Reflecting mirror and solar thermal power generation device

Abstract

The invention provides a reflector and a solar thermal power generation device, and relates to the technical field of solar thermal power generation. The reflecting mirror comprises a base which comprises a support and a mirror bracket, and the support is connected with the mirror bracket; the mirror body is arranged on the mirror frame and comprises a reflecting layer and a conversion layer which are connected, the reflecting layer is stacked on the conversion layer, the reflecting layer is used for reflecting light rays, and the conversion layer is used for converting light energy into heat energy and transmitting the heat energy to the reflecting layer. The defrosting efficiency can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of solar thermal power generation, and in particular to a reflector and a solar thermal power generation device. Background Art

[0002] As a clean and renewable energy utilization technology, solar thermal power generation technology has received widespread attention and application in China because of its ability to store energy, achieve continuous and stable power generation and peak-shaving power generation.

[0003] The reflectors in solar thermal power generation devices can focus solar energy onto the absorber, and the availability of the reflectors has a crucial impact on the annual power generation of the power station. However, the mirror surface of existing reflectors is prone to frost, which affects the power generation efficiency.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] The present disclosure provides a reflector, which is convenient for improving defrosting efficiency and further improving power generation efficiency.

[0006] According to one aspect of the present disclosure, there is provided a reflector, comprising:

[0007] A base, comprising a bracket and a frame, wherein the bracket is connected to the frame;

[0008] The mirror body is arranged on the mirror frame and includes a connected reflection layer and a conversion layer, wherein the reflection layer is stacked on the conversion layer, the reflection layer is used to reflect light, and the conversion layer is used to convert light energy into heat energy and transfer the heat energy to the reflection layer.

[0009] In one embodiment of the present disclosure, the reflective layer includes a protective layer, a metal layer, and a light-transmitting layer stacked sequentially on the conversion layer;

[0010] Wherein, the protective layer is used to protect the metal layer;

[0011] The metal layer is used to reflect light;

[0012] The light-transmitting layer is used for transmitting light.

[0013] In one embodiment of the present disclosure, the protective layer includes a first protective layer, a second protective layer, and a third protective layer stacked sequentially on the conversion layer, and the thickness of the first protective layer, the second protective layer, and the third protective layer is not less than 30 μm.

[0014] In one embodiment of the present disclosure, the metal layer includes a first metal layer and a second metal layer sequentially stacked on the protective layer; the reflectivity of the second metal layer is greater than the reflectivity of the first metal layer.

[0015] In one embodiment of the present disclosure, the material of the first metal layer is copper, and the mass per unit area of ​​the first metal layer is not less than 300 mg / m 2 .

[0016] In one embodiment of the present disclosure, the material of the second metal layer is silver, and the mass per unit area of ​​the second metal layer is not less than 1200 mg / m 2 .

[0017] In one embodiment of the present disclosure, the material of the conversion layer is black nickel, and the thickness of the conversion layer is not less than 30 μm.

[0018] In one embodiment of the present disclosure, the wavelength of light absorbed by the conversion layer is 400nm-2500nm, and the absorption rate of the conversion layer to light is not less than 85%.

[0019] In one embodiment of the present disclosure, a protective layer is provided on a side of the conversion layer away from the reflective layer.

[0020] According to another aspect of the present disclosure, there is also provided a solar thermal power generation device, comprising the reflector described in any one of the above embodiments.

[0021] The reflector and solar thermal power generation device disclosed in the present invention, by arranging a conversion layer on one side of the reflective layer, during the defrosting process of the reflector, the conversion layer can absorb solar energy and convert the absorbed solar energy into heat energy, and then transfer it to the reflective layer. The frost on the reflective layer will be quickly eliminated by the heat energy transferred by the conversion layer, which is conducive to improving the defrosting efficiency of the reflective layer, accelerating the defrosting speed of the reflective layer, facilitating the reflector to be quickly put into the use scenario of power generation, improving the availability of the reflector, and then improving the power generation efficiency. At the same time, because the reflector uses solar energy for defrosting, it has the effect of energy saving and environmental protection compared to the defrosting method of electric heating wire. In addition, the conversion layer can provide protection for the reflective layer, so that the reflective layer can work stably in an environment of -40℃ to 80℃, reducing the possibility of the reflective layer being eroded by the environment.

[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0024] Figure 1 Schematic diagram of the structure of a mirror body in one embodiment of the present disclosure.

[0025] Figure 2 Schematic diagram of the film layer of the mirror body in one embodiment of the present disclosure.

[0026] Description of reference numerals:

[0027] 1. Reflective layer; 11. Protective layer; 111. First protective layer; 112. Second protective layer; 113. Third protective layer; 12. Metal layer; 121. First metal layer; 122. Second metal layer; 13. Transparent layer; 2. Conversion layer; 3. Protective layer. DETAILED DESCRIPTION

[0028] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0029] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0030] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0031] In solar thermal power plants in extremely cold regions, frost may form on the surface of the reflectors, so a lot of time is required to defrost the reflectors, which reduces the availability of the reflectors and affects the power generation efficiency.

[0032] The embodiment of the present disclosure provides a reflector for solar thermal power generation. The reflector includes a base and a mirror body. The base includes a bracket and a mirror frame, and the bracket is connected to the mirror frame. The mirror body is arranged on the mirror frame, see Figure 1 and Figure 2 The mirror body includes a connected reflective layer 1 and a conversion layer 2, wherein the reflective layer 1 is stacked on the conversion layer 2, the reflective layer 1 is used to reflect light, and the conversion layer 2 is used to convert light energy into heat energy and transfer the heat energy to the reflective layer 1.

[0033] In the embodiment of the present disclosure, by arranging the conversion layer 2 on one side of the reflective layer 1, during the defrosting process of the reflector, the conversion layer 2 can absorb solar energy and convert the absorbed solar energy into heat energy, which is then transferred to the reflective layer 1. The frost on the reflective layer 1 will be quickly eliminated by the heat energy transferred by the conversion layer 2, which is conducive to improving the defrosting efficiency of the reflective layer 1, accelerating the defrosting speed of the reflective layer 1, facilitating the reflector to be quickly put into the use scenario of power generation, improving the availability of the reflector, and thus improving the power generation efficiency. At the same time, since the reflector uses solar energy for defrosting, it has the effect of energy saving and environmental protection compared to the defrosting method of electric heating wire. In addition, the conversion layer 2 can provide protection for the reflective layer 1, so that the reflective layer 1 can work stably in an environment of -40°C to 80°C, reducing the possibility of the reflective layer 1 being corroded by the environment.

[0034] In one embodiment of the present disclosure, the bracket may include a column, and the column may be rotatably connected to the mirror frame through a connecting piece, so as to adjust the angle of the reflector, so that the conversion layer 2 faces the sun, which is beneficial for the rapid defrosting of the reflective layer 1; and the reflective layer 1 faces the sun, which is beneficial for the reflector to be put into normal power generation use scenarios. In other embodiments of the present disclosure, the bracket may include multiple columns, for example, the number of columns may be two, three, four, etc., to provide more stable support for the reflector.

[0035] In one embodiment of the present disclosure, the shape of the frame can be a triangle, a rectangle, a circle or other shapes, which are not limited here. The frame can be connected to the lens body by means of clamping, bolting, bonding, etc.

[0036] In one embodiment of the present disclosure, the mirror body can be a plane mirror or a curved mirror, which is not limited here, as long as it can achieve reflection.

[0037] In one embodiment of the present disclosure, see Figure 1 and Figure 2 The reflective layer 1 includes a protective layer 11, a metal layer 12, and a light-transmitting layer 13 stacked in sequence on the conversion layer 2. The protective layer 11 is used to protect the metal layer 12 and improve the wear resistance of the mirror body. The metal layer 12 is used to reflect light. The light-transmitting layer 13 is used to transmit light.

[0038] In one embodiment of the present disclosure, see Figure 2 , the protective layer 11 includes a first protective layer 111, a second protective layer 112, and a third protective layer 113 stacked sequentially on the conversion layer 2. The thickness of the first protective layer 111, the second protective layer 112, and the third protective layer 113 is not less than 30μm. In the embodiment of the present disclosure, the first protective layer 111, the second protective layer 112, and the third protective layer 113 can be a reflective paint layer or an anti-corrosion paint layer to protect the metal layer 12 and improve the reflectivity of the reflective layer 1, thereby improving the stability of the reflector. For example, the thickness of the first protective layer 111 can be 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, or 60μm. The thickness of the second protective layer 112 can be 30μm, 34μm, 38μm, 42μm, 46μm, or 50μm. The thickness of the third protective layer 113 can be 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm or 75 μm. In this way, the thickness of the entire protective layer 11 is not less than 90 μm, which prevents the protective layer 11 from being too thin and weakening the protective effect on the metal layer 12, thereby improving the stability of the reflector.

[0039] In one embodiment of the present disclosure, the thickness of the first protective layer 111, the second protective layer 112, and the third protective layer 113 are all 30μm to 50μm. For example, the thickness of the first protective layer 111 can be 30μm, 35μm, 40μm, 45μm, or 50μm. The thickness of the second protective layer 112 can be 30μm, 34μm, 38μm, 42μm, 46μm, or 50μm. The thickness of the third protective layer 113 can be 30μm, 35μm, 40μm, 45μm, or 50μm. In this way, the thickness of the entire protective layer 11 is between 90μm and 150μm. On the one hand, it prevents the protective layer 11 from being too thin and weakening the protective effect on the metal layer 12, thereby improving the stability of the reflector; on the other hand, it also prevents the protective layer 11 from being too thick and increasing the weight and cost of the reflector.

[0040] In one embodiment of the present disclosure, see Figure 2 The metal layer 12 includes a first metal layer 121 and a second metal layer 122 stacked sequentially on the third protective layer 113. The reflectivity of the second metal layer 122 is greater than that of the first metal layer 121. In this way, on the one hand, solar energy can be reflected by the first metal layer 121 and the second metal layer 122, so as to facilitate the reflection of the reflector; on the other hand, the first metal layer 121 and the second metal layer 122 have good thermal conductivity, so that the heat energy generated by the conversion layer 2 is quickly conducted to the light-transmitting layer 13, which is conducive to the rapid defrosting of the light-transmitting layer 13. In addition, the first metal layer 121 can protect the second metal layer 122 from oxidation and corrosion, thereby increasing the service life of the second metal layer 122.

[0041] In one embodiment of the present disclosure, the material of the light-transmitting layer 13 may be ultra-white glass, so as to achieve light transmission while protecting the metal layer 12 from environmental corrosion, thereby improving the stability of the reflector.

[0042] In one embodiment of the present disclosure, the material of the light-transmitting layer 13 may be silicon dioxide nanoparticles, fluorosilane composite materials, etc., because they are hydrophobic and can reduce water droplets attached to the light-transmitting layer 13 to facilitate the normal operation of the reflector.

[0043] In one embodiment of the present disclosure, the material of the second metal layer 122 is silver, and the mass per unit area of ​​the second metal layer 122 is not less than 1200 mg / m 2 Specifically, the mass per unit area of ​​the second metal layer 122 is 1200 mg / m 2 ~1300 mg / m 2 For example, the mass per unit area of ​​the second metal layer 122 may be 1200 mg / m 2 , 1210mg / m 2 , 1220mg / m 2, 1230mg / m 2 , 1240mg / m 2 , 1250mg / m 2 , 1260mg / m 2 , 1270mg / m 2 , 1280mg / m 2 , 1290mg / m 2 or 1300 mg / m 2 In this way, the second metal layer 122 can have a suitable thickness, which can prevent the second metal layer 122 from being too thin and affecting the reflective effect of the reflector, and can also prevent the second metal layer 122 from being too thick and increasing the weight of the reflector, thereby reducing the cost of the reflector. In other embodiments of the present disclosure, the material of the second metal layer 122 can be aluminum.

[0044] In one embodiment of the present disclosure, the material of the first metal layer 121 is copper, and the mass per unit area of ​​the first metal layer 121 is not less than 300 mg / m 2 Specifically, the mass per unit area of ​​the first metal layer 121 is 300 mg / m 2 ~380 mg / m 2 For example, the mass per unit area of ​​the first metal layer 121 may be 300 mg / m 2 , 310mg / m 2 , 320mg / m 2 , 330mg / m 2 , 340mg / m 2 , 350mg / m 2 , 360mg / m 2 , 370mg / m 2 or 380 mg / m 2 In this way, the first metal layer 121 can have a suitable thickness, which can prevent the first metal layer 121 from being too thin and affecting the reflective effect of the reflector, and can also prevent the first metal layer 121 from being too thick and increasing the weight of the reflector, thereby reducing the cost of the reflector. In other embodiments of the present disclosure, the material of the first metal layer 121 can be aluminum.

[0045] In one embodiment of the present disclosure, the material of the first metal layer 121 may be aluminum, and the material of the second metal layer 122 may be copper.

[0046] In one embodiment of the present disclosure, the material of the conversion layer 2 may be black nickel (nickel zinc sulfur compound or nickel phosphorus compound), and the thickness of the conversion layer 2 may be not less than 30 μm. Specifically, the thickness of the conversion layer 2 may be 30 μm to 40 μm. For example, the thickness of the conversion layer 2 may be 30 μm, 31.5 μm, 33 μm, 34.5 μm, 36 μm, 37.5 μm, 39 μm or 40 μm. In this way, on the one hand, the conversion layer 2 may be prevented from being too thin and affecting the efficiency of light-to-heat conversion, and on the other hand, the conversion layer 2 may be prevented from being too thick and increasing the weight of the reflector, which is beneficial to reducing the cost of the reflector. In other embodiments of the present disclosure, the material of the conversion layer 2 may be materials such as graphene, graphene oxide (GO), reduced graphene oxide (rGO), carbon nanotubes, graphite and carbon black.

[0047] In one embodiment of the present disclosure, the wavelength of light that the conversion layer 2 can absorb is 400nm to 2500nm. In other words, the conversion layer 2 can absorb visible light, near-infrared light and mid-infrared light in solar energy, and the absorptivity of the conversion layer 2 to light is not less than 85%. For example, the absorptivity of the conversion layer 2 to light can be 85%, 87%, 89%, 91%, 93%, 95%, 97% or 98%. In this way, the conversion layer 2 has a high absorptivity to solar energy, and can make full use of the solar radiation band to defrost the reflector. Due to the low emissivity of the solar radiation band, the loss and loss of heat energy are reduced, further improving the defrosting efficiency.

[0048] In one embodiment of the present disclosure, see Figure 1 , Figure 2 A protective layer 3 is provided on the side of the conversion layer 2 away from the reflective layer 1. The material of the protective layer 3 can be transparent materials such as ultra-white glass, silicon dioxide, aluminum oxide, etc., which can protect the conversion layer 2 from water and oxygen erosion, increase the service life of the reflector, and have good light transmittance, which is convenient for the conversion layer 2 to absorb solar energy.

[0049] In one embodiment of the present disclosure, the thermal conductivity of the conversion layer 2 may be no less than 1.2W / (m·K). Specifically, the thermal conductivity of the conversion layer 2 may be 1.2W / (m·K) to 1.5W / (m·K). For example, the thermal conductivity of the conversion layer 2 may be 1.2W / (m·K), 1.25W / (m·K), 1.3W / (m·K), 1.35W / (m·K), 1.4W / (m·K), 1.45W / (m·K) or 1.5W / (m·K). In this way, the conversion layer 2 has better thermal conductivity, which facilitates the rapid transfer of heat generated by the conversion layer 2 to the reflective layer 1, so as to improve the defrosting efficiency of the reflective layer 1.

[0050] The present disclosure also provides a method for using a reflector, comprising the following steps:

[0051] Step S1, determining whether defrosting is required according to the frost condition of the light-transmitting layer 13; if defrosting is required, adopting the following steps S2 and S3; if defrosting is not required and directly entering the sun-chasing preparation state, directly jumping to step S4;

[0052] Step S2, adjusting the angle of the reflector so that the conversion layer 2 faces the sun;

[0053] Step S3, adjusting the angle between the normal of the mirror and the solar energy to be no greater than 15°, and starting defrosting;

[0054] Step S4, after the light-transmitting layer 13 is defrosted or does not need to be defrosted, the angle of the reflector is adjusted so that the light-transmitting layer 13 enters a sun-chasing preparation state and can be put into focusing use at any time.

[0055] It should be noted that the sun-chasing preparation state is a focusing state of the reflector applied in solar power generation.

[0056] By using the reflector provided by the present invention, during the defrosting process of the reflector, compared with the traditional defrosting method, 30 minutes to 60 minutes of defrosting time can be saved, thereby improving the utilization rate of the reflector.

[0057] The disclosed embodiment also provides a solar thermal power generation device, including a power generation device body and a reflector as described in any of the above embodiments. The specific structure and beneficial effects of the reflector can be referred to the embodiment of the display device above, and will not be described in detail here.

[0058] In one embodiment of the present disclosure, the power generation device body can be a tower power generation device body, a trough power generation device body, or a linear Fresnel power generation device body. In one example, the power generation device is a tower power generation device body, and there are multiple reflectors, which are arranged around the tower power generation device body to reflect solar energy onto the heat absorber of the tower power generation device body.

[0059] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A reflector, characterized in that: include: A base, comprising a bracket and a frame, wherein the bracket is connected to the frame; The mirror body is arranged on the mirror frame and comprises a connected reflection layer and a conversion layer, wherein the reflection layer is stacked on the conversion layer, the reflection layer is used to reflect light, and the conversion layer is used to convert light energy into heat energy and transfer the heat energy to the reflection layer.

2. The reflector according to claim 1, characterized in that The reflective layer comprises a protective layer, a metal layer, and a light-transmitting layer stacked in sequence on the conversion layer; Wherein, the protective layer is used to protect the metal layer; The metal layer is used to reflect light; The light-transmitting layer is used for transmitting light.

3. The reflector according to claim 2, characterized in that The protective layer includes a first protective layer, a second protective layer, and a third protective layer which are sequentially stacked on the conversion layer. The thickness of the first protective layer, the second protective layer, and the third protective layer is not less than 30 μm.

4. The reflector according to claim 2, characterized in that The metal layer includes a first metal layer and a second metal layer stacked sequentially on the protective layer; the reflectivity of the second metal layer is greater than the reflectivity of the first metal layer.

5. The reflector according to claim 4, characterized in that The material of the first metal layer is copper, and the mass per unit area of ​​the first metal layer is not less than 300 mg / m 2 .

6. The reflector according to claim 5, characterized in that The material of the second metal layer is silver, and the mass per unit area of ​​the second metal layer is not less than 1200 mg / m 2 .

7. The reflector according to claim 1, characterized in that The material of the conversion layer is black nickel, and the thickness of the conversion layer is not less than 30 μm.

8. The reflector according to claim 1, characterized in that The wavelength of the light absorbed by the conversion layer is 400nm-2500nm, and the absorption rate of the conversion layer to the light is not less than 85%.

9. The reflector according to any one of claims 1 to 8, characterized in that: A protective layer is provided on a side of the conversion layer away from the reflection layer.

10. A solar thermal power generation device, characterized in that: A reflector comprising the reflector according to any one of claims 1 to 9.

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