WO2018133116A1

WO2018133116A1 - Fresnel light concentrating apparatus

Info

Publication number: WO2018133116A1
Application number: PCT/CN2017/072244
Authority: WO
Inventors: 胡笑平
Original assignee: 博立多媒体控股有限公司; 胡笑平
Priority date: 2017-01-23
Filing date: 2017-01-23
Publication date: 2018-07-26

Abstract

A Fresnel light concentrating apparatus comprises a first light-receiving device (110) having a first light-acceptance surface. The first light-acceptance surface comprises a first light-acceptance region (111) and a second light-acceptance region (112) having the same axis of symmetry, wherein the second light-receiving region (112) is located in a central region of the first light-acceptance surface, and the first light-acceptance region (111 ) is located outside the second light-acceptance region (112). The first light-acceptance region (111) is formed of a tooth face of a first Fresnel lens, and the first Fresnel lens is a concentrating Fresnel lens. The second light-acceptance region (112) is formed of a tooth surface of a second Fresnel lens, or is formed of a smooth surface or an opening. The focal point of the first Fresnel lens and the focal point of the second Fresnel lens are located at different positions on the same optical axis or are located on different optical axes. By dividing the light-acceptance surface into different regions according to the distance from the axis of symmetry and by adopting different optical designs in different regions, a more uniform light energy distribution can be presented on a focal plane.

Description

Title of the invention: Fresnel concentrator

Technical field

[0001] The present invention relates to the field of optical components, and in particular to a Fresnel concentrating device including a Fresnel lens.

Background technique

[0002] A Fresnel lens is a thin lens. The continuous curved surface of the ordinary lens is divided into several segments, and the Fresnel lens is formed by placing each curved surface on the same plane or a substantially smooth curved surface after reducing the thickness of each segment. The refractive surface of a Fresnel lens is generally discontinuously stepped or toothed and is therefore often referred to as a "toothed surface". A detailed description of the Fresnel lens can be found in the PCT application entitled "Finnel Lens System", published on June 2, 2016, and International Publication No. WO/2016/082097.

[0003] Fresnel lenses are often used for signal detection systems or solar system focusing due to their peculiar shape (the macroscopic shape is usually a thin layer), which is beneficial for enhancing signal or light intensity and reducing system size.

[0004] Conventional Fresnel concentrating systems typically have a common focus for better concentrating effects.

However, this also makes the distribution of light intensity on the focal plane very uneven, and the closer to the focus area, the stronger the light energy. When such a concentrating system is applied to a photovoltaic panel, uneven light energy distribution causes a decrease in the power generation efficiency of the photovoltaic panel and an increase in local temperature, which is undesirable. It is therefore necessary to improve the existing Fresnel concentrating system.

technical problem

[0005] Type the technical problem description paragraph here.

Problem solution

Technical solution

According to the present invention, there is provided a Fresnel concentrating device comprising a first light receiving device having a first light receiving surface.

The first light receiving surface includes a first light receiving region and a second light receiving region having the same symmetry axis, wherein the second light receiving region is located at a central region of the first light receiving surface, and the first light receiving region is located outside the second light receiving region. The first light receiving region is formed by the tooth surface of the first Fresnel lens, and the first Fresnel lens is a concentrating Fresnel Lens. The second light-receiving area is formed by the tooth surface of the second Fresnel lens, or by a smooth surface or a cornice. The focus of the first Fresnel lens is at a different location on the same optical axis as the focus of the second Fresnel lens, or on a different optical axis.

Advantageous effects of the invention

Beneficial effect

[0007] According to the Fresnel concentrating device of the present invention, the light-receiving surface is divided into different regions according to the distance from the symmetry axis, and different optical designs are adopted in different regions, so that the surface can be more uniform in the focal plane. Light energy distribution. The traditional Fresnel concentrating system, in design, usually does not use the light energy distribution on the focal plane as the main design indicator. Applying the concentrating device according to the present invention to a photovoltaic panel concentrating enamel for a solar energy system can improve the efficiency of the photovoltaic panel and reduce the maximum temperature rise of the photovoltaic panel, thereby enabling the cost of the concentrating system to be increased without increasing the cost of the concentrating system. Improve the performance of concentrating solar systems.

The specific examples according to the present invention will be described in detail below with reference to the accompanying drawings. The numbers or serial numbers used herein, such as "first", "second", etc., are merely indicative and do not have any limiting meaning. Brief description of the drawing

DRAWINGS

1 is a schematic view of a Fresnel concentrating device of Embodiment 1;

2 is a schematic view showing an example of several different shapes of a first light-receiving device in the present invention;

3 is a schematic view of a Fresnel concentrating device of Embodiment 2;

4 is a schematic view of a Fresnel concentrating device of Embodiment 3; [0012] FIG.

5 is a schematic view of a Fresnel concentrating device of Embodiment 4; [0013] FIG.

6 is a schematic view of a Fresnel concentrating device of Embodiment 5.

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] The paragraphs describing the best mode of the invention are entered here.

Embodiments of the invention

[0016] Embodiment 1 [0017] An embodiment of a Fresnel concentrating device according to the present invention can refer to FIG. 1 and includes a first light receiving device 110.

[0018] The first light receiving device 110 has a first light receiving surface including a first light receiving region 111 and a second light receiving region 112 having the same axis of symmetry. The second light receiving region 112 is located in a central region (inner region) of the first light receiving surface, and the first light receiving region 111 is located outside the second light receiving region (peripheral region).

The first light receiving region 111 is formed by the tooth surface of the first Fresnel lens, and as shown in FIG. 1, the tooth surface includes a plurality of annular teeth 1111. The first Fresnel lens can generally employ a concentrating Fresnel lens. The so-called "concentrating type" Fresnel lens refers to a Fresnel lens whose tooth surface is derived from the convex lens surface, and thus has a convergence effect on light.

[0020] The second light receiving region 112 is formed by a transparent plane, which can also be regarded as a Fresnel lens having a focal length of infinity (the height of the teeth is 0). In other embodiments, the second light-receiving area may also be a smooth surface of another shape, or a hollowed-mouth opening, or formed by the tooth flanks of the second Fresnel lens. When the second Fresnel lens is used to form the second light receiving region 吋, the focus of the first Fresnel lens is at a different position on the same optical axis as the focus of the second Fresnel lens, or on a different optical axis. By differently designing the optical characteristics of the two light-receiving regions on the first light-receiving surface, the convergence of the light rays as a whole does not concentrate the light intensity on the only focus, but can be more evenly distributed. Distributed on the focal plane.

[0021] Only two light receiving regions are shown in FIG. 1. In other embodiments, in the case where the first light receiving surface area is large, more light receiving regions may be similarly divided, for example, in the first light receiving region. A third light-receiving area or the like having the same axis of symmetry is continuously divided between the second light-receiving area, so as to improve the uniformity of light intensity on the focal plane by a finer optical design. It is worth noting that, based on the manufacturing characteristics of the Fresnel lens, the method of sub-region design of the light-receiving surface only increases the workload of the design link, and does not increase the manufacturing cost of the Fresnel lens, but can bring Significant improvements in performance.

[0022] As an alternative embodiment, the second Fresnel lens may be an astigmatic Fresnel lens. The so-called "astigmatism type" Fresnel lens refers to a Fresnel lens whose tooth surface is derived from a concave lens surface, and thus has a diverging effect on light. The use of an astigmatic Fresnel lens in the central region of the first light receiving surface prevents the light incident from the central region from being concentrated to the same position.

[0023] As an optional implementation manner, the first Fresnel lens or the second Fresnel lens may be both sides The double-sided Fresnel lens of the tooth surface can multiply the optical effect of the lens and, in addition, facilitate different optical designs on both sides of the lens.

[0024] As a preferred embodiment, the tooth flanks of the first Fresnel lens or the flanks of the second Fresnel lens may be composed of at least one linear Fresnel unit. The so-called "linear" Fresnel unit, including a linear astigmatic Fresnel unit and a linear concentrating Fresnel unit, usually means that the center of focus of the Fresnel unit is a line. An advantageous aspect of applying "linear" astigmatism in the present invention is that the light is diverged only in one direction, so that the light is easily confined to the desired area. An advantageous aspect of applying "linear" concentrating in the present invention is that the focus center of the light itself has a certain uniformity, not concentrated at one point. For example, the tooth surface of the linear astigmatic Fresnel unit may originate from a concave cylindrical surface, a concave elliptical cylinder surface, or a concave polynomial cylinder surface, and the tooth surface of the linear concentrating Fresnel unit may be derived from the convex surface Cylindrical surface, convex elliptical cylinder, or convex polynomial cylinder.

[0025] In this embodiment, the first light receiving device 110 is a transmissive optical device. In other embodiments, reflective optics may also be employed, for example, a reflective film is deposited on the back side of the first Fresnel lens or the second Fresnel lens, or a mirror is disposed on the back side thereof to form a reflective type. lens. With a reflective lens, since the light passes through the lens twice, the optical effect of the lens can be multiplied without increasing the cost.

In this embodiment, the contours of the first light receiving region and the second light receiving region are circular. In other embodiments, contours of other shapes may also be used to divide the light-receiving regions, such as square, elliptical, and polygonal.

[0027] In this embodiment, the macroscopic shape of the first light receiving surface is a plane. The term "macroscopic shape" refers to the overall shape after undulation of the flank of the tooth surface of the Fresnel lens. In other embodiments, the first light-receiving surface (including the first and second light-receiving regions) may employ a plurality of rich surface shapes. For example, the macroscopic shape of the first light receiving surface may be other forms of smooth curved surfaces, such as cylindrical surfaces, second order or higher order polynomial circumferential symmetry planes. Alternatively, the first light receiving surface may be a folded surface. In this case, the macroscopic shape of the first light receiving device is a ladder shape, the first light receiving region is located around the terrace, and the second light receiving region is located at the top of the ladder. The so-called ladder can be selected from the group consisting of: spherical ladders, ellipsoidal ladders, high-order polynomial circumferential symmetry ladders, quadrilateral frustums, and conical frustums. The use of a curved surface or a first light-receiving surface of a folded surface shape can effectively enhance the adaptability of the concentrating device to the deflection of the incident angle of the sun. [0028] FIG. 2 shows an example of several different shapes employed by the first light-receiving device in the present invention. 2 (a) is a schematic view of a quadrangular frustum, the first light receiving region 011 is located around the frustum (the fringe of the Fresnel lens 0111, the same below), and the second light receiving region 012 is located at the frustum Fig. 2(b) is a schematic view showing a smooth circumferential symmetry plane, the first light receiving region 011 is located in a region around the curved surface, and the second light receiving region 012 is located at a central region at the top of the curved surface; Fig. 2(c) is a smooth A schematic view of a cylinder (e.g., a cylindrical surface, or an elliptical cylinder, or other secondary or higher order surface), the first light receiving region 011 is located outside the cylinder surface, and the second light receiving region 012 is located at the top of the cylinder surface.

[0029] In order to achieve a better control effect on the light intensity distribution, in other embodiments, the second light receiving device may be further disposed on the optical path after the first light receiving device, and specifically may include a single or multiple light receiving regions. Fresnel lens, in order to provide more freedom for optical design, to achieve better results.

[0030] In addition, in order to enhance the concentrating effect, in other embodiments, other concentrating devices used in combination with the first light receiving device, such as a tapered concentrating device or a tapered light guiding device, may be further provided, thereby ensuring The homogeneity of the uniformity of light intensity further increases the concentration ratio.

Embodiment 2

Another embodiment of the Fresnel concentrating device according to the present invention can be referred to FIG. 3, including a first light receiving device 210 and a second light receiving device 220.

The macroscopic shape of the first light receiving device 210 is a plane on which the first light receiving region 211 and the second light receiving region 212 having the same axis of symmetry are distributed. The first light-receiving area 211 has a square shape and is formed by a tooth surface of the first Fresnel lens, and the tooth surface includes a plurality of annular teeth 2111. The second light-receiving area 212 is located at a central position surrounded by the first light-receiving area 211, and is formed of a planar light-transmitting material (for example, a glass piece or a transparent plastic piece) having a square shape.

[0034] The second light receiving device 220 is disposed along the optical path after the first light receiving device. In this embodiment, the second light receiving device is served by a third Fresnel lens. The tooth surface of the third Fresnel lens can be regarded as a third light receiving area, which includes a plurality of annular teeth 2201. In other embodiments, the second light-receiving device may also divide the plurality of light-receiving regions similarly to the first light-receiving device, and adopt different optical designs in different light-receiving regions.

[0035] In this embodiment, by using two layers of light receiving devices, more design freedom can be provided to achieve higher The optical design of precision further enhances the convergence effect or improves the uniformity of light intensity on the focal plane.

[0036] As an alternative embodiment, the third Fresnel lens may adopt an astigmatic Fresnel lens to facilitate uniform distribution of light intensity. Further, optionally, the tooth flanks of the third Fresnel lens are composed of at least one linear Fresnel unit to achieve "linear" astigmatism or concentrating.

Example 3

Another embodiment of the Fresnel concentrating device according to the present invention can be referred to FIG. 4, including the first light receiving device 310.

The macroscopic shape of the first light receiving device 210 is a plane on which the first light receiving region 311 and the second light receiving region 312 having the same axis of symmetry are distributed.

[0040] wherein the first light receiving region 311 has a square shape and is formed by a tooth surface of the first Fresnel lens, and the tooth surface includes a plurality of annular ridges 3111. The second light-receiving area 312 is located at a central position surrounded by the first light-receiving area 311, and has a circular shape, formed by the tooth surface of the second Fresnel lens, and the tooth surface includes a plurality of annular ridges 3121 (in FIG. 4 Shown in dotted lines for easy viewing). The rib 3111 is different from the rib 3121 such that the first Fresnel lens has a different focal length from the second Fresnel lens.

In this embodiment, the back surface of the first Fresnel lens and the second Fresnel lens are further plated with a reflective film 3101, so that the apparatus of the present embodiment is formed as a reflective concentrating device. In other embodiments, the reflective concentrating device may be formed by providing a mirror on the optical path after the first light receiving surface.

Embodiment 4

Another embodiment of the Fresnel concentrating device according to the present invention can be referred to FIG. 5, including a first light receiving device 410, and a tapered concentrating device 430 and a tapered light guiding device 440.

The macroscopic shape of the first light-receiving device 410 is a plane on which two light-receiving regions having a square shape, that is, a first light-receiving region 411 and a second light-receiving region 412, which are nested inside and outside, are distributed. The first light receiving region 411 is located outside and is formed by the tooth flanks of the first Fresnel lens. The tooth flanks of the first Fresnel lens include a plurality of quadrilateral ribs 4111, each of which can be regarded as a linear Fresnel unit for concentrating toward a central region of the symmetry axis ZZ. The second light-receiving region 412 is located inside and is formed of a planar light transmissive material or is a hollowed cornice.

[0045] As a preferred embodiment, an auxiliary concentrating device, such as a conical concentrating device 430, is further disposed in the embodiment, and has a larger opening at one end and a smaller opening at the other end, and is disposed along the optical path. First light receiving device The rear end and the larger end of the cornice face the first light receiving region 411. The inner surface of the conical concentrating device 430 is formed by a mirror or a reflective linear astigmatic Fresnel lens for further concentrating the light from the first light receiving surface, thereby ensuring the uniformity of the light intensity. , further increase the concentration ratio.

Preferably, in this embodiment, a tapered light guiding device 440 is further disposed, which has a larger opening at one end and a smaller opening at the other end, and is disposed behind the first light receiving device along the optical path and has a larger opening. One end faces the second light receiving region 412. The tapered light guiding device 440 is disposed within the tapered concentrating device 430, and its inner and outer surfaces are formed by a mirror or a reflective linear astigmatic Fresnel lens. In addition to having a certain converging effect, the tapered light guiding device is also used to change the optical path to ensure that light from the first light receiving region and the second light receiving region is not reflected by the tapered light collecting device to the outside of the device.

In the present embodiment, the shape of the conical concentrating device and the conical light guiding device adopts a quadrangular frustum. The advantage of this shape is that it is convenient to arrange a plurality of concentrating devices together. In other embodiments, other shapes of frustum can also be used, such as a conical frustum, which can be determined according to design needs.

Embodiment 5

Another embodiment of the Fresnel concentrating device according to the present invention can refer to FIG. 6, including a first light receiving device 510, and a tapered concentrating device 530 and a tapered light guiding device 540.

[0050] The difference between this embodiment and the embodiment 4 is that the first light receiving region 511 and the second light receiving region 512 of the first light receiving device 510 have a circular contour, and the tooth surface of the first Fresnel lens is A plurality of circular toroids 5111 are formed. And, correspondingly, both the tapered concentrating device 530 and the tapered light guiding device 540 employ a conical frustum to better correspond to the contours of the first light receiving region 511 and the second light receiving region 512, respectively.

[0051] The advantage of using a conical shape is that the area of the side wall of the frustum is relatively small and easy to process. Moreover, many photovoltaic panels are currently circular in shape, so that circular concentrating devices are easier to match with existing photovoltaic panels, thereby reducing the overall cost of the system.

[0052]

The above embodiments are intended to be illustrative of the principles and embodiments of the present invention. It is understood that the above embodiments are only used to assist the understanding of the invention and are not to be construed as limiting. Variations to the above-described embodiments may be made by those skilled in the art in light of the teachings herein. . Industrial applicability

[0054] Enter the paragraph of industrial applicability description here. Sequence table free content

Type the sequence table free content description paragraph here.

Claims

Claim

[Claim 1] A Fresnel concentrating device, comprising:

a first light receiving device having a first light receiving surface, the first light receiving surface including a first light receiving region and a second light receiving region having the same symmetric axis,

The second light receiving area is located at a central area of the first light receiving surface, and the first light receiving area is located outside the second light receiving area.

The first light receiving region is formed by a tooth surface of the first Fresnel lens, and the first Fresnel lens is a concentrating Fresnel lens.

The second light receiving region is formed by the tooth surface of the second Fresnel lens, or is formed by a smooth surface or a cornice.

The focus of the first Fresnel lens is at a different location on the same optical axis as the focus of the second Fresnel lens, or on a different optical axis.

[Claim 2] The apparatus according to claim 1, wherein

The second Fresnel lens is an astigmatic Fresnel lens.

[Claim 3] The apparatus according to claim 1 or 2, wherein

The macroscopic shape of the first light receiving surface is a smooth curved surface selected from the group consisting of: a plane, a cylindrical surface, a second-order or a high-order polynomial circumferential symmetry plane.

[Claim 4] The apparatus according to claim 1 or 2, wherein

The macroscopic shape of the first light-receiving device is a ladder shape, the first light-receiving region is located around the ladder, and the second light-receiving region is located at the top of the ladder. The ladder is selected from the group consisting of: a spherical step, an ellipsoidal ladder, a high-order polynomial Circumferential symmetrical step, quadrilateral frustum, conical frustum.

[Claim 5] The device according to any one of claims 1 to 4, characterized in that it has at least one of the following features: a tooth surface of the first Fresnel lens or a tooth of the second Fresnel lens The face is composed of at least one linear Fresnel unit;

The first Fresnel lens or the second Fresnel lens is double-sided Fresnel through which both sides are tooth flanks

The back of the first Fresnel lens or the second Fresnel lens is plated with a reflective film or provided with a mirror

[Claim 6] The apparatus according to any one of claims 1 to 5, further comprising

The second light receiving device is disposed along the optical path after the first light receiving device, and the second light receiving device includes the third Fresnel lens.

[Claim 7] The apparatus according to claim 6, wherein at least one of the following features: the third Fresnel lens is an astigmatic Fresnel lens;

The tooth flanks of the third Fresnel lens consist of at least one linear Fresnel unit.

[Claim 8] The apparatus according to any one of claims 1 to 7, further comprising

The tapered concentrating device has a larger opening at one end and a smaller opening at the other end, and is disposed along the optical path after the first light receiving device and the larger end of the opening faces the first light receiving region.

The inner surface of the tapered concentrating device is formed by a mirror or a reflective linear astigmatic Fresnel lens.

[Claim 9] The apparatus according to claim 8, wherein

The shape of the tapered concentrating device is selected from the group consisting of: a quadrilateral frustum, a conical frustum.

[Claim 10] The device according to claim 8 or 9, further comprising

The tapered light guiding device has a larger opening at one end and a smaller opening at the other end, and is disposed along the optical path after the first light receiving device and the larger end of the opening faces the second light receiving region;

The inner surface and the outer surface of the tapered light guiding device are formed by a mirror or a reflective linear astigmatism type Fresnel lens;

The tapered light guiding device is disposed within the tapered concentrating device.