WO2020128987A1 - Atmospheric water generation system - Google Patents
Atmospheric water generation system Download PDFInfo
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- WO2020128987A1 WO2020128987A1 PCT/IB2019/061161 IB2019061161W WO2020128987A1 WO 2020128987 A1 WO2020128987 A1 WO 2020128987A1 IB 2019061161 W IB2019061161 W IB 2019061161W WO 2020128987 A1 WO2020128987 A1 WO 2020128987A1
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- condenser vessel
- air
- vessel
- condenser
- water
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D5/00—Condensation of vapours; Recovering volatile solvents by condensation
- B01D5/0003—Condensation of vapours; Recovering volatile solvents by condensation by using heat-exchange surfaces for indirect contact between gases or vapours and the cooling medium
- B01D5/0006—Coils or serpentines
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D5/00—Condensation of vapours; Recovering volatile solvents by condensation
- B01D5/0033—Other features
- B01D5/0039—Recuperation of heat, e.g. use of heat pump(s), compression
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D5/00—Condensation of vapours; Recovering volatile solvents by condensation
- B01D5/0033—Other features
- B01D5/0051—Regulation processes; Control systems, e.g. valves
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- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03B—INSTALLATIONS OR METHODS FOR OBTAINING, COLLECTING, OR DISTRIBUTING WATER
- E03B3/00—Methods or installations for obtaining or collecting drinking water or tap water
- E03B3/28—Methods or installations for obtaining or collecting drinking water or tap water from humid air
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
Abstract
The present invention provides an atmospheric water generation system for generating water from atmospheric humid air. The system includes a fan/ compressor which operates at a very low compression ratio to push or pull humid air through a condenser vessel. Very low compression ratio of fan/ compressor is attained by using a condenser vessel of large dimensions with an air exit/ air inlet of large size. Also, the bypassing of humid air from air inlet to air exit is avoided and residence time of humid air in the condenser vessel is increased so that the air in the condenser vessel becomes saturated with water vapors resulting in more condensation of water by placing one or more vertical overlapping baffles in the condensation vessel.
Description
ATMOSPHERIC WATER GENERATION SYSTEM
FIELD OF THE INVENTION
The present invention generally relates to a water generation system, and more particularly, relates to a flexible compression and cooling based atmospheric water generation system.
BACKGROUND OF THE INVENTION
Moisture in some quantity is always present in atmospheric air. In places near seashore, atmospheric air is more humid containing substantial amounts of moisture. This moisture could be condensed from atmospheric air producing ultrapure water which can be made potable by suitable post treatment procedures. Atmospheric water generation systems produce water by condensing the humidity present in the atmospheric air. Generally, a combination of compression and cooling of humid air is used for condensation of water out of humid air. However, these compression and cooling based atmospheric water generation systems are highly energy intensive requiring high input of energy. In conventional compression and cooling based atmospheric water generation system, humid air is passed over a cooling coil using a compressor or fan. Cooling fluid is passed through the cooling coil resulting in cooling of pressurized humid air resulting in condensation of water. Cooling of the humid air is performed at pressurized condition so as to enhance the condensation of water. However, as the compression ratio of the compressor or fan is high and as the energy consumed in the compressor or fan is directly proportional to compression ratio of the compressor or fan so this results in high energy consumption in the conventional atmospheric water generation system. Also, as the humid air passes over a cooling coil at high flow rate, a large amount of humid air bypasses from inlet to outlet without condensing water resulting in relative humidity of outlet air to be substantially less than 100 % and thus resulting in less efficient operation of the conventional atmospheric water generation system. Therefore, there exists a possibility of development of a more efficient and
less energy consuming atmospheric water generation system by rectifying the aforementioned problems.
SUMMARY OF THE INVENTION
The present invention generally relates to a new more efficient and operationally flexible type of atmospheric water generation system. The invention particularly relates to new more efficient and operationally flexible type of compression and cooling based atmospheric water generation system.
In an embodiment, an atmospheric water generation system for generating water from atmospheric humid air is provided. The system comprises a condenser vessel including an inlet opening for the humid air and an outlet for exiting dehumidified air, wherein the inlet opening is disposed on a top portion of a first side of the condenser vessel and the outlet opening is disposed on a top portion of a second side of the condenser vessel, wherein the inlet opening and the outlet opening are placed at a relative distance to increase residence time of the humid air within the condenser vessel; at least one compressor or fan disposed near the inlet to push the humid air to enter the condensing vessel through said inlet; at least one means of cooling to cool the condenser vessel to decrease temperature of the condenser vessel below the dew point temperature of the humid air entering the condenser vessel to condense water present within the humid air; ; and a flow control valve disposed within a flow channel of the dehumidified air to control outflow rate of the dehumidified air from the condenser vessel to maintain a compression ratio, wherein flow rate of the humid air flowing in the condenser vessel, pressure and temperature of the condenser vessel, flow rate of dehumidified air flowing out of the condenser vessel and flow rate of condensed water flowing out of the condenser vessel respectively are automatically adjusted such that mass/ molar flow rate of humid air flowing in the condenser vessel is equal to the mass/ molar flow rate of dehumidified air flowing out of the condenser vessel added to mass/ molar flow rate of condensed water condensing/ flowing out of the condenser vessel. In an alternative embodiment, an atmospheric water generation system for generating water from atmospheric humid air is provided. The system comprises a condenser vessel including an air inlet valve for entry of humid air in said condenser vessel; a flow control
valve connected to line of air inlet valve regulate flow of humid air through the condenser vessel and pressure of the condenser vessel; at least one fan or a compressor in an air exit line to suck air out of condenser vessel and create a negative pressure in the condenser vessel, wherein increase in suction pressure of said fan or compressor causes decrease in compressor ratio and increases the flow rate of dehumidified air; at least one means of cooling to cool the condenser vessel to decrease temperature of the condenser vessel below the dew point temperature of the humid air entering the condenser vessel to condense water present within the humid air; a water outlet valve for controlling level of condensed water in the condenser vessel; a pump attached to bottom of condenser vessel to flow condensed water flow out of condenser vessel, wherein flow rate of the humid air flowing in the condenser vessel, pressure and temperature of the condenser vessel, flow rate of dehumidified air flowing out of the condenser vessel and flow rate of condensed water flowing out of the condenser vessel respectively is automatically adjusted such that mass/ molar flow rate of humid air flowing in the condenser vessel is equal to the mass/ molar flow rate of dehumidified air flowing out of the condenser vessel added to mass/ molar flow rate of condensed water condensing/ flowing out of the condenser vessel.
In an implementation, this includes a condenser vessel of large dimensions with humid air entering the condenser vessel from one side near the top of the vessel, dehumidified air exiting from the other side near the top of the condenser vessel and cooling coil being placed inside or on the walls of the condenser vessel. Heat transfer liquid at suitable low inlet temperature and high flow rate is circulated through the cooling coil to decrease the temperature of condenser vessel below the dew point temperature of humid air entering the condenser vessel to condense water. Also, in order to make the invention more flexible in operation, a flow control valve is placed in the air exit pipe of the condenser vessel. The opening of this flow control valve is varied to vary the flow rate of air through the condenser vessel and the pressure of the condenser vessel. It is observed that in case of a conventional compression and cooling based atmospheric water generation system, increase in operating compression ratio of the fan / compressor to increase the water condensed out of humid air for the same inlet temperature and flow rate of heat transfer fluid flowing in the heat transfer coil decreases the energy efficiency of the process. Therefore, a conventional compression and cooling based atmospheric water generation system can be made highly energy efficient if operating compression ratio of fan/
compressor is decreased. However prior art teaches that dew point temperature of humid air entering the condenser vessel decreases as the compression ratio of the fan / compressor pushing the humid air in the condenser vessel decreases resulting in lesser condensation of water in the condensation vessel for the same temperature and flow rate of heat transfer fluid flowing in the heat transfer coil. However, it is observed that as the compression ratio of fan / compressor pushing the humid air in the condenser vessel decreases, the flow rate of humid air entering the condenser vessel increases as the compression ratio of fan / compressor is inversely proportional to flow rate of gas flowing through it. This enables more moisture to be available in the condenser vessel at any time for condensation which compensates for the decrease in dew point of humid air entering the condenser vessel resulting in similar or greater quantity of water condensed in the condenser vessel from humid air. To implement low compression ratio of fan / compression in the present invention, a condenser vessel of large dimensions, a large air exit and a fan / compressor capable of operating at a very low compression ratio are used. It is also observed in a conventional compression and cooling based atmospheric water generation system that the air coming out of the atmospheric water generation system is not saturated with water vapors and the temperature of air coming out of the atmospheric water generation system is higher than the dew point temperature of air coming out of the atmospheric water generation system. This implies that some volume of the humid air entering the condenser vessel is bypassing directly to the air exit because of momentum provided to the humid air by the fan / compressor and due to proximity of air exit to air inlet resulting in less average residence time of humid air inside the condenser vessel. Less average residence time of humid air in the condenser vessel means that the humid air is not becoming saturated with water vapors at the pressure and temperature conditions existing in the condenser vessel. This results in less amount of water condensed in the condenser vessel compared to the theoretically possible amount. This problem is resolved to some extent by using a condenser vessel of large dimensions such that air exit is not in close proximity of air inlet. Also, a condenser vessel of large dimensions results in decrease in momentum of humid air increasing the average residence time humid air inside the condenser vessel. To further avoid direct bypassing of humid air from the air inlet near the top of condenser vessel on one side of the condenser vessel to the air exit near the top of the condenser vessel on the other side of the condenser vessel thus increasing the average residence time of air
inside the condenser vessel resulting in more time for the humid air for condensation of water and to get saturated with moisture in the condenser vessel, a vertical baffle is placed in the condenser vessel in the present invention. The baffle is attached to the top of the condenser vessel dividing the condenser vessel into two parts and ends some distance above the bottom of the condenser vessel. Level of the water condensed in the vessel is controlled to be below the level of the bottom end of the baffle to always allow passage of air from air inlet to air exit avoiding buildup of pressure in the condenser vessel. The condenser vessel is chosen to be of large dimensions as larger the dimensions of the condenser vessel, more will be the average residence time of air inside the condenser vessel resulting in more time for the humid air to get saturated with water vapors in the condenser vessel and more amount of water condensed in the condenser vessel. Also, a condenser vessel of large dimension would enable design of a large air exit meaning a low compression ration of the fan / compressor and a lower energy consumption of fan / compressor.
It is an object of the invention to provide a compression and cooling based atmospheric water generation system with better efficiency and more operational flexibility.
It is another object of the invention to provide a water generation system that can be used and optimized for low energy consumption to condense water out of any other gas or mixture of gases apart from air.
It is another object of the invention to provide a liquid generation system that can used and optimized for low energy consumption to condense liquid out of any mixture of gases other than the mixture of air and water vapors as described above at suitable temperature and pressure of condenser vessel using suitable fan / compressor to push or pull the mixture of gases through the condenser vessel and suitable conductive, convective and radiative means of cooling the condenser vessel.
It is another object of the invention to mechanism for dehumidifying humid air using wet or solid desiccants and for humidifying dry air.
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof,
which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.
BRIEF DESCRIPTION OF FIGURES
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure 1 shows a block diagram of an atmospheric water generation system for generating water from atmospheric humid air;
Figure 2 illustrates a schematic of the atmospheric water generation system with a single baffle in accordance with an embodiment of the invention;
Figure 3 illustrates a schematic of the atmospheric water generation system with a plurality of baffles in accordance with an alternative embodiment of the invention;
Figure 4 illustrates a schematic of the atmospheric water generation system without baffles in accordance with an alternative embodiment of the invention;
Figure 5 illustrates a schematic of the atmospheric water generation system using a cooling tower instead of using a refrigeration system in accordance with an alternative embodiment of the invention;
Figure 6 illustrates a schematic of the atmospheric water generation system using water at ambient temperature to cool the condenser vessel in accordance with an alternative embodiment of the invention;
Figure 7 illustrates a schematic of the atmospheric water generation system using a fan or compressor in the air exit line with a single baffle in accordance with an alternative embodiment of the invention;
Figure 8 illustrates a schematic of the atmospheric water generation system using a fan or compressor in the air exit line with a plurality of baffles in accordance with an alternative embodiment of the invention;
Figure 9 illustrates a schematic of the atmospheric water generation system using a fan or compressor in the air exit line without baffles in accordance with an alternative embodiment of the invention; and
Figure 10 illustrates schematic of the atmospheric water generation system using cooling water to cool the condenser vessel in accordance with an alternative embodiment of the invention is illustrated.
Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. Furthermore, in terms of the construction of the system, one or more components of the system may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION:
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
Reference throughout this specification to “an aspect”, “another aspect” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase“in an embodiment”,“in another embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more systems or sub-systems or elements or structures or components proceeded by "comprises...a" does not, without more constraints, preclude the existence of other systems or other sub-systems or other elements or other structures or other components or additional systems or additional sub-systems or additional elements or additional structures or additional components.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
The present invention provides an atmospheric water generation system for generating water from atmospheric humid air. The system includes a fan / compressor which operates at a very low compression ratio to push or pull humid air through a condenser vessel. Very low
compression ratio of fan / compressor is attained by using a condenser vessel of large dimensions with an air exit/ air inlet of large size. Also, the bypassing of humid air from air inlet to air exit is avoided and residence time of humid air in the condenser vessel is increased so that the air in the condenser vessel becomes saturated with water vapors resulting in more condensation of water by placing one or more vertical overlapping baffles in the condensation vessel.
Referring to Figure 1, a block diagram of an atmospheric water generation system for generating water from atmospheric humid air is provided. The system 100 comprises: a condenser vessel 102 including an inlet 104 opening for the humid air and an outlet 106 for exiting dehumidified air, wherein the inlet 104 opening is disposed on a top portion of a first side of the condenser vessel 102 and the outlet 106 opening is disposed on a top portion of a second side of the condenser vessel 102, wherein the inlet 104 opening and the outlet 106 opening are placed at a relative distance to increase residence time of the humid air within the condenser vessel 102. The system 100 further includes at least one compressor or fan 108 disposed near the inlet 104 to push the humid air to enter the condensing vessel 102 through said inlet 104 opening; and at least one condensing coil 110 disposed within an interior space of the condenser vessel or external to the condenser vessel 102 to cool the condenser vessel resulting in condensation of water from humid air present therein; wherein a heat transfer liquid having a predetermined inlet temperature and a predetermined flow rate is circulated through the at least one condensing coil 110 to decrease temperature of the condenser vessel 102 below the dew point temperature of the humid air entering the condenser vessel 102 to condense water present within the humid air. The heat transfer liquid is selected from one or more of water, glycol or any other heat transfer liquid. A flow control valve 112 disposed within a flow channel of the dehumidified air to control outflow rate of the dehumidified air from the condenser vessel 102 to maintain a compression ratio, wherein flow rate of the humid air flowing in the condenser vessel 102, pressure and temperature of the condenser vessel 102, flow rate of dehumidified air flowing out of the condenser vessel 102 and flow rate of condensed water flowing out of the condenser vessel 102 respectively is automatically adjusted such that mass/ molar flow rate of humid air flowing in the condenser vessel 102 is equal to the mass/ molar flow rate of dehumidified air flowing out of the condenser vessel 102 added to mass/ molar flow rate of condensed water
condensing/ flowing out of the condenser vessel 102. The opening of the outlet 106 is automatically adjusted depending on increase or decrease in level of the condensed water in the condenser vessel 102. A compression ratio of less than 1.1 or more particularly less than 1.01 is preferred for the present invention.
In an implementation, the system 100 includes at least one vertical baffle 114 disposed within an inner space of the condenser vessel 102 to increase the average residence time of air in the condenser vessel 102, wherein the top portion of the vertical baffle 114 is attached to an interior top portion of the condenser vessel 102 and a bottom portion of the vertical baffle 114 is near to an interior bottom portion of the condenser vessel 102. In another implementation, the system 100 includes at least two overlapping baffles 114 configured in said condenser vessel 102 such that alternate baffles are connected to top portion of the condenser vessel 102 and bottom portion of the condenser vessel 102 respectively and the bottom portion of the baffles connected to the top portion of the condenser vessel 102 is lower than the top portion of the alternate baffles connected to bottom portion of the condenser vessel 102 to increase the average residence time of air in the condenser vessel 102. A plurality of openings near bottom of the baffles 114 connected to the bottom portion of the condenser vessel 102 are provided to equalize level of condensed water on both sides of the baffles 114. Instead of a plurality of openings near bottom of the baffle 114 to equalize level of condensed water on both sides of the baffle 114, separate openings are provided on both sides of the baffle 114 connected to the bottom portion of the condenser vessel 102 for water outlet.
In an implementation, a gas-gas heat exchanger 116 to cool the humid air entering the condenser vessel using the cold dehumidified air coming out of the condenser vessel 102.
In an implementation, a water outlet valve 118 to extract condensed water from the condenser vessel 102; and at least a fan or compressor in air exit line to suck air out of condenser vessel 102 and create a negative pressure in the condenser vessel 102 is provided. A sensing means 120 is provided to detect level of condensed water within the condenser vessel and extract the condensed water from the condenser vessel. The sensing means 120 include one or more of air humidity detector, moisture level detector, water level detectors known to a person skilled in the art.
In an implementation, the system 100 further comprises a plurality of air inlet valves/air exit valves and vents for controlling flow rate and pressure in the condenser vessel, wherein increasing opening of the air inlet valve or air exit valve causes increase or decrease in pressure inside the condenser vessel respectively and decrease in compression ratio.
In an implementation, the condenser vessel 102 is cooled at least by: blowing air on the condenser vessel 102 using a plurality of fans; and covering outer surface of the condenser vessel by wet cloth or ice.
Referring to Figure 2, a schematic of the atmospheric water generation system referred in Figure 1 in accordance with an embodiment of the invention is illustrated. The system includes a condenser vessel 102 with an air inlet 104 and an air exit 106 on opposite sides of the condenser vessel 102 near the top of the condenser vessel 102, a vertical baffle 114 between the air inlet 102 and air exit 104, a fan or a compressor 108 configured near the air inlet 102, a flow control valve 112 configured in the air exit 106, a cooling/ condensing coil 110 placed inside the condenser vessel 102 or on the walls of the condenser vessel 102, a condensed water outlet valve 118, a level transmitter/ sensing means 120 to transmit level of condensed water to condensed water outlet valve 118, a refrigeration system comprising of a refrigeration compressor 202, an expansion valve 204 and a condenser 206 to cool a tank 208 (glycol tank) containing heat transfer liquid, a heat transfer liquid pump 210 to circulate heat transfer liquid in the cooling coil and a flow control valve 112 to control flow of heat transfer liquid in the cooling coil 110. The condenser vessel 102 is insulated to avoid cooling loss to the atmosphere. The compressor or fan 108 is operated to push humid air inside the condenser vessel 102. The refrigeration system is started and heat transfer liquid circulation inside the cooling coil is started. The air exit valve 122 is opened to allow the dehumidified air to go out of the condenser vessel 102. The condensed water is continuously taken out from the bottom of the condenser vessel 102 by using a pump or by gravity. The condensed water outlet valve 118 is opened sufficiently to control the level of condensed water in the condenser vessel 102 by sensing the level of condensed water using a level transmitter/ sensing means 120. Any heat transfer liquid like ethylene glycol, water etc. can be used in the cooling coil to cool the condenser vessel. As the opening of the air exit valve 122
is increased, the pressure inside the condenser vessel decreases decreasing the compression ratio (= outlet pressure/ inlet pressure). This results in higher flow rate of humid air through the compressor as the flow rate through a compressor is inversely proportional to the compression ratio. As the air exit valve 122 is opened, for same inlet temperature and flow rate of heat transfer liquid flowing in the cooling coil 110, water will start condensing at a different rate in the condenser vessel 102. Also, the outlet temperature of heat transfer liquid and temperature of condenser vessel will change with changed opening of the air exit valve 122. Depending on the increase or decrease in the level of condensed water in the condenser vessel 102, the opening of the condensed water outlet valve 118 gets automatically adjusted resulting in condensed water flowing out of condenser vessel 102 at the same rate at which it is being condensed. For any opening of the air exit valve 122, the flow rate of humid air flowing in the condenser vessel 102, pressure and temperature of the condenser vessel, flow rate of dehumidified air flowing out of the condenser vessel 102 and flow rate of condensed water flowing out of the condenser vessel 102 will automatically get adjusted so that mass/ molar flow rate of humid air flowing in the condenser vessel 102 is equal to the mass/ molar flow rate of dehumidified air flowing out of the condenser vessel 102 added to mass/ molar flow rate of condensed water condensing/ flowing out of the condenser vessel 102. The air exit valve 122 is always kept sufficiently open so that the compression ratio of compressor 108 never exceeds its maximum rated value. The pressure in the condenser vessel 102 and flow rate of air through the condenser vessel 102 is primarily controlled by controlling the opening of air exit valve 122 whereas the temperature of condenser vessel 102 and amount of water condensed out of humid air entering the condenser vessel 102 is primarily controlled by controlling the inlet temperature and flow rate of heat transfer liquid in the cooling coil 110. The pressure in the condenser vessel 102 is adjusted to as low a value as possible so as to decrease the compression ratio to a very low value resulting in very low energy consumption in the compressor or fan 108. A compression ratio of less than 1.1 or more particularly less than 1.01 is preferred for the present invention.
In an implementation, the condenser vessel 102 can be cooled by blowing air on the condenser vessel 102 using fans instead of using a refrigeration system. In another implementation, wet cloth or ice covering of outer surface can also be used to cool the condenser vessel 102 instead of using a refrigeration system.
Referring to Figure 3, a schematic of the atmospheric water generation system with plurality of baffles in accordance with an alternative embodiment of the invention is illustrated. In this particular embodiment, more than one overlapping baffles 114 can be used in the condenser vessel 102 to increase the average residence time of air in the condenser vessel 102 resulting in more time for the humid air to get saturated with water vapors in the condenser vessel 102 and more amount of water condensed in the condenser vessel 102. In case of overlapping baffles 102 attached to the bottom of the condenser vessel 102 and ending some distance away from the top of the condenser vessel 102, one or more openings can be provided near the bottom of such baffles 102 to equalize the level of condensed water on both sides of the baffles 102. Instead of a plurality of openings near bottom of the baffle 114 to equalize level of condensed water on both sides of the baffle 114, separate openings are provided on both sides of the baffles 114 connected to the bottom portion of the condenser vessel 102 for water outlet. Also, a gas-gas heat exchanger 116 can be used to cool the humid air entering the condenser vessel 102 using the cold dehumidified air coming out of the condenser vessel 102. This would result in saving of energy used in the refrigeration system as lesser cooling of humid air entering the condenser vessel 102 in the condenser vessel would be required.
Referring to Figure 4, a schematic of the atmospheric water generation system without baffles in accordance with an alternative embodiment of the invention is illustrated. The present invention as illustrated in Figure 4 can be designed without any baffle 114 in the condenser vessel 102 resulting in some bypassing of humid inlet air to outlet 106 resulting in lesser amount of water condensed in the condenser vessel 102 but with a lesser complicated and cheaper design. Also, a fixed air exit opening could be provided without any air exit valve 122 resulting in less flexibility but decreased cost of the system. Continuous level control of water in the condenser vessel 102 by continuously sensing the level of water in the condenser vessel 102 and regulating the size of bottom opening can also be avoided and water can be removed from the condenser vessel from time to time in a discontinuous manner. This would further decrease the cost of the system.
Referring to Figure 5, a schematic of the atmospheric water generation system using a cooling tower instead of using a refrigeration system in accordance with an alternative embodiment of the invention is illustrated. In case cooling tower is available for supplying cooling water through cooling water inlet 502, then cooling water can be used for cooling the condenser vessel 102 instead of using a refrigeration system for cooling the condenser vessel 102. For using cooling water to cool the condenser vessel 102, the pressure of the condenser vessel 102 should be kept high using a suitable compressor and by a suitable opening of the air exit valve such that the dew point temperature of humid air entering the condenser vessel 102 is more than the temperature of the condenser vessel 102. The flow rate of cooling water through the cooling coil 110 can be increased to decrease the temperature of the condenser vessel 102 and to increase the rate of condensation of water. In case the dew point temperature of humid air entering the condenser vessel 102 is more than the inlet temperature of cooling water then cooling water can be used to condense water from the humid air and taken from cooling water outlet 504 using the embodiment illustrated in Figure 5.
Referring to Figure 6, a schematic of the atmospheric water generation system using water at ambient temperature to cool the condenser vessel in accordance with an alternative embodiment of the invention is illustrated. In this embodiment, water at ambient temperature can be used to cool the condenser vessel instead of using cooling water or a refrigeration system for cooling the condenser vessel 102. Similar to using cooling water to cool the condenser vessel 102, for using water at ambient temperature to cool the condenser vessel 102, the pressure of the condenser vessel 102 should be kept high using a suitable compressor and by a suitable opening of the air exit valve 122 such that the dew point temperature of humid air entering the condenser vessel is more than the temperature of the condenser vessel 102. The flow rate of ambient water through the cooling coil 110 can be increased to decrease the temperature of the condenser vessel 102 and to increase the rate of condensation of water. The water coming out of the cooling coil 110 will be at an elevated temperature which can be used as a heating utility or can be collected and allowed to be cooled to ambient temperature and reused for cooling the condenser vessel 102.
In case the operating compression ratio of fan / compressor used in embodiments shown in figure 2, figure 3, figure 4, figure 5 or figure 6 is high, then a turbo expander or expansion
turbine is used in air exit to transfer the pressure energy to the fan / compressor 108 used in the air inlet thus saving compression energy.
Referring to Figure 7, a schematic of the atmospheric water generation system using a fan or compressor in the air exit line in accordance with an alternative embodiment of the invention is illustrated. In this embodiment, a fan or compressor 702 is used in the air exit line to suck the air out of condenser vessel 102 and create a negative pressure in the condenser vessel 102. A flow control valve 112 can be used in the humid air inlet line to regulate the flow of air through the condenser vessel 102 and pressure of the condenser vessel 102. A refrigeration system comprising of a refrigeration compressor 202, an expansion valve 204, a condenser 204 and a heat transfer liquid tank 208 can be used to cool the heat transfer liquid in the heat transfer liquid tank 208 which can be circulated through a cooling coil 110 placed inside the condenser vessel 102 or outside the condenser vessel 102 to cool the condenser vessel resulting in condensation of water. As the air inlet valve 704 is opened, the flow rate of humid air flowing in the condenser vessel 102 increases. This results in an increase in the pressure existing in the condenser vessel 102 which is also the suction pressure of fan or compressor. As the suction pressure of the compressor increases, the compression ratio (= outlet pressure/ inlet pressure) of the compressor decreases. This leads to an increase in the flow rate of dehumidified air through the fan or compressor as flow rate through a fan or compressor 702 is inversely proportional to compression ratio. Similar to earlier described embodiments, condensed water is allowed to flow out of condenser vessel 102 by a pump attached to the bottom of the condenser vessel 102 and level of condensed water in the condenser vessel 102 is controlled by controlling the opening of the condensed water outlet valve 118. For any opening of the air inlet valve 704, the flow rate of humid air flowing in the condenser vessel 102, pressure and temperature of the condenser vessel 102, flow rate of dehumidified air flowing out of the condenser vessel 102 and flow rate of condensed water condensing/ flowing out of the condenser vessel 102 will automatically get adjusted so that mass/ molar flow rate of humid air flowing in the condenser vessel 102 is equal to the mass/ molar flow rate of dehumidified air flowing out of the condenser vessel 102 added to mass/ molar flow rate of condensed water condensing in/ flowing out of the condenser vessel 102. Air inlet valve 704 is always kept sufficiently open so that the compression ratio of fan or
compressor 702 never exceeds its maximum rated value. A compression ratio of less than 1.1 or more particularly less than 1.01 is preferred for the present invention.
In an implementation, the condenser vessel 102 can be cooled by blowing air on the condenser vessel 102 using fans instead of using a refrigeration system. Also, wet cloth or ice covering of outer surface can also be used to cool the condenser vessel 102 instead of using a refrigeration system.
Referring to Figure 8, a schematic of the atmospheric water generation system using a fan or compressorl08 in the air exit line with plurality of baffles in accordance with an alternative embodiment of the invention is illustrated. In this particular embodiment, more than one overlapping baffles 114 can be used in the condenser vessel 102 to increase the average residence time of air in the condenser vessel 102 resulting in more time for the humid air to get saturated with water vapors in the condenser vessel 102 and more amount of water condensed in the condenser vessel 102. In case of overlapping baffles 102 attached to the bottom of the condenser vessel 102 and ending some distance away from the top of the condenser vessel 102, one or more openings can be provided near the bottom of such baffles 102 to equalize the level of condensed water on both sides of the baffles 102. Instead of a plurality of openings near bottom of the baffle 114 to equalize level of condensed water on both sides of the baffle 114, separate openings are provided on both sides of the baffles 114 connected to the bottom portion of the condenser vessel 102 for water outlet 118. Also, a gas-gas heat exchanger 116 can be used to cool the humid air entering the condenser vessel 102 using the cold dehumidified air coming out of the condenser vessel 102. This would result in saving of energy used in the refrigeration system as lesser cooling of humid air entering the condenser vessel 102 in the condenser vessel 102 would be required.
Referring to Figure 9, a schematic of the atmospheric water generation system using a fan or compressor in the air exit line without baffles in accordance with an alternative embodiment of the invention is illustrated. The present invention as illustrated in Figure 4 can be designed without any baffle 114 in the condenser vessel 102 resulting in some bypassing of humid inlet air
to outlet 106 resulting in lesser amount of water condensed in the condenser vessel 102 but with a lesser complicated and cheaper design. Also, a fixed air exit opening could be provided without any air exit valve 122 resulting in less flexibility but decreased cost of the system. Continuous level control of water in the condenser vessel 102 by continuously sensing the level of water in the condenser vessel 102 and regulating the size of bottom opening can also be avoided and water can be removed from the condenser vessel from time to time in a discontinuous manner. This would further decrease the cost of the system.
Referring to Figure 10, a schematic of the atmospheric water generation system using cooling water to cool the condenser vessel in accordance with an alternative embodiment of the invention is illustrated. In this embodiment, cooling water through cooling water inlet 1002 can be used to cool the condenser vessel 102 in this case only if ambient temperature and relative humidity of the humid air are high. The embodiment includes a cooling water outlet 1004 for exit of the cooling water. High temperature and high relative humidity of the humid air imply high dew point of humid air entering the condenser vessel 102. Dew point of air is directly proportional to pressure. A negative pressure exists in the condenser vessel 102 resulting in lowering of dew point as compared to ambient conditions and a lower condensation rate of water for same temperature and flow rate of heat transfer liquid as compared to ambient conditions. In case, the dew point temperature value of humid air entering the condenser vessel at pressure existing in the condenser vessel 102 is more than the inlet temperature value of cooling water then cooling water through a cooling water inlet 1002 can be used to condense water from the humid air using the embodiment shown in Figure 10. For the same reason, water at ambient temperature cannot be used to cool the condenser vessel 102 in this case as the dew point temperature of humid air entering the condenser vessel 102 at the pressure existing in the condenser vessel 102 will always be lower than the ambient temperature resulting in no cooling of humid air and no condensation of water at the pressure and temperature conditions of condenser vessel 102 in case ambient water is used for cooling the condenser vessel 102. Further, any stream of water or any other fluid available continuously at a temperature lower than the dew point temperature of humid air entering the condenser vessel 102 at the pressure
existing in the condenser vessel can be used to condense water from the humid air using the proposed embodiment shown in Figure 5 or Figure 7.
In an implementation, any other conductive, convective, radiative or inductive means of cooling can be used to lower the temperature of condenser vessel 102 below the dew point temperature value of humid air entering the condenser vessel 102 at pressure existing in the condenser vessel 102 to condense water from the humid air using the invention. Instead of continuously taking out condensed water from the condenser vessel 102, the condensed water can be collected in the condenser vessel 102 for some time. After sufficient amount of condensed water is collected in the condenser vessel 102, the condensed water outlet valve is opened or pump in the condensed water outlet is operated for some time to take out condensed water from the condenser vessel 102.
In an alternative embodiment, instead of using air exit valve in embodiments referred in Figure 2, 3, 5 and 6 or air inlet valve in embodiment referred in Figure 7, 8, 10 numerous vents can be used in the air exit of Figure 2, 3, 5 and 6 or air inlet valve in embodiment referred in Figure 7, 8, 10. Some of these vents could be kept permanently open to avoid increase of compression ratio of fan or compressor beyond the maximum allowed compression ratio to ensure safe and efficient operation of fan or compressor. Other vents can be opened or closed to control the flow rate of air through the condenser vessel and pressure of condenser vessel 102. A combination of one or more than one air inlet valves/ air exit valves and vents could also be used for controlling the flow rate and pressure in the condenser vessel 102.
In another embodiment, a demister could be provided in the air exit to avoid any entrainment of liquid water with the air going out of the condenser vessel. A fine screen or a filter could be placed in the air inlet in case of embodiment referred in Figure 7, 8, 9 and 10 and in compressor/ fan inlet in case of embodiment referred in Figure 2, 3, 4, 5, and 6 to avoid entry of solids like dust and vegetation from entering the condenser vessel or compressor/ fan.
The water generated from the present system could be used for industrial purpose. In case drinkable water is desired then suitable post treatment of ultrapure water can be carried out to
make it drinkable. The present invention n can be used and optimized for low energy consumption to condense water out of any other gas or mixture of gases apart from air. Also, the present invention can be used and optimized for low energy consumption to condense liquid out of any mixture of gases other than the mixture of air and water vapors as described above at suitable temperature and pressure of condenser vessel using suitable fan / compressor to push or pull the mixture of gases through the condenser vessel and suitable conductive, convective, radiative and inductive means of cooling the condenser vessel.
Further, the present invention can be used for dehumidifying humid air using wet or solid desiccants. Also, apart from dehumidifying humid air, the proposed invention can be used for humidifying dry air. To use the present invention for humidifying dry air, the temperature of the vessel is maintained higher than the dew point of dry air entering the vessel by suitable conductive, convective, radiative or inductive means.
Apart from using conventional sources of electricity, any renewable source of energy like solar energy or wind energy can be used to drive the refrigeration system being used for cooling the humid air to condense of water from humid air and fan or compressor being used to transfer air through the condenser vessel.
The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.
Claims
1. An atmospheric water generation system for generating water from atmospheric humid air, said system comprising:
a condenser vessel including an inlet opening for the humid air and an outlet for exiting dehumidified air, wherein the inlet opening is disposed on a top portion of a first side of the condenser vessel and the outlet opening is disposed on a top portion of a second side of the condenser vessel, wherein the inlet opening and the outlet opening are placed at a relative distance to increase residence time of the humid air within the condenser vessel;
at least one compressor or fan disposed near the inlet opening to push the humid air to enter the condensing vessel through said inlet opening;
at least one means of cooling to cool the condenser vessel to decrease temperature of the condenser vessel below the dew point temperature of the humid air entering the condenser vessel to condense water present within the humid air; and
a flow control valve disposed within a flow channel of the dehumidified air to control outflow rate of the dehumidified air from the condenser vessel to maintain a compression ratio, wherein flow rate of the humid air flowing in the condenser vessel, pressure and temperature of the condenser vessel, flow rate of dehumidified air flowing out of the condenser vessel and flow rate of condensed water flowing out of the condenser vessel respectively is automatically adjusted such that mass/ molar flow rate of humid air flowing in the condenser vessel is equal to the mass/ molar flow rate of dehumidified air flowing out of the condenser vessel added to mass/ molar flow rate of condensed water condensing/ flowing out of the condenser vessel.
2. The system as claimed in claim 1 further comprising a baffle disposed within an inner space of the condenser vessel to increase the average residence time of air in the condenser vessel, wherein the top portion of the vertical baffle is attached to an interior top portion of the condenser vessel and a bottom portion of the vertical baffle is near to an interior bottom portion of the condenser vessel.
3. The system as claimed in claim 2 further comprising at least two baffles configured in said condenser vessel to increase the average residence time of air in the condenser
vessel, wherein alternate baffles are connected to top portion of the condenser vessel and bottom portion of the condenser vessel respectively and bottom portion of each of the baffles connected to the top portion of the condenser vessel is lower than the top portion of the alternate baffles connected to bottom portion of the condenser vessel to increase the average residence time of air in the condenser vessel.
4. The system as claimed in claim 2 further comprising: a plurality of openings near bottom of the baffles connected to the bottom portion of the condenser vessel; and wherein separate openings are provided on both sides of the baffle connected to the bottom portion of the condenser vessel for water outlet.
5. The system as claimed in claim 1, wherein opening of the outlet is automatically adjusted depending on increase or decrease in level of the condensed water in the condenser vessel.
6. The system as claimed in claim 1 further comprising a gas-gas heat exchanger to cool the humid air entering the condenser vessel using the cold dehumidified air coming out of the condenser vessel.
7. The system as claimed in claim 1 further comprising a water outlet valve to extract condensed water from the condenser vessel;
8. The system as claimed in claim 1 further comprising a sensing means to detect level of condensed water within the condenser vessel and extract the condensed water from the condenser vessel.
9. The system as claimed in claim 1 further comprising a plurality of air exit valves and vents for controlling flow rate and pressure in the condenser vessel, wherein increasing opening of the air exit valve causes decrease in pressure inside the condenser vessel and decrease in compression ratio respectively.
10. The system as claimed in claim 1, wherein the compression ratio is less than 1.1 or more particularly less than 1.01.
11. The system as claimed in claim 1 , wherein said system further comprises at least one condensing coil disposed within an interior space of the condenser vessel or external to the condenser vessel to cool the condenser vessel resulting in condensation of water from humid air present therein; wherein a heat transfer liquid having a predetermined inlet temperature and a predetermined flow rate is circulated through the at least one condensing coil, and wherein the heat transfer liquid is selected from one or more of water, glycol or other heat transfer liquid.
12. The system as claimed in claim 1, wherein the condenser vessel is cooled at least by: using a cooling tower; blowing air on the condenser vessel using fans; and covering outer surface of the condenser vessel by wet cloth or ice.
13. The system as claimed in claim 1, wherein said means of cooling comprise at least one of conductive, convective, radiative or inductive means of cooling to lower temperature of condenser vessel below dew point temperature value of humid air entering the condenser vessel at a pressure existing in the condenser vessel to condense water from the humid air.
14. An atmospheric water generation system for generating water from atmospheric humid air, said system comprising:
a condenser vessel including an air inlet valve for entry of humid air in said condenser vessel;
a flow control valve connected to line of air inlet valve regulate flow of humid air through the condenser vessel and pressure of the condenser vessel;
at least one fan or a compressor in an air exit line to suck air out of condenser vessel and create a negative pressure in the condenser vessel, wherein increase in suction pressure of said
fan or compressor causes decrease in compressor ratio and increases the flow rate of dehumidified air; at least one means of cooling to cool the condenser vessel to decrease temperature of the condenser vessel below the dew point temperature of the humid air entering the condenser vessel to condense water present within the humid air; a water outlet valve for controlling level of condensed water in the condenser vessel; and a pump attached to bottom of condenser vessel to flow condensed water flow out of condenser vessel, wherein flow rate of the humid air flowing in the condenser vessel, pressure and temperature of the condenser vessel, flow rate of dehumidified air flowing out of the condenser vessel and flow rate of condensed water flowing out of the condenser vessel respectively is automatically adjusted such that mass/ molar flow rate of humid air flowing in the condenser vessel is equal to the mass/ molar flow rate of dehumidified air flowing out of the condenser vessel added to mass/ molar flow rate of condensed water condensing/ flowing out of the condenser vessel.
15. The system as claimed in claim 14 further comprising a baffle disposed within an inner space of the condenser vessel to increase the average residence time of air in the condenser vessel, wherein the top portion of the vertical baffle is attached to an interior top portion of the condenser vessel and a bottom portion of the vertical baffle is near to an interior bottom portion of the condenser vessel.
16. The system as claimed in claim 15 further comprising at least two baffles configured in said condenser vessel to increase the average residence time of air in the condenser vessel, wherein alternate baffles are connected to top portion of the condenser vessel and bottom portion of the condenser vessel respectively and bottom portion of each of the baffles connected to the top portion of the condenser vessel is lower than the top portion of the alternate baffles connected to bottom portion of the condenser vessel to increase the average residence time of air in the condenser vessel.
17. The system as claimed in claim 16 further comprising a plurality of openings near bottom of the baffles connected to the bottom portion of the condenser vessel; and wherein separate openings are provided on both sides of the baffle connected to the bottom portion of the condenser vessel for water outlet.
18. The system as claimed in claim 14 further comprising a gas-gas heat exchanger to cool the humid air entering the condenser vessel using cold dehumidified air coming out of the condenser vessel.
19. The system as claimed in claim 14, wherein said system further comprises at least one condensing coil disposed within an interior space of the condenser vessel or external to the condenser vessel to cool the condenser vessel resulting in condensation of water from humid air present therein; wherein a heat transfer liquid having a predetermined inlet temperature and a predetermined flow rate is circulated through the at least one condensing coil, wherein the heat transfer liquid is selected from one or more of water, glycol or other heat transfer liquid.
20. The system as claimed in claim 15 further comprising a cooling water inlet for supplying cooling water to cool the condenser vessel, and a cooling water outlet for exiting the cooling water.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IN201811048605 | 2018-12-21 | ||
| IN201811048605 | 2018-12-21 |
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| Publication Number | Publication Date |
|---|---|
| WO2020128987A1 true WO2020128987A1 (en) | 2020-06-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/IB2019/061161 WO2020128987A1 (en) | 2018-12-21 | 2019-12-20 | Atmospheric water generation system |
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| Country | Link |
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| WO (1) | WO2020128987A1 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040040322A1 (en) * | 2002-08-30 | 2004-03-04 | Engel Daniel R. | Apparatus and method for extracting potable water from atmosphere |
| US10071918B2 (en) * | 2013-10-14 | 2018-09-11 | John R Ackerman | Water harvester and purification system |
-
2019
- 2019-12-20 WO PCT/IB2019/061161 patent/WO2020128987A1/en active Application Filing
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040040322A1 (en) * | 2002-08-30 | 2004-03-04 | Engel Daniel R. | Apparatus and method for extracting potable water from atmosphere |
| US10071918B2 (en) * | 2013-10-14 | 2018-09-11 | John R Ackerman | Water harvester and purification system |
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