature becomes lower than the set temperature, and the compressor (31) must be stopped again.
  • control target value changing unit (66) of the present embodiment sets the low pressure target value to a value higher than the standard target value for a while after the compressor (31) is started. Accordingly, even immediately after the compressor (31) is started, the difference between the measured value of the low pressure sensor (52) and the low pressure target value is smaller than when the low pressure target value remains the standard target value. . As a result, the rapid capacity increase of the compressor (31) after the start of the compressor (31) is suppressed, and the cooling capacity of the air conditioner (10) also changes gradually. Therefore, if the control target value changing unit (66) makes the low pressure target value higher than the standard target value as in the present embodiment, the compressor control unit (63) compresses if the low pressure target value remains the standard target value. Even in a situation where the machine (31) has to be stopped, the possibility that the operation of the compressor (31) can be continued increases.
  • the control target value changing unit (66) performs an operation for forcibly changing the high pressure target value as a control target value changing operation. Specifically, when the number of times the compressor is stopped by the compressor control unit (63) reaches a predetermined number within a predetermined time, the control target value changing unit (66) causes the compressor control unit (63) to The high-pressure target value to be used is lowered from the standard target value that is a value determined by the high-pressure target value setting unit (62). Then, when the compressor (31) is subsequently started, the compressor control unit (63) uses the high-pressure target value lowered by the control target value changing unit (66), so that the compressor (31) Adjust the operating capacity. Further, the compressor control unit (63) sets the value of the high pressure target value so that the high pressure target value becomes the standard target value when a predetermined time (for example, 4 minutes) has elapsed since the start of the compressor (31). Pull it up gradually.
  • a predetermined time for example, 4 minutes
  • the compressor (31) immediately after the compressor (31) is started, the difference between the measured value of the high pressure sensor (51) and the standard target value is large. For this reason, if the high pressure target value remains the standard target value immediately after the compressor (31) is started, the compressor (31) is used to bring the measured value of the high pressure sensor (51) close to the standard target value as soon as possible. ) Is rapidly increased. And if the heating capacity of the air conditioner (10) increases suddenly with the sudden increase in capacity of the compressor (31), the room temperature will be reduced in a relatively short time after the compressor (31) is started. The temperature exceeds the set temperature, and the compressor (31) must be stopped again.
  • control target value changing unit (66) of the present embodiment sets the high pressure target value to a value lower than the standard target value for a while after the compressor (31) is started. Accordingly, even immediately after the compressor (31) is started, the difference between the measured value of the high pressure sensor (51) and the high pressure target value is smaller than when the high pressure target value remains the standard target value. . As a result, the rapid capacity increase of the compressor (31) after the start of the compressor (31) is suppressed, and the heating capacity of the air conditioner (10) also changes gradually. For this reason, if the control target value changing unit (66) makes the high pressure target value lower than the standard target value as in this embodiment, the compressor control unit (63) compresses if the high pressure target value remains the standard target value. Even in a situation where the machine (31) has to be stopped, the possibility that the operation of the compressor (31) can be continued increases.
  • Embodiment 2- in the air conditioner (10) performing a so-called supercritical cycle, the compressor (31) can be stopped due to the capacity of the air conditioner (10) being excessive with respect to the load. Can be reduced. Therefore, according to the present embodiment, as in the first embodiment, the power consumed during the operation of the air conditioner (10) is reduced by reducing the number of times the compressor (31) is started and stopped for capacity adjustment. The operating efficiency of the air conditioner (10) can be improved.
  • the compressor control unit (63) of the present embodiment may be configured to use the evaporation temperature of the refrigerant in the indoor heat exchanger (41, 46) operating as an evaporator as a control parameter during cooling operation. .
  • an evaporation temperature target value setting unit is provided instead of the low pressure target value setting unit (61).
  • the evaporating temperature target value setting unit sets a target value of the evaporating temperature of the refrigerant in the indoor heat exchanger (41, 46) according to the cooling load of the air conditioner (10).
  • control target value changing unit (66) of the present modified example uses the evaporation temperature target value setting unit to set the evaporation temperature target value used in the compressor control unit (63) as the control target value changing operation during the cooling operation.
  • the evaporating temperature target value is gradually increased so that the evaporating temperature target value becomes the standard target value when a predetermined time has elapsed from the start of the compressor (31) while being raised from the standard target value which is the determined value. I will pull it down.
  • Embodiment 3 of the Invention will be described.
  • the present embodiment is obtained by changing the configuration of the main controller (60) in the air conditioner (10) of the first embodiment.
  • the main controller (60) of the present embodiment is provided with a gain adjusting unit (67) instead of the superheat degree target value changing unit (65) of the first embodiment.
  • the operations of the low pressure target value setting unit (61), the high pressure target value setting unit (62), the compressor control unit (63), and the outdoor expansion valve control unit (64) Is the same as the operation in the first embodiment.
  • the gain adjusting unit (67) is configured to perform a gain adjusting operation. In this gain adjustment operation, the gain adjustment unit (67) is configured to change the compressor control unit (63) according to the difference between the measured value of the outside air temperature sensor (58) (that is, the actually measured value of the outside air temperature) and the indoor set temperature. ) Is adjusted.
  • the gain adjuster (67) compares the measured value of the outside air temperature sensor (58) with the indoor set temperature.
  • the cooling load in the room decreases as the value obtained by subtracting the set temperature in the room from the measured value of the outside air temperature sensor (58) decreases. Therefore, the gain adjuster (67) sets the control gain used in the compressor controller (63) to a smaller value as the value obtained by subtracting the indoor set temperature from the measured value of the outside air temperature sensor (58) becomes smaller. .
  • the compressor control unit (63) of the present embodiment adjusts the capacity of the compressor (31) using a small control gain set by the gain adjustment unit (67). Specifically, the compressor control unit (63) uses the difference between the measured value of the low pressure sensor (52), the low pressure target value, and the control gain to determine the frequency of the alternating current supplied to the motor of the compressor (31). The command value for the amount of change is calculated. When the difference between the measured value of the low-pressure pressure sensor (52) and the low-pressure target value is the same, in the compressor control unit (63), the command value for the change amount of the AC frequency decreases as the control gain value decreases. .
  • the gain adjuster (67) compares the measured value of the outside air temperature sensor (58) with the set temperature in the room.
  • the indoor heating load decreases as the value obtained by subtracting the measured value of the outside air temperature sensor (58) from the indoor set temperature decreases. Therefore, the gain adjustment unit (67) sets the control gain used in the compressor control unit (63) to a smaller value as the value obtained by subtracting the measured value of the outside air temperature sensor (58) from the indoor set temperature becomes smaller. .
  • the compressor control unit (63) of the present embodiment adjusts the capacity of the compressor (31) using a small control gain set by the gain adjustment unit (67). Specifically, the compressor control unit (63) uses the difference between the measured value of the high pressure sensor (51), the high pressure target value, and the control gain to determine the frequency of the alternating current supplied to the motor of the compressor (31). The command value for the amount of change is calculated. When the difference between the measured value of the high pressure sensor (51) and the high pressure target value is the same, in the compressor control unit (63), the command value for the change amount of the AC frequency decreases as the control gain value decreases. .
  • the control gain used in the compressor control unit (63) remains large despite the load on the air conditioner (10) being small, the measured value of the low pressure sensor (52) and the low pressure target value Or the command value for the change amount of the AC frequency determined based on the difference between the measured value of the high pressure sensor (51) and the high pressure target value.
  • the capacity of the air conditioner (10) becomes excessive with respect to the load, and there is a high possibility that the compressor (31) must be stopped.
  • the gain adjuster (67) of the present embodiment decreases the value of the control gain as the load on the air conditioner (10) decreases.
  • the command value calculated using the measured value of the low pressure sensor (52) or the high pressure sensor (51) and the control gain is smaller than when the control gain is constant. Therefore, when the gain adjustment unit (67) reduces the control gain as in this embodiment, the compressor control unit (63) has to stop the compressor (31) if the control gain remains constant. Even in the situation, there is a high possibility that the operation of the compressor (31) can be continued.
  • the compressor (31) in the air conditioner (10) performing a so-called supercritical cycle, the compressor (31) can be stopped due to the capacity of the air conditioner (10) being excessive with respect to the load. Can be reduced. Therefore, according to the present embodiment, as in the first embodiment, the power consumed during the operation of the air conditioner (10) is reduced by reducing the number of times the compressor (31) is started and stopped for capacity adjustment. The operating efficiency of the air conditioner (10) can be improved.
  • the present invention is useful for a refrigeration apparatus that performs a refrigeration cycle in which the high pressure is set to a value higher than the critical pressure of the refrigerant.

Abstract

Provided is a freezing apparatus which constitutes an air conditioner (10) including a main controller (60) and auxiliary controllers (70a and 70b). The main controller (60) has a compressor control unit for adjusting the running capacity of a compressor (31), to stop the compressor (31) when the capacity of the air conditioner (10) exceeds a load. When the starts/stops of the compressor (31) by the compressor control unit become highly frequent, a target overheat degree changing unit of the main controller (60) raises a target value of overheat forcibly. In a cooling run, the auxiliary controllers (70a and 70b) then adjust the openings of indoor expansion valves (42 and 47) by using the raised target value of overheat. In a warming run, on the other hand, the main controller (60) adjusts the opening of an outdoor expansion valve (34) by using the raised target value of overheat.

Description

冷凍装置Refrigeration equipment
 本発明は、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷凍装置に関するものである。 The present invention relates to a refrigeration apparatus that performs a refrigeration cycle in which the high pressure is set to a value higher than the critical pressure of the refrigerant.
 従来より、冷媒回路で冷媒を循環させて冷凍サイクルを行う冷凍装置が知られている。特許文献1に開示された冷凍装置では、冷媒回路で行われる冷凍サイクルの高圧が冷媒の臨界圧力よりも高い値に設定されている。つまり、この冷凍装置の冷媒回路では、いわゆる超臨界サイクルが行われる。 Conventionally, a refrigeration apparatus that performs a refrigeration cycle by circulating a refrigerant in a refrigerant circuit is known. In the refrigeration apparatus disclosed in Patent Document 1, the high pressure of the refrigeration cycle performed in the refrigerant circuit is set to a value higher than the critical pressure of the refrigerant. That is, a so-called supercritical cycle is performed in the refrigerant circuit of the refrigeration apparatus.
 また、特許文献2に開示された空気調和装置では、高圧が冷媒の臨界圧力よりも低い値に設定される一般的な冷凍サイクルが行われる。この特許文献2の空気調和装置では、圧縮機の起動と停止の頻度を少なくするために、空気調和装置の運転を制御する際の目標値を調節している。
特開2001-116376号公報 特開2002-061925号公報
Moreover, in the air conditioning apparatus disclosed in Patent Document 2, a general refrigeration cycle in which the high pressure is set to a value lower than the critical pressure of the refrigerant is performed. In the air conditioner of Patent Document 2, the target value for controlling the operation of the air conditioner is adjusted in order to reduce the frequency of starting and stopping of the compressor.
JP 2001-116376 A JP 2002-061925 A
 ところで、いわゆる超臨界サイクルを行う冷凍装置においても、冷凍装置の能力を調節するために圧縮機を発停させる場合がある。例えば、圧縮機が可変容量型の場合であっても、圧縮機の容量を最小値にしても冷凍装置の能力が負荷に対して大きすぎることがあり、そのような状況では圧縮機が停止させられる。 Incidentally, even in a refrigeration apparatus that performs a so-called supercritical cycle, the compressor may be started and stopped to adjust the capacity of the refrigeration apparatus. For example, even if the compressor is a variable capacity type, the capacity of the refrigeration system may be too large for the load even if the capacity of the compressor is minimized. In such a situation, the compressor is stopped. It is done.
 超臨界サイクルでは、一般的な冷凍サイクルに比べて高圧が高くなる。このため、高圧が冷媒の臨界圧力よりも低い一般的な冷凍サイクルに比べると、超臨界サイクルを行う冷凍装置では、圧縮機を起動させてから冷凍サイクルの高圧や低圧が適切な値に達するまでに要する動力が嵩んでしまう。それにも拘わらず、これまでは、超臨界サイクルを行う冷凍装置において圧縮機の発停頻度を削減するための対策が充分に講じられていなかった。 In the supercritical cycle, the high pressure is higher than in a general refrigeration cycle. For this reason, in comparison with a general refrigeration cycle in which the high pressure is lower than the critical pressure of the refrigerant, in the refrigeration system that performs the supercritical cycle, the high pressure and low pressure of the refrigeration cycle reach appropriate values after starting the compressor. The power required for this increases. Nevertheless, until now, sufficient measures have not been taken to reduce the frequency of start and stop of the compressor in a refrigeration apparatus that performs a supercritical cycle.
 本発明は、かかる点に鑑みてなされたものであり、その目的は、いわゆる超臨界サイクルを行う冷凍装置において、圧縮機の発停回数を削減して冷凍装置の運転効率を向上させることにある。 The present invention has been made in view of the above points, and an object of the present invention is to improve the operating efficiency of the refrigeration apparatus by reducing the number of times the compressor is started and stopped in a refrigeration apparatus that performs a so-called supercritical cycle. .
 第1の発明は、圧縮機(31)、膨張機構(34,42,47)、熱源側熱交換器(33)、及び利用側熱交換器(41,46)が接続され、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷媒回路(20)と、上記圧縮機(31)及び上記膨張機構(34,42,47)の制御を行う制御手段(80)とを備える冷凍装置を対象とする。そして、上記制御手段(80)は、上記冷媒回路(20)で行われる冷凍サイクルの動作状態を示す物理量が制御目標値となるように、上記圧縮機(31)の容量を調節する容量制御動作と、上記熱源側熱交換器(33)及び上記利用側熱交換器(41,46)のうち蒸発器として動作する方から上記圧縮機(31)へ向かう冷媒の過熱度が過熱度目標値となるように、上記膨張機構(34,42,47)を通過する冷媒の流量を調節する流量制御動作と、上記容量制御動作によって上記圧縮機(31)が停止させられたときは、上記過熱度目標値を強制的に引き上げる過熱度目標値変更動作とを行うように構成されるものである。 In the first invention, the compressor (31), the expansion mechanism (34, 42, 47), the heat source side heat exchanger (33), and the use side heat exchanger (41, 46) are connected, and the high pressure is the refrigerant. A refrigerant circuit (20) for performing a refrigeration cycle set to a value higher than the critical pressure, and a control means (80) for controlling the compressor (31) and the expansion mechanism (34, 42, 47) are provided. For refrigeration equipment. And the said control means (80) is capacity | capacitance control operation | movement which adjusts the capacity | capacitance of the said compressor (31) so that the physical quantity which shows the operation state of the refrigerating cycle performed by the said refrigerant circuit (20) becomes a control target value. And the degree of superheat of the refrigerant from the heat source side heat exchanger (33) and the use side heat exchanger (41, 46) operating as an evaporator to the compressor (31) is the superheat degree target value. When the compressor (31) is stopped by the flow rate control operation for adjusting the flow rate of the refrigerant passing through the expansion mechanism (34, 42, 47) and the capacity control operation, the degree of superheat The superheat degree target value changing operation for forcibly raising the target value is performed.
 第2の発明は、圧縮機(31)、膨張機構(34,42,47)、熱源側熱交換器(33)、及び利用側熱交換器(41,46)が接続され、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷媒回路(20)と、上記圧縮機(31)の制御を行う制御手段(80)とを備え、上記熱源側熱交換器(33)がガスクーラとして動作して上記利用側熱交換器(41,46)が蒸発器として動作する冷却運転を少なくとも行う冷凍装置を対象とする。そして、上記制御手段(80)は、上記利用側熱交換器(41,46)での冷媒の蒸発温度または上記冷媒回路(20)で行われる冷凍サイクルの低圧を制御パラメータとし、該制御パラメータが制御目標値となるように上記圧縮機(31)の容量を調節する容量制御動作と、上記圧縮機(31)の起動から所定時間が経過した後に上記制御目標値が所定の標準目標値となるように、上記圧縮機(31)の起動後に上記制御目標値を次第に低下させる制御目標値変更動作とを行うように構成されるものである。 In the second invention, the compressor (31), the expansion mechanism (34, 42, 47), the heat source side heat exchanger (33), and the use side heat exchanger (41, 46) are connected, and the high pressure is the refrigerant. A refrigerant circuit (20) for performing a refrigeration cycle set to a value higher than the critical pressure, and a control means (80) for controlling the compressor (31), wherein the heat source side heat exchanger (33) A refrigeration apparatus that operates as a gas cooler and performs at least a cooling operation in which the use side heat exchanger (41, 46) operates as an evaporator is an object. The control means (80) uses the evaporation temperature of the refrigerant in the use side heat exchanger (41, 46) or the low pressure of the refrigeration cycle performed in the refrigerant circuit (20) as a control parameter. A capacity control operation for adjusting the capacity of the compressor (31) so as to be a control target value, and the control target value becomes a predetermined standard target value after a predetermined time has elapsed since the start of the compressor (31). As described above, the control target value changing operation for gradually decreasing the control target value after the start of the compressor (31) is performed.
 第3の発明は、圧縮機(31)、膨張機構(34,42,47)、熱源側熱交換器(33)、及び利用側熱交換器(41,46)が接続され、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷媒回路(20)と、上記圧縮機(31)の制御を行う制御手段(80)とを備え、上記利用側熱交換器(41,46)がガスクーラとして動作して上記熱源側熱交換器(33)が蒸発器として動作する加熱運転を少なくとも行う冷凍装置を対象とする。そして、上記制御手段(80)は、上記冷媒回路(20)で行われる冷凍サイクルの高圧を制御パラメータとし、該制御パラメータが制御目標値となるように上記圧縮機(31)の容量を調節する容量制御動作と、上記圧縮機(31)の起動から所定時間が経過した後に上記制御目標値が所定の標準目標値となるように、上記圧縮機(31)の起動後に上記制御目標値を次第に上昇させる制御目標値変更動作とを行うように構成されるものである。 In the third invention, the compressor (31), the expansion mechanism (34, 42, 47), the heat source side heat exchanger (33), and the use side heat exchanger (41, 46) are connected, and the high pressure is the refrigerant. A refrigerant circuit (20) for performing a refrigeration cycle set to a value higher than the critical pressure; and a control means (80) for controlling the compressor (31), the utilization side heat exchanger (41, 46) ) Is operated as a gas cooler, and the heat source side heat exchanger (33) is a refrigeration apparatus that performs at least a heating operation that operates as an evaporator. The control means (80) uses the high pressure of the refrigeration cycle performed in the refrigerant circuit (20) as a control parameter, and adjusts the capacity of the compressor (31) so that the control parameter becomes a control target value. The control target value is gradually set after starting the compressor (31) so that the control target value becomes a predetermined standard target value after a predetermined time has elapsed since the start of the compressor (31). The control target value changing operation is increased.
 第4の発明は、圧縮機(31)、膨張機構(34,42,47)、熱源側熱交換器(33)、及び利用側熱交換器(41,46)が接続され、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷媒回路(20)と、上記圧縮機(31)の制御を行う制御手段(80)とを備える冷凍装置を対象とする。そして、上記制御手段(80)は、上記冷媒回路(20)で行われる冷凍サイクルの動作状態を示す物理量が制御目標値となるように、該物理量と制御ゲインとを用いて算出した指令値に基づいて上記圧縮機(31)の容量を調節する容量制御動作と、上記冷凍装置の負荷が小さくなるほど上記制御ゲインを小さくするゲイン調節動作とを行うように構成されるものである。 In the fourth aspect of the invention, the compressor (31), the expansion mechanism (34, 42, 47), the heat source side heat exchanger (33), and the use side heat exchanger (41, 46) are connected, and the high pressure is the refrigerant. A refrigeration apparatus including a refrigerant circuit (20) that performs a refrigeration cycle set to a value higher than the critical pressure and a control means (80) that controls the compressor (31) is an object. Then, the control means (80) sets the command value calculated using the physical quantity and the control gain so that the physical quantity indicating the operating state of the refrigeration cycle performed in the refrigerant circuit (20) becomes a control target value. Based on this, a capacity control operation for adjusting the capacity of the compressor (31) and a gain adjustment operation for reducing the control gain as the load of the refrigeration apparatus decreases are configured.
 第1,第2,第3,第4の各発明では、冷媒回路(20)で冷媒が循環することによって冷凍サイクルが行われる。その際、圧縮機(31)から吐出される冷媒の圧力は、その冷媒の臨界圧力よりも高くなっている。また、冷媒回路(20)に設けられた熱源側熱交換器(33)と利用側熱交換器(41,46)は、その一方がガスクーラとして動作し、他方が蒸発器として動作する。 In each of the first, second, third, and fourth inventions, the refrigeration cycle is performed by circulating the refrigerant in the refrigerant circuit (20). At that time, the pressure of the refrigerant discharged from the compressor (31) is higher than the critical pressure of the refrigerant. Further, one of the heat source side heat exchanger (33) and the use side heat exchanger (41, 46) provided in the refrigerant circuit (20) operates as a gas cooler, and the other operates as an evaporator.
 第1の発明において、制御手段(80)は、容量制御動作を行う。この容量制御動作では、所定の物理量が制御目標値となるように、圧縮機(31)の容量が調節される。制御手段(80)は、所定の物理量が制御目標値から外れているのに圧縮機(31)の容量をそれ以上引き下げられない状態になると、圧縮機(31)を停止させる。容量制御動作によって圧縮機(31)が停止させられると、制御手段(80)は、過熱度目標値変更動作を行い、過熱度目標値を強制的に引き上げる。その後に圧縮機(31)の運転が再開されると、制御手段(80)は、過熱度目標値変更動作によって引き上げられた過熱度目標値を用いて流量制御動作を行う。つまり、制御手段(80)は、蒸発器として動作する熱交換器(33,41,46)から圧縮機(31)へ向かう冷媒の過熱度が引き上げられた過熱度目標値となるように、膨張機構(34,42,47)を通過する冷媒の流量を調節する。 In the first invention, the control means (80) performs a capacity control operation. In this capacity control operation, the capacity of the compressor (31) is adjusted so that the predetermined physical quantity becomes the control target value. The control means (80) stops the compressor (31) when the predetermined physical quantity deviates from the control target value but the capacity of the compressor (31) cannot be reduced any more. When the compressor (31) is stopped by the capacity control operation, the control means (80) performs the superheat degree target value changing operation and forcibly raises the superheat degree target value. Thereafter, when the operation of the compressor (31) is resumed, the control means (80) performs a flow rate control operation using the superheat degree target value raised by the superheat degree target value changing operation. In other words, the control means (80) expands so that the superheat degree of the refrigerant heading from the heat exchanger (33, 41, 46) operating as an evaporator to the compressor (31) becomes the superheat degree target value raised. The flow rate of the refrigerant passing through the mechanism (34, 42, 47) is adjusted.
 第1の発明において、膨張機構(34,42,47)は、過熱度目標値が高くなるほど、そこを通過する冷媒の流量が少なくなるような状態に設定される。圧縮機(31)の容量が同じ場合で比べると、過熱度目標値が高くなるほど冷媒回路(20)における冷媒の循環量が少なくなるため、冷凍装置(10)の能力が低くなる。つまり、過熱度目標値が高くなるほど、冷凍装置(10)の能力の下限値が低くなる。このため、目標過熱度を引き上げる前は制御手段(80)が圧縮機(31)を停止させざるを得なかった状況においても、目標過熱度を引き上げた後は圧縮機(31)の運転を継続できる可能性が高くなる。 In the first invention, the expansion mechanism (34, 42, 47) is set to a state in which the flow rate of the refrigerant passing therethrough decreases as the superheat degree target value increases. Compared with the case where the capacity of the compressor (31) is the same, the higher the superheat degree target value, the smaller the amount of refrigerant circulating in the refrigerant circuit (20), so the capacity of the refrigeration apparatus (10) becomes lower. That is, the lower the superheat degree target value, the lower the lower limit value of the capacity of the refrigeration apparatus (10). For this reason, even if the control means (80) had to stop the compressor (31) before raising the target superheat, the compressor (31) continued to operate after raising the target superheat. The possibility of being able to be increased.
 第2の発明において、制御手段(80)は、冷却運転中に容量制御動作と制御目標値変更動作とを行う。この容量制御動作において、制御手段(80)は、利用側熱交換器(41,46)での冷媒の蒸発温度または冷媒回路(20)で行われる冷凍サイクルの低圧を制御パラメータとし、制御パラメータが制御目標値となるように圧縮機(31)の容量を調節する。制御手段(80)は、制御パラメータが制御目標値から外れているのに圧縮機(31)の容量をそれ以上引き下げられない状態になると、圧縮機(31)を停止させる。その後に圧縮機(31)の運転が再開されると、制御手段(80)は、制御目標値変更動作を行う。この制御目標値変更動作において、制御手段(80)は、圧縮機(31)の運転が再開された時点における制御目標値を標準目標値よりも高い値に設定し、その時点から所定時間が経過するまでの間に制御目標値を次第に引き下げて標準目標値に近付けてゆく。その間、容量制御動作では、制御目標値変更動作によって調節された制御目標値を用いて、圧縮機(31)の容量調節が行われる。 In the second invention, the control means (80) performs a capacity control operation and a control target value changing operation during the cooling operation. In this capacity control operation, the control means (80) uses the refrigerant evaporation temperature in the use side heat exchanger (41, 46) or the low pressure of the refrigeration cycle performed in the refrigerant circuit (20) as a control parameter. The capacity of the compressor (31) is adjusted so as to reach the control target value. The control means (80) stops the compressor (31) when the capacity of the compressor (31) cannot be further reduced even though the control parameter deviates from the control target value. Thereafter, when the operation of the compressor (31) is resumed, the control means (80) performs a control target value changing operation. In this control target value changing operation, the control means (80) sets the control target value at the time when the operation of the compressor (31) is resumed to a value higher than the standard target value, and a predetermined time has elapsed from that point. In the meantime, the control target value is gradually lowered to approach the standard target value. Meanwhile, in the capacity control operation, the capacity adjustment of the compressor (31) is performed using the control target value adjusted by the control target value changing operation.
 ここで、圧縮機(31)が起動された直後は、制御パラメータである冷媒の蒸発温度や冷凍サイクルの低圧の実測値と標準目標値との差が大きくなっている。このため、圧縮機(31)が起動された直後において制御目標値が標準目標値のままだと、制御パラメータを標準目標値にできるだけ早く近付けるために、圧縮機(31)の容量が急激に増大させられることになる。そして、圧縮機(31)の急激な容量増加に伴って冷凍装置(10)の冷却能力が急激に増大すると、圧縮機(31)が起動してから比較的短時間の間に冷却能力が過剰となり、再び圧縮機(31)を停止させざるを得ない状態になってしまう。 Here, immediately after the compressor (31) is started, the difference between the measured value of the refrigerant evaporation temperature and the low pressure of the refrigeration cycle, which are control parameters, and the standard target value is large. Therefore, if the control target value remains at the standard target value immediately after the compressor (31) is started, the capacity of the compressor (31) increases rapidly in order to bring the control parameter close to the standard target value as soon as possible. Will be allowed to. And if the cooling capacity of the refrigeration system (10) suddenly increases with the rapid capacity increase of the compressor (31), the cooling capacity will be excessive in a relatively short time after the compressor (31) is started. Thus, the compressor (31) must be stopped again.
 それに対し、第2の発明の制御手段(80)は、圧縮機(31)が起動されてから暫くの間は制御目標値を標準目標値よりも高い値に設定している。従って、圧縮機(31)が起動された直後においても、制御パラメータである冷媒の蒸発温度や冷凍サイクルの低圧の実測値と制御目標値との差は、制御目標値が標準目標値のままである場合に比べて小さくなる。その結果、圧縮機(31)の起動後における圧縮機(31)の急激な容量増加が抑えられ、冷凍装置(10)の冷却能力も緩やかに変化することとなる。このため、この発明のように制御手段(80)が制御目標値を標準目標値よりも高くすると、制御目標値が標準目標値のままだと制御手段(80)が圧縮機(31)を停止させざるを得なかった状況においても、圧縮機(31)の運転を継続できる可能性が高くなる。 In contrast, the control means (80) of the second invention sets the control target value to a value higher than the standard target value for a while after the compressor (31) is started. Therefore, even immediately after the compressor (31) is started, the control target value remains the standard target value in terms of the difference between the measured value of the evaporation temperature of the refrigerant and the low pressure of the refrigeration cycle and the control target value. Smaller than in some cases. As a result, the rapid increase in capacity of the compressor (31) after the start of the compressor (31) is suppressed, and the cooling capacity of the refrigeration apparatus (10) also changes gradually. Therefore, when the control means (80) makes the control target value higher than the standard target value as in the present invention, the control means (80) stops the compressor (31) if the control target value remains the standard target value. There is a high possibility that the operation of the compressor (31) can be continued even in a situation where it has been necessary to do so.
 第3の発明において、制御手段(80)は、加熱運転中に容量制御動作と制御目標値変更動作とを行う。この容量制御動作において、制御手段(80)は、冷媒回路(20)で行われる冷凍サイクルの高圧を制御パラメータとし、制御パラメータが制御目標値となるように圧縮機(31)の容量を調節する。制御手段(80)は、制御パラメータが制御目標値から外れているのに圧縮機(31)の容量をそれ以上引き下げられない状態になると、圧縮機(31)を停止させる。その後に圧縮機(31)の運転が再開されると、制御手段(80)は、制御目標値変更動作を行う。この制御目標値変更動作において、制御手段(80)は、圧縮機(31)の運転が再開された時点における制御目標値を標準目標値よりも低い値に設定し、その時点から所定時間が経過するまでの間に制御目標値を次第に引き上げて標準目標値に近付けてゆく。その間、容量制御動作では、制御目標値変更動作によって調節された制御目標値を用いて、圧縮機(31)の容量調節が行われる。 In the third invention, the control means (80) performs a capacity control operation and a control target value changing operation during the heating operation. In this capacity control operation, the control means (80) uses the high pressure of the refrigeration cycle performed in the refrigerant circuit (20) as a control parameter, and adjusts the capacity of the compressor (31) so that the control parameter becomes a control target value. . The control means (80) stops the compressor (31) when the capacity of the compressor (31) cannot be further reduced even though the control parameter deviates from the control target value. Thereafter, when the operation of the compressor (31) is resumed, the control means (80) performs a control target value changing operation. In this control target value changing operation, the control means (80) sets the control target value at the time when the operation of the compressor (31) is resumed to a value lower than the standard target value, and a predetermined time has elapsed from that point. In the meantime, the control target value is gradually raised to approach the standard target value. Meanwhile, in the capacity control operation, the capacity adjustment of the compressor (31) is performed using the control target value adjusted by the control target value changing operation.
 ここで、圧縮機(31)が起動された直後は、制御パラメータである冷凍サイクルの高圧の実測値と標準目標値との差が大きくなっている。このため、圧縮機(31)が起動された直後において制御目標値が標準目標値のままだと、制御パラメータを標準目標値にできるだけ早く近付けるために、圧縮機(31)の容量が急激に増大させられることになる。そして、圧縮機(31)の急激な容量増加に伴って冷凍装置(10)の加熱能力が急激に増大すると、圧縮機(31)が起動してから比較的短時間の間に加熱能力が過剰となり、再び圧縮機(31)を停止させざるを得ない状態になってしまう。 Here, immediately after the compressor (31) is started, the difference between the measured value of the high pressure of the refrigeration cycle, which is a control parameter, and the standard target value is large. Therefore, if the control target value remains at the standard target value immediately after the compressor (31) is started, the capacity of the compressor (31) increases rapidly in order to bring the control parameter close to the standard target value as soon as possible. Will be allowed to. And if the heating capacity of the refrigeration system (10) increases rapidly with the sudden increase in capacity of the compressor (31), the heating capacity will be excessive in a relatively short time after the compressor (31) is started. Thus, the compressor (31) must be stopped again.
 それに対し、第3の発明の制御手段(80)は、圧縮機(31)が起動されてから暫くの間は制御目標値を標準目標値よりも低い値に設定している。従って、圧縮機(31)が起動された直後においても、制御パラメータである冷凍サイクルの高圧の実測値と制御目標値との差は、制御目標値が標準目標値のままである場合に比べて小さくなる。その結果、圧縮機(31)の起動後における圧縮機(31)の急激な容量増加が抑えられ、冷凍装置(10)の加熱能力も緩やかに変化することとなる。このため、この発明のように制御手段(80)が制御目標値を標準目標値よりも低くすると、制御目標値が標準目標値のままだと制御手段(80)が圧縮機(31)を停止させざるを得なかった状況においても、圧縮機(31)の運転を継続できる可能性が高くなる。 In contrast, the control means (80) of the third invention sets the control target value to a value lower than the standard target value for a while after the compressor (31) is started. Therefore, even immediately after the compressor (31) is started, the difference between the measured value of the high pressure of the refrigeration cycle, which is the control parameter, and the control target value is compared with the case where the control target value remains the standard target value. Get smaller. As a result, the rapid capacity increase of the compressor (31) after the start of the compressor (31) is suppressed, and the heating capacity of the refrigeration apparatus (10) also changes gradually. For this reason, if the control means (80) makes the control target value lower than the standard target value as in the present invention, the control means (80) stops the compressor (31) if the control target value remains the standard target value. There is a high possibility that the operation of the compressor (31) can be continued even in a situation where it has been necessary to do so.
 第4の発明では、制御手段(80)が容量制御動作と制御目標値変更動作とを行う。この容量制御動作では、所定の物理量が制御目標値となるように、圧縮機(31)の容量が調節される。制御手段(80)は、所定の物理量が制御目標値から外れているのに圧縮機(31)の容量をそれ以上引き下げられない状態になると、圧縮機(31)を停止させる。一方、制御手段(80)は、ゲイン調節動作を行い、冷凍装置(10)の負荷が小さくなるのに従って、容量制御動作において用いられる制御ゲインの値を引き下げてゆく。 In the fourth invention, the control means (80) performs the capacity control operation and the control target value changing operation. In this capacity control operation, the capacity of the compressor (31) is adjusted so that the predetermined physical quantity becomes the control target value. The control means (80) stops the compressor (31) when the predetermined physical quantity deviates from the control target value but the capacity of the compressor (31) cannot be reduced any more. On the other hand, the control means (80) performs a gain adjustment operation, and decreases the value of the control gain used in the capacity control operation as the load on the refrigeration apparatus (10) decreases.
 ここで、冷凍装置(10)の負荷が小さくなっているにも拘わらず制御ゲインが高いままだと、所定の物理量と制御目標値の偏差に基づいて定められる圧縮機(31)の容量の変更量が大きくなってしまう。その結果、冷凍装置(10)の能力が負荷に対して過剰となり、圧縮機(31)を停止させざるを得ない状態に陥る可能性が高くなる。 Here, if the control gain remains high even though the load of the refrigeration apparatus (10) is small, the change in the capacity of the compressor (31) determined based on the deviation between the predetermined physical quantity and the control target value The amount will increase. As a result, the capacity of the refrigeration apparatus (10) becomes excessive with respect to the load, and there is a high possibility that the compressor (31) must be stopped.
 それに対し、第4の発明の制御手段(80)は、冷凍装置(10)の負荷が小さくなるに従って制御ゲインの値を引き下げてゆく。その結果、所定の物理量と制御ゲインとを用いて算出される指令値は、制御ゲインが一定の場合に比べて小さくなる。このため、この発明のように制御手段(80)が制御ゲインを小さくすると、制御ゲインが一定のままだと制御手段(80)が圧縮機(31)を停止させざるを得なかった状況においても、圧縮機(31)の運転を継続できる可能性が高くなる。 On the other hand, the control means (80) of the fourth invention reduces the value of the control gain as the load of the refrigeration apparatus (10) decreases. As a result, the command value calculated using the predetermined physical quantity and the control gain is smaller than that when the control gain is constant. For this reason, when the control means (80) reduces the control gain as in the present invention, the control means (80) must stop the compressor (31) if the control gain remains constant. The possibility that the operation of the compressor (31) can be continued increases.
 上述したように、上記第1の発明では、過熱度目標値を高くして冷凍装置(10)の能力の下限値を低下させることによって、冷凍装置(10)の能力が負荷に対して過剰になったことに起因して圧縮機(31)が停止する可能性を低減している。また、上記第2の発明では、圧縮機(31)の起動直後に冷却運転中の制御パラメータを高めに設定することで、冷凍装置(10)の冷却能力が負荷に対して過剰になったことに起因して圧縮機(31)が停止する可能性を低減している。また、上記第3の発明では、圧縮機(31)の起動直後に加熱運転中の制御パラメータを低めに設定することで、冷凍装置(10)の加熱能力が負荷に対して過剰になったことに起因して圧縮機(31)が停止する可能性を低減している。また、上記第4の発明では、冷凍装置(10)の負荷が小さい時は制御ゲインを小さめに設定することで、冷凍装置(10)の能力が負荷に対して過剰になったことに起因して圧縮機(31)が停止する可能性を低減している。 As described above, in the first invention, the capacity of the refrigeration apparatus (10) is excessive with respect to the load by increasing the superheat degree target value and lowering the lower limit value of the capacity of the refrigeration apparatus (10). This reduces the possibility of the compressor (31) stopping due to the failure. In the second aspect of the invention, the cooling capacity of the refrigeration apparatus (10) becomes excessive with respect to the load by setting the control parameter during the cooling operation to a higher value immediately after the compressor (31) is started. This reduces the possibility that the compressor (31) will stop. Moreover, in the said 3rd invention, the heating capability of the freezing apparatus (10) became excessive with respect to load by setting the control parameter in heating operation low immediately after starting of a compressor (31). This reduces the possibility that the compressor (31) will stop. In the fourth aspect of the invention, when the load of the refrigeration apparatus (10) is small, the control gain is set to be small, thereby causing the capacity of the refrigeration apparatus (10) to be excessive with respect to the load. This reduces the possibility of the compressor (31) stopping.
 このように、本発明によれば、いわゆる超臨界サイクルを行う冷凍装置(10)において、冷凍装置(10)の能力が負荷に対して過剰になったことに起因して圧縮機(31)が停止する可能性を低減させることができる。つまり、“圧縮機(31)を起動させてから冷凍サイクルの高圧や低圧が適切な値に達するまでに要する動力が嵩む”という特性を有する超臨界サイクルを行う冷凍装置(10)において、能力調節のために圧縮機(31)が発停する回数を削減することができる。従って、本発明によれば、能力調節のための圧縮機(31)の発停回数を削減することで、冷凍装置(10)の運転中に消費される動力を削減でき、冷凍装置(10)の運転効率を向上させることができる。 Thus, according to the present invention, in the refrigeration apparatus (10) performing a so-called supercritical cycle, the compressor (31) is caused by the fact that the capacity of the refrigeration apparatus (10) is excessive with respect to the load. The possibility of stopping can be reduced. In other words, capacity adjustment in the refrigeration system (10) that performs the supercritical cycle with the characteristic that “the power required for the high pressure and low pressure of the refrigeration cycle to reach appropriate values after starting the compressor (31) increases” Therefore, the number of times the compressor (31) starts and stops can be reduced. Therefore, according to the present invention, the power consumed during the operation of the refrigeration apparatus (10) can be reduced by reducing the number of times the compressor (31) for adjusting the capacity is started and stopped, and the refrigeration apparatus (10) The driving efficiency can be improved.
図1は、実施形態1の空調機の概略構成を示す冷媒回路図である。FIG. 1 is a refrigerant circuit diagram illustrating a schematic configuration of the air conditioner according to the first embodiment. 図2は、実施形態1の主コントローラ及び副コントローラの構成を示すブロック図である。FIG. 2 is a block diagram illustrating configurations of the main controller and the sub controller according to the first embodiment. 図3は、実施形態2の主コントローラの構成を示すブロック図である。FIG. 3 is a block diagram illustrating a configuration of the main controller according to the second embodiment. 図4は、実施形態3の主コントローラの構成を示すブロック図である。FIG. 4 is a block diagram illustrating a configuration of the main controller according to the third embodiment.
符号の説明Explanation of symbols
 10  空調機(冷凍装置)
 20  冷媒回路
 31  圧縮機
 33  室外熱交換器(熱源側熱交換器)
 34  室外膨張弁(膨張機構)
 41  室内熱交換器(利用側熱交換器)
 42  室内膨張弁(膨張機構)
 46  室内熱交換器(利用側熱交換器)
 47  室内膨張弁(膨張機構)
 60  主コントローラ
 70a  副コントローラ
 70b  副コントローラ
 80  制御手段
10 Air conditioner (refrigeration equipment)
20 Refrigerant circuit 31 Compressor 33 Outdoor heat exchanger (heat source side heat exchanger)
34 Outdoor expansion valve (expansion mechanism)
41 Indoor heat exchanger (use side heat exchanger)
42 Indoor expansion valve (expansion mechanism)
46 Indoor heat exchanger (use side heat exchanger)
47 Indoor expansion valve (expansion mechanism)
60 Main controller 70a Sub controller 70b Sub controller 80 Control means
 以下、本発明の実施形態を図面に基づいて詳細に説明する。以下で説明する各実施形態は、冷凍装置によって構成された空調機(10)である。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Each embodiment described below is an air conditioner (10) configured by a refrigeration apparatus.
 《発明の実施形態1》
 図1に示すように、本実施形態の空調機(10)は、1台の室外ユニット(11)と、2台の室内ユニット(12,13)とを備えている。室外ユニット(11)は、屋外に設置されている。各室内ユニット(12,13)は、屋内に設置されている。なお、ここに示す室外ユニット(11)や室内ユニット(12,13)の台数は、単なる例示である。また、この空調機(10)は、主コントローラ(60)と副コントローラ(70a,70b)とを備えている。主コントローラ(60)と副コントローラ(70a,70b)は、制御手段(80)を構成している。
Embodiment 1 of the Invention
As shown in FIG. 1, the air conditioner (10) of this embodiment is provided with one outdoor unit (11) and two indoor units (12, 13). The outdoor unit (11) is installed outdoors. Each indoor unit (12, 13) is installed indoors. The number of outdoor units (11) and indoor units (12, 13) shown here is merely an example. The air conditioner (10) includes a main controller (60) and sub controllers (70a, 70b). The main controller (60) and the sub-controllers (70a, 70b) constitute control means (80).
 本実施形態の空調機(10)では、室外ユニット(11)の室外回路(30)と、各室内ユニット(12,13)の室内回路(40,45)とを液側連絡配管(21)及びガス側連絡配管(22)で接続することによって冷媒回路(20)が形成されている。この冷媒回路(20)には、二酸化炭素(CO2)が冷媒として充填されている。また、この冷媒回路(20)で行われる冷凍サイクルでは、その高圧が冷媒である二酸化炭素の臨界圧力よりも高い値に設定されている。 In the air conditioner (10) of the present embodiment, the outdoor circuit (30) of the outdoor unit (11) and the indoor circuit (40, 45) of each indoor unit (12, 13) are connected to the liquid side communication pipe (21) and The refrigerant circuit (20) is formed by connecting with the gas side connecting pipe (22). The refrigerant circuit (20) is filled with carbon dioxide (CO 2 ) as a refrigerant. In the refrigeration cycle performed in the refrigerant circuit (20), the high pressure is set to a value higher than the critical pressure of carbon dioxide, which is a refrigerant.
 室外ユニット(11)には、1つの室外回路(30)が収容されている。室外回路(30)には、圧縮機(31)と、四方切換弁(32)と、熱源側熱交換器である室外熱交換器(33)と、膨張機構である室外膨張弁(34)と、レシーバ(35)と、液側閉鎖弁(36)と、ガス側閉鎖弁(37)とが設けられている。また、室外ユニット(11)には、室外熱交換器(33)へ室外空気を送るための室外ファン(16)が設けられている。 The outdoor unit (11) accommodates one outdoor circuit (30). The outdoor circuit (30) includes a compressor (31), a four-way switching valve (32), an outdoor heat exchanger (33) that is a heat source side heat exchanger, and an outdoor expansion valve (34) that is an expansion mechanism. A receiver (35), a liquid side closing valve (36), and a gas side closing valve (37) are provided. The outdoor unit (11) is provided with an outdoor fan (16) for sending outdoor air to the outdoor heat exchanger (33).
 室外回路(30)において、圧縮機(31)は、その吐出側が四方切換弁(32)の第1のポートに接続され、その吸入側が四方切換弁(32)の第2のポートに接続されている。室外熱交換器(33)は、そのガス側端が四路切換弁の第3のポートに接続され、その液側端が室外膨張弁(34)の一端に接続されている。室外膨張弁(34)の他端は、レシーバ(35)を介して液側閉鎖弁(36)に接続されている。四方切換弁(32)の第4のポートはガス側閉鎖弁(37)に接続されている。 In the outdoor circuit (30), the compressor (31) has its discharge side connected to the first port of the four-way switching valve (32) and its suction side connected to the second port of the four-way switching valve (32). Yes. The outdoor heat exchanger (33) has a gas side end connected to the third port of the four-way switching valve and a liquid side end connected to one end of the outdoor expansion valve (34). The other end of the outdoor expansion valve (34) is connected to the liquid side closing valve (36) via the receiver (35). The fourth port of the four-way switching valve (32) is connected to the gas side closing valve (37).
 各室内ユニット(12,13)には、室内回路(40,45)が1つずつ収容されている。各室内回路(40,45)には、利用側熱交換器である室内熱交換器(41,46)と、膨張機構である室内膨張弁(42,47)とが1つずつ接続されている。各室内回路(40,45)では、室内熱交換器(41,46)と室内膨張弁(42,47)が直列に配置されている。また、各室内ユニット(12,13)には、室内熱交換器(41,46)へ室内空気を送るための室内ファン(17,18)が1つずつ設けられている。 Each indoor unit (12, 13) contains one indoor circuit (40, 45). Each indoor circuit (40, 45) is connected to an indoor heat exchanger (41, 46) which is a use side heat exchanger and an indoor expansion valve (42, 47) which is an expansion mechanism. . In each indoor circuit (40, 45), the indoor heat exchanger (41, 46) and the indoor expansion valve (42, 47) are arranged in series. Each indoor unit (12, 13) is provided with one indoor fan (17, 18) for sending indoor air to the indoor heat exchanger (41, 46).
 冷媒回路(20)において、液側連絡配管(21)は、その一端が液側閉鎖弁(36)に接続されている。液側連絡配管(21)の他端は、二手に分岐されて各室内回路(40,45)の室内膨張弁(42,47)側の端部に接続されている。一方、ガス側連絡配管(22)は、その一端がガス側閉鎖弁(37)に接続されている。ガス側連絡配管(22)の他端は、二手に分岐されて各室内回路(40,45)の室内熱交換器(41,46)側の端部に接続されている。つまり、この冷媒回路(20)では、2つの室内回路(40,45)が1つの室外回路(30)に対して並列に接続されている。 In the refrigerant circuit (20), one end of the liquid side connecting pipe (21) is connected to the liquid side closing valve (36). The other end of the liquid side connecting pipe (21) is bifurcated and connected to the end of each indoor circuit (40, 45) on the indoor expansion valve (42, 47) side. On the other hand, one end of the gas side communication pipe (22) is connected to the gas side closing valve (37). The other end of the gas side connection pipe (22) is bifurcated and connected to the end of each indoor circuit (40, 45) on the indoor heat exchanger (41, 46) side. That is, in this refrigerant circuit (20), two indoor circuits (40, 45) are connected in parallel to one outdoor circuit (30).
 圧縮機(31)は、圧縮機構と電動機が1つのケーシング内に収容された全密閉型の圧縮機である。室外熱交換器(33)と各室内熱交換器(41,46)は、何れも冷媒と空気を熱交換させるように構成されたフィン・アンド・チューブ型の空気熱交換器である。室外膨張弁(34)と各室内膨張弁(42,47)は、何れも開度可変の電動膨張弁である。四方切換弁(32)は、第1のポートと第3のポートが連通し且つ第2のポートと第4のポートが連通する第1状態(図1に実線で示す状態)と、第1のポートと第4のポートが連通し且つ第2のポートと第3のポートが連通する第2状態(図1に破線で示す状態)とに切り換わる。 The compressor (31) is a hermetic compressor in which a compression mechanism and an electric motor are accommodated in one casing. Both the outdoor heat exchanger (33) and the indoor heat exchangers (41, 46) are fin-and-tube type air heat exchangers configured to exchange heat between refrigerant and air. Both the outdoor expansion valve (34) and the indoor expansion valves (42, 47) are electric expansion valves with variable opening. The four-way switching valve (32) includes a first state (state indicated by a solid line in FIG. 1) in which the first port and the third port communicate with each other, and the second port and the fourth port communicate with each other. The state is switched to a second state (state indicated by a broken line in FIG. 1) in which the port communicates with the fourth port and the second port communicates with the third port.
 室外ユニット(11)には、高圧圧力センサ(51)と、低圧圧力センサ(52)と、吸入温度センサ(53)と、室外ガス側温度センサ(54)と、外気温センサ(58)とが1つずつ設けられている。高圧圧力センサ(51)は、冷媒回路(20)における圧縮機(31)の吐出側と四方切換弁(32)の第1のポートとの間に接続され、圧縮機(31)から吐出された冷媒の圧力を計測する。低圧圧力センサ(52)は、冷媒回路(20)における圧縮機(31)の吸入側と四方切換弁(32)の第2のポートとの間に接続され、圧縮機(31)へ吸入される冷媒の圧力を計測する。吸入温度センサ(53)は、冷媒回路(20)における圧縮機(31)の吸入側と四方切換弁(32)の第2のポートとの間に設けられ、圧縮機(31)へ吸入される冷媒の温度を計測する。室外ガス側温度センサ(54)は、室外回路(30)のうち室外熱交換器(33)のガス側の端部の近傍に設けられ、そこを通過する冷媒の温度を計測する。外気温センサ(58)は、室外熱交換器(33)を通過する前の室外空気の温度を計測する。 The outdoor unit (11) includes a high pressure sensor (51), a low pressure sensor (52), an intake temperature sensor (53), an outdoor gas side temperature sensor (54), and an outside air temperature sensor (58). One by one. The high pressure sensor (51) is connected between the discharge side of the compressor (31) in the refrigerant circuit (20) and the first port of the four-way switching valve (32), and is discharged from the compressor (31). Measure the refrigerant pressure. The low pressure sensor (52) is connected between the suction side of the compressor (31) and the second port of the four-way switching valve (32) in the refrigerant circuit (20), and is sucked into the compressor (31). Measure the refrigerant pressure. The suction temperature sensor (53) is provided between the suction side of the compressor (31) and the second port of the four-way switching valve (32) in the refrigerant circuit (20), and is sucked into the compressor (31). Measure the temperature of the refrigerant. The outdoor gas side temperature sensor (54) is provided in the vicinity of the gas side end of the outdoor heat exchanger (33) in the outdoor circuit (30), and measures the temperature of the refrigerant passing therethrough. The outdoor air temperature sensor (58) measures the temperature of the outdoor air before passing through the outdoor heat exchanger (33).
 各室内ユニット(12,13)には、室内温度センサ(55a,55b)と、室内ガス側温度センサ(56,56b)と室内液側温度センサ(57,57b)とが1つずつ設けられている。室内温度センサ(55a,55b)は、室内熱交換器(41,46)を通過する前の室内空気の温度を計測する。室内ガス側温度センサ(56,56b)は、各室内回路(40,45)のうち室内熱交換器(41,46)の室内膨張弁(42,47)とは逆側の端部の近傍に設けられ、そこを通過する冷媒の温度を計測する。室内液側温度センサ(57,57b)は、各室内回路(40,45)のうち室内熱交換器(41,46)の室内膨張弁(42,47)側の端部の近傍に設けられ、そこを通過する冷媒の温度を計測する。 Each indoor unit (12, 13) is provided with one indoor temperature sensor (55a, 55b), one indoor gas side temperature sensor (56, 56b), and one indoor liquid side temperature sensor (57, 57b). Yes. The indoor temperature sensor (55a, 55b) measures the temperature of the indoor air before passing through the indoor heat exchanger (41, 46). The indoor gas side temperature sensor (56, 56b) is located near the end of each indoor circuit (40, 45) opposite to the indoor expansion valve (42, 47) of the indoor heat exchanger (41, 46). The temperature of the refrigerant | coolant which is provided and passes there is measured. The indoor liquid side temperature sensor (57, 57b) is provided in the vicinity of the end of each indoor circuit (40, 45) on the indoor expansion valve (42, 47) side of the indoor heat exchanger (41, 46), The temperature of the refrigerant passing there is measured.
 主コントローラ(60)は、室外ユニット(11)に設置されている。図2に示すように、主コントローラ(60)には、低圧目標値設定部(61)と、高圧目標値設定部(62)と、圧縮機制御部(63)と、室外膨張弁制御部(64)と、過熱度目標値変更部(65)とが設けられている。主コントローラ(60)には、高圧圧力センサ(51)、低圧圧力センサ(52)、吸入温度センサ(53)、室外ガス側温度センサ(54)、各室内温度センサ(55a,55b)、及び外気温センサ(58)の計測値が入力される。 The main controller (60) is installed in the outdoor unit (11). As shown in FIG. 2, the main controller (60) includes a low pressure target value setting unit (61), a high pressure target value setting unit (62), a compressor control unit (63), and an outdoor expansion valve control unit ( 64) and a superheat degree target value changing section (65). The main controller (60) includes a high pressure sensor (51), a low pressure sensor (52), a suction temperature sensor (53), an outdoor gas side temperature sensor (54), each indoor temperature sensor (55a, 55b), and an outside The measured value of the temperature sensor (58) is input.
 副コントローラ(70a,70b)は、各室内ユニット(12,13)に一つずつ設置されている。図2に示すように、各副コントローラ(70a,70b)には、室内膨張弁制御部(71a,71b)が設けられている。各副コントローラ(70a,70b)には、低圧圧力センサ(52)の計測値が入力される。また、各副コントローラ(70a,70b)には、それぞれと同じ室内ユニット(12,13)に設置された室内ガス側温度センサ(56,56b)及び室内液側温度センサ(57,57b)の計測値が入力される。 Sub-controllers (70a, 70b) are installed in each indoor unit (12, 13). As shown in FIG. 2, each sub-controller (70a, 70b) is provided with an indoor expansion valve controller (71a, 71b). The measured values of the low-pressure sensor (52) are input to the sub controllers (70a, 70b). In addition, each sub-controller (70a, 70b) measures the indoor gas side temperature sensor (56, 56b) and the indoor liquid side temperature sensor (57, 57b) installed in the same indoor unit (12, 13). A value is entered.
 主コントローラ(60)及び副コントローラ(70a,70b)は、各センサから入力された計測値を用いて空調機(10)の運転を制御する。主コントローラ(60)と副コントローラ(70a,70b)が行う制御動作の詳細は、後述する。 The main controller (60) and the sub-controllers (70a, 70b) control the operation of the air conditioner (10) using the measured values input from the sensors. Details of the control operation performed by the main controller (60) and the sub-controllers (70a, 70b) will be described later.
  -空調機の運転動作-
 本実施形態の空調機(10)は、冷却運転である冷房運転と、加熱運転である暖房運転を選択的に行う。冷房運転と暖房運転の切り換えは、四方切換弁(32)を操作することによって行われる。
-Operation of air conditioners-
The air conditioner (10) of the present embodiment selectively performs a cooling operation that is a cooling operation and a heating operation that is a heating operation. Switching between the cooling operation and the heating operation is performed by operating the four-way switching valve (32).
   〈冷房運転〉
 冷房運転中の空調機(10)の動作を説明する。冷房運転時には、四方切換弁(32)が第1状態(図1に実線で示す状態)に設定される。また、冷房運転時には、室外膨張弁(34)が全開に設定され、各室内膨張弁(42,47)の開度が適宜調節される。
<Cooling operation>
The operation of the air conditioner (10) during the cooling operation will be described. During the cooling operation, the four-way switching valve (32) is set to the first state (the state indicated by the solid line in FIG. 1). Moreover, at the time of air_conditionaing | cooling operation, an outdoor expansion valve (34) is set to full open, and the opening degree of each indoor expansion valve (42, 47) is adjusted suitably.
 冷媒回路(20)では、冷媒が循環して冷凍サイクルが行われる。冷房運転時の冷媒回路(20)では、室外熱交換器(33)がガスクーラとして動作し、各室内熱交換器(41,46)が蒸発器として動作する。 In the refrigerant circuit (20), the refrigerant circulates to perform a refrigeration cycle. In the refrigerant circuit (20) during the cooling operation, the outdoor heat exchanger (33) operates as a gas cooler, and each indoor heat exchanger (41, 46) operates as an evaporator.
 具体的に、圧縮機(31)から吐出された超臨界状態の冷媒は、四方切換弁(32)を通って室外熱交換器(33)へ送られ、室外空気へ放熱する。室外熱交換器(33)から流出した冷媒は、室外膨張弁(34)とレシーバ(35)を通って液側連絡配管(21)へ流入し、その後に各室内回路(40,45)へ分配される。 Specifically, the supercritical refrigerant discharged from the compressor (31) is sent to the outdoor heat exchanger (33) through the four-way switching valve (32) and dissipates heat to the outdoor air. The refrigerant flowing out of the outdoor heat exchanger (33) flows into the liquid side communication pipe (21) through the outdoor expansion valve (34) and the receiver (35), and is then distributed to each indoor circuit (40, 45). Is done.
 各室内回路(40,45)へ流入した冷媒は、室内膨張弁(42,47)を通過する際に減圧されて気液二相状態となり、その後に室内熱交換器(41,46)で室内空気から吸熱して蒸発する。各室内ユニット(12,13)は、室内熱交換器(41,46)で冷却された室内空気を室内へ供給する。各室内熱交換器(41,46)を通過した冷媒は、ガス側連絡配管(22)へ流れ込んで合流し、その後に四方切換弁(32)を通って圧縮機(31)へ吸入される。圧縮機(31)は、吸入した冷媒を圧縮してから吐出する。 The refrigerant flowing into each indoor circuit (40, 45) is reduced in pressure when passing through the indoor expansion valve (42, 47) to become a gas-liquid two-phase state, and then indoors in the indoor heat exchanger (41, 46). It absorbs heat from the air and evaporates. Each indoor unit (12, 13) supplies indoor air cooled by the indoor heat exchanger (41, 46) to the room. The refrigerant that has passed through the indoor heat exchangers (41, 46) flows into the gas side communication pipe (22) and joins, and then is sucked into the compressor (31) through the four-way switching valve (32). The compressor (31) compresses the sucked refrigerant and discharges it.
   〈暖房運転〉
 暖房運転中の空調機(10)の動作を説明する。暖房運転時には、四方切換弁(32)が第2状態(図1に破線で示す状態)に設定される。また、暖房運転時には、室外膨張弁(34)及び各室内膨張弁(42,47)の開度が適宜調節される。
<Heating operation>
The operation of the air conditioner (10) during the heating operation will be described. During the heating operation, the four-way selector valve (32) is set to the second state (the state indicated by the broken line in FIG. 1). Further, during the heating operation, the opening degrees of the outdoor expansion valve (34) and the indoor expansion valves (42, 47) are appropriately adjusted.
 冷媒回路(20)では、冷媒が循環して冷凍サイクルが行われる。暖房運転時の冷媒回路(20)では、各室内熱交換器(41,46)がガスクーラとして動作し、室外熱交換器(33)が蒸発器として動作する。 In the refrigerant circuit (20), the refrigerant circulates to perform a refrigeration cycle. In the refrigerant circuit (20) during the heating operation, each indoor heat exchanger (41, 46) operates as a gas cooler, and the outdoor heat exchanger (33) operates as an evaporator.
 具体的に、圧縮機(31)から吐出された超臨界状態の冷媒は、四方切換弁(32)を通ってガス側連絡配管(22)へ流入し、その後に各室内回路(40,45)へ分配される。各室内回路(40,45)へ流入した冷媒は、室内熱交換器(41,46)で室内空気へ放熱する。各室内ユニット(12,13)は、室内熱交換器(41,46)で加熱された室内空気を室内へ供給する。室内熱交換器(41,46)から流出した冷媒は、室内膨張弁(42,47)を通過後に液側連絡配管(21)へ流入し、その後に室外回路(30)へ流入する。 Specifically, the supercritical refrigerant discharged from the compressor (31) flows into the gas side communication pipe (22) through the four-way switching valve (32), and then to each indoor circuit (40, 45). Distributed to. The refrigerant that has flowed into the indoor circuits (40, 45) radiates heat to the indoor air by the indoor heat exchanger (41, 46). Each indoor unit (12, 13) supplies indoor air heated by the indoor heat exchanger (41, 46) to the room. The refrigerant flowing out of the indoor heat exchanger (41, 46) flows into the liquid side connection pipe (21) after passing through the indoor expansion valve (42, 47), and then flows into the outdoor circuit (30).
 室外回路(30)へ流入した冷媒は、レシーバ(35)を通過後に室外膨張弁(34)へ送られ、室外膨張弁(34)を通過する際に減圧されて気液二相状態となる。室外膨張弁(34)を通過した冷媒は、室外熱交換器(33)へ送られ、室外空気から吸熱して蒸発する。室外熱交換器(33)から流出した冷媒は、四方切換弁(32)を通って圧縮機(31)へ吸入される。圧縮機(31)は、吸入した冷媒を圧縮してから吐出する。 The refrigerant flowing into the outdoor circuit (30) is sent to the outdoor expansion valve (34) after passing through the receiver (35), and is reduced in pressure when passing through the outdoor expansion valve (34) to be in a gas-liquid two-phase state. The refrigerant that has passed through the outdoor expansion valve (34) is sent to the outdoor heat exchanger (33), and absorbs heat from the outdoor air to evaporate. The refrigerant flowing out of the outdoor heat exchanger (33) is sucked into the compressor (31) through the four-way switching valve (32). The compressor (31) compresses the sucked refrigerant and discharges it.
  -主コントローラおよび副コントローラの動作-
 上述したように、主コントローラ(60)及び副コントローラ(70a,70b)は、各センサから入力された計測値を用いて空調機(10)の運転制御を行う。
-Operation of main controller and sub-controller-
As described above, the main controller (60) and the sub-controllers (70a, 70b) control the operation of the air conditioner (10) using the measurement values input from the sensors.
   〈冷房運転〉
 冷房運転中における主コントローラ(60)及び副コントローラ(70a,70b)の動作について説明する。冷房運転中において、主コントローラ(60)では、低圧目標値設定部(61)と圧縮機制御部(63)と過熱度目標値変更部(65)とが動作を行う、また、主コントローラ(60)では、室外膨張弁制御部(64)が室外膨張弁(34)の開度を全開に保持する動作だけを行い、高圧目標値設定部(62)が休止する。更に、各副コントローラ(70a,70b)では、それぞれの室内膨張弁制御部(71a,71b)が動作を行う。
<Cooling operation>
The operation of the main controller (60) and the sub controllers (70a, 70b) during the cooling operation will be described. During the cooling operation, the main controller (60) is operated by the low pressure target value setting unit (61), the compressor control unit (63), and the superheat degree target value changing unit (65). ), The outdoor expansion valve control section (64) performs only the operation of keeping the opening degree of the outdoor expansion valve (34) fully open, and the high pressure target value setting section (62) is stopped. Furthermore, in each sub controller (70a, 70b), each indoor expansion valve control part (71a, 71b) operates.
 各副コントローラ(70a,70b)の室内膨張弁制御部(71a,71b)は、対応する室内ユニット(12,13)に設けられた室内膨張弁(42,47)の開度調節を行う。つまり、第1の室内ユニット(12)において、副コントローラ(70a)の室内膨張弁制御部(71a)は、第1の室内熱交換器(41)の出口における冷媒の過熱度が所定の過熱度目標値となるように、第1の室内膨張弁(42)の開度を調節する。また、第2の室内ユニット(13)において、副コントローラ(70b)の室内膨張弁制御部(71b)は、第2の室内熱交換器(46)の出口における冷媒の過熱度が所定の過熱度目標値となるように、第2の室内膨張弁(47)の開度を調節する。 The indoor expansion valve controller (71a, 71b) of each sub controller (70a, 70b) adjusts the opening of the indoor expansion valve (42, 47) provided in the corresponding indoor unit (12, 13). That is, in the first indoor unit (12), the indoor expansion valve control unit (71a) of the sub controller (70a) has a degree of superheat of the refrigerant at the outlet of the first indoor heat exchanger (41). The opening degree of the first indoor expansion valve (42) is adjusted so as to be the target value. In the second indoor unit (13), the indoor expansion valve control unit (71b) of the sub controller (70b) has a superheat degree of the refrigerant at the outlet of the second indoor heat exchanger (46). The opening degree of the second indoor expansion valve (47) is adjusted so as to reach the target value.
 各室内膨張弁制御部(71a,71b)が行う制御動作について、詳細に説明する。室内膨張弁制御部(71a,71b)は、対応する室内ユニット(12,13)に設けられた室内ガス側温度センサ(56,56b)の検出値から、低圧圧力センサ(52)の検出値における冷媒の飽和温度を差し引くことによって、対応する室内ユニット(12,13)に設けられた室内熱交換器(41,46)の出口における冷媒の過熱度を算出する。そして、この過熱度の算出値が過熱度目標値となるように、対応する室内ユニット(12,13)に設けられた室内膨張弁(42,47)の開度を調節する。室内膨張弁制御部(71a,71b)による室内膨張弁(42,47)の開度制御は、PID制御等の一般的なフィードバック制御によって行われる。 The control operation performed by each indoor expansion valve controller (71a, 71b) will be described in detail. The indoor expansion valve control unit (71a, 71b) determines the detected value of the low pressure sensor (52) from the detected value of the indoor gas side temperature sensor (56, 56b) provided in the corresponding indoor unit (12, 13). By subtracting the saturation temperature of the refrigerant, the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger (41, 46) provided in the corresponding indoor unit (12, 13) is calculated. And the opening degree of the indoor expansion valve (42, 47) provided in the corresponding indoor unit (12, 13) is adjusted so that the calculated value of the superheat degree becomes the superheat degree target value. The opening control of the indoor expansion valves (42, 47) by the indoor expansion valve control units (71a, 71b) is performed by general feedback control such as PID control.
 具体的に、室内膨張弁制御部(71a,71b)は、過熱度の算出値が過熱度目標値よりも小さい場合は、室内熱交換器(41,46)の出口における冷媒の過熱度を大きくするために、室内膨張弁(42,47)の開度を絞って室内熱交換器(41,46)を通過する冷媒の流量を減少させる。また、室内膨張弁制御部(71a,71b)は、過熱度の算出値が過熱度目標値よりも大きい場合は、室内熱交換器(41,46)の出口における冷媒の過熱度を小さくするために、室内膨張弁(42,47)の開度を拡大して室内熱交換器(41,46)を通過する冷媒の流量を増加させる。なお、室内膨張弁制御部(71a,71b)において、過熱度目標値は、過熱度目標値変更部(65)によって変更される場合を除き、一定の標準値(例えば5℃)に設定されている。 Specifically, the indoor expansion valve control unit (71a, 71b) increases the superheat degree of the refrigerant at the outlet of the indoor heat exchanger (41, 46) when the calculated superheat value is smaller than the superheat degree target value. In order to do so, the flow rate of the refrigerant passing through the indoor heat exchanger (41, 46) is reduced by reducing the opening of the indoor expansion valve (42, 47). Further, the indoor expansion valve control unit (71a, 71b) reduces the superheat degree of the refrigerant at the outlet of the indoor heat exchanger (41, 46) when the calculated value of the superheat degree is larger than the superheat degree target value. The flow rate of the refrigerant passing through the indoor heat exchanger (41, 46) is increased by increasing the opening of the indoor expansion valve (42, 47). In the indoor expansion valve control units (71a, 71b), the superheat degree target value is set to a constant standard value (for example, 5 ° C.) except when it is changed by the superheat degree target value changing part (65). Yes.
 低圧目標値設定部(61)は、低圧目標値設定動作を行うように構成されている。この低圧目標値設定動作では、冷凍サイクルの低圧の目標値である低圧目標値が、冷房運転時の室内ユニット(12,13)における冷房負荷に応じた値に設定される。 The low pressure target value setting unit (61) is configured to perform a low pressure target value setting operation. In this low pressure target value setting operation, the low pressure target value, which is the low pressure target value of the refrigeration cycle, is set to a value corresponding to the cooling load in the indoor units (12, 13) during the cooling operation.
 具体的に、低圧目標値設定部(61)は、各室内温度センサ(55a,55b)の計測値や冷房時の室内設定温度等に基づき、室内ユニット(12,13)における冷房能力の過不足を判断する。そして、低圧目標値設定部(61)は、室内ユニット(12,13)における冷房能力が不足していると判断した場合は、冷房能力を増大させるために低圧目標値を引き下げる。また、低圧目標値設定部(61)は、室内ユニット(12,13)における冷房能力が過剰であると判断した場合は、冷房能力を減少させるために低圧目標値を引き上げる。 Specifically, the low pressure target value setting unit (61) determines whether the indoor unit (12, 13) has sufficient or insufficient cooling capacity based on the measured value of each indoor temperature sensor (55a, 55b), the indoor set temperature during cooling, etc. Judging. If the low pressure target value setting unit (61) determines that the cooling capacity of the indoor units (12, 13) is insufficient, the low pressure target value setting unit (61) decreases the low pressure target value to increase the cooling capacity. Further, when the low pressure target value setting unit (61) determines that the cooling capacity in the indoor units (12, 13) is excessive, it raises the low pressure target value in order to decrease the cooling capacity.
 圧縮機制御部(63)は、容量制御動作を行うように構成されている。この容量制御動作では、低圧圧力センサ(52)の計測値(即ち、冷凍サイクルの低圧の実測値)が低圧目標値となるように、圧縮機(31)の運転容量が調節される。つまり、圧縮機制御部(63)は、制御パラメータとして冷凍サイクルの低圧を用い、その制御パラメータが低圧目標値となるように圧縮機(31)の運転容量を調節する。 The compressor control unit (63) is configured to perform a capacity control operation. In this capacity control operation, the operating capacity of the compressor (31) is adjusted so that the measured value of the low pressure sensor (52) (that is, the measured value of the low pressure of the refrigeration cycle) becomes the low pressure target value. That is, the compressor control unit (63) uses the low pressure of the refrigeration cycle as a control parameter, and adjusts the operating capacity of the compressor (31) so that the control parameter becomes the low pressure target value.
 具体的に、圧縮機制御部(63)は、圧縮機(31)の電動機へ供給される交流の周波数を変更し、電動機で駆動される圧縮機構の回転速度を変化させることによって圧縮機(31)の運転容量を変化させる。そして、圧縮機制御部(63)は、低圧圧力センサ(52)の計測値が低圧目標値よりも高い場合は、冷凍サイクルの低圧を低下させるために、圧縮機(31)の電動機の回転速度を上昇させて圧縮機(31)の運転容量を増加させる。また、圧縮機制御部(63)は、低圧圧力センサ(52)の計測値が低圧目標値よりも低い場合は、冷凍サイクルの低圧を上昇させるために、圧縮機(31)の電動機の回転速度を低下させて圧縮機(31)の運転容量を減少させる。 Specifically, the compressor control unit (63) changes the frequency of the alternating current supplied to the electric motor of the compressor (31) and changes the rotational speed of the compression mechanism driven by the electric motor (31). ) Is changed. When the measured value of the low pressure sensor (52) is higher than the low pressure target value, the compressor control unit (63) rotates the rotation speed of the motor of the compressor (31) to reduce the low pressure of the refrigeration cycle. To increase the operating capacity of the compressor (31). Further, when the measured value of the low pressure sensor (52) is lower than the low pressure target value, the compressor control unit (63) rotates the motor speed of the compressor (31) to increase the low pressure of the refrigeration cycle. To reduce the operating capacity of the compressor (31).
 その際、圧縮機制御部(63)は、低圧圧力センサ(52)の計測値と所定の制御ゲインを用いて、圧縮機(31)の電動機へ供給される交流の周波数の変更量の指令値を算出する。具体的に、圧縮機制御部(63)では、低圧圧力センサ(52)の計測値と低圧目標値の差が大きくなるほど、交流周波数の変更量の指令値が大きな値となり、低圧圧力センサ(52)の計測値と低圧目標値の差が小さくなるほど、交流周波数の変更量の指令値が小さな値となる。 At that time, the compressor control unit (63) uses the measured value of the low-pressure sensor (52) and a predetermined control gain to command the change amount of the AC frequency supplied to the motor of the compressor (31). Is calculated. Specifically, in the compressor control unit (63), as the difference between the measured value of the low pressure sensor (52) and the low pressure target value increases, the command value for the change amount of the AC frequency becomes larger, and the low pressure sensor (52 The smaller the difference between the measured value) and the low pressure target value, the smaller the command value for changing the AC frequency.
  また、圧縮機制御部(63)は、圧縮機(31)の電動機へ供給される交流の周波数が下限値に達しているにも拘わらず低圧圧力センサ(52)の計測値が低圧目標値よりも低い状態が所定時間に亘って継続すると、冷房能力が冷房負荷に対して過剰と判断し、圧縮機(31)を停止させる。更に、圧縮機制御部(63)は、室内温度センサ(55a,55b)の計測値と冷房時の室内設定温度等との差がある程度以上に達すると、室内を冷却する必要があると判断し、圧縮機(31)を起動させる。 In addition, the compressor control unit (63) determines that the measured value of the low pressure sensor (52) is lower than the low pressure target value even though the frequency of the alternating current supplied to the motor of the compressor (31) has reached the lower limit value. If the low state continues for a predetermined time, it is determined that the cooling capacity is excessive with respect to the cooling load, and the compressor (31) is stopped. Furthermore, the compressor control unit (63) determines that the room needs to be cooled when the difference between the measured value of the room temperature sensor (55a, 55b) and the indoor set temperature during cooling reaches a certain level. Start the compressor (31).
 過熱度目標値変更部(65)は、過熱度目標値変更動作を行うように構成されている。この過熱度目標値変更動作において、過熱度目標値変更部(65)は、圧縮機制御部(63)によって圧縮機(31)が停止させられた回数を計数する。そして、過熱度目標値変更部(65)は、圧縮機制御部(63)によって圧縮機が停止させられた回数が所定の時間内(例えば15分以内)に所定の値(例えば2回)に達すると、過熱度目標値を標準値(例えば5℃)から強制的に引き上げる。過熱度目標値変更部(65)が過熱度目標値を強制的に引き上げた後において、室内膨張弁制御部(71a,71b)は、標準値から引き上げられた過熱度目標値を用いて室内膨張弁(42,47)の開度調節を行う。 The superheat degree target value changing unit (65) is configured to perform a superheat degree target value changing operation. In this superheat degree target value changing operation, the superheat degree target value changing section (65) counts the number of times the compressor (31) is stopped by the compressor control section (63). The superheat degree target value changing unit (65) sets the number of times the compressor is stopped by the compressor control unit (63) to a predetermined value (for example, twice) within a predetermined time (for example, within 15 minutes). When reaching, the superheat target value is forcibly increased from a standard value (for example, 5 ° C.). After the superheat degree target value changer (65) forcibly raises the superheat degree target value, the indoor expansion valve controller (71a, 71b) uses the superheat degree target value raised from the standard value to expand the room. Adjust the opening of the valves (42, 47).
 ただし、冷房運転中に室内熱交換器(41,46)から流出する冷媒の過熱度が高くなり過ぎると、圧縮機(31)へ吸入される冷媒の過熱度が高くなり過ぎ、圧縮機(31)から吐出される冷媒の温度が高くなり過ぎるおそれがある。このため、過熱度目標値変更部(65)では、過熱度目標値変更動作による過熱度目標値の引き上げ幅について、圧縮機(31)から吐出される冷媒の温度が高くなり過ぎないように上限値が設定されている。 However, if the superheat degree of the refrigerant flowing out from the indoor heat exchanger (41, 46) becomes too high during the cooling operation, the superheat degree of the refrigerant sucked into the compressor (31) becomes too high, and the compressor (31 There is a possibility that the temperature of the refrigerant discharged from the above will become too high. For this reason, in the superheat degree target value changing unit (65), the upper limit of the superheat degree target value by the superheat degree target value changing operation is limited so that the temperature of the refrigerant discharged from the compressor (31) does not become too high. Value is set.
   〈暖房運転〉
 暖房運転中における主コントローラ(60)及び副コントローラ(70a,70b)の動作について説明する。暖房運転中において、主コントローラ(60)では、高圧目標値設定部(62)と圧縮機制御部(63)と室外膨張弁制御部(64)と過熱度目標値変更部(65)とが動作を行い、低圧目標値設定部(61)が休止する。更に、各副コントローラ(70a,70b)では、それぞれの室内膨張弁制御部(71a,71b)が動作を行う。
<Heating operation>
Operations of the main controller (60) and the sub controllers (70a, 70b) during the heating operation will be described. During the heating operation, the main controller (60) operates the high pressure target value setting unit (62), the compressor control unit (63), the outdoor expansion valve control unit (64), and the superheat degree target value changing unit (65). And the low pressure target value setting unit (61) is suspended. Furthermore, in each sub controller (70a, 70b), each indoor expansion valve control part (71a, 71b) operates.
 各副コントローラ(70a,70b)の室内膨張弁制御部(71a,71b)は、対応する室内ユニット(12,13)に設けられた室内膨張弁(42,47)の開度調節を行う。この点は、冷房運転中における動作と同じである。但し、暖房運転中の室内膨張弁制御部(71a,71b)は、対応する室内ユニット(12,13)に設けられた室内液側温度センサ(57,57b)の検出値が所定の目標値となるように、室内膨張弁(42,47)の開度を調節する。つまり、暖房運転中の室内膨張弁制御部(71a,71b)は、ガスクーラとして動作する室内熱交換器(41,46)の出口における冷媒の温度が所定の目標値となるように、室内膨張弁(42,47)の開度を調節する。室内膨張弁制御部(71a,71b)による室内膨張弁(42,47)の開度制御は、PID制御等の一般的なフィードバック制御によって行われる。 The indoor expansion valve controller (71a, 71b) of each sub controller (70a, 70b) adjusts the opening of the indoor expansion valve (42, 47) provided in the corresponding indoor unit (12, 13). This point is the same as the operation during the cooling operation. However, the indoor expansion valve control units (71a, 71b) during heating operation have the detection values of the indoor liquid side temperature sensors (57, 57b) provided in the corresponding indoor units (12, 13) as the predetermined target values. The opening degree of the indoor expansion valve (42, 47) is adjusted so as to be. That is, the indoor expansion valve control unit (71a, 71b) during the heating operation is configured so that the refrigerant temperature at the outlet of the indoor heat exchanger (41, 46) operating as a gas cooler becomes a predetermined target value. Adjust the opening of (42,47). The opening control of the indoor expansion valves (42, 47) by the indoor expansion valve control units (71a, 71b) is performed by general feedback control such as PID control.
 具体的に、室内膨張弁制御部(71a,71b)は、室内液側温度センサ(57,57b)の検出値が目標値よりも高い場合は、室内熱交換器(41,46)の出口における冷媒の温度を低下させるために、室内膨張弁(42,47)の開度を絞って室内熱交換器(41,46)を通過する冷媒の流量を減少させる。また、室内膨張弁制御部(71a,71b)は、室内液側温度センサ(57,57b)の検出値が目標値よりも低い場合は、室内熱交換器(41,46)の出口における冷媒の温度を上昇させるために、室内膨張弁(42,47)の開度を拡大して室内熱交換器(41,46)を通過する冷媒の流量を増加させる。 Specifically, when the detected value of the indoor liquid side temperature sensor (57, 57b) is higher than the target value, the indoor expansion valve control unit (71a, 71b) is arranged at the outlet of the indoor heat exchanger (41, 46). In order to reduce the temperature of the refrigerant, the flow rate of the refrigerant passing through the indoor heat exchanger (41, 46) is reduced by reducing the opening of the indoor expansion valve (42, 47). Further, the indoor expansion valve control unit (71a, 71b), when the detected value of the indoor liquid side temperature sensor (57, 57b) is lower than the target value, the refrigerant at the outlet of the indoor heat exchanger (41, 46). In order to increase the temperature, the flow rate of the refrigerant passing through the indoor heat exchanger (41, 46) is increased by increasing the opening of the indoor expansion valve (42, 47).
 高圧目標値設定部(62)は、高圧目標値設定動作を行うように構成されている。この高圧目標値設定動作では、冷凍サイクルの高圧の目標値である高圧目標値が、暖房運転時の室内ユニット(12,13)における暖房負荷に応じた値に設定される。 The high pressure target value setting unit (62) is configured to perform a high pressure target value setting operation. In this high pressure target value setting operation, the high pressure target value, which is the high pressure target value of the refrigeration cycle, is set to a value corresponding to the heating load in the indoor units (12, 13) during the heating operation.
 具体的に、高圧目標値設定部(62)は、各室内温度センサ(55a,55b)の計測値や暖房時の室内設定温度等に基づき、室内ユニット(12,13)における暖房能力の過不足を判断する。そして、高圧目標値設定部(62)は、室内ユニット(12,13)における暖房能力が不足していると判断した場合は、暖房能力を増大させるために高圧目標値を引き上げる。また、高圧目標値設定部(62)は、室内ユニット(12,13)における暖房能力が過剰であると判断した場合は、暖房能力を減少させるために高圧目標値を引き下げる。 Specifically, the high-pressure target value setting unit (62) determines whether the indoor unit (12, 13) is overheated or insufficient based on the measured value of each indoor temperature sensor (55a, 55b), the indoor set temperature during heating, etc. Judging. When the high pressure target value setting unit (62) determines that the heating capacity of the indoor units (12, 13) is insufficient, the high pressure target value setting unit (62) raises the high pressure target value to increase the heating capacity. Further, when the high pressure target value setting unit (62) determines that the heating capacity in the indoor units (12, 13) is excessive, the high pressure target value setting unit (62) lowers the high pressure target value in order to decrease the heating capacity.
 圧縮機制御部(63)は、容量制御動作を行うように構成されている。この容量制御動作では、高圧圧力センサ(51)の計測値(即ち、冷凍サイクルの高圧の実測値)が高圧目標値となるように、圧縮機(31)の運転容量が調節される。つまり、圧縮機制御部(63)は、制御パラメータとして冷凍サイクルの高圧を用い、その制御パラメータが高圧目標値となるように、圧縮機(31)の運転容量を調節する。 The compressor control unit (63) is configured to perform a capacity control operation. In this capacity control operation, the operating capacity of the compressor (31) is adjusted so that the measured value of the high pressure sensor (51) (that is, the actual measured value of the high pressure of the refrigeration cycle) becomes the high pressure target value. That is, the compressor control unit (63) uses the high pressure of the refrigeration cycle as a control parameter, and adjusts the operating capacity of the compressor (31) so that the control parameter becomes the high pressure target value.
 具体的に、圧縮機制御部(63)は、圧縮機(31)の電動機へ供給される交流の周波数を変更し、電動機で駆動される圧縮機構の回転速度を変化させることによって圧縮機(31)の運転容量を変化させる。そして、圧縮機制御部(63)は、高圧圧力センサ(51)の計測値が高圧目標値よりも低い場合は、冷凍サイクルの高圧を上昇させるために、圧縮機(31)の電動機の回転速度を上昇させて圧縮機(31)の運転容量を増加させる。また、圧縮機制御部(63)は、高圧圧力センサ(51)の計測値が高圧目標値よりも高い場合は、冷凍サイクルの高圧を低下させるために、圧縮機(31)の電動機の回転速度を低下させて圧縮機(31)の運転容量を減少させる。 Specifically, the compressor control unit (63) changes the frequency of the alternating current supplied to the electric motor of the compressor (31) and changes the rotational speed of the compression mechanism driven by the electric motor (31). ) Is changed. When the measured value of the high pressure sensor (51) is lower than the high pressure target value, the compressor control unit (63) rotates the motor speed of the compressor (31) to increase the high pressure of the refrigeration cycle. To increase the operating capacity of the compressor (31). Further, when the measured value of the high pressure sensor (51) is higher than the high pressure target value, the compressor control unit (63) rotates the rotational speed of the motor of the compressor (31) to reduce the high pressure of the refrigeration cycle. To reduce the operating capacity of the compressor (31).
 その際、圧縮機制御部(63)は、高圧圧力センサ(51)の計測値と所定の制御ゲインを用いて、圧縮機(31)の電動機へ供給される交流の周波数の変更量の指令値を算出する。具体的に、圧縮機制御部(63)では、高圧圧力センサ(51)の計測値と高圧目標値の差が大きくなるほど、交流周波数の変更量の指令値が大きな値となり、高圧圧力センサ(51)の計測値と高圧目標値の差が小さくなるほど、交流周波数の変更量の指令値が小さな値となる。 At that time, the compressor control unit (63) uses the measured value of the high pressure sensor (51) and a predetermined control gain to command the change amount of the AC frequency supplied to the motor of the compressor (31). Is calculated. Specifically, in the compressor control unit (63), as the difference between the measured value of the high pressure sensor (51) and the high pressure target value becomes larger, the command value for the change amount of the AC frequency becomes larger, and the high pressure sensor (51 The smaller the difference between the measured value and the high pressure target value, the smaller the command value for the change amount of the AC frequency.
 室外膨張弁制御部(64)は、流量制御動作を行うように構成されている。この流量制御動作では、暖房運転中に蒸発器として動作する室外熱交換器(33)の出口における冷媒の過熱度が過熱度目標値となるように、室外膨張弁(34)の開度が調節される。つまり、室外膨張弁制御部(64)は、室外膨張弁(34)の開度を調節することによって、室外膨張弁(34)を通過する冷媒の流量を制御する。室外膨張弁制御部(64)による室外膨張弁(34)の開度制御は、PID制御等の一般的なフィードバック制御によって行われる。 The outdoor expansion valve control unit (64) is configured to perform a flow rate control operation. In this flow control operation, the degree of opening of the outdoor expansion valve (34) is adjusted so that the superheat degree of the refrigerant at the outlet of the outdoor heat exchanger (33) that operates as an evaporator during heating operation becomes the superheat degree target value. Is done. That is, the outdoor expansion valve control unit (64) controls the flow rate of the refrigerant passing through the outdoor expansion valve (34) by adjusting the opening degree of the outdoor expansion valve (34). The opening degree control of the outdoor expansion valve (34) by the outdoor expansion valve control unit (64) is performed by general feedback control such as PID control.
 室外膨張弁制御部(64)は、室外ガス側温度センサ(54)の検出値から、低圧圧力センサ(52)の検出値における冷媒の飽和温度を差し引くことによって、室外熱交換器(33)の出口における冷媒の過熱度を算出する。そして、この過熱度の算出値が過熱度目標値となるように、室外膨張弁(34)の開度を調節する。具体的に、室外膨張弁制御部(64)は、過熱度の算出値が過熱度目標値よりも小さい場合は、室外熱交換器(33)の出口における冷媒の過熱度を大きくするために、室外膨張弁(34)の開度を絞って室外熱交換器(33)を通過する冷媒の流量を減少させる。また、室外膨張弁制御部(64)は、過熱度の算出値が過熱度目標値よりも大きい場合は、室外熱交換器(33)の出口における冷媒の過熱度を小さくするために、室外膨張弁(34)の開度を拡大して室外熱交換器(33)を通過する冷媒の流量を増加させる。 The outdoor expansion valve control unit (64) subtracts the saturation temperature of the refrigerant at the detection value of the low-pressure sensor (52) from the detection value of the outdoor gas side temperature sensor (54), so that the outdoor heat exchanger (33) The degree of superheat of the refrigerant at the outlet is calculated. And the opening degree of an outdoor expansion valve (34) is adjusted so that the calculated value of this superheat degree may become a superheat degree target value. Specifically, when the calculated value of the superheat degree is smaller than the superheat degree target value, the outdoor expansion valve control unit (64) increases the superheat degree of the refrigerant at the outlet of the outdoor heat exchanger (33). The flow rate of the refrigerant passing through the outdoor heat exchanger (33) is reduced by reducing the opening of the outdoor expansion valve (34). Further, the outdoor expansion valve control unit (64), when the calculated value of the superheat degree is larger than the target value of the superheat degree, increases the outdoor expansion in order to reduce the superheat degree of the refrigerant at the outlet of the outdoor heat exchanger (33). The flow rate of the refrigerant passing through the outdoor heat exchanger (33) is increased by increasing the opening of the valve (34).
 過熱度目標値変更部(65)は、過熱度目標値変更動作を行うように構成されている。つまり、冷房運転中と同様に、過熱度目標値変更部(65)は、圧縮機制御部(63)によって圧縮機が停止させられた回数が所定の時間内に所定の値に達すると、過熱度目標値を標準値(例えば5℃)から強制的に引き上げる。過熱度目標値変更部(65)が過熱度目標値を強制的に引き上げた後において、室外膨張弁制御部(64)は、標準値から引き上げられた過熱度目標値を用いて室外膨張弁(34)の開度調節を行う。 The superheat degree target value changing unit (65) is configured to perform a superheat degree target value changing operation. That is, as in the cooling operation, when the number of times the compressor is stopped by the compressor control unit (63) reaches a predetermined value within a predetermined time, the superheat degree target value changing unit (65) The degree target value is forcibly increased from a standard value (for example, 5 ° C.). After the superheat degree target value changing unit (65) forcibly raises the superheat degree target value, the outdoor expansion valve control part (64) uses the superheat degree target value raised from the standard value to set the outdoor expansion valve ( Adjust the opening in 34).
 ただし、暖房運転中に室外熱交換器(33)から流出する冷媒の過熱度が高くなり過ぎると、圧縮機(31)へ吸入される冷媒の過熱度が高くなり過ぎ、圧縮機(31)から吐出される冷媒の温度が高くなり過ぎるおそれがある。このため、過熱度目標値変更部(65)では、過熱度目標値変更動作による過熱度目標値の引き上げ幅について、圧縮機(31)から吐出される冷媒の温度が高くなり過ぎないように上限値が設定されている。 However, if the superheat degree of the refrigerant flowing out of the outdoor heat exchanger (33) becomes too high during the heating operation, the superheat degree of the refrigerant sucked into the compressor (31) becomes too high, and the refrigerant (31) There is a possibility that the temperature of the discharged refrigerant becomes too high. For this reason, in the superheat degree target value changing unit (65), the upper limit of the superheat degree target value by the superheat degree target value changing operation is limited so that the temperature of the refrigerant discharged from the compressor (31) does not become too high. Value is set.
  -実施形態1の効果-
 本実施形態において、主コントローラ(60)の過熱度目標値変更部(65)は、空調機(10)の能力が過剰となって圧縮機制御部(63)が圧縮機(31)を停止させる頻度が高くなると、過熱度目標値を標準値から強制的に引き上げる。そして、冷房運転中には、副コントローラ(70a,70b)の室内膨張弁制御部(71a,71b)が、室内熱交換器(41,46)から圧縮機(31)へ向かう冷媒の過熱度が引き上げられた過熱度目標値となるように、室内膨張弁(42,47)の開度を調節する。また、暖房運転中には、主コントローラ(60)の室外膨張弁制御部(64)が、室外熱交換器(33)から圧縮機(31)へ向かう冷媒の過熱度が引き上げられた過熱度目標値となるように、室外膨張弁(34)の開度を調節する。
-Effect of Embodiment 1-
In this embodiment, the superheat target value changing unit (65) of the main controller (60) has an excessive capacity of the air conditioner (10), and the compressor control unit (63) stops the compressor (31). When the frequency increases, the superheat target value is forcibly increased from the standard value. During the cooling operation, the indoor expansion valve controller (71a, 71b) of the sub controller (70a, 70b) causes the degree of superheat of the refrigerant from the indoor heat exchanger (41, 46) to the compressor (31). The opening degree of the indoor expansion valve (42, 47) is adjusted so that the raised superheat degree target value is obtained. During heating operation, the outdoor expansion valve control unit (64) of the main controller (60) is used to increase the superheat degree of the refrigerant from the outdoor heat exchanger (33) to the compressor (31). The opening degree of the outdoor expansion valve (34) is adjusted so as to be a value.
 ここで、蒸発器へ送られる空気の温度や流量が一定と仮定すると、蒸発器の出口における冷媒の過熱度は、蒸発器を通過する冷媒の流量が少なくなるほど高くなる。従って、室内膨張弁(42,47)や室外膨張弁(34)は、過熱度目標値が高くなるほど、その開度が小さくなる。つまり、室内膨張弁(42,47)や室外膨張弁(34)は、そこを通過する冷媒の流量が少なくなるような状態(即ち、その開度が小さめに設定された状態)となる。このため、圧縮機(31)に設けられた圧縮機構の回転速度が同じ場合で比べると、過熱度目標値が高くなるほど冷媒回路(20)における冷媒の循環量が少なくなり、その結果、空調機(10)の能力が低くなる。 Here, assuming that the temperature and flow rate of air sent to the evaporator are constant, the degree of superheat of the refrigerant at the outlet of the evaporator increases as the flow rate of the refrigerant passing through the evaporator decreases. Therefore, the opening degree of the indoor expansion valves (42, 47) and the outdoor expansion valve (34) decreases as the superheat degree target value increases. That is, the indoor expansion valves (42, 47) and the outdoor expansion valve (34) are in a state where the flow rate of the refrigerant passing therethrough is reduced (that is, the opening degree is set to be small). For this reason, compared with the case where the rotational speed of the compression mechanism provided in the compressor (31) is the same, the higher the superheat degree target value, the smaller the amount of refrigerant circulating in the refrigerant circuit (20). As a result, the air conditioner (10) ability is reduced.
 つまり、過熱度目標値が高くなるほど、空調機(10)の能力の下限値が低くなる。このため、目標過熱度を引き上げる前は圧縮機制御部(63)が圧縮機(31)を停止させざるを得なかった状況においても、目標過熱度を引き上げた後は圧縮機(31)の運転を継続できる可能性が高くなる。 In other words, the lower the lower limit value of the capacity of the air conditioner (10), the lower the superheat degree target value. For this reason, even if the compressor control unit (63) had to stop the compressor (31) before raising the target superheat, the operation of the compressor (31) was increased after raising the target superheat. Is likely to continue.
 このように、本実施形態によれば、いわゆる超臨界サイクルを行う空調機(10)において、空調機(10)の能力が負荷に対して過剰になったことに起因して圧縮機(31)が停止する可能性を低減させることができる。つまり、“圧縮機(31)を起動させてから冷凍サイクルの高圧や低圧が適切な値に達するまでに要する動力が嵩む”という特性を有する超臨界サイクルを行う空調機(10)において、能力調節のために圧縮機(31)が発停する回数を削減することができる。従って、本実施形態によれば、能力調節のための圧縮機(31)の発停回数を削減することで、空調機(10)の運転中に消費される動力を削減でき、空調機(10)の運転効率を向上させることができる。 Thus, according to this embodiment, in the air conditioner (10) that performs a so-called supercritical cycle, the compressor (31) is caused by the capacity of the air conditioner (10) being excessive with respect to the load. Can be reduced. In other words, capacity adjustment in the air conditioner (10) that performs the supercritical cycle with the characteristic that “the power required for the high pressure and low pressure of the refrigeration cycle to reach appropriate values after starting the compressor (31) increases” Therefore, the number of times the compressor (31) starts and stops can be reduced. Therefore, according to the present embodiment, the power consumed during the operation of the air conditioner (10) can be reduced by reducing the number of times the compressor (31) is started and stopped for capacity adjustment. ) Driving efficiency can be improved.
 《発明の実施形態2》
 本発明の実施形態2について説明する。本実施形態は、上記実施形態1の空調機(10)において、主コントローラ(60)の構成を変更したものである。
<< Embodiment 2 of the Invention >>
A second embodiment of the present invention will be described. The present embodiment is obtained by changing the configuration of the main controller (60) in the air conditioner (10) of the first embodiment.
 図3に示すように、本実施形態の主コントローラ(60)には、上記実施形態1の過熱度目標値変更部(65)に代えて、制御目標値変更部(66)が設けられている。なお、本実施形態の主コントローラ(60)において、低圧目標値設定部(61)、高圧目標値設定部(62)、圧縮機制御部(63)、及び室外膨張弁制御部(64)の動作は、上記実施形態1における動作と同様である。 As shown in FIG. 3, the main controller (60) of the present embodiment is provided with a control target value changing unit (66) instead of the superheat degree target value changing unit (65) of the first embodiment. . In the main controller (60) of the present embodiment, the operations of the low pressure target value setting unit (61), the high pressure target value setting unit (62), the compressor control unit (63), and the outdoor expansion valve control unit (64) Is the same as the operation in the first embodiment.
 制御目標値変更部(66)は、制御目標値変更動作を行うように構成されている。この制御目標値変更動作において、制御目標値変更部(66)は、圧縮機制御部(63)によって圧縮機(31)が停止させられた回数を計数する。そして、制御目標値変更部(66)は、圧縮機制御部(63)によって圧縮機が停止させられた回数が所定の時間内(例えば15分以内)に所定の値(例えば2回)に達すると、圧縮機制御部(63)で用いられる制御目標値を強制的に変更する。 The control target value changing unit (66) is configured to perform a control target value changing operation. In this control target value changing operation, the control target value changing unit (66) counts the number of times the compressor (31) is stopped by the compressor control unit (63). Then, the control target value changing unit (66) reaches the predetermined value (for example, twice) within a predetermined time (for example, within 15 minutes) the number of times the compressor has been stopped by the compressor control unit (63). Then, the control target value used in the compressor control unit (63) is forcibly changed.
   〈冷房運転中の動作〉
 冷房運転中において、制御目標値変更部(66)は、低圧目標値を強制的に変更する動作を、制御目標値変更動作として行う。具体的に、制御目標値変更部(66)は、圧縮機制御部(63)によって圧縮機が停止させられた回数が所定の時間内に所定回数に達すると、圧縮機制御部(63)で用いられる低圧目標値を、低圧目標値設定部(61)で決定された値である標準目標値から引き上げる。そして、その後に圧縮機(31)が起動された時点において、圧縮機制御部(63)は、制御目標値変更部(66)によって引き上げられた低圧目標値を用いて、圧縮機(31)の運転容量を調節する。また、圧縮機制御部(63)は、圧縮機(31)の起動時から所定時間(例えば4分間)が経過した時点で低圧目標値が標準目標値となるように、低圧目標値の値を徐々に引き下げてゆく。
<Operation during cooling operation>
During the cooling operation, the control target value changing unit (66) performs an operation for forcibly changing the low pressure target value as a control target value changing operation. Specifically, when the number of times the compressor is stopped by the compressor control unit (63) reaches a predetermined number within a predetermined time, the control target value changing unit (66) causes the compressor control unit (63) to The low pressure target value to be used is raised from the standard target value which is the value determined by the low pressure target value setting unit (61). Then, when the compressor (31) is subsequently started, the compressor control unit (63) uses the low-pressure target value raised by the control target value changing unit (66), and the compressor (31) Adjust the operating capacity. Further, the compressor control unit (63) sets the value of the low pressure target value so that the low pressure target value becomes the standard target value when a predetermined time (for example, 4 minutes) has elapsed since the start of the compressor (31). Pull it down gradually.
 ここで、圧縮機(31)が起動された直後は、低圧圧力センサ(52)の計測値と標準目標値との差が大きくなっている。このため、圧縮機(31)が起動された直後において低圧目標値が標準目標値のままだと、低圧圧力センサ(52)の計測値を標準目標値にできるだけ早く近付けるために、圧縮機(31)の容量が急激に増大させられることになる。そして、圧縮機(31)の急激な容量増加に伴って空調機(10)の冷房能力が急激に増大すると、圧縮機(31)が起動してから比較的短時間の間に室内の気温が設定温度を下回り、再び圧縮機(31)を停止させざるを得ない状態になってしまう。 Here, immediately after the compressor (31) is started, the difference between the measured value of the low-pressure sensor (52) and the standard target value is large. For this reason, if the low pressure target value remains the standard target value immediately after the compressor (31) is started, the compressor (31) is used to bring the measured value of the low pressure sensor (52) close to the standard target value as soon as possible. ) Is rapidly increased. And if the cooling capacity of the air conditioner (10) suddenly increases with the sudden increase in capacity of the compressor (31), the room temperature will be reduced within a relatively short time after the compressor (31) is started. The temperature becomes lower than the set temperature, and the compressor (31) must be stopped again.
 それに対し、本実施形態の制御目標値変更部(66)は、圧縮機(31)が起動されてから暫くの間は低圧目標値を標準目標値よりも高い値に設定している。従って、圧縮機(31)が起動された直後においても、低圧圧力センサ(52)の計測値と低圧目標値との差は、低圧目標値が標準目標値のままである場合に比べて小さくなる。その結果、圧縮機(31)の起動後における圧縮機(31)の急激な容量増加が抑えられ、空調機(10)の冷房能力も緩やかに変化することとなる。このため、本実施形態のように制御目標値変更部(66)が低圧目標値を標準目標値よりも高くすると、低圧目標値が標準目標値のままだと圧縮機制御部(63)が圧縮機(31)を停止させざるを得なかった状況においても、圧縮機(31)の運転を継続できる可能性が高くなる。 In contrast, the control target value changing unit (66) of the present embodiment sets the low pressure target value to a value higher than the standard target value for a while after the compressor (31) is started. Accordingly, even immediately after the compressor (31) is started, the difference between the measured value of the low pressure sensor (52) and the low pressure target value is smaller than when the low pressure target value remains the standard target value. . As a result, the rapid capacity increase of the compressor (31) after the start of the compressor (31) is suppressed, and the cooling capacity of the air conditioner (10) also changes gradually. Therefore, if the control target value changing unit (66) makes the low pressure target value higher than the standard target value as in the present embodiment, the compressor control unit (63) compresses if the low pressure target value remains the standard target value. Even in a situation where the machine (31) has to be stopped, the possibility that the operation of the compressor (31) can be continued increases.
   〈暖房運転中の動作〉
 暖房運転中において、制御目標値変更部(66)は、高圧目標値を強制的に変更する動作を、制御目標値変更動作として行う。具体的に、制御目標値変更部(66)は、圧縮機制御部(63)によって圧縮機が停止させられた回数が所定の時間内に所定回数に達すると、圧縮機制御部(63)で用いられる高圧目標値を、高圧目標値設定部(62)で決定された値である標準目標値から引き下げる。そして、その後に圧縮機(31)が起動された時点において、圧縮機制御部(63)は、制御目標値変更部(66)によって引き下げられた高圧目標値を用いて、圧縮機(31)の運転容量を調節する。また、圧縮機制御部(63)は、圧縮機(31)の起動時から所定時間(例えば4分間)が経過した時点で高圧目標値が標準目標値となるように、高圧目標値の値を徐々に引き上げてゆく。
<Operation during heating operation>
During the heating operation, the control target value changing unit (66) performs an operation for forcibly changing the high pressure target value as a control target value changing operation. Specifically, when the number of times the compressor is stopped by the compressor control unit (63) reaches a predetermined number within a predetermined time, the control target value changing unit (66) causes the compressor control unit (63) to The high-pressure target value to be used is lowered from the standard target value that is a value determined by the high-pressure target value setting unit (62). Then, when the compressor (31) is subsequently started, the compressor control unit (63) uses the high-pressure target value lowered by the control target value changing unit (66), so that the compressor (31) Adjust the operating capacity. Further, the compressor control unit (63) sets the value of the high pressure target value so that the high pressure target value becomes the standard target value when a predetermined time (for example, 4 minutes) has elapsed since the start of the compressor (31). Pull it up gradually.
 ここで、圧縮機(31)が起動された直後は、高圧圧力センサ(51)の計測値と標準目標値との差が大きくなっている。このため、圧縮機(31)が起動された直後において高圧目標値が標準目標値のままだと、高圧圧力センサ(51)の計測値を標準目標値にできるだけ早く近付けるために、圧縮機(31)の容量が急激に増大させられることになる。そして、圧縮機(31)の急激な容量増加に伴って空調機(10)の暖房能力が急激に増大すると、圧縮機(31)が起動してから比較的短時間の間に室内の気温が設定温度を上回り、再び圧縮機(31)を停止させざるを得ない状態になってしまう。 Here, immediately after the compressor (31) is started, the difference between the measured value of the high pressure sensor (51) and the standard target value is large. For this reason, if the high pressure target value remains the standard target value immediately after the compressor (31) is started, the compressor (31) is used to bring the measured value of the high pressure sensor (51) close to the standard target value as soon as possible. ) Is rapidly increased. And if the heating capacity of the air conditioner (10) increases suddenly with the sudden increase in capacity of the compressor (31), the room temperature will be reduced in a relatively short time after the compressor (31) is started. The temperature exceeds the set temperature, and the compressor (31) must be stopped again.
 それに対し、本実施形態の制御目標値変更部(66)は、圧縮機(31)が起動されてから暫くの間は高圧目標値を標準目標値よりも低い値に設定している。従って、圧縮機(31)が起動された直後においても、高圧圧力センサ(51)の計測値と高圧目標値との差は、高圧目標値が標準目標値のままである場合に比べて小さくなる。その結果、圧縮機(31)の起動後における圧縮機(31)の急激な容量増加が抑えられ、空調機(10)の暖房能力も緩やかに変化することとなる。このため、本実施形態のように制御目標値変更部(66)が高圧目標値を標準目標値よりも低くすると、高圧目標値が標準目標値のままだと圧縮機制御部(63)が圧縮機(31)を停止させざるを得なかった状況においても、圧縮機(31)の運転を継続できる可能性が高くなる。 In contrast, the control target value changing unit (66) of the present embodiment sets the high pressure target value to a value lower than the standard target value for a while after the compressor (31) is started. Accordingly, even immediately after the compressor (31) is started, the difference between the measured value of the high pressure sensor (51) and the high pressure target value is smaller than when the high pressure target value remains the standard target value. . As a result, the rapid capacity increase of the compressor (31) after the start of the compressor (31) is suppressed, and the heating capacity of the air conditioner (10) also changes gradually. For this reason, if the control target value changing unit (66) makes the high pressure target value lower than the standard target value as in this embodiment, the compressor control unit (63) compresses if the high pressure target value remains the standard target value. Even in a situation where the machine (31) has to be stopped, the possibility that the operation of the compressor (31) can be continued increases.
  -実施形態2の効果-
 本実施形態によれば、いわゆる超臨界サイクルを行う空調機(10)において、空調機(10)の能力が負荷に対して過剰になったことに起因して圧縮機(31)が停止する可能性を低減させることができる。従って、本実施形態によれば、上記実施形態1と同様に、能力調節のための圧縮機(31)の発停回数を削減することで、空調機(10)の運転中に消費される動力を削減でき、空調機(10)の運転効率を向上させることができる。
-Effect of Embodiment 2-
According to this embodiment, in the air conditioner (10) performing a so-called supercritical cycle, the compressor (31) can be stopped due to the capacity of the air conditioner (10) being excessive with respect to the load. Can be reduced. Therefore, according to the present embodiment, as in the first embodiment, the power consumed during the operation of the air conditioner (10) is reduced by reducing the number of times the compressor (31) is started and stopped for capacity adjustment. The operating efficiency of the air conditioner (10) can be improved.
  -実施形態2の変形例-
 本実施形態の圧縮機制御部(63)は、冷房運転時の制御パラメータとして、蒸発器として動作する室内熱交換器(41,46)における冷媒の蒸発温度を用いるように構成されていてもよい。本変形例の主コントローラ(60)では、低圧目標値設定部(61)に代えて、蒸発温度目標値設定部が設けられる。蒸発温度目標値設定部は、空調機(10)の冷房負荷に応じて、室内熱交換器(41,46)における冷媒の蒸発温度の目標値を設定する。また、本変形例の制御目標値変更部(66)は、冷房運転中の制御目標値変更動作として、圧縮機制御部(63)で用いられる蒸発温度目標値を、蒸発温度目標値設定部で決定された値である標準目標値から引き上げると共に、圧縮機(31)の起動時から所定時間が経過した時点で蒸発温度目標値が標準目標値となるように、蒸発温度目標値の値を徐々に引き下げてゆく。
-Modification of Embodiment 2-
The compressor control unit (63) of the present embodiment may be configured to use the evaporation temperature of the refrigerant in the indoor heat exchanger (41, 46) operating as an evaporator as a control parameter during cooling operation. . In the main controller (60) of this modification, an evaporation temperature target value setting unit is provided instead of the low pressure target value setting unit (61). The evaporating temperature target value setting unit sets a target value of the evaporating temperature of the refrigerant in the indoor heat exchanger (41, 46) according to the cooling load of the air conditioner (10). In addition, the control target value changing unit (66) of the present modified example uses the evaporation temperature target value setting unit to set the evaporation temperature target value used in the compressor control unit (63) as the control target value changing operation during the cooling operation. The evaporating temperature target value is gradually increased so that the evaporating temperature target value becomes the standard target value when a predetermined time has elapsed from the start of the compressor (31) while being raised from the standard target value which is the determined value. I will pull it down.
 《発明の実施形態3》
 本発明の実施形態3について説明する。本実施形態は、上記実施形態1の空調機(10)において、主コントローラ(60)の構成を変更したものである。
<< Embodiment 3 of the Invention >>
Embodiment 3 of the present invention will be described. The present embodiment is obtained by changing the configuration of the main controller (60) in the air conditioner (10) of the first embodiment.
 図4に示すように、本実施形態の主コントローラ(60)には、上記実施形態1の過熱度目標値変更部(65)に代えて、ゲイン調節部(67)が設けられている。なお、本実施形態の主コントローラ(60)において、低圧目標値設定部(61)、高圧目標値設定部(62)、圧縮機制御部(63)、及び室外膨張弁制御部(64)の動作は、上記実施形態1における動作と同様である。 As shown in FIG. 4, the main controller (60) of the present embodiment is provided with a gain adjusting unit (67) instead of the superheat degree target value changing unit (65) of the first embodiment. In the main controller (60) of the present embodiment, the operations of the low pressure target value setting unit (61), the high pressure target value setting unit (62), the compressor control unit (63), and the outdoor expansion valve control unit (64) Is the same as the operation in the first embodiment.
 ゲイン調節部(67)は、ゲイン調節動作を行うように構成されている。このゲイン調節動作において、ゲイン調節部(67)は、外気温センサ(58)の計測値(即ち、外気温の実測値)と室内の設定温度との差に応じて、圧縮機制御部(63)で用いられる制御ゲインを調節する。 The gain adjusting unit (67) is configured to perform a gain adjusting operation. In this gain adjustment operation, the gain adjustment unit (67) is configured to change the compressor control unit (63) according to the difference between the measured value of the outside air temperature sensor (58) (that is, the actually measured value of the outside air temperature) and the indoor set temperature. ) Is adjusted.
 冷房運転中において、ゲイン調節部(67)は、外気温センサ(58)の計測値と室内の設定温度とを比較する。冷房運転中には、外気温センサ(58)の計測値から室内の設定温度を差し引いた値が小さくなるにつれて、室内の冷房負荷が小さくなる。そこで、ゲイン調節部(67)は、外気温センサ(58)の計測値から室内の設定温度を差し引いた値が小さくなるほど、圧縮機制御部(63)で用いられる制御ゲインを小さな値に設定する。 During the cooling operation, the gain adjuster (67) compares the measured value of the outside air temperature sensor (58) with the indoor set temperature. During the cooling operation, the cooling load in the room decreases as the value obtained by subtracting the set temperature in the room from the measured value of the outside air temperature sensor (58) decreases. Therefore, the gain adjuster (67) sets the control gain used in the compressor controller (63) to a smaller value as the value obtained by subtracting the indoor set temperature from the measured value of the outside air temperature sensor (58) becomes smaller. .
 冷房運転中において、本実施形態の圧縮機制御部(63)は、ゲイン調節部(67)によって設定された小さな値の制御ゲインを用いて、圧縮機(31)の容量調節を行う。具体的に、圧縮機制御部(63)は、低圧圧力センサ(52)の計測値と低圧目標値の差と制御ゲインとを用いて、圧縮機(31)の電動機へ供給される交流の周波数の変更量の指令値を算出する。低圧圧力センサ(52)の計測値と低圧目標値の差が同じ場合で比較すると、圧縮機制御部(63)では、制御ゲインの値が小さくなるほど、交流周波数の変更量の指令値が小さくなる。 During the cooling operation, the compressor control unit (63) of the present embodiment adjusts the capacity of the compressor (31) using a small control gain set by the gain adjustment unit (67). Specifically, the compressor control unit (63) uses the difference between the measured value of the low pressure sensor (52), the low pressure target value, and the control gain to determine the frequency of the alternating current supplied to the motor of the compressor (31). The command value for the amount of change is calculated. When the difference between the measured value of the low-pressure pressure sensor (52) and the low-pressure target value is the same, in the compressor control unit (63), the command value for the change amount of the AC frequency decreases as the control gain value decreases. .
 暖房運転中においても、ゲイン調節部(67)は、外気温センサ(58)の計測値と室内の設定温度とを比較する。暖房運転中には、室内の設定温度から外気温センサ(58)の計測値を差し引いた値が小さくなるにつれて、室内の暖房負荷が小さくなる。そこで、ゲイン調節部(67)は、室内の設定温度から外気温センサ(58)の計測値を差し引いた値が小さくなるほど、圧縮機制御部(63)で用いられる制御ゲインを小さな値に設定する。 Even during the heating operation, the gain adjuster (67) compares the measured value of the outside air temperature sensor (58) with the set temperature in the room. During the heating operation, the indoor heating load decreases as the value obtained by subtracting the measured value of the outside air temperature sensor (58) from the indoor set temperature decreases. Therefore, the gain adjustment unit (67) sets the control gain used in the compressor control unit (63) to a smaller value as the value obtained by subtracting the measured value of the outside air temperature sensor (58) from the indoor set temperature becomes smaller. .
 暖房運転中において、本実施形態の圧縮機制御部(63)は、ゲイン調節部(67)によって設定された小さな値の制御ゲインを用いて、圧縮機(31)の容量調節を行う。具体的に、圧縮機制御部(63)は、高圧圧力センサ(51)の計測値と高圧目標値の差と制御ゲインとを用いて、圧縮機(31)の電動機へ供給される交流の周波数の変更量の指令値を算出する。高圧圧力センサ(51)の計測値と高圧目標値の差が同じ場合で比較すると、圧縮機制御部(63)では、制御ゲインの値が小さくなるほど、交流周波数の変更量の指令値が小さくなる。 During the heating operation, the compressor control unit (63) of the present embodiment adjusts the capacity of the compressor (31) using a small control gain set by the gain adjustment unit (67). Specifically, the compressor control unit (63) uses the difference between the measured value of the high pressure sensor (51), the high pressure target value, and the control gain to determine the frequency of the alternating current supplied to the motor of the compressor (31). The command value for the amount of change is calculated. When the difference between the measured value of the high pressure sensor (51) and the high pressure target value is the same, in the compressor control unit (63), the command value for the change amount of the AC frequency decreases as the control gain value decreases. .
 ここで、空調機(10)の負荷が小さくなっているにも拘わらず圧縮機制御部(63)で用いられる制御ゲインが大きいままだと、低圧圧力センサ(52)の計測値と低圧目標値の差、あるいは高圧圧力センサ(51)の計測値と高圧目標値の差に基づいて定められる交流周波数の変更量の指令値が大きくなってしまう。その結果、空調機(10)の能力が負荷に対して過剰となり、圧縮機(31)を停止させざるを得ない状態に陥る可能性が高くなる。 Here, if the control gain used in the compressor control unit (63) remains large despite the load on the air conditioner (10) being small, the measured value of the low pressure sensor (52) and the low pressure target value Or the command value for the change amount of the AC frequency determined based on the difference between the measured value of the high pressure sensor (51) and the high pressure target value. As a result, the capacity of the air conditioner (10) becomes excessive with respect to the load, and there is a high possibility that the compressor (31) must be stopped.
 それに対し、本実施形態のゲイン調節部(67)は、空調機(10)の負荷が小さくなるに従って制御ゲインの値を引き下げてゆく。その結果、低圧圧力センサ(52)や高圧圧力センサ(51)の計測値と制御ゲインとを用いて算出される指令値は、制御ゲインが一定の場合に比べて小さくなる。従って、本実施形態のようにゲイン調節部(67)が制御ゲインを低くすると、制御ゲインが一定のままだと圧縮機制御部(63)が圧縮機(31)を停止させざるを得なかった状況においても、圧縮機(31)の運転を継続できる可能性が高くなる。 In contrast, the gain adjuster (67) of the present embodiment decreases the value of the control gain as the load on the air conditioner (10) decreases. As a result, the command value calculated using the measured value of the low pressure sensor (52) or the high pressure sensor (51) and the control gain is smaller than when the control gain is constant. Therefore, when the gain adjustment unit (67) reduces the control gain as in this embodiment, the compressor control unit (63) has to stop the compressor (31) if the control gain remains constant. Even in the situation, there is a high possibility that the operation of the compressor (31) can be continued.
  -実施形態3の効果-
 本実施形態によれば、いわゆる超臨界サイクルを行う空調機(10)において、空調機(10)の能力が負荷に対して過剰になったことに起因して圧縮機(31)が停止する可能性を低減させることができる。従って、本実施形態によれば、上記実施形態1と同様に、能力調節のための圧縮機(31)の発停回数を削減することで、空調機(10)の運転中に消費される動力を削減でき、空調機(10)の運転効率を向上させることができる。
-Effect of Embodiment 3-
According to this embodiment, in the air conditioner (10) performing a so-called supercritical cycle, the compressor (31) can be stopped due to the capacity of the air conditioner (10) being excessive with respect to the load. Can be reduced. Therefore, according to the present embodiment, as in the first embodiment, the power consumed during the operation of the air conditioner (10) is reduced by reducing the number of times the compressor (31) is started and stopped for capacity adjustment. The operating efficiency of the air conditioner (10) can be improved.
 以上説明したように、本発明は、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷凍装置について有用である。 As described above, the present invention is useful for a refrigeration apparatus that performs a refrigeration cycle in which the high pressure is set to a value higher than the critical pressure of the refrigerant.

Claims (4)

  1.  圧縮機(31)、膨張機構(34,42,47)、熱源側熱交換器(33)、及び利用側熱交換器(41,46)が接続され、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷媒回路(20)と、
     上記圧縮機(31)及び上記膨張機構(34,42,47)の制御を行う制御手段(80)とを備える冷凍装置であって、
     上記制御手段(80)は、
      上記冷媒回路(20)で行われる冷凍サイクルの動作状態を示す物理量が制御目標値となるように、上記圧縮機(31)の容量を調節する容量制御動作と、
      上記熱源側熱交換器(33)及び上記利用側熱交換器(41,46)のうち蒸発器として動作する方から上記圧縮機(31)へ向かう冷媒の過熱度が過熱度目標値となるように、上記膨張機構(34,42,47)を通過する冷媒の流量を調節する流量制御動作と、
      上記容量制御動作によって上記圧縮機(31)が停止させられたときは、上記過熱度目標値を強制的に引き上げる過熱度目標値変更動作とを行うように構成されている
    ことを特徴とする冷凍装置。
    The compressor (31), expansion mechanism (34, 42, 47), heat source side heat exchanger (33), and use side heat exchanger (41, 46) are connected, and the high pressure is higher than the critical pressure of the refrigerant. A refrigerant circuit (20) for performing a refrigeration cycle set to
    A refrigeration apparatus comprising control means (80) for controlling the compressor (31) and the expansion mechanism (34, 42, 47),
    The control means (80)
    A capacity control operation for adjusting the capacity of the compressor (31) so that the physical quantity indicating the operation state of the refrigeration cycle performed in the refrigerant circuit (20) becomes a control target value;
    Of the heat source side heat exchanger (33) and the use side heat exchanger (41, 46), the degree of superheat of the refrigerant from the one operating as an evaporator toward the compressor (31) becomes the superheat degree target value. And a flow rate control operation for adjusting the flow rate of the refrigerant passing through the expansion mechanism (34, 42, 47),
    When the compressor (31) is stopped by the capacity control operation, a superheat degree target value changing operation for forcibly raising the superheat degree target value is performed. apparatus.
  2.  圧縮機(31)、膨張機構(34,42,47)、熱源側熱交換器(33)、及び利用側熱交換器(41,46)が接続され、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷媒回路(20)と、
     上記圧縮機(31)の制御を行う制御手段(80)とを備え、
     上記熱源側熱交換器(33)がガスクーラとして動作して上記利用側熱交換器(41,46)が蒸発器として動作する冷却運転を少なくとも行う冷凍装置であって、
     上記制御手段(80)は、
      上記利用側熱交換器(41,46)での冷媒の蒸発温度または上記冷媒回路(20)で行われる冷凍サイクルの低圧を制御パラメータとし、該制御パラメータが制御目標値となるように上記圧縮機(31)の容量を調節する容量制御動作と、
      上記圧縮機(31)の起動から所定時間が経過した後に上記制御目標値が所定の標準目標値となるように、上記圧縮機(31)の起動後に上記制御目標値を次第に低下させる制御目標値変更動作とを行うように構成されている
    ことを特徴とする冷凍装置。
    The compressor (31), expansion mechanism (34, 42, 47), heat source side heat exchanger (33), and use side heat exchanger (41, 46) are connected, and the high pressure is higher than the critical pressure of the refrigerant. A refrigerant circuit (20) for performing a refrigeration cycle set to
    Control means (80) for controlling the compressor (31),
    The refrigeration apparatus performs at least a cooling operation in which the heat source side heat exchanger (33) operates as a gas cooler and the use side heat exchanger (41, 46) operates as an evaporator,
    The control means (80)
    The compressor is set such that the refrigerant evaporation temperature in the use side heat exchanger (41, 46) or the low pressure of the refrigeration cycle performed in the refrigerant circuit (20) is a control parameter, and the control parameter becomes a control target value. A capacity control operation for adjusting the capacity of (31);
    A control target value for gradually decreasing the control target value after starting the compressor (31) so that the control target value becomes a predetermined standard target value after a predetermined time has elapsed since the start of the compressor (31). A refrigeration apparatus configured to perform a changing operation.
  3.  圧縮機(31)、膨張機構(34,42,47)、熱源側熱交換器(33)、及び利用側熱交換器(41,46)が接続され、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷媒回路(20)と、
     上記圧縮機(31)の制御を行う制御手段(80)とを備え、
     上記利用側熱交換器(41,46)がガスクーラとして動作して上記熱源側熱交換器(33)が蒸発器として動作する加熱運転を少なくとも行う冷凍装置であって、
     上記制御手段(80)は、
      上記冷媒回路(20)で行われる冷凍サイクルの高圧を制御パラメータとし、該制御パラメータが制御目標値となるように上記圧縮機(31)の容量を調節する容量制御動作と、
      上記圧縮機(31)の起動から所定時間が経過した後に上記制御目標値が所定の標準目標値となるように、上記圧縮機(31)の起動後に上記制御目標値を次第に上昇させる制御目標値変更動作とを行うように構成されている
    ことを特徴とする冷凍装置。
    The compressor (31), expansion mechanism (34, 42, 47), heat source side heat exchanger (33), and use side heat exchanger (41, 46) are connected, and the high pressure is higher than the critical pressure of the refrigerant. A refrigerant circuit (20) for performing a refrigeration cycle set to
    Control means (80) for controlling the compressor (31),
    A refrigeration apparatus that performs at least a heating operation in which the use side heat exchanger (41, 46) operates as a gas cooler and the heat source side heat exchanger (33) operates as an evaporator,
    The control means (80)
    A capacity control operation in which the high pressure of the refrigeration cycle performed in the refrigerant circuit (20) is a control parameter, and the capacity of the compressor (31) is adjusted so that the control parameter becomes a control target value;
    A control target value for gradually increasing the control target value after starting the compressor (31) so that the control target value becomes a predetermined standard target value after a predetermined time has elapsed since the start of the compressor (31). A refrigeration apparatus configured to perform a changing operation.
  4.  圧縮機(31)、膨張機構(34,42,47)、熱源側熱交換器(33)、及び利用側熱交換器(41,46)が接続され、高圧が冷媒の臨界圧力よりも高い値に設定された冷凍サイクルを行う冷媒回路(20)と、
     上記圧縮機(31)の制御を行う制御手段(80)とを備える冷凍装置であって、
     上記制御手段(80)は、
      上記冷媒回路(20)で行われる冷凍サイクルの動作状態を示す物理量が制御目標値となるように、該物理量と制御ゲインとを用いて算出した指令値に基づいて上記圧縮機(31)の容量を調節する容量制御動作と、
      上記冷凍装置の負荷が小さくなるほど上記制御ゲインを小さくするゲイン調節動作とを行うように構成されている
    ことを特徴とする冷凍装置。
    The compressor (31), expansion mechanism (34, 42, 47), heat source side heat exchanger (33), and use side heat exchanger (41, 46) are connected, and the high pressure is higher than the critical pressure of the refrigerant. A refrigerant circuit (20) for performing a refrigeration cycle set to
    A refrigeration apparatus comprising control means (80) for controlling the compressor (31),
    The control means (80)
    The capacity of the compressor (31) based on the command value calculated using the physical quantity and the control gain so that the physical quantity indicating the operating state of the refrigeration cycle performed in the refrigerant circuit (20) becomes the control target value. Capacity control operation to adjust,
    A refrigeration apparatus configured to perform a gain adjustment operation for decreasing the control gain as the load of the refrigeration apparatus decreases.
PCT/JP2009/001097 2008-03-24 2009-03-11 Freezing apparatus WO2009119023A1 (en)

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