Saline-alkali soil leaching water recycling device

Abstract

The invention belongs to the technical field of saline-alkali soil treatment, and particularly relates to a saline-alkali soil leaching water recycling device which comprises a water collecting well used for collecting leaching water; the heating module is arranged at the bottom of the water collecting well and used for heating and evaporating the leaching water to form water vapor; the steam channel comprises a first conical pipeline, a straight pipeline and a second conical pipeline which are sequentially and coaxially arranged, the first conical pipeline and the second conical pipeline are provided with an inlet end and an outlet end respectively, the diameter of the inlet end of the first conical pipeline is larger than that of the outlet end, and the diameter of the inlet end of the second conical pipeline is smaller than that of the outlet end. The diameters of the outlet end of the first conical pipeline and the inlet end of the second conical pipeline are the same as the diameter of the straight pipeline; the inlet end of the first conical pipeline is communicated with the heating module; the condensation module is connected to the outlet end of the second conical pipeline and used for cooling the water vapor into condensed water; the power supply module comprises a solar power generation assembly and a wind power generation assembly and is used for guaranteeing power supply.

Description

Technical Field

[0001] This invention belongs to the field of saline-alkali land management technology, specifically relating to a device for recycling and utilizing leachate from saline-alkali land. Background Technology

[0002] The scientific management of saline-alkali land is crucial for safeguarding the national red line for arable land and food security. Currently, underground drainage and salt leaching technology has become the mainstream method for improving saline-alkali land in arid areas due to its ability to effectively regulate groundwater levels and reduce soil salinity. However, if the high-salt leachate (salt concentration of approximately 3.5%) produced by this technology is directly discharged, it will lead to increased mineralization of surrounding water bodies and exacerbate secondary soil salinization, posing a serious threat to the ecological environment.

[0003] Current research on the recycling of leachate from saline-alkali land mainly draws on seawater purification technologies, such as reverse osmosis membranes or microbial cell desalination methods, to desalinate the leachate from coastal saline-alkali land. However, in arid regions of Northwest China such as Ningxia and Gansu, reverse osmosis membrane desalination is prone to clogging due to the high salinity and turbidity of the water, while microbial cell desalination is sensitive to temperature fluctuations and easily affected by large temperature differences in the arid Northwest region. Both methods are difficult to adapt to, resulting in low desalination efficiency and inconsistent desalination quality. Therefore, there is an urgent need for a saline-alkali land leachate recycling device to meet the specific environmental requirements of saline-alkali land leachate recycling in Northwest China. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this invention is to provide a saline-alkali land leaching water recycling device that can utilize natural resources such as solar and wind energy to adapt to different regional environments in the arid Northwest region for leaching water desalination, thereby improving the leaching water desalination efficiency and quality. The device has a simple structure and low operation and maintenance costs.

[0005] The technical solution of this invention is: A device for recycling and utilizing leachate from saline-alkali land includes: A collection well is used to collect shower water. The heating module, located at the bottom of the water collection well, is used to heat the rinse water, causing it to evaporate into water vapor; The steam passage includes a first conical pipe, a straight pipe, and a second conical pipe arranged coaxially in sequence. The first and second conical pipes are respectively provided with an inlet end and an outlet end. The diameter of the inlet end of the first conical pipe is larger than the diameter of the outlet end, and the diameter of the inlet end of the second conical pipe is smaller than the diameter of the outlet end. The outlet end of the first conical pipe and the inlet end of the second conical pipe are connected through the straight pipe. The inlet end of the first conical pipe is connected to the output end of the heating module. A condensation module, connected to the outlet end of the second conical pipe, is used to cool water vapor and form condensate. The power supply module, including solar power generation components and wind power generation components, is used to provide power to the heating module.

[0006] Preferably, the condensation module includes: A ring rectifier, the inlet of which is connected to the outlet end of the second conical pipe; Multiple eccentric reducers are arranged in a circumferential array around the annular rectifier, with one end of each eccentric reducer connected to the annular rectifier. Multiple heat exchange components are provided, each corresponding to one of the multiple eccentric reducers. The heat exchange components are connected to the other end of the eccentric reducers to cool the steam distributed to the eccentric reducers into condensate.

[0007] Preferably, the heat exchange assembly includes: The steam distribution pipe is inclined, with its lower end in the inclined direction connected to the end of the eccentric reducer away from the annular rectifier, and the other end closed. Multiple heat exchange tube bundles, each including a heat dissipation tube and multiple heat dissipation fins evenly distributed on the outer side of the heat dissipation tube wall. The heat dissipation tube has a flat, thin-walled structure. One end of the heat dissipation tube is connected to the steam distribution pipe, and the other end is connected to a water collection pipe. The water collection pipe is used to communicate with a water storage tank to collect condensate. The water storage tank is an annular cavity fitted onto the upper end of the second conical pipe.

[0008] Preferably, the upper end of the second conical pipe is also provided with a shell, the lower end of which is fitted onto the outer wall of the water storage tank and the two are fixedly connected. The upper end of the shell is higher than the annular rectifier. The annular rectifier, the eccentric reducer, the steam distribution pipe and the heat exchange tube bundle are all placed inside the shell. The side wall of the shell is provided with louvers to allow cold air to flow in and contact the heat exchange tube bundle and the heat dissipation fins.

[0009] Preferably, a fan is provided between the top wall of the housing and the annular rectifier. The air inlet of the fan is located inside the housing, and the air outlet of the fan passes through the top wall of the housing and is located on the outside of the housing, for discharging hot air from the housing.

[0010] Preferably, the top of the rectifier is arc-shaped, and the connection between the eccentric reducer and the annular rectifier is close to the second conical pipe.

[0011] Preferably, the steam channel is wrapped with an insulation layer on the outside and a salt-proof protective layer on the inside.

[0012] Preferably, the heating module includes: A heating chamber is fixed at the bottom of the water collection well, with an opening at its upper end. The opening of the heating chamber is connected to the inlet end of the first conical pipe and is used to hold the rinsing water entering the water collection well. A heating coil is wound around the outer wall of the heating cavity; A storage battery is located at the bottom of the heating chamber and is electrically connected to the heating coil and the power supply module, respectively.

[0013] Preferably, the heating coil is made of high-temperature mica-wrapped glass fiber cable.

[0014] Preferably, the heating coil is wrapped with high-temperature insulation cotton to reduce heat loss.

[0015] Compared with the prior art, the saline-alkali land leaching water recycling device of the present invention has the following beneficial effects: This device is adapted to local conditions, taking into account the arid climate of Northwest China. It utilizes solar and wind power for power supply and incorporates a water collection well in the saline-alkali land. The heating module and steam channel are placed in the water collection well, saving construction space and costs and reducing interference. The steam channel of this device forms a Venturi-like structure through a first conical pipe, a straight pipe, and a second conical pipe, creating a "gradually narrowing-straight section-gradually expanding" steam channel. This effectively improves the efficiency and stability of water vapor flow and reduces backflow. Furthermore, a condensation module is installed at the outlet end of the second conical pipe to cool the water vapor into condensate for water recovery. The power supply module uses a combination of solar and wind power generation components to generate electricity, fully adapting to the natural advantages of the arid Northwest region. It utilizes natural resources to provide power for the heating module and other electrical equipment. The device has no complex internal structure or precision parts, operates stably, is easy to maintain, and can adapt to different regional needs. It is highly practical and achieves efficient and stable desalination and recovery of leaching water in the arid Northwest region. The recovered water can be directly used for freshwater leaching or irrigation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the actual use of the device in an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the overall structure of the device in an embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the heating module and heating channel structure in an embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram of the structure of the ring rectifier in an embodiment of the present invention.

[0020] Figure 5 This is a schematic diagram of the condensation module in an embodiment of the present invention.

[0021] Figure 6 This is a velocity streamline diagram of water vapor in an embodiment of the present invention.

[0022] Figure 7 This is a vector diagram showing the velocity of water vapor in an embodiment of the present invention.

[0023] Figure 8 This is a schematic diagram of temperature changes within the steam channel in an embodiment of the present invention.

[0024] Figure 9 This is a schematic diagram of the gas pressure change in the steam channel in an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures: 1. Water collection well; 2. Heating module; 21. Heating chamber; 22. Heating coil; 3. Steam passage; 31. First conical pipe; 32. Straight pipe; 33. Second conical pipe; 4. Condensation module; 41. Circular rectifier; 42. Eccentric reducer; 43. Steam distribution pipe; 44. Heat exchange tube bundle; 441. Heat dissipation pipe; 442. Water collection pipe; 5. Power supply module; 6. Louver; 7. Water storage tank; 8. Outer shell; 9. Fan; 10. Insulation layer; 11. Drainage pipe; 12. Gravity pipe. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0028] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0029] See Figures 1 to 5 As shown, in order to adapt to different regional environments such as the arid Northwest region, achieve efficient desalination and recycling of leachate, ensure stable desalination quality, simplify structural complexity, and reduce operation and maintenance costs, this embodiment provides a saline-alkali land leachate recycling device, including a water collection well 1, a heating module 2, a steam channel 3, a condensation module 4, and a power supply module 5.

[0030] The water collection well 1 is constructed directly within the working area. Specifically, it is formed by excavating the ground to create a vertical shaft, and the well walls are reinforced. The rinse water is collected in the water collection well 1 via a drainage pipe 11 and a blind pipe. A heating module 2 is located at the bottom of the water collection well 1 to collect and heat the rinse water, evaporating it into steam. The steam outlet of the heating module 2 is connected to a steam channel 3. Specifically, the steam channel 3 includes a first conical pipe 31, a straight pipe 32, and a second conical pipe 33 arranged coaxially in sequence. The first conical pipe 31 and the second conical pipe 33 are respectively provided with an inlet end and an outlet end. The diameter of the inlet end of the first conical pipe 31 is larger than the diameter of the outlet end, and the diameter of the inlet end of the second conical pipe 33 is smaller than the diameter of the outlet end. The diameters of the outlet end of the first conical pipe 31 and the inlet end of the second conical pipe 33 are both the same as the diameter of the straight pipe 32. The outlet end of the first conical pipe 31 and the inlet end of the second conical pipe 33 are connected through the straight pipe 32. The inlet end of the first conical pipe 31 is connected to the steam output port of the heating module 2, which is used to guide the steam flow and accelerate the steam flow. Thus, the steam channel 3, through the first conical pipe 31, the straight pipe 32, and the second conical pipe 33, forms a structure similar to a Venturi tube, i.e., a "constriction-straight section-expansion" steam channel 3. This effectively improves the efficiency and stability of water vapor flow, reduces backflow, and utilizes a condensation module 4 installed at the outlet end of the second conical pipe 33 to cool the water vapor and collect the condensate for recycling. The recycled water can be used for drinking or irrigation. Simultaneously, to adapt to the arid environment of Northwest China and to save costs, the power supply module 5 uses a combination of solar and wind power generation components for power generation, fully utilizing the natural advantages of the arid Northwest region and leveraging natural resources to provide electricity to the heating module 2 and other electrical equipment.

[0031] Furthermore, the steam channel 3 is entirely constructed of 316L stainless steel with a wall thickness of 10mm. Differentiated surface treatments and external structural design meet the functional requirements of each section. Specifically, the first tapered pipe 31 (converging section) undergoes plasma spraying with NiCr-Cr3C2 coating, 80μm thick, to resist high-speed salt particle erosion. The straight pipe 32 is electropolished to achieve Ra < 0.8μm, reducing flow resistance and salt spray adhesion. The second tapered pipe 33 (expanding section) undergoes gas nitriding treatment, achieving a hardness ≥ 800HV, to enhance wear resistance and resist condensate droplet impact. A rigid polyurethane foam insulation layer 10, 80mm thick, is installed between the steam channel 3 and the water collection well 1, covering the outer wall of the steam channel 3. For straight and tapered pipe sections, rigid polyurethane foam boards are used for assembly and covering; for irregular areas such as flanges and valves, on-site spraying of foamed PUR can be used for filling, ensuring a continuous and seamless insulation layer. The joints of the insulation layer should be sealed with a special adhesive to reduce thermal bridging. The inner wall of the insulation layer 10 is provided with a salt-proof protective layer, which is made of 0.5mm thick galvanized steel plate and sprayed with anti-salt spray primer. The galvanized steel plate shell is fixed with self-tapping screws, and the joints are sealed with silicone sealant.

[0032] See Figure 2 and Figure 3As shown, to ensure that the heating of the rinsing water is not affected by external temperature differences, the heating module 2 is located at the bottom of the water collection well 1, specifically including a heating chamber 21, a heating coil 22, high-temperature insulation cotton, and a battery. The heating chamber 21 is fixed to the bottom of the water collection well 1 and is cylindrical, matching the shape of the well. It is used to hold the rinsing water entering the water collection well 1. The drain pipe 11 and blind pipe transport the collected rinsing water to the heating chamber 21. The heating chamber 21 is made of 316 stainless steel with good magnetic permeability to ensure electromagnetic induction efficiency. The chamber is 10mm thick, and the inner wall is polished to reduce salt scale adhesion. An output port adapted to the inlet end of the first conical pipe 31 is reserved on the upper side of the heating chamber 21. The heating coil 22 uses high-temperature mica-wrapped fiberglass cable, which is wrapped around the outer wall of the heating chamber 21. The fiberglass and mica composite form a multi-layer insulation structure, which can withstand the eddy current heating effect of high-frequency current and prevent the coil from aging, leaking, or short-circuiting due to high temperature. The coil is circular and tightly wrapped around the heating cavity 21, ensuring uniform eddy current distribution within the cavity and preventing localized overheating or heating dead zones. High-temperature insulation cotton is wrapped around the outside of the heating coil 22, isolating it from the well wall of the water collection well 1 to reduce heat loss and environmental abrasion. A battery is located at the bottom of the heating cavity 21, electrically connected to both the heating coil 22 and the power supply module 5, storing the electricity generated by the power supply module 5 and supplying power to the heating coil 22. During use, the heating coil 22 utilizes high-frequency electromagnetic heating, directly generating eddy currents within the heating cavity 21 through electromagnetic induction. The heat is concentrated inside the container, reducing external heat dissipation and interference from ambient temperature on heating efficiency, making it suitable for the large diurnal temperature range of Ningxia.

[0033] See Figure 2 and Figure 4 As shown, in order to ensure that water vapor can be cooled into condensate smoothly, the condensation module 4 includes an annular rectifier 41, an eccentric reducer 42, and a heat exchange assembly.

[0034] The inlet of the annular rectifier 41 is connected to the outlet of the second conical pipe 33. After water vapor enters the annular rectifier 41, it collides with the top, consuming kinetic energy. The airflow velocity decreases, the airflow becomes more stable, and salt particles settle to the bottom due to gravity. The annular rectifier 41 is made of 10mm thick 316 stainless steel with an arc-shaped, 10mm thick top. The inner wall of the annular rectifier 41 is coated with a 100μm thick WC-10Co-4Cr coating with a hardness ≥1100HV to resist steam erosion. The inlet of the annular rectifier 41 is connected to the steam channel 3. Multiple eccentric reducers 42 are distributed in a circular array on the lower part of the side wall of the annular rectifier 41, with the connection points of the eccentric reducers 42 and the annular rectifier 41 close to the second conical pipe 33. Each eccentric reducer 42 is connected to a condenser to cool the steam distributed to the eccentric reducer 42 into condensate. The eccentric reducer 42 decreases in size from Φ0.40m to Φ0.25m, with an eccentricity of 400mm. The eccentric reducer 42 is made of 5mm thick 316 stainless steel, with its inner wall electropolished to achieve a Ra < 0.8μm, effectively reducing scale buildup. The annular rectifier 41 is entirely covered with an 80mm thick rigid polyurethane foam insulation layer (λ = 0.040W / m·K). A 20mm thick rubber shock-absorbing pad is installed at the bottom to reduce noise and vibration from impacts.

[0035] See Figure 2 and Figure 5 As shown, the heat exchange assembly includes a steam distribution pipe 43 and multiple heat exchange tube bundles 44. The steam distribution pipe 43 is inclined, with its lower end connected to the end of the eccentric reducer 42 away from the annular rectifier 41, and the other end closed. The heat exchange tube bundles 44 include heat dissipation pipes 441 and multiple heat dissipation fins evenly distributed on the outer side of the heat dissipation pipe 441 wall. The heat dissipation pipe 441 is a flat, thin-walled structure, and the surface of the heat dissipation fins is coated with an anti-salt spray coating. The heat dissipation pipe 441 is a flat, welded, thin-walled steel pipe, with one end connected to the steam distribution pipe 43 and the other end connected to a water collection pipe 442. The water collection pipe 442 is used to connect to the water storage tank 7 to collect condensate. Preferably, to ensure heat exchange efficiency and quality, each steam distribution pipe 43 is connected to two heat exchange tube bundles 44, forming a type A heat exchange structure. The heat dissipation pipe 441 is a flat, welded, thin-walled steel pipe with corrugated aluminum heat dissipation fins brazed on the outside.

[0036] Furthermore, to improve heat exchange efficiency, an outer shell 8 is installed at the upper end of the second conical pipe 33. The lower end of the outer shell 8 is fitted onto the outer wall of the water storage tank 7 and the two are fixedly connected. Preferably, the lower side of the shell is completely sealed by fixing it to the water storage tank 7. The upper end of the outer shell 8 is higher than the annular rectifier 41. The outer shell 8 encloses the annular rectifier 41, the eccentric reducer 42, the steam distribution pipe 43, and the condensing module 4, including the heat exchange tube bundle 44, inside it. At the same time, louvers 6 are provided on the side wall of the outer shell 8 to allow cold air to flow in and contact the heat exchange tube bundle 44 and the heat dissipation fins. This design ensures that the cold air is directed towards the heat exchange tube bundle 44 and that the cold air flows in evenly, thereby enabling the heat exchange tube bundle 44 to achieve efficient heat exchange.

[0037] Furthermore, to improve heat exchange efficiency, a fan 9 is installed between the top wall of the outer casing 8 and the annular rectifier 41. The fan 9 is an axial flow fan, with its inlet located inside the outer casing 8 and its exhaust outlet passing through the top wall of the outer casing 8 on its outer side, thus expelling hot air from the outer casing 8 to the outside. This upward air extraction by the fan 9 directly draws in hot air and discharges it through the wellhead, avoiding conflict with the natural convection entering through the louvers 6. This ensures rapid exchange of cold and hot air inside the outer casing 8, improving the condensation efficiency of water vapor.

[0038] Water vapor is distributed to each heat exchange tube bundle 44 by the annular rectifier 41. Inside the tubes, the water vapor is gradually cooled from top to bottom into condensate by the action of the heat dissipation fins. The condensate at the bottom is collected in the water collection pipe 442, and after passing through the filter screen, it flows into the water storage tank 7 for later use. The water storage tank 7 extends into the soil through the gravity pipe 12 for direct irrigation.

[0039] Specifically, in practical applications, the heating module 2 and the steam channel 3 are placed inside the water collection well 1. The overall height of the heating chamber 21 and the steam channel 3 is generally set to 6.45m, where the heating chamber 21 is 1.85m high and has a diameter of 1.50m. The steam channel 3 is 4.60m long: the first conical pipe 31 is 1.80m high, and its diameter changes from 1.50m to 0.80m. The straight pipe 32 is 1.80m high, and its diameter remains at 0.80m. The second conical pipe 33 is 1.00m high, and its diameter changes from 0.80m to 1.00m. The annular rectifier 41 has a diameter of 1.00m and is smoothly connected to the steam channel 3 by welding. The annular condenser has a diameter of 1.00m and is connected to the rectifier by an eccentric reducer 42 with a length of 0.40m. One end of the eccentric reducer 42 has a diameter of 0.40m and connects to the annular rectifier 41, while the other end has a diameter of 0.25m and connects to the annular condenser.

[0040] Furthermore, the solar power generation module includes multiple north-south oriented and tilted photovoltaic panels. High-efficiency monocrystalline silicon photovoltaic panels are selected, which are resistant to sand and dust abrasion, adaptable to the climate of Northwest China, and exhibit lower power degradation than polycrystalline silicon photovoltaic panels under the same high-temperature conditions. Eight 400W monocrystalline silicon modules are installed, each with an area of ​​approximately 1.8m². The north-south oriented tilted installation angle of the photovoltaic panels matches the latitude of their installation location at 38°, effectively reducing dust shading. The photovoltaic panels are concentrated on the south side of the water collection well 1, forming multiple rows, with the distance between the front and rear rows ideally set at approximately 2.50m to avoid mutual shading.

[0041] Furthermore, the wind power generation components include a wind turbine and a permanent magnet direct-drive wind turbine 9 for pressurizing and accelerating the wind blowing towards the wind turbine at low wind speeds. Three permanent magnet direct-drive wind turbines 9 with a rated power of 3kW are selected, each with a rotor diameter of approximately 3.00m, corresponding to a swept area A. rotor ≈7.07m 2 It can start at low wind speeds and adapt to the peak wind speeds at night in Yinchuan; the permanent magnet motor eliminates the gearbox structure and adopts a closed bearing and dustproof coating to reduce sand and dust intrusion and extend service life. The three fans are stably arranged in a triangular formation on the north side of the water collection well 1 via independent supports.

[0042] The storage battery is a lithium iron phosphate battery with a capacity of about 5.0kWh and a rated voltage of 48V. It is installed in the lower side compartment of the heating zone of water collection well 1 to reduce ground occupation and utilize the temperature of the space below water collection well 1 for heat preservation.

[0043] Furthermore, the water storage tank 7 is made of 5mm thick PVC anti-corrosion plastic tub, resistant to sand and dust abrasion, suitable for outdoor use, and cost-effective. To avoid the effects of high-temperature heating, the outer wall should be insulated with a thickness of 20mm. The volume depends on the needs. An inspection cover is provided on the top for easy cleaning and maintenance. A drain valve and filter screen box are provided at the bottom to remove foreign objects. A gravity water conveyance channel is installed on the side wall of the water collection tank, using polyethylene agricultural pipes. The diameter and volume depend on the needs, and the pipes are laid with a slope of 1%–2% to ensure smooth water flow. The end of the pipe is connected to a drip irrigation ceramic pipe for underground drip irrigation. A louvered air inlet 6 is installed above the water storage tank 7, offset from the ventilation structure of the water collection well 1. The ventilation opening is equipped with an insect screen and dust filter gauze to prevent insects and debris and facilitate airflow exchange during condensation.

[0044] Theoretical design and analysis: Theoretical calculations were performed based on condensing 10 kg per day, with the heating temperature ranging from an initial temperature of 20℃ (liquid state) to 100℃ (gaseous state).

[0045] Evaporation energy consumption calculation Heating the rinse water from a liquid to a gaseous state mainly involves heat transfer and energy conversion: heating water from its initial temperature T1 to its boiling point T2 requires energy Q.显 The energy Q required to change water from a liquid to a gaseous state. 潜 Meanwhile, some heat loss Q during the heat transfer process is also considered. 损失 This energy is all provided by heating equipment. 输入 .

[0046] According to the principle of conservation of energy E 输入 The calculation formula is as follows: .

[0047] In the formula: E 输入 Q represents the electrical energy input to heating module 2 per unit time, expressed in kW·h. 显 Q represents the heat required for the heating stage, in kW·h. 潜 Q represents the energy required for the phase transition stage, in kW·h. 损失 The energy loss during the heating phase is expressed in kW·h.

[0048] Sensible heat calculation Q 显 The energy consumed when heating to the boiling point. .

[0049] In the formula: m is the mass of brine, m = 10 kg; c is the specific heat capacity of brine, c is taken as 4.18 kJ / (kg·℃); ΔT is the temperature difference between the initial temperature and the boiling point, ΔT = 100℃ - 20℃. The calculated Q... 显 = 3344kJ≈0.93kWh.

[0050] Latent heat calculation Qlatent: Energy requirement for phase change. .

[0051] In the formula: m is the mass of the salt water, m = 10 kg. v For the latent heat of vaporization, L v ≈2256 kJ / kg. The calculated Q is... 潜 =22560kJ≈6.27kWh.

[0052] Energy loss Q 损失 In the continuous process of heating-evaporation-condensation, the system may experience various energy losses, mainly heat conduction loss Q. loss,cond Water vapor loss Q loss,leak : .

[0053] Heat conduction loss Q loss,cond Considering the heat loss of the rinse water to the external environment during the entire heating and condensation process, Fourier's law of steady-state heat conduction is adopted: .

[0054] In the formula: k The thermal conductivity of the insulation material is k = 0.025 W / (m·K) for rigid polyurethane foam. A The total heat dissipation area of ​​the device (m²) is approximately [missing information]. A= 25m 2 Δ T The temperature difference (K) between the interior and the environment is given by Δ. T= 25℃ The thickness (m) of the insulation material. ≈0.39m, t is the heating duration in seconds, calculated as 10 hours, which translates to 36000 seconds. The calculated Q is... loss,cond ≈5.86 kWh.

[0055] Water vapor loss Q loss,leak Considering that steam carries tiny liquid droplets that cannot be converted into usable water, the amount of water lost is proportional to the amount of water evaporated: .

[0056] In the formula: The water vapor escape coefficient has an empirical value of 0.05–0.15; we take 0.1 for calculation. 蒸 The mass of water evaporated is expressed in kg or L. v For the latent heat of vaporization, L v ≈2256 kJ / kg. The calculated Q is... loss,leak = 2256kJ≈0.63kWh.

[0057] The calculation yields: Q 损失 =Q loss,cond +Q loss,leak =6.49kWh, E 输入1 = Q 显 +Q 潜 +Q 损 = 13.69 kWh.

[0058] Calculation of power generation 1. Heating efficiency of high-frequency electromagnetic heaters: Power generation efficiency was analyzed based on sunshine and wind power statistics from Yinchuan, Ningxia, from 2019 to 2024, as published in the *China Statistical Yearbook*. Yinchuan, Ningxia, experiences approximately 7 hours of sunshine daily. The high-frequency electromagnetic heating system utilizes the eddy current thermal effect: an alternating magnetic field (10kHz-30kHz) induces eddy currents within a 316L stainless steel cavity, achieving an efficiency of converting electrical energy into heat energy. =95%.

[0059] .

[0060] Q was calculated 输出 =14.41kWh.

[0061] Solar power generation principle and conversion efficiency The formula for calculating the output power of a photovoltaic module is: .

[0062] In the formula: E pv The photovoltaic output power is measured in kWh. pv For photoelectric conversion efficiency, the commonly used monocrystalline silicon module efficiency is 0.18~0.22, and we take 0.2. G Total solar irradiance, W / m², is approximately 700 W / m² per day in Ningxia. A The area of ​​the photovoltaic panel is in m², which is 12.6m². 2 , t For effective illumination time, h, take... t =7h. Calculated E pv =14.11kWh.

[0063] Wind energy conversion formula and efficiency: The average annual wind speed in the Yinchuan area ranges from 3 m / s to 4.5 m / s, with some areas reaching 5.5 m / s, indicating potential for deploying small wind turbines. Rated power generation formula: .

[0064] In the formula: P Rated power generation capacity, W. ρ The air density is 1.2 kg / m³. 3 ). A rotor To correspond to the swept area, a single wind turbine is 4.91m². 2 . v The wind speed is measured in m / s, with an average daily wind speed of approximately 4 m / s in Ningxia. C p The power factor is set to 0.3. The calculated raw power generation of a single wind turbine for the entire day is E. wind =1.95kWh.

[0065] However, due to unstable wind speeds, based on the actual utilization rate (85%), the estimated daily power generation is: E wind-实际 =1.66kWh. Total daily power generation of the three wind turbines E wind-总实际=4.98 kWh.

[0066] Overall power generation capacity: The photovoltaic system's output over 7 hours is approximately 14.11 kWh. The wind power system's output over 24 hours is approximately 4.98 kWh. Considering inverter and energy storage losses, the overall efficiency is estimated at 0.85. .

[0067] Based on the assumptions and analysis above, evaporation requires 9.82 kWh, and the system power supply is 10.91 kWh, which meets the target of processing 10 kg per day.

[0068] Condensation calculation Based on the condenser structure layout described above, and considering engineering references: the condensation efficiency of industrial air condensers under natural ventilation + fan assistance is generally 70%~85%, where η is taken as... 冷凝 =80.0%, and considering the environment of Ningxia, according to the "Water Quality Report of Saline-Alkali Land in Yanchi County, Ningxia", the saline concentration in Ningxia is C. 盐 =3.5%.

[0069] The theoretical maximum value of evaporable water is calculated as follows: .

[0070] Therefore, the actual amount of water obtained is: .

[0071] In the formula, m 水实际 This represents the actual water production of the condensing module; m 水,max This represents the theoretical maximum evaporation rate; m 盐水 C is the volume of rinsing water. 盐 η is the concentration of salt water in the rinsing water. 冷凝 This refers to the condensation efficiency.

[0072] Simulation Analysis The flow of water vapor in steam channel 3 was simulated and analyzed using CFX software to prevent backflow or eddies from affecting the condensation effect. The steam pipeline was divided into unstructured grids with a grid size of 0.015m. The grid size at the interfaces of each section was adjusted, and the final number of grids was 12,173,090, with all grid quality values ​​above 0.3.

[0073] Boundary conditions were set as follows: the computational domain fluid medium was ideal water vapor at 100℃, the ambient pressure was 1 atm, the turbulence model was the k-α turbulence model, and heat transfer was solved using the internal energy form of the energy equation. A velocity inlet and an average static pressure outlet were used. The simulated inlet velocity was set to 0.91 m / s, the temperature to 100℃, the ambient temperature to 25℃, the thermal conductivity coefficient to λ = 0.025 W / (m·K), and the outlet relative pressure to 0 Pa.

[0074] The main results obtained from the simulation are as follows: See Figures 6 to 9 As shown, the scrubbing water, after being heated, forms steam that enters the first conical pipe 31. The inlet velocity is 0.91 m / s, the gauge pressure is 9.51 Pa, and the temperature is 373.15 K. Due to the gradual reduction in the cross-section of the channel, the steam accelerates significantly, with the outlet velocity increasing to 4.28 m / s, the gauge pressure decreasing to 4.23 Pa, and the temperature reaching 373.14 K. This conforms to the gas flow characteristics under the Venturi effect, and the kinetic energy increases significantly.

[0075] Subsequently, water vapor enters straight pipe 32. At the outlet end of straight pipe 32, the flow velocity slightly decreases to 4.26 m / s, the gauge pressure is 3.88 Pa, and the temperature is 373.13 K, indicating that the airflow remains stable and free from vortex interference. Water vapor then enters the second conical pipe 33. Due to the gradual increase in the cross-section of the channel, the water vapor velocity decreases. At the end of the second conical pipe 33, the water vapor velocity drops to 2.51 m / s, the gauge pressure rises back to 6.89 Pa, and the temperature is 373.10 K, conforming to the velocity-pressure reciprocal conversion law. At the top of steam channel 3, due to the bending of the arc-shaped structure of the top wall of the annular rectifier 41 or the influence of local disturbances, the gauge pressure rises to 9.65 Pa, and the temperature is 371.00 K. This is a localized minor disturbance and does not affect the overall flow direction. Finally, the steam enters the steam distribution pipe 43 through the eccentric reducer 42. Due to the reduced diameter of the eccentric reducer 42, the steam velocity increases again to 5.13 m / s, the temperature is 373.11 K, and the pressure is consistent with the environment, ensuring that the steam can smoothly exchange heat and condense in the heat exchange tube bundle 44 area.

[0076] The temperature trend shows that the steam gradually decreases from 373.14 K at the inlet of steam channel 3 to 373.11 K at the outlet without undergoing a phase change, indicating that the insulation effect within steam channel 3 is good and the heat loss is controlled within a reasonable range. The steam is transported at a high flow rate, resulting in greater kinetic energy, which effectively overcomes the surface resistance of the condenser, increases the disturbance of the heat exchange film system, and thus improves the condensation efficiency.

[0077] In summary, simulations have verified the rationality of the "constriction-straight section-expansion" structure of steam channel 3. The steam flow exhibits no significant backflow or vortex within the entire steam channel 3, with uniform velocity distribution, smooth pressure transition, and moderate temperature changes, providing favorable input conditions for the subsequent condensation heat exchange process. This structure is expected to effectively improve steam utilization and system condensation efficiency in actual operation.

[0078] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A device for recycling and utilizing leachate from saline-alkali land, characterized in that, include: Water collection well (1) is used to collect rinsing water; Heating module (2) is located at the bottom of water collection well (1) and is used to heat the rinsing water so that it evaporates to form water vapor; The steam passage (3) includes a first conical pipe (31), a straight pipe (32), and a second conical pipe (33) arranged coaxially in sequence. The first conical pipe (31) and the second conical pipe (33) are respectively provided with an inlet end and an outlet end. The diameter of the inlet end of the first conical pipe (31) is larger than the diameter of the outlet end, and the diameter of the inlet end of the second conical pipe (33) is smaller than the diameter of the outlet end. The outlet end of the first conical pipe (31) and the inlet end of the second conical pipe (33) are connected through the straight pipe (32). The inlet end of the first conical pipe (31) is connected to the output end of the heating module (2). A condensation module (4) is connected to the outlet end of the second conical pipe (33) to cool water vapor and form condensate. The power supply module (5) includes a solar power generation component and a wind power generation component, which are used to provide power to the heating module (2).

2. The saline-alkali land leaching water recycling device according to claim 1, characterized in that, The condensation module (4) includes: The inlet of the annular rectifier (41) is connected to the outlet end of the second conical pipe (33); Multiple eccentric reducers (42) are arranged in a circular array around the annular rectifier (41), and one end of each eccentric reducer (42) is connected to the annular rectifier (41). Multiple heat exchange components are provided, each corresponding to one of the multiple eccentric reducers (42). The heat exchange components are connected to the other end of the eccentric reducers (42) to cool the steam distributed to the eccentric reducers (42) into condensate.

3. The saline-alkali land leaching water recycling device according to claim 2, characterized in that, The heat exchange assembly includes: The steam distribution pipe (43) is inclined, with its lower end in the inclined direction connected to the end of the eccentric reducer (42) away from the annular rectifier (41), and the other end is closed. Multiple heat exchange tube bundles (44) are provided. Each heat exchange tube bundle (44) includes a heat dissipation tube (441) and multiple heat dissipation fins evenly distributed on the outer side of the tube wall of the heat dissipation tube (441). The heat dissipation tube (441) is a flat thin-walled structure. One end of the heat dissipation tube (441) is connected to the steam distribution pipe (43), and the other end is connected to a water collection pipe (442). The water collection pipe (442) is used to communicate with the water storage tank (7) to collect condensate. The water storage tank (7) is an annular cavity fitted on the upper end of the second conical pipe (33).

4. The saline-alkali land leaching water recycling device according to claim 3, characterized in that, The upper end of the second conical pipe (33) is also provided with a shell (8). The lower end of the shell (8) is fitted onto the outer wall of the water storage tank (7) and the two are fixedly connected. The upper end of the shell (8) is higher than the annular rectifier (41). The annular rectifier (41), the eccentric reducer (42), the steam distribution pipe (43), and the heat exchange tube bundle (44) are all placed inside the shell (8). The side wall of the shell (8) is provided with louvers (6) to allow cold air to flow in and contact the heat exchange tube bundle (44) and the heat dissipation fins.

5. The saline-alkali land leaching water recycling device according to claim 4, characterized in that, A fan (9) is provided between the top wall of the outer casing (8) and the annular rectifier (41). The air inlet of the fan (9) is located inside the outer casing (8), and the air outlet of the fan (9) passes through the top wall of the outer casing (8) and is located outside the outer casing (8) to discharge hot air from the outer casing (8).

6. A saline-alkali land leaching water recycling device according to claim 2, characterized in that, The top of the annular rectifier (41) is arc-shaped, and the connection end of the eccentric reducer (42) to the annular rectifier (41) is close to the second conical pipe (33).

7. The saline-alkali land leaching water recycling device according to claim 1, characterized in that, The steam channel (3) is wrapped with an insulation layer (10) on the outside and a salt-proof protective layer on the inside.

8. The saline-alkali land leaching water recycling device according to claim 1, characterized in that, The heating module (2) includes: The heating chamber (21) is fixed at the bottom of the water collection well (1), and its upper end is set as an opening. The opening of the heating chamber (21) is connected to the inlet end of the first conical pipe (31) and is used to hold the washing water entering the water collection well (1). A heating coil (22) is wrapped around the outer wall of the heating cavity (21); A storage battery is located at the bottom of the heating chamber (21) and is electrically connected to the heating coil (22) and the power supply module (5), respectively.

9. A saline-alkali land leaching water recycling device according to claim 8, characterized in that, The heating coil (22) is made of high-temperature mica-wrapped glass fiber cable.

10. A saline-alkali land leaching water recycling device according to claim 8, characterized in that, The heating coil (22) is wrapped with high-temperature insulation cotton to reduce heat loss.

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