Radiation cooling film based on cypress fluff

Abstract

The application discloses a kind of radiation cooling films based on plane tree fluff, the radiation cooling film is made of plane tree fluff cellulose and silica microspheres according to 10:1 mass ratio, and is prepared by hot-pressing method.The plane tree fluff cellulose is prepared by removing impurities, waxes, lignin, hemicellulose and other processes after plane tree fluff, and is dried to complete preparation.The application uses silica microspheres and plane tree fluff widely existing in nature as a substrate, which not only reduces the cost of preparation process, but also reduces the harm of plane tree fluff to environment and health.

Description

Technical Field

[0001] This invention belongs to the field of passive energy utilization, specifically, it relates to a radiation cooling film based on sycamore fluff. Background Technology

[0002] With the acceleration of global industrialization and urbanization, greenhouse gas emissions are constantly increasing, leading to global warming. The construction industry accounts for approximately 30%-40% of carbon emissions. Within the building sector, air conditioning systems are major energy consumers and have a certain environmental impact during operation. Radiative cooling technology, as a passive cooling technology, can directly transfer its heat to outer space through the atmospheric infrared window (8-13μm) in the form of thermal radiation, thereby lowering the temperature of objects. Because this process requires no external energy input, it can effectively reduce energy consumption and greenhouse gas emissions, helping to mitigate the trend of global warming.

[0003] Among the currently published reports, Chinese patent CN118186339A discloses a colored sub-environmental radiation-cooling thin film and its preparation method. This invention has a multilayer film structure, including alternating layers of metal and non-metal, and can achieve three colors with an average emissivity of 0.98 in the 8-13 μm range. Chinese patent CN115572399A discloses a passive radiation-cooling thin film and its preparation method. This invention includes a flexible polyethylene terephthalate substrate, a UV-curable adhesive layer, and a dipentaerythritol pentaacrylate thin film layer arranged sequentially from bottom to top, achieving an average reflectivity of 90.7% in the wavelength range of 0.36-1.2 μm. Although the above-disclosed technologies can achieve good radiation-cooling effects, their preparation processes require the use of metal as a reflective substrate, resulting in high costs, or the use of multiple chemical reagents, which can cause environmental pollution.

[0004] To address the aforementioned problems, this invention discloses a radiation cooling film based on sycamore fluff. This film utilizes sycamore fluff, which is widely present in nature and causes environmental pollution and health problems, as a raw material. While achieving radiation cooling function, it reduces the cost of the preparation process and the harm of sycamore fluff to the environment and health. Summary of the Invention

[0005] The purpose of this invention is to provide a radiation-cooling thin film based on sycamore fluff and its preparation method. By combining sycamore fluff cellulose with silica microspheres, the film has high reflectivity in the solar band and high emissivity in the atmospheric window band, thereby achieving radiation cooling.

[0006] The technical solution of the present invention is: a radiation cooling film based on sycamore fluff, characterized in that the radiation cooling film based on sycamore fluff is composed of sycamore fluff cellulose and silica microspheres in a mass ratio of 10:1.

[0007] Preferably, one of the above-mentioned radiation-cooling films based on sycamore fluff is wherein the sycamore fluff cellulose is obtained by the following method:

[0008] (a) Removal of impurities from sycamore fluff: Soak sycamore fluff in distilled water at a mass ratio of 10:1 and stir at a speed of 90-100 rpm for 15-20 minutes to dissolve or separate the impurities in the sycamore fluff and obtain a sycamore fluff suspension.

[0009] Use a glass funnel with filter paper for filtration. Slowly pour the suspension of sycamore fluff into the funnel along a glass rod, allowing the suspension to flow down naturally while the solid sycamore fluff remains on the filter paper. This will result in sycamore fluff with the water removed. Place the sycamore fluff with the water removed into an oven and dry it at 40-50℃ for 1-2 hours to obtain dried sycamore fluff.

[0010] (b) Removal of wax from sycamore fluff: The dried sycamore fluff is ground into fine powder. The filter paper is rolled into a cylindrical shape, with the bottom of the filter paper closed and the top open. The fine powder of sycamore fluff is then placed into the cylinder to obtain a filter paper cylinder containing the fine powder of sycamore fluff.

[0011] A benzene-ethanol mixture with a volume ratio of 2:1 was added to the distillation flask to 1 / 2 to 2 / 3 of the volume of the distillation flask, wherein the mass ratio of the benzene-ethanol mixture to the fine powder of sycamore fluff in the filter paper tube was 20:1 to 50:1.

[0012] Place the filter paper tube containing fine sycamore fluff powder into the extraction tube. The height of the filter paper tube should be lower than the top of the extraction tube. Then connect the extraction tube and the condenser, ensuring a good seal at the interface. Connect the inlet and outlet of the condenser to the circulating cooling water device. The inlet of the condenser should be at the bottom of the condenser, and the outlet should be at the top of the condenser to ensure good condensation effect.

[0013] The distillation flask is heated to evaporate the solvent. The solvent vapor rises and enters the inner tube of the condenser through the vapor conduit. In the inner tube of the condenser, it is cooled and liquefied into droplets. The droplets drip from the inner tube of the condenser into a filter paper tube containing fine sycamore fluff powder, dissolving the wax in the sycamore fluff powder. At the same time, the solvent flows into the filter paper tube and seeps into the extraction tube. When the solvent level in the extraction tube is higher than the highest point of the siphon tube, the solvent, along with the wax extracted from the fine sycamore fluff powder in the filter paper tube, is siphoned back into the distillation flask. The extraction process lasts for 6-8 hours to remove the wax from the sycamore fluff components.

[0014] After the entire extraction device has cooled down, the extracted fine powder of sycamore fluff in the filter paper tube is placed in an oven and dried at 40-50℃ for 1-2 hours to obtain sycamore fluff with the wax removed.

[0015] (c) Removal of lignin from sycamore fluff: The wax-removed sycamore fluff is soaked in a mixed solution containing 1-3% hydrogen peroxide and 1-2% sodium hydroxide, wherein the mass ratio of the mixed solution of hydrogen peroxide and sodium hydroxide to the wax-removed sycamore fluff is 10:1-20:1. The mixture is stirred at 100-300 rpm for 5-10 minutes at a temperature of 50-60℃, and then allowed to stand for 30-45 minutes. The stirring and standing process is repeated for 2-3 hours to remove lignin from the sycamore fluff, thus obtaining sycamore fluff with wax and lignin removed.

[0016] (d) Removal of hemicellulose from sycamore fluff: The sycamore fluff after removing wax and lignin is soaked in a 2-3% sodium hydroxide solution. The mass ratio of sodium hydroxide solution to the sycamore fluff after removing wax and lignin is 10:1-20:1. The mixture is stirred at 200-400 rpm for 30-45 minutes at 80-90℃ and then allowed to stand for 10-15 minutes. The stirring and standing process is repeated for 1-2 hours to remove hemicellulose from the sycamore fluff components, resulting in sycamore fluff after removing wax, lignin and hemicellulose.

[0017] (e) Drying of Fiber from Fiberwood Floss: Fiberwood fluff is rinsed with distilled water to remove wax, lignin and hemicellulose until the pH of the rinsing solution is 6.5-7.5, resulting in a Fiberwood Floss cellulose suspension. The suspension is then filtered using a glass funnel with filter paper to obtain Fiberwood Floss cellulose with the water removed. The Fiberwood Floss cellulose with the water removed is placed in an oven and dried at 40-50℃ for 1-2 hours to obtain Fiberwood Floss cellulose.

[0018] The present invention also provides a method for preparing the above-mentioned radiation-cooling thin film based on sycamore fluff, the specific steps of which are as follows:

[0019] (a) Mix the cellulose from the sycamore fluff with silica microspheres at a mass ratio of 10:1 and add it to a beaker containing distilled water. The mass ratio of distilled water to the mixture of cellulose from the sycamore fluff and silica microspheres is 10:1-20:1. Stir with a stirrer at a speed of not less than 2000 rpm for 7-8 hours to ensure that the cellulose from the sycamore fluff and silica microspheres are evenly dispersed in the distilled water.

[0020] (b) The mixture of sycamore cellulose, silica microspheres and distilled water was vacuum filtered for 10-12 hours and hot-pressed at 80-100°C for 12 hours to obtain the above-mentioned sycamore cellulose-based radiation cooling film.

[0021] The preferred embodiment of the above-mentioned radiative cooling film based on sycamore fluff is characterized in that, in the solar band, the reflectivity of the radiative cooling film is not less than 90%, and in the atmospheric window band, the emissivity of the radiative cooling film is not less than 85%.

[0022] The preferred embodiment of the above-mentioned radiation-cooling film based on sycamore fluff is characterized in that the particle size of the silica microspheres is 2-8 μm.

[0023] The preferred embodiment of the above-mentioned radiation-cooling film based on sycamore fluff is characterized in that the thickness of the radiation-cooling film is 100-200 μm.

[0024] The circulating cooling water device of the present invention includes: a constant temperature water tank and a water pump;

[0025] The constant temperature water tank, water pump, and condenser are connected by hoses; circulating cooling water flows in a closed loop consisting of the constant temperature water tank, water pump, and condenser; circulating cooling water flows in the outer tube of the condenser to cool the solvent vapor in the inner tube of the condenser, causing the solvent vapor to condense into solvent droplets; the temperature of the circulating cooling water at the inlet of the condenser is maintained at 5-15℃.

[0026] The extraction device of the present invention includes: a distillation flask, an extraction tube, a condenser, an inner tube, an outer tube, a condenser inlet, a condenser outlet, a steam conduit, and a siphon tube.

[0027] The present invention has the following advantages and beneficial effects:

[0028] The present invention discloses a radiation cooling film based on sycamore fluff, which uses silica microspheres and sycamore fluff, which is widely present in nature and causes environmental pollution and health problems, as a substrate. This not only reduces the cost of the preparation process, but also reduces the harm of sycamore fluff to the environment and health. At the same time, the preparation process of this film is simple and easy to mass-produce. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0030] Figure 1 This is a schematic diagram of the structure of a radiation-cooling thin film based on sycamore fluff according to the present invention.

[0031] Figure 2 This is a schematic diagram showing the connection between the entire extraction device and the circulating water cooling device in an embodiment of the present invention.

[0032] Figure 1 and Figure 2The components include: 1. Fiber from sycamore fluff; 2. Silica microspheres; 21. Filter paper tube; 22. Distillation flask; 23. Extraction tube; 24. Condenser; 2401. Inner tube; 2402. Outer tube; 25. Condenser inlet; 26. Condenser outlet; 27. Steam conduit; 28. Siphon tube; 2901. Constant temperature water tank; and 2902. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] In an embodiment of the present invention, the radiation-cooling film based on sycamore fluff is as follows: Figure 1 As shown, it includes 1 pine filament cellulose and 2 silica microspheres, with the pine filament cellulose 1 and silica microspheres 2 arranged in a mass ratio of 10:1.

[0035] The cellulose from the sycamore fluff used was extracted from collected sycamore fluff and obtained by the following method:

[0036] (a) Removal of impurities from sycamore fluff: Soak sycamore fluff in distilled water at a mass ratio of 10:1 and stir at a speed of 90-100 rpm for 15-20 minutes to dissolve or separate the impurities in the sycamore fluff and obtain a sycamore fluff suspension.

[0037] Use a glass funnel with filter paper for filtration. Slowly pour the suspension of sycamore fluff into the funnel along a glass rod, allowing the suspension to flow down naturally while the solid sycamore fluff remains on the filter paper. This will result in sycamore fluff with the water removed. Place the sycamore fluff with the water removed into an oven and dry it at 40-50℃ for 1-2 hours to obtain dried sycamore fluff.

[0038] (b) Removal of waxy substance from sycamore fluff: The dried sycamore fluff is ground into fine powder, and the filter paper is rolled into a cylindrical shape with the bottom closed and the top open. The fine powder of sycamore fluff is then loaded into the cylinder to obtain a filter paper cylinder 21 containing the fine powder of sycamore fluff.

[0039] A benzene-ethanol mixture with a volume ratio of 2:1 is added to the distillation flask 22 until it is 1 / 2 to 2 / 3 full. The mass ratio of the benzene-ethanol mixture to the fine powder of sycamore fluff in the filter paper tube 21 is 20:1 to 50:1.

[0040] Place the filter paper tube 21 containing fine powder of sycamore fluff into the extraction tube 23. The height of the filter paper tube 21 should be lower than the top of the extraction tube 23. Then connect the extraction tube 23 and the condenser 24, ensuring that the interface is well sealed. Connect the inlet 25 and outlet 26 of the condenser to the circulating cooling water device. The inlet 25 of the condenser is at the bottom of the condenser 24, and the outlet 26 of the condenser is at the top of the condenser 24 to ensure good condensation effect.

[0041] The distillation flask 22 is heated to evaporate the solvent. The solvent vapor rises and enters the inner tube 2401 of the condenser 24 through the vapor conduit 27. In the inner tube 2401 of the condenser 24, it is cooled and liquefied into droplets. The droplets drip from the inner tube 2401 of the condenser 24 into the filter paper tube 21 containing fine sycamore fluff powder, dissolving the wax in the fine sycamore fluff powder. At the same time, the solvent flows into the filter paper tube 21 and seeps into the extraction tube 23. When the solvent level in the extraction tube 23 is higher than the highest point of the siphon tube 28, the solvent, along with the wax extracted from the fine sycamore fluff powder in the filter paper tube 21, is siphoned back into the distillation flask 22. The extraction process lasts for 6-8 hours to remove the wax from the sycamore fluff components.

[0042] After the entire extraction device has cooled down, the extracted fine powder of sycamore fluff in filter paper tube 21 is placed in an oven and dried at 40-50℃ for 1-2 hours to obtain sycamore fluff with the wax removed.

[0043] (c) Removal of lignin from sycamore fluff: The wax-removed sycamore fluff is soaked in a mixed solution containing 1-3% hydrogen peroxide and 1-2% sodium hydroxide, wherein the mass ratio of the mixed solution of hydrogen peroxide and sodium hydroxide to the wax-removed sycamore fluff is 10:1-20:1. The mixture is stirred at 100-300 rpm for 5-10 minutes at a temperature of 50-60℃, and then allowed to stand for 30-45 minutes. The stirring and standing process is repeated for 2-3 hours to remove lignin from the sycamore fluff, thus obtaining sycamore fluff with wax and lignin removed.

[0044] (d) Removal of hemicellulose from sycamore fluff: The sycamore fluff after removing wax and lignin is soaked in a 2-3% sodium hydroxide solution. The mass ratio of sodium hydroxide solution to the sycamore fluff after removing wax and lignin is 10:1-20:1. The mixture is stirred at 200-400 rpm for 30-45 minutes at 80-90℃ and then allowed to stand for 10-15 minutes. The stirring and standing process is repeated for 1-2 hours to remove hemicellulose from the sycamore fluff components, resulting in sycamore fluff after removing wax, lignin and hemicellulose.

[0045] (e) Drying of Fiber from Fiberwood Floss: Fiberwood fluff is rinsed with distilled water to remove wax, lignin and hemicellulose until the pH of the rinsing solution is 6.5-7.5, resulting in a Fiberwood Floss cellulose suspension. The suspension is then filtered using a glass funnel and filter paper to obtain Fiberwood Floss cellulose with the water removed. The Fiberwood Floss cellulose with the water removed is placed in an oven and dried at 40-50℃ for 1-2 hours to obtain Fiberwood Floss cellulose 1.

[0046] The method for preparing a radiation-cooling thin film based on sycamore fluff includes the following steps:

[0047] (a) Mix 1 filamentous cellulose and 2 silica microspheres at a mass ratio of 10:1 and add them to a beaker containing distilled water, wherein the mass ratio of distilled water to the mixture of 1 filamentous cellulose and 2 silica microspheres is 10:1-20:1. Stir with a stirrer at a stirring speed of not less than 2000 rpm for 7-8 hours to ensure that 1 filamentous cellulose and 2 silica microspheres are uniformly dispersed in distilled water.

[0048] (b) The mixture of 1 pine filament cellulose, 2 silica microspheres and distilled water was vacuum filtered for 10-12 hours and hot-pressed at 80-100°C for 12 hours to obtain the above-mentioned pine filament-based radiation cooling film.

[0049] The obtained radiation-cooling film based on sycamore fluff is characterized in that the reflectivity of the radiation-cooling film is not less than 90% in the solar band, and the emissivity of the radiation-cooling film is not less than 85% in the atmospheric window band.

[0050] The obtained radiation-cooling film based on sycamore fluff is characterized in that the particle size of the silica microspheres is 2-8 μm.

[0051] The obtained radiation-cooling film based on sycamore fluff is characterized in that the thickness of the radiation-cooling film is 100-200μm.

[0052] The extraction apparatus used includes: a distillation flask 22, an extraction tube 23, a condenser 24, an inner tube 2401, an outer tube 2402, a condenser inlet 25, a condenser outlet 26, a steam conduit 27, and a siphon tube 28.

[0053] The circulating cooling water device used includes: a constant temperature water tank 2901 and a water pump 2902;

[0054] The constant temperature water tank 2901, water pump 2902, and condenser 24 are connected by hoses; the circulating cooling water flows in the closed loop formed by the constant temperature water tank 2901, water pump 2902, and condenser 24.

[0055] The circulating cooling water flows in the outer tube 2402 of the condenser 24 to cool the solvent vapor in the inner tube (2401) of the condenser 24, causing the solvent vapor to condense into solvent droplets; the temperature of the circulating cooling water at the inlet 25 of the condenser is maintained at 5-15℃.

[0056] The specific working process of the circulating cooling water device is as follows:

[0057] Cooling water flows from the condenser inlet 25 into the outer tube 2402 of the condenser 24. Flowing within the outer tube 2402, it cools the solvent vapor in the inner tube 2401 of the condenser 24, causing the solvent vapor to condense into solvent droplets. The heated cooling water then flows out from the condenser outlet 26 and into a constant-temperature water tank 2901. In the constant-temperature water tank, the cooling water is cooled to 5-15℃. The cooled water, now at 5-15℃, flows out from the constant-temperature water tank 2901 and into the water pump 2902. After being pressurized in the water pump 2902, it flows back into the condenser inlet 25 along the pipe, completing the cooling water circulation.

[0058] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A radiation-cooling thin film based on sycamore fluff, characterized in that, The radiation cooling film is composed of sycamore fiber (1) and silica microspheres (2) in a mass ratio of 10:1; The cellulose from the sycamore fluff is prepared by the following method: (a) Removal of impurities from sycamore fluff: Soak sycamore fluff in distilled water at a mass ratio of 10:1 and stir at a speed of 90-100 rpm for 15-20 minutes to dissolve or separate the impurities in the sycamore fluff and obtain a sycamore fluff suspension. Use a glass funnel with filter paper for filtration. Slowly pour the suspension of sycamore fluff into the funnel along a glass rod, allowing the suspension to flow down naturally while the solid sycamore fluff remains on the filter paper. This will result in sycamore fluff with the water removed. Place the sycamore fluff with the water removed into an oven and dry it at 40-50℃ for 1-2 hours to obtain dried sycamore fluff. (b) Removal of wax from sycamore fluff: The dried sycamore fluff is ground into fine powder, and the filter paper is rolled into a cylindrical shape with the bottom closed and the top open. The fine powder of sycamore fluff is then placed into the cylinder to obtain a filter paper cylinder (21) containing the fine powder of sycamore fluff. A benzene-ethanol mixture with a volume ratio of 2:1 was added to the distillation flask (22) to 1 / 2-2 / 3 of the volume of the distillation flask (22), wherein the mass ratio of the benzene-ethanol mixture to the fine powder of sycamore fluff in the filter paper tube (21) was 20:1-50:

1. Place the filter paper tube (21) containing fine powder of sycamore fluff into the extraction tube (23). The height of the filter paper tube (21) should be lower than the top of the extraction tube (23). Then connect the extraction tube (23) and the condenser (24) to ensure a good seal at the interface. Connect the inlet (25) and outlet (26) of the condenser to the circulating cooling water device. The inlet (25) of the condenser is at the bottom of the condenser (24), and the outlet (26) of the condenser is at the top of the condenser (24) to ensure a good condensation effect. The distillation flask (22) is heated to evaporate the solvent. The solvent vapor rises and enters the inner tube (2401) of the condenser (24) through the steam pipe (27). It is cooled and liquefied into droplets in the inner tube (2401) of the condenser (24). The droplets drip from the inner tube (2401) of the condenser (24) into the filter paper tube (21) containing fine sycamore fluff powder, dissolving the wax in the fine sycamore fluff powder. The solvent flows into the filter paper tube (21) and then seeps into the extraction tube (23). When the solvent level in the extraction tube (23) is higher than the highest point of the siphon tube (28), the solvent, along with the wax extracted from the fine sycamore fluff powder in the filter paper tube (21), is siphoned back into the distillation flask (22). The extraction process lasts for 6-8 hours to remove the wax in the sycamore fluff components. After the entire extraction device has cooled down, the extracted fine powder of sycamore fluff in the filter paper tube (21) is placed in an oven and dried at 40-50℃ for 1-2 hours to obtain sycamore fluff with the wax removed. (c) Removal of lignin from sycamore fluff: The wax-removed sycamore fluff is soaked in a mixed solution containing 1-3% hydrogen peroxide and 1-2% sodium hydroxide, wherein the mass ratio of the mixed solution of hydrogen peroxide and sodium hydroxide to the wax-removed sycamore fluff is 10:1-20:

1. The mixture is stirred at 100-300 rpm for 5-10 minutes at a temperature of 50-60℃, and then allowed to stand for 30-45 minutes. The stirring and standing process is repeated for 2-3 hours to remove lignin from the sycamore fluff, thus obtaining sycamore fluff with wax and lignin removed. (d) Removal of hemicellulose from sycamore fluff: The sycamore fluff after removing wax and lignin is soaked in a 2-3% sodium hydroxide solution. The mass ratio of sodium hydroxide solution to the sycamore fluff after removing wax and lignin is 10:1-20:

1. The mixture is stirred at 200-400 rpm for 30-45 minutes at 80-90℃ and then allowed to stand for 10-15 minutes. The stirring and standing process is repeated for 1-2 hours to remove hemicellulose from the sycamore fluff components, resulting in sycamore fluff after removing wax, lignin and hemicellulose. (e) Drying of Fiber from Fiberwood Floss: Fiberwood floss is rinsed with distilled water to remove wax, lignin and hemicellulose until the pH of the rinsing solution is 6.5-7.5, and Fiberwood floss cellulose suspension is obtained. The suspension is filtered using a glass funnel with filter paper to obtain Fiberwood floss cellulose with the water removed. The Fiberwood floss cellulose with the water removed is placed in an oven and dried at 40-50℃ for 1-2 hours to obtain Fiberwood floss cellulose (1). The specific steps of the method for preparing the radiation-cooling thin film based on sycamore fluff are as follows: (a) Mix 1 sycamore fiber (1) and silica microspheres (2) at a mass ratio of 10:1 and add them to a beaker containing distilled water. The mass ratio of distilled water to the mixture of 1 sycamore fiber (1) and silica microspheres (2) is 10:1-20:

1. Stir with a stirrer at a stirring speed of not less than 2000 rpm for 7-8 hours to ensure that 1 sycamore fiber (1) and silica microspheres (2) are evenly dispersed in distilled water. (b) The mixture of sycamore cellulose (1), silica microspheres (2) and distilled water was vacuum filtered for 10-12 hours and hot-pressed at 80-100°C for 12 hours to obtain the above-mentioned sycamore cellulose-based radiation cooling film.

2. A radiation-cooling thin film based on sycamore fluff according to claim 1, characterized in that, Within the solar band, the reflectivity of the radiation-cooling film is no less than 90%, while within the atmospheric window band, the emissivity of the radiation-cooling film is no less than 85%.

3. The radiation-cooling thin film based on sycamore fluff according to claim 1, characterized in that, The silica microspheres (2) have a particle size of 2-8 μm.

4. The radiation-cooling thin film based on sycamore fluff according to claim 1, characterized in that, The thickness of the radiation-cooling film is 100-200 μm.

5. The radiative cooling film based on sycamore fluff according to claim 1, characterized in that, The circulating cooling water device includes: a constant temperature water tank (2901) and a water pump (2902). The constant temperature water tank (2901), water pump (2902), and condenser (24) are connected by a hose; the circulating cooling water flows in the closed loop formed by the constant temperature water tank (2901), water pump (2902), and condenser (24); The circulating cooling water flows in the outer tube (2402) of the condenser (24) to cool the solvent vapor in the inner tube (2401) of the condenser (24), causing the solvent vapor to condense into solvent droplets; the temperature of the circulating cooling water at the inlet (25) of the condenser is maintained at 5-15℃.

6. The radiative cooling film based on sycamore fluff according to claim 1, characterized in that, The entire extraction device includes: a distillation flask (22), an extraction tube (23), a condenser (24), an inner tube (2401), an outer tube (2402), a condenser inlet (25), a condenser outlet (26), a steam conduit (27), and a siphon tube (28).

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