Composite heat dissipation photovoltaic module and heat dissipation method of solar cell

Abstract

The invention relates to the technical field of thermal management of photovoltaic modules, and discloses a composite heat dissipation photovoltaic module and a heat dissipation method of a solar cell, and the composite heat dissipation photovoltaic module comprises the solar cell which comprises a front surface and a back surface which are oppositely arranged; the graphite soaking layer is positioned on the back surface of the solar cell; the radiator is used for diffusing heat of the solar cell in a plane direction; and the micro-channel liquid cooling heat dissipation layer is positioned on one side, back on to the solar cell, of the graphite soaking layer and is used for transferring heat to the outside. According to the invention, rapid temperature equalization and efficient heat dissipation of the solar cell can be realized, so that high photoelectric conversion efficiency of the cell is maintained under a high-temperature condition, and the service life of the cell is remarkably prolonged.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module thermal management technology, and specifically to a heat dissipation method for a composite heat dissipation photovoltaic module and solar cells. Background Technology

[0002] In related technologies, solar cells (especially perovskite / silicon heterojunction solar cells) are extremely sensitive to temperature, and perovskite / silicon heterojunction solar cells face the problem of insufficient thermal management. When the cell operating temperature rises (e.g., the temperature of perovskite / silicon heterojunction solar cells > 60°C), the photoelectric conversion efficiency of the photovoltaic module decreases significantly. Therefore, in order to maintain high-efficiency power generation performance and extend cell life, it is necessary to adopt an efficient heat dissipation structure to quickly dissipate the heat accumulated during operation and prevent excessive temperature.

[0003] Currently, common heat dissipation methods for photovoltaic modules include: (1) Natural convection heat dissipation: relying on air flow to remove heat, but the efficiency is limited and it is difficult to meet the requirements in a calm environment; (2) Backsheet thermal conductive layer: using metal or ceramic backsheets to improve thermal conductivity, but the heat dissipation path is long and the thermal resistance is large; (3) Active cooling (air cooling / liquid cooling): air cooling has noise and energy consumption problems, while liquid cooling solutions have not been widely used in traditional batteries, especially lacking integrated designs that match the perovskite / silicon heterojunction battery structure.

[0004] Therefore, there is an urgent need to propose a novel heat dissipation structure that is compact, has high heat transfer efficiency, and is compatible with photovoltaic module packaging, in order to improve the stability and efficiency of solar cells under high temperature conditions. Summary of the Invention

[0005] This invention provides a heat dissipation method for composite heat dissipation photovoltaic modules and solar cells, which solves the problems in related technologies where each heat dissipation method is independent, difficult to coordinate for cooling, has low heat dissipation efficiency, high energy consumption, and is difficult to integrate with photovoltaic modules, resulting in poor stability of solar cells at high temperatures and reduced photoelectric conversion efficiency.

[0006] In a first aspect, the present invention provides a composite heat dissipation photovoltaic module, comprising:

[0007] Solar cells, including a front and a back side arranged opposite to each other; A graphite heat spreader is located on the back of the solar cell; it is used to diffuse the heat of the solar cell in a planar direction. The microchannel liquid cooling heat dissipation layer is located on the side of the graphite heat spreader that faces away from the solar cell and is used to transfer heat to the outside.

[0008] The composite heat-dissipating photovoltaic module provided by this invention has two main advantages. First, the graphite heat-dissipating layer possesses excellent thermal conductivity and in-plane thermal conductivity, enabling rapid heat dissipation from the solar cells and diffusion in the planar direction. This reduces temperature while preventing excessive localized temperatures within the solar cells. Simultaneously, the graphite heat-dissipating layer converts point heat sources into planar heat flow input, providing more stable heat flow input conditions for the underlying structure. Second, by incorporating a microchannel liquid-cooled heat dissipation layer, the graphite heat-dissipating layer can be actively cooled as needed, transferring heat to the outside, thus improving the heat dissipation efficiency and flexibility of the composite heat-dissipating photovoltaic module. Furthermore, the microchannel liquid-cooled heat dissipation layer can be activated as needed, reducing operating costs and energy consumption. Therefore, the composite heat-dissipating photovoltaic module provided by this invention achieves rapid temperature equalization and efficient heat dissipation of the solar cells through both the graphite heat-dissipating layer and the microchannel liquid-cooled heat dissipation layer, thereby maintaining high photoelectric conversion efficiency of the cells under high-temperature conditions and significantly extending their lifespan.

[0009] In one alternative embodiment, the solar cell is a perovskite / silicon heterojunction solar cell; The in-plane thermal conductivity of the graphite heat spreader is greater than or equal to 500 W / m·K; The thickness of the graphite heat spreader is 50μm~150μm; The materials for graphite heat spreaders include highly oriented pyrolytic graphite or expanded graphite / graphene composites.

[0010] The composite heat dissipation photovoltaic module provided by this invention can effectively improve the heat dissipation effect of perovskite / silicon heterojunction solar cells, achieving high thermal conductivity, rapid temperature equalization, and active temperature control. It effectively overcomes the bottleneck of efficiency degradation and lifespan reduction in this type of cell under high-temperature operation, ensuring that the perovskite / silicon heterojunction solar cell still maintains high photoelectric conversion efficiency at high temperatures. The in-plane thermal conductivity of the graphite heat spreader is greater than or equal to 500 W / m·K, which can diffuse local heat along the planar direction to adjacent areas, achieving rapid heat diffusion and equalization in a very short time. This effectively avoids excessive local temperature of the solar cell, preventing cell damage and improving module lifespan. The thickness of the graphite heat spreader is 50 μm to 150 μm, ensuring the mechanical strength and reliability of the graphite heat spreader while reducing the thermal resistance of graphite.

[0011] In one alternative embodiment, the graphite heat spreader includes opposing first and second surfaces, with the first surface relatively close to the back side of the solar cell. The first and / or second surfaces of the graphite heat spreader are provided with a nano-metal coating; the nano-metal coating is suitable for formation by chemical plating or magnetron sputtering processes; The first and / or second surfaces of the graphite heat spreader are provided with micro-bump structures; the micro-bump structures are suitable for formation by laser ablation or micro-pressing processes.

[0012] The composite heat dissipation photovoltaic module provided by this invention, by setting a nano-metal coating, can fill the microporous structure on the graphite surface, forming a continuous and dense metal-carbon composite thermally conductive interface, which can effectively reduce the interfacial contact thermal resistance between the graphite heat dissipation layer and the upper and lower structures, and improve mechanical stability. By setting a micro-bump structure, the graphite heat dissipation layer can achieve micro-elastic deformation when it is attached to the upper and lower structures, effectively filling micro-gaps, thereby further reducing the interfacial thermal resistance and improving the thermal coupling performance between the graphite heat dissipation layer and the upper and lower layers. At the same time, the bumps can also form micro-scale "heat dissipation nodes" in the heat conduction direction, increasing the contact area and promoting heat flow diffusion.

[0013] In one optional embodiment, the composite heat dissipation photovoltaic module further includes: a heat pipe heat transfer layer located between the graphite heat dissipation layer and the microchannel liquid cooling heat dissipation layer, for transferring heat from the graphite heat dissipation layer to the microchannel liquid cooling heat dissipation layer. The heat pipe heat transfer layer includes a heat-conducting substrate and a heat pipe; the heat pipe is at least partially embedded inside the heat-conducting substrate; the heat pipe is planar or loop-type. The thermal conductivity of the heat-conducting substrate is greater than or equal to 200 W / m·K; the heat pipe is filled with a phase change working fluid; The heat pipe heat transfer layer includes an evaporation side and a condensation side arranged opposite to each other; the evaporation side is relatively close to the graphite heat dissipation layer; the condensation side is in contact with the microchannel liquid cooling heat dissipation layer; the heat pipe is located on the evaporation side.

[0014] The composite heat dissipation photovoltaic module provided by this invention has a heat pipe heat transfer layer between a graphite heat dissipation layer and a microchannel liquid cooling heat dissipation layer. This allows the heat from the graphite heat dissipation layer to be transferred from the evaporation side to the condensation side, and then to the microchannel liquid cooling heat dissipation layer, achieving rapid vertical heat transfer. The thermal conductivity of the thermally conductive substrate is greater than or equal to 200 W / m·K. The heat pipe is filled with a phase change working fluid, which can improve the heat transfer rate and thus enhance the heat dissipation efficiency of the composite heat dissipation photovoltaic module.

[0015] In one alternative embodiment, the heat pipe is further embedded in the graphite heat spreader layer on the side facing away from the solar cell; the depth to which the heat pipe is embedded in the thermally conductive substrate is 50% to 60% of the heat pipe diameter; The thermally conductive substrate is made of aluminum alloy or copper-based material; the phase change working fluid is a mixture of methanol, acetone and ammonia. The heat pipe has a diameter of 2mm to 4mm and a wall thickness of 0.3mm to 0.5mm; the center-to-center distance between adjacent heat pipes is 10mm to 15mm; the heat pipe has a liquid filling rate of 20% to 40% and an internal vacuum degree ≤10. - ³Pa.

[0016] The composite heat dissipation photovoltaic module provided by this invention features a heat pipe embedded in a thermally conductive substrate to a depth of 50%–60% of its diameter, ensuring stability and good contact. The substrate is made of a high-thermal-conductivity metal such as aluminum alloy or copper-based material, improving thermal conductivity. The heat pipe is filled with a low-boiling-point phase-change working fluid of a mixture of methanol, acetone, and ammonia, enabling rapid heat absorption and vapor-liquid circulation. The heat pipe wall thickness is 0.3 mm–0.5 mm, balancing mechanical strength and thermal response speed. The center-to-center distance between the heat pipes is 10–15 mm, ensuring uniform heat absorption coverage without affecting the liquid cooling channel arrangement. The liquid filling rate is in the range of 20%–40% by volume, ensuring gas-liquid phase balance. The internal vacuum degree is ≤10. - ³ Pa can lower the boiling point temperature (by about 30~40℃).

[0017] In one optional embodiment, the composite heat dissipation photovoltaic module further includes: The first interface layer, located between the graphite heat spreader and the solar cell, is used to bond the graphite heat spreader and the solar cell and to conduct interfacial heat. The second interface layer is located between the graphite heat spreader layer and the heat pipe heat transfer layer; it is used to bond the graphite heat spreader layer and the heat pipe heat transfer layer and to conduct heat conduction between the interfaces. The third interface layer is located between the heat pipe heat transfer layer and the microchannel liquid cooling heat dissipation layer; it is used to bond the heat pipe heat transfer layer and the microchannel liquid cooling heat dissipation layer and to conduct heat conduction between the interfaces. The thermal conductivity of the first interface layer, the second interface layer, and the third interface layer are all ≥8W / m·K; The material of the first interface layer is either nano-silver thermal conductive adhesive or boron nitride thermal conductive adhesive.

[0018] The composite heat dissipation photovoltaic module provided by this invention uses nano-silver paste or boron nitride thermally conductive adhesive to bond the layers together, forming a first interface layer, a second interface layer, and a third interface layer with high thermal conductivity. This makes the interfacial thermal resistance between adjacent structural layers less than 0.05 K·cm² / W, which can form a continuous low thermal resistance heat transfer link, effectively avoiding heat conduction interruption or heat accumulation, enhancing the continuity of the thermal coupling path, and thus improving the heat dissipation efficiency of the photovoltaic module.

[0019] In one optional embodiment, the microchannel liquid cooling heat dissipation layer includes a liquid cooling plate and its internal microchannels; the structure of the microchannels is a biomimetic vascular microchannel network structure; the microchannels are filled with coolant; and the microchannels are connected to an external coolant circulation system. The thermal conductivity of the liquid cooling plate is greater than or equal to 200 W / m·K.

[0020] The composite heat dissipation photovoltaic module provided by this invention utilizes a biomimetic network structure of microchannels within a liquid-cooled plate with high thermal conductivity. This allows the microchannel liquid-cooled heat dissipation layer to serve as the core and main body of the entire module's heat dissipation. First, the microchannel liquid-cooled heat dissipation layer is the primary heat transfer pathway; heat from the back of the solar cells is ultimately carried away by the cooling medium (e.g., deionized water / nanofluid) within the microchannel liquid-cooled heat dissipation layer. Second, the microchannel liquid-cooled heat dissipation layer offers the highest controllability; the flow rate and temperature of the microchannel liquid cooling system can be adjusted in real time, achieving active temperature control. Third, the microchannel liquid-cooled heat dissipation layer has a large heat capacity; the coolant possesses a high specific heat capacity, enabling it to absorb transient heat and prevent drastic temperature fluctuations. Therefore, the microchannel liquid-cooled heat dissipation layer serves as the heat outlet for the entire heat dissipation system, thereby improving the overall heat dissipation efficiency of the module.

[0021] In one optional embodiment, the liquid cooling plate is made of aluminum alloy with a thermal conductivity of 200 W / m·K to 220 W / m·K; The width of the microchannel is 200μm to 500μm, the depth is 300μm to 800μm, and the wall thickness is ≥0.3mm; The inner wall of the microchannel is provided with a micro-concave lattice structure or a corrugated turbulence structure; the period of the corrugated turbulence structure is 20μm~50μm and the depth is 5μm~10μm. The coolant includes a mixture of ethylene glycol and deionized water; The coolant flow rate control range is 0.3 m / s to 0.6 m / s; the flow rate control accuracy is ±0.02 L / min; the working pressure of the microchannel liquid cooling heat dissipation layer is 50 kPa to 100 kPa. Microchannels consist of interconnected main channels and branch channels; the branching angle between the main channels and branch channels is 30° to 45°.

[0022] The composite heat dissipation photovoltaic module provided by this invention has two main advantages. Firstly, the channel wall thickness is ≥0.3 mm, ensuring both mechanical strength and fluid sealing. The channel branch angle is 30°~45°, conforming to biomimetic streamline diffusion principles and avoiding dead zones. Through the parameter design of the liquid cooling plate and microchannels, the liquid can flow through the main channel and then gradually branch into the branch channels, ultimately covering the entire condensation end area of ​​the heat pipe, achieving uniform heat dissipation. Secondly, the inner wall surface of the microchannel is provided with a micro-concave lattice structure or a corrugated turbulence structure, which can locally form micro-scale eddies, increasing fluid remixing and improving the convective heat transfer coefficient by 20%~35%. This effectively enhances liquid turbulence and convective heat transfer, thereby improving the heat dissipation effect of the microchannel liquid-cooled heat dissipation layer.

[0023] In one optional embodiment, the microchannel liquid cooling heat dissipation layer further includes: an adjustment module, which includes a coolant flow adjustment valve and a temperature adjustment valve; The composite heat dissipation photovoltaic module also includes: a sensing module and an intelligent control module; the intelligent control module connects the sensing module and the adjustment module, and is used to control the adjustment module to adjust the flow rate and / or temperature of the coolant in the microchannel liquid cooling heat dissipation layer based on the information from the sensing module. The sensing module includes: The first temperature sensor, located on the first surface of the graphite heat spreader, is used to monitor the temperature on the back of the solar cell; The second temperature sensor, located at the interface between the heat pipe heat transfer layer and the microchannel liquid cooling heat dissipation layer, is used to monitor the temperature of the heat pipe heat transfer layer. The third and fourth temperature sensors are located at the inlet and outlet of the microchannel liquid cooling heat dissipation layer, respectively, to monitor the temperature of the cooling source at the inlet and outlet and to calculate the heat absorbed by the coolant.

[0024] The composite heat dissipation photovoltaic module provided by this invention comprises a graphite heat dissipation layer, a heat pipe heat transfer layer, a microchannel liquid cooling heat dissipation layer, and an intelligent control module, forming a multi-layered synergistic heat dissipation system that significantly reduces the thermal resistance network. Firstly, the two-dimensional-three-dimensional coupling structure formed by the graphite heat dissipation layer and the heat pipe enables rapid temperature diffusion, while the microchannel liquid cooling heat dissipation layer further balances the overall thermal field, keeping the surface temperature difference of the module within 2°C. This temperature equalization effect significantly reduces local "hot spots," preventing thermal mismatch and performance degradation of the solar cells and achieving uniform heat distribution. Secondly, through the multi-layered synergistic system of "high thermal conductivity graphite heat dissipation layer + heat pipe phase change heat transfer + microchannel liquid cooling," a composite thermal management channel combining in-plane diffusion, vertical conduction, and forced convection is constructed. Compared to traditional single heat dissipation methods, the overall thermal resistance is reduced by more than 35% to 50%, optimizing the heat transfer path and improving heat dissipation efficiency. Thirdly, the intelligent control module can control the adjustment module to regulate the flow rate and / or temperature of the coolant based on the information from the sensor module, thereby achieving active thermal management of the photovoltaic module. This can improve the flexibility and accuracy of heat dissipation for the photovoltaic module, thus ensuring that the solar cells maintain a high photoelectric conversion efficiency.

[0025] In a second aspect, the present invention provides a heat dissipation method for a solar cell, used to dissipate heat using the composite heat dissipation photovoltaic module described in the first aspect above, the heat dissipation method comprising: When the temperature of the solar cell is lower than the first temperature, the microchannel liquid cooling heat dissipation layer is in energy-saving mode, and the graphite heat dissipation layer is used to heat the solar cell. When the temperature of the solar cell is greater than or equal to the first temperature, the solar cell is heated by a graphite heat dissipation layer, and the microchannel liquid cooling heat dissipation layer is controlled to dissipate heat from the solar cell.

[0026] The solar cell heat dissipation method provided by this invention allows for the following steps: When the solar cell temperature is greater than or equal to a first temperature, the microchannel liquid cooling heat dissipation layer operates in energy-saving mode. A graphite heat spreader and heat pipe heat transfer layer are used to evenly distribute and conduct heat from the solar cell, rapidly removing heat and preventing excessive localized temperatures, while simultaneously reducing energy consumption. When the solar cell temperature is greater than or equal to the first temperature, the graphite heat spreader and heat pipe heat transfer layer are used to evenly distribute and conduct heat from the solar cell, and the microchannel liquid cooling heat dissipation layer is controlled to operate in a second cooling mode. This rapidly reduces the temperature of the graphite heat spreader, thereby lowering the temperature of the solar cell and improving the heat dissipation effect of the photovoltaic module. Therefore, the solar cell heat dissipation method provided by this invention allows for the microchannel liquid cooling heat dissipation layer to be turned on / off as needed, employing different heat dissipation measures at different temperature stages. This effectively dissipates heat from the solar cell while reducing energy consumption, keeping the cell temperature within a suitable range, improving the photoelectric conversion efficiency of the cell, and extending its lifespan. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a composite heat dissipation photovoltaic module according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a heat dissipation method for a solar cell according to an embodiment of the present invention; Figure 3 This is a schematic flowchart illustrating a heat dissipation method for a solar cell according to an embodiment of the present invention. Figure 4 This is a schematic flowchart of a method for preparing a composite heat dissipation photovoltaic module according to an embodiment of the present invention.

[0029] Figure label: 10. Solar cell; 20. Graphite heat spreader layer; 30. Heat pipe heat transfer layer; 31. Thermally conductive substrate; 32. Heat pipe; 40. Microchannel liquid cooling heat dissipation layer; 41. Liquid cooling plate; 42. Microchannel; 50. Support base plate. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the invention and not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] In the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts of the present invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These drawings are not to scale, and some details are enlarged for clarity, and some details may be omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0032] Perovskite / Si heterojunction (PSC-Si HJ) tandem solar cells represent a significant direction in current photovoltaic technology development. Perovskite cells possess high absorption coefficients and low-temperature fabrication processes, while silicon cells exhibit high maturity and stability. Combining the two can overcome the theoretical limit (Shockley-Queisser limit) of traditional single-junction cells, achieving efficiencies exceeding 30%. However, in practical applications, while perovskite / Si heterojunction solar cells are high-efficiency photovoltaic devices, their performance is extremely sensitive to temperature, leading to inadequate thermal management.

[0033] When the battery operating temperature increases (e.g., >60℃), the photoelectric conversion efficiency decreases significantly. The main reasons are: 1. Increased carrier recombination rate (electrons and holes recombine more easily at high temperatures, reducing output current); 2. Changes in band structure (high temperatures lead to a decrease in band gap and open-circuit voltage); 3. Decreased material stability (the perovskite layer is prone to decomposition or phase transition, affecting battery life). Therefore, to maintain high-efficiency power generation performance and extend battery life, an efficient heat dissipation structure must be used to quickly dissipate the heat accumulated during operation and prevent excessively high temperatures.

[0034] Common heat dissipation methods include: (1) Natural convection heat dissipation: relies on air flow to remove heat, but the efficiency is limited and it is difficult to meet the needs in a calm environment; (2) Backplate thermal conductive layer: uses metal or ceramic backplate to improve thermal conductivity, but the heat dissipation path is long and the thermal resistance is large; (3) Active cooling (air cooling / liquid cooling): air cooling has noise and energy consumption problems, while liquid cooling solutions have not been widely used in traditional batteries, especially lacking integrated design that matches the perovskite / silicon heterojunction battery structure.

[0035] Therefore, there is an urgent need to propose a novel heat dissipation structure that is compact, has high heat transfer efficiency, and is compatible with photovoltaic module packaging, in order to improve the stability and efficiency of solar cells under high temperature conditions.

[0036] like Figure 1 As shown, this embodiment provides a composite heat dissipation photovoltaic module, including: Solar cell 10, including a front side and a back side arranged opposite to each other; A graphite heat spreader 20 is located on the back of the solar cell 10; it is used to diffuse the heat of the solar cell 10 in a planar direction. The microchannel liquid cooling heat dissipation layer 40 is located on the side of the graphite heat dissipation layer 20 facing away from the solar cell 10, and is used to transfer heat to the outside.

[0037] In actual use, the temperature of the solar cell 10 does not increase uniformly. In fact, local temperatures may become too high. Conventional heat dissipation methods cannot effectively dissipate heat from point heat sources, resulting in low heat dissipation effect.

[0038] In practice, the graphite heat spreader 20 can provide uniform temperature diffusion in the planar direction; the microchannel liquid cooling heat dissipation layer 40 can carry out heat convection heat transfer over a wide range.

[0039] The composite heat dissipation photovoltaic module provided in this embodiment has two advantages. First, the graphite heat dissipation layer has excellent thermal conductivity and in-plane thermal conductivity, which can quickly dissipate the heat from the solar cells and diffuse it in the planar direction. This reduces the temperature while preventing excessive local temperature of the solar cells. Simultaneously, the graphite heat dissipation layer can convert point heat sources into planar heat flow input, providing more stable heat flow input conditions for the underlying structure. Second, by setting a microchannel liquid cooling heat dissipation layer, the graphite heat dissipation layer can be actively cooled as needed, transferring heat to the outside, which can improve the heat dissipation efficiency and flexibility of the composite heat dissipation photovoltaic module. Furthermore, the microchannel liquid cooling heat dissipation layer can be activated as needed, reducing operating costs and energy consumption. Therefore, the composite heat dissipation photovoltaic module provided in this embodiment achieves rapid temperature equalization and efficient heat dissipation of the solar cells through two heat dissipation methods: the graphite heat dissipation layer and the microchannel liquid cooling heat dissipation layer. This maintains the high photoelectric conversion efficiency of the cells under high-temperature conditions and significantly extends their service life.

[0040] In some alternative implementations, the solar cell 10 can be a crystalline silicon cell, a perovskite cell, a perovskite / silicon heterojunction solar cell 10, or other types of cells.

[0041] In some alternative embodiments, the solar cell 10 is a perovskite / silicon heterojunction solar cell 10.

[0042] In related technologies, the perovskite material in the perovskite / silicon heterojunction solar cell 10 has poor thermal stability, and ion migration and interface degradation occur above 60℃; in addition, band mismatch occurs in the heterojunction interface layer at high temperatures, leading to an increased recombination probability; at the same time, the cell has high conversion efficiency and high heat power density, which places higher demands on the response speed of the heat dissipation system.

[0043] Therefore, the composite heat dissipation photovoltaic module provided in this embodiment can effectively improve the heat dissipation effect of perovskite / silicon heterojunction solar cells, such as high thermal conductivity, rapid temperature equalization, and active temperature control. It effectively overcomes the bottleneck of efficiency degradation and lifespan reduction of this type of cell under high temperature operation, and ensures that perovskite / silicon heterojunction solar cells still have high photoelectric conversion efficiency at high temperatures.

[0044] In a specific implementation, the back side of the solar cell 10 includes a transparent conductive film and / or a passivation layer. The solar cell 10 is the core power generation unit of the entire system, primarily absorbing light energy and converting it into electrical energy. Waste heat generated during operation needs to be rapidly dissipated to avoid a decrease in photoelectric conversion efficiency due to temperature rise. The back side of the cell layer undergoes specific treatment (such as depositing a transparent conductive film ITO and a passivation layer) to improve thermal contact performance with the graphite heat spreader layer 20.

[0045] In some alternative embodiments, the in-plane thermal conductivity of the graphite heat spreader 20 is greater than or equal to 500 W / m·K; The thickness of the graphite heat spreader layer 20 is 50μm~150μm; The material of the graphite heat spreader 20 includes highly oriented pyrolytic graphite or expanded graphite / graphene composite material.

[0046] In practical implementation, the highly thermally conductive graphite heat spreader layer is a key intermediate layer connecting the heat source (perovskite / silicon heterojunction cell) and the heat transfer unit (heat pipe layer). Its main function is to achieve in-plane heat diffusion and local temperature difference equalization. The in-plane thermal conductivity of the graphite heat spreader layer 20 is greater than or equal to 500 W / m·K, which can meet the heat diffusion requirements of high power density photovoltaic modules.

[0047] The thickness of the graphite heat spreader layer 20 is 50μm to 150μm, such as 50μm, 80μm, 100μm, 120μm, or 150μm. When the thickness is <50μm, the mechanical strength is insufficient, and cracks are easily generated during assembly; when the thickness is >150μm, the thermal resistance increases and the flexibility decreases, which is not conducive to bonding with the backing plate.

[0048] The composite heat dissipation photovoltaic module provided in this embodiment has an in-plane thermal conductivity of 500 W / m·K or greater in the graphite heat spreader layer. This allows localized heat to diffuse along the planar direction to adjacent areas, achieving rapid heat diffusion and equalization in a very short time. This effectively prevents excessive localized temperatures in the solar cells, avoids cell damage, and improves the module's lifespan. The thickness of the graphite heat spreader layer is 50 μm to 150 μm, which ensures the mechanical strength and reliability of the graphite heat spreader layer while reducing the thermal resistance of the graphite.

[0049] Therefore, the highly thermally conductive graphite heat spreader 20 acts as a "thermal spreader" in the entire heat dissipation system, enabling rapid heat diffusion and equalization in a very short time. In some examples, when the local temperature rise of the photovoltaic cell reaches 70°C, the graphite heat spreader can diffuse the local heat along the planar direction to adjacent areas within 10-20 milliseconds, and the temperature difference quickly converges to ±2°C. The graphite heat spreader 20 can transform point heat sources into planar heat flow input, providing more stable heat flow input conditions for the underlying structure.

[0050] Preferably, highly oriented pyrolytic graphite (HOPG) with a thickness of 100 μm is selected, or expanded graphite / graphene composite sheets are used to balance high thermal conductivity and flexibility.

[0051] In some alternative embodiments, the graphite heat spreader 20 includes opposing first and second surfaces, with the first surface relatively close to the back side of the solar cell 10; The first and / or second surfaces of the graphite heat spreader 20 are provided with a nano-metal coating; the nano-metal coating is suitable for formation by chemical plating or magnetron sputtering processes; The first and / or second surfaces of the graphite heat spreader 20 are provided with micro-bump structures; the micro-bump structures are suitable for formation by laser ablation or micro-pressing processes; In specific implementation, in order to enhance the thermal contact performance between the graphite heat dissipation layer 20 and the back side and lower structure of the solar cell 10, the present invention adopts a dual surface treatment mechanism: nano-metal coating + micro-bump structure.

[0052] In some alternative embodiments, the material of the nano-metal coating is copper or silver; the thickness of the nano-metal coating is 0.5~2μm; In the micro-bump structure, the height of the bumps is 10~20μm, and the distance between adjacent bumps is 0.5~1 mm.

[0053] In some optional embodiments, the formation process of the nano-metal coating includes: using copper (Cu) or silver (Ag) as the coating material, and depositing a metal film with a thickness of 0.5~2μm on the graphite surface using chemical plating or magnetron sputtering. The nano-metal coating fills the microporous structure of the graphite surface, forming a continuous and dense metal-carbon composite thermally conductive interface. This treatment can reduce the interfacial contact thermal resistance between the graphite heat spreader 20 and the upper and lower layers by approximately 30%~40%, and improve mechanical stability.

[0054] In some optional embodiments, the formation process of the micro-bump structure includes: forming a uniformly distributed array of micro-bumps (bump height 10~20μm, spacing 0.5~1 mm) on the graphite surface using laser ablation or micro-pressurization techniques. This structure can achieve micro-elastic deformation during interlayer bonding, effectively filling micro-gaps and further reducing interfacial thermal resistance. Simultaneously, the bumps can also form microscale "heat dissipation nodes" in the heat conduction direction, increasing the contact area and promoting heat diffusion.

[0055] By simultaneously employing nano-metal coatings and micro-bump structures, the thermal coupling performance between the graphite heat spreader layer 20 and the upper and lower layers is significantly improved, reducing the interfacial contact thermal resistance from the original 2.5 × 10⁻⁶. -5 m²•K / W decreased to approximately 1.0×10⁻⁶ -5 m²•K / W.

[0056] In some optional embodiments, the composite heat dissipation photovoltaic module further includes: a heat pipe heat transfer layer 30, located between the graphite heat dissipation layer 20 and the microchannel liquid cooling heat dissipation layer 40, for transferring heat from the graphite heat dissipation layer 20 to the microchannel liquid cooling heat dissipation layer 40. The heat pipe heat transfer layer 30 includes a heat-conducting substrate 31 and a heat pipe; the heat pipe is at least partially embedded inside the heat-conducting substrate 31; the heat pipe is planar or loop-type. The thermal conductivity of the thermally conductive substrate 31 is greater than or equal to 200 W / m·K; the heat pipe is filled with a phase change working fluid; The heat pipe heat transfer layer 30 includes an evaporation side and a condensation side arranged opposite to each other; the evaporation side is relatively close to the graphite heat dissipation layer 20; the condensation side is in contact with the microchannel liquid cooling heat dissipation layer 40; and the heat pipe is located on the evaporation side.

[0057] While the graphite heat spreader 20 exhibits excellent in-plane thermal conductivity, its vertical thermal conductivity is relatively poor (approximately 10–20 W / m•K). Therefore, a heat pipe heat transfer layer 30 is required between the graphite heat spreader 20 and the microchannel liquid cooling heat dissipation layer 40. This transfers heat from the graphite heat spreader 20 to the condensation side via the evaporation side, and then to the microchannel liquid cooling heat dissipation layer 40, improving the temperature uniformity of the graphite heat spreader 20 and achieving rapid vertical heat transfer. The thermally conductive substrate 31 has a thermal conductivity greater than or equal to 200 W / m•K. The heat pipe is filled with a phase change working fluid, and the thermally conductive substrate 31 enhances structural support and thermal coupling stability. This improves the heat transfer rate, thereby increasing the heat dissipation efficiency of the composite heat dissipation photovoltaic module. Therefore, this invention achieves complementary material layering: the graphite heat spreader 20 handles rapid in-plane heat conduction and temperature uniformity; the thermally conductive substrate 31 handles vertical heat transfer; and the heat pipe enhances cooling. The combination of these two elements forms an anisotropically optimized three-dimensional heat transfer pathway.

[0058] The composite heat dissipation photovoltaic module provided in this embodiment forms a heat transfer composite structure of "two-dimensional in-plane heat expansion + three-dimensional vertical phase change conduction" with a graphite heat spreader and heat pipe heat transfer layer. The graphite heat spreader layer undertakes rapid in-plane heat conduction and temperature equalization; the metal heat-conducting plate undertakes vertical heat transfer; and a three-dimensional phase change heat transfer network is constructed below the graphite heat spreader layer to achieve an efficient heat flow channel from the battery surface to the microchannel liquid cooling heat dissipation layer. Through this composite structure, local heat can be rapidly diffused within the graphite heat spreader layer (XY direction), while heat is transferred from the graphite heat spreader layer to the microchannel liquid cooling heat dissipation layer along the vertical direction (Z direction), significantly reducing the battery operating temperature gradient and preventing hot spot effects.

[0059] In the composite heat dissipation photovoltaic module provided in this embodiment, the two-dimensional-three-dimensional thermal coupling mechanism of the heat transfer composite structure formed by the graphite heat dissipation layer 20 and the heat pipe heat transfer layer 30 during the operation of the photovoltaic module is as follows: (1) Battery heating stage: Perovskite / silicon heterojunction cells generate local heat under strong light conditions; (2) Diffusion of graphite heat spreader 20: The highly thermally conductive graphite heat spreader 20 rapidly diffuses heat along the in-plane direction, homogenizing the temperature difference; (3) Heat pipe evaporation: The heat at the bottom of the graphite heat spreader 20 is transferred to the heat pipe evaporation end, causing the internal working fluid to vaporize; (4) Longitudinal heat transfer: Steam flows rapidly along the internal cavity of the heat pipe to the condensing end (the upper surface of the microchannel liquid cooling heat dissipation layer 40) and releases heat to condense into liquid; (5) Liquid reflux and recirculation: The condensate returns to the evaporation end under the action of the capillary structure, forming a continuous closed loop.

[0060] Through this mechanism, heat can be rapidly transferred layer by layer between the solar cell 10, the graphite heat dissipation layer 20, the heat pipe heat transfer layer 30, and the microchannel liquid cooling heat dissipation layer 40 within hundreds of milliseconds, forming a three-dimensional synergistic heat conduction network.

[0061] In some alternative embodiments, the heat pipe 32 is also embedded in the side surface of the graphite heat spreader 20 facing away from the solar cell 10; the depth to which the heat pipe 32 is embedded in the thermally conductive substrate 31 is 50% to 60% of the heat pipe diameter; The thermally conductive substrate 31 is made of aluminum alloy or copper-based material; the phase change working fluid is a mixture of methanol, acetone and ammonia. The diameter of heat pipe 32 is 2mm~4mm, and the wall thickness is 0.3mm~0.5mm; the center distance between adjacent heat pipes 32 is 10~15mm; the liquid filling rate of heat pipe 32 is 20%~40%, and the internal vacuum degree is ≤10. - ³ Pa.

[0062] In practice, the upper half of the heat pipe 32 is embedded in the graphite heat spreader layer 20, and the lower half is embedded in the thermally conductive substrate 31. The formation process generally involves first precisely forming a semi-circular or elliptical groove on the thermally conductive substrate 31 below the graphite heat spreader layer, and then partially embedding the heat pipe 32 in the groove; then, a high thermal conductivity interface adhesive (such as nano silver paste or boron nitride paste) is used to tightly bond the heat pipe 32 to the graphite heat spreader layer above it to form a continuous heat flow path.

[0063] The composite heat dissipation photovoltaic module provided in this embodiment has a heat pipe embedded in the thermally conductive substrate to a depth of 50%~60% of the heat pipe diameter, ensuring the stability and good contact of the pipe body. The embedded heat pipe heat transfer layer and the upper graphite heat spreader form a coupling structure, realizing directional and rapid heat transfer. The thermally conductive substrate is made of high thermal conductivity metals such as aluminum alloy or copper-based materials, which can improve thermal conductivity. The heat pipe is filled with a low-boiling-point phase change working fluid of a mixture of methanol, acetone, and ammonia, which can achieve rapid heat absorption and vapor-liquid circulation. The wall thickness of the heat pipe is 0.3mm~0.5mm, which can balance mechanical strength and thermal response speed. The center distance of the heat pipe is 10~15mm, which can ensure a uniform heat absorption coverage without affecting the liquid cooling channel arrangement. The liquid filling rate is in the range of 20%~40% of the volume, which can ensure gas-liquid phase balance; the internal vacuum degree is ≤10. - ³Pa can lower the boiling point temperature (by about 30~40℃).

[0064] In some alternative implementations, heat pipe 32 is a flat loop heat pipe.

[0065] In some optional embodiments, a flexible thermally conductive pad (thermal conductivity > 8 W / m·K) can be provided in the contact area between the heat pipe 32 and the graphite heat spreader 20 to buffer thermal expansion stress. Specifically, vacuum pressing technology can be used to ensure that the adhesive layer thickness is ≤ 30 μm and the interface porosity is < 2%. This structure ensures that a stable, highly coupled thermal interface is formed between the evaporation end of the heat pipe and the graphite heat spreader 20, avoiding abrupt changes in thermal resistance caused by air gaps.

[0066] In some alternative implementations, the length of heat pipe 32 can be customized according to the component size (commonly 150~300mm).

[0067] In some alternative implementations, the heat pipe 32 is made of a high thermal conductivity metal, such as copper or aluminum alloy (Al6061). Copper has a thermal conductivity of 390~400 W / m•K, making it suitable for high power density batteries; aluminum alloy is lightweight and easy to process, making it suitable for modular design.

[0068] In some alternative embodiments, the outer surface of the heat pipe 32 is provided with an anti-corrosion coating; the anti-corrosion coating is a Ni-P electroplated layer or a fluoride ceramic film, which can enhance the anti-oxidation performance and compatibility with interface materials.

[0069] In some optional embodiments, the heat pipe 32 further includes a capillary structure (core); typically a sintered copper powder core or a grooved capillary core structure is used to achieve capillary reflux of the liquid. The capillary radius is controlled in the range of 5~20 μm to ensure that the capillary pumping capacity matches the liquid reflux rate.

[0070] In some optional implementations, the composite heat dissipation photovoltaic module further includes: The first interface layer is located between the graphite heat dissipation layer 20 and the solar cell 10, and is used to bond the graphite heat dissipation layer 20 and the solar cell 10 and to conduct interfacial heat conduction. The second interface layer is located between the graphite heat spreader layer 20 and the heat pipe heat transfer layer 30; it is used to bond the graphite heat spreader layer 20 and the heat pipe heat transfer layer 30 and to conduct heat conduction between the interfaces. The third interface layer is located between the heat pipe heat transfer layer 30 and the microchannel liquid cooling heat dissipation layer 40; it is used to bond the heat pipe heat transfer layer 30 and the microchannel liquid cooling heat dissipation layer 40 and to conduct interfacial heat conduction. The thermal conductivity of the first interface layer, the second interface layer, and the third interface layer are all ≥8W / m·K; The material of the first interface layer is either nano-silver thermal conductive adhesive or boron nitride thermal conductive adhesive.

[0071] In practice, the thickness of the adhesive layers for the first, second, and third interface layers is controlled between 10 and 30 μm, and the interfacial air gap is less than 2 μm after curing. A vacuum pressing process is used during bonding to prevent air bubble inclusion. These interface layers not only improve interfacial thermal conductivity but also buffer thermal stress and prevent peeling.

[0072] The composite heat dissipation photovoltaic module provided in this embodiment uses nano-silver paste or boron nitride thermally conductive adhesive to bond the layers together, forming a first interface layer, a second interface layer, and a third interface layer with high thermal conductivity. This makes the interfacial thermal resistance between adjacent structural layers less than 0.05 K·cm² / W, which can form a continuous low thermal resistance heat transfer link, effectively avoiding heat conduction interruption or heat accumulation, enhancing the continuity of the thermal coupling path, and thus improving the heat dissipation efficiency of the photovoltaic module.

[0073] In some optional embodiments, the composite heat dissipation photovoltaic module further includes a supporting base plate 50 located on the side of the microchannel liquid-cooled heat dissipation layer 40 facing away from the graphite heat dissipation layer 20. The supporting base plate 50 is made of high-strength aluminum alloy or carbon fiber composite material, which provides structural support and also has a certain thermal conductivity to ensure the overall stability and reliability of the system.

[0074] In some optional embodiments, the microchannel liquid cooling heat dissipation layer 40 includes a liquid cooling plate 41 and microchannels 42 inside it; the structure of the microchannels 42 is a biomimetic vascular microchannel network structure; the microchannels 42 are filled with coolant; the microchannels 42 are connected to an external coolant circulation system. The thermal conductivity of the liquid cooling plate 41 is greater than or equal to 200 W / m·K.

[0075] To address the problems of uneven fluid distribution, low heat dissipation efficiency in the edge region, and high flow resistance loss inherent in traditional parallel-channel liquid cooling plates 41, this embodiment employs a biomimetic vascular microchannel network structure. This design concept originates from the "optimal fluid distribution system" in nature—such as leaf veins, blood vessel networks, and insect wing vein systems. Its channel branches follow the fractal diminishing law and the principle of flow resistance self-balancing, achieving maximum heat transfer area and minimum flow energy consumption within a limited volume. Through this biomimetic structure, the coolant can be uniformly distributed throughout the liquid cooling plate 41 and generate localized turbulence, significantly improving the heat transfer coefficient and temperature uniformity.

[0076] The composite heat dissipation photovoltaic module provided in this embodiment utilizes a biomimetic microchannel network structure within a liquid-cooled plate with high thermal conductivity. This allows the microchannel liquid-cooled heat dissipation layer to serve as the core and main body of the entire module's heat dissipation. First, the microchannel liquid-cooled heat dissipation layer is the primary heat transfer pathway; heat from the back of the solar cells is ultimately carried away by the cooling medium (e.g., deionized water / nanofluid) within the microchannel liquid-cooled heat dissipation layer. Second, the microchannel liquid-cooled heat dissipation layer offers the highest controllability; the flow rate and temperature of the microchannel liquid cooling system can be adjusted in real time, achieving active temperature control. Third, the microchannel liquid-cooled heat dissipation layer has a large heat capacity; the coolant possesses a high specific heat capacity, enabling it to absorb transient heat and prevent drastic temperature fluctuations. Therefore, the microchannel liquid-cooled heat dissipation layer serves as the heat outlet for the entire heat dissipation system, improving the overall heat dissipation efficiency of the module.

[0077] In some optional implementations, the biomimetic vein-like microchannel network structure employs a fractal tree pattern. Its branching ratio follows Murray's law (r0³ = r1³ + r2³) to ensure flow resistance balance. The main channel extends along the central axis from the inlet; secondary and tertiary branches expand outwards in a symmetrical bifurcation manner, ultimately forming a leaf-vein-like fluid distribution network; rounded transitions (radius of curvature ≥ 0.2 mm) are used in corner regions to reduce local flow resistance and fluid separation effects. This layout can create a biomimetic flow pattern of "uniform flow rate—enhanced heat transfer—controllable pressure drop" throughout the entire domain.

[0078] In some optional implementations, the thickness of the microchannel liquid cooling heat dissipation layer 40 is controlled at 3~5mm, which ensures sufficient heat exchange capacity while taking into account the overall structural thickness of the photovoltaic module.

[0079] In some alternative implementations, the coolant is deionized water or nanofluid.

[0080] In some alternative embodiments, the liquid cooling plate 41 is made of aluminum alloy with a thermal conductivity of 200 W / m·K to 220 W / m·K; The width of the microchannel 42 is 200μm to 500μm, the depth is 300μm to 800μm, and the wall thickness is ≥0.3mm; The inner wall of the microchannel 42 is provided with a micro-concave lattice structure or a corrugated turbulence structure; the period of the corrugated turbulence structure is 20μm~50μm and the depth is 5μm~10μm. The coolant includes a mixture of ethylene glycol and deionized water; The coolant flow rate control range is 0.3 m / s to 0.6 m / s; the flow rate control accuracy is ±0.02 L / min; the working pressure of the microchannel liquid cooling heat dissipation layer 40 is 50 kPa to 100 kPa. The microchannel 42 includes a main channel and branch channels that are interconnected; the branch angle of the main channel and branch channels is 30°~45°.

[0081] In practice, the liquid cooling plate 41 is made of a high thermal conductivity aluminum alloy (model 6063-T5 or 5052), with a thermal conductivity of 200~220 W / m·K. It is integrally die-cast to ensure the consistency of the microchannel 42 morphology and the integrity of the seal. In some examples, the surface of the liquid cooling plate 41 is anodized (oxide layer thickness 10~15μm) to achieve corrosion resistance and enhance oxidation resistance.

[0082] The composite heat dissipation photovoltaic module provided in this embodiment has the following characteristics: First, the channel wall thickness is ≥0.3 mm, ensuring mechanical strength and fluid sealing; the channel branch angle is 30°~45°, conforming to the biomimetic streamline diffusion law and avoiding dead zone stagnation; through the parameter design of the liquid cooling plate and microchannels, the liquid can flow through the main channel and then gradually branch into the branch channels, ultimately covering the entire condensation end area of ​​the heat pipe, achieving uniform heat dissipation. Second, the inner wall surface of the microchannel is provided with a micro-concave lattice structure or a corrugated turbulence structure, which can form micro-scale eddies locally, increasing the fluid remixing degree and improving the convective heat transfer coefficient by 20%~35%, thereby effectively enhancing the liquid turbulence and convective heat transfer effect, and thus improving the heat dissipation effect of the microchannel liquid cooling heat dissipation layer.

[0083] In some alternative implementations, the coolant includes an ethylene glycol / deionized water mixture (volume ratio 1:1); this mixture has a high specific heat capacity (approximately 3.4 J / g•K) and a low freezing point (-35°C), making it suitable for year-round operation of outdoor photovoltaic systems; it also has good anti-corrosion and anti-scaling properties, which can extend the service life of the system.

[0084] In some optional implementations, the flow parameters of the coolant are: flow rate control range: 0.~0.6m / s; flow rate control accuracy: ±0.02L / min; system operating pressure: 50~100kPa.

[0085] Within this range, the fluid can be kept in a transitional turbulent state (Re≈1000~2500), which significantly improves the heat exchange efficiency. After simulation optimization, the optimal operating point is located at Re≈1800~2000, and the convective heat transfer coefficient can reach 9000~12000W / m²·K.

[0086] In some alternative implementations, the graphite heat dissipation layer 20, the heat pipe heat transfer layer 30, and the microchannel liquid cooling heat dissipation layer 40 are stacked to form a composite heat dissipation system.

[0087] The composite heat dissipation photovoltaic module provided by this invention comprises a graphite heat dissipation layer, a heat pipe heat transfer layer, and a microchannel liquid cooling heat dissipation layer stacked together to form a composite heat dissipation system. Each of the three layers performs a different thermal function and forms a progressive heat transfer chain during the heat flow transfer process. Firstly, the graphite sheet has excellent in-plane thermal conductivity (thermal conductivity 500-1500 W / m•K), which can rapidly diffuse the non-uniform heat flow generated on the back of the solar cell in the planar direction, thereby reducing the local heat flux density and eliminating "hot spots". The presence of the graphite heat dissipation layer makes the temperature distribution on the back of the cell more uniform, providing more stable heat input boundary conditions for the underlying heat pipe and liquid cooling structure. Secondly, the heat pipes in the heat pipe heat transfer layer possess phase change heat transfer characteristics, enabling high-power heat transfer with extremely low temperature differences. Their evaporation side is embedded in the bottom of the graphite heat spreader, absorbing heat diffused through the graphite heat spreader and achieving rapid heat conduction through the vaporization of the internal working fluid. The condensing end of the heat pipe is tightly coupled to the surface of the microchannel liquid cooling heat dissipation layer, releasing latent heat of vaporization which is then carried away by the coolant. The heat pipe acts as a "vertical thermal bridge" in the entire system, allowing heat to quickly pass through the multi-layer structure, achieving efficient heat flux transfer. Thirdly, the microchannel liquid cooling heat dissipation layer is the main heat dissipation path of the system, achieving efficient convective heat transfer through forced flow of the coolant. The coolant has a high specific heat capacity, effectively absorbing heat from the condensing end of the heat pipe and discharging it from the system through an external circulation pump. The microchannel liquid cooling heat dissipation layer is also the only heat dissipation layer with active adjustment capabilities, enabling dynamic temperature control by controlling flow rate and temperature.

[0088] In the composite heat dissipation system, the graphite heat spreader layer 20, the heat pipe heat transfer layer 30, and the microchannel liquid cooling heat dissipation layer 40 do not operate independently, but rather form a composite heat dissipation network with a gradient thermal resistance distribution. The graphite heat spreader layer provides rapid in-plane temperature homogenization; the heat pipe layer achieves efficient longitudinal heat conduction; and the microchannel liquid cooling heat dissipation layer 40 completes the final heat dissipation. This hierarchical heat transfer mode significantly reduces the equivalent thermal resistance, ensuring that the temperature difference of the battery backplane is maintained within 5°C. Experiments show that compared with a single liquid cooling or heat pipe heat dissipation structure, the overall heat transfer efficiency of the composite structure of this invention is improved by approximately 25% to 35%.

[0089] The composite heat dissipation system of this invention is designed strictly according to the heat transfer logic of "heat conduction → heat transfer → heat exchange", and the sequence is as follows: solar cell 10 → graphite heat spreader layer 20 → heat pipe heat transfer layer 30 → microchannel liquid cooling heat dissipation layer 40. The upper part of the heat pipe is embedded in the bottom of the graphite heat spreader layer (to ensure a high heat contact area); the lower part of the heat pipe is embedded in the upper surface of the heat-conducting plate (to facilitate fixation and thermal coupling with the microchannel liquid cooling heat dissipation layer 40).

[0090] Placing the microchannel liquid cooling heat dissipation layer 40 or the heat pipe heat transfer layer directly below the battery layer may cause the following problems: direct contact between the microchannel liquid cooling heat dissipation layer 40 and the battery may damage electrical insulation and encapsulation integrity; the heat pipe being close to the battery may cause condensation droplet accumulation, resulting in electrode corrosion and uneven thermal stress. If the order is adjusted to "heat pipe → graphite → liquid cooling", the temperature homogenization effect of the graphite heat dissipation layer will be weakened because the temperature gradient of its upper heat source will no longer be concentrated, and the in-plane heat diffusion efficiency will decrease.

[0091] The differences between the composite heat dissipation system provided in this embodiment and the single-layer heat dissipation structure are shown in the following table:

[0092] Therefore, the composite heat dissipation system of the present invention represents the optimal comprehensive result in terms of thermal, mechanical, and packaging aspects.

[0093] In some optional embodiments, the microchannel liquid cooling heat dissipation layer 40 further includes: an adjustment module, which includes a coolant flow adjustment valve and a temperature adjustment valve; The composite heat dissipation photovoltaic module also includes: a sensing module and an intelligent control module; the intelligent control module connects the sensing module and the adjustment module, and is used to control the adjustment module to adjust the flow rate and / or temperature of the coolant in the microchannel liquid cooling heat dissipation layer 40 according to the information of the sensing module. The sensing module includes: The first temperature sensor, located on the first surface of the graphite heat spreader 20, is used to monitor the temperature on the back of the solar cell 10. The second temperature sensor is located at the interface between the heat pipe heat transfer layer 30 and the microchannel liquid cooling heat dissipation layer 40, and is used to monitor the temperature of the heat pipe heat transfer layer 30. The third and fourth temperature sensors are located at the inlet and outlet of the microchannel liquid cooling heat dissipation layer 40, respectively, to monitor the temperature of the cooling source at the inlet and outlet and to calculate the heat absorbed by the coolant.

[0094] In practice, heat first diffuses rapidly in-plane after entering the graphite heat spreader layer 20 from the solar cell 10. Second, heat is conducted downwards through embedded heat pipes and transferred vertically via vaporization of the working fluid. Third, the condensation end of the heat pipes transfers heat to the microchannel liquid-cooled heat dissipation layer 40, where the coolant rapidly removes heat through turbulent heat exchange. Simultaneously, the intelligent control module actively adjusts the flow rate and / or temperature of the coolant in the microchannel liquid-cooled heat dissipation layer 40 based on information from the sensor module, achieving dynamic and stable temperature control. This forms a closed-loop thermal management system of "area diffusion—vertical heat conduction—fluid heat exchange—intelligent adjustment."

[0095] The composite heat dissipation photovoltaic module provided in this embodiment constructs a multi-layered synergistic heat dissipation system comprised of a graphite heat spreader layer, a heat pipe heat transfer layer, a microchannel liquid cooling heat dissipation layer, and an intelligent control module, which can significantly reduce the thermal resistance network. Firstly, the two-dimensional-three-dimensional coupling structure formed by the graphite heat spreader layer and the heat pipe enables rapid temperature diffusion, while the microchannel liquid cooling heat dissipation layer further balances the overall thermal field, keeping the surface temperature difference of the module within 2°C. This temperature equalization effect significantly reduces local "hot spots," preventing thermal mismatch and performance degradation of the solar cells and achieving uniform heat distribution. Secondly, through the multi-layered synergistic system of "high thermal conductivity graphite heat spreader layer + heat pipe phase change heat transfer + microchannel liquid cooling," a composite thermal management channel combining in-plane diffusion, vertical conduction, and forced convection is constructed. Compared to traditional single heat dissipation methods, the overall thermal resistance is reduced by more than 35% to 50%, optimizing the heat transfer path and improving heat dissipation efficiency. Thirdly, the intelligent control module can control the adjustment module to regulate the flow rate and / or temperature of the coolant based on the information from the sensor module, thereby achieving active thermal management of the photovoltaic module. This can improve the flexibility and accuracy of heat dissipation for the photovoltaic module, thus ensuring that the solar cells maintain a high photoelectric conversion efficiency.

[0096] In some optional implementations, complete temperature gradient data can be obtained through multiple temperature sensors in the sensing module, which can be used to determine whether the heat transfer status of each layer is normal. For example, when the temperature of the graphite heat spreader rises while the liquid cooling outlet temperature does not change significantly, it can be determined that the heat pipe circulation is abnormal; conversely, it can be determined that the liquid flow is insufficient. The graphite heat transfer layer and the heat pipe layer themselves are passive heat dissipation elements and cannot be directly adjusted, but their temperature can be used as a feedback parameter for the liquid cooling system control algorithm.

[0097] In some alternative implementations, a first temperature sensor is used to monitor the temperature on the back of the solar cell 10, so that the intelligent control module can adjust the flow rate and / or temperature of the coolant as needed.

[0098] For example, when the temperature on the back of the solar cell 10 is lower than a first temperature (e.g., 40°C), the intelligent control module can automatically control the microchannel liquid cooling heat dissipation layer 40 to enter an energy-saving mode, i.e., the coolant flow rate is 0. When the temperature on the back of the solar cell 10 is greater than or equal to the first temperature, at a set threshold (e.g., 60°C), the intelligent control module automatically controls the microchannel liquid cooling heat dissipation layer 40 to enter a first cooling mode, maintaining the coolant at the first cooling temperature and the first cooling flow rate. When the temperature on the back of the solar cell 10 exceeds a second temperature (e.g., 60°C), the intelligent control module automatically increases the coolant flow rate or decreases the coolant temperature; i.e., the coolant reaches the second cooling temperature and the second cooling flow rate. The second cooling temperature is less than the first cooling temperature and / or the second cooling flow rate is greater than the first cooling flow rate.

[0099] In some optional implementations, each functional layer (graphite heat spreader 20, heat pipe heat transfer layer 30, microchannel liquid cooling heat dissipation layer 40, and supporting base plate 50) adopts an independent modular splicing method, with standardized dimensions and interfaces, allowing for flexible assembly to suit photovoltaic modules of different specifications (182mm, 210mm). Each layer is independent of the others, the assembly process is simple, and it has strong mass production capabilities, making it suitable for large-scale manufacturing.

[0100] In some optional implementations, the intelligent control module and the coolant circulation system adopt a pluggable interface design, which facilitates on-site inspection and system upgrades, improves operation and maintenance efficiency, and makes maintenance and replacement convenient.

[0101] In some optional implementations, the sensing module includes a temperature sensing unit and a flow sensing unit; the temperature sensing unit includes a first temperature sensor, a second temperature sensor, a third temperature sensor, and a fourth temperature sensor. The flow sensing unit includes a flow sensor located at the inlet of the microchannel liquid cooling heat dissipation layer 40, used to detect the circulation flow rate and provide feedback on the opening degree of the coolant flow regulating valve.

[0102] An NTC thermistor (Negative Temperature Coefficient Thermistor) is used as the temperature sensing unit. Temperature measurement range: -20℃ to 120℃; accuracy: ±0.2℃; response time: <100 ms; packaging: thin-film or surface-mount (suitable for planar deployment). The sensor's resistance decreases as temperature increases, facilitating real-time sampling and signal linearization processing by analog circuits.

[0103] In some optional implementations, the temperature sensing unit further includes a fifth temperature sensor located on the lower surface of the microchannel liquid-cooled heat dissipation layer 40. Specifically, the fifth temperature sensors are evenly distributed in the area where the main flow channel and secondary tributaries of the liquid-cooled plate 41 intersect, forming a two-dimensional temperature sampling grid. Typical distribution density: one fifth temperature sensor is set every 20~30cm²; approximately 8~12 temperature sensors are arranged for a standard 600×400mm liquid-cooled plate 41; each node is connected via a bus (I²C or 1-Wire), and sampling is polled by the central control module. The distribution locations are determined through CFD (Computational Fluid Dynamics) simulation, covering the high-temperature fluid region, the return end, and areas prone to heat accumulation, ensuring the integrity and representativeness of the temperature field information.

[0104] In some alternative implementations, multiple fifth temperature sensors constitute a temperature sensing layer.

[0105] In practice, the temperature sensing layer calculates the "equivalent thermal resistance change rate" in real time based on the temperature difference at multiple points. If an abnormal increase is detected, a cooling enhancement mode is triggered, and the intelligent control module automatically increases the coolant flow rate or decreases the coolant temperature. This feedback control ensures the battery temperature stability under different environmental conditions.

[0106] The intelligent control module also includes a signal acquisition and filtering module, which is connected to the temperature sensing layer. The signal output by the fifth temperature sensor is digitized by a 24-bit A / D converter with a sampling frequency of approximately 10Hz. The system uses a Kalman filter algorithm to suppress noise interference and improve data smoothness. The sampling results are transmitted to the control algorithm module in real time for temperature trend prediction and flow rate decision-making.

[0107] In some alternative implementations, the regulating module is located in an external coolant circulation system.

[0108] In some alternative implementations, the coolant flow control valve is located in the main liquid-cooled circulation loop of the coolant circulation system. The coolant flow control valve is a micro-electro-controlled valve with a body made of PPS or aluminum alloy, featuring rapid response characteristics. Drive type: stepper motor / electromagnetic coil drive; response time: <500ms; adjustment accuracy: flow resolution 0.01L / min; service life: >10 years. 7 The system operates in a cycle of opening and closing. The coolant flow regulating valve in the coolant circulation system works in conjunction with the micro pump, and the opening degree is controlled by a PWM (Pulse Width Modulation) signal to achieve real-time dynamic adjustment of the coolant flow rate.

[0109] In some alternative implementations, the intelligent control module adjusts the coolant flow regulating valve based on the temperature information transmitted by the sensing module, thereby controlling the flow rate of coolant in the microchannel liquid cooling heat dissipation layer 40.

[0110] In some optional implementations, the intelligent control module uses a PID (proportional-integral-derivative) algorithm to achieve temperature control feedback, with the following logic:

[0111] The PID control formula is as follows:

[0112] in: : Controls valve opening or pump speed output; = Temperature deviation; These are the proportional, integral, and differential coefficients, respectively.

[0113] In some alternative implementations, the intelligent control module can achieve intelligent predictive optimization.

[0114] To further improve control accuracy, the intelligent control module's calculation system incorporates a temperature trend prediction algorithm: when the detected temperature rise rate dT / dt > 1℃ / s, the system pre-increases the flow rate to prevent thermal hysteresis. Conversely, when dT / dt < –0.5℃ / s, the flow rate is gradually reduced to achieve stable cooling.

[0115] In some alternative implementations, the intelligent control module can be connected to the power management unit (PMU) of the solar cell 10 to enable zoned adjustment of cooling intensity based on power load: when the module power output decreases (e.g., due to shading), the system automatically reduces the flow rate to achieve on-demand cooling. This strategy can reduce overall energy consumption by approximately 15% to 25% while maintaining module temperature equilibrium, thereby improving power generation efficiency and lifespan.

[0116] In some alternative implementations, the regulating module includes a coolant flow regulating valve, a temperature regulating valve, and a micro pump in the coolant circulation system.

[0117] In some alternative implementations, the intelligent control module includes a control unit, a drive unit, and a communication interface; wherein the drive unit is used to connect to and control the coolant flow regulating valve, temperature regulating valve, and micro pump in the regulating module.

[0118] In some alternative implementations, the intelligent control module is integrated into the surface or interior of the support base plate 50.

[0119] In some alternative implementations, the intelligent control module can be located in other locations, for example, taking into account factors such as thermal coupling, packaging reliability, wiring convenience, maintainability, and electrical safety.

[0120] In some alternative implementations, the intelligent control module is integrated below the liquid cooling layer, resulting in shorter sensor wiring, faster temperature / flow measurement response, and lower control loop latency.

[0121] In some alternative implementations, the intelligent control module is located in a junction box or combiner box at the edge of the photovoltaic module, which facilitates power and communication access, allows for easy integration of the intelligent control module with the module's electrical system, and makes maintenance convenient and easy to achieve waterproofing and dustproofing.

[0122] In some alternative implementations, the intelligent control module is located in the computer room or inverter cabinet, enabling centralized remote control of the composite heat-dissipating photovoltaic modules. This approach offers ease of centralized management, redundancy backup, and strong computing power; however, it requires extensive on-site wiring, necessitates remote sensors and field actuators, and suffers from greater signal latency. It is suitable for centralized management solutions in large-scale photovoltaic farms.

[0123] In some optional implementations, the intelligent control module possesses intelligent features such as self-sensing, self-adjustment, and self-optimization. Through a multi-point temperature array (NTC network), it achieves real-time global temperature acquisition and dynamic mapping, enabling millisecond-level response to thermal anomalies, thus achieving self-sensing. The control module automatically adjusts flow rate, pump speed, and valve opening based on PID algorithms and trend prediction logic, dynamically maintaining optimal temperature control balance within the 40-50℃ range, achieving self-adjustment. The system can automatically correct its control strategy based on historical operating data and environmental parameters (irradiance, wind speed), achieving learning-based energy consumption optimization and improving cooling efficiency by approximately 15%, thus achieving self-optimization. Furthermore, the intelligent control module supports wireless communication (LoRa / Wi-Fi / 4G), allowing it to interface with photovoltaic power plant SCADA systems for remote monitoring, anomaly warnings, and cloud control, forming a closed-loop intelligent thermal management system.

[0124] like Figure 2 As shown, this embodiment provides a heat dissipation method for a solar cell, including but not limited to steps S11 to S12.

[0125] Step S11: When the temperature of the solar cell is lower than the first temperature, the microchannel liquid cooling heat dissipation layer is in energy-saving mode, and the graphite heat dissipation layer is used to heat the solar cell.

[0126] Step S12: When the temperature of the solar cell is greater than or equal to the first temperature, the solar cell is heated by the graphite heat dissipation layer, and the microchannel liquid cooling heat dissipation layer is controlled to dissipate heat from the solar cell.

[0127] The solar cell heat dissipation method provided in this embodiment operates as follows: When the solar cell temperature is greater than or equal to a first temperature, the microchannel liquid cooling heat dissipation layer operates in energy-saving mode. It utilizes a graphite heat spreader and heat pipe heat transfer layer to evenly distribute and conduct heat from the solar cell, rapidly removing heat and preventing excessive localized temperatures while reducing energy consumption. When the solar cell temperature is greater than or equal to the first temperature, the graphite heat spreader and heat pipe heat transfer layer continue to evenly distribute and conduct heat, while the microchannel liquid cooling heat dissipation layer is controlled to operate in a second cooling mode. This rapidly reduces the temperature of the graphite heat spreader, thereby lowering the temperature of the solar cell and improving the heat dissipation effect of the photovoltaic module. Therefore, the solar cell heat dissipation method provided in this embodiment allows the microchannel liquid cooling heat dissipation layer to be turned on / off as needed, employing different heat dissipation measures at different temperature stages. This effectively dissipates heat from the solar cell while reducing energy consumption, keeping the cell temperature within a suitable range, improving the photoelectric conversion efficiency, and extending the cell's lifespan.

[0128] like Figure 3As shown in the figure, this embodiment provides a detailed flowchart of a heat dissipation method for a solar cell, including but not limited to steps S21 to S23.

[0129] Step S21: When the temperature of the solar cell is lower than the first temperature, the intelligent control module adjusts the microchannel liquid cooling heat dissipation layer to energy-saving mode, and uses the graphite heat dissipation layer and heat pipe heat transfer layer to heat the solar cell for heat dissipation and conduction.

[0130] Step S22: When the temperature of the solar cell is greater than or equal to the first temperature and less than the second temperature, the solar cell is heated and conducted using a graphite heat dissipation layer and a heat pipe heat transfer layer. The intelligent control module adjusts the microchannel liquid cooling heat dissipation layer to dissipate heat from the solar cell in the first cooling mode. In the first cooling mode, the coolant is maintained at the first cooling temperature and the first cooling flow rate.

[0131] Step S23: When the temperature of the solar cell is greater than or equal to the second temperature, the solar cell is homogenized and heated using a graphite heat dissipation layer and a heat pipe heat transfer layer. The intelligent control module adjusts the microchannel liquid cooling heat dissipation layer to dissipate heat from the solar cell in the second cooling mode. In the second cooling mode, the coolant has a second cooling temperature and a second cooling flow rate. The second cooling temperature is lower than the first cooling temperature, and / or the second cooling flow rate is greater than the first cooling flow rate.

[0132] In practice, the flow rate and / or temperature of the coolant in the microchannel liquid cooling heat dissipation layer can be adjusted according to the real-time temperature to achieve dynamic and stable control of the solar cell temperature.

[0133] The solar cell heat dissipation method provided in this embodiment includes the following steps: When the solar cell temperature is greater than or equal to a first temperature, the microchannel liquid cooling heat dissipation layer operates in energy-saving mode, utilizing a graphite heat dissipation layer and a heat pipe heat transfer layer to homogenize and conduct heat to the solar cell, rapidly dissipating heat and preventing excessive local temperatures while reducing energy consumption. When the solar cell temperature is greater than or equal to the first temperature, the graphite heat dissipation layer and heat pipe heat transfer layer are used to homogenize and conduct heat to the solar cell, and the microchannel liquid cooling heat dissipation layer is controlled to dissipate heat in a first cooling mode, rapidly reducing the temperature of the graphite heat dissipation layer, thereby reducing the temperature of the solar cell and improving the heat dissipation effect of the photovoltaic module. When the solar cell temperature is greater than or equal to a second temperature, the graphite heat dissipation layer and heat pipe heat transfer layer are used to homogenize and conduct heat to the solar cell, and the microchannel liquid cooling heat dissipation layer is controlled to dissipate heat to the solar cell in a second cooling mode. The flow rate of the coolant in the microchannel liquid cooling heat dissipation layer is adjusted according to the real-time temperature to achieve dynamic and stable control of the solar cell temperature.

[0134] In some optional implementations, the temperature sensing unit further includes a fifth temperature sensor located on the lower surface of the microchannel liquid-cooled heat dissipation layer. Multiple fifth temperature sensors constitute a temperature sensing layer, enabling real-time acquisition and dynamic mapping of global temperature through a multi-point temperature array (NTC network), and providing millisecond-level response to thermal anomaly regions.

[0135] The heat dissipation method for solar cells further includes: when the temperature measured by the temperature sensing layer is greater than or equal to a second temperature in a certain area, controlling the microchannel liquid cooling heat dissipation layer to dissipate heat from the solar cell in a third cooling mode; in the third cooling mode, the coolant has a third cooling temperature and a third cooling flow rate. The third cooling temperature is lower than the first cooling temperature, and / or the third cooling flow rate is greater than the first cooling flow rate.

[0136] To verify the practical application of this invention, experiments were conducted to test the heat dissipation method of the composite heat dissipation photovoltaic module and solar cell provided by this invention. The test results show that the battery maintains high-efficiency output and improves stability under high-temperature conditions. The experimental results are as follows: 1. When the ambient temperature reaches 70℃, this solution can control the battery operating temperature within the range of 45℃±℃, while maintaining a photoelectric conversion efficiency of over 95%. Compared to traditional air-cooled structures, the output power is increased by approximately 6%~10% under the same irradiation conditions; this demonstrates that this application can effectively improve photoelectric conversion efficiency. 2. The component's service life is extended by approximately 25% to 30%, and it can effectively suppress perovskite layer phase transformation, silicon interface stress diffusion, and solder joint fatigue caused by high temperatures; this demonstrates that the present application can effectively slow down thermally induced aging. 3. After 1000 hours of continuous operation at 60–80℃, the performance degradation rate of the composite heat dissipation photovoltaic module is less than 1%, which proves that this application can enhance the high-temperature stable operation capability of photovoltaic modules and ensure excellent thermal reliability and long-term stability.

[0137] like Figure 4 As shown, this embodiment provides a method for preparing a composite heat dissipation photovoltaic module, which includes, but is not limited to, steps S101 to S104.

[0138] Step S101, providing a solar cell, including a front and a back side arranged opposite to each other.

[0139] Step S102: Form a graphite heat spreader layer.

[0140] Step S103: Form a microchannel liquid cooling heat dissipation layer.

[0141] In step S104, the microchannel liquid cooling heat dissipation layer, the graphite heat dissipation layer, and the solar cell are sequentially stacked and encapsulated to form a composite heat dissipation photovoltaic module; the graphite heat dissipation layer is located on the back side of the solar cell; the microchannel liquid cooling heat dissipation layer is located on the side of the graphite heat dissipation layer facing away from the solar cell.

[0142] In some alternative embodiments, the preparation method further includes: forming a heat pipe heat transfer layer; The steps for forming a graphite heat spreader include: Provide the initial graphite layer; A nano-metal coating is formed on the surface of the initial graphite layer using chemical plating or magnetron sputtering processes; A micro-bump structure is formed on the surface of the initial graphite layer by laser ablation or micro-pressing to obtain a graphite heat spreader layer; The steps for forming the heat pipe heat transfer layer include: cutting a groove in a thermally conductive substrate and partially embedding the heat pipe in the groove; The graphite heat spreader layer is bonded to the top of the heat pipe via a second interface layer; the heat pipe is partially embedded within the graphite heat spreader layer.

[0143] The method for fabricating the composite heat dissipation photovoltaic module provided in this embodiment allows for the mass production of each structural layer (graphite heat dissipation layer, heat pipe heat transfer layer, and microchannel liquid cooling heat dissipation layer) using existing CNC machining and vacuum hot pressing processes, without requiring major equipment modifications. The manufacturing process is compatible with existing production lines.

[0144] In some optional embodiments, the preparation method further includes: The first surface of the graphite heat spreader is subjected to plasma activation treatment; The first surface of the graphite heat spreader is bonded to the back of the solar cell via a first interface layer.

[0145] In practice, due to the natural inertness of the graphite surface, interfacial air gaps are easily formed, thus affecting heat transfer performance. To improve the bonding performance between the graphite heat spreader and the perovskite / silicon battery backsheet, this invention performs low-temperature plasma activation treatment on the graphite surface before laying: oxygen plasma (O2) or argon plasma (Ar) is used to treat it in a vacuum chamber for 5-10 minutes; plasma bombardment can introduce hydroxyl (-OH) and carboxyl (-COOH) functional groups on the graphite surface, improving surface energy and adhesion.

[0146] The graphite heat spreader layer after plasma activation treatment has comprehensive characteristics of high thermal conductivity, high adhesion, and flexible matching. It can form a stable and low-resistance thermal interface with the battery backsheet, which increases the interface adhesion rate by about 20%, ensures the continuity of the heat flow path, and reduces the thermal resistance effect of air layer formation.

[0147] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0148] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0149] The above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described above, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of protection of the present invention is determined by the scope of the appended claims.

Claims

1. A composite heat dissipation photovoltaic module, characterized in that, include: Solar cells, including a front and a back side arranged opposite to each other; A graphite heat spreader is located on the back of the solar cell; Used to diffuse the heat of solar cells in a planar direction; A microchannel liquid-cooled heat dissipation layer is located on the side of the graphite heat dissipation layer facing away from the solar cell, and is used to transfer heat to the outside.

2. The composite heat dissipation photovoltaic module according to claim 1, characterized in that, The solar cell is a perovskite / silicon heterojunction solar cell. The in-plane thermal conductivity of the graphite heat spreader is greater than or equal to 500 W / m·K; The thickness of the graphite heat spreader is 50μm~150μm; The material of the graphite heat spreader includes highly oriented pyrolytic graphite or expanded graphite / graphene composite material.

3. The composite heat dissipation photovoltaic module according to claim 1, characterized in that, The graphite heat spreader includes a first surface and a second surface opposite to each other, with the first surface relatively close to the back side of the solar cell; The first and / or second surfaces of the graphite heat spreader are provided with a nano-metal coating; the nano-metal coating is suitable for formation by chemical plating or magnetron sputtering processes; The first and / or second surfaces of the graphite heat spreader are provided with micro-bump structures; the micro-bump structures are suitable for formation by laser ablation or micro-press forming processes.

4. The composite heat dissipation photovoltaic module according to claim 1, characterized in that, The composite heat dissipation photovoltaic module further includes: a heat pipe heat transfer layer, located between the graphite heat dissipation layer and the microchannel liquid cooling heat dissipation layer, for transferring heat from the graphite heat dissipation layer to the microchannel liquid cooling heat dissipation layer; The heat pipe heat transfer layer includes a heat-conducting substrate and a heat pipe; the heat pipe is at least partially embedded inside the heat-conducting substrate; the heat pipe is planar or loop-type. The thermal conductivity of the thermally conductive substrate is greater than or equal to 200 W / m·K; the heat pipe is filled with a phase change working fluid. The heat pipe heat transfer layer includes an evaporation side and a condensation side arranged opposite to each other; the evaporation side is relatively close to the graphite heat dissipation layer; the condensation side is in contact with the microchannel liquid cooling heat dissipation layer; and the heat pipe is located on the evaporation side.

5. The composite heat dissipation photovoltaic module according to claim 4, characterized in that, The heat pipe is also embedded in the graphite heat dissipation layer on the side surface facing away from the solar cell; the depth to which the heat pipe is embedded in the thermally conductive substrate is 50% to 60% of the heat pipe diameter; The thermally conductive substrate is made of aluminum alloy or copper-based material; the phase change working fluid is a mixture of methanol, acetone and ammonia. The heat pipe has a diameter of 2mm to 4mm and a wall thickness of 0.3mm to 0.5mm; the center-to-center distance between adjacent heat pipes is 10mm to 15mm; the liquid filling rate of the heat pipe is 20% to 40%, and the internal vacuum degree is ≤10. - ³Pa.

6. The composite heat dissipation photovoltaic module according to claim 4, characterized in that, The composite heat dissipation photovoltaic module also includes: The first interface layer is located between the graphite heat dissipation layer and the solar cell, and is used to bond the graphite heat dissipation layer and the solar cell and to conduct interfacial heat. The second interface layer is located between the graphite heat spreader layer and the heat pipe heat transfer layer; it is used to bond the graphite heat spreader layer and the heat pipe heat transfer layer and to conduct heat conduction between the interfaces. The third interface layer is located between the heat pipe heat transfer layer and the microchannel liquid cooling heat dissipation layer; it is used to bond the heat pipe heat transfer layer and the microchannel liquid cooling heat dissipation layer and to conduct interfacial heat. The thermal conductivity of the first interface layer, the second interface layer, and the third interface layer are all ≥8W / m·K; The material of the first interface layer is nano-silver thermal conductive adhesive or boron nitride thermal conductive adhesive.

7. The composite heat dissipation photovoltaic module according to claim 1, characterized in that, The microchannel liquid cooling heat dissipation layer includes a liquid cooling plate and its internal microchannels; the structure of the microchannels is a biomimetic vascular microchannel network structure; the microchannels are filled with coolant; the microchannels are connected to an external coolant circulation system; The thermal conductivity of the liquid cooling plate is greater than or equal to 200 W / m·K.

8. The composite heat dissipation photovoltaic module according to claim 7, characterized in that, The liquid cooling plate is made of aluminum alloy with a thermal conductivity of 200W / m·K~220W / m·K. The microchannel has a width of 200μm to 500μm, a depth of 300μm to 800μm, and a wall thickness of ≥0.3mm; The inner wall of the microchannel is provided with a micro-concave lattice structure or a corrugated turbulence structure; the period of the corrugated turbulence structure is 20μm~50μm and the depth is 5μm~10μm. The coolant includes a mixture of ethylene glycol and deionized water. The flow rate of the coolant is controlled within the range of 0.3 m / s to 0.6 m / s; the flow rate control accuracy is ±0.02 L / min; and the working pressure of the microchannel liquid cooling heat dissipation layer is 50 kPa to 100 kPa. The microchannels include interconnected main channels and branch channels; the branch angles of the main channels and branch channels are 30° to 45°.

9. The composite heat dissipation photovoltaic module according to claim 4, characterized in that, The composite heat dissipation photovoltaic module further includes: an adjustment module connected to the microchannel liquid cooling heat dissipation layer; the adjustment module includes a coolant flow adjustment valve and a temperature adjustment valve, which are used to adjust the flow rate and temperature of the coolant in the microchannel liquid cooling heat dissipation layer, respectively. The composite heat dissipation photovoltaic module further includes: a sensing module and an intelligent control module; the intelligent control module is connected to the sensing module and the adjustment module, and is used to control the adjustment module to adjust the flow rate and / or temperature of the coolant in the microchannel liquid cooling heat dissipation layer according to the information of the sensing module. The sensing module includes: A first temperature sensor, located on the first surface of the graphite heat spreader, is used to monitor the temperature on the back of the solar cell; The second temperature sensor is located at the interface between the heat pipe heat transfer layer and the microchannel liquid cooling heat dissipation layer, and is used to monitor the temperature of the heat pipe heat transfer layer. The third and fourth temperature sensors are located at the inlet and outlet of the microchannel liquid cooling heat dissipation layer, respectively, to monitor the temperature of the cooling source at the inlet and outlet and to calculate the heat absorbed by the coolant.

10. A method for heat dissipation of a solar cell, characterized in that, The heat dissipation method is used for heat dissipation using the composite heat dissipation photovoltaic module according to any one of claims 1 to 9, the heat dissipation method comprising: When the temperature of the solar cell is lower than the first temperature, the microchannel liquid cooling heat dissipation layer is in energy-saving mode, and the graphite heat dissipation layer is used to heat the solar cell. When the temperature of the solar cell is greater than or equal to the first temperature, the solar cell is heated by a graphite heat dissipation layer, and the microchannel liquid cooling heat dissipation layer is controlled to dissipate heat from the solar cell.

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