WATER VAPOR ADSORPTION AIR DRYING SYSTEM AND METHOD FOR GENERATING LIQUID WATER FROM AIR.

Abstract

Systems for generating liquid water are provided. In the embodiments, the systems comprise a thermal desiccant unit comprising a porous hygroscopic material located within a housing that includes a fluid inlet and a fluid outlet, a working fluid that accumulates heat and water vapor as it flows from the fluid inlet of the housing, through the porous hygroscopic material and to the fluid outlet of the housing, and a condenser comprising a fluid inlet and a fluid outlet for condensing water vapor from the working fluid.an enthalpy exchange unit operatively coupled between the thermal desiccant unit and the condenser, wherein the enthalpy exchange unit transfers enthalpy between the working fluid outlet of the thermal desiccant unit and the working fluid inlet to the thermal desiccant unit, and wherein the enthalpy exchange unit transfers enthalpy between the working fluid outlet of the condenser and the working fluid inlet to the condenser.

Description

WATER VAPOR ADSORPTION AIR DRYING SYSTEM AND METHOD FOR GENERATING LIQUID WATER FROM AIR FIELD OF INVENTION This description relates to systems, methods, devices, and techniques for generating liquid water from ambient air. BACKGROUND OF THE INVENTION Producing liquid water by extracting water vapor from ambient or atmospheric air can present several challenges. These include maximizing the water production rate and / or efficiency while maintaining low cost and high reliability. There is a need for improved systems and methods for producing liquid water from ambient or atmospheric air. BRIEF DESCRIPTION OF THE FIGURES The following figures are provided as examples and are not intended as a limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, and the reference numbers may not be identical. The views in the figures are drawn to scale (unless otherwise indicated), meaning that the sizes of the elements shown are accurate relative to one another for at least the modality in the view. Figure 1 shows a water generation system that includes a thermal desiccant, an enthalpy exchange unit, and a condenser, according to various modalities; Figure 2 shows a water generation system that includes a thermal desiccant, auxiliary desiccant unit, enthalpy exchange unit and condenser, according to various modalities; Figure 3 shows a thermal desiccant unit, according to various CCQ7 Ln / Lznz / Ε / ΥΙΛΙ modalities; - 2 Figure 4 shows a graph of loading time versus fluid flow fluctuation, according to various modalities; Figure 5 shows a thermal desiccant unit, according to various modalities; Figure 6 shows a thermal desiccant unit, according to various modalities; Figure 7 shows a water generation system that includes multiple thermal desiccant units, according to various modalities; Figure 8 shows a water generation system that includes an auxiliary or batch desiccant unit, according to various modalities; Figure 9 shows a flow diagram of a method of operation of a water generation system, according to various modalities; Figure 10 shows a flow diagram of a method of operation of a water generation system, according to various modalities; Figure 11 shows a flow diagram of a method for a water generation system comprising an auxiliary desiccant unit, according to various modalities; Figures 12A to 12F show graphs of data relating to the operation of a thermal desiccant unit, according to various modes; Figure 13 shows data graphs showing the maximum water production rate (liters of water per hour) and the overall system efficiency for a system with an embedded photovoltaic (PV) panel and a system without an embedded photovoltaic (PV) panel; and Figure 14 shows data graphs comparing heat loss and overall system efficiency between a solar thermal unit without a desiccant, a solar thermal unit with a desiccant that lacks an enthalpy exchange unit, and a solar thermal unit with a desiccant that has an enthalpy exchange unit. DETAILED DESCRIPTION This description includes system modalities and methods such as, for example, generating liquid water from air. The term coupled is defined as CCQ7 Ln / Lznz / E / YILI - 3 connected, although not necessarily directly and not necessarily mechanically. The terms "a" and "one" are defined as one or more, unless explicitly stated otherwise in this description. The term "substantially" is defined as mainly, but not necessarily entirely, as specified (and includes what is specified; for example, "substantially 90 degrees" includes 90 degrees and "substantially parallel" includes parallel), as understood by a person generally skilled in the field. In any modality described, the terms "substantially" and "approximately" may be replaced with "within [a percentage] of as specified," where the percentage may comprise 0.1, 1.5, or 10%. Furthermore, a device or system that is configured in a certain way is configured in at least that way, but may also be configured in ways other than those specifically described. The terms "comprises" (and any form of "comprises," such as "comprising" and "comprising"), "has" (and any form of "has," such as "having" and "having"), "includes" (and any form of "includes," such as "including" and "including"), and "contains" (and any form of "contains," such as "containing" and "containing") are verbs that relate open concepts. As a result, an apparatus that comprises, has, includes, or contains one or more elements possesses these one or more elements, but is not limited to possessing only these elements. Similarly, a method that comprises, has, includes, or contains one or more operations or steps possesses one or more operations or steps, but is not limited to possessing only those one or more operations or steps. As used in this description, the terms sorption, adsorption, absorption, and similar terms may be used interchangeably. Although absorption is generally understood to be a volume phenomenon and sorption a surface-based phenomenon, the hygroscopic materials, desiccants, and / or sorption media described herein may capture water vapor by adsorption, absorption, or a combination thereof. Any modality of any of the apparatuses, systems, and methods may consist or consist essentially of — rather than comprising / including / containing, CCQ7 Ln / Lznz / E / YILI - 4 have—any of the stages, elements, and / or features. Thus, in any of the claims, the term consisting of or essentially consisting of may be substituted by any of the open-term linking verbs mentioned above in order to change the scope of a given claim from what would otherwise be used as an open-concept linking verb. The feature or features of a modality may apply to other modalities or implementations, even if not described or illustrated, unless expressly prohibited by this description or by the nature of the modalities. As will be described in detail below, this description introduces various approaches to efficient water production by maintaining a net fluctuation of water vapor captured and released to a condenser in a closed-loop system that includes a thermal desiccant unit. The systems and methods described herein efficiently provide a continuous driving force to release the water captured by a thermal desiccant unit to a working or transfer medium for condensation in a condenser at any given time during system operation. As described herein, the thermal desiccant units combine a working medium in a flowing architecture for the parallel production of water vapor and heat. Passive and / or active control schemes can be used to maintain a gradient that enables efficient water production.Some of these solutions may include deliberate enthalpy energy exchange to drive system conditions in which a recirculating working medium is driven to continuously move water to a condenser with additional energy acquired by the system further evolving into water vapor towards the condenser. Some details associated with the modalities described above and others are described below. Figure 1 shows a water generation system 100 for generating liquid water from a process gas containing water vapor, for example, ambient air. The water generation system 100 comprises a thermal desiccant unit 102, which includes a housing 104, a process gas inlet 106 for allowing a process gas to enter the thermal desiccant unit 102, and a process gas outlet. CCQ7 Ln / Lznz / E / YILI - 5 108 to allow process gas to exit the thermal desiccant unit 102. For clarity, the process gas flow is indicated by arrows with narrow dashed lines. The process gas inlet 106 and / or the process gas outlet 108 may comprise a valve or other flow management device that allows process gas (e.g., ambient air) to enter the thermal desiccant unit 102, for example, during a loading time or loading cycle, and that can be sealed or otherwise closed at other times. The process gas inlet 106 and / or the process gas outlet 108 may be designed or configured to balance and distribute the process gas by the use of any desirable static or active means, for example, flow dividers, separators, baffles, flow straighteners, and / or manifolds.System 100 may further include a process blower or fan 110 to increase or adjust the flow of ambient air within the thermal desiccant unit 102. The process gas may be characterized by an ambient temperature, Ta, and a relative humidity, RHa. The thermal desiccant unit 102 further comprises a porous hygroscopic material 120 located within the housing 104. The porous hygroscopic material 120 is retained within the housing 104 of the thermal desiccant unit 102 and can be configured to capture water vapor from the process gas, for example, during a loading time or loading cycle. The term porous or porosity, as used herein, can describe a through-flow implementation, as opposed to an overflow or flat-plate implementation, of the hygroscopic material in the thermal desiccant unit. Overflow or flat-plate implementations may be used without departing from the scope of this invention. However, in several embodiments, a through-flow implementation allows for small boundary layers with a high degree of percolation.In other words, in several modalities, a through-flow implementation decreases the resistance to vapor fluctuation through the hygroscopic material and / or improves the distribution of the process gas through a large area of ​​the hygroscopic material, either or both of which can result in improved water vapor uptake by the hygroscopic material. The porous hygroscopic material 120 can be further configured to absorb thermal energy (e.g., solar radiant thermal energy) and release vapor CCQ7 Ln / Lznz / E / YILI - 6 of water captured into a working or regeneration fluid, for example, during the release time or release cycle. The porous hygroscopic material 120 can be placed within a flow distributor, such as, but not limited to, a grid structure, rigid upper and lower porous plates, intercorrugated fluid channels, and / or woven mesh and fiber to withstand backpressure and distribute flow. The working fluid can be a gas, for example, air, which circulates through the system 100 in a working gas flow path indicated by thick solid lines in Figure 1. The working fluid can be a gas, for example, air.The working gas flow path can be a substantially closed cycle and can include the following flow segments: a first working fluid flow path segment inside the thermal desiccant unit 102, a second working fluid path segment 142 from the thermal desiccant unit 102 to a condenser 130, a third working fluid path segment inside the condenser 130, and a fourth working fluid path segment 144 from the condenser 130 to the thermal desiccant unit 102. Porous hygroscopic material 120 can be provided as one or more layered layers, a packed bed of hygroscopic particles or spheres, or a substantially continuous or monolithic structure. Porous hygroscopic material 120 may include one or more light-absorbing or light-activated hygroscopic materials. For example, the hygroscopic particles may be agglomerated by means of a binder or dispersed in a large surface area matrix or support medium. The hygroscopic material and / or support medium (if present) may be selected to minimize the reflection of solar radiation and / or to enhance the absorption or conduction of thermal energy. For example, the hygroscopic material and / or support medium (if present) may be dark in color or black.In some embodiments, the hygroscopic material can be mixed, combined, and / or embedded with materials or structures to efficiently absorb and / or transfer heat. For example, the hygroscopic material can be dispersed around a metallic structure with a thermal conductivity greater than 50 W / mK. In other embodiments, the hygroscopic material is a self-supporting structure housed within the thermal desiccant unit. In one example, the porous hygroscopic material is selected to capture 50 to 300% of its own mass as water vapor. CCQ7 Ln / Lznz / E / YILI - 7 water. The hygroscopic materials, sorption media, or desiccants (e.g., 120) of the present systems may comprise any desirable medium in any desirable configuration (e.g., such that the hygroscopic material, desiccant, or sorption medium is capable of adsorption and desorption of water). The following description of hygroscopic materials and sorption media is provided for illustrative purposes only. In some implementations, the hygroscopic material is capable of sorption at a first temperature, relative humidity, and / or pressure and desorption at a second temperature, relative humidity, and / or pressure. The hygroscopic material may be provided as a liquid, solid, and / or combinations thereof. The hygroscopic material may be provided as a porous solid impregnated with hygroscopic materials.For example, hygroscopic material may comprise one or more materials such as silica, silica gel, alumina, alumina gel, montmorillonite clay, zeolites, molecular sieves, metal-organic frameworks, activated carbon, metal oxides, lithium salts, calcium salts, potassium salts, sodium salts, magnesium salts, phosphoric salts, organic salts, metal salts, glycerin, glycols, hydrophilic polymers, polyols, polypropylene fibers, cellulosic fibers, derivatives thereof, and combinations thereof. This includes hygroscopic material and any suitable medium for use in a thermal desiccant unit. In some embodiments, the hygroscopic material may be selected and / or configured to prevent the sorption of certain molecules (e.g., those molecules that may be poisonous or otherwise harmful when ingested by, in contact with, or upon exposure to a human or other organism).The term sorption, as used herein, refers to absorption, adsorption, or a combination thereof. In several embodiments, the thermal desiccant unit 102 comprises a photovoltaic (PV) panel. The photovoltaic panel may consist of one or more photovoltaic cells. The photovoltaic panel may generally be positioned adjacent to a porous hygroscopic material 120. The photovoltaic panel may generally be positioned parallel to the porous hygroscopic material 120. The photovoltaic panel may be positioned within the housing 104. However, the photovoltaic panel may be positioned within and / or on top of CCQ7 Ln / Lznz / E / YILI - 8 of any portion, layer and / or material of the thermal desiccant unit 102 suitable for the generation of electrical energy by the photovoltaic panel and / or heat transmission to the porous hygroscopic material 120. In various modalities, the electrical energy generated by the photovoltaic panel is used by the water generation system 100 to power the electrical components thereof, including fans, pumps, blowers, valves, controllers, batteries or battery systems and any other component of the water generation system 100. In several configurations, the photovoltaic panel generates heat and / or releases the generated heat to the porous hygroscopic material 120 or other components of the thermal desiccant unit 102. This heat can be generated by direct solar irradiation on the photovoltaic panel and / or by heat release from inefficiencies in the photovoltaic process. In several configurations, the heat generated by the photovoltaic panel enhances the release of water vapor from the porous hygroscopic material 120 during a release time or release cycle. In Figure 13, the maximum water production and system efficiency are compared in a tested system comprising a photovoltaic (PV) panel and a tested system without a photovoltaic (PV) panel. The maximum water production rate is measured from the moment the system is loaded to a designated relative humidity (RH) on the porous hygroscopic material and subjected to solar irradiation of 7000 Whr / m² for a period of time.As used herein, system efficiency means the energy equivalent of the total water produced relative to the total solar irradiance incident on the active areas of the porous hygroscopic material and the photovoltaic (PV) panel. As shown in Figure 13, water generation systems comprising a photovoltaic (PV) panel can be configured for increased water production and / or system efficiency. The thermal desiccant unit 102 includes a working fluid inlet 112 to permit a working fluid to enter the thermal desiccant unit 102 and a working fluid outlet 114 to permit the working fluid to exit the thermal desiccant unit 102. The working fluid inlet 112 and / or the working fluid outlet 114 may comprise a valve or other flow management device to permit the working fluid gas to enter the thermal desiccant unit 102. CCQ7 Ln / Lznz / E / YILI - 9 For example, during a release time or release cycle, and may be sealed or otherwise closed at other times. The system 100 may additionally include one or more working fluid blowers or fans 116 to increase or adjust the flow rate of the working fluid in the thermal desiccant unit 102. During a release time, the working fluid may accumulate both heat and water vapor before the flow from the fluid inlet 112, through the porous hygroscopic material 120, and to the fluid outlet 114. In various embodiments, a thermal desiccant unit 102 may include any desired number of fluid inlets and fluid outlets for the process and / or working fluid inlet and outlet from the thermal desiccant housing.In various embodiments, the thermal desiccant unit may include any desirable fluid path or routing approach for the process and / or working fluid by means of any desirable internal and / or external structure or mechanism to the thermal desiccant housing, but not limited to flow dividers and / or inlet and outlet manifolds. In several configurations, the number of fans and / or blowers can be minimized and / or reduced to decrease costs, maintenance, and / or other complexities. For example, a single fan can be provided instead of fans 110 and 116 as shown in Figure 1, and any desired valves (e.g., one or more 3-way valves) and / or other pneumatic or fluid routing devices can be used to change the operational flow between processes and working fluids. As shown in Figure 1, the water generation system 100 may further comprise a condenser 130 for condensing water vapor from the working fluid, which may enter the condenser 130 at the inlet of condenser 132 and exit through the outlet of condenser 134. The condenser 130 is configured to receive working fluid in the working fluid path and produce liquid water from the received fluid (e.g., by condensing water vapor in the fluid, in the working fluid path). The condensers herein may comprise any suitable material and may be configured in any desirable configuration (e.g., to efficiently condense water vapor in the working fluid into liquid water). For example, suitable condensers may comprise polymers, metals, and / or the like. The condensers may comprise coils, fins, plates, with tortuous passages and / or CCQ7 Ln / Lznz / E / YILI- 10 similar. In some implementations, the condenser 130 can be cooled by ambient air in an ambient air path 136, with or without the aid of a fan or blower. For clarity, the ambient air path is indicated by broad dashed arrows. In one example, the blower or fan 110 can be configured or upgraded to provide cooling air via the ambient air path 136 to the condenser 130 during the release time or release cycle. The condensers can be configured to transfer thermal energy from the working fluid downstream of the thermal desiccant unit to the air in the ambient air path 136 (for example, so that the air in the ambient air path 136 facilitates the cooling of the condenser 130).In several configurations, the 130 condenser can be assisted by an active cooling device, such as, but not limited to, vapor compression cycles, thermoelectric devices and / or recirculating heat pumped fluids. The water generation system 100 may further comprise an enthalpy exchange unit 140 operatively coupled between the thermal desiccant unit 102 and the condenser 130. The enthalpy exchange unit 140 can exchange sensible energy (i.e., heat) and / or latent energy (i.e., humidity) between the working fluid in the second segment of the working fluid path 142 and the fourth segment of the working fluid path 144. In various embodiments, the enthalpy exchange unit 140 can transfer enthalpy between the working fluid outlet from the thermal desiccant unit 102 and the working fluid inlet to the thermal desiccant unit 102. In various embodiments, the enthalpy exchange unit 140 can transfer enthalpy between the working fluid outlet from the condenser 130 and the working fluid inlet to the condenser 130.The enthalpy exchange unit 140 enables the recovery of sensible and / or latent energy for efficient operation of system 100. In various configurations, the enthalpy exchange unit 140 can transfer heat from a working fluid flow at a higher temperature to a working fluid flow at a lower temperature. In various configurations, the enthalpy exchange unit 140 can also transfer water vapor from a working fluid flow at a higher vapor pressure to a working fluid flow at a lower vapor pressure. CCQ7 Ln / Lznz / E / YILI - 11 In various embodiments, the enthalpy exchange unit 140 is configured to transfer moisture from a first portion of the working fluid (for example, the working fluid placed in the second segment of the working fluid path 142) to a second portion of the working fluid entering the condenser inlet 132. In various embodiments, the enthalpy exchange unit 140 is configured to transfer heat from a third portion of the working fluid (for example, the working fluid placed in the fourth segment of the working fluid path 144) to a fourth portion of the working fluid entering the working fluid inlet 112. The enthalpy exchange unit 140 can be a passive sensible heat transfer unit (e.g., a heat exchanger), a passive latent energy transfer unit (e.g., a vapor transfer membrane), a passive total heat transfer unit (i.e., sensible and latent energy) (e.g., a rotating desiccant wheel), or an active heat transfer unit (refrigeration unit, vapor compression cycle unit). In some embodiments, both heat energy (i.e., sensible) and moisture energy (i.e., latent) are exchanged by the enthalpy exchange unit 140. In other implementations, only sensible heat is exchanged, for example, with a conventional heat exchanger.Sensible heat can be transferred in the form of a temperature difference between one or more segments of the working fluid path by means of the enthalpy exchange unit 140. Latent heat can be transferred in the form of a humidity difference between different segments of the working fluid path by means of the enthalpy exchange unit 140. In some implementations, the enthalpy exchange unit 140 may comprise a plurality of subunits, for example, a separate heat exchange subunit and a humidity exchange subunit, and / or multiple heat and / or humidity exchange subunits. System 100 includes a controller 160 configured to control system 100 to maintain a net fluctuation of water vapor transferred by the working gas to the condenser 130, thereby maximizing liquid water production in the condenser 130. The controller 160 can maximize liquid water production in the CCQ7 Ln / Lznz / E / YILI - 12 condenser 130 by optimizing or adjusting the exchange rate of the enthalpy exchange unit 140 (for example, by adjusting the rotation speed for a rotating desiccant), the flow rate of the working fluid in the working fluid path (for example, by means of a fan 116), or a combination thereof. As used herein, the terms exchange rate or enthalpy exchange rate mean a rate of energy change and are used interchangeably herein to refer to a rate of heat exchange in the enthalpy exchange unit, a rate of water production, and / or a rate of temperature change, and may be described in units of watts and / or kg / hr. The control system can dynamically maximize liquid water production during the day cycle based on current or predicted environmental conditions (e.g., solar irradiance, ambient temperature, ambient humidity) and current or predicted system properties (e.g., working fluid temperature, working fluid humidity, water content of hygroscopic materials in the system). The control system can utilize a set of sensors, an embedded deterministic and / or machine learning algorithm, information on water vapor thermodynamics, information on the properties of hygroscopic materials, information on the amount of liquid water produced, information on the amount of water vapor retained by the thermal desiccant unit, and / or other factors that can be synthesized in the controller to optimize water production in the condenser. Various solutions can be used to control or maximize water production by system 100 by driving the water vapor captured by the hygroscopic material 120 during the charging time to vapor pressure saturation in the working fluid during the release time. In other words, system 100 can be controlled and / or configured to maximize the relative humidity of the working fluid and / or the inlet of the nearby condenser 132 and / or in the condenser 130. The controller 160 can operate system 100 to vary the exchange rate and the enthalpy exchange unit 140 based on ambient solar fluctuations, ambient temperature, ambient relative humidity, working fluid temperature, and a CCQ7 Ln / Lznz / E / YILI - 13 relative humidity of the working fluid, the amount of water present in the hygroscopic material 120, elapsed time, user input, etc. For example, under low solar flux conditions, the controller can reduce the working fluid flow rate, thereby increasing the working fluid temperature and the rate of water vapor desorption from the porous hygroscopic material. For example, under certain conditions, an increase in the exchange rate of the enthalpy exchange unit 140 can increase the relative humidity of the working fluid at the condenser inlet 132 and / or in the condenser 130. The 160 controller can operate the 100 system based on one or more of the following: a user selection, data received from one or more sensors, predicted conditions, programmatic control, and / or any other desirable basis. The 160 controller can be associated with peripheral devices (including sensors) to detect data information, data collection components to store data information, and / or communication components to communicate data information related to system operation. The inputs to the 160 controller can be measured as indicated in the data captured by one or more sensors.In one example, the 160 controller can set process gas flow rates, working fluid flow or circulation rates, enthalpy, exchange rates (for example, by adjusting the rotation speed of the rotating desiccant), and transitions between loading and release times based on a lookup table of parameters stored on the controller. In another example, the controller can automatically adjust process gas flow rates, enthalpy exchange rates, loading / release transition times, and monitor water production signals in an effort to learn itself or learn established optimum points. The 160 controller can be programmed or configured to optimize liquid water production based on measurements from one or more inputs (for example, the 160 controller can optimize liquid water production based on current or expected environmental and system conditions) that include, but are not limited to, external conditions such as ambient air temperature, ambient pressure, relative humidity, solar insolation, solar fluctuation, and predicted CCQ7 Ln / Lznz / E / YILI - 14 climate, time of day, etc. In addition, the 160 controller can be programmed or configured to optimize liquid water production based on inputs related to system operational parameters such as working fluid temperature, working fluid pressure, working fluid relative humidity, working fluid water vapor partial pressure, condenser discharge temperature, liquid water production rate, liquid water production volume, liquid water usage rate, liquid water quality, etc. During a loading time, the flow rate of the process gas (e.g., ambient air) within the thermal desiccant unit 102 can be varied by the controller 160 in wired or wireless communication with the fan 110. During a release time, the flow rate of the working fluid can be varied by the controller 160 in wired or wireless communication with the fan 116 based on ambient solar fluctuation, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, amount of water present in the hygroscopic material 120, and elapsed time, or a combination thereof.During a release time, the enthalpy exchange rate can be varied by the controller 160 through wired or wireless communication with the enthalpy exchange unit 140 based on input variables such as ambient solar fluctuation, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, the amount of water present in the hygroscopic material 120, elapsed time, or a combination thereof. In a particular implementation where the enthalpy exchange unit is a rotating desiccant wheel, the enthalpy exchange rate can be varied by adjusting the rotational speed of the rotating desiccant wheel. System 100 may comprise a telematics unit 162 (e.g., a transmitter, receiver, transponder, transvector, repeater, transceiver, and / or the like) for communicating operational parameters and / or data to and / or from System 100 (e.g., the controller 160) by means of a wired and / or wireless interconnection. For example, wireless communications may conform to or be standardized using communication protocols such as GSM, SMS components that operate CCQ7 Ln / Lznz / E / YILI - 15 at relatively low speeds (e.g., operating every few minutes), protocols that can be geographically specified and / or similar). System 100 may include indicators (e.g., lights, such as LEDs) which can be configured to provide information regarding the system's operation. For example, in some configurations, the indicator lights can be configured to provide information (e.g., visually, to a user) that the system is operating, the amount of solar energy available, that maintenance is recommended, or that a component has failed and / or is failing, and / or similar information. Any desirable information (including the information described above with reference to the indicators) can be transmitted over a communications network (e.g., alone and / or in addition to the operation of any of the indicators). In various configurations, System 100 may include or be associated with one or more energy generation and / or storage systems (e.g., a photovoltaic panel, battery, etc.). For example, System 100 may include a battery system for storing energy collected during daylight hours (e.g., by means of a photovoltaic panel) and using it during hours without sunlight. Any desirable energy source for auxiliary components or that may otherwise be used by System 100 includes, but is not limited to, solar, auxiliary, AC / DC, etc. Figures 1–3 and 5–8 illustrate some implementations of the water generation systems and related components. Unless otherwise specified below, the numerical indicators used to refer to the components in Figures 2–3 and 5–8 are similar to those used to refer to the components or features in Figure 1 above, except that the index has been increased by 100. Figure 2 shows a water generation system 200 comprising a thermal desiccant unit 202, a condenser 230, and an enthalpy exchange unit 240. The system 200 further comprises an auxiliary desiccant unit 250 comprising a hygroscopic material capable of transitioning between an adsorption zone 252 and a desorption zone 254 of the auxiliary desiccant unit 250. In a CCQ7 Ln / Lznz / E / YILI - 16. Focus: The hygroscopic material 220 of the thermal desiccant unit 202 differs from the hygroscopic material of the auxiliary desiccant unit 250. For example, the hygroscopic materials of the thermal desiccant unit and the auxiliary desiccant unit may vary based on the percentage of water absorption by mass, the water absorption and release rates (in some cases, as a function of the exposed humidity and temperature), the water absorption and release rates as a function of the airflow rates, etc. In a non-limiting example, the hygroscopic material in the thermal desiccant unit 202 has a higher water absorption capacity compared to the hygroscopic material in the auxiliary desiccant unit 250. In another non-limiting example, the hygroscopic material in the auxiliary desiccant unit 250 has a higher water absorption or release rate compared to the hygroscopic material in the thermal desiccant unit 202. In one implementation, the auxiliary desiccant unit is a rotating desiccant where the hygroscopic material is provided as a hygroscopic wheel that rotates between the process gas and the working gas flows. In an operational example, the auxiliary desiccant unit may be active (e.g., rotating) during a release time or cycle and inactive or free during a loading time or cycle. In the adsorption zone 252, a process gas (e.g., ambient air) 256 may flow through the hygroscopic material in the adsorption zone 252 of the auxiliary desiccant unit 250. In the adsorption zone 252, the hygroscopic material may capture water vapor from the process gas 256. The system 200 may further include a process blower or fan 258 to increase or adjust the flow rate of the process gas 256 within the adsorption zone 252 of the auxiliary desiccant unit 250.In one implementation, the process gas can be vented to the outside environment after flowing through the auxiliary desiccant unit 250. In another implementation, the process gas 236 exiting the adsorption zone 252 of the auxiliary desiccant unit 250 can be directed to the condenser 230 to remove heat from the condenser, thereby improving its cooling capacity and, consequently, its liquid water generation rate. In yet another implementation, the system may have a fan configured to adjust the direct airflow through the condenser. In one implementation, the fans or... CCQ7 Ln / Lznz / E / YILI - 17 blowers 210 and 258 may be the same component, with their functions of supplying a process gas (e.g., ambient air) through the process gas inlet 206 and / or into an auxiliary desiccant unit 250, activated by means of control valves in the fluid paths. In the desorption zone 254, the hygroscopic material of the auxiliary desiccant unit 250 can release water into the working fluid downstream of the thermal desiccant unit 202 and upstream of the condenser 230. As shown in Figure 2, the auxiliary desiccant unit 250 can be positioned so that the hygroscopic material in the desorption zone 254 releases water into the working fluid outlet from the thermal desiccant unit 214 upstream of the enthalpy exchange unit 240 and the condenser 230. However, it will be appreciated that one or more auxiliary desiccant units can be positioned at different locations along the working fluid paths 242, 244. During a loading time, the flow rate of the process gas (e.g., ambient air) within the thermal desiccant unit 202 can be varied by the controller 260 in wired or wireless communication with the fan 210. During the release time, the flow rate of the working fluid can be varied by the controller 260 in wired or wireless communication with the fan 216 based on the ambient solar fluctuation, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, the amount of water present in the hygroscopic material 220, the amount of water present in the hygroscopic material of the auxiliary desiccant unit 250, the elapsed time, or a combination thereof.During the release time, the enthalpy exchange rate can be varied (for example, by adjusting the rotational speed of the desiccant wheel) by the controller 260 in wired or wireless communication with the enthalpy unit 240, based on input variables or on ambient solar fluctuations, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, the amount of water present in the hygroscopic material, and elapsed time, or a combination thereof. Additionally, the movement rate of the second hygroscopic material between the adsorption and desorption zones of the unit is also a factor. CCQ7 Ln / Lznz / E / YILI The speed of the auxiliary desiccant 250 (e.g., the rotational speed of the rotating desiccant wheel) can be varied to maximize the rate of water production in the condenser 230 during the release time or release cycle. The movement rate of the hygroscopic material between the adsorption zone 252 and the desorption zone 254 of the auxiliary desiccant unit 250 can be based on ambient solar fluctuation, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, the amount of water present in the hygroscopic material 220 or 250, elapsed time, or a combination thereof.In one example, the exchange rate of the auxiliary desiccant unit 250 can be controlled so that the temperature and relative humidity of the working fluid path 214, coupled with the amount of water vapor loaded into the adsorption zone 252, results in a net increase of water vapor within the working fluid path 242. In the water generation system 100 of Figure 1, the amount of water introduced into, or captured by, the system (for transfer via the working fluid to the condenser for condensation into liquid water) can be the amount of water captured by the thermal desiccant unit during a loading time (e.g., during the night). In the operation of system 200 of Figure 2, in addition to the amount of water captured by the thermal desiccant unit 202, an additional amount of water can be introduced into the system or captured by the auxiliary desiccant unit 250 during the release time (e.g., daytime).The additional amount of water introduced into system 200 by the auxiliary desiccant unit 250 can be captured continuously during the day, intermittently during the day, or intermittently in one or more day / night cycles by the controller, based on actual / expected ambient conditions, the properties of the working gas (e.g., temperature, relative humidity), and / or the amount of water in the thermal desiccant unit. In system 100, the water sorption and release medium may not be independent of the system's heat source, i.e., the thermal desiccant unit. In system 200, the auxiliary desiccant unit can be relatively independent of the heat source. In this way, system 200 can provide an additional degree of freedom for the controller to optimize water generation in the condenser. In an illustrative example, the controller... CCQ7 Ln / Lznz / E / YILI - 19 can activate the auxiliary desiccant unit when the relative humidity of the working gas is below a predetermined value and deactivate the auxiliary desiccant unit when the relative humidity of the working gas is above a predetermined value to continuously increase the net fluctuation of water vapor in the working fluid towards the condenser. In several implementations, a thermal desiccant unit can be provided as a solar thermal desiccant unit that can convert solar insolation into thermal energy by transferring energy from sunlight to the working fluid flowing through the unit. In at least some examples, the solar thermal desiccant units of the present technology can be configured so that the working fluid flows along one or more flow paths from the inlet to the outlet of the thermal desiccant unit. Figure 3 shows an exemplary solar thermal desiccant unit comprising a transparent cover 305 (e.g., glass) configured to allow solar radiation to pass into the interior of the thermal desiccant housing 304. The solar thermal desiccant unit 302 may comprise one or more interstitial layers (e.g., interstitial layers similar to the transparent cover layer 305) between the transparent cover layer and the porous hygroscopic material. One or more interstitial layers and / or the transparent cover layer of a solar thermal desiccant unit may comprise a photovoltaic material, one or more photovoltaic cells, and / or a photovoltaic (PV) panel. In various embodiments, a solar thermal desiccant unit 302 comprises a photovoltaic (PV) panel 306. The photovoltaic panel 306 can generally be placed adjacent to the interstitial layer 307. The photovoltaic panel 306 can generally be placed parallel to the interstitial layer 307. However, the photovoltaic panel 306 can be placed within, and / or on, any portion, layer, and / or material of the solar thermal desiccant unit 302 suitable for the generation of electrical power by the photovoltaic panel and / or heat transmission to the layer comprising the porous hygroscopic material 320a, 320b. CCQ7 Ln / Lznz / E / YILI As shown in Figure 3, the working fluid can flow from the - 20 fluid inlet 32 ​​along the transparent cover layer 305 and the interstitial layer 307, and then through the layer comprising the porous hygroscopic material 320a, 320b, such that the working fluid collects heat from the interstitial layer 307 below the transparent cover layer 305 and collects water and heat from the porous hygroscopic material 320a, 320b before exiting the solar thermal desiccant unit 302 at the fluid outlet 314. The solar thermal desiccant unit of Figure 3 comprises a split-flow design including porous hygroscopic material 320a, 320b placed in two layers and with two fluid flow paths; however, additional fluid paths of a single fluid flow path within the thermal desiccant unit may be used in accordance with the embodiments described herein. For water generation, the thermal desiccant unit can be configured to operationally improve the interaction of the process fluid with the hygroscopic material during the loading time and / or the interaction of the working fluid with the hygroscopic material during the release time. Figure 4 shows exemplary data for a typical thermal desiccant unit loading operation. In various configurations, an increase in flow rate or fluctuation (i.e., the process air flow rate per unit area of ​​the thermal desiccant, in cubic feet per minute (CFM)) reduces the amount of time required to load the hygroscopic material into the thermal desiccant unit to a desired amount of water capture (e.g., percentage of water capture by mass).By supporting this water-capturing behavior, the thermal desiccant units described herein can be configured to enable efficient water production by maintaining a high fluctuation of water vapor captured and released through the thermal desiccant unit via its configuration and operation. This solution will be described in the following examples. Figure 5 and Figure 6 show thermal desiccant units comprising flow architectures of both: 1) increasing the flow fluctuation of the process fluid during a loading time, and 2) efficient transport of absorbed solar heat from the upper portions of the thermal desiccant unit to the lower portions of the thermal desiccant unit by means of a working fluid during a CCQ7 Ln / Lznz / E / YILI - 21 release time. The hygroscopic material within the thermal desiccant unit can be configured around and / or within one or more flow separators, distributors, sectioned layers and / or segments according to the favored flow paths for both the collection and release operations and thus maximize water generation. Figure 5 shows a thermal desiccant unit 502 comprising a split or segmented flow architecture to enhance the interaction and / or water transfer between the working fluid and the hygroscopic material by means of a substantially or generally top-down flow path in which heat absorbed from an upper portion of the thermal desiccant unit is transferred to the hygroscopic material in a lower portion of the thermal desiccant unit. In several embodiments, the thermal desiccant unit 502 comprises a solar thermal desiccant unit, and at least a portion of the heat absorbed from an upper portion of the thermal desiccant unit comprises solar heat. In several embodiments, the thermal desiccant unit 502 further comprises a photovoltaic panel, and at least a portion of the heat absorbed from an upper portion of the thermal desiccant unit comprises heat generated by the photovoltaic panel. As shown in Figure 5, the working fluid flows (in a path shown by solid arrows) from fluid inlets 512a and 512b along an upper portion 505 to collect heat, and then flows to lower segmented portions or layers 507a and 507b defined by a static baffle or separator 509 to collect water and heat from a segmented hygroscopic porous body of layers 507a and 507b before exiting the thermal desiccant unit 502 at the lower segmented fluid outlets 514a and 514b. In this way, the working fluid efficiently transports absorbed solar heat through the thermal desiccant unit to maximize water uptake from the hygroscopic material during the release time. In several embodiments, the hygroscopic material in the thermal desiccant unit, the flow architecture of the thermal desiccant unit 502 is configured to enhance the interaction of the process fluid with the hygroscopic material by means of serial exposure of the subdivided areas (e.g., 507a, 507b) to the same flow rate of CCQ7 Ln / Lznz / E / YILI - 22 process fluid, in order to increase the flow fluctuation of the process fluid during the loading time. As shown in Figure 5, the process fluid comprising water vapor enters the thermal desiccant unit 502 through inlet 512c and flows (in a path shown by dashed lines) through the lower segmented portions or layers 507a, 507b, under the separator 509, to deposit water on the hygroscopic porous body portion before exiting the thermal desiccant unit 502 at fluid outlet 514c. Figure 5 shows a single separator; however, any desired number and configuration of fluid inlets, fluid outlets, separators, and other flow-directing means, structures, or devices can be provided to enhance the interaction of the process gas with the hygroscopic material at a high process gas fluctuation.For example, various configurations of the thermal desiccant unit can be provided to maintain a process gas fluctuation through the hygroscopic absorber preferably greater than 50 CFM / m2, greater than 100 CFM / m2, greater than 200 CFM / m2, greater than 300 CFM / m2 or greater than 400 CFM / m2. The thermal desiccant unit 502 shown in Figure 5 shows the working fluid path being introduced into the thermal desiccant unit approximately perpendicularly (i.e., at an angle of approximately 90 degrees) to the process fluid path and shows a single separator 509 to maintain the desired top-down flow of the working fluid. However, any desirable configuration (e.g., separation, placement, relative angles, etc.) and / or number of fluid inlets, fluid outlets, separators, and other flow-directing means, structures, or devices can be provided to define the process and working fluid flow paths in the thermal desiccant unit for both loading and unloading operations.Furthermore, various flow solutions can be used, including through-flow hygroscopic body implementations, top-flow or flat-plate implementations of the hygroscopic material, as well as combinations or derivatives thereof. Additionally, the hygroscopic material can be configured in various ways in relation to the medium, structure, or flow direction distributors, for example, but not limited to, lattice structures, rigid porous plates, intercorrugated fluidic channels, and / or woven or fiber meshes to withstand backpressure. CCQ7 Ln / Lznz / E / YILI - 23 distribute the flow. As another example, Figure 6 shows a thermal desiccant unit 602 comprising a split or segmented flow architecture to enhance the interaction and / or water transfer between the process and / or working fluids and the hygroscopic material. The process fluid and the working fluid share at least a portion of the same flow path (as shown by the lightly dashed lines) defined by the separators 609a and 609b between the hygroscopic absorbers 620a and 620b. The shared flow path can achieve a primarily top-down flow direction for the working fluid through the porous hygroscopic material in the absorbers 620a and 620b while also providing a high process flow rate fluctuation from the hygroscopic absorbers 620a and 620b. In various embodiments, the thermal desiccant unit 602 comprises a solar thermal desiccant unit. In several embodiments, the thermal desiccant unit 602 comprises a photovoltaic (PV) panel 606. The photovoltaic panel 606 can generally be positioned parallel to cover the layer 605. However, the photovoltaic panel 606 can be positioned within and / or on any portion, layer, and / or material of the thermal desiccant unit 602 suitable for generating electricity by the photovoltaic panel and / or transferring heat to the absorbers 620a and 620b. As shown in Figure 6, the working fluid flows (in a path indicated by solid and lightly dashed lines) from fluid inlet 612a along the cover layer 605, collecting heat, and then flows through the lower segmented hygroscopic absorbers 620a and 620b in the path defined by the separators 609a and 609b to collect water and heat from the hygroscopic absorbers 620a and 620b before exiting the thermal desiccant unit 602 at the lower fluid outlet 614a. In this way, the working fluid efficiently transports absorbed solar heat through the thermal desiccant unit to maximize water uptake from the hygroscopic material during the release time. The flow architecture of the thermal desiccant unit 602 also improves the interaction or exchange of water from the process fluid by means of the serial exposure of the subdivided absorber 620a and 620b to the same flow rate of process fluid to CCQ7 Ln / Lznz / E / YILI - 24 in this way increase the fluctuation of the process fluid flow during the loading time. As shown in Figure 6, the process fluid comprises water vapor that enters the thermal desiccant unit 602 through inlet 612b and flows (in a path indicated by lines with many dots and with light dots) through the segmented hygroscopic portions 620a and 620b so as to deposit water on the hygroscopic material before exiting the thermal desiccant unit 602 at fluid outlet 614b. In the example shown in Figure 6, multiple fluid inlets and outlets are displayed; however, any desired number or configuration can be used, for example, in conjunction with any desired valve or fluid routing device to manage the flow between the process and working fluids. To minimize complexity, maintenance, leakage, and / or cost, fans, blowers, actuators, and other fluid routing devices can be used in smaller quantities or in simplified versions. In some implementations, a water generation system may comprise a plurality of enthalpy exchange units operatively coupled between a thermal desiccant unit and a condenser. As shown in Figure 7, the water generation system 700 may comprise enthalpy exchange unit 740a and enthalpy exchange unit 740b between the thermal desiccant unit 702 and the condenser 730. Enthalpy exchange unit 740a transfers enthalpy between the working fluid directly at the inlet and outlet from the thermal desiccant unit 702. Enthalpy exchange unit 740b transfers enthalpy between the working fluid directly entering and exiting the condenser 730. Each enthalpy exchange unit in a water generation system may have different enthalpy exchange characteristics, resulting in a difference in the amount of sensible and / or latent heat transferred between the working fluid flow segments. For example, enthalpy exchange unit 740a and enthalpy exchange unit 740b may comprise different hygroscopic materials. In another example, enthalpy exchange unit 740a may transfer a greater amount of sensible heat than enthalpy exchange unit 740b. In yet another example, enthalpy exchange unit 740b transfers a greater amount of heat. CCQ7 Ln / Lznz / E / YILI - 25 latent than the enthalpy exchange unit 740a. In a further example, the enthalpy exchange unit 740a can be configured to have a higher rate of water vapor adsorption and desorption, while the enthalpy exchange unit 740b can be configured to have a lower rate of water vapor adsorption and desorption. Figure 8 shows a water generation system 800 comprising a thermal desiccant unit 802, a condenser 830, and an enthalpy exchange unit 840. The system 800 may further comprise an auxiliary or batch desiccant unit 870 comprising a batch hygroscopic material. The batch hygroscopic material can capture water vapor from the working fluid upstream of the thermal desiccant unit 802. The batch desiccant unit 870 can collect residual water vapor from the working fluid that has not been condensed by the condenser 830 earlier in the cycle.The hygroscopic material of the batch desiccant unit 870 may become saturated (i.e., stop collecting water vapor) after a portion of the release time; however, since the working fluid conditions change (e.g., if the working fluid temperature between the condenser outlet 834 and the thermal desiccant unit inlet 812 is too hot or the moisture content is too dry for saturation), the batch desiccant may release water vapor back into the recirculating working fluid. In one embodiment, the hygroscopic material 820 of the thermal desiccant unit 802 is different from the hygroscopic material of the batch desiccant unit 870. For example, the hygroscopic materials of the thermal desiccant unit and the batch desiccant unit may vary based on the percentage of water capture by mass, the rates of water capture and release (in some cases, as a function of the exposed humidity and temperature), the rates of water capture and release as a function of air flow rates, etc. As shown in Figure 8, a batch desiccant unit can be provided to capture water vapor in the working fluid path between the condenser and the thermal desiccant unit. This can be advantageous in that the batch desiccant unit can modulate the water vapor content of the working fluid during the time of CCQ7 Ln / Lznz / E / YILI - 26. Release occurs by adsorbing excess water vapor released from the thermal desiccant unit. Furthermore, the batch desiccant unit can modulate the water vapor content of the working fluid during the release time by desorbing water vapor under conditions where the thermal desiccant releases minimal or no water vapor into the working fluid. In this way, the batch desiccant unit can serve as a supplementary water source for the system. The present description further provides methods or processes for generating water using a thermal desiccant unit. With reference to Figure 9, a flow diagram of a method for operating a water generation system according to one embodiment of the present invention is shown. In operation 902, a process gas can flow through a thermal desiccant unit comprising a porous hygroscopic material, for example, during a loading time (e.g., nighttime). In operation 902, the porous hygroscopic material in the thermal desiccant unit can capture water vapor from the process gas. In 904, the method can include the transition from the loading time to a release time (e.g., daytime).In one example, the method comprises monitoring ambient conditions (e.g., solar fluctuation, relative humidity, temperature) and / or the actual or estimated amount of water in the water generation system (e.g., equivalent relative humidity of the hygroscopic material loaded into the thermal desiccant unit) and, based on the monitored or estimated data, making a transition from loading time to release time. As shown in flow diagram 900, the method may comprise flowing a working fluid through a thermal desiccant unit comprising the porous hygroscopic material during the release time in operation 906. In operation 906, the working fluid may accumulate both heat and water vapor while flowing through the thermal desiccant unit. In operation 908, the method may include condensing, by means of a condenser, water vapor from the working fluid into liquid water during the release time. In operation 910, enthalpy can be transferred or exchanged, by an enthalpy exchange unit, between the working fluid paths during time CCQ7 Ln / Lznz / E / YILI - 27 of release. In operation 910, the enthalpy exchange rate can be varied based on one or more of the following: a user selection, data received from one or more sensors (e.g., data relating to one or more environmental conditions, data relating to the water content in the working fluid, water content in the thermal desiccant unit, etc.), predicted conditions, programmatic control, an algorithm, and / or any other desirable basis. In one example, the method comprises continuous monitoring of environmental conditions (e.g., solar fluctuation, relative humidity, temperature) and / or the actual or estimated amount of water in the working fluid or the thermal desiccant unit, and, based on the monitored or estimated data. In operation 912, the method may further include transitioning from the charging time to the release time. In operation 914, the process may be repeated or cycle. The transition between the charging time and the release time may be based on one or more of the following: a user selection, data received from one or more sensors (e.g., data relating to one or more environmental conditions, data relating to the water content in the working fluid, water content in the thermal desiccant unit, etc.), predicted conditions, programmatic control, an algorithm, and / or any other desirable basis.In one example, the method comprises continuous monitoring of environmental conditions (e.g., solar fluctuation, relative humidity, temperature) and / or actual or estimated amount of water in the working fluid or thermal desiccant unit and, based on the monitored or estimated data, the transition from charging time to release time. Figures 9 through 11 illustrate various methods for preparing water generation systems comprising a thermal desiccant unit. Unless otherwise specified below, the numerical indicators used to refer to operations in Figures 10 through 11 are similar to those used to refer to operations or features in Figure 9 above, except that the index has been increased by 100. With reference to Figure 10, a flow diagram 1000 of a method of operating a water generation system, according to one embodiment of the present description, is shown. In operation 1002, a process gas can flow through CCQ7 Ln / Lznz / E / YILI - 28 The thermal desiccant unit comprises a porous hygroscopic material during a loading time. In operation 1004, the system can transition to a release time and a working fluid flows through the thermal desiccant unit in 1006. In operation 1008, water vapor can condense from the working fluid into liquid water and, in operation 1010, enthalpy can be exchanged between the working fluid paths during the release time. In operation 1011 of flow diagram 1000, the method may include maximizing the condenser's liquid water production (e.g., the actual or estimated water production rate, the total amount of water produced during a release time, etc.) by varying the exchange rate of the first enthalpy exchange unit, the working fluid flow rate, the process gas flow rate, or a combination thereof. For example, a controller may vary the enthalpy exchange rate and / or the working fluid flow rate based on ambient solar fluctuation, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, the amount of water present in the hygroscopic material in the thermal desiccant unit, elapsed time, a user selection, a predefined program, or a combination thereof.As another example, a controller can vary the enthalpy exchange rate and / or the working fluid flow rate to maintain an increase in the net fluctuation of water vapor into the condenser. In operation 1012, the method can further include the transition from the charging time to the release time. In operation 1014, the process can be repeated or cycled. In systems comprising an auxiliary desiccant unit with an adsorption zone and a desorption zone, the method may further comprise moving a hygroscopic material within the auxiliary desiccant unit between an adsorption zone and a desorption zone. With reference to Figure 11, flow diagram 1100 shows a method of operating a water generation system comprising an auxiliary desiccant unit according to several embodiments. In operation 1102, a process gas may flow through a thermal desiccant unit comprising a porous hygroscopic material during a loading time. In operation 1104, the system may perform a CCQ7 Ln / Lznz / E / YILI - 29 transition to a release time and a working fluid flows through the thermal desiccant unit in operation 1106. As shown in flow diagram 1100, the method may include flowing a process gas through a hygroscopic material in the adsorption zone of the auxiliary desiccant unit during the release time in operation 1107. In the adsorption zone, the auxiliary hygroscopic material can capture water vapor from the process gas, and in the desorption zone, the auxiliary hygroscopic material can release water into the working fluid flow. In 1108, the water vapor can be condensed from the working fluid into liquid water, and in operation 1110, enthalpy can be exchanged between the working fluid paths during the release time. In the lili operation, the method may include maximizing the condenser's liquid water production (e.g., the actual or estimated water production rate, the total amount of water produced during a release time, etc.) by varying the exchange rate of the first enthalpy exchange unit, the working fluid flow rate, the movement rate of the auxiliary hygroscopic material between the adsorption zone and the desorption zone, or a combination thereof.For example, a controller can vary the enthalpy exchange rate, the working fluid flow rate, and / or the movement rate of the auxiliary hygroscopic material between the adsorption and desorption zones based on ambient solar fluctuations, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, the amount of water present in the hygroscopic material in the thermal desiccant unit, the amount of water present in the hygroscopic material in the auxiliary desiccant unit, elapsed time, a user selection, a preset program, or a combination thereof. In operation 1112, the system can transition from the charging time to the release time. In operation 1114, the process can be repeated or cycled. Figures 12A to 12F show plotted data versus time for a thermal desiccant unit during a release cycle that includes solar insolation (Figure 12A); specific humidity (Figure 12B); and working fluid flow rate through the unit. CCQ7 Ln / Lznz / E / YILI - 30 thermal desiccant (Figure 12C); the power of the thermal desiccant unit multiplied by the total power, sensible power, and latent power (Figure 12D); the inlet temperature and outlet temperature (Figure 12E); and the water removed or generated by the thermal desiccant unit (Figure 12F). The thermal desiccant unit is charged with water from a process gas during the previous charging cycle (e.g., at an equivalent of 83% RH). At 11:00 h, the charged thermal desiccant unit is exposed to solar thermal radiation, and a working fluid flows through it. The total power (sum of sensible and latent heat) extracted from the thermal desiccant unit is shown in Figure 12D, and the amount of water leaving the thermal desiccant unit is shown in Figure 12F, which is approximately 2 liters of water. Figure 14 shows plotted data comparing the system efficiency and heat losses of various water generation systems, each as a function of relative humidity. The plots compare a system known in the prior art (i.e., a solar thermal unit without a desiccant, lacking a desiccant or porous hygroscopic material placed in a thermal desiccant unit) with two embodiments of the present description, each including a porous hygroscopic material in the thermal desiccant unit, and one further comprising an enthalpy exchange unit, each according to various embodiments. System efficiency and heat loss are measured from the moment the system is charged to the designated relative humidity and subjected to solar irradiation of 1000 Whr / m² for a period of time at 25 °C.Figure 14 shows that heat losses in a solar thermal unit without a desiccant are greater than in the described configurations that include a thermal desiccant unit and / or an enthalpy exchange unit. In contrast, the configurations that include a thermal desiccant unit, as described herein, have less heat loss due to the evaporative work of the system, which captures latent heat as water production. The configurations that include an enthalpy exchange unit can increase the temperature and / or decrease the moisture content of the working fluid entering the thermal desiccant unit, thereby increasing the efficiency of the thermal desiccant unit. CCQ7 Ln / Lznz / E / YILI 31 The foregoing specification and examples provide a complete description of the structure and use of the illustrative embodiments. Although certain embodiments have been described herein with a degree of particularity, or with reference to one or more individual embodiments, those skilled in the art may make numerous alterations to the described embodiments without departing from the scope of this invention. Thus, the various illustrative embodiments of the methods and systems are not intended to be limited to the particular forms described. Rather, they include all modifications and alternatives within the scope of the claims, and embodiments different from those shown may include some or all of the features of the embodiment shown. For example, elements may be omitted or combined as a unitary structure, and / or connections may be substituted.Furthermore, the appropriate aspects of any of the examples described above can be combined with aspects of any of the other examples described to form additional examples that have comparable or different properties and / or functions, and that solve the same or different problems. Similarly, it will be understood that the benefits and advantages described above can be related to one modality or to several modalities. The claims are not intended to include, and should not be construed as including, means-plus-function or stage-plus-function limitations, unless such limitation is explicitly mentioned in a given claim by using one or more of the phrases "means to" or "stage to," respectively. The term "substantially," as used herein, is intended to encompass minor deviations rather than define an exact value.

Claims

1. A system for generating liquid water, characterized in that it comprises: a thermal desiccant unit comprising: a housing including a working fluid inlet and a working fluid outlet; and a first porous hygroscopic material located within the housing, the first porous hygroscopic material being configured to absorb thermal energy; a working fluid accumulating heat and water vapor as it flows from the working fluid inlet of the housing, through the first porous hygroscopic material, and to the working fluid outlet of the housing; a condenser for condensing water vapor from the working fluid, the condenser comprising a condenser inlet and a condenser outlet;and at least one enthalpy exchange unit operatively coupled between the thermal desiccant unit and the condenser, wherein the at least one enthalpy exchange unit transfers enthalpy between the working fluid outlet from the thermal desiccant unit and the working fluid inlet to the thermal desiccant unit; and wherein at least one enthalpy exchange unit transfers enthalpy between the working fluid outlet of the condenser and the working fluid inlet to the condenser.

2. The system according to claim 1, characterized in that the generation of water by the system is increased in response to the accumulation by the working fluid of at least one of heat or water vapor from the first porous hygroscopic material.

3. The system according to claim 1, characterized in that the thermal desiccant unit further comprises a photovoltaic panel.

4. The system according to claim 3, characterized in that the working fluid accumulates heat from the photovoltaic panel as it flows from the CCQ7 Ln / Lznz / E / YILI - 33 working fluid inlet to the working fluid outlet.

5. The system according to claim 4, characterized in that the water generation by the system is increased in response to accumulation by the working fluid of heat from the photovoltaic panel.

6. The system according to claim 1, characterized in that the enthalpy transfer comprises transferring heat from the working fluid outlet of the thermal desiccant unit to the working fluid inlet of the thermal desiccant unit.

7. The system according to claim 1, characterized in that the enthalpy transfer comprises transferring moisture from the working fluid outlet of the condenser to the working fluid inlet of the condenser.

8. The system according to claim 1, characterized in that at least one enthalpy exchange unit transfers at least one sensible heat or latent heat.

9. The system according to claim 1, characterized in that at least one enthalpy exchange unit transfers enthalpy by means of at least one of a passive enthalpy exchange mechanism or an active enthalpy exchange mechanism.

10. The system according to claim 1, characterized in that the first porous hygroscopic material comprises at least one of a light-absorbing hygroscopic material or a light-activated hygroscopic material.

11. The system according to claim 1, characterized in that it further comprises: an auxiliary desiccant unit comprising a second porous hygroscopic material that can be moved between an adsorption zone and a desorption zone of the auxiliary desiccant unit; and a process gas flowing through the second porous hygroscopic material in the adsorption zone of the auxiliary desiccant unit, wherein, in the adsorption zone, the second porous hygroscopic material captures water vapor from the process gas, and wherein, in the desorption zone, the second porous hygroscopic material releases water vapor to the working fluid downstream of the thermal desiccant unit and ahead of the condenser.

12. The system according to claim 11, characterized in that in the desorption zone, the second porous hygroscopic material releases water to the outlet of the working fluid of the thermal desiccant unit in advance of at least one enthalpy exchange unit and the condenser.

13. The system according to claim 11, characterized in that the first porous hygroscopic material and the second porous hygroscopic material are different hygroscopic materials.

14. The system according to claim 13, characterized in that the first porous hygroscopic material has a higher water absorption capacity than the second porous hygroscopic material.

15. The system according to claim 11, characterized in that it further comprises a fan configured to adjust a flow rate of the process gas through the second porous hygroscopic material in the adsorption zone of the auxiliary desiccant unit.

16. The system according to claim 11, characterized in that it further comprises a microcontroller configured to maximize the liquid water production rate of the condenser by varying at least one of an exchange rate of at least one enthalpy exchange unit, a flow rate of the working fluid, or the movement rate of the second porous hygroscopic material between the adsorption zone and the desorption zone of the auxiliary desiccant unit.

17. The system according to claim 16, characterized in that the movement rate of the second porous hygroscopic material between the adsorption zone and the desorption zone of the auxiliary desiccant unit is based on at least one of the following: ambient solar fluctuation, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, working fluid flow rate, exchange rate of at least one enthalpy exchange unit, quantity of water present in the first porous hygroscopic material, or elapsed time.

18. The system according to claim 1, characterized in that it further comprises a fan configured to adjust the flow rate of the working fluid.

19. The system according to claim 1, characterized in that it further comprises a fan configured to adjust a flow rate of a process gas flow through the condenser so as to remove heat from the condenser.

20. The system according to claim 1, characterized in that it further comprises a microcontroller configured to maximize a liquid water production rate from the condenser by varying at least one of an exchange rate of at least one enthalpy exchange unit or a flow rate of the working fluid.

21. The system according to claim 20, characterized in that the exchange rate of at least one enthalpy exchange unit is varied based on at least one of the following: ambient solar fluctuation, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, amount of water present in the first porous hygroscopic material, elapsed time, user selection, or predetermined program.

22. The system according to claim 20, characterized in that the flow rate of the working fluid is varied based on at least one of an ambient solar fluctuation, an ambient temperature, an ambient relative humidity, a temperature of the working fluid, a relative humidity of the working fluid, an amount of water present in the first porous hygroscopic material, or an elapsed time.

23. The system according to claim 1, characterized in that the thermal desiccant unit further comprises a transparent cover layer that allows solar radiation to pass through it, the transparent cover layer being placed above a layer comprising the first porous hygroscopic material.

24. The system according to claim 23, characterized CCQ7 Ln / Lznz / E / YILI - 36 in that it further comprises: one or more interstitial layers between the transparent cover layer and the layer comprising the first porous hygroscopic material, wherein the working fluid flows along one or more interstitial layers and then through the layer comprising the first porous hygroscopic material such that the working fluid collects heat from one or more interstitial layers beneath the transparent cover layer and collects water vapor and heat from the first porous hygroscopic material.

25. The system according to claim 1, characterized in that it further comprises: a batch desiccant unit comprising a batch hygroscopic material placed between a batch desiccant inlet and a batch desiccant outlet, wherein the batch hygroscopic material captures water vapor from the working fluid upstream of the inlet to the thermal desiccant unit.

26. The system according to claim 1, characterized in that at least one enthalpy exchange unit comprises: a first enthalpy exchange unit configured to transfer enthalpy between the working fluid outlet directly from the thermal desiccant unit and the working fluid inlet directly to the thermal desiccant unit; and a second enthalpy exchange unit configured to transfer enthalpy between the working fluid outlet directly from the condenser and the working fluid inlet directly to the condenser, wherein the first enthalpy exchange unit and the second enthalpy exchange unit have different enthalpy exchange characteristics resulting in a difference in the amount of sensible or latent heat transferred.

27. The system according to claim 26, characterized in that the first enthalpy exchange unit and the second enthalpy exchange unit comprise different hygroscopic materials.

28. The system according to claim 26, characterized in that the first enthalpy exchange unit transfers a greater amount of sensible heat CCQ7 Ln / Lznz / E / YILI - 37 than the second enthalpy exchange unit, or the second enthalpy exchange unit transfers a greater amount of latent heat than the first enthalpy exchange unit.

29. A method for extracting liquid water from a process gas, characterized in that it comprises: flowing a process gas through a thermal desiccant unit comprising a first porous hygroscopic material during a loading time, wherein the first porous hygroscopic material captures water vapor from the process gas during the loading time; transitioning from the loading time to a release time; flowing a working fluid through the thermal desiccant unit comprising the first porous hygroscopic material during a release time, wherein the working fluid accumulates heat and water vapor while flowing through the thermal desiccant unit during the release time; and transferring, by the enthalpy exchange unit, heat from the working fluid outlet of the thermal desiccant unit to the working fluid inlet of the thermal desiccant unit during the release time.Condense, by means of a condenser, water vapor from the working fluid into liquid water during the release time; transfer, by means of the enthalpy exchange unit, water vapor from the working fluid outlet of the condenser to the working fluid inlet of the condenser during the release time.

30. The method according to claim 29, characterized in that the method further comprises: monitoring one or more environmental conditions; and performing a transition between the loading time and the release time based on one or more environmental conditions.

31. The method according to claim 29, characterized in that the method further comprises maximizing the liquid water production rate of the condenser by varying at least one of an exchange rate of the CCQ7 Ln / Lznz / E / YILI - 38 enthalpy exchange unit or a flow rate of the working fluid.

32. The method according to claim 29, characterized in that it further comprises maximizing a liquid water production rate based on at least one of the following: ambient solar fluctuation, ambient temperature, ambient relative humidity, working fluid temperature, working fluid relative humidity, quantity of water present in the first porous hygroscopic material, elapsed time, user selection, or predetermined program.

33. The method according to claim 29, characterized in that the method further comprises: moving a second porous hygroscopic material between an adsorption zone and a desorption zone of an auxiliary desiccant unit; and flowing a process gas through the second porous hygroscopic material in the adsorption zone of the auxiliary desiccant unit during the release time, wherein, in the adsorption zone, the second porous hygroscopic material captures water vapor from the process gas, and wherein, in the desorption zone, the second porous hygroscopic material releases water vapor to the working fluid.

34. The method according to claim 33, characterized in that the method further comprises varying at least one of an exchange rate of the enthalpy exchange unit, a flow rate of the working fluid, or the movement rate of the second porous hygroscopic material between the adsorption zone and the desorption zone of the auxiliary desiccant unit.

35. The method according to claim 29, characterized in that the method further comprises maximizing the liquid water production rate of the condenser by increasing the net fluctuation of water vapor in the working fluid to the condenser.

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