A photovoltaic and thermal combined power generation device based on solar frequency division

Abstract

The present invention discloses a photovoltaic and solar-thermal combined power generation device based on solar frequency division. The device comprises a concentrator module, a spectrum splitter, a solar-thermal power generation module, a photovoltaic power generation module, and a battery for storing electrical energy. The concentrator module is used to focus sunlight on the spectrum splitter. The spectrum splitter is used to split the sunlight focused by the concentrator module into two paths according to the spectrum: one path is a high-frequency solar-thermal power generation path, and the other is a low-frequency photovoltaic power generation path. The solar-thermal power generation module comprises a heat collecting plate capable of absorbing high-frequency light and a first thermoelectric assembly attached to the bottom of the heat collecting plate. The photovoltaic power generation module comprises an outer shell and a photovoltaic assembly disposed within the bottom of the outer shell. A frequency splitter is disposed at the opening of the outer shell of the photovoltaic power generation module for absorbing infrared light for solar-thermal power generation. Heat from the frequency splitter and waste heat from the photovoltaic assembly are generated by a second thermoelectric assembly. The device has a simple structure and not only improves the efficiency of photovoltaic power generation but also increases the efficiency of solar energy utilization.

Description

Technical Field

[0001] The present invention belongs to the field of solar power generation, relates to a solar power generation technology, and specifically relates to a photovoltaic and thermal combined power generation device based on solar frequency division. Background Art

[0002] As an important clean energy source, efficient utilization of solar energy can improve the overall utilization rate of clean energy and promote the widespread application of solar energy. A key application of solar energy is photovoltaic power generation using solar cells. The maximum photoelectric conversion efficiency of typical commercial solar cells is approximately 15%-20%. Most of the unused solar radiation energy is absorbed by the cells and converted into heat energy. If this heat is not removed promptly, the battery temperature will rise, reducing the power generation efficiency. The efficiency decreases by approximately 0.5% for every 1°C increase in battery temperature. Furthermore, long-term operation of solar cells at high temperatures will shorten their service life due to rapid aging. Existing solar photovoltaic and thermal power generation devices are equipped with thermal power generation modules that use excess heat for power generation, preventing overheating of the panels, improving efficiency, and extending service life. Currently, there are three types of solar thermal power generation systems: trough, tower, and dish (panel) systems. However, all three types have their own drawbacks, primarily due to immature technology and complex structures, which prevent large-scale deployment. Currently, there is no system that can comprehensively utilize the above-mentioned photovoltaic and thermal power generation methods. Summary of the Invention

[0003] The present invention solves the problems of low or immature power generation efficiency and inability to comprehensively utilize solar thermal and photovoltaic power generation in existing solar thermal power generation, and designs a solar frequency-divided photovoltaic and solar thermal power generation system with a simple structure, which can efficiently utilize the heat generated by solar thermal energy and photovoltaic power generation for comprehensive power generation.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A photovoltaic and thermal combined power generation device based on solar frequency division, comprising

[0006] Concentrating module, used to focus sunlight;

[0007] The spectrum splitter is located at the focal point below the concentrating module and is used to split the sunlight focused by the concentrating module into two paths according to the spectrum: one path is a high-frequency solar thermal power generation path, and the other is a low-frequency photovoltaic power generation path;

[0008] A solar thermal power generation module is arranged in a solar thermal power generation optical path for performing solar thermal power generation;

[0009] A photovoltaic power generation module is provided on the optical path of the photovoltaic power generation optical path for performing photovoltaic power generation;

[0010] The battery is used to store electricity generated by the solar thermal power generation module and the photovoltaic power generation module.

[0011] Furthermore, the solar thermal power generation module includes a heat collecting plate capable of absorbing high-frequency light and a first thermoelectric component attached to the bottom of the heat collecting plate, wherein the first thermoelectric component generates electricity using heat collected by the heat collecting plate.

[0012] Furthermore, the photovoltaic power generation module includes an outer shell and a photovoltaic component arranged at the bottom of the outer shell.

[0013] A frequency divider is provided at the opening of the outer shell of the photovoltaic power generation module, and a second thermoelectric component is provided in the outer shell. The frequency divider includes a transparent interlayer, silicone oil that can absorb infrared spectra and flows freely between the transparent interlayers, and a heat exchanger connected to the silicone oil. A cooling coil is provided on the back of the photovoltaic component; the cold ends of the cooling coil and the heat exchanger are connected to the hot end of the second thermoelectric component through a heat exchange pipe filled with a heat exchange medium. The heat absorbed by the silicone oil and the waste heat generated by the photovoltaic component generate electricity through the second thermoelectric component.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The photovoltaic-thermal power generation device of the present invention divides sunlight into different wavelengths for utilization. A spectrum splitter is used to perform a primary frequency division of the sunlight, directing only the low-frequency, long-wavelength sunlight with high photovoltaic cell power generation efficiency to the photovoltaic power generation module. The spectrum splitter then further processes the sunlight, filtering out the infrared wavelengths, which have low absorption efficiency, allowing the highly efficient light to strike the photovoltaic cell. The infrared wavelengths are absorbed by the silicone oil in the spectrum splitter and converted into heat energy, which is then used to generate electricity through the second thermoelectric assembly. The remaining wavelengths are refracted by the spectrum splitter onto the heat collecting plate of the photovoltaic power generation module, which is then converted into heat energy. This heat energy is then used to generate electricity through the first thermoelectric assembly. The first and second thermoelectric assemblies generate electricity through a temperature difference. Generally, the first thermoelectric assembly has a higher operating temperature, so materials with a higher operating temperature are required. Furthermore, the present invention can also incorporate heat sinks at the cold ends of the first and second thermoelectric assemblies to improve the efficiency of temperature difference power generation. The present invention, with its simple structure, not only improves the efficiency of photovoltaic power generation but also increases the efficiency of solar energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of a photovoltaic and solar-thermal combined power generation device in an embodiment of the present invention.

[0017] Figure 2 This is a partial schematic diagram of the photovoltaic and solar-thermal combined power generation device in an embodiment of the present invention after removing the concentrating module.

[0018] 1-Fresnel focusing lens, 2-spectral splitter, 3-heat collecting plate, 4-first thermoelectric component, 5-heat exchange medium, 6-frequency divider, 7-silicon oil, 8-photovoltaic panel, 9-cooling medium, 10-second thermoelectric component, 11-circulating pump, 12-heat exchanger, 13-radiator, 14-cooling medium storage tank, 15-outer shell, 16-photovoltaic component. DETAILED DESCRIPTION

[0019] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0020] The present invention solves the problems of low or immature power generation efficiency and inability to comprehensively utilize solar thermal and photovoltaic power generation in existing solar thermal power generation. It designs a photovoltaic and solar thermal combined power generation device with simple structure based on solar frequency division, which can efficiently utilize the heat generated by solar thermal energy and photovoltaic power generation for comprehensive power generation. Figure 1 and Figure 2 As shown, the device includes

[0021] Concentrating module, used to focus sunlight;

[0022] The spectrum splitter 2 is located at the focus below the concentrating module and is used to split the sunlight focused by the concentrating module into two paths according to the spectrum, one of which is a high-frequency solar thermal power generation path and the other is a low-frequency photovoltaic power generation path;

[0023] A solar thermal power generation module is arranged in a solar thermal power generation optical path for performing solar thermal power generation;

[0024] A photovoltaic power generation module is provided on the optical path of the photovoltaic power generation optical path for performing photovoltaic power generation;

[0025] The battery (not shown) is used to store the electricity generated by the solar thermal power generation module and the photovoltaic power generation module.

[0026] The present invention utilizes a concentrating module to focus sunlight on a spectrum splitter 2, which splits the focused sunlight into two paths: one path is high-frequency, short-wavelength light suitable for solar thermal power generation, and the other path is low-frequency, long-wavelength light suitable for photovoltaic modules 16 to generate electricity. The selection is based on the power generation materials of the solar thermal power generation module and the photovoltaic power generation module. For example, in an embodiment of the present invention, a SiO2 / TiO2 interference thin film filter or an ethylene glycol ZnO nanofluid absorption filter is used as the spectrum splitter 2. With a wavelength of 450 nanometers as the dividing point, wavelengths below 450 nanometers are split by the spectrum splitter 2 and then sent to the solar thermal power generation module. Wavelengths above or equal to 450 nanometers are split by the spectrum splitter 2 and then sent to the photovoltaic power generation module. The solar thermal power generation module and the photovoltaic power generation module generate electricity at their respective efficient absorption wavelengths, thereby greatly improving power generation efficiency.

[0027] It should be noted that the spectrum splitter 2 of the present invention can also be divided into two light paths by using a grating spectrometer, or by prism refraction, and the light path position can be adaptively adjusted ( Figure 1 The relative positions of the two light paths split by the spectrum splitter 2 are schematic positions and do not mean that only one can refract and the other can project two light paths).

[0028] As a preferred embodiment, the solar thermal power generation module includes a heat collecting plate 3 that can absorb high-frequency light and a first thermoelectric component 4 attached to the bottom of the heat collecting plate 3. The first thermoelectric component 4 generates electricity using the heat collected by the heat collecting plate 3, and the electricity generated by the first thermoelectric component 4 is stored in a battery. The material of the first thermoelectric component 4 can be materials in the existing technology, such as bismuth telluride and its alloys. Of course, in order to smoothly store electricity, control circuits and wires are also required to be connected, etc., all of which can be achieved using existing mature technologies. This is not the inventive point of the present invention and the present invention does not make specific limitations.

[0029] As a preferred embodiment, Figure 1 As shown, the photovoltaic power generation module includes an outer shell 15 and a photovoltaic component 16 arranged at the bottom of the outer shell 15.

[0030] As a preferred embodiment, Figure 2 As shown, a frequency divider 6 is provided at the opening of the outer shell 15 of the photovoltaic power generation module, and a second thermoelectric component 10 is provided in the outer shell 15 (the material can be the same as that of the first thermoelectric component 4, or a thermoelectric material with a lower operating temperature can be selected). The frequency divider 6 includes a transparent interlayer, silicone oil 7 that can absorb infrared spectrum and flows freely between the transparent interlayer (absorbs infrared rays with a wavelength of 1100nm to 2500nm and heats up), and a heat exchanger 12 connected to the silicone oil 7. A cooling coil is provided on the back of the photovoltaic component 16; the cold ends of the cooling coil and the heat exchanger 12 are connected to the hot end of the second thermoelectric component 10 through a heat exchange pipe filled with a heat exchange medium 5. The heat absorbed by the silicone oil 7 and the waste heat generated by the photovoltaic component 16 are used to generate electricity through the second thermoelectric component 10. The transparent interlayer of the present invention can be made of two pieces of transparent glass, and the silicone oil 7 flows freely in the interlayer between the two pieces of glass. The heat exchanger 12 can be a plate type or a shell and tube heat exchanger. The inlet and outlet of the hot end of the heat exchanger 12 are respectively connected to different areas between the two pieces of transparent glass, and can be arranged up and down. In this way, high and low temperature convection is used to make the silicone oil 7 flow between the interlayer space between the two pieces of transparent glass and the hot end of the heat exchanger 12 without the need for power.

[0031] As a preferred embodiment, the cold ends of the first thermoelectric component 4 and the second thermoelectric component 10 are both provided with cooling and heat dissipation devices, such as heat dissipation fins attached to the cold ends, which utilize air to passively dissipate heat, thereby increasing the temperature difference between the hot and cold ends of the hot end components and thus improving the power generation effect.

[0032] As a preferred embodiment, the cooling and heat dissipation device can also adopt an active radiator, specifically including a radiator 13 (such as a heat dissipation fin), a cooling medium storage tank 14 and a circulation pump 11. The cold end of the first thermoelectric component 4, the cold end of the second component thermoelectric component, the radiator 13, the cooling medium storage tank 14, and the circulation pump 11 are connected in sequence through a pipeline cycle. The circulation pump 11 sends the cooling medium 9 in the cooling medium storage tank 14 to the cold ends of the first thermoelectric component 4 and the second thermoelectric component 10 in sequence or separately. The cooling medium 9 absorbs heat to cool the cold ends of the first thermoelectric component 4 and the second thermoelectric component 10, and then dissipates heat through the radiator 13 and returns to the cooling medium storage tank 14 for recycling.

[0033] As a preferred embodiment, the circulating medium for cooling the cold ends of the first thermoelectric assembly 4 and the second thermoelectric assembly 10 may be water. In this case, the cooling medium storage tank 14 is a water tank, and the circulating pump 11 is a water pump.

[0034] As a preferred embodiment, the focusing module is a Fresnel focusing lens 1 .

[0035] As a preferred embodiment, the photovoltaic assembly 16 is a plurality of photovoltaic panels 8 arranged at different heights, such as Figure 2 As shown, it includes a lower one in the middle and two higher ones on both sides, which are staggered in height, which is beneficial to heat dissipation and improving light absorption efficiency. Of course, if the outer shell 15 is cylindrical as a whole, it can also be set as a circular photovoltaic panel in the middle and annular photovoltaic panels on the surrounding areas, depending on the shape of the outer shell and needs. The photovoltaic panel 8 is made of mechanically stacked perovskite / crystalline silicon laminated solar film cells, which have a higher power generation efficiency for wavelengths above 450 nanometers.

[0036] It should be noted that the power generated by the first thermoelectric component 4, the second thermoelectric component 10 and the photovoltaic component 16 is transmitted to the battery for storage, and corresponding charge and discharge control circuits need to be set up. This is a mature technology and can be adopted with existing technology. The present invention does not impose any special restrictions.

[0037] The photovoltaic-thermal power generation device of the present invention divides sunlight into different wavelengths for utilization. A spectrum splitter 2 performs a primary frequency division on the sunlight, directing only the low-frequency, long-wavelength sunlight with a high photovoltaic cell power generation efficiency to the photovoltaic power generation module. This light is then further processed by a frequency splitter 6, filtering out the infrared wavelengths, which have low photovoltaic absorption efficiency, allowing the highly efficient light to strike the photovoltaic cell. The infrared wavelengths are absorbed by the silicone oil 7 within the frequency splitter 6 and converted into heat energy, which is then transferred to the second thermoelectric assembly 10 for power generation. The remaining wavelengths are refracted by the spectrum splitter 2 onto the heat collecting plate 3 of the photovoltaic power generation module, where it is converted into heat energy. This heat energy is then transferred to the first thermoelectric assembly 4 for power generation. The first and second thermoelectric assemblies 4 and 10 generate electricity through temperature differences. Generally, the first thermoelectric assembly 4 has a higher operating temperature, so materials with a higher operating temperature are preferred. Furthermore, the present invention can also incorporate heat sinks at the cold ends of the first and second thermoelectric assemblies 4 and 10 to improve the efficiency of temperature-differential power generation. The present invention's simple structure not only improves the efficiency of photovoltaic power generation but also increases the efficiency of solar energy utilization.

[0038] The above embodiments are intended to illustrate the present invention only and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be encompassed by the scope of the claims of the present invention.

Claims

1. A photovoltaic and thermal combined power generation device based on solar frequency division, characterized in that: include Concentrating module, used to focus sunlight; The spectrum splitter is located at the focal point below the concentrating module and is used to split the sunlight focused by the concentrating module into two paths according to the spectrum: one path is a high-frequency solar thermal power generation path, and the other is a low-frequency photovoltaic power generation path; A solar thermal power generation module is arranged in a solar thermal power generation optical path for performing solar thermal power generation; A photovoltaic power generation module, disposed on an optical path of the photovoltaic power generation optical path, for performing photovoltaic power generation; and Storage batteries, used to store electricity generated by solar thermal power generation modules and photovoltaic power generation modules; The solar thermal power generation module includes a heat collecting plate capable of absorbing high-frequency light and a first thermoelectric component attached to the bottom of the heat collecting plate, wherein the first thermoelectric component generates electricity using the heat collected by the heat collecting plate; The photovoltaic power generation module includes an outer shell and a photovoltaic assembly disposed within the bottom of the outer shell; a frequency divider is disposed at the opening of the outer shell, and a second thermoelectric assembly is disposed within the outer shell. The frequency divider includes a transparent interlayer, silicone oil capable of absorbing infrared light and freely flowing between the transparent interlayers, and a heat exchanger connected to the silicone oil. A cooling coil is disposed on the back of the photovoltaic assembly; the cold ends of the cooling coil and the heat exchanger are both connected to the hot end of the second thermoelectric assembly via a heat exchange pipe filled with a heat exchange medium. Heat absorbed by the silicone oil and waste heat generated by the photovoltaic assembly generate electricity through the second thermoelectric assembly. The cold ends of the first thermoelectric assembly and the second thermoelectric assembly are both provided with a cooling and heat dissipation device, the cooling and heat dissipation device comprising a radiator, a cooling medium storage tank and a circulation pump. The cold end of the first thermoelectric assembly, the cold end of the second thermoelectric assembly, the radiator, the cooling medium storage tank and the circulation pump are sequentially connected through a pipeline circulation. The circulation pump sends the cooling medium in the cooling medium storage tank to the cold ends of the first thermoelectric assembly and the second thermoelectric assembly. The cooling medium absorbs heat and cools the cold ends of the first thermoelectric assembly and the second thermoelectric assembly, then dissipates heat through the radiator and returns to the cooling medium storage tank for recycling. The spectrum splitter is a SiO2 / TiO2 interference thin film filter or an ethylene glycol ZnO nanofluid absorption filter; The outer shell is cylindrical in shape as a whole, and the photovoltaic assembly is a plurality of photovoltaic panels arranged at different heights, including a circular photovoltaic panel at a lower position in the middle and an annular photovoltaic panel at higher positions on all sides.

2. The photovoltaic-thermal combined power generation device according to claim 1, characterized in that: The focusing module is a Fresnel focusing lens.

3. The photovoltaic-thermal combined power generation device according to claim 1, characterized in that: The photovoltaic assembly is a plurality of photovoltaic panels arranged at different heights, and the photovoltaic panels are mechanically stacked perovskite / crystalline silicon laminated solar thin film cells.

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