CN115980988B - Low-mirror-number annular Fresnel Gao Yun light system - Google Patents
Low-mirror-number annular Fresnel Gao Yun light system Download PDFInfo
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- CN115980988B CN115980988B CN202211616972.4A CN202211616972A CN115980988B CN 115980988 B CN115980988 B CN 115980988B CN 202211616972 A CN202211616972 A CN 202211616972A CN 115980988 B CN115980988 B CN 115980988B
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Abstract
The application discloses a low-mirror-number annular Fresnel Gao Yun light system which comprises an annular Fresnel condenser, fresnel lenses, a composite parabolic reflector and a receiver, wherein the annular Fresnel condenser comprises a plurality of annular radially distributed condensing lenses, the width of each condensing lens in the annular Fresnel condenser is sequentially increased from outside to inside, the Fresnel lenses are symmetrically arranged at the central position of the annular Fresnel condenser, the composite parabolic reflector is arranged below the focal point of the annular Fresnel condenser, the outline of the composite parabolic reflector is formed by rotating a standard parabola around a central axis, the inner surface of the composite parabolic reflector is a reflecting mirror, and the receiver is arranged below a light emitting opening of the composite parabolic reflector. The application can reduce the number of the mirror surfaces of the annular Fresnel condenser, can effectively reduce the manufacturing and assembling cost, and can achieve the optimal comprehensive performance of higher light concentration ratio and high uniform light spots by utilizing the secondary light homogenizing element composite parabolic reflector with matched design.
Description
Technical Field
The application belongs to the field of solar light condensation, relates to the technologies of comprehensive utilization of light and heat, high-power light condensation and uniform photovoltaics, and particularly relates to a low-mirror-surface-number annular Fresnel Gao Yun light system.
Background
The Chinese operators are wide, and have extremely rich solar energy resources. According to statistical data analysis, the total amount of solar radiation received by China land area every year is equivalent to 24 multiplied by 10 4 Reserve of hundred million tons of standard coal. Solar energy is taken as a renewable new energy source, has the advantages of cleanness, environmental protection, persistence, long time and the like, becomes one of important choices for coping with energy shortage, climate change, energy conservation and emission reduction, and has great development prospects that the large-scale utilization can effectively reduce the dependence on fossil energy sources. However, since the energy density is low and the direct utilization efficiency is low, it is necessary to use a condenser to improve the utilization efficiency. Solar concentrators are currently widely used in the field of solar concentration, such as solar power generation, solar fuel production, solar lighting, solar pump lasers, photobiological and photochemical interactions, and the like.
Solar concentrators are important optical elements in the overall concentrating system and are one of the main factors affecting the efficiency of the overall concentrating system. Solar concentrators alter the optical path, primarily by reflection or refraction. For example, parabolic trough concentrators, linear fresnel concentrators and dish concentrators are reflective concentrators, and fresnel lenses are refractive concentrators.
Most concentrators have uneven concentration distribution, incident solar rays form local hot spots on a receiving surface after being focused, the local hot spots can reduce the conversion efficiency of a battery in the field of concentrating photovoltaics, damage the battery, shorten the service life of the battery, and cause the local temperature of a catalyst to be too high in the field of photochemistry, so that the catalyst is reduced or even loses activity. Therefore, finding a condensing system that can uniformly condense light has become one of the important issues.
Compared with a parabolic condenser and a disc condenser, the annular Fresnel condensing focal point is arranged below the parabolic condenser, so that the receiver can be placed below the parabolic condenser, the receiver is prevented from shielding solar rays, and the solar ray utilization efficiency is improved. And also placed underneath to facilitate maintenance of the receiver.
However, the inclination angles of two adjacent annular mirror surfaces of the existing annular Fresnel condenser are very small, so that the number of the mirror surfaces is large, the manufacturing difficulty is increased, the debugging difficulty is increased, and the cost is high; and meanwhile, the mirror surface of the annular Fresnel condenser is difficult to clean and maintain. The annular Fresnel condenser is in a point focusing mode, the uniformity of light spots is extremely low while the condensing ratio is high, and the problem that the high condensing ratio and the uniform illumination are mutually restricted exists, so that the condensing effect is difficult to reach an ideal state.
Disclosure of Invention
The application aims to: in order to overcome the defects that the existing annular Fresnel condenser is high in manufacturing precision requirement and extremely uneven in condensing light spot energy distribution and difficult to meet comprehensive utilization requirements of high condensing light and high light spot uniformity, the annular Fresnel Gao Yun optical system with low mirror number is provided, the design of the annular Fresnel condenser is optimized, the purpose of reducing the mirror number of the annular Fresnel condenser is achieved, manufacturing and assembling costs can be effectively reduced, and accordingly the overall cost of the system is reduced.
The technical scheme is as follows: in order to achieve the above purpose, the application provides a low-mirror-number annular Fresnel Gao Yun light system, which comprises an annular Fresnel condenser, fresnel lenses, a composite parabolic reflector and a receiver, wherein the annular Fresnel condenser comprises a plurality of annular radially distributed condensing lenses, the widths of the condensing lenses in the annular Fresnel condenser are sequentially increased from outside to inside, the Fresnel lenses are symmetrically arranged at the central position of the annular Fresnel condenser, the composite parabolic reflector is arranged below the focal point of the annular Fresnel condenser, the outline of the composite parabolic reflector is formed by rotating a standard parabola around a central axis, the inner surface of the composite parabolic reflector is a reflecting mirror, the receiver is arranged below a light emitting opening of the composite parabolic reflector, the composite parabolic reflector is used for carrying out secondary light homogenization on focused light, and the receiver is used for receiving the light after secondary light homogenization.
Further, the condensing mirrors are symmetrically arranged with the central axis. The annular fresnel concentrators vary in mirror width, length, position, and tilt angle for each concentrator lens, but each ring has a common central axis of rotation.
Further, the condenser is a silver-plated condenser. The silver plating condenser can ensure that the reflectivity of each ring of mirror surface is the same, and each ring of mirror surface maintains consistent roughness, so that the reflection angle of solar rays is the same, and the solar rays are focused at the same position.
Further, the method for obtaining the mirror surface parameters of each condensing lens in the annular Fresnel condenser comprises the following steps:
the mirror surfaces of the condenser lenses from outside to inside are respectively a 1 st mirror surface, a 2 nd mirror surface, an n th mirror surface, and the outer radius of the annular mirror surface is a out An inner radius of a in Considering the thickness of the mirror surface, the gap between two adjacent mirror surfaces is set as the thickness d of the mirror surface t ；
All the mirrors of the condenser have the same focal length, which is set as h f ；
The lower ends of the mirror surfaces of all the collecting mirrors are positioned on the same horizontal line;
let the mirror surface height be H n The horizontal width of the annular mirror surface is delta a n ；
Definition of the definition
Radius of curvature of the annular mirror
Height of arbitrary annular mirror
The parameters of the first ring mirror determine the remaining mirror parameters, which are defined by a out1 Can obtain a in1 ；
The mirror parameters of the second mirror can be found:
a out2 ＝a in1 -d t ；
radius of curvature
Mirror height
And obtaining a second ring mirror surface parameter from the first ring mirror surface parameter, and sequentially obtaining the rest mirror surface parameters in an iterative manner.
Further, the Fresnel lens is a circular lens.
Further, the receiver is of a circular structure, the area of the receiver is smaller than that of the light emergent opening of the compound parabolic reflector, and the receiver is positioned below the light emergent opening of the compound parabolic reflector.
Further, the composite parabolic reflector is hollow, has no upper and lower round bottom surfaces, and is provided with a receiving opening facing the light collecting direction.
Further, the focal length of the Fresnel lens is equal to that of the annular Fresnel condenser, and the Fresnel lens and the annular Fresnel condenser are all arranged inside the composite parabolic reflector.
Further, the part above the focus of the compound parabolic reflector is cut off, and only the part below the focus is reserved, so that the cost can be reduced while the light homogenizing effect is not influenced.
According to the application, the design of the annular Fresnel condenser is optimized, the lowest point of each ring is kept on the same horizontal line, the width of the mirror surface of each ring is prolonged, the mirror surface area of each ring is increased, and the mirror surface area of each ring is increased under the condition of the same mirror field occupation area, so that the purpose of reducing the number of the mirror surfaces of the annular Fresnel condenser is achieved.
The beneficial effects are that: compared with the prior art, the application has the following advantages:
1. the application improves the annular Fresnel condenser, the width of the condenser lens is sequentially increased from outside to inside, the inclination angle of the mirror surface can be sequentially increased by adopting the design structure, the number of the mirror surfaces can be reduced by adopting the design structure, and the manufacturing and assembling cost can be effectively reduced, so that the overall cost of the system is reduced.
2. On the premise of not changing the structure of the condenser, the optimal comprehensive performance of high light concentration ratio and high uniform light spots is achieved by utilizing the secondary light homogenizing element composite parabolic reflector which is matched with the condenser, light is focused by the condenser, and after entering the composite parabolic reflector for homogenizing, the light spots with uniform energy distribution can be output at high output, the comprehensive utilization of the light spots with high light concentration ratio and high light spot uniformity can be realized, and the problem that the high light concentration ratio and the illumination uniformity are mutually restricted is solved.
3. On the basis of keeping high light concentration ratio, the uniformity of output light spots can be improved, the problem of local hot spots is solved, and the uniform light concentration effect is improved.
Drawings
FIG. 1 is a schematic structural diagram of a circular Fresnel condensing and homogenizing system provided by the application;
FIG. 2 is a schematic diagram of a system apparatus according to the present application;
FIG. 3 is a graph of the output energy profile on a receiving surface with a focal length of the annular Fresnel concentrator of 500mm, a radius of 500m, and a focal length of the compound parabolic reflector of 30mm, with an axial tilt of 40;
fig. 4 is a plot of output spot uniformity trend for the system of fig. 1 with an axis tilt varying between 20 ° and 70 °.
Detailed Description
The present application is further illustrated in the accompanying drawings and detailed description which are to be understood as being merely illustrative of the application and not limiting of its scope, and various modifications of the application, which are equivalent to those skilled in the art upon reading the application, will fall within the scope of the application as defined in the appended claims.
As shown in fig. 1, the application provides a low-mirror-number annular Fresnel Gao Yun optical system, which comprises an annular Fresnel condenser 1, a Fresnel lens 2, a composite parabolic reflector 3 and a receiver 4, wherein the Fresnel lens 2 is made of acrylic, the manufacturing cost is low, the annular Fresnel condenser 1 comprises 7 annular radially distributed condensers which are silver-plated condensers, all the condensers are symmetrically arranged with a central axis, the mirror width, the length, the position and the inclination angle of each condenser in the annular Fresnel condenser 1 are different, but each ring has a common rotation central axis, the widths of the condensers in the annular Fresnel condenser 1 are sequentially increased from outside to inside, the Fresnel lens 2 with a circular structure is symmetrically arranged at the central position of the annular Fresnel condenser 1, the compound parabolic reflector 3 is arranged below the focal point of the annular Fresnel condenser 1, the outline of the compound parabolic reflector 3 is formed by rotating a standard parabola around a central axis, the inner surface is a reflecting mirror surface, the inside of the compound parabolic reflector 3 is hollow, the part above the focal point of the compound parabolic reflector 3 is cut off, only the part below the focal point is reserved, no upper round bottom surface and no lower round bottom surface are arranged, the narrower surface is a receiving port, the receiving port faces the light collecting direction, the focal length of the Fresnel lens 2 is equal to the focal length of the annular Fresnel condenser 1, the area of the receiver 4 with a circular structure is smaller than the area of the light outlet of the compound parabolic reflector 3, and the area of the receiver 4 with the circular structure is positioned below the light outlet of the compound parabolic reflector 3.
The method for obtaining the mirror surface parameters of 7 condensing mirrors in the annular Fresnel condenser in the embodiment is as follows:
the mirror surfaces of the condenser lenses from outside to inside are respectively a 1 st mirror surface, a 2 nd mirror surface, a 7 th mirror surface, and the outer radius of the annular mirror surface is a out An inner radius of a in Considering the thickness of the mirror surface, the gap between two adjacent mirror surfaces is set as the thickness d of the mirror surface t ；
All the mirrors of the condenser have the same focal length, which is set as h f ；
The lower ends of the mirror surfaces of all the collecting mirrors are positioned on the same horizontal line;
let the mirror surface height be H n The horizontal width of the annular mirror surface is delta a n ；
Definition of the definition
Radius of curvature of the annular mirror
Height of arbitrary annular mirror
The parameters of the first ring mirror determine the remaining mirror parameters, which are defined by a out1 Can obtain a in1 ；
The mirror parameters of the second mirror can be found:
a out2 ＝a in1 -d t ；
radius of curvature
Mirror height
And obtaining a second ring mirror surface parameter from the first ring mirror surface parameter, and sequentially obtaining the rest mirror surface parameters in an iterative manner.
The parameters of each of the remaining ring mirrors can be obtained by determining the outer radius of the outermost mirror, the horizontal projection width of the mirror, the focal length of the ring fresnel concentrator 1, and the thickness of each ring mirror.
In this embodiment, the above annular fresnel Gao Yun optical system is applied as an example, specifically:
as shown in fig. 2, the focal point of the compound parabolic reflector 3 is located at a position 15mm below the focal point of the condenser, and at this time, the diameter of the light spot is just smaller than the incident caliber of the light ray of the compound parabolic reflector 3, so that the area of the light spot is maximized and higher receiving rate is ensured;
the inclination of the axis of the compound parabolic reflector 3 is the included angle between the symmetry axis of the parabola and the rotation center axis, and when the focal length of the compound parabolic reflector 3 is determined, the shape of the standard parabola can be determined; in the embodiment, the focal length of the compound parabolic reflector 3 is determined to be 30mm, the inclination of the axis is 40 degrees, and as the light reflection is mainly concentrated on the inner surface of the lower end of the compound parabolic reflector, the light reflection is cut off from above the focal point of the compound parabolic reflector, and only the lower end is reserved, so that the cost can be reduced while the light homogenizing effect is not influenced;
referring to fig. 2, solar rays are irradiated on the annular fresnel condenser 1, the rays are focused at a focal point under the reflection and light transmission effects of all the condensing mirrors and the fresnel lens 2, focused solar rays have a high condensing ratio, but the light spot energy distribution is uneven, the focused solar rays enter the compound parabolic reflector 3, the uniform light is reflected by the internal reflecting mirrors, and the uniform light irradiates the receiver 4.
In order to verify the actual effect of the annular Fresnel Gao Yun light system provided by the application, the final performance data is detected as follows:
FIG. 3 is a graph showing the distribution of output energy on a receiving surface of a ring Fresnel condenser having a focal length of 500mm, a radius of 500m and a compound parabolic reflector having a focal length of 30mm and an axial tilt of 40. As can be seen from FIG. 3, irradiance distribution is relatively dispersed, and the average irradiance reaches 59150W/m within a radius of 40mm on the receiving surface 2 Irradiance maximum of 76163W/m 2 The uniformity of the light spot reaches 0.8743. The average irradiance in the receiving plane of the non-compound parabolic reflector is 124260W/m 2 Irradiance maximum of 18033000W/m 2 The uniformity of the light spot is 0.0137, so that the uniformity of the light spot is greatly improved.
The average irradiance in the receiving surface is 124260W/m 2 Down to 76163W/m 2 I.e. the condensing ratio is reduced by about 50% and is 76 times, the theoretical temperature reached by the condensing ratio can meet most of the demands.
Fig. 4 shows a trend of uniformity of light spots output by the system according to the present application when the inclination of the axis is changed from 20 ° to 70 °, it can be seen that the uniformity of illumination on the surface of the receiver 4 may be more than 0.85, and in practical application, the uniformity may be more than 0.7, which is considered to be uniform.
Claims (7)
1. The annular Fresnel Gao Yun light system with the low mirror number is characterized by comprising an annular Fresnel condenser, fresnel lenses, a composite parabolic reflector and a receiver, wherein the annular Fresnel condenser comprises a plurality of annular radially distributed condensing lenses, the widths of the condensing lenses in the annular Fresnel condenser are sequentially increased from outside to inside, the Fresnel lenses are symmetrically arranged at the center position of the annular Fresnel condenser, the composite parabolic reflector is arranged below the focus of the annular Fresnel condenser, the outline of the composite parabolic reflector is formed by rotating a standard parabola around a central axis, the inner surface of the composite parabolic reflector is a reflecting mirror, the receiver is arranged below a light outlet of the composite parabolic reflector, and the composite parabolic reflector is used for carrying out secondary light homogenization on focused light;
the method for acquiring the mirror surface parameters of each condensing lens in the annular Fresnel condenser comprises the following steps:
the mirror surfaces of the condenser lenses from outside to inside are respectively a 1 st mirror surface, a 2 nd mirror surface, an n th mirror surface, and the outer radius of the annular mirror surface is a out An inner radius of a in Considering the thickness of the mirror surface, the gap between two adjacent mirror surfaces is set as the thickness d of the mirror surface t ；
All the mirrors of the condenser have the same focal length, which is set as h f ；
The lower ends of the mirror surfaces of all the collecting mirrors are positioned on the same horizontal line;
let the mirror surface height be H n The horizontal width of the annular mirror surface is delta a n ；
Definition of the definition
Radius of curvature of the annular mirror
Height of arbitrary annular mirror
The parameters of the first ring mirror determine the remaining mirror parameters, which are defined by a out1 Can obtain a in1 ；
The mirror parameters of the second mirror can be found:
a out2 ＝a in1 -d t ；
radius of curvature
Mirror height
Obtaining a second annular mirror surface parameter by the first annular mirror surface parameter, and sequentially obtaining the rest mirror surface parameters in an iterative manner;
the composite parabolic reflector is hollow, has no upper and lower round bottom surfaces, and has a narrower surface which is a receiving port and faces the light collecting direction.
2. A low mirror count annular fresnel Gao Yun light system according to claim 1 wherein said collection mirrors are symmetrically disposed about a central axis.
3. A low mirror number annular fresnel Gao Yun gloss system according to claim 1 or 2, wherein the condenser is a silvered condenser.
4. A low mirror number annular fresnel Gao Yun light system according to claim 1, wherein the fresnel lens is a circular lens.
5. A low mirror number annular fresnel Gao Yun light system according to claim 1 wherein the receiver is of circular configuration having an area less than the light exit area of the compound parabolic reflector and is positioned below the compound parabolic reflector light exit.
6. A low mirror number annular fresnel Gao Yun light system according to claim 1 wherein the focal length of the fresnel lens is equal to the focal length of the annular fresnel concentrator and the focal points are all above the compound parabolic reflector.
7. A low mirror number annular fresnel Gao Yun light system according to claim 1, wherein the upper focal portion of the compound parabolic reflector is truncated and only the lower focal portion remains.
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| CN116931258B (en) * | 2023-06-29 | 2024-02-23 | 西安电子科技大学 | Multi-ring band grouping light-equalizing Fresnel lens design method for condensing system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101694540A (en) * | 2009-08-13 | 2010-04-14 | 苏州纳米技术与纳米仿生研究所 | Fresnel spotlight and realization method thereof |
| CN102621693A (en) * | 2012-03-19 | 2012-08-01 | 泰山集团泰安市普瑞特机械制造有限公司 | Light balancing device for concentrated solar energy |
| CN104849844A (en) * | 2015-03-19 | 2015-08-19 | 浙江大学 | Dish type Fresnel reflection concentration method and apparatus thereof |
| CN107884851A (en) * | 2017-12-25 | 2018-04-06 | 西安邮电大学 | A kind of wide scope submarine optical communication optical receiver antenna with even light |
| CN107919848A (en) * | 2016-10-11 | 2018-04-17 | 华北电力大学 | A kind of annular linear Fresnel high power concentrator device |
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- 2022-12-15 CN CN202211616972.4A patent/CN115980988B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101694540A (en) * | 2009-08-13 | 2010-04-14 | 苏州纳米技术与纳米仿生研究所 | Fresnel spotlight and realization method thereof |
| CN102621693A (en) * | 2012-03-19 | 2012-08-01 | 泰山集团泰安市普瑞特机械制造有限公司 | Light balancing device for concentrated solar energy |
| CN104849844A (en) * | 2015-03-19 | 2015-08-19 | 浙江大学 | Dish type Fresnel reflection concentration method and apparatus thereof |
| CN107919848A (en) * | 2016-10-11 | 2018-04-17 | 华北电力大学 | A kind of annular linear Fresnel high power concentrator device |
| CN107884851A (en) * | 2017-12-25 | 2018-04-06 | 西安邮电大学 | A kind of wide scope submarine optical communication optical receiver antenna with even light |
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