Concentrated brine interface evaporation apparatus resistant to salt crystallization

Abstract

The application provides a concentrated brine interface evaporation device for anti-salt crystallization, comprising a photothermal evaporation unit, the photothermal evaporation unit comprises a hydrophilic hollow porous tube and a photothermal material layer coated on the outside of the hydrophilic hollow porous tube, the hollow axial direction and the diameter direction of the hydrophilic hollow porous tube form a three-dimensional multi-directional evaporation channel, on the one hand, the photothermal evaporation rate is improved, on the other hand, the salt ions in the photothermal material layer are quickly exchanged through the convection effect, and then flow into the inner layer low-concentration water, so that the photothermal layer is prevented from appearing salt crystallization. The inner layer and the peripheral wall of the hydrophilic hollow porous tube are formed with a porous structure through the hydrophilic hollow porous tube, the convection effect of the liquid in the hollow tube is enhanced, the evaporation amount of the device is evenly distributed to the surrounding through the three-dimensional structure design, the concentration of the evaporation surface is prevented from being too high, and the synergistic effect makes the device effectively inhibit the crystallization of salt in the device during the evaporation process.

Description

Technical Field

[0001] This invention relates to the field of interfacial evaporation apparatus technology, and more particularly to a concentrated brine interfacial evaporation apparatus resistant to salt crystallization. Background Technology

[0002] With industrialization and explosive global population growth, freshwater scarcity has become a global problem. Seawater desalination has emerged as a promising solution. Solar-driven interfacial evaporation technology utilizes solar energy—a natural, pollution-free, and renewable energy source—to heat the surface layer of seawater. This effectively converts solar radiation into heat, thereby increasing steam production and demonstrating excellent prospects for addressing water scarcity. Furthermore, it can be used to treat concentrated saline wastewater, saving energy and costs associated with wastewater treatment.

[0003] Solar-powered interfacial evaporation devices typically utilize the heat absorption properties of photothermal materials to rapidly evaporate water and obtain freshwater resources. To ensure the evaporation rate, the photothermal material layer usually needs to possess good photothermal absorption performance and a porous structure to increase the specific surface area and provide sufficient channels for water evaporation. For example, patent CN202011395670.X discloses a thermoelectric power generation device based on solar interfacial evaporation, including a solar energy collection structure, an interfacial evaporation structure, a thermoelectric power generation structure, and a water storage structure. The interfacial evaporation structure includes a porous thermoelectric float and hydrophilic fibers. Liquid water permeates from the lower interface of the float to the upper interface through the pores, is centrally heated, and converted into high-temperature steam, thereby achieving seawater desalination or water purification and realizing the conversion of solar thermal energy.

[0004] However, the problem of salt in interfacial evaporation seriously hinders its development. Salt crystallization on the evaporator surface will block the steam overflow channel and enhance the specular reflection on the evaporator surface, leading to a decrease in photothermal conversion efficiency, and thus reducing the photothermal conversion efficiency. Many solutions have been proposed to solve the salt formation problem: (1) hydrophobic treatment of the evaporator surface to avoid the direct generation of salt from the source; (2) removal of crystallized salt by external force or water washing; (3) fluid convection to move salt ions from high-concentration brine to low-concentration brine; (4) use ion pumps to transport the repelled salt ions, but none of the above methods can achieve efficient evaporation in high-concentration brine. Therefore, further improving the evaporation rate on the basis of treating high-concentration brine is a major challenge in the field of interfacial evaporation.

[0005] In view of this, it is necessary to design an improved concentrated brine interface evaporation device resistant to salt crystallization in order to solve the above problems. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention aims to provide a concentrated brine interface evaporation device that resists salt crystallization. It forms a three-dimensional multi-directional evaporation channel through a hydrophilic hollow porous tube and a photothermal material layer covering the outside of the tube. On the one hand, it improves the photothermal evaporation rate, and on the other hand, it promotes the rapid exchange of salt ions in the photothermal material layer through convection, which then flows back into the inner low-concentration water, thus preventing salt crystallization in the photothermal layer.

[0007] To achieve the above-mentioned objectives, this invention provides a concentrated brine interface evaporation device for resisting salt crystallization, comprising a photothermal evaporation unit. The photothermal evaporation unit includes a hydrophilic hollow porous tube and a photothermal material layer covering the outside of the hydrophilic hollow porous tube. The hydrophilic hollow porous tube is arranged perpendicular to the water surface. The interface evaporation device forms dual water supply channels in the hollow axial and diametrical directions of the hydrophilic hollow porous tube to promote the convective exchange of salt ions from the photothermal material layer to the hydrophilic hollow porous tube, thereby achieving the purpose of resisting salt crystallization.

[0008] As a further improvement of the present invention, the hydrophilic hollow porous tube has an outer diameter of 1-10 mm, an inner diameter of 0.5-2 mm, and a peripheral wall pore diameter of 1-500 μm.

[0009] As a further improvement of the present invention, the hydrophilic hollow porous tube is a hydrophilic hollow porous braided tube, a hydrophilic hollow porous fiber tube, or a hydrophilic hollow porous membrane tube; preferably, it is a hydrophilic hollow porous braided tube; the hydrophilic hollow porous tube is obtained by spinning, 3D printing, braiding or injection molding.

[0010] As a further improvement of the present invention, the hydrophilic hollow multi-braided tube is obtained by 3D printing, or by using a linear material with a diameter of 0.5-2mm as a template, weaving a layer of fiber fabric on its surface, and then removing the linear material to obtain the hydrophilic hollow multi-braided tube; the fiber used for weaving is one or more blended yarns selected from cellulose fiber, cotton fiber, nylon fiber, ethylene-vinyl alcohol copolymer fiber or hydrophilically modified polyester fiber.

[0011] As a further improvement of the present invention, after the hydrophilic hollow porous tube is shaped by casting solution, the linear material is then removed.

[0012] As a further improvement of the present invention, the photothermal material layer is a woven structure composed of photothermal fibers.

[0013] As a further improvement of the present invention, the photothermal fiber is a photothermal material modified fiber, and the photothermal material includes one or more of carbon-based inorganic materials, metal-based inorganic materials, organic polymers, organic-inorganic hybrid materials, and organic eutectic materials.

[0014] As a further improvement of the present invention, the concentrated brine interface evaporation device further includes a floating unit disposed below the photothermal evaporation unit for supporting the photothermal evaporation unit to float on the surface of the concentrated brine to be treated; the hollow axis of the hydrophilic hollow porous tube is placed perpendicular to the surface of the concentrated brine to be treated.

[0015] As a further improvement of the present invention, the floating unit is a porous foam material, and an aluminum foil is provided between the porous foam material and the photothermal evaporation unit.

[0016] As a further improvement of the present invention, the photothermal evaporation unit is assembled in multiple vertical parallel groups and placed above the floating unit; preferably, the photothermal evaporation unit is spirally wound into a multi-layer cylindrical shape, and the gap between two adjacent spirals is 1-5mm wide.

[0017] The beneficial effects of this invention are:

[0018] 1. The salt crystallization-resistant concentrated brine interface evaporation device provided by this invention differs from traditional seawater desalination systems. It uses a hydrophilic hollow porous tube as the inner water supply layer, containing hollow pipes and a hydrophilic porous structure on its periphery. This allows for the formation of dual water supply channels along both the axial and diametrical directions, enhancing the convection effect within the device. During interface evaporation, water molecules are rapidly transported to the photothermal material layer under the wicking effect of the hydrophilic hollow porous tube. The photothermal material layer absorbs sunlight, generating heat and causing the water to evaporate rapidly. This results in a higher salt concentration in the photothermal material layer compared to the hydrophilic hollow porous tube. Furthermore, the presence of multi-directional water supply channels allows for rapid exchange of salt ions through convection, which then flow back into the large volume of water in the inner layer. This continuously facilitates the removal of salt ions from the photothermal material layer, achieving the goal of preventing salt crystallization.

[0019] 2. This invention utilizes a woven hollow strip fabric structure, facilitating the formation of a porous structure in its inner layer and peripheral walls. Compared to hollow fibers in existing technologies, this structure offers greater structural adjustability, a simpler preparation method, and is easier for large-scale production. Furthermore, the water channels exhibit stronger dynamics, promoting the exchange and transfer of salt ions from the photothermal material layer. The three-dimensional structural design of this invention distributes the evaporation rate evenly across the surrounding area, preventing excessively high concentrations on the evaporation surface. This synergistic effect prevents salt crystallization within the device during evaporation.

[0020] 3. The hydrophobicity and low density of expanded polystyrene ensure that the evaporator can float on the water surface and physically separate from the concentrated brine, controlling heat loss from the photothermal layer. Aluminum foil, with its excellent light reflectivity, enhances the diffuse reflection of light within the evaporator, further improving the efficiency of photothermal conversion. Furthermore, the three-dimensional spiral structure provides numerous vertical gaps, allowing light to undergo multiple reflections, further reflected on the aluminum foil, increasing the evaporator's capture rate of sunlight. The highly light-absorbing carbon fibers collect solar energy and convert it into heat. This spiral structure not only increases the diffuse reflectivity of light within the evaporator but also increases the escape area of ​​steam, significantly improving the evaporation rate. Attached Figure Description

[0021] Figure 1 A schematic cross-sectional view of a concentrated brine interface evaporation device designed to resist salt crystallization.

[0022] Figure 2 A schematic diagram of the cross-sectional structure of a concentrated brine interface evaporation device designed to resist salt crystallization.

[0023] Figure 3 This is a schematic diagram of a hydrophilic hollow porous tube.

[0024] Figure 4 This is a schematic diagram of the cross-sectional structure of the photothermal evaporation unit.

[0025] Figure 5 These are 3D microscope images of the Modal hollow braided tube before and after coating with casting solution in Example 1.

[0026] Figure 6 The surface salt crystallization and mass loss curves of the concentrated brine interface evaporation device provided in Example 1 of the present invention and Comparative Examples 1 and 2 after evaporation in 15% NaCl solution for 8 hours are shown. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to specific embodiments.

[0028] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the solution of the present invention are shown in the specific embodiments, while other details that are not closely related to the present invention are omitted.

[0029] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] Please see Figure 1-3 As shown, the salt crystallization resistant concentrated brine interface evaporation device provided by the present invention includes a photothermal evaporation unit, which is placed at the interface of the water to be treated to achieve water evaporation treatment through photothermal exchange.

[0031] The photothermal evaporation unit comprises a hydrophilic hollow porous tube (water supply layer) and a photothermal material layer (photothermal layer) covering the outside of the hydrophilic hollow porous tube. The hydrophilic hollow porous tube is positioned perpendicular to the water surface. The outer diameter of the hydrophilic hollow porous tube is 1-10 mm, the inner diameter is 0.5-2 mm, and the pore size of the peripheral wall is 1-500 μm. Because the hydrophilic hollow porous tube contains hollow pipes and its peripheral wall is designed with a hydrophilic porous structure, it can form dual water supply channels in both the axial and diametrical directions. When used for interfacial evaporation, water molecules are rapidly transported to the photothermal material layer under the wicking effect of the hydrophilic hollow porous tube. The photothermal material layer absorbs sunlight, generates heat, and promotes the rapid evaporation of water. Therefore, the salt concentration in the photothermal material layer is higher than that in the hydrophilic hollow porous tube. Due to the presence of multi-directional water supply channels, salt ions are rapidly exchanged through convection and then flow back into the large volume of water in the inner layer, thereby promoting the continuous transfer of salt ions from the photothermal material layer and achieving the purpose of anti-salt crystallization. Therefore, when used for concentrated brine treatment, this invention can maintain a high water evaporation rate for a long time, and its application value is significant.

[0032] The hydrophilic hollow porous tube is a hydrophilic hollow porous braided tube, a hydrophilic hollow porous fiber tube, or a hydrophilic hollow porous membrane tube; preferably, it is a hydrophilic hollow porous braided tube; the hydrophilic hollow porous tube is obtained by spinning, 3D printing, braiding, or injection molding. This invention preferably uses a hydrophilic hollow porous braided tube, which is inexpensive and readily available, and its porous structure can be easily controlled through weaving, thereby forming a three-dimensional multi-channel structure with the photothermal material layer.

[0033] Preferably, the hydrophilic hollow porous tube has an outer diameter of 1-8 mm and an inner diameter of 0.5-5 mm, for example, an outer diameter of 2 mm and an inner diameter of 1 mm; an outer diameter of 3 mm and an inner diameter of 2 mm; an outer diameter of 1.5 mm and an inner diameter of 0.8 mm, etc. The wall thickness can be adjusted by controlling the fiber diameter or the weaving thickness.

[0034] In some embodiments, the preparation method of the hydrophilic hollow porous braided tube includes: using a linear material with a diameter of 0.5-8 mm as a template, weaving a layer of fiber fabric around its surface, and then removing the linear material to obtain the hydrophilic hollow porous tube. The linear material can be metal wire, plastic tube, etc. This invention, by weaving a hollow strip-shaped fabric, facilitates the formation of a porous structure in its inner layer and peripheral wall. Compared with hollow fibers in the prior art, it has greater structural adjustability, a simpler preparation method, and is easier for large-scale production. Furthermore, it provides stronger water channel dynamics, facilitating the exchange and transfer of salt ions from the photothermal material layer.

[0035] The fibers used in the weaving are hydrophilic fibers or core-spun or covered yarns composed of hydrophilic fibers and metal wires. Combining hydrophilic fibers with metal wires can improve the fiber's supporting strength, thus making it easier to float upright on the water surface during use.

[0036] The hydrophilic fiber is a blended yarn of one or more of the following: cellulose fiber, cotton fiber, nylon fiber, and ethylene-vinyl alcohol copolymer fiber; or a composite fiber composed of one or more of the following: cellulose fiber, cotton fiber, nylon fiber, and ethylene-vinyl alcohol copolymer fiber with polyester, polypropylene, etc.; or a fiber of polyester, polypropylene, etc. that has been modified with hydrophilicity; the cellulose fiber can be viscose fiber, modal fiber, acetate fiber, etc.

[0037] Specifically, after shaping the hydrophilic hollow porous braided tube using a casting solution, the linear material is then removed. The casting solution can be PVDF, PVP-K30, ethanol, acetone, DMAC solvent, etc. For example, 15% PVDF or PVA, 3% PVP-K30, 1% ethanol, 1% acetone, and 80% DMAC solvent are placed in a container, stirred at 90°C for 4 hours, and then vacuum-evacuated for 5 hours to obtain a uniform casting solution. A layer of the casting solution is coated onto the surface of the hydrophilic hollow porous tube, which is then placed in a coagulation bath (pure water) for 48 hours for displacement, dried, and the rod is removed to produce a PVDF-hydrophilic hollow porous tube. Figure 5 As shown in the figure, the fabric surface is smoother and the support strength is improved after the setting process.

[0038] Specifically, the photothermal material layer is a woven structure composed of photothermal fibers. These photothermal fibers are modified fibers containing one or more of the following: carbon-based inorganic materials, metal-based inorganic materials, organic polymers, organic-inorganic hybrid materials, and organic eutectic materials. For example, the photothermal fibers can be carbon fibers, carbon black, graphene-modified fibers, etc. Setting the photothermal material layer as a woven structure facilitates integrated molding with the hydrophilic hollow porous tube through weaving, and also increases its specific surface area, thereby improving the evaporation rate.

[0039] Specifically, the concentrated brine interface evaporation device also includes a floating unit located below the photothermal evaporation unit to support the unit and allow it to float on the surface of the concentrated brine to be treated; the hollow axis of the hydrophilic hollow porous tube is placed perpendicular to the surface of the concentrated brine to be treated. This placement creates both horizontal and vertical water supply channels, improving the salt ion exchange rate and preventing salt crystallization in the photothermal layer.

[0040] Preferably, the floating unit is a porous foam material, such as expanded polystyrene, with aluminum foil positioned between the porous foam material and the photothermal evaporation unit. The hydrophobicity and low density of expanded polystyrene ensure that the evaporation device can float on the water surface and be physically separated from the bulk water, controlling heat loss from the photothermal layer. The aluminum foil has good light reflectivity; the aluminum foil wrapped around the expanded polystyrene enhances the diffuse reflection of light in the evaporator, further improving the efficiency of photothermal conversion.

[0041] Specifically, the photothermal evaporation units are assembled in multiple vertical parallel groups and placed above the floating unit to increase the number of evaporation units per unit area. In one embodiment, the photothermal evaporation units are spirally wound into a cylindrical shape and placed above the floating unit, with a gap of 1-5 mm between adjacent spirals. The three-dimensional spiral structure provides numerous vertical gaps, allowing light to undergo multiple reflections, further reflected on the aluminum foil, improving the evaporator's sunlight capture rate. The highly light-absorbing carbon fibers can collect solar energy and convert it into heat. This spiral structure not only increases the diffuse reflectance of light within the evaporator but also increases the steam escape area, significantly improving the evaporation rate.

[0042] This invention relates to an evaporation device for efficiently treating concentrated brine under sunlight, based on solar interface evaporation, achieving an evaporation rate of 2.26 kg m³. -2 h -1 Even in a high-concentration brine solution of 15%, a stable and efficient steam generation rate of 2.06 kg m³ can still be achieved. -2 h -1 This avoids salt crystallization. This work provides a promising strategy for improving the efficient steam generation of current interfacial evaporation-based solar desalination systems for high-concentration brine.

[0043] Example 1

[0044] A concentrated brine interface evaporation device resistant to salt crystallization is disclosed. This device utilizes a two-dimensional high-speed braiding machine to weave 16 modal strands onto a 1mm diameter iron wire. A layer of PVA casting solution is uniformly coated onto the treated modal braided tube. After displacement in a coagulation bath (pure water) for 48 hours, the tube is dried. The iron wire is then removed to form a PVA-modal hollow fiber braided tube (2mm outer diameter, 1mm inner diameter). The PVA-modal hollow fibers are then woven with 6k carbon fiber using a textile process to create a modal-carbon fiber hybrid fabric. Finally, the fabric is rolled up laterally and fixed with expanded polystyrene foam. The foam layer is 0.5cm thick, and the rolled-up spiral structure evaporator is approximately a cylinder with a radius of 15mm, with a spiral gap width of 3mm.

[0045] The preparation method of PVA casting solution includes: placing 15% PVA, 3% PVP-K30, 1% ethanol, 1% acetone and 80% DMAC solvent in a container, stirring at 90°C for 4 hours, and then using a vacuum oil pump to remove bubbles for 5 hours to finally obtain a uniform casting solution.

[0046] The weaving process of the modal-carbon fiber blend fabric is as follows: 28 black polyester threads are used as warp yarns throughout. First, a 10mm long plain weave is performed using polyester threads as the weft to prevent fabric dispersion. Second, 6k carbon fiber is used as the weft yarn, and two sets are woven using a special pattern. Third, PVA-modal hollow fiber is used as the weft yarn, and one weft is woven in plain weave. Then, the weft yarn is replaced with carbon fiber, and step two is repeated. After repeating the above operations for 1100mm, the polyester threads are replaced as the weft yarn, and a 10mm plain weave is used for the finishing.

[0047] The carbon fiber photothermal layer is 25mm wide, and the PVA-modal hollow fiber water supply layer is 55mm long, of which 25mm is covered by carbon fiber.

[0048] Comparative Example 1

[0049] A concentrated brine interface evaporation device resistant to salt crystallization, which differs from Example 1 in that the water supply layer has a single water channel structure, and the specific material is a comparative modal-carbon fiber fabric woven from PVA-modal hollow fibers and carbon fibers with the hollow part blocked by resin rods.

[0050] Comparative Example 2

[0051] A concentrated brine interface evaporation device resistant to salt crystallization is disclosed. The difference between this device and Example 1 is that the PVA-modal hollow fiber braided tube is replaced with cotton yarn. Otherwise, it is largely the same as Example 1 and will not be described further.

[0052] Photothermal evaporation tests were conducted on this salt crystallization-resistant concentrated brine interface evaporation device, such as... Figure 6 As shown, under one sun, the evaporation rate of the evaporation device for high-efficiency treatment of concentrated brine based on solar interface evaporation can reach up to 2.26 kg m³. -2 h -1 Even in a high-concentration brine solution of 15%, a stable and efficient steam generation rate of 2.06 kg m³ can still be achieved. -2 h -1 And salt crystallization will not occur. From Figure 6 It can be seen that when the interfacial evaporation device of the present invention processes pure water or 15% NaCl, the water quality decreases linearly. However, when the interfacial evaporation device is not placed, the water loss is extremely low within one hour. Figure 6In the study, the initial water evaporation rates of the three groups of samples were basically the same, indicating that, under the condition that water transport can be guaranteed (the inner side of all three groups of samples is a hydrophilic layer, which facilitates the transport of water to the photothermal layer), the water evaporation rate is mainly related to the structure of the outer photothermal layer (photothermal conversion capacity). Specifically, when using the dual-channel fabric-based interface evaporation device of this invention to treat 15% high-concentration salt water, the water evaporation rate did not decrease significantly within 8 hours (horizontal triangular dotted line in the figure), and the total amount of water evaporated increased linearly, reaching approximately 18 kg of water evaporated per square meter after 8 hours. However, when using a conventional single-channel water supply layer (solid tube), the water evaporation rate decreased significantly after 1 hour, dropping to 1.2 kg / m² after 8 hours. -2 h -1 After 8 hours, only about 13 kg of water evaporated per square meter, indicating severe salt crystallization in the photothermal layer, which reduced the evaporation rate and affected water treatment efficiency. When using cotton yarn, the water evaporation rate and efficiency were comparable to those of the solid tube, both lower than those of this invention. This demonstrates that this invention, by constructing multi-directional salt ion channels, can effectively suppress the decrease in evaporation rate caused by salt crystallization. This is because the PVA-hollow fiber water supply layer in the interfacial evaporation device of this invention, due to its hollow structure, forms a water column approximately 20 mm high inside under capillary action, and its outer wall is made of highly hydrophilic modal fiber. The concentrated brine evaporates rapidly on the surface of the photothermal layer, resulting in a concentration difference between the photothermal layer and the water supply layer. This dual water supply channel structure allows salt ions to be rapidly exchanged through convection, and then flowed back into the large volume of water, preventing salt crystallization in the photothermal layer.

[0053] The key feature of this invention is the construction of multi-directional ion exchange channels through an inner layer of hydrophilic hollow porous tubes. This allows salt ions from the photothermal layer to continuously transfer to the inner layer via convection, thus inhibiting salt crystallization. Example 1 presents a relatively easy-to-operate woven structure, which is superior in terms of practicality and economy. However, other materials capable of achieving the convection structure described in this invention are also within the scope of protection of this invention and are not limited thereto.

[0054] In summary, the salt-crystallization-resistant concentrated brine interface evaporation device provided by this invention uses a hydrophilic hollow porous tube as the inner water supply layer. This tube contains hollow pipes, and its peripheral walls are designed with a hydrophilic braided structure. Therefore, it possesses both hydrophilicity and a porous structure, allowing for the formation of dual water supply channels in both the axial and diametrical directions, enhancing the convection effect within the device. During interface evaporation, water molecules are rapidly transported to the photothermal material layer under the wicking effect of the hydrophilic hollow porous tube. The photothermal material layer absorbs sunlight, generating heat and causing the water to evaporate rapidly. This results in a higher salt concentration in the photothermal material layer compared to the hydrophilic hollow porous tube. Furthermore, the presence of multi-directional water supply channels allows for rapid exchange of salt ions through convection, which then flow back into the large volume of water in the inner layer, continuously facilitating the removal of salt ions from the photothermal material layer and achieving the goal of preventing salt crystallization.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A concentrated brine interface evaporation device resistant to salt crystallization, characterized in that, The interface evaporation device comprises a photo-thermal evaporation unit, the photo-thermal evaporation unit comprises a hydrophilic hollow porous tube and a photo-thermal material layer coated outside the hydrophilic hollow porous tube; the interface evaporation device forms double water supply channels in the hollow axial direction and the diameter direction of the hydrophilic hollow porous tube to promote the convective exchange of salt ions from the photo-thermal material layer to the hydrophilic hollow porous tube, thereby achieving the purpose of resisting salt crystallization. The outer diameter of the hydrophilic hollow porous tube is 1-10 mm, the inner diameter is 0.5-2 mm, and the pore diameter of the peripheral wall is 1-500 μm. The interface evaporation device for concentrated brine further comprises a floating unit arranged below the photo-thermal evaporation unit for supporting the photo-thermal evaporation unit to float on the surface of the concentrated brine to be treated; the hollow axial direction of the hydrophilic hollow porous tube is arranged in a vertical state with the surface of the concentrated brine to be treated. The floating unit is a porous foam material, and an aluminum foil is arranged between the porous foam material and the photo-thermal evaporation unit. The photo-thermal evaporation unit is arranged above the floating unit in the form of multiple groups of vertical parallel arrangement; and the photo-thermal evaporation unit is spirally wound into a multi-layer cylindrical shape.

2. The anti-salt-crystallization concentrated brine interface evaporation unit of claim 1, wherein, The hydrophilic hollow porous tube is a hydrophilic hollow porous woven tube, a hydrophilic hollow porous fiber tube or a hydrophilic hollow porous membrane tube; the hydrophilic hollow porous tube is obtained by weaving, 3D printing or injection molding.

3. The anti-salt-crystallization concentrated brine interface evaporation unit of claim 2, wherein, The hydrophilic hollow porous tube is a hydrophilic hollow porous woven tube.

4. The anti-salt-crystallization concentrated brine interface evaporation unit of claim 3, wherein, The hydrophilic hollow porous woven tube uses a linear material with a diameter of 0.5-2 mm as a template, and a layer of fiber fabric is wrapped on the surface of the linear material by weaving, and then the linear material is taken out to obtain the hydrophilic hollow porous woven tube; the fiber used in the weaving is one or more of a mixture of cellulose fiber, cotton fiber, nylon fiber, ethylene-vinyl alcohol copolymer fiber or hydrophilically modified polyester fiber.

5. The anti-salt-crystallization concentrated brine interface evaporation unit of claim 4, wherein, The hydrophilic hollow porous tube is subjected to shaping treatment by using a casting solution, and then the linear material is taken out.

6. The anti-salt-crystallization concentrated brine interface evaporation unit of claim 1, wherein, The photo-thermal material layer is a woven structure composed of photo-thermal fibers.

7. The anti-salt-crystallization concentrated brine interface evaporation unit of claim 6, wherein, The photo-thermal fiber is a photo-thermal material modified fiber, and the photo-thermal material comprises one or more of carbon-based inorganic material, metal-based inorganic material, organic polymer, organic-inorganic hybrid material and organic eutectic material.

8. The anti-salt-crystallization concentrated brine interface evaporation unit of claim 1, wherein, When the photo-thermal evaporation unit is spirally wound into a multi-layer cylindrical shape, the gap width between adjacent two spirals is 1-5 mm.

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