WO2007139010A1 - Dispositif frigorifique - Google Patents

Dispositif frigorifique Download PDF

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Publication number
WO2007139010A1
WO2007139010A1 PCT/JP2007/060688 JP2007060688W WO2007139010A1 WO 2007139010 A1 WO2007139010 A1 WO 2007139010A1 JP 2007060688 W JP2007060688 W JP 2007060688W WO 2007139010 A1 WO2007139010 A1 WO 2007139010A1
Authority
WO
WIPO (PCT)
Prior art keywords
heat exchanger
refrigerant
expansion valve
heating
indoor
Prior art date
Application number
PCT/JP2007/060688
Other languages
English (en)
Japanese (ja)
Inventor
Masaaki Takegami
Kazuyoshi Nomura
Azuma Kondo
Yoshinari Oda
Kenji Tanimoto
Original Assignee
Daikin Industries, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries, Ltd. filed Critical Daikin Industries, Ltd.
Priority to EP07744122.8A priority Critical patent/EP2023061B1/fr
Priority to US12/302,478 priority patent/US20090282848A1/en
Priority to CN2007800188127A priority patent/CN101449117B/zh
Publication of WO2007139010A1 publication Critical patent/WO2007139010A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
    • F24F3/06—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the arrangements for the supply of heat-exchange fluid for the subsequent treatment of primary air in the room units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63—Electronic processing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F5/00—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater
    • F24F5/0007—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater cooling apparatus specially adapted for use in air-conditioning
    • F24F5/001—Compression cycle type
    • 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
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0231—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units with simultaneous cooling and heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0233—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor 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
    • F25B2313/02743—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
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/031—Sensor arrangements
    • F25B2313/0314—Temperature sensors near the indoor heat exchanger
    • 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
    • F25B2400/19—Pumping down refrigerant from one part of the cycle to another part of the cycle, e.g. when the cycle is changed from cooling to heating, or before a defrost cycle is started
    • 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
    • F25B2400/22—Refrigeration systems for supermarkets
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2513—Expansion valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/04—Refrigerant level

Definitions

  • the present invention relates to a refrigeration apparatus having a plurality of utilization units, and particularly relates to measures against refrigerant stagnation in a calo heat heat exchanger in a dormant state.
  • the refrigeration apparatus of Patent Document 1 has one heat source side unit having a compressor and a heat source side heat exchanger, and each has a use side heat exchange (heating heat exchange) and an expansion valve. With a user-side unit.
  • each expansion valve is opened at a predetermined opening, so that heating operation can be performed individually in each use-side heat exchanger.
  • both expansion valves are opened, and the refrigerant is sent to both usage-side heat exchangers.
  • heat is released from the refrigerant flowing through each use side heat exchanger to the indoor air, and heating operation is performed in each use side heat exchanger.
  • the room corresponding to each use-side heat exchanger is heated.
  • the expansion valve corresponding to the user-side unit to be operated is opened, while the expansion valve corresponding to the user-side unit to be in a closed state is closed. ing.
  • the refrigerant is sent only to the operation side use side unit, and the room is heated only by the use side heat exchanger.
  • Patent Document 1 JP-A-8-159590
  • the present invention has been made in view of the strong point, and an object of the present invention is to reliably prevent the stagnation of the refrigerant in the utilization side heat exchanger that is in a dormant state.
  • a plurality of usage side units (12, 13, 14) are arranged in parallel with a heat source side unit (11) having a compressor (41, 42) and a heat source side heat exchanger (44).
  • a refrigerant circuit (20) configured to be connected, and at least one of the plurality of usage-side units (12, 13, 14) has a heating heat exchanger capable of performing a heating operation for releasing heat from the refrigerant (71) and a refrigeration apparatus provided with an expansion valve (72) corresponding to the heating heat exchanger (71).
  • the refrigeration apparatus includes a first control operation for fully closing or narrowing the opening of the expansion valve (72) to a small opening when the heating heat exchanger (71) is in a pause state.
  • a plurality of use side units (12, 13, 14) are connected in parallel to the heat source side unit (11), thereby forming a so-called multi-type refrigeration apparatus.
  • a vapor compression refrigeration cycle is performed by circulating the refrigerant.
  • the refrigerant evaporates or condenses in each of the usage-side units (12, 13, 3, 14), and these usage-side units (12, 13, 14) ), For example, indoor heating and cooling, or cooling inside the cabinet is performed individually.
  • the opening degree control means (101) performs the first control operation.
  • the expansion valve (72) corresponding to the heating and heat exchange (71) is fully closed or limited to a very small opening degree that is almost fully closed.
  • the expansion valve (72) is narrowed in this way, the refrigerant in the heating heat exchanger (71) gradually condenses, and the heating heat exchange. Liquid refrigerant accumulates in the vessel (71). As a result, in the heat exchanger (71) in the resting state, the refrigerant stagnation occurs.
  • the opening degree control means (101) of the present invention provides the second control in order to prevent the refrigerant from stagnation in the heating heat exchanger (71) after the end of the first control operation. Perform the action.
  • an index indicating the amount of refrigerant accumulated in the heating heat exchanger (71) is detected by a predetermined method. Based on this index, the opening of the expansion valve (72) is adjusted as appropriate.
  • the opening control means (101) increases the opening of the expansion valve (72).
  • the refrigerant accumulated in the heating heat exchanger (71) passes through the expansion valve (72) and is discharged to the outside of the use side unit (12).
  • the second invention is that in the refrigeration apparatus of the first invention, the first control operation of the opening control means (101) is an operation of fully closing the expansion valve (72). It is a feature.
  • the opening control means (101) when performing the operation of stopping the heating heat exchanger (71), performs the first control operation to fully close the expansion valve (72). As a result, the refrigerant does not flow to the use side unit (12) provided with the heating heat exchanger (71), so that much refrigerant is sent to the other use side units (13, 14). .
  • a third invention is the refrigeration apparatus of the first or second invention, wherein in the second control operation of the opening degree control means (101), the amount of refrigerant accumulated in the heating heat exchanger (71) is reduced.
  • the degree of supercooling of the refrigerant on the inlet side of the heating heat exchanger (71) or the degree of supercooling of the refrigerant in the heating heat exchanger (71) is used.
  • the degree of refrigerant subcooling is used as an index indicating the amount of refrigerant accumulated in the heating heat exchanger (71).
  • the liquid refrigerant when the refrigerant condenses in the heating heat exchanger (71) in the resting state and the liquid refrigerant accumulates in the heating heat exchanger (71), the liquid refrigerant further dissipates and enters a supercooled state. Therefore, by detecting the degree of supercooling of the refrigerant in the heating heat exchanger (71), it is possible to grasp the amount of refrigerant accumulated in the heating heat exchanger (71).
  • the liquid refrigerant when the liquid refrigerant has completely accumulated in the heating heat exchanger (71), the refrigerant may condense near the inlet of the heating heat exchanger (71), resulting in a supercooled state. Therefore, by detecting the degree of supercooling of the refrigerant on the inlet side of the heating heat exchanger (71), the amount of refrigerant accumulated in the heating heat exchanger (71) can be grasped.
  • a fourth invention is the refrigeration apparatus of the third invention, wherein, in the second control operation of the opening degree control means (101), the expansion valve (72) is continuously closed for a predetermined time or more. If this is the case, the expansion valve (72) is forcibly opened at a predetermined opening.
  • the opening degree control means (101) during the second control operation controls the opening degree of the expansion valve (72) V based on the degree of refrigerant supercooling.
  • the expansion valve (72) is forcibly opened.
  • the influence of the ambient temperature of the heating heat exchanger (71) is affected.
  • the amount of refrigerant in the heating heat exchanger (71) may not be obtained accurately.
  • the temperature differential force supercooling degree is calculated.
  • the ambient temperature of the heating heat exchanger (71) is relatively high, the temperature Thl detected by the sensor tends to increase.
  • the supercooling degree of the refrigerant detected by the sensor is reduced even though a large amount of refrigerant is actually sleeping in the heating heat exchanger (71). .
  • the expansion valve (72) may continue to be fully closed.
  • the expansion valve (72) is forcibly opened when the expansion valve (72) continues to be fully closed for a predetermined time or more during the second control operation.
  • the opening degree of the expansion valve (72) is preferably as small as possible!
  • a fifth invention is the refrigeration apparatus of the first invention, wherein the use side unit (13, 14) different from the use side unit (12) provided with the heating heat exchanger (71) includes a refrigerant.
  • the refrigerant circuit (20) is provided with a cooling heat exchanger (81, 91) capable of performing a cooling operation for absorbing heat from the air, and the refrigerant discharged from the compressor (41, 42) is supplied to the heating heat exchanger (71). ), After which heat is absorbed by the cooling heat exchanger (81, 91) and is sucked into the force compressor (41, 42).
  • the opening control means (101) During the second control operation, the heat recovery operation is temporarily performed when the index indicating the amount of refrigerant accumulated in the heating heat exchanger (71) continuously exceeds a specified value for a predetermined time or more. It is characterized by comprising control means (102)
  • a cooling heat exchanger (81, 91) is provided in another use side unit (13, 14) other than the use side unit (12) provided with the heating heat exchanger (71). It is done.
  • the cooling heat exchanger 0 cools the interior of the cabinet or the like by the refrigerant absorbing heat by aerodynamic force.
  • the refrigerant discharged from the compressor (41, 42) is sent in the order of the heating heat exchanger (71) and the cooling heat exchanger (81, 91), and the compressor (41, 42) The heat recovery operation to return to the suction side is possible.
  • the discharge refrigerant of the compressor (41, 42) is not sent to the heat source side heat exchanger (44) of the heat source side unit (11), and the discharge refrigerant is heated to the heating heat exchanger (71 ), While the condensed refrigerant is decompressed by the expansion valve (72) and then cooled by the cooling heat exchanger (81, 82). Freezing cycle is performed.
  • the operation control means (102) of the present invention performs the second control operation by the opening degree control means (101), the stagnation of the refrigerant in the heating heat exchanger (71) is not eliminated. !, Forcibly perform the heat recovery operation in the refrigerant circuit (20). As a result, since the refrigerant is actively sent into the heating heat exchanger (71), the stagnation of the refrigerant in the heating heat exchanger (71) is surely eliminated. At the same time, the refrigerant flowing out of the heating heat exchanger (71) and flowing through the cooling heat exchanger (81, 82) is used for the cooling operation of the cooling heat exchanger (81, 82). The invention's effect
  • the opening degree of the expansion valve (72) is reduced by the first control operation, and then the heating heat exchanger (71) 71)
  • a second control operation is performed to adjust the opening of the expansion valve (72) based on an index indicating the amount of refrigerant accumulated in the interior. Therefore, according to the present invention, by detecting the stagnation of the refrigerant in the heating heat exchanger (71), the opening degree of the expansion valve (72) is increased and accumulated in the heating heat exchanger (71).
  • the refrigerant can be sent to other users (13, 14). That is, according to the present invention, it is possible to reliably eliminate the stagnation of the refrigerant in the heating heat exchanger (71) in the dormant state, thereby reducing the capacity of the other use side units (13, 14). Can be avoided.
  • the opening degree of the expansion valve (72) can be reduced. For this reason, since the stagnation of the refrigerant in the heating heat exchanger (71) has already been eliminated, the refrigerant is not excessively sent to the heating heat exchanger (71). A sufficient amount of refrigerant sent to (13, 14) can be secured. Accordingly, it is possible to more effectively avoid a decrease in the capacity of the other use side units (13, 14).
  • the first control operation for fully closing the expansion valve (72) is performed when the heating and heat exchange (71) is suspended. Therefore, according to the present invention, it is possible to further increase the amount of refrigerant sent to the other use side units (13, 14), and to improve the capacity of the use side unit (13, 14). be able to.
  • the inlet side of the heating heat exchanger (71) is used using the degree of supercooling of the refrigerant inside the heating heat exchanger (71), Heat exchanger (71) The amount of refrigerant accumulated inside is detected. Therefore, according to the present invention, it is possible to easily grasp the stagnation of the refrigerant in the heating heat exchanger (71) using a temperature sensor, a pressure sensor, or the like provided in the refrigerant circuit (20).
  • the expansion valve in consideration of the fact that the degree of supercooling of the refrigerant is reduced due to the influence of the ambient temperature of the heating heat exchanger (71), the expansion valve is operated during the second control operation.
  • the expansion valve (72) is opened! /. Therefore, according to the present invention, it is possible to avoid that the expansion valve (72) remains closed despite the fact that the refrigerant is actually trapped in the heating heat exchanger (71). The refrigerant stagnation in the heating heat exchanger (71) can be surely eliminated.
  • the expansion valve (72 ) can be controlled.
  • the temperature of the refrigerant flowing on the inflow side and inside of the heating heat exchanger (71) is less affected by the ambient temperature of the heating heat exchanger (71).
  • the amount of refrigerant can be accurately detected.
  • the opening degree of the expansion valve (72) can be appropriately controlled according to the amount of refrigerant accumulated in the heating heat exchanger (71). Accordingly, the stagnation of the refrigerant in the heating heat exchanger (71) can be surely eliminated, and a sufficient amount of refrigerant can be secured to the other use side units (13, 14).
  • the heating heat exchanger even if the second control operation by the opening degree control means (101) is performed.
  • the heat recovery operation is performed in the refrigerant circuit (20). Therefore, according to the present invention, it is possible to eliminate the stagnation of the refrigerant in the heating heat exchanger (71) by sending the refrigerant into the heating heat exchanger (71). At this time, in the present invention, the refrigerant discharged from the compressor (41, 42) is not sent to the heat source side heat exchanger (44) or the like, but actively sent to the heating heat exchanger (71). Therefore, according to the present invention, the refrigerant in the heating heat exchanger (71) can be reliably discharged to the outside.
  • the refrigerant is evaporated by cooling heat exchange (81, 91) while discharging the refrigerant accumulated in the heating heat exchanger (71). That is, according to the present invention, it is possible to reliably eliminate the stagnation of the refrigerant in the heating heat exchanger (71) without stopping the cooling operation by the cooling heat exchanger (81, 91).
  • FIG. 1 is a piping system diagram of a refrigerant circuit of a refrigeration apparatus according to an embodiment.
  • FIG. 2 is a piping system diagram showing a refrigerant flow during cooling operation.
  • FIG. 3 is a piping system diagram showing the refrigerant flow during heating operation.
  • FIG. 4 is a piping system diagram showing a refrigerant flow immediately after the thermo-off operation of the indoor heat exchanger.
  • FIG. 5 is a flowchart showing a second control operation by the opening degree control means.
  • FIG. 6 is a flowchart showing the control operation of the operation control means.
  • FIG. 7 is a piping system diagram showing a refrigerant flow during heat recovery operation.
  • Air conditioning unit (Usage unit)
  • the refrigeration apparatus (10) is provided in a convenience store or the like, and performs cooling of a refrigerator and a freezer and air conditioning in a room at the same time.
  • the refrigeration apparatus (10) includes an outdoor unit (11), an air conditioning unit (12), and a cooling unit.
  • a warehouse showcase (13) and a frozen showcase (14) are provided.
  • the outdoor unit (11) is provided with an outdoor circuit (40) constituting a heat source side circuit.
  • the air conditioning unit (12) is provided with an air conditioning circuit (70) that constitutes a first use side circuit.
  • the refrigerated showcase (13) is provided with a refrigerated circuit (80) that constitutes a second use side circuit.
  • the refrigeration showcase (14) is provided with a refrigeration circuit (90) constituting a third user side circuit.
  • a refrigerant circuit (20) for performing a vapor compression refrigeration cycle is obtained by connecting a plurality of usage-side circuits (70, 80, 90) in parallel to the outdoor circuit (40). Composed!
  • the outdoor circuit (40) and each use side circuit (70, 80, 90) include a liquid side communication pipe (31), a first gas side communication pipe (32), and a second gas side communication pipe (33). Connected to each other by One end of the liquid side connecting pipe (31) is connected to the liquid side closing valve (21) of the outdoor circuit (40). The other end of the liquid side connection pipe (31) branches into three parts: the first liquid branch pipe (31a), the second liquid branch pipe (31b), and the third liquid branch pipe (3 lc).
  • the first liquid branch pipe (31a) is in the air conditioning circuit (70)
  • the second liquid branch pipe (31 b) is in the refrigeration circuit (80)
  • the third liquid branch pipe (31c) is in the refrigeration circuit (90). It is connected.
  • the first gas side communication pipe (32) has one end connected to the first gas side shut-off valve (22) of the outdoor circuit (40) and the other end connected to the air conditioning circuit (70).
  • One end of the second gas side communication pipe (33) is connected to the second gas side closing valve (23) of the outdoor circuit (40).
  • the other end of the second gas side connecting pipe (33) is branched into two parts, a first gas branch pipe (33a) and a second gas branch pipe (33b), and the first gas branch pipe (33a) ) Is connected to the refrigeration circuit (80), and the second gas branch pipe (33b) is connected to the refrigeration circuit (90).
  • the outdoor circuit (40) of the outdoor unit (11) includes three compressors (41, 42, 43) from 1 to 3, an outdoor heat exchanger (44), and a receiver (45). And an outdoor expansion valve (46) and three four-way switching valves (47, 48, 49) from first to third.
  • the first to third compressors (41, 42, 43) are high-pressure dome type scroll compressors.
  • the first compressor (41) constitutes a variable capacity compressor. That is, the first compressor (41) is configured such that the rotational speed is variable by inverter control.
  • the second compressor (42) and the third compressor (43) constitute a fixed capacity compressor having a constant rotational speed.
  • One end of the first suction pipe (51) is connected to the suction side of the first compressor (41).
  • the other end of the first suction pipe (51) is connected to the second gas side shut-off valve (23).
  • One end of a second suction pipe (52) is connected to the suction side of the second compressor (42).
  • the other end of the second suction pipe (52) is connected to the third four-way selector valve (49).
  • One end of a third suction pipe (53) is connected to the suction side of the third compressor (43).
  • the other end of the third suction pipe (53) is connected to the second four-way switching valve (48).
  • a first discharge pipe (54) is connected to the discharge side of the first compressor (41). The other end of the first discharge pipe (54) is connected to the first four-way switching valve (47) through a discharge pipe (57).
  • a second discharge pipe (55) is connected to the discharge side of the second compressor (42). The other end of the second discharge pipe (55) is connected to the discharge pipe (57).
  • a third discharge pipe (56) is connected to the discharge side of the third compressor (43). The other end of the third discharge pipe (56) is connected in the middle of the discharge pipe (57).
  • the outdoor heat exchanger (44) is a fin-and-tube heat exchanger of a cross fin type and constitutes heat source side heat exchange.
  • An outdoor fan (50) is provided near the outdoor heat exchanger (44). In this outdoor heat exchange (44), heat is exchanged between the outdoor air blown by the outdoor fan (50) and the refrigerant.
  • One end of the outdoor heat exchanger (44) is connected to the first four-way selector valve (47).
  • the other end of the outdoor heat exchanger (44) is connected to the top of the receiver (45) via the first liquid pipe (58).
  • the bottom of the receiver (45) is connected to the liquid side stop valve (21) via the second liquid pipe (59).
  • first bypass pipe (60) In the middle of the first liquid pipe (58), one ends of a first bypass pipe (60) and a second bypass pipe (61) are respectively connected. The other ends of the first bypass pipe (60) and the second bypass pipe (62) are connected to the second liquid pipe (59), respectively.
  • the first bypass pipe (60) is provided with the outdoor expansion valve (46).
  • the outdoor expansion valve (46) is an electronic expansion valve whose opening degree is adjustable.
  • One end of the liquid injection pipe (62) is connected to the middle of the second bypass pipe (61).
  • the other end of the liquid injection pipe (62) is connected to the middle of the first suction pipe (51).
  • the liquid injection pipe (62) is provided with a flow rate adjusting valve (63) whose opening degree can be adjusted.
  • the four-way switching valves (47, 48, 49) from the first to the third are respectively the first to the fourth. Has a port.
  • the first port is the discharge pipe (57)
  • the second port is the fourth port of the second four-way selector valve (48)
  • the third port is the outdoor heat exchanger ( 44)
  • the 4th port is connected to the 1st gas side stop valve (22), respectively.
  • the second four-way selector valve (48) the first port is connected to the third discharge pipe (56) and the second port is connected to the third suction pipe (53), while the third port is closed. Yes.
  • the first port is closed, while the second port is connected to the second suction pipe (52), the third port is connected to the third suction pipe (53), and the fourth port is connected. Are connected to the first suction pipe (51).
  • Each four-way switching valve (47, 48, 49) is in a first state (first port and third port communicate with each other, and second port and fourth port communicate with each other). (The state indicated by the solid line in Fig. 1) and the second state where the first port and the fourth port communicate with each other and the second port and the third port communicate with each other (the state indicated by the broken line in Fig. 1) And can be switched to each other.
  • the first suction pipe (51) has a first suction temperature sensor (111) and a first suction pressure sensor (112), and the third suction pipe (53) has a second suction temperature sensor (113) and A second suction pressure sensor (114) is provided for each.
  • the first discharge pipe (54) has a first high pressure switch (115), the second discharge pipe (55) has a second high pressure switch (116), and the third discharge pipe (56) has a third high pressure switch.
  • a pressure switch (117) is provided for each.
  • the discharge pipe (57) is provided with a first discharge temperature sensor (118) and a first discharge pressure sensor (119), and the third discharge pipe (56) is provided with a second discharge temperature sensor (120).
  • the outdoor heat exchanger (44) is provided with an outdoor refrigerant temperature sensor (121) in its heat transfer tube.
  • An outdoor temperature sensor (122) is provided in the vicinity of the outdoor heat exchanger (44).
  • the outdoor circuit (40) is also provided with a plurality of check valves that allow the refrigerant to flow in one direction but prohibit the refrigerant from flowing in the opposite direction.
  • a check valve (CV-1) is provided in the pipe between the first suction pipe (51) and the second suction pipe (52), and the second suction pipe (52) and the third suction pipe (53).
  • a check valve (CV-2) is provided in each pipe between the two.
  • the second discharge pipe (55) is provided with a check valve (CV-3), and the third discharge pipe (56) is provided with a fourth check valve (CV-4).
  • the first liquid pipe (58) has a check valve (CV-5), the second liquid pipe (59) has a check valve (CV-6), and the second bypass pipe (61) has a check valve.
  • Each valve (CV-7) is provided.
  • These check valves (CV-l, CV-2, ---) is configured to allow only the refrigerant to flow in the direction of the arrow attached to the check valve symbol in FIG.
  • the air conditioning circuit (70) of the air conditioning unit (12) is provided with an indoor heat exchanger (71) and an indoor expansion valve (72).
  • the indoor heat exchanger (71) is a fin-and-tube heat exchanger of the cross fin type and constitutes a first use side heat exchanger.
  • the indoor heat exchanger (71) constitutes a heating heat exchanger capable of performing a heating operation for releasing heat from the refrigerant.
  • An indoor fan (73) is provided in the vicinity of the indoor heat exchanger (71). In this indoor heat exchange (71), heat is exchanged between the indoor air blown by the indoor fan (73) and the refrigerant.
  • the indoor expansion valve (72) is an electronic expansion valve whose opening degree can be adjusted by a pulse motor.
  • the first refrigerant temperature sensor (123) is connected to the pipe between the first gas side communication pipe (32) and the indoor heat exchanger (71), and the indoor heat exchanger (71).
  • a second refrigerant temperature sensor (124) is provided for each heat transfer officer.
  • an indoor temperature sensor (125) is provided near the indoor heat exchanger (71).
  • the refrigeration circuit (80) of the refrigerated showcase (13) is provided with a refrigeration heat exchanger (81) and a refrigeration expansion valve (82).
  • the refrigerated heat exchanger (81) is a fin-and-tube type heat exchanger of the cross fin type and constitutes the second usage side heat exchanger. Further, the refrigeration heat exchanger (81) constitutes a cooling heat exchanger in which the refrigerant absorbs aerodynamic force and cools the inside of the warehouse.
  • a refrigeration fan (83) is provided in the vicinity of the refrigeration heat exchanger (81). In this refrigeration heat exchanger (81), heat is exchanged between the internal air blown by the refrigeration fan (83) and the refrigerant.
  • a first outlet refrigerant temperature sensor (126) is provided on the outflow side of the refrigeration heat exchanger (81).
  • the refrigeration expansion valve (82) is a temperature-sensitive expansion valve whose opening degree is adjusted according to the temperature detected by the first outlet refrigerant temperature sensor (126).
  • a first solenoid valve (SV-1) whose opening degree can be freely opened and closed is provided.
  • the temperature of the air inside the refrigerated showcase (13) is detected.
  • a first internal temperature sensor (127) is provided.
  • the refrigeration circuit (90) of the refrigeration showcase (14) is provided with a refrigeration heat exchanger (91), a refrigeration expansion valve (92), and a booster compressor (94).
  • the refrigeration heat exchanger (91) is a cross-fin type fin-and-tube heat exchanger, and constitutes a third use side heat exchanger.
  • the refrigeration heat exchanger (91) constitutes a cooling heat exchange in which the refrigerant absorbs heat from the air and cools the interior of the refrigerator.
  • a freezing fan (93) is provided in the vicinity of the freezing heat exchange (91). In the refrigeration heat exchanger (91), heat is exchanged between the internal air blown by the refrigeration fan (93) and the refrigerant.
  • the second outlet refrigerant temperature sensor (128) is provided on the outflow side of the refrigeration heat exchanger (91).
  • the refrigeration expansion valve (92) is a temperature-sensitive expansion valve whose opening degree is adjusted according to the temperature detected by the second outlet refrigerant temperature sensor (128).
  • a second solenoid valve (SV-2) whose opening degree can be freely opened and closed is provided.
  • a second internal temperature sensor (129) for detecting the temperature of the internal air in the freezer showcase (14) is provided in the vicinity of the refrigeration heat exchanger (91).
  • the booster compressor (94) is a high-pressure dome type scroll compressor, and constitutes a variable capacity compressor.
  • a fourth suction pipe (95) is connected to the suction side of the booster compressor (94), and a fourth discharge pipe (96) is connected to the discharge side.
  • the fourth discharge pipe (96) is provided with a fourth high pressure switch (130), an oil separator (97), and a check valve (CV-8).
  • the oil separator (98) for returning the refrigeration oil separated from the refrigerant to the suction side of the booster compressor (94) is connected to the oil separator (97).
  • This oil return officer (98) is equipped with a single tube (98a)!
  • the refrigeration circuit (90) is also provided with a third bypass pipe (99) for connecting the fourth suction pipe (95) and the fourth discharge pipe (96).
  • the third bypass pipe (99) is provided with a check valve (CV-9).
  • the third bypass pipe (99) bypasses the booster compressor (94) to the fourth discharge pipe (96) by allowing the refrigerant flowing through the fourth suction pipe (95) to bypass the booster compressor (94) when the booster compressor (94) fails. It is configured to send.
  • the refrigeration apparatus (10) is provided with a controller (100) for controlling each control target device provided in the refrigerant circuit (20).
  • the controller (100) is configured to be able to receive signals from each sensor provided in the refrigerant circuit (20). Then, the controller (100) performs operation control of each compressor, switching control of each four-way switching valve, and the like in accordance with the signals of these sensors.
  • the controller (100) is provided with opening control means (101) and operation control means (102), which are features of the present invention.
  • the opening control means (101) and the operation control means (102) are means for preventing refrigerant from accumulating in the indoor heat exchanger (71) when the heating operation of the indoor heat exchanger (71) is stopped. Configure. Details of the control operations by the opening degree control means (101) and the operation control means (102) will be described later.
  • the air conditioning unit (12) cools the interior of the room, and the storage of each showcase (13, 14). While cooling the interior, it is possible to perform a heating operation that heats the room with an air conditioning unit (12).
  • the first four-way switching valve (47), the second four-way switching valve (48), and the third four-way switching valve (49) are set to the first state.
  • the outdoor expansion valve (46) and the flow rate adjustment valve (63) are fully closed, and the first solenoid valve (SV-1) and the second solenoid valve (SV-2) are opened.
  • the opening degrees of the indoor expansion valve (72), the refrigeration expansion valve (82), and the refrigeration expansion valve (92) are adjusted as appropriate.
  • the fans (50, 73, 83, 93), the first to third compressors (41, 42, 43), and the booster compressor (94) are in operation.
  • the refrigerant compressed by the first to third compressors (41, 42, 43) joins at the discharge pipe (57) and then passes through the first four-way switching valve (47). Flows through the outdoor heat exchanger (44). In the outdoor heat exchanger (44), the refrigerant dissipates heat to the outdoor air and condenses.
  • the refrigerant condensed in the outdoor heat exchanger (44) flows through the first liquid pipe (58), the receiver (45), and the second liquid pipe (59) in this order, and flows into the liquid side connecting pipe (31).
  • the refrigerant flowing into the liquid side connection pipe (31) flows into the first liquid branch pipe (31a) and the second liquid It is divided into the branch pipe (31b) and the third liquid branch pipe (31c).
  • the refrigerant flowing into the first liquid branch pipe (31a) is decompressed when passing through the indoor expansion valve (72), and then flows through the indoor heat exchanger (71).
  • the indoor heat exchanger (71) the refrigerant absorbs heat from the indoor air and evaporates. As a result, the room is cooled.
  • the refrigerant evaporated in the indoor heat exchanger (71) flows into the first gas-side connecting pipe (32), the first four-way switching valve (47), the second four-way switching valve (48), and the third suction pipe ( 53) in order and sucked into the third compressor (43).
  • the refrigerant flowing into the second liquid branch pipe (31b) is depressurized when passing through the refrigeration expansion valve (82), and then flows through the refrigeration heat exchanger (81).
  • the refrigerant absorbs heat from the internal air and evaporates.
  • the inside of the refrigerator showcase (13) is cooled.
  • the inside temperature is maintained at 5 ° C.
  • the refrigerant evaporated in the refrigeration heat exchanger (81) flows into the first gas branch pipe (33a).
  • the refrigerant flowing into the third liquid branch pipe (31c) is reduced in pressure when passing through the refrigeration expansion valve (92), and then flows through the refrigeration heat exchanger (91).
  • the refrigerant absorbs heat from the internal air and evaporates.
  • the inside of the freezer showcase (14) is cooled.
  • the internal temperature is maintained at -10 ° C.
  • the refrigerant evaporated in the refrigeration heat exchanger (91) is compressed by the booster compressor (94) and then flows into the second gas branch pipe (33b).
  • the refrigerant combined in the second gas side communication pipe (33) is again divided into the first suction pipe (51) and the second suction pipe (52), and then the first compressor (41) and the second Each is sucked into the compressor (42).
  • the first four-way switching valve (47) and the second four-way switching valve (48) are set to the second state, and the third four-way switching valve (49) is set to the first state.
  • the outdoor expansion valve (46) and the flow rate adjustment valve (63) are fully closed, and the first solenoid valve (SV-1) and the second solenoid valve (SV-2) are opened.
  • the opening degrees of the indoor expansion valve (72), the refrigeration expansion valve (82), and the refrigeration expansion valve (92) are adjusted as appropriate.
  • the fans (50, 73, 83, 93), the first compressor (41), the second compressor (42), and the booster compressor (94) are in operation.
  • the refrigerant compressed in each of the first compressor (41) and the second compressor (42) is discharged into a discharge pipe (57 ) And then split again into two hands.
  • One refrigerant passes through the second four-way switching valve (48) and condenses through the outdoor heat exchanger (44), and is condensed into the first liquid pipe (58), the receiver (45), and the second liquid pipe (59 ) In order and flows into the liquid side connecting pipe (31).
  • the other refrigerant passes through the first four-way selector valve (47) and flows through the indoor heat exchanger (71).
  • the indoor heat exchanger (71) the refrigerant dissipates heat to the indoor air and condenses. As a result, the room is heated.
  • the refrigerant condensed in the indoor heat exchanger (71) is depressurized when passing through the indoor expansion valve (72), and then flows into the first liquid branch pipe (31a).
  • the refrigerant merged in the liquid side connecting pipe (31) is divided again into the second liquid branch pipe (31b) and the third liquid branch pipe (31c).
  • the refrigerant flowing into the second liquid branch pipe (31b) is used for cooling the inside of the refrigerated showcase (13) in the same manner as the cooling operation described above.
  • the refrigerant flowing into the third liquid branch pipe (31c) is used for cooling the inside of the freezer showcase (14) in the same manner as the cooling operation described above.
  • the refrigerant used for cooling the interior of each showcase (13, 14) joins the second gas side connecting pipe (33), and then enters the first compressor (41) and the second compressor (42). Each is inhaled.
  • the heating operation by the indoor heat exchanger (71) may be unnecessary. Therefore, in the refrigeration apparatus (10), during the heating operation described above, when a predetermined condition is satisfied, a first control operation (thermo-off operation) is performed in which the indoor heat exchange (71) is temporarily suspended.
  • the opening control means (101) of the controller (100) narrows down the opening of the indoor expansion valve (72). Close.
  • the refrigerant discharged from the first compressor (41) and the second compressor (42) is generally sent to the outdoor heat exchanger (44) side.
  • the refrigerant condensed in the outdoor heat exchanger (44) is sent to each showcase (13, 14) through the same flow path as in the heating operation described above, and is stored in the storage of each showcase (13, 14). Used for cooling.
  • the indoor expansion valve (72) is fully closed as described above, but the gas side of the indoor heat exchanger (71) is also at this time. It remains in communication with the coolant circulation path. For this reason, after this thermo-off operation, the refrigerant enters the indoor heat exchanger (71) and gradually condenses, and the condensed liquid refrigerant gradually accumulates in the indoor heat exchanger (71). That is, in the indoor heat exchanger (71) in the thermo-off state, there is a risk that so-called refrigerant stagnation occurs.
  • the opening control means (101) of this embodiment sets the opening of the indoor expansion valve (72) after the indoor expansion valve (72) is fully closed when the air conditioning unit (12) is thermo-off.
  • the stagnation of the refrigerant in the indoor heat exchanger (71) is eliminated by performing an opening degree control operation (second control operation) that is appropriately adjusted.
  • step S1 it is determined whether or not there is a sufficient amount of refrigerant accumulated in the indoor heat exchanger (71). Specifically, in step S1, the high pressure equivalent saturation temperature Pc obtained from the detection values of the first discharge temperature sensor (118) and the first discharge pressure sensor (119) and the first refrigerant temperature sensor (123) are detected. The temperature difference (Pc – Thl) from the measured refrigerant temperature Thl is calculated. That is, in step S1, the degree of refrigerant supercooling (Pc-Thl) in the vicinity of the inlet of the indoor heat exchanger (71) is calculated.
  • the degree of cooling (Pc— Thl) also increases. That is, the degree of refrigerant supercooling (Pc ⁇ Thl) is an index indicating the amount of refrigerant in the indoor heat exchanger (71). Therefore, if the degree of supercooling (Pc—TH1) is greater than T1 ° C (eg 2 ° C) in step S1, a large amount of refrigerant is present in the indoor heat exchanger (71). It is determined that it has accumulated, and the process proceeds to step S2.
  • step S2 the current opening of the indoor expansion valve (72) is increased by a predetermined pulse (for example, 352 pulses).
  • a predetermined pulse for example, 352 pulses.
  • step S1 when the degree of supercooling (Pc ⁇ Thl) of the refrigerant is equal to or lower than T1 ° C., the process proceeds from step S1 to step S3. In step S3, it is determined whether or not the refrigerant stagnation in the indoor heat exchanger (71) has been eliminated.
  • step S3 if the supercooling degree (Pc—Thl) of the refrigerant on the inflow side of the indoor heat exchanger (71) continues for tl minutes (for example, 3 minutes) or more and is T1 ° C or less, It is determined that the refrigerant hardly accumulates in the alternating current ⁇ (71), and the process proceeds to step S4. As a result, the indoor expansion valve (72) is fully closed.
  • step S3 a temperature difference (Pc-Th2) between the equivalent saturated temperature Pc of high pressure and the refrigerant temperature Th2 detected by the second refrigerant temperature sensor (124) is also calculated. That is, in step S3, the degree of supercooling (Pc—Th2) of the refrigerant immediately before the outlet in the indoor heat exchanger (71) is also calculated. Even when the degree of supercooling (Pc-Th2) continues for t2 minutes (for example, 2 minutes) or less and is less than T2 ° C (for example, 5 ° C), the liquid refrigerant in the indoor heat exchanger (71) It is determined that there is almost no accumulation and moves to step S4. As a result, the indoor expansion valve (72) is fully closed. On the other hand, if the difference between the above two conditions does not hold for step S3, the opening of the indoor expansion valve (72) is maintained at the current opening.
  • the refrigerant amount in the indoor heat exchanger (71) using the degree of supercooling of the refrigerant in Step S1 and Step S3 described above the refrigerant amount may not be obtained accurately. Specifically, for example, when the indoor fan (73) is stopped simultaneously with the start of the thermo-off operation, the ambient temperature of the indoor heat exchanger (71) becomes a relatively high temperature. On the other hand, in such a state, the temperature detected by the first refrigerant temperature sensor (123) and the second refrigerant temperature sensor (124) is also affected by the temperature around the indoor heat exchanger (71), and is less than the actual refrigerant temperature. Is also likely to be high! For this reason, in Step S1 and Step S3, although the refrigerant is actually accumulated in the indoor heat exchanger (71), the degree of supercooling of the refrigerant becomes a small value and the indoor expansion The valve (72) may remain fully closed.
  • step S5 the indoor expansion valve (72) is in the fully closed state for more than t3 minutes (for example, 20 minutes) in step S5, the indoor heat exchange (71) If the amount of the refrigerant is accurately detected, the process proceeds to step S6 as there is a possibility.
  • step S6 the opening of the indoor expansion valve (72) is opened at a predetermined opening (for example, 352 pulses). As a result, if the refrigerant has accumulated in the indoor heat exchanger (71), the refrigerant is quickly discharged outside the indoor heat exchanger (71)!
  • the amount of refrigerant in the indoor heat exchanger (71) is accurately determined in the subsequent determination in step S1 and step S3. It becomes easier to detect. That is, after step S6 is completed, the refrigerant is successively sent into the indoor heat exchanger (71), so that the refrigerant flowing through the indoor heat exchanger (71) is difficult to receive the ambient temperature. For this reason, it is avoided that the supercooling degree of the refrigerant becomes a small value due to the ambient temperature. Therefore, in the subsequent determinations in step S1 and step S3, the amount of refrigerant in the indoor heat exchanger (71) can be accurately detected, and the opening degree of the indoor expansion valve (72) can be controlled.
  • the above steps S1 to S6 are repeated, and the indoor expansion is performed according to the amount of refrigerant accumulated in the indoor heat exchanger (71) in the thermo-off state.
  • the opening degree of the valve (72) is appropriately adjusted. As a result, the stagnation of the refrigerant in the indoor heat exchanger (71) is eliminated, and the cooling capacity of the refrigerated heat exchanger (81) and the refrigeration heat exchanger (91) may be reduced. To be avoided.
  • the stagnation of the refrigerant in the indoor heat exchanger (71) may not be eliminated even if the opening degree control operation described above is performed after the thermo-off operation of the indoor heat exchanger (71).
  • the air conditioning unit (12) is installed at a relatively high position with respect to the outdoor unit (11) of the refrigeration system (10), and the space between the outdoor unit (11) and the air conditioning unit (12) is reached. If the head difference of the first connection pipe (first gas side connection pipe (32)) is large, the opening degree of the indoor expansion valve (72) is fully opened (for example, 2000 pulses) by the opening degree control operation described above.
  • the refrigerant discharged from each compressor (41, 42) is forced to the outdoor heat exchanger (44) side, and the refrigerant accumulated in the indoor heat exchanger (71) cannot be sufficiently discharged! / There is a fear. Therefore, in the refrigeration apparatus (10) of the present embodiment, after the indoor heat exchanger (71) is in the thermo-off state during heating operation, the indoor heat exchanger ( 71) If the refrigerant stagnation is not eliminated, the operation control means (102) of the controller (100) performs the following control operation.
  • step S11 it is determined whether or not the stagnation of the refrigerant in the indoor heat exchanger (71) has yet to be resolved. Specifically, go to step S11! If the refrigerant supercooling degree (Pc-Thl) on the inlet side of the indoor heat exchanger (71) continues for more than t4 minutes (for example, 20 minutes) and is greater than T1 ° C, the indoor heat exchanger It is determined that the refrigerant stagnation in (71) has not yet been eliminated, and the process proceeds to step S12. As a result, in the refrigeration apparatus (10), the following heat recovery operation is performed.
  • Pc-Thl refrigerant supercooling degree
  • the first four-way selector valve (47) is set to the second state, and the second four-way selector valve (48) and the third four-way selector valve (49) are set to the first state. Is done. Also, the outdoor expansion valve (46) and the flow rate adjustment valve (63) are fully closed, and the first solenoid valve (SV-1) and the second solenoid valve (SV-2) are opened. Further, the opening degrees of the indoor expansion valve (72), the refrigeration expansion valve (82), and the refrigeration expansion valve (92) are adjusted as appropriate. Also, the fans (50, 73, 83, 93), the first compressor (41), the second compressor (42), and the booster compressor (94) are in operation.
  • Refrigerant compressed by the first compressor (41) and the second compressor (42) respectively joins at the discharge pipe (57), and then passes through the first four-way switching valve (47) to pass through the room.
  • the indoor heat exchanger (71) the refrigerant accumulated inside is pumped by the high-pressure refrigerant and discharged to the outside of the indoor heat exchanger (71).
  • the heating operation is temporarily performed in the indoor heat exchanger (71).
  • the refrigerant flowing out of the indoor heat exchanger (71) is decompressed when passing through the indoor expansion valve (72), and then flows into the first liquid branch pipe (31a).
  • the refrigerant flowing into the first liquid branch pipe (31a) is divided into the second liquid branch pipe (31b) and the third liquid branch pipe (31c).
  • the refrigerant flowing into the second liquid branch pipe (31b) is used for cooling the inside of the refrigerator showcase (13).
  • the refrigerant flowing into the third liquid branch pipe (31c) is used for cooling the inside of the freezer showcase (14).
  • the refrigerant used for cooling the interior of each showcase (13, 14) joins the second gas side connecting pipe (33), and then enters the first compressor (41) and the second compressor (42). That Each is inhaled.
  • the refrigerant discharged from the first compressor (41) and the second compressor (42) is sent only to the air conditioning unit (12) side.
  • the high-pressure refrigerant can be reliably sent to the air conditioning unit (12) even in an installation situation where the head unit to the outdoor unit (11) force air conditioning unit (12) is large.
  • the refrigerant accumulated in the indoor heat exchanger (71) is reliably discharged from the air conditioning unit (12) and used for cooling the interior of each showcase (13, 14). .
  • step S13 of Fig. 6 it is determined whether or not the stagnation of the refrigerant is eliminated in the indoor heat exchanger (71). Specifically, in step S13, if the degree of supercooling (Pc-Th2) of the refrigerant in the indoor heat exchanger (71) continues for more than t5 minutes (for example, 2 minutes) and is less than T2 ° C, Is determined to have been eliminated, and the process proceeds to step S14. As a result, in step S14, the heat recovery operation is completed, and the indoor heat exchanger (71) is turned off again. In Step S14, when the heat recovery operation is continued for t6 minutes (for example, 3 minutes) or longer, it is considered that the stagnation of the refrigerant is surely eliminated, and the process proceeds to Step S14.
  • Pc-Th2 degree of supercooling
  • the indoor heat exchanger (71) after the indoor heat exchanger (71) is in the thermo-off state during the heating operation, it is based on an index (degree of refrigerant subcooling) indicating the amount of refrigerant accumulated in the indoor heat exchanger (71).
  • the opening control operation for adjusting the opening of the indoor expansion valve (72) is performed. Specifically, in this opening degree control operation, when the amount of refrigerant accumulated in the indoor heat exchanger (71) increases, the opening degree of the indoor expansion valve (72) is increased.
  • the refrigerant accumulated in the indoor heat exchanger (71) can be appropriately discharged to the outside and sent to the refrigerated showcase (13) and the refrigerated showcase (14). Accordingly, it is possible to reliably eliminate the stagnation of the refrigerant in the indoor heat exchanger (71) in the thermo-off state, thereby avoiding a decrease in the cooling capacity in the storage of each showcase (13, 14). Can do.
  • the opening degree of the expansion valve (72) is reduced when the amount of refrigerant accumulated in the indoor heat exchanger (71) is small. Therefore, according to the above embodiment, the chamber Even though the refrigerant stagnation in the internal heat exchanger (71) has already been eliminated, the refrigerant will not be sent excessively to the indoor heat exchanger (71), so each showcase (13, 14) A sufficient amount of refrigerant to be sent can be secured. Accordingly, it is possible to more effectively avoid a decrease in the cooling capacity in the cabinet of each showcase (13, 14).
  • the amount of refrigerant accumulated in the indoor heat exchanger (71) using the degree of supercooling of the refrigerant on the inlet side or inside of the indoor heat exchanger (71). Is detected. For this reason, according to the above embodiment, the stagnation of the refrigerant in the indoor heat exchanger (71) can be grasped relatively easily.
  • the indoor expansion valve (71) is taken into consideration that the degree of supercooling of the refrigerant is reduced due to the influence of the ambient temperature of the indoor heat exchanger (71).
  • the indoor expansion valve (72) is opened when 72) has been fully closed for a predetermined time or longer. Therefore, according to the above-described embodiment, the indoor expansion valve (72) remains in a closed state even though the refrigerant is actually stagnant in the indoor heat exchanger (71). It is possible to avoid the refrigerant stagnation in the indoor heat exchanger (71).
  • the opening degree of the expansion valve (72) can be appropriately controlled according to the amount of refrigerant accumulated in the indoor heat exchanger (71). Therefore, it is possible to reliably eliminate the stagnation of the refrigerant in the indoor heat exchanger (71) and to secure a sufficient amount of the refrigerant to be sent to each showcase (13, 14).
  • heat recovery operation is performed in the refrigerant circuit (20).
  • the full amount of refrigerant discharged from each compressor (41, 42) is sent to the indoor heat exchanger (71) side. Therefore, according to the above-described embodiment, the refrigerant discharged from the compressor (41, 42) is discharged to the indoor heat exchanger even when the head difference of the communication piping from the outdoor unit (11) to the air conditioning unit (12) is relatively large. (71) can be reliably sent to the indoor heat exchanger (71) Can be resolved.
  • one air conditioning unit (12) is connected to the outdoor unit (11).
  • a plurality of air conditioning units of this type may be connected to the outdoor unit (11).
  • the refrigerant stagnation in each indoor heat exchanger can be eliminated by performing the above-described opening control operation after thermo-off each indoor heat exchange of each air conditioning unit.
  • the indoor expansion valve (72) is fully closed as a thermo-off operation of the indoor heat exchanger (71) during the heating operation.
  • the indoor expansion valve (72) may be narrowed to a very small opening degree. Also in this case, since the refrigerant accumulates in the indoor heat exchanger (71) thereafter, the stagnation of the refrigerant can be eliminated by performing the opening degree control operation described above.
  • the amount of the refrigerant accumulated in the indoor heat exchanger (71) in the thermo-off state is obtained as the supercooling degree force of the refrigerant on the inflow side of the indoor heat exchanger (71) or inside. ing.
  • the amount of refrigerant accumulated in the indoor heat exchange (71) may be obtained by other methods.
  • the present invention is useful for measures against refrigerant stagnation in a heat exchanger that is in a dormant state for a refrigeration apparatus having a plurality of utilization units.

Abstract

La présente invention concerne un dispositif frigorifique comprenant, dans un circuit de réfrigération (20), une unité de climatiseur (12), une vitrine réfrigérée (13) et une vitrine négative (14), parallèlement connectées à une unité d'extérieur (11). Pour faire passer un échangeur de chaleur d'intérieur (71) de l'unité de climatiseur (12) à un état éteint (thermo-off), un moyen de commande du degré d'ouverture (101) ferme complètement un détendeur d'intérieur (72). Après cela, le moyen de commande du degré d'ouverture (101) détecte la quantité de fluide frigorigène restant dans l'échangeur de chaleur d'intérieur (71), et règle le degré d'ouverture du détendeur d'intérieur (72) en fonction de la quantité de fluide frigorigène.
PCT/JP2007/060688 2006-05-26 2007-05-25 Dispositif frigorifique WO2007139010A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP07744122.8A EP2023061B1 (fr) 2006-05-26 2007-05-25 Système de réfrigération
US12/302,478 US20090282848A1 (en) 2006-05-26 2007-05-25 Refrigeration system
CN2007800188127A CN101449117B (zh) 2006-05-26 2007-05-25 冷冻装置

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2006146923A JP4069947B2 (ja) 2006-05-26 2006-05-26 冷凍装置
JP2006-146923 2006-05-26

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JP5240332B2 (ja) * 2011-09-01 2013-07-17 ダイキン工業株式会社 冷凍装置
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CN103033007B (zh) * 2011-09-29 2015-11-18 杭州三花研究院有限公司 一种汽车空调系统电子膨胀阀的控制方法
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JP5741512B2 (ja) * 2012-04-05 2015-07-01 ダイキン工業株式会社 空気調和機
JP6064412B2 (ja) * 2012-07-30 2017-01-25 株式会社富士通ゼネラル 空気調和装置
US9669346B2 (en) * 2014-05-28 2017-06-06 Ingersoll-Rand Company Compressor system and oil separation system
JP2016003848A (ja) * 2014-06-19 2016-01-12 日立アプライアンス株式会社 空気調和システムおよびその制御方法
KR101591188B1 (ko) * 2014-07-07 2016-02-18 엘지전자 주식회사 축열식 공조장치 및 그 제어방법
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JP2019086251A (ja) * 2017-11-09 2019-06-06 三菱重工サーマルシステムズ株式会社 マルチ型空気調和装置の制御装置、マルチ型空気調和装置、マルチ型空気調和装置の制御方法及びマルチ型空気調和装置の制御プログラム
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JP2009293899A (ja) * 2008-06-09 2009-12-17 Daikin Ind Ltd 冷凍装置

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KR20090009315A (ko) 2009-01-22
EP2023061B1 (fr) 2017-09-27
US20090282848A1 (en) 2009-11-19
JP2007315702A (ja) 2007-12-06
EP2023061A1 (fr) 2009-02-11
CN101449117A (zh) 2009-06-03
EP2023061A4 (fr) 2014-04-02
CN101449117B (zh) 2010-10-20
TW200809151A (en) 2008-02-16

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