WO2009147852A1 - Dispositif de congélation - Google Patents

Dispositif de congélation Download PDF

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Publication number
WO2009147852A1
WO2009147852A1 PCT/JP2009/002505 JP2009002505W WO2009147852A1 WO 2009147852 A1 WO2009147852 A1 WO 2009147852A1 JP 2009002505 W JP2009002505 W JP 2009002505W WO 2009147852 A1 WO2009147852 A1 WO 2009147852A1
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WO
WIPO (PCT)
Prior art keywords
compressor
refrigerant
heat exchanger
pipe
valve
Prior art date
Application number
PCT/JP2009/002505
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English (en)
Japanese (ja)
Inventor
阪江覚
竹上雅章
加藤勝三
Original Assignee
ダイキン工業株式会社
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Filing date
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Publication of WO2009147852A1 publication Critical patent/WO2009147852A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F25B1/10—Compression machines, plants or systems with non-reversible cycle with multi-stage compression
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/025—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units
    • F25B2313/0253—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units in parallel arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
    • F25B2313/02741—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using one four-way valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
    • F25B2313/02743—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using three four-way valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/07—Details of compressors or related parts
    • F25B2400/075—Details of compressors or related parts with parallel compressors
    • F25B2400/0751—Details of compressors or related parts with parallel compressors the compressors having different capacities
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/13—Economisers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/01—Geometry problems, e.g. for reducing size
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/02—Compressor control
    • F25B2600/021—Inverters therefor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Definitions

  • the present invention relates to a refrigeration apparatus having a plurality of compressors and performing a vapor compression refrigeration cycle, and more particularly to a refrigeration apparatus having an injection circuit for injecting refrigerant into each compressor.
  • a refrigeration apparatus including a refrigerant circuit having a plurality of compressors connected in parallel to each other and performing a vapor compression refrigeration cycle is known.
  • this type of refrigeration apparatus as shown in Patent Document 1, there is an apparatus provided with an injection circuit that injects a refrigerant into each compressor.
  • One end of the injection circuit is connected to a refrigerant pipe branched from a high-pressure pipe (a pipe through which the high-pressure refrigerant flows) of the refrigerant circuit, and the other end is branched into a plurality of intermediate parts opened to a compression chamber at an intermediate pressure position in each compressor. Each is connected to a port.
  • a pressure reducing valve for reducing the pressure of the refrigerant is provided between one end of the injection circuit and the branch point.
  • the high-pressure refrigerant discharged from the plurality of compressors is condensed in the outdoor heat exchanger, a part thereof flows into the refrigerant pipe branched from the high-pressure pipe and flows into the injection circuit.
  • the high-pressure refrigerant that has flowed into the injection circuit is depressurized to a predetermined pressure by the pressure reducing valve and becomes an intermediate pressure refrigerant.
  • this intermediate pressure refrigerant is diverted toward each intermediate port, it is injected into each compressor via each intermediate port.
  • the refrigerant discharge gas temperature of each compressor can be reduced to a predetermined temperature or less.
  • the operating capacity of the variable capacity compressor is reduced.
  • the intermediate pressure refrigerant that has flowed out of the pressure reducing valve may flow more easily toward the variable capacity compressor than the fixed capacity compressor.
  • the drift of the intermediate pressure refrigerant toward the variable capacity compressor increases as the operating capacity of the variable capacity compressor decreases.
  • variable capacity compressor is configured such that the volume of the compression chamber repeats increasing and decreasing periodically and the period can be freely changed within a predetermined range.
  • the time during which the compression chamber is at the intermediate pressure position is longer than before. Become.
  • the opening time of the intermediate port that opens to the intermediate pressure position of the compression chamber also becomes longer. Then, the intermediate pressure refrigerant is likely to flow into the compression chamber at the intermediate pressure position as much as the opening time becomes longer.
  • the refrigerant discharge gas temperature of the variable capacity compressor becomes too low, and the fixed capacity compression. This causes a problem that the refrigerant discharge gas temperature does not decrease.
  • the present invention has been made in view of such a point, and an object of the present invention is to provide a refrigeration apparatus including a plurality of compressors composed of a variable capacity compressor and a fixed capacity compressor connected in parallel to each other.
  • the intermediate pressure refrigerant of the injection circuit is injected into both compressors while suppressing the imbalance of the refrigerant discharge gas temperature generated between the compressors as much as possible.
  • the first invention includes a refrigerant circuit (10) (200) in which a plurality of compressors (21a, 21b, 21c) (114a, 114b, 114c) connected in parallel to each other to perform a refrigeration cycle, Intermediate ports (5, 6, 7) opening to the intermediate pressure position of the compression chambers (4a, 4b, 4c) in the compressors (21a, 21b, 21c) (114a, 114b, 114c), and the refrigerant circuit (10) And branch pipes (37) (130) for connecting the intermediate ports (5, 6, 7) and branching the high-pressure refrigerant flowing through the refrigerant circuit (10) (200) to generate intermediate pressure refrigerant
  • a refrigeration apparatus including an injection circuit (40) (130) for injecting the intermediate pressure refrigerant into the compression chambers (4a, 4b, 4c) is assumed.
  • At least one of the plurality of compressors (21a, 21b, 21c) (114a, 114b, 114c) is composed of a variable capacity compressor (21a) (21a, 21b) (114a, 114b).
  • Others are composed of fixed capacity compressors (21b, 21c) (21c) (114c) and intermediate ports (5a) of the variable capacity compressors (21a) (21a, 21b) (114a, 114b).
  • ) (5, 6) is characterized in that it has a smaller diameter than the intermediate ports (6, 7) (7) of the fixed capacity compressors (21b, 21c) (21c) (114c).
  • the variable capacity compressor (21a) (21a, 21b) (114a, 114b) of the present invention adjusts the operating capacity by changing the rotation speed or frequency of an actuator such as an electric motor.
  • the operating capacity of the variable capacity compressor (21a) (21a, 21b) (114a, 114b) is reduced, the opening time of the intermediate port (5) is increased, and the intermediate pressure refrigerant is Even if it becomes easier to flow toward the variable capacity compressor (21a) (21a, 21b) (114a, 114b), the intermediate port of the variable capacity compressor (21a) (21a, 21b) (114a, 114b) (5) is formed to have a smaller diameter than the intermediate ports (6, 7) of the fixed capacity compressors (21b, 21c), (21c), and (114c), so that the intermediate pressure refrigerant is supplied to the variable capacity compressor (21a). (21a, 21b) (114a, 114b) can be made difficult to flow.
  • the flow rate of the refrigerant provided in the injection circuit (40) (130) and injected into the variable capacity compressor (21a) (21a, 21b) (114a, 114b) The first flow rate adjustment valve (30a) (211,212) for adjusting the first flow rate adjustment valve (30a) (211,212) as the operating capacity of the variable displacement compressor (21a) (21a, 21b) decreases.
  • the operating capacity of the variable capacity compressor (21a) (21a, 21b) (114a, 114b) is reduced and the variable capacity compressor (21a) (21a, 21b) (114a, 114b) is reduced. Even if the opening time of the intermediate port (5) is long, the intermediate pressure refrigerant can be reduced by reducing the valve opening of the first flow rate adjusting valve (30a) (211,212). 21a) (21a, 21b) (114a, 114b) can be made difficult to flow.
  • the branch pipe (37) (130) is a first branch pipe connected to the variable capacity compressor (21a) (21a, 21b) (114a, 114b).
  • the first branch pipe (37a) (37a, 37b) is provided with the first flow rate adjusting valve (30a) (211,212), and the second branch pipe (37b, 37c) (37c) is fixed to the first branch pipe (37a) (37a, 37b).
  • a second flow rate adjusting valve (30b, 30c) (30c) (213) for adjusting the flow rate of the refrigerant injected into the capacity type compressor (21b, 21c) (21c) (114c) is provided, while the control means ( 9) (210) is the second flow rate adjusting valve (30b, 30c) (30c) (213) as the operating capacity of the variable displacement compressor (21a) (21a, 21b) (114a, 114b) decreases.
  • the second capacity of the variable capacity compressor (21a) is increased.
  • the intermediate pressure refrigerant becomes easier to flow toward the fixed capacity compressor (21b, 21c). It becomes difficult to flow toward (21a).
  • the branch pipe (37) (130) includes a decompression means (29) for decompressing the high-pressure refrigerant to generate an intermediate-pressure refrigerant.
  • the injection circuit (40) includes a supercooling heat exchanger (extra-cooling heat exchanger) that exchanges heat between the intermediate-pressure refrigerant flowing out of the branch pipes (37) and (130) and the high-pressure refrigerant flowing through the refrigerant circuits (10) and (200). 28) (117) is provided.
  • the intermediate pressure refrigerant flowing out from the branch pipes (37) (130) is not directly injected into the compression chambers (4a, 4b, 4c), but from the branch pipes (37) (130).
  • the intermediate pressure refrigerant that has flowed out is once depressurized and heat-exchanged with the high-pressure refrigerant to cool the high-pressure refrigerant, and then injected into the compression chambers (4a, 4b, 4c).
  • the refrigerant circuit (10) 200) includes a use side heat exchanger (54) of an air conditioning system and a use side heat exchange of a refrigeration / refrigeration system.
  • a use side heat exchanger (54) of an air conditioning system and a use side heat exchange of a refrigeration / refrigeration system (64a, 64b) are provided, and each compressor (114a, 114b, 114c) has a compressor connected to the heat exchanger (54) on the use side of the air conditioning system and the use of the refrigeration / refrigeration system.
  • a refrigeration apparatus in which the refrigerant circuit (200) is provided with a use side heat exchanger for an air conditioning system and a use side heat exchanger for a refrigeration / refrigeration system.
  • the refrigerant circuit (200) is provided with a use side heat exchanger for an air conditioning system and a use side heat exchanger for a refrigeration / refrigeration system.
  • (114a, 114b, 114c) includes a compressor connected to the use side heat exchanger of the air conditioning system and a compressor connected to the use side heat exchanger of the refrigeration / refrigeration system.
  • the intermediate port (5) of the variable capacity compressor (21a) (21a, 21b) (114a, 114b) is connected to the middle of the fixed capacity compressor (21b, 21c) (21c) (114c).
  • the intermediate pressure refrigerant can be made difficult to flow toward the variable capacity compressors (21a) (21a, 21b) (114a, 114b).
  • variable capacity compressor (21a) (21a, 21a, 21a, 21b, 114a, 114b) is compared with the case where the intermediate port (5) of the variable capacity compressor (21a) (21a, 21b) (114a, 114b) is not formed with a small diameter.
  • the refrigerant discharge gas temperature of (114a, 114b) can be prevented from becoming too low.
  • the intermediate-pressure refrigerant is less likely to flow toward the variable capacity compressors (21a) (21a, 21b) (114a, 114b), and the fixed capacity compressors (21b, 21c) (21c).
  • the fixed capacity compressor is compared with the case where the intermediate port (5) of the variable capacity compressor (21a) (21a, 21b) (114a, 114b) is not formed with a small diameter.
  • the refrigerant discharge gas temperature of (21b, 21c) (21c) (114c) can be lowered. From the above, the refrigerant discharge gas temperature imbalance between the variable displacement compressor (21a) (21a, 21b) (114a, 114b) and the fixed displacement compressor (21b, 21c) (21c) (114c) It is possible to inject into both the compressors (21a, 21b, 21c) (114a, 114b, 114c) while suppressing as much as possible.
  • the control means (9) (210) opens the valve opening of the first flow rate adjustment valve (30a). Make it smaller.
  • coolant can be made hard to flow toward the variable capacity type compressor (21a).
  • control means (9) (210) is configured so as to reduce the operating capacity of the variable capacity compressor (21a) (21a, 21b) (114a, 114b).
  • the valve opening degree of the flow rate adjusting valves (30a) (211, 212) is reduced, and the valve opening degree of the second flow rate adjusting valves (30b, 30c) (30c) (213) is increased.
  • the intermediate pressure refrigerant is supplied to the variable capacity compressors (21a) (21a, 21b) (114a, 114b).
  • the degree of supercooling of the high-pressure refrigerant can be increased while injecting into each compressor (21a, 21b, 21c) (114a, 114b, 114c).
  • the variable capacity compressor (21a) (21a, 21b) (114a, 114b) and the fixed capacity compressor (21b, 21c) (21c) (114c) The imbalance in the refrigerant discharge gas temperature that occurs in the engine can be suppressed as much as possible.
  • a refrigeration apparatus in which the refrigerant circuit (200) is provided with a use side heat exchanger for an air conditioning system and a use side heat exchanger for a refrigeration / refrigeration system.
  • Each of the compressors (114a, 114b, 114c) includes a compressor connected to the use side heat exchanger of the air conditioning system and a compressor connected to the use side heat exchanger of the refrigeration / refrigeration system. If the operating capacity of the variable capacity compressor (21a) (21a, 21b) (114a, 114b) is small, the injection amount can be suppressed.
  • FIG. 1 is a refrigerant circuit diagram of the refrigeration apparatus according to the first embodiment.
  • FIG. 2 is a cross-sectional view illustrating a main part of the compression mechanism in the compressor according to the first embodiment.
  • FIG. 3 is a refrigerant circuit diagram of a refrigeration apparatus according to a modification of the first embodiment.
  • FIG. 4 is a refrigerant circuit diagram of the refrigeration apparatus according to the second embodiment.
  • FIG. 5 is a refrigerant circuit diagram showing a refrigerant flow during the cooling operation in the second embodiment.
  • FIG. 6 is a refrigerant circuit diagram illustrating a refrigerant flow during heating operation in the second embodiment.
  • FIG. 7 is a refrigerant circuit diagram showing a refrigerant flow during the refrigeration operation in the second embodiment.
  • FIG. 1 is a refrigerant circuit diagram of the refrigeration apparatus according to the first embodiment.
  • FIG. 2 is a cross-sectional view illustrating a main part of the compression mechanism in the compressor according to the first
  • FIG. 8 is a refrigerant circuit diagram illustrating the flow of the refrigerant during the cooling and cooling operation in the second embodiment.
  • FIG. 9 is a refrigerant circuit diagram illustrating another refrigerant flow during the cooling / cooling operation in the second embodiment.
  • FIG. 10 is a refrigerant circuit diagram illustrating a refrigerant flow during the first cooling / air-heating operation in the second embodiment.
  • FIG. 11 is a refrigerant circuit diagram illustrating a refrigerant flow during the second cooling / air-heating operation in the second embodiment.
  • FIG. 12 is a refrigerant circuit diagram illustrating a refrigerant flow during the third cooling / air-heating operation in the second embodiment.
  • Embodiment 1 of the Invention A first embodiment of the present invention will be described.
  • the refrigeration apparatus (1) of the present embodiment cools a plurality of refrigerated warehouses.
  • the refrigeration apparatus (1) includes an external unit (2), a plurality of internal units (3), and a controller (9).
  • the outside unit (2) is installed outdoors, and each inside unit (3) is installed in each refrigerated warehouse.
  • the outside unit (2) is provided with an outside circuit (20), and each inside unit (3) is provided with an inside circuit (50).
  • the refrigerant circuit (10) of the refrigeration apparatus (1) is configured by connecting a plurality of internal circuits (50) in parallel to the external circuit (20) so as to perform a vapor compression refrigeration cycle. Has been.
  • first connection pipe (14) is connected to a first closing valve (11) provided at one end of the external circuit (20), and the other end of the first connection pipe (14) is branched. And it is connected to one end of each internal circuit (50), respectively.
  • One end of the second connection pipe (15) is connected to a second closing valve (12) provided at the other end of the external circuit (20), and the other of the second connection pipe (15). The end branches and is connected to the other end of each internal circuit (50).
  • the external circuit (20) of the external unit (2) includes three compressors (21a, 21b, 21c) from first to third, a four-way switching valve (24), and external heat.
  • An exchanger (25), a receiver (27), a supercooling heat exchanger (28), a supercooling pressure reducing valve (pressure reducing means) (29), and an external expansion valve (31) are provided. .
  • All compressors (21a, 21b, 21c) are all hermetic high-pressure dome type scroll compressors, and each compressor (21a, 21b, 21c) has an intermediate port that opens to an intermediate pressure position.
  • a compression mechanism having a compression chamber (4a, 4b, 4c) having (5, 6, 7) and an electric motor for driving the compression mechanism are provided.
  • the electric motor of the first compressor (variable capacity compressor) (21a) is provided with an inverter that can freely change the rotational speed of the electric motor within a predetermined range.
  • the inverter adjusts the rotational speed of the electric motor to increase or decrease the operating capacity of the first compressor (21a).
  • the motors of the second and third compressors (fixed capacity compressors) (21b, 21c) are not provided with the inverter, and the rotation speed of the motors is fixed. Therefore, the operating capacity of the second and third compressors (21b, 21c) is constant.
  • FIG. 2 is a cross-sectional view showing the main part of the compression mechanism (47) in the first compressor (21a).
  • the compression mechanism of the second and third compressors (21b, 21c) is different from the compression mechanism (47) of the first compressor (21a) except that the diameter of the intermediate port (6, 7) described later is different. Since it is the same structure, description is abbreviate
  • the compression mechanism (47) includes a fixed scroll (41) and a movable scroll (42) meshing with the fixed scroll (41). And the 1st, 2nd compression which the fixed side wrap (41a) provided in the said fixed scroll (41) and the movable side wrap (42b) provided in the said movable scroll (42) meshed, and was divided and formed. It has chambers (43,44).
  • the first compression chamber (43) is formed between the inner peripheral surface of the fixed side wrap (41a) and the outer peripheral surface of the movable side wrap (42b), and the outer peripheral surface of the fixed side wrap (41a).
  • the second compression chamber (44) is formed between the inner peripheral surface of the movable wrap (42b).
  • a suction port (45) is formed on the outer peripheral side of the fixed scroll (41).
  • the suction port (45) is configured to intermittently communicate with both compression chambers (43, 44) as the movable scroll (42) revolves.
  • a discharge port (46) is formed at the center of the fixed scroll (41). The discharge port (46) is configured to intermittently communicate with both compression chambers (43, 44) as the movable scroll (42) revolves.
  • an intermediate port (5) is formed in the fixed scroll (41).
  • the intermediate port (5) is configured to intermittently communicate with the first compression chamber (43) as the movable scroll (42) revolves.
  • the intermediate compression port (5) and the first compression chamber (43) are blocked.
  • the intermediate port (5) of the first compressor (21a) is more than the intermediate ports (6, 7) of the second and third compressors (21b, 21c) shown by phantom lines in FIG. It has a small diameter.
  • Discharge pipes (22a, 22b, 22c) are connected to the discharge sides of the compressors (21a, 21b, 21c), respectively.
  • Each discharge pipe (22a, 22b, 22c) is provided with a check valve (CV).
  • These discharge pipes (22a, 22b, 22c) are connected to the first port of the four-way switching valve (24) via the discharge junction pipe (22).
  • the check valve (CV) is provided in such a direction as to allow only the refrigerant flow from each compressor (21a, 21b, 21c) toward the discharge junction pipe (22).
  • each discharge pipe (22a, 22b, 22c) is provided with an oil separator (38a, 38b, 38c) on the upstream side of the check valve (CV).
  • Each said oil separator (38a, 38b, 38c) is for isolate
  • Each oil separator (38a, 38b, 38c) is connected to an oil return pipe (39a, 39b, 39c).
  • These three oil return pipes (39a, 39b, 39c) are joined at one end of the oil return joining pipe (39).
  • the other end of the oil return merging pipe (39) is connected to a connection portion of a gas vent pipe (48) in a second injection pipe (38) described later.
  • Each oil return pipe (39a, 39b, 39c) is provided with a check valve (CV) and a capillary tube (CP) in order from the oil separator (38a, 38b, 38c) side. .
  • tube (39a, 39b, 39c) is provided in the direction which accept
  • a suction pipe (23a, 23b, 23c) is connected to the suction side of each compressor (21a, 21b, 21c). These suction pipes (23a, 23b, 23c) are connected to the second port of the four-way switching valve (24) via the suction junction pipe (23).
  • the four-way switching valve (24) 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; And the fourth port communicate with each other and the second port and the third port communicate with each other.
  • the other end of the external heat exchanger (25) is connected to the top of the receiver (27) via the first refrigerant pipe (32).
  • the external heat exchanger (25) is a cross-fin type fin-and-tube heat exchanger.
  • An external fan (26) is provided in the vicinity of the external heat exchanger (25).
  • the external heat exchanger (25) is configured to exchange heat between the external air sent by the external fan (26) and the refrigerant flowing in the external heat exchanger (25). Yes.
  • the first refrigerant pipe (32) is provided with a check valve (CV), and the check valve (CV) only sends the refrigerant flow from the external heat exchanger (25) to the receiver (27). It is provided in an allowable direction.
  • the supercooling heat exchanger (28) has a high pressure side flow path (28a) and an intermediate pressure side flow path (28b), and flows through the high pressure side flow path (28a) and the intermediate pressure side flow path (28b).
  • the refrigerant is configured to exchange heat.
  • the inflow end of the high-pressure channel (28a) is connected to the bottom of the receiver (27).
  • the outflow end of the high-pressure channel (28a) is connected to the first closing valve (11) via the second refrigerant pipe (33).
  • the second refrigerant pipe (33) is provided with a check valve (CV), and the check valve (CV) is a refrigerant directed from the supercooling heat exchanger (28) to the first closing valve (11). It is provided in a direction that allows only the flow of air.
  • the inflow end and the outflow end of the intermediate pressure side flow path (28b) are respectively connected to the injection circuit (40) according to the present invention.
  • the injection circuit (40) is for injecting refrigerant into the compressors (21a, 21b, 21c), and includes a first injection pipe (branch pipe) (37), a second injection pipe (38), and a first injection pipe (38). 1, second and third branch injection pipes (37a, 37b, 37c).
  • the first injection pipe (37) branches from the upstream side of the check valve (CV) in the second refrigerant pipe (33) and is connected to the inflow end of the intermediate pressure side flow path (28b).
  • the first injection pipe (37) is provided with a supercooling pressure reducing valve (pressure reducing means) (29).
  • the supercooling pressure reducing valve (29) is an electronic expansion valve having a variable opening.
  • One end of the second injection pipe (38) is connected to the outflow end of the intermediate pressure side flow path (28b), and the other end of the second injection pipe (38) is connected to the first, second, and third branch injections.
  • the first, second, and third branch injection pipes (37a, 37b, 37c) are connected to the intermediate ports (5, 6, 7) of the compressors (21a, 21b, 21c), respectively.
  • the first branch injection pipe (37a) constitutes the first branch pipe (37a) according to the present invention
  • the second and third branch injection pipes (37b, 37c) constitute the second branch pipe (37b) according to the present invention. 37c).
  • the first branch injection pipe (37a) is provided with a first flow rate adjusting valve (30a), and the second and third branch injection pipes (37b, 37c) are respectively provided with second flow rate adjusting valves (30b, 30c). Is provided.
  • the first and second flow rate adjusting valves (30a, 30b, 30c) are constituted by electronic expansion valves with variable opening degrees.
  • the receiver (27) is disposed between the external heat exchanger (25) and the supercooling heat exchanger (28) as described above, and temporarily stores the high-pressure refrigerant condensed in the external heat exchanger (25). Can be stored.
  • One end of a gas vent pipe (48) having a solenoid valve (SV) is connected to the top of the receiver (27).
  • the other end of the gas vent pipe (48) is connected in the middle of the second injection pipe (38).
  • the gas vent pipe (48) is configured such that the gas refrigerant flows from the receiver (27) to the second injection pipe (38) by opening the solenoid valve (SV).
  • the third refrigerant pipe (35) is connected between the check valve (CV) and the first closing valve (11) in the second refrigerant pipe (33).
  • the other end of the third refrigerant pipe (35) is connected to the downstream side of the check valve (CV) in the first refrigerant pipe (32).
  • the third refrigerant pipe (35) is provided with a check valve (CV), and the check valve (CV) is only for the flow of refrigerant from the first closing valve (11) to the first refrigerant pipe (32). It is provided in a direction that allows
  • a fourth refrigerant pipe (36) that bypasses the receiver (27) and the supercooling heat exchanger (28) is connected between the first refrigerant pipe (32) and the second refrigerant pipe (33). Yes.
  • One end of the fourth refrigerant pipe (36) is connected to the upstream side of the check valve (CV) in the first refrigerant pipe (32).
  • the other end of the fourth refrigerant pipe (36) is connected to the upstream side of the connection portion of the first injection pipe (37) in the second refrigerant pipe (33).
  • the fourth refrigerant pipe (36) is provided with an external expansion valve (31).
  • the external expansion valve (31) is an electronic expansion valve whose opening degree can be adjusted.
  • the external circuit (20) is provided with various sensors and pressure switches. Specifically, each discharge pipe (22a, 22b, 22c) is provided with a discharge pipe temperature sensor (61) and a high-pressure switch (62).
  • the discharge pipe temperature sensor (61) detects the temperature of the discharge pipe (22a, 22b, 22c), and the high pressure switch (62) detects the discharge pressure, and when the abnormally high pressure is detected, the refrigeration system (1) is urgently stopped It is something to be made.
  • the suction junction pipe (23) is provided with a suction pipe temperature sensor (63) for detecting the temperature of the suction junction pipe (23).
  • a discharge pressure sensor (21a, 21b, 21c) for detecting the discharge pressure of the compressor (21a, 21b, 21c) is provided at the junction of each discharge pipe (22a, 22b, 22c) (that is, the inflow end of the discharge junction pipe (22)). 64).
  • a suction pressure sensor (65) for detecting the suction pressure of the compressors (21a, 21b, 21c) is provided at the junction of each suction pipe (23a, 23b, 23c).
  • An outside air temperature sensor (67) for detecting the outside air temperature is provided in the vicinity of the outside-compartment fan (26).
  • the second refrigerant pipe (33) is provided with a first liquid temperature sensor (68).
  • a second liquid temperature sensor (69) is provided downstream of the supercooling pressure reducing valve (29) in the first injection pipe (37).
  • Each liquid temperature sensor (68, 69) detects the temperature of the liquid refrigerant.
  • Each in-compartment unit (3) is provided with an in-compartment circuit (50).
  • the internal circuit (50) is provided with a heating pipe (51), an internal expansion valve (52), and an internal heat exchanger (53) in order from one end side to the other end side.
  • the heating pipe (51) is attached to a drain pan (55) provided below the internal heat exchanger (53).
  • the drain pan (55) collects the condensed water dripping from the internal heat exchanger (53).
  • the heating pipe (51) is attached to the drain pan (55) because the ice mass generated by freezing of the condensed water is converted into the heat of the high-pressure refrigerant flowing through the heating pipe (51). It is for melting using.
  • the internal expansion valve (52) is an electronic expansion valve whose opening degree can be adjusted.
  • the internal heat exchanger (53) is a cross-fin type fin-and-tube heat exchanger, and an internal fan (54) is provided in the vicinity of the internal heat exchanger (53). It has been.
  • the internal heat exchanger (53) is configured to exchange heat between the internal air sent by the internal fan (54) and the refrigerant flowing through the internal heat exchanger (53). Has been.
  • the temperature circuit (50) is provided with three temperature sensors. Specifically, the heat transfer tube of the internal heat exchanger (53) is provided with an evaporation temperature sensor (72) for detecting the evaporation temperature of the refrigerant. A refrigerant temperature sensor (73) for detecting the temperature of the gas refrigerant is provided in the vicinity of the gas side end of the internal circuit (50). In the vicinity of the internal fan (54), an internal temperature sensor (74) for detecting the internal temperature is provided.
  • the controller (9) receives the detection values of the sensors (61 to 69, 71 to 74) and the high pressure switch (62). Based on these detected values, the controller (9) controls the drive of the compressors (21a, 21b, 21c) and the fans (26, 54) and various valves (24, 29, 31, 52, SV). ) And the opening degree are adjusted, and the operation of the refrigeration apparatus (1) is controlled.
  • the opening degree of the supercooling pressure reducing valve (29) is adjusted based on each discharge pipe temperature sensor (61).
  • the controller (9) adjusts the opening of the first flow control valve (30a) and the first controller (9a) that adjusts the opening of the first flow control valve (30a).
  • a second control unit (9b) is provided in the controller (9).
  • the first control unit (9a) is configured to adjust the valve opening degree of the first flow rate adjusting valve (30a) based on the operating frequency of the inverter provided in the first compressor (21a).
  • the second control unit (9b) is configured to adjust the valve opening degree of the second flow rate adjusting valves (30b, 30c) based on the operation frequency of the inverter.
  • the refrigeration apparatus (1) is configured to perform a cooling operation for maintaining the inside of the refrigerated warehouse at a predetermined temperature (for example, 5 ° C.).
  • the high-pressure gas refrigerant compressed by the first, second, and third compressors (21a, 21b, 21c) is discharged from the discharge pipes (22a, 22b, 22c).
  • the high-pressure gas refrigerant discharged from each discharge pipe (22a, 22b, 22c) flows into each oil separator (38a, 38b, 38c).
  • each oil separator (38a, 38b, 38c) the refrigeration oil is separated from the high-pressure refrigerant.
  • the separated refrigerating machine oil is once stored in each oil separator (38a, 38b, 38c), and then passed through each oil return pipe (39a, 39b, 39c) and oil return junction pipe (39). It flows into the injection pipe (38).
  • the high-pressure refrigerant from which the refrigerating machine oil has been separated flows out from the oil separators (38a, 38b, 38c) and joins in the discharge junction pipe (22).
  • the high-pressure refrigerant joined in the discharge junction pipe (22) flows into the external heat exchanger (25) through the four-way switching valve (24).
  • the high-pressure refrigerant condenses by exchanging heat with external air.
  • the condensed refrigerant passes through the first refrigerant pipe (32), the receiver (27), and the high-pressure channel (28a) of the supercooling heat exchanger (28) in this order, and then flows into the second refrigerant pipe (33).
  • a part of the refrigerant flowing into the second refrigerant pipe (33) flows to the first injection pipe (37), and the other flows to the first connection pipe (14) via the first shut-off valve (11).
  • the high-pressure refrigerant that has flowed toward the first injection pipe (37) is depressurized to a predetermined pressure by the supercooling pressure reducing valve (29) to become an intermediate pressure refrigerant, and then the supercooling heat exchanger (28). Flows into the intermediate pressure channel (28b).
  • the supercooling heat exchanger (28) the intermediate-pressure refrigerant and the high-pressure refrigerant flowing through the high-pressure side flow path (28a) exchange heat.
  • the high-pressure refrigerant is cooled to increase the degree of supercooling, while the intermediate-pressure refrigerant is heated to become a gas refrigerant.
  • This gas refrigerant flows out of the supercooling heat exchanger (28) and then splits into the first, second, and third branch injection pipes (37a, 37b, 37c) via the second injection pipe (38). .
  • the first intermediate pressure position in the first compressor (21a) is set. It is injected into the compression chamber (43).
  • the valve opening degree of the first flow rate adjusting valve (30a) is decreased.
  • the intermediate pressure refrigerant flowing into the second and third branch injection pipes (37b, 37c) is adjusted to the second, third flow rate adjusting valves (30b, 30c) after the respective flow rates are adjusted by the second and third flow rate adjusting valves (30b, 30c).
  • the third compressor (21b, 21c) is injected into each compression chamber at the intermediate pressure position.
  • the valve opening degree of the second and third flow rate adjusting valves (30b, 30c) is increased.
  • the high-pressure refrigerant that has flowed toward the first communication pipe (14) is divided into each internal circuit (50).
  • the high-pressure refrigerant that has flowed into the internal circuit (50) flows through the heating pipe (51).
  • the drain pan (55) ice blocks in which condensed water has been frozen by the refrigerant flowing through the heating pipe (51) are melted by the refrigerant in the heating pipe (51).
  • the high-pressure refrigerant flowing through the heating pipe (51) is further subcooled.
  • the high-pressure refrigerant that has flowed out of the heating pipe (51) is depressurized by the internal expansion valve (52) to become low-pressure refrigerant, and then flows into the internal heat exchanger (53).
  • the low-pressure refrigerant evaporates by exchanging heat with the internal air. Thereby, the air in a warehouse is cooled.
  • the refrigerant evaporated in each internal heat exchanger (53) flows again into the external circuit (20) through the second connection pipe (15).
  • the low-pressure refrigerant that has flowed into the external circuit (20) flows to the suction junction pipe (23) via the four-way switching valve (24), and from the suction pipe (23a, 23b, 23c) to each compressor (21a, 21b, Inhaled to 21c).
  • the low-pressure refrigerant sucked into the compressors (21a, 21b, 21c) is compressed to a predetermined pressure together with the intermediate-pressure refrigerant flowing from the intermediate ports (5, 6, 7), and becomes high-pressure refrigerant.
  • the high-pressure refrigerant is discharged again from the compressors (21a, 21b, 21c). As the refrigerant circulates in this manner, a cooling operation for maintaining the inside of each refrigerated warehouse at a predetermined temperature is performed.
  • the intermediate port (5) of the first compressor (21a) is formed to have a smaller diameter than the intermediate ports (6, 7) of the second and third compressors (21b, 21c).
  • the intermediate pressure refrigerant flowing through the second injection pipe (38) can be made difficult to flow toward the first compressor (21a).
  • the temperature of the high-pressure refrigerant in the first compressor (21a) is not formed with a small diameter. It can. Further, since the intermediate-pressure refrigerant is less likely to flow toward the first compressor (21a), it flows toward the second and third compressors (21b, 21c), so that the first compressor (21a ), The temperature of the high-pressure refrigerant in the second and third compressors (21b, 21c) can be lowered compared to the case where the intermediate port (5) is not formed with a small diameter.
  • the first compressor (21a) and the second and second compressors (21a) and the second and third compressors (21b, 21c) are selected according to the ratio of the operating capacities set for the first compressor (21a) and the second and third compressors (21b, 21c).
  • the size of the intermediate ports (5, 6, 7) of the third compressor (21b, 21c) may be determined. That is, when the variable operating capacity of the first compressor (21a) is larger than the fixed operating capacity of the second and third compressors (21b, 21c), the second and third compressors (21b) , 21c), the intermediate port (5) of the first compressor (21a) is made smaller than the intermediate port (6, 7).
  • both compressors (21a, 21b, 21c) are suppressed while minimizing the temperature imbalance of the high-pressure refrigerant generated between the first compressor (21a) and the second and third compressors (21b, 21c). ) Can be injected.
  • the valve opening degree of the first flow rate adjusting valve (30a) is reduced as the operating capacity of the first compressor (21a) is reduced. .
  • coolant can be made hard to flow toward the 1st compressor (21a).
  • the valve opening degree of the second flow rate adjusting valves (30b, 30c) is reduced. Enlarge. Thereby, compared with the case where only the valve opening degree of the said 1st flow regulating valve (30a) is adjusted, the said intermediate pressure refrigerant
  • coolant can be made difficult to flow toward the 1st compressor (21a).
  • the temperature of the high-pressure refrigerant in the first compressor (21a) is prevented from becoming too much lower than when only the valve opening degree of the first flow rate adjusting valve (30a) is adjusted. Can do.
  • the present embodiment it is possible to increase the degree of supercooling of the high-pressure refrigerant while injecting into each compressor (21a, 21b, 21c). As a result, the temperature imbalance of the high-pressure refrigerant generated between the first compressor (21a) and the second and third compressors (21b, 21c) can be suppressed as much as possible while improving the COP of the refrigeration apparatus. .
  • FIG. 3 is a refrigerant circuit diagram of a refrigeration apparatus according to a modification of the first embodiment.
  • This modification is a combination of a variable capacity compressor and a fixed capacity compressor used for three compressors (21a, 21b, 21c), and one of the three flow rate regulating valves (30a, 30b, 30c). The form of one valve is changed from the example of FIG.
  • the first compressor (21a) is a variable capacity compressor and the third compressor (21c) is a fixed capacity compressor
  • the second compressor is the same as the first embodiment in FIG. Unlike the example of FIG. 1, the machine (21b) is composed of a variable capacity compressor.
  • first branch injection pipe (37a) and the second branch injection connected to the intermediate ports (5, 6) of the first compressor (21a) and the second compressor (21b), which are variable capacity compressors, respectively.
  • the pipe (37b) is provided with a first flow rate adjustment valve (30a, 30b) consisting of an electronic expansion valve with a variable opening, but an intermediate port of a third compressor (21c) which is a fixed capacity compressor.
  • the third branch injection pipe (37c) connected to (7) is provided with a second flow rate adjusting valve (30b) made up of an electromagnetic valve that can be freely opened and closed.
  • the intermediate ports (5, 6) of the first compressor (21a) and the second compressor (21b) which are variable capacity compressors are the third compression which is a fixed capacity compressor. It has a smaller diameter than the intermediate port (7) of the machine (21c).
  • the refrigerant circuit (10) including the external circuit (20) and the internal circuit (50) is configured in the same manner as in Embodiment 1 of FIG. 1 except for the above points.
  • the 1st control part (9a) of the said controller (9) which controls the said 1st flow regulating valve (30a, 30b) is comprised similarly to Embodiment 1 of FIG.
  • the second control unit (9b) that controls the second flow rate adjusting valve (30c) the operation frequency of the inverters of the first compressor (21a) and the second compressor (21b) is larger than a predetermined value. In some cases, control is performed to close the second flow rate adjustment valve (30c).
  • the diameters of the intermediate ports (5, 6, 7) of the compressors (21a, 21b, 21c) are different from each other, and each flow rate depends on the frequency of the inverter. Since the operation of the regulating valves (30a, 30b, 30c) is controlled, the refrigerant injection amount to each compressor (21a, 21b, 21c) can be adjusted. Therefore, the refrigerant discharge gas temperature generated between the first compressor (21a) and the second compressor (21b), which are variable displacement compressors, and the third compressor (21c), which is a fixed displacement compressor. Unbalance can be suppressed.
  • Embodiment 2 of the Invention A second embodiment of the present invention will be described.
  • the refrigeration apparatus (100) according to Embodiment 2 is provided, for example, in a convenience store. As shown in FIG. 4, the refrigeration apparatus (100) includes an outdoor unit (110) installed outside the room, an indoor unit (150) that air-conditions the store space, and two internal units ( 160a, 160b) and a booster unit (180).
  • the two internal units (160a, 160b) are composed of a first internal unit (160a) for refrigeration and a second internal unit (160b) for freezing.
  • the outdoor unit (110) has an outdoor circuit (111), the indoor unit (150) has an indoor circuit (152), the first internal unit (160a) has a first internal circuit (161a), The internal unit (160b) is provided with a second internal circuit (161b), and the booster unit (180) is provided with a booster circuit (181).
  • an outdoor circuit (111), an indoor circuit (152), a first internal circuit (161a), a second internal circuit (161b), and a booster circuit (181) are connected to four connecting pipes.
  • the refrigerant circuit (200) which performs a vapor compression refrigeration cycle is comprised.
  • the first internal circuit (161a) and the second internal circuit (161b) are connected in parallel.
  • the second internal circuit (161b) and the booster circuit (181) are connected in series.
  • the refrigerant circuit (200) is provided with a use side heat exchanger for the air conditioning system and a use side heat exchanger for the refrigeration / refrigeration system.
  • Each compressor (114a, 114b, 114c), which will be described later, includes a compressor connected to the use side heat exchanger of the air conditioning system, and a compressor connected to the use side heat exchanger of the refrigeration / refrigeration system. It is included.
  • the four connecting pipes (201, 202, 203, 204) are the first liquid side connecting pipe (201), the second liquid side connecting pipe (202), the first gas side connecting pipe (203), and the second gas side connecting pipe (204). It is composed of One end of the first liquid side connection pipe (201) is connected to the first liquid side shut-off valve (205) of the outdoor circuit (111), and the other end is connected to the indoor circuit (152). One end of the second liquid side communication pipe (202) is connected to the second liquid side shut-off valve (206) of the outdoor circuit (111), and the other end branches into two hands to connect the first internal circuit (161a). It is connected to the second internal circuit (161b).
  • the first gas side communication pipe (203) has one end connected to the first gas side shut-off valve (207) of the outdoor circuit (111) and the other end connected to the indoor circuit (152).
  • One end of the second gas side communication pipe (204) is connected to the second gas side shut-off valve (208) of the outdoor circuit (111), and the other end branches into two hands to connect with the first internal circuit (161a). It is connected to the second internal circuit (161b).
  • the second internal circuit (161b) and the booster circuit (181) are connected by a connection gas pipe (194).
  • the outdoor circuit (111) is provided with a compression mechanism (140), an outdoor heat exchanger (115), and a receiver (112).
  • the compression mechanism (140) includes a first variable capacity compressor (114a), a fixed capacity compressor (114c), and a second variable capacity compressor (114b).
  • the discharge sides of these compressors (114a, 114b, 114c) are connected to each other. Further, these compressors (114a, 114b, 114c) are connected to a third four-way switching valve (133) described later on the suction side.
  • the first variable capacity compressor (114a) constitutes the first compressor (114a), and the fixed capacity compressor (114c) and the second variable capacity compressor (114b) are the second and second compressors, respectively. 3 compressors (114b, 14c) are configured.
  • the first and second variable capacity compressors (114a, 114b) are configured such that their operating capacities can be adjusted in stages by changing the output frequency of the inverter.
  • the fixed capacity compressor (114c) the electric motor is always operated at a constant rotational speed, and the operation capacity cannot be changed.
  • the first variable capacity compressor (114a) constitutes an in-compartment compressor that sucks the refrigerant evaporated in the in-compartment units (160a, 160b).
  • the first variable capacity compressor (114a) is a compressor dedicated to the interior.
  • the fixed capacity compressor (114c) constitutes an indoor compressor that sucks the refrigerant evaporated in the indoor unit (150) during the cooling operation.
  • the second variable capacity compressor (114b) is a compressor dedicated to the room.
  • the second variable capacity compressor (114b) constitutes an internal compressor when a later-described third four-way switching valve (133) is in the first state, and the third four-way switching valve (133). Constitutes an indoor compressor when in the second state. That is, the second variable capacity compressor (114b) is used both as an internal compressor and an indoor compressor.
  • the first variable capacity compressor (114a) Is set as the internal compressor, and the operating capacity of the first variable capacity compressor (114a) is set so that, for example, the pressure of the suction pipe (157a) of the first variable capacity compressor (114a) becomes a constant value. Adjusted to. As a result, the operating capacity of the first variable capacity compressor (114a) is adjusted according to the internal load. When the internal load exceeds the maximum operating capacity of the first variable capacity compressor (114a), the fixed capacity compressor (114c) is also set as the internal compressor. At this time, the total operating capacity of the internal compressor is adjusted by the first variable capacity compressor (114a).
  • the first variable capacity compressor (114b) when the cooling load in the indoor heat exchanger (154) is relatively small, only the first variable capacity compressor (114b) is set as the indoor compressor. When the cooling load increases, the fixed capacity compressor (114c) is also set as the indoor compressor. When both the internal load and the cooling load are large, the fixed capacity compressor (114c) is preferentially used as the internal compressor.
  • the first variable capacity compressor (114a), the fixed capacity compressor (114c), and the second variable capacity compressor (114b) are all constituted by, for example, a hermetic high-pressure dome type scroll compressor.
  • Each compressor (114) includes a scroll type compression mechanism (47) similar to that already described in FIG. Although a detailed description of the compression mechanism (47) is omitted, the intermediate ports (5, 6) of the first variable capacity compressor (114a) and the second variable capacity compressor (114b) are fixed capacity compressor (114c). The diameter is smaller than that of the intermediate port (7).
  • the first discharge pipe (156a) of the first variable capacity compressor (114a), the second discharge pipe (156b) of the fixed capacity compressor (114c), and the third discharge pipe (156c) of the second variable capacity compressor (114b). ) Is connected to the discharge junction pipe (121).
  • the discharge junction pipe (121) is connected to the first four-way switching valve (131).
  • a discharge branch pipe (122) branches from the discharge junction pipe (121).
  • the discharge branch pipe (122) is connected to the second four-way switching valve (132).
  • Each discharge pipe (156) has an oil separator (137a, 137b, 137c), high pressure switch (139a, 139b, 139c) and check valve (CV1, CV2, CV3) in order from the compressor (114) side. And are arranged.
  • Each high pressure switch (139) is configured to urgently stop the compressor (114) at an abnormally high pressure.
  • Each check valve (CV1, CV2, CV3) is configured to prohibit the flow of refrigerant toward the compressor (114).
  • the first suction pipe (157a) of the first variable capacity compressor (114a) is connected to the second gas side shut-off valve (208).
  • the second suction pipe (157b) of the second variable capacity compressor (114b) is connected to the second four-way switching valve (132).
  • the third suction pipe (157c) of the fixed capacity compressor (114c) is connected to the third four-way switching valve (133).
  • a first suction branch pipe (158a) branches off from the first suction pipe (157a).
  • a second suction branch pipe (158b) branches from the second suction pipe (157b).
  • Both the first suction branch pipe (158a) and the second suction branch pipe (158b) are connected to the third four-way switching valve (133).
  • the first suction branch pipe (158a) and the second suction branch pipe (158b) have check valves (CV7, CV8) that prohibit the flow of refrigerant from the third four-way switching valve (133) side, respectively. Is provided.
  • the outdoor heat exchanger (115) is a cross-fin type fin-and-tube heat exchanger.
  • the outdoor heat exchanger (115) constitutes a heat source side heat exchanger.
  • An outdoor fan (123) that sends outdoor air to the outdoor heat exchanger (115) is provided in the vicinity of the outdoor heat exchanger (115). In the outdoor heat exchanger (115), heat is exchanged between the refrigerant and the outdoor air.
  • the gas side of the outdoor heat exchanger (115) is connected to the first four-way switching valve (131).
  • the liquid side of the outdoor heat exchanger (115) is connected to the top of the receiver (112) via the first liquid pipe (124).
  • the first liquid pipe (124) is provided with a check valve (CV9) that prohibits the flow of refrigerant toward the outdoor heat exchanger (115).
  • the receiver (112) is configured as a vertically long sealed container. In the receiver (112), the high-pressure refrigerant condensed in the outdoor heat exchanger (115) or the like is temporarily stored.
  • One end of the second liquid pipe (125) is connected to the bottom of the receiver (112).
  • the other end of the second liquid pipe (125) branches into a first branch pipe (126) and a second branch pipe (127).
  • the first branch pipe (126) is connected to the first liquid side stop valve (205).
  • the first branch pipe (126) communicates with the indoor circuit (152) via the first liquid side connecting pipe (201).
  • the first branch pipe (126) is provided with a check valve (CV10) that prohibits the flow of refrigerant toward the second liquid pipe (125).
  • the third branch pipe (128) is provided with a check valve (CV11) that prohibits the flow of refrigerant toward the first branch pipe (126).
  • the second branch pipe (127) is connected to the second liquid side stop valve (206).
  • the second branch pipe (127) communicates with the internal circuits (161a, 161b) via the second liquid side connecting pipe (202).
  • a second intermediate heat exchanger (117) described later is connected to the second branch pipe (127).
  • the fourth branch pipe (129) branches from between the second intermediate heat exchanger (117) and the second liquid side shut-off valve (206).
  • the fourth branch pipe (129) is connected to the second branch pipe (127) at the opposite end of the outdoor heat exchanger (115) and the check valve (CV9) in the first liquid pipe (124).
  • the fourth branch pipe (129) is provided with a first outdoor expansion valve (166) constituted by an electronic expansion valve having a variable opening.
  • the injection pipe (130) is branched from between the branch point of the fourth branch pipe (129) and the second liquid side shut-off valve (206).
  • the injection pipe (130) constitutes an injection passage.
  • the injection pipe (130) has a main injection pipe (130d) extending from the second branch pipe (127) and a branch from the main injection pipe (130d) to the intermediate port (5) of the first variable capacity compressor (114a).
  • the left branch injection pipe (130a) to be connected, the right branch injection pipe (130b) branched from the main injection pipe (130d) and connected to the intermediate port (6) of the second variable capacity compressor (114b), and the main injection A central branch injection pipe (130c) branched from the pipe (130d) and connected to the intermediate port (7) of the fixed capacity compressor (114c).
  • the left branch injection pipe (130a) and the right branch injection pipe (130b) constitute the first branch pipe of the present invention
  • the central branch injection pipe (130c) constitutes the second branch pipe.
  • the intermediate port (5) of the first variable capacity compressor (114a) and the intermediate port (6) of the second variable capacity compressor (114b) are smaller in diameter than the intermediate port (7) of the fixed capacity compressor (114c). It is.
  • the main injection pipe (130d) is provided with a second outdoor expansion valve (pressure reduction means) (167).
  • the second outdoor expansion valve (167) is an electronic expansion valve with a variable opening. In the second outdoor expansion valve (167), the refrigerant flowing into the main injection pipe (130d) from the second branch pipe (127) is reduced to an intermediate pressure in the refrigeration cycle.
  • Each branch injection pipe (130a, 130b, 130c) is provided with an electronic expansion valve (211, 212, 213) as a flow control valve.
  • the function of the flow rate adjusting valve is the same as that of the first embodiment.
  • the first intermediate heat exchanger (116) is configured to exchange heat between the refrigerant flowing through the first flow path (116a) and the refrigerant flowing through the second flow path (116b).
  • the first intermediate heat exchanger (116) is constituted by, for example, a double tube heat exchanger.
  • the first flow path (116a) is connected to the second liquid pipe (125), and the second flow path (116b) formed inside the first flow path (116a). Is connected downstream of the second outdoor expansion valve (167) in the main injection pipe (130d).
  • the high-pressure refrigerant in the second liquid pipe (125) is cooled by the intermediate-pressure refrigerant in the main injection pipe (130d).
  • the second intermediate heat exchanger (117) is configured to exchange heat between the refrigerant flowing through the first flow path (117a) and the refrigerant flowing through the second flow path (117b).
  • the second intermediate heat exchanger (117) is constituted by, for example, a plate heat exchanger.
  • the first flow path (117a) is connected to the second branch pipe (127), and the second flow path (117b) is the first intermediate heat exchange in the main injection pipe (130d). Connected downstream of the vessel (116).
  • the high-pressure refrigerant in the second branch pipe (127) is cooled by the intermediate-pressure refrigerant in the main injection pipe (130d).
  • the first four-way switching valve (131) has a first port (P1) connected to the discharge junction pipe (121) and a second port (P2) connected to the fourth port (P4) of the second four-way switching valve (132).
  • the third port (P3) is connected to the outdoor heat exchanger (115), and the fourth port (P4) is connected to the first gas side shut-off valve (1113).
  • the second four-way selector valve (132) has a first port (P1) connected to the discharge branch pipe (122), a second port (P2) connected to the second suction pipe (157b), and a fourth port (P4). Are connected to the second port (P2) of the first four-way selector valve (131), respectively.
  • the third port (P3) of the second four-way selector valve (132) is configured as a closed port.
  • the third four-way selector valve (133) has a first port (P1) connected to the discharge junction pipe (121) at the high pressure pipe (136) and a second port (P2) connected to the third suction pipe (157c). ),
  • the third port (P3) is connected to the second suction branch pipe (158b), and the fourth port (P4) is connected to the first suction branch pipe (158a).
  • the first port (P1) and the third port (P3) communicate with each other to connect the second port (P2) and the fourth port (P4).
  • ) Are in communication with each other (shown by a solid line in FIG. 4), the first port (P1) and the fourth port (P4) are in communication with each other, and the second port (P2) and the third port (P3).
  • a second state a state indicated by a broken line in FIG. 4 communicating with each other.
  • the first oil separator (137a) is provided in the first discharge pipe (156a), the second oil separator (137b) is provided in the second discharge pipe (156b), and the third discharge pipe (156c) is provided.
  • a third oil separator (137c) is provided.
  • Each oil separator (137) is configured in a sealed container shape, and is configured to separate the refrigerating machine oil from the refrigerant discharged from the corresponding compressor (114).
  • the first oil separator (137a) is connected to the first oil return pipe (142), the second oil separator (137b) is connected to the second oil return pipe (143), and the third oil separator is separated.
  • a third oil return pipe (144) is connected to the vessel (137c).
  • Each oil return pipe (142, 143, 144) is configured to send the refrigerating machine oil separated by the oil separator (137) to the compression chamber of the intermediate pressure of the compressor (114) through the injection pipe (130).
  • the oil return pipes (142, 143, 144) join together, are connected to the injection pipe (130), and are injected into the compressors (114) from the intermediate ports (5, 6, 7).
  • the first oil return pipe (142) includes a check valve (CV12) for inhibiting the flow of refrigeration oil returning to the first oil separator (137a) in order from the first oil separator (137a) side, There is provided a capillary tube (141a) for reducing the high pressure refrigerating machine oil to an intermediate pressure.
  • the second oil return pipe (143) includes a check valve (CV13) for prohibiting the flow of refrigeration oil returning to the second oil separator (137b) side in order from the second oil separator (137b) side, There is provided a capillary tube (141b) for reducing the high pressure refrigerating machine oil to an intermediate pressure.
  • the third oil return pipe (144) includes a check valve (CV14) that prohibits the flow of refrigeration oil returning to the third oil separator (137c) in order from the third oil separator (137c) side, There is provided a capillary tube (141c) for reducing the high pressure refrigerating machine oil to an intermediate pressure.
  • CV14 check valve
  • capillary tube (141c) for reducing the high pressure refrigerating machine oil to an intermediate pressure.
  • the discharge junction pipe (121) is provided with a discharge pressure sensor (118).
  • Each discharge pipe (156) is provided with a discharge temperature sensor (not shown).
  • the first suction pipe (157a) is provided with a first suction pressure sensor (119a) and a first suction temperature sensor (120a).
  • the second suction pipe (157b) is provided with a second suction pressure sensor (119b) and a second suction temperature sensor (120b).
  • the second branch pipe (127) is provided with a liquid temperature sensor (172). The detection values of these sensors are input to a controller (210) described later.
  • an indoor expansion valve (153) and an indoor heat exchanger (154) are provided in that order from the liquid side end to the gas side end.
  • the indoor expansion valve (153) is an electronic expansion valve whose opening degree can be adjusted.
  • the indoor heat exchanger (154) is a cross-fin type fin-and-tube heat exchanger.
  • the indoor heat exchanger (154) constitutes a second usage side heat exchanger (154).
  • An indoor fan (155) that sends indoor air to the indoor heat exchanger (154) is provided in the vicinity of the indoor heat exchanger (154). In the indoor heat exchanger (154), heat is exchanged between the refrigerant and the room air.
  • an evaporation temperature sensor (221) is provided in the heat transfer tube of the indoor heat exchanger (154).
  • a gas temperature sensor (222) is provided in the vicinity of the gas side end of the indoor circuit (152).
  • a room temperature sensor (223) is provided in the indoor unit.
  • each of the internal expansion valves (163a, 163b) is an electronic expansion valve whose opening degree can be adjusted.
  • Each of the in-compartment heat exchangers (164a, 164b) is configured by a cross fin type fin-and-tube heat exchanger.
  • the internal heat exchanger (164a) of the first internal circuit (161a) constitutes a first usage-side heat exchanger (164a).
  • an evaporation temperature sensor (224a, 224b) is provided in the heat transfer tube of the internal heat exchanger (164a, 64b).
  • gas temperature sensors (225a, 225b) are provided in the vicinity of the gas side end in the internal circuit (161a, 61b).
  • An internal temperature sensor (226a, 226b) is provided in the internal unit.
  • the booster circuit (181) is provided with a booster compressor (186) having a variable operation capacity.
  • the discharge pipe (178) of the booster compressor (186) is provided with an oil separator (187), a high pressure switch (188), and a check valve (CV15) in this order from the booster compressor (186) side.
  • An oil return pipe (192) provided with a capillary tube (191) is connected to the oil separator (187).
  • the booster circuit (181) is provided with a bypass pipe (195) that bypasses the booster compressor (186).
  • the bypass pipe (195) is provided with a check valve (CV16).
  • the controller (210) includes a first controller (210a) that adjusts an opening degree of the first flow rate adjusting valve (211, 212) connected to the variable capacity compressor (114a, 114b), and the fixed capacity compressor. And a second controller (210b) that adjusts the opening of the second flow rate adjustment valve (213) connected to (114c).
  • the first control unit (210a) adjusts the valve opening degree of the first flow rate adjusting valve (211, 212) based on the operating frequency of the inverter provided in the variable capacity compressor (114a, 114b). It is configured.
  • the second control unit (210b) is configured to adjust the valve opening degree of the second flow rate adjusting valve (213) based on the operating frequency of the inverter.
  • the refrigeration apparatus (100) is configured to be able to set seven types of operation modes. Specifically, ⁇ i> cooling operation for cooling only the indoor unit (150), ⁇ ii> heating operation for heating only the indoor unit (150), ⁇ iii> first indoor unit (160a) and Refrigerated refrigeration operation that only cools the inside of the warehouse with the two inside units (160b), ⁇ iv> indoor unit with the cooling inside the inside of the first inside unit (160a) and the second inside unit (160b) ( 150) Cooling and cooling operation in which the cooling is performed, and ⁇ v> without cooling the outdoor heat exchanger (115), the cooling in the storage in the first storage unit (160a) and the second storage unit (160b) The first cooling / heating operation for heating the indoor unit (150), ⁇ vi> the second cooling / heating operation performed when the heating capacity of the indoor unit (150) is excessive in the first cooling / heating operation, and ⁇
  • a vapor compression refrigeration cycle is performed in which the outdoor heat exchanger (115) serves as a condenser and the indoor heat exchanger (154) serves as an evaporator.
  • the fixed capacity compressor (114c) is also operated.
  • the third four-way selector valve (133) is set to the second state, and the fixed capacity compressor (114c) constitutes an indoor compressor.
  • the first variable capacity compressor (114a) is always stopped.
  • the refrigerant discharged from the second variable capacity compressor (114b) is condensed in the outdoor heat exchanger (115), and flows into the indoor circuit (152) through the receiver (112).
  • the indoor circuit (152) the refrigerant flowing in is depressurized by the indoor expansion valve (153), and then absorbs heat from the indoor air by the indoor heat exchanger (154) and evaporates.
  • the indoor air cooled by the refrigerant is supplied to the store space.
  • the refrigerant evaporated in the indoor heat exchanger (154) is sucked into the second variable capacity compressor (114b) and discharged again.
  • the evaporation temperature of the refrigerant in the indoor heat exchanger (154) is, for example, about 10 ° C.
  • a vapor compression refrigeration cycle is performed in which the indoor heat exchanger (154) serves as a condenser and the outdoor heat exchanger (115) serves as an evaporator.
  • the fixed capacity compressor (114c) is also operated.
  • the third four-way selector valve (133) is set to the second state. The first variable capacity compressor (114a) is always stopped.
  • the refrigerant discharged from the second variable capacity compressor (114b) flows into the indoor circuit (152), dissipates heat to the indoor air in the indoor heat exchanger (154), and condenses.
  • the room air heated by the refrigerant is supplied to the store space.
  • the refrigerant condensed in the indoor heat exchanger (154) is depressurized by the first outdoor expansion valve (166), then evaporated by the outdoor heat exchanger (115), and sucked into the second variable capacity compressor (114b). It is discharged again.
  • ⁇ Refrigeration operation> In the refrigeration operation, as shown in FIG. 7, the first variable capacity compressor (114a) is operated with the first four-way selector valve (131) set to the first state.
  • the indoor expansion valve (153) is set to a closed state.
  • the opening of the internal expansion valve (163a, 163b) is adjusted so that the superheat of the refrigerant that has passed through the internal heat exchanger (164, 64b) becomes the target superheat (for example, 5 ° C). Is controlled. This is the same in the cooling and cooling operation and the cooling and heating operation described later.
  • a vapor compression refrigeration cycle is performed in which the outdoor heat exchanger (115) serves as a condenser and each of the internal heat exchangers (164) serves as an evaporator.
  • the fixed capacity compressor (114c) is also operated when the internal cooling capacity is insufficient.
  • the third four-way selector valve (133) is set to the first state, and the fixed capacity compressor (114c) constitutes the internal compressor.
  • the second variable capacity compressor (114b) is always stopped.
  • the refrigerant discharged from the first variable capacity compressor (114a) is condensed in the outdoor heat exchanger (115).
  • the refrigerant condensed in the outdoor heat exchanger (115) is distributed to the first internal circuit (161a) and the second internal circuit (161b) via the receiver (112).
  • the refrigerant flowing in is depressurized by the internal expansion valve (16203), and then absorbs heat from the internal air in the internal heat exchanger (164a) and evaporates.
  • the inside air cooled by the refrigerant is supplied to the inside of the refrigerated showcase.
  • the refrigerant that has flowed in is decompressed by the internal expansion valve (16204), and then absorbs heat from the internal air in the internal heat exchanger (164b) to evaporate.
  • the internal air cooled by the refrigerant is supplied into the freezer showcase.
  • the refrigerant evaporated in the internal heat exchanger (164b) is compressed by the booster compressor (186).
  • the refrigerant evaporated in the internal heat exchanger (164a) and the refrigerant compressed by the booster compressor (186) are drawn into the first variable capacity compressor (114a) and discharged again after joining.
  • the refrigerant evaporation temperature in the internal heat exchanger (164a) is set to 5 ° C., for example, and the refrigerant evaporation temperature in the internal heat exchanger (164b) is set to ⁇ 30 ° C., for example. Is done.
  • the suction refrigeration cycle for sucking the evaporated refrigerant is performed.
  • the first variable displacement compressor (114a) and the second variable displacement are set with both the first four-way switching valve (131) and the second four-way switching valve (132) set to the first state.
  • the compressor (114b) is operated.
  • a vapor compression refrigeration cycle is performed in which the outdoor heat exchanger (115) serves as a condenser and the indoor heat exchanger (154) and each internal heat exchanger (164) serve as an evaporator.
  • the fixed capacity compressor (114c) In the cooling and cooling operation, when the cooling capacity of the indoor unit (150) and the cooling capacity of the internal unit (160) are sufficient, the fixed capacity compressor (114c) is stopped. Further, when the cooling capacity in the internal unit (160) is insufficient, as shown in FIG. 8, the third four-way switching valve (133) is set to the first state and the fixed capacity compressor (114c) Driving is performed. In this case, the fixed capacity compressor (114c) is an internal compressor. Further, when the cooling capacity of the indoor unit (150) is insufficient, as shown in FIG. 9, the third four-way selector valve (133) is set to the second state and the fixed capacity compressor (114c) is operated. Is done. In this case, the fixed capacity compressor (114c) is an indoor compressor.
  • the refrigerant discharged from the first variable capacity compressor (114a) and the second variable capacity compressor (114b) is condensed in the outdoor heat exchanger (115).
  • the refrigerant condensed in the outdoor heat exchanger (115) is distributed to the first internal circuit (161a), the second internal circuit (161b), and the indoor circuit (152) via the receiver (112). .
  • the refrigerant distributed to the first internal circuit (161a) and the second internal circuit (161b) flows in the same flow as the refrigeration operation, and is sucked into the first variable capacity compressor (114a) and discharged again. Is done.
  • the refrigerant distributed to the indoor circuit (152) flows in the same flow as in the cooling operation, and is sucked into the second variable capacity compressor (114b) and discharged again.
  • the evaporation temperature of the refrigerant in the indoor heat exchanger (154) becomes, for example, about 10 ° C., and the refrigerant evaporates in the internal heat exchanger (164a) of the first internal circuit (161a).
  • the temperature is set to 5 ° C., for example, and the evaporation temperature of the refrigerant in the internal heat exchanger (164b) of the second internal circuit (161b) is set to ⁇ 30 ° C., for example.
  • the refrigerant evaporation temperature in the indoor heat exchanger (154) is higher than the refrigerant evaporation temperature in the internal heat exchanger (164a) of the first internal circuit (161a).
  • the first variable capacity compressor (114a) sucks the refrigerant evaporated in the internal heat exchanger (164a) of the first internal circuit (161a), and the internal heat exchanger (164a) Then, another suction refrigeration cycle is performed in which the second variable capacity compressor (114b) sucks the refrigerant evaporated in the indoor heat exchanger (154) where the evaporation temperature of the refrigerant becomes higher.
  • the fixed capacity compressor (114c) is an indoor compressor
  • the fixed capacity compressor (114c) also sucks the refrigerant evaporated in the indoor heat exchanger (154).
  • the fixed capacity compressor (114c) is an internal compressor
  • the first variable capacity compressor (114a) and the fixed capacity compressor (114c) are the same internal heat exchanger ( It also becomes a refrigerating cycle for sucking the refrigerant evaporated in 164a).
  • First cooling and heating operation In the first cooling / heating operation, as shown in FIG. 10, the first four-way selector valve (131) is set to the second state and the second four-way selector valve (132) is set to the first state.
  • the first variable capacity compressor (114a) is operated.
  • the fixed capacity compressor (114c) In the first cooling / heating operation, the fixed capacity compressor (114c) is also operated when the internal cooling capacity is insufficient.
  • the third four-way selector valve (133) is set to the first state, and the fixed capacity compressor (114c) serves as an internal compressor.
  • a vapor compression refrigeration cycle is performed in which the indoor heat exchanger (154) serves as a condenser and each internal heat exchanger (164) serves as an evaporator.
  • the cooling capacity (one evaporation heat amount) of the first internal unit (160a) and the second internal unit (160b), and the heating capacity (one condensation heat amount) of the indoor unit (150) Balance and 100% heat recovery is performed.
  • the refrigerant discharged from the first variable capacity compressor (114a) dissipates heat to the indoor air in the indoor heat exchanger (154) and condenses.
  • the refrigerant condensed in the indoor heat exchanger (154) is distributed to the first internal circuit (161a) and the second internal circuit (161b), respectively.
  • the refrigerant distributed to the first internal circuit (161a) and the second internal circuit (161b) flows in the same flow as the refrigeration operation, and is sucked into the first variable capacity compressor (114a) and discharged again. Is done.
  • the suction refrigeration cycle for sucking the evaporated refrigerant is performed. This is the same in the second cooling / heating operation and the third cooling / heating operation described later.
  • the second cooling / heating operation is performed by switching the second four-way switching valve (132) to the second state as shown in FIG. 11 when the heating capacity is surplus during the first cooling / heating operation. .
  • the outdoor heat exchanger (115) operates as a condenser.
  • the settings for the second cooling / air-heating operation are basically the same as those for the first cooling / air-heating operation except for the second four-way switching valve (132).
  • the refrigerant discharged from the first variable capacity compressor (114a) flows into the outdoor heat exchanger (115).
  • the outdoor heat exchanger (115) the inflowing refrigerant dissipates heat to the outdoor air and condenses.
  • the refrigerant condensed in the outdoor heat exchanger (115) merges with the refrigerant condensed in the indoor heat exchanger (154) and is distributed to the first internal circuit (161a) and the second internal circuit (161b), respectively.
  • the cooling capacity (one evaporation heat amount) of the first internal unit (160a) and the second internal unit (160b) and the heating capacity (one condensation heat amount) of the indoor unit (150) are: Without balancing, excess condensation heat is released in the outdoor heat exchanger (115).
  • ⁇ Third cooling and heating operation when the heating capacity is insufficient during the first cooling and heating operation, as shown in FIG. 12, the second four-way switching valve (132) is set to the first state and the first outdoor This is done by operating the second variable capacity compressor (114b) with the expansion valve (166) set to the open state.
  • a vapor compression refrigeration cycle is performed in which the indoor heat exchanger (154) serves as a condenser and each of the internal heat exchangers (164) and the outdoor heat exchanger (115) serves as an evaporator.
  • the refrigerant condensed in the indoor heat exchanger (154) moves not only to the first internal circuit (161a) and the second internal circuit (161b) but also to the outdoor heat exchanger (115) side. Distributed.
  • the refrigerant distributed to the outdoor heat exchanger (115) is depressurized by the first outdoor expansion valve (166), then evaporated by the outdoor heat exchanger (115), and sucked into the second variable capacity compressor (114b). And discharged again.
  • the cooling capacity (one evaporation heat amount) of the first internal unit (160a) and the second internal unit (160b) and the heating capacity (one condensation heat amount) of the indoor unit (150) are: Without balancing, the insufficient heat of evaporation is absorbed by the outdoor heat exchanger (115).
  • each compressor (114a, 114b, 114c) is performed in each of the above-described operation states, as in the first embodiment.
  • the intermediate ports (5, 6) of the first and third compressors (114a, 114b) which are variable capacity compressors are connected to the intermediate port (7) of the second compressor (114c) which is a fixed capacity compressor. Because of the small diameter, the injection amount when the frequency of the inverter is low can be suppressed.
  • the controller (210) adjusts the opening of the flow rate adjustment valves (211, 212, 213) according to the inverter operating frequency, so the amount of injection to the variable capacity compressor (114a, 114b) when the inverter frequency is low It can be suppressed more reliably.
  • the refrigerant circuit (200) is provided with a use side heat exchanger for an air conditioning system and a use side heat exchanger for a refrigeration / refrigeration system.
  • the compressor (114a, 114b, 114c) includes a compressor connected to the use side heat exchanger of the air conditioning system and a compressor connected to the use side heat exchanger of the refrigeration / refrigeration system
  • the intermediate ports (5, 6) of the first and third compressors (114a, 114b), which are variable capacity compressors, are more than the intermediate ports (7) of the second compressor (114c), which is a fixed capacity compressor.
  • variable capacity compressor (114a, 114b) when the inverter frequency is low by reducing the diameter and adjusting the opening of the flow rate adjustment valve (211, 212, 213) according to the operating frequency of the inverter. Can be reliably suppressed.
  • the temperature of the high-pressure refrigerant in the variable capacity compressor (114a, 114b) can be prevented from becoming too low. This is because the injection refrigerant is less likely to flow toward the variable capacity compressors (114a, 114b) than the fixed capacity compressor (114c), as in the first embodiment. In the fixed capacity compressor (114c), since a sufficient injection amount can be secured, the temperature of the high-pressure refrigerant can be lowered.
  • the three compressors (21a, 21b, 21c) (114a, 114b, 114c) are provided in the external circuit (20).
  • the number of compressors is not limited to this. Two or four or more, and at least one of them may be a variable capacity compressor. Even in this case, the same effect can be obtained.
  • the said 2nd flow regulating valve (30b, 30c) was comprised with the electronic expansion valve with variable opening, it is not limited to this, As described in the modification of Embodiment 1, You may comprise with a solenoid valve which can be opened and closed freely. In this case, if the CV value when the solenoid valve is fully open is larger than the CV value when the opening of the first flow rate adjustment valve (30a) is fully open, all the flow rate adjustment valves (30a , 30b, 30c) is fully open, a large amount of intermediate pressure refrigerant may flow toward the second and third compressors (21b, 21c). Therefore, the CV value when the electromagnetic valve is fully opened is preferably smaller than the CV value when the opening of the first flow rate adjusting valve (30a) is fully opened.
  • the present invention is useful for a refrigeration apparatus having a plurality of compressors and performing a vapor compression refrigeration cycle.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)

Abstract

L'invention porte sur un dispositif de congélation (1) comprenant une pluralité de compresseurs formés par un compresseur à volume variable (21a) et des compresseurs à volume fixe (21b, 21c) qui sont reliés en parallèle les uns aux autres. Un orifice intermédiaire (5) du premier compresseur (21a), constituant le compresseur à volume variable, est formé avec un diamètre plus petit que ceux des orifices intermédiaires (6, 7) des deuxième et troisième compresseurs (21b, 21c), constituant les compresseurs à volume fixe, de telle sorte qu'un fluide frigorigène à pression intermédiaire d'un circuit d'injection peut être injecté dans tous les compresseurs (21a) et (21b, 21c) tout en supprimant le déséquilibre de la température de gaz d'évacuation frigorigène généré entre les compresseurs (21a) et (21b, 21c).
PCT/JP2009/002505 2008-06-03 2009-06-03 Dispositif de congélation WO2009147852A1 (fr)

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JP2008-145875 2008-06-03

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2320159A1 (fr) * 2008-07-31 2011-05-11 Daikin Industries, Ltd. Dispositif de réfrigération
JP2016171465A (ja) * 2015-03-12 2016-09-23 パナソニックＩｐマネジメント株式会社 運転状態管理装置
CN113654113A (zh) * 2021-08-10 2021-11-16 中山市爱美泰电器有限公司 一种具有除湿功能的热泵空调
US11796238B2 (en) * 2020-08-28 2023-10-24 Daikin Industries, Ltd. Heat source unit and refrigeration apparatus

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04222352A (ja) * 1990-12-21 1992-08-12 Daikin Ind Ltd 冷凍装置の運転制御装置
JPH0518613A (ja) * 1991-07-12 1993-01-26 Mitsubishi Electric Corp 冷凍サイクル装置
JPH1113664A (ja) * 1997-06-27 1999-01-19 Daikin Ind Ltd ロータリ圧縮機
JP2007178052A (ja) * 2005-12-27 2007-07-12 Daikin Ind Ltd 冷凍装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04222352A (ja) * 1990-12-21 1992-08-12 Daikin Ind Ltd 冷凍装置の運転制御装置
JPH0518613A (ja) * 1991-07-12 1993-01-26 Mitsubishi Electric Corp 冷凍サイクル装置
JPH1113664A (ja) * 1997-06-27 1999-01-19 Daikin Ind Ltd ロータリ圧縮機
JP2007178052A (ja) * 2005-12-27 2007-07-12 Daikin Ind Ltd 冷凍装置

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2320159A1 (fr) * 2008-07-31 2011-05-11 Daikin Industries, Ltd. Dispositif de réfrigération
EP2320159A4 (fr) * 2008-07-31 2017-04-05 Daikin Industries, Ltd. Dispositif de réfrigération
JP2016171465A (ja) * 2015-03-12 2016-09-23 パナソニックＩｐマネジメント株式会社 運転状態管理装置
US11796238B2 (en) * 2020-08-28 2023-10-24 Daikin Industries, Ltd. Heat source unit and refrigeration apparatus
CN113654113A (zh) * 2021-08-10 2021-11-16 中山市爱美泰电器有限公司 一种具有除湿功能的热泵空调

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