A solar water desalination device and method

Abstract

The application provides a solar water desalination device and method, which comprises a water collecting cylinder, a plurality of evaporators arranged in the water collecting cylinder, distillation plates arranged between the evaporators, support rods sleeved on the distillation plates and connected with the evaporators, first collecting cylinders arranged on the evaporators, foam rods arranged in the first collecting barrels, evaporation columns sleeved on the foam rods, evaporation membranes arranged at the top of the first collecting cylinders, heat insulation foams arranged below the evaporation membranes, and heating units arranged below the first collecting cylinders; the outer diameter of the first collecting cylinders is smaller than the inner diameter of the water collecting cylinder. The solar water desalination device and method can increase the evaporation surface of the evaporation device, improve the water desalination flux, maximize the utilization of condensation heat, improve the desalination efficiency, and realize continuous water desalination under the condition of no light by means of electric heating assisted evaporation.

Description

Technical Field

[0001] This invention relates to the field of solar-powered seawater desalination, and in particular to a solar-powered desalination device and method. Background Technology

[0002] Solar desalination is an effective measure to achieve zero carbon emissions, but existing solar desalination equipment suffers from low output and high cost due to limitations in solar energy density and the enthalpy of water phase change. Therefore, inventing a high-output, low-cost solar evaporation device is a pressing issue for researchers in this field. Summary of the Invention

[0003] The purpose of this invention is to provide a solar-powered water desalination device and method that increases the evaporation surface area within the device, thereby improving the desalination throughput. It maximizes the utilization of condensation heat, enhancing desalination efficiency. Electric heating-assisted evaporation enables continuous desalination even without sunlight.

[0004] To achieve the above objectives, the present invention provides a solar water desalination device, including a water collection cylinder, a multi-layer evaporator disposed inside the water collection cylinder, a distillation plate disposed between the evaporators, a support rod sleeved on the distillation plate, and the support rod connected to the evaporator;

[0005] The evaporator is provided with a first collecting cylinder, a foam rod is provided inside the first collecting cylinder, an evaporation column is sleeved on the foam rod, an evaporation film is provided at the top of the first collecting cylinder, heat insulation foam is provided below the evaporation film, and a heating unit is provided below the first collecting cylinder.

[0006] The outer diameter of the first collecting cylinder is smaller than the inner diameter of the water collecting cylinder.

[0007] Preferably, a top cover is provided above the water collection cylinder, and the top cover is connected to the water collection cylinder.

[0008] Preferably, the outer diameter of the evaporation film and the heat insulation foam is equal to the inner diameter of the first collecting cylinder.

[0009] Preferably, a support plate is provided below the heating unit, and a first opening is provided at the bottom of the first collecting cylinder as the inlet and outlet of the first collecting cylinder, and an outlet is provided on the collecting cylinder.

[0010] Preferably, the distillation plate is inclined.

[0011] Preferably, the support rod is connected to the support plate and the distillation plate, and at least one support rod is provided, as well as at least one foam rod and one evaporation column.

[0012] Preferably, the evaporation column and the evaporation membrane are both made of porous structures containing photothermal materials.

[0013] Preferably, a water storage tank and a water level control tank are provided on one side of the water collection cylinder. The water level control tank is arranged in a multi-level stepped manner, and the water storage tank is higher than all the water level control tanks to form a pressure difference, so that water can automatically flow into the water level control tank.

[0014] Preferably, the water level control tank is equipped with a float valve, the water storage tank is connected to the inlet of the float valve, and the water level control tank is connected to the first opening.

[0015] A solar-powered water desalination method includes two operating modes:

[0016] In the first working mode, under good lighting conditions, sunlight passes through the top cover and shines on the evaporator. The evaporation column and evaporation film inside the evaporator absorb solar energy and convert it into heat energy to drive water evaporation. Water vapor condenses on the surface of the top cover, accumulates and drips into the water collection cylinder below. The condensed desalinated water flows out from the outlet and is used. As water evaporates and condenses inside the top cover, it releases heat, causing the temperature inside the desalination device to rise, which in turn causes the evaporator below the top evaporator, which is not exposed to sunlight, to be heated and evaporated.

[0017] In the second working mode, under poor or no lighting conditions, the heating unit at the bottom of the evaporator is activated and the temperature inside the top cover is controlled to rise, making the temperature inside the top cover significantly higher than the outside temperature. The temperature difference between the inside and outside of the top cover will also drive the evaporation of water on the surface of the evaporation column inside the evaporator, and the water droplets will be collected on the transparent cover or distillation plate, thus obtaining condensate.

[0018] Therefore, this invention employs the aforementioned solar-powered water desalination device and method to increase the evaporation surface area within the desalination device and improve the water desalination throughput. It maximizes the utilization of condensation heat, thereby enhancing desalination efficiency. Electric heating-assisted evaporation enables continuous water desalination even without sunlight. Multi-layered evaporators utilize condensation heat more effectively than single-layered evaporators. In multi-layered evaporators, except for the top layer, the other layers are not exposed to sunlight, and the energy for evaporation comes from condensation heat. The increased total evaporation area from multi-layered evaporators significantly increases the evaporation capacity of a single unit, improving utilization and increasing freshwater production. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a solar-powered water desalination device according to the present invention;

[0020] Figure 2 This is a schematic diagram of an evaporator;

[0021] Figure 3 This is a cross-sectional view of the evaporator;

[0022] Figure 4This is a schematic diagram of the evaporation column and the foam rod;

[0023] Figure 5 This is a schematic diagram of the second embodiment when there are multiple (two) evaporators.

[0024] Figure Labels

[0025] 1. Water collection cylinder; 2. Top cover; 3. Evaporator; 31. First collection cylinder; 32. Evaporation column; 33. Foam rod; 34. Evaporation film; 35. Insulating foam; 36. Support plate; 37. Heating unit; 4. Distillation plate; 5. Support rod; 6. Water outlet; 7. First opening; 8. Water storage tank; 9. Water level control tank. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0028] Example 1

[0029] like Figure 1-4 As shown, a solar-powered water desalination device, when equipped with an evaporator 3, includes a water collection cylinder 1, with the evaporator 3 installed inside the water collection cylinder 1. A first collecting cylinder 31 is installed on the evaporator 3, and the outer diameter of the first collecting cylinder 31 is smaller than the inner diameter of the water collection cylinder 1. This allows the evaporated desalinated water to condense and flow into the space between the water collection cylinder 1 and the first collecting cylinder 31, and then flow out through the water outlet 6 provided in the water collection cylinder 1.

[0030] A top cover 2 is provided above the water collection cylinder 1. The top cover 2 is connected to the water collection cylinder 1, so that the water collection cylinder and the water collection cylinder 1 form a closed environment, and the evaporation and condensation of water take place in the closed space.

[0031] The first collection tank contains a foam rod 33, on which an evaporation column 32 is mounted. At least one foam rod 33 and one evaporation column 32 are provided. When multiple foam rods 33 and evaporation columns 32 are used, they are arranged in an array. The evaporation column 32 has a significant three-dimensional height to obtain a larger evaporation surface area, thereby increasing the evaporation rate. The evaporation column 32 is made of a porous structure containing photothermal materials; it can be carbonized wood, hydrogel rich in photothermal materials, or a 3D-printed photothermal structure. The height of the evaporation column 32 needs to consider water supply capacity and salt resistance.

[0032] An evaporation membrane 34 is provided at the top of the first collecting cylinder 31, and a heat insulation foam 35 is provided below the evaporation membrane 34. The outer diameter of the evaporation membrane 34 and the heat insulation foam 35 are equal to the inner diameter of the first collecting cylinder 31.

[0033] The evaporation column 32 passes through the insulating foam 35 and is immersed in the desalination water at the bottom of the insulating foam 35. The insulating foam 35 is provided with through holes corresponding to the dimensions of the evaporation column 32, and the positions of the evaporation columns 32 are separated and fixed by the through holes on the insulating foam 35.

[0034] The evaporation membrane 34 is also made of a porous structure containing photothermal materials. The material of the evaporation membrane 34 can be the same as that of the evaporation column 32, or it can be a different material. The evaporation membrane 34 has an array of through-hole structures corresponding to the heat-insulating foam 35.

[0035] A heating unit 37 is installed below the first collection cylinder 31. The heating unit 37 is a commonly available heater. The heating unit 37 is located at the bottom of the evaporator 3, enabling electric heating of the evaporator 3 and regulating the internal temperature of the desalination device. Through the heating unit 37, electrically assisted thermal evaporation can be achieved even without external light, thus ensuring uninterrupted water desalination operation of the evaporation device around the clock.

[0036] A support plate 36 is provided below the heating unit 37. A first opening 7 is provided at the bottom of the first collecting cylinder 31 as its inlet and outlet. An inlet / outlet adapter is connected to the first opening 7, and this adapter is connected to a hose. The hose passes through the support plate 36, the collecting cylinder 1, and connects to the water level control tank 9. The side wall of the collecting cylinder 1 has a corresponding number of inlet / outlet adapters as the evaporator 3. These adapters are connected to the inlet / outlet connectors at the bottom of the evaporator 3 via hoses. Water is injected into the evaporator 3 through the first hose.

[0037] A water storage tank 8 and a water level control tank 9 are provided on one side of the water collection cylinder 1. The water level control tank 9 is arranged in a multi-stage stepped manner. The water storage tank 8 is higher than all the water level control tanks 9 to form a pressure difference, so that water can automatically flow into the water level control tank 9.

[0038] The water level control tank 9 is equipped with a float valve, a common on / off water level controller on the market. The inlet of the float valve is connected to the outlet at the bottom of the water storage tank 8. The float valve maintains the water level inside the evaporator 3, allowing for timely replenishment when the water level inside the evaporator 3 decreases due to evaporation. Through water level control, the evaporator can operate continuously.

[0039] Example 2

[0040] like Figure 1-5As shown, a solar-powered water desalination device, when equipped with multiple evaporators 3, includes a water collection cylinder 1 and a top cover 2 positioned above the water collection cylinder 1, forming an internal sealed space where water evaporation and condensation both occur. A water outlet 6 is located at the bottom of the water collection cylinder 1. The desalinated water flows out through the water outlet 6 and is collected for use. The multi-layer evaporators 3 are housed within the top cover 2.

[0041] The evaporator 3 includes an array of evaporation columns 32, each with a significant three-dimensional height to achieve a larger evaporation surface area and thus increase the evaporation rate. The evaporation columns 32 are made of a porous structure containing photothermal materials; they can be carbonized wood, hydrogel rich in photothermal materials, or 3D-printed photothermal structures. The height of the evaporation columns 32 needs to take into account water supply capacity and salt resistance.

[0042] Generally, assuming sufficient water supply and no salt accumulation on the evaporation surface during the evaporation process, the evaporation column 32 of the top-layer evaporator 3 should have the largest possible height to increase the total evaporation surface area of ​​the evaporation column 32. For the lower-layer evaporators 3 (excluding the top layer), since there is only dark evaporation and the evaporation rate is significantly less than that of the top-layer evaporator 3, the evaporation column 32 in the lower-layer evaporator 3 can be set to a greater height than that of the top-layer evaporator 3. The evaporation column 32 is loosely fitted onto the foam rod 33 to ensure the vertical position of the evaporation column 32 in the evaporator 3. The evaporation column 32 passes through the insulating foam 35 and is immersed in the desalination water below the insulating foam 35. The insulating foam 35 is provided with through holes corresponding to the dimensions of the evaporation column 32, and the positions of the evaporation columns 32 are separated and fixed by the through holes on the insulating foam 35. The insulating foam 35 of the top-layer evaporator 3 is provided with an evaporation film 34 to increase the total area of ​​the overall photothermal material, thereby improving the utilization rate of solar energy. The insulation foam 35 of the lower evaporator 3 can be equipped with an evaporation membrane 34 or not.

[0043] The evaporation membrane 34 is also made of a porous structure containing photothermal materials. The material of the evaporation membrane 34 can be the same as that of the evaporation column 32, or a different material can be selected. The evaporation membrane 34 has an array of through-hole structures corresponding to the heat insulation foam 35. When the evaporation column 32 and the evaporation membrane 34 on the surface of the top evaporator 3 are exposed to sunlight, they absorb solar energy and convert it into heat energy to achieve water evaporation. The water vapor generated by water evaporation condenses and accumulates on the inner surface of the top cover 2. When it accumulates into a sufficiently large water droplet, it will slide to the bottom of the top cover 2 and drip into the water collection cylinder 1.

[0044] When water condenses on the inner surface of the top cover 2 within the evaporator, it releases condensation heat, causing the temperature inside the top cover 2 to rise. The lower evaporator 3 utilizes the condensation heat released after the water vapor inside the top cover 2 to perform dark evaporation. A distillation plate 4 is installed between the different layers of evaporators 3 to prevent condensate from the bottom outer surface of the upper evaporator 3 from dripping back into the lower evaporator 3. A heating unit 37 is installed at the bottom of the top evaporator 3, which can electrically heat the evaporator 3 and regulate the internal temperature of the evaporator. The heating unit 37 enables electrically assisted thermal evaporation even in the absence of external light, thus ensuring uninterrupted water desalination operation around the clock.

[0045] Evaporators 3 at different levels are supported by support plates 36, and support plates 36 at different heights are supported by support rods 5. At least one support rod 5 is periodically arranged; in this embodiment, four support rods 5 are evenly arranged inside the evaporator. The bottom of the support rod 5 rests on the inner surface of the water collection cylinder 1. The support rod 5 is configured in a stepped structure, with the first step used to fix the top support plate 36 and the second step used to fix the lower support plate 36. The distillation plates 4 between the evaporators 3 are provided with a number of through holes corresponding to the number and evenly distributed of the support rods 5. The distillation plates 4 are tilted and loosely fitted onto the support rods 5, forming an angle with the horizontal plane. The side wall of the water collection cylinder 1 is provided with at least three holes, the uppermost hole being used for the passage of control lines or electrical wires entering the desalination device.

[0046] A water storage tank 8 and a water level control tank 9 are provided on one side of the water collection cylinder 1. The water level control tank 9 is arranged in a multi-stage stepped manner. The water storage tank 8 is higher than all the water level control tanks 9 to form a pressure difference, so that water can automatically flow into the water level control tank 9.

[0047] The water level control tank 9 is equipped with a float valve (not shown). The float valve is a common on / off water level controller on the market. The inlet of the float valve is connected to the outlet at the bottom of the water storage tank 8. The float valve maintains the water level inside the evaporator 3, and can be replenished in time when the water inside the evaporator 3 decreases due to evaporation. Through water level control, the evaporator 3 can be operated continuously.

[0048] The side wall of the water collection tank 1 is equipped with a corresponding number of inlet and outlet water adapters as the evaporator 3, and these adapters are connected to the outlet water connector inside the water level control tank. The number of water level control tanks is the same as that of the evaporator 3.

[0049] The side wall of the water collection tank 1 is equipped with a corresponding number of inlet and outlet water adapters as the evaporator 3. These adapters are connected to the inlet of the float valve in the water level control tank below. The number of water level control tanks 9 is the same as that of the evaporator 3. The outlet of the water level control tank 9 is connected to the inlet and outlet of the evaporator 9 via a flexible hose.

[0050] The desalinated water is injected into the top-level evaporator 3 through the water level control tank 9 outlet adapter. After desalination, the high-concentration brine remaining in the top-level evaporator 3 flows out through the inlet / outlet adapter. The water level control tank 9 outlet adapter is connected to the inlet / outlet 6 of the lower-level evaporator 3 via a hose. The desalinated water is injected into the lower-level evaporator 3 through the water level control tank 9 outlet adapter. After desalination, the high-concentration brine remaining in the lower-level evaporator 3 flows out through the inlet / outlet adapter.

[0051] A solar-powered water desalination method includes two operating modes:

[0052] In the first working mode, under good lighting conditions, sunlight passes through the top cover 2 and shines on the evaporator 3. The evaporation column 32 and evaporation film 34 inside the evaporator 3 absorb solar energy and convert it into heat energy to drive water evaporation. Water vapor condenses on the surface of the top cover 2, accumulates and drips into the water collection cylinder 1 at the bottom. The condensed desalinated water flows out from the outlet 6 and is used. As water evaporates and condenses inside the top cover 2, it releases heat, causing the temperature inside the desalination device to rise, which in turn causes the evaporator below the top evaporator, which is not exposed to sunlight, to be heated and evaporated.

[0053] In the second working mode, under poor or no lighting conditions, the heating unit 37 at the bottom of the evaporator 3 is activated and controls the temperature inside the top cover 2 to rise, so that the temperature inside the top cover 2 is significantly higher than the outside temperature. There is a temperature difference from the inside to the outside of the top cover 2, which will also drive the water on the surface of the evaporation column 32 inside the evaporator 3 to evaporate and collect into water droplets on the transparent cover or distillation plate 4, thereby obtaining condensate.

[0054] Therefore, this invention employs the aforementioned solar-powered water desalination device and method to increase the evaporation surface area within the desalination device and improve the water desalination flux. It maximizes the utilization of condensation heat, thereby enhancing desalination efficiency. Electric heating-assisted evaporation enables continuous water desalination even without sunlight.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A solar-powered water desalination method, characterized in that, The desalination process is carried out using a solar water desalination device, which includes a water collection cylinder, a multi-layer evaporator inside the water collection cylinder, a distillation plate between the evaporators, a support rod on the distillation plate, the support rod being connected to the evaporator, a water outlet on the water collection cylinder, and a top cover on the top of the water collection cylinder, which is connected to the water collection cylinder. The evaporator is provided with a first collecting cylinder, a foam rod is provided inside the first collecting cylinder, an evaporation column is sleeved on the foam rod, an evaporation film is provided at the top of the first collecting cylinder, heat insulation foam is provided below the evaporation film, and a heating unit is provided below the first collecting cylinder. The outer diameter of the first collecting cylinder is smaller than the inner diameter of the water collecting cylinder; The distillation plate is tilted. A water storage tank and a water level control tank are provided on one side of the water collection cylinder. The water level control tank is arranged in a multi-level stepped manner. The water storage tank is higher than all the water level control tanks to form a pressure difference, so that water can automatically flow into the water level control tank. The solar-powered water desalination method includes two operating modes: In the first working mode, under good lighting conditions, sunlight passes through the top cover and shines on the evaporator. The evaporation column and evaporation film inside the evaporator absorb solar energy and convert it into heat energy to drive water evaporation. Water vapor condenses on the surface of the top cover, accumulates and drips into the water collection cylinder below. The condensed desalinated water flows out from the outlet and is used. As water evaporates and condenses inside the top cover, it releases heat, causing the temperature inside the desalination device to rise, which in turn causes the evaporator below the top evaporator, which is not exposed to sunlight, to be heated and evaporated. In the second working mode, under poor or no lighting conditions, the heating unit at the bottom of the evaporator is activated and the temperature inside the top cover is controlled to rise, making the temperature inside the top cover significantly higher than the outside temperature. This will also drive the water on the surface of the evaporation column inside the evaporator to evaporate and accumulate into water droplets on the top cover or distillation plate, thereby obtaining condensate.

2. The solar water desalination method according to claim 1, characterized in that, The outer diameter of the evaporation film and the heat insulation foam is equal to the inner diameter of the first collecting cylinder.

3. The solar-powered water desalination method according to claim 1, characterized in that, A support plate is provided below the heating unit, and a first opening is provided at the bottom of the first collecting cylinder as the inlet and outlet of the first collecting cylinder.

4. The solar water desalination method according to claim 3, characterized in that, The support rod is connected to the support plate and the distillation plate. At least one support rod is provided, and at least one foam rod and one evaporation column are provided.

5. The solar water desalination method according to claim 1, characterized in that, The evaporation column and evaporation membrane are both made of porous structures containing photothermal materials.

6. The solar water desalination method according to claim 3, characterized in that, The water level control tank is equipped with a float valve, the water storage tank is connected to the inlet of the float valve, and the water level control tank is connected to the first opening.

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