Solar energy heat collecting evaporation type seawater desalination device and method

Abstract

The application provides a solar heat collecting and evaporative seawater desalination device and method, and relates to the technical field of seawater desalination. The device comprises a base part, an evaporator and a condensation and collection part. The evaporator is arranged obliquely, the high end is provided with a steam outlet, the bottom of the internal evaporation cavity is provided with an evaporation flow channel with a heat absorption coating, and the evaporation flow channel is provided with an overflow protrusion. The condensation and collection part is provided with a condensation component with deep seawater as a cold source, and the steam inlet is arranged below the condensation component. The evaporator is further provided with an inclination angle adjusting mechanism. Seawater forms a liquid film on the surface of the evaporation flow channel, is evaporated through solar heating, water vapor enters the condensation and collection box under the action of self-rising, is gathered below the condensation component and is condensed into fresh water. The system further comprises a closed loop control composed of an online conductivity detection device, a control unit and an electric flow regulating valve, so that flow self-adaptive regulation is realized. The application does not need external power, is energy-saving and environment-friendly, is efficient and stable, and is suitable for coastal and island areas.

Description

Technical Field

[0001] This invention relates to the field of seawater desalination technology, specifically to a solar-powered evaporative seawater desalination device and method. Background Technology

[0002] Seawater desalination is an important way to solve the shortage of freshwater resources. Currently, the mainstream industrial seawater desalination methods mainly include reverse osmosis, multi-stage flash distillation, and multi-effect distillation. However, these traditional technologies generally suffer from problems such as high equipment costs, complex processes, and high energy consumption.

[0003] In the field of seawater desalination using solar energy, existing technologies generally employ a passive evaporation method. Its core structure involves a sealed, transparent container with seawater at a certain depth at the bottom. Sunlight shines directly through a sloping transparent cover, heating the seawater and causing the surface water to evaporate naturally. The resulting water vapor rises and condenses into liquid water upon encountering the relatively cool inner wall of the sloping transparent cover. The condensate then slides down the sloping wall into a collection tank, achieving freshwater recovery. While this technology has low operating costs, it suffers from limitations due to the low heat flux density of solar energy, resulting in slow evaporation rates and low condensation efficiency. Summary of the Invention

[0004] To address the problems of slow evaporation rate and low condensation efficiency in existing seawater desalination technologies, this application provides a solar thermal collector evaporative seawater desalination device and method, which aims to achieve efficient and low-energy-consumption seawater desalination by optimizing the evaporation and condensation processes.

[0005] The technical solution adopted by this invention to solve its technical problem is: A solar-powered evaporative seawater desalination device includes a base assembly, an evaporator, and a condensate collection assembly; The evaporator is arranged at an angle, with a light-transmitting window on its light-facing side, an evaporation chamber inside, an evaporation flow channel at the bottom of the evaporation chamber, and a steam outlet at the high end of the evaporator. The condensation collection unit includes a condensation collection box, which is equipped with a condensation component that uses deep seawater as a cold source. The condensation collection box is equipped with a steam inlet. The steam outlet of the evaporator is connected to the steam inlet via a flexible connection, and the lower end of the evaporator is rotatably connected to the base assembly. It also includes a tilt adjustment mechanism for adjusting the tilt angle of the evaporator. The tilt adjustment mechanism includes a slide and a drive assembly. The lower end of the slide is slidably connected to the base assembly, and the upper end is slidably hinged to the evaporator. The drive assembly is used to drive the slide to move back and forth along the base assembly to change the tilt angle of the evaporator.

[0006] Furthermore, the evaporator includes an outer shell and a partition disposed inside the outer shell. The partition divides the lower space of the evaporation chamber into multiple parallel evaporation channels. The surface of the evaporation channels is provided with a heat-absorbing coating. An overflow protrusion is provided in the evaporation channels downstream of the water inlet.

[0007] Furthermore, the overflow protrusion has a triangular cross-section, with an angle of 90°-130° between its front surface and the bottom surface of the evaporation channel, and an angle of 120°-170° between its back surface and the bottom surface of the evaporation channel.

[0008] Furthermore, the carriage includes two columns, a first crossbeam connecting the two columns, and a drive shaft disposed at the top of the columns. The base is equipped with a first slide rail, and the lower end of the columns is provided with a first slider that cooperates with the first slide rail. The back surface of the evaporator is provided with a second slide rail, and the second slide rail is provided with a second slider. The second slider is fixed with a connecting seat that is rotatably connected to the drive shaft.

[0009] Furthermore, the drive assembly includes a lead screw and a mating nut, the lead screw being rotatably connected to the base, and the nut being disposed on the first crossbeam of the carriage. Rotating the lead screw can drive the carriage to move.

[0010] Furthermore, the condensation collection unit includes, from top to bottom, a sealing cover, a condenser, and a main housing. The condenser includes a condensation frame and condensation components disposed therein. The condensation components include several condensation tubes with fins. The steam inlet is disposed on the main housing.

[0011] Furthermore, the surface of the condenser tube and fins is provided with a hydrophobic coating, the surface of the evaporation channel is provided with a heat-absorbing coating, and a transparent hydrophilic coating is provided on the upper side of the heat-absorbing coating.

[0012] Furthermore, it also includes a solar collector, the outlet of which is connected to the inlet of the evaporator for preheating the seawater to be desalinated.

[0013] Furthermore, it also includes a control unit, an electric flow regulating valve installed on the inlet pipe of the evaporator, and an online conductivity detection device installed at the concentrated seawater outlet of the evaporator. The control unit receives the conductivity signal fed back by the online conductivity detection device and controls the opening degree of the electric flow regulating valve according to the signal.

[0014] A solar-powered evaporative seawater desalination method includes the following steps: S1. The seawater to be desalinated is evenly distributed on the surface of the inclined evaporation channel to form a liquid film, and water vapor is generated by solar energy heating. S2. The water vapor, under its own rising action, enters the condensation and collection unit through the steam outlet and steam inlet, and condenses into fresh water after contacting the condensation component through which low-temperature deep seawater flows, and is then collected. S3. During the evaporation process, the conductivity signal of the concentrated seawater outlet is acquired in real time. The control unit adjusts the opening of the electric flow regulating valve according to the conductivity signal to control the seawater flow rate entering the evaporation channel, thereby realizing closed-loop adaptive adjustment of the liquid film evaporation state.

[0015] The beneficial effects of this invention are: 1. This application uses deep seawater (temperature 5℃ to 15℃) as the condensation cold source. Deep seawater has a low and stable temperature year-round, eliminating the need for additional electrical energy for refrigeration. This creates a stable low-temperature zone on the condenser tube surface, allowing for rapid condensation of the water vapor produced by evaporation. Compared to traditional condensation methods such as air cooling or electric cooling, this system consumes no additional electricity, reducing system operating energy consumption and freshwater production costs. The hydrophobic coating on the condenser tube surface promotes rapid dripping of condensate droplets, further enhancing condensation heat exchange efficiency. Furthermore, the steam inlet is located below the condensation components. Water vapor, after rising, enters the condensation collection box and naturally accumulates in the upper space where the condensation components are located, creating a high-concentration accumulation zone around the condenser tubes. This prolongs the contact residence time between the steam and the condenser tube surface, facilitating complete steam condensation and improving freshwater production rate.

[0016] 2. A heat-absorbing coating is applied to the surface of the evaporation channel, allowing for efficient absorption of solar radiation and direct transfer to the thin liquid film covering it, reducing heat loss in intermediate heat exchange stages. The evaporator's tilt adjustment mechanism can flexibly adjust its angle according to changes in latitude and seasonal solar altitude, ensuring optimal solar radiation reception and maximizing solar energy utilization efficiency. Furthermore, a solar collector preheats the incoming water, increasing the initial temperature of the seawater entering the evaporation channel and thus enhancing overall evaporation efficiency.

[0017] 3. An overflow protrusion is installed within the evaporation channel. The water storage area formed upstream of this protrusion allows seawater to spread evenly across the channel surface after passing over it, forming a thin liquid film of uniform thickness. A transparent hydrophilic coating on the upper side of the heat-absorbing coating of the evaporation channel further facilitates the even spreading and thinning of the liquid film, increasing the contact area between the liquid film and the hot surface, effectively improving the evaporation rate. The optimized design of the angle between the upstream and downstream sides of the overflow protrusion ensures a smooth transition of the liquid film, reducing splashing and eddies, and maintaining the continuity and stability of the evaporation process.

[0018] 4. By installing an online conductivity detector at the concentrated seawater outlet to monitor the salt concentration of the discharged concentrated seawater in real time, and combining it with a control unit and an electric flow regulating valve to form a closed-loop control system, the flow rate of seawater entering the evaporation channel can be automatically adjusted according to the actual evaporation conditions. When solar radiation is strong and the evaporation rate is high, the flow rate is automatically increased to prevent drying and scaling; when radiation weakens, the flow rate is automatically reduced to ensure sufficient evaporation of the liquid film, thereby achieving real-time optimization of the liquid film evaporation state and ensuring stable and efficient operation of the system under different meteorological conditions.

[0019] 5. The evaporator is inclined, with the steam outlet located at the high end. Water vapor rises naturally along the inclined evaporation chamber due to its own upward movement and enters the condensation and collection unit. This eliminates the need for fans or other power devices to drive the steam flow, reducing system complexity and operating energy consumption, and improving the reliability and service life of the unit. A flexible connection is used between the steam outlet and steam inlet, in conjunction with an angle adjustment mechanism, to ensure reliable sealing at the connection point during angle adjustment.

[0020] 6. This device integrates solar energy collection, evaporation, and condensation into one compact structure, making it easy to transport and install. It can adapt to different geographical conditions and application scenarios, and is suitable for coastal areas, islands, and regions lacking freshwater resources but rich in solar energy and seawater resources. Attached Figure Description

[0021] Figure 1 A three-dimensional structural diagram of a solar-powered evaporative seawater desalination device provided in this application. Figure 1 ; Figure 2 for Figure 1 A magnified structural diagram of part A in the middle; Figure 3 for Figure 1 A magnified structural diagram of part B in the middle section; Figure 4 A side view of a solar thermal evaporative seawater desalination device provided in this application; Figure 5 for Figure 4 A magnified structural diagram of section C; Figure 6 A cross-sectional structural schematic diagram of a solar thermal collector evaporative seawater desalination device provided in this application; Figure 7 for Figure 6 A magnified structural diagram of section D; Figure 8 A three-dimensional structural diagram of a solar-powered evaporative seawater desalination device provided in this application. Figure 2 ; Figure 9 for Figure 8A magnified structural diagram of section E in the middle; Figure 10 A three-dimensional structural diagram of the base assembly; Figure 11 for Figure 10 Enlarged structural diagram of section F in the middle; Figure 12 This is a three-dimensional structural diagram of the carriage; Figure 13 This is a schematic diagram of the installation structure of the support block; Figure 14 This is a schematic diagram of the exploded structure of the evaporator; Figure 15 for Figure 14 Enlarged structural diagram of the G section; Figure 16 for Figure 14 Enlarged structural diagram of section H in the middle; Figure 17 A schematic diagram of the exploded structure of the condensation collection unit.

[0022] In the diagram: 1. Base assembly; 11. Base frame; 111. First rectangular frame; 112. Second rectangular frame; 113. Support beam; 114. Support frame; 115. Second crossbeam; 1151. First mounting plate; 116. Third crossbeam; 1161. Second mounting plate; 12. First slide rail; 13. Vertical mounted spherical bearing; 2. Evaporator; 21. Outer shell; 211. Steam outlet; 212. Light-transmitting window; 213. Evaporation channel; 2131. Overflow protrusion; 214. Stepped structure; 215. Baffle; 216. Concentrated seawater outlet; 217. Guide slope; 218. Transparent cover; 22. Water distribution pipe; 231. Water outlet; 24. Locking nut; 25. Rotating shaft; 26. Hinge seat; 261. Sleeve; 262. Connecting plate; 263. Rib; 27. Second slide rail; 3. Condensation collection unit; 31. Encapsulation cover plate; 32. Condenser; 321. Condensation frame; 3211. Buckle plate; 3212. Water inlet pipe; 3213. Water outlet pipe; 322. Condensation tube; 3221. Fin; 33. Main casing; 331. Steam inlet; 4. Flexible connection; 51. Carriage; 511. Column; 5111. Square tube vertical beam; 5112. Base plate; 5113. Support block; 512. First crossbeam; 5121. Nut; 513. Drive shaft; 514. First slider; 5151. Second slider; 5152. Connecting seat; 521. Lead screw; 522. Handwheel; 523. Bearing-type lead screw anti-rotation fixing seat; 6. Solar collectors. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings. The described embodiments are merely a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort should fall within the protection scope of this application.

[0024] To facilitate understanding of the specific embodiments of this application, a coordinate system is now defined as follows: Figure 1 As shown, the left and right directions are horizontal, the front and back directions are vertical, and the up and down directions are vertical.

[0025] Example 1 like Figure 1 and Figure 4 As shown, a solar-powered evaporative seawater desalination device includes a base assembly 1, an evaporator 2, and a condensation collection assembly 3. The base assembly 1 serves as the foundation for supporting the entire device, supporting the evaporator 2 and the condensation collection assembly 3, and providing stable installation positioning for each functional module.

[0026] like Figure 4 and Figure 6 As shown, the base assembly 1 includes a base frame 11, one end of which (according to...) Figure 1 The coordinate system shown is the rear end) where the condensation collection unit 3 is installed, and the other end of the base frame 11 (according to Figure 1 The coordinate system shown is the front end) where the evaporator 2 is installed.

[0027] like Figure 4 , Figure 6 and Figure 17 As shown, the condensation collection unit 3 includes a condensation collection box, and a condensation component is provided at the top of the condensation collection box. The condensation component uses deep seawater as a cold source for condensation.

[0028] The term "deep seawater" is not limited to a specific depth, but rather refers to a seawater layer that can provide stable low-temperature conditions. Typically, deep seawater has a lower and relatively stable temperature, which effectively promotes the liquefaction process of water vapor on the surface of condensing components, thereby improving condensation efficiency and freshwater production. As a specific implementation, the deep seawater in this embodiment refers to low-temperature seawater with a temperature between 5°C and 15°C. The specific depth at which this deep seawater is obtained can be flexibly determined based on the hydrological conditions of the actual sea area.

[0029] In one specific embodiment, the condensation collection box described in this example includes, from top to bottom, a sealing cover 31, a condenser 32, and a main body 33. The sealing cover 31, condenser 32, and main body 33 are stacked sequentially and fixedly connected by fasteners. A steam inlet 331 is provided on the side of the main body 33 facing the evaporator 2, and a fresh water outlet (not shown in the figure) is provided at the bottom of the main body 33. The condenser 32 includes a condensation frame 321 formed by four side plates connected end-to-end. The condensing component is disposed within the condensation frame 321. The condensing component includes several condensing tubes 322, which are arranged horizontally or vertically. For example, in this embodiment, several condensing tubes 322 are arranged horizontally. The left and right ends of the condenser frame 321 are respectively provided with buckle plates 3211. The buckle plates 3211 have a box-like structure with the opening facing the condenser frame 321. The open ends of the buckle plates 3211 are fixedly connected to the condenser frame 321 by welding. One buckle plate 3211 and the condenser frame 321 together form a water inlet chamber, and the other buckle plate 3211 and the condenser frame 321 together form a water outlet chamber. The two ends of the condenser pipes 322 pass through the condenser frame 321 and are connected to the water inlet chamber and the water outlet chamber, respectively, so that deep seawater can flow from the water inlet chamber into each condenser pipe 322, and after flowing through the condenser pipes 322, it collects in the water outlet chamber and is discharged, thereby forming a low-temperature area on the surface of the condenser pipes 322 for the rising water vapor to condense into fresh water. One buckle plate 3211 is provided with a water inlet pipe 3212 connected to the water inlet chamber, and the other buckle plate 3211 is provided with a water outlet pipe 3213 connected to the water outlet chamber. Each of the aforementioned condenser tubes 322 has spiral fins 3221 arranged inside the condenser frame 321 to increase the heat exchange area and enhance the condensation effect. The encapsulation cover 31 is fixedly connected to the upper end of the condenser frame 321 by fasteners. The main housing 33 is a box structure with an open top. The lower end of the condenser frame is fixedly connected to the main housing 33. The encapsulation cover 31, the condenser frame 321, and the main housing 33 together form the condensation collection box.

[0030] In one specific embodiment, the cross-sections of the four side plates used to form the condenser frame 321 are all C-shaped. The C-shaped openings of the four side plates face outwards from the condenser frame 321. The upper flanges of the four side plates together form the upper flange of the condenser frame 321, and the lower flanges of the four side plates together form the lower flange of the condenser frame 321. The upper flange is fixedly connected to the encapsulation cover plate 31 by bolts, and the lower flange is fixedly connected to the top opening edge of the main housing 33 by bolts, thereby ensuring the sealing performance and structural stability between the condenser frame 321, the encapsulation cover plate 31, and the main housing 33.

[0031] The evaporator 2 includes an inclined outer shell 21. The steam outlet 211 of the outer shell 21 is located at the high end and is sealed to the steam inlet 331 of the condensation collection unit 3, so that water vapor can rise naturally into the condensation area. A light-transmitting window 212 is provided on the light-facing surface of the outer shell 21, and a transparent cover plate 22 is enclosed at the light-transmitting window 212. The transparent cover plate 22 is made of low-iron tempered glass to maximize the transmission of solar radiation and reduce heat loss. The interior of the outer shell 21 is an evaporation chamber. Several parallel evaporation channels 213 are provided at the bottom of the evaporation chamber. The surface of the evaporation channels 213 is provided with a heat-absorbing coating to enhance the absorption efficiency of solar radiation. A water inlet is provided at the upper end of the evaporation channel 213, and a water outlet is provided at the lower end of the evaporation channel 213. The water outlet is connected to a concentrated seawater discharge pipeline (not shown in the figure) to discharge the concentrated high-salt seawater in a timely manner. The evaporation channel 213 is arranged parallel to the inclined direction of the outer shell 21, and its cross-section is rectangular or trapezoidal to increase the contact area between seawater and the heat-absorbing coating and improve evaporation efficiency. The inlet of the evaporation channel 213 is connected to a seawater transfer pump (not shown in the figure) through a pipeline (not shown in the figure) to ensure that seawater flows into the evaporation channel 213 continuously and stably.

[0032] As one specific implementation method, such as Figure 14 and Figure 16 As shown, the outer casing 21 in this embodiment has a square cross-section. A recess is provided on the light-facing surface of the outer casing 21, and a light-transmitting window 212 is disposed within the recess. A stepped structure 214 for supporting the transparent cover plate 22 is formed between the edge of the light-transmitting window 212 and the sidewall of the recess. The transparent cover plate 22 is located within the recess, and its edge is bonded to the stepped structure 214. Sealant is applied to the joint to form a reliable waterproof seal, preventing external rainwater or dust from entering the evaporation chamber and reducing heat loss through gaps.

[0033] As one specific implementation method, such as Figure 14 and Figure 15As shown, in this embodiment, the evaporation chamber has several parallel partitions 215 arranged on its sidewall opposite the light-transmitting window 212. These partitions 215 divide the lower space of the outer casing 21 into multiple independent evaporation channels 213. For example, both the lower side of the evaporation chamber and the surface of the partitions 215 are coated with a heat-absorbing coating. The evaporator 2 also includes a water distribution pipe 23 located at the upper end of the outer casing 21. The water distribution pipe 23 is detachably fixed to the outer casing 21. The water distribution pipe 23 has multiple water outlet holes 231 corresponding one-to-one with each evaporation channel 213 to evenly distribute seawater to each evaporation channel 213. One end of the water distribution pipe 23 is closed, and the other end is connected to a seawater transfer pump (not shown in the figure) via a pipeline (not shown).

[0034] In one specific embodiment, the water distribution pipe 23 in this embodiment penetrates the outer casing 21 in a left-right direction. A baffle (not shown in the figure) is provided at the closed end of the water distribution pipe 23. A sealing gasket (not shown in the figure) is fitted on the water distribution pipe 23 between the baffle and the outer casing 21. The open end of the water distribution pipe 23 is located outside the outer casing 21 and is provided with a locking nut 24. Under the locking action of the locking nut 24, the sealing gasket is pressed between the outer casing 21 and the baffle, forming a reliable sealing structure. The partition plate 215 is provided with clearance holes for accommodating the water distribution pipe 23. During installation, the sealing gasket is first fitted onto the water distribution pipe 23, then the water distribution pipe 23 is passed through the side wall of the outer casing 21, aligning the water outlet 231 with each evaporation channel 213. Then, the locking nut 24 is tightened at the open end, causing the sealing gasket to deform under pressure, achieving a reliable seal between the water distribution pipe 23 and the outer casing 21. The water distribution pipe 23 is made of seawater-resistant engineering plastic or stainless steel, and its inner diameter is determined according to the design flow rate, typically 10 mm. The diameter is 30 mm to ensure smooth seawater flow within the pipe and minimal pressure loss. The diameter of the outlet hole 231 is typically 1 mm. 3 mm, to ensure that seawater enters the evaporation channel 213 evenly in the form of a thin stream or droplets, forming a stable film flow.

[0035] As one specific implementation method, such as Figure 14 and Figure 16 As shown, in this embodiment, there is a gap between the partition 215 and the lower sidewall of the outer shell 21, and the area between the partition 215 and the lower sidewall of the outer shell 21 forms a confluence area 216 for collecting concentrated seawater flowing out of each evaporation channel 213. A concentrated seawater outlet 217 is provided on the lower sidewall of the outer shell 21, and the concentrated seawater outlet 217 is connected to a concentrated seawater discharge pipeline (not shown in the figure).

[0036] Furthermore, in order to prevent concentrated seawater from stagnating in the confluence zone 216, guide slopes 218 are respectively provided on the side wall of the confluence zone 216 on both sides of the concentrated seawater outlet 217 to guide the concentrated seawater to flow smoothly to the outlet and avoid dead corner accumulation.

[0037] Furthermore, such as Figure 7 and Figure 15 As shown, an overflow protrusion 2131 is provided in the evaporation channel 213 downstream of the water distribution pipe 23. When the evaporator 2 is in operation, a water storage area is formed upstream of the overflow protrusion 2131, causing seawater to accumulate under the obstruction of the overflow protrusion 2131. When the liquid level exceeds the height of the overflow protrusion 2131, the seawater flows downstream over the overflow protrusion 2131 and spreads evenly on the bottom surface of the evaporation channel 213, forming a uniform and stable thin liquid film.

[0038] Preferably, the overflow protrusion 2131 has a triangular cross-section. The angle α between the upstream surface of the overflow protrusion 2131 and the bottom surface of the evaporation channel 213 is 90°-130° to form a stable water storage area, allowing the seawater to form a stable liquid level difference in front of the overflow protrusion 2131, thereby ensuring uniform spreading of the liquid film. The angle β between the downstream surface of the overflow protrusion 2131 and the bottom surface of the evaporation channel 213 is 120°-170° to guide the liquid film to transition smoothly, reduce flow resistance, and prevent splashing or eddies on the downstream surface, thereby maintaining the continuity and stability of the evaporation process.

[0039] Preferably, the top of the overflow protrusion 2131 can be configured as a rounded transition to reduce shear disturbance to the liquid film, making the liquid film more stable when passing over the protrusion and avoiding excessive local flow velocity that could cause the liquid film to rupture.

[0040] Furthermore, a flow regulating valve (not shown in the figure) is installed on the water distribution pipe 23 or on the pipe connected to the water distribution pipe 23 to control the flow rate of seawater entering the evaporation channel 213 in real time. By adjusting the flow rate, the evaporation requirements under different operating conditions can be adapted, avoiding excessive flow leading to an excessively thick liquid film and reduced evaporation efficiency, or insufficient flow leading to liquid film interruption and dry spots. The evaporation requirements mentioned here are closely related to factors such as solar radiation intensity, ambient temperature, and seawater temperature. For example, the flow rate can be appropriately increased under strong midday sunlight to fully utilize the heat collection capacity; while the flow rate can be reduced on cloudy days or in the evening to avoid insufficient heat source leading to a decrease in evaporation efficiency.

[0041] Furthermore, it also includes a control unit (not shown in the figure). The flow regulating valve is an electric flow regulating valve. An online conductivity detection device (i.e., a TDS meter, not shown in the figure) is installed at the concentrated seawater outlet 217 of the evaporator 2. By monitoring the conductivity of the discharged concentrated seawater in real time, the salt concentration of the discharged concentrated seawater can be determined, thereby indirectly reflecting the liquid film state and evaporation efficiency in the evaporation channel 213, providing real-time feedback for flow regulation. The control unit receives the conductivity signal fed back by the online conductivity detection device and generates an adjustment command based on a preset concentration threshold to control the opening of the electric flow regulating valve, realizing closed-loop adaptive adjustment of the liquid film thickness and flow rate in the evaporation channel 213.

[0042] Furthermore, since there are differences in the latitude of different regions and the solar altitude angle in different seasons in the same region, in order to adapt to the solar altitude angle in different regions and so that the evaporator 2 is always at the optimal receiving angle, an angle adjustment mechanism for adjusting the tilt angle of the evaporator 2 is provided between the evaporator 2 and the base assembly 1. The steam outlet of the evaporator 2 is connected to the steam inlet 331 on the main housing 33 through a flexible connection 4.

[0043] As a specific implementation, the flexible connection 4 described in this embodiment adopts a retractable canvas flexible joint. The canvas flexible joint has good flexibility and sealing performance, effectively compensating for the displacement caused by the angle adjustment of the evaporator 2, while preventing steam leakage. The canvas flexible joint is existing technology and can be obtained through external purchase; its structure will not be described in detail here.

[0044] like Figure 1 , Figure 4 , Figure 6 and Figure 8 As shown, the front end of the evaporator 2 is rotatably connected to the base frame 11 via a rotating shaft 25. The tilt adjustment mechanism includes a slide 51 and a drive assembly for driving the slide 51 to move back and forth along the base frame 11. The lower end of the slide 51 is slidably connected to the base frame 11 via a sliding assembly, and the upper end of the slide 51 is slidably hinged to the evaporator 2. When the slide 51 moves back and forth along the base frame 11, it drives the evaporator 2 to rotate around the rotating shaft 25, thereby changing its tilt angle to adapt to different solar altitude angles and ensure maximum heat collection efficiency. Here, the slidable hinge means that the slide 51 can both slide relative to the evaporator 2 and rotate relative to the evaporator 2, thereby maintaining a stable connection during angle adjustment.

[0045] As one specific implementation method, such as Figure 12As shown, the carriage 51 in this embodiment includes two uprights 511, and a first crossbeam 512 extending in a left-right direction is provided between the two uprights 511. The two ends of the first crossbeam 512 are fixedly connected to the uprights 511 by welding, and the uprights 511 and the first crossbeam 512 together form a stable rigid frame. A drive shaft 513 is provided at the top of the uprights 511, and the two ends of the drive shaft 513 are detachably fixedly connected to the uprights 511. The sliding assembly includes a first slide rail 12 disposed on the base frame 11. Two parallel first slide rails 12 are provided on the base frame 11, and each of the two first slide rails 12 corresponds one-to-one with an upright 511. A first slider 514 is provided at the lower end of each upright 511 to cooperate with the corresponding first slide rail 12, thereby achieving smooth guidance when the carriage 51 moves.

[0046] As one specific implementation method, such as Figure 3 , Figure 12 and Figure 13 As shown, the column 511 in this embodiment includes a square tube vertical beam 5111 as the supporting body. A base plate 5112 is welded to the lower end of the square tube vertical beam 5111, and the base plate 5112 is fixedly connected to the first slider 514 by bolts. A support block 5113 is provided at the upper end of the square tube vertical beam 5111. The lower end of the support block 5113 is inserted into the square tube vertical beam 5111 and fixed by bolts to ensure reliable connection. An ear plate is provided at the upper end of the support block 5113, and the end of the drive shaft 513 passes through the through hole on the ear plate and is locked and fixed by a nut.

[0047] As one specific implementation method, such as Figure 6 , Figure 8 and Figure 10 As shown, the driving assembly in this embodiment includes a lead screw 521. The front and rear ends of the lead screw 521 are rotatably connected to the base frame 11 via bearing assemblies. A nut 5121, which mates with the lead screw 521, is provided on the first crossbeam 512 of the slide 51. The nut 5121 is threadedly engaged with the lead screw 521. When the lead screw 521 rotates, it drives the slide 51 to move back and forth along the base frame 11. A handwheel 522 is provided at the front end of the lead screw 521. The handwheel 522 is fixedly connected to the lead screw 521, allowing the operator to manually rotate the lead screw 521 to precisely adjust the position of the slide 51.

[0048] As one specific implementation method, such as Figure 1 , Figure 2 and Figure 4As shown, in this embodiment, the lower end of the outer shell 21 of the evaporator 2 is provided with a hinge seat 26. The hinge seat 26 includes a sleeve 261, on which two mutually perpendicular connecting plates 262 are welded. The two connecting plates 262 together form an L-shaped structure that matches the bottom side rib of the lower end of the outer shell 21, and are fixedly connected to the outer shell 21 by bolts or welding. A stiffening plate 263 is welded between the outer side of the connecting plate 262 (with the side facing the outer shell 21 as the inner side) and the sleeve 261. Preferably, the lower end of the outer shell 21 is provided with two hinge seats 26, and the two hinge seats 26 are respectively located at the two ends of the outer shell 21. The rotating shaft 25 passes through the sleeve 261 and is fixedly connected to the sleeve 261 by a set screw. The two ends of the rotating shaft 25 are respectively fixedly connected to the base frame 11 by bearing assemblies.

[0049] As one specific implementation method, such as Figure 1 and Figure 2 As shown, the base frame 11 in this embodiment includes a first rectangular frame 111 welded from structural steel. A second rectangular frame 112 welded from structural steel is located at the rear end of the first rectangular frame 111. Support beams 113 are respectively located at the four corners of the second rectangular frame 112. The upper ends of the support beams 113 are fixedly connected to the second rectangular frame 112 by welding, and the lower ends of the support beams 113 are fixedly connected to the first rectangular frame 111 by welding. Support frames 114 are respectively located on the left and right sides of the front end of the first rectangular frame 111. Both ends of the rotating shaft 25 are rotatably connected to the support frames 114 via bearing assemblies. For example, a vertical mounted spherical roller bearing 13 is provided at the upper end of the support frame 114. Both ends of the rotating shaft 25 pass through the inner rings of the two vertical mounted spherical roller bearings 13 and are fixedly connected to the inner rings by set screws. A second crossbeam 115 is disposed between the two support frames 114, below the rotating shaft 25. First mounting plates 1151 are welded to both ends of the second crossbeam 115, and the first mounting plates 1151 are fixedly connected to the support frames 114 by screws. A third crossbeam 116 is disposed between the two support beams 113 on the front side. Second mounting plates 1161 are welded to both ends of the third crossbeam 116, and the second mounting plates 1161 are fixedly connected to the corresponding support beams 113 by screws. The rear end of the lead screw 521 is rotatably connected to the third crossbeam 116 via a bearing assembly, and the front end of the lead screw 521 is rotatably connected to the second crossbeam 115 via a bearing assembly.

[0050] Furthermore, such as Figure 11As shown, the front end of the lead screw 521 is connected to the second crossbeam 115 via a bearing-type lead screw anti-rotation fixing seat 523. When the bearing-type lead screw anti-rotation fixing seat 523 is in the locked state, the lead screw 521 cannot rotate; when the bearing-type lead screw anti-rotation fixing seat 523 is in the loosened state, the lead screw 521 can rotate freely to adjust the tilt angle of the evaporator 2. By setting this bearing-type lead screw anti-rotation fixing seat 523, the evaporator 2 can be effectively prevented from shifting due to vibration or external force after being adjusted to the required angle, ensuring the angular stability and reliability of the evaporator 2 during operation. The bearing-type lead screw anti-rotation fixing seat 523 is existing technology and can be obtained directly by purchasing it; its internal structure will not be described in detail here.

[0051] As one specific implementation method, such as Figure 5 and Figure 9 As shown, in this embodiment, two second slide rails 27 are provided on the backlit surface of the outer shell 21 of the evaporator 2. A second slider 5151 that can slide along the second slide rail 27 is provided. A connecting seat 5152 is provided on the second slider 5151. One end of the connecting seat 5152 is fixedly connected to the second slider 5151 by a screw, and the other end of the connecting seat 5152 is rotatably connected to the drive shaft 513.

[0052] Furthermore, a transparent hydrophilic coating is provided on the upper side of the heat-absorbing coating of the evaporation channel 213. The hydrophilic coating helps seawater to spread evenly on the surface of the evaporation channel 213, forming a thinner liquid film, thereby increasing the evaporation area and improving the evaporation efficiency.

[0053] As one specific implementation, the hydrophilic coating described in this embodiment is a transparent nano-titanium dioxide coating, which has excellent hydrophilicity and light transmittance.

[0054] Furthermore, the surfaces of the condenser tube 322 and fins 3221 are provided with a hydrophobic coating to promote the rapid dripping of condensate droplets and improve the condensation heat exchange efficiency.

[0055] As one specific implementation, the hydrophobic coating described in this embodiment is a polytetrafluoroethylene coating, which has excellent hydrophobicity and durability.

[0056] Furthermore, such as Figure 1 and 4As shown, a detachable solar collector 6 is fixedly installed on the top of the condensation collection unit 3. The inlet of the solar collector 6 is connected to a water source through a first pipeline, and the outlet of the solar collector 6 is connected to the inlet of the water distribution pipe 23 through a second pipeline. The seawater delivery pump and flow regulating valve are both installed on the second pipeline. After being preheated by the solar collector 6, the seawater to be desalinated enters the evaporation channel 213 for evaporation, which can effectively utilize solar energy for preheating, reduce the heat load during the evaporation process, and improve overall energy efficiency.

[0057] In one specific implementation, the solar collector 6 described in this embodiment is fixedly mounted on the encapsulation cover plate 31 in a detachable manner.

[0058] A solar-powered evaporative seawater desalination method includes the following steps: First, water distribution and liquid film formation.

[0059] The seawater to be desalinated, preheated by the solar collector 6, is transported through pipelines to the water distribution pipe 23 at the upper end of the evaporator 2. The seawater is then evenly distributed into each evaporation channel 213 via axially distributed outlet holes 231 on the water distribution pipe 23. Within each evaporation channel 213, the seawater is first blocked by a triangular overflow protrusion 2131, forming a water storage area on the upstream side of the overflow protrusion 2131, thus buffering and evenly distributing the water flow. Once the liquid level exceeds the top of the overflow protrusion 2131, the seawater spreads evenly over the protrusion, forming a thin liquid film of uniform thickness on the surfaces of the hydrophilic coating and the heat-absorbing coating, and flows steadily downstream along the inclined evaporation channel 213.

[0060] Second, solar evaporation and steam production.

[0061] Sunlight shines through the light-transmitting window 212 and the transparent cover 22 onto the evaporation channel 213. The bottom surface of the channel, coated with a heat-absorbing layer, efficiently absorbs solar radiation and directly transfers it to the liquid film. The liquid film rapidly heats up and continues to evaporate during the flow, generating a large amount of water vapor. The concentration of the unevaporated seawater gradually increases, becoming concentrated seawater. After flowing to the end of the evaporation channel 213, it is collected in the confluence area 216 and discharged from the concentrated seawater outlet 217.

[0062] During evaporation operation, an online conductivity detection device installed at the concentrated seawater outlet 217 monitors the conductivity of the discharged concentrated seawater in real time and transmits the signal to the control unit. The control unit compares the measured conductivity with a preset concentration threshold. If the conductivity is higher than the upper limit threshold, it indicates that the liquid film is too thin and the concentration factor is too high, which poses a risk of scaling. The control unit increases the opening of the electric flow regulating valve to increase the seawater flow rate entering the evaporation channel 213. If the conductivity is below the lower threshold, it indicates that the liquid film is too thick and the evaporation is not sufficient. The control unit reduces the opening of the electric flow regulating valve and appropriately reduces the flow rate to allow the liquid film to evaporate fully.

[0063] Through the aforementioned real-time monitoring and closed-loop regulation, the entire desalination process maintains the liquid film in the optimal evaporation state, ensuring water production efficiency and operational stability.

[0064] Third, deep seawater condensation and freshwater collection The generated water vapor rises along an inclined direction within the evaporation chamber and enters the main body 33 of the condensation collection tank via the steam outlet and flexible connection 4. Simultaneously, deep seawater at a temperature of 5°C to 15°C is continuously injected into the inlet chamber through the inlet pipe 3212 and evenly distributed into the interiors of each condenser tube 322, eventually converging and discharging into the outlet chamber. Upon contact with the outer surface of the condenser tubes 322, cooled by the low-temperature deep seawater, the water vapor rapidly condenses, forming droplets under the action of the hydrophobic coating. These droplets collect at the bottom of the main body 33 and are collected from the freshwater outlet as product freshwater.

[0065] This method utilizes the formation of a uniform liquid film on the inclined evaporation channel 213, direct solar heating, deep seawater condensation, and conductivity feedback for adaptive flow control to achieve efficient and stable solar-powered seawater desalination production.

[0066] Example 2 Removing the second slider 5151, the connecting seat 5152, guide plates are respectively provided on the left and right sides of the backlight surface of the outer shell 21. Each guide plate includes a first plate and a second plate, the first plate being perpendicular to the second plate and forming an L-shaped structure. The first plate is fixedly connected to the outer shell 21 with screws, and the second plate has a long, narrow groove, within which the drive shaft 513 is located. The remaining structure is the same as in Embodiment 1.

[0067] Example 3 The condenser frame 321 is removed, and the two retaining plates 3211 are respectively fixedly installed on the left and right sides of the main housing 33 by welding. Correspondingly, the condenser pipe 322 is located inside the main housing 33, and the steam inlet 331 is located on the lower side of the condenser component. The encapsulation cover 31 is directly fixedly connected to the upper end of the main housing 33 by fasteners. The remaining structure is the same as in Embodiment 1.

[0068] Other embodiments obtained by those skilled in the art based on the embodiments provided in this application by combining, splitting, or reorganizing the embodiments of this application do not exceed the protection scope of this application.

[0069] The above detailed embodiments have provided a detailed explanation of the purpose, technical solutions, and beneficial effects of the embodiments of this application. The above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. That is, any modifications, equivalent substitutions, improvements, etc., made on the basis of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A solar-powered evaporative seawater desalination device, comprising a base assembly (1), an evaporator (2), and a condensation collection assembly (3), characterized in that: The evaporator (2) is arranged at an angle, with a light-transmitting window (212) on its light-facing side, an evaporation chamber inside, an evaporation flow channel (213) at the bottom of the evaporation chamber, and a steam outlet at the high end of the evaporator (2); The condensation collection unit (3) includes a condensation collection box, which is equipped with a condensation component that uses deep seawater as a cold source. The condensation collection box is equipped with a steam inlet (331). The steam outlet of the evaporator (2) is connected to the steam inlet (331) via a flexible connection (4), and the lower end of the evaporator (2) is rotatably connected to the base assembly (1). It also includes a tilt adjustment mechanism for adjusting the tilt angle of the evaporator (2), the tilt adjustment mechanism including a slide (51) and a drive assembly, the lower end of the slide (51) being slidably connected to the base assembly (1) and the upper end being slidably hinged to the evaporator (2), the drive assembly being used to drive the slide (51) to move back and forth along the base assembly (1) to change the tilt angle of the evaporator (2).

2. The solar-powered evaporative seawater desalination device according to claim 1, characterized in that: The evaporator (2) includes an outer shell (21) and a partition (215) disposed inside the outer shell (21). The partition (215) divides the lower space of the evaporation chamber into multiple parallel evaporation channels (213). The surface of the evaporation channel (213) is provided with a heat-absorbing coating. An overflow protrusion (2131) is provided in the evaporation channel (213) downstream of the water inlet of the evaporation channel (213).

3. The solar-powered evaporative seawater desalination device according to claim 2, characterized in that: The overflow protrusion (2131) has a triangular cross section, with an angle of 90°-130° between its front surface and the bottom surface of the evaporation channel (213), and an angle of 120°-170° between its back surface and the bottom surface of the evaporation channel (213).

4. The solar-powered evaporative seawater desalination device according to claim 1, characterized in that: The carriage (51) includes two columns (511), a first crossbeam (512) connecting the two columns (511), and a drive shaft (513) set at the top of the column (511). The base assembly (1) is provided with a first slide rail (12). The lower end of the column (511) is provided with a first slider (514) that cooperates with the first slide rail (12). The back surface of the evaporator (2) is provided with a second slide rail (27). The second slide rail (27) is provided with a second slider (5151). The second slider (5151) is fixed with a connecting seat (5152) that is rotatably connected to the drive shaft (513).

5. A solar-powered evaporative seawater desalination device according to claim 4, characterized in that: The drive assembly includes a lead screw (521) and a nut (5121) that cooperates with it. The lead screw (521) is rotatably connected to the base assembly (1). The nut (5121) is disposed on the first crossbeam (512) of the slide (51). Rotating the lead screw (521) can drive the slide (51) to move.

6. The solar-powered evaporative seawater desalination device according to claim 1, characterized in that: The condensation collection unit (3) includes, from top to bottom, a sealing cover plate (31), a condenser (32) and a main housing (33). The condenser (32) includes a condensation frame (321) and a condensation component disposed therein. The condensation component includes several condensation tubes (322). The condensation tubes (322) are provided with fins (3221). The steam inlet (331) is disposed on the main housing (33).

7. A solar-powered evaporative seawater desalination device according to claim 6, characterized in that: The surfaces of the condenser tube (322) and fins (3221) are provided with a hydrophobic coating, the surface of the evaporation channel (213) is provided with a heat-absorbing coating, and a transparent hydrophilic coating is provided on the upper side of the heat-absorbing coating.

8. A solar-powered evaporative seawater desalination device according to claim 1, characterized in that: It also includes a solar collector (6), the outlet of which is connected to the inlet of the evaporator (2) for preheating the seawater to be desalinated.

9. A solar-powered evaporative seawater desalination device according to claim 1, characterized in that: It also includes a control unit, an electric flow regulating valve installed on the inlet pipe of the evaporator (2), and an online conductivity detection device installed at the concentrated seawater outlet (217) of the evaporator (2). The control unit receives the conductivity signal fed back by the online conductivity detection device and controls the opening degree of the electric flow regulating valve according to the signal.

10. A seawater desalination method using the solar thermal evaporative seawater desalination device according to claim 9, characterized in that: Includes the following steps, S1. The seawater to be desalinated is evenly distributed on the surface of the inclined evaporation channel (213) to form a liquid film, and water vapor is generated by solar energy heating. S2. The water vapor rises on its own and enters the condensation and collection unit (3) through the steam outlet and steam inlet (331). After contacting the condensation component with low-temperature deep seawater, it condenses into fresh water and is collected. S3. During the evaporation process, the conductivity signal of the concentrated seawater outlet (217) is acquired in real time. The control unit adjusts the opening of the electric flow regulating valve according to the conductivity signal to control the seawater flow rate entering the evaporation channel (213) and realize the closed-loop adaptive adjustment of the liquid film evaporation state.

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