Solar film distillation device

Abstract

This invention provides a solar membrane distillation device, comprising: a brine tank having a receiving cavity for containing brine and an outlet and an inlet connected to the receiving cavity; a tubular photothermal conversion membrane, one end of which is connected to the outlet and the other end of which is connected to the inlet, the outer surface of which is coated with a heat-absorbing material and the inner surface of which is coated with a hydrophobic material; and a collection unit including a freshwater tank and a transparent cover covering the freshwater tank, the freshwater tank having a freshwater storage cavity for containing freshwater, the inner cavity of which is connected to the freshwater storage cavity, and the tubular photothermal conversion membrane disposed inside the transparent cover. The technical solution provided by this application can solve the problem in related technologies where membrane fouling easily occurs during brine treatment, thus affecting the brine separation efficiency of the photothermal conversion membrane.

Description

Technical Field

[0001] This invention relates to the field of membrane distillation technology, and more specifically, to a solar membrane distillation apparatus. Background Technology

[0002] Due to the scarcity of freshwater resources and the increasing amount of brine, the demand for desalination technology is becoming increasingly urgent. Membrane distillation, as an emerging separation technology, combines membrane separation technology and low-temperature evaporation technology. It mainly utilizes the vapor pressure difference across a photothermal conversion membrane. Volatile substances (usually water) in the brine vaporize on the hot side of the membrane and pass through the photothermal conversion membrane under the action of the vapor pressure difference, then condense into a liquid. Non-volatile substances are retained by the photothermal conversion membrane, thereby achieving the purpose of separating freshwater.

[0003] Among the related technologies, one type uses a photothermal conversion membrane made of hydrophilic material, with a heat-absorbing material coated on the membrane, so that the heat-absorbing material is on top of the membrane and the brine is below. The heat-absorbing material absorbs solar energy to heat the photothermal conversion membrane, thereby heating the brine and achieving freshwater vaporization separation. Another type uses a photothermal conversion membrane made of hydrophobic material, with a heat-absorbing material coated on the membrane, so that the heat-absorbing material is on top of the membrane and the brine is above it. The heat-absorbing material absorbs solar energy to heat the photothermal conversion membrane, thereby heating the brine and achieving freshwater vaporization separation.

[0004] However, in related technologies, photothermal conversion membranes made of hydrophilic materials are used to treat brine. The high thermal conductivity of hydrophilic materials results in low heat utilization. Conversely, photothermal conversion membranes made of hydrophobic materials require careful control of the water layer thickness on the membrane surface, and are prone to scaling. Therefore, both types of photothermal conversion membranes are susceptible to membrane fouling when treating brine, thus affecting the brine separation efficiency. Summary of the Invention

[0005] This invention provides a solar membrane distillation device to solve the problem in related technologies where membrane fouling easily occurs during brine treatment, thereby affecting the brine separation efficiency of the photothermal conversion membrane.

[0006] This invention provides a solar membrane distillation device, comprising: a brine tank having a receiving cavity for containing brine and an outlet and an inlet connected to the receiving cavity; a tubular photothermal conversion membrane, one end of which is connected to the outlet and the other end of which is connected to the inlet, the outer surface of which is coated with a heat-absorbing material and the inner surface of which is coated with a hydrophobic material; and a collection unit comprising a freshwater tank and a transparent cover covering the freshwater tank, the freshwater tank having a freshwater storage cavity for containing freshwater, the inner cavity of which is connected to the freshwater storage cavity, and the tubular photothermal conversion membrane being disposed inside the transparent cover.

[0007] Furthermore, the collection unit also includes a support plate with multiple connecting holes, the support plate is set at the upper end of the freshwater tank, the tubular photothermal conversion membrane is placed on the upper surface of the support plate, and the support plate is connected to the freshwater tank through multiple connecting holes.

[0008] Furthermore, the upper surface of the support plate is coated with a reflective material.

[0009] Furthermore, there is a flow guide groove between the end wall of the support plate and the inner wall of the transparent cover. The upper end of the flow guide groove is connected to the inner cavity of the transparent cover, and the lower end of the flow guide groove is connected to the freshwater tank.

[0010] Furthermore, a condenser plate extending laterally is installed inside the freshwater tank, and the upper surface of the condenser plate and the inner wall of the freshwater tank together form a freshwater storage cavity.

[0011] Furthermore, the lower surface of the condenser plate and the inner wall of the freshwater tank together form a cooling chamber, and a cooling medium is installed inside the cooling chamber.

[0012] Furthermore, the solar membrane distillation unit also includes a product water tank, which has a drain outlet connected to the fresh water storage chamber and connected to the inlet of the product water tank.

[0013] Furthermore, the solar film distillation device includes multiple tubular photothermal conversion membranes, which are spaced apart inside a transparent cover. One end of each tubular photothermal conversion membrane is connected to a water inlet, and the other end of each tubular photothermal conversion membrane is connected to a water inlet.

[0014] Furthermore, the tubular photothermal conversion membrane includes a tubular ceramic membrane; and / or, the inner diameter of the tubular photothermal conversion membrane is between 3 mm and 10 mm.

[0015] Furthermore, the tubular photothermal conversion membrane is a hollow fiber hydrophobic membrane; or, the tubular photothermal conversion membrane is a tubular polymer hydrophobic membrane; or, the tubular photothermal conversion membrane is a flat sheet hydrophobic membrane.

[0016] According to the technical solution of this invention, the solar membrane distillation device includes a brine tank, a tubular photothermal conversion membrane, and a collection unit. The outlet of the brine tank is connected to one end of the tubular photothermal conversion membrane, allowing the brine in the brine tank to enter the membrane. The other end of the membrane is connected to the inlet of the brine tank, enabling the brine to circulate and improving the separation of fresh water from the brine. During brine treatment, the brine in the tank is passed through the membrane. Under sunlight, the membrane is heated. A transparent cover facilitates sunlight exposure, further heating the brine within the membrane. This causes the water to vaporize and pass through the membrane. The condensate is collected in a freshwater tank within the collection unit and stored in a freshwater storage chamber, thus achieving salt / water separation. Furthermore, because the outer surface of the membrane is coated with a heat-absorbing material, it absorbs solar energy and converts it into heat, heating the brine within the membrane. On the other hand, because a hydrophobic material is coated on the inner surface of the tubular photothermal conversion membrane, the brine will not enter the membrane pores when it comes into contact with the inner surface of the membrane, preventing salt accumulation and scaling. Simultaneously, organic matter will not adhere to the inner surface of the membrane, thus reducing membrane fouling. Therefore, when the brine flows inside the membrane tubes of the tubular photothermal conversion membrane, the heat-absorbing material coated on the outer surface absorbs solar energy and heats the inner surface of the membrane, causing the freshwater inside the membrane to vaporize and pass through the membrane pores. Furthermore, the hydrophobic material coated on the inner surface prevents organic matter and salt in the brine from adhering to the inner surface of the membrane, thus preventing membrane fouling and scaling, and also preventing membrane tube blockage that would affect the flow of brine. This, in turn, improves the brine separation efficiency of the tubular photothermal conversion membrane. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of a solar membrane distillation apparatus provided according to an embodiment of the present invention is shown;

[0019] Figure 2 A schematic diagram of a collection unit provided according to an embodiment of the present invention is shown;

[0020] Figure 3 A schematic diagram of a collection unit provided according to an embodiment of the present invention is shown from another perspective.

[0021] The above figures include the following reference numerals:

[0022] 10. Brine tank; 11. Receiving cavity; 12. Outlet; 13. Inlet;

[0023] 20. Tubular photothermal conversion membrane; 21. Tubular ceramic membrane;

[0024] 30. Collection unit; 31. Freshwater tank; 311. Freshwater storage chamber; 312. Condensation plate; 313. Cooling chamber; 3131. Cooling medium; 314. Drain outlet; 32. Transparent cover; 33. Support plate; 331. Guide channel;

[0025] 41. Product water tank; 42. Centrifugal pump; 43. Valve; 44. Flow meter. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] like Figures 1 to 3 As shown, this embodiment of the invention provides a solar membrane distillation device, which includes a brine tank 10, a tubular photothermal conversion membrane 20, and a collection unit 30. The brine tank 10 has a receiving cavity 11 for containing brine and an outlet 12 and an inlet 13 connected to the receiving cavity 11. One end of the tubular photothermal conversion membrane 20 is connected to the outlet 12, and the other end of the tubular photothermal conversion membrane 20 is connected to the inlet 13. The outer surface of the tubular photothermal conversion membrane 20 is coated with a heat-absorbing material, and the inner surface of the tubular photothermal conversion membrane 20 is coated with a hydrophobic material. The collection unit 30 includes a freshwater tank 31 and a transparent cover 32 covering the freshwater tank 31. The freshwater tank 31 has a freshwater storage cavity 311 for containing freshwater. The inner cavity of the transparent cover 32 is connected to the freshwater storage cavity 311, and the tubular photothermal conversion membrane 20 is disposed inside the transparent cover 32.

[0028] The solar membrane distillation apparatus provided in this embodiment includes a brine tank 10, a tubular photothermal conversion membrane 20, and a collection unit 30. The outlet 12 of the brine tank 10 is connected to one end of the tubular photothermal conversion membrane 20, allowing the brine in the receiving cavity 11 of the brine tank 10 to enter the tubular photothermal conversion membrane 20. The other end of the tubular photothermal conversion membrane 20 is connected to the inlet 13 of the brine tank 10, enabling the brine to circulate and improving the separation effect of fresh water from the brine. When treating brine, the brine in the brine tank 10 is passed through the tubular photothermal conversion membrane 20. Under sunlight, the membrane 20 is heated. A transparent cover 32 facilitates sunlight exposure, further heating the brine within the membrane 20. This causes the water to vaporize and pass through the membrane 20, where the condensate is collected in the freshwater tank 31 of the collection unit 30 and stored in the freshwater storage chamber 311, thus achieving salt / water separation. On one hand, the outer surface of the membrane 20 is coated with a heat-absorbing material, which absorbs solar energy and converts it into heat to heat the brine within the membrane 20. On the other hand, the inner surface of the membrane 20 is coated with a hydrophobic material, ensuring that when the brine comes into contact with the inner surface, it does not enter the membrane pores, preventing salt accumulation and scaling. Simultaneously, organic matter does not adhere to the inner surface of the membrane, thus reducing membrane fouling. Therefore, when brine flows inside the tubular photothermal conversion membrane 20, the heat-absorbing material coated on the outer surface can absorb solar energy and heat the inner surface of the tubular photothermal conversion membrane 20, causing the fresh water inside the membrane to vaporize and pass through the membrane pores. Furthermore, the hydrophobic material coated on the inner surface of the membrane prevents organic matter in the brine from adhering to the inner surface of the membrane, thus preventing membrane fouling and scaling, and also avoiding clogging of the membrane tubes, which would affect the flow of brine. This, in turn, improves the brine separation efficiency of the tubular photothermal conversion membrane 20.

[0029] It should be noted that the inner cavity of the transparent cover 32 in the collection unit 30 is a sealed cavity, which allows the tubular photothermal conversion membrane 20 to be placed inside the sealed cavity, thereby preventing water vapor loss and blocking dust from entering, ensuring the collection effect of condensate.

[0030] The heat-absorbing materials can be metal plasma, polymers, carbon-based materials, and semiconductor materials. Metal plasma includes nanoparticles such as gold, silver, aluminum, and copper. Polymers include polyaniline, polypyrrole, and polydopamine. Carbon-based materials include carbon nanotubes, carbon black, reduced graphene oxide, and activated carbon. Semiconductor materials include Mxene, Ti2O3, and CuS.

[0031] The thickness of the hydrophobic layer formed by the hydrophobic material is between 10 nm and 10 μm.

[0032] It should be noted that the thickness of the hydrophobic layer formed by the hydrophobic material can be 10 nm, 10 μm, or any other value between 10 nm and 10 μm.

[0033] Specifically, the outer surface of the tubular conversion membrane is coated with a heat-absorbing material, which enables the membrane to perform photothermal conversion. Therefore, the membrane is called a tubular photothermal conversion membrane 20 when the outer surface of the membrane is coated with a heat-absorbing material. The tubular photothermal conversion membrane 20 is then used to heat and vaporize the water inside the membrane, thereby completing the separation of brine.

[0034] like Figures 1 to 3 As shown, the collection unit 30 also includes a support plate 33 with multiple connecting holes. The support plate 33 is disposed at the upper end of the freshwater tank 31, and the tubular photothermal conversion membrane 20 is placed on the upper surface of the support plate 33. The support plate 33 is connected to the freshwater tank 31 through the multiple connecting holes. With the above structure, by setting the support plate 33 and placing the tubular photothermal conversion membrane 20 on the support plate 33, and the support plate 33 having multiple connecting holes, the separated water vapor can be condensed on the outer surface of the tubular photothermal conversion membrane 20 and then flow to the freshwater tank 31 through the multiple connecting holes of the support plate 33. Thus, the support plate 33 can both support the tubular photothermal conversion membrane 20 and condense the water vapor separated by the tubular photothermal conversion membrane 20 into liquid, which flows into the freshwater tank 31 for collection through the connecting holes, thereby improving the reliability of the solar membrane distillation device.

[0035] It should be noted that the support plate 33 can support the tubular photothermal conversion membrane 20 and has a heat insulation function, thereby isolating the high-temperature transparent cover 32 from the freshwater tank 31, thus preventing the freshwater condensed below the freshwater tank 31 from being vaporized again due to temperature, and ensuring the collection of freshwater.

[0036] In this embodiment, the upper surface of the support plate 33 is coated with a reflective material. Using the above structure, by coating the upper surface of the support plate 33 with a reflective material, the support plate 33 can reflect sunlight, thereby allowing most of the sunlight to irradiate the tubular photothermal conversion film 20. This enables the tubular photothermal conversion film 20 to convert solar energy into heat energy, achieving a heating effect, improving energy utilization, and simultaneously enhancing the heating efficiency of the tubular photothermal conversion film 20.

[0037] It should be noted that silver plating on the upper surface of the support plate 33 can improve the reflection effect of sunlight and increase the utilization rate of sunlight.

[0038] like Figure 2 and Figure 3As shown, there is a flow guide groove 331 between the end wall of the support plate 33 and the inner wall of the transparent cover 32. The upper end of the flow guide groove 331 is connected to the inner cavity of the transparent cover 32, and the lower end of the flow guide groove 331 is connected to the freshwater tank 31. By adopting the above structure, a guide channel 331 is set between the support plate 33 and the transparent cover 32, so that water vapor is separated under the action of the tubular photothermal conversion membrane 20. The water vapor condenses on the inner surface of the transparent cover 32 and adheres to the inner wall of the transparent cover 32. As the amount of condensate increases, it can flow down along the inner wall of the transparent cover 32 and flow into the freshwater tank 31 through the guide channel 331. Thus, the support plate 33 can both allow the condensate on the outer surface of the tubular photothermal conversion membrane 20 to flow into the freshwater tank 31 through the connecting hole, and allow the condensate on the inner wall of the transparent cover 32 to flow into the freshwater tank 31 through the guide channel 331 between the support plate 33 and the transparent cover 32. This ensures that the separated freshwater can be collected and improves the reliability of the solar membrane distillation device.

[0039] like Figure 2 As shown, a condenser plate 312 extending laterally is provided inside the freshwater tank 31. The upper surface of the condenser plate 312 and the inner wall of the freshwater tank 31 together form a freshwater storage cavity 311. By providing the condenser plate 312 inside the freshwater tank 31, and the upper surface of the condenser plate 312 forming the freshwater storage cavity 311 with the inner wall of the freshwater tank 31, the freshwater tank 31 can both collect freshwater and, through the condenser plate 312, lower the temperature inside the freshwater storage cavity 311, preventing the freshwater from vaporizing into water vapor under sunlight, thereby ensuring the effective freshwater storage of the freshwater tank 31.

[0040] like Figure 2 As shown, the lower surface of the condenser plate 312 and the inner wall of the freshwater tank 31 together form a cooling cavity 313, and a cooling medium 3131 is disposed inside the cooling cavity 313. Using the above structure, the lower surface of the condenser plate 312 and the inner wall of the freshwater tank 31 form a cooling cavity 313, and the cooling medium 3131 is disposed inside the cooling cavity 313. This cooling medium 3131 is used to cool the temperature inside the freshwater storage cavity 311, allowing water vapor to condense into liquid water and preventing the water in the freshwater storage cavity 311 from re-vaporizing under sunlight, thus improving the reliability and practicality of the solar membrane distillation device.

[0041] It should be noted that the cooling medium 3131 can be cold water or refrigerant.

[0042] like Figure 1 and Figure 2As shown, the solar membrane distillation device also includes a product water tank 41. The freshwater tank 31 has a drain outlet 314 connected to the freshwater storage chamber 311, and the drain outlet 314 is connected to the inlet of the product water tank 41. By setting up the product water tank 41 and using the drain outlet 314 on the freshwater tank 31 to connect the freshwater storage chamber 311 and the product water tank 41, freshwater can be discharged from the freshwater tank 31 to the product water tank 41. This allows for the collection and treatment of condensed freshwater. Furthermore, when the water in the freshwater tank 31 reaches a certain level, the freshwater is discharged through the drain outlet 314, further ensuring that the freshwater tank 31 can condense and collect water vapor for an extended period, thus improving the practicality of the solar membrane distillation device.

[0043] like Figure 3 As shown, the solar membrane distillation device includes multiple tubular photothermal conversion membranes 20, which are spaced apart within a transparent cover 32. One end of each tubular photothermal conversion membrane 20 is connected to a water inlet 13, and the other end of each tubular photothermal conversion membrane 20 is also connected to the water inlet 13. By using multiple tubular photothermal conversion membranes 20, and by spacing them within the transparent cover 32, the separation efficiency of the brine can be improved.

[0044] It should be noted that, in this embodiment, the solar membrane distillation device also includes a centrifugal pump 42, a valve 43, and a flow meter 44. The centrifugal pump 42 is located between the brine tank 10 and the inlet of the tubular photothermal conversion membrane 20, so that the brine can enter the tubular photothermal conversion membrane 20 through the centrifugal pump 42, thereby ensuring that the brine is in a flowing state and avoiding the problem of membrane fouling caused by the brine staying in the tubular photothermal conversion membrane 20 for a long time. This improves the service life of the tubular photothermal conversion membrane 20. Furthermore, the brine flow process can be controlled by the valve 43 and monitored in real time by the flow meter 44, thereby improving the reliability of the solar membrane distillation device.

[0045] In other embodiments, a heat source can be added to the inlet of the tubular photothermal conversion membrane 20 to increase the membrane flux. Adding a heat source means setting a heating device at the inlet of the tubular photothermal conversion membrane 20 to heat the incoming brine. Membrane flux refers to the amount of liquid passing through a unit area per unit time under operating conditions.

[0046] In this embodiment, the tubular photothermal conversion membrane 20 includes a tubular ceramic membrane 21. By setting the tubular ceramic membrane 21, the tubular ceramic membrane 21 has a large diameter, allowing brine to flow inside the tubular ceramic membrane 21 without causing blockage, thereby reducing membrane fouling and improving the separation efficiency of brine. Furthermore, the tubular ceramic membrane 21 has high mechanical strength and good high-temperature resistance.

[0047] In this embodiment, the inner diameter of the tubular photothermal conversion membrane 20 is between 3 mm and 10 mm. Setting the inner diameter of the tubular photothermal conversion membrane 20 within the above range allows the brine to flow within the tubular photothermal conversion membrane 20, thereby preventing the brine from clogging within the tubular photothermal conversion membrane 20, thus preventing membrane fouling and extending the service life of the tubular photothermal conversion membrane 20.

[0048] It should be noted that the inner diameter of the tubular photothermal conversion film 20 can be 3mm, 5mm, 8mm, 10mm, or any other value between 3mm and 10mm.

[0049] In other embodiments, the tubular photothermal conversion membrane 20 is a hollow fiber hydrophobic membrane. This structure provides the hollow fiber hydrophobic membrane with self-support, ensuring structural strength and improving separation efficiency.

[0050] In other embodiments, the tubular photothermal conversion membrane 20 is a tubular polymer hydrophobic membrane. Using the above structure, the tubular polymer hydrophobic membrane allows salt water to flow on its inner surface, preventing water from adhering to the inner surface. This enables water to vaporize during the heat absorption process, thus achieving the separation of fresh water.

[0051] In other embodiments, the tubular photothermal conversion membrane 20 is a flat hydrophobic membrane. Using the above structure, the flat hydrophobic membrane has heat absorption function and features high heat transfer efficiency, high mechanical strength, and long service life. Furthermore, the flat hydrophobic membrane can be an organic flat hydrophobic membrane or an inorganic flat hydrophobic membrane.

[0052] The apparatus provided by the embodiments has the following beneficial effects:

[0053] (1) When the brine flows on the inner surface of the tubular photothermal conversion membrane 20, the heat-absorbing material coated on the outer surface can absorb solar energy and heat the inner surface of the tubular photothermal conversion membrane 20, so that the fresh water in the membrane vaporizes and then passes through the membrane pores. Furthermore, the hydrophobic material coated on the inner surface of the membrane allows the brine to flow inside the membrane. Organic matter and salt will not adhere to the inner surface of the membrane, which can prevent membrane fouling and scaling. Moreover, the brine inside the membrane is constantly flowing, thereby avoiding membrane tube blockage and ensuring that the brine inside the membrane is continuously heated and vaporized, thereby improving the brine separation efficiency of the tubular photothermal conversion membrane 20.

[0054] (2) By setting the support plate 33, the support plate 33 can not only support the tubular photothermal conversion membrane 20, but also condense the water vapor separated by the tubular photothermal conversion membrane 20 into liquid and flow into the fresh water tank 31 through the connecting hole for collection, thereby improving the reliability of the solar membrane distillation device.

[0055] (3) By setting a condenser plate 312 inside the freshwater tank 31, the freshwater tank 31 can collect freshwater and reduce the temperature inside the freshwater storage chamber 311, thereby ensuring the freshwater storage effect of the freshwater tank 31.

[0056] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0057] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0058] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0059] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0060] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A solar membrane distillation apparatus, characterized in that, The solar membrane distillation apparatus includes: The brine tank (10) has a receiving cavity (11) for containing brine and an outlet (12) and an inlet (13) connected to the receiving cavity (11). A tubular photothermal conversion membrane (20) is provided, with one end of the tubular photothermal conversion membrane (20) connected to the water outlet (12) and the other end of the tubular photothermal conversion membrane (20) connected to the water inlet (13). The outer surface of the tubular photothermal conversion membrane (20) is coated with a heat-absorbing material, and the inner surface of the tubular photothermal conversion membrane (20) is coated with a hydrophobic material. The collection unit (30) includes a freshwater tank (31) and a transparent cover (32) covering the freshwater tank (31). The freshwater tank (31) has a freshwater storage cavity (311) for containing freshwater. The inner cavity of the transparent cover (32) is connected to the freshwater storage cavity (311). The tubular photothermal conversion membrane (20) is disposed inside the transparent cover (32). The collection unit (30) also includes a support plate (33) with multiple connecting holes. The support plate (33) is disposed at the upper end of the freshwater tank (31). The tubular photothermal conversion membrane (20) is placed on the upper surface of the support plate (33). The support plate (33) is connected to the freshwater tank (31) through the multiple connecting holes. The freshwater tank (31) is provided with a condenser plate (312) extending laterally, and the upper surface of the condenser plate (312) and the inner wall of the freshwater tank (31) together form the freshwater storage cavity (311).

2. The solar membrane distillation apparatus according to claim 1, characterized in that, The upper surface of the support plate (33) is coated with a reflective material.

3. The solar membrane distillation apparatus according to claim 1, characterized in that, The end wall of the support plate (33) has a guide groove (331) between it and the inner wall of the transparent cover (32). The upper end of the guide groove (331) is connected to the inner cavity of the transparent cover (32), and the lower end of the guide groove (331) is connected to the freshwater tank (31).

4. The solar membrane distillation apparatus according to claim 1, characterized in that, The lower surface of the condenser plate (312) and the inner wall of the fresh water tank (31) together form a cooling cavity (313), and a cooling medium (3131) is provided in the cooling cavity (313).

5. The solar membrane distillation apparatus according to claim 1, characterized in that, The solar membrane distillation device also includes a water production tank (41), and the freshwater tank (31) has a drain outlet (314) connected to the freshwater storage chamber (311), and the drain outlet (314) is connected to the inlet of the water production tank (41).

6. The solar membrane distillation apparatus according to claim 1, characterized in that, The solar membrane distillation device includes a plurality of tubular photothermal conversion membranes (20), which are spaced apart inside the transparent cover (32). One end of each of the tubular photothermal conversion membranes (20) is connected to the water inlet (13), and the other end of each of the tubular photothermal conversion membranes (20) is connected to the water inlet (13).

7. The solar membrane distillation apparatus according to claim 1, characterized in that, The tubular photothermal conversion film (20) includes a tubular ceramic film (21); and / or, The inner diameter of the tubular photothermal conversion film (20) is between 3 mm and 10 mm.

8. The solar membrane distillation apparatus according to claim 1, characterized in that, The tubular photothermal conversion membrane (20) is a hollow fiber hydrophobic membrane; or, The tubular photothermal conversion membrane (20) is a tubular polymer hydrophobic membrane; or, The tubular photothermal conversion membrane (20) is a flat hydrophobic membrane.

Images