Solar distiller with separated functions and preparation method thereof

Abstract

The invention discloses a solar distiller with separated functions and a preparation method thereof, the solar distiller comprises a solar distiller body composed of a bottom wall and four side walls, the upper end of the solar distiller body is an inclined opening and is fixedly connected with a cover plate, and a plurality of solar evaporators are placed in the solar distiller body; the four side walls are fixedly connected in sequence, the four corners of the bottom wall are fixedly connected with the lower ends of the side walls, and gaps are reserved between the bottom wall and the side walls. A water collecting tank for collecting purified water is fixedly mounted at the lower end of the inner surface of the side wall, and a water outlet communicated with the water collecting tank is formed in the side wall; the side wall is a multi-heterogeneous surface formed by fixedly connecting high-thermal-conductivity hydrophilic plates and low-thermal-conductivity super-hydrophilic porous structure plates which are arranged in a staggered manner; an inclined cover plate is fixedly mounted on the solar evaporator body, and the cover plate is made of super-hydrophilic transparent glass. The solar distiller disclosed by the invention can accelerate steam condensation and condensed water falling, and effectively reduce photo-thermal loss, so that the water production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of solar-driven seawater desalination technology, specifically a functionally separated solar distiller and its preparation method. Background Technology

[0002] With industrial development and continuous population growth, the shortage of freshwater resources is increasingly threatening human survival and development. Providing affordable and safe drinking water for all remains a major challenge. Seawater is a resource with huge reserves, and by desalinating seawater, it is possible to fully meet human needs for freshwater.

[0003] Solar-driven interfacial evaporation technology, characterized by high efficiency, low cost, and convenience, is gradually becoming a promising seawater desalination strategy. However, most existing single-stage solar distillers typically employ a single-sloping or double-sloping design, with a transparent cover plate. Sunlight penetrates the transparent cover plate evaporator and causes steam condensation. In application, light transmission, steam condensation, and condensate shedding all occur on the top transparent cover plate. Steam condensation on the transparent cover plate often results in light loss of up to 35% or more for the entire system. Simultaneously, the top transparent cover plate, made of polymers or glass with low thermal conductivity, exhibits poor heat transfer when water droplets form on its surface, leading to a smaller temperature difference during condensation and consequently lower condensation efficiency. Furthermore, the condensed water droplets on the transparent cover plate are difficult to detach, and the water droplets covering the cover plate occupy most of the surface area, reducing the effective condensation area and drastically decreasing condensation efficiency and freshwater yield.

[0004] In summary, the low condensation efficiency and water production rate of existing solar stills are the main challenges restricting the large-scale practical application of solar interfacial evaporation technology. Therefore, it is necessary to design a solar still with a simple structure, high condensation efficiency, and fast freshwater production rate. Summary of the Invention

[0005] The purpose of this invention is to provide a functionally separated solar still and its preparation method. The prepared solar still can accelerate steam condensation and condensate removal, effectively reduce light and heat loss, and thus improve water production efficiency.

[0006] This invention is achieved through the following technical solution: A functionally separate solar still includes a solar still body consisting of a bottom wall and four side walls. The upper end of the solar still body has an inclined opening and a cover plate that can close the opening is fixedly connected. Several solar evaporators are placed inside the solar still body. The four side walls are fixedly connected in sequence, and the four corners of the bottom wall are fixedly connected to the lower end of the side walls. A gap is left between the bottom wall and the side walls to allow sewage or seawater to enter. A water collection tank for collecting purified water is fixedly installed on the lower end of the inner surface of the side wall. The water collection tanks located on the four side walls are interconnected, and a water outlet hole that is interconnected with the water collection tank is opened on one of the side walls. The sidewall is a multi-heterogeneous surface, which is formed by interlaced high thermal conductivity hydrophilic plates and low thermal conductivity superhydrophilic porous structure plates fixedly connected together. The high thermal conductivity hydrophilic plates are silver-plated copper plates or silver-plated aluminum plates. The low thermal conductivity superhydrophilic porous structure plates are acrylic plates with hydrophilic modified nickel foam glued to the surface or acrylic plates with hydrophilic modified melamine sponge glued to the surface. The cover plate is made of superhydrophilic transparent glass.

[0007] Furthermore, the thermal conductivity of the silver-plated copper plate and the silver-plated aluminum is ≥200 W·m. -1 ·k -1 And the surface water contact angle is ≤85°.

[0008] Furthermore, the thermal conductivity of the acrylic sheet is ≤1 W·m. -1 ·k -1 .

[0009] Furthermore, the thermal conductivity of the hydrophilically modified nickel foam and the hydrophilically modified melamine sponge is ≤15 W·m. -1 ·k -1 The porosity is 75%~98% and the water contact angle of the surface is ≤5°.

[0010] Furthermore, the superhydrophilic transparent glass is a silica-based glass with a hydrophilic coating on its surface, and the light transmittance of the silica-based glass is ≥90%.

[0011] A method for preparing a functionally separated solar-powered distiller includes the following steps: Step 1: Preparation of multiple heterogeneous surfaces Step 1.1: Cut the silver-plated copper plate or silver-plated aluminum plate into long strips to obtain a hydrophilic material with high thermal conductivity. Step 1.2: Take porous nickel foam or melamine sponge, immerse it in a hydrophilic coating solution for 30 seconds, take it out and dry it in a constant temperature oven at 40℃ for 24 hours to obtain hydrophilic modified nickel foam or hydrophilic modified melamine sponge. Then cut it into strips with the same width as the acrylic sheet and stick them on the surface of the acrylic sheet to obtain a super-hydrophilic porous structure board with low thermal conductivity. Step 1.3: Arrange and paste high thermal conductivity hydrophilic plates and low thermal conductivity superhydrophilic porous structure plates alternately to obtain multiple heterogeneous surfaces; Step 2: Assemble the solar-powered distiller body Step 2.1: First, take four pieces of multi-heterogeneous surface and cut them into the required shape and size. Use the four cut pieces of multi-heterogeneous surface as four side walls and fix them together in sequence. Then, take a piece of low-density board as the bottom wall and fix the four corners of the bottom wall to the bottom of the side wall, leaving a gap between the side wall and the bottom wall, to obtain the solar distiller body with the top opening tilted. Step 2.2: Fix and install water collection tanks on the lower inner surface of the four side walls, and make the water collection tanks on the four side walls interconnected. Make a water outlet hole on one of the side walls that is interconnected with the water collection tank. Then, place the four solar evaporators vertically inside the solar distiller body. Step 2.3: Apply a hydrophilic coating solution to one side of the transparent glass and dry it in a constant temperature oven at 40°C for 24 hours to obtain superhydrophilic transparent glass. Fix it as a cover plate on the top of the four side walls to obtain a solar distiller.

[0012] Furthermore, the high thermal conductivity hydrophilic plate of step 1.1 has a thickness of 0.8 mm and a width of 10 mm.

[0013] Furthermore, the acrylic sheet in step 1.2 has a width of 5 mm and a thickness of 0.8 mm, and the porous nickel foam and melamine sponge have a width of 5 mm and a thickness of 1 mm. The lengths of the porous nickel foam and melamine sponge are both half the length of the acrylic sheet.

[0014] Furthermore, the thickness of the transparent glass in step 2.3 is 1 mm.

[0015] Further, the hydrophilic coating solutions in steps 1.2 and 2.3 are prepared by the following method: dispersing silica powder and polyvinyl alcohol powder in water and stirring evenly to obtain a hydrophilic coating solution, wherein: the mass fraction of silica is 4% and the mass fraction of polyvinyl alcohol is 1%.

[0016] The present invention has the following beneficial technical effects: 1) The solar distiller of this invention separates the functions of light transmission, condensation, and condensate removal, which can accelerate steam condensation and condensate removal, balance the conflict between steam generation and condensation, and effectively and significantly reduce light and heat loss, thereby improving water production efficiency and condensation efficiency. Specifically, it is reflected in: accelerating steam condensation with the help of hydrophilic plates with high thermal conductivity; accelerating the removal of condensate from the surface of hydrophilic plates with high thermal conductivity by the functional groups and capillary action of superhydrophilic porous structure plates with low thermal conductivity, thereby effectively preventing condensate from covering the wall surface and improving the continuity of condensation; the water vapor generated by evaporation can form a water film on the inner surface of transparent glass, which is conducive to sunlight transmission and effectively reduces light loss.

[0017] 2) This invention does not require high energy consumption and can be scaled up or down, making it suitable for wastewater purification and seawater desalination in remote areas and islands where people are not concentrated.

[0018] 3) The materials for the functional separation solar distillation apparatus prepared by this invention are readily available and the preparation method is simple, allowing for mass production. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the functional separation solar distiller of the present invention; Figure 2 This is a flowchart illustrating the preparation process of the multiple heterogeneous surfaces of the present invention. Figure 3 This is a comparison of the water production of the solar-powered distillers prepared in Example 1 of the present invention with those prepared in Comparative Examples 1 to 3. Figure 4 This is a comparison of the water production rates of the solar-powered distillers prepared in Example 1 of the present invention with those prepared in Comparative Examples 1 to 3. Figure 5 This is a comparison of the condensation efficiency of the solar-powered distillers prepared in Example 1 of the present invention with those prepared in Comparative Examples 1 to 3. Figure 6 A photograph of the functional separation solar distiller prepared in Example 1 of this invention; Figure 7 This is a comparison of the condensate shedding behavior of the solar distiller in Example 1 and Comparative Example 1 of the present invention; Figure 8 This is a comparison of the surface temperatures of the solar-powered distillers in Embodiment 1 and Comparative Example 1 of the present invention. Figure 9 This is a temperature comparison of the internal sidewall surface of the solar distiller in Embodiment 1 and Comparative Example 1 of the present invention; Figure 10 This is a comparison of the surface and internal sidewall temperature difference of the solar distillers in Embodiment 1 and Comparative Example 1 of the present invention; Figure 11 The outdoor water production performance test results of the solar distiller prepared in Example 1 of this invention; Figure 12 The outdoor water circulation performance test results of the solar distiller prepared in Example 1 of this invention; Figure 13 The wastewater treatment results of the solar-powered distiller prepared in Example 1 of this invention; Figure 14 The result of seawater treatment by the solar-powered distiller prepared in Example 1 of this invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0021] The solar evaporator used in this invention is prepared according to the technical solution described in Chinese Invention Patent No. CN118005122B.

[0022] refer to Figure 1 As shown, a functionally separated solar still includes a solar still body consisting of a bottom wall and four side walls. The upper end of the solar still body has an inclined opening and a cover plate that can close the opening is fixedly connected. Several solar evaporators are placed inside the solar still body. The four side walls are fixedly connected in sequence, and the four corners of the bottom wall are fixedly connected to the lower end of the side walls. A gap is left between the bottom wall and the side walls to allow sewage or seawater to enter. A water collection tank for collecting purified water is fixedly installed on the lower end of the inner surface of the side wall. The water collection tanks located on the four side walls are interconnected. A water outlet hole that is interconnected with the water collection tank is opened on one of the side walls. The cover is made of superhydrophilic transparent glass, which seals the opening at the top of the solar distiller body while allowing sunlight to enter the interior of the distiller body. During seawater or sewage purification, the solar distiller body floats on the surface of the seawater or sewage, with the lower end of the solar distiller body in contact with the seawater or sewage. The seawater or sewage enters the interior of the solar distiller body through the gap between the bottom wall and the side wall. Sunlight shines through the superhydrophilic transparent glass onto the evaporator, purifying the sewage or seawater that has entered the solar distiller body. The resulting water vapor comes into contact with the side wall and the superhydrophilic transparent glass, forming condensate. The condensate flows along the side wall into the water collection tank and is discharged from the outlet hole for collection. The sidewall is a multi-heterogeneous surface, which is formed by interlaced high thermal conductivity hydrophilic plates and low thermal conductivity superhydrophilic porous structure plates. Specifically: the high thermal conductivity hydrophilic plate is a silver-plated copper plate or a silver-plated aluminum plate with a width of 10 mm; the low thermal conductivity superhydrophilic porous structure plate is an acrylic plate with hydrophilic modified nickel foam glued to the surface or an acrylic plate with hydrophilic modified melamine sponge glued to the surface, with a width of 5 mm. When the low thermal conductivity superhydrophilic porous structure board is an acrylic sheet with hydrophilic modified nickel foam pasted on the surface, the preparation process is as follows: the porous nickel foam is immersed in a hydrophilic coating solution for 30 seconds, then removed and dried in a constant temperature oven at 40℃ for 24 hours to obtain hydrophilic modified nickel foam. The nickel foam is then cut into strips with a width of 5 mm and pasted onto the surface of an acrylic sheet with a width of 5 mm to obtain an acrylic sheet with hydrophilic modified nickel foam pasted on the surface. The length of the hydrophilic modified nickel foam is half the length of the acrylic sheet. When the low thermal conductivity superhydrophilic porous structure board is an acrylic sheet with hydrophilic modified melamine sponge glued to its surface, the preparation process is as follows: immerse the melamine sponge in a hydrophilic coating solution for 30 seconds, remove it, and dry it in a 40℃ constant temperature oven for 24 hours to obtain the hydrophilic modified melamine sponge. Then cut it into strips with a width of 5mm × 50mm, and glue them to the surface of an acrylic sheet with a width of 5mm to obtain an acrylic sheet with hydrophilic modified melamine sponge glued to its surface. The length of the hydrophilic modified melamine sponge is half the length of the acrylic sheet.

[0023] Preferably, the thermal conductivity of the silver-plated copper plate and the silver-plated aluminum plate is ≥200 W·m. -1 ·k -1 Its surface water contact angle is ≤85°; Preferably, the thermal conductivity of the acrylic sheet is ≤1 W·m. -1 ·k -1 .

[0024] Preferably, the thermal conductivity of the hydrophilic modified nickel foam and the hydrophilic modified melamine sponge is ≤15 W·m. -1 ·k -1 It has a porosity of 75%~98% and a water contact angle of ≤5° on the surface.

[0025] Preferably, the superhydrophilic transparent glass is a silica-based glass with a hydrophilic coating on its surface. The preparation process is as follows: take silica-based glass with a light transmittance ≥90%, and brush a hydrophilic coating solution onto one side of its surface. Then it was placed in a constant temperature oven at 40℃ and dried for 24 h to obtain superhydrophilic transparent glass with a water contact angle of ≤5° for the hydrophilic coating on its surface.

[0026] Preferably, the hydrophilic coating solution is prepared by dispersing silica powder and polyvinyl alcohol powder in water and stirring until homogeneous to obtain the hydrophilic coating solution, wherein the mass fraction of silica is 4% and the mass fraction of polyvinyl alcohol is 1%.

[0027] Example 1 Step 1: Prepare the hydrophilic coating solution Silica powder and polyvinyl alcohol powder were dispersed in water and stirred until homogeneous to obtain a hydrophilic coating solution, wherein the mass fraction of silica was 4% and the mass fraction of polyvinyl alcohol was 1%. Step 2, as follows Figure 2 As shown, multiple heterogeneous surfaces are prepared. Step 2.1: Select a material with a thickness of 0.8 mm and a thermal conductivity ≥ 200 W·m. -1 ·k -1 Silver-plated copper sheets are cut into strips with a width of 10 mm to obtain hydrophilic sheets with high thermal conductivity. Step 2.2, select a thermal conductivity ≤15 W·m -1 ·k -1 Porous nickel foam with a porosity of 92% and a thickness of 1 mm was immersed in a hydrophilic coating solution for 30 seconds. After removal, it was dried in a constant temperature oven at 40℃ for 24 hours to obtain hydrophilic modified nickel foam. It was then cut into strips with a width of 5 mm and pasted onto the surface of an acrylic sheet with a width of 5 mm and a thickness of 0.8 mm to obtain a superhydrophilic porous structure board with low thermal conductivity. The length of the hydrophilic modified nickel foam was half the length of the acrylic sheet. Step 2.3: Arrange and bond high thermal conductivity hydrophilic plates and low thermal conductivity superhydrophilic porous structure plates alternately to obtain multiple heterogeneous surfaces; Step 3: Assemble the solar-powered distiller body Step 3.1: First, take four pieces of multi-heterogeneous surface and cut them into the required shape and size. Use the four cut pieces of multi-heterogeneous surface as four side walls and fix them together in sequence. Then, take a piece of low-density board as the bottom wall and fix the four corners of the bottom wall to the lower end of the side wall through the bracket, leaving a gap between the side wall and the bottom wall to obtain the solar distiller body. Step 3.2: Fix and install water collection tanks on the lower inner surface of the four side walls, and make the water collection tanks on the four side walls interconnected. Make a water outlet hole on one of the side walls that is interconnected with the water collection tank. Then, place four solar evaporators with dimensions of 20 mm × 20 mm × 40 mm vertically inside the solar distiller body. Step 3.3: Take a 1 mm thick silica-based transparent glass with 92% light transmittance, coat one side of it with a hydrophilic coating solution, and dry it in a 40°C constant temperature oven for 24 h to obtain superhydrophilic transparent glass. Then, fix the superhydrophilic transparent glass as a cover plate on the top of the four side walls. The tilt angle of the superhydrophilic transparent glass is 53°, resulting in... Figure 6 The solar-powered still shown measures 80 mm × 80 mm × 100 mm.

[0028] Example 2 The difference from Example 1 is that the solar still measures 160 mm × 160 mm × 200 mm and contains nine solar evaporators inside the solar still body.

[0029] Example 3 The difference from Example 1 is that the high thermal conductivity hydrophilic plate has a thickness of 0.8 mm and a thermal conductivity ≥200 W·m. -1 ·k -1 Silver-plated aluminum sheets are cut into strips measuring 10 mm × 100 mm to obtain hydrophilic sheets with high thermal conductivity.

[0030] Example 4 The difference from Example 1 is that the low thermal conductivity superhydrophilic porous structure board is an acrylic board with hydrophilic modified melamine sponge glued to its surface. The preparation process is as follows: melamine sponge with a porosity of 96% and a thickness of 1 mm is immersed in a hydrophilic coating solution for 30 seconds. After being taken out, it is dried in a constant temperature oven at 40°C for 24 hours to obtain hydrophilic modified melamine sponge. Then, it is cut into strips with a width of 5 mm and glued to the surface of an acrylic board with a width of 5 mm to obtain an acrylic board with hydrophilic modified melamine sponge glued to its surface. The length of the hydrophilic modified melamine sponge is half the length of the acrylic board.

[0031] Comparative Example 1 The difference from Example 1 is that the four side walls of the solar distiller body are made of a single piece of acrylic sheet with a thickness of 0.8 mm, and the cover is a 1 mm thick transparent silica-based glass with a light transmittance of 92% without a hydrophilic coating.

[0032] Comparative Example 2 The difference from Example 1 is that the four side walls of the solar distiller body are made of a single piece of acrylic sheet with a thickness of 0.8 mm.

[0033] Comparative Example 3 The difference from Example 1 is that the low thermal conductivity superhydrophilic porous structure plate of Example 1 is replaced with a low thermal conductivity acrylic plate.

[0034] The solar-powered distillers prepared in Example 1 and Comparative Examples 1-3 were used for seawater purification. Their water production performance and condensation efficiency are described in [reference needed]. Figures 3-5 , of which: from Figure 3It can be seen that under a certain solar irradiance, after working for 3.5 hours, the water production of the solar distillers prepared in Example 1 and Comparative Examples 1 to 3 were 9.5 kg / m², 8.68 kg / m², 7.5 kg / m², and 6.44 kg / m², respectively. Furthermore, the water production of the solar distiller prepared in Example 1 was 47.5% higher than that of the solar distiller prepared in Comparative Example 1. Figure 4 It can be seen that the highest freshwater production rate of the solar still prepared in Example 1 reached 3.125 kg / m²·h, which is much higher than the freshwater production rate of only 2.125 kg / m²·h of the solar still prepared in Comparative Example 1; from Figure 5 It can be seen that the solar still prepared in Example 1 has the highest condensation efficiency of 64.7%, which is 47.3% higher than the condensation efficiency of 43.9% of the solar still prepared in Comparative Example 1.

[0035] For the condensate shedding behavior of the solar distillers prepared in Example 1 and Comparative Example 1, please refer to [reference needed]. Figure 7 The solar-powered stills prepared in Example 1 and Comparative Example 1 were used for seawater desalination, and the phenomenon of condensate shedding was observed. The results are as follows: Figure 7 As shown in (a), it can be seen that most of the wall surface of the solar distiller prepared in Comparative Example 1 is covered with condensate, while the walls of the solar distillers prepared in Example 1 and Comparative Example 1 have very little condensate. This is because the low thermal conductivity superhydrophilic porous structure plate with multiple heterogeneous surfaces allows the condensate on the surface of the high thermal conductivity hydrophilic plate to fall off quickly through functional groups and capillary action, effectively preventing condensate from covering the wall surface and improving the continuity of condensation. To further verify the condensate shedding situation of the multiple heterogeneous surfaces, such as... Figure 7 As shown in (b), when a water droplet is added to its surface, the water droplet disappears completely after 1 second, indicating that the multi-heterogeneous surface can quickly remove the water droplet, thereby ensuring the cleanliness of the wall and thus ensuring the continuity of condensation.

[0036] The solar distillers prepared in Example 1 and Comparative Example 1 were used for seawater desalination, and the changes in surface temperature and the temperature of the inner sidewalls of the cavity over time were measured. The results are shown in [reference needed]. Figures 8-10 It can be seen that, compared with the solar distiller prepared in Comparative Example 1, the solar distiller prepared in Example 1 has a larger temperature difference between the surface and the inner sidewall of the cavity. This is attributed to the fact that the low thermal conductivity superhydrophilic porous structure plate of Example 1 can effectively reduce heat loss, thereby reducing ineffective heat loss.

[0037] The solar-powered distiller prepared in Example 1 was used for outdoor seawater desalination, and the changes in freshwater yield and circulation performance over different time periods were recorded. The results are as follows: Figure 11 and Figure 12As shown, it can be seen that the freshwater yield changes with the intensity of solar radiation; moreover, when it is recycled, the freshwater yield changes very little, indicating that the solar distiller prepared in Example 1 can be recycled multiple times for seawater desalination.

[0038] The solar-powered distiller prepared in Example 1 was used to purify wastewater, and the results were as follows: Figure 13 and Figure 14 As shown, where: from Figure 13 It can be seen that the concentrations of methyl orange and methylene blue in the condensate produced by solar evaporation have dropped to extremely low levels, indicating that the solar distiller prepared in Example 1 can efficiently separate and remove methyl orange and methylene blue from wastewater; from Figure 14 It can be seen that the concentration of various metal ions in the condensate produced by desalination is significantly reduced.

Claims

1. A solar-powered distiller with separate functions, characterized in that, The solar still body consists of a bottom wall and four side walls. The upper end of the solar still body has an inclined opening and a cover plate that can close the opening is fixedly connected. Several solar evaporators are placed inside the solar still body. The four side walls are fixedly connected in sequence, and the four corners of the bottom wall are fixedly connected to the lower end of the side walls. A gap is left between the bottom wall and the side walls to allow sewage or seawater to enter. A water collection tank for collecting purified water is fixedly installed on the lower end of the inner surface of the side wall. The water collection tanks located on the four side walls are interconnected, and a water outlet hole that is interconnected with the water collection tank is opened on one of the side walls. The sidewall is a multi-heterogeneous surface, which is formed by interlaced high thermal conductivity hydrophilic plates and low thermal conductivity superhydrophilic porous structure plates fixedly connected together. The high thermal conductivity hydrophilic plates are silver-plated copper plates or silver-plated aluminum plates. The low thermal conductivity superhydrophilic porous structure plates are acrylic plates with hydrophilic modified nickel foam glued to the surface or acrylic plates with hydrophilic modified melamine sponge glued to the surface. The cover plate is made of superhydrophilic transparent glass.

2. The functionally separated solar distiller according to claim 1, characterized in that, The thermal conductivity of the silver-plated copper plate and the silver-plated aluminum plate is ≥200 W·m. -1 ·k -1 And the surface water contact angle is ≤85°.

3. The functionally separated solar distiller according to claim 1 or 2, characterized in that, The thermal conductivity of the acrylic sheet is ≤1 W·m -1 ·k -1 .

4. The functionally separated solar distiller according to claim 1 or 2, characterized in that, The thermal conductivity of the hydrophilically modified nickel foam and the hydrophilically modified melamine sponge is ≤15 W·m. -1 ·k -1 The porosity is 75%~98% and the water contact angle of the surface is ≤5°.

5. The functionally separated solar distiller according to claim 1 or 2, characterized in that, The superhydrophilic transparent glass is a silica-based glass with a hydrophilic coating on its surface, and the light transmittance of the silica-based glass is ≥90%.

6. A method for preparing a functionally separated solar distiller as described in claim 1, characterized in that, Includes the following steps: Step 1: Preparation of multiple heterogeneous surfaces Step 1.1: Cut the silver-plated copper plate or silver-plated aluminum plate into long strips to obtain a hydrophilic material with high thermal conductivity. Step 1.2: Take porous nickel foam or melamine sponge, immerse it in a hydrophilic coating solution for 30 seconds, take it out and dry it in a constant temperature oven at 40℃ for 24 hours to obtain hydrophilic modified nickel foam or hydrophilic modified melamine sponge. Then cut it into strips with the same width as the acrylic sheet and stick them on the surface of the acrylic sheet to obtain a super-hydrophilic porous structure board with low thermal conductivity. Step 1.3: Arrange and paste high thermal conductivity hydrophilic plates and low thermal conductivity superhydrophilic porous structure plates alternately to obtain multiple heterogeneous surfaces; Step 2: Assemble the solar-powered distiller body Step 2.1: First, take four pieces of multi-heterogeneous surface and cut them into the required shape and size. Use the four cut pieces of multi-heterogeneous surface as four side walls and fix them together in sequence. Then, take a piece of low-density board as the bottom wall and fix the four corners of the bottom wall to the bottom of the side wall, leaving a gap between the side wall and the bottom wall, to obtain the solar distiller body with the top opening tilted. Step 2.2: Fix and install water collection tanks on the lower inner surface of the four side walls, and make the water collection tanks on the four side walls interconnected. Make a water outlet hole on one of the side walls that is interconnected with the water collection tank. Then, place the four solar evaporators vertically inside the solar distiller body. Step 2.3: Apply a hydrophilic coating solution to one side of the transparent glass and dry it in a constant temperature oven at 40°C for 24 hours to obtain superhydrophilic transparent glass. Fix it as a cover plate on the top of the four side walls to obtain a solar distiller.

7. The method for preparing a functionally separated solar distiller according to claim 6, characterized in that, The high thermal conductivity hydrophilic plate material in step 1.1 has a thickness of 0.8 mm and a width of 10 mm.

8. The method for preparing a functionally separated solar distiller according to claim 6, characterized in that, The acrylic sheet in step 1.2 has a width of 5 mm and a thickness of 0.8 mm, and the porous nickel foam and melamine sponge have a width of 5 mm and a thickness of 1 mm. The lengths of the porous nickel foam and melamine sponge are both half the length of the acrylic sheet.

9. The method for preparing a functionally separated solar distiller according to claim 6, characterized in that, The thickness of the transparent glass in step 2.3 is 1 mm.

10. The method for preparing a functionally separated solar distiller according to claim 6, characterized in that, The hydrophilic coating solutions in steps 1.2 and 2.3 are prepared by dispersing silica powder and polyvinyl alcohol powder in water and stirring until homogeneous to obtain the hydrophilic coating solution, wherein the mass fraction of silica is 4% and the mass fraction of polyvinyl alcohol is 1%.

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