Desalination device and method for saline-alkali soil based on water recycling

Abstract

The application discloses a kind of salinization soil desalination device and method based on water recycling, for solving the problem that traditional soil desalination method is easy to cause huge water resource burden.This device includes underground water level control system for regulating soil underground water level, salt collection blanket, solar heat collection evaporation shed for accelerating soil salting and preventing water vapor escape, water vapor condensation collection system for evaporative water condensation and photovoltaic power supply system, wherein the salt collection blanket is laid on the soil surface;Solar heat collection evaporation shed is set above the salt collection blanket, which is a closed space structure with annular air duct inside;Water vapor condensation collection system is set in annular air duct and connected with underground water level control system, and condensate water is recycled and transported to underground water level control system;Photovoltaic power supply system is connected with underground water level control system and water vapor condensation collection system.This device can effectively realize the recycling of desalination water resources and reduce the water resource burden of saline-alkali soil, and can effectively reduce the cost of saline-alkali soil improvement.

Description

Technical Field

[0001] This application relates to the field of soil improvement technology, and in particular to a desalination device and method for salinized soil based on water recycling. Background Technology

[0002] Saline-alkali land is a common type of land degradation worldwide. Its main characteristics are excessive soluble salts (such as sodium chloride, sodium sulfate, sodium carbonate, and sodium bicarbonate) and a high pH value, which severely inhibits normal plant growth and development, leading to low land productivity and even barrenness. Therefore, effectively managing and improving saline-alkali land is of paramount strategic importance for increasing arable land area, ensuring national food security, improving the ecological environment, and promoting regional sustainable development.

[0003] Existing traditional soil desalination methods mainly rely on flood irrigation. The basic principle is to use large amounts of fresh water (or relatively low-salinity water) to irrigate saline-alkali land for extended periods with high flow rates. This causes soluble salts in the soil to dissolve in the water and infiltrate downwards under gravity. The saline water is then drained from the soil through deeper layers or artificial drainage systems (such as underground pipes or open ditches), thus reducing the salt concentration in the root zone. However, traditional methods, due to their reliance on flood irrigation, consume enormous amounts of water. This can create a significant water burden for water-scarce saline-alkali areas (especially arid inland regions), and is inconsistent with the requirements of sustainable development.

[0004] Therefore, there is an urgent need to develop a new type of soil salinization improvement device to achieve the recycling of water resources. Summary of the Invention

[0005] The purpose of this application is to provide a device and method for desalinizing saline-alkali soil based on water recycling, so as to solve the problem that traditional soil desalination methods easily cause a huge water resource burden, and to realize the recycling of water resources.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0007] On one hand, embodiments of this application provide a desalination device for saline-alkali soil based on water recycling, comprising:

[0008] A groundwater level control system, wherein the groundwater level control system is used to control the soil groundwater level;

[0009] Salt-collecting blanket, which is laid on the soil surface to collect and condense soil salts;

[0010] A solar thermal evaporation shed is installed above the salt collection blanket to accelerate the leaching of soil salts and prevent water vapor from escaping; the solar thermal evaporation shed is a closed space structure with an internal annular air duct.

[0011] A water vapor condensation collection system is installed in the annular air duct to condense the evaporated water; the water vapor condensation collection system is connected to the groundwater level control system, and the water vapor condensation collection system circulates and transports the condensate to the groundwater level control system.

[0012] A photovoltaic power supply system is electrically connected to the groundwater level control system and the water vapor condensation collection system, and is used to provide power to the groundwater level control system and the water vapor condensation collection system.

[0013] In some embodiments, the groundwater level control system includes a water storage tank disposed below the mudline, and the water vapor condensation collection system includes a drain pipe connected to the water storage tank.

[0014] In some embodiments, the water vapor condensation collection system further includes a refrigerated dehumidifier for accelerating the condensation of evaporated water. The refrigerated dehumidifier is disposed in the annular air duct, and the air inlet of the refrigerated dehumidifier faces the wind direction of the annular air duct.

[0015] In some embodiments, one end of the drain pipe is connected to the water storage tank, and the other end is connected to the refrigeration dehumidifier.

[0016] In some embodiments, the water-recycling-based desalination device for saline-alkali soil includes a partition disposed in the middle of the enclosed space structure, and the partition extends along the length of the solar thermal evaporation shed; the partition causes the annular air duct to form a first air duct and a second air duct, and the refrigeration dehumidifier is disposed in the first air duct.

[0017] In some embodiments, the groundwater level control system includes a main water supply pipe and a plurality of perforated branch water supply pipes. The main water supply pipe is connected to a water pump located in the water storage tank. One end of each of the branch water supply pipes is connected to the main water supply pipe, and the other end extends along the length of the salt collection blanket. The branch water supply pipes are arranged at intervals along the width of the salt collection blanket.

[0018] In some embodiments, the photovoltaic power supply system includes a photovoltaic panel for photovoltaic power generation, a battery for storing electrical energy, an MPPT controller for charging the battery, and an inverter. The photovoltaic panel, battery, MPPT controller, and inverter are connected by cables. The groundwater level control system and the water vapor condensation collection system are connected to the output terminal of the inverter.

[0019] In some embodiments, the solar thermal evaporation shed is a frame structure covered with a plastic film or a structure assembled from multiple rigid plastic panels. The inner side of the plastic film structure is coated with a black heat-absorbing coating, and the inner side of the panels of the structure assembled from multiple rigid plastic panels is coated with a black heat-absorbing coating.

[0020] On the other hand, this application provides a method for desalinating saline-alkali soil, using the water recycling-based desalination device for saline-alkali soil provided in any of the foregoing embodiments, including the following steps:

[0021] S100. The compacted soil in the saline-alkali land area to be improved shall be properly tilled and loosened, and the land shall be leveled and the ground leveled.

[0022] S200. Install a groundwater level control system and bury at least a portion of the groundwater level control system below the mudline of the saline-alkali land area to be improved.

[0023] S300, Lay salt-collecting blankets in the saline-alkali land area to be improved;

[0024] S400. Install a solar thermal evaporation shed above the salt collection blanket, and make the interior of the solar thermal evaporation shed form a closed space structure with an annular air duct.

[0025] S500. Install a water vapor condensation collection system inside the solar thermal evaporation shed, and connect the water vapor condensation collection system to the groundwater level control system.

[0026] S600. Install a photovoltaic power supply system on the ground adjacent to the saline-alkali land area to be improved, and connect the photovoltaic power supply system to the groundwater level control system and the water vapor condensation collection system.

[0027] S700, Start the equipment, regulate the groundwater level of the saline-alkali land area to be improved through the groundwater level regulation system, and accelerate the decomposition of soil salts and prevent water vapor from escaping through the solar thermal evaporation shed.

[0028] Water vapor is condensed through a water vapor condensation collection system, and the condensate is circulated and transported to the groundwater level control system.

[0029] The photovoltaic power supply system provides working power to the groundwater level control system and the water vapor condensation and collection system.

[0030] S800: Take samples of the soil to be desalinated and test whether the salinity reaches the target value. If it does not reach the target, continue to step S700; if it does reach the target, proceed to step S900.

[0031] S900, Dismantle the water recycling-based desalination device for saline-alkali soil.

[0032] This application has the following beneficial effects:

[0033] This application provides a desalination device for saline-alkali soil based on water recycling. A solar-powered evaporation shed is placed above a salt-collecting blanket, and the shed is designed as a closed space with an internal annular air duct. A water vapor condensation collection system is integrated into the annular air duct and connected to a groundwater level control system. Therefore, utilizing the soil capillary principle, through precise groundwater level control and rapid soil moisture evaporation, rapid desalination of saline-alkali soil can be achieved with minimal water usage. This effectively prevents water vapor escape, enables the recycling of desalinated water resources, and effectively reduces the water resource burden in saline-alkali areas.

[0034] Furthermore, the device is equipped with a photovoltaic power supply system that is electrically connected to the groundwater level control system and the water vapor condensation collection system, which can provide working power for the groundwater level control system and the water vapor condensation collection system, effectively reducing the cost of improving saline-alkali soil. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a water recycling-based desalination device for saline-alkali soil in an embodiment of this application.

[0036] Figure 2 This is a schematic plan view of a water recycling-based desalination device for saline-alkali soil in an embodiment of this application.

[0037] Figure 3 This is a schematic diagram of the water supply network in the embodiments of this application;

[0038] Figure 4 This is a schematic diagram of the process for desalinizing saline-alkali soil in the embodiments of this application.

[0039] Figure label:

[0040] 10-Groundwater level control system; 11-Water storage tank; 12-Main water supply pipe; 13-Branch water supply pipe; 14-Water pump;

[0041] 15-Intelligent water pump controller; 16-Groundwater level sensor;

[0042] 20-Collect salt blankets;

[0043] 30 - Solar thermal evaporation shed; 31 - Circular air duct; 311 - First air duct; 312 - Second air duct;

[0044] 40 - Water vapor condensation collection system; 41 - Drain pipe; 42 - Refrigeration dehumidifier;

[0045] 50-Photovoltaic power supply system; 51-Photovoltaic panel; 52-Battery; 53-MPPT controller; 54-Inverter;

[0046] 60-partition;

[0047] 70-Battery cabinet;

[0048] 80-Electrical cabinet. Detailed Implementation

[0049] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification.

[0050] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the accompanying drawings and embodiments. To enable those skilled in the art to better understand the solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0051] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element; for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0052] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0053] In the embodiments of this application, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design; rather, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0054] Saline-alkali land is a common type of land degradation worldwide. Its main characteristics are excessive soluble salts (such as sodium chloride, sodium sulfate, sodium carbonate, and sodium bicarbonate) and a high pH value, which severely inhibits normal plant growth and development, leading to low land productivity and even barrenness. Therefore, effectively managing and improving saline-alkali land is of paramount strategic importance for increasing arable land area, ensuring national food security, improving the ecological environment, and promoting regional sustainable development.

[0055] However, existing traditional soil desalination methods mainly rely on flood irrigation. The basic principle is to use large amounts of fresh water (or relatively low-salinity water) to irrigate saline-alkali land for extended periods with high flow rates. This causes soluble salts in the soil to dissolve in the water and infiltrate downwards under gravity. The saline water is then drained from the soil through deeper layers or artificial drainage systems (such as underground pipes or open ditches), thus reducing the salt concentration in the root zone. However, traditional methods, due to their reliance on flood irrigation, consume enormous amounts of water, placing a significant burden on water resources in already water-scarce saline-alkali areas (especially in arid inland regions).

[0056] To address the aforementioned technical problems, this application provides a water recycling-based desalination device for saline-alkali soil. Figure 1 This is a schematic diagram of a water recycling-based desalination device for saline-alkali soil in an embodiment of this application. Figure 2 This is a schematic plan view of a water recycling-based desalination device for saline-alkali soil in an embodiment of this application.

[0057] like Figure 1 and Figure 2As shown, in some embodiments, the water recycling-based desalination device for saline-alkali soil may include a groundwater level control system 10, a salt collection blanket 20, a solar thermal evaporation shed 30, a water vapor condensation collection system 40, and a photovoltaic power supply system 50. The groundwater level control system 10 is used to control the soil groundwater level; the salt collection blanket 20 is laid on the soil surface to collect and condense soil salts; the solar thermal evaporation shed 30 is positioned above the salt collection blanket 20 to accelerate soil salt condensation and prevent water vapor escape. The heat collection and evaporation shed 30 is a closed space structure with an internal annular air duct 31; the water vapor condensation collection system 40 is installed in the annular air duct 31 to condense the evaporated water; the water vapor condensation collection system 40 is connected to the groundwater level control system 10, and the water vapor condensation collection system 40 circulates and transports the condensate to the groundwater level control system 10; the photovoltaic power supply system 50 is electrically connected to the groundwater level control system 10 and the water vapor condensation collection system 40 to provide power to the groundwater level control system 10 and the water vapor condensation collection system 40.

[0058] Based on this structure, the solar thermal evaporation shed 30 is placed above the salt collection blanket 20, and the solar thermal evaporation shed 30 is designed as a closed space structure with an internal annular air duct 31. Simultaneously, the water vapor condensation collection system 40 is placed within the annular air duct 31 and connected to the groundwater level control system 10. Utilizing the soil capillary principle, through precise groundwater level control and rapid soil moisture evaporation, rapid desalination of saline-alkali soil can be achieved with minimal water usage, effectively preventing water vapor escape and enabling the recycling of desalinated water resources. This also effectively reduces the water resource burden in saline-alkali areas. Furthermore, this saline-alkali soil desalination device is equipped with a photovoltaic power supply system 50 electrically connected to the groundwater level control system 10 and the water vapor condensation collection system 40, providing operating power to both systems and effectively reducing the cost of saline-alkali soil improvement.

[0059] For example, the salt collection blanket 20 can be made of dark-colored, weather-resistant synthetic fiber material, featuring a multi-layered structure with a strong, water-wicking bottom layer and a finely porous surface layer with excellent capillary absorption and a large evaporative surface area. The edges are reinforced and designed with reliable anchor points, facilitating installation, salt crystal collection, and cleaning for reuse. When the salt collection blanket 20 is saturated with salt, it can be removed to quickly remove the salt condensed on the ground; moreover, when saturated with salt, the salt collection blanket 20 can be reused after cleaning and desalination.

[0060] For example, the solar thermal evaporation shed 30 can adopt an arched, enclosed space structure, which can play a role in absorbing and storing heat, promoting surface water evaporation and accelerating soil salt release, preventing water vapor escape, and providing rain protection.

[0061] The solar thermal evaporation shed 30 can be configured in various structural forms. For example, it can adopt a frame covered with a plastic film structure, where the plastic can be made of a transparent material, and the inner side of the plastic film is coated with a black heat-absorbing coating. Based on this structure, by coating the inner side of the plastic film with a black heat-absorbing coating, the absorption of solar radiation by the solar thermal evaporation shed 30 can be improved, increasing the temperature of the air and the ground surface inside the shed. This can accelerate the leaching of soil salts, improve the efficiency of saline-alkali soil improvement, and reduce the cost of saline-alkali soil improvement due to the use of solar thermal evaporation.

[0062] For example, the solar thermal evaporation shed 30 can adopt a structure composed of multiple rigid plastic panels. These panels can be made of transparent material, and the inner sides of the panels are coated with a black heat-absorbing coating. Based on this structure, the black heat-absorbing coating on the inner sides of the panels can accelerate the rise in surface temperature, thereby enhancing the capillary action of the underground pipe network and accelerating soil moisture evaporation, thus increasing the efficiency of salt leaching. By condensing and collecting the water vapor generated during desalination, the desalination water can be recycled.

[0063] like Figure 1 As shown, in some embodiments, the groundwater level control system 10 may include a water storage tank 11 located below the mudline, and the water vapor condensation collection system 40 may include a drain pipe 41 connected to the water storage tank 11. Based on this structure, by burying the water storage tank 11 below the mudline of the saline-alkali land area to be improved, and connecting the drain pipe 41 and the water storage tank 11, the evaporated water can be condensed by the water vapor condensation collection system 40, and the condensate can be circulated back to the water storage tank 11 to replenish the groundwater level, thereby reducing water consumption.

[0064] For example, the drainage pipe 41 can be set above the mud line or buried below the mud line, depending on the actual design requirements of the saline-alkali soil desalination device. For instance, when the drainage pipe 41 is buried below the mud line, the horizontal height of the drainage pipe 41 is greater than the top elevation of the water storage tank 11, and the condensate can automatically flow back to the water storage tank under its own weight, without the need for additional transportation power, further reducing the cost of improving saline-alkali soil.

[0065] For example, such as Figure 1As shown, the water vapor condensation collection system 40 may further include a refrigerated dehumidifier 42 to accelerate the condensation of evaporated water. The refrigerated dehumidifier 42 is disposed in the annular air duct 31, and the air inlet of the refrigerated dehumidifier 42 faces the airflow direction of the annular air duct 31. One end of the drain pipe 41 is connected to the water storage tank 11, and the other end of the drain pipe 41 is connected to the refrigerated dehumidifier 42. By installing the refrigerated dehumidifier 42 in the sealed space structure of the solar thermal evaporation shed 30, water vapor can be quickly condensed and the condensate can be transported to the water storage tank for recycling.

[0066] like Figure 2 As shown, in some embodiments, the water recycling-based desalination device for saline-alkali soil may include a partition 60 disposed in the middle of a closed space structure, and the partition 60 extends along the length of the solar thermal evaporation shed 30; the partition 60 causes the annular air duct 31 to form a first air duct 311 and a second air duct 312, and a refrigerated dehumidifier 42 is disposed in the first air duct 311. Based on this structure, the annular air duct 31 can be formed by setting the partition 60, and the water vapor in the closed space structure of the solar thermal evaporation shed 30 can be condensed into condensate by the refrigerated dehumidifier 42, and returned to the water storage tank 11 through the drain pipe 41, so as to realize the recycling of water resources within the system and effectively alleviate the water resource burden of saline-alkali land.

[0067] like Figure 1 and 3 As shown, in some embodiments, the groundwater level control system 10 may include a main water supply pipe 12 and a plurality of perforated branch water supply pipes 13. The main water supply pipe 12 is connected to a water pump 14 located in a water storage tank 11. One end of each branch water supply pipe 13 is connected to the main water supply pipe 12, and the other end of each branch water supply pipe 13 extends along the length of the salt collection blanket 20. The branch water supply pipes 13 are spaced apart along the width of the salt collection blanket 20. The groundwater level control system 10 may include a water pump intelligent controller 15 located in an electrical cabinet 80 and a groundwater level sensor 16 buried underground in the saline-alkali land area to be improved. The water pump intelligent controller 15 is electrically connected to the water pump 14 and the groundwater level sensor 16 via cables or wireless signals, respectively.

[0068] Based on this structure, the water pump 14 is controlled to start and stop according to the groundwater level change signal fed back by the groundwater level sensor 16. When the soil groundwater level is lower than the depth threshold for the formation of capillary action in the surface soil, the intelligent water pump controller 15 starts the water pump 14 to replenish the groundwater level and accelerate soil salinization. When the soil groundwater level reaches the set maximum value, the intelligent water pump controller 15 stops the water pump 14. Utilizing the soil capillary principle, through precise control of the groundwater level and rapid evaporation of soil moisture, rapid soil desalination can be achieved with a small amount of water.

[0069] like Figure 1 As shown, in some embodiments, the photovoltaic power supply system 50 may include photovoltaic panels 51 for photovoltaic power generation, a battery 52 for storing electrical energy, an MPPT controller 53 for charging the battery 52, and an inverter 54. The photovoltaic panels 51, battery 52, MPPT controller 53, and inverter 54 are connected by cables. The groundwater level control system 10 and the water vapor condensation collection system 40 are connected to the output terminal of the inverter 54. To improve safety, the battery 52 is independently installed in the battery cabinet 70. The photovoltaic panels 51 are mounted on a bracket, and the MPPT controller 53 and inverter 54 are installed in an electrical cabinet 80 with ventilation holes and a fan. The inverter 54 can convert direct current to alternating current, enabling independent power supply.

[0070] Based on this structure, it can provide working power for groundwater level control systems and water vapor condensation collection systems, which can effectively reduce the cost of improving saline-alkali soil; moreover, it can also solve the power supply problem in arid saline-alkali areas without power grids.

[0071] On the other hand, embodiments of this application provide a method for desalinating saline-alkali soil, and any of the foregoing embodiments provide a desalination device for saline-alkali soil based on water recycling. Figure 4 This is a schematic diagram of the process for desalinating saline-alkali soil in an embodiment of this application, as shown below. Figure 4 As shown, the method specifically includes the following steps S100 to S900:

[0072] S100. The compacted soil in the saline-alkali land area to be improved shall be properly tilled and loosened, and the land shall be leveled and the ground leveled.

[0073] S200, Install the groundwater level control system 10, and bury at least a portion of the groundwater level control system 10 below the mudline of the saline-alkali land area to be improved. Specifically, this includes burying the water storage tank 11 below the mudline of the saline-alkali land area to be improved.

[0074] S300, Lay salt-collecting blankets 20 in areas of saline-alkali land to be improved.

[0075] S400. A solar thermal evaporation shed 30 is installed above the salt collection blanket 20, and the interior of the solar thermal evaporation shed 30 forms a sealed space structure with an annular air duct 31. Specifically, this includes installing the solar thermal evaporation shed 30 as a frame covered with a plastic film structure or a structure assembled from multiple rigid plastic panels, and coating the inner side of the film of the frame covered with a plastic film structure with a black heat-absorbing coating, or coating the inner side of the panels of the structure assembled from multiple rigid plastic panels with a black heat-absorbing coating.

[0076] S500, Install a water vapor condensation collection system 40 inside the solar thermal evaporation shed 30, and connect the water vapor condensation collection system 40 to the groundwater level control system 10.

[0077] S600. Install a photovoltaic power supply system 50 on the ground in the adjacent saline-alkali land area to be improved, and connect the photovoltaic power supply system 50 to the groundwater level control system 10 and the water vapor condensation collection system 40.

[0078] S700: Start the equipment, regulate the groundwater level of the saline-alkali land area to be improved through the groundwater level regulation system 10, and accelerate the precipitation of soil salt and prevent water vapor from escaping through the solar thermal evaporation shed 30; condense the water vapor through the water vapor condensation collection system 40, and circulate the condensate to the groundwater level regulation system 10; provide working power to the groundwater level regulation system 10 and the water vapor condensation collection system 40 through the photovoltaic power supply system 50.

[0079] S800: Take samples of the soil to be desalinated and test whether the salinity reaches the target value. If it does not reach the target, continue to step S700; if it does reach the target, proceed to step S900.

[0080] S900, dismantle the desalination device for saline-alkali soil based on water recycling.

[0081] The desalination method for saline-alkali soil provided in this application has the following significant technical effects: (1) low water consumption, saving water and energy; (2) fast desalination speed and good desalination effect: compared with traditional desalination methods, this application can achieve rapid soil desalination, controllable desalination degree, and good desalination effect; (3) ecological and environmental protection: no high-concentration saline wastewater is generated, and it will not cause secondary soil salinization; in addition, this application is an in-situ treatment technology, which has little soil disturbance, no chemical additives, and low negative impact on the ecological environment; (4) low operating cost: solar energy is used to power the equipment, and solar energy is used for evaporation desalination, resulting in low operating cost; (5) salt and alkali resource extraction: the salt crystals enriched on the salt collection blanket can be collected to realize the resource extraction of soil salt and alkali; (6) high degree of automation and convenient operation: the automatic control system of groundwater level sensor, water pump intelligent controller, water pump and other automatic control system starts and stops.

[0082] Overall, the desalination method for saline-alkali soil provided in this application has technical advantages such as rapid desalination, water and energy saving, environmental protection, low operating cost, extraction of saline-alkali resources, and convenient operation, and has broad application prospects and practical value.

[0083] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. All embodiments obtained by any modifications, alterations or equivalent substitutions made by those skilled in the art without departing from the technical concept of this application shall fall within the scope of protection of the claims of this application.

Claims

1. A method for desalinating saline-alkali soil, characterized in that, A water-recycling-based desalination device for salinized soil is employed, comprising: Groundwater level control system (10), the groundwater level control system (10) is used to control the soil groundwater level; Salt-collecting blanket (20), which is laid on the soil surface to collect and condense soil salts; A solar thermal evaporation shed (30) is set above the salt collection blanket (20) to accelerate the release of soil salt and prevent water vapor from escaping; the solar thermal evaporation shed (30) is an arched, enclosed space structure with an internal annular air duct (31); A partition (60) is disposed in the middle of the enclosed space structure, and the partition (60) extends along the length of the solar thermal evaporation shed (30); the partition (60) causes the annular air duct (31) to form a first air duct (311) and a second air duct (312). A water vapor condensation collection system (40) is installed in the annular air duct (31) for condensing evaporated water. The water vapor condensation collection system (40) is connected to the groundwater level control system (10). The water vapor condensation collection system (40) circulates the condensate to the groundwater level control system (10). The water vapor condensation collection system (40) also includes a refrigerated dehumidifier (42) for accelerating the condensation of evaporated water. The refrigerated dehumidifier (42) is installed in the annular air duct (31), and the air inlet of the refrigerated dehumidifier (42) faces the wind direction of the annular air duct (31). The refrigerated dehumidifier (42) is installed in the first air duct (311). A photovoltaic power supply system (50) is electrically connected to the groundwater level control system (10) and the water vapor condensation collection system (40) to provide electrical energy to the groundwater level control system (10) and the water vapor condensation collection system (40). The method for desalinating saline-alkali soil includes the following steps: S100. The compacted soil in the saline-alkali land area to be improved shall be properly tilled and loosened, and the land shall be leveled and the ground leveled. S200. Install a groundwater level control system (10) and bury at least a portion of the groundwater level control system (10) below the mudline of the saline-alkali land area to be improved. S300, Lay a salt-collecting blanket (20) in the saline-alkali land area to be improved. S400, Install a solar thermal evaporation shed (30) above the salt collection blanket (20), and make the interior of the solar thermal evaporation shed (30) form a closed space structure with an annular air duct (31); S500, Install a water vapor condensation collection system (40) inside the solar thermal evaporation shed (30), and connect the water vapor condensation collection system (40) to the groundwater level control system (10); S600. Install a photovoltaic power supply system (50) on the ground adjacent to the saline-alkali land area to be improved, and connect the photovoltaic power supply system (50) to the groundwater level control system (10) and the water vapor condensation collection system (40). S700, start the equipment, regulate the groundwater level of the saline-alkali land area to be improved through the groundwater level regulation system (10), and accelerate the release of soil salt and prevent water vapor from escaping through the solar thermal evaporation shed (30); Water vapor is condensed by a water vapor condensation collection system (40), and the condensate is circulated and transported to the groundwater level control system (10). The photovoltaic power supply system (50) provides working power to the groundwater level control system (10) and the water vapor condensation collection system (40); S800: Take samples of the soil to be desalinated and test whether the salinity reaches the target value. If it does not reach the target, continue to step S700; if it does reach the target, proceed to step S900. S900, Dismantle the water recycling-based desalination device for saline-alkali soil.

2. The method for desalinizing saline-alkali soil according to claim 1, characterized in that, The groundwater level control system (10) includes a water storage tank (11) located below the mudline, and the water vapor condensation collection system (40) includes a drain pipe (41) connected to the water storage tank (11).

3. The method for desalinizing saline-alkali soil according to claim 2, characterized in that, One end of the drain pipe (41) is connected to the water storage tank (11), and the other end is connected to the refrigerated dehumidifier (42).

4. The method for desalinizing saline-alkali soil according to claim 2, characterized in that, The groundwater level control system (10) includes a water supply main pipe (12) and a number of water supply branch pipes (13) with perforations. The water supply main pipe (12) is connected to a water pump (14) located in the water storage tank (11). One end of each of the water supply branch pipes (13) is connected to the water supply main pipe (12), and the other end extends along the length of the salt collection blanket (20). The water supply branch pipes (13) are arranged at intervals along the width of the salt collection blanket (20).

5. The method for desalinizing saline-alkali soil according to claim 1, characterized in that, The photovoltaic power supply system (50) includes a photovoltaic panel (51) for photovoltaic power generation, a battery (52) for storing electrical energy, an MPPT controller (53) for charging the battery (52), and an inverter (54). The photovoltaic panel (51), battery (52), MPPT controller (53), and inverter (54) are connected by cables. The groundwater level control system (10) and the water vapor condensation collection system (40) are connected to the output end of the inverter (54).

6. The method for desalinizing saline-alkali soil according to claim 1, characterized in that, The solar thermal evaporation shed (30) is a frame covered with a plastic film or a multi-piece rigid plastic board assembly structure. The inner side of the plastic film of the frame covered with a plastic film is coated with a black heat-absorbing coating, and the inner side of the board of the multi-piece rigid plastic board assembly structure is coated with a black heat-absorbing coating.

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