Tower type photo-thermal power station light condensing device

Abstract

The invention discloses a tower type photo-thermal power station light condensation device, belongs to the technical field of tower type photo-thermal power stations, and can solve the problem that the solar ray quantity captured by a light condensation system in an existing tower type photo-thermal power station has huge cosine loss, so that the generating capacity of the photo-thermal power station is small. The light condensing device comprises: a first optical mirror for reflecting or transmitting solar rays; the first angle regulation and control unit is used for regulating the angle of the first optical lens so as to enable the solar rays to be vertically incident to the light incident surface of the first optical lens all the time; the second optical lens is used for converting emergent light of the first optical lens into parallel light; the optical axis of the second optical lens coincides with the optical axis of the first optical lens. The third optical lens is used for reflecting the parallel light emitted by the second optical lens; and the second angle regulation and control unit is connected with the third optical mirror and used for adjusting the angle of the third optical mirror so that the third optical mirror can reflect the parallel light to a heat absorber of the tower type photo-thermal power station. The invention is used for the light condensing device.

Description

Technical Field

[0001] The present invention relates to a concentrating device for a tower-type solar thermal power station, belonging to the technical field of tower-type solar thermal power stations. Background Art

[0002] Solar thermal power stations complement wind power generation and photovoltaic power generation, playing roles such as energy storage and peak shaving, and are an important part of the future clean energy system and smart grid construction. There are mainly three types of solar thermal power stations: trough type, dish type, and tower type. Among them, the tower type is currently the most suitable for large-capacity development. In the construction cost of tower-type solar thermal power stations, the concentrating system accounts for about 50%, with a huge cost. Therefore, how to reduce costs and increase efficiency of the concentrating system is an extremely important research topic.

[0003] Currently, the concentrating method of tower-type solar thermal power stations basically uses flat heliostats to directly reflect sunlight onto the absorber. However, through this concentrating method, there will be a huge cosine loss in the amount of sunlight captured, resulting in less power generation of the solar thermal power station. Summary of the Invention

[0004] The present invention provides a concentrating device for a tower-type solar thermal power station, which can solve the problem that there is a huge cosine loss in the amount of sunlight captured by the concentrating system in the current tower-type solar thermal power station, resulting in less power generation of the solar thermal power station.

[0005] The present invention provides a concentrating device for a tower-type solar thermal power station, and the concentrating device includes:

[0006] A first optical mirror, arranged on the sunlight path, for reflecting or transmitting sunlight;

[0007] A first angle adjustment unit, connected to the first optical mirror, for adjusting the angle of the first optical mirror so that sunlight always perpendicularly enters the incident surface of the first optical mirror;

[0008] A second optical mirror, arranged on the outgoing light path of the first optical mirror, for converting the outgoing light of the first optical mirror into parallel light; the optical axis of the second optical mirror coincides with the optical axis of the first optical mirror;

[0009] A third optical mirror, arranged on the outgoing light path of the second optical mirror, for reflecting the parallel light outgoing from the second optical mirror;

[0010] A second angle adjustment unit, connected to the third optical mirror, for adjusting the angle of the third optical mirror so that the third optical mirror reflects the parallel light onto the absorber of the tower-type solar thermal power station.

[0011] Optionally, the object distance focus of the second optical mirror coincides with the image distance focus of the first optical mirror.

[0012] Optionally, the concentrator further includes:

[0013] A connection frame, where the first optical mirror and the second optical mirror are both fixed on the connection frame.

[0014] Optionally, the first optical mirror and the second optical mirror have the same shape.

[0015] Optionally, the first optical mirror and the second optical mirror are both circular in shape.

[0016] Optionally, the first optical mirror is a concave mirror or a linear Fresnel lens.

[0017] Optionally, the second optical mirror is a linear Fresnel lens, a convex lens or a concave lens.

[0018] Optionally, the third optical mirror is a plane mirror.

[0019] Optionally, the first angle adjustment unit is a solar tracking controller.

[0020] Optionally, the second angle adjustment unit is a biaxial adjuster.

[0021] The beneficial effects that the present invention can produce include:

[0022] For the concentrator of the tower-type solar thermal power station provided by the present invention, the angle of the first optical mirror is adjusted by the first angle adjustment unit to ensure that the light incident surface of the first optical mirror is always facing the sun directly, receiving light maximally; and the angle of the third optical mirror is adjusted by the second angle adjustment unit, so that the third optical mirror reflects all the parallel light converted from solar light to the heat absorber of the tower-type solar thermal power station. Compared with the current concentration technology, the cosine loss of solar rays is greatly reduced. Description of the Drawings

[0023] Figure 1 Structural schematic diagram of the concentrator of the tower-type solar thermal power station provided by the embodiment of the present invention Figure 1 ;

[0024] Figure 2 Structural schematic diagram of the concentrator of the tower-type solar thermal power station provided by the embodiment of the present invention Figure 2 ;

[0025] Figure 3 Structural schematic diagram of the concentrator of the tower-type solar thermal power station provided by the embodiment of the present invention Figure 3 ;

[0026] Figure 4 Structural schematic diagram of the concentrator of the tower-type solar thermal power station provided by the embodiment of the present invention Figure 4 ;

[0027] Figure 5 Schematic diagram of the structure of the concentrating device of the tower-type solar thermal power station provided by the embodiment of the present invention Figure 5 ;

[0028] Figure 6 Schematic diagram of the structure of the concentrating device of the tower-type solar thermal power station provided by the embodiment of the present invention Figure 6 ;

[0029] Figure 7 Schematic diagram of the power generation principle of the tower-type solar thermal power station in the prior art;

[0030] Figure 8 Schematic diagram of the direct solar radiation mirror surface provided by the embodiment of the present invention;

[0031] Figure 9 Schematic diagram of the inclined solar radiation mirror surface provided by the embodiment of the present invention;

[0032] Figure 10 Schematic diagram of the concentrating method of the tower-type solar thermal power station in the prior art.

[0033] Reference numerals:

[0034] 1, First optical mirror; 2, Second optical mirror; 3, Third optical mirror; 4, Heat absorber; 5, Plane mirror. Detailed implementation manners

[0035] The present invention will be described in detail below in conjunction with embodiments, but the present invention is not limited to these embodiments.

[0036] In the existing concentrating methods of tower-type power stations, basically, the plane heliostats in the heliostat field are used to directly reflect sunlight to the heat absorber, and then pass through the high-temperature heat storage tank, steam generator and generator in sequence for power generation. The schematic diagram of the power generation principle of the tower-type solar thermal power station is as Figure 7 shown.

[0037] To more clearly describe the basic principle and beneficial value of the present invention, the following uses a simple model of a plane mirror receiving light to discuss an important problem in the current concentrating method of tower-type solar thermal power stations - cosine loss.

[0038] As Figure 8 shown, assume that the length of the plane mirror 5 is , and the distance between the light rays is , then when the light rays are vertically incident, the number of light rays received on the mirror is . The number of light rays represents the amount of light energy.

[0039] As Figure 9 shown, when the light rays are obliquely incident (compared with the vertically incident case, there is a deflection angle ), at this time, it is easy to calculate that the number of light rays received on the mirror is It can be seen that the light received by the plane mirror 5 is reduced. That is the so-called cosine efficiency of the mirror. (Specifically, when , that is, when the mirror surface is parallel to the light, , that is, the mirror receives no light).

[0040] The following gives the schematic diagram of the principle of the heliostat's light reflection in a tower-type solar thermal power station. As Figure 10 shown, is the solar altitude angle, is the elevation angle of the heliostat to the absorber. It is not difficult to calculate that the cosine efficiency expression of the heliostat is as follows:

[0041] .

[0042] Taking a certain province with better construction conditions for the solar thermal power station as an example, from 9 am to 1 pm, the value of the solar altitude angle changes approximately between 35° and 75°; in the heliostat field, the absorber height is considered to be 200m according to the conventional design, and the horizontal spacing between thousands of heliostats and the absorber is distributed approximately between 0 and 1000m. Taking the mirror in the middle position as an example, that is, when the mirror is 500m away from the absorber, the elevation angle of the heliostat can be easily calculated at this time. When takes the middle value of 55°, ;

[0043] Cosine efficiency .

[0044] In fact, in the entire heliostat field (usually circularly arranged), the proportion of heliostats within the middle circle is only 1 / 4, that is, most of the heliostats are arranged outside the middle circle, and the cosine efficiency of these heliostats is less than 0.62. It can be seen that in the tower-type solar thermal power station, according to the current light concentration method, the cosine loss is huge. Most of the light energy is lost because the angle of the heliostat deflects and does not face the sun directly.

[0045] To solve the problem of inevitable and huge cosine loss existing in the current light concentration method in the tower-type solar thermal power station, the embodiment of the present invention provides a light concentration device for a tower-type solar thermal power station. As Figures 1 to 6 shown, the light concentration device includes:

[0046] The first optical mirror 1 is arranged on the sunlight path and is used to reflect or transmit the sun's rays;

[0047] The first angle adjustment unit is connected to the first optical mirror 1 and is used to adjust the angle of the first optical mirror 1 so that the sun's rays are always perpendicularly incident on the incident surface of the first optical mirror 1;

[0048] The second optical mirror 2 is disposed on the outgoing light path of the first optical mirror 1 and is configured to convert the outgoing light of the first optical mirror 1 into parallel light; the optical axis of the second optical mirror 2 coincides with the optical axis of the first optical mirror 1;

[0049] The third optical mirror 3 is disposed on the outgoing light path of the second optical mirror 2 and is configured to reflect the parallel light outgoing from the second optical mirror 2;

[0050] The second angle adjustment unit is connected to the third optical mirror 3 and is configured to adjust the angle of the third optical mirror 3 so that the third optical mirror 3 reflects the parallel light onto the heat absorber 4 of the tower-type solar thermal power station.

[0051] The present invention adopts an optical combination system composed of multiple lenses and mirrors to achieve maximum collection of sunlight and accurately reflect it onto the heat absorber 4.

[0052] Further, the object distance focus of the second optical mirror 2 coincides with the image distance focus of the first optical mirror 1. This can ensure that the light outgoing from the second optical mirror 2 is parallel light.

[0053] Preferably, the condensing device further includes:

[0054] A connecting frame, and both the first optical mirror 1 and the second optical mirror 2 are fixed on the connecting frame.

[0055] By fixing the first optical mirror 1 and the second optical mirror 2 with a connecting frame, it can be ensured that their relative positions remain unchanged. In this way, when the first angle adjustment unit adjusts the angle of the first optical mirror 1, the angle of the second optical mirror 2 also changes accordingly, ensuring that the optical axis of the second optical mirror 2 always coincides with the optical axis of the first optical mirror 1.

[0056] In the present invention, the shapes of the first optical mirror 1 and the second optical mirror 2 are the same.

[0057] In practical applications, the shapes of the two mirrors should be similar. Specifically, the shapes of the first optical mirror 1 and the second optical mirror 2 can both be square or circular, and the present invention embodiment does not limit this. The size ratio and spacing of the two mirrors can be determined according to design calculations.

[0058] In the present invention, the first optical mirror 1 is a concave mirror or a linear Fresnel lens. The first angle adjustment unit is a solar tracking controller.

[0059] The first optical mirror 1 can adopt a concave mirror or a linear Fresnel lens, and use a solar tracking controller to ensure that it is always facing the sun.

[0060] The second optical mirror 2 is a linear Fresnel lens, a convex lens or a concave lens.

[0061] The second optical mirror 2 can be a convex lens, a concave lens, or a linear Fresnel lens, but it should be made to have a similar shape, coincident optical axis, coincident foci, and fixed relative position with the first optical mirror 1. The light rays emerging from the second optical mirror 2 will become parallel rays again.

[0062] The third optical mirror 3 is a plane mirror. The second angle adjustment unit is a biaxial adjuster.

[0063] The third optical mirror 3 should be a plane mirror and use a biaxial adjuster to adjust its azimuth angle in real time to ensure that the light rays it reflects are always directed at the heat absorber 4.

[0064] The above-mentioned linear Fresnel lens can be made of materials such as PMMA (acrylic), PC (polycarbonate glass), PP (polypropylene), etc. Concave mirrors and plane mirrors can be made of silver-plated glass mirrors.

[0065] The present invention can ensure that the concentrating device is always facing the sun, receiving light maximally, and greatly reducing the cosine loss compared with the current concentrating method. That is, for the same land area for sunlight collection, the present invention can significantly increase the amount of solar light rays captured, and thus greatly increase the power generation of the solar thermal power station. In other words, when building a power station with the same installed capacity, adopting the solution of the present invention, the land area is significantly reduced and the corresponding investment is also significantly reduced.

[0066] The following provides several specific structures of the concentrating device to elaborate on the technical solution of the present invention.

[0067] Embodiment 1

[0068] Reference Figure 1 As shown, the first optical mirror 1 is a concave mirror, and the second optical mirror 2 is a linear Fresnel lens; the concave mirror and the linear Fresnel lens are fixed with a connecting frame to ensure that their relative positions remain unchanged, and the two mirrors should have a coincident optical axis and coincident foci.

[0069] Then, through the solar tracking controller, the angles of the concave mirror and the linear Fresnel lens are adjusted to ensure that the concave mirror faces the sun (so that the sunlight is always perpendicularly incident on the mirror surface).

[0070] The third optical mirror 3 is a plane mirror; the plane mirror is set at an appropriate position on the light rays emerging from the linear Fresnel lens, and the angle of the plane mirror is adjusted using a biaxial adjuster to ensure that it always reflects the light rays onto the heat absorber 4.

[0071] The concave mirror adjusts its own angle with the help of a solar tracking controller, facing the sun directly in real time, "catching" the sunlight completely, maximizing the reception of light energy without cosine loss; the linear Fresnel lens is arranged at an appropriate position, parallel to the concave mirror in terms of the mirror surface and coinciding with the optical axis, and the object distance focus of the linear Fresnel lens coincides with the image distance focus of the concave mirror to ensure that the outgoing light rays of the linear Fresnel lens are parallel. The parallel light rays are then incident on a plane mirror, and this plane mirror adjusts its own angle through a biaxial adjuster to reflect the light rays onto the heat absorber 4 at the center of the mirror field.

[0072] Example 2

[0073] Reference Figure 2 As shown, the first optical mirror 1 uses a concave mirror, and the second optical mirror 2 uses a convex lens. The concave mirror and the convex lens are fixed with a connecting frame to ensure that their relative positions remain unchanged, and the two mirrors should have the same optical axis and the same focus.

[0074] Then, through the solar tracking controller, the angles of the concave mirror and the convex lens are adjusted to ensure that the concave mirror faces the sun directly (so that the sunlight is always perpendicularly incident on the mirror surface).

[0075] The third optical mirror 3 uses a plane mirror; the plane mirror is set at an appropriate position of the outgoing light rays of the convex lens, and the angle of the plane mirror is adjusted by a biaxial adjuster to ensure that it always reflects the light rays onto the heat absorber 4.

[0076] Example 3

[0077] Reference Figure 3 As shown, the first optical mirror 1 uses a concave mirror, and the second optical mirror 2 uses a concave lens; the concave mirror and the concave lens are fixed with a connecting frame to ensure that their relative positions remain unchanged, and the two mirrors should have the same optical axis and the same focus.

[0078] Then, through the solar tracking controller, the angles of the concave mirror and the concave lens are adjusted to ensure that the concave mirror faces the sun directly (so that the sunlight is always perpendicularly incident on the mirror surface).

[0079] The third optical mirror 3 uses a plane mirror; the plane mirror is set at an appropriate position of the outgoing light rays of the concave lens, and the angle of the plane mirror is adjusted by a biaxial adjuster to ensure that it always reflects the light rays onto the heat absorber 4.

[0080] Example 4

[0081] Reference Figure 4 As shown, both the first optical mirror 1 and the second optical mirror 2 use linear Fresnel lenses. The two linear Fresnel lenses are fixed with a connecting frame to ensure that their relative positions remain unchanged, and the two mirrors should have the same optical axis and the same focus.

[0082] Then, through the solar tracking controller, the angles of the two linear Fresnel lenses are adjusted to ensure that the linear Fresnel lens serving as the first optical mirror 1 faces the sun directly (so that sunlight always perpendicularly irradiates the mirror surface).

[0083] The third optical mirror 3 uses a plane mirror; the plane mirror is arranged at an appropriate position on the outgoing light of the linear Fresnel lens serving as the second optical mirror 2, and a biaxial adjuster is used to adjust the angle of the plane mirror to ensure that it always reflects the light onto the heat absorber 4.

[0084] Embodiment 5

[0085] Reference Figure 5 As shown, the first optical mirror 1 uses a linear Fresnel lens, and the second optical mirror 2 uses a convex lens; the linear Fresnel lens and the convex lens are fixed with a connecting frame to ensure that their relative positions remain unchanged, and the optical axes and foci of the two mirrors should coincide.

[0086] Then, through the solar tracking controller, the angles of the linear Fresnel lens and the convex lens are adjusted to ensure that the linear Fresnel lens faces the sun directly (so that sunlight always perpendicularly irradiates the mirror surface).

[0087] The third optical mirror 3 uses a plane mirror; the plane mirror is arranged at an appropriate position on the outgoing light of the convex lens, and a biaxial adjuster is used to adjust the angle of the plane mirror to ensure that it always reflects the light onto the heat absorber 4.

[0088] Embodiment 6

[0089] Reference Figure 6 As shown, the first optical mirror 1 uses a linear Fresnel lens, and the second optical mirror 2 uses a concave lens; the linear Fresnel lens and the concave lens are fixed with a connecting frame to ensure that their relative positions remain unchanged, and the optical axes and foci of the two mirrors should coincide.

[0090] Then, through the solar tracking controller, the angles of the linear Fresnel lens and the concave lens are adjusted to ensure that the linear Fresnel lens faces the sun directly (so that sunlight always perpendicularly irradiates the mirror surface).

[0091] The third optical mirror 3 uses a plane mirror; the plane mirror is arranged at an appropriate position on the outgoing light of the concave lens, and a biaxial adjuster is used to adjust the angle of the plane mirror to ensure that it always reflects the light onto the heat absorber 4.

[0092] The concentrating device of the tower-type solar thermal power station capable of reducing cosine loss disclosed by the present invention uses lenses and mirrors (a total of three), and through designing appropriate focal lengths and arrangement positions, forms an optical system to achieve the maximum collection and directional reflection of sunlight, so as to solve the cosine loss problem in the current concentrating method of the tower-type solar thermal power station.

[0093] As described above, these are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the relevant art, without departing from the technical solution of the present application, making some changes or modifications using the technical content disclosed above is equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A tower-type solar thermal power station concentrator, characterized in that: The light focusing device comprises: A first optical mirror is arranged on the sunlight path and is used to reflect or transmit sunlight; a first angle control unit, connected to the first optical mirror, and used to adjust the angle of the first optical mirror so that the sunlight is always incident vertically on the light incident surface of the first optical mirror; a second optical mirror, arranged on an outgoing light path of the first optical mirror, and used for converting the outgoing light of the first optical mirror into parallel light; the optical axis of the second optical mirror coincides with the optical axis of the first optical mirror; A third optical mirror is arranged on the outgoing light path of the second optical mirror and is used to reflect the parallel light emitted by the second optical mirror; The second angle control unit is connected to the third optical mirror and is used to adjust the angle of the third optical mirror so that the third optical mirror reflects the parallel light onto the absorber of the tower-type solar thermal power station.

2. The light focusing device according to claim 1, characterized in that: The object distance focus of the second optical lens coincides with the image distance focus of the first optical lens.

3. The light focusing device according to claim 1 or 2, characterized in that: The light focusing device also includes: A connecting frame, on which the first optical mirror and the second optical mirror are both fixed.

4. The light focusing device according to claim 1, characterized in that: The first optical mirror and the second optical mirror have the same shape.

5. The light focusing device according to claim 4, characterized in that: The first optical mirror and the second optical mirror are both circular in shape.

6. The light focusing device according to claim 1, characterized in that: The first optical mirror is a concave mirror or a linear Fresnel lens.

7. The light focusing device according to claim 6, characterized in that: The second optical mirror is a linear Fresnel lens, a convex lens or a concave lens.

8. The light focusing device according to claim 1, characterized in that: The third optical mirror is a plane reflecting mirror.

9. The light focusing device according to claim 1, characterized in that: The first angle control unit is a sun tracking controller.

10. The light focusing device according to claim 1, characterized in that: The second angle control unit is a dual-axis adjuster.

Images