A low-tortuosity hierarchical pore structure aerogel interface evaporation device

Abstract

The present invention discloses an aerogel interfacial evaporation device with a low tortuosity layered stepped pore structure, which is intended to maintain a high-efficiency and stable interfacial evaporation rate and evaporation efficiency when applied to seawater desalination under high salt concentration. The aerogel interfacial evaporation device is composed of an interfacial evaporator and a flat-plate thermal insulation support structure, and the main structure of the interfacial evaporator is cylindrical and is prepared by a directional freeze-drying method. The pore size of the interfacial evaporator presents a stepped distribution in the vertical direction, wherein the bottom layer is a large pore structure, the middle layer is a medium pore structure, and the top layer is a small pore structure. The aerogel interfacial evaporator of the present invention improves the water transport rate during the evaporation process through the layered stepped pore structure, effectively coordinates the competitive relationship between the water transport performance and the thermal insulation performance of the aerogel interfacial evaporator, and significantly reduces the diffusion and reflux resistance of salt ions, thereby greatly improving the salt resistance performance of the interfacial evaporation device.

Description

Technical Field

[0001] The invention relates to the field of solar-driven seawater desalination, and in particular to an aerogel interface evaporation device with a low-tortuosity layered stepped pore structure. Background Art

[0002] With the continuous growth of the world's population, the intensification of environmental pollution and global warming, the severe shortage of freshwater resources has become a major challenge to human scientific and technological progress and social and economic development. Therefore, it is urgent to develop efficient, low-cost and sustainable wastewater purification or seawater desalination technology. At present, wastewater purification and treatment technologies based on physical, chemical and biological filtration, as well as seawater desalination technologies based on reverse osmosis membrane and distillation have been developed for the production of clean water. However, these methods have complex process flows, large equipment footprints and high energy consumption, making them difficult to promote in remote mountainous areas and islands with backward infrastructure.

[0003] In recent years, solar-driven interfacial evaporation technology has shown broad application prospects in seawater desalination due to its high evaporation rate, superior energy conversion efficiency under natural sunlight, and easy installation, and has attracted widespread attention from scholars. Conventional interfacial evaporators are mainly composed of a top light-absorbing layer and a water transfer channel. The light-absorbing layer is used to capture sunlight and convert it into heat energy, while the hydrophilic water transfer channel continuously supplies water to the light-absorbing layer. Therefore, the water transfer capacity of the water transfer channel and the light-heat conversion capacity of the light-absorbing layer are the key factors affecting the device's ability to achieve efficient interfacial evaporation. On the other hand, during the long-term operation of the interfacial evaporator, salt will continue to accumulate on the surface of the evaporator until it precipitates, thereby affecting the light-absorbing layer's ability to capture sunlight and the evaporation rate of the device system. In order to achieve long-term and stable operation of the evaporator, a variety of salt blocking schemes have been developed: (1) ion diffusion reflux method; (2) potential flow driven method; (3) direct salt blocking of the water transfer layer; (4) zero liquid discharge method, etc. However, the first two methods use the method of enhancing the water transfer capacity of the water transfer channel, which will increase the thermal conductivity loss of the evaporator and the evaporation efficiency is not high. The latter two methods have problems such as high difficulty in preparation and complex structure, which are not convenient for preparation. Therefore, it is necessary to design and prepare an evaporator with high evaporation rate, simple structure and good salt resistance. Summary of the invention

[0004] The object of the present invention is to provide a low-tortuosity hierarchical stepped pore structure aerogel interface evaporation device which can enhance water transport through stepped capillary driving force and maintain a low thermal conductivity, thereby achieving rapid evaporation in high-salinity seawater.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: including a top layer of small pore structure, a middle layer of medium pore structure, a bottom layer of large pore structure and a flat plate thermal insulation support structure with a circular through hole in the middle, which are closely connected in sequence from top to bottom, and a cross-shaped support frame is arranged in the circular through hole. The bottom layer of large pore structure is placed on the cross-shaped support frame in the flat plate thermal insulation support structure to form an evaporation device floating on the water surface, and the upper surface of the top layer of small pore structure serves as the photothermal evaporation interface.

[0006] The top layer of small pore structure has a thickness of 9-11 mm, a diameter of 24-26 mm, and a maximum pore size of 140-165 μm.

[0007] The middle layer has a medium pore structure with a thickness of 9-11 mm, a diameter of 24-26 mm, and an internal maximum pore size of 170-230 μm.

[0008] The bottom macroporous structure has a thickness of 9-11 mm, a diameter of 24-26 mm, and an internal maximum pore size of 280-320 μm.

[0009] The thickness of the flat plate heat insulation support structure is 9-11 mm, and the diameter of the circular through hole is 26-27 mm; the cross-shaped support frame is embedded in the middle of the circular through hole of the flat plate heat insulation support structure.

[0010] The top layer small pore structure, the middle layer medium pore structure and the bottom layer large pore structure are made of hydrophilic monomer material and photothermal material in a mass ratio of 1:1.5-3.

[0011] The hydrophilic monomer material is sodium alginate, silicon dioxide, water glass or nanocellulose.

[0012] The photothermal material is one or two of polypyrrole, carbon black or short multi-walled carbon nanotubes.

[0013] The flat plate heat insulation support structure has a density lower than 800kg / m3 and a low thermal conductivity lower than 0.5W·m -1 ·K -1 It is made of polyurethane foam, polystyrene foam, polyethylene foam, polypropylene foam, polyvinyl chloride foam and phenolic resin foam.

[0014] The cross-shaped support frame is a conductor with an insulating shell that does not react with water, a plastic rod, or a hard material, such as etc.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. Compared with the current seawater desalination technology mainly based on reverse osmosis membrane method and distillation method, the only energy source of this invention is the sun, and it does not need to consume high-grade energy to drive. Therefore, it does not need to rely on mature infrastructure and industrial production technology, and is suitable for remote mountainous areas and islands.

[0017] 2. Compared with conventional two-dimensional interface evaporation devices, the present invention can absorb energy from the surrounding environment, thereby increasing the overall evaporation rate.

[0018] 3. Compared with the existing three-dimensional interface evaporation device, the present invention provides a step-type mutation capillary driving force for water transport in the interface evaporator by regulating the pore structure of each layer, so as to meet the demand for uneven capillary driving force of water in the interface evaporator during the entire transportation process, thereby enhancing its water transport capacity. In addition, the aerogel interface evaporator described in the present invention effectively limits the transfer of heat to the middle layer due to the low thermal conductivity of the small pore structure of the top layer, greatly reducing the thermal conductivity loss. In addition, the structure described in the present invention has an extremely low tortuosity, and the salt accumulated at the photothermal evaporation interface has extremely low resistance during the diffusion and reflux process, which makes the aerogel interface evaporation device have super salt resistance. Based on the above characteristics, the present invention has excellent evaporation and salt resistance, and can achieve efficient and stable seawater desalination under natural light and simulated seawater with different salt concentrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 It is a schematic diagram of the flat plate heat insulation support structure of the present invention.

[0021] Figure 3 It is a comparison of SEM images of each layer of the aerogel interface evaporator in Example 1 of the present invention and Comparative Example 1, wherein a to c are the pore structures of the bottom layer, middle layer and top layer of Example 1 respectively; e to i are the pore structures of the bottom layer, middle layer and top layer of Comparative Example 1 and their enlarged views respectively.

[0022] Figure 4 It is a comparison of the water transfer capacity (complete wetting time) of Example 1 of the present invention and Comparative Example 1.

[0023] Figure 5 It is a comparison diagram of the evaporation mass change curves in pure water under one times the light intensity of Example 1 of the present invention and Comparative Example 1.

[0024] Figure 6 It is the mass change curve of Example 1 of the present invention and Comparative Example 1 when they are continuously operated for 8 hours in simulated seawater with a concentration of 25 wt % under one times the light intensity.

[0025] Among them, 1-top layer small pore structure; 2-middle layer medium pore structure; 3-bottom layer large pore structure; 4-flat plate insulation support structure; 5-photothermal evaporation interface; 6-circular through hole; 7-cross-shaped support frame. DETAILED DESCRIPTION

[0026] The present invention is further explained below in conjunction with the drawings and specific embodiments of the specification. It is worth noting that the described embodiment is one of the schemes of the present application. In addition to the embodiments described in this application, all other cases obtained based on the present invention without making creative improvements are within the scope of protection of this application.

[0027] See also Figure 1 , 2. The present invention comprises a top layer of small pore structure 1, a middle layer of medium pore structure 2, a bottom layer of large pore structure 3 and a flat plate heat insulation support structure 4 with a circular through hole 6 in the middle, which are closely connected in sequence from top to bottom, and a cross-shaped support frame 7 is arranged in the circular through hole 6. The bottom layer of large pore structure 3 is placed on the cross-shaped support frame 7 in the flat plate heat insulation support structure 4 to form an evaporation device floating on the water surface, and the upper surface of the top layer of small pore structure 1 is used as a photothermal evaporation interface 5. The top layer of small pore structure 1, the middle layer of medium pore structure 2 and the bottom layer of large pore structure 3 of the present invention are made of hydrophilic monomer materials such as sodium alginate, silicon dioxide, water glass or nanocellulose and photothermal materials such as polypyrrole, carbon black or short multi-walled carbon nanotubes, and the mass ratio of 1:1.5 to 3 is 1:1.5 to 3. The top layer of the small pore structure 1 has a thickness of 9-11 mm, a diameter of 24-26 mm, and a maximum pore size of 140-165 μm, the middle layer of the medium pore structure 2 has a thickness of 9-11 mm, a diameter of 24-26 mm, and an internal maximum pore size of 170-230 μm, the bottom layer of the large pore structure 3 has a thickness of 9-11 mm, a diameter of 24-26 mm, and an internal maximum pore size of 280-320 μm, the flat plate thermal insulation support structure 4 has a thickness of 9-11 mm, and a circular through hole 6 has a diameter of 26-27 mm; the cross-shaped support frame 7 is embedded in the middle of the circular through hole 6 of the flat plate thermal insulation support structure 4, and the flat plate thermal insulation support structure 4 has a density of less than 800 kg / m3 and a low thermal conductivity of less than 0.5 W·m -1 ·K -1 The cross-shaped support frame 7 is made of polyurethane foam, polystyrene foam, polyethylene foam, polypropylene foam, polyvinyl chloride foam, or phenolic resin foam. The cross-shaped support frame 7 is a hard material that does not react with water, such as a wire with an insulating shell, a plastic rod, etc.

[0028] The present invention can quickly pump water to the photothermal evaporation interface 5 of the top layer 1 of the small pore structure through the layered and stepped pore structure for interfacial evaporation, and the salt accumulated on the photothermal evaporation interface 5 flows back to the bottom bulk water by convection and diffusion. At the same time, the side surfaces of the top layer 1 of the small pore structure, the middle layer 2 of the medium pore structure, and the bottom layer 3 of the large pore structure will absorb energy from the environment to further increase the evaporation rate of the device.

[0029] Embodiment 1:

[0030] In this embodiment, sodium alginate is used as a monomer, and polypyrrole and short multi-walled carbon nanotubes are used as photothermal materials. First, 0.33g of sodium alginate is poured into 7mL of polypyrrole dispersion, stirred thoroughly until dissolved, poured into a cylindrical silicone mold, and then frozen using directional freezing technology to form a macroporous structure bottom layer 3 with a thickness of 9-11mm, a diameter of 24-26mm, and an internal maximum pore size of 280-320μm; then, 0.40g of sodium alginate is poured into 7mL of polypyrrole dispersion, stirred thoroughly, and poured into the top of the macroporous structure bottom layer 3 in the silicone mold, and directionally frozen again to form a macroporous structure bottom layer 3 with a thickness of 9-11mm, a diameter of 24-26mm, and an internal maximum pore size of 280-320μm. The maximum pore size of the medium pore structure middle layer 2 is 170-230μm; then, take 0.47g of sodium alginate and pour it into 7mL of polypyrrole aqueous dispersion, add 0.3g of short multi-walled carbon nanotubes, stir thoroughly until dissolved, pour it into the silica gel mold on top of the medium pore structure middle layer 2, and form a top layer of small pore structure 1 with a thickness of 9-11mm, a diameter of 24-26mm, and a maximum pore size of 140-165μm after directional freezing, thereby obtaining a colloid with a hierarchical stepped pore structure, and the upper surface of the top layer of small pore structure 1 is used as the photothermal evaporation interface 5. Then, the frozen colloid is vacuum freeze-dried at -60℃ for 40h, then immersed in 5wt% CaCl solution for 12h, and finally frozen again and dried to obtain a hierarchical stepped pore structure aerogel with low tortuosity. A circular polystyrene foam with a diameter of 50mm is used as the thermal insulation support structure 4, on which there is a hole as follows Figure 2 A through hole 6 with a diameter of 28 mm is arranged as shown; a cross-shaped support frame 7 is embedded in the through hole 6. The aerogel is placed on the cross-shaped support frame 7 as a whole, and its lower surface is in contact with the bulk water, so that an aerogel solar interface evaporator with a hierarchical pore structure with low tortuosity can be obtained. During the experiment, the entire device needs to be kept just floating on the water surface.

[0031] Furthermore, the microscopic pore structure of each layer side of Example 1 was observed by scanning electron microscopy. Figure 3a~3c. It can be seen that there are a large number of low tortuosity microchannel structures in the aerogel interface evaporator in Example 1, and the size decreases from bottom to top. The maximum pore size in the bottom macroporous structure is about 307.4 μm, the maximum pore size in the middle medium pore structure is about 225.7 μm, and the maximum pore size in the top small pore structure is about 162.3 μm.

[0032] Comparative Example 1:

[0033] Compared with Example 1, the difference is that in the aerogel preparation process, 1.2 g of sodium alginate is dissolved in 21 mL of polypyrrole aqueous dispersion, and 0.9 g of short multi-walled carbon nanotubes is added, and then conventional freezing technology is used. Other processes and structural parameters are consistent with Example 1.

[0034] According to the method of Example 1, the SEM image of Comparative Example 1 was obtained. Figure 3 d~3f. It can be seen that the pores in different layers of the aerogel interface evaporator in Comparative Example 1 are evenly distributed, and each layer shows a rule of decreasing size from bottom to top. The maximum pore size in the bottom macroporous structure is about 283.2 μm, the maximum pore size in the middle medium pore structure is about 178.7 μm, and the maximum pore size in the top microporous structure is about 140.1 μm.

[0035] Comparative analysis between Example 1 and Comparative Example 1:

[0036] In the interfacial evaporator, the capillary force drives the bulk water to be transported from bottom to top to the photothermal evaporation interface. The entire transport process can be described by Darcy's law, and the calculation formula is as follows:

[0037]

[0038] Where m is the mass flow rate, kg / s; K is the permeability of the porous medium; ρ is the density of bulk water, kg·m -3 ; g is the acceleration due to gravity, m·s -2 ;P c is the capillary driving force, Pa; L is the height of the interface evaporator, m; A is the cross-sectional area of ​​the interface evaporator, m 2 ; μ is the viscosity of bulk water, Pa·s. Since the pore size of Example 1 presents a step-wise change, it can provide a capillary driving force for the bulk water to overcome the gravity during the transportation process, and the macroporous structure of the bottom layer makes the interface evaporator have a large permeability to ensure sufficient water supply. Figure 4 As shown, compared with Comparative Example 1, the water transport capacity of Example 1 is greatly improved, and the time for the entire interface evaporator to be completely wetted is reduced from 27s to 8s.

[0039] In addition, through the analysis of heat transfer during the interfacial evaporation process, it was found that after the evaporation interface was exposed to sunlight, the photothermal material converted solar energy into thermal energy. Most of the heat was used to heat the water at the interface for evaporation, and the remaining energy was dissipated to the surrounding environment and the underlying bulk water through convection, heat conduction and radiation. In addition, for the three-dimensional interfacial evaporator, some non-illuminated areas will absorb energy from the environment for non-photothermal evaporation. The evaporation rate of this embodiment 1 is The calculation formula is as follows:

[0040]

[0041] in, is the mass change of the system, kg; t is the time the system is exposed to sunlight, h. Further, during the interface evaporation process, the evaporator absorbs energy from the surrounding environment while absorbing solar energy. Therefore, when calculating the evaporation efficiency, the evaporation rate under dark field needs to be considered. The evaporation efficiency of Example 1 and Comparative Example 1 is calculated using the following formula.

[0042]

[0043]

[0044] E=M dark,water c=M dark h

[0045] Where Q is the energy absorbed by the evaporation of water, kW·m -2 ; Pin represents the solar radiation intensity, kW·m -2 ; Copt represents the concentration ratio; c represents the heat capacity of water (4200 kJ·kg -2 ); is the evaporation rate of the evaporator under dark field conditions, kg·m -2 ·h -1 ; is the temperature difference between the evaporation interface and the bulk water, °C; h is the evaporation enthalpy of water in the aerogel interface evaporator, kJ·kg -2 ; E represents the heat absorbed from the environment under dark field conditions, kW·m -2 ; represents the evaporation rate of pure water in dark field, kg·m -2 ·h -1 .

[0046] Figure 5 The mass change curves of Example 1 and Comparative Example 1 under one-fold light intensity are shown in Table 1. The evaporation rates and evaporation efficiencies of Example 1 and Comparative Example 1 are calculated according to the above formulas. The results are shown in Table 1. Figure 5It can be seen from Table 1 that the evaporation rate and evaporation efficiency of Example 1 are higher than those of Comparative Example 1 under one-fold light intensity, and the evaporation rate is increased by 14.37%, and the evaporation efficiency is increased by 9.05 percentage points. It can be seen that compared with Comparative Example 1, Example 1 has a better evaporation performance.

[0047] Furthermore, the salt resistance of Example 1 and Comparative Example 1 was compared. A seawater desalination experiment was carried out in simulated seawater with a salt concentration of 25wt% and a light intensity of 1, and the evaporation mass changes of the two were monitored within 8 hours. Figure 6 As shown in the figure, in the 8-hour evaporation experiment, the mass of Example 1 decreases substantially linearly, while the mass change curve of Comparative Example 1 begins to decay at around 2.5 hours, proving that salt is precipitated on the surface of Comparative Example 1 at this time, thereby affecting the evaporation of Comparative Example 1. It can be seen that Example 1 can operate stably at an ultra-high salt concentration of 25wt%, showing a more excellent salt resistance.

[0048] Table 1 Comparison of evaporation performance of Example 1 and Comparative Example 1

[0049] Examples and Comparative Examples <![CDATA[Evaporation rate (kg·m -2 ·h -1 )]]> Evaporation efficiency (%) Example 1 2.801 97.95 Comparative Example 1 2.449 88.92

[0050] Embodiment 2:

[0051] Aerogels were prepared using nanocellulose as monomers and polypyrrole and carbon black as photothermal materials. First, 0.33 g of nanocellulose was poured into 7 mL of polypyrrole dispersion, stirred thoroughly until dissolved, poured into a cylindrical silicone mold, and then frozen using directional freezing technology to form a macroporous structure bottom layer 3; then, 0.40 g of nanocellulose was poured into 7 mL of polypyrrole dispersion, stirred thoroughly, poured into the silicone mold on top of the macroporous structure bottom layer 3, and directional freezing was performed again to form a medium-porous structure middle layer 2; then, 0.47 g of nanocellulose was poured into 7 mL of polypyrrole aqueous dispersion, 0.3 g of carbon black was added, stirred thoroughly until dissolved, and poured into the silicone mold on top of the medium-porous structure middle layer 2. After directional freezing, a colloid with a hierarchical pore structure can be initially obtained. Next, the frozen colloid was freeze-dried at -60°C for 40 hours, then immersed in a 5wt% CaCl solution for 12 hours, and finally frozen again and dried to obtain a hierarchical pore structure aerogel with low tortuosity. A circular polystyrene foam with a diameter of 50 mm was used as the thermal insulation support structure 5, on which a Figure 1 A through hole 6 with a diameter of 28 mm is arranged as shown; a cross-shaped support frame 7 is embedded in the through hole 6. The aerogel is placed on the cross-shaped support frame 7 as a whole, and its lower surface is in contact with the bulk water, so that an aerogel solar interface evaporator with a hierarchical pore structure with low tortuosity can be obtained. During the experiment, the entire device needs to be kept just floating on the water surface.

[0052] Embodiment 3:

[0053] Aerogels were prepared using silica as a monomer and polypyrrole and carbon black as photothermal materials. First, 0.33 g of silica was poured into 7 mL of polypyrrole dispersion, stirred thoroughly until dissolved, poured into a cylindrical silicone mold, and then frozen using directional freezing technology to form a macroporous structure bottom layer 3; then, 0.40 g of silica was poured into 7 mL of polypyrrole dispersion, stirred thoroughly, poured into the top of the macroporous structure bottom layer 3 in the silicone mold, and directionally frozen again to form a medium-porous structure middle layer 2; then, 0.47 g of silica was poured into 7 mL of polypyrrole aqueous dispersion, 0.3 g of carbon black was added, stirred thoroughly until dissolved, and poured into the top of the medium-porous structure middle layer 2 in the silicone mold. After directional freezing, a colloid with a hierarchical pore structure can be initially obtained. Next, the frozen colloid was freeze-dried at -60°C for 40 hours, then immersed in a 5wt% CaCl solution for 12 hours, and finally frozen again and dried to obtain a hierarchical pore structure aerogel with low tortuosity. A circular polystyrene foam with a diameter of 50 mm was used as the thermal insulation support structure 5, on which a Figure 1 A through hole 6 with a diameter of 28 mm is arranged as shown; a cross-shaped support frame 7 is embedded in the through hole 6. The aerogel is placed on the cross-shaped support frame 7 as a whole, and its lower surface is in contact with the bulk water, so that an aerogel solar interface evaporator with a hierarchical pore structure with low tortuosity can be obtained. During the experiment, the entire device needs to be kept just floating on the water surface.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low tortuosity hierarchical pore structure aerogel interface evaporation device, characterized in that: The invention comprises a top layer of small pore structure (1), a middle layer of medium pore structure (2), a bottom layer of large pore structure (3) and a flat plate heat insulation support structure (4) with a circular through hole (6) in the middle, which are closely connected in sequence from top to bottom, and a cross-shaped support frame (7) is arranged in the circular through hole (6). The bottom layer of large pore structure (3) is placed on the cross-shaped support frame (7) in the flat plate heat insulation support structure (4) to form an evaporation device floating on the water surface, and the upper surface of the top layer of small pore structure (1) serves as a photothermal evaporation interface (5). The top layer of small pore structure (1), the middle layer of medium pore structure (2) and the bottom layer of large pore structure (3) are made of hydrophilic monomer material and photothermal material in a mass ratio of 1:1.5 to 3.

2. The low tortuosity hierarchical pore structure aerogel interface evaporation device according to claim 1, characterized in that: The top layer of small pore structure (1) has a thickness of 9-11 mm, a diameter of 24-26 mm, and a maximum pore size of 140-165 μm.

3. The low tortuosity hierarchical pore structure aerogel interface evaporation device according to claim 1, characterized in that: The intermediate layer medium pore structure (2) has a thickness of 9-11 mm, a diameter of 24-26 mm, and an internal maximum pore size of 170-230 μm.

4. The low tortuosity hierarchical pore structure aerogel interface evaporation device according to claim 1, characterized in that: The bottom macroporous structure (3) has a thickness of 9-11 mm, a diameter of 24-26 mm, and an internal maximum pore size of 280-320 μm.

5. The low tortuosity hierarchical pore structure aerogel interface evaporation device according to claim 1, characterized in that: The thickness of the flat thermal insulation support structure (4) is 9-11 mm, and the diameter of the circular through hole (6) is 26-27 mm; the cross-shaped support frame (7) is embedded in the middle of the circular through hole (6) of the flat thermal insulation support structure (4).

6. The low tortuosity hierarchical pore structure aerogel interface evaporation device according to claim 1, characterized in that: The hydrophilic monomer material is sodium alginate, silicon dioxide, water glass or nanocellulose.

7. The low tortuosity hierarchical pore structure aerogel interface evaporation device according to claim 1, characterized in that: The photothermal material is one or two of polypyrrole, carbon black or short multi-walled carbon nanotubes.

8. The low tortuosity hierarchical pore structure aerogel interface evaporation device according to claim 1, characterized in that: The flat plate heat insulation support structure (4) has a density lower than 800 kg / m 3 , low thermal conductivity less than 0.5W·m -1 ·K -1 It is made of polyurethane foam, polystyrene foam, polyethylene foam, polypropylene foam, polyvinyl chloride foam and phenolic resin foam.

9. The low tortuosity hierarchical pore structure aerogel interface evaporation device according to claim 1, characterized in that: The cross-shaped support frame (7) is a hard material of a wire or plastic rod with an insulating shell that does not react with water.

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