Air Cooling System

Abstract

The air cooling system includes an evaporator configured to cool air and a reservoir for storing and providing a liquid to the evaporator. The air cooling system also includes a pressure reduction system fluidly coupled to the evaporator and configured to create a relatively low pressure within the evaporator to facilitate converting liquid flowing through the evaporator into vapor. The pressure reduction system includes a liquid ejector having an inlet portion configured to receive liquid from the reservoir, a throat portion disposed downstream of the inlet portion and fluidly coupled to the evaporator, and an outlet portion disposed downstream of the throat portion and configured to increase the pressure within the liquid ejector. The pressure reduction system also includes a pump fluidly connected to the liquid ejector and the reservoir to supply liquid from the reservoir to the liquid ejector.

Description

[Technical Field]

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 704,864, filed May 31, 2020, and U.S. Provisional Patent Application No. 63 / 129,206, filed December 22, 2020, the contents of which are incorporated herein by reference for all purposes.

[0002] The present disclosure relates to an air cooling system having an evaporator and a liquid ejector for reducing the pressure within the evaporator to cool air flowing through the evaporator. [Background technology]

[0003] Climate change, global warming, and urbanization are increasing the demand for air-cooling systems to cool the interior of occupied spaces. Air-cooling systems typically include a refrigerant or desiccant dehumidifier to remove heat and humidity from the air. However, air conditioner operation requires high energy. Conventional refrigerant-based air conditioners manage sensible and latent heat loads in a complex process, when moisture is extracted by vapor condensation around a heat exchanger during the refrigerant evaporation phase. This process is energy-intensive and inefficient.

[0004] Air coolers, such as desert coolers or cooling towers, are also used to provide relatively cool air to the interior of occupied spaces. These systems generally operate on the principle of water evaporation, cooling the air by evaporating water from surfaces. However, these systems do not always work well in humid environments.

[0005] U.S. Patent No. 8,496,732 discloses an air-cooling system for dehumidifying air by establishing a humidity gradient across a water-selective permeable membrane within a dehumidification unit. This humidity gradient is established by creating a vacuum on one side of the membrane using a vacuum pump that compresses air to create a vacuum. Due to the compressibility of air, creating a vacuum by compressing air is relatively inefficient and consumes more energy. In addition, vacuum pumps that create a vacuum by compressing air generally use a large amount of non-condensable fluid, such as dry air, for operation and do not respond well to environments containing highly condensable loads, such as water vapor or humidity. The air-cooling system further includes a condenser for condensing water vapor extracted from the air. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 8,496,732 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, there remains a need for improved energy efficient air cooling systems to facilitate the removal of heat from the air. [Means for solving the problem]

[0008] In a first aspect, an air cooling system is disclosed. The air cooling system is pressurizable and vacuum resistant. The system includes an evaporator configured to cool air passing through the evaporator and a reservoir for storing liquid fluidly connected to the evaporator to provide the liquid to the evaporator. The system further includes a pressure reduction system fluidly coupled to the evaporator and configured to generate a pressure below the saturated vapor pressure of the liquid at ambient temperature within the evaporator to facilitate converting at least a portion of the liquid flowing through the evaporator into vapor. The pressure reduction system includes a liquid ejector and a pump. The liquid ejector includes an inlet portion configured to receive the liquid from the reservoir and a throat portion disposed downstream of the inlet portion and fluidly coupled to the evaporator. The throat portion is configured to increase the velocity of the liquid received from the inlet portion. The liquid ejector also includes an outlet portion disposed downstream of the throat portion and configured to increase the pressure within the liquid ejector to facilitate condensation of the vapor received from the evaporator. The pump is fluidly connected to the fluid ejector and the reservoir and is configured to deliver fluid from the reservoir to the fluid ejector.

[0009] According to one embodiment, the pressure reduction system further includes a booster pump disposed upstream of the liquid ejector and fluidly coupled to the evaporator to reduce the pressure in the evaporator to a pressure below the saturated vapor pressure of the liquid.

[0010] In one embodiment, the liquid is water and the booster pump facilitates reducing the pressure to a value of 31.7 mbarA or less at 25 degrees Celsius.

[0011] In one embodiment, the booster pump facilitates reducing the pressure to a value below the saturated vapor pressure of the fluid in the evaporator.

[0012] In one embodiment, the booster pump facilitates reducing the pressure to a value between 20 mbarA and 40 mbarA or between 10 mbarA and 20 mbarA.

[0013] According to one embodiment, the reservoir includes a drain valve to facilitate drainage of liquid from the reservoir when the level of the liquid exceeds a first threshold level.

[0014] In some embodiments, the reservoir is made from a thermally conductive material to facilitate heat transfer from the liquid stored in the reservoir to the surroundings.

[0015] In some embodiments, the air cooling system further includes a heat exchanger fluidly connected to the liquid ejector and configured to receive at least a portion of the liquid exiting the liquid ejector, the heat exchanger configured to cool the received liquid.

[0016] In one embodiment, the heat exchanger is located upstream of the reservoir and supplies cooled liquid to the reservoir.

[0017] In one embodiment, the liquid ejector is a water ejector configured to receive liquid water from a pump.

[0018] According to one embodiment, the air cooling system also includes a throttle valve disposed between the reservoir and the evaporator to control the flow of liquid from the reservoir to the evaporator.

[0019] In some embodiments, the air cooling system further includes a dehumidifying core, the dehumidifying core being disposed upstream or downstream of the evaporator and configured to be fluidly coupled to the liquid ejector. The dehumidifying core includes an air channel, at least one vapor channel separated from the air channel, and a membrane separating the at least one vapor channel from the air channel, the membrane configured to facilitate the removal of moisture from air flowing through the air channel. The membrane is selectively permeable to water and water vapor and impermeable to air. The throat portion is fluidly coupled to the at least one vapor channel to create a pressure within the at least one vapor channel that is relatively lower than within the air channel to facilitate the flow of moisture from the air flowing through the air channel to the at least one vapor channel. The outlet portion also facilitates condensation of water vapor received from the at least one vapor channel.

[0020] In one embodiment, the membrane comprises, consists essentially of, or consists of a sulfonated polymer.

[0021] According to one embodiment, the air cooling system also includes a valve disposed between the reduced pressure system and the dehumidifying core to control fluid connection of the dehumidifying core to the reduced pressure system.

[0022] In one embodiment, the pressure in the reservoir is reduced at start-up of the air cooling system to a value greater than the saturated vapor pressure of the liquid at ambient temperature by at least 5%, or 7-20%, or up to 25%.

[0023] In one embodiment, when the liquid is water, the pressure in the reservoir is reduced to a value between 40 mbarA and 150 mbarA at the start of the air cooling system.

[0024] In one embodiment, the air cooling system is pre-conditioned before start-up to a pressure value that is greater than 5%, or 7-20%, or up to 25% greater than the saturated vapor pressure of the liquid.

[0025] In a second aspect, an air cooling system is disclosed. The air cooling system includes at least one dehumidifying core defining an air channel and at least one vapor channel separated from the air channel. The dehumidifying core further includes a membrane separating the at least one vapor channel from the air channel. The membrane is configured to facilitate the removal of moisture from air flowing through the air channel. Furthermore, the membrane is selectively permeable to water and water vapor and impermeable to air. The air cooling system further includes an evaporator configured to cool air passing through the evaporator and disposed upstream or downstream of the dehumidifying core. The air cooling system further includes a pressure-resistant reservoir for storing liquid fluidly connected to the evaporator to provide the liquid to the evaporator. The air cooling system further includes a pressure-reducing system fluidly coupled to at least one of the evaporator or the dehumidifying core. When fluidly coupled to the evaporator, the pressure-reducing system is configured to generate a pressure below the saturated vapor pressure of the liquid at ambient temperature within the evaporator to facilitate converting at least a portion of the liquid flowing through the evaporator to vapor. The pressure reduction system, when fluidly coupled to the dehumidifying core, is configured to generate a pressure in the at least one vapor channel that is lower than the pressure in the air channel to facilitate extraction of moisture from air flowing through the air channel into the at least one vapor channel. The pressure reduction system includes a liquid ejector and a pump. The liquid ejector has an inlet portion configured to receive liquid from the reservoir and a throat portion disposed downstream of the inlet portion and fluidly coupled to at least one of the evaporator or the at least one vapor channel. The throat portion is configured to increase the velocity of the liquid received from the inlet portion. The liquid ejector also includes an outlet portion disposed downstream of the throat portion and configured to increase the pressure in the liquid ejector to facilitate condensation of the vapor received from at least one of the evaporator or the dehumidifying core. The pump is fluidly connected to the liquid ejector and the reservoir and configured to supply liquid from the reservoir to the liquid ejector.

[0026] According to one embodiment, the air cooling system also includes at least one valve for controlling fluid coupling of the pressure reducing system to at least one of the evaporator or the dehumidifying core.

[0027] In one embodiment, the at least one valve includes a first valve for controlling fluid coupling of the evaporator and the reduced pressure system and a second valve for controlling fluid coupling of the dehumidifying core and the reduced pressure system.

[0028] In one embodiment, the pressure reducing system further includes a booster pump, the booster pump being positioned upstream of the liquid ejector for reducing the pressure inside at least one of the evaporators to a pressure below the saturated vapor pressure of the liquid or for reducing the pressure in at least one vapor channel of the dehumidifying core to a pressure below the saturated vapor pressure of water.

[0029] In one embodiment, the liquid is water and the booster pump facilitates reducing the pressure to a value of 31.7 mbarA or less at 25 degrees Celsius.

[0030] In one embodiment, the booster pump facilitates reducing the pressure to the saturated vapor pressure of the fluid in the evaporator, or to a value between 20 mbarA and 40 mbarA, or between 10 mbarA and 20 mbarA.

[0031] In one embodiment, the reservoir includes a drain valve to facilitate drainage of liquid from the reservoir when the level of the liquid exceeds a first threshold level.

[0032] In some embodiments, the reservoir is made from a thermally conductive material to facilitate heat transfer from the liquid water stored in the reservoir to the surroundings.

[0033] In one embodiment, the air cooling system further includes a heat exchanger, the heat exchanger being fluidly connected to the liquid ejector and configured to receive at least a portion of the liquid exiting the liquid ejector, the heat exchanger being configured to cool the received liquid, and in some embodiments, the heat exchanger being positioned upstream of the reservoir and supplying the cooled liquid to the reservoir.

[0034] In one embodiment, the liquid ejector is a water ejector configured to receive liquid water from a pump.

[0035] In an embodiment, the air cooling system also includes a throttle valve disposed between the reservoir and the evaporator to control the flow of liquid from the reservoir to the evaporator.

[0036] In one embodiment, the pressure in the reservoir is reduced at the start of the air cooling system to a value greater than the saturated vapor pressure of the liquid at ambient temperature by more than 5%, or between 7 and 20%, or up to 25%.

[0037] In one embodiment, the pressure in the reservoir is reduced to a value of at least 30 mbarA, or between 40 mbarA and 150 mbarA, or less than 120 mbarA, at the start of the air cooling system when the liquid is water.

[0038] In one embodiment, the air cooling system is pre-conditioned before start-up to a pressure value that is greater than 5%, or 7-20%, or up to 25% greater than the saturated vapor pressure of the liquid. [Brief explanation of the drawings]

[0039] [Figure 1] 1 is a schematic diagram of an embodiment of an air cooling system having an evaporator and a pressure reduction system connected to the evaporator. [Figure 2] 1 is a schematic diagram of an embodiment of an air cooling system having an evaporator and a pressure reduction system connected to the evaporator, depicting a heat exchanger positioned upstream of a liquid ejector. [Figure 3]1 is a schematic diagram of an embodiment of an air cooling system having an evaporator and a reduced pressure system connected to the evaporator, depicting a heat exchanger independently connected to a reservoir of the reduced pressure system. FIG. [Figure 4] 1 is a schematic diagram of an embodiment of an air cooling system having an evaporator, a dehumidifying core having air channels separated from vapor channels by a membrane, and a pressure reduction system connected to the evaporator and the dehumidifying core. [Figure 5] 1 is a schematic top view of a portion of one embodiment of a dehumidifying core having water vapor flow from air flowing through air channels to vapor channels. FIG. [Figure 6] 1 is a perspective view of one embodiment of a dehumidifying core having air channels extending from a first side to a second side. FIG. [Figure 7] 5 is a cross-sectional view of the dehumidifying core of FIG. 4 depicting vapor channels extending substantially perpendicular to the elongation of the air channels. DETAILED DESCRIPTION OF THE INVENTION

[0040] As used herein, the following terms have the following meanings:

[0041] "Ion exchange capacity" or IEC refers to the total active sites or functional groups within a polymer that are responsible for ion exchange. Traditional acid-based titration methods are typically used to determine IEC. See, for example, "Determination of the ion exchange capacity of anion-selective membranes," International Journal of Hydrogen Energy, Volume 39, Issue 10, March 26, 2014, pp. 5054-5062. IEC is the inverse of "equivalent weight," or EW, which is the weight of polymer required to provide one mole of exchangeable protons.

[0042] "At least one of A or B," as in the examples "at least one of [a group such as A, B, or C]" or "any one of [a group such as A, B, or C]," means a single member from the group, two or more members from the group, or a combination of members from the group. For example, at least one of A, B, or C includes, e.g., A only, B only, or C only, as well as A and B, A and C, B and C, or A, B, and C, or any other combination of A, B, and C.

[0043] A list of embodiments presented as "A, B, or C" should be interpreted as including A only, B only, C only, "A or B," "A or C," "B or C," or "A, B, or C" embodiments. For example, "at least one of an evaporator or a dehumidifying core" includes an evaporator only, a dehumidifying core only, and both an evaporator and a dehumidifying core.

[0044] The present disclosure relates to an air cooling system for facilitating cooling and / or removing moisture from air. The system comprises, consists essentially of, or comprises an evaporator, a reservoir, and a pressure reduction system, the pressure reduction system having a liquid ejector and a pump connected to the liquid ejector and the reservoir. In embodiments, the air cooling system further includes a dehumidifying core positioned upstream or downstream of the evaporator and configured to be fluidly coupled to the liquid ejector. The dehumidifying core is characterized as having a membrane that is selectively permeable to water and water vapor and impermeable to air.

[0045] Liquids for use in air cooling systems: The liquid ejectors referred to herein are contemplated as water ejectors. While water is used as the liquid or motive fluid, it will be understood that any other suitable incompressible liquid may also be used in the air cooling system. Thus, reference to water may include other liquids such as, but not limited to, acetone, acetonitrile, acrolein, acrylonitrile, alcohols (e.g., ethyl, allyl, butyl, methyl, propyl, among others), allylamine, aniline, anisole, benzene, chloroform, cyclohexane, cyclopentane, diethyl ether, ethanol, chemical refrigerants (including R-11, R-12, R-22), isopentane, and methyl acetate.

[0046] Liquid ejector: The liquid ejector operates on the Venturi effect and has a narrowed throat section with a relatively small diameter through which liquid, such as water, is pumped. As the liquid flows through the throat section, its velocity or speed increases, lowering the pressure within the throat section. This lower pressure is communicated to the vapor channel and / or evaporator. In this way, when connected to the dehumidifying core, the liquid ejector facilitates the creation of a pressure difference between the air channel and the vapor channel of the dehumidifying core, enabling moisture to flow from the air flowing through the air channel to the vapor channel. The liquid ejector also facilitates the creation of a vacuum or low pressure within the evaporator, enabling at least a portion of the liquid flowing within the evaporator to be converted to vapor. To control the pressure drop within the throat section, the velocity and volume of the liquid entering the inlet section of the liquid ejector are controlled.

[0047] In embodiments for use with water, the liquid ejector may generate a vacuum pressure of 40 mbar to 120 mbar. It will be appreciated that the vacuum generating capability of the liquid ejector is limited by the saturated vapor pressure of the liquid. In one embodiment, the liquid ejector may generate a pressure of up to 960 mbar gauge pressure.

[0048] To further increase the vacuum level in the vapor channel or to lower / reduce the pressure in the vapor channel, a booster pump is positioned upstream of the liquid ejector and fluidly coupled to at least one of the evaporator and the dehumidifying core.

[0049] Booster Pump: A booster pump is a Roots pump including at least one pair of interlocking lobes that rotate in generally opposite directions. Fluid is trapped within pockets surrounding the lobes and transported from the inlet side to the outlet side. The booster pump facilitates reducing the pressure in the vapor channel to a pressure equal to or less than the partial vapor pressure of water at ambient temperature and / or reducing the pressure in the evaporator to a pressure equal to or less than the saturated vapor pressure of the liquid. In one embodiment, the liquid is water, and the saturated vapor pressure of water at 25 degrees Celsius is approximately 31.7 mbarA. In one embodiment, the booster pump in combination with the liquid ejector facilitates creating a pressure equal to or less than 20 mbarA in the vapor channel and / or evaporator. In some embodiments, the booster pump facilitates reducing the pressure to a value between 10 mbarA and 20 mbarA. In one embodiment, the booster pump reduces the pressure to a value between 10 mbarA and 40 mbarA. In some embodiments, the booster pump facilitates reducing the pressure to a value below 150 mbarA.

[0050] Membrane: The membrane for use in the system is a moisture permeable membrane having good water vapor transport rate (MVTR) properties and good ion exchange capacity (IEC). The membrane is characterized as being selectively permeable, i.e., permeable, to air moisture but not to other air components. In embodiments, the membrane is nearly impermeable to air. In embodiments, the membrane is capable of carrying a moisture content of 100 g / m per day. 2 Over 500g / m 2 Over 1,000 g / m 2The membrane is characterized as having an MVTR of greater than 5 g / m per day. ASTM E-96B and ASTM F1249 provide standard methods for measuring MVTR. In embodiments, the membrane has a MVTR of greater than 5 g / m per day. 2 It is characterized as having an air permeability of less than 100 .mu.m.

[0051] In embodiments, the membranes are characterized as having favorable ion exchange capacity and proton conductivity, as well as glass transition temperatures, providing both flexibility and material strength, even when hydrated, and good stability and swelling. The membranes are formed mostly or substantially entirely from sulfonated polymers (SPs) that have been sufficiently sulfonated to contain 10-100 mol% sulfonic acid or sulfonate functional groups, based on the number of monomer units in the copolymer. In embodiments, the SPs are used to form coatings on substrate surfaces, and the substrates are made of the same or different materials. In other embodiments, the membranes are used as single or multiple SP layers or films, with each SP layer or film having a specific or preselected thickness.

[0052] In embodiments, the SP is a sulfonated block copolymer having a block copolymer molecular structure containing three or more blocks, designed to phase separate and form ion-conducting regions that enable water permeation, a process that can be accelerated by the application of a voltage. In embodiments, the SP is selected from the group consisting of sulfonated tetrafluoroethylene copolymers, perfluorosulfonic acid polymers such as polystyrene sulfonates, sulfonated block copolymers, polysulfones such as polyethersulfones, polyketones such as polyetherketones, and mixtures thereof.

[0053] In embodiments, the sulfonated polymer is characterized as being fully or selectively sulfonated to contain 10-100 mol% sulfonic acid or sulfonate functional groups, based on the number of sulfonatable monomer units in the sulfonated copolymer ("degree of sulfonation"). In embodiments, the sulfonated polymer has a degree of sulfonation greater than 25 mol%, or greater than 50 mol%, or less than 95 mol%, or 25-70 mol%.

[0054] In embodiments, the sulfonated polymer is characterized as being self-sterilizing, killing at least 99% of microorganisms within 5 minutes of contacting the coating material.

[0055] In embodiments, the sulfonated polymer is a sulfonated block copolymer, such as ABA, ABABA, (ABA) n X, (AB) n X, ADBDA, ABDBA, (ADB) n X, (ABD) n In embodiments, SP has one or more copolymer block architectures corresponding to either ABA, (AB)X, ABDBA, (ABD)X, ADBDA, and (ADB)X, or mixtures thereof, where n is an integer from 2 to about 30, X is a coupling agent residue, and each D block is preferably a polymer block resistant to sulfonation. In embodiments, SP has a linear structure corresponding to ABA, (AB)X, ABDBA, (ABD)X, ADBDA, and (ADB)X, or (AB) n X and (ADB) n X, where n is in the range of 3 to 6. Two or more of the A, B, C, and D blocks may be the same or different.

[0056] In embodiments, the A block is a polymer segment of an acrylic ester or a methacrylic ester. In embodiments, the A block is selected from polymerized para-substituted styrene monomers, ethylene, α-olefins of 3 to 18 carbon atoms, 1,3-cyclodiene monomers, monomers of conjugated dienes having a vinyl content of less than 35 mol percent before hydrogenation, acrylic esters, methacrylic esters, and mixtures thereof. When the A block is a polymer of 1,3-cyclodiene or a conjugated diene, these blocks are preferably hydrogenated after polymerization of the block copolymer and before sulfonation of the block copolymer. When the A block is a hydrogenated polymer of a 1,3-cyclodiene monomer, such a monomer can be selected from the group consisting of 1,3-cyclohexadiene, 1,3-cycloheptadiene, and 1,3-cyclooctadiene. The A block can contain up to 15 mol percent of a vinyl aromatic monomer, such as that present in the B block.

[0057] The B block may contain from about 10 to about 100 mol percent sulfonic acid or sulfonate ester functional groups, based on the number of monomer units, and contains segments of one or more polymerized vinyl aromatic monomers selected from unsubstituted styrene monomers, ortho-substituted styrene monomers, meta-substituted styrene monomers, alpha-methylstyrene monomers, 1,1-diphenylethylene monomers, 1,2-diphenylethylene monomers, and mixtures thereof.

[0058] The D block may comprise a hydrogenated polymer or copolymer of a conjugated diene selected from isoprene, 1,3-butadiene, and mixtures thereof.

[0059] X is a coupling agent residue, and the coupling agent is selected from those known in the art, including polyalkenyl coupling agents, dihaloalkanes, silicon halides, siloxanes, polyfunctional epoxides, silica compounds, esters of monohydric alcohols with carboxylic acids (e.g., methyl benzoate and dimethyl adipate), and epoxidized oils.

[0060] In embodiments, SP is AB, ABA, (AB) n , (ABA) n , (ABA) n X, (AB) n The hydrogenated sulfonated block copolymers have the general structure of: n, n, n-1, n-2, n-3, n-4, n-5, n-6, n-7, n-8, n-9, n-10, n-11, n-12, n-13, n-14, n-15, n-16, n-17, n-18, n-19, n-20, n-21, n-22, n-23, n-24, n-25, n-30, n-40, n-50, n-60, n-70, n-8, n-11, n-12, n-14, n-15, n-16, n-17, n-18, n-19, n-20, n-21, n-22, n-23, n-24, n-25, n-30, n-40, n-50, n-60, n-70, n-80, n-10, n-11, n-12, n-14, n-15, n-16, n-17, n-18, n-19, n-20, n-21, n-22, n-23, n-24, n-25, n-30, n-40, n-50, n-60, n-10, n-11, n-12, n-25, n-13, n-14, n-20, n-15, n-21, n-16, n-22, n-17, n-23, n-18, n-24, n-25, n-26, n-27, n-28, n-30, n-30, n-40, n-50, n-10, n-11, n-25, n-12, n-25, n-13, n-26, n- The total amount of monoalkenyl arenes in the hydrogenated block copolymer is about 20 weight percent to about 80 weight percent. The weight percent of monoalkenyl arenes in each B block is about 10 weight percent to about 75 weight percent, and at least 25% of the aromatic rings of the alkenyl arenes are sulfonated. The hydrogenated sulfonated block copolymer has an ionic conductivity greater than 0.08 Siemens / cm.

[0061] In embodiments, the sulfonated copolymer having a polytetrafluoroethylene (PTFE) backbone is a sulfonated tetrafluoroethylene copolymer in which vinyl ether side chains (e.g., -O-CF2-CF-O-CF2-CF2-) terminate in sulfonic acid groups within the cluster regions.

[0062] In embodiments, the sulfonated polymer is polystyrene sulfonate, examples of which include potassium polystyrene sulfonate, sodium polystyrene sulfonate, copolymers of sodium polystyrene sulfonate and potassium polystyrene sulfonate (e.g., polystyrene sulfonate copolymers) having molecular weights of greater than 100,000 daltons, greater than 400,000 daltons, and up to 1,500,000 daltons. The polystyrene sulfonate polymer may be crosslinked or uncrosslinked. In embodiments, the polystyrene sulfonate polymer is uncrosslinked and water soluble.

[0063] In embodiments, the sulfonated polymer is a polysulfone and is selected from the group consisting of aromatic polysulfone, polyphenylene sulfone, aromatic polyether sulfone, dichlorodiphenoxy sulfone, sulfonated substituted polysulfone polymers, and mixtures thereof. In embodiments, the sulfonated polymer is a sulfonated polyether sulfone copolymer and can be made by reactants including a sulfonate salt, such as 2-potassium hydroquinone sulfonate (HPS), along with other monomers, such as bisphenol A and 4-fluorophenyl sulfone. The degree of sulfonation of the polymer can be controlled by the amount of HPS units in the polymer backbone.

[0064] In embodiments, the sulfonated polymer is polysulfone or polyaryletherketone, such as sulfonated polyetherketone (SPEEK), obtained by sulfonating polyetherketoneketone (PEKK). Polyetherketoneketone is produced using diphenyl ether and benzenedicarboxylic acid derivatives. Sulfonated PEEK is available as an alcohol and / or water-soluble product for subsequent use in membrane coatings, casting into membranes and films.

[0065] The use of sulfonated copolymers makes SP membranes hydrophilic and hygroscopic, permeable to moisture but impermeable to air and gases such as nitrogen and oxygen. Membranes containing sulfonated copolymers are characterized as selectively permeable by their ion exchange properties. SP membranes are also characterized as having excellent water vapor transport rate (MVTR) properties and excellent ion exchange capacity.

[0066] SP membranes are also characterized as undergoing substantial swelling upon absorption of water, e.g., at least 100% swelling at ambient temperature. In embodiments using sulfonated block copolymers having a degree of sulfonation (e.g., at least 25 mol%), SP membranes also exhibit antimicrobial properties, making them particularly useful for sterilizing air in addition to cooling indoor spaces.

[0067] In embodiments, the SP has an IEC of greater than 0.5 meq / g, or between 1.5 and 3.5 meq / g, or greater than 1.25 meq / g, or greater than 2.2 meq / g, or greater than 2.5 meq / g, or greater than 4.0 meq / g, or less than 4.0 meq / g.

[0068] In embodiments, the SP membrane (film) or coating containing SP has a thickness greater than 1 μm, or greater than 5 μm, or 5-50 μm, or less than 100 μm, or less than 75 μm, or less than μm. In embodiments, the membrane / coating may contain nanocomposite materials and may have an average pore size less than 1 μm, or less than 0.5 μm, or less than 0.1 μm.

[0069] In use, moisture from the air can be extracted by the water-permeable membrane by creating a pressure differential between the inlet side and the downstream end or portion of the membrane assembly, thereby encouraging the diffusion of water molecules from the inlet side of the membrane to the other side.

[0070] In embodiments, the SP membrane may be in a form other than a sheet, such as a mesh, a screen or grid, a woven or nonwoven fabric, a perforated or perforated plate, a foam, a hollow fiber membrane, or a pad with interconnected gaps and passageways therethrough onto which the SP is coated or bonded. In embodiments, the SP membranes may be spirally wound or arranged in stacks, parallel or perpendicular to the direction of airflow.

[0071] In embodiments, the SP membrane is in the form of a hollow fiber. Humid air flows through the hollow fiber under vacuum. The hollow fiber provides a large dehumidifying surface area and may be oriented parallel or perpendicular to the air flow. When the interior of the hollow fiber membrane is placed under vacuum, an osmotic gradient is created between the hollow core of the fiber (which is substantially under vacuum) and the exterior surface of the fiber. In hollow membrane embodiments, the SP coating or film may be applied to the interior, exterior, or both interior and exterior surfaces of the hollow fiber. Hollow fiber membranes are known in the art and are disclosed, for example, in U.S. Pat. No. 5,762,798, which is incorporated herein by reference.

[0072] The membrane may comprise an SP bonded or embedded in a frame, another membrane or membranes, a polymer matrix, or a plurality of fiber bundles by processes known in the art, such as casting. SP membranes can also be applied as a coating to a fiber matrix or to fan blades in an evaporative cooler.

[0073] The membrane can be bonded to a frame or another perforated layer, which acts as a support structure through which air and moisture can flow freely. The frame may comprise metal or plastic and can be formed into any conceivable geometric shape, including, but not limited to, honeycomb and corrugated structures. In embodiments, the frame can have a honeycomb, spiral, nonwoven, or multi-porous design for a large surface area, with proton-conducting membranes on multiple sides and an opening on one side for air flow. In other embodiments, the frame is in the form of a corrugated sheet with channels to increase the exposed area. The number of membrane frames can also be varied by adding or removing one or more frames, depending, for example, on the amount of moisture to be removed or the size of the room.

[0074] The shape-retaining frame can be formed thermally or mechanically and is preferably rigid, semi-rigid, or substantially rigid. As used herein, a rigid, semi-rigid, or substantially rigid frame refers to a frame made of a material or structure capable of maintaining its shape under its own weight. Suitable frame materials include fiberglass, aluminum, carbon, or polyester, polyethylene, polypropylene, polyethylene terephthalate, rigid polymers based on polyvinyl chloride, styrene / acrylonitrile / butadiene copolymer, nylon, polytetrafluoroethylene, aramid-based polymer fibers, metals, metal alloys, cellulose, cellulose nitrate, cellulose acetate, and combinations thereof.

[0075] Operation: In an embodiment, an air cooling system facilitates cooling and / or removing moisture from air to reduce the humidity level in air supplied to a room with minimal energy consumption. To cool the air, the air cooling system includes an evaporator through which a liquid, e.g., water, flows, and a pressure reduction system having a liquid ejector and a booster pump for reducing the pressure in the evaporator. The pressure in the evaporator is reduced to a value equal to or greater than the saturated vapor pressure of the liquid at ambient temperature. As the liquid flows through the evaporator, it is converted to vapor and absorbs latent heat of evaporation from the air passing through the evaporator, thereby cooling the air.

[0076] To reduce the humidity level of the air, the air cooling system includes a dehumidifying core having a membrane configured to facilitate the removal of moisture from air flowing through the membrane's air channels. The membrane is selectively permeable to water and water vapor and impermeable to air. The dehumidifying core is fluidly coupled to a reduced pressure system to create a vacuum within the membrane's vapor channels to extract moisture from the air flowing through the membrane's air channels. The reduced pressure system thereby facilitates creating a pressure differential between the dehumidifying core's vapor channels and air channels, enabling moisture flow within the vapor channels from the air channels. In one embodiment, the pressure differential or vacuum can correspond to the saturated vapor pressure of ambient water. The reduced pressure system is selectively connected to the evaporator and / or the dehumidifying core.

[0077] To reduce the temperature of the air provided to a room or area, liquid from a reservoir is provided to an evaporator through an inlet conduit, and the evaporator is connected to a pressure reduction system to generate a pressure within the evaporator that is below the saturated vapor pressure of the liquid at ambient temperature. To do so, a liquid ejector and, optionally, a booster pump are operated. To operate the liquid ejector, liquid from the reservoir is pumped into the inlet portion of the liquid ejector. The liquid then enters the throat portion of the liquid ejector. Because the cross-sectional area or diameter of the throat portion is smaller than the cross-sectional area of ​​the inlet portion, the velocity of the liquid within the throat portion increases due to the Venturi effect. This reduces the pressure within the throat portion. Because the throat portion is in communication with the booster pump and the evaporator, a corresponding reduced pressure is generated within the evaporator. It will be appreciated that the liquid ejector and / or booster pump are controlled to reduce the pressure within the evaporator to a value below the saturated vapor pressure of the liquid at ambient temperature. The reduction in pressure within the evaporator converts at least a portion of the liquid flowing through the evaporator into vapor. The evaporation process of the liquid within the evaporator absorbs sensible heat energy from the ambient air passing outside the evaporator, delivering cooled air to the room.

[0078] In one embodiment, the booster pump may be omitted. In such a case, the entire system is pre-conditioned to a pressure just above the saturated vapor pressure of the cooling / motive fluid before the system is powered on, and because this is a closed-loop system, the pre-conditioned pressure is maintained throughout the system's life. In one embodiment, the air cooling system is pre-conditioned to a pressure value 5% to 20% above the saturated vapor pressure of the liquid before start-up. For example, if the motive fluid is water, the pressure in the reservoir is reduced to 40 mbarA to 60 mbarA (when the liquid is water). After reducing the pressure in the reservoir to the desired value, the motive fluid pump is operated to provide liquid to the liquid ejector, thus moving the liquid from the evaporator to the liquid reservoir via the liquid ejector. In this example, two things occur simultaneously: the pressure in the evaporator is further reduced above the saturated vapor pressure of the liquid, and in the process, the liquid evaporates and absorbs heat. This evaporated fluid then condenses in the liquid ejector, increasing the amount of liquid in the liquid reservoir and therefore increasing the pressure in the reservoir and ejection system relative to the evaporator. In one embodiment, at least a portion of the liquid flowing from the liquid ejector to the reservoir is cooled by a heat exchanger. This process results in a more efficient vacuum pressure in the ejector, thus making a booster pump an optional component.

[0079] In an embodiment for removing moisture from air and delivering it to a room or area, a pressure reduction system is connected to the vapor channels of the dehumidifying core, and reducing the pressure increases the moisture gradient between the vacuum and ambient air sides, thus accelerating the moisture flow from the ambient to the vacuum medium, effectively dehumidifying the ambient air. It is known that moisture flow increases significantly as the pressure approaches and exceeds the saturated water vapor pressure threshold. The water vapor then flows to the throat portion of the liquid ejector, where it is converted to liquid water in the outlet portion of the liquid ejector due to the presence of higher pressure in the outlet portion, and then returns to the reservoir. In an embodiment, at least a portion of the liquid flowing from the liquid ejector to the reservoir is cooled by a heat exchanger.

[0080] The booster pump and liquid ejector can be controlled to generate a vacuum (i.e., pressure) depending on the amount of cooling, the water removal rate, and / or the reservoir pressure. For example, for larger systems, such as commercial air-chilled systems, where relatively larger cooling capacities are required, the required water evaporation also increases proportionally, and in such cases, a booster pump can facilitate reducing the pressure to below 10 mbar. In such cases, a multi-stage or variable-speed booster pump can be utilized. Alternatively, for smaller installations where relatively smaller water vapor extraction rates and / or smaller amounts of air need to be cooled, a pressure corresponding to 10 mbar to 20 mbar is sufficient. In such cases, a single-stage booster pump can be utilized. Furthermore, the speed of the booster pump can be controlled to vary the pressure in the vapor channel and / or evaporator.

[0081] Please refer to the figures which illustrate various embodiments of the device and methods of using the device.

[0082] Referring to FIG. 1 , an air cooling system 100 is shown having an evaporator 102 and a pressure reduction system 104 for reducing the pressure within the evaporator 102. The air cooling system 100 receives an incoming air flow (hereinafter referred to as a first air flow) 200A into a room and delivers or generates air having a relatively reduced temperature (hereinafter referred to as a second air flow 200B). As shown, the evaporator 102 is an evaporator coil 106 fluidly connected to the pressure reduction system 104 and a reservoir 108, e.g., a water reservoir 110, to receive liquid, e.g., liquid water, from the reservoir 108. The reservoir 108 is a pressure-resistant reservoir configured to hold a liquid at a pressure greater than atmospheric pressure and to store a liquid at a relatively low pressure. For example, the reservoir 108 can store a liquid at a pressure equal to or less than the vapor pressure (i.e., saturated vapor pressure) of the liquid. In one embodiment, the liquid is water, which has a vapor pressure of approximately 31.7 mbarA at 25 degrees Celsius. As shown, the inlet of the evaporator 102 is connected to the reservoir 108 via an inlet conduit 112, and the outlet of the evaporator 102 is connected to the pressure reduction system 104 via an outlet conduit 114. The liquid thereby flows from the reservoir 108 to the evaporator 102, is converted to a vapor, e.g., water vapor, by the low pressure or vacuum generated / created within the evaporator 102 by the pressure reduction system 104, and returns to the reservoir 108 via the pressure reduction system 104. As the liquid is converted to a vapor within the evaporator 102, the liquid receives the latent heat energy of the conversion of the air flow 200A passing through the evaporator 102 to a vapor, and is therefore cooled. To facilitate the suction of the first air flow 200A and the passage of the first air flow 200A through the evaporator 102, the air cooling system 100 may include a fan 116 disposed downstream of the evaporator 102.

[0083] As shown, the pressure reduction system 104 includes a liquid ejector 120, e.g., a water ejector 122, fluidly coupled to the outlet of the evaporator 102, a pump 124 for supplying a liquid, e.g., liquid water, to the liquid ejector 120, and a reservoir 108 for storing the liquid and receiving the liquid discharged from the liquid ejector 120.

[0084] As shown, the liquid ejector 120 is in fluid communication with the evaporator 102 via the outlet conduit 114. Accordingly, in response to the creation of low pressure within the liquid ejector 120, vapor generated within the evaporator flows toward the liquid ejector 120 via the outlet conduit 114. As shown, the liquid ejector 120 includes an inlet portion 128 that defines an inlet port 130 of the liquid ejector 120, a throat portion 132 that extends longitudinally from the inlet portion 128, and an outlet portion 134 that extends from the throat portion 132 and defines an outlet port 136 of the liquid ejector 120. The liquid ejector 120 also defines a vapor inlet port 138 fluidly coupled to the evaporator 102 via the outlet conduit 114 and positioned in fluid communication with the throat portion 132 to create / maintain a relatively low pressure (i.e., vacuum) within the evaporator 102 and to facilitate vapor entering the liquid ejector 120 (i.e., throat portion 132) from the evaporator 102.

[0085] Additionally, the inlet portion 128 may include a nozzle portion 140 defining an orifice 142 for injecting / delivering liquid into the throat portion 132 at a relatively high velocity, with the cross-sectional area of ​​the outlet portion 134 gradually increasing from the throat portion 132 to the outlet port 136 to decrease the velocity of the liquid received from the throat portion 132. In some embodiments, the cross-sectional area of ​​the inlet portion 128 may gradually decrease from the inlet port 130 to the throat portion 132 to facilitate a gradual increase in the velocity / velocity of the liquid. The inlet portion 128 thereby facilitates an increase in the velocity / velocity of the liquid as it flows from the inlet port 130 to the throat portion 132, and the outlet portion 134 is configured to decrease the velocity / velocity of the liquid as it flows from the throat portion 132 to the outlet port 136. As a result, the pressure at the throat portion 132 is lower than the pressure at the inlet port 130 and the outlet port 136. The level of pressure (i.e., vacuum) in the throat portion 132 may be adjusted / controlled by controlling the rate and / or amount of liquid entering the inlet portion 128. Thus, the throat portion 132 is in fluid communication with the evaporator 102, thereby creating a vacuum (i.e., reduced pressure) within the evaporator 102. The level of pressure in the throat portion 132 is controlled such that the reduced pressure created within the evaporator 102 is below a threshold value. In one embodiment, when the liquid is liquid water, the threshold value is equal to or less than the saturated vapor pressure of water at room temperature to effect conversion of at least a portion of the liquid water received from the water reservoir 110 via the inlet conduit 112 to water vapor.

[0086] To create and maintain a pressure within the evaporator 102 below a threshold, the pressure reduction system 104 may include a booster pump 148 disposed between the liquid ejector 120 and the evaporator 102. The booster pump 148 enables a further reduction in pressure within the evaporator 102, and therefore an increase in vacuum. In one embodiment, the booster pump 148 and the liquid ejector 120 together reduce the pressure within the evaporator 102 to between 20 mbarA and 40 mbarA. In one embodiment, the pressure reduction system 104 can create a pressure of less than 20 mbarA at the inlet of the booster pump 148. In one embodiment, the pressure reduction system 104 can create a pressure of less than 10 mbarA at the inlet of the booster pump 148. In one embodiment, the pressure reduction system 104 can create a pressure of between 10 mbarA and 20 mbarA at the inlet of the booster pump 148. The booster pump 148 and liquid ejector 120 may be controlled to reduce the pressure in the evaporator 102 based on the size of the air cooling system 100 and the desired water extraction rate. In one embodiment, the booster pump 148 is a Roots pump. However, it will be understood that any type of vacuum booster pump known in the art may be utilized.

[0087] To control and provide the flow of liquid to the liquid ejector 120, the pump 124 is disposed upstream of the liquid ejector 120 and fluidly connected to the inlet port 130 via a first pipe 150. In one embodiment, the pump 124 may be a variable speed pump to allow control of the amount of liquid pumped to the liquid ejector 120. Furthermore, the pump 124 is connected to the reservoir 108 via a second pipe 152 to receive liquid from the reservoir 108 and provide the liquid to the liquid ejector 120 at a desired speed / rate. In one embodiment, the reservoir 108 may include a plurality of fins (not shown) along an outer surface of the reservoir 108 to facilitate heat transfer between the liquid stored in the reservoir 108 and the surroundings. In some embodiments, the reservoir 108 is made from a material with high thermal conductivity to facilitate heat transfer between the liquid stored in the reservoir 108 and the surroundings.

[0088] In some embodiments, at least a portion of the liquid exiting the liquid ejector 120 is cooled before being delivered to the reservoir 108. To do so, the ejector 120 is fluidly connected to a heat exchanger 154 for cooling (i.e., reducing the temperature of) the liquid discharged by the liquid ejector 120. The heat exchanger 154 may be an air-to-liquid heat exchanger and may be located downstream of the liquid ejector 120 and upstream of the reservoir 108, and may be configured to receive liquid from the liquid ejector 120 and deliver cooled liquid to the reservoir 108. As shown, the heat exchanger 154 is fluidly connected to the outlet port 136 via a third pipe 158 and receives liquid from the liquid ejector 120 via the third pipe 158. Similarly, the heat exchanger 154 is fluidly connected to the reservoir 108 via a fourth pipe 160 and delivers cooled liquid to the reservoir 108 via the fourth pipe 160. In some implementations, only the portion of the liquid discharged from the liquid ejector 120 is provided to the heat exchanger 154 by a bypass conduit. In one embodiment, the portion of the liquid cooled by the heat exchanger 154 is mixed with the remainder of the liquid before the liquid enters the reservoir 108. In some implementations, the portion of the liquid cooled by the heat exchanger 154 may flow directly into the reservoir 108. In one embodiment, the reduced pressure system 104 may include a blower 162 to increase the flow of air to the heat exchanger 154 to facilitate cooling of the liquid flowing through the heat exchanger 154. The blower 162 may be located upstream or downstream in the direction of air flow to the heat exchanger 154.

[0089] In operation, the ejector's vacuum-generating capacity is only as high as the vapor pressure of the motive fluid. As shown in FIG. 1, the motive fluid in conduit 150 determines how much vacuum the ejector can generate. In pump 124, pressure increases when the pump's pumping speed increases. The vapor pressure of water at 1 atmosphere is approximately 40 millibars, but if a higher-pressure fluid is used (i.e., if the pump is pumping at a very high speed), the vacuum-drawing capacity may be optimized. Thus, when the system is pressurized, a vacuum pressure of less than 40 millibars can be generated. In an embodiment, the pressure in the tank exceeds the vapor pressure of the motive fluid. If the fluid is water and the pressure is 1 atmosphere, the water reservoir needs to be above approximately 30 millibars. Because the pressure of the motive fluid is what creates the vacuum, the pump 124 significantly increases the pressure of the motive fluid.

[0090] In an embodiment (not shown), the system further includes a pressure monitoring device, controller, etc., so that the rate is adjusted based on the pressure reading. Note that the (relative) pressure can be less than 1 atmosphere. In an embodiment, the pressure in the water reservoir 110 is maintained at a level above the vapor pressure of the motive fluid, allowing the condensate from the coil to actually become a liquid (condense). The pressure in the conduit 150 is then maintained above the water reservoir, thereby creating a significant vacuum within the coil. In an embodiment, a software program can be implemented to monitor / adjust the supply to maintain conditions above and below the vapor pressure of the motive fluid. The use of a booster pump helps facilitate operation of the system.

[0091] According to an alternative embodiment, as shown in FIG. 2, the heat exchanger 154 is located downstream of the pump 124, rather than upstream of the reservoir 108 (as shown in FIG. 1). In such a case, a third pipe 158 connects the liquid ejector 120 to the reservoir 108. The heat exchanger 154 is configured to cool at least a portion of the liquid pumped by the pump 124 to the liquid ejector 120. In such a case, a portion of the motive fluid traveling through the conduit 150 is diverted to the conduit 161 at a location downstream of the pump 124. This diverted fluid passes through the heat exchanger 154 and returns to the reservoir 108 via the conduit 160. Also, a blower 162 is shown located upstream of the heat exchanger 154 to enable air to flow through the heat exchanger 154. However, the blower 162 may be located downstream of the heat exchanger.

[0092] In another embodiment, as shown in FIG. 3 , the liquid reservoir 108 has an independent cooling system including a liquid pump 124B, an air-to-liquid heat exchanger 154, and a fan 162. The system can be activated based on how the liquid temperature compares to a programmed setpoint. As shown in FIG. 3 , the heat exchanger 154 is connected to the reservoir 108 via an inlet conduit 157 and an outlet conduit 159, and a second pump 124B provides liquid from the reservoir 108 via the inlet conduit 157 to the heat exchanger 154 for cooling the liquid. The cooled liquid returns to the reservoir 108 via the outlet conduit 159. In one embodiment, the second pump 124B pumps liquid into the heat exchanger 154 when the temperature of the liquid in the reservoir 108 exceeds a threshold temperature value. A blower 162 is also disposed or positioned upstream of the heat exchanger 154 to allow air to flow through the heat exchanger 154 to cool the liquid. However, the blower 162 may also be positioned downstream of the heat exchanger 154 .

[0093] The air cooling system 100 further includes a throttle valve 166 to control the amount of liquid flowing from the reservoir 108 to the evaporator 102. The throttle valve 166 may be an electrically controlled valve and is controlled based on the ambient temperature and / or the pressure generated within the evaporator 102. In one embodiment, a controller may control the booster pump 148, the pump 124, and the throttle valve 166 to provide a desired level of air cooling.

[0094] In some embodiments, prior to starting the pump 124 to provide liquid from the reservoir 108 to the liquid ejector 120, the pressure in the reservoir 108 is reduced by engaging a vacuum pump (not shown) on the reservoir 108. In embodiments, the pressure in the reservoir 108 is reduced to a value between 5% and 20% greater than the saturated vapor pressure of the liquid at ambient temperature. In embodiments involving the use of water, the pressure in the reservoir 108 is reduced to a value depending on the saturated vapor pressure of the liquid at ambient temperature, for example, between 40 mbarA and 150 mbarA. After the pressure in the reservoir 108 is reduced to the desired value, the pump 124 is operated to provide liquid to the liquid ejector 120. Because the liquid leaving the liquid ejector 120 has a higher pressure than the liquid entering the liquid ejector 120, the pressure in the reservoir 108 increases, increasing the pressure of the liquid delivered to the liquid ejector 120 by the pump 124. This results in a larger pressure drop across the throat section 132, creating a desired lower pressure within the evaporator 102. In this manner, the liquid ejector facilitates creating a pressure in the evaporator 102 that is below the saturated vapor pressure of the liquid at ambient temperature. In some embodiments, this facilitates limiting the use of the booster pump 148. In some embodiments, the booster pump 148 may be omitted.

[0095] Referring to FIG. 4, an air cooling system 100′ according to an alternative embodiment of the present disclosure is shown. The air cooling system 100′ is similar to the air cooling system 100, except that the air cooling system 100′ further includes a dehumidifying core 210 fluidly coupled to the pressure reduction system 104 to facilitate extraction of moisture from the air, thereby facilitating control of the moisture or humidity level in the air delivered to the room or area (second air flow 200B). The dehumidifying core 210 thereby receives air having a relatively high moisture content (also referred to as inlet air 400A) and emits air having a relatively low moisture content (also referred to as outlet air 400B). The pressure difference between the channels creates a moisture gradient, resulting in a lower moisture content in the lower-pressure environment, thus accelerating the moisture flow.

[0096] To do so, with reference to Figures 4, 5, 6, and 7, the dehumidifying core 210 defines at least one air channel 214 through which inlet air 400A flows and at least one vapor channel 216 that receives moisture (e.g., water vapor 220 extracted from inlet air 400A) flowing through the at least one air channel 214. As shown, each vapor channel 216 is disposed adjacent to one or more of the air channels 214 and separated by membranes 222. Conversely, each air channel 214 is disposed adjacent to one or more of the vapor channels 216 and separated from adjacent vapor channels 216 by membranes 222.

[0097] 6, the dehumidifying core 210 has a box-shaped structure with a first face 226 disposed generally perpendicular to the flow of inlet air 400A and defining an inlet 228 for each of the air channels 214, and a second face 230 disposed generally parallel to the first face 226 and defining an outlet 232 for each of the air channels 214. The inlet air 400A thereby enters the air channels 214 through the first face 226 and exits the dehumidifying core 210 through the second face 230 as outlet air 400B. Moisture (i.e., water vapor 220) so removed from the inlet air 400A is collected in the vapor channels 216 (shown in FIG. 5).

[0098] As shown, each vapor channel 216 may extend in a direction substantially perpendicular to the extension direction of the air channels 214, and may extend in a direction substantially perpendicular to a third surface 234 (i.e., top surface 234) and a fourth surface 236 (i.e., bottom surface 236) of the dehumidifying core 210. Furthermore, the fourth surface 236 may define a closed end of each of the vapor channels 214, thereby preventing water vapor 220 from exiting the dehumidifying core 210 through the bottom surface 236, and an outlet 238 (shown in FIG. 7 ) for each vapor channel 214 may be disposed proximate the top surface 234 to facilitate exit of the water vapor 220 from the vapor channel 216. In one embodiment, the dehumidifying core 210 may include one or more collection channels (not shown) disposed proximate the top surface 234 in fluid communication with the outlets 238 of the vapor channels 216. In such cases, the outlets 238 may be defined by an intermittent surface of the dehumidifying core 210, which may be disposed proximate the top surface 234, with such intermittent surface extending parallel to the bottom surface 236. In some embodiments, one or more collection channels (not shown) may extend substantially parallel to the air channels 214 and may include closed ends at the first surface 226 and the second surface 230.

[0099] 6 and 7, the dehumidifying core 210 is formed by arranging multiple stacks 241 so that the stacks 241 are arranged parallel to and spaced apart from one another to define air channels 214 between the stacks 241. The stacks 241 are arranged so that the membranes 222 of one stack 241 face the membranes 222 of an adjacent stack 241. Each stack 241 further includes an outer frame 242 and a corrugated structure 243 disposed within and supported by the outer frame 242. As shown, the outer frame 242 is attached to the outer edge of the corrugated structure 243. Each corrugated structure 243 further defines multiple vapor channels 216 having a substantially rectangular shape. Each corrugated structure 243 further includes two membranes 222, one membrane 222 disposed on a first side of the corrugated structure 243 and the other membrane 222 disposed on a second side of the corrugated structure 243 opposite the first side. The corrugations 243 are thereby disposed between two membranes 222. The membranes 222 thereby separate the vapor channels 216 of the corrugations 243 from the air channels 214 defined between two adjacent stacks 241.

[0100] While a box-shaped, e.g., cubic, structure is contemplated having vapor channels 216 extending generally perpendicular to air channels 214, it will be understood that dehumidifying core 210 may include any other suitable shape or structure known in the art. It is further contemplated that air channels 214 and vapor channels 216 may extend in substantially the same direction or may run parallel to one another. It is also contemplated that dehumidifying core 210 may have concentric air channels 214 and vapor channels 216. Furthermore, dehumidifying core 210 may include conduits 240 (shown in FIGS. 4 and 6 ) in fluid communication with each vapor channel 216 to receive water vapor 220 and facilitate the exit of water vapor 220 from dehumidifying core 210.

[0101] 5 , the movement of water vapor 220 from the air flowing through air channel 214 to vapor channel 216 is facilitated by membrane 222, while the flow of other components 244 of the air, such as nitrogen, oxygen, carbon dioxide, etc., from air channel 214 to vapor channel 216 is substantially prevented by membrane 222. In some embodiments, membrane 222 may prevent approximately 99 percent of the flow of other components 244 from air channel 214 to vapor channel 216. In certain implementations, membrane 222 may prevent approximately 95 to 99 percent of the flow of other components 244 from air channel 214 to vapor channel 216.

[0102] Membrane 222 facilitates the extraction of water vapor 220 from air flowing through air channel 214 and facilitates the flow of water vapor 220 through membrane 220 to adjacent vapor channel 216 in response to the presence of a relatively lower pressure in vapor channel 216 than in air channel 214. Thus, a humidity gradient is established between air channel 214 and adjacent vapor channel 216. The humidity gradient is created by creating a pressure gradient / differential between air channel 214 and adjacent vapor channel 216. In particular, the partial pressure of water vapor in vapor channel 216 is maintained at a level lower than the partial pressure of water vapor in air channel 214, such that water vapor 220 in the air flowing through air channel 214 is drawn toward the suction side (i.e., vapor channel 216).

[0103] Conduit 240 facilitates connection of pressure reduction system 104 to vapor channel 216 and facilitates maintaining a desired reduced pressure within vapor channel 216 to create a desired pressure differential between vapor channel 216 and air channel 214. Similar to evaporator 102, pressure reduction system 104 (i.e., liquid ejector 120 and booster pump 148) creates a pressure within vapor channel 216 that corresponds to the saturated vapor pressure of a liquid, such as water, at ambient temperature. In one embodiment, booster pump 148 and water ejector 122 together reduce the pressure within vapor channel 216 to between 20 mbarA and 40 mbarA. In one embodiment, pressure reduction system 104 may create a pressure of less than 20 mbarA at the inlet of booster pump 148. In one embodiment, pressure reduction system 104 may create a pressure of less than 10 mbarA at the inlet of booster pump 148. In one embodiment, the pressure reduction system 104 may create a pressure of 10 mbarA to 20 mbarA at the inlet of the booster pump 148. The booster pump 148 and the water ejector 122 may be controlled to reduce the pressure in the steam channel based on the size of the air cooling system 100' and the desired water extraction rate.

[0104] Additionally, the air cooling system 100′ includes at least one valve, e.g., a first valve 170 and a second valve 180, to facilitate selective connection of the evaporator 102 and / or the dehumidifying core 210 to the reduced pressure system 104. As shown, the first valve 170 is positioned to control connection or disconnection of the evaporator 102 to the reduced pressure system 104 and is configured to move between a first position and a second position. In the first position, the first valve 170 allows fluid connection from the evaporator 102 to the reduced pressure system 104, allowing vapor flow from the evaporator to the liquid ejector 120, and in the second position, the first valve 170 fluidly disconnects the evaporator 102 from the reduced pressure system 104, thus preventing vapor flow from the evaporator 102 to the liquid ejector 120. As shown, the first valve 170 is positioned upstream of the reduced pressure system 104 and downstream of the evaporator 102.

[0105] Similarly, second valve 180 is positioned to control connection or disconnection of dehumidifying core 210 to reduced pressure system 104 and is configured to move between an open position and a closed position. In the open position, second valve 180 allows fluid connection from vapor channel 216 to reduced pressure system 104, allowing the flow of water vapor 220 from vapor channel 216 to liquid ejector 120; in the closed position, second valve 180 fluidly disconnects vapor channel 216 from reduced pressure system 104, thus preventing the flow of water vapor 220 from vapor channel 216 to liquid ejector 120. As shown, second valve 180 is positioned upstream of reduced pressure system 104 and downstream of dehumidifying core 210. In one embodiment, first valve 170 and second valve 180 are electrically controlled valves and are operated by a controller based on the desired cooling and humidity levels of air received from the room. In some scenarios, only the evaporator 102 is fluidly connected to the reduced pressure system 104 by moving the first valve 170 to a first position and the second valve 180 to a closed position. Similarly, only the dehumidifying core 210 can be fluidly connected to the reduced pressure system 104 by moving the second valve 180 to an open position and moving the first valve 170 to a second position. Furthermore, to simultaneously connect the evaporator 102 and the dehumidifying core 210 to the reduced pressure system 104, the first valve 170 is moved to a first position and the second valve 180 is moved to an open position.

[0106] Additionally, in some embodiments, air cooling system 100' may include a controller and multiple sensors for controlling the operation of air cooling system 100'. In one embodiment, air cooling system 100' may include one or more temperature sensors and one or more humidity sensors for monitoring the temperature and humidity of at least one of first air flow 200A, inlet air 400A, outlet air 400B, and second air flow 200B. The controller may thereby control pump 124 to deliver liquid at an optimal rate and may control booster pump 148 to maintain or create a desired level of vacuum or pressure within vapor channel 216 and / or evaporator 102.

[0107] Although an air cooling system 100' having a single evaporator 102 and a single dehumidifying core 210 is shown and contemplated, it will be understood that the air cooling system 100' may include any number of dehumidifying cores 210 and evaporators 102 arranged in a series or parallel configuration or a combination thereof.

[0108] The operation of the air cooling system 100′ having the dehumidifying core 210 and evaporator 102 fluidly connected to the pressure reduction system 104 will now be described. To do so, the first valve 170 is moved to a first position, and the second valve 180 is moved to an open position. The air cooling system 100 receives a first air flow 200A from a room having a relatively high humidity level and a high temperature, and supplies a second air flow 200B to the room having a relatively low humidity level and a low temperature. To do so, the air cooling system 100′ receives the first air flow 200A from the room. In one embodiment, the fan 116 can facilitate the suction / draw of the first air flow 200A from the room. Upon entering the first unit 700, the first air flow 200A enters the dehumidifying core 210 as inlet air 400A, flows through the air channel 214, and exits the dehumidifying core 210 as outlet air 400B. As inlet air 400A flows through air channel 214, at least a portion of water vapor 220 present in inlet air 400A flows through membrane 222 into adjacent vapor channel 216. A pressure differential is created to facilitate the extraction of water vapor 220 from inlet air 400A and the movement of water vapor 220 within vapor channel 216. The pressure differential is created by creating or maintaining a relatively lower pressure within vapor channel 216 compared to the pressure within air channel 214. In practice, to ensure that water vapor 220 flows across membrane 222, the partial pressure of water vapor within vapor channel 216 is maintained at a value lower than the saturated vapor pressure of water at ambient temperature within air channel 214. To do so, the controller can control and operate the pump 124 to pump liquid, in this case liquid water, from the reservoir 108 into the inlet port 130 of the liquid ejector 120, in this case the water ejector 122, at an appropriate rate (i.e., a predetermined amount of liquid water enters the inlet portion 128 per second), and operates and controls the booster pump 148.The appropriate rate of liquid water entering the water ejector 122 and the rate of the booster pump 148 may be determined based on the humidity level of the room and / or the humidity level of the inlet air 400A, the temperature of the inlet air 400A, the desired temperature and humidity level of the air delivered to the room, and / or the rate and amount of the first air flow 200A entering the air cooling system 100′.

[0109] As liquid water flows through inlet portion 128 and enters throat portion 132, the velocity of the liquid water increases and reaches a maximum value at throat portion 132. As a result, because vapor channel 216 is in fluid communication with throat portion 132 via vapor inlet port 138 and conduit 240, a relatively low pressure (i.e., vacuum) is created at throat portion 132, and therefore a relatively low pressure is created within vapor channel 216. It will be appreciated that due to the length of conduit 240 and the loss of vacuum caused by other bends within conduit 240, the value of the pressure within vapor channel 216 may be relatively high compared to the value of the pressure at the outlet of booster pump 148. Furthermore, pressure reduction system 104 is controlled so that the pressure at the outlet of booster pump 148 is lower than the pressure within air channel 214, creating a desired pressure differential. The pressure differential between vapor channel 216 and air channel 214 extracts water vapor 220 from the air flowing through air channel 214 and moves across membrane 222 into vapor channel 216. Similarly, the pressure difference between the steam channel 216 and the throat portion 132 may cause the water vapor 220 extracted from the inlet air 400A to travel / flow through the conduit 240 and the booster pump 148 and enter the throat portion 132 via the steam inlet port 138. Upon entering the water ejector 122 (i.e., the throat portion 132), the water vapor 220 may move along with the liquid water and enter the outlet portion 134 of the water ejector 122. Due to the increased cross-sectional area within the outlet portion 134, the velocity of the liquid water decreases, thereby creating a relatively high pressure within the outlet portion 134 compared to the pressure within the throat portion 132. The water vapor 220 received from the steam channel 216 thereby condenses within the outlet portion 134 before leaving the water ejector 122. This eliminates the need for a separate condenser to condense the water vapor 220 into liquid water, thereby improving the efficiency of the air cooling system 100′.

[0110] Heat may be generated by the condensation of water vapor 220 within the outlet portion 134 of the water ejector 122, resulting in an increase in the temperature of the liquid water exiting the outlet port 136 of the water ejector 122. To lower the temperature of the liquid water before delivering it to the water reservoir 110, at least a portion of the liquid water is directed to the heat exchanger 154, which facilitates cooling the received liquid water. The cooled liquid water is then supplied to the water reservoir 110 for storage and is available for later supply to the water ejector 122 by the pump 124. Note that due to the condensation of water vapor 220 received from the dehumidifying core 210, the volume of liquid water received by the water reservoir 110 leaving the water ejector 122 may be greater than the volume of liquid water supplied to the water ejector 122 by the pump 124. This may increase the level of liquid water in the water reservoir 110. The drain valve 182 may be opened when the level of liquid water in the water reservoir 110 exceeds a first threshold level to prevent the reservoir 110 from overflowing and causing liquid water to spill from the water reservoir 110. Opening the drain valve 182 may allow the liquid water to drain from the water reservoir 110. Additionally, the drain valve 182 may be closed in response to the level of liquid water dropping below a second threshold. In certain implementations, the drain valve 182 is configured to automatically open and close in response to the level of liquid water rising above the first threshold and falling below the second threshold, respectively.

[0111] Although not shown in FIGS. 1-3, in an embodiment, the air cooling system 100 further includes a drain valve to facilitate draining / removal of liquid from the reservoir 108.

[0112] Furthermore, the outlet air 400B discharged from the dehumidifying core 210 is received by and cooled by the evaporator 102 and exits the evaporator 102 as the second air flow 200B. As the outlet air 400B passes through the evaporator 102, the low pressure generated in the evaporator coil 106 by the water ejector 122 and the latent heat energy provided by the outlet air 400B may evaporate the liquid water flowing within the evaporator coil 106 and convert at least a portion of the liquid water flowing within the evaporator coil 106 into water vapor. This reduces the temperature of the outlet air 400B as it passes through the evaporator 102. Therefore, the second air flow 200B discharged from the evaporator is relatively cooler than the outlet air 400B received from the dehumidifying core 210. After passing through the evaporator 102, the second air flow 200B exits the air cooling system 100′ and enters the room. Utilizing liquid water as a motive fluid to create a low pressure within the throat portion 132, and therefore within the vapor channel 216, facilitates reduced energy consumption due to the incompressibility of liquid water. Furthermore, using the water ejector 122 as a pressure reduction means prevents cavitation-related damage compared to scenarios in which a conventional pump is used to create a low pressure or vacuum within the vapor channel 216. The use of the water ejector 122 also facilitates reducing the overall size of the air cooling system. When the second valve is moved to a closed position, the dehumidifying core 210 is isolated, and the air cooling system 100′ cools only the first air flow 200A and provides cooled air to the room. In this case, the air cooling system 100′ can thereby function similarly to the air cooling system 100. In one scenario, the second valve 180 can be moved to an open position, and the first valve 170 is moved to a second position. In such a case, the evaporator 102 is separate from the air cooling system 100′, which facilitates the removal of humidity from the first air flow 200A, such that the second air flow 200B delivered to the room has a lower humidity level compared to the first air flow 200A.

[0113] The use of the water ejector 122 provides the ability to handle highly condensable fractions in the form of water vapor as well as a source of fresh water for condensing moisture extracted in the dehumidification core 210. Additionally, the water ejector 122 is capable of generating vacuum pressures as low as 5 mbar absolute (expressed as mbarA). The water ejector 122, along with the booster pump 148, can also be adjusted to operate over a range of vacuum pressures, such as 100 mbarA, 150 mbarA, or even 500 mbarA or more. The vacuum pressure is regulated by adjusting fluid variables such as pressure and flow rate.

[0114] As used herein, the term "include" and grammatical variations thereof are intended to be non-limiting, and thus the recitation of items in a list does not exclude other similar items, and such items may be substituted for or added to the listed items. The terms "comprises" and / or "comprising," as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

Claims

1. 1. An air cooling system comprising: an evaporator configured to cool air passing therethrough; a reservoir for storing liquid, fluidly connected to the evaporator to provide the liquid to the evaporator; a pressure reduction system fluidly coupled to the evaporator and configured to create a pressure within the evaporator that is less than or equal to a saturated vapor pressure of the liquid at ambient temperature to facilitate converting at least a portion of the liquid flowing through the evaporator to vapor, the pressure reduction system comprising: A liquid ejector, comprising: an inlet portion configured to receive liquid from a reservoir; a throat section disposed downstream of the inlet section and fluidly coupled to the evaporator, the throat section configured to increase a velocity of the liquid received from the inlet section; an outlet portion disposed downstream of the throat portion and configured to increase pressure within the liquid ejector to facilitate condensation of vapor received from the evaporator; a liquid ejector having a pressure reducing system including: a booster pump disposed upstream of the liquid ejector and fluidly coupled to the evaporator to reduce the pressure in the evaporator to a pressure below the saturated vapor pressure of the liquid, the liquid being water, the booster pump facilitating the reduction of the pressure to a value of 31.7 mbarA or less at 25 degrees Celsius; a pump fluidly connected to the fluid ejector and the reservoir and configured to supply fluid from the reservoir to the fluid ejector; An air cooling system comprising:

2. 10. The air cooling system of claim 1, wherein the booster pump facilitates reducing the pressure to a value below the saturated vapor pressure of the fluid in the evaporator, or to a value between 20 mbarA and 40 mbarA, or between 10 mbarA and 20 mbarA.

3. The air cooling system of claim 1 , wherein the reservoir includes a drain valve for facilitating drainage of liquid from the reservoir when the level of liquid in the reservoir exceeds a first threshold level.

4. 10. The air cooling system of claim 1, further comprising a heat exchanger fluidly connected to the liquid ejector and configured to receive at least a portion of the liquid exiting the liquid ejector, the heat exchanger configured to cool the received liquid.

5. 5. The air cooling system of claim 4, wherein the heat exchanger is positioned upstream of the reservoir and supplies cooled liquid to the reservoir.

6. 10. The air cooling system of claim 1, wherein the liquid ejector is a water ejector configured to receive liquid water from the pump, and the air cooling system further includes a throttle valve disposed between the reservoir and the evaporator to control the flow of liquid from the reservoir to the evaporator.

7. 10. The air cooling system of claim 1, a dehumidifying core disposed upstream or downstream of the evaporator and configured to be fluidly coupled to the liquid ejector; The dehumidifying core is an air channel; at least one vapor channel separated from an air channel by a membrane; Including, the membrane is selectively permeable to water and water vapor to facilitate removal of moisture from air flowing through the air channels, is impermeable to air, and comprises an ion exchange capacity of at least 1.0 milliequivalents per gram; the throat portion is fluidly coupled to the at least one steam channel to create a relatively lower pressure within the at least one steam channel than within the air channel to facilitate a flow of moisture from air flowing through the air channel to the at least one steam channel; the outlet portion facilitates condensation of water vapor received from the at least one vapor channel; Air cooling system.

8. 8. The air cooling system of claim 7, wherein the pressure reduction system further comprises a booster pump disposed upstream of the liquid ejector and connected to the dehumidifying core to reduce the pressure in the at least one vapor channel to a pressure below the saturated vapor pressure of water.

9. The air cooling system of claim 7 , further comprising a valve disposed between the reduced pressure system and the dehumidifying core to control fluid connection of the dehumidifying core to the reduced pressure system.

10. 8. The air cooling system of claim 7, wherein the membrane comprises a sulfonated polymer.

11. 2. The air cooling system of claim 1, wherein the pressure in the reservoir is reduced to a value greater than the saturated vapor pressure of the liquid at ambient temperature by 5% to 20% when the liquid is water, or to a value between 40 mbarA and 150 mbarA when the air cooling system is started.

12. 10. The air cooling system of claim 1, wherein the air cooling system is pre-adjusted to a pressure value that is 5% to 20% greater than the saturated vapor pressure of the liquid before starting.

13. 1. An air cooling system comprising: at least one dehumidifying core defining an air channel and at least one vapor channel separated from the air channel; a membrane separating the at least one vapor channel from the air channel, the membrane configured to facilitate removal of moisture from air flowing through the air channel; the membrane is selectively permeable to water and water vapor and impermeable to air; the membrane comprises at least one dehumidifying core comprising a membrane containing an ion exchange capacity of at least 1.0 milliequivalents per gram; an evaporator configured to cool air passing through the evaporator, the evaporator positioned downstream or upstream of the dehumidifying core; a pressure-resistant reservoir for storing liquid, fluidly connected to the evaporator to provide the liquid to the evaporator; a pressure reduction system fluidly coupled to at least one of the evaporator or the dehumidifying core, the pressure reduction system comprising: when fluidly coupled to the evaporator, to create a pressure within the evaporator that is less than or equal to the saturated vapor pressure of the liquid at ambient temperature to facilitate converting at least a portion of the liquid flowing through the evaporator into vapor; and configured, when fluidly coupled to the dehumidifying core, to create a relatively lower pressure in the at least one vapor channel than in the air channel to facilitate extraction of moisture from air flowing through the air channel into the at least one vapor channel; The pressure reducing system is a liquid ejector, the liquid ejector comprising: an inlet portion configured to receive liquid from a pressure-resistant reservoir; a throat portion disposed downstream of the inlet portion, fluidly coupled to at least one of the evaporator or the at least one vapor channel, and configured to increase a velocity of liquid received from the inlet portion; and an outlet portion disposed downstream of the throat portion and configured to increase pressure within the liquid ejector to facilitate condensation of vapor received from at least one of the evaporator or the dehumidifying core; a liquid ejector having a booster pump disposed upstream of the liquid ejector for reducing the pressure inside at least one of the evaporators to a pressure below the saturated vapor pressure of the liquid or reducing the pressure in at least one vapor channel of the dehumidifying core to a pressure below the saturated vapor pressure of water, the liquid being water, and facilitating the reduction of the pressure to a value of 31.7 mbarA or less at 25 degrees Celsius; a pump fluidly connected to the liquid ejector and the pressure-resistant reservoir and configured to supply liquid from the pressure-resistant reservoir to the liquid ejector; Air cooling system.

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