SOLAR THERMAL PANEL AND METHOD FOR PRODUCING WATER

Abstract

Solar thermal panel (1) for producing water, comprising a frame (2), a reflective solar concentration surface (3), a heat exchanger (10) which is positioned at the solar focusing axis (A) and comprising a container (11) comprising an ambient humidity desiccator material (11a), at least one opening (12), a first valve (13) which is positioned at the at least one opening (12) and selectively actuatable by moving from an open configuration to a closed configuration so as to selectively and reversibly allow the fluid-dynamic connection between the desiccator material (11a) and surrounding ambient air.

Claims

1. A solar thermal panel (1) for producing water, comprising a frame (2), a reflective solar concentration surface (3) which is secured to the frame (2) having a solar focusing axis (A), at which it concentrates incident solar rays, a heat exchanger (10) which is positioned at the solar focusing axis (A) and comprising a container (11) comprising an ambient humidity desiccator material (11a), at least one opening (12), a first valve (13) which is positioned at the at least one opening (12) and which is selectively actuatable by moving from an open configuration to a closed configuration so as to selectively and reversibly allow the fluid-dynamic connection between the desiccator material (11a) and surrounding ambient air.

2. A thermal panel (1) according to the preceding claim, wherein the container (1) has an elongate form and is arranged parallel with the solar focusing axis (A).

3. A solar thermal panel (1) according to the preceding claim, comprising two openings (12a, 12b) which are arranged at opposite ends of the container (1).

4. A solar thermal panel (1) according to claim 2 or 3, wherein the container (11) is a tubular cylinder.

5. A solar thermal panel (1) according to claims 3 and 4, wherein the openings (12a, 12b) are constructed at respective opposing bases of the tubular cylinder.

6. A solar thermal panel (1) according to any one of the preceding claims, wherein the container (11) has an opaque surface layer.

7. A solar thermal panel (1) according to any one of the preceding claims, wherein the container (11) comprises a forced air circulation device (14) which is received near the at least one opening (12) so as to generate a forced air current ingoing into or outgoing from the container (11).

8. A solar thermal panel (1) according to any one of the preceding claims, comprising a transparent closure surface (4) which is secured to the frame (2) and/or the reflective surface (3) so as to define an internal closed space (Si) of the solar thermal panel (1) and the container (11) being at least partially contained, in a radial direction with respect to the focusing axis (A), inside the internal closed space (Si).

9. A solar thermal panel (1) according to the preceding claim, wherein the container (11) is completely contained in a radial direction with respect to the focusing axis (A), inside the internal closed space (Si).

10. A solar thermal panel (1) according to any one of the preceding claims when dependent on claim 2, wherein the desiccator material (11a) is arranged in accordance with a longitudinal axis of the container.

11. A solar thermal panel (1) according to any one of the preceding claims, comprising a collection device (30) for the water which is produced inside the container (11) and which is released from the desiccator material (11a), which collection device (30) is fluid-dynamically connected to a collection opening (18) of the container (11) by means of a first duct (31).

12. A solar thermal panel (1) according to any one of the preceding claims, comprising a photovoltaic panel (80).

13. A solar thermal panel (1) according to claim 12 when dependent on claim 8, wherein the photovoltaic panel (80) is secured to the closure surface (4).

14. A solar thermal panel (1) according to claim 12 or 13, wherein the photovoltaic panel comprises three modules which are arranged in an I-shaped manner, wherein two of the three modules are arranged externally with respect to the reflective solar surface (3) and a third module is at least partially overlaid on the container (11).

15. A solar thermal panel (1) according to any one of the preceding claims, wherein the desiccator material (11a) is arranged in accordance with a multi-layered arrangement.

16. A solar thermal panel (1) according to any one of the preceding claims, comprising a collection device (30) for the water which is produced inside the container (11) and which is released from the desiccator material (11a), which collection device is fluid-dynamically connected to a collection opening (18) of the container (11) by means of a first duct (31).

17. A solar thermal panel (1) according to any one of the preceding claims, wherein the desiccator material (11) comprises silica gel or zeolites, MOF, ACF (Activity Carbon Felt made from woven or nonwoven fabric).

18. A solar thermal panel (1) according to any one of the preceding claims, wherein the container (11) comprises at least one housing which is made from woven/nonwoven fabric and which is provided to contain the desiccator material.

19. A solar thermal panel (1) according to any one of the preceding claims, wherein the desiccator material (11a) comprises respective desiccating elements which are arranged in a plurality of successive desiccation zones in the advance direction of the air flow.

20. A solar thermal panel (1) according to claim 19, wherein each desiccation zone of the plurality of desiccation zones has a uniform or increasing number of desiccating elements in the direction of the air flow.

21. A solar thermal panel (1) according to any one of the preceding claims, wherein the solar concentration thermal panel is parabolic.

22. A solar thermal panel (1) according to claim 21, wherein the parabolic form is determined according to a parabola having the formula:
Y=x{circumflex over ()}2/4F where F is between 300 mm and 500 mm.

23. A solar thermal panel (1) according to any one of the preceding claims, wherein there is defined a gap (17) which is contained between the exchanger (10) and the container (11), which comprises channels (17a) which are arranged in a radial direction with respect to a longitudinal axis of the container (11) and which are formed so as to allow the free passage of water vapour when it is desorbed by the desiccator material (11a).

24. A solar thermal panel (1) according to any one of the preceding claims, comprising at least one humidity sensor (16) for measuring a humidity value inside the container.

25. A solar thermal panel (1) according to the preceding claim, comprising two humidity sensors (16, 16) which are arranged at respective ends of the container and which are configured so as to monitor a variation in the humidity inside the container (11).

26. A solar thermal panel (1) according to any one of the preceding claims when dependent on claim 3, wherein the two openings (12a, 12b) define an introduction side and a discharge side of the container (11) and/or the heat exchanger (10), an advance direction of an air flow being defined between the introduction side and discharge side.

27. A solar thermal panel (1) according to the preceding claim, wherein the direction of the air flow is linear and the openings (12a, 12b) directly face the heat exchanger in the advance direction of the air flow.

28. An apparatus (100) for producing water from ambient humidity, comprising at least one solar thermal panel (1) for producing water according to any one of the preceding claims, a support device (110) which is configured to secure the solar thermal panel (1) with permitted rotation with respect to a support plane.

29. An apparatus (100) for producing water from ambient humidity according to the preceding claim, comprising a hydroponic or aeroponic greenhouse device connected to the solar thermal panel (1).

30. A method for producing water from ambient humidity, comprising: circulating forced air comprising humidity in a heat exchanger (10) by means of a forced air circulation device (14), the heat exchanger (10) comprising a desiccator material (11a) which is suitable for retaining a portion of the ambient humidity contained in the circulating air, heating, by means of a solar concentration thermal panel (1) comprising the heat exchanger (10), the desiccator material (11a) to a temperature greater than 100 C., evaporating water vapour from the desiccator material (11a), condensing the evaporated water vapour by cooling on at least one wall of the heat exchanger and collecting it in a collection device (30).

31. A method for producing water from ambient humidity according to claim 30, comprising circulating air comprising humidity in the heat exchanger for a time less than or equal to half an hour, evaporating water from the desiccator material for a time less than or equal to half an hour, completing all the operations previously described as being relevant to the above-mentioned method within one hour.

32. A method for producing water from ambient humidity according to claim 30 or 31, wherein the air is circulated in the heat exchanger for a time of 12 hours, during the day, and is evaporated for a time of 12 hours, during the night.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The features and advantages of the invention will be better appreciated from the detailed description of an embodiment which is illustrated, by way of non-limiting example, with reference to the appended drawings, in which:

[0084] FIG. 1 is a schematic, perspective illustration of a solar thermal panel for producing water,

[0085] FIG. 2 is a perspective view of an apparatus for producing water, comprising the solar thermal panel of FIG. 1,

[0086] FIG. 3 is a side view of the apparatus of FIG. 2,

[0087] FIG. 4 is a plan view of the solar thermal panel of FIG. 1,

[0088] FIG. 5 is a perspective view of the cross-section V of the solar thermal panel of FIG. 4,

[0089] FIG. 6 is a perspective view of the cross-section VI of the solar thermal panel of FIG. 4,

[0090] FIG. 7 is another perspective view of the solar thermal panel according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0091] In FIG. 1, there is generally designated 1 a solar thermal panel for producing water from ambient humidity.

[0092] The invention produced according to the embodiments of the present invention allows drinking water with a high level of purity to be produced without bacteria or other contaminating factors.

[0093] Furthermore, the above-mentioned invention is capable of operating correctly in environments having an ambient humidity level between 10 and 100%.

[0094] As schematically illustrated in FIG. 1, the improved solar thermal panel 1 for producing water according to the present invention comprises a heat exchanger 10, the features of which will be described in greater detail below. The solar thermal panel 1 comprises a frame 2 and a reflective solar concentration surface 3 which is secured to the frame 2, having a solar focusing axis A, at which it concentrates incident solar rays.

[0095] Still with reference to FIG. 1, the heat exchanger 10 is positioned at the solar focusing axis A.

[0096] In greater detail, the heat exchanger 10 comprises a container 11 comprising in turn a desiccator material 11a for ambient humidity, at least one opening 12 and at least a first valve 13 which is positioned in the region of the at least one opening 12.

[0097] The first valve 13 is selectively actuatable by moving from an open configuration to a closed configuration so as to allow in a selective and reversible manner the fluid-dynamic connection between the desiccator material 11a and the surrounding ambient air.

[0098] With reference to FIGS. 1 to 6, it may be noted that the concentrated solar thermal panel 1 is thermally connected to the heat exchanger 10 in order to impart heat thereto.

[0099] In the context of the present invention, and as will be illustrated in greater detail below, the term concentrated solar panel is intended to refer to a reflective panel or a system of panels, wherein the solar radiation is concentrated at a respective focusing location or axis. Typically, concentrated solar panels allow extremely high temperatures to be reached, even greater than 600 C., in the region of the above-mentioned focusing location or axis.

[0100] With reference to FIG. 1, the concentrated solar thermal panel 1 is parabolic, that is to say, a reflective portion of the panel extends in accordance with a geometric parabola.

[0101] As shown in FIGS. 1, 4 and 5, the container 11 has a cylindrical tubular shape.

[0102] As shown in FIGS. 5 and 6, the heat exchanger 10 has a cylindrical tubular shape and the container 11 is a tube which is placed inside it coaxially.

[0103] Still with reference to FIGS. 5 and 6, it may be noted how the container 11 extends longitudinally beyond the heat exchanger 10. In some embodiments, the at least one opening 12 includes two opposite openings 12a, 12b. Advantageously, the openings 12a, 12b are defined at each of the two opposite bases of the container 11, respectively.

[0104] These openings 12a and 12b are functional and allow the passage of air and therefore of ambient humidity inside the container 11 so that the desiccator material contained therein can adsorb the humidity present.

[0105] Still with reference to FIGS. 5 and 6, it may be noted that the container 11 has curved tubular portions once it is extended beyond the dimension of the exchanger 10 and the solar reflective surface 3. In this manner, it is possible to insert additional desired devices which are connected fluid-dynamically to the air passing through in the tube of the container 11, further reducing the required dimensions.

[0106] As shown in FIG. 6, the tubular container 11 extends beyond the exchanger 10, producing a first curved portion 30 which rotates through approximately 90 and in which a thermal sensor 15 (preferably an NTC probe), a humidity sensor 16 and a first forced air circulation device 14 are received. In the embodiment described by way of non-limiting example, this forced air circulation device 14 is an impeller.

[0107] Still considering FIG. 6, the tubular container 11 extends beyond the exchanger 10 at the opposite side to the side of the first curved portion 30, also curving in this case and rotating through approximately 90, thereby forming a second curved portion 35. In this second curved portion 35, there are received an additional humidity sensor 16 and a second valve 13.

[0108] The presence of the two humidity sensors 16, 16 at respective ends allows monitoring of the variation in the humidity inside the container 11 and therefore an understanding of how the evaporation process is working.

[0109] Preferably, in this sense, when the relative difference in humidity read between the two humidity sensors 16, 16 is substantially zero, the evaporation step is ended and the adsorption process begins.

[0110] In this configuration, the first valve 13 acts as an inlet valve for the humid air into the container 11 while the second valve 13 acts as an outlet valve for the humid air out of the container 11.

[0111] With reference to FIG. 5, it may be noted that there is present a gap 17 which is contained between the exchanger 10 and the container 11 and which comprises channels 17a which are arranged in a radial direction with respect to the longitudinal axis of the container 11 (and the focusing axis A) and which are formed so as to allow the free passage of the water vapour when it is desorbed by the desiccator material 11a.

[0112] In this manner, it is possible to condense and collect the desorbed water vapour by cooling on the walls.

[0113] Furthermore, this gap can be used to facilitate the recirculation of the humid air during the adsorption steps.

[0114] According to another embodiment shown in FIG. 7, the second portion 35 comprises in an initial section thereof a pit 40 which is fluid-dynamically connected to the container 11 and which is formed so as to collect or remove the water vapour which is desorbed by the desiccator material 11a. Preferably, the pit 40 has a spatial extent which is substantially U-shaped and is connected to a coil arrangement 41 which serves to condense the collected water vapour in an optimum manner.

[0115] In an alternative form, the desiccator material 11a can be positioned in the gap 17 and the tubular container 11 comprises holes which are suitable for discharging the water vapour in a uniform manner so that it is adsorbed by the desiccator material 11a.

[0116] Preferably, the water vapour which is desorbed and condensed on the walls of the heat exchanger 10 is collected and brought into the region of a collection opening 18 which is connected by means of a first duct 31 to a collection device 30.

[0117] According to a preferred embodiment, the desiccator material 11a comprises silica gel or similar hygroscopic materials.

[0118] The Applicant has found that silica gel is capable of adsorbing and desorbing the ambient humidity in a highly efficient and rapid manner without having significant hysteresis during the repetition of the cycles.

[0119] This affords the advantage of being able to repeat the adsorption and desorption operations a high number of times while keeping constant the performance levels of the desiccator material 11a.

[0120] In order to be able to be contained in a simple manner, the desiccator material can be inserted inside a woven/nonwoven bag.

[0121] This woven/nonwoven bag allows the desiccator material 11a to be retained therein efficiently and at the same time allows an effective transpiration by means of the individual holes present in the structure during the adsorption and desorption steps.

[0122] In any case, it is evident that there can also be provided different solutions and configurations of the desiccator material 11a inside the heat exchanger 10.

[0123] With reference to FIGS. 1 and 2, the solar thermal panel 1 comprises a closure surface 4 which is transparent to incident radiation and which is secured to the frame 2 so as to define an internal closed space Si of the solar thermal panel 1. As may be noted, the container 11 is at least partially contained inside the internal closed space Si in a longitudinal direction while it is completely contained in the internal closed space Si in a radial direction with respect to the focusing axis A.

[0124] With reference to FIGS. 1 and 2, the solar thermal panel 1 comprises a photovoltaic panel 80, which is preferably secured to the closure surface 4. Still with reference to FIG. 2, the photovoltaic panel 80 comprises three modules which are arranged in an I-shaped manner.

[0125] With reference to FIGS. 2 and 3, it may be noted that the solar thermal panel 1 is rotatably secured to a support 110, thereby forming an apparatus 100 for producing water.

[0126] In greater detail, the support 110 allows a rotation about a horizontal axis so as to be able to bring about a preferred inclination with respect to the vertical and a rotation about a vertical axis so as to rotate the solar thermal panel 1, in a manner best tracking the trajectory of the sun.

[0127] The support 110 also comprises one or more motors which are necessary for moving the desired members.

[0128] Furthermore, the apparatus 100 comprises a hydroponic or aeroponic greenhouse (not shown in the Figures) which is connected fluid-dynamically downstream of the water collection device 30.

[0129] Not only does it thereby become possible to produce purified water which can be consumed by human beings, but it is also possible to cultivate desired plants efficiently.

[0130] The operating modes of the apparatus 1 for producing water from ambient humidity, defining the method of the present invention, comprise the operations set out below.

[0131] Air comprising humidity is circulated by means of the impeller 14 through the first opening 12a and inside the container 11 of the heat exchanger 10 and, as a result of the presence of the desiccator material 11a, a portion of the ambient humidity contained in the air is retained.

[0132] The heat exchanger 10 is heated by means of the concentrated solar thermal panel 1 to a temperature greater than or equal to 100 C.

[0133] The two operations can be carried out at the same time or separately as a result of the presence of the first valve 13. When the desiccator material 11a has absorbed sufficient humidity, the first valve 13 is closed. The opposite second valve 13 is also preferably closed so as to delimit a finite volume to be processed.

[0134] The concentrated solar radiation from the reflective surface 2 heats the heat exchanger 10, bringing it to temperatures greater than 100 C. Under these conditions, the water vapour which is collected by the desiccator material 11a is desorbed by evaporation and then condensed by cooling on the walls of the heat exchanger 10 itself.

[0135] At this point, it is possible to collect the water vapour which is condensed to form water in the collection device 30.

[0136] Preferably, the above-mentioned method comprises condensing the evaporated water vapour either by cooling on a wall which is contained in the heat exchanger 10 under standard ambient pressure conditions (equal to approximately 1 atm) or by cooling with mixing of air at temperatures less than the temperature of the water vapour.

[0137] Alternatively, the condensation of the water can be optimized by using a centrifugal filter (advantageously comprising a lamellar filter) which allows the condensed water to be separated from the mixed gas by means of a centrifuge.

[0138] The management of the two water adsorption and desorption/condensation steps can be assigned to a simple processing unit (not shown in the Figures) which allows the actuation operations to be controlled and programmed.

[0139] In one embodiment of the above-mentioned method, for example, it is possible for air comprising ambient humidity, and therefore absorbed humidity, to be circulated in the heat exchanger 10 for a time of at least half an hour.

[0140] Preferably, the circulation of the air may be carried out for a time greater than one hour.

[0141] In this manner, the desiccator material 11a is placed under conditions so as to be able to adsorb molecules of water therein (if it is not already saturated).

[0142] Subsequently, water vapour is evaporated from the desiccator material 11a for a time which is preferably at least half an hour.

[0143] Preferably, all the operations previously described in the water adsorption and desorption steps in the desiccator material 11a are completed within an hour.

[0144] Advantageously, these operations are repeated a number of times over the course of twenty four hours. This operating mode allows programming of the water production on a daily basis and therefore having an expectation of the possibility of production which is predictable and reproducible.

[0145] Alternatively, for example, it may be possible to programme the two above-mentioned steps in such a manner that each one lasts 12 hours.

[0146] The final user will have the ability to define the water adsorption and desorption steps in accordance with individual specific needs.