Salinized soil repairing equipment based on solar multi-stage distillation

Abstract

The saline soil remediation equipment based on solar multi-stage distillation comprises a distillation condensation unit and a water taking unit, the distillation condensation unit comprises a plurality of evaporation-condensation assemblies and heat conduction layers which are arranged in a stacked mode, each evaporation-condensation assembly comprises an evaporation layer and a condensation layer, and the water taking unit comprises a plurality of wicking belts. The plurality of wicking belts are respectively connected to or penetrate through the evaporation layers of the plurality of evaporation-condensation assemblies, the wicking belts can continuously draw a saline solution from soil under the capillary action and convey the saline solution to the evaporation layers, and in the same evaporation-condensation assembly, the evaporation layers and the condensation layers are arranged at intervals; the evaporation layer is configured to receive a saline solution in soil and evaporate the saline solution through heating to form water vapor, the condensation layer is configured to receive the water vapor and condense the water vapor to form distilled water, and every two adjacent evaporation-condensation assemblies are separated through a heat conduction layer. Latent heat released by water vapor in the condensation process of the condensation layer can be transferred to the evaporation layer of the next-stage evaporation-condensation assembly through the heat conduction layer.

Description

Technical Field

[0001] This application belongs to the field of soil remediation and water resource utilization technology, and specifically relates to a saline soil remediation device based on solar multi-stage distillation. Background Technology

[0002] Currently, soil salinization has caused significant reductions in arable land yields and even land abandonment worldwide, seriously threatening regional and global food security. Among traditional methods for saline soil remediation, soil leaching is the most widely used technology. By irrigating saline soil with fresh water, soluble salts are leached into deeper soil layers or removed from the soil, thereby reducing the salt content of the topsoil and restoring soil productivity.

[0003] However, conventional soil washing methods have significant limitations. On the one hand, these methods usually require a large amount of fresh water, making them difficult to implement on a long-term and large scale in arid, semi-arid, and remote areas. On the other hand, if the large amount of high-salt wastewater generated during the washing process is directly discharged into the downstream environment, it can easily cause secondary salinization and water pollution.

[0004] To reduce freshwater consumption, some technological solutions attempt to recycle and reuse the brine solutions obtained from leaching. For example, brine solutions can be pumped from the soil and desalinated using membrane separation processes such as reverse osmosis and nanofiltration, or distillation, to obtain reusable freshwater. However, these solutions typically rely on electricity for pumping and desalination, resulting in complex structures, high energy consumption, and large investments, making them difficult to implement in arid and remote areas lacking stable power and infrastructure.

[0005] In recent years, some in-situ freshwater recovery technologies based on solar interfacial evaporation have emerged, but most are designed for surface salt solutions or concentrated saline wastewater, and research directly coupled to soil salt leaching processes remains limited. For saline soil remediation scenarios, the following key challenges have not yet been effectively addressed:

[0006] (1) How to continuously extract salt solution from soil pores and transport it to the evaporation interface without relying on electricity and mechanical pumping.

[0007] (2) How to achieve efficient freshwater recycling by utilizing solar evaporation while minimizing additional freshwater demand and realizing water-saving restoration.

[0008] (3) How to avoid direct discharge of leaching salt solution, realize controllable crystallization and resource utilization of salt, and reduce secondary environmental risks. Summary of the Invention

[0009] This application aims to propose a solar-powered multi-stage distillation-based saline soil remediation device to meet the needs of arid, semi-arid, and remote areas.

[0010] This application proposes a solar-based multi-stage distillation saline soil remediation device, comprising a distillation-condensation unit and a water intake unit. The distillation-condensation unit includes multiple stacked evaporation-condensation components and a heat-conducting layer. Each evaporation-condensation component includes an evaporation layer and a condensation layer. The water intake unit includes multiple wicking strips made of absorbent material. The multiple wicking strips are respectively connected to or pass through the evaporation layers of the multiple evaporation-condensation components. The wicking strips can continuously draw salt solution from the soil and transport it to the evaporation layers under capillary action. In the same evaporation-condensation component, the evaporation layer and the condensation layer are spaced apart. The evaporation layer is configured to receive the salt solution in the soil and evaporate it by heating to form water vapor. The condensation layer is configured to receive the water vapor and condense it to form distilled water. Adjacent evaporation-condensation components are separated by the heat-conducting layer. The latent heat released by the water vapor during condensation in the condensation layer can be transferred to the evaporation layer of the next stage evaporation-condensation component through the heat-conducting layer.

[0011] In at least one possible implementation, the saline soil remediation device further includes a photothermal absorption layer configured to absorb solar radiation and convert it into heat, the photothermal absorption layer being disposed on the surface of the evaporation layer of the evaporation-condensation assembly in the first stage of the distillation-condensation unit.

[0012] In at least one possible implementation, the heat-conducting layer is disposed between the photothermal absorption layer and the evaporation layer of the first-stage evaporation-condensation assembly.

[0013] In at least one possible implementation, the saline soil remediation device further includes a heat insulation layer covering the surface of the photothermal absorption layer, the heat insulation layer separating the photothermal absorption layer from the external environment, and the heat insulation layer being made of a light-transmitting heat-insulating material.

[0014] In at least one possible implementation, the saline soil remediation device further includes a condensate collection unit connected to or passing through the condensation layer of the plurality of evaporation-condensation components, the condensate collection unit being capable of collecting condensate from the condensation layer, and the condensate collection unit and the condensation layer being integral.

[0015] In at least one possible implementation, the distillation condensation unit is inclined relative to a horizontal plane, and the condensate collection unit is connected to the bottom end of the inclined surface of the condensation layer, so that the condensate can flow along the surface of the condensation layer to the condensate collection unit.

[0016] In at least one possible implementation, the saline soil remediation device further includes a crystallization unit, which includes a crystallization body and a plurality of water supply sections. The evaporation layer of the plurality of evaporation-condensation components and the crystallization body are connected through the plurality of water supply sections, and at least one side of the crystallization body is in contact with the outside air.

[0017] In at least one possible implementation, the crystallizing body is thermally disposed in the condensation layer of the final stage of the evaporation-condensation assembly, thereby enabling the utilization of the latent heat of condensation of the condensation layer of the final stage of the evaporation-condensation assembly.

[0018] In at least one possible implementation, the saline soil remediation device further includes an insulation layer that encloses the distillation and condensation unit.

[0019] In at least one possible implementation, the wicking belt, the evaporation layer, and the water delivery section are integrated.

[0020] By adopting the above technical solution, adjacent evaporation-condensation components are separated by a heat-conducting layer, enabling multi-stage evaporation-condensation components to recover the latent heat of water vapor condensation step by step, which significantly improves solar energy utilization efficiency and energy efficiency. Attached Figure Description

[0021] Figure 1 A schematic diagram of a solar-powered multi-stage distillation-based saline soil remediation device according to an embodiment of this application is shown.

[0022] Figure 2 A schematic diagram of a solar-powered multi-stage distillation-based saline soil remediation device according to an embodiment of this application is shown.

[0023] Figure 3 A cross-sectional view of a solar-powered multi-stage distillation-based saline soil remediation device according to an embodiment of this application is shown.

[0024] Figure 4 A schematic diagram of the structure of a solar-based multi-stage distillation-based saline soil remediation device (without insulation or heat preservation layer shown) according to an embodiment of this application is illustrated.

[0025] Figure 5 A partial structural cross-sectional view of a solar-powered multi-stage distillation-based saline soil remediation device according to an embodiment of this application is shown.

[0026] Explanation of reference numerals in the attached figures

[0027] 1. Insulation layer

[0028] 2 Photothermal Absorption Layer

[0029] 3 Water intake unit 31 core suction belt

[0030] 4. Distillation and condensation unit; 41. Evaporation layer; 42. Condensation layer; 43. Heat-conducting layer; 44. Frame.

[0031] 5. Condensate collection unit

[0032] 6. Insulation layer

[0033] 7 Crystallization Unit 71 Crystallization Body 711 Attachment Part 712 Drooping Part 72 Water Conveying Part

[0034] 8 Supporting Frame

[0035] Z-thickness direction Detailed Implementation

[0036] To more clearly illustrate the above-mentioned objectives, features, and advantages of this application, specific embodiments of this application are described in detail in conjunction with the accompanying drawings in this section. Besides the embodiments described in this section, this application can also be implemented in other different ways. Those skilled in the art can make corresponding improvements, modifications, and substitutions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed in this section. The scope of protection of this application should be determined by the claims.

[0037] like Figures 1 to 5 As shown, the embodiments of this application propose a saline soil remediation device based on solar multi-stage distillation (hereinafter referred to as saline soil remediation device), which includes a heat insulation layer 1, a photothermal absorption layer 2, a water intake unit 3, a distillation condensation unit 4, a condensate collection unit 5, a heat insulation layer 6, a crystallization unit 7, and a support frame 8.

[0038] like Figure 4 and Figure 5 As shown, the distillation-condensation unit 4 can be connected to the support frame 8. The distillation-condensation unit 4 can include multiple evaporation-condensation components, which can be stacked along the thickness direction Z of the distillation-condensation unit 4. For example, the distillation-condensation unit 4 can include 2 to 20 stages of evaporation-condensation components. Optionally, the distillation-condensation unit 4 can include 4 to 10 stages of evaporation-condensation components. The uppermost evaporation-condensation component in the distillation-condensation unit 4 can be referred to as the first-stage evaporation-condensation component, and the lowermost evaporation-condensation component in the distillation-condensation unit 4 can be referred to as the final-stage evaporation-condensation component.

[0039] The evaporation-condensation assembly may include an evaporation layer 41 and a condensation layer 42, which may be spaced apart in the thickness direction Z of the distillation-condensation unit 4. The condensation layer 42 may be disposed below the evaporation layer 41. For example, a frame 44 may be disposed between the evaporation layer 41 and the condensation layer 42. The frame 44 may be hollow, and the evaporation layer 41 and the condensation layer 42 may be disposed on two sides of the frame 44, with the distance between the evaporation layer 41 and the condensation layer 42 being equal to the thickness of the frame 44.

[0040] The evaporation layer 41 and the condensation layer 42 can absorb solutions and / or vapors. The evaporation layer 41 and the condensation layer 42 can be made of one or more of the following: non-woven fabric, fiber membrane, woven fabric, paper-based material, porous polymer membrane, porous ceramic, and porous carbon material.

[0041] Adjacent evaporation-condensation units can be separated by a heat-conducting layer 43; that is, the condensation layer 42 of the preceding evaporation-condensation unit and the evaporation layer 41 of the following evaporation-condensation unit can be separated by the heat-conducting layer 43. The heat-conducting layer 43 can be made of a material with a high thermal conductivity, such as stainless steel. It is understood that the latent heat released during the condensation process in the condensation layer 42 can be transferred through the heat-conducting layer 43 to the evaporation layer 41 of the next-stage evaporation-condensation unit, allowing the next-stage evaporation layer 41 to utilize this heat to evaporate the salt solution. The resulting water vapor can then condense into condensate (fresh water) on the surface of the condensation layer 42 in the same stage. This multi-stage evaporation-condensation unit structure allows for multi-stage latent heat recovery, fully utilizing thermal energy and improving overall water production efficiency.

[0042] like Figure 4 and Figure 5 As shown, the photothermal absorption layer 2 can be disposed on the surface of the distillation condensation unit 4. The photothermal absorption layer 2 is configured to absorb solar radiation and convert it into heat, which can provide a heat source for the evaporation process carried out in the distillation condensation unit 4.

[0043] The photothermal absorption layer 2 can be a dark (e.g., black) flat plate. The photothermal absorption layer 2 can be made of at least one material with high solar absorption rate. For example, the photothermal absorption layer 2 can include one or more of the following: carbon-based coating, metallic black coating, metal-polymer composite absorption layer, carbon nanotube coating, and graphene-based coating.

[0044] The photothermal absorption layer 2 can be disposed on the surface of the evaporation layer 41 of the first-stage evaporation-condensation assembly. Figure 4 In the upper layer of the first-stage evaporation-condensation assembly, the first-stage evaporation-condensation component can receive heat from the photothermal absorption layer 2. Optionally, a heat-conducting layer 43 can be provided between the photothermal absorption layer 2 and the evaporation layer 41 of the first-stage evaporation-condensation assembly, and the photothermal absorption layer 2 can be disposed on one side of the heat-conducting layer 43. Figure 4 , Figure 5 (On the upper side), the evaporation layer 41 of the first-stage evaporation-condensation assembly can be disposed on the other side of the heat-conducting layer 43. Figure 4 , Figure 5 (Lower side of the middle). The photothermal absorption layer 2 can convert solar radiation into heat energy. The heat energy can be transferred to the evaporation layer 41 of the first-stage evaporation-condensation component through the heat-conducting layer 43, so that the salt solution in the evaporation layer 41 is heated and evaporated to form water vapor. The water vapor is condensed into condensate in the condensation layer 42 of the first-stage evaporation-condensation component at a lower temperature.

[0045] like Figure 1 and Figure 3 As shown, the heat insulation layer 1 can cover the surface of the photothermal absorption layer 2, separating the photothermal absorption layer 2 from the external environment. The heat insulation layer 1 can be made of a light-transmitting heat-insulating material, possessing high light transmittance to allow for greater absorption of solar radiation by the photothermal absorption layer 2. Furthermore, the heat insulation layer 1 has a low thermal conductivity, reducing convective and radiative heat loss between the photothermal absorption layer 2 and the external environment, thus minimizing heat loss. For example, the heat insulation layer 1 can include one or more of the following: transparent aerogel, glass cover, insulated glass, and transparent polymer insulation board.

[0046] Furthermore, the thickness of the insulation layer 1 can be from 0.5 mm to 10 mm, and the thermal conductivity of the insulation layer 1 is less than or equal to 0.05 W / m·°C. -1 ·K -1 ).

[0047] like Figures 1 to 5 As shown, the water intake unit 3 can be connected to the evaporation layer 41 of the distillation and condensation unit 4. The water intake unit 3 can absorb the salt solution in the soil and transport it to the evaporation layer 41.

[0048] The water intake unit 3 may include multiple wicking strips 31, which may be made of porous absorbent materials, such as non-woven fabric, fiber membrane, woven fabric, paper-based materials, porous polymer membranes, porous ceramics, and porous carbon materials. One end of each wicking strip 31 may be inserted into the saline soil layer to be remediated, and the other end may be connected to or pass through the evaporation layer 41 of multiple evaporation-condensation components. The wicking strips 31 can continuously draw salt solution from the pores of the soil and transport it to the evaporation layer 41 under the influence of soil matrix potential (capillary action).

[0049] like Figure 4 As shown, the number of wicking belts 31 and the number of evaporation-condensation components can be the same. For example, the water intake unit 3 may include 5 wicking belts 31, and the distillation-condensation unit 4 may include 5 evaporation-condensation components.

[0050] like Figures 1 to 5As shown, the crystallization unit 7 may include a crystallization body 71 and a plurality of water conveying parts 72. The crystallization body 71 and the water conveying parts 72 may be made of one or more of the following: non-woven fabric, fiber membrane, fabric, paper-based material, porous polymer membrane, porous ceramic, and porous carbon material.

[0051] The wicking belt 31, the evaporation layer 41, and the water conveying section 72 are integrated and can be made of the same material. The width of the evaporation layer 41 can be greater than the width of the wicking belt 31 and the width of the water conveying section 72, thus the evaporation layer 41 has a larger surface area and higher evaporation efficiency.

[0052] The evaporation layer 41 and crystallization body 71 of multiple evaporation-condensation components can be connected by multiple water supply sections 72. The water supply sections 72 allow the crystallization body 71 to receive the concentrated salt solution enriched by distillation from the evaporation layer 41 of the multi-stage evaporation-condensation components. At least one side of the crystallization body 71 can be in contact with the outside air, which can promote further evaporation of water from the concentrated salt solution and promote the crystallization of salt on the surface of the crystallization body 71.

[0053] The crystallizing body 71 may include an attachment portion 711 and a drooping portion 712. The drooping portion 712 may be connected to the attachment portion 711. Optionally, the attachment portion 711 and the drooping portion 712 may be integrated. The attachment portion 711 can be thermally disposed on the condensation layer 42 of the final-stage evaporation-condensation assembly. For example, the attachment portion 711 may be connected to the lower surface of the condensation layer 42 of the final-stage evaporation-condensation assembly via a heat-conducting layer 43. Under the action of latent heat of condensation and external air, the concentrated salt solution can be further evaporated on the attachment portion 711 and the salt can crystallize on the surface of the crystallizing body 71. The crystals can be periodically mechanically removed and collected for resource utilization.

[0054] The drooping portion 712 can hang naturally from the edge of the attachment portion 711. Both sides of the drooping portion 712 can be in contact with the outside air, so that the concentrated salt solution and the air can be fully contacted, promoting the crystallization of salt on the surface of the drooping portion 712.

[0055] Under the influence of the latent heat of condensation and ambient air in the final stage, salt crystals can form on the surface of the crystallizing body 71. All the salt leached from the saline soil is collected in the form of solid crystals, and the saline soil remediation equipment can achieve zero discharge of salt solution.

[0056] The support frame 8 may be provided with a crystallization salt collection section, which may be located below the crystallization body 71. The crystallization salt scraped off from the crystallization body 71 may fall into the crystallization salt collection section for collection.

[0057] The support frame 8 allows the photothermal absorption layer 2 and / or the distillation and condensation unit 4 to be tilted relative to the horizontal plane. Depending on the installation environment of the saline soil remediation equipment, a suitable support frame 8 can be designed so that the photothermal absorption layer 2 has an appropriate installation angle, allowing it to face the sunlight as vertically as possible for the longest possible period of time.

[0058] The condensate collection unit 5 can be connected to or pass through the condensation layer 42 of multiple evaporation-condensation components. The condensate collection unit 5 may include a wicking belt or a pipe, and the condensate from the condensation layer 42 can be collected by the condensate collection unit 5. The condensate collection unit 5 can be connected to the bottom end of the inclined surface of the condensation layer 42 of the distillation-condensation unit 4, so that the condensate can flow along the surface of the condensation layer 42 to the condensate collection unit 5 under the action of gravity.

[0059] In this embodiment, the condensate collection unit 5 may include a wicking strip, and the condensate collection unit 5 and the condensation layer 42 may be integral and made of the same material. The width of the evaporation layer 41 may be greater than the width of the wicking strip.

[0060] The condensate collection unit 5 can be connected to a water collection container or to the soil to collect fresh water or discharge it into the soil for further soil leaching. It is understood that the condensate collection unit 5 can be connected to soil located far from the saline soil remediation equipment to leach soil in other areas.

[0061] Optionally, the angle at which the distillation and condensation unit 4 is tilted relative to the horizontal plane can be 5 to 60 degrees.

[0062] like Figures 1 to 3 As shown, the insulation layer 6 can wrap around the distillation and condensation unit 4. For example, the insulation layer 6 can wrap around the sides and bottom of the distillation and condensation unit 4 to reduce heat loss from the sides and bottom of the distillation and condensation unit 4 to the environment, thereby improving overall energy efficiency. The insulation layer 6 can be made of foam plastic, insulation cotton, or other low thermal conductivity materials.

[0063] The following describes the operation process of the saline soil remediation equipment based on solar multi-stage distillation proposed in this application.

[0064] 1. Add a certain amount of fresh water to the saline soil at one time to rinse the soil, so that the soluble salts in the soil pores dissolve to form a salt solution.

[0065] 2. One end of the water intake unit 3 is buried in the saline soil. Driven by capillary force, it passively draws salt solution from the soil pores and transports it to the evaporation layer 41.

[0066] 3. Under solar radiation, the photothermal absorption layer 2 can convert solar energy into thermal energy and transfer the thermal energy to the multi-stage evaporation-condensation component. The salt solution evaporates in the evaporation layer 41 to form water vapor and condenses in the condensation layer 42 to form condensate. The multi-stage evaporation-condensation component evaporates and condenses step by step, thereby recovering and utilizing the latent heat of condensation and significantly improving the thermal energy utilization efficiency.

[0067] 4. The concentrated salt solution discharged from the multi-stage evaporation-condensation assembly further enters the crystallization unit 7. Under the latent heat of the ambient air and the condensation layer 42 of the final stage evaporation-condensation assembly, the water in the concentrated salt solution is evaporated, and the salt is crystallized and deposited on the surface of the crystallization body 71, realizing salt enrichment and solid phase recovery.

[0068] 5. Collect the condensate from the condensation layer 42 as a freshwater source for subsequent soil rinsing.

[0069] The saline soil remediation equipment based on solar multi-stage distillation proposed in this application has the following beneficial effects.

[0070] 1. By closely coupling soil washing with solar multi-stage distillation, the freshwater in the condensate layer is recovered, which significantly reduces the amount of exogenous freshwater required for saline soil remediation, saves freshwater resources, and has good applicability in water-scarce areas.

[0071] 2. The solar-powered multi-stage distillation-based saline soil remediation equipment requires no external power supply, has a simple structure, and is suitable for remote areas. It relies on solar energy to provide the heat needed for evaporation and uses wicking to complete the soil water extraction and supply process. It eliminates the need for complex electromechanical equipment such as water pumps and can operate stably for extended periods in remote areas lacking power grids and large-scale infrastructure.

[0072] 3. Multi-stage latent heat recovery improves energy efficiency. By using multi-stage evaporation-condensation components to recover the latent heat of water vapor condensation in stages, the freshwater production per unit of solar energy input is significantly increased, resulting in higher solar energy utilization efficiency compared to single-stage evaporation-condensation components.

[0073] 4. In-situ freshwater recovery and salt resource utilization are achieved simultaneously. The freshwater generated by condensation can be directly reinjected into the soil for continuous leaching, while the salt enriched in the salt solution crystallizes and deposits in the crystallization unit and is easy to collect, realizing "freshwater recycling + salt solid phase recovery", avoiding the risk of secondary salinization caused by the discharge of high-salt wastewater.

[0074] 5. Modular and highly scalable. The saline soil remediation equipment of this application can be expanded by parallel or array arrangement according to the remediation area and target water production, which is convenient for promotion and application in land of different sizes (e.g., potted plants, experimental fields, farmland).

[0075] It should be understood that at least some aspects or features of the above-described implementation methods, embodiments, or examples can be appropriately combined.

[0076] It is understood that, in this application, when the number of parts or components is not specifically limited, the number can be one or more, where multiple refers to two or more. For cases where the number of parts or components shown in the drawings and / or described in the specification is, for example, two, three, four, etc., this specific number is generally exemplary and not restrictive, and can be understood as multiple, i.e., two or more; however, this does not mean that this application excludes the case of one.

[0077] In this application, unless otherwise expressly stated or limited, terms such as "installation," "assembly," "connection," "linking," "joining," "linking," "abutment," "communication," "connection," "conduction," "fixing," and "fastening" should be interpreted broadly, for example, they can be direct or indirect. For instance, regarding connection, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly stated or limited. For instance, regarding communication / conduction, it can be direct communication / conduction or indirect communication / conduction through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] In this application, unless otherwise expressly stated or limited, a component being disposed / installed / located / enclosed / placed within, inside, or incorporated in another component can be either of the following two situations: a portion or a majority of the one component is located within the other component; or the one component is completely enclosed within the other component.

[0079] Although the present application has been described in detail using the above embodiments, it will be apparent to those skilled in the art that the present application is not limited to the embodiments described herein. The present application can be modified and implemented as alternative embodiments without departing from the spirit and scope of the present application as defined by the claims. Therefore, the description in this specification is for illustrative purposes only and does not have any limiting meaning for the present application.

Claims

1. A saline soil remediation device based on solar multi-stage distillation, characterized in that, It includes a distillation-condensation unit (4) and a water intake unit (3). The distillation-condensation unit (4) includes multiple evaporation-condensation components and a heat-conducting layer (43) stacked together. The evaporation-condensation components include an evaporation layer (41) and a condensation layer (42). The water intake unit (3) includes multiple wicking strips (31), which are made of absorbent material. The multiple wicking strips (31) are connected to or pass through the evaporation layer (41) of the multiple evaporation-condensation components. The wicking strips (31) can continuously draw salt solution from the soil and transport it to the evaporation layer (41) under capillary action. In the same evaporation-condensation assembly, the evaporation layer (41) and the condensation layer (42) are spaced apart. The evaporation layer (41) is configured to receive a salt solution from the soil and evaporate it by heating to form water vapor. The condensation layer (42) is configured to receive the water vapor and condense it to form distilled water. The adjacent evaporation-condensation components are separated by the heat-conducting layer (43), and the latent heat released by the water vapor during condensation in the condensation layer (42) can be transferred through the heat-conducting layer (43) to the evaporation layer (41) of the next stage evaporation-condensation component.

2. The saline soil remediation equipment based on solar multi-stage distillation according to claim 1, characterized in that, The saline soil remediation equipment also includes a photothermal absorption layer (2), which is configured to absorb solar radiation and convert it into heat. The photothermal absorption layer (2) is disposed on the surface of the evaporation layer (41) of the evaporation-condensation assembly of the first stage of the distillation-condensation unit (4).

3. The saline soil remediation equipment based on solar multi-stage distillation according to claim 2, characterized in that, The heat-conducting layer (43) is disposed between the photothermal absorption layer (2) and the evaporation layer (41) of the first-stage evaporation-condensation assembly.

4. The saline soil remediation equipment based on solar multi-stage distillation according to claim 2, characterized in that, The saline soil remediation equipment also includes a heat insulation layer (1), which covers the surface of the photothermal absorption layer (2). The heat insulation layer (1) separates the photothermal absorption layer (2) from the external environment. The heat insulation layer (1) is made of a light-transmitting heat insulation material.

5. The saline soil remediation equipment based on solar multi-stage distillation according to claim 1, characterized in that, The saline soil remediation equipment also includes a condensate collection unit (5), which is connected to or passes through the condensation layer (42) of the plurality of evaporation-condensation components. The condensate collection unit (5) is capable of collecting the condensate from the condensation layer (42). The condensate collection unit (5) and the condensate layer (42) are integrated.

6. The saline soil remediation equipment based on solar multi-stage distillation according to claim 5, characterized in that, The distillation condensation unit (4) is inclined relative to the horizontal plane, and the condensate collection unit (5) is connected to the bottom end of the inclined surface of the condensation layer (42), so that the condensate can flow along the surface of the condensation layer (42) to the condensate collection unit (5).

7. The saline soil remediation equipment based on solar multi-stage distillation according to claim 1, characterized in that, The saline soil remediation equipment also includes a crystallization unit (7), which includes a crystallization body (71) and multiple water supply sections (72). The evaporation layer (41) of the multiple evaporation-condensation components and the crystallization body (71) are connected through the multiple water supply sections (72). At least one side of the crystallization body (71) is in contact with the outside air.

8. The saline soil remediation equipment based on solar multi-stage distillation according to claim 7, characterized in that, The crystallizing body (71) can be thermally disposed on the condensation layer (42) of the final stage evaporation-condensation assembly, thereby enabling the utilization of the latent heat of condensation of the condensation layer (42) of the final stage evaporation-condensation assembly.

9. The saline soil remediation equipment based on solar multi-stage distillation according to claim 1, characterized in that, The saline soil remediation equipment also includes a heat insulation layer (6), which encloses the distillation and condensation unit (4).

10. The saline soil remediation equipment based on solar multi-stage distillation according to claim 7, characterized in that, The wicking belt (31), the evaporation layer (41), and the water conveying section (72) are integrated.

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