DESC:Field of the invention:
The present invention relates generally to atmospheric water generator systems. More specifically, the present invention relates to a system and method for extracting moisture from air, and recovering the heat lost during condensation.
Background of the invention:
Over time, fresh water supplies have diminished while the population continues to grow. Water is an essential element for drinking purposes, for agriculture, and for food production for both humans and animals. Fresh water, for drinking and crops, has become an increasingly valuable resource. Although most of our planet is covered with water, only a small fraction of that water is drinkable or suitable for crops. Our water supply has become increasingly contaminated with chemicals from pharmaceuticals, agriculture and industry and microbials. However, water treatment becomes more complicated, expensive, and less effective as water becomes more contaminated.
One remedy for a lack of clean water is to generate water from the atmosphere. Systems for converting atmospheric moisture into potable water are known. Examples of known systems can be found in various atmospheric water generator systems and methods disclosed in the art.
The United States Patent 11338220 discloses an atmospheric water generator apparatus. The apparatus includes a fluid cooling device. A water condensing surface is thermally connected to the fluid cooling device, the water condensing surface having a superhydrophobic condensing surface, a highly hydrophobic condensing surface, a super hydrophilic condensing surface, a highly hydrophilic condensing surface, or a combination thereof. An air-cooled heat rejection device is in fluid communication with a fluid cooling device. An air fan is configured to induce airflow across the water condensing surface in order to condense and extract water from the atmosphere.
The United States Patent Application 20210230846 discloses an atmospheric water generator utilizing a centrifugal hydraulic air compressor for harvesting water from the atmosphere. The purpose of atmospheric water generator is to provide potable water. The atmospheric generator includes a housing having a reservoir, a plurality of centrifugal discs, drive components, water pump, heat exchangers, and air filters. The housing reservoir further includes an indication device to determine the water level in device. The centrifugal discs can utilize centripetal forces to hydraulically compress the humid air to harvest the water from the atmosphere. The drive components further comprise a hollow shaft to direct the water to the centrifugal discs. In addition, the shape of the centrifugal disc utilizes the compressed air and water exiting the discs to help rotate the discs.
The United States Patent 10913028 discloses a wirelessly controlled device for atmospheric water generation. The wireless external control system comprises one or more display presentation pages for displaying a plurality of operating parameters for the atmospheric water generator, including content display with a variety of operation parameters and historical water collection data for operation of the atmospheric water generator. The wireless external control also has one or more display pages configured for user input for a user to select one or more water generation parameters for operation of the atmospheric water generator. Once the device is directed by the wireless external control system to generate water, the device is capable of automatic water generation until the device fulfils the one or more set water generation parameters.
Atmospheric Water Generators are primarily of two types, one is based on the conventional air-conditioning based technology where air is cooled below the dew point to liquefy a fraction of the moisture present in it. The others are based on an ab/adsorption - desorption cycle, where a deliquescent/hygroscopic substance is used to trap moisture (ab/adsorption), and the substance is provided with energy, typically in the form of heat to release this moisture (desorption), which can then be condensed. Desorption increases the concentration of moisture in the air within a sealed environment, and is much easier to condense and liquefy, as compared to the air-conditioning-based technologies. In the ab/adsorption - desorption based systems, efficient methods of providing heat have been adopted, like for example, the use of heat pumps. Both the technologies for atmospheric water generation, i.e. the air-conditioning based technology and the ab/adsorption- desorption based technology rely on eliminating the latent heat of water, however, this significant chunk of energy is lost to the atmosphere. Capital intensive solutions like MED (Multiple Effect Distillation), MSF (Multiple Stage Flash) and MVR (Mechanical Vapor Recompression) are able to recover latent heat of water, however, no prior art exists on recovering this energy in an economically viable way.
For the reasons stated above, which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need for a system and method thereof that generates atmospheric water using energy recovery in the form of latent heat recovery in an economically viable way that is re-useable, scalable and independent of complicated technological mechanism and is portable and can be deployed anywhere in very little time quickly.
Objects of the invention:
An object of the present invention is to provide a system and a method for generating atmospheric water using energy recovery in the form of latent heat recovery in an economically viable way.
Another object of the present invention is to provide a portable and scalable system and for generating atmospheric water, that is independent of complicated technological mechanism and can be deployed anywhere in very little time.
Summary of the invention
Accordingly, the present invention provides a system for atmospheric water generation using energy recovery in the form of latent heat recovery. The system comprises a desiccant unit that holds a desiccant, a heat pump and a thermal storage unit. The desiccant unit is configured to work in an absorption/ adsorption mode and a desorption mode. The desiccant holder is configured to hold the desiccant in two separate sections in fluidic communication with each other, wherein a first section holds the desiccant with absorbed moisture and the second section holds the desiccant without the moisture. The absorption section of the desiccant holder is fitted with a cooling element, while the desorption section is fitted with a heating element. The desiccant unit is provided with an inlet for receiving stream of atmospheric air, an inlet for receiving a stream of returning air, an outlet for exhausting a stream of dry air and an outlet for exhausting a stream of moist air (mixture of air and water vapor). The heat pump includes a gas-liquid heat exchanger, a compressor, a liquid-liquid heat exchanger and a throttling valve in fluidic communication with each other through a refrigerant liquid and a high-pressure tubing.
The heat pump is configured for selectively receiving the stream of moist air and an atmospheric air through valves and a fan. Either the stream of moist air or a stream of atmospheric air is received in the gas-liquid heat exchanger for extracting heat therefrom, in the refrigerant liquid and condensate the vapor content to get pure, potable water. The stream of air after condensation is recirculated to the desiccant unit, while the refrigerant liquid is further heated by compressing in a compressor of the heat pump. Heat of the refrigerant liquid is transferred to a heat transfer fluid in the liquid-liquid heat exchanger and further used for heating the desiccant, by circulating the heat transfer fluid through the heating element. The thermal storage unit is optionally fitted to receive and store the extracted heat from the heat pump and supply the extracted heat to the heating element and the cooling element. The thermal storage unit includes a hot medium storage tank for receiving and storing the extracted heat from the heat pump and a cold medium tank for receiving and storing a cold heat transfer fluid from the heating element.
In another aspect, the present invention provides a method for atmospheric water generation, the method comprising the steps of: enabling a desiccant in a desiccant unit to interact with a humid atmospheric air thereby adsorbing/ absorbing the moisture and exhausting a stream of dry atmospheric air; operating valves and a fan to allow a flow of atmospheric air through a gas-liquid heat exchanger of a heat pump to extract heat therefrom and transferring the extracted heat to a refrigerant fluid and converting the refrigerant fluid to a gaseous state; further heating the refrigerant fluid by pressurizing in a compressor and extracting the heat of the refrigerant fluid in a liquid-liquid heat exchanger of the heat pump; passing the refrigerant fluid through the throttling device to return back to lower pressure state, to repeat the process; supplying the extracted heat to the desiccant and a return stream of air from the heat pump to the desiccant saturated with moisture to produce a stream of moist air; operating valves and the fan to break the flow of atmospheric air into the gas-liquid heat exchanger; operating valves and the fan to allow the flow of a stream of moist air into the gas-liquid heat exchanger to lose heat, causing the stream of moist air to cool down and condense the moisture into water. The present invention enables the heat pump to boost the coefficient of performance limit to 4.5 to 7.0, by replacing the source, which was previously the ambient temperature atmospheric air, with a source of much higher temperature which is the heated vapours emanating from the deliquescent and/or hygroscopic substance.
Brief description of the drawings:
The embodiments can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, the emphasis instead being placed upon illustrating the principals of the embodiments. Moreover, the figures, like reference numerals designate corresponding parts throughout the different views.
Reference will be made to embodiments of the invention, example of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figures 1 and 2 illustrate a system (200) for atmospheric water generation, according to exemplary implementations of various embodiments of the present invention;
Figures 3 and 4 illustrate details of a desiccant unit (010) of the system (200) for atmospheric water generation, according to exemplary implementations of embodiments of the present invention;
Figure 5 illustrates details of a heat pump (040) of the system (200) for atmospheric water generation, according to exemplary implementations of embodiments of the present invention;
Figure 6 illustrates details of a thermal storage unit (050) of the system (200) for atmospheric water generation, according to exemplary implementations of embodiments of the present invention; and
Figure 7 illustrates details of a desiccant unit (010) of the system (200) for atmospheric water generation, according to exemplary implementations of embodiments of the present invention;
Figure 8 illustrates details of the heat pump (040) of the system (200) for atmospheric water generation, according to exemplary implementations of embodiments of the present invention;
Figure 9 illustrates details of a gas-liquid heat exchanger (041) of the system (200) for atmospheric water generation, according to an exemplary implementation of one of the embodiments of the present invention.
Figure 10 illustrates details of a desiccant unit (010) of the system (200) for atmospheric water generation, according to exemplary implementations of embodiments of the present invention;
Figures 11, 12 and 13 illustrate the system (200) for atmospheric water generation, according to exemplary implementations of various embodiments of the present invention;
Figure 14 illustrates details of the heat pump (040A) of the system (200) for atmospheric water generation, according to exemplary implementations of embodiments of the present invention;
Detailed description of the embodiments:
The present invention is a system and method thereof for atmospheric water generation using advanced energy recovery in the form of advanced latent heat recovery in an economically viable way. On heating of any substance, typically there are two forms of heat, one is the sensible heat, which goes into raising the temperature of the substance, and the other is the latent heat, that helps in changing the state of the substance. In atmospheric water generators, the air-cooled condensers lose this latent heat, which is the most significant part of the heat balance of the substance. The use of different kinds of heat pumps has been common in prior art, however, the efficiencies, commonly measured by a factor called coefficient of performance (COP), has improved to 3.0 to 3.5. According to the present invention this heat can be recovered and provided back to the system to further carry on the process using a set of heat exchangers and a fluid/ or a mixture of low normal boiling point fluids (liquid refrigerants/ refrigerant fluid) to boost the COP to 4.5 to 7.0. This is done by a heat exchanger extracting heat from the vapours that are produced as a result of heating the desiccant/deliquescent and/or hygroscopic substance. Heat from the vapours is extracted in the refrigerant fluid of the heat exchanger, the refrigerant fluid is further heated in a compressor and the heat of the refrigerant fluid is transferred to a heat transfer fluid in another heat exchanger. This is done by modulating the characteristics of the refrigerant fluid using changes in pressures. This invention enables the heat pump to boost the COP limit to 4.5 to 7.0, by replacing the source, which was previously the ambient temperature atmospheric air, with a source of much higher temperature which is the heated vapours emanating from the deliquescent and/or hygroscopic substance.
In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these details. One skilled in the art will recognize that embodiments of the present invention, some of which are described below, may be incorporated into a number of systems.
The various embodiments of the present invention provide a system and a method thereof for atmospheric water generation using advanced energy recovery in the form of advanced heat recovery that is universal, inexpensive, robust, and simple in operation and control using both batch mode and continuous mode.
Furthermore, connections between components and/or modules within the figures are not intended to be limited to direct connections. Rather, these components and modules may be modified, re-formatted or otherwise changed by intermediary components and modules.
The systems/devices and methods described herein are explained using examples with specific details for better understanding. However, the disclosed embodiments can be worked on by a person skilled in the art without the use of these specific details.
Throughout this application, with respect to all reasonable derivatives of such terms, and unless otherwise specified (and/or unless the particular context clearly dictates otherwise), each usage of:
“a” or “an” is meant to read as “at least one.”
“the” is meant to be read as “the at least one.”
References in the present invention to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
Embodiments of the present invention include various steps, which will be described below. The steps may be performed by mechanical, thermal or hardware components. Alternatively, steps may be performed by a combination of mechanical, thermal and hardware and/or by human operators.
If the specification states a component or feature "may” can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
As used in the description herein and throughout the claims that follow, the meaning of "a, “an” and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.
Exemplary embodiments will now be described in more detail fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this invention will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). For clarity of the description, known constructions and functions will be omitted. Parts of the description may be presented in terms of operations performed by a mechanical and/or a thermal and/or hardware system, using terms such as state, ab/adsorption, section, desiccant, desorption module, valves, heat exchangers, low normal boiling fluid, liquid refrigerant, vapour refrigerant and the like, consistent with the manner commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description and in the table below.
Table:
Ref No: Component/ element Ref No: Component/ element
010 Desiccant unit 071 Returning stream of air
020 Ad/Absorption section 080 Atmospheric air
021 Ad/Absorption mode 081 Humid atmospheric air
030 Desorption section 082 Dry atmospheric air
031 Desorption mode 90A Heat exchanger
040 Heat pump 90B Heat exchanger
040A Heat pump (alternate embodiment) 091 Second heat exchanger
041 Gas-liquid heat exchanger 092 Third heat exchanger
042 Compressor 093 Forth heat exchanger
043 Liquid- liquid heat exchanger 100 Desiccant
044 Throttling device 110 Desiccant holder
045 High pressure tubing 120 Desiccant heating element
046 Set of valves 121 Desiccant cooling element
048 Low normal boiling point fluid 130 Heat transfer fluid
049 Electrical input 131 Hot Heat transfer fluid
050 Thermal storage unit 132 Cold Heat transfer fluid
051 Hot medium tank 140 Drain point
052 Cold medium tank 145 Water collection tank
060 Fan 150 Water outlet
070 Stream of moist air 180 Hybrid unit
Referring to the figures 1 to 14 a system (200) for atmospheric water generation using energy recovery and a method thereof is shown.
In one aspect, the present invention provides a system (200) for atmospheric water generation using energy recovery. Referring to figures 1 and 2, the system (200) comprises a desiccant unit (010), a heat pump (040), a set of valves (046), a fan (060) and optionally a thermal storage unit (050).
The desiccant unit (010) holding a desiccant (100) is fitted with an inlet arrangement for receiving a stream of atmospheric air (081) to interact with the desiccant (100) to absorb moisture, an outlet arrangement for exhausting a stream of dry air (082) after absorption of moisture by the desiccant (100), a heating element (120) for enabling the desiccant to undergo desorption mode and exhaust moisture in the form of water vapours, an inlet arrangement for receiving a stream of air (071) to interact with the desiccant (100) in desorption mode, and an outlet arrangement for exhausting a stream of moist air (070) containing water vapor and air. The desiccant unit (010) is configured to function in an absorption mode (021) and a desorption mode (031). In the absorption mode (021), a desiccant material (100) in the desiccant unit (010) is in fluidic communication with a humid atmospheric air (081). In absorption mode (021), the desiccant material (100) either adsorbs or absorbs the moisture depending upon nature of the desiccant, while a stream of dry atmospheric air (082) is exhausted back to the atmosphere. In an embodiment, the desiccant material (100) is selected from: lithium chloride, potassium formate, copper (II) sulphate, calcium chloride and mixtures thereof. In the desorption mode (031), the desiccant material (100) is heated to lose the moisture in the form of water vapours, which, along with a stream of air is carried out to the heat pump (040).
The heat pump (040) is configured to selectively interact with an atmospheric air (080) and also with the stream of moist air (070) received from the desiccant unit (010), to extract heat, condense a significant part of the moisture, and recirculate a returning stream of air (071) to the desiccant unit (010). The extracted heat is further provided for heating the desiccant (100), by circulating a heat transfer fluid (130) from the heat pump (040) through the desiccant heating element (120) of the desiccant unit (010). A set of valves (046) is configured to break, establish or switch fluidic communication of the desiccant unit (010) with the heat pump (040) and with the atmospheric air (080). The electrically operated fan (060) is configured to provide circulation of either the stream of moist air (070) or the atmospheric air (080) through the heat pump (040) and the desiccant unit (010).
Referring to figure 2, the heat transfer fluid (130) is carried to and from the desiccant unit (010) and the heat pump (040), optionally via the thermal storage unit (050). In an embodiment, the thermal storage unit (050) is configured to store heat from a range of a few minutes, to a few hours (seasonal storage).
Referring to figure 3, the desiccant unit (010) is provided with but not limited to a desiccant holder (110), an absorption section (020), a desorption section (030), a desiccant heating element (120). The absorption section (020), the desorption section (030) and the desiccant holder (110) are in fluidic communication with each other, wherein a suitable arrangement for transfer of the desiccant (100) is provided. In an embodiment, the arrangement for transfer of the desiccant (100) is a single stage or multistage centrifugal pump/s fitted in the desiccant unit (010). In the absorption section (020) the desiccant (100) is enabled to interact with the humid atmospheric air (081) for extracting moisture therefrom through either absorption or adsorption. After extracting the moisture, the dry air (082) is exhausted back to the atmosphere. The desiccant (100), after reaching its moisture uptake limit, is transferred to the desorption section (030) and enabled to undergo desorption (031) by heating, while passing air therethrough, to recover absorbed moisture in the form of water vapours. In an embodiment, the desiccant heating element (120) is a heat exchanger selected from a plate and frame heat exchanger, a shell & tube heat exchanger, a double pipe heat exchanger and a spiral heat exchanger. In another embodiment, the desiccant (100) in the desorption section (030) is heated to a temperature typically between 40ºC to 90ºC, preferably between 50ºC to 80ºC and most preferably at 75ºC. The recovered water vapor mixed with the air forms a stream of moist air (070) which is further carried to the heat pump (040).
In another embodiment, referring to figure 4, the desiccant holder (110) is configured to hold the desiccant (100) in two separate sections in fluidic communication, wherein a first section holds the desiccant (100) with absorbed moisture and the second section holds the desiccant (101) without the moisture. The hot lean desiccant is cooled and transferred to absorption section (020) to uptake moisture from humid atmospheric air (082) and comes down as absorbed desiccant (100) which overflows into the hot desiccant storage where it is heated again to liberate absorbed moisture which is sent out as stream of moist air (070).
Referring to figure 5, in an embodiment, the heat pump (040) includes but not limited to a gas-liquid heat exchanger (041), a compressor (042), a liquid-liquid heat exchanger (043), a throttling device (044) and a plurality of high-pressure tubing (045) connecting all the components of the heat pump (040). The gas liquid heat exchanger (041) is configured to receive either the stream of moist air (070) or the atmospheric air (080) through the set of valves (046) and the fan (060). The gas-liquid heat exchanger (041) is configured to extract heat either from the stream of moist air (070) or from the atmospheric air (080), to condense a significant part of the moisture to obtain water, and exhaust a returning stream of air (071) that is further carried to the desorption section (030) of the desiccant unit (010). Initially, the set of valves (046) are operated to allow the gas-liquid heat exchanger (041) to interact with the atmospheric air (080) via the electrically operated fan (060), and once the desiccant (100) is heated to a sufficiently high temperature, the valves (046) are operated to break the fluid communication of the gas-liquid heat exchanger (041) with the atmospheric air (080) and establish communication with the stream of moist air (070). The heat extracted from the stream of atmospheric air (080) or the stream of moist air (070) is transferred to the refrigerant fluid (048) flowing there through at low pressure. The refrigerant fluid (048) is a low normal boiling point fluid or a mixture of low normal boiling point fluids, selected from R134a, R407C, R410A, R22, R513A, R717, R744, R32 and mixtures thereof. The refrigerant fluid (048) carried to the compressor (042) is converted to gaseous state while passing through the high-pressure tubing (045). The plurality of high-pressure tubing connects all the components of the heat pump (040) and handles the refrigerant fluid (048), across a wide range of pressure and temperature variations. The refrigerant fluid (048) is pressurized by the compressor (042), which uses electrical input (049) to perform mechanical work, further heating the refrigerant fluid (048). Heat of the high-pressure refrigerant fluid (048) is extracted by a heat transfer fluid (130) in the liquid-liquid heat exchanger (043) and the high-pressure refrigerant fluid (048) changes state from gaseous state to a liquid state. The high-pressure refrigerant fluid (048) passes through the throttling device (044) to return back to its lower pressure state, to repeat the process. The throttling device (044) is configured to balance and isolate high pressure side and low-pressure side of the heat exchangers (041, 043). The incoming stream of moist air (070) that loses its heat to the gas-liquid heat exchanger (041), which causes the stream of moist air (070) to cool down and condense a significant portion of the moisture into water. This water can now be collected and used.
In an embodiment, the heat transfer fluid (130) is carried to and from the heating element (120) and the heat pump (040), optionally via the thermal storage unit (050). The heat transfer fluid (130) is stored in the thermal storage unit (050) thereby storing heat from a range of a few minutes, to a few hours (seasonal storage) (Ref: figure 6). The thermal storage unit (050) comprises a hot medium tank (051) configured to receive and store a hot heat transfer fluid (131) from the heat pump (040), and a cold medium tank (052) configured to receive and store a cold heat transfer fluid (132) from the heating element (120) of the desiccant unit (010). The hot heat transfer fluid (130) from the hot storage tank (051) passes through the desiccant heating element (120) losing its heat to the desiccant (100) and received back into the cold storage tank (052). In an implementation according to one of the embodiments of the present invention, the system (200) may or may not comprise the thermal storage unit (050) based on the availability of energy at the site of installation.
Referring to figure 7, in another embodiment, a desiccant cooling element (121) is fitted in the absorption section (020) of the desiccant holder (110) for circulating the cold heat transfer fluid (132) from the cold storage tank (052), for cooling the desiccant (100). The cold heat transfer fluid (132) is circulated from the cold media tank (052) through the desiccant cooling element (121) fitted in the absorption section (020) of the desiccant holder (110), for cooling the desiccant (100); while the hot heat transfer fluid (131) is circulated from the hot media tank (051) through the desiccant heating element (120), fitted in the desorption section (030) of the desiccant holder (110) for heating the desiccant (100).
In still another embodiment, the desiccant heating element (120) and the desiccant cooling element (121) are provided as external devices (Ref. Figure 10). The external devices are a second heat exchanger (091) and a third heat exchangers (092). The second heat exchanger (091) and the third heat exchangers (092) are of any type selected from: a plate and frame heat exchanger, shell & tube heat exchanger, double pipe heat exchanger and spiral heat exchanger. The desiccant (100) is cooled down to a temperature ranging from 20ºC to 30ºC and more preferably to 25ºC, using a cooling medium that passes through the internal coils and through the external cooling devices. In an embodiment, a separate chamber is provided in the desiccant holder (110) as a buffer tank (102) to control the heating and cooling of the desiccant (100).
In another embodiment, referring to figure 8 and 9, the refrigerant fluid (048) received from the throttling device (044) is split into two parts : a first part is passed through a heat exchanger (90B) to condense the moisture in the stream of moist air (070) received from the desorption section (030); and the second part is passed through a heat exchanger (90A) for cooling the heat transfer liquid (130) received from the cold medium tank (052). Alternately, the water produced by condensation of the stream of moist air (070) can be further cooled and the subcooled water can be circulated through the desiccant cooling element (121).
In yet another embodiment, the system (200) is fitted with a fourth heat exchanger (093) for condensing the stream of moist air (070) using the cold heat transfer fluid (132) from the cold storage tank (052) (Ref.: figure 11). In an embodiment, the cold heat transfer fluid (132) is water. The mixture of condensed water and air then enters water collection tank (120) where water (150) and returning stream of air (071) is separated. The dry returning stream of air (071) is recirculated through the heat pump (040) and the desiccant unit (010) using fan (060). The water (150) may be drained continuously or in batches. The fan (060) is arranged after fourth heat exchanger (093) and before the heat pump (040) so as to consume less power and circulate more air. In case when the fan (060) is arranged before the fourth heat exchanger (093), as shown in figure 12, more power is consumed thereby making the process slightly inefficient.
In yet another embodiment, the system (200) is fitted with the fourth heat exchanger (093) for condensing the stream of moist air (070) using the cold heat transfer liquid (132) received from a cold medium tank (052) of a hybrid unit (180) (Ref.: figure 13 and figure 14). The hybrid unit (180) is assembled by coupling the thermal storage unit (050) and a heat pump (040A). The heat pump (040A) is different from the heat pump (040) in that, both the heat exchangers in the heat pump (040A) are liquid-liquid heat exchangers (043). Heat from the cold heat transfer liquid (132) is extracted in a first liquid-liquid heat exchanger (043) using the refrigerant fluid (048) and the cold heat transfer liquid (132) is stored in the cold medium tank (052) for further circulating through the desiccant cooling element (121). The refrigerant fluid (048) further flows through the compressor (042) wherein the electrically powered compressor (042) performs mechanical work to compress the refrigerant fluid (048) and heat thereto. Heat of the refrigerant fluid (048) passing through the second liquid-liquid heat exchanger (043) is extracted by the hot heat transfer fluid (131) which is then stored in the hot medium tank (051) for supplying to the desiccant heating element (120)
In another aspect, the present invention provides a method for atmospheric water generation using energy recovery through the system (200). The process of ad/absorption of moisture from the humid atmospheric air (081) using a desiccant (100) and desorption and generation of water vapours is done either in a continuous process or in a batch process, depending upon the ambient humid air (081) conditions. The method is explained in detail as follows:
In first step, the method involves enabling the desiccant (100) in a desiccant unit (010) to interact with a humid atmospheric air (081) thereby adsorbing/ absorbing the moisture and exhausting a stream of dry atmospheric air (082).
In next step, the method involves operating valves (046) and a fan (060) to allow a flow of atmospheric air (080) through a gas-liquid heat exchanger (041) of a heat pump (040) to absorb heat therefrom and transferring the absorbed heat to a refrigerant fluid (048) flowing through the gas-liquid heat exchanger (041) and through a high-pressure tubing (045) and converting the refrigerant fluid (048) to a gaseous state.
In next step, the method involves further heating the refrigerant fluid (048) by pressurizing in a compressor (042) performing mechanical work. In an embodiment, the compressor (042) uses electrical input (049) to perform the mechanical work.
In next step, the method involves extracting heat of the refrigerant fluid (048) in a liquid-liquid heat exchanger (043) of the heat pump (040) using a heat transfer fluid (130), and changing the state of the refrigerant fluid (048) from gaseous state to liquid state.
In next step, the method involves passing the high-pressure refrigerant fluid (048) through a throttling device (044) to return back to lower pressure state, to repeat the process.
In next step, the method involves circulating the heat transfer fluid (130) through a heating element (120) for heating the desiccant (100), while supplying a return stream of air (071) to the desiccant (100), when the desiccant (100) reaches its moisture uptake limit.
In next step, the method involves operating valves (046) and a fan (060) to break the flow of atmospheric air (080) to the gas-liquid heat exchanger (041).
In next step, the method involves operating valves (046) and a fan (060) to allow the flow of stream of moist air (070) received from the desiccant unit (010), to lose heat to the refrigerant fluid (048) in the gas-liquid heat exchanger (041) causing the stream of moist air (070) to cool down and condense the moisture into water.
In final step, the method involves collecting the condensed water.
In an embodiment, the desiccant unit (010) includes a desiccant holder (110), an absorption section (020) and a desorption section (030) in fluidic communication with each other; a desiccant heating element (120), and optionally a desiccant cooling element (121).
In an embodiment, the refrigerant fluid (048) is a low normal boiling point fluid or a mixture of low normal boiling point fluids. The refrigerant fluid (048) is a low normal boiling point fluid selected from: R134a, R407C, R410A, R22, R513A, R717, R744, R32, and mixtures thereof.
In an embodiment, the method involves carrying the heat transfer fluid (130) to and from the desiccant unit (010) and the heat pump (040) via a thermal storage unit (050). The thermal storage unit (050) comprises a hot medium storage tank (051) configured to receive and store hot heat transfer fluid (132) from the heat pump (040), and a cold medium storage tank (052) configured to receive and store the cold heat transfer fluid (132) from the heating element (120) of the desiccant unit (010).
In an embodiment, the method involves splitting the refrigerant fluid (048) received from the throttling device (044) into two parts to pass through two heat exchangers (90A and 90B), wherein one part condenses the moisture in the stream of moist air (070) received from the desorption section (030) in a heat exchanger (90B) and the other part cools the heat transfer liquid (130) received from the cold storage tank (052).
In an embodiment, the method involves condensing the stream of moist air (070) in a fourth heat exchanger (093) using the cold heat transfer liquid (132) received from a cold media tank (052) of a hybrid unit (180). The hybrid unit (180) is assembled by coupling the thermal storage unit (050) and a heat pump (040A). The heat pump (040A) is different from the heat pump (040) in that, both the heat exchangers in the heat pump (040A) are liquid-liquid heat exchangers (043). Heat from the cold heat transfer liquid (132) is extracted in a first liquid-liquid heat exchanger (043) using the refrigerant fluid (048) and the cold heat transfer liquid (132) is stored in the cold medium tank (052) for further circulating through the desiccant cooling element (121). The refrigerant fluid (048) further flows through the compressor (042) wherein the electrically powered compressor (042) performs mechanical work to compress the refrigerant fluid (048) and heat thereto. Heat of the refrigerant fluid (048) passing through the second liquid-liquid heat exchanger (043) is extracted by the hot heat transfer fluid (131) which is then stored in the hot medium tank (051) for supplying to the desiccant heating element (120).
The system (200) and the method of the present invention, for atmospheric water generation using advanced energy recovery in the form of latent heat recovery in an economically viable way exhibits advantageous features including but not limited to:
? Significantly lower energy consumption of the heating device;
? Lowers energy losses within the system;
? Provides a decentralized system for production of water;
? Thermal storage can be incorporated to reduce the preheating time for the desiccant material.
? Can operate flexibly based upon ambient air conditions
The present invention as implemented through various embodiments is economically viable and can be adopted by the businesses easily as it provides the higher graded utility in economical plans.
Further, while one or more operations have been described as being performed by or otherwise related to certain modules, devices or entities, the operations may be performed by or otherwise related to any module, device, or entity.
Further, the operations need not be performed in the disclosed order, although in some examples, an order may be preferred. Also, not all functions need to be performed to achieve the desired advantages of the disclosed system and method, and therefore not all functions are required.
While selected examples of the disclosed system and method have been described, alterations and permutations of these examples will be apparent to those of ordinary skill in the art. Other changes, substitutions, and alterations are also possible without departing from the disclosed system and method in its broader aspects.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention.
,CLAIMS:We claim:
1. A system (200) for atmospheric water generation, the system (200) comprising:
a desiccant unit (010) holding a desiccant (100) and fitted with
an inlet arrangement for receiving a stream of atmospheric air (081) and interact with the desiccant (100) to absorb moisture,
an outlet arrangement for exhausting a stream of dry air (082) after absorption of moisture by the desiccant (100);
a heating element (120) for enabling the desiccant to undergo desorption mode and exhaust moisture in the form of water vapours;
an inlet arrangement for receiving a returning stream of air (071) and interact with the desiccant (100) in desorption mode, and
an outlet arrangement for exhausting a stream of moist air (070) containing water vapor and air;
a heat pump (040) selectively receiving the stream of moist air (070) and an atmospheric air (080) through valves (046) and a fan (060), the heat pump (040) configured to extract heat from the stream of moist air (070) and from the atmospheric air (080), and condense the moisture content into water (150), the heat pump (040) configured to supply the dry returning stream of air (071) to the desiccant unit (010) and supply the extracted heat to the heating element (120); and
a thermal storage unit (050) optionally fitted to receive and store the extracted heat from the heat pump (040) and supply the extracted heat to the heating element (120) and the cooling element (121).
2. The system (200) as claimed in claim 1, wherein the desiccant (100) is selected from: calcium chloride, lithium chloride, potassium formate, copper (II) sulphate and mixtures thereof.
3. The system (200) as claimed in claim 1, wherein the desiccant heating element (120) is a heat exchanger selected from a plate and frame heat exchanger, a shell & tube heat exchanger, a double pipe heat exchanger and a spiral heat exchanger.
4. The system (200) as claimed in claim 1, wherein the desiccant unit (010) includes a desiccant holder (110), an absorption section (020) and a desorption section (030) in fluidic communication with each other.
5. The system (200) as claimed in claim 4, wherein the desiccant holder (110) is configured to hold the desiccant (100) in two separate sections in fluidic communication with each other, wherein a first section holds the desiccant (100) with absorbed moisture and the second section holds the desiccant (101) without the moisture.
6. The system (200) as claimed in claim 4, wherein the absorption section (020) is fitted with a desiccant cooling element (121).
7. The system (200) as claimed in claim 1, wherein the heat pump (040) includes:
a gas-liquid heat exchanger (041) selectively receiving the stream of moist air (070) and an atmospheric air (080) and configured to extract heat therefrom in a refrigerant fluid (048) flowing therethrough, thereby condensing moisture;
a compressor (042) configured to receive and pressurize the refrigerant fluid at low pressure;
a liquid-liquid heat exchanger (043) configured to extract heat from the high pressure refrigerant fluid (048) and transfer to a heat transfer fluid (130), and
a throttling device (044) configured to receive the refrigerant fluid (048) and balance the pressure on the refrigerant fluid (048) to return back to its lower pressure state.
8. The system (200) as claimed in claim 1, wherein the thermal storage unit (50) includes a hot medium storage tank (051) for receiving and storing the extracted heat from the heat pump (040) and a cold medium tank (052) for receiving and storing a cold heat transfer fluid (130) from the heating element (120).
9. The system (200) as claimed in claim 1, wherein a fourth heat exchanger (093) is fitted to receive the stream of moist air (070) and condense water, using the cold heat transfer liquid (132) received from a cold medium tank (052) of a hybrid unit (180).
10. The system (200) as claimed in claim 9, wherein the hybrid unit (180) is assembled by coupling the thermal storage unit (050) and a heat pump (040A), wherein the heat pump (040A) is configured to extract heat from cold heat transfer fluid (132) and transfer the extracted heat to a hot heat transfer fluid (131), and the thermal storage unit (050) is configured to store the hot heat transfer fluid (131) and the cold heat transfer fluid (132).
11. A method for atmospheric water generation, the method comprising the steps of:
enabling a desiccant (100) in a desiccant unit (010) to interact with a humid atmospheric air (081) thereby adsorbing/ absorbing the moisture and exhausting a stream of dry atmospheric air (082);
operating valves (046) and a fan (060) to allow a flow of atmospheric air (080) through a gas-liquid heat exchanger (041) of a heat pump (040) to extract heat therefrom and transferring the extracted heat to a refrigerant fluid (048) and converting the refrigerant fluid (048) to a gaseous state;
further heating the refrigerant fluid (048) by pressurizing in a compressor (042) and extracting the heat of the refrigerant fluid (048) in a liquid-liquid heat exchanger (043) of the heat pump (040);
passing the refrigerant fluid (048) through the throttling device (044) to return back to lower pressure state, to repeat the process;
supplying the extracted heat to the desiccant (100) and a return stream of air (071) from the heat pump (040) to the desiccant (100) saturated with moisture to produce a stream of moist air (070);
operating valves (046) and the fan (060) to break the flow of atmospheric air (080) into the gas-liquid heat exchanger (041);
operating valves (046) and the fan (060) to allow the flow of a stream of moist air (070) into the gas-liquid heat exchanger (041) to lose heat, causing the stream of moist air (070) to cool down and condense the moisture into water (150).
12. The method for atmospheric water generation as claimed in claim 11, wherein the desiccant unit (010) includes a desiccant holder (110), an absorption section (020) and a desorption section (030) in fluidic communication with each other; a desiccant heating element (120), and optionally a desiccant cooling element (121).
13. The method for atmospheric water generation as claimed in claim 11, wherein the extracted heat is carried from the heat pump (040) to the desiccant unit (010) via a thermal storage unit (050).
14. The method for atmospheric water generation as claimed in claim 13 wherein the thermal storage unit (050) includes a hot medium storage tank (051) for receiving and storing extracted heat from the heat pump (040) and a cold medium storage tank (052) for receiving and storing a cold heat transfer fluid (130) from the heating element (120).
15. The method for atmospheric water generation as claimed in claim 13 wherein the refrigerant fluid (048) received from the throttling device (044) is split into two parts to pass through two heat exchangers (90A and 90B), wherein one part extracts heat from the stream of moist air (070) and the other part extracts heat from the heat transfer liquid (130) received from the thermal storage unit (50).
16. The method for atmospheric water generation as claimed in claim 11, wherein the stream of moist air (070) is condensed in a fourth heat exchanger (093) using a cold heat transfer liquid (132) received from a cold media tank (052) of a hybrid unit (180).
Dated this on 30th day of September, 2023

Ashwini Kelkar
(Agent for the applicant)
(IN/PA-2461)