CN121124716A

CN121124716A - A solar photovoltaic-photothermal full-spectrum utilization system

Info

Publication number: CN121124716A
Application number: CN202511297687.4A
Authority: CN
Inventors: 韩巍; 宋新阳; 焦钒; 刘丽莎
Original assignee: Institute of Engineering Thermophysics of CAS
Current assignee: Institute of Engineering Thermophysics of CAS
Priority date: 2025-09-11
Filing date: 2025-09-11
Publication date: 2025-12-12

Abstract

This invention provides a solar photovoltaic-thermal full-spectrum utilization system, comprising: a photovoltaic power generation system and a solar thermal subsystem. The photovoltaic power generation system includes: a photovoltaic array comprising multiple photovoltaic devices arranged in an array; each photovoltaic device has a spectrally selective beam splitter on its light-receiving surface, the spectrally selective beam splitter being used to transmit beams of sunlight in a preset wavelength band and reflect beams of sunlight in a non-preset wavelength band, the photovoltaic device being adapted to convert the transmitted beams into direct current electrical energy; the solar thermal subsystem includes a linear absorber arranged above the center of the photovoltaic array, receiving the beams reflected by the beam splitter and converting the received beams into thermal energy; wherein the orientation of each of the multiple photovoltaic devices is configured such that the beams reflected by all the beam splitters form a focal band at the linear absorber, thereby realizing the thermal energy conversion of the received beams by the linear absorber.

Description

Solar photovoltaic-photo-thermal full spectrum utilization system

Technical Field

The invention relates to a solar comprehensive utilization technology, in particular to a solar photovoltaic-photo-thermal full spectrum utilization system.

Background

Solar energy is the most abundant renewable energy source on earth, and its efficient development and utilization is critical to sustainable energy supply. The solar energy utilization mode is mainly divided into photoelectric conversion and photo-thermal conversion, wherein the photoelectric conversion directly converts solar energy into electric energy through a photovoltaic cell, and the photo-thermal conversion utilizes solar radiation to heat working media so as to realize heat energy storage and application. However, due to non-uniformity of the solar spectrum and limitations of the prior art, photovoltaic and photo-thermal systems each have short plates in terms of energy utilization.

The current photovoltaic system mainly relies on semiconductor materials to absorb visible light with high energy and perform photoelectric conversion, but has limited utilization capacity on the spectrum of an infrared band, so that a large amount of solar energy is not effectively converted, and the overall efficiency of the system is affected. Meanwhile, the spectral response range of the photovoltaic cell is limited by materials, so that the energy utilization rate is difficult to break through the existing bottleneck. Although multi-junction photovoltaic cells or spectral separation techniques can extend the absorption range, their manufacturing cost is high, limiting large-scale applications. In contrast, photothermal systems are capable of directly absorbing solar radiation (including infrared light) in a wider band, but conventional photothermal conversion paths are longer, and additional concentrating devices are generally required to concentrate sunlight to a high temperature absorber to increase temperature and increase energy utilization. This approach increases system complexity and construction costs, while being limited by optical and thermodynamic efficiency, heat loss is difficult to avoid.

Disclosure of Invention

In view of this, the present invention provides a system for solar photovoltaic-photothermal complementation.

According to an embodiment of the invention, the solar photovoltaic-photothermal complementary system comprises:

a photovoltaic power generation subsystem comprising:

The photovoltaic array comprises a plurality of photovoltaic devices distributed in an array manner, wherein a light receiving surface of each photovoltaic device is provided with a spectrum selective light splitting film, the spectrum selective light splitting film is used for transmitting light beams with preset wave bands in sunlight and reflecting light beams with non-preset wave bands in the sunlight, and the photovoltaic devices are suitable for converting the transmitted light beams into direct-current electric energy;

A solar photo-thermal subsystem including a linear absorber disposed over a center of the photovoltaic array, receiving the light beam reflected by the light splitting film, and performing thermal energy conversion on the received light beam;

Wherein the pose of each of the plurality of photovoltaic devices is configured to cause the light beams reflected by all of the light splitting films to form focal zones at the linear absorber, thereby effecting thermal energy conversion of the received light beams by the linear absorber.

According to the embodiment of the invention, the preset wave band is 400-1100 nm, the average transmittance of the spectrum selective light splitting film to the wave band of 400-1100 nm is more than or equal to 90%, and the average reflectivity is more than or equal to 85% in the wave band of 280-400 nm and the wave band of 1100-2500 nm.

According to an embodiment of the invention, the solar photo-thermal subsystem further comprises:

And the secondary condenser is used for secondarily capturing and converging the light beams which are not directly received by the linear absorber and reflected by the spectrum selective light splitting film, and reflecting the converged light beams to the linear absorber.

According to an embodiment of the invention, the secondary concentrator is a compound parabolic concentrator and the outer wall of the linear absorber is provided with an absorption-selective coating to reduce radiation losses.

According to the embodiment of the invention, the installation height of the linear absorber is higher than the height of the photovoltaic array, and the height difference between the linear absorber and the photovoltaic array is 6-8 m, preferably 6 m.

According to an embodiment of the invention, the photovoltaic power generation subsystem further comprises:

And the ray tracking mechanism is used for adjusting the inclination angle of each photovoltaic device in a linkage way along with the change of the solar altitude angle so that the light beam reflected by the spectrum selective light splitting film can be always reflected to the linear absorber.

According to an embodiment of the present invention, the spectrally selective beam splitting film is an all-dielectric multilayer interference film comprising alternately stacked high refractive index dielectric layers and low refractive index dielectric layers, wherein the high refractive index dielectric comprises、Or (b)At least one or more of the low refractive index media comprisesOr (b)At least one or more of;

the spectrally selective light splitting film is deposited on the outside glass surface of the photovoltaic device,

An antireflection film is arranged on the battery side of the photovoltaic device.

According to an embodiment of the present invention, the spectrally selective spectral film is configured to have band-edge drift within a range such that the passband is not lower than 380 nm and not higher than 1150 nm.

and an inverter for converting the direct current power into alternating current power.

According to embodiments of the invention, the solar photo-thermal subsystem is in fluid communication with a thermal storage device and/or a thermochemical reaction device to effect thermal energy storage, heat exchange, or process heating.

The solar photovoltaic-photo-thermal complementary system provided by the embodiment of the invention realizes the full spectrum efficient utilization of sunlight by plating the selective light splitting film on the surface of the photovoltaic device, wherein the light splitting film can enable visible light and partial infrared light in a wave band of 400-1100nm to be transmitted to the photovoltaic device for efficient power generation, and simultaneously reflect ultraviolet light in a wave band of 280-400nm and infrared light in a wave band of 1100-2500nm to the solar photo-thermal subsystem for converting the ultraviolet light into heat energy, so that the solar photovoltaic-photo-thermal complementary system has the dual functions of power generation and light condensation, the full spectrum utilization of solar energy can be realized, the thermal load of the photovoltaic device can be reduced, the problem of photoelectric conversion efficiency reduction caused by high temperature is avoided, the long-term stability and the working performance of the photovoltaic device are improved, and the service life of the photovoltaic device is prolonged.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 shows a schematic diagram of a solar photovoltaic-photothermal complementary system according to an embodiment of the present invention.

Fig. 2 shows a layout of individual photovoltaic devices in a photovoltaic array provided according to an embodiment of the present invention.

Description of the reference numerals

1 Photovoltaic power generation subsystem

11 Photovoltaic device

12 Spectral selectivity light splitting film

13 Ray tracing mechanism

2 Solar photo-thermal subsystem

21 Support assembly

22 Linear absorber

23 Secondary condenser

Detailed Description

In the process of realizing the invention, the Fresnel condensing system is used as an efficient solar condensing technology, and sunlight is reflected and focused on the linear receiver through a plurality of groups of plane mirrors, so that the photo-thermal conversion efficiency is improved. Compared with the traditional parabolic trough type condensation system, the Fresnel reflector system has the advantages of simple structure, low cost, suitability for large-scale deployment and the like, and is widely applied to the field of photo-thermal power generation. However, the existing fresnel system mainly focuses on photo-thermal utilization, and cannot effectively combine with photovoltaic technology, so that the multiband energy advantage of solar spectrum is fully exploited. Therefore, how to efficiently cooperate with the photovoltaic and photo-thermal technology and optimize the full spectrum utilization of solar energy becomes an important research direction for improving the comprehensive utilization efficiency of solar energy.

The present invention will be further described in detail below with reference to specific embodiments and with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprises," "comprising," and/or the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

It should be noted that, in the embodiments, directional terms, such as "upper", "lower", "front", "rear", "left", "right", etc., refer to the directions of the drawings only, and are not intended to limit the scope of the present invention. Like elements are denoted by like or similar reference numerals throughout the drawings. Conventional structures or constructions will be omitted when they may cause confusion in understanding the present invention.

Fig. 1 shows a schematic diagram of a solar photovoltaic-photothermal complementary system provided according to an embodiment of the invention.

As shown in fig. 1, the solar photovoltaic-photothermal complementary system comprises a photovoltaic power generation subsystem 1 and a solar photothermal subsystem 2. The photovoltaic power generation subsystem comprises a photovoltaic array, the photovoltaic array comprises a plurality of photovoltaic devices 11 distributed in an array mode, a spectrum selective light splitting film 12 is arranged on a light receiving surface of each photovoltaic device 11, the spectrum selective light splitting film 12 is suitable for transmitting light beams with preset wave bands in sunlight and reflecting light beams with non-preset wave bands (other wave bands) in the sunlight, and the photovoltaic devices 11 are suitable for converting the light beams transmitted through the selective light splitting films into direct-current electric energy. The solar photo-thermal subsystem 2 comprises a linear absorber 15 arranged above the center of the photovoltaic array 1, receives the light beams reflected by the light splitting films, and performs thermal energy conversion on the received light beams, which is suitable for receiving the light beams reflected by the plurality of spectrum-selective light splitting films, and performs thermal energy conversion on the received light beams.

Wherein the respective poses of the plurality of photovoltaic devices 11 of the preset wave band are configured to cause the light beams reflected by all the light-splitting films of the preset wave band to form focal zones at the linear absorber, thereby realizing the thermal energy conversion of the received light beams by the linear absorber of the preset wave band.

The solar photovoltaic-photo-thermal complementary system provided by the embodiment of the invention realizes the full spectrum efficient utilization of sunlight by plating the spectrum selective light splitting film 12 on the surface of the photovoltaic device 11, wherein the spectrum selective light splitting film 12 can enable visible light with a wave band of 400-1100nm to be transmitted to the photovoltaic device 11 for efficient power generation, and simultaneously reflects ultraviolet light with a wave band of 280-400nm and infrared light with a wave band of 1100-2500nm to the solar photo-thermal subsystem for converting into heat energy, so that the solar photovoltaic-photo-thermal complementary system has the dual functions of power generation and light condensation, the full spectrum utilization of solar energy can be realized, the thermal load of the photovoltaic device can be reduced, the problem of photoelectric conversion efficiency reduction caused by high temperature is avoided, the long-term stability and the working performance of the photovoltaic device are improved, and the service life of the photovoltaic device is prolonged.

According to an embodiment of the invention, the photovoltaic devices 11 are distributed in an array at a specific inclination angle (generally less than 30 °), for example forming a bilaterally symmetrical arrangement of the linear fresnel-type condenser fields, the photovoltaic panels of the columns (called columns in a direction parallel to the extension direction of the linear absorber) being arranged in parallel straight lines, all facing the same linear absorber. A solar photothermal subsystem (e.g., a linear absorber) that precisely concentrates the reflected light beam to a central location. The design omits an independent condensing reflector of the traditional photo-thermal system, reduces optical loss and system complexity, and reduces the occupied area.

According to the embodiment of the invention, the preset wave band is 400-1100 nm. The average transmittance of the spectrum selective light-splitting film 12 to the wave band of 400-1100 nm is more than or equal to 90%, and the average reflectivity is more than or equal to 85% in the wave band of 280-400 nm and the wave band of 1100-2500 nm.

The spectrum cut-off boundary between the 400-1100 nm wave band and the adjacent 280-400 nm and 1100-2500 nm wave bands is clear, no obvious transition wave band exists (namely, the condition that the preset wave band is too high in reflection or the non-target wave band is too high in transmission does not occur), the spectrum screening accuracy is ensured, and the efficiency of heat conversion and light conversion is ensured.

According to an embodiment of the present invention, the spectrally selective beam splitting film is an all-dielectric multilayer interference film comprising alternating layers of high refractive index medium and low refractive index medium, wherein the high refractive index medium comprises、Or (b)At least one or more of the low refractive index media comprisesOr (b)At least one or more of (a) and (b).

According to an embodiment of the present invention, the spectrally selective spectral film is configured to have band-edge drift within a range such that the passband is not lower than 380 nm and not higher than 1150 nm. 380 nm is the boundary point of visible light and ultraviolet light, the wave band below 380 nm cannot be converted into electric energy by the photovoltaic cell, and ageing and yellowing of component packaging materials (EVA adhesive films and back plates) can be accelerated, so that the long-term power generation efficiency is attenuated. The lower limit of the drift of the band edge is not less than 380 nm, the passband of the light splitting film can be ensured not to extend towards the ultraviolet region, invalid ultraviolet light is prevented from entering the photovoltaic system, the ultraviolet light can not occupy passband resources (the effective light transmittance is reduced), the high reflectivity of the ultraviolet light below 380 nm can be realized through the light splitting film, the corrosion of the light splitting film to a battery and packaging materials is reduced, and the long-term power generation stability of the photovoltaic device is ensured. The upper limit of the band edge drift is less than or equal to 1150 nm, the passband of the light splitting film is ensured not to excessively extend towards the near infrared long wave region, only the high-efficiency response wave band within 1150 nm is reserved, the heat loss caused by invalid light entering a battery is reduced, meanwhile, near infrared long waves above 1150 nm are accurately reflected to a photo-thermal system (such as a linear absorber) and converted into heat energy for use, the spectrum utilization mismatch of photovoltaic-photo-thermal is avoided, and the total utilization rate of full spectrum energy is ensured.

Compared with the light splitting film (such as aluminum and silver film) containing the metal layer,、The all-dielectric material has excellent weather resistance (high temperature resistance, humidity resistance, ultraviolet aging resistance) and chemical stability. The long-term exposure to the outdoor environment can not generate the attenuation of the spectral performance caused by metal oxidation and corrosion, ensure the long-term effectiveness of the spectral selectivity light splitting film and prolong the stable operation period of the system. When the spectrum selective light splitting film is deposited on the outer glass of the photovoltaic device, if the light splitting film is damaged in subsequent maintenance, the surface of the glass is only required to be treated, a photovoltaic cell is not required to be disassembled, and the operation and maintenance cost is reduced. The spectrum selective light splitting film is deposited on the surface of the outer glass of the photovoltaic device, and an antireflection film is arranged on the battery side of the photovoltaic device.

The photovoltaic power generation subsystem further comprises a ray tracing mechanism 13 for adjusting the inclination angle of each photovoltaic device 11 in a linkage manner along with the change of the solar altitude, so that the light beams reflected by the spectrum selective beam splitting films can be always reflected to the linear absorber 22.

According to an embodiment of the present invention, the main purpose of the present invention is to provide the ray tracing mechanism 13 to ensure that the inclination angle of each photovoltaic device 11 matches the solar altitude by synchronously adjusting the inclination angle of the photovoltaic devices 11 when the solar altitude is dynamically changed. The arrangement of the ray tracing mechanism 13 has the advantages of firstly maintaining the stability of the formation of the fresnel mirror type optical arrangement, making the inclination angles of the respective photovoltaic devices 11 parallel to the extending direction of the linear absorber 15 the same, ensuring that the respective reflected light is always accurately converged to the solar photo-thermal subsystem, and secondly, by tracing the sun position in real time, enabling the panel of the photovoltaic device 11 to always receive sunlight efficiently (for example, the panel of the photovoltaic device is perpendicular to the incident ray), reducing the energy loss (i.e. reducing cosine loss) caused by non-perpendicular incidence of the ray. While the ray tracing mechanism 13 is also capable of maintaining the optimum operating angle of the spectrally selective light-splitting film 12. Therefore, the ray tracing mechanism 13 can make the photovoltaic device 11 meet the requirement of tracking the maximum power point of photovoltaic power generation and consider the requirement of the light condensing function of the photo-thermal system.

According to an embodiment of the invention, the solar photo-thermal subsystem 2 comprises a support assembly 21, a linear absorber 22, a secondary concentrator 23. The linear absorber 22 is mounted on the support assembly 21 and is adapted to receive the light beam reflected by the spectrally selective beam splitting film 12 and to convert the received light beam into thermal energy. The secondary condenser 23 is erected on the linear absorber 22, and is adapted to secondarily capture and condense the light beam reflected by the spectrally selective light-splitting film 12 and not directly received by the linear absorber, and reflect the condensed light beam to the linear absorber 22.

According to the embodiment of the invention, the linear absorber 22 directly receives the light beam reflected by the light splitting film to realize high-efficiency photo-thermal conversion, the secondary condenser 23 is utilized to carry out secondary capture and focusing on the escaping light beam, the photo-thermal conversion efficiency of the system is improved, and the cooperative work of the linear absorber 22 and the secondary condenser 23 effectively reduces the energy loss, so that the solar photo-thermal subsystem 2 can stably and efficiently finish heat energy conversion and collection. The solar heat energy absorbed by the linear absorber 22 is conducted to an internal working medium (such as molten salt, heat conducting oil or chemical raw material) through the pipe wall for heat energy storage and conversion, and a small amount of heat energy is dissipated in the forms of heat radiation and convection, so that the heat loss can be reduced through optimizing the structural design, and the overall heat efficiency of the system can be improved.

According to an embodiment of the present invention, the secondary concentrator 23 has a compound parabolic structure. According to the embodiment of the invention, the special parabolic curved surface design of the compound parabolic secondary condenser (CPC) can effectively capture the edge light beams escaping from the reflection of the photovoltaic array, the light-heat conversion efficiency is improved through secondary focusing, the CPC and the linear absorber 22 form a light trap structure, the heat energy radiated by the surface of the absorber is reflected and recovered, the heat loss is reduced, and finally, the wide-angle receiving characteristic of the CPC is perfectly matched with the dynamic tracking of the Fresnel photovoltaic array, and the stable light-gathering effect can be maintained when the solar altitude changes.

According to the embodiment of the invention, the height of the linear absorber 22 is larger than that of the photovoltaic array, and the height difference between the linear absorber and the photovoltaic array is 6-8, and the specific installation height depends on the column number distribution of the photovoltaic array. The linear absorber 22 is arranged at a position 6-8 meters higher than the photovoltaic array, and has the remarkable advantages that the power generation efficiency of the photovoltaic array directly depends on 'no-shading direct sunlight', if the height of the linear absorber 22 is too low, shadows can be formed on the ground, the shadows can be changed along with the solar altitude (such as longer shadows in the morning and evening when the solar altitude is low) to cover the panel of the photovoltaic array, and otherwise, if the photovoltaic array is too high, the 'light receiving path' of the linear absorber can be shaded. This height differential design allows the light beams reflected by each photovoltaic device 11 to converge at an optimal angle to a linear absorber 22 located at the center of the array when the photovoltaic array is arranged in a fresnel mirror type distribution. Secondly, the height difference of 6-8 meters provides enough installation space and working distance for the secondary condenser 23 (CPC), so that scattered light which is not directly received by the linear absorber 22 can be effectively captured and secondarily focused, and the photo-thermal conversion efficiency is improved. In addition, the absorber is located at the symmetrical center of the whole system by the height configuration, so that the optical path layout is optimized, the occupied area is reduced, and the system is more suitable for large-scale deployment. If the height difference is too large, the reflected light beam may not be precisely projected onto the linear absorber, thereby increasing light loss of the photo-thermal system and reducing photo-thermal conversion efficiency. The difference between the height of the linear absorber 22 and the height of the photovoltaic array is preferably 6 meters to maximize the focusing effect of the infrared light.

According to an embodiment of the present invention, the outer wall of the linear absorber 22 is coated with a coating for absorbing the light beam reflected by the secondary condenser 23. The coating is designed to avoid energy waste. Even if the light beam is not directly focused on the core area of the absorber, the coating can still capture residual light energy, so that the overall light-heat conversion efficiency of the system is remarkably improved.

According to an embodiment of the invention, the photovoltaic power generation subsystem 1 further comprises an inverter adapted to convert the direct current obtained after the conversion of the direct current power into alternating current.

According to an embodiment of the invention, the Fresnel concentrated solar photovoltaic-photothermal full spectrum utilization system further comprises a thermochemical reaction device, a heat storage device and the like. The solar photo-thermal subsystem 2 is in fluid communication with a thermal storage device and/or a thermochemical reaction device to effect thermal energy storage, heat exchange or process heating.

The embodiment of the invention realizes the full spectrum high-efficiency conversion of solar energy and overcomes the respective limitations of the traditional photovoltaic and photo-thermal systems. Through the accurate regulation and control of the spectrum selective light splitting film, the photovoltaic cell and the photo-thermal absorber can efficiently distribute solar energy, realize the cooperative optimization of photoelectricity and photo-thermal, and improve the overall performance of the system. Meanwhile, the system utilizes the photovoltaic array to serve as a Fresnel light condensing unit, so that the dependence on an additional light condensing component is reduced, the structure is more compact, the optical loss and the system occupation are reduced, and the system integration level is improved. Meanwhile, the embodiment of the invention effectively reduces the invalid heat load of the photovoltaic device, enhances the long-term stability of the photovoltaic power generation subsystem, and combines the solar heat utilization to adapt to the application requirements of heat supply, thermochemical reaction and the like. Compared with the traditional photovoltaic system, the solar energy comprehensive utilization efficiency is improved to more than 40% by the system, and an innovative solution is provided for the efficient utilization of solar energy and the development of renewable energy sources.

The solar photovoltaic-photothermal complementary system of the present invention is described below with reference to fig. 1 and by way of example only.

Referring to fig. 1, a solar photovoltaic-photothermal complementary system according to an embodiment of the present invention includes a photovoltaic power generation subsystem 1 and a solar photothermal subsystem 2 coupled to each other. The photovoltaic power generation subsystem includes a photovoltaic array coated with a spectrally selective beam splitting film 12, a ray tracing mechanism 13 connected to the photovoltaic device 11, and an inverter, and the like, and the ray tracing mechanism 13 may be, for example, a uniaxial ray tracker. The solar photo-thermal subsystem includes a linear absorber 22 (e.g., a linear photo-thermal absorber), a secondary concentrator 23 (e.g., a compound parabolic secondary concentrator), and associated devices such as a corresponding thermal medium storage tank for storing and transmitting thermal energy.

Referring to fig. 2, each photovoltaic device 111 in the photovoltaic array 1 is arranged in a fresnel mirror type distribution, and each column of photovoltaic devices 11 is installed with a set width and inclination angle to ensure maximum reflection of infrared light to the linear absorber 22. Specifically, the system adopts a column photovoltaic array, which is distributed symmetrically left and right. The width of the photovoltaic device 11 was 0.6m, the length was 2m, and the pitch of the photovoltaic device 11 was 0.2m.

When the solar altitude angle β is 90 °, the inclination angle of the photovoltaic device 11 gradually increases from inside to outside (the incident angle is also gradually increased, the incident angle is the angle between the incident beam and the normal line of the photovoltaic device panel), and the inclination angle β of the outermost photovoltaic device 11 is about 23 °. The position distribution and corresponding tilt angle of a specific photovoltaic device 11 are shown in table 1. In table 1, 8 photovoltaic devices 11 located on any side of the solar photo-thermal subsystem 1 are numbered 1 to 8, wherein the photovoltaic device 11 with the number 1 is the nearest one to the solar photo-thermal subsystem 1, and the rest are numbered 2 to 8 in sequence gradually far from the solar photo-thermal subsystem. As can be seen in fig. 2, the reflected light beams of the individual photovoltaic devices 111 are concentrated into a linear absorber 22.

TABLE 1

The details of the parameters of the photovoltaic device 11 and the linear absorber 22 and the secondary concentrator 23 are shown in Table 2.

TABLE 2

As can be seen from table 2, the solar photovoltaic-photo-thermal complementary system in the embodiment of the invention can realize 2465W of rated condition power generation and 4450W of rated condition heat collection. The solar radiation input under the rated working condition is 16320W, and the comprehensive utilization rate of the solar energy is 42.37.

The photovoltaic device 11 of the embodiment of the invention adopts the spectrum selective light splitting film 12, so that the high transmittance and low reflection (ideal transmittance of 95%) of the visible light wave band are realized, and the rest wave band is reflected (ideal reflectance of 90%) to the solar photo-thermal subsystem. The spectrally selective beam splitter film 12 reduces the ineffective thermal load of the photovoltaic device 111 from the source, and avoids the problem of the reduction of the photoelectric conversion efficiency caused by high temperature.

And meanwhile, the composite parabolic secondary condenser is combined to recycle solar radiation beams which are not intercepted by the primary reflector, so that the optical efficiency of the system is improved.

According to the system provided by the embodiment of the invention, the photovoltaic array is arranged in a Fresnel reflector field mode, and the spectrum selective light splitting film is directly plated on the surface of the photovoltaic cell, so that visible light is transmitted to the photovoltaic device for photoelectric conversion, and ultraviolet light and infrared light are reflected to the linear absorber for heat energy conversion. The absorber can be filled with molten salt, heat conducting oil or chemical raw materials so as to meet the application requirements of power generation, heat supply, thermochemical reaction and the like. The design improves the utilization efficiency of solar energy spectrum and realizes the full spectrum utilization of solar energy.

According to the system provided by the embodiment of the invention, the light splitting film selectively transmits visible light and simultaneously reflects solar radiation in other wave bands, so that the ineffective heat load of the photovoltaic cell is reduced from the source, and the problem of reduction of photoelectric conversion efficiency caused by high temperature is avoided. The optimization obviously improves the long-term stability and the working performance of the photovoltaic system, prolongs the service life of the assembly, reduces the thermal load of the photovoltaic cell and improves the photoelectric conversion stability.

According to the system provided by the embodiment of the invention, the Fresnel light condensation function is integrated, and the optical loss and the occupied space are reduced. The arrangement mode of the coated photovoltaic cell array is similar to that of a Fresnel reflector, and infrared light is accurately focused to the tubular photo-thermal reactor by optimizing the reflection angle, so that efficient photo-thermal conversion is realized. The method does not need an additional independent reflecting mirror system, so that the optical loss is reduced, the occupied area is reduced, the space utilization rate is improved, and the system is more suitable for large-scale application scenes.

According to the system provided by the embodiment of the invention, on one hand, the invalid thermal load of the photovoltaic device is restrained, the efficiency and service life attenuation caused by temperature rise are relieved, and on the other hand, the photovoltaic array is used as a mirror field, so that an optical link is shortened, the occupied area and the complexity of the system are reduced, and the system can be coupled with a thermal storage unit or a thermochemical unit to realize electric-thermal dual output, so that the cooperative application of the electric-thermal dual output is realized. Under the typical sunlight condition, the comprehensive utilization efficiency of solar energy is obviously improved. The solar energy utilization rate of the traditional photovoltaic system is generally about 20% -25%, and the comprehensive solar energy utilization rate is improved to more than 40% (the solar energy utilization rate of the system can reach 42%) through a photovoltaic-photo-thermal complementary mechanism, so that the overall energy conversion efficiency is greatly improved, and an effective method is provided for efficient utilization of solar energy. Compared with the traditional photovoltaic or photo-thermal system, the invention fully exerts the solar energy spectrum characteristic, proposes a spectrum distribution photo-thermal coordination mechanism, realizes full spectrum directional coupling utilization of solar radiation and realizes full spectrum efficient utilization of solar energy. Meanwhile, the coated photovoltaic cell has the functions of power generation and light condensation, replaces an independent photo-thermal condenser, reduces the complexity and cost of the system, and improves the engineering adaptability and practicality.

The embodiments of the present invention are described above. These examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the embodiments are described above separately, this does not mean that the measures in the embodiments cannot be used advantageously in combination. The scope of the invention is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be made by those skilled in the art without departing from the scope of the invention, and such alternatives and modifications are intended to fall within the scope of the invention.

Claims

1. A solar photovoltaic-photothermal full spectrum utilization system, comprising:

a photovoltaic power generation subsystem comprising:

A solar photo-thermal subsystem including a linear absorber disposed over a center of the photovoltaic array, receiving the light beam reflected by the spectrally selective beam splitting film, and performing thermal energy conversion on the received light beam;

2. The system of claim 1, wherein the predetermined wavelength band is 400-1100 nm;

the average transmittance of the spectrum selective light splitting film to the wave band of 400-1100 nm is more than or equal to 90%, and the average reflectivity is more than or equal to 85% in the wave band of 280-400 nm and the wave band of 1100-2500 nm.

3. The system of claim 1, wherein the solar photothermal subsystem further comprises:

4. The system of claim 3, wherein the secondary concentrator is a compound parabolic concentrator and the linear absorber outer wall is provided with an optional absorption coating to reduce radiation losses.

5. The system according to claim 1, wherein the mounting height of the linear absorber is higher than the height of the photovoltaic array, the height difference between the linear absorber and the photovoltaic array being 6-8 m, preferably 6 m.

6. The system of claim 1, wherein the photovoltaic power generation subsystem further comprises:

7. The system of claim 1, wherein the spectrally selective light-splitting film is an all-dielectric multilayer interference film comprising alternating layers of high refractive index medium and low refractive index medium, wherein the high refractive index medium comprises、Or (b)At least one or more of the low refractive index media comprisesOr (b)At least one or more of;

8. The system of claim 2, wherein the spectrally selective spectral film is configured to have band-edge drift within a range that causes a passband not less than 380 nm and not more than 1150 nm.

9. The system of claim 1, wherein the photovoltaic power generation subsystem further comprises:

10. The system of claim 1, wherein the solar photo-thermal subsystem is in fluid communication with a thermal storage device and/or a thermochemical reaction device to effect thermal energy storage, heat exchange, or process heating.