阅读说明：本技术 一种三维球壳状海水光热蒸发器及其制备方法 (Three-dimensional spherical shell-shaped seawater photo-thermal evaporator and preparation method thereof ) 是由 邓大祥 孙玮 曾龙 马启贤 孙健 于 2021-01-15 设计创作，主要内容包括：本发明提供了一种三维球壳状海水光热蒸发器,包括漂浮层、高反射薄膜层、输水通道和三维球壳状光热蒸发结构。漂浮层为多孔泡沫层,其上表面涂镀有高反射薄膜,其中心设置有通孔,内嵌吸水棉棒作为输水通道,吸水棉棒下端伸入海水水体接触,由下部水体向光热蒸发结构供水。三维球壳状光热蒸发结构与吸水棉棒上端相连,其由吸水棉芯球壳状支撑骨架支撑,外包覆一层棉质网纱状结构,并在其上制备亲水性纸基层,并在纸基上均匀蒸镀沉积金或银纳米颗粒光吸收材料层。从而大大增加了光热蒸发面积,保证了光热蒸发水的快速充足供应,实现高效太阳能光热蒸发及海水淡化。且制备过程简单,成本低,易于推广。本发明还提供了上述海水光热蒸发器的制备方法。(The invention provides a three-dimensional spherical shell-shaped seawater photothermal evaporator which comprises a floating layer, a high-reflection film layer, a water delivery channel and a three-dimensional spherical shell-shaped photothermal evaporation structure. The floating layer is a porous foam layer, the upper surface of the floating layer is coated with a high-reflection film, the center of the floating layer is provided with a through hole, a water-absorbing cotton stick is embedded into the floating layer to be used as a water delivery channel, the lower end of the water-absorbing cotton stick extends into the seawater body to be contacted, and water is supplied to the photo-thermal evaporation structure from the lower water body. The three-dimensional spherical shell-shaped photo-thermal evaporation structure is connected with the upper end of the water-absorbing cotton stick, is supported by a spherical shell-shaped supporting framework of a water-absorbing cotton core, is coated with a layer of cotton gauze-shaped structure, is provided with a hydrophilic paper base layer, and is uniformly coated with a gold or silver nanoparticle light-absorbing material layer by evaporation deposition on the paper base. Thereby greatly increasing the photo-thermal evaporation area, ensuring the rapid and sufficient supply of photo-thermal evaporation water and realizing efficient solar photo-thermal evaporation and seawater desalination. And the preparation process is simple, the cost is low, and the popularization is easy. The invention also provides a preparation method of the seawater photo-thermal evaporator.)

1. A three-dimensional spherical shell-shaped seawater photo-thermal evaporator is characterized by comprising: the device comprises a floating layer, a high-reflection film layer, a water delivery channel and a three-dimensional spherical shell-shaped photo-thermal evaporation structure;

the floating layer is fixed or floats above the seawater body, and the high-reflection film layer is coated on the upper surface of the floating layer; a through hole is formed in the center of the floating layer, and a water absorbing cotton stick is embedded in the through hole and used as a water delivery channel; the lower end of the water absorption cotton stick extends into a seawater body, and the upper end of the water absorption cotton stick is connected with the three-dimensional spherical shell-shaped photo-thermal evaporation structure; the three-dimensional spherical shell-shaped photo-thermal evaporation structure and the floating layer have a certain height difference and are not in direct contact;

the cross section material of three-dimensional spherical shell-shaped photothermal evaporation structure comprises from outside to inside in sequence: a light absorbing material layer, a hydrophilic paper substrate layer and a gauze material layer.

2. The three-dimensional spherical shell-shaped seawater photothermal evaporator according to claim 1 wherein the side wall of the floating layer is a cylindrical side wall with a diameter of 40-60mm and a thickness of 20-30 mm; the upper surface of the floating layer is in a conical concave shape, and the concave angle is 30-45 degrees; the through hole is arranged in the center of the conical concave shape, and the diameter of the through hole is 3-6 mm.

3. The three-dimensional spherical shell seawater photothermal evaporator according to claim 1, wherein: the floating layer material is one of polystyrene foam, polyurethane foam, polyethylene foam and silicon-based porous material.

4. The three-dimensional spherical shell seawater photothermal evaporator according to claim 1, wherein: the high-reflection film layer is made of one of metal aluminum and silver.

5. The three-dimensional spherical shell seawater photothermal evaporator according to claim 1, wherein: the upper end and the lower end of the water absorption cotton stick extend out of the through hole of the floating layer by 2-5 cm.

6. The three-dimensional spherical shell-shaped seawater photothermal evaporator according to claim 1, wherein the supporting skeletons of the three-dimensional spherical shell-shaped photothermal evaporation structure are arranged in an equiangular rotation manner with a vertical axis as a reference, the interval arrangement angle is 20-45 °, the supporting skeletons are semicircular, and the diameter of the supporting skeletons is 20-40 mm.

7. The three-dimensional spherical shell seawater photothermal evaporator according to claim 1 wherein the light absorbing material is one of a plasmon-based material and a carbon-based material.

8. The method for preparing the three-dimensional spherical shell-shaped seawater photothermal evaporator according to any one of claims 1 to 7, comprising the steps of:

(1) inserting fine iron wires into the water-absorbing cotton cores, bending the water-absorbing cotton cores into a semicircle, concentrically arranging 8-18 water-absorbing cotton cores in an equiangular rotation manner, and fixing to form a spherical shell-shaped support framework;

(2) coating a layer of cotton gauze-like structure outside the spherical shell-like supporting framework, immersing the spherical shell-like supporting framework into a paper pulp solution to enable paper pulp to be uniformly covered on gauze, taking out the paper pulp, putting the paper pulp into a drying oven with the temperature of 50-100 ℃ for heat preservation for 2-3h, taking out the paper pulp, and cooling the paper pulp to room temperature to obtain a paper-based spherical shell-like substrate;

(3) clamping the prepared paper-based spherical shell-shaped substrate on a substrate platform of a vacuum chamber of an evaporation instrument, putting a proper amount of gold or silver nanoparticles into a crucible, uniformly depositing a gold or silver nanoparticle coating on the surface of a spherical shell structure by adopting an evaporation method, adjusting evaporation current, and controlling the thickness of the deposited coating to be 20-40nm to serve as a spherical shell-shaped surface light absorption material layer; obtaining a three-dimensional spherical shell-shaped photo-thermal evaporation structure;

(4) and connecting the three-dimensional spherical shell-shaped photo-thermal evaporation structure with one end of a water-absorbing cotton stick, and enabling the other end of the water-absorbing cotton stick to penetrate through the through hole of the floating layer and extend into the seawater body to form a water delivery channel, thereby obtaining the complete three-dimensional spherical shell-shaped seawater photo-thermal evaporator.

Technical Field

The invention relates to the field of solar seawater desalination, in particular to a three-dimensional spherical shell-shaped seawater photo-thermal evaporator and a preparation method thereof.

Background

Seawater desalination is an important strategic choice for solving the contradiction between water resource supply and demand in coastal and coastal areas in China, optimizing the water resource structure and guaranteeing the water supply safety. The solar seawater desalination thermal method technology mainly utilizes solar photo-thermal resources to heat seawater, phase change evaporation is carried out on the seawater, and fresh water is obtained through condensation and collection. The seawater desalination technology based on solar photo-thermal evaporation has the advantages of environmental friendliness, no pollution and high energy utilization continuity, is widely applied to the field of seawater desalination, becomes a new way for purifying water and solving the problem of water resource shortage, and particularly provides a feasible solution for small-range domestic water in remote areas, islands and the like.

In a traditional solar photo-thermal evaporation structure, a layer of black substance is generally laid at the bottom of a water pool, sunlight irradiates a water inlet pool, and the black substance absorbs solar energy and is converted into heat energy, so that seawater is evaporated to generate steam. The structure is simple and stable, but the whole water body needs to be heated, the black absorbing material is single in type, and the light absorption rate is not high, so that the photo-thermal conversion efficiency is low, and the actual requirement is difficult to meet.

In recent years, researchers have focused on exploring various optical functional materials in order to obtain high efficiency photothermal conversion efficiency. And a photo-thermal conversion material system mainly comprising a plasmon material, a carbon material and a semiconductor doping material is formed at present, and the light absorption rate of the material is close to an ideal level. The interface evaporation structure prepared from the photo-thermal material is single in form, mainly adopts a two-dimensional plane type photo-thermal structure, is thin in thickness, is usually directly suspended or floats on the surface of a water body to perform photo-thermal conversion, and generates steam through heating a thin layer water nearby, so that the large water body is prevented from being heated, and the photo-thermal evaporation efficiency is improved to a certain extent. However, in the above process, the film structure floating on the interface has a small thickness, so that the heat loss to the lower water body is large, resulting in serious heat loss; in addition, the effective evaporation area of the two-dimensional plane structure is small, and the plane structure has high requirement on the incident angle of sunlight and is easy to cause light reflection and scattering loss, so that the light absorption efficiency and the photo-thermal conversion efficiency are still low.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the three-dimensional spherical shell-shaped seawater photo-thermal evaporator, so that the effective photo-thermal evaporation area is greatly increased, and the requirement of a photo-thermal absorption structure on the light irradiation angle is reduced; and the hydrophilic paper base layer is used as a base material of the photo-thermal absorption layer, so that the transport rate of seawater in the three-dimensional spherical shell structure is greatly increased, and the photo-thermal evaporation performance and the seawater desalination efficiency are remarkably improved.

The invention also aims to provide a preparation method of the three-dimensional spherical shell-shaped seawater photo-thermal evaporator.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a three-dimensional spherical shell seawater photothermal evaporator comprising: the device comprises a floating layer, a high-reflection film layer, a water delivery channel and a three-dimensional spherical shell-shaped photo-thermal evaporation structure;

the floating layer is fixed or floats above the seawater body, and the high-reflection film layer is coated on the upper surface of the floating layer; a through hole is formed in the center of the floating layer, and a water absorbing cotton stick is embedded in the through hole and used as a water delivery channel; the lower end of the water absorption cotton stick extends into a seawater body, and the upper end of the water absorption cotton stick is connected with the three-dimensional spherical shell-shaped photo-thermal evaporation structure; the three-dimensional spherical shell-shaped photo-thermal evaporation structure and the floating layer have a certain height difference and are not in direct contact;

the cross section material of three-dimensional spherical shell-shaped photothermal evaporation structure comprises from outside to inside in sequence: a light absorbing material layer, a hydrophilic paper substrate layer and a gauze material layer.

In a preferred embodiment: the side wall of the floating layer is a cylindrical side wall, the diameter of the side wall is 40-60mm, and the thickness of the side wall is 20-30 mm; the upper surface of the floating layer is in a conical concave shape, and the concave angle is 30-45 degrees; the through hole is arranged in the center of the conical concave shape, and the diameter of the through hole is 3-6 mm.

In a preferred embodiment: the floating layer material is one of polystyrene foam, polyurethane foam, polyethylene foam and silicon-based porous material.

In a preferred embodiment: the high-reflection film layer is made of one of metal aluminum and silver.

In a preferred embodiment: the upper end and the lower end of the water absorption cotton stick extend out of the through hole of the floating layer by 2-5 cm.

In a preferred embodiment: the supporting frameworks of the three-dimensional spherical shell-shaped photo-thermal evaporation structure are arranged in an equiangular rotation mode by taking a vertical shaft as a reference, the interval arrangement angle is 20-45 degrees, the supporting frameworks are semicircular, and the diameter of the supporting frameworks is 20-40 mm.

In a preferred embodiment: the light absorption material is one of a plasmon material and a carbon material.

The invention also provides a preparation method of the three-dimensional spherical shell-shaped seawater photo-thermal evaporator, which comprises the following steps:

(1) inserting fine iron wires into the water-absorbing cotton cores, bending the water-absorbing cotton cores into a semicircle, concentrically arranging 8-18 water-absorbing cotton cores in an equiangular rotation manner, and fixing to form a spherical shell-shaped support framework;

(2) coating a layer of cotton gauze-like structure outside the spherical shell-like supporting framework, immersing the spherical shell-like supporting framework into a paper pulp solution to enable paper pulp to be uniformly covered on gauze, taking out the paper pulp, putting the paper pulp into a drying oven with the temperature of 50-100 ℃ for heat preservation for 2-3h, taking out the paper pulp, and cooling the paper pulp to room temperature to obtain a paper-based spherical shell-like substrate;

(3) clamping the prepared paper-based spherical shell-shaped substrate on a substrate platform of a vacuum chamber of an evaporation instrument, putting a proper amount of gold or silver nanoparticles into a crucible, uniformly depositing a gold or silver nanoparticle coating on the surface of a spherical shell structure by adopting an evaporation method, adjusting evaporation current, and controlling the thickness of the deposited coating to be 20-40nm to serve as a spherical shell-shaped surface light absorption material layer; obtaining a three-dimensional spherical shell-shaped photo-thermal evaporation structure;

(4) and connecting the three-dimensional spherical shell-shaped photo-thermal evaporation structure with one end of a water-absorbing cotton stick, and enabling the other end of the water-absorbing cotton stick to penetrate through the through hole of the floating layer and extend into the seawater body to form a water delivery channel, thereby obtaining the complete three-dimensional spherical shell-shaped seawater photo-thermal evaporator.

Compared with the prior art, the invention has the following remarkable advantages:

(1) compared with a two-dimensional plane photothermal absorption layer, the three-dimensional spherical shell-shaped seawater photothermal evaporator obviously reduces the requirement on the illumination incidence angle, greatly increases the actual photothermal evaporation area, and effectively reduces the heat loss of the photothermal evaporation structure.

(2) The hydrophilic paper base layer is used as a substrate material of the photo-thermal absorption structure, so that the wetting rate of seawater on the surface of the photo-thermal absorption body of the three-dimensional spherical shell is greatly accelerated, and sufficient water supply in the evaporation process of the photo-thermal structure is ensured.

(3) The design of the high-reflection metal film deposited on the concave conical surface on the upper part of the floating layer can reflect illumination to the backlight surface of the spherical shell structure after receiving solar illumination, so that the full heat radiation of the whole structure is realized, and the photo-thermal absorption energy is improved.

(4) The application of the plasmon nanoparticles can fully exert the thermal local performance in photo-thermal conversion, spontaneously inhibit the heating of the whole water body, and the plasmon nanoparticles can absorb solar spectrum in a large range, thereby effectively improving the light absorption efficiency.

Drawings

FIG. 1 is a schematic diagram of the operation of a three-dimensional spherical shell-shaped seawater photothermal evaporator according to the present invention;

FIG. 2 is a schematic diagram of a three-dimensional spherical shell-shaped seawater photothermal evaporator according to the present invention;

FIG. 3 is a schematic view of the shape of the floating layer of the present invention;

FIG. 4 is a cross-sectional view of a three-dimensional spherical shell photothermal absorption structure of the present invention;

1 is a floating layer; 2 is a high reflection film; 3 is a water delivery channel; 4 is a three-dimensional spherical shell-shaped photo-thermal evaporation structure; 41 is a light absorbing material layer; 42 is a hydrophilic paper substrate; 43 is a layer of gauze material; and 44 is a support framework.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise specifically stated or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are used in a broad sense, and for example, "connected" may be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, and a communication between two elements.

With reference to fig. 1 to 4, the present embodiment provides a three-dimensional spherical shell seawater photothermal evaporator, which includes a floating layer 1, a high reflection film layer 2, a water delivery channel 3 and a three-dimensional spherical shell photothermal evaporation structure 4;

the floating layer 1 is fixed or floats above the seawater body and plays a role of heat insulation, the high-reflection film layer 2 is coated on the upper surface of the floating layer 1, a through hole is formed in the center of the floating layer 1, and a water-absorbing cotton rod with certain strength and toughness is embedded in the through hole to serve as a water delivery channel 3. The lower end of the water absorption cotton stick extends into the seawater body, and the upper end of the water absorption cotton stick is connected with the three-dimensional spherical shell-shaped photo-thermal evaporation structure 4. The three-dimensional spherical shell-shaped photo-thermal evaporation structure 4 and the floating layer 1 have a certain height difference and are not in direct contact.

The cross section material of the three-dimensional spherical shell-shaped photothermal evaporation structure sequentially comprises a light absorption material layer 41, a hydrophilic paper base layer 42 and a gauze material layer 43 from outside to inside.

In the embodiment, the side wall of the floating layer 1 is a cylindrical side wall, the diameter d1 of the side wall is 40-60mm, and the thickness h of the side wall is 20-30 mm; the upper surface of the floating layer 1 is in a conical concave shape, so that sunlight can be reflected conveniently, and the concave angle theta is 30-45 degrees; a circular through hole is arranged in the center and penetrates through the upper surface and the lower surface, and the diameter d2 is 3-6 mm;

in this embodiment, the material of the floating layer 1 is one of polystyrene foam, polyurethane foam, polyethylene foam, and silicon-based porous material.

In this embodiment, the high-reflection thin film layer 2 is coated on the concave conical surface on the upper portion of the floating layer 1, and the thin film material is one of metal aluminum and silver.

In the embodiment, the upper end and the lower end of the water absorption cotton stick extend out of the through hole of the floating layer 1 by 2-5 cm.

In this embodiment, the supporting frameworks 44 of the three-dimensional spherical shell-shaped photothermal evaporation structure are arranged in an equiangular rotation manner with a vertical axis as a reference, the interval arrangement angle α is 20 to 45 °, the supporting frameworks 44 are bent into a semicircle, and the diameter of the support framework is 20 to 40 mm;

preferably, the light absorbing material is one of a plasmon material and a carbon-based material.

The embodiment also provides a preparation method of the three-dimensional spherical shell-shaped photothermal evaporation structure 4, which comprises the following steps:

(1) inserting thin iron wires into the water-absorbing cotton cores, bending the water-absorbing cotton cores into a semicircle, concentrically arranging 8-18 cotton core rings with equal size in an equal-angle rotation manner, and fixing to form a spherical shell-shaped supporting framework 44;

(2) coating a layer of cotton gauze material outside the spherical skeleton, immersing the cotton gauze material into a paper pulp solution to enable paper pulp to uniformly cover the gauze spherical surface, taking out the paper pulp, putting the paper pulp into a drying oven to dry, adjusting the temperature of the drying oven to be 50-100 ℃, and the drying time to be 2-3h, taking out the paper pulp, and cooling the paper pulp to room temperature to obtain a paper-based spherical shell-shaped substrate;

(3) cleaning a vacuum evaporation instrument clamp and an object carrying plate by taking a proper amount of absolute ethyl alcohol, fixing the prepared paper-based spherical shell structure on an object carrying table of the evaporation instrument, putting a proper amount of gold or silver particles with the purity of 99.99% into an evaporation crucible as a coating material, starting evaporation equipment to extract vacuum, and then carrying out evaporation treatment on the spherical shell-shaped substrate, wherein the vacuum degree of a control device is 2.5-4x10^-3Pa, the evaporation distance is 30-50cm, the evaporation rate is 0.5-1nm/s, and the evaporation time is 10-20min, namely a layer of gold film can be deposited on the spherical surface of the paper base.

(4) And (3) changing the clamping angle of the spherical shell-shaped substrate, repeating the operation in the step (3) until a layer of gold nanoparticle film with uniform film thickness is evaporated on the surface of the spherical shell structure, and controlling the film thickness to be 20-40nm to obtain a spherical shell-shaped surface light absorption material layer, thereby obtaining the three-dimensional spherical shell-shaped photo-thermal evaporation structure 4.

(5) And connecting the three-dimensional spherical shell-shaped photothermal evaporation structure 4 with one end of a water absorption cotton stick, and enabling the other end of the water absorption cotton stick to penetrate through the through hole of the floating layer and extend into a seawater body to form a water delivery channel, thereby obtaining the complete three-dimensional spherical shell-shaped seawater photothermal evaporator.

The working principle of the three-dimensional spherical shell-shaped seawater photo-thermal evaporator is as follows:

the floating layer 1 floats on the surface of the seawater body, the water delivery channel 3 firstly absorbs the seawater body to the lower part of the three-dimensional spherical shell, the water absorption cotton core which is used as a supporting framework in the three-dimensional spherical shell structure then directionally transports the transported water, and the transported water is quickly diffused to the surface of the whole spherical shell structure by virtue of the hydrophilic property of the paper base layer. When light irradiates on the surface of the spherical shell, the upper spherical shell directly receives the light, the lower spherical shell receives and reflects the sunlight through the high-reflection film on the upper surface of the floating layer and indirectly receives the light, the plasmon nanoparticles on the surface absorb the sunlight to generate local heat through the plasmon effect, and therefore water absorbed by the paper-based material is evaporated to generate steam, the distillation and separation of water and salt in seawater are achieved, and the solar seawater desalination is achieved.

The above description is only a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto, and any person skilled in the art can make insubstantial changes in the technical scope of the present invention within the technical scope of the present invention, and the actions infringe the protection scope of the present invention are included in the present invention.