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WO2020118241A1 - Systèmes de climatisation à déshydratant liquide et procédés pour des serres et des cellules de croissance - Google Patents

Systèmes de climatisation à déshydratant liquide et procédés pour des serres et des cellules de croissance Download PDF

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Publication number
WO2020118241A1
WO2020118241A1 PCT/US2019/065050 US2019065050W WO2020118241A1 WO 2020118241 A1 WO2020118241 A1 WO 2020118241A1 US 2019065050 W US2019065050 W US 2019065050W WO 2020118241 A1 WO2020118241 A1 WO 2020118241A1
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Prior art keywords
liquid desiccant
air stream
air
conditioner
greenhouse
Prior art date
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Ceased
Application number
PCT/US2019/065050
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English (en)
Inventor
Peter LUTTIK
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Copeland LP
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7AC Technologies Inc
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Filing date
Publication date
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Publication of WO2020118241A1 publication Critical patent/WO2020118241A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
    • F24F3/12—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling
    • F24F3/14—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification
    • F24F3/1411—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification by absorbing or adsorbing water, e.g. using an hygroscopic desiccant
    • F24F3/1417—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification by absorbing or adsorbing water, e.g. using an hygroscopic desiccant with liquid hygroscopic desiccants
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
    • A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
    • A01G9/24—Devices or systems for heating, ventilating, regulating temperature, illuminating, or watering, in greenhouses, forcing-frames, or the like
    • A01G9/246—Air-conditioning systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F12/00—Use of energy recovery systems in air conditioning, ventilation or screening
    • F24F12/001—Use of energy recovery systems in air conditioning, ventilation or screening with heat-exchange between supplied and exhausted air
    • F24F12/006—Use of energy recovery systems in air conditioning, ventilation or screening with heat-exchange between supplied and exhausted air using an air-to-air heat exchanger
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
    • F24F3/06—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the arrangements for the supply of heat-exchange fluid for the subsequent treatment of primary air in the room units
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
    • Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
    • Y02A40/25—Greenhouse technology, e.g. cooling systems therefor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/56—Heat recovery units
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P60/00—Technologies relating to agriculture, livestock or agroalimentary industries
    • Y02P60/14—Measures for saving energy, e.g. in green houses

Definitions

  • the present application relates generally to liquid desiccant air conditioning (LDAC) systems and, more specifically, to liquid desiccant air-conditioning systems for greenhouses and closed building growth cells (also known as grow rooms).
  • LDAC liquid desiccant air conditioning
  • Greenhouses have direct access to sunlight, and have large sensible and latent loads during the summer, while heating and dehumidification is required in the winter. In winter, lights are an additional heat source to maintain 12-16 hour growth periods.
  • Growth cells are within closed buildings with limited or no ventilation. Lighting is artificial. Large volumes of water are added to the plants, which use it for growth and evaporation. This will also significantly cool the space. Heating sources are lights and production of carbon dioxide (C02) supplied to the space. The lights can be low efficiency sodium and natrium lights or high efficiency LEDs. C02 can be provided from burning gas or from bottled gas.
  • Greenhouse and growth-cell production conditions differ not only by crop but also by crop maturity. For example, many products maximize production at high relatively humidity (60-80%), but humidity levels above 80% can lead to significant damage to crops due to growth of pathogens. Some crops require much lower humidities, e.g., 50% RH for some marijuana products.
  • Various embodiments disclosed herein relate to combining superior dehumidification of liquid desiccants with appropriate energy management to maintain the required conditions at minimum temperature requirements.
  • a liquid desiccant air-conditioning system in accordance with one or more embodiments is provided for managing temperature and humidity conditions in a greenhouse or a growth cell.
  • the system includes a liquid desiccant conditioner utilizing a liquid desiccant to dehumidify a first air stream flowing therethrough.
  • the first air stream enters the liquid desiccant conditioner from a space within the greenhouse or growth cell and exits the liquid desiccant conditioner as supply air to the greenhouse or growth cell.
  • the system also includes a liquid desiccant regenerator receiving the liquid desiccant used in the liquid desiccant conditioner, and humidifying a second air stream flowing
  • An air-to-air heat exchanger is thermally coupled to the air stream exiting the liquid desiccant conditioner or an air stream drawn from the space within the greenhouse or growth cell and the second air stream exiting the liquid desiccant regenerator for cooling the second air stream and producing water therefrom.
  • the second air stream circulates between the liquid desiccant regenerator and the air-to-air heat exchanger within a closed enclosure.
  • a method for managing temperature and humidity conditions in a greenhouse or a growth cell using a liquid desiccant air conditioning system.
  • the method incudes the steps of: dehumidifying a first air stream flowing through a liquid desiccant conditioner utilizing a liquid desiccant, the first air stream being drawn into the liquid desiccant conditioner from a space within the greenhouse or growth cell and exiting the liquid desiccant conditioner as supply air to the greenhouse or growth cell; receiving, in a liquid desiccant regenerator, the liquid desiccant used in the liquid desiccant conditioner, and humidifying a second air stream flowing through the liquid desiccant regenerator to concentrate the liquid desiccant and then returning the liquid desiccant to the conditioner; and cooling the second air stream humidified by the liquid desiccant regenerator and producing water therefrom using an air- to-air heat exchanger thermally coupled to the air stream exiting the liquid desiccant conditioner or an air stream drawn from the space within the
  • a liquid desiccant air-conditioning system in accordance with one or more embodiments is disclosed for managing temperature and humidity conditions in a greenhouse or a growth cell.
  • the system includes a liquid desiccant conditioner utilizing a liquid desiccant to dehumidify a first air stream flowing therethrough to be provided as supply air to the greenhouse or growth cell, the first air stream entering the liquid desiccant conditioner from a space within the greenhouse or growth cell.
  • the system also includes a liquid desiccant regenerator receiving the liquid desiccant used in the liquid desiccant conditioner, and utilizing a second air stream flowing therethrough to concentrate the liquid desiccant, and then returning the liquid desiccant to the conditioner.
  • the liquid desiccant regenerator heats and humidifies the second air stream.
  • the second air stream enters the liquid desiccant regenerator from outside the greenhouse or growth cell and exits the liquid desiccant regenerator to be exhausted outside the greenhouse or growth cell.
  • the system further includes an air-to-air heat exchanger thermally coupled to the first air stream exiting the liquid desiccant conditioner and the second air stream exiting the liquid desiccant regenerator for heating the first air stream before the first air stream is provided as the supply air to the greenhouse or growth cell and the second air stream is exhausted from the greenhouse or growth cell.
  • a liquid desiccant air-conditioning system in accordance with one or more embodiments is provided for managing temperature and humidity conditions in a greenhouse or a growth cell.
  • the system includes a liquid desiccant conditioner utilizing a liquid desiccant to dehumidify a first air stream flowing therethrough to be provided as supply air to the greenhouse or growth cell.
  • the first air stream enters the liquid desiccant conditioner from a space within the greenhouse or growth cell.
  • a liquid desiccant regenerator receives the liquid desiccant used in the liquid desiccant conditioner, and utilizes a second air stream flowing therethrough to concentrate the liquid desiccant, and then returns the liquid desiccant to the conditioner, wherein the liquid desiccant regenerator heats and humidifies the second air stream, the second air stream provided to the liquid desiccant regenerator from outside the greenhouse or growth cell and exiting the liquid desiccant regenerator to be exhausted outside the greenhouse or growth cell.
  • An air-to-air heat exchanger is thermally coupled to the second air stream prior to entering the liquid desiccant regenerator and the second air stream exiting the liquid desiccant regenerator for preheating the second air stream entering the liquid desiccant regenerator and post cooling the second air stream exiting the liquid desiccant regenerator.
  • a liquid desiccant air-conditioning system in accordance with one or more embodiments is provided for managing temperature and humidity conditions in a greenhouse or a growth cell.
  • the system includes a liquid desiccant conditioner utilizing a liquid desiccant to dehumidify a first air stream flowing therethrough to be provided as supply air to the greenhouse or growth cell.
  • the first air stream enters the liquid desiccant conditioner from a space within the greenhouse or growth cell.
  • a liquid desiccant regenerator receives the liquid desiccant used in the liquid desiccant conditioner, and utilizes a second air stream flowing therethrough to concentrate the liquid desiccant, and then returns the liquid desiccant to the conditioner, wherein the liquid desiccant regenerator heats and humidifies the second air stream, the second air stream provided to the liquid desiccant regenerator from outside the greenhouse or growth cell and exits the liquid desiccant regenerator to be exhausted outside the greenhouse or growth cell.
  • An air-to-air heat exchanger is thermally coupled to the first air stream prior to entering the liquid desiccant conditioner and the first air stream exiting the liquid desiccant conditioner for precooling the first air stream entering the liquid desiccant conditioner and post heating the first air stream exiting the liquid desiccant conditioner.
  • FIG. l is a simplified diagram illustrating a prior art liquid desiccant air- conditioning system.
  • FIG. 2 illustrates a prior art three-way heat exchanger block of a liquid desiccant air conditioning system.
  • FIG. 3 is a simplified diagram illustrating a prior art three-way heat exchanger panel assembly in the heat exchanger block.
  • FIG. 4 is a simplified diagram illustrating another prior art liquid desiccant air conditioning system.
  • FIG. 5 is a Psychrometric charts showing air properties in summer
  • FIG. 6 is a simplified block diagram illustrating a liquid desiccant air- conditioning system in accordance with one or more embodiments.
  • FIG. 7 is a Psychrometric chart showing air properties in a winter operation.
  • FIGS. 8A and 8B are simplified block diagrams illustrating liquid desiccant air-conditioning systems with energy recovery for improved efficiency.
  • FIG. 9 is a simplified block diagram illustrating another liquid desiccant air- conditioning system in accordance with one or more embodiments.
  • FIG. 1 illustrates an exemplary prior art liquid desiccant air conditioning system as disclosed in U.S. Patent Application Publication No. 20120125020 and U.S. Patent Nos. 9243810 and 9631848 used in a cooling and dehumidifying mode of operation.
  • Liquid desiccant air conditioning systems can also operate in various other modes including cooling, heating, cooling and humidification, heating and dehumidification, and heating and
  • a conditioner 101 comprises a set of 3-way heat exchange plate structures that are internally hollow.
  • a cold heat transfer fluid is generated in a cold source 107 and introduced into the plates.
  • a liquid desiccant solution at 114 is flowed onto the outer surface of the plates.
  • the liquid desiccant runs over the outer surface of each of the plates behind a thin membrane, which is located between the air flow and the surface of the plates.
  • Return air, outside air 103, or mixture thereof is blown between the set of conditioner plates.
  • the liquid desiccant on the surface of the plates attracts the water vapor in the air flow and the cooling water (heat transfer fluid) inside the plates helps to inhibit the air temperature from rising.
  • the treated air 104 is introduced into a building space.
  • the liquid desiccant is collected at the other end of the conditioner plates at 111 and is transported through a heat exchanger 113 to the liquid desiccant entry point 115 of the regenerator 102 where the liquid desiccant is distributed across similar plates in the regenerator. Return air, outside air 105, or a mixture thereof is blown across the regenerator plates and water vapor is transported from the liquid desiccant into the leaving air stream 106.
  • An optional heat source 108 provides the driving force for the regeneration.
  • a hot heat transfer fluid 110 from a heat source can be flowed inside the plates of the regenerator similar to the cold heat transfer fluid in the conditioner. Again, the re-concentrated liquid desiccant is collected at one end of the plates and returned via the heat exchanger to the conditioner.
  • the desiccant flow through the regenerator can be horizontal or vertical. Air and water is preferably in counterflow to each other. They can also be a horizontal or vertical flow. A variety of configurations are possible from all flows being vertical, to a combination of horizontal and vertical flows in crossflow, to all flows being horizontal in flat plate structures.
  • An optional heat pump 116 can be used to provide cooling and heating of the liquid desiccant. It is also possible to connect a heat pump between the cold source 107 and the hot source 108, which is thus pumping heat from the cooling fluids rather than the liquid desiccant.
  • Cold sources could comprise an indirect evaporative cooler, a cooling tower, geothermal storage, cold water networks, black roof panel that cools down water during the night, and cold storage options like an ice box.
  • Heat sources could include waste heat from power generation, solar heat, geothermal heat, heat storage, and hot water networks. Those skilled in the art will understand that a wide variety of other sources for heating and cooling are possible including, e.g., heat from refrigeration in stores to heat from compressors in industrial applications.
  • FIG. 2 illustrates an exemplary prior art 3-way heat exchanger comprising a set of plate structures stacked in a block as disclosed in U.S. Patent No. 9,308,490.
  • a liquid desiccant enters the structure through ports 304 and is directed behind a series of membranes as described in FIG. 1. The liquid desiccant is collected and removed through ports 305.
  • a cooling or heating fluid is provided through ports 306 and runs counter to the air stream 301 inside the hollow plate structures, again as described in FIG. 1 and in greater detail in FIG. 3. The cooling or heating fluids exit through ports 307.
  • the treated air 302 is directed to a space in a building or is exhausted as the case may be.
  • the figure illustrates a 3-way heat exchanger in which the air and heat transfer fluid are in a primarily vertical orientation.
  • FIG. 3 schematically illustrates operation of an exemplary prior art membrane plate assembly or structure as disclosed in U.S. Patent No. 9,631,848.
  • the air stream 251 flows counter to a cooling fluid stream 254.
  • Membranes 252 contain a liquid desiccant 253 that is falling along the wall 255 that contains the heat transfer fluid 254.
  • Water vapor 256 entrained in the air stream is able to transfer through the membrane 252 and is absorbed into the liquid desiccant 253.
  • the heat of condensation of water 258 that is released during the absorption is conducted through the wall 255 into the heat transfer fluid 254.
  • Sensible heat 257 from the air stream is also conducted through the membrane 252, liquid desiccant 253 and wall 255 into the heat transfer fluid 254.
  • FIG. 4 illustrates a schematic representation of another prior art liquid desiccant air conditioner system operating in a cooling mode, as disclosed in U.S. Patent No. 10323867. Similar liquid air conditioning systems are disclosed in U.S. Patent Application Publication No. 20120125020 and U.S. Patent Nos. 9243810 and 9631848.
  • a three-way heat and mass exchanger conditioner 503 (which is similar to the conditioner 101 of FIG. 1) receives an air stream 501 from the outside (“OA”). Fan 502 pulls the air 501 through the conditioner 503 wherein the air is cooled and dehumidified. The resulting cool, dry air 504 (“SA”) is supplied to a space for occupant comfort.
  • SA cool, dry air 504
  • the three-way conditioner 503 receives a concentrated desiccant 527 in the manner explained under FIGS. 1-3. It is preferable to use a membrane on the three-way conditioner 503 to contain the desiccant and inhibit it from being distributed into the air stream 504.
  • the diluted desiccant 528 which contains the captured water vapor is transported to a heat and mass exchanger regenerator 522.
  • chilled water 509 is provided by pump 508, which enters the conditioner module 503 where it picks up heat from the air as well as latent heat released by the capture of water vapor in the desiccant 527.
  • the warmer water 506 is brought to the heat exchanger 507 on the chiller system 530.
  • the liquid desiccant 528 leaves the conditioner 503 and is moved through the optional heat exchanger 526 to the regenerator 522 by pump 525.
  • the chiller system 530 comprises a water to refrigerant evaporator heat exchanger 507, which cools the circulating cooling fluid 506.
  • the liquid, cold refrigerant 517 evaporates in the heat exchanger 507 thereby absorbing the thermal energy from the cooling fluid 506.
  • the gaseous refrigerant 510 is now re-compressed by compressor 511.
  • the compressor 511 ejects hot refrigerant gas 513, which is liquefied in the condenser heat exchanger 515.
  • the liquid refrigerant exiting the condenser 514 then enters expansion valve 516, where it rapidly cools and exits at a lower pressure.
  • the condenser heat exchanger 515 now releases heat to another cooling fluid loop 519 which brings hot heat transfer fluid 518 to the regenerator 522.
  • Circulating pump 520 brings the heat transfer fluid back to the condenser 515.
  • the three-way regenerator 522 thus receives a dilute liquid desiccant 528 and hot heat transfer fluid 518.
  • a fan 524 brings outside air 521 (“OA”) through the regenerator 522. The outside air picks up heat and moisture from the heat transfer fluid 518 and desiccant 528 which results in hot humid exhaust air (“EA”) 523.
  • the compressor 511 receives electrical power 512.
  • the fans 502 and 524 receive electrical power 505 and 529, respectively.
  • Pumps 508, 520, and 525 have relatively low power consumption.
  • Various embodiments disclosed herein relate to use of liquid desiccant air- conditioning systems in greenhouses and growth cells.
  • Greenhouses process recirculated air to maintain warm and humid conditions (e.g., 30 C/80% RH).
  • Liquid desiccant air conditioning systems have the ability to manage heat and humidity independently and can significantly improve greenhouse control over growth cycles with sharply increasing humidification loads as plants mature. Greenhouses tend to have a large sensible load from lights.
  • Liquid desiccant air conditioning systems work most efficiently at moderate concentrations of liquid desiccant (e.g., 15-25%), which fits well with the target RH (relative humidity) of about 70-80% in greenhouses, including the latent and sensible loads.
  • target RH relative humidity
  • regenerator air to maintain warm temperatures in the greenhouse can further improve efficiency.
  • a heat exchanger can be used to preheat/postcool regenerator air during cold periods.
  • One heat exchanger can be used to do both using a set of dampers.
  • Greenhouses and growth cells operate at high temperatures and high humidities, typically 30C and an RH of 80%. Cooling loads in greenhouses include significant solar heat, but in growth cells, the heat supply is nearly completely from artificial lights. The plants humidify and cool air. Air is refreshed to allow people to operate inside. Greenhouses have high sensible loads from sunlight and heating through low insulated walls. In the winter, the solar loads are reduced and partially replaced with artificial lighting, while heat losses through the walls require significant added heat. In-building growth cells rely 100% on artificial light, but they do have rest periods, which can be during the day while low cost night rates are used for powering the lights.
  • a single heat exchanger can support the liquid desiccant air conditioning system during dehumidification and either sensible cooling or sensible heating.
  • regeneration requires higher temperature at 602.
  • conditioning can be done from the return air condition 603 to condition 604, which is warm and dry.
  • Supply air 604 is humidified 612 and heated 613 because of the typical conditions in a greenhouse/growth cell humidification results when plants desorb large amounts of water to pump nutrients from the roots to the plant and heating results from radiation in a greenhouse or lights in a growth cell.
  • liquid desiccant at 30% or higher requires air with an RH of less than 40% to regenerate 630. While liquid desiccant at 20% can be regenerated at an RH of about 60% at 631.
  • FIG. 6 shows a liquid desiccant air conditioning system for a greenhouse (or growth cell) 700 that includes a heat exchanger 701, which takes the supply air 702 from the conditioner 703 and warms the supply air 702 up with the regeneration air 704 from regenerator 705 before returning it to the space 706 in the greenhouse 700 to be air conditioned.
  • Regenerator exhaust air is expelled from the greenhouse at 707.
  • Return air 708 from the space 706 is provided to the conditioner 703, and the outside air 709 is used by the regenerator 705 to concentrate the liquid desiccant.
  • the water (i.e., heat transfer fluid) and desiccant circuits in and between conditioner 703 and regenerator 705 are not shown. These can be as described in prior art, e.g., in FIG. 4.
  • liquid desiccant air conditioning systems are that they can dehumidify at low concentrations of liquid desiccant while maintaining high temperatures and controlling RH levels.
  • temperature and RH can be managed in a narrow bandwidth.
  • the heat exchanger can be used to precool and then reheat the process air.
  • the air can be further cooled to reach the target DP at 80% RH and a cooler temperature. This allows the regenerator to regenerate with just the condenser heat of the heatpump. However, additional waste heat or gas heat is then needed to post heat the process air. Determining which is the lower cost solution depends not only on starting conditions and loads in the greenhouse/growth cell and the outside air conditions esp. HR, but also on the availability and quality of waste heat, the cost of components, and the effectiveness of the liquid desiccant heat exchanger.
  • thermodynamic models can be used to evaluate alternative strategies and optimize control conditions.
  • FIGS. 8A and 8B are simplified block diagrams illustrating liquid desiccant air-conditioning systems with energy recovery for improved efficiency.
  • the air stream 720 in the regenerator 705 is preheated and post cooled. Outside air flows into a heat exchanger 701, which preheats the air stream 720 with the air stream exiting the
  • regenerator 705 before it is exhausted.
  • the air stream 722 in the conditioner 703 is precooled and post heated during the winter season.
  • the air stream 722 flows through a heat exchanger 701, which precools the air stream with the airstream exiting the conditioner 703.
  • the water (i.e., heat transfer fluid) and desiccant circuits in and between conditioner 703 and regenerator 705 are not shown. These can be as described in prior art, e.g., in FIG. 4.
  • FIG. 9 illustrates a liquid desiccant air conditioning system in accordance with one or more embodiments used in a greenhouse (or growth cell) 801.
  • the greenhouse 801 has a conditioner 802 that take air from a space 803 in the greenhouse 801 and returns it to the greenhouse space after dehumidifying it to a DP of 45-60F.
  • the optimal humidity level is crop dependent, with some crops preferring higher absolute humidity levels and others requiring dryer conditions. For example, tomatoes grow best at RH levels as high as 70% and
  • RH levels are a combination of DB temperature and absolute humidity levels. Optimal temperatures even differ by time of day, with temperature during dark periods being lower than when light is present to allow the plant to grow.
  • Maintaining the concentration of the liquid desiccant 804 used in the conditioner 802 is needed to maintain the RH of the air stream 830 coming out of the conditioner 802.
  • the liquid desiccant 804 is diluted in the conditioner 802 as humidity as absorbed in the liquid desiccant 804.
  • the regenerator 805 is used to reconcentrate the liquid desiccant 804 before returning it to the conditioner 802.
  • Waste heat 806 is used to heat up the air flowing through the regenerator 805 to a temperature of 40 to 60C (110-150F).
  • the waste heat 806 can come from various sources such as, e.g., solar power or a power generator 807, which results in C02 production 809. Cooling the generator 807 increases power production 808.
  • the air stream 831 flowing through regenerator 805 is enclosed in a space 810 and circulated by fan 811 to an air-to-air heat exchanger 812 that uses greenhouse air to cool the air to a DP equal to the DB condition in the greenhouse 801.
  • This produces water 820 which can either be used to water soil in the greenhouse 801 or to drive a cooling tower 821 that provide cooling water 822 to the conditioner 802.
  • a small chiller 823 can be used to accurately control cooling water conditions and thus DP depending on plant conditions and the quality and the amount of waste heat availability at any point during the day or year.
  • the greenhouse air can be provided to the air-to-air heat exchanger 812 in different ways.
  • the air stream 830 coming out of the conditioner 802 is flowed through the heat exchanger 812 and then returned to the greenhouse space 803.
  • the air stream 830 coming out of the conditioner 802 flows directly to the greenhouse space 803 as indicated at 840. Air from the greenhouse space 803 is directly provided to the heat exchanger 812 as indicated at 832.
  • some of the air stream 830 coming out of the conditioner 802 is provided to the air space 803 and some of the air stream 830 coming out of the conditioner 802 is flowed through the heat exchanger 812.

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  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
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Abstract

Cette invention concerne de manière générale des systèmes de climatisation à déshydratant liquide (LDAC) et, plus particulièrement, des systèmes de climatisation à déshydratant liquide destinés à être utilisés dans des serres et des cellules de croissance.
PCT/US2019/065050 2018-12-06 2019-12-06 Systèmes de climatisation à déshydratant liquide et procédés pour des serres et des cellules de croissance Ceased WO2020118241A1 (fr)

Applications Claiming Priority (2)

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US201862776210P 2018-12-06 2018-12-06
US62/776,210 2018-12-06

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Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2755800T3 (es) 2012-06-11 2020-04-23 7Ac Tech Inc Métodos y sistemas para intercambiadores de calor turbulentos y resistentes a la corrosión
US20250261580A1 (en) * 2013-03-15 2025-08-21 Viridis Arbor Llc Apparatus and method for growing vegetation in hot arid coastal environments
US10941948B2 (en) 2017-11-01 2021-03-09 7Ac Technologies, Inc. Tank system for liquid desiccant air conditioning system
US10921001B2 (en) 2017-11-01 2021-02-16 7Ac Technologies, Inc. Methods and apparatus for uniform distribution of liquid desiccant in membrane modules in liquid desiccant air-conditioning systems
US11022330B2 (en) 2018-05-18 2021-06-01 Emerson Climate Technologies, Inc. Three-way heat exchangers for liquid desiccant air-conditioning systems and methods of manufacture
US11117090B2 (en) 2018-11-26 2021-09-14 Palo Alto Research Center Incorporated Electrodialytic liquid desiccant dehumidifying system
US12085293B2 (en) 2021-03-17 2024-09-10 Mojave Energy Systems, Inc. Staged regenerated liquid desiccant dehumidification systems
WO2022235225A1 (fr) * 2021-05-05 2022-11-10 Enerama Çevre Teknoloji̇leri̇ Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇ Utilisation de la chaleur perdue dans un système de déshumidification à déshydratant liquide
US11944934B2 (en) * 2021-12-22 2024-04-02 Mojave Energy Systems, Inc. Electrochemically regenerated liquid desiccant dehumidification system using a secondary heat pump
US20230280049A1 (en) * 2021-12-22 2023-09-07 Mojave Energy Systems, Inc. Electrochemically regenerated liquid desiccant dehumidification system using a secondary heat pump
CN114402868B (zh) * 2022-01-14 2023-06-23 刘妍 一种基于液体内循环和室内温差棚内除湿装置及其方法
US12287101B2 (en) 2022-04-26 2025-04-29 Copeland Lp Combined cooling, heating, and power system
JP2025539498A (ja) 2022-12-12 2025-12-05 モハベ エネルギー システムズ，インコーポレイテッド 液体乾燥剤空調システム及び制御方法
CN121038880A (zh) 2023-04-07 2025-11-28 莫哈维能源系统公司 超低流量干燥剂空气调节系统装置和方法
US12337371B1 (en) 2023-12-20 2025-06-24 Copeland Lp Systems and methods for assembling liquid desiccant air conditioner panels using flexible alignment features

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN202734094U (zh) * 2012-08-09 2013-02-13 上海理工大学 余热回收利用空调系统
KR20150119345A (ko) * 2013-03-14 2015-10-23 7에이씨 테크놀로지스, 아이엔씨. 액체 흡수제 공조 시스템 개장을 위한 방법 및 시스템
US20160290666A1 (en) * 2011-09-02 2016-10-06 Nortek Air Solutions Canada, Inc. Energy exchange system for conditioning air in an enclosed structure
US9631824B1 (en) * 2016-09-14 2017-04-25 Grahame Ernest Maisey Liquid desiccant HVAC system
US20170184319A1 (en) * 2013-03-01 2017-06-29 7Ac Technologies, Inc. Desiccant air conditioning methods and systems

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160290666A1 (en) * 2011-09-02 2016-10-06 Nortek Air Solutions Canada, Inc. Energy exchange system for conditioning air in an enclosed structure
CN202734094U (zh) * 2012-08-09 2013-02-13 上海理工大学 余热回收利用空调系统
US20170184319A1 (en) * 2013-03-01 2017-06-29 7Ac Technologies, Inc. Desiccant air conditioning methods and systems
KR20150119345A (ko) * 2013-03-14 2015-10-23 7에이씨 테크놀로지스, 아이엔씨. 액체 흡수제 공조 시스템 개장을 위한 방법 및 시스템
US9631824B1 (en) * 2016-09-14 2017-04-25 Grahame Ernest Maisey Liquid desiccant HVAC system

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