Spectroscopic photovoltaic air collector based on fluid and heat transfer optimization

Abstract

The application discloses a kind of based on fluid and heat transfer optimization's spectroscopic formula photovoltaic air collector, including shell, light-collecting spectroscopic system, photovoltaic cell system and solar tracking system, wherein light-collecting spectroscopic system is assembled on the top surface of shell, photovoltaic cell system is assembled in the inner chamber of shell, solar tracking system is assembled at the bottom of shell, solar tracking system can drive shell to rotate and make sunlight vertically irradiate on shell.Light-collecting spectroscopic system includes light-transmitting mirror and optical filter, wherein light-transmitting mirror is curved surface lens, and a plurality of rows are symmetrically assembled on the top surface and bottom surface of optical filter on both sides of light-transmitting mirror.A beneficial effect: prolongs the heat exchange process of air, not only improves air heat collection quality, but also cooperatively improves photoelectric and photo-thermal conversion efficiency, effectively solves the problems existing in traditional solar air type collector.

Description

Technical Field

[0001] This invention relates to an air collector, and more particularly to a spectrophotometric air collector based on fluid and heat transfer optimization. Background Technology

[0002] Currently, photovoltaic (PV) cells are crucial components for converting solar energy into electricity. However, the widely used crystalline silicon PV cells have a narrow absorption band, resulting in low photoelectric conversion efficiency. Broadening the spectral absorption band is one important means to improve photoelectric conversion efficiency. This involves using a concentrating and splitting system to divide the solar spectrum into several bands, and then using PV cells made of materials with corresponding spectral responses to convert these bands into electrical energy. However, since photon energy outside the absorption band is ultimately converted into heat, the temperature of the PV cell rises, leading to a decrease in photoelectric conversion efficiency. Therefore, an effective cooling system is key to improving the efficiency of PV cells.

[0003] Solar photovoltaic (PV) collectors, as a type of combined heat and power (CHP) device, cool photovoltaic cells with a working medium while recovering heat, simultaneously converting solar energy of different wavelengths into electrical and thermal energy, thus achieving comprehensive utilization of solar energy. Currently, solar PV air collectors are commercially available, but due to factors such as low air heat capacity, low convective heat transfer coefficient, and short heat exchange path, the recovered air temperature is low, heat loss is large, and the device's heat collection efficiency is low. Therefore, by broadening the spectral absorption band and optimizing the device structure to control the internal airflow state, a spectral-splitting PV air collector based on fluid and heat transfer optimization is invented. This simultaneously improves both photoelectric conversion efficiency and photothermal conversion efficiency, which is of great significance for improving the current situation of low comprehensive utilization of solar energy. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of low recovered air temperature, large heat loss and low heat collection efficiency caused by low air heat capacity, low convective heat transfer coefficient and short heat exchange process in existing solar photovoltaic air collectors. The invention provides a spectral photovoltaic air collector based on fluid and heat transfer optimization.

[0005] The present invention provides a spectrophotometer-based photovoltaic air collector based on fluid and heat transfer optimization, comprising a shell, a concentrating and splitting system, a photovoltaic cell system, and a solar tracking system. The concentrating and splitting system is mounted on the top surface of the shell, the photovoltaic cell system is mounted in the inner cavity of the shell, and the solar tracking system is mounted on the bottom of the shell. The solar tracking system can drive the shell to rotate so that sunlight is perpendicularly irradiated onto the shell.

[0006] The focusing and beam-splitting system includes a lens and a filter. The lens is a curved lens, and several rows of lenses are symmetrically mounted on both sides of the top and bottom surfaces of the filter.

[0007] The photovoltaic cell system includes a strip substrate, photovoltaic cells, and a first rib. The strip substrate is assembled with an array of strip substrates, which are mounted in the middle of the inner cavity of the housing. An upper airflow channel is formed in the inner cavity above the array of strip substrates, and a lower airflow channel is formed in the inner cavity below the array of strip substrates. Each set of strip substrates is arranged with symmetrical light-transmitting mirrors on each row at the top of the housing. Each set of strip substrates consists of three rows of strip substrates arranged in a stepped manner, with the height of adjacent rows of strip substrates decreasing sequentially from front to back. The photovoltaic cells are mounted on the top surface of each row of strip substrates, and the first rib is mounted on the bottom surface of each row of strip substrates. Two gaps are formed between each set of three rows of strip substrates. A second rib is mounted on the bottom plate of the housing below each gap. Two rows of second ribs are mounted on the bottom plate of the housing below each set of three rows of strip substrates. The top of each row of second ribs is positioned to correspond to the gap between adjacent rows of strip substrates.

[0008] The strip substrate has a two-layer structure. The top layer of the strip substrate is a transparent PET board, and the photovoltaic cells are bonded to the PET board on the top surface of the strip substrate with EVA adhesive. The bottom layer of the strip substrate is a metal layer with high thermal conductivity.

[0009] In each group of strip substrates, the photovoltaic cells attached to the top surface of the first row of high-order strip substrates are upconversion photovoltaic cells. These upconversion photovoltaic cells consist of crystalline silicon photovoltaic cells with an upconversion material layer deposited on the top surface. The upconversion material layer is NaYF4:Er 3+ In the middle-tier second row, only photovoltaic cells are mounted on the top surface of the strip substrates. These photovoltaic cells are also crystalline silicon photovoltaic cells. In the lower-tier third row, the photovoltaic cells mounted on the top surface of the strip substrates are down-conversion photovoltaic cells. These down-conversion photovoltaic cells consist of organic photovoltaic cells with a down-conversion material layer deposited on the bottom surface. The down-conversion material layer is LaOF:Eu. 3+ .

[0010] The first rib is shaped like an isosceles right triangle, with the base angles of the isosceles right triangle facing downwards.

[0011] The two rows of second ribs are staggered, with the second ribs of the first row higher than the second ribs of the second row from front to back. Each second rib is pyramidal, and the windward side of the pyramidal second rib is curved.

[0012] The shell is surrounded by an insulation layer.

[0013] The solar tracking system includes a solar tracker, connecting rods, a turntable, support rods, a hydraulic shaft, and a controller. The solar tracker is fixed to the top of the housing and connected to the controller. There are two support rods, one end of which is connected to both ends of a rotating shaft on the lower side of the housing, and the other end of which is fixed to the outside of the hydraulic shaft. The hydraulic shaft is mounted on the turntable. The connecting rods connect the hydraulic shaft and the housing at both ends. The controller is connected to the turntable. The solar tracker can transmit the collected data to the controller in real time. The controller controls the turntable and hydraulic shaft to rotate the housing based on the data transmitted by the solar tracker, so that sunlight shines perpendicularly onto the housing.

[0014] The aforementioned light-transmitting mirror, filter, photovoltaic cell, solar tracker, turntable, hydraulic shaft, and controller are all assemblies of existing equipment; therefore, specific models and specifications are not detailed.

[0015] Working principle of the invention:

[0016] When the spectral photovoltaic air collector based on fluid and heat transfer optimization provided by this invention is working, in order to ensure the vertical irradiation of sunlight, the solar tracking system will collect the incident angle of sunlight through a solar energy tracker. After the data is transmitted to the controller, the controller controls the turntable and hydraulic shaft to respond. The turntable controls the lateral angle between the entire collector and the sunlight, and the hydraulic shaft controls the longitudinal angle between the entire collector and the sunlight.

[0017] Sunlight first penetrates the concentrating and splitting system directly. During the process of sunlight penetrating the concentrating and splitting system, each set of concentrating and splitting systems divides the sunlight into three wavelength bands in space. Along the direction from the inlet to the outlet of the collector, the first wavelength band has a wavelength greater than 1100nm, the second wavelength band has a wavelength between 560nm and 1100nm, and the third wavelength band has a wavelength less than 560nm. The sunlight of different wavelength bands shines on each set of three rows of strip substrates according to the refraction angle.

[0018] The energy conversion process of photovoltaic cells on each level of the strip substrate in each group of strip substrates is different. When the first wave of sunlight shines on the first row of high-order strip substrates, it passes through the upconversion material layer and is converted into light within the absorption spectrum of crystalline silicon photovoltaic cells. This light then shines on the crystalline silicon photovoltaic cells, is absorbed, and converted into electrical energy. When the second wave of sunlight shines on the second row of middle-order strip substrates, it is directly absorbed by the top crystalline silicon photovoltaic cells and converted into electrical energy. When the third wave of sunlight shines on the third row of low-order strip substrates, it passes through the organic... The photovoltaic cell is then converted into light within the absorption spectrum of the organic photovoltaic cell by the downconversion material layer. The light is then reflected back onto the organic photovoltaic cell, where it is absorbed and converted into electrical energy. However, the aforementioned photovoltaic cells can only efficiently convert most of the received sunlight into electrical energy. The remaining sunlight is irradiated by the transparent PET plate on the top layer of the strip substrate onto the metal layer on the bottom layer of the strip substrate. This portion of sunlight is converted into heat energy, which is efficiently absorbed by the air on both sides of the strip substrate. This process greatly reduces the temperature of the photovoltaic cell and improves the photoelectric conversion efficiency.

[0019] When the collector is running, the air is diverted to the upper and lower air ducts by the first row of high-order strip substrates in the first group. The stepped structure of the three rows of strip substrates in each group causes the upper and lower air ducts to be connected through the two gaps between the three rows of strip substrates in each group. Therefore, the upper and lower air ducts form a whole for flow and heat transfer.

[0020] For the upper airflow section, the surface of the light-transmitting mirrors of each row of curved surfaces in the concentrating and splitting system, along with a set of three rows of high, medium, and low-order strip substrates, sequentially form a tapering section, an approximately constant cross-section section, and an expanding section along the inflow direction. In the tapering section, the flow area gradually decreases. According to Bernoulli's principle, the air velocity gradually increases and the pressure gradually decreases, resulting in a pressure difference at the flow cross-section of the upper and lower airflow sections corresponding to the first gap of each set of three rows of strip substrates in the photovoltaic system. This causes air from the lower airflow section to be drawn into the upper airflow section through this gap. The air in the upper and lower airflow sections mix for the first time in the approximately constant cross-section section. In the approximately constant cross-section section, the flow area changes less, and the air maintains its original motion state. At the second gap of each set of three rows of strip substrates, shear stress causes the air from the lower airflow section to be drawn into the upper airflow section for the second time. The upper and lower airflow sections are then separated in the expanding section. The air is mixed again as the cross-section of the expansion section gradually increases, the air velocity gradually decreases, and the pressure gradually recovers. Then, the air in the upper air duct flows out of the photovoltaic cell system's strip substrate into the next strip substrate, and is diverted by the front end of the first row of higher-order strip substrates in the next strip substrate into the lower air duct. The air in the upper and lower air ducts is mixed for the third time. After that, the flow continues according to the above pattern. Because the flow in each strip substrate group generates three mixings of hot and cold air in the upper and lower air ducts, it promotes heat exchange within the air in the upper and lower air ducts. In addition, the stepped arrangement of the three rows of strip substrates in each group allows the boundary layer of each level of strip substrate in each group to be regenerated, solving the problem of continuous thickening of the boundary layer in traditional integrated substrates. This effectively reduces the convective heat transfer resistance and thus synergistically improves the photothermal conversion efficiency and photoelectric conversion efficiency of the collector.

[0021] For the downdraft, the first rib at the bottom of each of the three rows of strip substrates in each group increases the heat exchange area while having a small impact on the mainstream airflow. When the air flows through each group of second ribs at the bottom of the shell, it is guided by its windward curved surface to the two gaps of a group of strip substrates of the photovoltaic cell system above, promoting the upward airflow of the downdraft at the two gaps. The gap structure of the second ribs is narrow at the bottom and wide at the top, which throttles the airflow near the bottom and lifts the airflow at the bottom of the shell. The staggered arrangement of the two rows of second ribs in the same group makes the cold airflow at the bottom that flows through the gap of the second ribs in the front row rise again. While minimizing the flow resistance, it ensures that all parts of the air in the collector participate in the heat dissipation process. Furthermore, the leeward side of the second rib and the space behind it form a vortex, which promotes heat exchange between the bottom air and the upper air near the leeward side and disturbs the boundary layer on the surface of the nearby first rib, further enhancing convective heat transfer. Sufficient space is left between each group of second ribs to accommodate the air diverted into the downdraft by the front end of the high-order first row of strip substrates of the next group of strip substrates, and mixes with the cold air in the downdraft. It can be seen that the air in the downdraft flows repeatedly according to the above-mentioned pattern, echoing the structural function of the updraft and coupling with each other, greatly enhancing the mixing between the air inside the updraft and downdraft, improving the convective heat transfer coefficient of the air, thereby increasing the air outlet temperature and the heat collection efficiency of the collector, and synergistically improving the photothermal conversion efficiency and photoelectric conversion efficiency of the photovoltaic air collector.

[0022] The beneficial effects of this invention are:

[0023] The present invention provides a spectroscopic photovoltaic air collector based on fluid and heat transfer optimization. Combining the characteristics of a concentrating and splitting system, it optimizes the design through heat transfer and fluid flow characteristics. The different structures inside the upper and lower air ducts interact, complement each other, and promote each other, while extending the air heat exchange process. This not only improves the air heat collection quality but also synergistically improves the photovoltaic and photothermal conversion efficiency, effectively solving the problems existing in traditional solar air collectors. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the spectrophotometer-type photovoltaic air collector described in this invention.

[0025] Figure 2 This is a schematic diagram of the concentrated beam splitting system described in this invention.

[0026] Figure 3 This is a schematic diagram of the photovoltaic cell system structure described in this invention.

[0027] Figure 4 This is a schematic diagram of the cross-sectional structure of the photovoltaic cell system described in this invention.

[0028] Figure 5This is a schematic diagram of the arrangement of the second rib within the housing according to the present invention.

[0029] Figure 6 This is a schematic diagram of the cross-sectional structure of the casing of the spectrophotometer-type photovoltaic air collector described in this invention.

[0030] The annotations in the image above are as follows:

[0031] 1. Housing 2. Lens 3. Filter 4. Strip substrate 5. Photovoltaic cell

[0032] 6. First rib; 7. Upper air duct; 8. Lower air duct; 9. Gap; 10. Second rib.

[0033] 11. Upconversion material layer; 12. Downconversion material layer; 13. Solar tracker

[0034] 14. Connecting rod; 15. Turntable; 16. Support rod; 17. Hydraulic shaft; 18. Controller. Detailed Implementation

[0035] Please see Figures 1 to 6 As shown:

[0036] The present invention provides a spectrophotometer-based photovoltaic air collector based on fluid and heat transfer optimization, comprising a housing 1, a concentrating and splitting system, a photovoltaic cell system, and a solar tracking system. The concentrating and splitting system is mounted on the top surface of the housing 1, the photovoltaic cell system is mounted in the inner cavity of the housing 1, and the solar tracking system is mounted on the bottom of the housing 1. The solar tracking system can drive the housing 1 to rotate so that sunlight is perpendicularly irradiated onto the housing 1.

[0037] The focusing and beam-splitting system includes a light-transmitting lens 2 and a filter 3. The light-transmitting lens 2 is a curved lens, and several rows of light-transmitting lenses 2 are symmetrically assembled on both sides of the top and bottom surfaces of the filter 3.

[0038] The photovoltaic cell system includes a strip substrate 4, photovoltaic cells 5, and a first rib 6. The strip substrate 4 is assembled with an array of strip substrates, which are mounted in the middle of the inner cavity of the housing 1. An upper airflow channel 7 is formed in the inner cavity of the housing 1 above the array of strip substrates 4, and a lower airflow channel 8 is formed in the inner cavity of the housing 1 below the array of strip substrates 4. Each set of strip substrates 4 is arranged corresponding to each row of symmetrically positioned light-transmitting mirrors 2 at the top of the housing 1. Each set of strip substrates 4 consists of three rows of strip substrates 4 arranged in a stepped configuration. The height of the strip substrates 4 in adjacent rows decreases sequentially from front to back. Photovoltaic cells 5 are mounted on the top surface of each row of strip substrates 4, and first ribs 6 are mounted on the bottom surface of each row of strip substrates 4. Two gaps 9 are formed between each group of three rows of strip substrates 4. A second rib 10 is mounted on the bottom plate of the shell 1 below each gap 9. Two rows of second ribs 10 are correspondingly mounted on the bottom plate of the shell 1 below each group of three rows of strip substrates 4. The top of each row of second ribs 10 is set in relation to the gaps 9 between adjacent rows of strip substrates 4.

[0039] The strip substrate 4 has a two-layer structure. The top layer of the strip substrate 4 is a transparent PET board, and the photovoltaic cell 5 is bonded to the PET board on the top surface of the strip substrate 4 with EVA adhesive. The bottom layer of the strip substrate 4 is a metal layer with high thermal conductivity.

[0040] In each group of strip substrates 4, the photovoltaic cells 5 attached to the top surface of the first row of high-order strip substrates 4 are upconversion photovoltaic cells. The upconversion photovoltaic cells are composed of crystalline silicon photovoltaic cells with an upconversion material layer 11 deposited on the top surface. The upconversion material layer 11 is NaYF4:Er 3+ In the second row of the middle-tier strip substrates 4, only photovoltaic cells 5 are attached to the top surface. The photovoltaic cells 5 attached to the top surface of the second row of the middle-tier strip substrates 4 are also crystalline silicon photovoltaic cells. The photovoltaic cells 5 attached to the top surface of the third row of the low-tier strip substrates 4 are down-conversion photovoltaic cells. The down-conversion photovoltaic cells are composed of organic photovoltaic cells with a down-conversion material layer 12 deposited on the bottom surface. The down-conversion material layer 12 is LaOF:Eu 3+ .

[0041] The first rib 6 is shaped like an isosceles right triangle, with the apex of the isosceles right triangle facing downwards.

[0042] The two rows of second ribs 10 are staggered. From front to back, the second ribs 10 of the first row are higher than the second ribs 10 of the second row. Each second rib 10 is pyramidal in shape, and the windward side of the pyramidal second rib 10 is curved.

[0043] The periphery of the shell 1 is covered with an insulation layer.

[0044] The solar tracking system includes a solar tracker 13, a connecting rod 14, a turntable 15, a support rod 16, a hydraulic shaft 17, and a controller 18. The solar tracker 13 is fixed to the top of the housing 1 and connected to the controller 18. There are two support rods 16. One end of the support rod 16 is connected to both ends of the rotating shaft on the lower side of the bottom surface of the housing 1, and the other end of the support rod 16 is fixed to the outside of the hydraulic shaft 17. The hydraulic shaft 17 is mounted on the turntable 15. The connecting rod 14 connects the hydraulic shaft 17 and the housing 1 at both ends. The controller 18 is connected to the turntable 15. The solar tracker 13 can transmit the collected data to the controller 18 in real time. The controller 18 controls the turntable 15 and the hydraulic shaft 17 to rotate the housing 1 according to the data transmitted by the solar tracker 13, so that sunlight shines perpendicularly onto the housing 1.

[0045] The aforementioned light-transmitting mirror 2, filter 3, photovoltaic cell 5, solar tracker 13, turntable 15, hydraulic shaft 17 and controller 18 are all assemblies of existing equipment, therefore, their specific models and specifications are not described in detail.

[0046] Working principle of the invention:

[0047] When the spectral photovoltaic air collector based on fluid and heat transfer optimization provided by this invention is working, in order to ensure the vertical irradiation of sunlight, the solar tracking system will collect the incident angle of sunlight through the solar tracker 13. After the data is transmitted to the controller 18, the controller 18 controls the turntable 15 and the hydraulic shaft 17 to respond. The turntable 15 controls the lateral angle between the entire collector and the sunlight, and the hydraulic shaft 17 controls the longitudinal angle between the entire collector and the sunlight.

[0048] Sunlight first penetrates the concentrating and splitting system directly. During the process of sunlight penetrating the concentrating and splitting system, each set of concentrating and splitting systems divides the sunlight into three wavelength bands in space. Along the direction from the inlet to the outlet of the collector, the wavelength bands are respectively: the first wavelength band with a wavelength greater than 1100nm, the second wavelength band with a wavelength between 560nm and 1100nm, and the third wavelength band with a wavelength less than 560nm. The sunlight of different wavelength bands shines on each set of three rows of strip substrates 4 according to the refraction angle.

[0049] The energy conversion process of the photovoltaic cells 5 on each of the different orders of strip substrates 4 in each group of strip substrates 4 is different. When the first wave of sunlight shines on the first row of high-order strip substrates 4, it passes through the upconversion material layer 11 and is converted into light within the absorption spectrum of crystalline silicon photovoltaic cells. Then it shines on the crystalline silicon photovoltaic cells, is absorbed by them, and is converted into electrical energy. When the second wave of sunlight shines on the second row of middle-order strip substrates 4, it is directly absorbed by the top crystalline silicon photovoltaic cells and converted into electrical energy. When the third wave of sunlight shines on the third row of low-order strip substrates 4, it passes through the organic... The photovoltaic cell is then converted into light within the absorption spectrum of the organic photovoltaic cell by the downconversion material layer 12. The light is then reflected back onto the organic photovoltaic cell, where it is absorbed and converted into electrical energy. However, the aforementioned photovoltaic cells 5 can only efficiently convert most of the received sunlight into electrical energy. The remaining sunlight is irradiated by the transparent PET plate on the top layer of the strip substrate 4 onto the metal layer on the bottom layer of the strip substrate 4. This portion of sunlight is converted into heat energy, which is efficiently absorbed by the air on both sides of the strip substrate 4. This significantly reduces the temperature of the photovoltaic cell 5 and improves the photoelectric conversion efficiency.

[0050] When the collector is running, the air is diverted by the first row of high-order strip substrates 4 of the first group to the upper air duct 7 and the lower air duct 8. The stepped structure of the three rows of strip substrates 4 in each group causes the upper air duct 7 and the lower air duct 8 to be connected in the two gaps 9 between the three rows of strip substrates 4 in each group. Therefore, the upper air duct 7 and the lower air duct 8 form a whole for flow and heat transfer.

[0051] For the upper airflow channel 7, the surfaces of the light-transmitting mirrors 2 of each row of curved surfaces in the concentrating and splitting system, along with a group of three rows of high, medium, and low-order strip substrates 4, sequentially form a tapering section, an approximately equal cross-section section, and an expanding section along the inflow direction. In the tapering section, the flow area gradually decreases. According to Bernoulli's principle, the air velocity gradually increases, and the pressure gradually decreases. This results in a pressure difference at the flow cross-section of the upper airflow channel 7 and the lower airflow channel 8 corresponding to the first gap 9 of each group of three rows of strip substrates 4 in the photovoltaic system. This causes the air in the lower airflow channel 8 to be drawn into the upper airflow channel 7 through this gap 9. The air in the upper airflow channel 7 and the lower airflow channel 8 mix for the first time in the approximately equal cross-section section. Since the flow area change in the approximately equal interface section is small, the air maintains its original motion state. At the second gap 9 of each group of three rows of strip substrates 4, shear stress causes the air in the lower airflow channel 8 to be drawn into the upper airflow channel 7 for the second time. The mixing of the upper airflow channel 7 and the lower airflow channel 8 is completed in the expanding section. The air in channel 8 is mixed again. As the cross-section of the gradually expanding section increases, the air velocity gradually decreases and the pressure gradually recovers. Then, the air in the upper channel 7 flows out of the photovoltaic cell system's strip substrate 4 and enters the next group of strip substrates 4. It is then diverted by the front end of the first row of higher-order strip substrates 4 in the next group of strip substrates 4 and enters the lower channel 8. The air in the upper channel 7 and the lower channel 8 are mixed for the third time. After that, the flow continues according to the above pattern. Because the flow in each group of strip substrates 4 generates three mixings of hot and cold air in the upper and lower channels, it promotes the heat exchange inside the air in the upper channel 7 and the lower channel 8. In addition, the stepped arrangement of the three rows of strip substrates 4 in each group allows the boundary layer of each level of the three rows of strip substrates 4 in each group to be regenerated, which solves the problem of continuous thickening of the boundary layer of the traditional integrated substrate. This effectively reduces the convective heat transfer thermal resistance and thus synergistically improves the photothermal conversion efficiency and photoelectric conversion efficiency of the collector.

[0052] For the downdraft duct 8, the first rib 6 at the bottom of each of the three rows of strip substrates 4 of each group increases the heat exchange area while having a small impact on the mainstream airflow. When the air flows through each group of second ribs 10 at the bottom of the shell 1, it is guided by its windward curved surface to the two gaps 9 of the group of strip substrates 4 of the photovoltaic cell system above, which promotes the upward airflow duct 7 at the two gaps 9 to the downdraft duct 8. The gap structure of the second rib 10 is narrow at the bottom and wide at the top, which plays a throttling role on the airflow near the bottom and lifts the airflow at the bottom of the shell 1. The staggered arrangement of the two rows of second ribs 10 in the same group makes the bottom cold airflow flowing through the gap of the front row of second ribs 10 rise again. Under the premise of minimizing flow resistance, it ensures that all parts of the air in the collector participate in the heat dissipation process. In addition, the leeward side of the second rib 10 and the space behind it form a vortex, which promotes the heat exchange between the bottom air and the upper air near the leeward side and disturbs the boundary layer on the surface of the nearby first rib 6, further enhancing convective heat transfer. There is enough space between each group of second ribs 10 to accommodate the air diverted into the lower air duct 8 by the front end of the higher-order strip substrate 4 of the next group of strip substrates 4, and mixes with the cold air in the lower air duct 8. It can be seen that the air in the lower air duct 8 flows repeatedly according to the above-mentioned pattern, which corresponds to the structural function of the upper air duct 7 and couples with each other, greatly enhancing the mixing between the air inside the upper air duct 7 and the lower air duct 8, improving the convective heat transfer coefficient of the air, thereby increasing the air outlet temperature and the heat collection efficiency of the collector, and synergistically improving the photothermal conversion efficiency and photoelectric conversion efficiency of the air-type photovoltaic and photothermal collector.

Claims

1. A spectrophotometer-based photovoltaic air collector based on fluid and heat transfer optimization, comprising a shell, a concentrating and splitting system, a photovoltaic cell system, and a solar tracking system, wherein the concentrating and splitting system is mounted on the top surface of the shell, the photovoltaic cell system is mounted in the inner cavity of the shell, and the solar tracking system is mounted on the bottom of the shell, the solar tracking system being able to drive the shell to rotate so that sunlight is perpendicularly irradiated onto the shell; the concentrating and splitting system includes a light-transmitting lens and a filter, wherein the light-transmitting lens is a curved lens, and several rows of light-transmitting lenses are symmetrically mounted on both sides of the top and bottom surfaces of the filter, characterized in that: The photovoltaic cell system includes a strip substrate, a photovoltaic cell, and a first rib. The strip substrate is assembled with an array of strip substrates, which are assembled in the middle of the inner cavity of the housing. An upper air duct is formed in the inner cavity above the array of strip substrates, and a lower air duct is formed in the inner cavity below the array of strip substrates. Each set of strip substrates is arranged with symmetrical light-transmitting mirrors on each row at the top of the housing. Each set of strip substrates consists of three rows of strip substrates arranged in a stepped manner, with the height of adjacent rows of strip substrates decreasing sequentially from front to back. The photovoltaic cell is assembled on the top surface of each row of strip substrates, and the first rib is assembled on the bottom surface of each row of strip substrates. Two gaps are formed between each set of three rows of strip substrates. A second rib is assembled on the bottom plate of the housing below each gap. Two rows of second ribs are assembled on the bottom plate of the housing below each set of three rows of strip substrates. The top of each row of second ribs is set with respect to the gap between adjacent rows of strip substrates.

2. The spectral photovoltaic air collector based on fluid and heat transfer optimization according to claim 1, characterized in that: The strip substrate has a two-layer structure. The top layer of the strip substrate is a transparent PET board, and the photovoltaic cells are bonded to the PET board on the top surface of the strip substrate with EVA adhesive. The bottom layer of the strip substrate is a metal layer with high thermal conductivity.

3. A spectrophotometer-based photovoltaic air collector based on fluid and heat transfer optimization according to claim 1, characterized in that: In each group of strip substrates, the photovoltaic cells attached to the top surface of the first row of high-order strip substrates are upconversion photovoltaic cells. These upconversion photovoltaic cells consist of crystalline silicon photovoltaic cells with an upconversion material layer deposited on the top surface. The upconversion material layer is NaYF4:Er 3+ In the middle-tier second row, only photovoltaic cells are mounted on the top surface of the strip substrates. These photovoltaic cells are also crystalline silicon photovoltaic cells. In the lower-tier third row, the photovoltaic cells mounted on the top surface of the strip substrates are down-conversion photovoltaic cells. These down-conversion photovoltaic cells consist of organic photovoltaic cells with a down-conversion material layer deposited on the bottom surface. The down-conversion material layer is LaOF:Eu. 3+ .

4. A spectrophotometer-based photovoltaic air collector based on fluid and heat transfer optimization according to claim 1, characterized in that: The first rib is shaped like an isosceles right triangle, with the base angles of the isosceles right triangle facing downwards.

5. A spectrophotometer-based photovoltaic air collector based on fluid and heat transfer optimization according to claim 1, characterized in that: The two rows of second ribs are staggered, with the second ribs of the first row higher than the second ribs of the second row from front to back. Each second rib is pyramidal in shape, and the windward side of the pyramidal second rib is curved.

6. A spectrophotometer-based photovoltaic air collector based on fluid and heat transfer optimization according to claim 1, characterized in that: The periphery of the shell is covered with an insulation layer.

7. A spectrophotometer-based photovoltaic air collector based on fluid and heat transfer optimization according to claim 1, characterized in that: The solar tracking system includes a solar tracker, connecting rods, a turntable, support rods, a hydraulic shaft, and a controller. The solar tracker is fixed to the top of the housing and connected to the controller. There are two support rods, one end of which is connected to both ends of a rotating shaft on the lower side of the housing, and the other end of which is fixed to the outside of the hydraulic shaft. The hydraulic shaft is mounted on the turntable. The connecting rods connect the hydraulic shaft and the housing at both ends. The controller is connected to the turntable. The solar tracker can transmit the collected data to the controller in real time. The controller controls the turntable and hydraulic shaft to rotate the housing based on the transmitted data from the solar tracker, so that sunlight shines perpendicularly onto the housing.

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