A thermoelectric power generation device for a solar street lamp

Abstract

This invention discloses a thermoelectric power generation device for solar streetlights, belonging to the field of new energy. It includes a photovoltaic power generation layer and an LED light with a heat dissipation substrate. The backlight side of the photovoltaic power generation layer is provided with a thermoelectric power generation layer, and the side of the thermoelectric power generation layer away from the photovoltaic power generation layer is provided with a heat dissipation layer. A heat conduction layer is provided between the photovoltaic power generation layer and the thermoelectric power generation layer. The height of the heat conduction layer above the ground is greater than the height of the heat dissipation substrate above the ground. The heat dissipation substrate and the heat conduction layer are connected by a gravity heat pipe. Both the photovoltaic power generation layer and the thermoelectric power generation layer are connected to an energy storage device. This device uses only one thermoelectric power generation layer to achieve the recovery and utilization of waste heat from the photovoltaic power generation layer and the LED light located in different positions, improving the waste heat utilization rate of solar streetlights with lower installation costs.

Description

Technical Field

[0001] This invention belongs to the field of new energy, and more specifically, relates to a thermoelectric power generation device for solar streetlights. Background Technology

[0002] Solar-powered LED streetlights have become a core solution for green lighting due to their significant advantages of zero carbon emissions and zero pollution. However, this streetlight system has a significant problem of wasting heat during operation: when solar panels are exposed to direct sunlight, their surface temperature is usually 20-30°C higher than the ambient temperature, and can even exceed 70°C during the hottest summer months. This not only leads to a 10-15% decrease in power generation efficiency but also accelerates the aging of encapsulation materials and shortens the lifespan of the components. When LED lights are working continuously, the temperature of their heat dissipation substrate can reach 80-90°C. If the heat cannot be effectively dissipated, it will also accelerate the light decay of the LED beads and reduce brightness.

[0003] Thermoelectric power generation technology utilizes the temperature difference between the two ends of a material to generate voltage. This waste heat can be recovered and converted into electrical energy to power the street light control system, further improving energy efficiency and making the green attributes of solar street lights more complete. For example, Chinese utility model patent with publication number CN202406061U discloses a photovoltaic and thermoelectric hybrid power generation system. It uses a concentrator in a solar photovoltaic structure to focus sunlight onto a photovoltaic panel to generate electricity. Simultaneously, a thermoelectric power generation panel below the photovoltaic panel dissipates heat through a bottom radiator, creating a temperature difference between the upper and lower surfaces of the thermoelectric power generation panel to generate electricity. Chinese invention patent application with publication number CN105782890A discloses an LED self-generating lamp and its application, using a thermoelectric generator to recover heat energy from the LED lamp, increasing the lifespan of the LED lamp while saving energy.

[0004] However, none of the aforementioned and similar existing technologies can utilize both photovoltaic waste heat and LED lamp waste heat for thermoelectric power generation, thus failing to further improve the waste heat utilization rate of solar streetlights. Summary of the Invention

[0005] 1. The problem to be solved To improve the utilization rate of waste heat from solar streetlights, this invention provides a thermoelectric power generation device that can collect both photovoltaic waste heat and LED lamp waste heat for power generation.

[0006] 2. Technical Solution In solar streetlights, the photovoltaic (PV) power generation layer and LED lights are often installed separately on the light pole at different heights from the ground. Due to their different locations, the conventional solution for collecting waste heat from both PV and LED lights is to install a separate thermoelectric power generation layer for each layer, but this increases installation costs. This invention addresses this by placing a heat conduction layer between the PV and LED power generation layers and using gravity heat pipes to connect the heat conduction layer to the heat dissipation substrate of the LED lights. This heat conduction layer acts as a transfer station, transferring waste heat from both the PV and LED lights. Thus, using a single thermoelectric power generation layer, both PV and LED waste heat can be used for thermoelectric power generation, improving the waste heat utilization rate of solar streetlights with lower installation costs.

[0007] To solve the above problems, the technical solution adopted by the present invention is as follows: This invention provides a thermoelectric power generation device for solar streetlights, comprising a photovoltaic power generation layer and an LED lamp with a heat dissipation substrate. The back of the photovoltaic power generation layer is provided with a thermoelectric power generation layer, and the side of the thermoelectric power generation layer away from the photovoltaic power generation layer is provided with a heat dissipation layer. A heat conduction layer is provided between the photovoltaic power generation layer and the thermoelectric power generation layer. The height of the heat conduction layer from the ground is greater than the height of the heat dissipation substrate from the ground. The heat dissipation substrate and the heat conduction layer are connected by a gravity heat pipe. Both the photovoltaic power generation layer and the thermoelectric power generation layer are connected to an energy storage device.

[0008] Preferably, the interior of the heat conduction layer is provided with a heat conduction core, and the heat conduction coefficient of the heat conduction core is greater than that of the heat conduction layer.

[0009] More preferably, the heat-conducting core has a dendritic structure, including at least one main branch, and each main branch extends at least two branches to both sides.

[0010] More preferably, the side of the heat conduction layer is provided with blind holes, and one end of the gravity heat pipe is embedded in the blind holes.

[0011] More preferably, the blind hole is connected to the heat-conducting core.

[0012] Preferably, the surface of the heat conduction layer near the photovoltaic power generation layer has protrusions, and the protrusions are connected and distributed in an array.

[0013] Preferably, the thermoelectric power generation layer is provided with multiple thermoelectric generator modules, and the heat conduction layer has a groove on the surface near the thermoelectric power generation layer, into which the thermoelectric generator modules are embedded.

[0014] Preferably, the heat dissipation layer includes a cavity, a vent located on the side of the cavity, and a water outlet located at the bottom of the cavity. The cavity is provided with a porous metal skeleton and a metal-organic framework material film coated on the surface of the porous metal skeleton. The metal-organic framework material film adsorbs and desorbs moisture at low and high temperatures, respectively. The vent is provided with a switch assembly, which is used to control the opening and closing of the vent.

[0015] More preferably, the switching assembly includes a louver and a louver driving device located on the cavity. The louver covers the ventilation opening. One end of the louver driving device is provided with a rotating pull cord. The two ends of the rotating pull cord are a first end and a second end, respectively. Pulling down the first end and the second end will close and open the louver, respectively. The first end and the second end are connected to a spring driving assembly. The spring drive assembly includes a guide rail connected to the cavity and a first slider and a second slider located on both sides of the guide rail. The first slider and the second slider are slidably connected to the guide rail. The first slider and the cavity are connected by a first spring, and the second slider and the cavity are connected by a second spring. The first spring is made of shape memory alloy, and its first end and second end are connected to the first slider and the second slider, respectively.

[0016] More preferably, both the first slider and the second slider are provided with L-shaped buckles, and the guide rails below the first slider and the second slider are provided with locking seats perpendicular to the sliding direction of the guide rails, and the buckles and locking seats are movably connected.

[0017] 3. Beneficial effects Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The thermoelectric power generation device provided by the present invention has a heat conduction layer between the photovoltaic power generation layer and the thermoelectric power generation layer, and connects the heat conduction layer and the heat dissipation substrate of the LED lamp using a gravity heat pipe. When in use, the waste heat of the photovoltaic power generation layer is directly transferred to the heat conduction layer, while the waste heat of the LED lamp is indirectly transferred to the heat conduction layer through the gravity heat pipe. After the heat conduction layer receives the waste heat of the photovoltaic power generation layer and / or the LED lamp, it enables the thermoelectric power generation layer connected to it to work and generate electricity. This device only uses one set of thermoelectric power generation layer to realize the recycling of waste heat of the photovoltaic power generation layer and the LED lamp in different positions, thereby improving the waste heat utilization rate of solar street lights with a lower installation cost.

[0018] (2) The thermoelectric power generation device provided by the present invention has a protrusion on the surface of the heat conduction layer near the photovoltaic power generation layer, which improves the uniformity of heat input of the heat conduction layer; a heat conduction core with a larger thermal conductivity is provided inside the heat conduction layer, which improves the uniformity of heat transmission of the heat conduction layer; a groove matching the size of the thermoelectric generator module is provided on the surface of the heat conduction layer near the thermoelectric power generation layer, which increases the contact area between the two and improves the uniformity of heat output of the heat conduction layer. Therefore, by optimizing the uniformity of heat input, transmission and output, the temperature uniformity of the heat received by the thermoelectric power generation layer is increased, and the thermoelectric conversion efficiency is improved.

[0019] (3) The heat dissipation layer of the thermoelectric generator provided by the present invention utilizes the property of metal-organic framework material film to absorb heat and desorb water at high temperature. It can both cool down to increase the temperature difference on both sides of the thermoelectric generator layer and collect water, and can be used in remote and arid areas. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the thermoelectric power generation device in this invention; Figure 2 This is a schematic diagram of the structure of the heat-conducting core inside the heat-conducting layer in this invention; Figure 3 This is a schematic diagram of the surface groove of the heat conduction layer near the thermoelectric layer in this invention; Figure 4 This is a schematic diagram of one embodiment of the heat dissipation layer in this invention; Figure 5 This is a state diagram of the switch assembly and the spring drive assembly when the vent is closed in this invention; Figure 6 for Figure 5 Enlarged view of the spring drive assembly on the first spring side; Figure 7 for Figure 5 Enlarged view of the spring drive assembly on the second spring side; Figure 8 This is a state diagram of the switch assembly and the spring drive assembly when the vent is opened in this invention; Figure 9 This is an enlarged view of the heat transfer clamp in this invention.

[0021] In the picture: 1. Photovoltaic power generation layer; 2. Heat-conducting layer; 21. Heat-conducting core; 211. Main branch; 212. Branch; 22. Blind hole; 23. Protrusion; 24. Groove; 3. Thermoelectric generator layer; 31. Thermoelectric generator module; 4. Heat dissipation layer; 41. Cavity; 42. Ventilation opening; 43. Water outlet; 44. Porous metal frame; 45. Switch assembly; 451. Louver; 452. Louver drive device; 4521. First end; 4522. Second end; 46. Spring drive assembly; 461. Guide rail; 462. First slider; 463. Second slider; 464. First spring; 465. Second spring; 466. Adjusting nut; 467. Buckle; 468. Lock seat; 5. LED light; 51. Heat dissipation substrate; 516. Heat transfer clip; 6. Gravity heat pipe; 61. Insulation material; 7. Energy storage equipment. Detailed Implementation

[0022] It should be noted that when a component is referred to as being "mounted" on another component, it can be directly on the other component or the two components can be integrated as one unit; when a component is referred to as being "connected" to another component, it can be directly connected to the other component or the two components can be integrated as one unit. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0024] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0025] As used herein, “adjacent” means that two structures or elements are close to each other. Specifically, elements identified as “adjacent” may be adjacent or connected. Such elements may also be close to or near each other without necessarily touching. In some cases, the precision of proximity may depend on the specific context.

[0026] As used herein, the term “at least one of…” is intended to be synonymous with “one or more of…”. For example, “at least one of A, B, and C” explicitly includes only A, only B, only C, and combinations thereof.

[0027] The present invention will be further described below with reference to specific embodiments.

[0028] like Figure 1As shown, this embodiment provides a thermoelectric power generation device for solar streetlights, including a photovoltaic power generation layer 1 and an LED lamp 5 with a heat dissipation substrate 51. The backlight surface of the photovoltaic power generation layer 1 is provided with a thermoelectric power generation layer 3, and the side of the thermoelectric power generation layer 3 away from the photovoltaic power generation layer 1 is provided with a heat dissipation layer 4. A heat conduction layer 2 is provided between the photovoltaic power generation layer 1 and the thermoelectric power generation layer 3. The height of the heat conduction layer 2 from the ground is greater than the height of the heat dissipation substrate 51 from the ground. The heat dissipation substrate 51 and the heat conduction layer 2 are connected by a gravity heat pipe 6. Both the photovoltaic power generation layer 1 and the thermoelectric power generation layer 3 are connected to an energy storage device 7.

[0029] In one embodiment, the photovoltaic power generation layer 1 and the heat conduction layer 2 are connected by a thermally conductive adhesive, which can be a one-component thermally conductive adhesive, a two-component thermally conductive adhesive, a silicone grease-type thermally conductive adhesive, or an acrylic-based thermally conductive adhesive.

[0030] In one implementation, the surface of the heat-conducting layer 2 near the photovoltaic power generation layer 1 is provided with protrusions 23 to ensure that the heat from the photovoltaic power generation layer 1 is evenly transferred to the heat-conducting layer 2, preventing localized overheating. As a preferred embodiment, the protrusions 23 are interconnected and distributed in an array, such as... Figure 1 As shown, the distribution shape of the protrusions 23 is parallel strips. In addition, the distribution shape of the protrusions 23 can also be net-like, spiral, or radial.

[0031] In one implementation, a heat-conducting core 21 is provided inside the heat-conducting layer 2. The thermal conductivity of the heat-conducting core 21 is greater than that of the heat-conducting layer 2, so that heat is evenly transferred inside the heat-conducting layer 2, avoiding excessively high local temperatures inside the heat-conducting layer 2, which could then lead to excessively high local temperatures in the thermoelectric generation layer 3 below it. The heat-conducting layer 2 and the heat-conducting core 21 can be made of copper, aluminum, diamond, graphite, aluminum nitride, or boron nitride, respectively.

[0032] As one implementation method, such as Figure 2 As shown, the heat-conducting core 21 has a dendritic structure and may include at least one main branch 211, with each main branch 211 extending at least two branches 212 to both sides. When there is only one main branch 211, the axis of the main branch 211 may be parallel to the length or width direction of the heat-conducting layer 2. When there are multiple main branches 211, the main branches 211 may radiate from a center to the surrounding areas. As one embodiment, the angle between the branch 212 and the main branch 211 is 30 to 60 degrees, and the distance between two adjacent branches 212 is equal to ensure rapid and uniform heat transfer.

[0033] As one implementation method, such as Figure 2As shown, a blind hole 22 is provided on the side of the heat conduction layer 2, and one end of the gravity heat pipe 6 is embedded in the blind hole 22. The shape of the blind hole 22 can be processed into the shape of the gravity heat pipe 6 so that the two can be matched and connected. When the heat conduction layer 2 is thin and the diameter of the gravity heat pipe 6 is large, the connecting end of the gravity heat pipe 6 can be slightly flattened so that the gravity heat pipe 6 can be embedded in the blind hole 22. In order to improve the heat transfer efficiency, the blind hole 22 can be connected to the heat-conducting core 21. If the main body of the heat-conducting core 21 wraps around the blind hole 22, the heat from the heat dissipation substrate 51 can be quickly transferred to other parts of the heat conduction layer 2 through the heat-conducting core 21, avoiding excessive temperature at the connecting end.

[0034] Thermoelectric power generation layer 3 is equipped with multiple thermoelectric generator (TEG) modules 31, and the surface of heat conduction layer 2 near thermoelectric power generation layer 3 is provided with grooves 24 (such as...). Figure 3 As shown, the thermoelectric generator module is embedded in the groove 24. Since the size of the groove 24 matches the size of the TEG module 31, the contact surface between a single TEG module 31 and the heat conduction layer 2 can be changed from one to multiple, which is more conducive to the rapid and uniform transfer of heat.

[0035] In one implementation, the TEG modules 31 are arranged in a rectangular array to facilitate uniform reception of heat transferred from the heat conduction layer 2. The thickness of the TEG modules 31 is 3~5mm, the width is 30~50mm, and the length is 30~50mm.

[0036] Excessive local temperature in the thermoelectric power generation layer 3 may lead to decreased thermoelectric conversion efficiency, material damage, structural failure, and even safety risks. This invention improves the uniformity of heat input to the heat conduction layer 2 by providing protrusions 23 on the surface of the heat conduction layer 2 near the photovoltaic power generation layer 1; improves the uniformity of heat transmission by providing a heat-conducting core 21 with a higher thermal conductivity inside the heat conduction layer 2; and increases the contact area between the heat conduction layer 2 and the thermoelectric power generation layer 3 by providing grooves 24 matching the size of the thermoelectric generator module on the surface of the heat conduction layer 2 near the thermoelectric power generation layer 3. Therefore, by optimizing the uniformity of heat input, transmission, and output, the temperature uniformity of the heat received by the thermoelectric power generation layer 3 from the heat conduction layer 2 is increased, thereby improving the thermoelectric conversion efficiency.

[0037] In one embodiment, the heat dissipation layer 4 is made of one of copper, aluminum, diamond, graphite, aluminum nitride or boron nitride, and the heat dissipation layer 4 is a solid block or a porous structure.

[0038] As another implementation method, such as Figure 4As shown, the heat dissipation layer 4 includes a cavity 41, a vent 42 located on the side of the cavity 41, and a water outlet 43 located at the bottom of the cavity 41. The cavity 41 contains a porous metal skeleton 44 and a metal-organic framework (MOF) material film coated on the surface of the porous metal skeleton 44. The MOF material film adsorbs and desorbs moisture at low and high temperatures, respectively. A switch assembly 45 is provided on the vent 42 to control the opening and closing of the vent 42. The vent 42 opens when the ambient temperature is higher than a set value and closes when the temperature is lower than the set value. Preferably, the set value is 45~60℃.

[0039] Furthermore, the porous metal skeleton 44 is made of copper or aluminum with a porosity of 80%~95%, and the MOF material is one or more of MOF-303, MIL-101(Cr), or UiO-66. During the day when the temperature is high, the vent 42 is closed. The waste heat generated by the photovoltaic power generation layer 1 is transferred sequentially to the heat dissipation layer 4 through the heat conduction layer 2 and the thermoelectric power generation layer 3. The MOF material film in the heat dissipation layer 4 receives the heat from the thermoelectric power generation layer 3 and the surrounding air, and desorbs to release water vapor. This process is endothermic, which can reduce the temperature of the porous metal skeleton 44, thereby improving the heat dissipation performance of the heat dissipation layer 4. The released water vapor condenses into water droplets upon contact with the cavity 41 and flows to the water outlet 43 at the bottom of the cavity 41 for discharge. The water outlet 43 can be connected to a water collection device for water collection in remote and arid areas. When the temperature is low at night, the vent 42 is opened, and the MOF material film in the heat dissipation layer 4 automatically absorbs water vapor in the air. This process is exothermic, but since it is at night, the released heat is quickly carried away by the surrounding airflow, and it hardly affects the temperature of the porous metal skeleton 44, nor does it affect the heat dissipation performance of the heat dissipation layer 4.

[0040] As a specific implementation method, the specific steps for coating a MOF material film on the surface of the porous metal skeleton 44 are as follows: S1. The porous copper skeleton is sequentially immersed in dilute hydrochloric acid, anhydrous ethanol and deionized water for ultrasonic cleaning to remove the surface oxide layer and oil impurities. After cleaning, it is placed in a vacuum drying oven to dry and obtain pretreated foam copper. S2. Add the corresponding metal salt precursor (such as aluminum chloride) and organic ligand (such as 1H-pyrazole-3,5-dicarboxylic acid) to deionized water or organic solvent at a predetermined molar ratio, and stir magnetically until completely dissolved to obtain the reaction precursor solution of MOF material film. S3. The pretreated porous copper framework is completely immersed in a reaction vessel containing a reaction precursor solution, sealed and placed in a homogeneous reaction furnace at 100~120℃ for constant temperature reaction for 12~24 hours to promote the in-situ growth of MOF crystals with the copper framework as nucleation sites and the interweaving to form a dense film. S4. After the reactor has cooled to room temperature, take out the porous copper skeleton coated with MOF material film, wash it several times with deionized water and methanol alternately to remove free impurities on the surface, and then place it in a vacuum environment at 100~120℃ for 12~24 hours to completely remove solvent molecules in the material pores, and obtain a porous copper skeleton coated with MOF material film.

[0041] As one implementation method, such as Figures 5-8 As shown, the switch assembly 45 includes a louver 451 and a louver drive device 452 located on the cavity 41. The louver 451 covers the ventilation opening 42. The louver drive device 452 is commercially available, and its structure will not be described in detail here as it is widely used. One end of the louver drive device 452 is provided with a rotating pull cord, which is used to control the opening and closing of the louver 451. The two ends of the rotating pull cord are a first end 4521 and a second end 4522, respectively. Pulling down the first end 4521 of the rotating pull cord closes the louver 451, and pulling down the second end 4522 of the rotating pull cord opens the louver 451. Furthermore, the first end 4521 and the second end 4522 of the rotating pull cord are connected to a spring drive assembly 46.

[0042] The spring-driven assembly 46 includes a guide rail 461 connected to the cavity 41 and a first slider 462 and a second slider 463 located on both sides of the guide rail 461. Both the first slider 462 and the second slider 463 are slidably connected to the guide rail 461. The first slider 462 and the cavity 41 are connected by a first spring 464, and the second slider 463 and the cavity 41 are connected by a second spring 465. The first spring 464 is made of a shape memory alloy, such as a nickel-titanium alloy, a copper alloy, or an iron alloy. The first end 4521 of the rotating pull rope is connected to the first slider 462, and the second end 4522 of the rotating pull rope is connected to the second slider 463. During the day when the temperature is high, the first spring 464 undergoes an austenitic phase transformation and gradually hardens and contracts. When its contraction force exceeds the tension of the second spring 465, the first slider 462 slides downward, pulling down the first end 4521 of the rotating cord. At this time, the louver 451 closes, and the MOF material film in the heat dissipation layer 4 absorbs heat and desorbs and releases water vapor. At night when the temperature is low, the first spring 464 undergoes a martensitic phase transformation and gradually softens. The contraction force of the second spring 465 exceeds the tension of the first spring 464, causing the second slider 463 to slide downward, pulling down the second end 4522 of the rotating cord. At this time, the louver 451 opens, and the MOF material film in the heat dissipation layer 4 adsorbs water vapor in the air, preparing for heat absorption and desorption during the day. By changing the composition or manufacturing process to adjust the phase transformation point of the first spring 464 to near the set value of the target temperature, the automatic opening and closing of the louver 451 can be achieved.

[0043] Furthermore, the second spring 465 and the cavity 41 are connected by an adjusting nut 466. By loosening or tightening the adjusting nut 466, the length of the deformable part of the second spring 465 can be adjusted, thereby adjusting the initial preload of the second spring 465 and changing the temperature point at which the louver 451 automatically opens and closes.

[0044] Furthermore, both the first slider 462 and the second slider 463 are provided with L-shaped latches 467, and the guide rails 461 below the first slider 462 and the second slider 463 are provided with locking seats 468 perpendicular to the sliding direction of the guide rails 461. The latches 467 and the locking seats 468 are movably connected. When the ambient temperature is high, the first spring 464 contracts, at which time the latch 467 on the side of the first spring 464 is engaged with the locking seat 468 on the same side, while the latch 467 on the side of the second spring 465 disengages from the locking seat 468 on the same side. When the ambient temperature is low, the first spring 464 extends, at which time the latch 467 on the side of the first spring 464 disengages from the locking seat 468 on the same side, while the latch 467 on the side of the second spring 465 is engaged with the locking seat 468 on the same side. By setting the latches 467 and the locking seats 468, the pulling force required to pull the rotating pull cord can be adjusted, thereby changing the temperature point at which the venetian blind 451 automatically opens and closes.

[0045] In one implementation, the number of first springs 464 can be more than one, and the number of second springs 465 can also be more than one.

[0046] The gravity heat pipe 6 is a passive heat transfer device that relies on gravity to drive the condensate backflow and can only achieve unidirectional (from bottom to top) heat transfer. It is also called a thermosiphon or a two-phase closed thermosiphon. The gravity heat pipe 6 includes a shell material and an internal working fluid. The shell material can be copper or aluminum, and the internal working fluid is ammonia or acetone. Ammonia or acetone has a low boiling point, and the waste heat from the heat dissipation substrate 51 of the LED lamp 5 can evaporate it for heat transfer. As one embodiment, the portion of the gravity heat pipe 6 located between the heat dissipation substrate 51 and the thermoelectric layer 3 is wrapped with a heat insulation material 61. The heat insulation material 61 is made of polystyrene, polyurethane, or polyisocyanurate. As one embodiment, there can be more than one gravity heat pipe 6. The cross-sectional shape of the gravity heat pipe 6 can be circular, elliptical, or square. The diameter of the circle, the major axis of the ellipse, and any side length of the square are all no greater than 10 mm.

[0047] like Figure 9 As shown, the heat dissipation substrate 51 and the gravity heat pipe 6 are connected by a heat transfer clip 516. The heat dissipation substrate 51 is connected to the heat transfer clip 516, which clamps the other end of the gravity heat pipe 6. The heat transfer clip 516 can be a symmetrical structure, or it can be as follows: Figure 9The structure shown is asymmetrical, with one end connected to the edge of the heat dissipation substrate 51, and the other end extending to the lower surface of the heat dissipation substrate 51 after wrapping around the gravity heat pipe 6. The heat transfer clip 516 can be integrally formed with the heat dissipation substrate 51 or separately mounted from it. The heat transfer clip 516 should wrap around the circumference of the gravity heat pipe 6 as much as possible to increase the contact area and improve heat transfer efficiency. The heat transfer clip 516 is made of a material with good thermal conductivity, and can be selected from copper, aluminum, diamond, graphite, aluminum nitride, or boron nitride.

[0048] The above-described method of using the thermoelectric power generation device for solar streetlights is as follows: During the day, the photovoltaic power generation layer 1 generates waste heat while generating photovoltaic power. This waste heat is transferred to the thermoelectric power generation layer 3 through the heat conduction layer 2. The thermoelectric power generation layer 3 generates electricity using the temperature difference between the heat conduction layer 2 and the heat dissipation layer 4 on both sides. At night, the LED light 5 generates heat while working. The heat dissipation substrate 51 on the LED light 5 transfers the waste heat to the heat conduction layer 2 through the gravity heat pipe 6. The heat conduction layer 2 then transfers the heat to the thermoelectric power generation layer 3. The thermoelectric power generation layer 3 generates electricity using the temperature difference between the heat conduction layer 2 and the heat dissipation layer 4 on both sides. The electricity generated by the photovoltaic power generation layer 1 and the thermoelectric power generation layer 3 is stored in the energy storage device 7. Therefore, by using only one set of thermoelectric power generation layer 3, the device can recover and utilize the waste heat of the photovoltaic power generation layer 1 and the LED light 5 located in different positions, and improve their service life by reducing their operating temperature.

[0049] The above description provides an illustrative overview of the present invention and its embodiments. This description is not restrictive, and the embodiments shown are merely one example of the invention's implementation. Actual implementations are not limited to these examples. Therefore, if those skilled in the art are inspired by this description and design similar implementations and examples without departing from the spirit of the invention, such designs should fall within the scope of protection of the present invention.

Claims

1. A thermoelectric power generation device for solar streetlights, comprising a photovoltaic power generation layer (1) and an LED lamp (5) with a heat dissipation substrate (51), wherein a thermoelectric power generation layer (3) is provided on the back surface of the photovoltaic power generation layer (1), and a heat dissipation layer (4) is provided on the side of the thermoelectric power generation layer (3) away from the photovoltaic power generation layer (1), characterized in that: A heat conduction layer (2) is provided between the photovoltaic power generation layer (1) and the thermoelectric power generation layer (3). The height of the heat conduction layer (2) from the ground is greater than the height of the heat dissipation substrate (51) from the ground. The heat dissipation substrate (51) and the heat conduction layer (2) are connected by a gravity heat pipe (6). Both the photovoltaic power generation layer (1) and the thermoelectric power generation layer (3) are connected to an energy storage device (7).

2. The thermoelectric power generation device according to claim 1, characterized in that: The heat conduction layer (2) has a heat conduction core (21) inside, and the heat conduction coefficient of the heat conduction core (21) is greater than that of the heat conduction layer (2).

3. The thermoelectric power generation device according to claim 2, characterized in that: The heat-conducting core (21) has a dendritic structure, including at least one main branch (211), and each main branch (211) extends at least two branches (212) to both sides.

4. The thermoelectric power generation device according to claim 2 or 3, characterized in that: The heat conduction layer (2) has a blind hole (22) on its side, and one end of the gravity heat pipe (6) is embedded in the blind hole (22).

5. The thermoelectric generator according to claim 4, characterized in that: The blind hole (22) is connected to the heat-conducting core (21).

6. The thermoelectric power generation device according to claim 1, characterized in that: The heat conduction layer (2) has protrusions (23) on its surface near the photovoltaic power generation layer (1), and the protrusions (23) are connected and distributed in an array.

7. The thermoelectric generator according to claim 1, characterized in that: The thermoelectric power generation layer (3) is provided with multiple thermoelectric generator modules (31), and the heat conduction layer (2) has a groove (24) on its surface near the thermoelectric power generation layer (3), and the thermoelectric generator module (31) is embedded in the groove (24).

8. The thermoelectric generator according to claim 1, characterized in that: The heat dissipation layer (4) includes a cavity (41), a vent (42) located on the side of the cavity (41), and a water outlet (43) located at the bottom of the cavity (41). The cavity (41) is provided with a porous metal skeleton (44) and a metal-organic framework material film coated on the surface of the porous metal skeleton (44). The metal-organic framework material film adsorbs and desorbs moisture at low temperature and high temperature, respectively. The vent (42) is provided with a switch assembly (45), which is used to control the opening and closing of the vent (42).

9. The thermoelectric generator according to claim 8, characterized in that: The switching assembly (45) includes a louver (451) and a louver drive device (452) located on the cavity (41). The louver (451) covers the ventilation opening (42). One end of the louver drive device (452) is provided with a rotating pull cord. The two ends of the rotating pull cord are a first end (4521) and a second end (4522), respectively. Pulling down the first end (4521) and the second end (4522) will close and open the louver (451) respectively. The first end (4521) and the second end (4522) are connected to the spring drive assembly (46). The spring drive assembly (46) includes a guide rail (461) connected to the cavity (41) and a first slider (462) and a second slider (463) located on both sides of the guide rail (461). The first slider (462) and the second slider (463) are slidably connected to the guide rail (461). The first slider (462) and the cavity (41) are connected by a first spring (464), and the second slider (463) and the cavity (41) are connected by a second spring (465). The first spring (464) is made of shape memory alloy, and its first end (4521) and second end (4522) are connected to the first slider (462) and the second slider (463) respectively.

10. The thermoelectric generator according to claim 9, characterized in that: The first slider (462) and the second slider (463) are both provided with L-shaped buckles (467), and the guide rail (461) below the first slider (462) and the second slider (463) are both provided with locking seats (468) perpendicular to the sliding direction of the guide rail (461). The buckles (467) and the locking seats (468) are movably connected.

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