Atmospheric water generator powered by photovoltaic solar energy

Abstract

The invention relates to a photovoltaic device for generating atmospheric water, comprising: - a photovoltaic generator (2); - an air humidifier (H) including a storage compartment (4) for atmospheric water vapor; - a condenser (89) for the air humidified by the humidifier (H); - a power management module (3) for the electrical power produced by the photovoltaic generator (2), configured to prioritize supplying the condenser (89) as soon as the available power (P) exceeds the power (P0) required by the condenser (89), and to supply the air humidifier (H) with a variable electrical power P1, corresponding to the surplus of photovoltaic electrical power available at a given time and not consumed by the condenser (89). Figure for the Abstract: Figure 2

Description

Title of the invention: Atmospheric water generator powered by photovoltaic solar energy

[0001] FIELD OF THE INVENTION The present invention relates to the field of atmospheric water generators powered by photovoltaic solar energy. STATE OF THE ART.

[0002] An atmospheric water generator is a device that extracts water vapor from the air, generally by lowering the air temperature until it reaches the condensation temperature or "dew point". This condensation temperature is a function of numerous parameters including the concentration of water vapor in the air, the relative humidity level, and atmospheric pressure. To lower the air temperature, and therefore create cold, "heat pump" type devices are generally used, which use a compression, expansion, and condensation cycle, or devices that use thermoelectric cells.

[0003] In order to improve the efficiency of atmospheric water generators, there are devices that improve heat exchanges between the hot zones and the cold zones of "heat pumps", or devices that use solar thermal or photovoltaic energy. But solar energy is variable and intermittent and heat and cold generating devices are generally not adapted to this energy constraint. Particularly interesting known atmospheric water generator devices use an adsorption wheel that contains an element that adsorbs moisture from the air at ambient temperature and releases it at a higher temperature. This adsorbent element is, for example, silica gel (silicon hydroxide Si(OH)4)), which is a desiccant.This water generation process therefore requires firstly heating the air and sending it to the adsorbent element to recover the humidity that has been stored in the desiccant, so as to obtain a flow of hot and humid air. Then in a second step it is necessary to cool the flow of hot and humid air to condense its water vapor. The advantage of this device is that it can thus recover water vapor contained in the air even when its humidity level is low, in particular less than 20%.

[0004] Furthermore, the relative humidity of the ambient air increases when the temperature drops, and it might then be advantageous to operate atmospheric water generators preferably at night when the ambient temperature is cooler, rather than during the day. However, this is not possible when the water generator is powered by photovoltaic solar panels, because these do not produce electricity only with the sun's energy, therefore during the day, and it would be too expensive to use electric batteries to operate the water generators in this way at night.

[0005] An example of a known device is described in document WO 2022 / 074682 A1. It attempts to partially resolve this dilemma by thermally storing solar energy during the day by raising the temperature of a heat transfer liquid which will then be used to heat the desiccant which has, initially, stored the atmospheric water vapor. This solution has the advantage of operating the water generation device even during the night thanks to the thermal storage of solar energy from the previous day. But this device does not describe a method for producing cold in a dynamic manner, that is to say for producing temperatures lower than ambient temperature at any time. This would, however, have the advantage of improving the condensation phenomenon, particularly when the outside air temperature is relatively high, which is often the case, even at night, in many hot countries.

[0006] In summary, it can therefore be said that known atmospheric water generators that operate with solar energy do not fully benefit from ideal environmental conditions since they only operate with thermal solar radiation without generating cold, possibly supplemented by a device for storing humidity in desiccant tanks and heat storage which remains quite expensive. In addition, they only operate during the day, while the humidity level in the air is generally higher at night. PURPOSE OF THE INVENTION

[0007] The device which is the subject of the present invention aims in particular to resolve the problems previously set out which are not resolved by the atmospheric water generation devices known in the state of the art.

[0008] Another aim of the present invention is to propose a device using both photovoltaic solar panels arranged to be capable of producing heat and cold, and a buffer storage of humidity in desiccant products to increase the concentration of the humidity level in the air which will be treated by a humidity extractor or condenser.

[0009] Another object of the present invention is to propose a device capable of both minimizing the problem of variability of photovoltaic solar energy thanks to intelligent management of the production and use of photovoltaic electricity and of only needing minimal electrical power for the optimal operation of atmospheric water generators in comparison with the electrical power required in already known devices. SUBJECT OF THE INVENTION

[0010] The device (S) which is the subject of the invention is an atmospheric water generator whose function is to extract the water contained in the ambient air and which operates using solar energy. It comprises a photovoltaic generator supplying electricity to an air humidifier device and an atmospheric water vapor condenser, as well as a module for managing the electrical power produced by the photovoltaic generator and used by the humidifier and condenser devices.

[0011] The photovoltaic generator has a peak electrical power which is equal to Pc and a potential production power at a given instant which is equal to P and which varies over time depending on the sunshine.

[0012] In fact, a photovoltaic generator transforms the sun's irradiation energy into an electrical power which is substantially proportional to the intensity of this light irradiation. As the light intensity of the sun is variable due to its height in the sky and unpredictable cloud passages, the potential electrical power P that the photovoltaic generator can provide is also variable over time.

[0013] The air humidifying device has the function of increasing in absolute value the quantity of water (i.e. a certain number of grams of water contained in a given volume of air, independently of other parameters such as temperature) contained in the air passing through it. Since air is a gas whose weight varies according to its temperature and its capacity to contain water vapor also depends on its temperature, a relative humidity level of the air is also defined as the ratio between the water vapor content of the air and its maximum capacity to contain it at a given temperature. The air humidifying device comprises:

[0014] a) a compartment for storing atmospheric water vapor containing a solid or liquid material capable of adsorbing and then desorbing the water vapor. This material plays the same role as a sponge which can absorb water and then release it on demand. This adsorbent / desorbent material is considered a desiccant when it absorbs the water contained in the air.

[0015] b) a device for extracting the water vapor contained in the storage compartment, this extracting device comprising a means for heating an incoming air flow directed towards the inlet of the storage compartment and a means for cooling the outgoing air flow having passed through the storage compartment and which has become charged with humidity in contact with the desiccant material. The extracting device is supplied with electrical energy by the photovoltaic generator and operates with the surplus electrical power PI which is variable over time and which corresponds to the difference between the power P delivered by the photovoltaic generator and the power PO necessary to operate the condenser. It is in fact necessary to supply heat energy to the desiccant material so that it restores its water to the flow of incoming air whose absolute humidity will therefore increase in the same direction as the temperature of said desiccant material. The energy required to heat the desiccant material comes from the photovoltaic generator which will provide an electrical power PI which varies over time. Since the heating power PI is variable, the absolute humidity rate (quantity of water in grams) of the air leaving the storage compartment will also be variable but higher than that of the air entering this compartment. The cooling of the air leaving the water vapor storage compartment by the cooling means is a preparatory thermal step for the following operation which is the condensation of the water vapor by means of a cold generator forming part of the condenser.

[0016] The atmospheric water vapor condenser sucks in the air flow previously humidified by the humidifying device. It is supplied with electrical energy by the photovoltaic generator and operates with an electrical power consumption PO which is between values ​​POmax and POmin. Unlike the previous air humidification operation whose electrical power consumption PI could be zero (in this case the air flow entering the storage device is at a temperature equal to that of the ambient air), the condenser needs a minimum electrical power supply greater than or equal to a positive threshold POmin to operate.In fact, the condenser includes a cooling means and a heating means which are linked by thermal and electrical exchanges, for example of the "heat pump" type, whose settings, automation and control systems require a minimum of electrical power POmin to coordinate. There are indeed devices generating heat and cold which can operate with a very low electrical power supply close to zero, such as those operating with Pelletier effect thermoelectric components, but the energy performance of these devices is much lower than that of compressor-based devices.

[0017] The management module (3) of the electrical power produced by the photovoltaic generator (2) controls the supply of electricity to the atmospheric water vapor condenser device (89) and to the air humidifier device (H). The management module (3) comprises at least one means for measuring the potential electrical power P that the photovoltaic generator (2) can supply at each instant T, and a means for measuring the electrical power PO consumed at this instant T by the condenser device (89). The management module (3) is configured to be able to calculate the power PI representative of the difference between the potential production power P of the photovoltaic generator (2) at each instant and the power actually consumed PO at this instant by the condenser device (89), this surplus power PI is therefore PI = P - PO.

[0018] The device (S) according to the invention is characterized in that the management module (3) is configured to measure in real time the power P that the photovoltaic generator (2) can produce and to supply the condenser (89) as a priority with the power PO required for its operation, as soon as the power P produced by the photovoltaic generator (2) is greater than said power PO, and to supply the air humidifier device (H) with a variable electrical power PI, corresponding to the surplus photovoltaic electrical power available at a given time and which is not consumed by the condenser (89).

[0019] The electrical power PI therefore corresponds to the variable electrical power which remains available in production by the photovoltaic generator (2) and which has not been consumed by the water vapor condenser device (89). The management module (3) also controls the stopping of the two condenser (89) and humidifier (H) devices when the potential power P of the generator (2) is lower than the minimum operating power (POmin) required by the condenser (89).

[0020] In a preferred embodiment, the device (56) extracting the water vapor contained in the storage compartment (4) or the device (89) condensing the atmospheric vapor, comprises a thermodynamic module of the “heat pump” type using a compression, condensation, expansion and evaporation cycle.

[0021] Alternatively, the water vapor extractor device (56) uses Pelletier effect thermoelectric cells, or an electric heating resistor and air cooling (by means of a fan), and the atmospheric vapor condenser device (89) operates by means of a water vapor adsorption and desorption cycle known and materialized under the name of "adsorption wheel".

[0022] In a particular embodiment, the water vapor extractor device (56) is chosen to be able to operate with a variable electrical power of the PWM (“Pulse Width Modulation”) type, which is the case for example if the extractor device (56) comprises Joule effect thermal resistors or fans with direct current motors.

[0023] In another particular embodiment, the desiccant material (15) contained in the storage compartment (4) is taken from: silica gel, calcium chloride, activated carbon, a zeolite, a hydrogel, a glycol, or a mixture thereof, without this list being restrictive because many desiccant materials are possible which have particular adsorption and desorption characteristics, in particular depending on environmental parameters such as the temperature and the percentage of relative humidity of the air with which they are brought into contact.

[0024] In an advantageous embodiment, the power management module (3) is configured so that, during periods T1, T2, T3 during which the atmospheric water vapor condenser device (89) and the device (56) water vapor extraction are stopped due to an instantaneous potential photovoltaic power P too low to supply them (P being less than PO), said photovoltaic electrical power P is directed towards and consumed by other electrical devices (C1, C2, C3, C4) other than the extraction device (56) and the condenser (89), with an overall electrical power consumption P2 which will be less than or equal to P. This will be suitable for example for charging electric batteries, or for the process of storing atmospheric water vapor which is done by means of electric fans which draw ambient air through the storage compartment (4). This storage will take place during another period (T) preferably chosen during the night.

[0025] In one embodiment, the device (56) for extracting the water vapor contained in the compartment (4) or the condenser (89) of the atmospheric vapor comprises a thermodynamic module of the heat pump type using a cycle of compression, condensation, expansion and evaporation, or comprises thermoelectric cells with the Pelletier effect, or comprises an electric heating resistor and air cooling (fan), and the condenser (89) of the atmospheric vapor operates by means of a cycle of adsorption and desorption of the water vapor.

[0026] In another embodiment, the management module (3), which is capable of calculating the power PI representative of the difference between the potential production power P of the photovoltaic generator (2) at each instant and the power actually consumed PO at this instant by the condenser device (89), the management module (3) comprises a Hall effect direct current intensity sensor (21) which measures in real time the difference between on the one hand the electrical intensity produced by a control photovoltaic cell (22) representative of the potential power P that the generator (2) can produce and on the other hand the electrical intensity actually produced by the photovoltaic generator (2), this difference being representative of the surplus power PI which will be allocated by the management module (3) for the non-priority power supply of the humidifier device (H).

[0027] In another embodiment which is interesting from the point of view of energy savings, the incoming air flow (10) into the air humidifier device (H) is preheated by thermal or hybrid thermal and photovoltaic solar collectors (2). In this case, the thermal solar energy from the thermal or hybrid collectors will preheat the incoming air (10) only if the humidifier (H) and the condenser (89) are in operation, i.e. only if the photovoltaic power (P) is greater than the minimum operating power (PO) of the condenser (89).

[0028] In another embodiment, the atmospheric vapor condenser (89) is configured to send hot air flows to the injection and heating means (5) in order to heat the air entering the storage compartment (4), or to send cold air flows towards the extraction and cooling means (6) in order to cool the air leaving the storage compartment (4).

[0029] The means for injecting and heating (5) the ambient air is arranged so as to heat the ambient air (10) and to inject it (11) into the storage compartment (4);

[0030] In another embodiment, the humidifier (H) comprises a means for heating the interior of the storage compartment (4), in the form of an electrical heating resistor or an electromagnetic wave generator capable of irradiating the desiccant (15) by means of waves, for example of the infrared type or of the microwave type (whose frequency is of the order of 2.4 GHz).

[0031] In another embodiment, the incoming air flow (10) into the air humidifier device (H) is charged with humidity by means of an air duct (18) comprising suction openings (19) positioned above or in a vegetated environment (17). Indeed, the air (20) which is close to the plants is charged with the humidity which evaporates from the plants (17), both during the day when the temperature increases and promotes the natural evaporation of the plants, and at night when the temperature drops and increases the relative humidity level of the air. The device (not illustrated in the figures) which makes it possible to recharge the storage compartment (4) with humidity, will also have the advantage of sucking in the humid air (20) close to the plants (17) by means of this air duct (18) to increase its efficiency.

[0032] A particular embodiment and use of the device (S) according to the invention relates to a vegetated environment (17), possibly in a greenhouse, or whose plants are positioned on a roof (16) or on the facade of a building (not illustrated), and whose irrigation water is, for at least part, the condensation water (7) generated by the solar atmospheric water generator device (S).

[0033] Another embodiment and use of the device (S) makes it possible to save space at the level of the solar energy collection surfaces, in particular when these are positioned in an urban environment or on roofs, by juxtaposing said photovoltaic solar panels (2) and said air duct (18) which draws in the humid air (20) from the vegetated environment (17) in order to create between them (2 and 18) heat exchanges capable of preheating the humidified air (20) which enters (10) the air humidifier device (H). This combination between a photovoltaic surface (2) which heats up in the sun and an air duct (18) which heats up in contact with said photovoltaic surface (2) is an advantageous hybrid system because it makes it possible to reduce the overall surface area for capturing solar energy while maintaining its efficiency, even when the available space is limited.

[0034] Another embodiment and use of the device (S) allows it to operate in an isolated site without any electrical connection to a network of dis public electricity distribution. In this case the management module (3) is configured to be able to measure or calculate in real time the power values ​​PO, PI and P2 without the aid of a connection to any public electricity distribution network.

[0035] Finally, in another improved embodiment, the compartment (4) for storing atmospheric water vapor is formed by several compartments containing a material (15) capable of adsorbing or desorbing atmospheric water vapor, each of said compartments being able to operate, individually or in interconnection with each other, in adsorption or desorption mode, depending on the humidity level of the air leaving said compartments or depending on the weight of the water vapor stored in the different compartments. Indeed, the basic operation of the device (S) only provides for a single compartment (4) for storing humidity in adsorbent materials (15). However, it may be advantageous to store the humidity in a secondary compartment while the main compartment is in the process of discharging its humidity, then to reverse the compartments as soon as one of the two is full or empty.This procedure, which can be extended to several secondary compartments, makes it possible to operate the atmospheric water generator device (S) throughout the time during which the sunshine (1) is sufficient to supply the condenser (89) with electrical power (PO) and with pre-humidification by the humidifying device (H) whose efficiency is ensured by the importance of the humidity load of the different compartments in operation. The measurement of the humidity load of a given water vapor storage compartment (4) can be carried out simply by measuring its weight, compared to its dry weight.

[0036] DETAILED DESCRIPTION OF THE INVENTION The invention is now described in more detail with the aid of indexed figures 1 to 5, in which:

[0037] - [Fig.l] is a graph representing the evolution as a function of time of the electrical power P that a photovoltaic generator (2) can produce during a day; - [Fig.2] is a schematic representation of a solar device (S) generating atmospheric water in accordance with the invention; - [Fig.3] is a graph representing the water absorption capacity of a silica gel (“silica gel” in Anglo-Saxon terminology) at a given temperature, as a function of the humidity level of the ambient air; - [Fig.4] is a graph of water retention (in %) of silica gel as a function of temperature; - [Fig.5] is a schematic representation of the integration and use of the atmospheric water generation device (S) according to the invention, in a vegetated environment.

[0038] Referring to [Fig. 1]. The peak power Pc of a photovoltaic generator (2) like the one shown in [Fig.2] is defined as the power that the photovoltaic generator (2) can produce when it is illuminated by solar radiation of 1000 Watts per square meter perpendicular to its surface. The potential power P that the photovoltaic generator (2) can produce during a day depends on the solar irradiation power, which is a variable data over time.

[0039] This potential electrical power P is used (black area) to supply electricity to a condenser device (89) of atmospheric water vapor ([Fig.2]) which operates with a power PO which can vary between a minimum value POmin and a maximum value POmax which depend on the condenser device (89).

[0040] When the potential power P is greater than PO (corresponding to the horizontally hatched areas of the graph) the surplus power which is equal to PI = P - PO is used to supply electricity to the humidifying device (H) of the atmospheric air, therefore the heating device (5), the cooling device (6) and the ventilation device (not shown because it can be positioned at various locations on the air flow (10), (11), (12), (13) or (14).

[0041] When the electrical power P is lower than the operating power PO of the condenser device (89), then the condenser device (89) and the humidifier device (H) are stopped (corresponding to the zones T1, T2, T3 of the graph in [Fig.l]). The production power P of the generator is then equal to P2 (corresponding to the zones hatched with vertical lines) and it is used to power ancillary devices with preferably variable operating power, such as an electric battery or the humidity charge of said storage compartment (4) which will preferably be done during the night by means of a flow of fresh air which will pass through said compartment (4).The humidity recharge of the humidifier (H) should preferably be done with ambient air whose temperature is lower than that of its operation during the day, therefore mainly at night and by means of a fan powered by electricity from the batteries which will have been charged when the power P is not sufficient to supply the condenser (89) and the humidifier (H) in periods T1, T2, T3 in [Fig.l]. Furthermore, it would not be wise to continue to supply the humidifier (H) with ambient air during the day because the compartment (4) would cool down while a period of operation (zones in black) could arrive again and it will have to reheat the desiccant which will have cooled down.These periods of heating followed by cooling followed by heating would cause energy losses which could reduce the efficiency of the device, whereas a humidity recharging operation at night allows to benefit (continuously) from fresher air and with less energy expenditure (only a fan, the one which could be associated with the heating device (5), and with an air outlet (12) this time drier and which would be oriented (to the . by means of a three-way valve) towards the outside and not towards the cooling device (6) and neither towards the condenser (89).

[0042] [Fig. 2] is a diagram representing the main elements of the solar atmospheric water generator device (S) according to the invention. The solar energy (1) is transformed into electricity by a photovoltaic generator (2) which supplies electricity to both a device (89) for condensing atmospheric water vapor via a supply line (31) and a humidifying device (H) for humidifying atmospheric air (10) via a supply line (32). The humidifying device (H) comprises a compartment (4) which contains a material (15) for adsorbing and desorbing water vapor depending on its temperature. The compartment (4) has an inlet for a flow of hot air (11) which has been heated by a heating means (5) such as for example an electrical resistor, and an outlet for hot and humid air (12). The hot air from the inlet (11) has become loaded with humidity by passing through the adsorbent / desorbent material (15) and comes out as hot and humid air (12).The outgoing air flow (12) is then cooled (13) by a cooling means (6) and is sucked by the condenser (89) which comprises on the one hand a cooling means (8) for condensing the water vapor on a cold surface to obtain water (7), and which comprises on the other hand a means (9) for extracting the hot air (14) from the device. The means (8, 9) may be part of a “heat pump” type device which operates for example using a compressor and the search for performance of which requires an electrical power supply whose power varies between a minimum value POmin and a maximum value POmax.The cooling (6) and heating (5) means of the humidifier (H) may be part of a device (56) whose power supply is compatible with variable electrical power, such as for example electric heating resistors by Joule effect and cooling by an external air / air exchanger using electric fans. Alternatively, thermoelectric cells with Pelletier effect powered by a PWM (Pulse Width Modulation) type voltage may be used.

[0043] The electrical powers (PO, P1, P2) consumed by the different modules (89, 56) are managed by a management module (3) which measures or calculates in real time the different powers PO, PI, P2. This makes it possible to start the condenser (89) and the humidifier (H) only when the potential power P is sufficient to supply the condenser (89) (i.e. when P>P0). In addition, the management module (3) is configured to control the variable surplus power PI which is equal to PI = P - PO, and to supply the humidifier (H) with the available surplus power PI, so as to draw the maximum power (P) from the photovoltaic generator (2).

[0044] [Fig.3] is a graphical representation of the evolution of the adsorption capacity silica gel (in grams of water per 100 grams of silica gel) at a temperature of 25°C and as a function of relative humidity. It can be seen that the adsorption capacity is relatively proportional to the relative humidity. With a maximum adsorption of 33 g per 100 g at 80% relative humidity.

[0045] [Fig.4] is another graphical representation of the evolution of the adsorption capacity of silica gel (in grams of water per 100 grams of gel) as a function of temperature. It can be seen that the adsorption capacity is inversely proportional to the temperature with a minimum of adsorption around 90°C which corresponds to an adsorption rate of approximately 2 grams of water per 100 grams of silica gel. Hence the need to heat the silica gel contained in the reservoir (4) using the heating means (5) to extract the water from the silica gel.

[0046] [Fig. 5] represents a particular mode of use of the device (S) according to the invention, in which the photovoltaic generator (2) is a hybrid generator (photovoltaic and thermal) and is positioned in a vegetated environment (17). The vegetated environment (17) is for example located on a roof (16) and the humid air (20) created by the plants (17) is sucked in through orifices (19) positioned along a pipe (18) which is attached to the photovoltaic solar panel (2) so that the heat of the solar radiation (1) which appears on the surface of said photovoltaic panel (2) is transmitted by conduction to an incoming humid air flow (20) which circulates inside said pipe (18) and which heats up before circulating (10) and entering the humidifier device (H).The humid air flow (20) is preheated by the hybrid solar panel (2) and is heated again by a heating means (5) powered by electricity from the photovoltaic generator (2) with a variable electrical power PI which is a function of the solar radiation (1) at the time. The humid air flow (10) passes through the compartment (4) of the humidifier (H), then is cooled by a cooling means (6) before entering the device (89) to obtain condensation water (7). The management module (3) controls the variable power electrical supply of the humidification device (H) and the fixed power electrical supply of the condensation device (89), following a logic which is that the electrical power (PO) dedicated to the condenser (89) is given priority, and that the remaining surplus power (PI) is allocated to the humidifier (H).In this particular embodiment, the condensation water (7) is used to water the vegetation (17) on a roof (16), thus creating an economical recycling of the watering water. The atmospheric water generating device according to this embodiment comprises additional electrical devices (C1, C2, C3, C4) optionally powered by the photovoltaic generator (2) and serving if necessary for the operation of additional applications (not shown) such as the charging of an electric battery, a lifting pump for . roof watering, circulation of air flows by fan, lighting of premises, treatment of condensation water to make it drinkable. EXAMPLE OF ACHIEVEMENT

[0047] In a practical embodiment, an atmospheric water generator (S) according to the invention comprises: - 25 m2 of photovoltaic panels (2) with a peak power of Pc = 5 kWc. - An inverter (not shown) which transforms the direct current from the panels photovoltaic (2) in 230 V alternating current in self-consumption mode (without connection to a public electricity network).

[0048] The device is located at a latitude of 21° S (on Reunion Island).

[0049] The photovoltaic panels (2) receive an overall luminosity per day equivalent to 6 hours of sunshine at 1000 W / m2, i.e. a daily production of approximately 6x5 kWc = 30 kWh when all the electrical energy produced is consumed.

[0050] A compartment (4) for humidifying the ambient air contains 200 kilograms of silica gel in balls 3 mm in diameter and can adsorb 20% of its weight in water at 20°C and only 7% of its weight in water at 65°C, and can therefore restore 13% of its water thanks to this increase in temperature, i.e. 26 liters of water.

[0051] A dehumidifier type water vapor condenser (89) operates with an average electrical power of approximately PO = 2.2 kW and produces 2 liters of water (7) per hour when the ambient air is at 20°C and 60% relative humidity, and when it operates without the humidifier (H) during the 6 hours of operation it therefore produces 2x6 = 12 liters of water.

[0052] When the humidifier (H) operates thanks to the surplus power PI obtained using the management module (3), then the condenser (89) with the same operating power of 2.2 kW condenses 4 liters of water (7) per hour, or 24 liters during the 6 hours of operation.

[0053] The surplus photovoltaic energy PI not consumed by the condenser (89) will have been used to heat the inlet air of the water vapor storage compartment (4) from 20°C to 65°C in order to return 4 liters of water vapor per hour at the outlet at the condenser (89), i.e. double what it would have condensed under normal conditions of temperature and relative humidity of the ambient air and without the humidification device (H). This was made possible thanks to the photovoltaic energy management module (3) which was able to give priority to the use of the electrical production P to the dehumidifier / condenser (89) and use the remaining surplus energy PI for the operation of the humidifier (H). Without this management according to the invention, all of the potential photovoltaic energy P could not have been consumed with maximum efficiency for this water generation application. solar atmospheric (S). ADVANTAGES OF THE INVENTION

[0054] Ultimately, the invention responds well to the set aims by proposing a device which solves the problem of the variability of solar energy thanks to intelligent management of the production of photovoltaic electricity which is redistributed partly for the condensation of atmospheric water and partly to concentrate the humidity of the ambient air during periods of low sunshine, or even during the night, thanks to a humidity storage device combined with a management module (3) which optimally distributes the supply energy between the condenser and the humidifier.

[0055] Consequently, the device (S) according to the invention makes it possible to produce more water per unit of available photovoltaic surface. The additional water is obtained at low cost, since the device (S) only adds to the known systems inexpensive, non-polluting, long-life components that are infinitely recyclable, as is the case for silica gel. The surplus photovoltaic power obtained and used thanks to the intelligent management by the management module (3) is of the order of 30-40%, is used here to generate water, whereas this surplus available power is typically not used and therefore wasted in existing systems.

[0056] The invention is particularly useful in developing countries in the South that need systems capable of producing electrical energy and drinking water in an optimized manner. The invention is more generally useful when the photovoltaic generator is positioned in an isolated site, without any electrical connection to a public electricity distribution network.

Claims

Claims

1. Device (S) generating atmospheric water powered by solar energy (1) and comprising: - a photovoltaic generator (2) whose electrical production power P is variable over time (T) depending on the sunshine (1); - an air humidifying device (H) comprising: a) a storage compartment (4) for atmospheric water vapor containing a solid or liquid dehydrating material (15) capable of adsorbing and desorbing water vapor, the storage compartment (4) comprising an air inlet and an air outlet; b) means for injecting and heating (5) the ambient air arranged so as to heat the ambient air (10) and inject it (11) into the storage compartment (4); c) a means for extracting and cooling (6) the air flow (12) available at the outlet of the storage compartment (4) and which has become charged with humidity in contact with the dehydrating material (15), the assembly consisting of the injection and heating means (5) and the extraction and cooling means (6) forming a device (56) for extracting water vapor, capable of using for its operation a variable supply power a condenser (89) of atmospheric water vapor, which sucks in the air flow (13) previously humidified and cooled by the air humidifying device (H) and which requires for its operation an electrical supply power denoted PO; - a management module (3) of the electrical power produced by the photovoltaic generator (2) and used to electrically supply the air humidifier device (H) and the condenser device (89), this management module (3) of the electrical power being configured to measure in real time on the one hand the instantaneous electrical power P that the photovoltaic generator (2) can produce with regard to the power of the solar radiation that it receives and on the other hand a surplus PI of photovoltaic electrical power available and not used by the condenser device (89), this surplus PI of available electrical power being variable and being substantially equal to PI = P - PO; the device (S) being characterized in that said means (6) for cooling and extracting the air flow (12) leaving the storage compartment (4) is supplied with a variable electrical power corresponding to the surplus PI of photovoltaic electrical power available at a given time, since the electrical power P produced by the photovoltaic generator (2) is greater than said electrical power PO used by the condenser (89).

2. Device (S) according to the preceding claim 1, characterized in that the atmospheric vapor condenser (89) is configured to send hot air flows to the injection and heating means (5) in order to heat the air entering the storage compartment (4), or to send cold air flows to the extraction and cooling means (6) in order to cool the air leaving the storage compartment (4).

3. Device (S) according to any one of the preceding claims, characterized in that it comprises a means for heating the interior of the storage compartment (4), in the form of an electrical heating resistor or an electromagnetic wave generator capable of irradiating the desiccant (15) by means of waves, for example of the infrared type or of the microwave type, the frequency of which is of the order of 2.4 GHz.

4. Device (S) according to any one of the preceding claims, characterized in that the device (56) for extracting the water vapor contained in the compartment (4) or the condenser (89) of the atmospheric vapor comprises a thermodynamic module of the heat pump type using a cycle of compression, condensation, expansion and evaporation, or comprises thermoelectric cells with Pelletier effect, or comprises an electric heating resistor and air cooling (fan), and the condenser (89) of the atmospheric vapor operates by means of a cycle of adsorption and desorption of the water vapor.

5. Device (S) according to any one of the preceding claims, characterized in that the means for injecting and heating (5) the ambient air and the means for extracting and cooling (6) the air flow (12) are capable of operating with a variable electrical power of the PWM (“Pulse Width Modulation”) type.

6. Device (S) according to any one of the preceding claims, characterized in that the material (15) contained in the compartment of storage (4) is taken from: silica gel, calcium chloride, activated carbon, zeolites, hydrogels, glycols.

7. Device (S) according to any one of the preceding claims, characterized in that the power management module (3) is configured so that, during periods (T1, T2, T3) during which the condenser (89) and the water vapor extraction device (56) are stopped due to a photovoltaic power P that is too low to supply them (P being less than PO), said photovoltaic electrical power P is consumed, at least for a part noted P2, for charging electric batteries, or for supplying fans drawing ambient air through the storage compartment (4) during another period (T) preferably chosen during the night.

8. Device (S) according to any one of the preceding claims, characterized in that the management module (3) comprises a Hall effect direct current intensity sensor (21) which measures in real time the difference between, on the one hand, the electrical intensity produced by a control photovoltaic cell (22) representative of the potential power of the production P of the photovoltaic generator (2) and, on the other hand, the electrical intensity actually produced by the photovoltaic generator (2), this difference being representative of the surplus power PI which will be allocated to the non-priority power supply of the air humidifier device (H).

9. Device (S) according to any one of the preceding claims, characterized in that the air flow (10) entering the air humidifier device (H) is preheated by thermal or hybrid thermal and photovoltaic solar collectors.

10. Device (S) according to any one of the preceding claims, characterized in that the air flow (10) entering the air humidifier device (H) is charged with humidity by means of an air duct (18) comprising air suction openings (19) positioned above or in a vegetated environment (17).

11. Device (S) according to claim 11, characterized in that the vegetated environment (17) consists of plants positioned on a roof (16) or on the facade of a building, and at least part of the condensation water (7) generated by the device (S) is used for watering said plants.

12. Device (S) according to one of claims 11 to 12, characterized in that said photovoltaic solar panels (2) and said air duct (18) which sucks in the humid air (20) from the vegetated environment (17) are juxtaposed in order to create thermal exchanges between them capable of preheating the humidified air (20) which enters the air humidifier device (H).

13. Device (S) according to any one of the preceding claims, characterized in that it is installed in an isolated site without any electrical connection to a public electrical distribution network.

14. Device (S) according to any one of the preceding claims, characterized in that the storage compartment (4) comprises several compartments containing a material (15) capable of adsorbing or desorbing atmospheric water vapor, each of said compartments being able to operate, individually or in interconnection with each other, in adsorption or desorption mode, depending on the humidity level of the air leaving said compartments or depending on the weight of the water vapor stored in the different compartments.

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