Patent Description:
Numerous devices and methods for obtaining potable water from atmospheric humidity have been considered; however, most concepts are less than attractive for various reasons, including: a need for external power, a high degree of complexity, a low liquid water production rate, a high inefficiency, impurities in produced water, a high system cost, and/or a need for a large tract of land.

Various systems and methods employ sorption media to adsorb water from air to generate usable water. Once the sorption media, or desiccant, is saturated with water, it must typically be regenerated by a temperature or pressure swing. For example, several systems employ desiccants to produce water from atmospheric humidity by operating in one mode during the day and then operating in a second mode at night (e.g., in a batch process). For example, <CIT>, <CIT>,<CIT>, and <CIT> disclose systems which operate via adsorption of water at night, desorption of water by day (e.g., via solar energy), and condensation, which typically requires energy from an external energy source. The disadvantages of such systems may include a high degree of complexity, a large size, a low liquid water production rate, high inefficiencies, high electrical power requirements for operation, and/or the like. Furthermore, many such systems require complex and energy-intensive components (e.g., compressors, components used in refrigeration cycles, and/or the like). Some such systems that operate in different day and night modes may produce <CIT>, <CIT> and <CIT> disclose background art.

This disclosure includes embodiments of systems and methods, such as, for example, for generating liquid water from air. The invention is defined in claims <NUM> and <NUM>.

In some embodiments, the controller is configured to optimize liquid water production over a diurnal cycle based, at least in part, on diurnal variations in measurements of one or more of: an ambient air temperature, ambient air relative humidity, and a level of solar insolation. In some embodiments, the housing is configured such that dimensions of the adsorption zone and the desorption zone are adjustable.

Some embodiments of the present systems further comprise: a temperature sensor configured to capture data indicative of an ambient air temperature.

Some embodiments of the present systems further comprise: a humidity sensor configured to capture data indicative of an ambient air relative humidity.

In some embodiments, the solar insolation sensor comprises a temperature sensor configured to capture data indicative of a temperature of regeneration fluid in the regeneration fluid path downstream of the thermal unit.

Some embodiments of the present systems further comprise: a temperature sensor configured to capture data indicative of a temperature of air in the process airflow path; where the controller is configured to optimize liquid water production based, at least in part, on the data captured by the temperature sensor.

Some embodiments of the present systems further comprise: a humidity sensor configured to capture data indicative of a relative humidity of air in the process airflow path; where the controller is configured to optimize liquid water production based, at least in part, on the data captured by the humidity sensor.

Some embodiments of the present systems further comprise: a humidity sensor configured to capture data indicative of a relative humidity of regeneration fluid in the regeneration fluid path; where the controller is configured to optimize liquid water production based, at least in part, on the data captured by the humidity sensor.

Some embodiments of the present systems further comprise: a flow sensor configured to capture data indicative of a flow rate of air through the process airflow path; where the controller is configured to optimize liquid water production based, at least in part, on the data captured by the flow sensor.

Some embodiments of the present systems further comprise: a flow sensor configured to capture data indicative of a flow rate of regeneration fluid through the regeneration fluid path; where the controller is configured to optimize liquid water production based, at least in part, on the data captured by the flow sensor.

In some embodiments of the present systems, the thermal unit is configured to absorb sunlight to provide at least a portion of the thermal energy to regeneration fluid in the regeneration fluid path. In some embodiments, the thermal unit comprises: a transparent layer configured to allow sunlight to enter the casing of the thermal unit; an absorber configured to absorb thermal energy from the sunlight and provide at least a portion of the absorbed thermal energy to regeneration fluid in the regeneration fluid path; and an insulator configured to insulate at least a portion of the casing.

In some embodiments of the present systems, the condenser is configured to transfer thermal energy from regeneration fluid in the regeneration fluid path downstream of the desiccant to air in the process airflow path upstream of the desiccant.

Some embodiments of the present systems further comprise: a water collection unit configured to receive the produced liquid water from the condenser. In some embodiments, the water collection unit comprises a filter. In some embodiments, the water collection unit comprises an ultraviolet (UV) light source. In some embodiments, the water collection unit comprises a receptacle configured to receive one or more additives for introduction to the produced liquid water. In some embodiments, the water collection unit has a footprint with a maximum transverse dimension less than or equal to <NUM> (<NUM> feet (ft)). In some embodiments, an area of the footprint is less than or equal to <NUM><NUM> (<NUM> square feet (ft<NUM>)). In some embodiments, the water collection unit can be contained within a cubic volume less than or equal to <NUM><NUM> (<NUM> cubic feet (ft<NUM>)).

Some embodiments of the present systems further comprise: a solar power unit configured to provide electrical power to the system. In some embodiments, the solar power unit comprises a solar panel. In some embodiments, the system is configured to operate without an external source of electrical power.

Some embodiments of the present systems further comprise: a purge airflow path configured to transfer thermal energy from a portion of the adsorption zone to a portion of the desorption zone. In some embodiments, the controller is configured to optimize liquid water production based, at least in part, on a temperature of air in the purge airflow path.

Some embodiments of the present systems further comprise: a recovery heat exchanger configured to transfer thermal energy from regeneration fluid in the regeneration fluid path downstream of the desiccant to regeneration fluid in the regeneration fluid path upstream of the desiccant.

Some embodiments of the present systems further comprise: a second desiccant configured to transfer water from regeneration fluid in the regeneration fluid path downstream of the condenser to regeneration fluid in the regeneration fluid path upstream the condenser.

In some embodiments of the present systems, the desiccant is disposed on a disk, the desiccant configured to move between the adsorption zone and the desorption zone as the disk is rotated.

Some embodiments of the present systems are configured such that a first portion of the desiccant can be disposed within the adsorption zone with a second portion of the desiccant simultaneously disposed within the desorption zone.

In some embodiments of the present systems, each of the housing, the thermal unit, and the condenser have a footprint with a maximum transverse dimension less than or equal to <NUM> (<NUM> feet (ft)).

Some embodiments of the present systems further comprise: a transceiver configured to receive and transmit information associated with operation of the system.

In some embodiments of the present systems, the regeneration fluid path comprises a closed-loop.

Some embodiments of the present methods further comprise: generating the look-up table by: performing a simulation of a system of any of claims <NUM>-<NUM> at each of a plurality of operational parameter sets, each operational parameter set including at least: an ambient air temperature, ambient air relative humidity, and a level of solar insolation; determining, for each of the plurality of operational parameter sets, at least an optimal rate of desiccant movement that optimizes liquid water production by the system; and storing each optimal rate of desiccant movement in the look-up table.

In some embodiments of the present methods, the controlling comprises optimizing liquid water production based, at least in part, on a temperature of regeneration fluid in the regeneration fluid path downstream of the thermal unit.

In some embodiments of the present methods, the controlling comprises optimizing liquid water production based, at least in part, on a temperature of air in the process airflow path.

In some embodiments of the present methods, the controlling comprises optimizing liquid water production based, at least in part, on a relative humidity of air in the process airflow path.

In some embodiments of the present methods, the controlling comprises optimizing liquid water production based, at least in part, on a relative humidity of regeneration fluid in the regeneration fluid path.

In some embodiments of the present methods, the controlling comprises controlling at least a speed of a blower to adjust a flow rate of air through the process airflow path to optimize liquid water production.

In some embodiments of the present methods, the controlling comprises controlling at least a speed of a circulator to adjust a flow rate of regeneration fluid through the regeneration fluid path to optimize liquid water production.

Some embodiments of the present methods further comprise: absorbing sunlight with the thermal unit to heat regeneration fluid in the regeneration fluid path.

Some embodiments of the present methods further comprise: communicating air in the process airflow path through the condenser to transfer thermal energy from regeneration fluid in the regeneration fluid path to air in the process airflow path.

Some embodiments of the present methods further comprise: collecting liquid water produced by the condenser.

Some embodiments of the present methods further comprise: filtering liquid water produced by the condenser.

Some embodiments of the present methods further comprise: dissolving additives into liquid water produced by the condenser.

Some embodiments of the present methods further comprise: transferring, with a second desiccant, water from regeneration fluid in the regeneration fluid path downstream of the condenser to regeneration fluid in the regeneration fluid path upstream of the condenser.

In some embodiments of the present methods, a flow rate of air in the process airflow path is at least <NUM> times a flow rate of regeneration fluid in the regeneration fluid path.

In some of the present embodiments, the desiccant wheel may also act as an enthalpy wheel that is configured to transfer (and in use transfers) heat from one path of the regeneration fluid to another.

As used in this disclosure, the terms "adsorption" and "absorption," and the like, may be interchangeable. While it is generally appreciated that absorption is a bulk phenomenon and adsorption is a surface-based phenomenon, the desiccants and/or sorption mediums of the present disclosure may capture water vapor by adsorption, absorption, or a combination thereof.

The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically. The terms "a" and "an" are defined as one or more unless this disclosure explicitly requires otherwise. The term "substantially" is defined as largely but not necessarily wholly what is specified (and includes what is specified; e.g., substantially <NUM> degrees includes <NUM> degrees and substantially parallel includes parallel), as understood by a person of ordinary skill in the art. In any disclosed embodiment, the terms "substantially" and "approximately" may be substituted with "within [a percentage] of" what is specified, where the percentage includes. <NUM>, <NUM>, <NUM>, and <NUM>%.

The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), "include" (and any form of include, such as "includes" and "including"), and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, an apparatus that "comprises," "has," "includes," or "contains" one or more elements possesses those one or more elements, but is not limited to possessing only those elements. Likewise, a method that "comprises," "has," "includes," or "contains" one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps.

Any embodiment of any of the apparatuses, systems, and methods can consist of or consist essentially of - rather than comprise/include/contain/have - any of the described steps, elements, and/or features. Thus, in any of the claims, the term "consisting of" or "consisting essentially of" can be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb.

The feature or features of one embodiment may be applied to other embodiments, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the embodiments.

Some details associated with the embodiments described above and others are described below.

The following drawings illustrate by way of example and not 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, as may non-identical reference numbers. Views in the figures are drawn to scale (unless otherwise noted), meaning the sizes of the depicted elements are accurate relative to each other for at least the embodiment in the view.

Referring now to the drawings, and more particularly to <FIG>, shown therein and designated by the reference numeral <NUM> is a first embodiment of the present systems for generating liquid water from air. In the embodiment shown, system <NUM> is configured to function responsive to diurnal variations. For example, as described in more detail below, system <NUM> is configured to control one or more operational parameters (e.g., control and/or controlled variables) based on one or more diurnal variations (e.g., variations in ambient air temperature, ambient air relative humidity, solar insolation, and/or the like).

Throughout the following description, illustrative views of example components which may be suitable for use in some of the systems described below (e.g., <NUM>, <NUM>) are provided in <FIG>, which collectively depict an embodiment <NUM> of the present systems. The views of system <NUM>, shown in <FIG>, are provided only by way of illustration, and not by way of limitation. In other words, <FIG> may be used to illustrate and/or provide additional description of certain components of systems <NUM> and/or <NUM>, but shall not be used to limit systems <NUM> and/or <NUM>.

In this embodiment, system <NUM> comprises a desiccant unit <NUM>. In the depicted embodiment, desiccant unit <NUM> comprises a desiccant (e.g., sorption medium) <NUM>, where the desiccant <NUM> (e.g., or a portion thereof) is selectively (e.g., and/or alternatively) movable between an adsorption zone <NUM>, in which the desiccant is in fluid communication with a process air pathway (e.g., a process airflow path) <NUM> and a desorption zone <NUM>, in which the desiccant is in fluid communication with a (e.g., closed-loop) regeneration fluid pathway (e.g., a regeneration fluid path) <NUM>. In some embodiments, the adsorption and desorption zones may be defined by a housing (e.g., <NUM>) of the desiccant unit.

In the embodiment shown, desiccant unit <NUM> operates in a continuous, or non-batch, fashion. As used in this disclosure, the term "continuous," or "non-batch," may be used to refer to a desiccant unit (e.g., <NUM>) configured to absorb water and desorb water substantially simultaneously or simultaneously. On the other hand, the terms "noncontinuous," or "batch," may be used to refer to a desiccant unit wherein absorption of water and desorption of water are essentially consecutive operations (e.g., such that water storage in the desiccant or storage medium for a significant period of time may be necessary to reach viable liquid water production rates). For example, in the depicted embodiment, system <NUM> is configured such that a first portion of desiccant <NUM> can be disposed within adsorption zone <NUM> (e.g., such that the first portion can capture water from process air in process air pathway <NUM>), with a second portion of the desiccant simultaneously disposed within the desorption zone (e.g., such that the second portion can desorb water into regeneration fluid in regeneration fluid pathway <NUM>). Regeneration fluids suitable for use in some embodiments of the present systems include, but are not limited to, air (e.g., including any suitable amount of water vapor), super-saturated or high relative humidity gas (e.g., <NUM>-<NUM>% relative humidity), glycols, ionic liquids, and/or the like.

As described above, in the embodiment shown, desiccant unit <NUM> may comprise a hygroscopic material (e.g., desiccant or sorption medium <NUM>) configured to continuously alternate between a process air pathway <NUM> and a regeneration fluid pathway <NUM>. In some embodiments, it may be desirable that the desiccant or sorption medium be capable of quickly desorbing water back into low relative humidity air (e.g., to regenerate the desiccant). Therefore, in some embodiments, the performance of the desiccant or sorption medium may be driven by an ability to quickly cycle through an absorption state and a desorption state.

Desiccants (e.g., <NUM>) of the present systems can comprise any suitable medium in any suitable configuration (e.g., such that the desiccant or sorption medium is capable of adsorption and desorption of water). The follow description of desiccants and sorption mediums is provided only by way of example. In some embodiments, the desiccant or sorption medium is capable of sorption at a first temperature and/or pressure and desorption at a second temperature and/or pressure. Suitable desiccants or sorption mediums may comprise liquids, solids, and/or combinations thereof. In some embodiments, desiccants or sorption mediums may comprise any suitable porous solid impregnated with hygroscopic materials. For example, in the embodiment shown, desiccant <NUM> may comprise one or more materials selected from the group consisting of: silica, silica gel, alumina, alumina gel, montmorillonite clay, zeolites, molecular sieves, 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 of thereof. In some embodiments, the desiccant or sorption medium may be selected and/or configured to avoid sorption of certain molecules (e.g., those molecules that may be poisonous when consumed by a human).

In some embodiments, desiccant particles may be packed in a shallow bed to maximize a surface area for interaction with air or fluid within adsorption zone <NUM> and desorption zone <NUM>. In some embodiments, the desiccant particles may be agglomerated via a binder. In some embodiments, the desiccant particles may be dyed black (e.g., to improve absorption of thermal radiation). In some embodiments, the desiccant particles may be mixed and/or combined with thermal radiation absorbing materials.

In the depicted embodiment, system <NUM> includes one or more blowers (e.g., <NUM>) and/or one or more circulators (e.g., <NUM>). For example, in this embodiment, blower <NUM> is disposed in process air pathway <NUM> and is configured to adjust a flow rate of air through the process air pathway. Circulator <NUM>, in this embodiment, is disposed in regeneration fluid pathway <NUM> and is configured to adjust a flow rate of fluid through the regeneration fluid pathway. In some embodiments, blower <NUM> and/or circulator <NUM> may be controlled by controller <NUM> (e.g., controlling a speed of blower <NUM> and/or circulator <NUM> to optimize liquid water production). In some embodiments, blower <NUM> and/or circulator <NUM> may be configured to substantially maintain a pre-determined flow rate through process air pathway <NUM> and/or regeneration fluid pathway <NUM>, respectively.

In the embodiment shown, system <NUM> comprises a thermal unit <NUM> configured to provide thermal energy to fluid in regeneration fluid pathway <NUM> (e.g., such that desiccant <NUM> may be regenerated). In this embodiment, thermal unit <NUM> is a solar thermal unit (e.g., is configured to convert solar insolation to thermal energy). While the present systems may comprise any suitable thermal unit, whether solar or otherwise, the following description of thermal unit <NUM> is provided by way of example.

In the embodiment shown, thermal unit <NUM> comprises a transparent layer <NUM> configured to allow sunlight to enter casing <NUM> of the thermal unit (e.g., a sheet of transparent material, a lens, and/or the like, whether comprising glass, polymers, polycrystalline materials, derivatives thereof, combinations thereof, and/or the like). In embodiments comprising a glass transparent layer <NUM>, the glass may be configured to maximize transmissivity (e.g., low-iron and/or no-iron materials, and/or other compositions, uncoated materials, and/or the like). Transparent layers of the present systems may be comprised of multiple layers (e.g., multi-pane layers, such as, for example, double-paned glass).

In this embodiment, thermal unit <NUM> comprises an absorber <NUM> configured to absorb thermal energy from the sunlight and provide at least a portion of the absorbed thermal energy to fluid in the regeneration fluid pathway (e.g., absorber <NUM> comprises a thermally permeable material). Absorbers of the present disclosure can comprise any suitable material, such as, for example, metals (e.g. aluminum, copper, steel), thermally stable polymers, or other material, and/or the like. Absorbers may be substantially flat, roughened, channeled or for example, corrugated as depicted in <FIG>. In some embodiments, a matte black coating or selective film may be applied to the surface of the absorber material. In the embodiment shown, absorber <NUM> is configured to transfer thermal energy to fluid in the regeneration fluid pathway without an intervening heat transfer fluid; however, in other embodiments, a fluid (e.g., liquid, gas, and/or the like) may be thermally disposed between the absorber and fluid in the regeneration fluid pathway (e.g., to function as a medium to transfer heat between the absorber and fluid in the regeneration fluid pathway).

In the depicted embodiment, thermal unit <NUM> comprises an insulator <NUM> configured to insulate at least a portion of casing <NUM>. In this way, solar insolation may enter the casing of thermal unit <NUM> (e.g., through transparent layer <NUM>), and insulator <NUM> may insulate a portion of the casing to, for example, minimize thermal energy losses to an environment outside of the thermal unit. Insulator(s) of the present system may be comprised of any suitable material (e.g., a material capable of resisting the flow of thermal energy), such as, for example, a solid foam comprising trapped pockets of gas and/or liquid. In some embodiments, insulators be selected and/or configured for stability at high temperatures (e.g., temperatures exceeding <NUM>° C).

In the embodiment shown, one or more channels <NUM> may be disposed in thermal communication with absorber <NUM> such that the absorber may transfer absorbed thermal energy to fluid (e.g., regeneration fluid, a flowable heat carrier medium, and/or the like) within the one or more channels. In this embodiment, one or more channels <NUM> form part of regeneration fluid pathway <NUM> (e.g., one or more channels <NUM> are configured to convey regeneration fluid). One or more channels <NUM> of the present systems may comprise any suitable structure, such as, for example, tubular hollow bodies or a plurality of flat plates adapted for fluid flow therebetween, and/or the like.

In this embodiment, system <NUM> comprises a condenser <NUM> configured to receive fluid from the desorption zone via the regeneration fluid pathway and produce liquid water from the received fluid (e.g., by condensing water vapor in fluid in the regeneration fluid pathway). Condensers of the present disclosure may comprise any suitable material and comprise any suitable configuration (e.g., to condense water vapor in regeneration fluid into liquid water). For example, suitable condensers may comprise polymers, metals, and/or the like. For further example, suitable condensers may comprise coils, fins, plates, tortuous passages (as depicted in the example of <FIG>), and/or the like. In the embodiment shown, condenser <NUM> is configured to transfer thermal energy from fluid in regeneration fluid pathway <NUM> downstream of desiccant <NUM> to air in process air pathway <NUM> upstream of desiccant <NUM> (e.g., such that air in process air pathway <NUM> may facilitate cooling of condenser <NUM>). In some embodiments, condenser <NUM> may be cooled by ambient air.

In the depicted embodiment, system <NUM> comprises a water collection unit <NUM> configured to receive liquid water produced by condenser <NUM>. In this embodiment, liquid water produced by the condenser is provided to water collection unit <NUM> by way of gravity; however, in other embodiment, flow of liquid water from the condenser to the water collection unit may be assisted (e.g., by one or more pumps, any other suitable delivery mechanism, and/or the like).

In some embodiments, system <NUM> comprises a filter <NUM> (e.g., a filtration membrane), which, in some embodiments, may be positioned between condenser <NUM> and water collection unit <NUM> (e.g., to reduce an amount of impurities, such as, for example, sand, bacteria, fibrous, carbonaceous species, and/or the like, which may be present in liquid water produced by condenser <NUM>).

In some embodiments, water collection unit <NUM> (e.g., or filter <NUM> thereof) may comprise an ultraviolet (UV) light source (e.g., for disinfection of water produced by condenser <NUM>). In some embodiments, suitable light sources may comprise light emitting diodes (LEDs) having, for example: wavelengths below <NUM> nanometers (nm) (e.g., <NUM>, <NUM>, and/or the like), wavelengths below <NUM> (e.g., <NUM>), and/or the like.

In some embodiments, a water collection unit (e.g., <NUM>) may comprise one or more water level sensors (e.g., 122e). Such water level sensors may comprise conductance sensors (e.g., open and/or closed circuit resistance-type conductance sensors), which may operate via conductivity measurement of water in the range of <NUM> msiemens per cm.

In the embodiment shown, water collection unit <NUM> comprises a receptacle <NUM> configured to receive one or more additives for introduction to the produced liquid water. Such additives may be configured to dissolve slowly into liquid water stored in the water collection unit. Additives suitable for use in the present systems include, but are not limited to, minerals, salts, other compounds, and/or the like. In some embodiments, additives may impart flavor to the produced liquid water. To illustrate, such additives may be selected from the group consisting of: potassium salts, magnesium salts, calcium salts, fluoride salts, carbonate salts, iron salts, chloride salts, silica, limestone, and/or combinations thereof.

In some embodiments, the present systems may comprise indicators (e.g., lights, such as, for example, LEDs), which may be configured to provide information regarding system operation. For example, in some embodiments, indicator lights may be configured to provide information (e.g., visually, for example, to a user) that the system is running, that solar power (e.g., from power unit <NUM>) is available, that an air filter (e.g., within process air pathway <NUM>) may need to be changed, that a water collection unit (e.g., <NUM>) is full (e.g., in some embodiments, that the water collection unit contains <NUM> of liquid water), that an actuator (e.g., actuator <NUM>, blower <NUM>, circulator <NUM>, and/or the like) has failed and/or is failing, that telematics errors (e.g., as indicated by transceiver <NUM> operation) have and/or are occurring, and/or the like. As will be described below, any suitable information (including the information described above with reference to indicators), may be transmitted over a communications network (e.g., alone and/or in addition to operation of any indicators).

In this embodiment, a controller (e.g., processor) <NUM> controls exposure of desiccant <NUM> (or a portion thereof) to air in process air pathway <NUM> and regeneration fluid in regeneration fluid pathway <NUM> (e.g., to increase and/or optimize the liquid water ultimately produced by condenser <NUM>), and such control may vary over a diurnal cycle (e.g., in response to diurnal variations). Such variations in environmental conditions (e.g., inputs into controller <NUM>) can include, for example, ambient air temperature, ambient air relative humidity, and solar insolation. Other inputs to controller <NUM> can include, for example, an amount of thermal energy generated by thermal unit <NUM>, a relative humidity of air in process air pathway <NUM>, a relative humidity of fluid in regeneration fluid pathway <NUM>, a temperature of fluid in the regeneration fluid pathway between desiccant <NUM> and thermal unit <NUM>, a rate of water production, and/or the like. In embodiments that include a purge airflow path (e.g., <NUM>), inputs to controller <NUM> may include a flow rate, temperature, relative humidity and/or the like of air in the purge airflow path. In the embodiment shown, controller <NUM> is configured to optimize liquid water production by controlling a rate of desiccant <NUM> movement between the adsorption zone and the desorption zone, controlling a speed of blower <NUM> and/or circulator <NUM>, and/or the like, based, on measurements of one or more of such inputs (e.g., such that controller <NUM> may optimize liquid water production based on current environmental and system conditions). As described in more detail below, inputs to controller <NUM> may be measured in that they are indicated in data captured by one or more sensors (e.g., <NUM>).

<FIG> is a diagram of an embodiment <NUM> of the present systems for generating liquid water from air. System <NUM> may be substantially similar to system <NUM>, with the primary differences and/or additions described below. Otherwise, system <NUM> may comprise any and/or all features described with respect to system <NUM>.

In system <NUM>, as with system <NUM>, desiccant <NUM> (or a first portion thereof) can be in fluid communication with process air in process air pathway <NUM> while the desiccant <NUM> (or a second portion thereof) is simultaneously in fluid communication with regeneration fluid in regeneration fluid pathway <NUM>, and, thus, desiccant unit <NUM> operates in a continuous and non-batch manner. In this embodiment, sections of desiccant <NUM> are each exposed to air in process air pathway <NUM> and fluid in regeneration fluid pathway <NUM> in an alternating manner.

In the embodiment shown, system <NUM> comprises a rotatable disk <NUM> (e.g., with desiccant <NUM> disposed thereon). In this embodiment, desiccant <NUM> (or sections thereof) are configured to move between the adsorption zone and the desorption zone as disk <NUM> is rotated. For example, in the embodiment shown, in the depicted orientation of disk <NUM>, a portion <NUM> of the desiccant is in communication with process air pathway <NUM>, and a portion <NUM> of the disk is in communication with regeneration fluid pathway <NUM>. In the depicted embodiment, system <NUM> comprises an actuator (e.g., electrical motor) <NUM> configured to cause rotation of disk <NUM>. In this embodiment, controller <NUM> is configured to optimize liquid water production at least by controlling movement (e.g., through control of actuator <NUM>) of desiccant <NUM> (e.g., disk <NUM>) between the adsorption zone and the desorption zone; however, in other embodiments, motor <NUM> may rotate disk <NUM> at a predetermined rotation rate.

In the embodiment shown, system <NUM> comprises a solar power unit <NUM> configured to provide power to at least a portion of system <NUM> (e.g., blower <NUM>, circulator <NUM>, actuator <NUM>, and/or the like). In this embodiment, solar power unit <NUM> is configured to convert solar insolation to electrical power (e.g., solar power unit <NUM> comprises a solar panel). For example, in the depicted embodiment, solar power unit <NUM> may be provided as a photovoltaic solar panel comprising semiconducting materials exhibiting a photovoltaic effect. In these and similar embodiments, controller <NUM> may be configured to control system <NUM> in response to diurnal variations in solar insolation (e.g., an amount of electrical power generated by solar power unit <NUM>).

In some embodiments, the present systems for generating liquid water from air may be modular in nature. For example, the present systems may be configured such that each component (e.g. solar power unit <NUM>, thermal unit <NUM>, desiccant unit <NUM>, condenser <NUM>, water collection unit <NUM>, and/or the like) may be separated from one another, transported, assembled and/or re-assembled with one another (e.g., in a same or a different configuration), and/or the like in a relatively simple manner (e.g., some embodiments of the present systems and components thereof are modular in nature). For example, in some embodiments, the system is configured such that no dimension of any singular component (e.g., water collection unit <NUM>, desiccant unit <NUM>, solar power unit <NUM>, thermal unit <NUM>, condenser <NUM>, and/or the like) is larger than <NUM> to <NUM> (six to eight feet) (e.g., to facilitate transport of the system or components thereof, for example, in a single cab truck bed, such as a bed of a Toyota Hilux pickup truck) (e.g., each component has a footprint that is less than or equal to <NUM><NUM> (<NUM> square feet (ft<NUM>)) and/or each component can be contained within a cubic volume less than or equal to <NUM><NUM> (<NUM> cubic feet (ft<NUM>)).

In the embodiment shown, controller <NUM> is configured to control one or more of blower <NUM>, circulator <NUM>, actuator <NUM>, and/or the like (e.g., to optimize liquid water production, where such control may be in response to diurnal variations, for example, in ambient temperature, ambient air relative humidity, solar insolation, and/or the like). For example, controller <NUM> may be configured to increase a rate of liquid water production by controlling blower <NUM>, circulator <NUM>, actuator <NUM>, and/or the like, taking into account, for example, diurnal variations. To illustrate, such variations may change the amount of thermal energy generated by thermal unit <NUM>, the level of electrical power provided by solar power unit <NUM>, the level of humidity in process air entering the system, and/or the like. In some embodiments, ambient conditions can be measured in real-time or can be forecast based on, for example, historical averages and/or the like. In embodiments in which controller <NUM> receives real-time measurements, various sensors (described in more detail below) may provide data indicative of ambient conditions to controller <NUM> (e.g., continuously, periodically, when requested by controller <NUM>, and/or the like).

In this embodiment, controller <NUM> may operate the system based on one or more of: a user selection, data received from one or more sensors, programmatic control, and/or by any other suitable means. In the depicted embodiment, for example, controller <NUM> may be associated with peripheral devices (including sensors) for sensing data information, data collection components for storing data information, and/or communication components for communicating data information relating to the operation of the system.

In the depicted embodiment, system <NUM> comprises one or more peripheral devices, such as sensors <NUM> (e.g., temperature sensors 122a, humidity sensors 122b, solar insolation sensor 122c, flow rate sensors 122d, water level sensors 122e, and/or the like). In some embodiments, one or more sensors (e.g., <NUM>) may provide data indicative of ambient air temperature, ambient air relative humidity, solar insolation, process air temperature, regeneration fluid temperature, process air relative humidity, regeneration fluid relative humidity, process air flow rate, regeneration fluid flow rate, liquid water production rate, water usage rate, and/or the like.

In some embodiments, one or more sensors <NUM> may be located remotely from other components of the system, and may provide captured data to the other components of the system via a wired and/or wireless connection. For example, a town, village, city, and/or the like may include a plurality of the present systems, and one of the plurality of the present systems may provide data indicative of ambient environmental conditions (e.g., air temperature, air relative humidity, a solar insolation level, and/or the like) to another one of the plurality of the present systems. In this way, in some embodiments, a single sensor <NUM> may be shared by multiple systems. In some embodiments, data communicated to a controller (e.g., <NUM>) by one or more peripheral devices (e.g., one or more sensors <NUM>) may be stored in a data logging unit.

In the embodiment shown, system <NUM> comprises a telematics unit (e.g., a transmitter, receiver, transponder, transverter, repeater, transceiver, and/or the like, sometimes referred to herein as "transceiver <NUM>"). For example, in this embodiment, a transceiver <NUM> is configured to communicate data to and/or from the system (e.g., controller <NUM>) via a wired and/or wireless interface (e.g., which may conform to standardized communications protocols, such as, for example, GSM, SMS components operating at relatively low rates (e.g., operating every few minutes), protocols that may be geographically specified, and/or the like).

In some embodiments, a transceiver (e.g., <NUM>) may be associated with a server and a communications network for communicating information between the server and the transceiver (e.g., and thus the system and/or a controller <NUM> thereof). By way of illustration, such two-way communication may be facilitated by a cellular tower in cellular range of the system. In some embodiments, a database (e.g., which may be remote from the system) may be configured to store information received from the server over the communications network.

In embodiments with telematics capability, a network administrator or device owner may send a command to a controller (e.g., <NUM>) to update or delete look-up table data (described below) and/or a control algorithm. In this way, data security may be maintained, for example, in the case that the system is stolen or otherwise lost.

In the embodiment shown, controller <NUM> is configured to vary operation of system <NUM> at least based on real-time and/or forecast variations in ambient conditions. For example, controller <NUM> can control exposure of desiccant <NUM> (e.g., or sections thereof) to process air and regeneration fluid in response to changes in ambient conditions (e.g., by changing the rotational speed of disk <NUM>, such that the time that a portion of desiccant <NUM> disposed thereon is exposed to process air in process air pathway <NUM> or regeneration fluid in regeneration fluid pathway <NUM> may be increased or decreased). In some embodiments, a controller (e.g., <NUM>) may be configured to vary a size of an adsorption zone or a desorption zone (e.g., in response to diurnal variations).

<FIG> is a graph of diurnal variations in environmental conditions over one day, including ambient air relative humidity ("RH") and temperature. <FIG> is a graph of diurnal variations in environmental conditions over one day, including solar radiation (e.g., solar insolation). In general and as shown, during nighttime hours, ambient air relative humidity is relatively high and ambient temperature is relatively low. As the sun rises, solar insolation generally increases (e.g., peaking around noon), which may result in a decrease in ambient air relative humidity and an increase in ambient temperature. At a certain point during the day, ambient air relative humidity may reach a minimum, and, at a certain point during the day, ambient temperature may increase to a maximum, and these points may generally coincide. Finally, as the sun begins to set, ambient air relative humidity may tend to increase, and ambient temperature may tend to decrease (e.g., as solar insolation approaches its minimum during nighttime hours).

As shown, a particular set of environmental conditions may exist at each point in a diurnal cycle (e.g., ambient air relative humidity, ambient temperature, solar insolation, and/or the like). Some embodiments of the present systems are configured to vary operational parameters (e.g., control variables) of the system, taking into account variations in these environmental conditions, thus optimizing system performance (e.g., liquid water production) for each point of the diurnal cycle. By way of illustration, in the early part of a day, solar insolation may be relatively limited. Thus, in some embodiments, the system (e.g., or a controller <NUM> thereof) may adjust operational parameters to account for a relatively low amount of available solar thermal energy and/or a relatively low amount of electrical power available from solar power units, despite the relative high ambient air relative humidity. For example, in these circumstances, a controller may cause a desiccant to move more slowly between an adsorption zone and a desorption zone due to the relatively low amount of thermal energy and/or solar power available, despite the relatively high levels of ambient air relative humidity in available process air. On the other hand, later in the day, the controller may adjust operational parameters to account for a relatively low amount of ambient air relative humidity, despite a relatively high amount of available solar thermal energy and/or a relatively high amount of electrical power available from solar power units (e.g., due to a relatively high amount of solar insolation). Controllers of the present disclosure can make such adjustments to operational parameters periodically and/or continuously.

<FIG> is a diagram illustrating exemplary flow paths through some embodiments of the present systems for generating liquid water from air. Embodiments of the present systems for generating liquid water from air can comprise any suitable flow path (e.g., process air pathway and/or regeneration fluid pathway), including, for example, those described below (e.g., whether alone and/or in combination), which are provided merely by way of example.

In some embodiments, air within the process air pathway may enter the system from an outside environment, communicate with sections A, B, C, E, and F of a desiccant (e.g., <NUM>) (e.g., such that the desiccant or sections thereof may absorb water from the air in the process air pathway), pass through a condenser (e.g., <NUM>) (e.g., where air in the process air pathway may be heated by thermal energy from fluid in the regeneration fluid pathway), and be exhausted to the outside environment. In these and similar embodiments, regeneration fluid may pass through a condenser (e.g., <NUM>) (e.g., where fluid in the regeneration fluid pathway may transfer thermal energy to air in the process air pathway), pass through a thermal unit (e.g., <NUM>) (e.g., where fluid in the regeneration fluid pathway may be heated), communicate with section D of a desiccant (e.g., <NUM>) (e.g., such that the desiccant or sections thereof may release water to fluid in the regeneration fluid pathway), and flow back through the condenser (e.g., such that the condenser may produce liquid water from fluid in the regeneration fluid pathway).

In some embodiments, the present systems may include a purge airflow path <NUM> configured to transfer thermal energy from regeneration fluid in a regeneration fluid pathway downstream of a desiccant (e.g., <NUM>) to fluid in the regeneration fluid pathway upstream of the condenser. For example, in these and similar embodiments, process air may enter the system from an outside environment, communicate with sections A, B, and F of a desiccant (e.g., <NUM>), pass through a condenser (e.g., <NUM>), and be exhausted to the outside environment. In these and similar embodiments, regeneration fluid may pass through a condenser (e.g., <NUM>), pass through a thermal unit (e.g., <NUM>), communicate with section D of a desiccant (e.g., <NUM>), and flow back through the condenser. In these and similar embodiments, air in a purge airflow path <NUM> may communicate between section E of a desiccant (e.g., <NUM>) and section D of the desiccant (e.g., to transfer heat from section D of the desiccant, which may be provided to section D of the desiccant by regeneration fluid within the regeneration fluid pathway flowing from a thermal unit (e.g., <NUM>) to section E of the desiccant) (e.g., to perform a preheating operation before section E of the desiccant moves into a desorption zone).

Some embodiments of the present systems comprise a recovery heat exchanger <NUM> configured to transfer thermal energy from regeneration fluid in a regeneration fluid pathway downstream of a desiccant (e.g., <NUM>) to fluid in the regeneration fluid pathway upstream of the condenser. For example, in these and similar embodiments, process air may enter the system from an outside environment, communicate with sections A, B, C, E, and F of a desiccant (e.g., <NUM>), pass through a condenser (e.g., <NUM>), and be exhausted to the outside environment. In these and similar embodiments, regeneration fluid may pass through a condenser (e.g., <NUM>), pass through a heat exchanger (e.g., such that the heat exchanger may transfer thermal energy from fluid in the regeneration fluid pathway downstream of the desiccant to fluid in the regeneration fluid pathway upstream of the condenser), pass through a thermal unit (e.g., <NUM>), communicate with section D of the desiccant, flow back through the heat exchanger, and flow back through the condenser. In this way, thermal energy that may otherwise be lost to the environment through the condenser may be at least partially recovered to be used for desorption purposes.

Some embodiments of the present systems comprise a second desiccant <NUM> (e.g., which may be disposed on a disk, similarly to as described above for desiccant <NUM>) configured to transfer water from fluid in the regeneration fluid pathway downstream of a condenser (e.g., <NUM>) to fluid in the regeneration fluid pathway upstream of the condenser, and may also transfer heat from one path of the regeneration fluid to another. For example, in these and similar embodiments, process air may enter the system from an outside environment, communicate with sections A, B, C, E, and F of a desiccant (e.g., <NUM>), pass through a condenser (e.g., <NUM>), and be exhausted to the outside environment. In these and similar embodiments, regeneration fluid may pass through a condenser (e.g., <NUM>), communicate with section L of a second desiccant (e.g., <NUM>) (e.g., such that desiccant <NUM> may capture water in fluid in the regeneration fluid pathway before the fluid in the regeneration fluid pathway enters thermal unit <NUM>), pass through a thermal unit (e.g., <NUM>), communicate with section D of the desiccant, communicate with section K of the second desiccant (e.g., such that desiccant <NUM> may release water to fluid in the regeneration fluid pathway before fluid in the regeneration fluid pathway enters condenser <NUM>), and flow back through the condenser.

Some embodiments may achieve at least some of the functionality described above for a regeneration fluid pathway in communication with a second desiccant (e.g., <NUM>), without requiring a second desiccant. For example, in some embodiments, process air may enter the system from an outside environment, communicate with sections A, E, and F, of a desiccant (e.g., <NUM>), pass through a condenser (e.g., <NUM>), and be exhausted to the outside environment. In these and similar embodiments, regeneration fluid may pass through a condenser (e.g., <NUM>), communicate with section C of a desiccant (e.g., <NUM>), pass through a thermal unit (e.g., <NUM>), communicate with section D of the desiccant, communicate with section B of the desiccant, and flow back through the condenser.

In some embodiments, process air may enter the system from an outside environment, communicate with section A, E, and F of a desiccant (e.g., <NUM>), pass through a condenser (e.g., <NUM>), and be exhausted to an outside environment. In these and similar embodiments, regeneration fluid may pass through a condenser (e.g., <NUM>), communicate with section C of a desiccant (e.g., <NUM>), pass through a thermal unit (e.g., <NUM>), communicate with section D of the desiccant, and flow back through the condenser. Such embodiments may achieve at least some of the benefits of embodiments having a recovery heat exchanger (e.g., <NUM>) or a purge airflow path (e.g., <NUM>).

In some embodiments, process air may enter the system from an outside environment, communicate with sections A, B, E, and F of a desiccant (e.g., <NUM>), pass through a condenser (e.g., <NUM>), and be exhausted to an outside environment. In these and similar embodiments, regeneration fluid may pass through a condenser (e.g., <NUM>), flow through a recovery heat exchanger (e.g., <NUM>), communicate with section C of a desiccant (e.g., <NUM>), pass through a thermal unit (e.g., <NUM>), communicate with section D of the desiccant, flow back through the recovery heat exchanger, and flow back through the condenser.

In some embodiments of the present systems (e.g., <NUM>, <NUM>, and/or the like), production rate of liquid water (H<NUM>Orate) may be expressed, at least in part, as a function of environmental conditions (e.g., ambient air temperature (Tamb), ambient air relative humidity (RHamb), and solar insolation (Qsolar)), as well as system operating parameters (e.g., control variables) (e.g., process air flow rate (Vprocess), regeneration fluid flow rate (Vregen), and exposure time of a desiccant to process air and regeneration fluid (e.g., which, for a desiccant disposed on a rotatable disk, may be a function of a rotation rate of the rotatable disk (ωdisk)) (Eq. <NUM>).

Efficiency of some embodiments of the present systems may be expressed in a variety of ways. The following examples are provided only by way of illustration, and each of the following examples may be used alone or in combination with other expressions (whether or not explicitly disclosed below) to describe an efficiency of some embodiments of the present systems. For example, efficiency may be defined as: <MAT>
where η represents efficiency, ΔHvap,H<NUM>O represents the heat of vaporization of water, mliquid H<NUM>O,produced represents a mass of liquid water produced, and Qtotal represents the heat energy required by the system to produce the mass of liquid water. From Eq. <NUM>, it can be seen that an efficiency of <NUM>% equates to <NUM> joules (J) of heat energy required to produce <NUM> gram (g) of liquid water.

In some embodiments, efficiency may be defined as regeneration efficiency, or, for example: <MAT>
where mH<NUM>O,recirculating represents a total mass of water present in the regeneration fluid pathway. As seen in Eq. <NUM>, efficiency may generally improve as exit temperature of regeneration fluid from the condenser decreases.

In some embodiments, efficiency may be defined in terms of an effectiveness parameter (e.g., determined from psychrometric charts). Such an effectiveness parameter may be defined, for example, as the ratio of an actual amount of water adsorbed and/or desorbed by a desiccant to an idea isenthalpic path in the psychrometric chart. To illustrate, an effectiveness parameter may tend towards a value of unity (one), with higher gel carrying capacities, decreased disk rotation rates, lower disk heat capacity, and/or the like.

In some embodiments, efficiency may be defined as dehumidification effectiveness, or, for example: <MAT>
where mH<NUM>O,in represents a total mass of water present in air entering process air pathway <NUM>, and mH<NUM>O,out represents a total mass of water leaving process air pathway <NUM>.

As depicted in <FIG>, in some embodiments, a controller (e.g., <NUM>) may control the system operating parameters, based on one or more of the environmental conditions (e.g., which may be measured by and/or indicated in data captured by one or more sensors <NUM>) in order to optimize, for example, liquid water production. By way of illustration, in some embodiments, for each combination of particular environmental conditions corresponding to a given point in the diurnal cycle (e.g., <NUM>° C < Tamb < <NUM>° C; <NUM>% < RHamb <NUM>%; <NUM> watts per square meter (W/m<NUM>) < Qsolar < <NUM> W/m<NUM>), the controller may perform a simulation using a model of a system (e.g., <NUM>, <NUM>, and/or the like) to estimate the optimal system operating parameters (e.g., (ωdisk)optimum, (Vprocess)optimum, and (Vregen)optimum), that maximize and/or optimize liquid water production (e.g., as defined in Eq. <NUM>), where: <MAT> <MAT> <MAT>.

In some embodiments, a controller (e.g., <NUM>) may employ a control algorithm that incorporates design variables (e.g. disk <NUM> geometry, such as, for example, thickness, radius, and/or the like, thermal unit <NUM> geometry, and/or the like), and, in some embodiments, these design variables may be incorporated in the control algorithm along with environmental conditions (e.g. ambient air temperature, ambient air relative humidity, solar insolation, and/or the like).

As described above, in some embodiments, ambient air temperature and ambient air relative humidity may be measured directly with one or more sensors (e.g., <NUM>). In some embodiments, solar insolation may be measured indirectly (e.g., and continuously) by measuring a temperature of fluid in the regeneration fluid pathway between a thermal unit (e.g., <NUM>) and a desiccant (e.g., <NUM>) (e.g., at a known and controlled flow rate of regeneration fluid through the regeneration fluid pathway). In some embodiments, data captured by various sensor(s) may be transmitted to a controller (e.g., which may be in communication with a memory that stores a look-up table containing data generated during simulation runs) which then determines the optimum system operating parameters (e.g., process air flow rate, regeneration fluid flow rate, disk rotation rate, and/or the like).

In some embodiments, a numerical simulator may be used to create a look-up table of optimized operational parameters for the system. For example, in these embodiments, each run of the numerical simulator may take a single set of design specifications (e.g. disk kinetics, disk size, desiccant configuration, solar collector size, condenser geometry and performance, and/or the like), instantaneous and/or forecast ambient conditions (e.g. ambient air temperature, ambient air relative humidity, a level of solar insolation) and system operation variables (e.g., process air flow rate, regeneration fluid flow rate, desiccant exposure time to process air and/or regeneration fluid, and/or the like) to determine and/or estimate an optimized efficiency and/or liquid water production rate for the system (e.g., which optimized values may vary over a diurnal cycle).

<FIG> is a flow chart of a non-limiting example of simulation-based control suitable for use in some embodiments of the present systems. As shown, the system may be initialized at step <NUM> with one or more design inputs, control inputs, and/or controller variables. In this embodiment, design inputs can include one or more of system size, disk materials and/or dimensions, desiccant materials and/or dimensions, control inputs can include ambient air relative humidity (e.g., or a range thereof), ambient air temperature (e.g., or a range thereof), and a level of solar insolation (e.g., or a range thereof), and controller variables can include process air flow rate, regeneration fluid flow rate, desiccant rate of movement, and/or the like. In some embodiments, one or more of the steps of this example may be performed by a controller (e.g., <NUM>). In some embodiments, certain steps depicted in <FIG> may be omitted.

At step <NUM>, movement of a desiccant (e.g., <NUM>) can be simulated (e.g., by simulating rotation of disk <NUM> by a small amount, such as, for example, from <NUM>-<NUM>°). In this embodiment, at step <NUM>, simulated process air is passed over a simulated condenser (e.g., <NUM>). In the depicted embodiment, also at step <NUM>, process air temperature and process air relative humidity may be recalculated (e.g., using thermodynamic equations) after picking up thermal energy within the simulated condenser. At step <NUM>, in this embodiment, process air fluid communication with the desiccant may be simulated, and process air temperature and process air relative humidity may be recalculated based on the simulated interaction with the desiccant.

At step <NUM>, a simulation of regeneration fluid passing through a thermal unit (e.g., <NUM>) can be performed, where regeneration fluid temperature and regeneration fluid relative humidity may be recalculated (e.g., again, using thermodynamic equations). In the depicted embodiment, at step <NUM>, regeneration fluid fluid communication with the desiccant may be simulated, and the system may determine the regeneration fluid temperature and regeneration fluid relative humidity after the simulated interaction with the desiccant. In this embodiment, also at step <NUM>, the system may determine the temperature and water content of the desiccant (or a portion thereof). At step <NUM>, in the depicted embodiment, regeneration fluid passing through the condenser can be simulated, and the regeneration fluid temperature and the regeneration fluid relative humidity may be recalculated. In some embodiments, the amount of condensed water produced may also be calculated at step <NUM>. At step <NUM>, the systems of equations used to perform at least some of steps <NUM> through <NUM> can be evaluated to determine if a steady state solution has been reached. In this embodiment, if no steady state solution has been reached, the main loop may be repeated beginning at step <NUM>.

Once a steady state solution is reached, in the embodiment shown, the controller (e.g., <NUM>) may set the process air flow rate, the regeneration fluid flow rate, and the rate of movement of the desiccant (e.g., in a real system, for example, corresponding to the simulated system used to perform the steps of <FIG>) to optimize liquid water production and/or efficiency. The above steps are provided only by way of example, as, in some embodiments, the sequence of these steps may be changed. For example, in another embodiment, two separate process air pathways may exist such that in one of the process air pathways, process air passes through a condenser (e.g., <NUM>) and in the other of the process air pathways, process air passes through a desiccant (e.g., <NUM>), and the above steps may be modified accordingly.

In some embodiments, each run of the simulation depicted in <FIG> produces a single data point in the data look-up table (e.g., liquid water production rate and/or efficiency) as a function of the design inputs, control inputs, and/or control variables. Such a numerical simulation may be repeated many times (e.g. from <NUM> to <NUM>,<NUM> times or more) to produce a look-up table of liquid water production rates and/or efficiencies as a function of the relevant variables. Such a table may then be used by a controller (e.g., <NUM>) to operate a system (e. g, <NUM>, <NUM>, and/or the like), for example, by referencing optimal control variables (e.g., process air flow rate, regeneration fluid flow rate, desiccant movement rate, and/or the like) based upon known design inputs and/or measured control inputs (e.g., ambient air temperature, ambient air relative humidity, a level of solar insolation, and/or the like).

By way of example, Table <NUM>, below, provides optimized operating conditions (e.g., control variables) versus design inputs and control inputs for an embodiment of the present systems that includes a disk (e.g., <NUM>) having a silica desiccant disposed thereon.

To illustrate how a controller (e.g., <NUM>) may rely on a look-up table to operate a system (e.g., <NUM>, <NUM>, and/or the like) a series of graphs is provided with environmental conditions as independent variables, and efficiency or liquid water production rate and system operating parameters as the dependent variables (e.g., and values illustrated in the below graphs may be contained in a look-up table for reference by a controller).

For example, <FIG> is a graph illustrating an efficiency of some embodiments of the present systems for generating liquid air from water, at a constant process airflow rate of <NUM> cubic metres per minute (<NUM> (cfm)), versus ambient air temperature (°C) ("T1"), ambient air relative humidity ("RH1"), and solar insolation as indicated by heat (W) provided by a thermal unit, such that each point on the graph may represent a system efficiency at a point in a diurnal cycle.

<FIG> is a series of graphs illustrating an efficiency of some embodiments of the present systems for generating liquid air from water (e.g., highest efficiency represented as darkest gray), at constant ambient air relative humidities ("RH"), at a constant process airflow rate of <NUM> cubic metres per minute (<NUM> (cfm)), versus environmental diurnal variations, including ambient air temperature (°C) and solar insolation as indicated by heat (W) provided by a thermal unit, such that each point on each graph may represent a system efficiency at a point in a diurnal cycle.

<FIG> is a series of graphs illustrating a liquid water production rate in kilograms per hour (kg/hr) of some embodiments of the present systems for generating liquid water from air (e.g., highest liquid water production rate represented as darkest gray), at constant ambient air relative humidities ("RH"), at a constant process airflow rate of <NUM> cubic metres per minute (<NUM> (cfm)), versus environmental diurnal variations, including ambient air temperature (°C) and solar insolation as indicated by heat (W) provided by a thermal unit, such that each point on each graph may represent a system liquid water production rate at a point in a diurnal cycle (e.g., in Amman, Jordan, on a day in July, at <NUM>:<NUM> PM, RH was <NUM>% (approximately <NUM>%), and heat was <NUM> W (generated by a solar thermal unit having an area of <NUM> square meters (m2) at an efficiency of <NUM>%), which resulted in a liquid water production rate of approximately <NUM>/hr).

<FIG> is the series of graphs of <FIG>, including points representing various times on a given day. A total amount of liquid water produced during the day may be approximated by integrating across the series of graphs (e.g., in this example, approximately <NUM> liters (L) in the morning hours of the day, and approximately <NUM> over a <NUM> hour period).

In some embodiments, a controller (e.g., <NUM>) may reference a parametric function (e.g., and/or a table generated thereby) to operate according to optimal (e.g., in terms of liquid water production rate and/or efficiency) operational variables for the system. For example, for each system operational variable (e.g., process air flow rate, regeneration fluid flow rate, desiccant exposure time to process air and/or regeneration fluid, and/or the like), a parametric function can be created that provides the value of the system operational variable which optimizes efficiency and/or liquid water production rate of the system, and the parametric function may be dependent on design specifications (e.g., disk kinetics, disk size, desiccant configuration, solar collector size, condenser geometry and performance, and/or the like) and/or variable ambient conditions (e.g., ambient air temperature, ambient air relative humidity, a level of solar insolation).

By way of illustration, an example derivation of a (e.g., relatively simple two variable) parametric function is provided below. In this example, a simulation (e.g., as described above with respect to <FIG>) may be performed holding all variables constant except for a system operational variable (e.g., in the following example, ambient air temperature is held constant, and regeneration fluid flow rate may be varied). In subsequent steps, the simulation may be repeated, changing the value of the constant (e.g., ambient air temperature, in this example) between simulations in order to develop multiple data sets. Table <NUM> provides exemplary efficiency data obtained from such simulations (e.g., seven (<NUM>) data sets are represented in Table <NUM>, representing simulations performed at seven (<NUM>) values of constant ambient air temperature).

Data from Table <NUM>, above, is illustrated in <FIG>. In this example, a mathematical regression may be used to model each data set. To illustrate, a polynomial (e.g., quadratic) regression may be fitted to each data set using the following equations: <MAT> <MAT> <MAT>
where a, b, and, c, are coefficients of the quadratic regression for each n data set. These coefficients may then modeled with a (e.g., further) mathematical regression. To illustrate, in this example, a quadratic regression may be fitted to each set of coefficients, a, b, and c, using the following equations: <MAT> <MAT> <MAT>.

<FIG> and <FIG> provide graphs of these coefficients versus Tamb. Through substitution, it can be seen that the efficiency of the system as a function of Tamb and Vregen may then be expressed as: <MAT>.

While Eq. <NUM> is expressed in terms of two variables (e.g., Vregen, and Tamb), the same or a substantially similar process as described above can be performed to express efficiency (e.g., and/or liquid water production rate, and/or the like) as a function of any suitable number of variables (e.g., by performing an additional regression for each added variable).

The maximum efficiency and/or maximum liquid water production rate (e.g., which may be the desired operational state for a system) may be determined by maximizing Eq. <NUM> (or a similar equation) with respect to each operational variable (e.g., Vregen, in this example). By way of illustration, in the depicted example, the desired operational state that maximizes efficiency may be the value of Vregen at which the partial derivative of Eq. <NUM> with respect to Vregen at a given (e.g., or measured) Tamb is equal to zero, or: <MAT>.

Eq. <NUM> (or similar equation(s)) may be evaluated over a range of ambient conditions, which may be used to produce a table of optimal operational variables (e.g., in this example, optimal Vregen for a range of Tamb). Such tables may then be further modeled by a mathematical regression (e.g., a quadratic regression). In this example, this can be shown as: <MAT>
where Vregen,optimal represents the optimal regeneration fluid flow rate at a given temperature. A controller (e.g., <NUM>) may then reference any of: the table of optimal operational variables, a parametric equation based on the table of optimal operational variables (e.g., Eq. <NUM>), and/or the like. In some embodiments, a controller (e.g., <NUM>) may perform any and/or all of the above steps to develop such parametric equation(s) and/or tables. In some embodiments, a controller (e.g., <NUM>) may be programmed with such parametric equations, for example, in some embodiments, the controller may be programmed with the following equations: <MAT> <MAT> <MAT>
where ωdisk,optimal, Vprocess,optimal, and Vregen,optimal represent optimal disk rotation rate, process air flow rate, and regeneration fluid flow rate operational variables at given values of ambient air temperature, ambient air relative humidity, and regeneration fluid temperature (e.g., indicative of a level of solar insolation).

The process of liquid water production from humid air is distinct from the process of dehumidification of air. In particular, liquid water production from humid air involves achieving practical liquid water production rates, rather than simply dehumidifying a volume of air. To illustrate some of the differences between these two processes, Table <NUM> compares an example dehumidifier system with one embodiment of the present systems for generating liquid water from air, each system operating with a process air temperature of <NUM> and a process air relative humidity of <NUM>%.

As seen in Table <NUM>, systems of the present disclosure are efficient at generating liquid water from air. The present systems and the methods by which the present systems operate (e.g., via control by controller <NUM>) are distinct from dehumidification systems and/or dehumidification methods. For example, the process air flow rate within some embodiments of the present systems may be greater than the regeneration fluid flow rate (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or more times greater, for example, at least <NUM> times greater).

Further, the process air flow rate for some embodiments of the present systems is higher than viable process air flow rates for dehumidification systems and methods. Not to be bound by any particular theory, in general, some systems of the present disclosure may function more efficiently, or generate more liquid water, when a significant amount of humid air is processed (e.g., to facilitate production of liquid water at a practical water production rate). Additionally, the regeneration fluid flow rate for some embodiments of the present systems is lower than viable regeneration fluid flow rates for dehumidification systems and methods. Not to be bound by any particular theory, in general, an optimum process air flow rate for some embodiments of the present systems may be higher than a viable process air flow rate for a dehumidifier (e.g., which may target a relatively low relative humidity in exhausted process air). For example, as opposed to a dehumidifier, some of the present systems may be efficient (e.g., generate more liquid water) even if process air undergoes only a <NUM>% reduction in relative humidity throughout the system, due, at least in part, to a high process air flow rate (e.g., in some instances, <NUM> to <NUM> times a process air flow rate within a typical dehumidifier).

A non-limiting example of an embodiment of the invention will now be described. In the example described, an alumina desiccant (e.g., <NUM>) having a thickness of <NUM> and a diameter of <NUM> is disposed on a rotatable disk (e.g., <NUM>). In the following example, the process air flow rate is <NUM> cubic metres per minute (<NUM> cfm), and the regeneration fluid flow rate is <NUM> cubic metres per minute (<NUM> cfm). With these parameters, a controller may operate the system such that efficiency is greater <NUM>% (e.g., as determined from a multi-dimensional analysis as depicted in <FIG>, which may be stored in a memory in communication with the controller as a look-up table).

<FIG> is a graph, in one dimension, of a multi-dimensional analysis, illustrating an efficiency of some embodiments of the present systems for generating liquid water from air versus regeneration fluid flow rate (cfm) ("MFRi"). As shown, for this embodiment, an efficiency of approximately <NUM>% can be obtained at a regeneration fluid flow rate of <NUM> cubic metres per minute (<NUM> cfm).

<FIG> is a graph, in one dimension, of a multi-dimensional analysis, illustrating an efficiency of some embodiments of the present systems for generating liquid water from air versus desiccant disk rotation rate (°/s). As shown, for this embodiment, an efficiency over <NUM>% may be obtained at a desiccant disk rotation rate greater than <NUM> °/s.

<FIG> is a graph, in one dimension, of a multi-dimensional analysis, illustrating an efficiency of some embodiments of the present systems for generating liquid water from air versus solar insolation as indicated by heat (W) provided by a thermal unit. <FIG> is a graph, in one dimension, of a multi-dimensional analysis, illustrating a liquid water production rate (L/hr) of some embodiments of the present systems for generating liquid water from air, versus solar insolation as indicated by heat (W) provided by a thermal unit. As shown, for this embodiment, an efficiency over <NUM>% may be obtained when heat provided by a thermal unit is less than <NUM> W (<FIG>). Additionally, as shown, for this embodiment, a liquid water production rate may be greater than <NUM>/hr is determined when heat provided by a thermal unit is approximately <NUM> W (<FIG>).

<FIG> is a graph illustrating an efficiency of some embodiments of the present systems for generating liquid water from air versus desiccant disk rotation rate (°/s) and regeneration fluid flow rate (cfm). As shown, for this embodiment, an efficiency over <NUM>% may be obtained for a desiccant disk rotation between <NUM> and <NUM> °/s, and a regeneration fluid flow rate between <NUM> and <NUM> cubic metres per minute (<NUM> and <NUM> cfm).

<FIG> is a graph illustrating a liquid water production rate (L/hr) of some embodiments of the present systems for generating liquid water from air, versus desiccant thickness (m), regeneration fluid flow rate (cfm), and desiccant disk rotation rate (°/s). As shown, for this embodiment, the liquid water production rate may be greater than <NUM>/hr for a desiccant thickness greater than <NUM> centimeters (cm), a regeneration fluid flow rate between <NUM> and <NUM> cubic metres per minute (<NUM> and <NUM> cfm), and a desiccant disk rotation rate between <NUM> and <NUM> °/s.

If implemented in firmware and/or software, the functions described above may be stored as one or more instructions or code on a non-transitory computer-readable medium. Examples include non-transitory computer-readable media encoded with a data structure and non-transitory computer-readable media encoded with a computer program. Non-transitory computer-readable media are physical computer storage media. A physical storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such non-transitory computer-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other physical medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc includes compact discs (CD), laser discs, optical discs, digital versatile discs (DVD), floppy disks and Blu-ray discs. Generally, disks reproduce data magnetically, and discs reproduce data optically. Combinations of the above are also be included within the scope of non-transitory computer-readable media. Moreover, the functions described above may be achieved through dedicated devices rather than software, such as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components, all of which are non-transitory. Additional examples include programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like, all of which are non-transitory. Still further examples include application specific integrated circuits (ASIC) or very large scale integrated (VLSI) circuits. In fact, persons of ordinary skill in the art may utilize any number of suitable structures capable of executing logical operations according to the described embodiments.

The above specification and examples provide a complete description of the structure and use of illustrative embodiments. As such, the various illustrative embodiments of the methods and systems are not intended to be limited to the particular forms disclosed. For example, elements may be omitted or combined as a unitary structure, and/or connections may be substituted. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and/or functions, and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments.

Claim 1:
A system (<NUM>, <NUM>) for generating liquid water from air, the system comprising:
a housing (<NUM>) defining an adsorption zone and a desorption zone;
a desiccant (<NUM>) selectively movable between:
the adsorption zone (<NUM>) in which the desiccant is in fluid communication with a process airflow path (<NUM>) such that the desiccant can capture water from air in the process airflow path; and
the desorption zone (<NUM>) in which the desiccant is in fluid communication with a regeneration fluid path (<NUM>) such that the desiccant can release water to regeneration fluid in the regeneration fluid path; a first blower (<NUM>) configured to adjust a flow rate of air through the process airflow path;
an actuator (<NUM>) configured to move the desiccant between the adsorption zone and the desorption zone;
a circulator (<NUM>) configured to adjust a flow rate of regeneration fluid through the regeneration fluid path;
a thermal unit (<NUM>) comprising a casing (<NUM>) in fluid communication with the regeneration fluid path and configured to provide thermal energy to regeneration fluid in the regeneration fluid path;
a condenser (<NUM>) configured to receive regeneration fluid from the desorption zone via the regeneration fluid path and to produce liquid water from regeneration fluid received from the desorption zone;
a solar insolation sensor (122c) configured to capture data indicative of a level of solar insolation; and
a controller (<NUM>) configured to optimize liquid water production based, at least in part, on measurements of the level of solar insolation, wherein the controller (<NUM>) is configured to optimize liquid water production by controlling a speed of the first blower <NUM> and/or controlling a speed of the circulator.