US20190017730A1 - Refrigerating machine and control method thereof - Google Patents
Refrigerating machine and control method thereof Download PDFInfo
- Publication number
- US20190017730A1 US20190017730A1 US16/065,918 US201716065918A US2019017730A1 US 20190017730 A1 US20190017730 A1 US 20190017730A1 US 201716065918 A US201716065918 A US 201716065918A US 2019017730 A1 US2019017730 A1 US 2019017730A1
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- Prior art keywords
- refrigerant
- condenser
- expansion valve
- economizer
- liquid refrigerant
- Prior art date
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- Abandoned
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- 238000000034 method Methods 0.000 title claims description 12
- 239000003507 refrigerant Substances 0.000 claims abstract description 211
- 239000007788 liquid Substances 0.000 claims abstract description 74
- 238000011144 upstream manufacturing Methods 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 27
- 239000007789 gas Substances 0.000 description 20
- 230000007423 decrease Effects 0.000 description 12
- 239000000498 cooling water Substances 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 238000001704 evaporation Methods 0.000 description 7
- 230000008020 evaporation Effects 0.000 description 7
- 238000000926 separation method Methods 0.000 description 6
- 239000003595 mist Substances 0.000 description 4
- 238000001931 thermography Methods 0.000 description 4
- LVGUZGTVOIAKKC-UHFFFAOYSA-N 1,1,1,2-tetrafluoroethane Chemical compound FCC(F)(F)F LVGUZGTVOIAKKC-UHFFFAOYSA-N 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- CDOOAUSHHFGWSA-OWOJBTEDSA-N (e)-1,3,3,3-tetrafluoroprop-1-ene Chemical compound F\C=C\C(F)(F)F CDOOAUSHHFGWSA-OWOJBTEDSA-N 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000000112 cooling gas Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005057 refrigeration Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000004781 supercooling Methods 0.000 description 1
Images
Classifications
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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
- F25B1/04—Compression machines, plants or systems with non-reversible cycle with compressor of rotary type
- F25B1/053—Compression machines, plants or systems with non-reversible cycle with compressor of rotary type of turbine type
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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
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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
- F25B40/00—Subcoolers, desuperheaters or superheaters
- F25B40/02—Subcoolers
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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
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
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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
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
- F25B49/022—Compressor control arrangements
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- 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
- F25B2339/00—Details of evaporators; Details of condensers
- F25B2339/02—Details of evaporators
- F25B2339/024—Evaporators with refrigerant in a vessel in which is situated a heat exchanger
- F25B2339/0242—Evaporators with refrigerant in a vessel in which is situated a heat exchanger having tubular elements
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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
- F25B2339/00—Details of evaporators; Details of condensers
- F25B2339/04—Details of condensers
- F25B2339/047—Water-cooled condensers
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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
- 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
- F25B2400/04—Refrigeration circuit bypassing means
- F25B2400/0409—Refrigeration circuit bypassing means for the evaporator
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- 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
- F25B2400/04—Refrigeration circuit bypassing means
- F25B2400/0411—Refrigeration circuit bypassing means for the expansion valve or capillary tube
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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
- 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
- F25B2400/12—Inflammable refrigerants
- F25B2400/121—Inflammable refrigerants using R1234
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- 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
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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
- F25B25/00—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00
- F25B25/005—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00 using primary and secondary systems
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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
- F25B2500/00—Problems to be solved
- F25B2500/01—Geometry problems, e.g. for reducing size
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- 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
- F25B2600/022—Compressor control for multi-stage operation
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- 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
- F25B2600/026—Compressor control by controlling unloaders
- F25B2600/0261—Compressor control by controlling unloaders external to the compressor
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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
- F25B2600/00—Control issues
- F25B2600/02—Compressor control
- F25B2600/027—Compressor control by controlling pressure
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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
- F25B2600/00—Control issues
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- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2515—Flow valves
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- 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
- F25B2700/19—Pressures
- F25B2700/193—Pressures of the compressor
- F25B2700/1931—Discharge pressures
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- 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
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- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21151—Temperatures of a compressor or the drive means therefor at the suction side of the compressor
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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
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21152—Temperatures of a compressor or the drive means therefor at the discharge side of the compressor
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- 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
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- F25B2700/2116—Temperatures of a condenser
- F25B2700/21161—Temperatures of a condenser of the fluid heated by the condenser
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- 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
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- F25B2700/2116—Temperatures of a condenser
- F25B2700/21163—Temperatures of a condenser of the refrigerant at the outlet of the condenser
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- 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
- F25B2700/21—Temperatures
- F25B2700/2117—Temperatures of an evaporator
- F25B2700/21171—Temperatures of an evaporator of the fluid cooled by the evaporator
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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
- F25B39/00—Evaporators; Condensers
- F25B39/02—Evaporators
Definitions
- the present invention relates to a refrigerator having an economizer which is a plate type heat exchanger and a control method thereof.
- an economizer is a plate type heat exchanger. Accordingly, compared to a gas-liquid separation type economizer used in a two-stage compression subcooler two-stage expansion cycle, a refrigerant charge amount can be reduced.
- the present invention is made in consideration of the above-described circumstances, and an object thereof is to provide a refrigerator capable of being appropriately operated against an increase of a refrigerant circulation amount generated in a case where a plate type heat exchanger is used as the economizer and a control method thereof.
- a refrigerator and a control method thereof according to the present invention adopts the following means.
- a refrigerator including: a compressor which compresses a refrigerant; a condenser which condenses the refrigerant compressed by the compressor; an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve; a main expansion valve which expands the liquid refrigerant introduced from the economizer; and an evaporator which expands the refrigerant introduced from the main expansion valve, in which the plate type heat exchanger is configured such that a width of a plate is 100 mm or more and 400 mm or less, a height of the plate is 300 mm or more and 1,000 mm or less, and the number of stacked plates is 80 or more.
- the plate type heat exchanger is used as the economizer, the width of the stacked plates is 100 mm or more and 400 mm or less, the height of the stacked plates is 300 mm or more and 1,000 mm or less, and the number of the stacked plates is 80 or more. Accordingly, a pressure loss of the economizer can be 100 kPa or more, preferably, can be 150 kPa or more and 200 kPa or less. Therefore, even when a refrigerant circulation amount increases, a predetermined pressure loss can be secured, and thus, a refrigerant distribution in the economizer which is the plate type heat exchanger is appropriately performed, and it is possible to operate a refrigerator without damaging performance of the refrigerator.
- HFC-134a is appropriately used, or HFO-1234ze(E), HFO-1233zd(E), or HFO-1233zd(Z) may be used.
- a refrigerator including: a compressor which compresses a refrigerant; a condenser which condenses the refrigerant compressed by the compressor; an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve; a main expansion valve which expands the liquid refrigerant introduced from the economizer; an evaporator which evaporates the refrigerant introduced from the main expansion valve; a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to an upstream side of the main expansion valve; a bypass valve which is provided in the bypass path; and a controller which controls an opening degree of the bypass valve.
- the bypass valve is opened by a command of the controller, and a flow rate of the refrigerant flowing through the bypass path increases. Accordingly, it is possible to decrease a flow rate of the liquid refrigerant which flows into the economizer. Therefore, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- a refrigerator including: a compressor which compresses a refrigerant; a condenser which condenses the refrigerant compressed by the compressor; an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve; a main expansion valve which expands the liquid refrigerant introduced from the economizer; an evaporator which evaporates the refrigerant introduced from the main expansion valve; a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to a cooled-medium inlet side of the evaporator; a bypass valve which is provided in the bypass path; and a controller which controls an opening degree of the bypass valve.
- the bypass valve is opened by a command of the controller, and a flow rate of the refrigerant flowing through the bypass path increases. Accordingly, it is possible to decrease a flow rate of the liquid refrigerant which flows into the economizer. Therefore, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- the main expansion valve can be bypassed, and thus, it is not necessary to adopt an expansion valve having a large diameter in anticipation of an increase of the refrigerant circulation amount, and there is no possibility that control accuracy of the expansion valve deteriorates.
- the liquid refrigerant is introduced to the cooled-medium (for example, cold water) inlet side of the evaporator via the bypass path. Accordingly, the refrigerant can be introduced to the cooled-medium inlet side which is a region in which a heat exchange amount is large, the refrigerant is evaporated, and thus, dry-out easily occurs. Therefore, the dry-out in this region is suppressed, and it is possible to improve a heat transfer coefficient in the evaporator.
- the cooled-medium for example, cold water
- the controller increases the opening degree of the bypass valve.
- the difference between the pressure in the condenser and the pressure in the evaporator is equal to or less than the predetermined value or the opening degree of the main expansion valve is equal to or more than the predetermined value, it is determined that the refrigerant circulation amount is excessive, and thus, the opening degree of the bypass valve increases. Accordingly, it is possible to suppress occurrence of the failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- the refrigerator includes a compressor which compresses a refrigerant, a condenser which condenses the refrigerant compressed by the compressor, an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve, a main expansion valve which expands the liquid refrigerant introduced from the economizer, an evaporator which evaporates the refrigerant introduced from the main expansion valve, a bypass path which bypasses the economizer and introduces the liquid refrigerant from the condenser to an upstream side of the main expansion valve, and a bypass valve which is provided in the bypass path, the control method including: increasing the opening degree of the bypass valve in a case where a difference between a pressure in
- the bypass valve is opened and a flow rate of the refrigerant flowing through the bypass path increases. Accordingly, it is possible to decrease a flow rate of the liquid refrigerant which flows into the economizer. Therefore, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- the refrigerator includes a compressor which compresses a refrigerant, a condenser which condenses the refrigerant compressed by the compressor, an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve, a main expansion valve which expands the liquid refrigerant introduced from the economizer, an evaporator which evaporates the refrigerant introduced from the main expansion valve, a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to a cooled-medium inlet side of the evaporator, and a bypass valve which is provided in the bypass path, the control method including: increasing the opening degree of the bypass valve in a case
- the bypass valve is opened and a flow rate of the refrigerant flowing through the bypass path increases. Accordingly, it is possible to decrease a flow rate of the liquid refrigerant which flows into the economizer. Therefore, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- the main expansion valve can be bypassed, and thus, it is not necessary to adopt an expansion valve having a large diameter in anticipation of an increase of the refrigerant circulation amount, and there is no possibility that control accuracy of the expansion valve deteriorates.
- the liquid refrigerant is introduced to the cooled-medium (for example, cold water) inlet side of the evaporator via the bypass path. Accordingly, the refrigerant can be introduced to the cooled-medium inlet side which is a region in which the heat exchange amount is large, the refrigerant is evaporated, and thus, dry-out easily occurs. Therefore, the dry-out in this region is suppressed, and it is possible to improve a heat transfer coefficient in the evaporator.
- the cooled-medium for example, cold water
- the width, the height, and the number of the stacked plates it is possible to secure a predetermined pressure loss even when the refrigerant circulation amount increases. Accordingly, the refrigerant distribution in the economizer which is the plate type heat exchanger is appropriately performed, and it is possible to operate a refrigerator without damaging performance of the refrigerator.
- FIG. 1 is a schematic configuration diagram showing a turbo refrigerator according to a first embodiment of the present invention.
- FIG. 2 is a longitudinal sectional diagram showing a schematic configuration of an economizer of FIG. 1 .
- FIG. 3 is a diagram showing a result of thermography of an economizer according to the first embodiment.
- FIG. 4 is a diagram showing a result of thermography of an economizer according to a reference example.
- FIG. 5 is a schematic configuration diagram showing a turbo refrigerator according to a second embodiment of the present invention.
- FIG. 6 is a schematic configuration diagram showing a turbo refrigerator according to a third embodiment of the present invention.
- FIG. 7 is a longitudinal sectional diagram schematically showing an evaporator of FIG. 6 .
- a turbo refrigerator (refrigerator) 1 includes a turbo compressor (compressor) 2 , a condenser 3 , an economizer 4 , a main expansion valve 5 , an evaporator 7 , and a controller (not shown).
- the turbo compressor 2 is a centrifugal compressor which is driven by an inverter motor 9 and includes an intermediate intake port 2 C provided between a first impeller (not shown) and a second impeller (not shown) in addition to an intake port 2 A and a discharge port 2 B.
- a low-pressure gas refrigerant sucked from the intake port 2 A is compressed in two stages by rotations of the first impeller and the second impeller, and the compressed high-pressure gas refrigerant is discharged from the discharge port 2 B.
- HFC-134a As a refrigerant, HFC-134a is used. However, HFO-1234ze(E), HFO-1233zd(E), or HFO-1233zd(Z) may be used.
- the high-pressure gas refrigerant discharged from the discharge port 2 B of the turbo compressor 2 is introduced to an oil mist separation tank 10 , and oil in the refrigerant is centrifugally separated.
- the high-pressure cooling gas from which the oil is centrifugally separated is introduced from the oil mist separation tank 10 to the condenser 3 .
- the condenser 3 is a shell and tube type heat exchanger and performs heat exchange between the high-pressure gas refrigerant supplied via the oil mist separation tank 10 from the turbo compressor 2 and cooling water which circulates a cooling water circuit 11 , and thus, the high-pressure cooling gas is condensed and liquefied.
- the cooling water circuit 11 is connected to a cooling tower (not shown) and the cooling water is cooled to a predetermined temperature by the cooling tower.
- the flow of the cooling water supplied by a cooling water pump 12 and the flow of the high-pressure gas refrigerant are made to flow countercurrently.
- a plate type heat exchanger may be used as the condenser 3 .
- the economizer 4 is the plate type heat exchanger which performs heat exchange between a liquid refrigerant which flows through a main circuit of a refrigeration cycle 8 and is introduced from the condenser 3 and a two-phase refrigerant which branches off from the main circuit and is decompressed by the sub-expansion valve 13 and supercools the liquid refrigerant flowing through the main circuit by evaporation latent heat of the refrigerant.
- a gas circuit 14 through which a gas refrigerant (intermediate-pressure refrigerant) which is evaporated by supercooling the liquid refrigerant is injected into a compressed refrigerant having an intermediate pressure from the intermediate intake port 2 C of the turbo compressor 2 is connected to the economizer 4 .
- the refrigerant supercooled via the economizer 4 passes through the main expansion valve 5 to be expanded and is supplied to the evaporator 7 .
- the evaporator 7 is the shell and tube type heat exchanger and performs heat exchange between the refrigerant introduced from the main expansion valve 5 and the cold water (cooled medium) which circulates via a cold water circuit 15 , evaporates the refrigerant, and cools the cold water by the evaporation latent heat.
- the flow of the cold water supplied by the cold water pump 16 and the flow of the refrigerant are made to flow countercurrently.
- a plate type heat exchanger may be used as the evaporator 7 .
- the refrigeration cycle 8 includes a hot gas bypass circuit 17 which bypasses a portion of the high-pressure gas refrigerant in which the oil is separated by the oil mist separation tank 10 from between the condenser 3 and the turbo compressor 2 .
- a hot gas bypass valve 18 is provided in the hot gas bypass circuit 17 , and the hot gas bypass valve 18 adjusts a flow rate of the high-pressure gas refrigerant introduced from the hot gas bypass circuit 17 to the turbo compressor 2 .
- thermometers 31 , 32 , and 33 are provided in the intake port 2 A of the turbo compressor 2 , the discharge port 2 B, and the intermediate intake port 2 C, and thermometers 35 , 36 , 37 , and 38 are respectively provided in an inlet and an outlet of the cooling water circuit 11 and an inlet and an outlet of the cold water circuit 15 , and the thermometer 34 is provided in the inlet of the main expansion valve 5 .
- the turbo refrigerator 1 is controlled by the controller (not shown).
- the controller includes a Central Processing Unit (CPU), a Random Access Memory (RAM), a Read Only Memory (ROM), a computer readable storage medium, or the like.
- CPU Central Processing Unit
- RAM Random Access Memory
- ROM Read Only Memory
- a series of processing for realizing various functions is stored in the storage medium or the like as a program form, and the CPU reads the program to a RAM or the like and executes information processing/calculation processing to realize the various functions.
- the program may be installed in the ROM or other storage mediums in advance, may be supplied in a form stored in a computer readable storage medium, or may be distributed via wired or wireless communication means.
- the computer readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.
- FIG. 2 shows a schematic configuration of the economizer 4 .
- the economizer 4 is the plate type heat exchanger in which the plurality of stacked plates 40 are stacked to form a plurality of flow paths adjacent to each other in parallel.
- only six flow paths 42 a and 42 b are shown in FIG. 2 .
- this is merely an example, and actually, 80 flow paths or more may be formed.
- the flow paths 42 a of the liquid refrigerant which are introduced from the condenser 3 (indicated by “CON” in the drawing) and the flow paths 42 b of the two-phase refrigerant which branch from the condenser 3 and are introduced after passing through the sub-expansion valve are alternately provided and are made to flow countercurrently.
- the liquid refrigerant from the condenser 3 passes through the flow paths 42 a from the upper side in the drawing toward the lower side in the drawing to pass through the economizer 4 .
- the liquid refrigerant which has flowed through the economizer 4 is throttled by the main expansion valve 5 and, thereafter, is introduced to the evaporator 7 (indicated by “EVA” in the drawing).
- a portion of the liquid refrigerant branching from the condenser 3 is throttled by the sub-expansion valve 13 so as to be the two-phase refrigerant, and thereafter, flows into each of the flow paths 42 b of the economizer 4 , and flows from the upper side in the drawing to the lower side.
- a distributor 44 which applies a predetermined pressure loss is provided on the upstream side of each of the flow paths 42 b.
- the two-phase refrigerant can be uniformly distributed to each of the flow paths 42 b by the distributor 44 .
- the gas refrigerant which is changed from the two-phase refrigerant to the gas refrigerant while passing through the economizer 4 , flows from the intermediate intake port 2 C of the turbo compressor 2 (indicated by “COMP” in the drawing).
- the liquid refrigerant which is introduced from the condenser 3 and flows through the flow paths 42 a from the upper side to the lower side in the drawing is cooled by the evaporation latent heat of the adjacent two-phase refrigerant so as to be a supercooled refrigerant, and the two-phase refrigerant which is introduced from the sub-expansion valve 13 and flows through the flow path 42 b from the lower side to the upper side in FIG. 1 acquires the evaporation latent heat from the adjacent liquid refrigerant and is changed to the gas refrigerant.
- the width of the stacked plates 40 is 100 mm or more and 400 mm or less, the height of the stacked plates 40 is 300 mm or more and 1000 mm or less, and the number of the stacked plates 40 is 80 or more and 400 or less. Accordingly, the pressure loss of the economizer 4 can be 100 kPa or more, and, preferably, can be 150 kPa or more and 200 kPa or less. In addition, it is possible to suppress the failure in the refrigerant distribution of the flow path 42 b of the two-phase refrigerant.
- the pressure loss of the economizer 4 which is the plate type heat exchanger is adjusted by increasing or decreasing the number of the stacked plates 40 . Specifically, a total cross-sectional area of the flow path is increased by increasing the number of the stacked plates, a flow rate decreases, and thus, the pressure loss decreases. In addition, the total cross-sectional area of the flow path is decreased by decreasing the number of stacked plates, the flow rate increases, and thus, the pressure loss increases.
- FIGS. 3 and 4 show a state of the refrigerant distribution in the economizer 4 .
- FIG. 3 shows the economizer 4 according to the present embodiment, and the number of the stacked plates is 86.
- the refrigerant HFC-134a is used.
- FIG. 3 shows a result of thermography when the economizer 4 is viewed from the front surface as shown in FIG. 2 . That is, a right-left direction in the drawings is a stacking direction, the two-phase refrigerant flow from the lower side toward the upper side, and the liquid refrigerant flows from the upper side toward the lower side. It can be understood from FIG. 3 that a temperature difference in the right-left direction is not large. This means that the refrigerant distribution is good. In the case of FIG. 3 , the pressure loss is 100 kPa or more.
- FIG. 4 is a reference example and shows the result of the thermography similar to FIG. 3 .
- FIG. 4 is different from FIG. 3 in that the number of the stacked plates is 212 .
- the temperature difference in the right-left direction (stacking direction) is large and the refrigerant distribution is not good.
- the pressure loss is 10 to 20 kPa. In this way, if the number of the stacked plates increases according to the increase of the refrigerant circulation amount, the pressure loss in the economizer decreases, and thus, it can be understood that the failure in the refrigerant distribution occurs.
- the plate type heat exchanger is used as the economizer 4 , the width of the stacked plates 40 is 100 mm or more and 400 mm or less, the height of the stacked plates 40 is 300 mm or more and 1,000 mm or less, and the number of the stacked plates 40 is 80 or more. Accordingly, the pressure loss of the economizer 4 can be 100 kPa or more, preferably, can be 150 kPa or more and 200 kPa or less. Therefore, even when the refrigerant circulation amount increases, a predetermined pressure loss can be secured, and thus, a refrigerant distribution in the economizer 4 which is the plate type heat exchanger is appropriately performed, and it is possible to operate a refrigerator without damaging performance of the refrigerator.
- the present embodiment is different from the first embodiment in that a bypass path is provided, and other portions are similar to each other. Accordingly, the same reference numerals are assigned to the same configurations, and descriptions thereof are omitted.
- a bypass path 50 which bypasses the economizer 4 and through which the liquid refrigerant from the condenser 3 is introduced to the upstream side of the main expansion valve 5 , is provided.
- An upstream end of the bypass path 50 is provided on a downstream side of a branch point A from which branches to the sub-expansion valve 13 .
- a bypass valve 52 is provided in the bypass path 50 .
- the bypass valve 52 an electrical ball valve capable of adjusting an opening degree is used.
- a solenoid valve which is simply opened or closed may be used.
- a command of the opening degree of the bypass valve 52 is performed by the controller (not shown).
- the controller determines that the refrigerant circulation amount is excessive, and the controller increases the opening degree of the bypass valve 52 .
- the bypass valve 52 is opened by the command of the controller to increase the flow rate of the refrigerant flowing through the bypass path 50 . Accordingly, it is possible to decrease the flow rate of the liquid refrigerant flowing into the economizer 4 . Accordingly, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer 4 . Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer 4 which is the plate type heat exchanger.
- the plate type heat exchanger having the configuration shown in the first embodiment may not be used as the economizer 4 . That is, an economizer may be used in which the pressure loss is adjusted such that a desired refrigerant distribution is performed on the flow rate of the refrigerant which flows into the economizer 4 when the liquid refrigerant is bypassed through the bypass path 50 .
- the present embodiment is different from the first embodiment in that the bypass path is provided, and other portions are similar to each other. Accordingly, the same reference numerals are assigned to the same configurations, and descriptions thereof are omitted.
- a bypass path 60 which bypasses the economizer 4 and through which the liquid refrigerant from the condenser 3 is introduced to the cold water (cooled-medium) inlet side of the evaporator 7 , is provided.
- An upstream end of the bypass path 60 is provided on a downstream side of a branch point A from which branches to the sub-expansion valve 13 .
- a bypass valve 62 is provided in the bypass path 60 .
- the bypass valve 62 an electrical ball valve capable of adjusting an opening degree is used. However, a solenoid valve which is simply opened or closed may be used.
- a command of the opening degree of the bypass valve 62 is performed by the controller (not shown). In a case where the difference between the pressure in the condenser 3 and the pressure in the evaporator 7 is equal to or less than a predetermined value, or in a case where the opening degree of the main expansion valve 5 is equal or more than a predetermined value, the controller determines that the refrigerant circulation amount is excessive, and the controller increases the opening degree of the bypass valve 62 .
- FIG. 7 shows a schematic configuration of the evaporator 7 .
- the evaporator 7 is a shell and tube type evaporator and a cylindrical container which has an approximately circular cross section and a horizontal axis line.
- Water chambers to which the cold water is introduced are provided on both end portions of the evaporator 7 , and a space which is interposed between the water chambers 45 and 46 becomes an evaporation chamber 47 in which the refrigerant introduced from the economizer 4 exists.
- Pipe plates 48 are partitioned between the water chambers 45 and 46 and the evaporation chamber 47 .
- a plurality of heat transfer pipe 49 are connected to each other between the water chambers 45 and 46 .
- the heat transfer pipes 49 configures the plurality of pipe groups (not shown).
- a liquid distribution structure 68 which is a porous plate for distributing the two-phase refrigerant flowing into the evaporator 7 is provided below the heat transfer pipe 49 .
- one water chamber 45 partitions a chamber for the cold water inlet and a chamber for a cold water outlet.
- a refrigerant pipe 53 into which the refrigerant introduced via the main expansion valve 5 from the economizer 4 is introduced is connected to an approximately center position in the horizontal axis line below the evaporator 7 .
- a suction pipe 64 through which the refrigerant gas evaporated in the evaporator 7 is introduced to the intake port 2 A of the turbo compressor 2 is connected to an upper portion of the evaporator 7 .
- a gas-liquid separation structure 66 which is a porous plate so as to separate a gas and a liquid is provided in the vicinity of an upstream side of a position at which the suction pipe 64 is connected.
- a hot gas bypass pipe 65 is connected to an end portion of an upper portion of the evaporator 7 .
- bypass path 60 is connected to the cold water inlet side (the left side in the drawing) from the center position in a horizontal axial direction of the evaporator 7 . Accordingly, the refrigerant passing through the bypass valve 62 is introduced to the vicinity of the heat transfer pipe 49 through which the cold water on the cold water inlet side of the evaporator 7 flows.
- the bypass valve 62 is opened by the command of the controller to increase the flow rate of the refrigerant flowing through the bypass path 60 . Accordingly, it is possible to decrease the flow rate of the liquid refrigerant flowing into the economizer 4 . Accordingly, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer 4 . Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer 4 which is the plate type heat exchanger.
- the main expansion valve 5 can be bypassed, and thus, it is not necessary to adopt an expansion valve having a large diameter in anticipation of an increase of the refrigerant circulation amount, and there is no possibility that control accuracy of the expansion valve deteriorates.
- the refrigerant is introduced to the inlet side of the cold water of the evaporator 7 via the bypass path 60 . Accordingly, the refrigerant can be introduced to the inlet side of the cold water which is a region in which the heat exchange amount is large, the refrigerant is evaporated, and thus, dry-out easily occurs. Therefore, the dry-out in this region is suppressed, and it is possible to improve a heat transfer coefficient in the evaporator.
- the plate type heat exchanger having the configuration shown in the first embodiment may not be used as the economizer 4 . That is, an economizer may be used in which the pressure loss is adjusted such that a desired refrigerant distribution is performed on the flow rate of the refrigerant which flows into the economizer 4 when the liquid refrigerant is bypassed through the bypass path 60 .
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Abstract
A refrigerating machine which is equipped with: a turbocompressor 2 that compresses a refrigerant; a condenser 3 that condenses the refrigerant compressed by the turbocompressor 2; an intermediate cooler 4 that is a plate heat exchanger which performs heat exchange between the liquid refrigerant introduced from the condenser 3 and the two-phase refrigerant obtained by expanding, with a sub-expansion valve 13, part of the liquid refrigerant introduced from the condenser 3; a main expansion valve 5 that expands the liquid refrigerant introduced from the intermediate cooler 4; and an evaporator 7 that evaporates the refrigerant introduced from the main expansion valve 5. The plate heat exchanger includes 80 or more laminated plates, the width of which is 100-400 mm and the height of which is 300-1000 mm.
Description
- The present invention relates to a refrigerator having an economizer which is a plate type heat exchanger and a control method thereof.
- For example, as described in
PTL 1, in a two-stage compression subcooler one-stage expansion cycle, an economizer is a plate type heat exchanger. Accordingly, compared to a gas-liquid separation type economizer used in a two-stage compression subcooler two-stage expansion cycle, a refrigerant charge amount can be reduced. - [PTL 1] Japanese Unexamined Patent Application Publication No. 2012-77971 ([0034], FIG. 1)
- However, in a case where a temperature of cooling water is low and a refrigerant circulation amount is large, there is a problem that a differential pressure across expansion valve (=condensation pressure evaporation pressure−pressure loss of economizer) decreases, and there is a problem that an expansion valve opening degree becomes too large and cannot be controlled. As a countermeasure against this, it is conceivable to increase a diameter of an expansion valve. However, a flow rate adjustment amount with the minimum opening degree change increases, and thus, there is a problem that accuracy of an expansion valve control deteriorates.
- As another countermeasure, it is conceivable to increase the number of stacked economizers and increase a cross-sectional area of the entire flow path so as to reduce the pressure loss. However, even if the pressure loss is reduced by increasing the number of the stacked economizers, a resistance decreases when a two-phase refrigerant passing through a sub-expansion valve is distributed to each flow path, and thus, a deviation of a refrigerant distribution occurs. In this case, a heat transfer area of the economizer cannot be effectively used, and performance of a refrigerator deteriorates. In addition, a carry-over occurs in which the two-phase refrigerant flows into an intermediate intake port of a compressor in a state where the two-phase refrigerant is not fully gasified.
- The present invention is made in consideration of the above-described circumstances, and an object thereof is to provide a refrigerator capable of being appropriately operated against an increase of a refrigerant circulation amount generated in a case where a plate type heat exchanger is used as the economizer and a control method thereof.
- In order to achieve the object, a refrigerator and a control method thereof according to the present invention adopts the following means.
- That is, according to an aspect of the present invention, there is provided a refrigerator including: a compressor which compresses a refrigerant; a condenser which condenses the refrigerant compressed by the compressor; an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve; a main expansion valve which expands the liquid refrigerant introduced from the economizer; and an evaporator which expands the refrigerant introduced from the main expansion valve, in which the plate type heat exchanger is configured such that a width of a plate is 100 mm or more and 400 mm or less, a height of the plate is 300 mm or more and 1,000 mm or less, and the number of stacked plates is 80 or more.
- The plate type heat exchanger is used as the economizer, the width of the stacked plates is 100 mm or more and 400 mm or less, the height of the stacked plates is 300 mm or more and 1,000 mm or less, and the number of the stacked plates is 80 or more. Accordingly, a pressure loss of the economizer can be 100 kPa or more, preferably, can be 150 kPa or more and 200 kPa or less. Therefore, even when a refrigerant circulation amount increases, a predetermined pressure loss can be secured, and thus, a refrigerant distribution in the economizer which is the plate type heat exchanger is appropriately performed, and it is possible to operate a refrigerator without damaging performance of the refrigerator.
- As a refrigerant, HFC-134a is appropriately used, or HFO-1234ze(E), HFO-1233zd(E), or HFO-1233zd(Z) may be used.
- In addition, according to another aspect of the present invention, there is provided a refrigerator including: a compressor which compresses a refrigerant; a condenser which condenses the refrigerant compressed by the compressor; an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve; a main expansion valve which expands the liquid refrigerant introduced from the economizer; an evaporator which evaporates the refrigerant introduced from the main expansion valve; a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to an upstream side of the main expansion valve; a bypass valve which is provided in the bypass path; and a controller which controls an opening degree of the bypass valve.
- The bypass valve is opened by a command of the controller, and a flow rate of the refrigerant flowing through the bypass path increases. Accordingly, it is possible to decrease a flow rate of the liquid refrigerant which flows into the economizer. Therefore, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- In addition, according to still another aspect of the present invention, there is provided a refrigerator including: a compressor which compresses a refrigerant; a condenser which condenses the refrigerant compressed by the compressor; an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve; a main expansion valve which expands the liquid refrigerant introduced from the economizer; an evaporator which evaporates the refrigerant introduced from the main expansion valve; a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to a cooled-medium inlet side of the evaporator; a bypass valve which is provided in the bypass path; and a controller which controls an opening degree of the bypass valve.
- The bypass valve is opened by a command of the controller, and a flow rate of the refrigerant flowing through the bypass path increases. Accordingly, it is possible to decrease a flow rate of the liquid refrigerant which flows into the economizer. Therefore, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- In addition, the main expansion valve can be bypassed, and thus, it is not necessary to adopt an expansion valve having a large diameter in anticipation of an increase of the refrigerant circulation amount, and there is no possibility that control accuracy of the expansion valve deteriorates.
- In addition, the liquid refrigerant is introduced to the cooled-medium (for example, cold water) inlet side of the evaporator via the bypass path. Accordingly, the refrigerant can be introduced to the cooled-medium inlet side which is a region in which a heat exchange amount is large, the refrigerant is evaporated, and thus, dry-out easily occurs. Therefore, the dry-out in this region is suppressed, and it is possible to improve a heat transfer coefficient in the evaporator.
- In addition, in the refrigerator according to the aspects of the present invention, in a case where a difference between a pressure in the condenser and a pressure in the evaporator is equal or less than a predetermined value or an opening degree of the main expansion valve is equal to or more than a predetermined value, the controller increases the opening degree of the bypass valve.
- If the difference between the pressure in the condenser and the pressure in the evaporator is equal to or less than the predetermined value or the opening degree of the main expansion valve is equal to or more than the predetermined value, it is determined that the refrigerant circulation amount is excessive, and thus, the opening degree of the bypass valve increases. Accordingly, it is possible to suppress occurrence of the failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- In addition, according to still aspect of the present invention, there is provided a control method of a refrigerator, the refrigerator includes a compressor which compresses a refrigerant, a condenser which condenses the refrigerant compressed by the compressor, an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve, a main expansion valve which expands the liquid refrigerant introduced from the economizer, an evaporator which evaporates the refrigerant introduced from the main expansion valve, a bypass path which bypasses the economizer and introduces the liquid refrigerant from the condenser to an upstream side of the main expansion valve, and a bypass valve which is provided in the bypass path, the control method including: increasing the opening degree of the bypass valve in a case where a difference between a pressure in the condenser and a pressure in the evaporator is equal or less than a predetermined value or an opening degree of the main expansion valve is equal to or more than a predetermined value.
- The bypass valve is opened and a flow rate of the refrigerant flowing through the bypass path increases. Accordingly, it is possible to decrease a flow rate of the liquid refrigerant which flows into the economizer. Therefore, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- In addition, according to still aspect of the present invention, there is provided a control method of a refrigerator, the refrigerator includes a compressor which compresses a refrigerant, a condenser which condenses the refrigerant compressed by the compressor, an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve, a main expansion valve which expands the liquid refrigerant introduced from the economizer, an evaporator which evaporates the refrigerant introduced from the main expansion valve, a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to a cooled-medium inlet side of the evaporator, and a bypass valve which is provided in the bypass path, the control method including: increasing the opening degree of the bypass valve in a case where a difference between a pressure in the condenser and a pressure in the evaporator is equal or less than a predetermined value or an opening degree of the main expansion valve is equal to or more than a predetermined value.
- The bypass valve is opened and a flow rate of the refrigerant flowing through the bypass path increases. Accordingly, it is possible to decrease a flow rate of the liquid refrigerant which flows into the economizer. Therefore, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into the economizer. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
- In addition, the main expansion valve can be bypassed, and thus, it is not necessary to adopt an expansion valve having a large diameter in anticipation of an increase of the refrigerant circulation amount, and there is no possibility that control accuracy of the expansion valve deteriorates.
- In addition, the liquid refrigerant is introduced to the cooled-medium (for example, cold water) inlet side of the evaporator via the bypass path. Accordingly, the refrigerant can be introduced to the cooled-medium inlet side which is a region in which the heat exchange amount is large, the refrigerant is evaporated, and thus, dry-out easily occurs. Therefore, the dry-out in this region is suppressed, and it is possible to improve a heat transfer coefficient in the evaporator.
- By appropriately selecting the width, the height, and the number of the stacked plates, it is possible to secure a predetermined pressure loss even when the refrigerant circulation amount increases. Accordingly, the refrigerant distribution in the economizer which is the plate type heat exchanger is appropriately performed, and it is possible to operate a refrigerator without damaging performance of the refrigerator.
- Even when the refrigerant circulation amount increases, the flow rate of the refrigerant which flows through the bypass path which bypasses the economizer increases. Accordingly, it is possible to decrease the flow rate of the liquid refrigerant flowing into the economizer, and thus, it is possible to suppress occurrence of a failure of the refrigerant distribution in the economizer which is the plate type heat exchanger.
-
FIG. 1 is a schematic configuration diagram showing a turbo refrigerator according to a first embodiment of the present invention. -
FIG. 2 is a longitudinal sectional diagram showing a schematic configuration of an economizer ofFIG. 1 . -
FIG. 3 is a diagram showing a result of thermography of an economizer according to the first embodiment. -
FIG. 4 is a diagram showing a result of thermography of an economizer according to a reference example. -
FIG. 5 is a schematic configuration diagram showing a turbo refrigerator according to a second embodiment of the present invention. -
FIG. 6 is a schematic configuration diagram showing a turbo refrigerator according to a third embodiment of the present invention. -
FIG. 7 is a longitudinal sectional diagram schematically showing an evaporator ofFIG. 6 . - Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
- Hereinafter, a first embodiment of the present invention will be described.
- As shown in
FIG. 1 , a turbo refrigerator (refrigerator) 1 includes a turbo compressor (compressor) 2, acondenser 3, aneconomizer 4, amain expansion valve 5, anevaporator 7, and a controller (not shown). - The
turbo compressor 2 is a centrifugal compressor which is driven by aninverter motor 9 and includes anintermediate intake port 2C provided between a first impeller (not shown) and a second impeller (not shown) in addition to anintake port 2A and adischarge port 2B. A low-pressure gas refrigerant sucked from theintake port 2A is compressed in two stages by rotations of the first impeller and the second impeller, and the compressed high-pressure gas refrigerant is discharged from thedischarge port 2B. - As a refrigerant, HFC-134a is used. However, HFO-1234ze(E), HFO-1233zd(E), or HFO-1233zd(Z) may be used.
- The high-pressure gas refrigerant discharged from the
discharge port 2B of theturbo compressor 2 is introduced to an oilmist separation tank 10, and oil in the refrigerant is centrifugally separated. The high-pressure cooling gas from which the oil is centrifugally separated is introduced from the oilmist separation tank 10 to thecondenser 3. - The
condenser 3 is a shell and tube type heat exchanger and performs heat exchange between the high-pressure gas refrigerant supplied via the oilmist separation tank 10 from theturbo compressor 2 and cooling water which circulates a coolingwater circuit 11, and thus, the high-pressure cooling gas is condensed and liquefied. The coolingwater circuit 11 is connected to a cooling tower (not shown) and the cooling water is cooled to a predetermined temperature by the cooling tower. In addition, preferably, the flow of the cooling water supplied by a coolingwater pump 12 and the flow of the high-pressure gas refrigerant are made to flow countercurrently. Moreover, as thecondenser 3, a plate type heat exchanger may be used. - The
economizer 4 is the plate type heat exchanger which performs heat exchange between a liquid refrigerant which flows through a main circuit of arefrigeration cycle 8 and is introduced from thecondenser 3 and a two-phase refrigerant which branches off from the main circuit and is decompressed by thesub-expansion valve 13 and supercools the liquid refrigerant flowing through the main circuit by evaporation latent heat of the refrigerant. In addition, agas circuit 14 through which a gas refrigerant (intermediate-pressure refrigerant) which is evaporated by supercooling the liquid refrigerant is injected into a compressed refrigerant having an intermediate pressure from theintermediate intake port 2C of theturbo compressor 2 is connected to theeconomizer 4. - The refrigerant supercooled via the
economizer 4 passes through themain expansion valve 5 to be expanded and is supplied to theevaporator 7. Theevaporator 7 is the shell and tube type heat exchanger and performs heat exchange between the refrigerant introduced from themain expansion valve 5 and the cold water (cooled medium) which circulates via acold water circuit 15, evaporates the refrigerant, and cools the cold water by the evaporation latent heat. In addition, preferably, the flow of the cold water supplied by thecold water pump 16 and the flow of the refrigerant are made to flow countercurrently. Moreover, as theevaporator 7, a plate type heat exchanger may be used. - In addition, the
refrigeration cycle 8 includes a hotgas bypass circuit 17 which bypasses a portion of the high-pressure gas refrigerant in which the oil is separated by the oilmist separation tank 10 from between thecondenser 3 and theturbo compressor 2. A hotgas bypass valve 18 is provided in the hotgas bypass circuit 17, and the hotgas bypass valve 18 adjusts a flow rate of the high-pressure gas refrigerant introduced from the hotgas bypass circuit 17 to theturbo compressor 2. - As measuring means for measuring temperatures or pressures of the refrigerant, the cooling water, and the cold water, pressure gauges 41, 42, and 43 and
thermometers intake port 2A of theturbo compressor 2, thedischarge port 2B, and theintermediate intake port 2C, andthermometers water circuit 11 and an inlet and an outlet of thecold water circuit 15, and thethermometer 34 is provided in the inlet of themain expansion valve 5. - The
turbo refrigerator 1 is controlled by the controller (not shown). For example, the controller includes a Central Processing Unit (CPU), a Random Access Memory (RAM), a Read Only Memory (ROM), a computer readable storage medium, or the like. In addition, for example, a series of processing for realizing various functions is stored in the storage medium or the like as a program form, and the CPU reads the program to a RAM or the like and executes information processing/calculation processing to realize the various functions. The program may be installed in the ROM or other storage mediums in advance, may be supplied in a form stored in a computer readable storage medium, or may be distributed via wired or wireless communication means. The computer readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. -
FIG. 2 shows a schematic configuration of theeconomizer 4. Theeconomizer 4 is the plate type heat exchanger in which the plurality of stackedplates 40 are stacked to form a plurality of flow paths adjacent to each other in parallel. In addition, only sixflow paths FIG. 2 . However, this is merely an example, and actually, 80 flow paths or more may be formed. - The
flow paths 42 a of the liquid refrigerant which are introduced from the condenser 3 (indicated by “CON” in the drawing) and theflow paths 42 b of the two-phase refrigerant which branch from thecondenser 3 and are introduced after passing through the sub-expansion valve are alternately provided and are made to flow countercurrently. - The liquid refrigerant from the
condenser 3 passes through theflow paths 42 a from the upper side in the drawing toward the lower side in the drawing to pass through theeconomizer 4. The liquid refrigerant which has flowed through theeconomizer 4 is throttled by themain expansion valve 5 and, thereafter, is introduced to the evaporator 7 (indicated by “EVA” in the drawing). - A portion of the liquid refrigerant branching from the
condenser 3 is throttled by thesub-expansion valve 13 so as to be the two-phase refrigerant, and thereafter, flows into each of theflow paths 42 b of theeconomizer 4, and flows from the upper side in the drawing to the lower side. Adistributor 44 which applies a predetermined pressure loss is provided on the upstream side of each of theflow paths 42 b. The two-phase refrigerant can be uniformly distributed to each of theflow paths 42 b by thedistributor 44. The gas refrigerant, which is changed from the two-phase refrigerant to the gas refrigerant while passing through theeconomizer 4, flows from theintermediate intake port 2C of the turbo compressor 2 (indicated by “COMP” in the drawing). - In this way, the liquid refrigerant which is introduced from the
condenser 3 and flows through theflow paths 42 a from the upper side to the lower side in the drawing is cooled by the evaporation latent heat of the adjacent two-phase refrigerant so as to be a supercooled refrigerant, and the two-phase refrigerant which is introduced from thesub-expansion valve 13 and flows through theflow path 42 b from the lower side to the upper side inFIG. 1 acquires the evaporation latent heat from the adjacent liquid refrigerant and is changed to the gas refrigerant. - The width of the
stacked plates 40 is 100 mm or more and 400 mm or less, the height of thestacked plates 40 is 300 mm or more and 1000 mm or less, and the number of thestacked plates 40 is 80 or more and 400 or less. Accordingly, the pressure loss of theeconomizer 4 can be 100 kPa or more, and, preferably, can be 150 kPa or more and 200 kPa or less. In addition, it is possible to suppress the failure in the refrigerant distribution of theflow path 42 b of the two-phase refrigerant. - The pressure loss of the
economizer 4 which is the plate type heat exchanger is adjusted by increasing or decreasing the number of thestacked plates 40. Specifically, a total cross-sectional area of the flow path is increased by increasing the number of the stacked plates, a flow rate decreases, and thus, the pressure loss decreases. In addition, the total cross-sectional area of the flow path is decreased by decreasing the number of stacked plates, the flow rate increases, and thus, the pressure loss increases. -
FIGS. 3 and 4 show a state of the refrigerant distribution in theeconomizer 4. -
FIG. 3 shows theeconomizer 4 according to the present embodiment, and the number of the stacked plates is 86. As the refrigerant, HFC-134a is used.FIG. 3 shows a result of thermography when theeconomizer 4 is viewed from the front surface as shown inFIG. 2 . That is, a right-left direction in the drawings is a stacking direction, the two-phase refrigerant flow from the lower side toward the upper side, and the liquid refrigerant flows from the upper side toward the lower side. It can be understood fromFIG. 3 that a temperature difference in the right-left direction is not large. This means that the refrigerant distribution is good. In the case ofFIG. 3 , the pressure loss is 100 kPa or more. - Meanwhile,
FIG. 4 is a reference example and shows the result of the thermography similar toFIG. 3 . However,FIG. 4 is different fromFIG. 3 in that the number of the stacked plates is 212. It can be understood fromFIG. 4 that the temperature difference in the right-left direction (stacking direction) is large and the refrigerant distribution is not good. In the case ofFIG. 4 , the pressure loss is 10 to 20 kPa. In this way, if the number of the stacked plates increases according to the increase of the refrigerant circulation amount, the pressure loss in the economizer decreases, and thus, it can be understood that the failure in the refrigerant distribution occurs. - As described above, according to the present embodiment, the following effects are exerted.
- The plate type heat exchanger is used as the
economizer 4, the width of thestacked plates 40 is 100 mm or more and 400 mm or less, the height of thestacked plates 40 is 300 mm or more and 1,000 mm or less, and the number of thestacked plates 40 is 80 or more. Accordingly, the pressure loss of theeconomizer 4 can be 100 kPa or more, preferably, can be 150 kPa or more and 200 kPa or less. Therefore, even when the refrigerant circulation amount increases, a predetermined pressure loss can be secured, and thus, a refrigerant distribution in theeconomizer 4 which is the plate type heat exchanger is appropriately performed, and it is possible to operate a refrigerator without damaging performance of the refrigerator. - Next, a second embodiment of the present invention will be described with reference to
FIG. 5 . - The present embodiment is different from the first embodiment in that a bypass path is provided, and other portions are similar to each other. Accordingly, the same reference numerals are assigned to the same configurations, and descriptions thereof are omitted.
- As shown in
FIG. 5 , abypass path 50, which bypasses theeconomizer 4 and through which the liquid refrigerant from thecondenser 3 is introduced to the upstream side of themain expansion valve 5, is provided. An upstream end of thebypass path 50 is provided on a downstream side of a branch point A from which branches to thesub-expansion valve 13. - In addition, a
bypass valve 52 is provided in thebypass path 50. As thebypass valve 52, an electrical ball valve capable of adjusting an opening degree is used. However, a solenoid valve which is simply opened or closed may be used. A command of the opening degree of thebypass valve 52 is performed by the controller (not shown). In a case where a difference between a pressure in thecondenser 3 and a pressure in theevaporator 7 is equal to or less than a predetermined value, or in a case where an opening degree of themain expansion valve 5 is equal or more than a predetermined value, the controller determines that the refrigerant circulation amount is excessive, and the controller increases the opening degree of thebypass valve 52. - In this way, according to the present embodiment, the
bypass valve 52 is opened by the command of the controller to increase the flow rate of the refrigerant flowing through thebypass path 50. Accordingly, it is possible to decrease the flow rate of the liquid refrigerant flowing into theeconomizer 4. Accordingly, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into theeconomizer 4. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in theeconomizer 4 which is the plate type heat exchanger. - In addition, the plate type heat exchanger having the configuration shown in the first embodiment may not be used as the
economizer 4. That is, an economizer may be used in which the pressure loss is adjusted such that a desired refrigerant distribution is performed on the flow rate of the refrigerant which flows into theeconomizer 4 when the liquid refrigerant is bypassed through thebypass path 50. - Next, a third embodiment of the present invention will be described with reference to
FIGS. 6 and 7 . - The present embodiment is different from the first embodiment in that the bypass path is provided, and other portions are similar to each other. Accordingly, the same reference numerals are assigned to the same configurations, and descriptions thereof are omitted.
- As shown in
FIG. 6 , abypass path 60, which bypasses theeconomizer 4 and through which the liquid refrigerant from thecondenser 3 is introduced to the cold water (cooled-medium) inlet side of theevaporator 7, is provided. An upstream end of thebypass path 60 is provided on a downstream side of a branch point A from which branches to thesub-expansion valve 13. - In addition, a
bypass valve 62 is provided in thebypass path 60. As thebypass valve 62, an electrical ball valve capable of adjusting an opening degree is used. However, a solenoid valve which is simply opened or closed may be used. A command of the opening degree of thebypass valve 62 is performed by the controller (not shown). In a case where the difference between the pressure in thecondenser 3 and the pressure in theevaporator 7 is equal to or less than a predetermined value, or in a case where the opening degree of themain expansion valve 5 is equal or more than a predetermined value, the controller determines that the refrigerant circulation amount is excessive, and the controller increases the opening degree of thebypass valve 62. -
FIG. 7 shows a schematic configuration of theevaporator 7. Theevaporator 7 is a shell and tube type evaporator and a cylindrical container which has an approximately circular cross section and a horizontal axis line. Water chambers to which the cold water is introduced are provided on both end portions of theevaporator 7, and a space which is interposed between thewater chambers evaporation chamber 47 in which the refrigerant introduced from theeconomizer 4 exists.Pipe plates 48 are partitioned between thewater chambers evaporation chamber 47. - A plurality of
heat transfer pipe 49 are connected to each other between thewater chambers heat transfer pipes 49 configures the plurality of pipe groups (not shown). For example, aliquid distribution structure 68 which is a porous plate for distributing the two-phase refrigerant flowing into theevaporator 7 is provided below theheat transfer pipe 49. - The cold water flowing from one
water chamber 45 is returned to theother water chamber 46 through eachheat transfer pipe 49, and thereafter, is returned to thewater chamber 45 and is introduced to an external load. Accordingly, in this case, onewater chamber 45 partitions a chamber for the cold water inlet and a chamber for a cold water outlet. - A
refrigerant pipe 53 into which the refrigerant introduced via themain expansion valve 5 from theeconomizer 4 is introduced is connected to an approximately center position in the horizontal axis line below theevaporator 7. Asuction pipe 64 through which the refrigerant gas evaporated in theevaporator 7 is introduced to theintake port 2A of theturbo compressor 2 is connected to an upper portion of theevaporator 7. For example, a gas-liquid separation structure 66 which is a porous plate so as to separate a gas and a liquid is provided in the vicinity of an upstream side of a position at which thesuction pipe 64 is connected. A hotgas bypass pipe 65 is connected to an end portion of an upper portion of theevaporator 7. - In addition, the
bypass path 60 is connected to the cold water inlet side (the left side in the drawing) from the center position in a horizontal axial direction of theevaporator 7. Accordingly, the refrigerant passing through thebypass valve 62 is introduced to the vicinity of theheat transfer pipe 49 through which the cold water on the cold water inlet side of theevaporator 7 flows. - In this way, according to the present embodiment, the
bypass valve 62 is opened by the command of the controller to increase the flow rate of the refrigerant flowing through thebypass path 60. Accordingly, it is possible to decrease the flow rate of the liquid refrigerant flowing into theeconomizer 4. Accordingly, even in a case where the refrigerant circulation amount increases, it is possible to prevent the liquid refrigerant from excessively flowing into theeconomizer 4. Accordingly, it is possible to suppress occurrence of a failure of the refrigerant distribution in theeconomizer 4 which is the plate type heat exchanger. - In addition, the
main expansion valve 5 can be bypassed, and thus, it is not necessary to adopt an expansion valve having a large diameter in anticipation of an increase of the refrigerant circulation amount, and there is no possibility that control accuracy of the expansion valve deteriorates. - In addition, the refrigerant is introduced to the inlet side of the cold water of the
evaporator 7 via thebypass path 60. Accordingly, the refrigerant can be introduced to the inlet side of the cold water which is a region in which the heat exchange amount is large, the refrigerant is evaporated, and thus, dry-out easily occurs. Therefore, the dry-out in this region is suppressed, and it is possible to improve a heat transfer coefficient in the evaporator. - In addition, the plate type heat exchanger having the configuration shown in the first embodiment may not be used as the
economizer 4. That is, an economizer may be used in which the pressure loss is adjusted such that a desired refrigerant distribution is performed on the flow rate of the refrigerant which flows into theeconomizer 4 when the liquid refrigerant is bypassed through thebypass path 60. REFERENCE SIGNS LIST - 1: turbo refrigerator (refrigerator)
- 2: turbo compressor (compressor)
- 2A: intake port
- 2B: discharge port
- 2C: intermediate intake port
- 3: condenser
- 4: economizer
- 5: main expansion valve
- 7: evaporator
- 13: sub-expansion valve
- 40: stacked plate
- 50, 60: bypass path
- 52, 62: bypass valve
Claims (7)
1. A refrigerator comprising:
a compressor which compresses a refrigerant;
a condenser which condenses the refrigerant compressed by the compressor;
an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve;
a main expansion valve which expands the liquid refrigerant introduced from the economizer; and
an evaporator which evaporates the refrigerant introduced from the main expansion valve, wherein the plate type heat exchanger is configured such that a width of a plate is 100 mm or more and 400 mm or less, a height of the plate is 300 mm or more and 1,000 mm or less, and the number of stacked plates is 80 or more.
2. A refrigerator comprising:
a compressor which compresses a refrigerant;
a condenser which condenses the refrigerant compressed by the compressor;
an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve;
a main expansion valve which expands the liquid refrigerant introduced from the economizer;
an evaporator which evaporates the refrigerant introduced from the main expansion valve;
a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to an upstream side of the main expansion valve;
a bypass valve which is provided in the bypass path; and
a controller which controls an opening degree of the bypass valve.
3. A refrigerator comprising:
a compressor which compresses a refrigerant;
a condenser which condenses the refrigerant compressed by the compressor;
an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve;
a main expansion valve which expands the liquid refrigerant introduced from the economizer;
an evaporator which evaporates the refrigerant introduced from the main expansion valve;
a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to a cooled-medium inlet side of the evaporator;
a bypass valve which is provided in the bypass path; and
a controller which controls an opening degree of the bypass valve.
4. The refrigerator according to claim 2 ,
wherein in a case where a difference between a pressure in the condenser and a pressure in the evaporator is equal or less than a predetermined value or an opening degree of the main expansion valve is equal to or more than a predetermined value, the controller increases the opening degree of the bypass valve.
5. A control method of a refrigerator,
the refrigerator includes
a compressor which compresses a refrigerant,
a condenser which condenses the refrigerant compressed by the compressor,
an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve,
a main expansion valve which expands the liquid refrigerant introduced from the economizer,
an evaporator which evaporates the refrigerant introduced from the main expansion valve,
a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to an upstream side of the main expansion valve, and
a bypass valve which is provided in the bypass path,
the control method comprising:
increasing the opening degree of the bypass valve in a case where a difference between a pressure in the condenser and a pressure in the evaporator is equal or less than a predetermined value or an opening degree of the main expansion valve is equal to or more than a predetermined value.
6. A control method of a refrigerator,
the refrigerator includes
a compressor which compresses a refrigerant,
a condenser which condenses the refrigerant compressed by the compressor,
an economizer which is a plate type heat exchanger which performs heat exchange between a liquid refrigerant introduced from the condenser and a two-phase refrigerant obtained by expanding a portion of the liquid refrigerant introduced from the condenser by a sub-expansion valve,
a main expansion valve which expands the liquid refrigerant introduced from the economizer,
an evaporator which evaporates the refrigerant introduced from the main expansion valve,
a bypass path which bypasses the economizer and through which the liquid refrigerant from the condenser is introduced to a cooled-medium inlet side of the evaporator, and
a bypass valve which is provided in the bypass path,
the control method comprising:
increasing the opening degree of the bypass valve in a case where a difference between a pressure in the condenser and a pressure in the evaporator is equal or less than a predetermined value or an opening degree of the main expansion valve is equal to or more than a predetermined value.
7. The refrigerator according to claim 3 ,
wherein in a case where a difference between a pressure in the condenser and a pressure in the evaporator is equal or less than a predetermined value or an opening degree of the main expansion valve is equal to or more than a predetermined value, the controller increases the opening degree of the bypass valve.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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JP2016030060A JP2017146068A (en) | 2016-02-19 | 2016-02-19 | Refrigerating machine and its control method |
JP2016-030060 | 2016-02-19 | ||
PCT/JP2017/003828 WO2017141720A1 (en) | 2016-02-19 | 2017-02-02 | Refrigerating machine and control method therefor |
Publications (1)
Publication Number | Publication Date |
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US20190017730A1 true US20190017730A1 (en) | 2019-01-17 |
Family
ID=59626050
Family Applications (1)
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US16/065,918 Abandoned US20190017730A1 (en) | 2016-02-19 | 2017-02-02 | Refrigerating machine and control method thereof |
Country Status (4)
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US (1) | US20190017730A1 (en) |
JP (1) | JP2017146068A (en) |
CN (1) | CN108474598A (en) |
WO (1) | WO2017141720A1 (en) |
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US10578342B1 (en) * | 2018-10-25 | 2020-03-03 | Ricardo Hiyagon Moromisato | Enhanced compression refrigeration cycle with turbo-compressor |
CN113294925A (en) * | 2021-05-21 | 2021-08-24 | 浙江国祥股份有限公司 | Evaporative condensation type water chilling unit with combined economizer |
US11162723B2 (en) * | 2019-03-29 | 2021-11-02 | Trane International Inc. | Methods and systems for controlling working fluid in HVACR systems |
US20220381485A1 (en) * | 2019-10-07 | 2022-12-01 | Shinwa Controls Co., Ltd | Hydrogen cooling apparatus, hydrogen supply system, and refrigerator |
EP4137759A1 (en) * | 2021-08-20 | 2023-02-22 | Carrier Corporation | Expansion control system on a centrifugal chiller with an integral subcooler |
US20230296243A1 (en) * | 2021-06-16 | 2023-09-21 | Colorado State University Research Foundation | Air source heat pump system and method of use for industrial steam generation |
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JP6878550B2 (en) * | 2019-10-31 | 2021-05-26 | 三菱重工サーマルシステムズ株式会社 | Refrigerator |
DK3879207T3 (en) * | 2020-03-10 | 2023-11-20 | Trane Int Inc | REFRIGERATING APPARATUS AND METHOD OF OPERATING THEREOF |
JP2022085386A (en) * | 2020-11-27 | 2022-06-08 | 三菱重工サーマルシステムズ株式会社 | refrigerator |
CN113048667B (en) * | 2021-03-22 | 2022-04-05 | 西安交通大学 | Mixed working medium refrigerating system with low-temperature storage box started quickly and control method |
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Also Published As
Publication number | Publication date |
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CN108474598A (en) | 2018-08-31 |
JP2017146068A (en) | 2017-08-24 |
WO2017141720A1 (en) | 2017-08-24 |
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