Dehumidifying and water collecting device and method of manufacturing same

Abstract

In one embodiment, the membrane unit includes a support structure including an open space within the support structure for removing water vapor, and at least one membrane disposed on at least one surface of the support structure, the membrane having water permeability and water selectivity, and the membrane unit is configured such that, upon application of a vacuum to the open space of the support structure, water vapor is drawn across the membrane and through the support structure along an axis parallel to the interface between the support structure and the membrane.

Description

[Technical Field]

[0001] (Reference to Related Application) This application claims the benefit of priority to U.S. Provisional Application No. 63 / 479,825, entitled "Dehumidifying and Water Collecting Apparatus and Method for Manufacturing the Same," filed January 13, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0002] (Copyright) This patent disclosure may contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction of the patent document or patent disclosure as it appears in the U.S. Patent and Trademark Office patent files or records, but otherwise reserves all copyrights whatsoever.

[0003] This application relates to dehumidification and water collection systems and apparatus. In particular, this application relates to membranes and membrane support structures for dehumidification and water collection systems.

[0004] (Statement Regarding Federally Sponsored Research and Development) This invention was made with government support under award DE-EE0009061 from the U.S. Department of Energy (DOE). The government has certain rights in this invention. [Background technology]

[0005] Vacuum dehumidification systems recover water from moist air by using a vacuum to drive the water across a selective membrane. Freestanding membranes often rupture or deform, limiting the effectiveness and size of the membranes in vacuum dehumidification systems. Summary of the Invention

[0006] In one embodiment, the membrane unit includes a support structure including an open space within the support structure for removing water vapor, and at least one membrane disposed on at least one surface of the support structure, the membrane having water permeability and water selectivity, and the membrane unit is configured such that, upon application of a vacuum to the open space of the support structure, water vapor is drawn across the membrane and through the support structure along an axis parallel to the interface between the support structure and the membrane.

[0007] In some embodiments, the open space comprises a hole in the support structure.

[0008] In some embodiments, the pore shape varies spatially.

[0009] In some embodiments, the shape of the pores varies in an axis parallel to the interface between the support structure and the membrane.

[0010] In some embodiments, the shape of the pores varies in an axis perpendicular to the interface between the support structure and the membrane.

[0011] In some embodiments, the open space comprises a channel within the support structure.

[0012] In some embodiments, the shape of the flow channel varies spatially.

[0013] In some embodiments, the shape of the channel varies in an axis parallel to the interface between the support structure and the membrane.

[0014] In some embodiments, the shape of the channel varies in an axis perpendicular to the interface between the support structure and the membrane.

[0015] In some embodiments, the chemical nature of the support structure varies spatially.

[0016] In some embodiments, the chemical properties of the support structure vary in an axis parallel to the interface between the support structure and the membrane.

[0017] In some embodiments, the chemical properties of the support structure vary in an axis perpendicular to the interface between the support structure and the membrane.

[0018] In some embodiments, the shape of the membrane varies spatially.

[0019] In some embodiments, the shape of the membrane changes in an axis parallel to the interface between the support structure and the membrane.

[0020] In some embodiments, the shape of the membrane changes in an axis perpendicular to the interface between the support structure and the membrane.

[0021] In some embodiments, the film chemistry varies spatially.

[0022] In some embodiments, the film chemistry varies in an axis parallel to the interface between the support structure and the film.

[0023] In some embodiments, the film chemistry varies in an axis perpendicular to the interface between the support structure and the film.

[0024] In some embodiments, the membrane unit has a planar shape.

[0025] In some embodiments, the membrane unit has a non-planar shape.

[0026] In some embodiments, the membrane unit has a viscosity of at least 0.01 g H2O / m 2 / s water vapor transmission rate.

[0027] In some embodiments, the membrane unit has a water vapor selectivity H2O / N2 of at least 1000 H2O / N2.

[0028] In certain embodiments, the membrane comprises pores less than about 10 nm in diameter.

[0029] In one embodiment, the support structure comprises pores having diameters of about 100 μm to about 1 cm.

[0030] In some embodiments, the membrane unit further comprises a membrane support substrate disposed between the membrane and the support structure.

[0031] In some embodiments, the membrane support substrate contains pores with diameters of about 100 nm to about 10 mm.

[0032] In some embodiments, the membrane unit further comprises an inlet in fluid communication with the open space of the support structure for applying a vacuum.

[0033] In some embodiments, the membrane unit further comprises an outlet in fluid communication with the open space of the support structure for removing water vapor.

[0034] In some embodiments, the membrane unit further comprises a non-porous frame.

[0035] In some embodiments, the membrane unit is transparent to visible light.

[0036] In some embodiments, the membrane unit blocks the passage of infrared radiation.

[0037] In some embodiments, the membrane unit further comprises a membrane overlay disposed on the membrane.

[0038] In some embodiments, the membrane overlay comprises holes.

[0039] In some embodiments, the membrane overlay contains pores with diameters greater than 10 μm.

[0040] In some embodiments, the membrane overlay is chemically functionalized.

[0041] In some embodiments, the membrane overlay has one or more of the following properties: antifouling, antifouling, wettability, and antibacterial.

[0042] In some embodiments, the film overlay comprises a photocatalytic compound.

[0043] In some embodiments, the photocatalytic compound comprises titanium dioxide.

[0044] In some embodiments, the membrane overlay comprises at least one of high surface area particles or polymeric structures.

[0045] In some embodiments, at least one of the high surface area particles or polymeric structures comprises activated carbon, a metal organic framework, a zeolite, or a combination thereof.

[0046] In some embodiments, the membrane overlay comprises a biocidal compound.

[0047] In some embodiments, the biocidal compound comprises silver ions, copper ions, silver nanoparticles, copper nanoparticles, quaternary ammonium compounds, or combinations thereof.

[0048] In some embodiments, the membrane overlay induces turbulent mixing of non-water gas species at the membrane interface or reduces concentration polarization of non-water gas species.

[0049] In some embodiments, the membrane unit further comprises at least one impermeable barrier disposed on at least another surface of the support structure.

[0050] In some embodiments, the membrane unit further comprises a sensible cooling layer disposed on the surface of the impermeable barrier.

[0051] In some embodiments, the impermeable barrier is impermeable to water vapor.

[0052] In some embodiments, the impermeable barrier is impermeable to gas molecules.

[0053] In some embodiments, the impermeable barrier is non-porous.

[0054] In some embodiments, the impermeable barrier comprises a structural support layer.

[0055] In some embodiments, the impermeable barrier comprises a metal, an alloy, or a combination thereof.

[0056] In some embodiments, the impermeable barrier comprises a polymer.

[0057] In some embodiments, the impermeable barrier has a thermal conductivity in the range of 0.1-0.5 W / m·K.

[0058] In some embodiments, the impermeable barrier has a thermal conductivity in the range of 0.5-10 W / m·K.

[0059] In some embodiments, the impermeable barrier has a thermal conductivity in the range of 10-500 W / m·K.

[0060] In some embodiments, the impermeable barrier is hydrophobic.

[0061] In some embodiments, the discernible cooling layer comprises a wettable evaporative medium.

[0062] In some embodiments, the discernible cooling layer comprises a radiative cooler, a reflective barrier, or a combination thereof.

[0063] In some embodiments, the discernible cooling layer comprises holes.

[0064] In some embodiments, the discernible cooling layer is hydrophilic.

[0065] In some embodiments, the wettable evaporative medium comprises a heat transfer fluid.

[0066] In certain embodiments, the system includes one or more membrane units described herein, a vacuum pump configured to apply a vacuum to the open space of a support structure of the one or more membrane units, and one or more inlets configured to supply humidified feed air to each membrane of the one or more membrane units along an axis parallel to the interface between the support structure and the membrane.

[0067] In some embodiments, the system comprises multiple membrane units.

[0068] In some embodiments, the system further includes a vacuum manifold system.

[0069] In some embodiments, the system further comprises a vacuum reservoir.

[0070] In some embodiments, the system further comprises a plurality of vacuum pumps.

[0071] In some embodiments, the system further comprises an air-to-liquid heat exchanger.

[0072] In some embodiments, the system further comprises a water circuit.

[0073] In some embodiments, the system further comprises a water pump.

[0074] In some embodiments, the system further comprises a plurality of vacuum gates or valves.

[0075] In some embodiments, the system further includes a vapor compressor.

[0076] In some embodiments, the membrane units are arranged parallel to one another.

[0077] In some embodiments, at least one membrane unit is positioned perpendicular to the other membrane units.

[0078] In some embodiments, at least one membrane unit is arranged anti-parallel to the other membrane units.

[0079] In some embodiments, the inlet is configured to supply moist feed air to one or more spaces between the membrane units.

[0080] In certain embodiments, at least one membrane unit includes at least one impermeable barrier disposed on at least another surface of the support structure of the at least one membrane unit.

[0081] In certain embodiments, the system further includes one or more first inlets configured to supply working air to a location adjacent to a surface of each impermeable barrier of one or more membrane units along an axis parallel to the interface between the support structure and the impermeable barrier.

[0082] In some embodiments, the working air comprises dehumidified feed air.

[0083] In some embodiments, the system further includes a water mist device for dispensing water into the working air.

[0084] In some embodiments, the first inlet is configured to supply working air to one or more spaces between the plurality of membrane units.

[0085] Any one of the embodiments disclosed herein may be suitably combined with any other embodiment disclosed herein, and the combination of any one of the embodiments disclosed herein with any other embodiment disclosed herein is expressly contemplated.

[0086] Objects and advantages will become apparent from the following detailed description considered in conjunction with the accompanying drawings, in which like reference numerals refer to like parts. [Brief explanation of the drawings]

[0087] [Figure 1] Schematic of a membrane unit design according to an embodiment [Figure 2] (FIG. 2A) Schematic of a selective membrane according to an embodiment; (FIG. 2B) Schematic of a membrane unit according to an embodiment; (FIG. 2C) Schematic of a vacuum membrane dehumidification system according to an embodiment. [Figure 2D] FIG. 1 illustrates dry bulb temperature and humidity ratio for an isothermal dehumidification and water collection system according to an embodiment. [Figure 3](FIG. 3A) Schematic of a selective membrane according to an embodiment; (FIG. 3B) Schematic of a membrane unit including a non-porous barrier and a wettable evaporative medium according to an embodiment; (FIG. 3C) Schematic of a vacuum membrane dehumidification and evaporative cooling system according to an embodiment. [Figure 3D] FIG. 1 illustrates dry bulb temperature and humidity ratio for an exemplary system for dehumidification and evaporative cooling, in accordance with certain embodiments. [Figure 4] FIG. 1 illustrates features of a membrane unit and supported membrane assembly according to an embodiment. [Figure 5] FIG. 1 illustrates features of a membrane unit and supported membrane assembly including a non-porous barrier and a discernible cooling layer according to an embodiment. [Figure 6A] A diagram of a vacuum membrane dehumidification system retrofitted to a curtain wall system, according to one embodiment. [Figure 6B] A diagram of a vacuum manifold system for a vacuum membrane dehumidification system, according to an embodiment. [Figure 6C] FIG. 1 is a diagram of a membrane unit connected to a vacuum manifold according to an embodiment. [Figure 7] 1 is a diagram of features of a supported membrane assembly including a planar conformal membrane and a porous support structure according to an embodiment. [Figure 8AB] 1 is a diagram of features of a supported membrane assembly including a planar conformal membrane, an impermeable barrier, a discernible cooling layer, and a porous support structure according to an embodiment. [Figure 8CD] 1 is a diagram of features of a supported membrane assembly including a planar conformal membrane, an impermeable barrier, a discernible cooling layer, and a porous support structure according to an embodiment. [Figure 9] FIG. 1 is a diagram of a supported membrane assembly including a non-planar conformal membrane and a porous support structure according to an embodiment. [Figure 10] FIG. 1 is a diagram of a supported membrane assembly including a conformal membrane and a porous support structure having various porous interconnected geometries perpendicular to the feed plane, according to an embodiment. [Figure 11] FIG. 1 is a diagram of a supported membrane assembly including a conformal membrane and a porous support structure having various porous interconnected geometries parallel to the feed plane, according to an embodiment. [Figure 12] FIG. 1 is a diagram of a supported membrane assembly including a conformal membrane and a porous support structure having various porous interconnected geometries in a combination of directions perpendicular and parallel to the feed plane, according to an embodiment. [Figure 13] FIG. 1 is a diagram of a supported membrane assembly including a conformal membrane and a non-porous support structure with continuous flow channels according to an embodiment. [Figure 14] FIG. 1 is a diagram of a supported membrane assembly including a conformal membrane and a non-porous support structure with hierarchical continuous flow channels according to an embodiment. [Figure 15] 1 is a diagram of a supported membrane assembly including a conformal membrane, a conformal porous membrane substrate, and a porous support structure according to an embodiment. [Figure 16] FIG. 1 is a diagram of a supported membrane assembly including a conformal membrane overlay, a conformal porous membrane, and a porous support structure according to an embodiment. [Figure 17] 1 is a diagram of a supported membrane assembly including a conformal membrane overlay, a conformal porous membrane, a conformal porous membrane substrate, and a porous support structure according to an embodiment. [Figure 18] FIG. 1 is a diagram of a supported membrane assembly including conformal membranes with varying membrane chemistries perpendicular to the feed plane and a porous support structure according to an embodiment. [Figure 19] FIG. 1 is a diagram of a supported membrane assembly including conformal membranes with varying membrane chemistries parallel to the feed plane and a porous support structure according to an embodiment. [Figure 20] A matrix illustrating various combinations of membranes and support structures according to certain embodiments. [Figure 21] 1 is a matrix showing various combinations of recognizable cooling layers, film overlays, films, and film support substrates according to certain embodiments; [Figure 22AB] 1 is a diagram of a supported membrane assembly having a cylindrical configuration according to an embodiment. [Figure 22CD] FIG. 1 is a diagram of a supported membrane assembly having a cylindrical configuration including a membrane overlay according to an embodiment. [Figure 23AB] FIG. 1 is a diagram of a supported membrane assembly having a tubular configuration including a non-porous barrier layer according to an embodiment. [Figure 23CD] FIG. 1 is a diagram of a supported membrane assembly having a tubular configuration including a membrane overlay according to an embodiment. [Figure 24AB] FIG. 1 is a diagram of a supported membrane assembly having a tubular array configuration according to an embodiment. [Figure 24CD] FIG. 1 is a diagram of a supported membrane assembly having a tubular array configuration including a membrane overlay according to an embodiment. [Figure 25] FIG. 1 illustrates a supported membrane assembly having an annular configuration including a non-porous barrier layer and an evaporative cooling layer according to an embodiment. [Figure 26] FIG. 1 illustrates a supported membrane assembly having an annular configuration including a non-porous barrier layer and an evaporative cooling layer according to an embodiment. [Figure 27] FIG. 1 illustrates a supported membrane assembly having an annular configuration including a non-porous barrier and a radiative cooling layer, according to an embodiment. [Figure 28AB] FIG. 1 is a diagram of a supported membrane assembly having a spiral configuration according to an embodiment. [Figure 28CD] FIG. 1 is a diagram of a supported membrane assembly having a spiral configuration including a membrane overlay according to an embodiment. [Figure 29AB] FIG. 1 is a diagram of a supported membrane assembly having a spiral configuration according to an embodiment. [Figure 29CD] FIG. 1 is a diagram of a supported membrane assembly having a spiral configuration including a membrane overlay according to an embodiment. [Figure 30A] Illustration of a porous support material made from a 3D printed polymer gyro structure, according to an embodiment. [Figure 30B] FIG. 1 is a diagram of a rigid plastic frame with vacuum inlets for a porous support material according to an embodiment. [Figure 30C] 1 is a diagram of a water-selective membrane adhered to a frame for a support material according to an embodiment. [Figure 30D] 1 is a diagram of multiple porous support structures having a hierarchical structure with varying porosity and layer thickness, according to some embodiments. [Figure 30E] 1 is a diagram of an experimental setup for a dehumidification system according to an embodiment. [Figure 31A]1 is a plot of raw water permeability over time for a selection of membranes including various cellulose triacetate ("CA"), ethylene-methyl acrylate copolymer, silicone rubber ("PDMS"), polyolefin composite, and polyethyleneamide co-block polymer, according to certain embodiments. [Figure 31B] 1 is a diagram of calculated water vapor flux for a selection of membranes including various cellulose triacetate ("CA"), ethylene-methyl acrylate copolymer, silicone rubber ("PDMS"), polyolefin composite, and polyethyleneamide coblock polymer, according to certain embodiments. [Figure 31C] Graph of selectivity values ​​for a selection of membranes including various cellulose triacetate ("CA"), ethylene-methyl acrylate copolymer, silicone rubber ("PDMS"), polyolefin composite, and polyethyleneamide coblock polymer, according to certain embodiments. [Figure 32A] Illustration of porous 3D printed PLA (polylactic acid) support material according to one embodiment. [Figure 32B] An illustration of a nonwoven fibrous support material according to an embodiment. [Figure 32C] FIG. 1 is a diagram of a plastic screen mesh support material having corrugated supports according to an embodiment. [Figure 32D] An illustration of a laminated plastic screen mesh support material according to an embodiment. [Figure 32E] Illustration of a porous 3D printed PLA (polylactic acid) support material, according to one embodiment. [Figure 32F] An illustration of a nonwoven fibrous support material according to an embodiment. [Figure 32G] Illustration of a plastic screen mesh support material according to an embodiment. [Figure 32H] FIG. 1 is a diagram of a plastic screen mesh support material having corrugated supports according to an embodiment. [Figure 32I] Schematic of a porous 3D printed PLA (polylactic acid) support material, according to one embodiment. [Figure 32J] Schematic of a nonwoven fibrous support material according to certain embodiments. [Figure 32K]Schematic diagram of a laminated plastic screen mesh support material according to an embodiment. [Figure 32L] Schematic diagram of a plastic screen mesh support material with corrugated supports according to an embodiment. [Figure 32M] A diagram of water mass flux values ​​for panel geometries with various porous support structures, according to certain embodiments. [Figure 33A] FIG. 1 illustrates individual panels assembled into variably spaced "cassettes" according to one embodiment. [Figure 33B] FIG. 1 is a diagram of a cassette installed in a ducted air-side flow system with a permeate-side vacuum manifold, according to an embodiment. [Figure 33C] Illustrates the effect of panel spacing on water mass flux and overall system pressure drop according to an embodiment. [Figure 33D] FIG. 1 shows a panel with 3 mm membrane spacing according to an embodiment. [Figure 33E] Illustrated panel with 6mm membrane spacing according to an embodiment. [Figure 33F] FIG. 1 shows a panel with 12 mm membrane spacing according to an embodiment. [Figure 33G] Figure 1 shows experimentally measured mass fluxes and corresponding water extraction rates and predicted coefficients of performance for panel geometries with variable spacing. [Figure 34A] 1 is a diagram of a prototype tested in a demonstration building according to an embodiment; [Figure 34B] A diagram of a prototype installed next to a window AC according to one embodiment. [Figure 34C] FIG. 1 illustrates a demonstration of a prototype system according to one embodiment. [Figure 34D] Illustrated prototype with vacuum system installed according to an embodiment. [Figure 35A] FIG. 10 illustrates the dehumidification efficiency of three flow configurations field tested for 24 hours according to an embodiment. [Figure 35B] FIG. 10 illustrates the dehumidification efficiency of three flow configurations field tested for 24 hours according to an embodiment. [Figure 35C] FIG. 10 illustrates the dehumidification efficiency of three flow configurations field tested for 24 hours according to an embodiment. [Figure 36A] 10 is a diagram of relative humidity in fan-assisted airflow at air velocities of 0.7 to 1.5 m / s according to an embodiment. [Figure 36B] 10 is a diagram of the relative humidity of the fan-assisted airflow at an air velocity of 3.0 m / s according to an embodiment. [Figure 36C] Relative humidity diagrams for natural ventilation airflow configurations at air velocities from 0.0 to 0.3 m / s according to an embodiment. [Figure 36D] Absolute humidity diagram of fan-assisted airflow at air velocities from 0.7 to 1.5 m / s according to an embodiment. [Figure 36E] Absolute humidity diagram of fan-assisted airflow at an air velocity of 3.0 m / s according to an embodiment. [Figure 36F] Absolute humidity diagrams for natural ventilation airflow configurations at air velocities from 0.0 to 0.3 m / s according to an embodiment. [Figure 37] FIG. 10 illustrates the relationship between indoor absolute humidity and outdoor absolute humidity for a product air velocity of approximately 0.75 m / s according to an embodiment. [Figure 38] 1 illustrates the reduction in absolute humidity of the product air as a function of outdoor absolute humidity for a product air velocity of about 0.75 m / s according to one embodiment. [Figure 39] 1 shows the reduction in absolute humidity of the product air at a product air velocity of about 0.75 m / s during a 12-hour test according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0088] In one embodiment, the membrane unit includes a support structure including an open space within the support structure for removing water vapor, and at least one membrane disposed on at least one surface of the support structure, the membrane having water permeability and water selectivity, and the membrane unit is configured such that, upon application of a negative pressure (vacuum) to the open space of the support structure, water vapor is drawn across the membrane and through the support structure along an axis parallel to the interface between the support structure and the membrane.

[0089] Disclosed herein are engineered components of a water-selective vacuum membrane system for energy-efficient, low-carbon building dehumidification and water collection. As humid air passes through the system and enters the target environment, it can selectively capture water vapor using an array of mass exchangers with specially engineered membrane units or panels. The chemical composition of the membrane in the membrane panel promotes the separation of small molecules (H2O / N2 selective) through the preferential absorption and diffusion of water molecules, which is an isothermal process (e.g., humid air is dried without a change in temperature). Vacuum pressure can be applied to one side of the membrane, creating a driving force that amplifies water permeation through the membrane, achieving high water capture rates. The thin membranes (e.g., polymeric membranes) used in the membrane units may be supported by a structural support matrix (e.g., a porous support or a non-porous support with flow channels) that is sufficiently rigid to prevent permanent membrane deformation and rupture, and that is highly porous in a manner that limits or prevents concentration polarization of water vapor flux on both the feed and permeate sides to maintain high water vapor permeability throughout the system.

[0090] In some embodiments, a membrane unit or panel includes one or more water-selective membranes with uniform or variable shapes and positions and one or more support structures with uniform or variable shapes and positions. Membrane units may also be referred to as mass exchange units, membrane tiles, or membrane panels. In some embodiments, the support structure includes open spaces for permeate removal, such as a porous substrate, a hollow support structure, a hollow channel structure, or a combination thereof. For example, if the support structure material is not appropriately sized for its structure and porosity, water diffusion across the membrane can be limited by the formation of a stagnant boundary layer (i.e., concentration polarization due to localized accumulation of water vapor molecules on the permeate side (i.e., the collecting side)) and / or reduced pressure and concentration gradients across the membrane. A well-designed interconnected structure facilitates the transport of water molecules away from the membrane interface on the permeate side, resulting in improved permeability across the membrane and improved dehumidification of the target air. In some embodiments, a well-designed interconnected structure includes interconnected open spaces. In some embodiments, the interconnected open spaces may be connected in three dimensions, for example, allowing vapor to flow in all dimensions. In some embodiments, a well-designed interconnect structure includes open spaces, holes, or voids with a feature size of about 100 μm to 5 mm. In some embodiments, the structure includes open spaces, holes, or voids with a feature size of about 100 μm to 200 μm, 200 μm to 300 μm, 300 μm to 400 μm, 400 μm to 500 μm, 500 μm to 1 mm, 1 mm to 2 mm, 2 mm to 3 mm, 3 mm to 4 mm, 4 mm to 5 mm, or any feature size within a range encompassed by any feature size disclosed herein. In some embodiments, a well-designed interconnect structure has a porosity of about 20% to 80%. In some embodiments, a well-designed interconnect structure has a porosity of 40% to 60%. In some embodiments, a well-designed interconnect structure has a porosity of 20%-30%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 70%-80%, or any range encompassed by any porosity disclosed herein.In some embodiments, the percent surface area of ​​the membrane (e.g., membrane support substrate) with the membrane or membrane substrate in contact with the well-designed interconnect structure is about 15% to 30%. In some embodiments, the percent surface area of ​​the membrane (e.g., membrane support substrate) with the membrane or membrane substrate in contact with the well-designed interconnect structure is about 5-10%, 10% to 15%, 15-20%, 20% to 30%, or any percent surface area of ​​the membrane within a range encompassed by any percent surface area of ​​the disclosed membrane.

[0091] In some embodiments, the membrane unit has a high water vapor permeability, e.g., at least 0.01 g H2O / m 2 / s water flux and / or at least 1x10^ -13 mol*m / m 2 In some embodiments, the membrane unit has a water permeability of 0.01 to 1.0 gH2O / m 2 / s. In some embodiments, the membrane unit exhibits high water selectivity, e.g., at least 1000 H2O / N2. In some embodiments, the membrane unit exhibits a water selectivity of about 1000 to 10,000,000 H2O / N2. In some embodiments, the membrane unit exhibits low air permeability, e.g., about 1x10 -16 mol*m / m 2 In some embodiments, the membrane unit exhibits a low air permeability, for example, less than about 1x10 -20 mol*m / m 2 The membrane exhibits an air permeability of less than 100 s*Pa. In some embodiments, vacuum pressure is applied to achieve a large driving force across the membrane. In some embodiments, a pressure of about 95,000 to about 105,000 Pa can be applied.

[0092] FIG. 1 illustrates an exemplary membrane unit and associated design parameters. Membrane units are sometimes referred to as mass exchange units, membrane tiles, or membrane panels. As shown in FIG. 1, each membrane unit 101 includes a membrane material 102 and a core material or support structure 103. In this example, each membrane unit includes a planar core material and a membrane material on two opposing surfaces of the planar core material. However, the membrane units may have any configuration, as long as the core material has a membrane material disposed on at least one surface of the core material. For example, a membrane unit may include a membrane material on two opposing surfaces of the planar core material. In another example, a membrane unit may be a single-sided membrane unit, in which one surface of the planar core material includes a membrane material. In these embodiments, the other surface of the planar core material without a membrane can provide an additional vacuum input location and / or heat transfer benefits. In another example, a membrane unit may be surrounded or enclosed by a continuous boundary or frame. In some embodiments, the boundary or frame includes an inlet in the center of the planar core material, e.g., a channel. In these embodiments, the inlet can provide for the application of a vacuum to the planar core material. In another example, the membrane unit can include a cylindrical core material with membrane material on the sides of the cylinder. For example, the core material can have any shape surrounded by the membrane material. In some embodiments, the membrane is a conformal membrane that completely covers the support structure, e.g., a membrane covering the exterior surface of a cylinder or tube. In the example of FIG. 1, the target air to be dehumidified flows through the space between the membrane units 101 (e.g., the feed plane) via a pressure gradient (free or forced), creating a low pressure within the support structure. In this example, the water-selective membrane preferentially absorbs water molecules from the humid air feed stream. The vacuum pressure can provide a pressure and / or concentration gradient sufficient to draw water molecules into the permeate flow across the membrane (e.g., a pressure below the partial pressure of water vapor, typically less than 4 kPa). This results in a vapor concentration gradient within the support structure. This combination of pressure gradient and concentration gradient allows water vapor to migrate across the membrane and through the support structure, removing water vapor from the humid air at the feed plane.

[0093] In some embodiments, suitable membrane materials have high permeability (high solubility and diffusivity for water) and high selectivity (absorb water and reject oxygen and nitrogen). In some embodiments, suitable core or support materials are strong enough not to collapse under vacuum, smooth enough not to penetrate the membrane, contain sufficient open spaces (e.g., pores or channels) to prevent internal vapor flow blockage, inexpensive, quick to manufacture, and have minimal contact with the membrane to maximize active area. Such supporting structural materials can provide at least two functions: (1) structural support for the membrane material and (2) vapor transport for continuous removal of moisture. In some embodiments, the supporting structural materials contain open spaces, e.g., pores or channels, to facilitate vapor flow. In some embodiments, the shape and chemistry of the support material are selected to create internal vapor concentration gradients and facilitate vapor flow, for example, by creating spatial gradients in chemistry, shape, or a combination thereof. In some embodiments, the thickness of the membrane units and the spacing between the membrane units can be selected to optimize dehumidification. In some embodiments, the membrane tiles are adjustable to vary the spacing. For example, membrane tiles can be arranged in an adjustable bellows structure to vary the spacing and dehumidification capacity while maintaining a fixed or constant flow rate. In some embodiments, a pressure gradient can be applied to the membrane unit, e.g., by applying a vacuum to the core material or support structure, to create a driving force that increases water permeation across the membrane and into the support structure, e.g., via a vacuum inlet. In some embodiments, the membrane unit includes one or more inlets fluidly connected to the open space of the support structure for applying the vacuum. In some embodiments, the membrane unit includes an inlet with a controllable valve or solenoid valve. In some embodiments, such valves can be used for diagnostics, membrane unit replacement, and / or adaptive dehumidification throughput control. In some embodiments, the membrane unit includes one or more outlets fluidly connected to the open space of the support structure for removing water vapor from the support structure.In some embodiments, the membrane unit includes one or more outlets having a pressure sensor or transducer in fluid communication with the open space of the support structure to remove water vapor from the support structure.

[0094] Figures 2A-2C are schematic diagrams of an example vacuum membrane dehumidification system 200. Figure 2A shows a dense block copolymer film 202 that exhibits high water vapor permeability and selectivity based on its tailored molecular structure. In the example shown in Figure 2A, when humid feed air containing oxygen, nitrogen, and water flows through or parallel to a water-selective membrane, water can pass through the membrane to form a permeate, while oxygen and nitrogen permeate at a much lower rate. Such films can be used as selective membranes and are generally thin. Non-limiting examples of thicknesses for selective membranes include thicknesses of 1 μm, 15 μm, 50 μm, 100 μm, or any thickness within the range encompassed by any thickness disclosed herein. The feed and permeate paths can be parallel, antiparallel, perpendicular, or tangential. Figure 2B shows a membrane unit 201 including a support structure 203 and a membrane 202 on either surface of the support structure. As shown in FIG. 2B, a vacuum applied to the porous support structure can create a vacuum-driven concentration gradient such that water from the feed is trapped within the support structure and flows downward as part of the permeate. In the example of FIG. 2B, the concentration of water vapor can be optimized by selecting the thickness of the membrane unit. In some embodiments, the membrane unit thickness can be 5 mm or less. In some embodiments, the membrane unit thickness can be 6 mm or less. As shown in FIG. 2C, multiple membrane units 201 can be arranged to form a dehumidification system 200. In the example shown in FIG. 2C, humid air enters at (a) as part of the feed, dry air exits at (b), and water vapor is trapped within the support structure (e.g., as the permeate). In this example, the boundary layer can be optimized by selecting a spacing between the membrane units of, for example, 10 mm. As shown in FIG. 2D, this example system can achieve energy-efficient isothermal dehumidification and water collection. This example system can remove water vapor from air without changing its temperature.

[0095] In some embodiments, the membrane support structure includes an impermeable interface or barrier that is impermeable to water vapor. In some embodiments, the impermeable interface of the membrane support structure can be modified to function as an evaporative or radiative cooler. For example, one surface of the membrane support structure can include a water-selective membrane for dehumidification and water collection, while the other surface can include an impermeable barrier to incorporate cooling by evaporation (e.g., evaporative cooling) or radiation (e.g., radiative cooling). In some embodiments, the impermeable barrier is non-porous. In some embodiments, the membrane support structure including the impermeable barrier further includes a recognizable cooling layer. In some embodiments, the recognizable cooling layer includes a wettable evaporative medium for evaporative cooling. In some embodiments, the recognizable cooling layer includes a spectrally selective medium or a reflective barrier for radiative cooling. In some embodiments, the recognizable cooling layer includes a wettable evaporative medium for evaporative cooling and a spectrally selective medium or a reflective barrier for radiative cooling.

[0096] Figures 3A-3C are schematic diagrams of an example vacuum membrane dehumidification and evaporative cooling system 300. Figure 3A shows a dense block copolymer film 302 that exhibits high water vapor permeability and selectivity based on its tailored molecular structure. In the example shown in Figure 3A, when a feed (e.g., warm, humid feed air containing oxygen, nitrogen, and water, or a gas containing water) flows through or parallel to the water-selective membrane, water can pass through the membrane to form a permeate, while oxygen and nitrogen permeate at much lower rates. Such films can be used as selective membranes and are generally thin. Non-limiting examples of thicknesses for selective membranes include thicknesses of 1 μm, 15 μm, 50 μm, 100 μm, or any thickness within the range encompassed by any thickness disclosed herein. The feed and permeate paths can be parallel, antiparallel, perpendicular, or tangential. FIG. 3B shows a membrane unit 301 including a support structure 303, a membrane 302 on one surface of the support structure 302, and a non-permeable (e.g., non-porous) barrier 304 on the other surface of the support structure 303. In some embodiments, the membrane 302 may be in contact with or exposed to feed air for dehumidification, while the non-porous barrier 304 may be in contact with or exposed to working air for cooling. As shown in FIG. 3B, a vacuum applied to the porous support structure can create a vacuum-driven concentration gradient such that water from the feed air is trapped within the support structure through the membrane 302 and flows downward as part of the permeate. In some embodiments, the non-porous barrier 304 can cause evaporative cooling of the contacting working air. In some embodiments, the non-porous barrier 304 can be an insoluble (e.g., water-insoluble) and / or non-porous medium. In some embodiments, the other surface of non-porous barrier 304 (e.g., the surface not in contact with support structure 303) may include a wetted porous or wettable evaporative medium (i.e., a discernible cooling layer) 305. Wettable evaporative medium 305 may include porosity or voids to retain water.

[0097] In the example shown in FIG. 3B, the concentration of water vapor can be optimized by selecting a membrane unit thickness, e.g., 5 mm. As shown in FIG. 3C, multiple membrane units 301 can be arranged to form a dehumidification and cooling system 300. In the example shown in FIG. 3C, on the membrane side of membrane unit 301, warm, humid air enters at (a) as part of the feed, cool, dry air exits at (b), and water vapor is captured within the support structure (e.g., as permeate). In this example, on the non-porous barrier side of membrane unit 301, working air enters at one end and decreases in temperature and increases in humidity via evaporative cooling as it moves toward the other end. In some embodiments, a water mist device can be provided to distribute water with the working air to enhance evaporative cooling of the working air. In this example, the boundary layer can be optimized by selecting a spacing between membrane units, e.g., 10 mm.

[0098] In some embodiments, the examples shown in Figures 3A-3C illustrate a configuration with a dual-function membrane assembly coupled with sensible cooling via evaporative cooling. In this system, the sensible cooling layer (i.e., a wetted porous medium or wettable evaporative medium) 305 is cooled by evaporation (phase change of water or other liquid), transferring heat from the dry feed air through a porous support structure, which dehumidifies and cools the product supply air. Figure 3C illustrates that a portion of the sensibly cooled and dehumidified product air can be diverted to the wet working air to further reduce the air temperature through sub-wet bulb cooling. The working air flow paths and product air flow paths can be arranged in a variety of configurations, including, but not limited to, parallel, crossover, opposing, regenerative, multi-stage, and other heat exchange and flow configurations.

[0099] As shown in Figure 3D, the example dehumidification and evaporative cooling system shown in Figures 3A to 3C can achieve energy-efficient dehumidification and evaporative cooling. In this example system, water vapor can be removed so that both the temperature and humidity ratio (i.e., water content) of the feed air are reduced, resulting in cooler and drier target air. Meanwhile, the temperature of the working air is reduced and the humidity ratio of the working air is increased, resulting in cooler and humid working air.

[0100] In some embodiments, the non-porous barrier 304 may be thermally conductive and / or thin. For example, the non-porous barrier 304 may provide negligible or minimal thermal resistance. As another example, the non-porous barrier 304 may provide negligible or minimal boundary or interface thermal resistance between any surface materials. In some embodiments, the non-porous barrier 304 may include a unique support structure; for example, the non-porous barrier may include an impermeable layer and a structural layer. In some embodiments, the non-porous barrier 304 may be hydrophobic to mitigate water vapor penetration into the wetted porous medium (i.e., the discernible cooling layer) 305. In some embodiments, the wetted porous medium 305 may be hydrophilic in nature. In some embodiments, the wetted porous medium 305 may be a heat transfer fluid.

[0101] In some embodiments, the discernible cooling layer can be modified to function as a radiative cooler or a reflective barrier. In some embodiments, the discernible cooling layer can include a porous reflective coating or a spectrally selective medium (e.g., instead of a wettable evaporative medium).

[0102] In some embodiments, the recognizable cooling layer can include both a wettable evaporative medium and a radiative cooler. In some embodiments, the recognizable cooling layer can include both a wettable evaporative medium and a spectrally selective medium (e.g., a reflective barrier). In some embodiments, the recognizable cooling layer can function as both a wettable evaporative medium and a spectrally selective medium. For example, hydrophobic porous polyvinylidene fluoride can be used for both evaporative and radiative cooling.

[0103] In some embodiments, the impermeable barrier of the membrane support structure comprises a metal, an alloy, or a combination thereof. In some embodiments, the impermeable barrier can comprise a polymer.

[0104] In some embodiments, the impermeable barrier of the membrane support structure can have a thermal conductivity in the range of 0.1-500 W / m·K. In some embodiments, the impermeable barrier of the membrane support structure can have a thermal conductivity in the range of 10-500 W / m·K. In some embodiments, the impermeable barrier of the membrane support structure can have a thermal conductivity in the range of 0.5-10 W / m·K. In some embodiments, the impermeable barrier of the membrane support structure can have a thermal conductivity in the range of 0.1-0.5 W / m·K.

[0105] In some embodiments, the shape and / or chemistry of the porous membrane support structure may be selected to improve appreciable heat transfer (e.g., via thermal conduction) from the membrane to the impermeable barrier, thereby increasing the cooling rate of the feed air.

[0106] 4A-4B are schematic diagrams illustrating features of an example membrane unit or mass exchange unit 401. FIG. 4A shows a cross-sectional view, and FIG. 4B shows an isometric view. In this example, the membrane unit includes a supported membrane assembly including a support structure (e.g., a porous support structure) 403 and a membrane 402 on an opposing surface of the porous support structure. While a membrane unit can include at least a membrane assembly including a support structure and a membrane on at least one surface of the support structure, a membrane unit can also include other components. For example, the membrane unit shown in FIGS. 4A-4B also includes a non-porous boundary or frame 411, a connection to a negative pressure source 410 (e.g., a vacuum inlet), a region of feed air (air to be subjected to water vapor removal, indicated by white arrows), and a region of permeate (water vapor removed from the target air, indicated by black arrows). A membrane unit can include one or more of the features shown in FIGS. 4A-4B. As shown in Figure 4A, feed air is adjacent to the surface of membrane 402 and moves in space parallel to the surface of the membrane (e.g., in the feed plane), and permeate is removed through the porous substrate. In some embodiments, the membrane unit includes an inlet 410 for applying a vacuum that is in fluid connection with the pores of the porous support structure. In some embodiments, the membrane unit includes an outlet 420 for removing permeate that is in fluid connection with the pores of the porous support structure.

[0107] 5A-5B are schematic diagrams illustrating features of an example membrane unit or mass exchange unit 501, including a non-permeable (e.g., non-porous) barrier 504. FIG. 5A shows a cross-sectional view of membrane unit 501, and FIG. 5B shows an isometric view of membrane unit 501. In this example, the membrane unit includes a supported membrane assembly including a porous support structure (e.g., porous support structure) 503, a membrane 502 on one surface of porous support structure 503, and a non-porous barrier 504 on the other surface of support structure 503. A membrane unit can include at least a membrane assembly including a support structure, a membrane on one surface of the support structure, and a non-porous barrier on the other surface of the support structure, although a membrane unit can also include other components. For example, the membrane unit shown in Figures 5A-5B also includes a discernible cooling layer 505 disposed on the surface of the non-porous barrier 504 that is not in direct physical contact with the porous support structure 503, a non-porous boundary or frame 511, a connection to a negative pressure source 510 (e.g., a vacuum inlet), a region of feed air (air to be subjected to water vapor removal, indicated by white arrows), and a region of permeate (water vapor to be removed from the target air, indicated by black arrows). A membrane unit can include one or more of the features shown in Figures 5A-5B. As shown in Figure 5A, the feed air is adjacent to the surface of the membrane 502 and travels in a space parallel to the surface of the membrane (e.g., a feed plane), and the permeate is removed through a porous substrate. As shown in Figure 5A, the feed air is adjacent to the surface of the membrane 502 and travels in a space parallel to the surface of the membrane (e.g., a feed plane), and the permeate is removed through a porous substrate. Additionally, moist working air can move through spaces adjacent to and parallel to the surface of the impermeable barrier 504 (e.g., in the working air plane) to generate cooler working air.

[0108] 5A-5B show a configuration having a dual function (e.g., dehumidification and cooling) membrane assembly combined with identifiable cooling. In this system, the identifiable cooling layer transfers heat from dry feed air through a porous support structure, which dehumidifies and cools the target supply air (or feed air).

[0109] The energy-efficient isothermal membrane-based dehumidification systems disclosed herein rely on at least two key factors: a highly permeable and selective water vapor membrane and a large concentration gradient. Therefore, design parameters can significantly affect the overall performance of these systems, for example, by creating and maintaining concentration gradients within the membrane and / or support structure.

[0110] For example, performance can be influenced by membrane design parameters. A membrane's gas permeability (water vapor or otherwise) can be affected by its chemical composition, which affects the gas's solubility and diffusivity. Furthermore, membrane gas permeability is inversely proportional to its thickness; thinner membranes can transport more gas molecules in a given time. Because the overall vapor permeability across the membrane is also related to the concentration difference, a large negative pressure is induced behind the membrane to maximize flux. The use of thin membranes carries an inherent risk of failure due to physical damage (e.g., tearing, scratching, or rupture). However, chemical modification, bonding of membranes to rigid, porous support structures, and lamination to flexible substrates or support layers all present strategies to enhance the mechanical durability and, therefore, the feasibility of thin membranes for vacuum membrane dehumidification. In some embodiments, the flexible or rigid substrate or membrane substrate is porous and can contain pores ranging from the nanoscale to the millimeter scale (100 nm to 10 mm).

[0111] In some embodiments, the water-selective membrane is water "soluble." In some embodiments, the water-selective membrane contains molecular-scale (<10 nm) pores. Such pores may be the result of the polymer chemistry of the membrane material.

[0112] In some embodiments, chemical modification of regions within polymeric membranes through polymerization, crosslinking, crystallization, or the addition of additives offers a way to improve the durability of these membranes. The ability to spatially control these properties allows for structural reinforcement at high stress points. The ability to spatially control these properties also allows for targeted (efficient) removal of water vapor across a feed stream, for example, by creating chemical gradients within the membrane.

[0113] In some embodiments, a well-designed porous core material or support structure can enable the use of thinner membranes, resulting in improved permeability across the membrane and enabling target air dehumidification. For example, the support structure can provide mechanical support. In some embodiments, the support structure can also enable the use of more hydrophilic membranes, which tend to be increasingly soft, resulting in higher water vapor permeability. In some embodiments, the support structure includes metals, ceramics, polymers, composite / hybrid materials, and combinations thereof.

[0114] In some embodiments, a well-designed porous support structure can enable the formation of bonds (adhesion, bonding, etc.) between the membrane, the porous substrate, the support structure, and / or the non-porous boundary.

[0115] In some embodiments, the support structure comprises open spaces in the form of pores, channels, or a combination thereof. In some embodiments, the support structure comprises pores on the micrometer scale to the centimeter scale, e.g., in the range of 100 μm to 1 cm. In some embodiments, the support structure comprises channels on the micrometer scale to the centimeter scale, e.g., in the range of 100 μm to 1 cm.

[0116] In some embodiments, the support structure includes a surface chemistry, e.g., within the pores or channels, that can improve vapor transport within the support structure. For example, the support structure can include variations in chemistry, such as chemistry that varies along an axis perpendicular or parallel to the feed plane, to facilitate removal of water vapor or permeate.

[0117] In some embodiments, the supported membrane assembly comprises a porous support structure with interconnected pores that are single-, double-, or triple-periodic to enhance vapor flow and structural strength. Single periodicity refers to periodicity in one direction (e.g., x). Double periodicity refers to periodicity in two directions (e.g., x and y). Triple periodicity refers to periodicity in three directions (e.g., x, y, and z).

[0118] In some embodiments, the supported membrane assembly includes a support structure having a surface shape or topology that induces disruption, separation, mixing, or other alteration of the feed boundary layer to promote contact of water vapor with the membrane surface.

[0119] In some embodiments, a well-designed porous core material or support structure can reduce "concentration polarization" on the permeate side of a membrane. Concentration polarization can occur when water / gas vapors mix with a stagnant permeate boundary layer, limiting diffusion by reducing the internal vapor concentration gradient and essentially choking vapor flow through the membrane. In some embodiments, reduced concentration polarization can result in improved permeability across the membrane and dehumidification of the target air.

[0120] In some embodiments, the supported membrane assembly includes a support structure having a surface shape or topology that disrupts, separates, mixes, or otherwise alters the permeate boundary layer to reduce water vapor contact with the membrane surface.

[0121] In some embodiments, the supported membrane assembly can be encompassed by a non-porous boundary or frame, for example, to provide additional structural support. The non-porous boundary can include metallic, ceramic, polymeric, or composite / hybrid materials. For example, the membrane can be affixed to the frame using chemical, mechanical, or other bonding methods. In some embodiments, the frame can encompass all but one side of the membrane unit. In some embodiments, the frame can be attached to one side of the membrane unit, with the remaining edge providing a continuous airtight seal.

[0122] In some embodiments, the film chemistry, film geometry, film location, film substrate location, support structure location, or a combination thereof can be designed to selectively control the passage of visible and / or infrared light through the panel assembly. For example, the film units can be designed to allow visible light to pass. For example, the film units can be designed to block the passage of infrared light.

[0123] Figures 6A-6C show non-limiting examples of vacuum membrane dehumidification systems. Figure 6A shows a vacuum membrane dehumidification system retrofitted to an existing building's curtain wall system. In the example shown in Figure 6A, humid outside air passes through multiple membrane units 601, and dry air is sent to the interior of the building. In this example, fins 612 shade the membrane units from the sun, reducing UV degradation and heat transfer to the building / feed air. Figure 6B shows a vacuum manifold system for a vacuum membrane dehumidification system. In the example shown in Figure 6B, multiple membrane units 601 are connected to a manifold 614 connected to a vacuum pump 613. In this example, the membrane units are arranged parallel to each other, with the feed air flow passing between them. Alternatively, the membrane units can be arranged antiparallel or perpendicular to each other, for example, in serpentine, zigzag, spiral, and other configurations. Figure 6C shows an example of a membrane unit 601 connected to a vacuum manifold 614. In the example shown in Figure 6C, each membrane unit includes a porous support structure 603, support layers 606 on either side of the support structure, a water-selective membrane 602 on the outer surface of each support layer, and a structural frame 611. In this example, humid ambient air (e.g., feed air) moves in a plane parallel to the plane of the membrane 602. Water vapor moves across the water-selective membrane and through the porous support structure (e.g., as permeate) to the manifold where it can be removed via an outlet.

[0124] In some embodiments, the vacuum dehumidification system includes a vacuum system including one or more vacuum pumps, a plurality of pressure sensors or gauges, and a plurality of vacuum gates or valves.

[0125] In some embodiments, the vapor condenser system includes one or a combination of a gas-to-liquid heat exchanger and a chiller with a refrigerant and a pump.

[0126] In some embodiments, the indirect evaporative cooler and pump include a water circuit and a water pump.

[0127] The mass exchange unit or membrane assembly can include various support structure and membrane configurations to create vapor gradients and improve performance. For example, one or both of the support structure and membrane can include spatial variations in chemistry, shape, or a combination of chemistry and shape. In some embodiments, the membrane assembly can have a planar or non-planar configuration. In some embodiments, the membrane assembly can include a porous support structure with spatial variations in pore shape (e.g., pore shape that varies along an axis perpendicular or parallel to the feed plane). In some embodiments, the membrane assembly can include a non-porous support structure with continuous flow channels with various flow channel widths, lengths, heights, and wall thicknesses. In some embodiments, the membrane assembly can include a support structure with spatial variations in chemistry (e.g., chemistry that varies along an axis perpendicular or parallel to the feed plane). In some embodiments, the membrane assembly can include a porous membrane substrate. In some embodiments, the membrane assembly can include membranes with spatial variations in membrane chemistry (e.g., membrane chemistry that varies along an axis perpendicular or parallel to the feed plane). In some embodiments, the membrane assembly can include membranes with spatial variations in membrane shape (e.g., pore shape that varies along an axis perpendicular or parallel to the feed plane).

[0128] Figures 7A-19B, discussed below, show various exemplary configurations of mass exchange units or membrane assemblies. In Figures 7A-19B, panel A shows a cross-section of a membrane assembly, and panel B shows an isometric view of the membrane assembly. In each of these figures, the feed air (the target air from which water vapor is removed) is indicated by a white arrow, and the permeate (the water vapor removed from the target air) is indicated by a black arrow. As shown in these figures, in these examples, the feed air flow is parallel to the interface between the membrane and the support structure of the membrane assembly, and the permeate is removed through the support structure. Figures 7A-19B show exemplary combinations of membranes, support structures, non-porous barriers, identifiable cooling layers (e.g., wettable evaporative media or spectrally selective media), membrane substrates, and membrane overlays, but the combinations are not limited to those shown in Figures 7A-19B. For example, although Figures 7A-19B show exemplary configurations of the working air flow paths and product / feed air flow paths, the working air and product / feed air flow paths can be arranged in a variety of configurations, including, but not limited to, parallel, intersecting, opposing, perpendicular, non-orthogonal, radial, regenerative, multi-stage, and other heat exchange and flow configurations.

[0129] 7A-7B show features of a supported membrane assembly 701 that includes a planar membrane (e.g., a conformal membrane) 702 and a porous support structure 703. In some embodiments, the conformal membrane completely covers the support structure.

[0130] Figures 8A-8D show exemplary configurations where the mass exchange unit or membrane assembly includes a non-permeable (e.g., non-porous) barrier and a recognizable cooling layer (e.g., a wettable evaporative medium or a spectrally selective medium).

[0131] In some embodiments, the discernible cooling layer may be a wettable evaporative medium. The example shown in Figures 8A-8B illustrates features of a supported membrane assembly 801, including a planar membrane (e.g., a conformal membrane) 802, a porous support structure 803, a planar non-porous or impermeable barrier 804, and a discernible cooling layer 805. In the example shown in Figures 8A-8B, the discernible cooling layer 805 is a wettable evaporative medium. In some embodiments, the conformal membrane completely covers one surface of the support structure, and the impermeable barrier completely covers the other surface of the support structure. In the example shown in Figures 8A-8B, the feed air (the target air from which water vapor is removed), permeate (water vapor removed from the target air), and moist working air are indicated by white arrows, black arrows, and dotted arrows, respectively. In this example, the feed air flow is parallel to the interface between the membrane and the support structure of the membrane assembly, the working air flow is parallel to the interface between the impermeable barrier and the support structure of the membrane assembly, and the permeate is removed through the support structure.

[0132] 8A-8B show a configuration in which a dual-function membrane assembly 801 is coupled with tangible cooling via evaporative cooling. In this system, the tangible cooling layer can cool by evaporation (phase change of water or other liquid) and transfer heat from dry feed air through a porous support structure, thereby dehumidifying and cooling the target supply air.

[0133] In some embodiments, the discernible cooling layer can be a spectrally selective medium. Figures 8C-8D show a configuration having a dual-function membrane assembly 801 coupled with discernible cooling via radiant sky cooling. In the example shown in Figures 8C-8D, the discernible cooling layer 805 is a spectrally selective medium (e.g., a reflective barrier). In this system, the discernible cooling layer can cool by spectrally selective radiative exchange with the sky, transferring heat away from the dry feed air through a porous support structure, thereby simultaneously dehumidifying and cooling the target supply air.

[0134] Additional examples of mass exchange units or membrane assemblies including impermeable (e.g., non-porous) barriers include illustrative examples similar to Figures 7A-7B and 9A-19B described below, in which one membrane (including a membrane overlay and / or membrane substrate layer) is replaced with an impermeable barrier and a recognizable cooling layer (e.g., a wettable evaporative medium or a spectrally selective medium), and working air, rather than feed air, is moved over the space adjacent to the impermeable barrier.

[0135] 9A-9B show a supported membrane assembly 901 including a non-planar membrane (e.g., a conformal membrane) 902 and a porous support structure 903. The non-planar membrane may have any shape. Non-limiting examples of non-planar shapes include tubular, annular, spiral, sinusoidal, triangular, sawtooth, square, concave, curved, cylindrical, etc.

[0136] 10A-10B show a supported membrane assembly 1001 including a membrane (e.g., a conformal membrane) 1002 and a porous support structure 1003 having a variety of porous interconnected geometries perpendicular to the feed plane. In this example, the pore diameter varies along an axis perpendicular to the feed plane, with larger diameters at the center of the porous support structure and smaller diameters closer to the interface with the membrane. However, the geometry may be varied in any manner to provide a gradient perpendicular to the feed plane. Examples of such variations include pore size, shape, density, aspect ratio, and any combination thereof.

[0137] 11A-11B show a supported membrane assembly 1101 including a membrane (e.g., a conformal membrane) 1102 and a porous support structure 1103 having various porous interconnected geometries parallel to the feed plane. In this example, the pore diameter varies along an axis parallel to the feed plane, with smaller diameters in the direction of feed air movement and larger diameters in the direction of permeate removal. However, the geometry may be varied in any manner to provide a gradient perpendicular to the feed plane. Examples of such variations include pore size, shape, density, aspect ratio, and any combination thereof.

[0138] 12A-12B show a supported membrane assembly 1201 including a membrane (e.g., a conformal membrane) 1202 and a porous support structure 1203 having a variety of porous interconnected geometries in a combination of directions perpendicular and parallel to the feed plane. In this example, the pore diameter varies along axes perpendicular and parallel to the feed plane. However, the geometry may be varied in any manner to provide a gradient perpendicular to the feed plane. Examples of such variations include pore size, shape, density, aspect ratio, and any combination thereof.

[0139] 13A-13B show a supported membrane assembly 1301 including a membrane (e.g., a conformal membrane) 1302 and a non-porous support structure 1303 with continuous flow channels that allow permeate movement in place of the porous material. In this example, the support structure includes flow channels parallel to the feed plane, with permeate moving through the channels for removal. The support structure with flow channels can include flow channels with various flow widths, lengths, heights, and wall thicknesses. In some embodiments, the flow channels can be parallel, spiral, zigzag, branched, or have other configurations.

[0140] 14A-14B show a support membrane 1401 assembly including a membrane (e.g., a conformal membrane) 1402 and a non-porous support structure 1403 having hierarchical continuous flow channels. The support structure with the flow channels can include hierarchical flow channels with various flow channel widths, lengths, and heights in a branched or other configuration. In this example, the support structure includes flow channels parallel to the feed plane and flow channels perpendicular to the feed plane (e.g., in three different dimensions).

[0141] 15A-15B show a supported membrane assembly 1501 including a membrane (e.g., a conformal membrane) 1502, a conformal porous membrane substrate 1506, and a porous support structure 1503. In this example, the membrane substrate 1506 is disposed between the membrane 1502 and the support structure 1503. In some embodiments, the membrane support structure improves the durability of the membrane.

[0142] 16A-16B show a membrane unit 1601 further including a membrane overlay 1607 disposed between the membrane 1602 and the feed air stream (e.g., the overlay 1607 is disposed on the outer surface of the membrane 1602). For example, the supported membrane assembly 1601 can include a conformal membrane 1602, a conformal membrane overlay 1607, and a porous support structure 1603. In some embodiments, the membrane overlay of the membrane unit can include various surface functionalities, such as chemical functionalization. For example, the surface of the overlay can be functionalized to provide one or more of antifouling, wettability, fouling repellency, antibacterial properties, and filtration properties. In some embodiments, the overlay can be functionalized to drain bulk fluid without inhibiting molecular transport across the membrane. In some embodiments, the overlay can be disposable or replaceable. In some embodiments, the overlay is not adhered to the membrane. In some embodiments, the overlay can serve as an additional support layer for the membrane.

[0143] 17A-17B show a membrane unit 1701 including a membrane support substrate 1706 positioned between the membrane 1702 and a support structure 1703, and a membrane overlay 1707 positioned between the membrane 1702 and the air flow (i.e., a membrane overlayer positioned on the outer surface of the membrane assembly having the membrane substrate).

[0144] In some embodiments, the overlay is highly porous, with pores greater than 10 μm or greater than 50 μm, so as not to impede vapor diffusion or molecular transport.

[0145] In some embodiments, the membrane overlay can provide additional performance benefits, such as enhanced water capture due to micron-scale feature-induced condensation and coalescence, higher surface area for water absorption, and / or greater hydrophilicity.

[0146] In some embodiments, the membrane overlay can provide additional performance benefits, such as enhancing turbulent mixing and minimizing concentration polarization of non-permeating gas species at the membrane interface, thus achieving high levels of water vapor permeability.

[0147] In some embodiments, membrane overlays can provide additional performance benefits, such as extending membrane life through a physical barrier that filters particulates. For example, the physical barrier can prevent membrane fouling and impact rupture while improving overall product air quality. In some embodiments, such protective overlays can be replaced in-situ at scheduled service intervals without disturbing the underlying membrane.

[0148] In some embodiments, the film overlay can provide additional performance benefits, such as air purification of the product by including photocatalytic compounds for UV-activated decomposition of airborne contaminants. Non-limiting examples of photocatalytic compounds include titanium dioxide. In some embodiments, such functional and protective overlays can be replaced in-situ at scheduled service intervals without disturbing the underlying film.

[0149] In some embodiments, the membrane overlay can provide additional performance benefits, such as air purification, by including high surface area particulate / molecular structures for adsorption of gaseous air pollutants. Non-limiting examples of high surface area particulate / molecular structures include activated carbon, metal-organic frameworks, zeolites, and combinations thereof. Non-limiting examples of pollutants include CO, volatile organic compounds, unpleasant odors, harmful vapors, and combinations thereof. In some embodiments, such functional and protective overlays can be replaced in-situ at scheduled service intervals without disturbing the underlying membrane.

[0150] In some embodiments, the membrane overlay can provide additional performance benefits, such as air purification resulting from the disinfectant / antimicrobial treatment, by including a biocidal compound in the membrane overlay. Non-limiting examples of biocidal compounds include silver ions, copper ions, silver nanoparticles, copper nanoparticles, or quaternary ammonium compounds, and combinations thereof. In some embodiments, such functional and protective overlays can be replaced in-situ at scheduled service intervals without interfering with the underlying membrane.

[0151] In some embodiments, the membrane overlay can use any combination of the above examples to provide additional performance benefits.

[0152] 18A-18B show a supported membrane assembly 1801 including membranes (e.g., conformal membranes) with various membrane chemistries (1802a, 1802b, 1802c) perpendicular to the feed plane and porous support structure 1803. In this example, the membranes include three different membrane chemistries arranged perpendicular to the feed plane, e.g., as layered membranes with different membrane chemistries in each layer.

[0153] 19A-19B show a supported membrane assembly 1901 including membranes (e.g., conformal membranes) with varying membrane chemistries (1902a, 1902b, 1902c) parallel to the feed plane and a porous support structure 1903. In this example, the membranes include three different membrane chemistries arranged so that the membrane chemistry varies along the axis of feed air movement. For example, the membrane chemistries can include regions of different HO / N selectivity, e.g., regions of lower HO / N selectivity. In these embodiments, the region of lower HO / N selectivity can be located at the end of the dry air feed, opposite the vacuum inlet. This configuration allows an increased amount of dry air molecules to enter this region, creating a dry sweep gas that can improve water / gas vapor removal on the permeate side of the membrane, thereby improving permeability across the membrane. In this example, adding dry air can increase vacuum pressure and dehumidification, improving pump energy performance.

[0154] In another example, not shown, the supported membrane assembly can include membranes with different membrane chemistries (e.g., conformal membranes) in combinations perpendicular and parallel to the feed plane and porous support structure.

[0155] FIG. 20 is a matrix showing various exemplary combinations of membranes and support structures. The first row shows various exemplary support structure configurations (as shown in FIGS. 7A-7B, 9A-14B), and the first column shows various exemplary membrane configurations (as shown in FIGS. 7A-7B, 15A-15B, and 18A-19B). Any support structure configuration in the first row can be combined with any membrane configuration in the first column. While FIG. 20 shows exemplary combinations, the combinations of membrane and support structure configurations are not limited to those shown in FIG. 20.

[0156] For example, as shown in the second row of Figure 20, a membrane having a porous membrane substrate (Figures 15A-15B) can be combined with a planar porous support structure (Figures 7A-7B), a non-planar porous support structure (Figures 9A-9B), a porous support structure having various porous interconnected geometries perpendicular to the feed plane (Figures 10A-10B), a porous support structure having various porous interconnected geometries parallel to the feed plane (Figures 11A-11B), a porous support structure having various porous interconnected geometries in a combination of perpendicular and parallel directions to the feed plane (Figures 12A-12B), a non-porous support structure having continuous flow channels (Figures 13A-13B), a non-porous support structure having hierarchical continuous flow channels (Figures 14A-14B), or a combination thereof.

[0157] For example, as shown in the third row of FIG. 20, membranes with varying membrane chemistries perpendicular to the feed plane (FIGS. 18A-18B) can be combined with planar porous support structures (FIGS. 7A-7B), non-planar porous support structures (FIGS. 9A-9B), porous support structures with varying porous interconnected geometries perpendicular to the feed plane (FIGS. 10A-10B), porous support structures with varying porous interconnected geometries parallel to the feed plane (FIGS. 11A-11B), porous support structures with varying porous interconnected geometries in a combination of perpendicular and parallel directions to the feed plane (FIGS. 12A-12B), non-porous support structures with continuous flow channels (FIGS. 13A-13B), non-porous support structures with hierarchical continuous flow channels (FIGS. 14A-14B), or combinations thereof.

[0158] For example, as shown in the fourth row of FIG. 20, membranes with varying membrane chemistries parallel to the feed plane (FIGS. 19A-19B) can be combined with planar porous support structures (FIGS. 7A-7B), non-planar porous support structures (FIGS. 9A-9B), porous support structures with varying porous interconnected geometries perpendicular to the feed plane (FIGS. 10A-10B), porous support structures with varying porous interconnected geometries parallel to the feed plane (FIGS. 11A-11B), porous support structures with varying porous interconnected geometries in a combination of perpendicular and parallel directions to the feed plane (FIGS. 12A-12B), non-porous support structures with continuous channels (FIGS. 13A-13B), non-porous support structures with hierarchical continuous channels (FIGS. 14A-14B), or combinations thereof.

[0159] For example, membranes with varying membrane chemistries in a combination of directions perpendicular and parallel to the feed plane can be combined with planar porous support structures (FIGS. 7A-7B), non-planar porous support structures (FIGS. 9A-9B), porous support structures with varying porous interconnected geometries perpendicular to the feed plane (FIGS. 10A-10B), porous support structures with varying porous interconnected geometries parallel to the feed plane (FIGS. 11A-11B), porous support structures with varying porous interconnected geometries in a combination of directions perpendicular and parallel to the feed plane (FIGS. 12A-12B), non-porous support structures with continuous flow channels (FIGS. 13A-13B), non-porous support structures with hierarchical continuous flow channels (FIGS. 14A-14B), or combinations thereof.

[0160] FIG. 21 is a matrix showing various exemplary combinations of recognizable cooling layers, non-permeable barriers, membrane overlays, and combinations of membrane overlays with membrane substrates having different porous support structures. The first row shows various exemplary support structure configurations (e.g., corresponding to FIGS. 7A-7B and 9A-14B), while the first column shows various exemplary membrane configurations, including configurations in which one side of the membrane unit includes a non-porous barrier and a recognizable cooling layer, a membrane overlay, and a membrane overlay with a membrane substrate (as shown in FIGS. 8A-8B, 16A-17B, and 17A-17B). Any support structure configuration in row 1 can be combined with any membrane configuration in column 1. In some embodiments, the recognizable cooling layer can be an evaporative cooling layer. In some embodiments, the recognizable cooling layer can be a radiative cooling layer. While FIG. 21 shows exemplary combinations, the combinations of recognizable cooling layer, membrane overlay, and membrane substrate configurations are not limited to those shown in FIG. 21.

[0161] For example, as shown in the second row of Figure 21, a membrane configuration in which one side of the membrane unit includes a membrane and the other side includes a non-porous barrier and a discernible cooling layer (Figures 8A-8B) can be combined with a planar porous support structure (Figures 7A-7B), a non-planar porous support structure (Figures 9A-9B), a porous support structure having various porous interconnected shapes perpendicular to the feed plane (Figures 10A-10B), a porous support structure having various porous interconnected shapes parallel to the feed plane (Figures 11A-11B), a porous support structure having various porous interconnected shapes in a combination of perpendicular and parallel directions to the feed plane (Figures 12A-12B), a non-porous support structure with continuous flow channels (Figures 13A-13B), a non-porous support structure with hierarchical continuous flow channels (Figures 14A-14B), or a combination thereof.

[0162] For example, as shown in the third row of FIG. 21, a membrane having a membrane overlay (FIGS. 16A-16B) can be combined with a planar porous support structure (FIGS. 7A-7B), a non-planar porous support structure (FIGS. 9A-9B), a porous support structure having various porous interconnected geometries perpendicular to the feed plane (FIGS. 10A-10B), a porous support structure having various porous interconnected geometries parallel to the feed plane (FIGS. 11A-11B), a porous support structure having various porous interconnected geometries in a combination of perpendicular and parallel directions to the feed plane (FIGS. 12A-12B), a non-porous support structure having continuous flow channels (FIGS. 13A-13B), a non-porous support structure having hierarchical continuous flow channels (FIGS. 14A-14B), or a combination thereof.

[0163] For example, as shown in the fourth row of Figure 21, a membrane having a membrane overlay and supported on a membrane substrate (Figures 17A-17B) can be combined with a planar porous support structure (Figures 7A-7B), a non-planar porous support structure (Figures 9A-9B), a porous support structure having various porous interconnected geometries perpendicular to the feed plane (Figures 10A-10B), a porous support structure having various porous interconnected geometries parallel to the feed plane (Figures 11A-11B), a porous support structure having various porous interconnected geometries in a combination of perpendicular and parallel directions to the feed plane (Figures 12A-12B), a non-porous support structure with continuous flow channels (Figures 13A-13B), a non-porous support structure with hierarchical continuous flow channels (Figures 14A-14B), or a combination thereof.

[0164] Figures 22A-29D show exemplary non-planar configurations of a mass exchange unit or membrane assembly. Non-limiting non-planar configurations include cylindrical, tubular, annular, helical, spiral-wound, circular, rectangular, and combinations thereof. Non-limiting non-planar configurations include twisted, bent, distorted, or any combination thereof to improve membrane exchange. In Figures 22A-29D, panel A shows a cross-section of the membrane assembly, and panel B shows an isometric view of the membrane assembly. In each of these figures, the feed air (the target air from which water vapor is removed) is indicated by a white arrow, and the permeate (water vapor removed from the target air) is indicated by a black arrow. Figures 22A-29D show exemplary combinations of membranes, support structures, non-porous barriers, identifiable cooling layers (e.g., wettable evaporative media or spectrally selective media), membrane substrates, and membrane overlays, but the combinations are not limited to those shown in Figures 22A-29D. While Figures 22A-29D show exemplary configurations of the working air flow paths and product / feed air flow paths, the working air and product / feed air flow paths can be arranged in a variety of configurations, including, but not limited to, parallel, intersecting, opposing, perpendicular, non-orthogonal, radial, regenerative, multi-stage, and other heat exchange and flow configurations.

[0165] Figures 22A-22B show a supported membrane assembly 2201 having a cylindrical configuration including a membrane 2202 and a porous support structure 2203. In this example, the support structure is cylindrical and the membrane is disposed on the exterior surface of the cylinder. Figures 22C-22D show examples where the supported membrane assembly 2201 further includes a membrane overlay 2207 disposed on the membrane 2202. In these examples, the feed air stream is above the membrane on the exterior surface of the cylinder and the permeate is removed through the cylindrical support structure, for example, along the long axis of the cylinder.

[0166] 23A-23B show a supported membrane assembly 2301 having a tubular configuration including a membrane 2302 and a porous support structure 2303. In this example, the support structure is tubular, with the membrane disposed on the inner surface of the tube and a non-permeable (e.g., non-porous) barrier layer 2304 disposed on the outer surface of the tube (i.e., the barrier layer is disposed on the outer surface of the porous support structure). FIGS. 23C-23D show examples in which the supported membrane assembly 2301 further includes a membrane overlay 2307 disposed on the inner surface of the membrane 2302. In these examples, the feed air stream passes through the tube and over the membrane on the inner surface of the tube, and the permeate is removed via the tubular support structure, e.g., along the long axis of the tube.

[0167] 24A-24B show a "unit cell" having a membrane tube including a membrane 2402 and a porous support structure "shell" 2403, e.g., a "shell and tube" configuration of a supported membrane assembly 2401. FIGS. 24C-24D show an example in which the supported membrane assembly 2401 further includes a membrane overlay 2407 disposed on the inner surface of the membrane 2302. In some embodiments, the "tube" can have any cross-sectional shape, e.g., circular, hexagonal, square, triangular, etc. In this configuration, a vacuum can be applied to a volume having a continuous porous support structure in which the membrane tubes are arranged in a periodic unit cell pattern. Non-limiting examples of unit cell patterns include triangular, square, hexagonal, etc. In some embodiments, a non-porous boundary is assumed to encompass the porous structure as a shell structure. In some embodiments, an inlet is included to apply a vacuum to the non-porous boundary.

[0168] 25A-25B show an annular configuration having a dual-function membrane assembly 2501 including a membrane 2502 disposed on the inner surface of a membrane support 2503 and coupled with discernible cooling via evaporative cooling. In this system, a discernible cooling layer 2505 (e.g., a wettable evaporative medium) is disposed on an impermeable (e.g., non-porous) barrier 2504 disposed on the outer surface of a porous membrane support 2503. In this system, the discernible cooling layer 2505 is cooled by evaporation (phase change of water or other liquid) and transfers heat from dry feed air through the porous support structure 2503, which dehumidifies and cools the target supply air.

[0169] 26A-26B show an annular configuration having a dual-function membrane assembly 2601 including a membrane 2602 disposed on the outer surface of a membrane support 2603 and coupled with discernible cooling via evaporative cooling. In this system, a discernible cooling layer 2605 is disposed on the inner surface of a non-permeable (e.g., non-porous) barrier 2604, which is disposed on the inner surface of the porous membrane support 2603. In this system, the discernible cooling layer 2605 (e.g., a wettable evaporative medium) is cooled by evaporation (phase change of water or other liquid), transferring heat from dry feed air through the porous support structure 2603, which dehumidifies and cools target feed air that is fed onto the inner surface of the membrane assembly. In some embodiments, the non-permeable barrier 2604 can seal off a low-pressure vacuum environment for efficient dehumidification and prevent moisture from the discernible cooling layer 2605 from entering the low-pressure environment.

[0170] 27A-27B show an annular configuration having a dual-function membrane assembly 2701 including a membrane 2702 disposed on the inner surface of a membrane support 2703 and coupled with radiative sky cooling. In this system, a radiative cooling layer 2705 (e.g., a spectrally selective medium) is disposed on the outer surface of a non-porous barrier 2704, which is disposed on the outer surface of a porous membrane support 2703. In this system, the radiative cooling layer 2705 is cooled by spectrally selective radiative exchange with the sky, transferring heat from dry feed air through the porous support structure 2703, which dehumidifies and cools the target supply air. In this system, the membrane 2702 is disposed on the inner surface of the porous membrane support 2703.

[0171] 28A-28B show a supported membrane assembly 2801 having a spiral configuration including a membrane 2802 and a porous support structure 2803. In this example, the support structure is a spiral, and the membrane is disposed on the outer surface of the spiral. In this example, feed air flows over the membrane on the outer surface of the spiral, and permeate is removed through the support structure of the spiral, e.g., along the long axis of the spiral. FIGS. 28C-28D show an example in which the supported membrane assembly 2801 further includes a membrane overlay 2807 disposed on the membrane 2302.

[0172] 29A-29B show a supported membrane assembly 2901 having a spiral configuration including a membrane 2902 and a porous support structure 2903. In this example, the support structure is a spiral, and the membrane is disposed on the inner surface of the spiral. In this example, feed air flows over the membrane on the inner surface of the spiral, and permeate is removed through the support structure of the spiral, e.g., along the long axis of the spiral. FIGS. 29C-29D show an example in which the supported membrane assembly 2901 further includes a membrane overlay 2907 disposed on the membrane 2902.

[0173] (Example) Certain embodiments are described in the following non-limiting examples.

[0174] A laboratory-scale experimental setup was employed, as shown in Figures 30A-30E. The vacuum membrane unit in this setup included various components, as shown in Figures 30A-30C: a highly porous support material (Figure 30A), depicted as a 3D-printed polymer gyroid structure with a 60% open volume; a plastic frame designed to enclose the support matrix with a vacuum inlet (Figure 30B); and a water-selective membrane (Figure 30C), measuring 150 mm x 150 mm in size, attached to both sides of the support frame. Figure 30D depicts multiple porous support structures with a hierarchical structure of varying porosity and layer thickness (e.g., related to Figures 10A-10B). Individual panels and assemblies of multiple panels were tested in the laboratory using a custom experimental setup, as shown with a system diagram overlaid in Figure 30E.

[0175] The experimental design allowed for multiple test samples with different geometries. Generally, the test setup included a ducted housing to allow for interchangeable panel "cassettes" (labeled samples) and a programmable blower fan (Retrotec 300) to control the airflow at the panel cassette inlets and the differential pressure across the cassettes. To control the air-side humidity, a humidity sensor was installed at the cassette inlet. This humidity sensor signaled a solenoid valve to supply compressed air to the headspace of a heated water tank with a spray mist system. The upstream moist air velocity was set at 1 m / s for the majority of the experiment, and the differential pressure varied depending on the configuration. The inlet-side air velocity, pressure, relative humidity, and temperature were measured and recorded at spot points using an anemometer (TSI 9535). Both the inlet-side and outlet-side air-side relative humidity and temperature were measured and recorded using fixed sensors (Sensiron SHT31-D). For each test, vacuum pressure was applied to the panel using a dry scroll pump (Edwards nXDS20i) equipped with an energy monitor (Reed R5090). Permeate vacuum pressure was measured using a transducer (Edwards ASG2). Permeate water vapor was recovered from the vacuum pump exhaust using a liquid-air exchange element connected to a circulating chiller (VWR 89202-978) equipped with a 1°C water-glycol solution and a glass coil condenser. A secondary trap in an insulated ice bath was used in series with the permeate exhaust to capture residual water vapor not recovered by the chiller and condenser. Recovered water was recorded using a digital balance or scale (Cole-Parmer Symmetry SP5001). Tests were conducted for a minimum of 4 hours. Seal tests were performed to confirm that all panel samples could achieve a vacuum pressure of 1 mbar or less. To determine membrane selectivity, air permeability was approximated by the pressure rise of an evacuated membrane panel not already under active vacuum.

[0176] To demonstrate the variability in membrane performance, various polymer films were evaluated for water vapor transmission rate and selectivity, including, but not limited to, cellulose triacetate, ethylene-methyl acrylate copolymer, expanded polytetrafluoroethylene, silicone rubber ("PDMS"), polyolefin composites, and polyethyleneamide coblock polymer ("PEBAX"). The membranes were primarily characterized by their water vapor transmission rate (P), [mol / m 2 *s*Pa]) and the resulting mass flux [g / s / m 2 The membranes are evaluated by two performance criteria: water vapor permeability (S), [mol H2O / mol N2], and water selectivity (S). Figures 31A-31C show snapshots of the membrane material characterization and down-selection process. Figures 31A-31C show water permeability over time (Figure 31A), calculated water vapor flux (Figure 31B), and selectivity values ​​(Figure 31C) for a selection of different membranes: cellulose triacetate ("CA"), ethylene-methyl acrylate copolymer, polyethylene amide coblock polymer ("Pebax"), silicone rubber ("PDMS"), polyolefin composite, and cellulose acetate (microporous, "CA2"). Experimental parameters were 1 m / s wind speed, 85% RH, 28 °C, and surface area of ​​0.045 m2. 2 The temperature was fixed at 0.05°C. At least three samples were analyzed, and error bars represent one standard deviation. Mass flux and water selectivity results were compiled for a single (double-sided) panel sample measuring 150 mm x 150 mm (0.045 m²) with a 6 mm porous support material.

[0177] Once high water vapor permeability and selectivity were demonstrated, polyethylene amide coblock polymer membranes were used as the basis for variations in membrane support configurations. Higher mass flux allows for less membrane material to be used for the same amount of latent heat removal, and higher selectivity minimizes the amount of energy consumed by vacuum pumps to compress air.

[0178] Experimental results on optimizing mass exchange unit shapes (including support structure shapes), including those shown in Figures 32A-32L, indicate a significant relationship between the geometric configuration of the mass exchange shape and its mechanical robustness and permeability characteristics. Panel spacing, support materials, and module thicknesses were adjusted to enable the intended shape. Figures 32A-32L show exemplary porous, hollow, and channel support materials, including porous 3D-printed polylactic acid ("PLA") (Figures 32A, 32E, 32I), nonwoven fibers (nonporous fiber pads) (Figures 32B, 32F, 32J), plastic screen mesh (laminate mesh) (Figures 32D, 32G, 32K), and plastic screen mesh with corrugated supports (hybrid channel + mesh surface) (Figures 32C, 32H, 32L). This series of porous support materials was tested for mechanical stability under vacuum pressure and mass flux through polyethylene amide coblock polymer membrane panels incorporating various porous support materials. The experimental parameters were: wind speed 1 m / s, 85% RH, 28°C, and surface area 0.045 m 2 The porosity / density, compressibility, and cavity thickness of the support material are hypothesized to reduce permeate diffusion by limiting the permeate-side vapor concentration gradient. Figure 32M shows the mass flux values ​​for polyethyleneamide coblock polymer panel geometries with various porous support materials. Based on these results, fused PLA printed geometries with 60% void space and open-cell pore structure were systematically used for laboratory testing and prototype development.

[0179] A series of experiments, shown in Figures 33A-33G, evaluated the relationship between panel thickness, air gap spacing, pressure drop, and humidity removal. In the first series of tests, the relationship between permeate mass flux and air-side pressure drop was evaluated. Cassettes consisting of four panels (each containing a porous support with membranes attached to one or both sides) were tested with variable spacing and fixed air speeds. Individual panels were assembled into "cassettes" with variable spacing arrangements (Figure 33A) and installed in a ducted air-side flow system with a permeate vacuum manifold (Figure 33B). The effect on mass flux and overall system pressure drop (Figure 33C) was evaluated. Varying panel geometries with varying membrane spacing were tested (3 mm, 6 mm, and 12 mm depths, from top to bottom in Figures 33D-33F, respectively). Experimentally measured mass flux and corresponding water extraction rates and predicted coefficient of performance (COP) values ​​for the varying depth panel geometries are shown (Figure 33G). Data on the Y2 axis are plotted against a 1 m 2 The calculations were performed for a field site of a window prototype with an area of ​​1000 m². On the x-axis, samples labeled "x1" contain a membrane on one side, while samples labeled "x2" are double-sided (e.g., membrane spacing is halved). All geometries use a porous support material with 60% porosity and an open-cell geometry. The experimental parameters were a wind speed of 1 m / s, 85% RH, 28°C, and a surface area of ​​0.045 m². 2 It is fixed at

[0180] The results in Figures 33C and 33G show that a panel spacing below 5 mm (5 mm between panels) results in a significant pressure drop without a significant increase in mass flux. This result is consistent with boundary layer studies and the Nusselt similarity of heat exchange devices, so a 5 mm panel-to-panel spacing was adopted as the geometric specification. The results in Figures 33C and 33G also show that a reduction in unit (frame) thickness significantly reduces mass flux. In other words, the cavity thickness may reduce permeate diffusion by limiting the vapor concentration gradient on the permeate side. The optimal cavity thickness for the materials tested in this example is 6 mm or greater. However, additional structural considerations can be considered to improve performance.

[0181] The vacuum field test prototype, shown in Figures 34A-34D, included a 60-unit primary mass exchange cassette within an aluminum frame system. The prototype was tested in a demonstration building with high retrofit potential, as shown in Figure 34A, and the demonstrator was installed next to a conventional window AC, as shown in Figure 34B. Figure 34C shows a demonstration of the system, including the aluminum frame secured to the window header and sill, and the pump, water pan, and cooler mounted on a trolley. Figure 34D shows the installed vacuum system, demonstrating the system's installation and light and fresh air transmission, unlike the standard AC used as a baseline.

[0182] The vacuum field test prototype panel was a composite system consisting of a 3D-printed PLA support with an open-cell pore structure, a plastic frame with one barbed vacuum port at the bottom, and two 20 μm thick polyethylene amide coblock polymer membranes taped to the frame on either side of the PLA support. The bifacial panel had an active exchange area of ​​0.07 m. 2 So, the total length of 60 sheets is 4.14m 2 A vacuum manifold, shown in Figure 34D, connects all panels to a configurable "pod" at the base of the window wall, which houses the vacuum pump and connections. The interior surface of the cassette is fitted with a set of removable axial fans to provide adjustable airflow throughout the exchanger, and can be removed to test the unit under natural ventilation conditions.

[0183] Figures 35A-35C show the results of three flow rate configurations tested for 24 hours: fan-assisted airflow with a high measurement velocity of 3 m / s or a differential pressure of approximately 4 Pa ​​(i.e., high flow rate mode); fan-assisted airflow with a low measurement velocity of 0.7 to 1.5 m / s or a differential pressure of approximately 2 Pa (i.e., medium flow rate mode); and natural ventilation airflow with a measurement velocity of 0.0 to 0.3 m / s (peaking at 0.7 m / s) or a differential pressure of around 0.2 Pa (i.e., low flow rate mode). Figure 35A shows the indoor absolute humidity as a function of outdoor absolute humidity. Figure 35A shows that the medium and high flow rates generally do not result in a significant decrease in the absolute humidity of the indoor air (i.e., product air or process air) relative to the outdoor air, while the low flow rate mode results in a significant decrease in the absolute humidity of the indoor air compared to the outdoor air. Figures 35B and 35C show the reduction in absolute humidity of the product air relative to the ambient air, an indicator of dehumidification efficiency, as a function of the ambient air absolute humidity (Figure 35B) and the indoor-outdoor pressure differential (Figure 35C), respectively. Figures 35B and 35C show that dehumidification efficiency is low (ΔAH≦0.5 g HO / kg) in the medium and high flow modes. air ), indicating that high dehumidification was achieved in low flow mode (ΔAH Max =3.5g H2O / kg air ). Flow velocity 0.25m / s(0.019m 3 / s), approximately 0.2 L / h of water vapor was removed from the ambient air.

[0184] Figures 36A-36F show the outdoor and inlet relative and absolute humidity measurements over a 24-hour period for each of the three configurations: the fan-assisted airflow configuration with an airflow speed of 0.7-1.5 m / s (Figures 36A, 36D), the fan-assisted airflow configuration with an airflow speed of 3.0 m / s (Figures 36B, 36E), and the natural ventilation (NV) airflow configuration with an airflow speed of 0.0-0.3 m / s (Figures 36C, 36F).

[0185] In fan-assisted airflow mode (Figures 36A-36B and 36D-36E), the system achieves an average relative humidity reduction of 9% (peak 11%) and 6% (peak 7%), corresponding to specific humidity reductions of 0.27 g / kg and 0.21 g / kg for the low-speed and high-speed tests, respectively. This results in estimated moisture removal rates (mass flux) of 0.018 g / s to 0.027 g / s and 0.044 g / s for the medium-speed and high-speed tests, respectively. For natural ventilation airflow (Figures 36C and 36F), the system achieves an average relative humidity reduction of 26% (peak 39%), corresponding to 2.15 g / kg. This results in an average moisture removal rate (mass flux) of 0.036 g / s for the natural ventilation airflow tests.

[0186] In natural ventilation operation at low airflow rates, the initial pilot prototype achieved high dehumidification rates, achieving reductions of up to 39%. Figures 36A–36F show that during the morning and mid-afternoon, when the units receive direct sunlight, the system no longer captures water and instead allows residual water within the panels to evaporate. Alternative configurations could address whole-building solutions to mitigate direct radiant heat gain at the mass exchanger cassette. During natural ventilation testing, the target building reached positive pressure during the day. Future retrofit solutions could address the opportunity to maintain negative pressure through whole-building mechanical ventilation or buoyancy-driven ventilation strategies. Laboratory testing was performed on the panels under a vacuum pressure of 1 mbar (0.1 kPa). The average vacuum pressure during field studies was approximately 4 ± 3 mbar, potentially reducing the vapor pressure concentration gradient across the panels and decreasing mass flux. The increased pressure could likely be due to fabrication errors in the custom assembly.

[0187] The physical installation of the retrofit unit demonstrates that the water-selective vacuum membrane mass exchange cassette and pod system provides a highly configurable and scalable facade-integrated dehumidification system. The optimized panel shape provides a depth (approximately 150 mm) suitable for typical wall construction, while the panel width and height provide the ability to stack and arrange multiple cassettes to achieve desired wall opening area, comfort level, and ventilation rate. Furthermore, the remaining system pod approach—specifically, the vacuum pump and condenser unit—requires minimal installation, with only a single vacuum line connecting to the mass exchange cassette. Therefore, pod embodiments can be adapted to fit into casements or other structures, and, within limitations, do not need to be located directly adjacent to the mass exchange cassette.

[0188] Figures 37-39 show a compilation of dehumidification field data collected over three consecutive days (8am-8pm).

[0189] The dehumidification unit contained 62 dehumidification cartridges arranged in parallel with 5 mm spacing. Each cartridge was rectangular, measuring 250 × 170 × 5 mm (height × width × depth), and consisted of a 20 μm-thick coblock polymer membrane (230 × 150 mm) on its outer surface, which contacted the ambient air flow (the "feed side"). The inner surface of the membrane (the "permeate side") faced a porous cellulose nonwoven substrate film. A 3D-printed gyroid structure with 40% interconnected porosity was used as a rigid membrane support structure. Each membrane was mounted on a rigid, nonporous acrylic frame, which provided a continuous border width of 1 cm around the membrane support structure. One end of the cartridge was fitted with a single barb fitting for use as a vacuum inlet port. This vacuum port was in fluid communication with the pores in the membrane support structure. All cartridges were connected to a central vacuum manifold, which was connected to a dry scroll vacuum pump to establish a low pressure environment on the permeate side of the system.

[0190] To collect field test data, the dehumidification unit was fixed to the interior side of a window opening on the top floor of a renovated house. Tests were conducted in forced convection mode, with airflow controlled by four axial DC fans positioned inside the unit. Treated air was supplied at a mass flow rate of 165 (±60) kg / h. Figure 37 shows the absolute humidity of the product ("treated") air plotted as a function of the absolute humidity of the outdoor air. The downshift in the absolute humidity of the product air from the diagonal line X = Y (i.e., a straight line with a slope of 1) indicates that the degree of dehumidification increases with increasing outdoor humidity (i.e., higher moisture removal is achieved under higher absolute humidity conditions). At a product air velocity of approximately 0.75 m / s, the removed moisture was equivalent to suppressing the wet-bulb temperature by 1–2°C. Figure 38 shows the reduction in absolute humidity of the air by the dehumidification unit (Sunae Shuai, dehumidification by the dehumidification unit) plotted as a function of the absolute humidity of the outdoor air. It was found that the degree of dehumidification generally increased as the absolute humidity of the outdoor air increased. Figure 39 shows a plot of the difference in absolute humidity between the product and the indoor air over time during the three-day test period.

[0191] While one or more particular materials or steps have been shown and described for purposes of illustration, it will be understood that the materials or steps may be varied in particular respects, or the materials or steps may be combined, while still achieving desirable results. Furthermore, variations in the disclosed embodiments and claimed invention are possible and are within the scope of the disclosed invention.

Claims

1. a support structure including an open space within the support structure for removing water vapor; at least one water-permeable and water-selective membrane disposed on at least one surface of the support structure; A membrane unit configured such that when a vacuum is applied to the open space of the support structure, water vapor is drawn across the membrane and through the support structure along an axis parallel to the interface between the support structure and the membrane.

2. The membrane unit of claim 1 , wherein the open spaces comprise holes in the support structure.

3. The membrane unit of claim 2 , wherein the pore shape varies spatially.

4. 4. The membrane unit of claim 2 or 3, wherein the shape of the pores varies in an axis parallel to the interface between the support structure and the membrane.

5. The membrane unit according to any one of claims 2 to 4, wherein the shape of the pores varies in an axis perpendicular to the interface between the support structure and the membrane.

6. The membrane unit of any one of claims 1 to 5, wherein the open space comprises a channel within the support structure.

7. The membrane unit of claim 6 , wherein the shape of the flow channels varies spatially.

8. 8. The membrane unit of claim 6 or 7, wherein the shape of the flow channels varies in an axis parallel to the interface between the support structure and the membrane.

9. The membrane unit according to any one of claims 6 to 8, wherein the shape of the flow channels varies in an axis perpendicular to the interface between the support structure and the membrane.

10. The membrane unit according to any one of claims 1 to 9, wherein the chemical nature of the support structure varies spatially.

11. The membrane unit according to any one of claims 1 to 10, wherein the chemical properties of the support structure vary in an axis parallel to the interface between the support structure and the membrane.

12. The membrane unit according to any one of claims 1 to 11, wherein the chemical nature of the support structure varies in an axis perpendicular to the interface between the support structure and the membrane.

13. The membrane unit according to any one of claims 1 to 12, wherein the shape of the membrane varies spatially.

14. The membrane unit according to any one of claims 1 to 13, wherein the shape of the membrane varies in an axis parallel to the interface between the support structure and the membrane.

15. The membrane unit according to any one of claims 1 to 14, wherein the shape of the membrane varies in an axis perpendicular to the interface between the support structure and the membrane.

16. The membrane unit according to any one of claims 1 to 15, wherein the membrane chemistry varies spatially.

17. 17. The membrane unit of any one of claims 1 to 16, wherein the membrane chemistry varies in an axis parallel to the interface between the support structure and the membrane.

18. 18. The membrane unit of any one of claims 1 to 17, wherein the membrane chemistry varies in an axis perpendicular to the interface between the support structure and the membrane.

19. The membrane unit according to any one of claims 1 to 18, which has a planar shape.

20. The membrane unit according to any one of claims 1 to 19, having a non-planar shape.

21. At least 0.01 gH ２ O / m ２ The membrane unit according to any one of claims 1 to 20, having a water vapor transmission rate of 1 / 2 s.

22. At least 1000H ２ O / N ２ Water vapor selectivity H ２ O / N ２ The membrane unit according to any one of claims 1 to 21, having

23. 23. The membrane unit of any one of claims 1 to 22, wherein the membrane comprises pores less than about 10 nm in diameter.

24. 24. The membrane unit of any one of claims 1 to 23, wherein the support structure comprises pores having a diameter of about 100 μm to about 1 cm.

25. The membrane unit of any one of claims 1 to 24, further comprising a membrane support substrate disposed between the membrane and the support structure.

26. 26. The membrane unit of claim 25, wherein the membrane support substrate comprises pores having a diameter of about 100 nm to about 10 mm.

27. 27. The membrane unit of any one of claims 1 to 26, further comprising an inlet in fluid communication with the open space of the support structure for applying a vacuum.

28. 28. The membrane unit of any one of claims 1 to 27, further comprising an outlet in fluid communication with the open space of the support structure for removing water vapor.

29. The membrane unit according to any one of claims 1 to 28, further comprising a non-porous frame.

30. 30. The membrane unit according to any one of claims 1 to 29, which is transparent to visible light.

31. The membrane unit according to any one of claims 1 to 30, which blocks the passage of infrared rays.

32. The membrane unit of any one of claims 1 to 31, further comprising a membrane overlay disposed on the membrane.

33. 33. The membrane unit of claim 32, wherein the membrane overlay comprises holes.

34. 33. The membrane unit of claim 32, wherein the membrane overlay comprises pores with a diameter greater than 10 μm.

35. The membrane unit according to any one of claims 32 to 34, wherein the membrane overlay comprises chemical functional groups.

36. The membrane unit of any one of claims 32 to 35, wherein the membrane overlay has one or more of antifouling properties, fouling repellent properties, wettability, or antibacterial properties.

37. The membrane unit of any one of claims 32 to 36, wherein the membrane overlay comprises a photocatalytic compound.

38. 38. The membrane unit of claim 37, wherein the photocatalytic compound comprises titanium dioxide.

39. The membrane unit of any one of claims 32 to 38, wherein the membrane overlay comprises at least one of high surface area particles or polymeric structures.

40. 40. The membrane unit of claim 39, wherein at least one of the high surface area particles or the polymeric structures comprises activated carbon, a metal organic framework, a zeolite, or a combination thereof.

41. The membrane unit of any one of claims 32 to 40, wherein the membrane overlay comprises a biocidal compound.

42. 42. The membrane unit of claim 41, wherein the biocidal compound comprises silver ions, copper ions, silver nanoparticles, copper nanoparticles, a quaternary ammonium compound, or a combination thereof.

43. 43. The membrane unit of any one of claims 32 to 42, wherein the membrane overlay induces turbulent mixing of non-water gas species at the membrane interface or reduces concentration polarization of non-water gas species.

44. 44. The membrane unit of any one of claims 1 to 43, further comprising at least one impermeable barrier disposed on at least another surface of the support structure.

45. 45. The membrane unit of claim 44, further comprising a discernible cooling layer disposed on a surface of the impermeable barrier.

46. 46. ​​The membrane unit of claim 44 or 45, wherein the impermeable barrier is impermeable to water vapor.

47. 47. The membrane unit of any one of claims 44 to 46, wherein the impermeable barrier is impermeable to gas molecules.

48. 48. The membrane unit of any one of claims 44 to 47, wherein the impermeable barrier is non-porous.

49. 49. The membrane unit of any one of claims 44 to 48, wherein the impermeable barrier comprises a structural support layer.

50. 50. The membrane unit of any one of claims 44 to 49, wherein the impermeable barrier comprises a metal, an alloy, or a combination thereof.

51. The membrane unit of any one of claims 44 to 50, wherein the impermeable barrier comprises a polymer.

52. 52. The membrane unit of any one of claims 44 to 51, wherein the impermeable barrier has a thermal conductivity in the range of 0.1-0.5 W / m·K.

53. 52. The membrane unit of any one of claims 44 to 51, wherein the impermeable barrier has a thermal conductivity in the range of 0.5-10 W / m·K.

54. 52. The membrane unit of any one of claims 44 to 51, wherein the impermeable barrier has a thermal conductivity in the range of 10-500 W / m·K.

55. 55. The membrane unit of any one of claims 44 to 54, wherein the impermeable barrier is hydrophobic.

56. 56. The membrane unit of any one of claims 44 to 55, wherein the discernible cooling layer comprises a wettable evaporative medium.

57. 57. The membrane unit of any one of claims 44-56, wherein the discernible cooling layer comprises a radiative cooler, a reflective barrier, or a combination thereof.

58. 58. The membrane unit of any one of claims 44 to 57, wherein the visible cooling layer comprises holes.

59. 59. The membrane unit of any one of claims 44 to 58, wherein the visible cooling layer is hydrophilic.

60. 60. The membrane unit of any one of claims 44 to 59, wherein the wettable evaporative medium comprises a heat transfer fluid.

61. One or more membrane units according to any one of claims 1 to 60; a vacuum pump configured to apply a vacuum to the open space of the support structure of one or more of the membrane units; one or more inlets configured to supply moist feed air to each membrane of one or more of the membrane units along an axis parallel to the interface between the support structure and the membrane.

62. 62. The system of claim 61 comprising a plurality of membrane units.

63. 63. The system of claim 61 or 62, further comprising a vacuum manifold system.

64. 64. The system of any one of claims 61 to 63, further comprising a vacuum reservoir.

65. 65. The system of any one of claims 61 to 64, further comprising a plurality of vacuum pumps.

66. 66. The system of any one of claims 61 to 65, further comprising an air-to-liquid heat exchanger.

67. 67. The system of any one of claims 61 to 66, further comprising a water circuit.

68. 68. The system of any one of claims 61 to 67, further comprising a water pump.

69. 69. The system of any one of claims 61 to 68, further comprising a plurality of vacuum gates or valves.

70. 70. The system of any one of claims 61 to 69, further comprising a vapor compressor.

71. 71. The system of any one of claims 62 to 70, wherein a plurality of the membrane units are arranged parallel to one another.

72. 72. The system of any one of claims 62 to 71, wherein at least one of the membrane units is positioned perpendicular to the other of the membrane units.

73. 73. The system of any one of claims 62 to 72, wherein at least one of the membrane units is arranged anti-parallel to another of the membrane units.

74. 74. The system of any one of claims 62 to 73, wherein the inlet is configured to supply moist supply air to one or more spaces between a plurality of the membrane units.

75. 75. The system of any one of claims 62 to 74, wherein at least one of the membrane units comprises at least one non-permeable barrier disposed on at least another surface of the support structure of the at least one membrane unit.

76. 76. The system of claim 75, further comprising one or more first inlets configured to supply working air adjacent to a surface of each non-permeable barrier of one or more of the membrane units along an axis parallel to the interface between the support structure and the non-permeable barrier.

77. 77. The system of claim 76, wherein the working air comprises dehumidified supply air.

78. 78. The system of claim 76 or 77, further comprising a water misting device for dispensing water into the working air.

79. 79. The system of any one of claims 76 to 78, wherein the first inlet is configured to supply working air to one or more spaces between a plurality of the membrane units.

Images