CN107178772A - A kind of solar steam generation device of tri compound and its application - Google Patents

Abstract

The invention relates to a ternary composite solar steam generating device and its application. The device includes a water container, a light-to-heat conversion film, a heat insulation board and a water pipeline. The upper part of the water surface or only the lower part is immersed in the water. The light-to-heat conversion film is located above the heat shield or covers the outer surface of the upper part of the heat shield. The water delivery pipeline is a number of capillary tubes inserted into the heat shield. Or contact with light-to-heat conversion film. The advantage is that a heat shield and a capillary are introduced, and the capillary automatically sends water to the light-to-heat conversion film, and the heat shield isolates the high-temperature light-to-heat conversion film from the low-temperature water body, blocking its heat conduction to reduce heat loss, and the light-to-heat conversion generated The effective use of heat is equivalent to improving the efficiency of light-to-heat conversion; its unique and simple structure has high light-to-heat conversion efficiency, and has great commercial value and application prospects in the fields of solar power generation, seawater desalination, and sewage treatment.

Description

A ternary compound solar steam generating device and its application

technical field

The invention relates to the fields of nanotechnology and photothermal conversion materials, in particular to a ternary composite solar steam generating device and its application.

Background technique

In recent years, renewable energy has attracted widespread attention from all walks of life. Solar energy has become one of the focuses of research in the field of renewable energy due to its advantages of abundance, easy availability, and non-pollution. Photothermal conversion materials represented by graphene oxide, gold nanoparticles, etc. can effectively capture solar energy and convert it into heat energy that can be used to heat nanofluids and generate high-temperature steam, which is widely used for solar energy, such as from large-scale It provides possibilities for applications such as solar thermal power generation, seawater desalination and sewage treatment, to small-scale water purification and sterilization systems. Excellent photothermal conversion materials can improve the efficiency of solar energy conversion, thus fundamentally promoting the improvement and upgrading of energy systems and industries.

Carbon-based nanomaterials have a very large specific surface area (2600m ² g ^-1 ) and a large conjugated system, and can synergistically adsorb various functional nanomaterials to form composite/ hybrid materials. On the one hand, carbon-based photothermal conversion materials have obvious absorption (high absorption rate α) for the entire ultraviolet-visible (UV-vis) to near-infrared light region, and the electrons of carbon materials have obvious plasmon resonance effects. At the same time, carbon materials have high chemical and thermal stability, and long-term laser irradiation will not cause performance degradation. Therefore, carbon materials excited by near-infrared light can produce obvious thermal effects, which can rapidly increase the temperature of the surrounding medium. On the other hand, carbon nanomaterials are basically infrared inert (IRinactive), which can greatly reduce the loss of infrared heat radiation (low emissivity ε), and are a class of photothermal conversion materials with excellent performance and broad application prospects.

At present, the basic and applied research of photothermal conversion nanomaterials by scholars at home and abroad is mainly concentrated in the fields of biomedicine such as photothermal therapy and thermal imaging. Photothermal conversion nanomaterials generate thermal effects by absorbing near-infrared light with a wavelength of 700-1400nm, and near-infrared lasers have a very strong ability to penetrate biological tissues, and the light attenuation is particularly small during the penetration process. An important "biological window", so the research on near-infrared laser-driven photothermal therapy technology is quite extensive and in-depth, while the development and application research of photothermal conversion nanomaterials and technologies in the field of solar energy utilization has just started.

Common light-to-heat conversion materials are mainly divided into two types, one is a nanofluid containing metal nanoparticles, carbon materials, and polymer materials, and the other is a locally heated light-to-heat conversion film. Compared with nanofluids, the light-to-heat conversion film can limit the light to the film layer without irradiating the lower water body, thereby reducing the heat dissipation from the water body to the environment and improving the light-to-heat conversion efficiency. However, most of the current light-to-heat conversion films are placed directly on the water surface. Due to the high thermal conductivity of the film material itself, there is still heat loss from the film to the lower water body, which makes the light-to-heat conversion efficiency unable to break through this bottleneck.

Contents of the invention

The invention provides a ternary composite solar steam generating device and its application, aiming to solve the deficiencies in the prior art to a certain extent.

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a ternary composite solar steam generating device, which includes a water container, a light-to-heat conversion film, a heat insulation board and a water pipeline, and the water container is filled with water , the whole of the heat insulation board is located above the water surface or only the lower part is immersed in water, the light-to-heat conversion film is located above the heat insulation board or covers the outer surface of the upper part of the heat insulation board, and the water delivery pipeline includes an insert For the capillaries of the thermal insulation board, the lower openings of the capillaries are immersed in water, and the upper openings of the capillaries are close to or in contact with the light-to-heat conversion film.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Specifically, the water container is a glass container or a transparent plastic container with an open top.

Specifically, the light-to-heat conversion film is a carbon-based light-to-heat conversion film.

Specifically, the carbon-based light-to-heat conversion film is a reduced graphene oxide-based light-to-heat conversion film.

The reduced graphene oxide-based light-to-heat conversion film can be prepared by the following method: the reduced graphene oxide-based light-to-heat conversion film is prepared by the following method: (1) Synthesis of reduced graphene oxide: 200mg graphene oxide and 50mg Ascorbic acid was added to 200ml deionized water, and magnetically stirred for 10 minutes. The above dispersion was placed in a microwave reactor at 200W and 95°C for 10 minutes. Filter and dry the resulting solution to obtain reduced graphene oxide; (2) Preparation of reduced graphene oxide-based light-to-heat conversion film: add 100 mg of shaped filter paper to 100 mL of solvent, and stir magnetically at 100 ° C for 2 hours to obtain cellulose dispersion liquid. Add 60 mg of reduced graphene oxide to the cellulose dispersion, continue to stir for 0.5 hours, vacuum filter to obtain a reshaped fiber film, and vacuum dry at 35°C for 30 minutes to obtain a reduced graphene oxide-based light-to-heat conversion film.

It can be understood that, in addition to the above-mentioned light-to-heat conversion film, it can also be a light-to-heat conversion film obtained by other methods, all of which are applicable to the device provided by the present invention.

Specifically, the heat insulation board is made of foam heat insulation material.

Preferably, the foam insulation material is one or more of foamed polyethylene, expanded polyvinyl chloride, expanded polypropylene and expanded polystyrene, and the heat insulation board is floating above the water surface And its peripheral sidewall abuts against the inner sidewall of the water container. In addition to floating, the heat insulation board can be positioned above the water surface as a whole by clamping with the inner wall of the water container wall or resting on the ring-shaped shelf (the ring-shaped shelf is fixedly connected with the inner wall of the container).

Specifically, the capillary is a glass capillary or a plastic capillary.

Specifically, the thickness of the heat insulation board is 1.5-20 cm. The heat insulating board is disc-shaped, and the thickness refers to the dimension in the vertical direction when it is laid flat.

Specifically, the inner diameter of the capillary is 0.1-2 mm, and the capillary is evenly and vertically densely inserted on the heat shield.

The present invention also provides the application of the above-mentioned ternary composite solar steam generating device, which is applied to solar power generation, seawater desalination or sewage treatment.

Compared with prior art, the beneficial effect of the present invention is:

A new type of solar photothermal conversion steam generation device is provided, which isolates the high-temperature photothermal conversion film (about 50°C) from the low-temperature water body (about 20°C) by introducing a heat shield and a water delivery pipe (capillary), blocking It conducts heat to reduce heat loss, and at the same time, the water delivery device can automatically and continuously supply water to the photothermal conversion film for vaporization; under the synergy of the photothermal conversion film, heat insulation board and water delivery device, sunlight is limited to the surface of the film for use Because of photothermal conversion and steam generation, at the same time, the heat transfer from the photothermal conversion film to the water body below is effectively suppressed, and the heat generated by photothermal conversion is effectively used, which is essentially equivalent to a great improvement in photothermal conversion efficiency; The device has a unique and simple structure, high light-to-heat conversion efficiency, and has great commercial value and application prospects in the fields of solar power generation, seawater desalination, and sewage treatment.

Description of drawings

Fig. 1 is the structural representation of the ternary composite solar steam generating device provided by the present invention;

Fig. 2 is the change situation of the atomic ratio of carbon/oxygen element in the reduced graphene oxide obtained when the amount of reducing agent is different when the reduced graphene oxide-based light-to-heat conversion film is prepared in Examples 3 to 14;

Fig. 3 is the scanning electron micrograph and the atomic force micrograph of the reduced graphene oxide-based light-to-heat transition film prepared in Example 3;

Fig. 4 is the mass loss curve of embodiment 3, 6, 10 corresponding solar steam generating device at the irradiation light intensity of 1kw/m ² ;

Fig. 5 is the light-to-heat conversion efficiency of the corresponding solar steam generating device of embodiment 3, 6, 10 under the irradiation light intensity of 1kw/m ² ;

Fig. 6 is an infrared image of the solar steam generating device corresponding to Example 3 under the irradiation light intensity of 1 kw/m ² .

In the accompanying drawings, the list of parts represented by each label is as follows:

1. Water container; 2. Photothermal conversion film; 3. Heat shield; 4. Capillary.

detailed description

The principles and features of the present invention will be described below in conjunction with the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

Example 1

As shown in Figure 1, the present invention provides a kind of ternary composite solar steam generating device, which includes a water container 1, a light-to-heat conversion film 2, a heat insulation board 3 and a water pipeline, and the water container 1 contains If there is water, only the lower part of the heat insulation board 3 is immersed in the water, and the upper part is above the water surface. The light-to-heat conversion film 2 covers the upper surface of the upper part of the heat insulation board 3. The uniform and dense capillary tubes 4 of the plate 3 , the lower end openings of the capillary tubes 4 are immersed in water, and the upper end openings of the capillary tubes are close to or contact the light-to-heat conversion film 2 .

Specifically, the water container 1 is a glass container with an open top, the light-to-heat conversion film 2 is a reduced graphene oxide-based light-to-heat conversion film, and the heat insulation board 3 is made of foamed polyethylene, foamed polythene Made of vinyl chloride, expanded polypropylene or expanded polystyrene, the heat insulation board 3 floats above the water surface and its peripheral sidewall abuts against the inner sidewall of the water container 1. For example, the heat insulation board is Cylindrical, the height of the cylindrical heat shield is 3-20cm, the water container is a beaker, and the capillary 4 is a glass capillary with an inner diameter of 0.1-2mm.

Example 2

As shown in Figure 1, the present invention provides a kind of ternary composite solar steam generating device, which includes a water container 1, a light-to-heat conversion film 2, a heat insulation board 3 and a water pipeline, and the water container 1 contains If there is water, the heat insulation board 3 is located above the water surface as a whole and the lower surface is separated from the water surface. The light-to-heat conversion film 2 is located above the heat insulation board 3 and the heat insulation board is not in contact with the light-to-heat conversion film. The water delivery pipeline includes The uniform and dense capillary tubes 4 inserted into the heat insulation board 3 , the lower end openings of the capillary tubes 4 are immersed in water, and the upper end openings of the capillary tubes are close to or contact the light-to-heat conversion film 2 . In the above structure, the heat insulation board 3 and the light-to-heat conversion film 2 are fixed by any method that those skilled in the art can think of, such as by bonding or clamping with the inner wall of the water container, or setting them on the inner wall of the water container. A ring-shaped shelf for placing the heat insulation board or light-to-heat conversion film, etc.

Specifically, the water container 1 is a transparent plastic container with an open top, the light-to-heat conversion film 2 is a reduced graphene oxide-based light-to-heat conversion film, and the heat insulation board 3 is made of foamed polyethylene, foamed Made of PVC, expanded polypropylene or expanded polystyrene.

Example 3

It is basically the same as Example 1, more specifically: the glass container is a beaker, the heat shield is a cylinder and its diameter is the same as the inner diameter of the beaker, the diameter of the heat shield is 40mm, the height is 15mm, the capillary length is 30mm, and the inner diameter is 0.5mm, wherein the reduced graphene oxide-based light-to-heat conversion film is prepared by the following method:

(1) Synthesis of reduced graphene oxide: 200 mg of graphene oxide and 50 mg of ascorbic acid were added to 200 ml of deionized water, and magnetically stirred for 10 minutes. The above dispersion was placed in a microwave reactor at 200W and 95°C for 10 minutes. The resulting liquid was filtered and dried to obtain reduced graphene oxide.

(2) Preparation of reduced graphene oxide-based light-to-heat conversion film: 100 mg of shaped filter paper was added to 100 mL of solvent, and magnetically stirred at 100° C. for 2 hours to obtain a cellulose dispersion. Add 60 mg of reduced graphene oxide to the cellulose dispersion, continue to stir for 0.5 hours, vacuum filter to obtain a reshaped fiber film, and vacuum dry at 35°C for 30 minutes to obtain a reduced graphene oxide-based light-to-heat conversion film.

The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 4:1, the carbon/oxygen atom The number ratio is about 3.93.

Figure 3 shows the morphology characteristics of the reduced graphene oxide-based light-to-heat conversion film obtained in Example 3 under the observation of scanning electron microscope (SEM) and atomic force microscope (AFM). Dense layers (a and b in Figure 3), and porous structures on the other side of the membrane (d and e in Figure 3). Under the observation of the atomic force microscope, the relative roughness of the side of the reduced graphene oxide stack is 0.413 microns (c in Figure 3), while the relative roughness of the side with the porous structure is 2.248 microns (f in Figure 3). The main reason for the different structures on both sides of the cellulose-based light-to-heat conversion film is that graphene oxide and cellulose are combined through van der Waals force (weak electrical attraction). Graphene is detached from the fibers and deposited on one side of the film to form a "dense layer", while the fibers on the other side form a "porous layer" due to less graphene oxide wrapping, thus forming the two-sidedness of the light-to-heat conversion film. At the same time, the "porous layer" has good water absorption due to its countless microscopic openings, which can absorb the normal temperature water provided by the water delivery device and transport it to the "dense layer". The light-to-heat conversion layer has excellent light-to-heat conversion efficiency, thereby realizing the normal temperature water vaporization process driven by solar energy.

Example 4

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 100 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 2:1, the carbon/oxygen atom The number ratio is about 5.16.

Example 5

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 150 mg to obtain reduced graphene oxide. The prepared reduced graphene oxide powder is tested by EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 4:3, the carbon/oxygen atom The number ratio is about 5.70.

Example 6

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 200 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 1:1, the carbon/oxygen atom The number ratio is about 6.84.

Example 7

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 250 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 4:5, the carbon/oxygen atom The number ratio is about 7.54.

Example 8

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 300 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 2:3, the carbon/oxygen atom The number ratio is about 8.66.

Example 9

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 350 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 4:7, the carbon/oxygen atom The number ratio is about 9.80.

Example 10

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 400 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 1:2, the carbon/oxygen atom The number ratio is about 10.14.

Example 11

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 450 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 4:9, the carbon/oxygen atom The number ratio is about 10.17.

Example 12

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 500 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 2:5, the carbon/oxygen atom The number ratio is about 10.26.

Example 13

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 550 mg to obtain reduced graphene oxide. The obtained reduced graphene oxide powder is tested by an EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 4:11, the carbon/oxygen atom The number ratio is about 10.51.

Example 14

According to the preparation steps and reaction process of Example 1, only the amount of ascorbic acid was changed to 600 mg to obtain reduced graphene oxide. The prepared reduced graphene oxide powder is tested by EDS energy spectrometer for its carbon/oxygen element content ratio, as shown in Figure 2. Therefore, it can be seen from the results that when the ratio of graphene oxide to ascorbic acid is 1:3, the carbon/oxygen atom The number ratio is about 11.08.

As can be seen from Figure 2, when the amount of graphene oxide is controlled at a certain level, the degree of reduction (proportion of carbon content) of reduced graphene oxide increases as the amount of ascorbic acid increases. However, when the amount of ascorbic acid is twice the amount of graphene oxide, the reduction limit is reached, and the carbon/oxygen atomic number ratio is maintained at about 10.2.

With the ternary composite solar steam generating device obtained in Examples ³ , 6, and 10 as the test object, irradiate the solar steam generating device with a 1kW/m xenon lamp to simulate its vaporization efficiency under sunlight irradiation, and the test will contain 200mL The beaker of deionized water is placed on an electronic balance that can record mass data in real time. Under the irradiation of a xenon lamp with a light intensity of 1kW/ ^m2 , the mass change within 3000 seconds is measured, and the mass change curve is drawn. The test results are shown in Figure 4 , it can be seen from the figure that under the irradiation of 3000s, the vaporization amounts of the corresponding solar steam generators in Examples 3, 6, and 10 are 0.765kg/m ² , 0.836kg/m ² , and 0.931kg/m ² , which are the same situation. The vaporization rate is more than 25 times that when pure water is irradiated directly; in addition, if the reduced graphene oxide photothermal conversion film prepared in Example 3 is directly placed on the water surface, its vaporization amount is about 0.481 after 3000s time irradiation under the same circumstances. kg/m ² is only 62.88% of the corresponding vaporization amount in Example 3, that is, the light-to-heat conversion film of the present invention is basically separated from the water in the cup due to the existence of a heat shield, and the heat generated basically does not diffuse to the water in the cup, so Its vaporization efficiency is higher; Further, through the variation of the vaporization amount of embodiment 3,6,10 as can be known, along with the increase of corresponding reduced graphene oxide reduction degree, the photothermal conversion efficiency (photothermal conversion efficiency) of corresponding solar steam generating device The conversion efficiency (calculated from the water lost by evaporation into the energy absorbed by evaporation and the electric energy consumed) has also been significantly improved, as shown in Figure 5, from 74.1% to 90.2%.

In addition, in order to reflect the working performance of the ternary composite solar steam generating device provided by the present invention, an infrared thermal imager was used to take infrared images of the device at different irradiation times, and the results are shown in Figure 6 . Before the xenon lamp (1 kW/m ² ) was irradiated, the temperature of the light-to-heat conversion film was about 20.3°C, and the temperature of the heat shield was about 18.1°C. After irradiating for 1 minute, the temperature of the light-to-heat conversion film was about 33.5°C, and the temperature of the heat shield was about 22.5°C. After irradiating for 40 minutes, the temperature of the light-to-heat conversion film was about 38.0°C, and the temperature of the heat shield was about 22.7°C. After 90 minutes of irradiation, the temperature of the light-to-heat conversion film was about 39.5°C, and the temperature of the plate was about 24.9°C. It can be seen that within 1 minute of irradiation, the light-to-heat conversion film heats up rapidly and enters the working state, while the heat shield remains at about 25°C after 90 minutes of irradiation, which effectively isolates the heat dissipation from the high-temperature film to the low-temperature water body and improves The utilization rate of light energy. It can be seen that the device has excellent light-to-heat conversion performance.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (10)

1. the solar steam generation device of a kind of tri compound, it is characterised in that thin including water container (1), photothermal conversion Water is housed, the thermal insulation board (3) is integrally located on the water surface in film (2), thermal insulation board (3) and aqueduct, the water container (1) Side or only bottom is immersed in the water, the photothermal conversion film (2) be located at the thermal insulation board (3) top or be covered in described heat-insulated The outer surface on plate (3) top, the aqueduct includes some capillaries (4) for inserting the thermal insulation board (3), the capillary (4) lower ending opening is immersed in the water, and the upper end open of the capillary (4) comes close to or in contact with the photothermal conversion film (2).

2. the solar steam generation device of a kind of tri compound according to claim 1, it is characterised in that described to be filled with water Container (1) is the glass container or transparent plastic container of open topped.

3. a kind of solar steam generation device of tri compound according to claim 1, it is characterised in that the photo-thermal It is carbon-based photothermal conversion film to convert film (2).

4. the solar steam generation device of a kind of tri compound according to claim 3, it is characterised in that described carbon-based Photothermal conversion film is redox graphene base photothermal conversion film.

5. the solar steam generation device of a kind of tri compound according to claim 1, it is characterised in that described heat-insulated Plate (3) is made up of foamed heat-insulating material.

6. a kind of solar steam generation device of tri compound according to claim 5, it is characterised in that the foaming Heat-barrier material is one or more mixing in polyethylene foamed, foamed polyvinyl chloride, expanded polypropylene and expanded polystyrene (EPS), The thermal insulation board (3) floats on above the water surface and its peripheral sidewalls is abutted with the madial wall of the water container (1).

7. a kind of solar steam generation device of tri compound according to claim 1, it is characterised in that the capillary It is nature of glass capillary or plastics matter capillary to manage (4).

8. a kind of solar steam generation device of tri compound according to any one of claim 1 to 7, its feature exists In the thickness of the thermal insulation board (3) is 1.5-20cm.

9. a kind of solar steam generation device of tri compound according to claim 8, it is characterised in that the capillary The internal diameter for managing (4) is that homogeneous vertical is intensive inserted with the capillary (4) on 0.1-2mm, the thermal insulation board (3).

10. a kind of application of tri compound solar steam generation device as described in any one of claim 1 to 9, its feature It is, for solar power generation, desalinization or sewage disposal.