WO2018196351A1 - Novel device for photothermal evaporation of sea water by solar energy - Google Patents

Abstract

A novel device for photothermal evaporation of sea water by solar energy, comprising water tanks (1) on two sides, a hydrophilic photothermal conversion fabric (2) and a concentrated solution collection tank (3). The two sides of the hydrophilic photothermal conversion fabric (2) are respectively laid on the water tanks (1) at the two sides, and the two ends of the hydrophilic photothermal conversion fabric (2) are respectively placed in the water tanks (1) on two sides and immersed below the sea water surface. The hydrophilic photothermal conversion fabric (2) between the water tanks (1) on two sides is in a concave arc shape; the middle part of the hydrophilic photothermal conversion fabric (2) is a photothermal conversion area containing photothermal conversion materials; and the concentrated solution collection tank (3) is correspondingly arranged below the lowest point of the arc in the middle of the hydrophilic photothermal conversion fabric (2). The present invention employs solar energy resources to efficiently evaporate sea water, which reduces costs, improves evaporation efficiency of seawater, and avoids salt precipitation in seawater.

Description

Novel solar photothermal seawater evaporation device Technical field

The utility model belongs to the technical field of seawater evaporation, in particular to a novel solar thermal seawater evaporation device.

Background technique

Seawater accounts for more than 70% of the Earth's surface and is one of the most abundant resources on Earth. However, compared with abundant sea water resources, fresh water on the earth only accounts for 2.8% of all water resources, and 68.69% of fresh water is stored in permanent glaciers in the earth's poles, plateaus and snow-capped mountains. Freshwater shortage is recognized in the world. One of the most serious challenges. The most ideal way to overcome this problem is to use desalination of seawater to produce fresh water. To achieve this goal, various seawater desalination technologies have been developed, including seawater distillation, electrodialysis, and reverse osmosis filtration technologies. Most of these methods require direct or indirect consumption of large amounts of fossil energy, which increases costs and creates an environmental burden. The use of solar energy for seawater distillation can get rid of the consumption of fossil energy in the desalination process, attracting great attention.

As early as two thousand years ago, the ancients used direct sunlight to illuminate seawater to make salt. With this method, sunlight warms the seawater to accelerate the evaporation rate. However, in this case, the sunlight will uniformize all the seawater at a certain thickness. Heating, sea water temperature is not obvious, the effect is poor. In order to improve the utilization of sunlight and accelerate the evaporation rate of seawater, people use photothermal nanomaterials to combine with matrix materials to prepare a photothermal conversion layer, which is laid flat on the surface of seawater. The device diagram is shown in Figure 1. This method can efficiently convert sunlight into heat and concentrate on the surface of seawater. The relatively concentrated heat can effectively increase the surface temperature of the light-to-heat conversion layer and greatly increase the evaporation rate of seawater. However, the heat-generating layer of this method has a large area of contact with the surface of the seawater, and the generated heat is inevitably lost to the seawater, thereby reducing the utilization of solar energy; in addition, this method causes the salt in the seawater to be The surface of the heat generating layer is deposited to cover the light receiving surface and block the void, thereby causing the photothermal conversion layer to fail.

Therefore, it is necessary to develop a seawater evaporation device to prevent heat from being dissipated into the seawater, and at the same time, it is possible to take away the salt precipitated in the seawater.

Summary of the invention

The technical problem to be solved by the utility model is to provide a novel solar thermal seawater evaporation device, which utilizes solar energy resources to realize high-efficiency evaporation of seawater, reduce cost, improve seawater evaporation efficiency, and avoid salt conversion in seawater to reduce solar energy conversion efficiency.

The technical solution adopted by the utility model to solve the technical problem thereof is to provide a novel solar photothermal seawater evaporation device, which comprises a water tank on both sides, a hydrophilic photothermal conversion fabric and a concentrate collection box, and the hydrophilic photothermal conversion Fabric sides They are respectively laid on the water tanks on both sides, and the two ends of the hydrophilic photothermal conversion fabric are respectively placed in the water tanks on both sides and immersed below the sea surface, and the hydrophilic light-heat conversion fabric between the water tanks on both sides is under a concave arc shape, wherein the middle portion of the hydrophilic photothermal conversion fabric is a photothermal conversion region containing a photothermal conversion material, and the concentrate collection box is disposed below the lowest point of the central arc of the hydrophilic photothermal conversion fabric. .

The height difference h ₁ between the high point of the two ends of the hydrophilic photothermal conversion fabric and the intermediate low point is 0 < h ₁ ≤ ₁₀ m.

The height difference of the sea surface in the water tanks on both sides is greater than or equal to 0 and less than or equal to 10 m.

The height difference h ₂ between the sea surface and the high point of the hydrophilic photothermal conversion fabric is 0 < h ₂ ≤ ₁₀ m.

The hydrophilic photothermal conversion fabric is composed of a hydrophilic fabric substrate and a photothermal conversion material.

The hydrophilic fabric substrate is a knitted fabric, a woven fabric or a non-woven fabric made of one or more of natural fibers, regenerated cellulose fibers, and chemical fibers.

The natural fiber is cotton, hemp, silk, wool or pulp, and the regenerated cellulose fiber is Lyocell fiber, Modal fiber, bamboo fiber, chitin fiber or copper ammonia fiber, and the chemical fiber is polyester, spandex, acrylic fiber, Nylon, vinylon or polypropylene.

The non-woven fabric is a nonwoven fabric.

The photothermal conversion material includes one or more of metal nanoparticles, carbon nano materials, organic photothermal materials, and semiconductor photothermal nano materials.

The metal nanoparticles are gold nanoparticles, palladium nanoparticles, platinum nanoparticles or aluminum nanoparticles, and the carbon nano materials are carbon black, carbon powder, porous carbon, carbon nanotubes, graphene or fullerenes. The organic photothermal material is polypyrrole, polythiophene, polyaniline, polydopamine, phthalocyanine green or Prussian blue, and the semiconductor photothermal nano material is copper sulfide, copper selenide, barium sulfide, barium selenide, tungsten sulfide, Tungsten oxide, titanium dioxide, titanium trioxide, iron sulfide or molybdenum sulfide.

Beneficial effect

(1) Using solar energy to heat seawater and promote seawater evaporation, no additional energy consumption is required, and the generated steam can be condensed to obtain distilled water with extremely low salt content, and the concentrated concentrated seawater can be used for further seawater salt making process. Conducive to improving salt production efficiency and reducing costs;

(2) Water vapor can be generated from the upper and lower surfaces of the photothermal conversion fabric, increasing the area generated by the steam and improving the steam generation efficiency;

(3) Compared with the direct transfer of the photothermal conversion fabric to the surface of the seawater for seawater evaporation, the present invention can The heat produced by Yangneng concentrates on heating the seawater on the surface of the fabric, avoiding the longitudinal loss of heat to the interior of the seawater, and greatly improving the evaporation efficiency of seawater;

(4) The utility model relates to a continuous solar water evaporation-concentration synergistic generating device, which can remove residual salt on the surface of the fabric while evaporating seawater, so that the surface of the photothermal conversion fabric does not precipitate a salt cover layer and affects the solar energy. The utilization efficiency reduces the evaporation performance.

DRAWINGS

1 is a schematic structural view of a conventional solar thermal seawater evaporation device.

Figure 2 is a schematic view of the structure of the present invention.

3 is a comparison diagram of accumulated steam generation amount of the utility model and the conventional solar thermal seawater evaporation device in the first embodiment.

Figure 4 is a graph showing the evaporation rate of seawater at different times in the present embodiment in Example 2.

Fig. 5 is a graph showing the cumulative steam generation amount of the present invention in the second embodiment.

detailed description

The present invention is further illustrated below in conjunction with specific embodiments. It is to be understood that the examples are not intended to limit the scope of the invention. In addition, it should be understood that various modifications and changes may be made by those skilled in the art in the form of the present invention.

A novel solar thermal seawater evaporation device as shown in FIG. 2 includes a water tank on both sides, a hydrophilic photothermal conversion fabric 2, and a concentrate collection tank 3.

The two sides of the hydrophilic photothermal conversion fabric 2 are respectively laid on the water tanks 1 on both sides, and the two ends of the hydrophilic photothermal conversion fabric 2 are respectively placed in the water tanks 1 on both sides and submerged below the sea surface, and the water tanks on both sides 1 The height difference between the sea surface and the height of both ends of the hydrophilic photothermal conversion fabric ₂ is 0 < h ₂ ≤ 10 m. The hydrophilic photothermal conversion fabric 2 between the water tanks 1 on both sides has a concave arc shape, and the height difference h ₁ between the high point and the middle low point of the hydrophilic photothermal conversion fabric 2 is 0 < h ₁ ≤ 10m.

The hydrophilic photothermal conversion fabric 2 is composed of a hydrophilic fabric substrate and a photothermal conversion material. The hydrophilic fabric substrate is a knitted fabric, a woven fabric or a non-woven fabric (such as a non-woven fabric) made of one or more of natural fibers, regenerated cellulose fibers and chemical fibers, and the natural fibers are cotton, hemp and silk. , hair or pulp, etc., regenerated cellulose fiber is Lyocell fiber, Modal fiber, bamboo fiber, chitin fiber or copper ammonia fiber, chemical fiber is polyester, spandex, acrylic, nylon, vinylon or polypropylene. Photothermal conversion materials include metal nanoparticles, carbon nanomaterials, organic photothermal materials, and semiconductor light One or more of the thermal nanomaterials. The metal nanoparticles are gold nanoparticles, palladium nanoparticles, platinum nanoparticles or aluminum nanoparticles, carbon nano materials are carbon black, carbon powder, porous carbon, carbon nanotubes, graphene or fullerenes, and organic photothermal materials are poly Pyrrole, polythiophene, polyaniline, polydopamine, phthalocyanine green or Prussian blue, semiconductor photothermal nanomaterials are copper sulfide, copper selenide, antimony sulfide, antimony selenide, tungsten sulfide, tungsten oxide, titanium dioxide, trioxide Titanium, iron sulfide or molybdenum sulfide.

The middle portion of the hydrophilic photothermal conversion fabric 2 is a photothermal conversion region containing a photothermal conversion material, and the concentrate collection box 3 is disposed below the lowest point of the central arc of the hydrophilic photothermal conversion fabric 2.

Example 1

Add 45 mL of water, 5 mL of concentrated hydrochloric acid (HCl mass percentage: ～36%) and 1.141 g of ammonium persulfate in a beaker, and add 1 mL of a mixed solution of aniline and ethanol (volume ratio 1:1) under magnetic stirring, and stir. After 30 s, it was placed in a refrigerator at 6 ° C for 24 h, then the reaction solution was filtered under reduced pressure and washed with a sand core funnel and a 0.45 μm polyvinylidene fluoride filter, and the product polyaniline was redispersed into ethanol to prepare 8 mg/mL ethanol dispersion.

Take 10×20cm cotton cloth, add 5mL polyaniline ethanol dispersion to the cotton cloth multiple times, and control the dropping area to the 10×10cm part of the cotton cloth center, and dry it in an oven at 60°C. A polyaniline/cotton photothermal conversion fabric was obtained.

The obtained photothermal conversion fabric is fixed on the ports of two square polyethylene plastic boxes by clips, and the edge portion of the fabric naturally hangs down and contacts the seawater in the water box, and the height difference between the center of the fabric and the plastic box port is 1 cm, plastic The seawater level in the box is 2mm lower than the plastic box port. After the seawater is completely wetted by the light-heat conversion fabric, the fabric is irradiated with a xenon lamp simulator with an average light intensity of 0.16 W/cm ² and a circular spot diameter of about 10 cm. The situation is shown in Figure 3.

After the seawater evaporates, no significant mineral salt particles are precipitated on the surface of the photothermal conversion fabric. For comparison, the same photothermal conversion cloth was placed on a sea surface of 10×10 cm. Under the same xenon lamp simulator, the cumulative generation of water vapor is shown in Fig. 3. The steam generation speed of the device can be seen from the figure. About three times the traditional way.

Example 2

An ethanol dispersion of 8 mg/mL of polyaniline was prepared as in Example 1. Take 600mL of dispersion, drop it repeatedly in the middle part of 80×240cm cotton cloth, control the dropping area to the 80×140cm part of the cotton cloth center, and blow it dry with hair dryer, fix the two ends of the cotton cloth with clips. Two square polyethylene sinks (sink opening size: 80×15cm) port, the height difference between the center of the fabric and the sink port is 10cm, and the water surface in the water tank is 1cm lower than the plastic box port. After the water is completely wetted by the light heat conversion fabric The device is placed under the sunlight to record the change in the quality of the water evaporation. The sunlight intensity and the corresponding water evaporation rate at different times are shown in Figure 4. The device is accumulated in one day. The quality of the generated steam is shown in Figure 5.

Claims (10)

A novel solar photothermal seawater evaporation device comprises a water tank on both sides (1), a hydrophilic photothermal conversion fabric (2) and a concentrate collection tank (3), characterized in that: the hydrophilic photothermal conversion fabric (2) The two sides are respectively laid on the water tanks (1) on both sides, and the two ends of the hydrophilic photothermal conversion fabric (2) are respectively placed in the water tanks (1) on both sides and submerged below the sea surface, two The hydrophilic photothermal conversion fabric (2) between the side water tanks (1) has a concave curved shape, and the middle portion of the hydrophilic photothermal conversion fabric (2) is a photothermal conversion region containing a photothermal conversion material. The concentrate collection tank (3) is disposed below the lowest point of the arc shape in the middle of the hydrophilic photothermal conversion fabric (2). A novel solar thermal seawater evaporation device according to claim 1, wherein a height difference h ₁ between the high point of the two ends of the hydrophilic photothermal conversion fabric (2) and the intermediate low point is 0 < h ₁ ≤ 10m. A novel solar thermal seawater evaporation device according to claim 1, characterized in that the difference in sea surface height between the two sides of the water tank (1) is greater than or equal to 0 and less than or equal to 10 m. A novel solar thermal seawater evaporation device according to claim 1, wherein the height difference h ₂ between the sea surface and the high point of the hydrophilic photothermal conversion fabric (2) is 0 < h ₂ ≤10m. A novel solar thermal seawater evaporation apparatus according to claim 1, wherein said hydrophilic photothermal conversion fabric (2) is composed of a hydrophilic fabric substrate and a photothermal conversion material. A novel solar thermal seawater evaporation device according to claim 5, wherein the hydrophilic fabric substrate is knitted by one or more of natural fibers, regenerated cellulose fibers and chemical fibers. Fabric, woven or non-woven. A novel solar thermal seawater evaporation device according to claim 6, wherein the natural fiber is cotton, hemp, silk, wool or pulp, and the regenerated cellulose fiber is Lyocell fiber, Modal fiber, bamboo. Fiber, chitin fiber or copper ammonia fiber, the chemical fiber is polyester, spandex, acrylic, nylon, vinylon or polypropylene. A novel solar thermal seawater evaporation device according to claim 6, wherein the non-woven fabric is a nonwoven fabric. A novel solar thermal seawater evaporation device according to claim 1 or 7, wherein the photothermal conversion material comprises metal nanoparticles, carbon nano materials, organic photothermal materials and semiconductor photothermal nano materials. One or more. A novel solar thermal seawater evaporation device according to claim 9, wherein the metal nanoparticles are gold nanoparticles, palladium nanoparticles, platinum nanoparticles or aluminum nanoparticles, and the carbon nano materials are carbon Black, carbon powder, porous carbon, carbon nanotubes, graphene or fullerene, the organic photothermal material is polypyrrole, polythiophene, polyaniline, polydopamine, phthalocyanine green or Prussian blue, the semiconductor light Thermal nanomaterial is sulfur Copper, copper selenide, barium sulfide, barium selenide, tungsten sulfide, tungsten oxide, titanium dioxide, titanium oxide, iron sulfide or molybdenum sulfide.

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