A sugarcane bagasse-based solar interface evaporation system based on composite electrostatic field regulation

Abstract

The present application relates to the technical field of solar steam generator, and more particularly to a bagasse-based solar interfacial evaporation system based on composite electrostatic field regulation and control, which comprises an interfacial evaporation mechanism and a composite electric field regulation and control mechanism, wherein the interfacial evaporation mechanism comprises a buoyancy body, a water conveying layer and an evaporation layer; the composite electric field regulation and control mechanism comprises a high-voltage power supply, a first electrode assembly and a second electrode assembly; the first electrode assembly comprises a first grounding end electrode, a No. 1 wire, a No. 2 wire, a first high-voltage end electrode and a No. 3 wire; and the second electrode assembly comprises a second grounding end electrode, a No. 4 wire, a No. 5 wire, a support, a second high-voltage end electrode and a No. 6 wire. The present application can solve the problem of insufficient evaporation performance of the interfacial evaporator in the prior art, can significantly improve the evaporation efficiency, thereby improving the seawater desalination capacity, and can also improve the salt resistance and self-cleaning capacity of the interfacial evaporation mechanism, improve the system service life, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of solar steam generator technology, and in particular to a bagasse-based solar interface evaporation system based on composite electrostatic field regulation. Background Technology

[0002] Traditional seawater desalination technologies, such as reverse osmosis, multi-stage flash evaporation, and multi-effect distillation, rely on large-scale infrastructure and fossil fuels, resulting in high energy consumption, high costs, and environmental burdens. In recent years, solar interfacial evaporation technology, by confining photothermal conversion to the water-air interface, can significantly reduce heat loss and improve evaporation efficiency, providing a more efficient and environmentally friendly method for seawater desalination.

[0003] Existing solar interface evaporation devices face two major problems: First, during high light intensity or long-term operation, the imbalance between the moisture supply and evaporation rate of the photothermal material leads to the breakage of the liquid film at the evaporation interface, degradation of surface wettability, and a significant reduction in the effective evaporation area. Second, when treating saline bodies, the rapid crystallization and accumulation of salt forms an opaque scale layer, which not only hinders light absorption but also blocks the moisture transport channels, causing a continuous decline in system performance.

[0004] Sugarcane bagasse is an environmentally friendly and renewable agricultural byproduct of the sugarcane industry, containing 40-50% cellulose, 25-30% hemicellulose, and 20-25% lignin. Using sugarcane bagasse in solar interfacial evaporation systems offers advantages such as high porosity, low thermal conductivity, hydrophilicity, and eco-friendliness, but it suffers from disadvantages in evaporation rate and salt tolerance. Existing bagasse-based solar interfacial evaporation systems primarily improve evaporation efficiency and salt tolerance through chemical surface modification or micro / nanostructure design, but this increases cost and process complexity and fails to address the mismatch between hydrothermal management and evaporation.

[0005] Active electric field control technology boasts advantages such as low cost, simple structure, and low energy consumption. The electrostatic field not only strongly disturbs the meniscus, reducing surface tension, but also modulates the transport characteristics of solutions and the migration of salt ions in porous media, thereby improving evaporation capacity and mitigating salt crystallization issues in evaporators. Existing coupled-electrode solar interface steam systems primarily utilize a single electric field for two-dimensional control, which does not significantly improve evaporator efficiency and still offers room for further optimization. Summary of the Invention

[0006] The purpose of this invention is to provide a bagasse-based solar interface evaporation system based on composite electrostatic field regulation to solve the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A bagasse-based solar interfacial evaporation system based on composite electrostatic field control includes an interfacial evaporation mechanism and a composite electric field control mechanism. The interfacial evaporation mechanism includes a buoyancy body, a water conveying layer, and an evaporation layer. The water conveying layer is vertically disposed in the middle of the buoyancy body, with its upper and lower ends extending upwards and downwards, respectively. The evaporation layer is horizontally disposed on the top surface of the water conveying layer. The composite electric field control mechanism includes a high-voltage power supply, a first electrode assembly, and a second electrode assembly. The first electrode assembly includes a first grounding electrode, a first conductor, a second conductor, a first high-voltage electrode, and a third conductor. The first grounding electrode is sleeved on the lower part of the water conveying layer, located on the bottom surface of the buoyancy body, and connected to the high-voltage power supply through the first conductor. One end of the second conductor is connected to the first conductor, and the other end is grounded. The first high-voltage electrode is vertically positioned in the middle of the buoyancy body. It is a spiral electrode that surrounds the water transport layer. The first high-voltage electrode is connected to the high-voltage power supply via the No. 3 wire. The second electrode assembly includes a second grounding electrode, a No. 4 wire, a No. 5 wire, a support, a second high-voltage electrode, and a No. 6 wire. The second grounding electrode is sleeved on the water transport layer, located between the buoyancy body and the evaporation layer, and is connected to the high-voltage power supply via the No. 4 wire. One end of the No. 5 wire is connected to the No. 4 wire, and the other end is grounded. The support is located on the top surface of the buoyancy body. Multiple second high-voltage electrodes are mounted on the support and are needle-shaped electrodes. These multiple second high-voltage electrodes are connected to the high-voltage power supply via the No. 6 wire.

[0009] Furthermore, the water conveying layer is made of bagasse-based hydrogel material.

[0010] Furthermore, the bagasse-based hydrogel material is prepared from bagasse raw materials containing cellulose.

[0011] Furthermore, the evaporation layer is made of bagasse-based carbon aerogel material.

[0012] Furthermore, the bagasse-based carbon aerogel material is prepared by drying and carbonizing bagasse-based hydrogel material.

[0013] Furthermore, the first grounding terminal and the second grounding terminal electrodes are flat plate electrodes or mesh electrodes.

[0014] Furthermore, the buoyancy body is made of polyethylene foam or polyvinyl chloride foam.

[0015] Furthermore, the support includes a base, connecting columns, bearing rods, and support rods. The base is horizontally positioned on the top surface of the buoyancy body and has a circular ring structure. The connecting columns are vertically positioned on the top surface of the base and are arranged in multiple circumferentially spaced positions. Multiple bearing rods are provided, with one end of each bearing rod connected to the others, and the lower part bent downwards and connected to the connecting columns respectively, forming a radial structure. The support rods are sleeved on the outside of the multiple bearing rods to improve the stability of the multiple bearing rods. The second high-voltage end electrodes are respectively vertically positioned on the upper bottom surface of each bearing rod and the inner side of the support rod, and multiple second high-voltage end electrodes are equally spaced on each bearing rod and circumferentially spaced on the support rod.

[0016] Furthermore, the supporting rod, fixing platform, and support ring are all made of transparent polymer plastic.

[0017] Furthermore, the first grounding electrode and the second grounding electrode are made of a conductive material selected from copper, stainless steel, nickel foam, or copper foam; the first high-voltage electrode is made of a conductive material selected from copper, stainless steel, or aluminum, and its surface is covered with PE insulating material.

[0018] Furthermore, the voltage output by the high-voltage power supply is -10kV to 10kV.

[0019] The advantages of this invention compared to the prior art are as follows:

[0020] 1. This invention, by setting up an interface evaporation mechanism and a composite electric field control mechanism, transports seawater to the evaporation layer through the water transport layer of the interface evaporation mechanism for desalination. At the same time, the composite electric field control mechanism forms an electric field on the interface evaporation mechanism, which can significantly improve the evaporation efficiency of the interface evaporation mechanism, thereby improving the seawater desalination capacity. It can also improve the salt resistance and self-cleaning ability of the interface evaporation mechanism, and extend the service life of the system, showing good application prospects.

[0021] 2. This invention uses sugarcane bagasse, an agricultural waste, as raw material and prepares it into water conveying material and photothermal conversion material through simple processing. It is used for efficient solar interface evaporation, which greatly improves the green economic added value of the sugarcane industry.

[0022] 3. The system of the present invention can be equipped with different electrodes. By using different electrode combinations and different voltage outputs, the electric field generated by the electrodes in the system can be precisely controlled to adapt to the requirements of different environments for evaporation performance and salt resistance, thus providing high flexibility. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the connection structure of the bracket of the present invention;

[0025] Figure 3 This is a schematic diagram of the connection mechanism of the buoyancy body of the present invention;

[0026] Figure 4 This is a graph showing the evaporation rate of the present invention under different electric field strengths;

[0027] Figure 5 This is an evaporation curve diagram of the present invention operating in sodium chloride solutions of various concentrations under different electric field strengths;

[0028] Figure 6 This is a graph showing the evaporation rate of the present invention under different electric field intensities;

[0029] Figure 7 This is a graph showing the average evaporation rate of the present invention under different electric field intensities;

[0030] Figure 8 This invention describes the salt crystal morphology on the surface of the evaporation layer under different electric field intensities.

[0031] Figure 9 This is a diagram illustrating the dissolution process of sodium chloride crystals under different electric field strengths according to the present invention;

[0032] Figure 10 This is a diagram showing the dissolution time of sodium chloride crystals under different electric field strengths according to the present invention.

[0033] In the attached diagram,

[0034] 1-Interfacial evaporation mechanism; 11-Buoyancy body; 12-Water transport layer; 13-Evaporation layer;

[0035] 2- Composite electric field control mechanism; 21- High voltage power supply;

[0036] 22-First electrode assembly; 221-First grounding electrode; 222-Wire No. 1; 223-Wire No. 2; 224-First high-voltage electrode; 225-Wire No. 3

[0037] 23-Second electrode assembly; 231-Second grounding electrode; 232-Fourth wire; 233-Fifth wire;

[0038] 234-Bracket; 2341-Base; 2342-Connecting column; 2343-Bearing rod; 2344-Supporting rod;

[0039] 235 - Second high-voltage terminal electrode; 236 - Wire No. 6. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are merely to provide the reader with a thorough understanding of one or more aspects of the present invention, and these aspects of the invention can be implemented even without these specific details.

[0041] like Figure 1-3As shown, a bagasse-based solar interface evaporation system based on composite electrostatic field control includes an interface evaporation mechanism 1 and a composite electric field control mechanism 2. The interface evaporation mechanism 1 includes a buoyancy body 11, a water conveying layer 12, and an evaporation layer 13. The buoyancy body 11 is used to make the entire system float on the water. The water conveying layer 12 is vertically arranged in the middle of the buoyancy body 11, with its upper and lower ends extending upwards and downwards respectively, for conveying seawater upwards to the evaporation layer 13. The evaporation layer 13 is horizontally arranged on the top surface of the water conveying layer 12, for absorbing sunlight and converting it into heat to evaporate the seawater. The composite electric field control mechanism 2 includes a high-voltage power supply 21, a first electrode assembly 22, and a second electrode assembly 23. The high-voltage power supply 21 is used to provide different voltages with positive and negative polarities relative to the ground terminal. The effect of the electric field on the system can be adjusted by changing the output of the high-voltage power supply as needed. The high-voltage power supply is a programmable high-field micro-current power supply, capable of providing voltages from 0kV to 20kV with positive and negative polarities relative to the ground terminal. It also has the capability of constant DC output and periodic switching of positive and negative polarity output. By changing the output voltage, polarity, and switching period of the power supply, electric fields with different intensities, directions, and switching periods can be formed, thus changing the effect of the electric field on the system as needed. The first electrode assembly 22 includes a first ground terminal electrode 221, a first conductor 222, a second conductor 223, and a first high-voltage terminal electrode. 224, No. 3 conductor 225; The first grounding electrode 221 is sleeved on the lower part of the water conveying layer 12, located on the bottom surface of the buoyancy body 11, and connected to the high-voltage power supply 21 through the No. 1 conductor 222; One end of the No. 2 conductor 223 is connected to the No. 1 conductor 222, and the other end is grounded; The first high-voltage electrode 224 is vertically arranged in the middle of the buoyancy body 11. The first high-voltage electrode 224 is a spiral electrode and surrounds the outside of the water conveying layer 12. The first high-voltage electrode 224 is connected to the high-voltage power supply 21 through the No. 3 conductor 225; One end of the No. 2 conductor 223 is connected to the No. 1 conductor 222, and the other end is grounded; The first high-voltage electrode 224 The first high-voltage electrode 224 is vertically installed in the middle of the buoyancy body 11 and surrounds the water transport layer 12. It is connected to the high-voltage power supply 21 through the third wire 225. The second electrode assembly 23 includes a second grounding electrode 231, a fourth wire 232, a fifth wire 233, a bracket 234, a second high-voltage electrode 235, and a sixth wire 236. The second grounding electrode 231 is sleeved on the water transport layer 12, located between the buoyancy body 11 and the evaporation layer 13, and is connected to the high-voltage power supply 21 through the fourth wire 232. One end of the fifth wire 233 is connected to the fourth wire 232, and the other end is grounded. The bracket 234 is located on the top surface of the buoyancy body 11.The second high-voltage end electrode 235 is mounted on the bracket 234, and multiple second high-voltage end electrodes 235 are provided. Each second high-voltage end electrode 235 is a needle-shaped electrode. Multiple second high-voltage end electrodes 235 are connected to the high-voltage power supply 21 via a No. 6 wire 236. The grounding end electrode and the high-voltage end electrode of the first electrode assembly 22 and the second electrode assembly 23 generate a uniform or non-uniform electric field, and through coordinated control, generate a high-voltage composite electric field.

[0042] In the electric field formed by the first electrode assembly 22, water molecules are attracted by the electric field force due to the polarization effect, causing them to be transported upwards at an accelerated rate. This increases the capillary water transport rate, enhances the stable supply of water at the interface, and promotes steam separation. In the electric field formed by the second electrode assembly 23, the electric field acts on the evaporation layer 13, disrupting the hydrogen bond network between water molecules, reducing the enthalpy of vaporization, strengthening the evaporation effect, and increasing the rate of steam preparation. Simultaneously, the electric field reduces the size of ion clusters in the salt water, making ion crystallization more difficult, actively reducing the rate of salt crystallization on the evaporation layer 13, and removing existing salt crystals, thus improving the salt tolerance of the device and ensuring the efficient operation of the system.

[0043] The water conveying layer 12 has a cylindrical structure and is made of bagasse-based hydrogel material, which has good hydrophilicity and water conveyance properties.

[0044] The bagasse-based hydrogel material is prepared from cellulose-containing bagasse raw materials, and its preparation methods include sol-gel method, enzymatic hydrolysis method, and physical cross-linking method using sodium hydroxide, urea, and water as solvent systems.

[0045] The preparation method of the bagasse-based hydrogel material is as follows:

[0046] S1: After juicing sugarcane, dry and crush it, prepare a 4% NaOH solution, mix sugarcane bagasse with NaOH solution at a mass ratio of 1:20, and then filter it after magnetic stirring in an 80℃ constant temperature water bath for 4 hours. Wash it with ultrapure water until neutral and dry it to obtain crude cellulose.

[0047] S2: Dissolve 1 mL of glacial acetic acid and 1 g of sodium hypochlorite in 200 mL of ultrapure water. Mix 10 g of crude cellulose with the mixture and stir magnetically in an 80°C constant temperature water bath for 4 hours. Filter the mixture, wash it with ultrapure water until neutral, and dry it to obtain white sugarcane bagasse cellulose.

[0048] S3: Prepare a 140g sodium hydroxide / urea solution by mixing sodium hydroxide, urea and water in a mass ratio of 15:23:102, and pre-cool it to -12℃;

[0049] S4: Take 4g of sugarcane bagasse cellulose, disperse it evenly in 30mL of ultrapure water, and pre-cool it to 0~5℃;

[0050] S5: Mix sugarcane bagasse cellulose with sodium hydroxide / urea solution at -5℃ and mechanically stir for 1 hour to obtain a transparent cellulose sol, then place it in an oven at 50℃ for 12 hours to set.

[0051] S6: After the sol is set, it is taken out and regenerated in ultrapure water until the ultrapure water and the gel surface are neutral, thus obtaining a cylindrical sugarcane bagasse-based hydrogel.

[0052] The evaporation layer 13 has a cylindrical structure and is made of bagasse-based carbon aerogel material, which has a porous structure and excellent photothermal conversion capability.

[0053] The bagasse-based carbon aerogel material is prepared by drying and carbonizing bagasse-based hydrogel material. The drying methods include freeze-drying and hot air drying.

[0054] The preparation method of the bagasse-based carbon aerogel material is as follows:

[0055] S1: After pre-freezing the bagasse-based hydrogel at ultra-low temperature for 24 hours, freeze-dry it for 48 hours to obtain bagasse-based aerogel.

[0056] S2: The bagasse-based aerogel is placed in a tube furnace and carbonized with N2 as the protective gas. The heating rate is 5℃ / min and the carbonization time is 3h. After the tube furnace cools naturally to room temperature, bagasse-based carbon aerogel is obtained.

[0057] like Figure 3 As shown, the buoyancy body 11 is a cylindrical structure made of polyethylene foam or polyvinyl chloride foam, with a vertically penetrating channel in the middle for connecting the water transport layer 12, and a spiral channel in the middle for accommodating the spiral electrode.

[0058] like Figure 1-2As shown, the bracket 234 includes a base 2341, connecting columns 2342, bearing rods 2343, and support rods 2344. The base 2341 is horizontally positioned on the top surface of the buoyancy body 11. The base 2341 has a ring-shaped structure, giving it a low center of gravity and a large support area. Through a reasonable mass distribution, it provides stable support, effectively maintaining the mechanical balance of the overall structure. Even with multiple electrodes loaded, it maintains good stability, preventing swaying and overturning. The base 2341 can be made of 3D printed resin material, facilitating rapid prototyping and precise structural control. The connecting columns 2342 are vertically positioned on the top surface of the base 2341, forming a cylindrical structure with multiple columns spaced circumferentially. Multiple bearing rods 2343 are provided, with one end connected to each other, and the lower part bent downwards and connected to the multiple connecting columns 2342 respectively. The connecting column 2342 is connected to form a radial structure. The top surface of the connecting column 2342 has a connecting structure matching the bottom end of the supporting rod 2343, such as a groove, snap-fit, or thread, to achieve stable assembly between the connecting column 2342 and the supporting rod 2343. The supporting rod 2344 is sleeved on the outside of the multiple supporting rods 2343 to improve their stability. The second high-voltage end electrodes 235 are respectively vertically arranged on the upper bottom surface of each supporting rod 2343 and the inner side of the supporting rod 2344. Multiple second high-voltage end electrodes 235 are equidistantly arranged on each supporting rod 2343, and multiple second high-voltage end electrodes 235 are equidistantly arranged circumferentially on the supporting rod 2344, so that the second high-voltage end electrodes 235 are evenly distributed within the bracket 234, achieving a spatial arrangement of multiple second high-voltage end electrodes 235, thereby constructing a three-dimensional electric field system.

[0059] The load-bearing rod 2343 and the support rod 2344 are both made of transparent polymer plastic, which ensures structural strength while not blocking light and meeting the requirements for light transmission.

[0060] The first grounding electrode 221 and the second grounding electrode 231 are made of a conductive material selected from copper, stainless steel, nickel foam, or copper foam; the first high-voltage electrode 224 is made of a conductive material selected from copper, stainless steel, or aluminum, and its surface is covered with PE insulating material; when a thicker evaporation layer 13 is selected, the grounding electrode is combined with porous conductive materials such as nickel foam or copper foam, which can improve the efficiency of the electric field without affecting the water conveyance effect, thereby achieving efficient evaporation and salt resistance.

[0061] The voltage output by the high-voltage power supply 21 is -10kV to 10kV.

[0062] 1. Evaporation performance experiment

[0063] This device was placed in sodium chloride solutions with concentrations of 0 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%. A potential of -10 kV to 10 kV was input to the high-voltage terminal via a high-voltage power supply 21. The evaporation rate was measured using an electronic balance, and the results were output to a data acquisition system. The results are as follows: Figure 4-7 As shown.

[0064] from Figure 4-5 As can be seen, by forming an electric field in the interface evaporation mechanism 1 through the composite electric field control mechanism 2, the evaporation rate can be significantly increased in sodium chloride solutions of different concentrations.

[0065] Specifically, under a -10kV electric field, the evaporation rate increased by 20.23%, 29.14%, 27.44%, 23.34%, and 25.18% in sodium chloride solutions of 0wt.%, 5wt.%, 10wt.%, 15wt.%, and 20wt.%, respectively. Under a +10kV electric field, the increases were 17.54%, 26.03%, 27.44%, 27.16%, and 17.26%, respectively. This demonstrates that the composite electric field control mechanism 2, in conjunction with the interface evaporation mechanism 1, can significantly improve evaporation performance.

[0066] from Figure 6 As can be seen, without an electric field, the evaporation rate and efficiency of the system tend to stabilize over time when operating in 0 wt.% and 5 wt.% sodium chloride solutions. However, when the sodium chloride solution concentration is 10 wt.%, the evaporation rate and efficiency show a trend of first increasing and then decreasing. When the sodium chloride solution concentration is greater than 15 wt.%, the evaporation rate and efficiency of the system gradually decrease over time. This phenomenon is related to the salt precipitation formed on the surface of evaporation layer 13. In fact, insufficient working fluid supply will cause ions to remain in the vicinity of the surface of evaporation layer 13. Once the ion concentration in this region reaches the maximum solubility of sodium chloride, salt crystals will precipitate on the surface of evaporation layer 13. The presence of salt crystals hinders heat transfer, which will lead to additional thermal resistance. After the electric field is turned on, the effect of different electric field intensities on the evaporation performance of the system will be affected by the changing sodium chloride solution concentration.

[0067] When the system operates with pure water as the working fluid, its evaporation rate and evaporation efficiency tend to stabilize as the evaporation process proceeds in electric fields of 0 kV, +6 kV, +8 kV, and +10 kV. However, when the potential at the high-potential end is changed to other values, the system's evaporation performance gradually increases over time. For example, when pure water is used as the working fluid and the system operates under a -10 kV electric field, the evaporation rate is close to 1.436 kg·m³. -2 ·h -1The evaporation efficiency reached as high as 90.01%. As the sodium chloride solution concentration increased to 5 wt.%, the effect of the electric field on the system's evaporation performance was slightly weaker than when operating in pure water. At this point, the system's evaporation performance improved over time only in +2 kV, +8 kV, and +10 kV electric fields, exhibiting the greatest enhancement effect in the +10 kV field, with an evaporation rate of 1.338 kg·m³. -2 ·h -1 The evaporation efficiency was 83.91%. When the system operated in a 10 wt.% sodium chloride solution, the evaporation performance improved under each electric field condition, and compared to the state without an electric field, it did not exhibit a trend of first increasing and then decreasing as the evaporation process progressed. For example, in an -8 kV electric field, the system's evaporation rate increased from 0.901 kg·m³ 300 seconds after the start of the evaporation process. -2 ·h -1 1.38 kg·m at 7200 seconds -2 ·h -1 The evaporation efficiency increased from 56.50% to 86.92%.

[0068] When a 15 wt.% sodium chloride solution is used as the working fluid, spotty and blocky salt precipitates appear on the surface of evaporation layer 13 in the absence of an electric field. Furthermore, except when the potential is +2 kV, the evaporation performance of the system tends to stabilize over time. Under these concentration conditions, the enhancing effect of the electric field on the system's evaporation performance is greatest at a potential of +2 kV, corresponding to an evaporation rate of 1.320 kg·m³. -2 ·h -1 The evaporation efficiency was 82.79%. When the sodium chloride solution concentration increased to 20 wt.%, the higher electric fields at +6 kV, +8 kV, and +10 kV had a greater enhancing effect on the system's evaporation performance, and this effect gradually increased as the steam production process progressed. Particularly in the +10 kV electric field, the system's evaporation rate reached 1.447 kg·m³. -2 ·h -1 The evaporation efficiency was increased to 90.71%.

[0069] from Figure 6 As can be seen, the heating process on the surface of evaporation layer 13 typically requires a maximum of 2400 seconds, after which the dynamic evaporation rate tends to stabilize. Therefore, the stable evaporation rate between 2400 and 7200 seconds can be considered the average evaporation rate. Figure 7 As shown, based on the comparison of varying potential polarity, electric field strength, and sodium chloride solution concentration, in an electric field formed by a high potential, the evaporation rate of the system only tends to stabilize and approach its maximum value when the time is close to 7200 seconds.

[0070] In summary, the evaporation performance of the interface evaporation mechanism 1 of this application can be adjusted according to different salinity working conditions by using the composite electric field control mechanism 2 to adjust the magnitude and polarity of the potential, so as to achieve the best performance.

[0071] 2. Salt tolerance test

[0072] After each evaporation performance experiment, the morphology of salt crystal precipitation on the surface of evaporation layer 13 was recorded. The surface temperature during the operation was monitored by a thermal imager. Figure 8 As shown.

[0073] Under electric fields of varying intensities and polarities, the temperature on the surface of evaporation layer 13 tends to stabilize as the steam production process proceeds. When operating in a 5 wt.% sodium chloride solution, even without an electric field, the salt crystal precipitation on the surface of evaporation layer 13 is negligible, and the electric field's improvement on the salt resistance of evaporation layer 13 is not significant. However, when the sodium chloride solution concentration increases to 10 wt.% and 15 wt.%, the amount of salt crystal precipitation is significantly weakened by the electric field and almost completely removed by the high-potential electric field. Under each electric field condition, almost no salt crystal precipitation occurs on the surface of evaporation layer 13 when operating in a 10 wt.% sodium chloride solution, even less than when operating in a 5 wt.% sodium chloride solution. When the system operates in a 15 wt.% sodium chloride solution with the electric field activated, the salt crystal precipitation on the surface of evaporation layer 13 is significantly less than when there is no electric field. This is because the migration rates of chloride and sodium ions change under the influence of the electric field, leading to local concentration variations and affecting salt crystal precipitation. Figure 8 As shown, the weakening effect of a negative electric field on the salt crystal precipitation process is stronger than that of a positive electric field. However, this weakening effect has limitations. When the concentration of the sodium chloride solution reaches 20 wt.%, the electric fields formed by ±2 kV, ±4 kV, and ±6 kV potentials can only slightly reduce the salt crystal precipitation on the surface of evaporation layer 13. Under this concentration condition, electric fields of ±8 kV and ±10 kV can significantly reduce the salt crystal precipitation on the surface of evaporation layer 13 and adjust the morphology of the salt crystal precipitation. Considering the distribution of electric field intensity, the amount of salt crystal precipitation is smaller in areas with high electric field intensity and larger in areas with low electric field intensity, meaning that salt crystals are more difficult to precipitate on the surface of evaporation layer 13 near the electrode. Therefore, the electric field can not only reduce the salt crystal precipitation on the surface of evaporation layer 13, but also significantly improve the evaporation performance of the system and control the precipitation morphology of surface salt crystals. Therefore, the salt crystal precipitation area can be fixed by adjusting the electric field intensity distribution, and the salt crystals precipitated on the surface of evaporation layer 13 also have the potential to be a byproduct of the solar interface seawater desalination system.

[0074] 3. Self-cleaning experiment

[0075] During long-term use of solar-driven interfacial seawater desalination systems, salt crystals will inevitably precipitate on the surface of the evaporation layer 13. Therefore, the system's self-cleaning capability, and the strength of that capability, are crucial to its suitability for large-scale practical application.

[0076] Five grams of sodium chloride crystals were evenly spread on the cleaned surface of evaporation layer 13. Then, an electric field was applied, and the salt crystal removal process of this system under each electric field condition without simulated solar irradiation was observed and recorded. The data are as follows: Figure 9-10 As shown.

[0077] Without an electric field, most of the salt crystals on the surface of evaporation layer 13 are removed after 600 minutes, while the salt crystals in the central region of the surface are almost impossible to remove. However, when the electric field is maintained, the dissolution time of salt crystals on the surface of evaporation layer 13 is significantly shortened, with the dissolution time decreasing further with increasing potential. Specifically, under a -10kV electric field, most salt crystals on the surface of evaporation layer 13 are removed after 60 minutes, with a tendency for preferential removal of salt crystals in the central region. Under this condition, the dissolution time of salt crystals can be reduced from 600 minutes to 260 minutes, a reduction of approximately 56.7%. In a +10kV electric field, the degree of salt crystal removal is similar to that without an electric field until 120 minutes, but the dissolution rate is significantly faster after 120 minutes, with a further increase in the dissolution rate of salt in the central region. In contrast, the removal time of salt crystals on the surface of evaporation layer 13 is significantly reduced under an electric field, thus the electric field can greatly improve the self-cleaning ability of evaporation layer 13. In summary, the system's evaporation performance and salt resistance are significantly enhanced in an electric field, especially in a ±10kV electric field.

[0078] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A bagasse-based solar interfacial evaporation system based on composite electrostatic field control, comprising an interfacial evaporation mechanism and a composite electric field control mechanism, characterized in that: The interface evaporation mechanism includes a buoyancy body, a water conveying layer, and an evaporation layer. The water conveying layer is vertically positioned in the middle of the buoyancy body, with its upper and lower ends extending upwards and downwards respectively. The evaporation layer is horizontally positioned on the top surface of the water conveying layer. The composite electric field control mechanism includes a high-voltage power supply, a first electrode assembly, and a second electrode assembly. The first electrode assembly includes a first grounding electrode, a first wire, a second wire, a first high-voltage electrode, and a third wire. The first grounding electrode is located on the bottom surface of the buoyancy body and is connected to the high-voltage power supply via the first wire. One end of the second wire is connected to the first wire, and the other end is grounded. The first grounding electrode is vertically sleeved on the lower part of the water conveying layer, located on the bottom surface of the buoyancy body. The first high-voltage electrode is a spiral electrode, which is wrapped around the outside of the water conveying layer. The first high-voltage electrode is connected to the high-voltage power supply through the No. 3 wire. The second electrode assembly includes a second grounding electrode, a No. 4 wire, a No. 5 wire, a bracket, a second high-voltage electrode, and a No. 6 wire. The second grounding electrode is sleeved on the water conveying layer, located between the buoyancy body and the evaporation layer, and is connected to the high-voltage power supply through the No. 4 wire. One end of the No. 5 wire is connected to the No. 4 wire, and the other end is grounded. The bracket is located on the top surface of the buoyancy body. The second high-voltage electrode is located on the bracket, and there are multiple second high-voltage electrodes. The second high-voltage electrodes are needle-shaped electrodes, and the multiple second high-voltage electrodes are connected to the high-voltage power supply through the No. 6 wire.

2. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 1, characterized in that: The water conveyance layer is made of bagasse-based hydrogel material.

3. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 2, characterized in that: The bagasse-based hydrogel material is prepared from cellulose-containing bagasse raw materials.

4. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 1, characterized in that: The evaporation layer is made of bagasse-based carbon aerogel material.

5. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 4, characterized in that: The bagasse-based carbon aerogel material is prepared by drying and carbonizing bagasse-based hydrogel material.

6. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 1, characterized in that: The buoyancy body is made of polyethylene foam or polyvinyl chloride foam.

7. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 1, characterized in that: The support structure includes a base, connecting columns, load-bearing rods, and support rods. The base is horizontally positioned on the top surface of the buoyancy body and has a circular ring structure. The connecting columns are vertically positioned on the top surface of the base and are arranged in multiple circumferentially spaced columns. Multiple load-bearing rods are provided, with one end of each rod connected to the others, and the lower part bent downwards and connected to the connecting columns respectively, forming a radial structure. The support rods are sleeved on the outside of the multiple load-bearing rods to improve their stability. The second high-voltage end electrodes are vertically positioned on the upper bottom surface of each load-bearing rod and the inner side of the support rod, with multiple second high-voltage end electrodes evenly spaced on each load-bearing rod and multiple second high-voltage end electrodes evenly spaced circumferentially on the support rod.

8. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 7, characterized in that: The load-bearing rod and support rod are both made of transparent polymer plastic.

9. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 1, characterized in that: The first grounding electrode and the second grounding electrode are made of a conductive material selected from copper, stainless steel, nickel foam, or copper foam; the first high-voltage electrode is made of a conductive material selected from copper, stainless steel, or aluminum, and its surface is covered with PE insulating material.

10. The bagasse-based solar interface evaporation system based on composite electrostatic field control according to claim 1, characterized in that: The voltage output by the high-voltage power supply is -10kV to 10kV.

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