WO2022094115A1 - Système de refroidisseur ayant des évaporateurs à flux série - Google Patents

Système de refroidisseur ayant des évaporateurs à flux série Download PDF

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Publication number
WO2022094115A1
WO2022094115A1 PCT/US2021/057099 US2021057099W WO2022094115A1 WO 2022094115 A1 WO2022094115 A1 WO 2022094115A1 US 2021057099 W US2021057099 W US 2021057099W WO 2022094115 A1 WO2022094115 A1 WO 2022094115A1
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WO
WIPO (PCT)
Prior art keywords
evaporator
tubes
conditioning fluid
refrigerant
hvac
Prior art date
Application number
PCT/US2021/057099
Other languages
English (en)
Inventor
Yao YANG
Xingshun GAO
Original Assignee
Johnson Controls Building Efficiency Technology (Wuxi) Co., Ltd.
Johnson Controls Tyco IP Holdings LLP
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
Priority claimed from CN202011172089.1A external-priority patent/CN114484946A/zh
Priority claimed from CN202022441285.6U external-priority patent/CN215765883U/zh
Application filed by Johnson Controls Building Efficiency Technology (Wuxi) Co., Ltd., Johnson Controls Tyco IP Holdings LLP filed Critical Johnson Controls Building Efficiency Technology (Wuxi) Co., Ltd.
Priority to EP21887540.9A priority Critical patent/EP4237762A1/fr
Priority to US18/034,018 priority patent/US20230392828A1/en
Publication of WO2022094115A1 publication Critical patent/WO2022094115A1/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
    • F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
    • F25B5/04—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity arranged in series
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B39/00—Evaporators; Condensers
    • F25B39/02—Evaporators
    • 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
    • F25B41/00—Fluid-circulation 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
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/40—Fluid line 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
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/13—Economisers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
    • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
    • F28D2021/0068—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for refrigerant cycles
    • F28D2021/0071—Evaporators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
    • F28D7/0066—Multi-circuit heat-exchangers, e.g. integrating different heat exchange sections in the same unit or heat-exchangers for more than two fluids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
    • F28D7/16—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation

Definitions

  • Chiller systems utilize a working fluid (e.g., a refrigerant) that changes phases between vapor, liquid, and combinations thereof, in response to exposure to different temperatures and pressures within components of the chiller system.
  • a chiller system may place the working fluid in a heat exchange relationship with a conditioning fluid (e.g., water) and may deliver the conditioning fluid to conditioning equipment and/or a conditioned environment serviced by the chiller system.
  • the conditioning fluid may be passed through downstream equipment, such as air handlers, to condition other fluids, such as air in a building.
  • a chiller system may include multiple refrigerant circuits, and each refrigerant circuit includes a respective compressor, condenser, and evaporator.
  • the multiple refrigerant circuits may operate separately or in conjunction with one another to condition the conditioning fluid for delivery to the conditioning equipment.
  • existing chiller systems having multiple refrigerant circuits may be arranged in configurations that limit the performance and/or efficiency of the chiller system.
  • a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a first refrigerant circuit having a first evaporator configured to place a first refrigerant in a heat exchange relationship with a conditioning fluid, where the first evaporator includes a first set of first tubes and a second set of first tubes configured to direct the conditioning fluid through the first evaporator.
  • the HVAC&R system also includes a second refrigerant circuit having a second evaporator configured to place a second refrigerant in a heat exchange relationship with the conditioning fluid, where the second evaporator includes a first set of second tubes and a second set of second tubes configured to direct the conditioning fluid through the second evaporator.
  • the HVAC&R system further includes a conditioning fluid circuit configured to circulate the conditioning fluid serially through the first set of first tubes, the second set of first tubes, the first set of second tubes, and the second set of second tubes.
  • a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a first evaporator having a first lower tube bundle and a first upper tube bundle, where the first lower tube bundle and the first upper tube bundle are each configured to place a conditioning fluid in a heat exchange relationship with a first refrigerant, and a second evaporator having a second lower tube bundle and a second upper tube bundle, where the second lower tube bundle and the second upper tube bundle are each configured to place the conditioning fluid in a heat exchange relationship with a second refrigerant.
  • HVAC&R heating, ventilation, air conditioning, and/or refrigeration
  • the HVAC&R system also includes a conduit fluidly extending between the first evaporator and the second evaporator and fluidly coupling the first lower tube bundle and the second upper tube bundle and includes a conditioning fluid circuit configured to circulate the conditioning fluid serially through the second lower tube bundle, the second upper tube bundle, the conduit, the first lower tube bundle, and the first upper tube bundle.
  • a chiller system includes a first refrigerant circuit having a first evaporator configured to place a first refrigerant in a heat exchange relationship with a conditioning fluid, where the first evaporator includes a first plurality of first tubes and a second plurality of first tubes configured to direct the conditioning fluid through the first evaporator, the first plurality of first tubes defines a lower pass of the first evaporator, and the second plurality of first tubes defines an upper pass of the first evaporator.
  • the chiller system also includes a second refrigerant circuit having a second evaporator configured to place a second refrigerant in a heat exchange relationship with the conditioning fluid, where the second evaporator includes a first plurality of second tubes and a second plurality of second tubes configured to direct the conditioning fluid through the second evaporator, where the first plurality of second tubes defines a lower pass of the second evaporator, and the second plurality of second tubes defines an upper pass of the second evaporator.
  • the chiller system further includes a conduit fluidly coupled between the second plurality of second tubes and the first plurality of first tubes.
  • FIG. 1 is a perspective view of a building that may utilize an embodiment of a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system in a commercial setting, in accordance with an aspect of the present disclosure;
  • HVAC&R heating, ventilation, air conditioning, and/or refrigeration
  • FIG. 2 is a schematic of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure
  • FIG. 3 is a schematic of an embodiment of an HVAC&R system having multiple refrigerant circuits, illustrating evaporators of the multiple refrigerant circuits in a serial flow arrangement, in accordance with an aspect of the present disclosure
  • FIG. 4 is a side view of an embodiment of evaporators of multiple refrigerant circuits in a serial flow arrangement, illustrating the evaporators in an aligned configuration, in accordance with an aspect of the present disclosure
  • FIG. 5 is a top view of an embodiment of evaporators of multiple refrigerant circuits in a serial flow arrangement, illustrating the evaporators in a side-by-side configuration, in accordance with an aspect of the present disclosure
  • FIG. 6 is an axial view of an embodiment of evaporators of multiple refrigerant circuits in a serial flow arrangement, illustrating the evaporators in a side-by-side configuration, in accordance with an aspect of the present disclosure
  • FIG. 7 is a schematic of an embodiment of an HVAC&R system having multiple refrigerant circuits, illustrating a control system and evaporators of the multiple refrigerant circuits in a serial flow arrangement, in accordance with an aspect of the present disclosure.
  • Embodiments of the present disclosure relate to a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system, such as a chiller system.
  • HVAC&R heating, ventilation, air conditioning, and/or refrigeration
  • the HVAC&R system may include a vapor compression system through which a refrigerant is directed in order to heat and/or cool a conditioning fluid.
  • the vapor compression system may include a compressor configured to pressurize the refrigerant and to direct the pressurized refrigerant to a condenser configured to cool the pressurized refrigerant.
  • An evaporator of the vapor compression system may receive the cooled refrigerant and may place the cooled refrigerant in a heat exchange relationship with the conditioning fluid to absorb thermal energy or heat from the conditioning fluid, thereby cooling the conditioning fluid.
  • the cooled conditioning fluid may then be directed to conditioning equipment, such as air handlers and/or terminal units, for use in conditioning air supplied to a building or other conditioned space.
  • the vapor compression system may include multiple refrigerant circuits with each refrigerant circuit including a respective condenser, compressor, and evaporator.
  • the evaporators of the multiple refrigerant circuits may cooperatively cool the conditioning fluid for use with the conditioning equipment.
  • the evaporators may operate to cool a common flow of the conditioning fluid.
  • Some evaporators are configured to cool the conditioning fluid via tubes that form a flow path defining multiple passes through the evaporator.
  • the conditioning fluid may be directed through a first tube bundle of the evaporator in a first direction, and the flow of the conditioning fluid may be reversed (e.g., via a water box of the evaporator) and then directed through a second tube bundle of the evaporator in a second direction opposite the first direction.
  • Existing systems having multiple (e.g., two) refrigerant circuits typically include evaporators packaged together and configured to cool conditioning fluid by directing the conditioning fluid alternatingly between the evaporators.
  • existing systems may direct conditioning fluid sequentially through a first (e.g., lower) tube bundle or pass of a first evaporator and then through a first (e.g., lower) tube bundle or pass of the second evaporator. Thereafter, the flow direction of the conditioning fluid may be reversed, and the conditioning fluid may be directed sequentially through a second (e.g., upper) tube bundle or pass of the second evaporator and then through a second (e.g., upper) tube bundle or pass of the first evaporator.
  • serial flow refers to flow of conditioning fluid first through the passes of one evaporator of the HVAC&R system and subsequently through the passes of another evaporator of the HVAC&R system.
  • the conditioning fluid received from the conditioning equipment first flows through a first evaporator of the HVAC&R system, then flows through a second evaporator of the HVAC&R system, and is then directed back to the conditioning equipment.
  • the serial flow arrangement of the evaporators in a multiple refrigerant circuit system enables efficiency improvements and reductions in costs associated with the HVAC&R system.
  • FIG. 1 is a perspective view of an embodiment of an application for a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system.
  • HVAC&R heating, ventilation, air conditioning, and/or refrigeration
  • Such systems in general, may be applied in a range of settings, both within the HVAC&R field and outside of that field.
  • the HVAC&R systems may provide cooling to data centers, electrical devices, freezers, coolers, or other environments through vapor compression refrigeration, absorption refrigeration, or thermoelectric cooling.
  • HVAC&R systems may be used in residential, commercial, light industrial, industrial, and in any other application for heating or cooling a volume or enclosure, such as a residence, building, structure, and so forth.
  • the HVAC&R systems may be used in industrial applications, where appropriate, for basic cooling and heating of various fluids.
  • the illustrated embodiment shows an HVAC&R system for building environmental management that may utilize heat exchangers.
  • a building 10 is cooled by a system that includes a chiller 12 and a boiler 14.
  • the chiller 12 is disposed on the roof of building 10, and the boiler 14 is located in the basement; however, the chiller 12 and boiler 14 may be located in other equipment rooms or areas next to the building 10.
  • the chiller 12 may be an air cooled or water cooled device that implements a refrigeration cycle to cool water or other conditioning fluid.
  • the chiller 12 is housed within a structure that may include one or more refrigeration circuits, a free cooling system, and associated equipment such as pumps, valves, and piping.
  • the chiller 12 may be single package rooftop unit.
  • the boiler 14 is a closed vessel in which water is heated.
  • the water from the chiller 12 and the boiler 14 is circulated through the building 10 by water conduits 16.
  • the water conduits 16 are routed to air handlers 18 (e.g., conditioning equipment) located on individual floors and within sections of the building 10.
  • the air handlers 18 are coupled to ductwork 20 that is adapted to distribute air between the air handlers 18 and may receive air from an outside intake (not shown).
  • the air handlers 18 include heat exchangers that circulate cold water from the chiller 12 and hot water from the boiler 14 to provide heated or cooled air to conditioned spaces within the building 10.
  • Fans within the air handlers 18 draw air through the heat exchangers and direct the conditioned air to environments within building 10, such as rooms, apartments, or offices, to maintain the environments at a designated temperature.
  • a control device shown here as including a thermostat 22, may be used to designate the temperature of the conditioned air.
  • the control device 22 also may be used to control the flow of air through and from the air handlers 18.
  • control devices may be included in the system, such as control valves that regulate the flow of water and pressure and/or temperature transducers or switches that sense the temperatures and pressures of the water, the air, and so forth.
  • control devices may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building 10.
  • FIG. 2 is a schematic of an embodiment of a vapor compression system 30 of an HVAC&R system that includes a refrigerant circuit 34 configured to cool a conditioning fluid (e.g., water).
  • a conditioning fluid e.g., water
  • the vapor compression system 30 may be a part of an air-cooled chiller.
  • the refrigerant circuit 34 is configured to circulate a working fluid, such as refrigerant, therethrough with a compressor 36 (e.g., a screw compressor) disposed along the refrigerant circuit 34.
  • a compressor 36 e.g., a screw compressor
  • the refrigerant circuit 34 also includes the flash tank 32, a condenser 38, expansion valves or devices 40, and a liquid chiller or an evaporator 42.
  • the components of the refrigerant circuit 34 enable heat transfer between the working fluid and other fluids (e.g., a conditioning fluid, air, water, etc.) in order to provide cooling to an environment, such as an interior of the building 10.
  • HFC hydrofluorocarbon
  • R- 410A R-407, R-134a
  • HFO hydrofluoro-olefin
  • NH3 ammonia
  • R-717 R-717
  • CO2 carbon dioxide
  • R-744 R-744
  • hydrocarbon based refrigerants water vapor, refrigerants with low global warming potential (GWP), or any other suitable refrigerant.
  • GWP global warming potential
  • the vapor compression system 30 may be configured to efficiently utilize refrigerants having a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit or less) at one atmosphere of pressure, also referred to as low pressure refrigerants, versus a medium pressure refrigerant, such as R-134a.
  • refrigerants having a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit or less) at one atmosphere of pressure also referred to as low pressure refrigerants
  • medium pressure refrigerant such as R-134a.
  • “normal boiling point” may refer to a boiling point temperature measured at one atmosphere of pressure.
  • the vapor compression system 30 may further include a control panel 44 (e.g., controller) that has an analog to digital (A/D) converter 46, a microprocessor 48, a nonvolatile memory 50, and/or an interface board 52.
  • the vapor compression system 30 may use one or more of a variable speed drive (VSDs) 54 and a motor 56.
  • the motor 56 may drive the compressor 36 and may be powered by the VSD 54.
  • the VSD 54 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 56.
  • the motor 56 may be powered directly from an AC or direct current (DC) power source.
  • the motor 56 may include any type of electric motor that can be powered by the VSD 54 or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.
  • the compressor 36 compresses a refrigerant vapor and may deliver the vapor to an oil separator 58 that separates oil from the refrigerant vapor.
  • the refrigerant vapor is then directed toward the condenser 38, and the oil is returned to the compressor 36.
  • the refrigerant vapor delivered to the condenser 38 may transfer heat to a cooling fluid at the condenser 38.
  • the cooling fluid may be ambient air 60 forced across heat exchanger coils of the condenser 38 by condenser fans 62.
  • the refrigerant vapor may condense to a refrigerant liquid in the condenser 38 as a result of thermal heat transfer with the cooling fluid (e.g., the ambient air 60).
  • the first expansion device 64 may be a flash tank feed valve configured to control flow of the liquid refrigerant to the flash tank 32.
  • the first expansion device 64 is also configured to lower the pressure of (e.g., expand) the liquid refrigerant received from the condenser 38.
  • the flash tank 32 may be used to separate the vapor from the liquid received from the first expansion device 64.
  • the flash tank 32 may provide for further expansion of the liquid refrigerant due to a pressure drop experienced by the liquid refrigerant when entering the flash tank 32 (e.g., due to a rapid increase in volume experienced upon entering the flash tank 32).
  • the vapor in the flash tank 32 may exit and flow to the compressor 36.
  • the vapor may be drawn to an intermediate stage or discharge stage of the compressor 36 (e.g., not a suction stage).
  • a valve 66 e.g., economizer valve, solenoid valve, etc.
  • the valve 66 when the valve 66 is open (e.g., fully open), additional liquid refrigerant within the flash tank 32 may vaporize and provide additional subcooling of the liquid refrigerant within the flash tank 32.
  • the liquid refrigerant that collects in the flash tank 32 may be at a lower enthalpy than the liquid refrigerant exiting the condenser 38 because of the expansion in the first expansion device 64 and/or the flash tank 32.
  • the liquid refrigerant may flow from the flash tank 32, through a second expansion device 68 (e.g., expansion device 40, an orifice, etc.), and to the evaporator 42.
  • the refrigerant circuit 34 may also include a valve 70 (e.g., drain valve) configured to regulate flow of liquid refrigerant from the flash tank 32 to the evaporator 42.
  • the valve 70 may be controlled (e.g., via the control panel 44) based on an amount of suction superheat of the refrigerant.
  • the liquid refrigerant delivered to the evaporator 42 may absorb heat from a conditioning fluid, which may or may not be the same cooling fluid used in the condenser 38.
  • the liquid refrigerant in the evaporator 42 may undergo a phase change to become vapor refrigerant.
  • the evaporator 42 may include one or more tube bundles fluidly coupled to a supply line 72 and a return line 74 that are connected to a cooling load.
  • the conditioning fluid of the evaporator 42 e.g., water, oil, calcium chloride brine, sodium chloride brine, or any other suitable fluid
  • the evaporator 42 may reduce the temperature of the conditioning fluid in the tube bundle via thermal heat transfer with the refrigerant so that the conditioning fluid may be utilized to provide cooling for a conditioned environment.
  • the tube bundle in the evaporator 42 can include a plurality of tubes and/or a plurality of tube bundles. In some embodiments, the tubes or tube bundles may define multiple passes through the evaporator 42. In any case, the refrigerant vapor exits the evaporator 42 and returns to the compressor 36 by a suction line to complete the refrigerant cycle.
  • an HVAC&R system may include multiple refrigerant circuits configured to separately and/or cooperatively cool the conditioning fluid.
  • present embodiments include an HVAC&R system having multiple refrigerant circuits in which the evaporators of the multiple refrigerant circuits are arranged in a serial flow arrangement (e.g., relative to a flow of conditioning fluid through the evaporators).
  • the evaporators are arranged, fluidly coupled, and/or packaged such that the conditioning fluid received from the cooling load first flows through one evaporator of one refrigerant circuit, then flows through another evaporator of another refrigerant circuit, and is then directed back to the cooling load.
  • the conditioning fluid may first be sequentially directed through multiple passes of one evaporator and subsequently be sequentially directed through multiple passes of another evaporator.
  • the evaporator approach temperature(s) of the HVAC&R system may be reduced, which results in efficiency improvements and reductions in costs associated with the HVAC&R system.
  • FIG. 3 is a schematic of an embodiment of an HVAC&R system 100 having multiple refrigerant circuits 34. More specifically, the HVAC&R system 100 includes a first refrigerant circuit 102 (e.g., vapor compression circuit) having a first compressor 104, a first condenser 106, a first expansion device 108, and a first evaporator 110 and includes a second refrigerant circuit 112 (e.g., vapor compression circuit) having a second compressor 114, a second condenser 116, a second expansion device 118, and a second evaporator 120.
  • a first refrigerant circuit 102 e.g., vapor compression circuit
  • second refrigerant circuit 112 e.g., vapor compression circuit
  • Each of the refrigerant circuits 34 is configured to circulate a respective refrigerant therethrough and is configured to operate in a manner similar to that described above with reference to the refrigerant circuit 34 shown in FIG. 2. It should be noted that each of the refrigerant circuits 34 may also include components in addition to those shown in FIG. 3, such as one or more components illustrated in the refrigerant circuit 34 of FIG. 2. In some embodiments, the first and second refrigerant circuits 102 and 112 may be packaged together in a single package unit (e.g., a rooftop unit).
  • the first and second evaporators 110 and 120 of the HVAC&R system 100 are arranged in a serial flow arrangement.
  • the first and second evaporators 110 and 120 are configured to define a portion of a conditioning fluid flow path or circuit 124 that extends from a cooling load 122 (e.g., air handlers 118), sequentially through evaporators 110 and 120, and back to the cooling load 122.
  • a cooling load 122 e.g., air handlers 118
  • each of the first and second evaporators 110 and 120 may include multiple passes (e.g., tube passes, tube bundles, sets of tubes, etc.) configured to direct conditioning fluid therethrough.
  • the HVAC&R system 100 is configured to direct conditioning fluid received from the cooling load 122 first through the passes of one evaporator and subsequently through the passes of another evaporator before directing the conditioning fluid back to the cooling load 122.
  • the HVAC&R system 100 e.g., the conditioning fluid circuit 124
  • the HVAC&R system 100 may be configured to direct the conditioning fluid through the first evaporator 110, then through the second evaporator 120, before directing the conditioning fluid back to the cooling load 122.
  • the disclosed serial flow arrangement enables a reduction in the separate and/or combined evaporator approach temperature of the first evaporator 110 and/or the second evaporator 120.
  • the refrigerant pressure within the first evaporator 110 and/or the second evaporator 120 may be raised, which may reduce a lift of the first refrigerant circuit 102 and/or the second refrigerant circuit 112, respectively.
  • energy consumption of the first compressor 104 and/or the second compressor 114 may be reduced, which enables a reduction in costs associated with operating the HVAC system 100.
  • FIG. 4 is a side view of an embodiment of the first evaporator 110 and the second evaporator 120 of the HVAC&R system 100 connected in a serial flow arrangement 150 with respect to flow of conditioning fluid therethrough. More specifically, the first evaporator 110 and the second evaporator 120 are positioned in an aligned configuration (e.g., aligned along longitudinal axes of the first evaporator 110 and the second evaporator 120). The configuration shown in FIG. 4 may also be referred to as an end-to-end arrangement.
  • the serial flow arrangement 150 disclosed herein is described with reference to an implementation with the first evaporator 110 and the second evaporator 120, in other embodiments the serial flow arrangement 150 may be utilized with other types of heat exchangers, such as condensers, and/or with other numbers of heat exchangers.
  • the HVAC&R system 100 e.g., the conditioning fluid circuit 124 is configured to direct a conditioning fluid from the cooling load 122 first through the second evaporator 120, then through the first evaporator 110, and then back to the cooling load 122.
  • the first and second evaporators 110 and 120 are each configured as two-pass heat exchangers.
  • the first evaporator 110 includes a first pass 152 and a second pass 154
  • the second evaporator 120 include a first pass 156 and a second pass 158.
  • Each of the passes 152, 154, 156, and 158 may be defined by a respective set of tubes (e.g., a respective tube bundle) configured to direct the conditioning fluid therethrough.
  • each of the first and second evaporators 110 and 120 heat is exchanged between the conditioning fluid and a respective refrigerant directed through the first and second evaporators 110 and 120. That is, a first refrigerant flowing through the first refrigerant circuit 102, as indicated by arrow 160, may be directed into a shell 162 of the first evaporator 110, and heat may be transferred from the first refrigerant 160 to the conditioning fluid flowing through the tubes of the first and second passes 152 and 154 of the first evaporator 110.
  • a second refrigerant directed through the second refrigerant circuit 112, as indicated by arrow 164, may be directed into a shell 166 of the second evaporator 120, and heat may be transferred from the second refrigerant 164 to the conditioning fluid flowing through the tubes of the first and second passes 156 and 158 of the second evaporator 120.
  • the first evaporator 110 and/or the second evaporator 120 may be configured as a flooded evaporator, while in other embodiments the first evaporator 110 and/or the second evaporator 120 may be configured as a falling film evaporator.
  • the serial flow arrangement 150 of the first evaporator 110 and the second evaporator 120 receives the conditioning fluid, represented by arrow 168, via an inlet 170 of the second evaporator 120. That is, conditioning fluid from the cooling load 122 is directed into the serial flow arrangement 150 via the inlet 170.
  • the inlet 170 directs the conditioning fluid into a first water box 174 and a second section 176 by a baffle 178 that enables fluid separation of the first section 174 and the second section 176.
  • the conditioning fluid is directed through a first tube bundle 180 (e.g., a set of tubes) defining the first tube pass 156 of the second evaporator 120, as indicated by arrow 182.
  • first tube pass 156 is a lower tube pass of the second evaporator 120, but in other embodiments the first tube pass 156 may be an upper tube pass or an intermediate tube pass.
  • the conditioning fluid is directed into a second water box 184 of the second evaporator 120.
  • the second water box 184 reverses the flow direction of conditioning fluid through the second evaporator 120, as indicated by arrow 186, to direct the conditioning fluid through the second pass 158 of the second evaporator 120.
  • the conditioning fluid is directed through a second tube bundle 188 (e.g., a set of tubes) of the second pass 158, as indicated by arrow 190, which is an upper pass of the second evaporator 120.
  • the conditioning fluid is then directed into the second section 176 of the first water box 172, from which the condition fluid is discharged from the second evaporator 120 via an outlet 192 of the second evaporator 120.
  • the conditioning fluid is then circulated through the first evaporator 110.
  • the conditioning fluid is directed from the second evaporator 120 to the first evaporator 110 via a conduit (e.g., transfer conduit) 194 that fluidly couples the outlet 192 of the second evaporator 120 with an inlet 196 of the first evaporator 110.
  • the first evaporator 110 has a similar construction and/or configuration as the second evaporator 120, and the conditioning fluid is directed through the first evaporator 110 in a manner similar to that described above with reference to the second evaporator 120.
  • the inlet 196 of the first evaporator 110 directs the conditioning fluid into a first water box 198 of the first evaporator 110.
  • the first water box 198 is divided into a first section 200 and a second section 202 by a baffle 204 that enables fluid separation of the first section 200 and the second section 202.
  • the conditioning fluid is directed through a first tube bundle 206 defining the first tube pass 152 of the first evaporator 110, as indicated by arrow 208.
  • the first tube pass 152 is a lower tube pass of the first evaporator 110, but in other embodiments the first tube pass 152 may be an upper tube pass or an intermediate tube pass.
  • the conditioning fluid is directed into a second water box 210 of the first evaporator 110.
  • the second water box 210 reverses the flow of conditioning fluid through the first evaporator 110, as indicated by arrow 212, to direct the conditioning fluid through the second pass 154 of the first evaporator 110.
  • the conditioning fluid is directed through a second tube bundle 214 of the second pass 154, as indicated by arrow 216, which is an upper pass of the first evaporator 110.
  • the conditioning fluid is then directed into the second section 202 of the first water box 198, from which the conditioning fluid is discharged from the first evaporator 110 via an outlet 218 of the first evaporator 110, as indicated by arrow 220. Thereafter, the conditioning fluid is directed back to the cooling load 122 for use in conditioning air or another fluid.
  • the serial flow arrangement 150 of the first evaporator 110 and the second evaporator 120 enables a reduction in the evaporator approach temperature(s) of the first evaporator 110 and/or the second evaporator 120.
  • respective temperature differences of the entering and exiting conditioning fluid for each of the first and second evaporators 110 and 120 may also be reduced.
  • a difference between the temperature of the conditioning fluid leaving the second evaporator 120 via the outlet 192 and a saturated evaporating temperature of the second refrigerant 164 may be less than that of the existing systems described above.
  • a pressure of the second refrigerant 164 exiting the second evaporator 120, and therefore a suction pressure of the second refrigerant 164 may be greater than that of existing systems, which enables a reduced energy consumption of the second compressor 114.
  • a difference between the temperature of the conditioning fluid leaving the first evaporator 110 via the outlet 218 and a saturated evaporating temperature of the first refrigerant 160 may be less than that of existing systems.
  • a pressure of the first refrigerant 160 exiting the first evaporator 110, and therefore a suction pressure of the first refrigerant 160 may be greater than that of existing systems, which enables a reduced energy consumption of the first compressor 104.
  • HVAC&R system 100 may be reduced. Indeed, while the average refrigerant and/or conditioning fluid temperatures of the first evaporator and second evaporators 110 and 120 may be somewhat increased, an overall benefit and efficiency improvement of the HVAC&R system 100 may be realized with the serial flow arrangement 150 described herein by virtue of the advantages described above.
  • a further benefit of the serial flow arrangement 150 of the first and second evaporators 110 and 120 relates to manufacture of the HVAC&R system 100.
  • the first evaporator 110 and the second evaporator 120 have similar configurations and/or constructions and are connected via the conduit 194.
  • a common or single design of a heat exchanger may be manufactured and mass produced for use as each of the first evaporator 110 and the second evaporator 120.
  • costs of design and manufacture of the HVAC&R system 100 may be reduced.
  • positions of the first evaporator 110 and the second evaporator 120 relative to one another may be selected, and a suitable embodiment of the conduit 194 may be cost-effectively manufactured or produced to enable fluid coupling of the first evaporator 110 and the second evaporator 120.
  • configurations and/or orientations of the inlets 170 and 196 and outlets 192 and 218 may be readily selected or adjusted accordingly.
  • FIG. 5 is a top view of an embodiment of the first evaporator 110 and the second evaporator 120 of the HVAC&R system 100 connected in the serial flow arrangement 150.
  • FIG. 6 is an axial view of the embodiment of the first evaporator 110 and the second evaporator 120 shown in FIG. 5. More specifically, the first evaporator 110 and the second evaporator 120 in the illustrated embodiments are positioned or arranged in side-by-side configuration (e.g., positioned such that lengths of first evaporator 110 and the second evaporator 120 are adjacent or next to one another).
  • the embodiments of FIGS. 5 and 6 have similar elements and element numbers as the embodiment of FIG. 4 and are configured to operate in a similar manner as that described above.
  • the serial flow arrangement 150 of the first evaporator 110 and the second evaporator 120 enables conducive selection of a relative arrangement of the first evaporator 110 and the second evaporator 120, while also providing a reduction in costs associated with manufacture and operation of the HVAC&R system 100.
  • the first and second evaporators 110 and 120 may have other configurations relative to one another in the serial flow arrangement 150, such as a stacked configuration.
  • FIG. 7 is a schematic of an embodiment of the HVAC&R system 100 having multiple refrigerant circuits 34, including the first evaporator 110 and the second evaporator 120 in the serial flow arrangement 150.
  • the illustrated embodiment also includes features that enable selective and/or adjustable control of the HVAC&R system 100.
  • the HVAC&R system 100 includes a controller 240 (e.g., control panel 44) having a memory 242 (e.g., non-volatile memory 50) and a processor 244 (e.g., microprocessor 48).
  • the controller 240 may be included with or separate from the control panel 44.
  • the memory 242 may be a mass storage device, a flash memory device, removable memory, or any other non-transitory computer-readable medium that includes instructions for the processor 244 to execute.
  • the memory 242 may also include volatile memory such as randomly accessible memory (RAM) and/or non-volatile memory such as hard disc memory, flash memory, and/or other suitable memory formats.
  • RAM randomly accessible memory
  • the processor 244 may execute the instructions stored in the memory 242, in order to adjust operation of the HVAC&R system 100.
  • the controller 240 may be configured to control operation of components of the HVAC&R system 100, such as the components of the first refrigerant circuit 102 and the second refrigerant circuit 104 described herein. In some embodiments, the controller 240 may adjust operation of the HVAC&R system 100 based on feedback received by the controller 240, such as feedback received from sensors 246 of the HVAC&R system 100.
  • One or more of the sensors 246 may be configured to detect operating parameters of the HVAC&R system 100, such as a temperature or pressure of the first refrigerant 160 circulated by the first refrigerant circuit 102, a temperature or pressure of the second refrigerant 164 circulated by the second refrigerant circuit 104, a temperature of the conditioning fluid, an operating mode of the HVAC&R system or a component thereof, an operating load or capacity of the HVAC&R system, an ambient temperature, another suitable operating parameter, and/or any combination thereof.
  • operating parameters of the HVAC&R system 100 such as a temperature or pressure of the first refrigerant 160 circulated by the first refrigerant circuit 102, a temperature or pressure of the second refrigerant 164 circulated by the second refrigerant circuit 104, a temperature of the conditioning fluid, an operating mode of the HVAC&R system or a component thereof, an operating load or capacity of the HVAC&R system, an ambient temperature, another suitable operating parameter, and/or any combination thereof.
  • one or more of the sensors 246 may be positioned at any desirable location in order to detect an operating parameter, such as any desirable location along the first refrigerant circuit 102, the second refrigerant circuit 104, and/or the flow path of the conditioning fluid (e.g., the conditioning fluid circuit 124).
  • an operating parameter such as any desirable location along the first refrigerant circuit 102, the second refrigerant circuit 104, and/or the flow path of the conditioning fluid (e.g., the conditioning fluid circuit 124).
  • the controller may adjust operation of the HVAC&R system 100.
  • operation of the first and second refrigerant circuits 102 and 104 may be adjusted based on an operating load of the HVAC&R system 100.
  • the first refrigerant circuit 102 and the second refrigerant circuit 104 e.g., the compressors 104 and 114
  • the controller 240 may each be operated, via the controller 240, at 50 percent capacity.
  • the first refrigerant circuit 102 may be operated at 100 percent capacity
  • the second refrigerant circuit 104 may be operated at 25 percent capacity.
  • the controller 240 may control operation of the HVAC&R system 100 such that one refrigerant circuit operates and the other refrigerant circuit does not operate. For example, at 25 percent capacity of the HVAC&R system 100, the controller 240 may suspend operation of the second refrigerant circuit 104 and may operate the first refrigerant circuit 102.
  • the HVAC&R system 100 e.g., the conditioning fluid circuit 124 may include a bypass line configured to route the conditioning fluid from the cooling load 122, through the first evaporator 110, and back to the cooling load 122, such that the flow of conditioning fluid bypasses the second evaporator 120.
  • a bypass valve e.g., a three-way valve 248 is disposed along the conduit 194 and may be actuated (e.g., via the controller 240) to enable bypass of the second evaporator 120 and enable flow of the conditioning fluid from the cooling load 122 to the first evaporator 110, as indicated by arrow 250.
  • HVAC&R systems e.g., chillers
  • the serial flow arrangement of the evaporators of multiple refrigerant circuits enables a reduction in the evaporator approach temperature of the HVAC&R system.
  • refrigerant pressure in the evaporators may be raised, which may reduce a lift of the HVAC&R system and therefore reduce the work performed by compressors of the HVAC&R system. Accordingly, energy consumption of the HVAC system is reduced.
  • the serial flow arrangement enables cost-effective manufacture of the HVAC&R system in multiple different structural configurations or arrangements.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Other Air-Conditioning Systems (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

L'invention concerne un système de chauffage, de ventilation, de climatisation et/ou de réfrigération (CVC&R) qui comprend un premier circuit de fluide frigorigène ayant un premier évaporateur configuré pour placer un premier fluide frigorigène dans une relation d'échange de chaleur avec un fluide de conditionnement, le premier évaporateur comprenant un premier ensemble de premiers tubes et un second ensemble de premiers tubes configurés pour diriger le fluide de conditionnement à travers le premier évaporateur. Le système CVC&R comprend également un second circuit de fluide frigorigène ayant un second évaporateur configuré pour placer un second fluide frigorigène dans une relation d'échange de chaleur avec le fluide de conditionnement, le second évaporateur comprenant un premier ensemble de seconds tubes et un second ensemble de seconds tubes configurés pour diriger le fluide de conditionnement à travers le second évaporateur. Le système CVC&R comprend en outre un circuit de fluide de conditionnement configuré pour faire circuler le fluide de conditionnement en série à travers le premier ensemble de premiers tubes, le second ensemble de premiers tubes, le premier ensemble de seconds tubes et le second ensemble de seconds tubes.
PCT/US2021/057099 2020-10-28 2021-10-28 Système de refroidisseur ayant des évaporateurs à flux série WO2022094115A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP21887540.9A EP4237762A1 (fr) 2020-10-28 2021-10-28 Système de refroidisseur ayant des évaporateurs à flux série
US18/034,018 US20230392828A1 (en) 2020-10-28 2021-10-28 Chiller system with serial flow evaporators

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN202011172089.1A CN114484946A (zh) 2020-10-28 2020-10-28 具有串流蒸发器的冷却器系统
CN202022441285.6 2020-10-28
CN202022441285.6U CN215765883U (zh) 2020-10-28 2020-10-28 加热、通风、空调和/或制冷系统以及冷却器系统
CN202011172089.1 2020-10-28

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WO2022094115A1 true WO2022094115A1 (fr) 2022-05-05

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040050093A1 (en) * 2002-09-18 2004-03-18 Alexander Lifson Performance enhancement of vapor compression systems with multiple circuits
US20120111040A1 (en) * 2009-06-29 2012-05-10 Johnson Controls Technology Company System for limiting pressure differences in dual compressor chillers
US20180156505A1 (en) * 2007-09-18 2018-06-07 Carrier Corporation Methods and systems for controlling integrated air conditioning systems
CN109959183A (zh) * 2019-03-21 2019-07-02 华南理工大学 一种基于强化传质的吸附式制冷系统
US20200109880A1 (en) * 2012-10-09 2020-04-09 Inertech Ip Llc Cooling systems and methods incorporating a plural in-series pumped liquid refrigerant trim evaporator cycle

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040050093A1 (en) * 2002-09-18 2004-03-18 Alexander Lifson Performance enhancement of vapor compression systems with multiple circuits
US20180156505A1 (en) * 2007-09-18 2018-06-07 Carrier Corporation Methods and systems for controlling integrated air conditioning systems
US20120111040A1 (en) * 2009-06-29 2012-05-10 Johnson Controls Technology Company System for limiting pressure differences in dual compressor chillers
US20200109880A1 (en) * 2012-10-09 2020-04-09 Inertech Ip Llc Cooling systems and methods incorporating a plural in-series pumped liquid refrigerant trim evaporator cycle
CN109959183A (zh) * 2019-03-21 2019-07-02 华南理工大学 一种基于强化传质的吸附式制冷系统

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TW202225609A (zh) 2022-07-01
US20230392828A1 (en) 2023-12-07

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