A solar sea water desalination device

Abstract

The application discloses a solar seawater desalination device, which comprises an interfacial evaporation subsystem based on a photothermal conversion process of absorbing solar radiation, a feed liquid transportation subsystem for transporting feed liquid to a photothermal conversion interface, a condensation subsystem for recovering steam latent heat, and a phase change heat storage subsystem for solar heat storage and steam condensation latent heat storage. The device uses the photothermal conversion interface to absorb solar radiation energy, transports the feed liquid to the photothermal conversion interface through the feed liquid transportation subsystem, heats the feed liquid to perform interfacial evaporation, the first phase change heat storage material block in the phase change heat storage subsystem stores steam condensation latent heat and is used for heating the feed liquid, the second phase change heat storage material block stores solar energy in the daytime and inputs heat to the interfacial evaporation subsystem at night, and finally all the evaporated steam is condensed into product fresh water through the condensation subsystem. The device can store the heat of solar energy, and thus realizes interfacial evaporation desalination of seawater at night, and improves the working efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of seawater desalination, in particular to a solar seawater desalination device. BACKGROUND

[0002] Desalination of saltwater is an effective technology to meet the demand for fresh water. From ancient times to the present, seawater desalination technology has been continuously innovated. At present, the main seawater desalination processes include reverse osmosis, membrane distillation and multi-effect distillation, etc. These processes all rely on fossil fuels. The pollution caused by fossil fuels to the environment and the global energy crisis highlight the necessity of using renewable energy in the field of seawater desalination. As a renewable new energy, solar energy has the advantages of being clean, environmentally friendly, sustainable and long-lasting. Applying solar energy to seawater desalination systems to provide energy for the system and then obtain fresh water is an effective way to address freshwater resource shortages, solve environmental problems and achieve sustainable development.

[0003] Solar distillation technology has been used to produce fresh water since ancient times, but most existing solar steam generation systems involve using optical concentrators to heat water, which results in large heat loss due to heating a large amount of water, and the efficiency is very low. Limiting heat to the air / water interface (i.e. the evaporation surface) when seawater evaporates is considered a very promising method that can improve evaporation efficiency and fresh water production. The generation of steam through heat localization on the evaporation surface involves a large amount of light absorption on the surface, photothermal conversion of solar light, heat localization on the evaporation surface and delivery of seawater to the heat localization layer for effective evaporation, and finally condensation of the steam into fresh water, ultimately achieving efficient separation of saltwater. Solar energy is an intermittent energy source, and when there is no sunlight or the intensity of sunlight is weak at night, the solar seawater desalination device will stop working, resulting in low utilization efficiency of solar energy for existing solar interface evaporation technology, which affects the efficiency of seawater desalination. SUMMARY

[0004] The purpose of the present application is to provide a solar seawater desalination device to solve the problems existing in the prior art, which can interface evaporate seawater and store the heat of solar energy, thereby realizing interface evaporation of seawater at night and improving the working efficiency.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] The present application provides a solar seawater desalination device, comprising:

[0007] a housing, one side of which is provided with a liquid inlet, and the housing can store a feed liquid;

[0008] an interface evaporation subsystem for absorbing solar radiation and heating the feed liquid;

[0009] A liquid transporting subsystem for transporting the stored liquid to the light-heat conversion interface;

[0010] A condensing subsystem for condensing the steam generated by the evaporation of the liquid at the light-heat conversion interface to form fresh water;

[0011] A phase change heat storage subsystem capable of storing solar heat and latent heat of condensation, and the stored energy is used for heating the liquid at night.

[0012] Optionally, the light-heat conversion interface comprises a first light-heat conversion layer coated on the upper surface of the liquid transporting subsystem, and a transparent cover plate is arranged above the first light-heat conversion layer and fixedly arranged at the top opening of the shell.

[0013] Optionally, the liquid transporting subsystem comprises a water-absorbing substrate, the lower surface of the water-absorbing substrate is in contact with the liquid stored in the shell, and the upper surface of the water-absorbing substrate is provided with the light-heat conversion interface.

[0014] Optionally, the condensing subsystem comprises a condensing plate arranged around the outside of the light-heat conversion interface for condensing the steam to generate fresh water, and the condensing plate is externally connected with a first water outlet capable of transporting the condensed fresh water.

[0015] Optionally, the phase change heat storage subsystem comprises a first phase change heat storage material block and a second phase change heat storage material block, the first phase change heat storage material block is fixedly arranged on the lower side of the condensing subsystem for absorbing and storing the condensation latent heat of the condensing subsystem, the second phase change heat storage material block is arranged around the outside of the first phase change heat storage material block, the upper surface of the second phase change heat storage material block is provided with a second light-heat conversion layer, the second light-heat conversion layer is used for absorbing solar light and converting it into heat, which is then stored in the second phase change heat storage material block, and the lower ends of the first and second phase change heat storage material blocks are in contact with the liquid stored in the shell.

[0016] Optionally, a fresh water collecting groove is arranged on the inner side wall of the upper part of the shell, the fresh water collecting groove is open at the top for collecting the fresh water condensed on the lower surface of the transparent cover plate, and the fresh water collecting groove is externally connected with a second water outlet.

[0017] Optionally, the shell comprises a condensing subsystem shell, the condensing plate is arranged on the condensing subsystem shell, and a fresh water collecting groove is arranged on the inner wall of the condensing subsystem shell and connected with the first water outlet.

[0018] Optionally, the condensing plates have different heights, and the height of the condensing plate near the fresh water collecting groove is lower than that of other positions.

[0019] Optionally, a heat preservation layer is further included, and the heat preservation layer is wrapped outside the shell.

[0020] Optionally, the water absorption base comprises a porous sponge, and the light-heat conversion interface comprises a hydrophobic light-heat conversion coating layer covering the upper surface of the porous sponge.

[0021] The present application has the following technical effects relative to the prior art:

[0022] The present application absorbs solar radiation energy by using an efficient interface evaporation subsystem, transports the liquid to the light-heat conversion interface through a liquid transport subsystem, heats the liquid at the light-heat conversion interface for interface evaporation, stores the latent heat of vapor condensation in the first phase change heat storage material block in the phase change heat storage subsystem, uses the second phase change heat storage material block to store solar energy during the day and input heat to the interface evaporation subsystem at night, and finally condenses all the evaporated steam into product freshwater through the condensation subsystem. The present application has high performance-price ratio, can be organically combined in production scale, has good adaptability, relatively low investment, low water production cost, can be applied to energy shortage and high environmental protection requirement areas such as islands, can be expanded from industrial use to survival on deserted islands and survival at sea, and has strong competitiveness and broad application prospect in the freshwater supply market. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0024] Figure 1 The figure is a structural schematic diagram of the solar seawater desalination device of the present application.

[0025] In the figure, 1 is a transparent cover plate, 2 is a first light-heat conversion layer, 3 is a water absorption base, 4 is a condensation plate, 5 is a first phase change heat storage material block, 6 is a second light-heat conversion layer, 7 is a second phase change heat storage material block, 8 is a first water outlet, 9 is a freshwater collection tank, 10 is a second water outlet, 11 is a heat preservation layer, 12 is a seawater storage area, 13 is a shell, and 14 is a liquid inlet. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0027] The purpose of the present application is to provide a solar seawater desalination device to solve the above-mentioned problems existing in the prior art, which can interface evaporation desalination of seawater, store the heat of solar energy, and realize interface evaporation desalination of seawater at night, thereby improving the working efficiency.

[0028] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0029] Solar energy is an intermittent energy, and the solar seawater desalination device will stop working when there is no sunlight or the sunlight intensity is weak at night, so the coupling application of the heat storage material and the solar seawater desalination device is particularly important. In recent years, the use of phase change materials to store heat (sensible heat and latent heat) has become an important energy storage technology. Phase change heat storage materials have the advantages of large energy storage capacity per unit volume, large variable temperature range, and low cost. The use of phase change heat storage materials depends on their phase change temperature. In the process of heat recovery and storage, the temperature required by the application device must match the phase change temperature. Based on this, the present application designs a solar seawater desalination device, which mainly includes four subsystems. The first is an interface evaporation subsystem based on a high-efficiency solar radiation absorption and light-heat conversion process. The second is a liquid transport subsystem that can transport the liquid to the surface of the light-heat conversion material. The third is a condensation subsystem that can efficiently recover the latent heat of steam. The fourth is a phase change heat storage subsystem that can store solar heat and condensation latent heat of steam. The basic working principle of the system is as follows: high-efficiency light-heat conversion interface is used to absorb solar radiation energy, the liquid is transported to the light-heat conversion interface by the liquid transport subsystem, and the liquid is heated to interface evaporation at the light-heat conversion interface. The first phase change heat storage material block in the phase change heat storage subsystem stores the latent heat of steam condensation for heating the liquid, and the second phase change heat storage material block stores solar energy during the day and inputs heat to the interface evaporation subsystem at night. Finally, all the evaporated steam is condensed into product fresh water by the condensation subsystem.

[0030] In a specific embodiment, as Figure 1As shown, the structure of the present application comprises a large shell 13, one side of which is provided with a liquid inlet 14, and the shell 13 is provided with a seawater storage area 12, which can store the material liquid, i.e. seawater; the light-heat conversion interface comprises a first light-heat conversion layer 2 coated on the upper surface of the material liquid transport subsystem, and a transparent cover plate 1 is arranged above the first light-heat conversion layer 2, which is fixedly arranged at the top opening of the shell 13. The material liquid transport subsystem comprises a water-absorbing substrate 3, the lower surface of which is in contact with the material liquid stored in the shell 13, and the first light-heat conversion layer 2 is arranged on the upper surface of the water-absorbing substrate 3. The condensation subsystem comprises a condensing plate 4, which is annularly arranged outside the first light-heat conversion layer 2, and is used for condensing the vapor to produce fresh water, and the condensing plate 4 is externally connected with a first water outlet 8, which can transport the fresh water produced by condensation. The phase change heat storage subsystem comprises a first phase change heat storage material block 5 and a second phase change heat storage material block 7, the first phase change heat storage material block 5 is fixedly arranged on the lower side of the condensation subsystem, and is used for absorbing and storing the condensation latent heat of the condensation subsystem; the second phase change heat storage material block 7 is annularly arranged outside the first phase change heat storage material block 5, and the upper surface of the second phase change heat storage material block 7 is provided with a second light-heat conversion layer 6, which is used for absorbing the sunlight and converting it into heat, and then transferring it to the second phase change heat storage material block 7 for storage; the lower ends of the first phase change heat storage material block 5 and the second phase change heat storage material block 7 are both in contact with the material liquid stored in the shell 13.

[0031] In operation, the sunlight is transmitted through the transparent cover plate 1 to irradiate on the upper surface of the first and second light-heat conversion layers 2 and 6, the first light-heat conversion layer 2 absorbs the sunlight and converts it into heat, the seawater transported to the first light-heat conversion layer 2 through the water-absorbing base 3 is heated, and the seawater is evaporated to generate high-temperature water vapor, most of the high-temperature water vapor flows to the area where the condensing plate 4 is located (low-temperature area corresponding to low saturated vapor pressure), and is condensed outside the condensing plate 4 and collected, avoiding the influence of a large amount of small droplets generated by the condensation of a large amount of water vapor on the transparent cover plate 1 on the light transmission, so that the sunlight can be fully utilized, the latent heat of condensation is transmitted to the first phase-change heat storage material block 5 through the condensing plate 4, the heat is stored, and when there is no sunlight or the sunlight intensity is weak, the heat is released to provide heat for the system, ensure the continuous operation of the seawater desalination device, and improve the fresh water production and energy utilization rate; a small part of the water vapor is condensed on the lower side of the transparent cover plate 1 and flows into the fresh water collection tank 9 to be collected, realizing the separation of salt water; at the same time of normal evaporation, the second light-heat conversion layer 6 on the upper side of the second phase-change heat storage material block 7 absorbs the sunlight and converts it into heat, which is transmitted to the second phase-change heat storage material block 7 and stored, and when there is no sunlight or the sunlight intensity is weak, the heat is released to provide heat for the system, ensure the continuous operation of the seawater desalination device, and improve the fresh water production and energy utilization rate. The heat stored by the phase-change heat storage material can be released when there is no sunlight or the sunlight intensity is weak to provide heat for the system, ensure the continuous operation of the seawater desalination device, and improve the fresh water production and energy utilization rate. Compared with the device without using phase change, the fresh water production can be theoretically improved by at least 40%.

[0032] In order to avoid heat loss, the shell 13 is coated with a heat preservation layer 11 outside. In order to collect the fresh water condensed on the lower surface of the transparent cover plate 1, a fresh water collection tank 9 is arranged on the inner side wall of the upper part of the shell 13, the top of the fresh water collection tank 9 is open, and the fresh water condensed on the lower surface of the transparent cover plate 1 falls into the fresh water collection tank 9. The fresh water collection tank 9 is connected with a second water outlet 10, and the collected fresh water is discharged.

[0033] In order to fix the condensing sub-system, the condensing plate 4 is arranged on the condensing sub-system shell in the shell 13, so that the condensing plate 4 is fixed, and the inner wall of the condensing sub-system shell is also provided with a fresh water collection tank 9, the fresh water collection tank 9 is connected with the first water outlet 8, so as to collect the fresh water condensed on the condensing plate 4. In order to avoid the fresh water on the condensing plate 4 flowing everywhere and being inconvenient to collect, the height of the condensing plate 4 is not the same in this embodiment, and the height of the side of the condensing plate 4 close to the fresh water collection tank 9 is lower than the height of other positions, so that the fresh water is gathered in the fresh water collection tank 9, and the fresh water collection efficiency is improved.

[0034] In a specific embodiment, in order to achieve better water absorption performance and make the seawater transportation in the shell 13 more smooth, the water absorption substrate 3 is a porous sponge, which preferably comprises polyvinyl alcohol sponge, melamine sponge or polyurethane sponge, more preferably polyvinyl alcohol sponge or polyurethane sponge; the polyurethane sponge is preferably melamine sponge; the porosity of the porous sponge is preferably 80-99%, more preferably 80-90%, and the internal pore size distribution is preferably 40-180 μm, more preferably 60-180 μm. In the embodiment of the present application, the porosity of the polyvinyl alcohol sponge is 80.4%, and the internal pore size distribution is 60-155 μm; the porosity of the melamine sponge is 98.8%, and the internal pore size distribution is 60-180 μm. The present application does not have special limitations on the source of the porous sponge, and the porous sponge from a source known in the art can be used. The light-heat conversion interface comprises a hydrophobic light-heat conversion coating covering the upper surface of the porous sponge, and the hydrophobic light-heat conversion coating comprises a film formed by a hydrophobic polymer and light-heat conversion substances dispersed in the film; the light-heat conversion substances comprise one or more of multi-walled carbon nanotubes, nano-graphite powder, polydopamine, graphene and polypyrrole; the diameter of the multi-walled carbon nanotube is preferably 3-15 nm; and the length is preferably 15-30 μm. The present application does not have special limitations on the wall thickness of the multi-walled carbon nanotube, and the multi-walled carbon nanotube with a wall thickness known in the art can be used.

[0035] The hydrophobic polymer preferably comprises one or more of polydimethylsiloxane, polystyrene, polytetrafluoroethylene, polyvinyl butyral, polypropylene, polyether sulfone, polyvinylidene fluoride, polyurethane and polyvinylidene fluoride-hexafluoropropylene, more preferably polydimethylsiloxane; when the hydrophobic polymer is one of the above, the present application does not have special limitations on the ratio of different types of hydrophobic polymers, and any ratio can be used. In the present application, the mass ratio of the light-heat conversion substance and the hydrophobic polymer is preferably 0.5-3:1, more preferably 1-2:1. In the present application, the thickness of the hydrophobic light-heat conversion coating is preferably 0.5-5 mm, more preferably 1 mm.

[0036] In the description of the present application, it should be noted that the terms "center", "top", "bottom", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0037] The principles and implementation manners of the present application are described by using specific examples in the present application, and the above examples are only used for helping to understand the method of the present application and its core idea; meanwhile, for the general technical personnel in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed. In conclusion, the content of the present specification should not be understood as the limitation of the present application.

Claims

1. A solar sea water desalination device, characterized by, The application relates to a solar energy water production device, which comprises the following parts: a shell, one side of which is provided with a liquid inlet, the shell being capable of storing liquid, and a freshwater collection groove being arranged on the inner side wall of the upper part of the shell; an interface evaporation subsystem for absorbing solar radiation energy and heating the liquid; a liquid transport subsystem for transporting the stored liquid to a light-heat conversion interface; a condensation subsystem for condensing the steam generated by the evaporation of the liquid at the light-heat conversion interface to form freshwater; a phase change heat storage subsystem capable of storing solar energy and latent heat of steam condensation, and the stored energy being used for heating the liquid at night; the condensation subsystem comprises a condensation plate arranged around the outer side of the light-heat conversion interface and used for condensing the steam to generate freshwater, and the condensation plate is externally connected with a first water outlet capable of transporting the condensed freshwater; the phase change heat storage subsystem comprises a first phase change heat storage material block and a second phase change heat storage material block, the first phase change heat storage material block is fixedly arranged on the lower side of the condensation subsystem and used for absorbing and storing the condensation latent heat of the condensation subsystem; the second phase change heat storage material block is arranged around the outer side of the first phase change heat storage material block, and the upper surface of the second phase change heat storage material block is provided with a second light-heat conversion layer used for absorbing the sunlight and converting the sunlight into heat and then storing the heat in the second phase change heat storage material block; the lower ends of the first phase change heat storage material block and the second phase change heat storage material block are in contact with the liquid stored in the shell.

2. The solar seawater desalination device of claim 1, wherein, The light-heat conversion interface comprises a first light-heat conversion layer coated on the upper surface of the liquid transport subsystem, and a transparent cover plate is arranged above the first light-heat conversion layer and fixedly arranged at the top opening of the shell.

3. The solar desalination device of claim 1, wherein, The liquid transport subsystem comprises a water-absorbing substrate, the lower surface of the water-absorbing substrate is in contact with the liquid stored in the shell, and the upper surface of the water-absorbing substrate is provided with the light-heat conversion interface.

4. The solar seawater desalination device of claim 2, wherein, The freshwater collection groove is provided with a top opening for collecting the condensed freshwater on the lower surface of the transparent cover plate; and the freshwater collection groove is externally connected with a second water outlet.

5. The solar desalination device of claim 1, wherein, The shell comprises a condensation subsystem shell, the condensation plate is arranged on the condensation subsystem shell, the inner wall of the condensation subsystem shell is provided with the freshwater collection groove, and the freshwater collection groove is connected with the first water outlet.

6. The solar seawater desalination device of claim 5, wherein, The condensation plates have different heights, and the height of the side of the condensation plate close to the freshwater collection groove is lower than the height of other positions.

7. The solar desalination device of claim 1, wherein, The device further comprises an insulation layer wrapped on the outer part of the shell.

8. The solar desalination device of claim 3, wherein, The water-absorbing substrate comprises a porous sponge, and the light-heat conversion interface comprises a hydrophobic light-heat conversion coating layer coated on the upper surface of the porous sponge.

Images