Inverted solar multi-stage evaporation water purifier

Abstract

The embodiment of the present application discloses a kind of inverted solar multistage evaporation water purifier, comprising: multistage evaporator, multistage evaporator outside is provided with shell, the top of multistage evaporator is set to be connected with raw water pool by pipeline at opening, the lower surface of the multistage evaporator is provided with condenser.The multistage evaporator includes the heating disc of bottom layer, and a plurality of evaporation discs are arranged directly above the heating disc.The top of the heating disc and the evaporation disc is provided with hole.The top of the outer side of the heating disc and the evaporation disc is provided with baffle, and the bottom of the outer side of each evaporation disc is provided with sealing drainage cloth;The upper portion of each baffle and the bottom of sealing drainage cloth contact.The edge position of the heating disc and the evaporation disc is also provided with drainage outlet.The embodiment of the present application is high in water production efficiency, with self-cleaning function, frequent maintenance is not needed, energy utilization rate is high, and cost is low.

Description

Technical Field

[0001] This invention belongs to the field of water purification technology and relates to an inverted solar multi-stage evaporation water purifier. Background Technology

[0002] Solar water purification is a potential solution to freshwater shortages and the energy crisis because it uses a sustainable and clean energy source. In recent years, solar water purification technologies have been developed, including enhancing light absorption, desalination, reducing the latent heat of water to increase evaporation, and recovering latent heat to suppress heat loss. Among these, multi-stage solar stills (MSS) have become a promising technology for freshwater supply, wastewater, and brine management due to their zero-carbon characteristics. Multi-stage solar stills not only improve steam generation efficiency by recovering latent heat but also condense the steam, producing freshwater simultaneously. However, current multi-stage solar stills face challenges such as complex structure, low water production per unit area, high investment costs, and a tendency for dissolved substances like salts to concentrate and precipitate, making them unsuitable for long-term continuous operation and unsuitable for waste heat utilization applications requiring long-term operation. Examples include Chinese patents: Publication No. CN116495816A; Announcement No. CN217458892U; Publication No. CN107720863A. Therefore, commercially available multi-stage solar still products have not yet emerged.

[0003] In addition, existing technologies have long payback periods, making them particularly difficult to implement in remote areas with limited funding.

[0004] Increasing energy input density through concentrators is an effective way to reduce equipment costs, but there are no effective means to improve condensation efficiency, latent heat utilization is insufficient, and water production efficiency is still limited, typically below 2.5 L kWh. -1 The daily water production of the evaporative water purifier per unit area does not exceed 40L / m². -2 .

[0005] On the other hand, in existing technologies, ordinary solar water purifiers cannot work at all when the solar radiation power is too low. Due to insufficient driving energy input, the water evaporates too slowly and loses its working ability. Summary of the Invention

[0006] To achieve the above objectives, this invention provides an inverted solar multi-stage evaporation water purifier, which has high water production efficiency, a self-cleaning function that eliminates the need for frequent maintenance, high energy utilization, and low cost.

[0007] The technical solution adopted in this invention is an inverted solar multi-stage evaporation water purifier, comprising: a multi-stage evaporator, an outer shell for the multi-stage evaporator, an opening at the top of the multi-stage evaporator connected to a raw water tank via a pipe, and a concentrator disposed below the multi-stage evaporator.

[0008] Furthermore, the multi-stage evaporator includes a bottom heating plate, and multiple evaporation plates are arranged directly above the heating plate, with the inner wall of the outer shell not in contact with the edge of the evaporation plates.

[0009] Furthermore, the outer shell is conical, and the heating plate and evaporation plate in the multi-stage evaporator are also conical.

[0010] Furthermore, the cone apex angle of the heating plate and evaporation plate is between 30-75°.

[0011] Furthermore, the thickness of the heating plate and the evaporation plate is 0.1-1mm, and the distance between the heating plate and the evaporation plate, as well as between each evaporation plate, is 5-30mm.

[0012] Furthermore, the heating plate and evaporation plate are provided with evaporation cloth on their upper surfaces; the heating plate is provided with a photothermal conversion coating with a thickness of 0.2 to 0.3 mm at its bottom.

[0013] Furthermore, the top of both the heating plate and the evaporation plate is provided with a hole, the opening diameter of which is 5 to 10% of the cone radius of the evaporation plate.

[0014] Furthermore, a baffle is provided on the top of the outer side of the heating plate and the evaporation plate, and a sealing drainage cloth is provided at the bottom of the outer side of each evaporation plate; the upper part of each baffle and the bottom of the sealing drainage cloth are in contact.

[0015] Furthermore, the heating plate and evaporation plate are provided with water outlets at their edges. The water outlets are located on the inner side of the baffle in the vertical direction. The density of the water outlets is controlled at one per 3-10 cm. The diameter of the water outlet is 3-10 mm. The tubular part extending from the lower part of the water outlet is 3-10 mm in length and does not contact the lower layer.

[0016] Furthermore, a water collection tank is provided on the outermost side of the bottom of the outer casing.

[0017] The beneficial effects of the embodiments of the present invention are:

[0018] 1. Improve the water production efficiency of multi-stage solar stills, at 1kW m³ / s. -2 At the given energy input power, the water production efficiency can reach 6.2 L / kWh. Increasing energy utilization can achieve a 4kW / m³ capacity. -2 The above energy input power is still sufficient to effectively condense steam to obtain fresh water, and the energy efficiency has not decreased significantly. This promotes the increase in water production per unit area of ​​multi-stage solar distillers, reaching 6kWm³. -2At the specified energy input power, the water purifier can produce 30L / h of water per square meter, with a daily output exceeding 100L, which is more than 2.5 times the highest daily output achieved by current concentrating solar distillers. Furthermore, it continuously removes concentrated saline wastewater, inhibiting the precipitation of dissolved substances and reducing maintenance costs. However, existing multi-stage evaporation water purification technologies suffer from low energy recycling rates and insufficient interlayer spacing due to limited heat transfer. Under high-power input, the purified water becomes contaminated and salt accumulates, leading to either continuous operation or insufficient condensation efficiency to keep up with the evaporation rate, resulting in steam leakage and significant losses in latent heat recycling and water production. Additionally, in existing multi-stage evaporation water purifier structures, the evaporation layers are completely sealed, causing internal pressure to increase with heating power, which inhibits water evaporation. This invention, through a top opening, allows the entire device to operate within a range of 0–6kW / m². -2 With the energy input power, each layer operates at atmospheric pressure, which improves the water evaporation efficiency of all layers.

[0019] 2. The inverted solar multi-stage evaporation water purifier of this invention can also meet the solar water production needs in low-irradiance areas and cloudy / rainy areas, at 0.4kW / m³. -2 This device operates at low energy input power, enhancing water production capacity under low radiation power. It requires only solar energy, without other external energy inputs or mechanical auxiliary components, resulting in extremely low capital investment. It can meet the high-quality water supply needs of underdeveloped regions and is suitable for industrial application.

[0020] 3. The inverted solar multi-stage evaporation water purifier of this embodiment can produce wastewater with a concentration of more than 20%. Since the concentrated wastewater flows out continuously, it can prevent salt from accumulating. Dissolved salts and other impurities can be continuously carried away and will not accumulate and precipitate on the evaporation plate, thus eliminating the need for frequent cleaning and maintenance.

[0021] 4. In the inverted solar multi-stage evaporation water purifier of this invention, the evaporation plates are stacked from bottom to top, and the outer shell reduces steam loss and increases condensate. The evaporation surface of the internal multi-stage evaporation plates faces upward, which improves the evaporation rate and greatly enhances the overall evaporation efficiency.

[0022] 5. The improved evaporation efficiency makes it possible to input greater heat power. A focusing reflector can be used to supply solar energy from the bottom of the inverted solar multi-stage evaporation water purifier, achieving an energy density of 1 kW / m² of solar radiation per unit area. -2 The power is 4 to 6 times that of the inverted solar multi-stage evaporation water purifier, and the repeated use of latent heat of steam greatly improves the energy-fresh water efficiency of the inverted solar multi-stage evaporation water purifier, and increases the utilization rate of the inverted solar multi-stage evaporation water purifier per unit area. The cost of the condenser lens per unit area is much cheaper than that of the multi-stage evaporator, thus greatly reducing the equipment cost, which is only about 1 / 5 of the cost of the upright structure without the condenser lens.

[0023] 6. The raw water flows from top to bottom, naturally achieved under gravity without the need for other energy consumption. Only concentrated wastewater flows out from the bottom, and the raw water is heated and evaporated multiple times, resulting in high energy utilization. The more natural liquid flow ensures high water supply efficiency, allowing the inverted solar multi-stage evaporation water purifier to operate under high-power input conditions.

[0024] 7. The brine can continuously flow from top to bottom out of the evaporation pan and finally out of the device, carrying away the salt continuously without accumulation or precipitation, ensuring the device can operate stably under high power input conditions. Simultaneously, wastewater only flows out of the device from the bottom layer, maximizing heat retention within the evaporation layer and facilitating efficient energy utilization. Compared to known cavity-type structural designs that avoid salt accumulation (Passive solar desalination towards high efficiency and salt rejection via a reverse-evaporating water layer of millimeters-scale thickness. Nat Water, 2023, 1, 790-799, as in the literature...), this design offers significant advantages. Figure 3 As shown in the figure, it is necessary to adopt the method of drawing out concentrated brine from each layer separately. This device is not only extremely simple in structure, but also consumes about 5 to 8% less energy.

[0025] 8. According to technical and economic calculations, the capital cost of the inverted solar multi-stage evaporation water purifier of the present invention is about RMB 140, which is lower than the capital cost of RMB 170 recommended by the World Bank for obtaining tap water in remote areas. It has strong competitiveness and scalability. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the multi-stage evaporator section in an embodiment of the present invention.

[0029] Figure 3 This is a structural schematic diagram of the baffle position in an embodiment of the present invention.

[0030] Figure 4 This is a flow circulation diagram of raw water, steam, and purified water in an embodiment of the present invention.

[0031] Figure 5 This is a specific flow diagram of the raw water in an embodiment of the present invention.

[0032] Figure 6 This is a specific flow diagram of steam and purified water in an embodiment of the present invention.

[0033] Figure 7 This is a graph showing the ion concentration of seawater before it has been treated by the water purifier of this embodiment of the invention.

[0034] Figure 8 This is a graph showing the ion concentration of seawater after it has been treated by the water purifier according to an embodiment of the present invention.

[0035] Figure 9 This is a schematic diagram of the flow of raw water and purified water at the evaporation pan in an embodiment of the present invention.

[0036] Figure 10 This is a schematic diagram illustrating the design principle of the evaporation plate angle in an embodiment of the present invention. In this diagram, a represents the distribution of the salt to water molar ratio on the evaporation cloth after a certain period of surface moisture evaporation (different colors represent different salt molar ratios, as shown on the left); b represents the distribution of the salt to water molar ratio on the evaporation cloth after a certain period of surface moisture evaporation at different horizontal angles (different colors represent different salt molar ratios, as shown on the left); c represents the change in the total salt to water molar ratio within the evaporation cloth over time after a certain period of surface moisture evaporation; and d represents the change in the salt to water molar ratio on the surface of the evaporation cloth over time after a certain period of surface moisture evaporation.

[0037] Figure 11 This is a state diagram of the evaporation cloth in an existing ordinary multi-stage evaporator, operating continuously for 3.5 hours.

[0038] Figure 12 This is a photograph showing that no salt accumulation occurred after 200 hours of continuous operation when the evaporation cloth of this invention is at a 30-degree angle to the horizontal plane.

[0039] Figure 13 This is a graph showing the conductivity of the purified water produced after 200 hours of continuous operation according to an embodiment of the present invention.

[0040] In the diagram, 1-1, outer shell; 1-2, multi-stage evaporator; 1-3, raw water tank; 1-4, water collection tank; 1-5, wastewater drainage pipe; 1-6, concentrator; 1-7, baffle; 1-8, drainage outlet; 1-9, hole; 1-10, sealing drainage cloth.

[0041] 1-2-1, Heating plate; 1-2-2, Evaporation plate. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] This invention provides an inverted solar-powered multi-stage evaporation water purifier, the structure of which is as follows: Figure 1 As shown:

[0044] It includes a multi-stage evaporator 1-2, and an outer shell 1-1 is provided on the outside of the multi-stage evaporator 1-2. The outer shell 1-1 is conical, narrow at the top and wide at the bottom. The opening at the top of the multi-stage evaporator 1-2 is connected to the raw water tank 1-3 through a pipeline. A concentrator 1-6 is provided at the bottom of the multi-stage evaporator 1-2.

[0045] Furthermore, the outer casing 1-1 is designed to prevent steam leakage and reduce heat loss. The outer casing 1-1 is made of plastic and insulated with foam on the outside. The inner wall of the outer casing 1-1 does not contact the edge of the internal evaporator 1-2-2, leaving a distance of 1-10mm.

[0046] Condensers 1-6 can be condenser lenses with 6x-10x focusing magnification.

[0047] The structure of the multi-stage evaporator 1-2 is as follows Figure 2 As shown: The multi-stage evaporator 1-2 includes a bottom heating plate 1-2-1, and multiple evaporation plates 1-2-2 are arranged directly above the heating plate 1-2-1. Both the heating plate 1-2-1 and the evaporation plate 1-2-2 are conical.

[0048] The apex angle of the cone surface of heating plate 1-2-1 and evaporating plate 1-2-2 is 30-75°. For example... Figure 10 As shown. If the cone apex angle is higher than 75° (i.e. the cone surface is more horizontal), salt will accumulate and precipitate on the surface of the evaporation cloth on evaporation plate 1-2-2; when the cone apex angle is lower than 30°, the capillary transport effect in the evaporation cloth is insufficient to effectively transport low-concentration brine, and the top is prone to drying out, resulting in salt accumulation. The setting of this parameter was discovered through multiple experiments.

[0049] The thickness of both the heating plate 1-2-1 and the evaporation plate 1-2-2 is 0.1-1mm.

[0050] The distance between heating plate 1-2-1 and evaporation plate 1-2-2, as well as between each evaporation plate 1-2-2, is 5-30mm.

[0051] Preferably, the evaporation pan 1-2-2 has 20 layers.

[0052] Optionally, the heating plate 1-2-1 and the evaporating plate 1-2-2 are made of metal, preferably aluminum; the area of ​​the heating plate 1-2-1 and the evaporating plate 1-2-2 is 600 cm². 2 The heating plate 1-2-1 and the evaporator plate 1-2-2 cannot be made of plastic because plastic is not strong enough. If the strength is sufficient, excessive thickness will cause heat transfer to deteriorate.

[0053] The heating plate 1-2-1 and the evaporation plate 1-2-2 are covered with evaporation cloth, so the upper surface of the evaporation plate 1-2-2 serves as the evaporation surface. The evaporation cloth is a commercially available hydrophilic fabric, preferably porous cotton or linen, with a thickness of 1-2 mm.

[0054] The bottom of the heating plate 1-2-1 is equipped with a photothermal conversion coating, which absorbs light and converts it into heat to evaporate moisture on the upper surface. The photothermal conversion coating is obtained by applying and drying commercially available solar thermal coating. The coating is composed of polyacrylic resin mixed with light-absorbing particles such as copper oxide, manganese dioxide, cobalt oxide, chromium oxide, iron oxide, lead sulfide, and nickel sulfide. The photothermal conversion rate of the coating reaches 90-95%. It is applied 3-5 times to achieve a coating thickness of 0.2-0.3 mm, ensuring the light absorption and heat transfer efficiency under high radiation conditions.

[0055] The operating temperature range of the heating plate 1-2-1 is between 30 and 100℃.

[0056] Furthermore, both the heating plate 1-2-1 and the evaporation plate 1-2-2 have holes 1-9 at their tops. The holes 1-9 allow non-condensable water vapor to rise quickly, preventing it from stagnating in this layer. This avoids inhibiting the evaporation of moisture on the evaporation cloth and also reduces the temperature difference between layers to 1-2°C. The opening diameter of the holes 1-9 is 5-10% of the cone radius of the evaporation cloth. Openings that are too large reduce the evaporation area and result in insufficient heat exchange, while openings that are too small are unsuitable for steam transport and limit the evaporation rate.

[0057] like Figure 3 As shown, a baffle 1-7 is provided on the top of the outer side of the heating plate 1-2-1 and the evaporation plate 1-2-2, and a sealing drainage cloth 1-10 is provided at the bottom of the outer side of each evaporation plate 1-2-2; the upper part of each baffle 1-7 is in contact with the bottom of the sealing drainage cloth 1-10.

[0058] As an example, a baffle 1-7 is installed 1 cm away from the bottom of the evaporator 1-2-2 to prevent the raw water from flowing to the bottom edge, so that the raw water can flow smoothly to the next layer from the drain outlet 1-8.

[0059] The baffle 1-7 serves to support the heating plate 1-2-1 and the evaporation plate 1-2-2, and also prevents the raw material water from flowing to the bottom edge and mixing with the condensate, so that the raw material water can flow smoothly to the next layer from the outlet.

[0060] Drainage outlets 1-8 are provided along the edges of the heating plate 1-2-1 and the evaporation plate 1-2-2, allowing brine to flow out. The drainage outlets 1-8 are located on the inner side of the baffle 1-7 in the vertical direction. The density of the drainage outlets is controlled to one every 3-10 cm. If the density is less than 3 cm, the water cannot be absorbed by the evaporation cloth in time; if it is greater than 10 cm, the downward flow of water is too slow to keep up with the evaporation rate under high power conditions. The preferred diameter of the drainage outlet is 3-10 mm. If it is less than 3 mm, the water flow is too slow; if it is greater than 10 mm, it is not conducive to effectively utilizing the area of ​​the evaporation plate 1-2-2 for evaporation. The tubular portion extending from the lower part of the drainage outlet should be 3-10 mm long and not in contact with the lower layer for proper assembly. If it is less than 3 mm, the condensed freshwater will be contaminated; if it is too long, a tight assembly is not possible.

[0061] The sealing and drainage cloth is made of absorbent paper that is not easily compressed or deformed. Using absorbent paper ensures that the liquid moisture transport performance of the bottom layer of absorbent paper remains unchanged even when constructing a multi-stage evaporator 1-2-2 with 30 layers. The sealing and drainage cloth fits tightly against the lower surface of the baffle 1-7, effectively preventing steam leakage from the bottom of the evaporator 1-2-2 and thus preventing it from circulating within the multi-stage evaporator 1-2, thereby fully utilizing its latent heat.

[0062] In the traditional upright structure, heat is transferred from top to bottom through thermal conduction. To achieve efficient heat transfer, the spacing between evaporation layers must be small enough. Generally, the heat transfer efficiency drops significantly when the spacing exceeds 10mm. This means that boiling occurs when high power is input, which contaminates the purified water.

[0063] Compared to the upright structure, this invention utilizes the upward transport of steam, a natural convection process. This convection is more efficient than heat conduction, so changing the distance does not decrease but rather increases heat transfer efficiency. This allows the distance between the evaporator plates 1-2-2 to be increased to 3 cm without a significant drop in heat transfer efficiency, greatly reducing the possibility of water contamination. Furthermore, the upward evaporation process allows for more efficient mass transfer, permitting a higher energy input power.

[0064] The outermost part of the bottom of the outer shell 1-1 is provided with a water collection tank 1-4, and the clean water collected in the water collection tank 1-4 is discharged by the external pipe.

[0065] The concentrated wastewater flowing out of outlets 1-8 is discharged through external wastewater drainage pipes 1-5.

[0066] This invention provides a working process for an inverted solar multi-stage evaporation water purifier, as follows: Figure 4-6 and Figure 9 As shown, it specifically includes:

[0067] Sunlight is reflected to the bottom of the multi-stage evaporator 1-2 by the concentrator 1-6. The heating plate 1-2-1 generates heat and conducts the heat to the evaporation cloth on the upper surface. The water adsorbed and distributed on the evaporation cloth evaporates. The water vapor reaches the upper evaporation plate 1-2-2 and is condensed on its lower surface to form water droplets. It flows down the lower surface to the sealing drainage cloth 1-10, and then through the pores inside the sealing drainage cloth 1-10 to reach the bottom edge of the evaporation plate 1-2-2, where it gathers and drips freely, and is collected and flows out. The latent heat released by steam condensation is released and heats the evaporation plate 1-2-2. When the evaporation plate 1-2-2 is heated, the evaporation cloth on the evaporation plate 1-2-2 allows water to flow to the next layer under gravity. Then, the water in the next layer flows upward through the capillary action of the evaporation cloth and is evenly distributed on the upper surface of the evaporation plate 1-2-2. As the water evaporates, the salinity and density of the water increase, which is higher than the density of the inlet water at the bottom of the evaporation plate 1-2-2, thus causing convection. This causes the high-concentration brine to flow downward, while the feed water continues to move upward, preventing salt from accumulating and crystallizing.

[0068] Water vapor condenses on the lower surface of evaporation pan 1-2-2 to form condensate. Raw water can flow downwards layer by layer, but the purified water will not directly contact the raw water, avoiding secondary pollution. This achieves the separation and removal of salts in the water, yielding condensate as purified water. Very little salt in the raw water enters the water vapor during evaporation. The saline water can continuously flow from top to bottom out of evaporation pan 1-2-2 and finally out of the device, continuously carrying away the salts and preventing them from accumulating and precipitating. This ensures the device can operate continuously and stably under high-power energy input conditions. Wastewater only flows out of the device from the bottom layer, maximizing heat retention within the evaporation layer and facilitating efficient energy utilization.

[0069] Steam flows from bottom to top, and the uncondensed portion is cooled by the outer shell 1-1; purified fresh water is collected in the bottom water collection tank 1-4 and flows out through the outlet. During operation, the heat from the outflowing wastewater and distilled water can be recovered by the raw water through an external heat exchanger, preheating the inlet water and increasing its temperature when it enters the evaporator.

[0070] Example 1

[0071] The inverted solar-powered multi-stage evaporation water purifier of this invention operates under sunlight, with a radiation power of approximately 1000 W / m². -2 At that time, through a 6x focusing lens, the water purifier can produce up to 30L of water per hour. -1 m -2 Daily water production exceeds 100L / m³-2 When seawater is used as the raw water source, the conductivity of the resulting purified water is only 20–30 μS / cm. -1 The levels are far below drinking water requirements. Further compositional analysis of the purified water, conducted by ICP-MS, showed that the major salt ions were effectively removed, such as... Figure 7-8 As shown, the concentrations of sodium, potassium, and magnesium ions all decreased to below 10 ppm, more than two thousand times that of the raw seawater, while the calcium ion concentration was also below 140 ppm, meeting the requirements of the national standard GB5749-2006. A techno-economic analysis of the device shows that the capital cost of this embodiment is approximately RMB 140.

[0072] Figure 12 The photo shows that when the evaporation cloth of this invention is at a 30-degree angle to the horizontal plane, it has been working continuously for 200 hours without salt accumulation, confirming that it does not affect work efficiency.

[0073] Figure 13 The figure shows that after 200 hours of continuous operation, the conductivity of the produced water is far below the drinking water standard and no pollution has occurred.

[0074] Example 2

[0075] The inverted solar multi-stage evaporation water purifier of this invention treats high-hardness water with a calcium hardness of 180 ppm. A commercially available scale inhibitor, HT-521, is added to the raw water at a ratio of 5-200 mg per liter of water. The resulting wastewater has a calcium concentration of 1.5 g / L. After 200 hours of continuous operation, no scaling was observed. The conductivity of the resulting freshwater is 20-30 μS / cm. -1 .

[0076] Example 3

[0077] The heating plate is replaced with a resistance wire heating method, and the concentrator is not used; the rest of the structure is the same as the embodiment described in this article. The heating power is 1000W / m. -2 At that time, the water purifier can produce up to 30L of water per hour. -1 m -2 Water production exceeds 2400 L / m³ in 8 hours. -2 When seawater is used as the raw water source, the conductivity of the resulting purified water is only 20-30 μS / cm. -1 The levels are far below drinking water requirements. This device can serve as a supplementary solution during cloudy or rainy days when sunlight is scarce.

[0078] Example 4

[0079] Concentrators 1-6 with 10x focusing power are used, and the solar radiation power is 400W / m². -2 At the same time, by appropriately reducing the inflow rate of the raw water, the water purifier's output can reach 18L / h.-1 m -2 Water production exceeds 140 L / m³ in 8 hours. -2 When seawater is used as the raw water source, the conductivity of the resulting purified water is only 20–30 μS / cm. -1 This device can be used in applications that address cloudy days, low solar radiation levels, or specific regions.

[0080] Example 5

[0081] Using the structure described in this embodiment, the solar radiation power is 400 W / m². -2 At the same time, using a 6x condenser lens, compared with Example 1, the influent flow rate was reduced by 60%, and the per-unit-time water production rate was 14.4 L / h. -1 m -2 Water production in 8 hours: 115 L / m³ -2 It is evident that simply adjusting the multiplier of concentrators 1-6 cannot achieve the same water production as in Example 4. In contrast, the concentrators 1-6 of this device are completely independent of the multi-stage evaporators 1-2, allowing for convenient and appropriate adjustments based on changes in solar radiation at different times to meet specific usage requirements.

[0082] Example 6

[0083] A positive-position evaporative water purifier that does not use concentrators 1-6 has a multi-stage evaporation structure with the light-absorbing and heating surface facing upwards and the evaporation surface facing downwards. When the positive-position evaporative water purifier reaches 1000W / m... -2 At that time, the water production efficiency reached 4.5L / h. -1 m -2 Total water production in 8 hours: 36 L / h -1 m -2 At a solar radiation power of 400W / m -2 During the first three hours, almost no distilled water was produced; after eight hours of heating, distilled water was only produced in the last five hours. The total water production over eight hours was only 8 L / m³. -2 Example 6 produced significantly less water than Example 5, less than 1 / 10. This was because the temperature of the evaporation layer inside the evaporator was too low, the temperature difference between the layers was too large, the latent heat recycling effect was poor, the energy efficiency decreased, and the total water production was severely reduced.

[0084] In addition, such as Figure 11 As shown, salt buildup occurs after 3.5 hours of continuous operation.

[0085] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. Inverted solar multi-stage evaporation water purifier, including: A multi-stage evaporator (1-2) is provided with an outer shell (1-1) on the outside of the multi-stage evaporator (1-2). The multi-stage evaporator (1-2) is characterized in that the opening at the top of the multi-stage evaporator (1-2) is connected to the raw water tank (1-3) through a pipeline, and a concentrator (1-6) is provided at the bottom of the multi-stage evaporator (1-2). The multi-stage evaporator (1-2) includes a bottom heating plate (1-2-1), and multiple evaporation plates (1-2-2) are arranged directly above the heating plate (1-2-1). The inner wall of the outer shell (1-1) does not contact the edge of the evaporation plate (1-2-2), and the evaporation plates (1-2-2) are stacked from bottom to top. The outer shell (1-1) is conical, and the heating plate (1-2-1) and evaporation plate (1-2-2) in the multi-stage evaporator (1-2) are also conical. The cone apex angle of the conical surface of the heating plate (1-2-1) and evaporation plate (1-2-2) is 30-75°; The distance between the heating plate (1-2-1) and the evaporation plate (1-2-2), as well as between each evaporation plate (1-2-2), is 5-30mm; The top of both the heating plate (1-2-1) and the evaporation plate (1-2-2) is provided with a hole (1-9), and the opening diameter of the hole (1-9) is 5 to 10% of the cone radius of the evaporation plate. A sealing drainage cloth (1-10) is provided at the bottom of the outer side of each evaporation plate (1-2-2). The material of the sealing drainage cloth (1-10) is absorbent paper that is not easily compressed and deformed. By using absorbent paper, the liquid moisture transport performance of the bottom layer of absorbent paper can be maintained even when 30 layers of evaporation plates (1-2-2) are built. Baffles (1-7) are provided at the top of the outer side of the heating plate (1-2-1) and the evaporation plate (1-2-2). The upper part of each baffle (1-7) is in contact with the bottom of the sealing drainage cloth (1-10), which effectively prevents steam from leaking from the bottom of the evaporation plate (1-2-2). The heating plate (1-2-1) and evaporation plate (1-2-2) are also provided with drainage outlets (1-8) at their edges. The drainage outlets (1-8) are located on the inner side of the baffle (1-7) in the vertical direction. The density of drainage outlets (1-8) is controlled at one per 3-10 cm. The diameter of drainage outlets (1-8) is 3-10 mm. The tubular part extending from the lower part of drainage outlets (1-8) is 3-10 mm in length and does not contact the lower layer.

2. The inverted solar multi-stage evaporation water purifier according to claim 1, characterized in that, The thickness of both the heating plate (1-2-1) and the evaporation plate (1-2-2) is 0.1-1mm.

3. The inverted solar multi-stage evaporation water purifier according to claim 1, characterized in that, The upper surfaces of the heating plate (1-2-1) and the evaporation plate (1-2-2) are provided with evaporation cloth; the bottom of the heating plate (1-2-1) is provided with a photothermal conversion coating with a thickness of 0.2-0.3 mm.

4. The inverted solar multi-stage evaporation water purifier according to claim 1, characterized in that, A water collection tank (1-4) is provided on the outermost side of the bottom of the outer shell (1-1).

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