Photovoltaic-thermal integrated modules, seawater desalination devices and manufacturing methods

Abstract

This application relates to the field of solar photovoltaic and photothermal technology, and discloses an integrated photovoltaic and photothermal module, a seawater desalination device, and a manufacturing method. The module includes a photothermal layer, a heat transfer medium layer, and a photovoltaic layer. The photothermal layer comprises a first transparent substrate, a second transparent substrate, and a photothermal film for absorbing ultraviolet and near-infrared wavelengths of sunlight. The first and second transparent substrates are stacked, with the photothermal film disposed between them. The heat transfer medium includes a heat-conducting medium that is fluidly disposed between the photothermal film and the second transparent substrate. The photovoltaic layer is located on the side of the second transparent substrate facing away from the photothermal film. By using the photothermal and photovoltaic layers, selective absorption and utilization of sunlight across different wavelengths is achieved, effectively utilizing the entire spectrum and realizing efficient solar energy conversion. Simultaneously, the absorbed heat is provided for seawater desalination, thereby improving the energy utilization efficiency of seawater desalination and avoiding energy waste.

Description

Technical Field

[0001] This invention relates to the field of solar photovoltaic and solar thermal technology, and in particular to an integrated photovoltaic and solar thermal module, a seawater desalination device, and a manufacturing method thereof. Background Technology

[0002] Solar energy, as a green energy source, is undoubtedly the most promising renewable energy source on Earth. Sunlight contains ultraviolet (wavelengths between 190 and 390 nm), visible (wavelengths between 390 and 780 nm), and near-infrared (wavelengths between 780 and 3500 nm) light. Visible light has the highest energy, accounting for 42% of the total energy, and can be used for power generation, thus belonging to the high-value spectrum. Ultraviolet light has the highest energy, but only accounts for 3%, and can be used for photocatalysis, thus belonging to the medium-value spectrum. Near-infrared light has lower energy, but accounts for 55%, thus belonging to the low-value spectrum.

[0003] Based on different energy conversion methods, solar energy utilization can be divided into two types: photovoltaic (PV) and solar thermal. "Photovoltaics" refers to the direct conversion of light energy into electrical energy using the photovoltaic effect at semiconductor interfaces, while "solar thermal" refers to the absorption of light energy of different wavelengths in the solar radiation spectrum by materials and conversion into heat energy. The utilization rate of solar energy using photovoltaic methods is generally less than 20%, with the majority of the remaining energy being converted into heat energy. Some of this heat is dissipated into the air, while the rest is stored in batteries, raising their temperature. Therefore, Photovoltaic-Thermal (PVT) technology constructs integrated photovoltaic and solar thermal modules, combining both photovoltaic and solar thermal methods to effectively collect the aforementioned heat, thus improving the overall utilization efficiency of solar energy. The current conventional approach for photovoltaic-thermal integrated modules is to add a water-cooling system to the crystalline silicon photovoltaic panel. That is, the front of the crystalline silicon photovoltaic panel receives sunlight, and the water-cooling system is attached to the back of the crystalline silicon photovoltaic panel. This way, the crystalline silicon photovoltaic panel can absorb all the spectrum first, so that the photovoltaic panel heats up and then transfers the heat to the water-cooling system. However, this type of photovoltaic-thermal integrated module has low photothermal conversion efficiency, and ultraviolet rays are not utilized. Direct absorption will cause the photovoltaic panel to age. Summary of the Invention

[0004] To solve the above-mentioned technical problems, or at least partially solve them, this application provides a photovoltaic-thermal integrated module, a seawater desalination device, and a manufacturing method, which can effectively utilize the full spectrum, achieve efficient conversion of solar energy, and provide the heat absorbed from solar energy to seawater desalination, thereby improving the energy utilization efficiency of seawater desalination.

[0005] In a first aspect, this application provides a photovoltaic-thermal integrated module, including a photothermal layer, a thermal medium layer, and a photovoltaic layer;

[0006] The photothermal layer includes a first transparent substrate, a second transparent substrate, and a photothermal film for absorbing ultraviolet and near-infrared wavelengths in sunlight. The first transparent substrate and the second transparent substrate are stacked together, and the photothermal film is disposed between the first transparent substrate and the second transparent substrate.

[0007] The heat transfer medium layer includes a heat-conducting medium, which is fluidly disposed between the photothermal film and the second transparent substrate;

[0008] The photovoltaic layer is located on the side of the second transparent substrate away from the photothermal film, and is used to absorb visible light transmitted through the photothermal layer and convert it into electrical energy.

[0009] In one embodiment, the photovoltaic layer includes a backsheet and a solar cell. The backsheet and the second transparent substrate are stacked opposite each other along the light propagation direction. The solar cell is encapsulated between the backsheet and the second transparent substrate to absorb visible light transmitted through the photothermal film and convert it into electrical energy.

[0010] In one embodiment, a spacer structure is further included, which is disposed between the second transparent substrate and the photothermal film to form a flow cavity between the second transparent substrate and the photothermal film, through which the heat-conducting medium can flow.

[0011] In one embodiment, the photovoltaic-thermal integrated module further includes an outer frame, with the first transparent substrate and the back plate respectively disposed on the front and rear sides of the outer frame to define an installation space, the second transparent substrate, the photothermal film and the battery cell located within the installation space, and an inlet pipe and an outlet pipe connected to the flow cavity and located on the same side of the side wall of the outer frame to introduce a flowable heat transfer medium into the flow cavity, thereby forming a flowable heat transfer medium layer.

[0012] In one embodiment, a sealant layer is provided at the contact point between the first transparent substrate and the outer frame; and / or, a sealant layer is provided at the contact point between the back panel and the outer frame.

[0013] In one embodiment, the surface of the first transparent substrate facing away from the heat transfer medium layer is provided with an anti-reflective layer.

[0014] In one embodiment, the heat-conducting medium is a transparent medium with high transmittance to visible light; wherein, at 25°C, the average transmittance of the heat-conducting medium to visible light in the 400–780 nm wavelength band is ≥85%. Preferably, the heat-conducting medium can be selected from water or aqueous solutions (containing a volume fraction of corrosion inhibitors / antifreeze additives ≤20%), or from silicon-based organic coolants (such as polydimethylsiloxane, phenyl-modified silicone oil, or mixtures thereof), or from fluorine-based organic coolants (such as hydrofluoroethers, perfluoropolyethers, or perfluorocarbon liquids).

[0015] In one embodiment, the thickness of the photothermal film is 1 μm to 100 μm, the thickness of the heat transfer medium layer is 0.1 cm to 5 cm, and the flow rate of the heat transfer medium layer is 0.1 mm / s to 10 mm / s.

[0016] Secondly, this application also provides a method for manufacturing a photovoltaic-thermal integrated module, comprising the following steps:

[0017] S100: A photothermal film capable of absorbing ultraviolet and near-infrared wavelengths in sunlight is provided on the inner side of the first transparent substrate, and an anti-reflection layer is provided on the outer side of the first transparent substrate.

[0018] S200. A second transparent substrate is stacked below the photothermal film, and a spacer structure is provided on one side of the photothermal film so that the first transparent substrate, the second transparent substrate and the spacer structure together define a flow cavity for containing a heat-conducting medium. Then, a flowable heat-conducting medium is introduced into the flow cavity to form a heat medium layer.

[0019] S300: A photovoltaic layer is formed by laminating the battery cell and backsheet using an encapsulating film, and the photovoltaic layer is placed on the side of the second transparent substrate away from the photothermal film.

[0020] S400: The first transparent substrate, the second transparent substrate, and the photovoltaic layer are sealed and laminated as a whole to obtain a photovoltaic-thermal integrated module.

[0021] In one embodiment, the step of forming a photothermal film capable of absorbing ultraviolet and near-infrared wavelengths in sunlight on the inner surface of the first transparent substrate includes:

[0022] The photothermal material was mixed with ethanol at a mass ratio of 1:(5-15) and ball-milled for 2-2.5 hours to form a stable dispersion.

[0023] The dispersion and acrylic resin were mixed at a mass ratio of 1:(0.25~2) to prepare a coating.

[0024] The coating is uniformly applied to the inner side of the first transparent substrate facing away from the substrate. After coating, the substrate is placed in a drying oven at 80℃~85℃ for 1h~1.5h to allow the coating to cure and form the photothermal film.

[0025] Thirdly, this application also provides a seawater desalination apparatus, comprising:

[0026] Seawater pretreatment facilities are used to pretreat seawater.

[0027] The heat exchange mechanism includes a first heat exchanger and a second heat exchanger. The outlet of the seawater pretreatment mechanism is connected to the cold end inlet of the first heat exchanger, and the hot end outlet of the first heat exchanger is connected to the cold end inlet of the second heat exchanger.

[0028] The distillation mechanism has its vapor end connected to the hot end inlet of the second heat exchanger, and its liquid end connected to the hot end inlet of the first heat exchanger.

[0029] As described in the above embodiments, in the photovoltaic-thermal integrated module, the cold end outlet of the second heat exchanger is connected to the liquid inlet pipe of the photovoltaic-thermal integrated module, and the liquid outlet pipe of the photovoltaic-thermal integrated module is connected to the feed inlet of the distillation mechanism.

[0030] The technical solutions provided in this application have the following advantages compared with the prior art:

[0031] When sunlight shines on the first transparent substrate, the light passes through the heat transfer medium layer and acts on the photothermal layer. The photothermal layer absorbs ultraviolet and near-infrared wavelengths and converts them into heat energy, which is then transferred to the heat transfer medium layer. This causes the heat transfer medium to absorb the heat energy and heat up. Since the heat transfer medium is in a flowable state, it can output stable heat to meet the heating needs of different scenarios. Visible light, which is not absorbed by the photothermal layer, passes through the heat transfer medium layer and the second transparent substrate and acts on the solar cells, enabling the solar cells to convert solar energy into electrical energy. In other words, this photovoltaic-thermal integrated module cleverly achieves selective absorption and utilization of solar light by different wavelengths through the photothermal and photovoltaic layers, effectively utilizing the entire spectrum and achieving efficient solar energy conversion while avoiding energy waste. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] In the attached image:

[0035] Figure 1 This is a structural schematic diagram of a photovoltaic-thermal integrated module according to this application;

[0036] Figure 2 This is a schematic diagram of the structure of a photovoltaic-thermal integrated module installed in an outer frame according to this application;

[0037] Figure 3 This is a schematic diagram of a seawater desalination device according to this application.

[0038] Icon labels:

[0039] 10. Photovoltaic-thermal integrated module; 11. Photothermal layer; 111. First transparent substrate; 112. Second transparent substrate; 113. Photothermal film; 12. Heat transfer medium layer; 13. Photovoltaic layer; 131. Backsheet; 132. Solar cell; 14. Outer frame; 15. Liquid inlet pipe; 16. Liquid outlet pipe; 17. Spacing structure; 20. Seawater pretreatment mechanism; 30. Centrifugal pump; 40. Heat exchange mechanism; 41. Second heat exchanger; 42. First heat exchanger; 50. Distillation mechanism; 60. Tank; 70. Vacuum pump. Detailed Implementation

[0040] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0041] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0042] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0043] Example 1

[0044] In related technologies, the solar spectrum is a continuous electromagnetic spectrum, encompassing a wide range from high-energy short waves to low-energy long waves. According to the Earth's surface standard spectrum (AM1.5G), the most commonly used reference standard in solar photovoltaic, agricultural, and building fields, the energy distribution of light reaching the ground after passing through 1.5 times the mass of the atmosphere is mainly divided into ultraviolet (approximately 3%-5%), visible light (approximately 42%-43%), and near-infrared (approximately 52%-55%). However, current photovoltaic-thermal integrated modules do not selectively distribute the energy absorption of different wavelengths of the solar spectrum, resulting in low spectral utilization and poor energy conversion efficiency, leading to energy waste. Therefore, this application provides a photovoltaic-thermal integrated module that effectively utilizes the entire spectrum, achieving efficient solar energy conversion and avoiding energy waste.

[0045] Specifically, please refer to Figure 1The photovoltaic-thermal integrated module 10 includes a photothermal layer 11, a heat transfer medium layer 12, and a photovoltaic layer 13. The photothermal layer 11 includes a first transparent substrate 111, a second transparent substrate 112, and a photothermal film 113. The first transparent substrate 111 and the second transparent substrate 112 are stacked. The photothermal film 113 is disposed between the first transparent substrate 111 and the second transparent substrate 112 and is attached to the surface of the first transparent substrate 111 facing the second transparent substrate 112. The photothermal film 113 can absorb ultraviolet light in the 190nm-400nm wavelength range and near-infrared light in the 780nm-2500nm wavelength range from sunlight, while visible light in the 400nm-780nm wavelength range can be transmitted. Both the first transparent substrate 111 and the second transparent substrate 112 can be made of transparent glass, or they can be made of transparent materials commonly used in existing solar photovoltaic-thermal technologies to allow sunlight to pass through; there is no limitation on this. The photovoltaic layer 13 is located on the side of the second transparent substrate 112 away from the photothermal film 113, and is used to absorb visible light transmitted through the photothermal layer 11 and convert it into electrical energy.

[0046] For example, the photothermal film is used to absorb ultraviolet and near-infrared rays in the solar spectrum to absorb thermal radiation from sunlight and heat the heat transfer medium layer. For this purpose, the photothermal film can be made of one or more materials, including but not limited to cesium tungsten bronze and its composites, graphene oxide, polypyrrole, benzotriazole, carbon nanotubes, and any combination thereof.

[0047] The heat transfer medium layer 12 includes a heat-conducting medium that is fluidly disposed between the photothermal film 113 and the second transparent substrate 112. The heat-conducting medium has good thermal conductivity and is fluidly located between the photothermal film 113 and the second transparent substrate 112. When the photothermal film 113 absorbs heat radiation from sunlight, it heats the heat-conducting medium. As the heat-conducting medium continuously flows, it carries away the absorbed heat, allowing the heat transfer medium layer 12 to be used as a heat output layer. Simultaneously, the flowing heat-conducting medium carries away heat, thus maintaining the solar cell 132 within its optimal operating temperature range. Furthermore, the flow direction of the heat-conducting medium includes, but is not limited to, bottom-up, top-down, horizontal, or multi-directional composite flow.

[0048] In this embodiment, the photovoltaic-thermal integrated module 10, when sunlight shines on the first transparent substrate 111, acts on the photothermal film 113. The photothermal film 113 absorbs ultraviolet and near-infrared wavelengths and converts them into heat energy, which is transferred to the heat transfer medium layer 12. This causes the heat transfer medium 12 to absorb the heat energy and heat up. Since the heat transfer medium is in a flowable state, it can output stable heat to meet the heating needs of different scenarios. Visible light that is not absorbed by the photothermal film 113 passes through the heat transfer medium layer 12 and the second transparent substrate 112 and acts on the photovoltaic layer 13. The photovoltaic layer 13 absorbs the visible light transmitted through the photothermal layer and converts it into electrical energy, thereby realizing the conversion of solar energy into electrical energy. In other words, this photovoltaic-thermal integrated module 10 cleverly achieves selective absorption and utilization of solar energy by different wavelengths through the photothermal film 113 and the photovoltaic layer 13, which can effectively utilize the entire spectrum, achieve efficient conversion of solar energy, and avoid energy waste.

[0049] In practical applications, if ultraviolet and near-infrared wavelengths in sunlight are not absorbed, the temperature of the solar cell 132 will rise when sunlight shines on it, leading to a decrease in power generation efficiency. Therefore, this application utilizes a photothermal film 113 to absorb ultraviolet and near-infrared wavelengths in sunlight, ensuring that most of the thermal radiation from sunlight is absorbed. This allows the photovoltaic layer 13 to operate at an environment where the temperature does not exceed ambient temperature, thereby improving the photoelectric conversion efficiency.

[0050] Furthermore, it should be noted that the photovoltaic layer 13 described above serves to absorb visible light from sunlight that is not absorbed by the photothermal film 113 and convert it into electrical energy. Therefore, the photovoltaic layer 13 in this embodiment can be a photovoltaic module commonly used in the prior art for absorbing sunlight and converting it into electrical energy. However, for ease of understanding the working principle of this embodiment, the photovoltaic layer of the following embodiment will be used as an example for explanation, but it is not limited to this. The specific details are as follows:

[0051] The photovoltaic layer 13 includes a backsheet 131 and solar cells 132. The backsheet 131 and the second transparent substrate 112 are stacked opposite each other along the light propagation direction. The solar cells 132 are encapsulated between the backsheet 131 and the second transparent substrate 112 to absorb visible light transmitted through the photothermal film 113 and convert it into electrical energy. The solar cells 132 may be, but are not limited to, one of the following: perovskite photovoltaic cells, organic photovoltaic cells (OPV), monocrystalline silicon photovoltaic cells, polycrystalline silicon photovoltaic cells, cadmium telluride photovoltaic cells, and copper indium gallium selenide photovoltaic cells.

[0052] During the process of sunlight irradiating the first transparent substrate 111, the outer surface of the first transparent substrate 111 will reflect light, preventing a small portion of sunlight from reaching the photothermal film 113, resulting in energy loss. Therefore, in one embodiment, an anti-reflection layer (not shown) is provided on the surface of the first transparent substrate 111 facing away from the second transparent substrate 112. That is, by providing an anti-reflection layer (not shown) on the surface of the first transparent substrate 111 facing away from the second transparent substrate 112, Fresnel reflection on the surface of the first transparent substrate 111 can be reduced, thereby allowing more incident light to be transmitted to the heat transfer medium layer 12 and the solar cell 132 below the first transparent substrate 111, thereby improving the absorption of thermal energy in sunlight and the photoelectric conversion efficiency, maximizing light energy input.

[0053] In one embodiment, a spacer structure 17 is further included. The spacer structure 17 is disposed between the second transparent substrate 112 and the photothermal film 113, thereby creating a flow cavity between the second transparent substrate 112 and the photothermal film 113, through which the heat transfer medium can flow. In other words, by utilizing the spacer structure 17 between the second transparent substrate 112 and the photothermal film 113, a flow cavity is formed between the two, allowing the heat transfer medium layer 12 to flow through them. This rapidly removes heat, reduces the operating temperature of the solar cell 132, and improves the photothermal conversion efficiency. In a specific application, the spacer structure 17 can be a support block. One end of the support block is fixed to the surface of the second transparent substrate 112 facing the photothermal film 113 using an adhesive. Then, an adhesive is applied to the other end of the support block and bonded to the surface of the photothermal film 113 facing the second transparent substrate 112. At this point, a space is formed between the second transparent substrate 112 and the photothermal film 113, and this space serves as the flow cavity. It should be noted that the support blocks can be made of materials that are resistant to high temperatures and have good structural strength, such as ceramic blocks or high-temperature resistant plastic blocks, and there are no restrictions on this.

[0054] The adhesive is fixed to the surface of the second transparent substrate 112 facing the photothermal film 113, or to the surface of the photothermal film 113 facing the second transparent substrate 112. The height of the support block determines the thickness of the flow cavity. The support block can be made of a high-temperature resistant material with good chemical stability, such as polytetrafluoroethylene, ceramic, or glass, to ensure that it is not easily deformed or corroded in long-term contact with the heat transfer medium and in high-temperature environments, thereby ensuring the stability and service life of the flow cavity structure. In addition, the distribution of the support blocks can be designed according to actual needs, such as uniformly spaced, so that the support between the second transparent substrate 112 and the photothermal film 113 is more stable, avoiding inconsistent flow cavity gaps caused by uneven local stress, which would affect the flow efficiency and heat exchange effect of the heat transfer medium. In some preferred embodiments, the shape of the support block can be cylindrical, square, or other polygonal, and its size can be adjusted according to the overall size and structural strength requirements of the device, so as to minimize the obstruction to the flow of the heat transfer medium while meeting the support strength requirements.

[0055] Water is used as the heat transfer medium. An external water source is connected to the inlet of the flow chamber via a pipeline, and the water user is connected to the outlet of the flow chamber via a pipeline. As the water user demands water, the external water source continuously supplies water into the flow chamber. When the water flows through the flow chamber, it comes into full contact with the photothermal film 113 and the second transparent substrate 112, absorbing the heat generated by the photothermal film 113 through photothermal conversion and the excess heat emitted by the battery cell 132 during operation, thereby raising its own temperature. The heated water is then transported to the water user through the outlet pipe, such as in a home heating system or a domestic hot water supply system, to meet the actual heat energy utilization needs.

[0056] Please refer to Figure 2In one embodiment, the photovoltaic-thermal integrated module 10 further includes an outer frame 14. A first transparent substrate 111 and a backplate 131 are respectively disposed on the front and rear sides of the outer frame 14 to define an installation space. A second transparent substrate 112, a photothermal film 113, and a solar cell 132 are located within the installation space. An inlet pipe 15 and an outlet pipe 16, connected to a flow cavity and located on the same side, are provided on the side wall of the outer frame 14 to allow liquid to be introduced into the flow cavity, thereby forming a heat transfer medium layer 12. In other words, the outer frame 14 seals the second transparent substrate 112, the photothermal film 113, and the solar cell 132 within the installation space, thus isolating them from environmental corrosion and providing mechanical protection. Furthermore, external pipes are connected to the inlet pipe 15 and the outlet pipe 16, allowing liquid to enter the flow cavity from the inlet pipe 15 and then flow out from the outlet pipe 16. This allows the heat transfer medium to flow, quickly carrying away heat and reducing the operating temperature of the solar cell 132, thereby improving the photothermal conversion efficiency. Furthermore, the dimensions of the flow cavity are 100-200mm in length, 50-100mm in width, and 0.1cm-5cm in height. This design ensures sufficient flow space and heat exchange area for the heat transfer medium within the flow cavity, guaranteeing full contact with the photothermal film 113 and the solar cell 132 for heat exchange. It also adapts to the overall structural dimensions of the photovoltaic-thermal integrated module 10, avoiding an excessively large flow cavity that would increase the overall thickness and weight of the module, or an excessively small flow cavity that would affect the flow velocity and heat exchange efficiency of the heat transfer medium. In practical applications, the specific length, width, and height dimensions of the flow cavity can be fine-tuned according to different application scenarios and power requirements to achieve optimal photothermal conversion and heat dissipation effects.

[0057] In one embodiment, a sealant layer is provided at the contact point between the first transparent substrate 111 and the outer frame 14; and / or, a sealant layer is provided at the contact point between the back panel 131 and the outer frame 14. It should be noted that the aforementioned "and / or" is merely a description of the relationship between the associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, the character " / " in this application generally indicates that the preceding and following associated objects have an "or" relationship.

[0058] Specifically, in this embodiment, a sealant layer is provided at the contact point between the first transparent substrate 111 and the outer frame 14, and a sealant layer is also provided at the contact point between the back plate 131 and the outer frame 14, so as to ensure better sealing of the first transparent substrate 111, the back plate 131 and the outer frame 14, and to ensure the overall waterproofness and weather resistance of the component.

[0059] In one embodiment, the thickness of the photothermal film 113 is 1 μm to 20 μm; and / or, the thickness of the heat transfer medium layer 12 is 0.1 cm to 5 cm, and the flow rate of the heat transfer medium layer 12 is 0.1 mm / s to 10 mm / s. That is, by setting the thickness of the photothermal film 113 between 1 μm and 20 μm (inclusive), the skin depth of the solar spectrum can be covered, allowing for better absorption of ultraviolet and near-infrared wavelengths. If the photothermal film 113 is too thin, it cannot adequately absorb ultraviolet and near-infrared wavelengths, resulting in energy loss; if the photothermal film 113 is too thick, the thermal resistance increases, reducing heat dissipation efficiency and increasing material costs. It should be noted that the thickness of the photothermal film can be controlled by adjusting the spraying time, number of sprays, and nozzle flow rate, etc., which will not be elaborated upon here.

[0060] In one embodiment, the heat-conducting medium is a transparent medium with high transmittance to visible light, and the average transmittance of the heat-conducting medium to visible light in the 400nm-780nm wavelength band is ≥85% at 25°C. This ensures that most of the visible light in sunlight can pass through the heat-conducting medium and irradiate the solar cell 132, thereby improving the photoelectric conversion efficiency. Specifically, the heat-conducting medium can be selected from liquids with high transmittance to visible light, such as water or aqueous solutions (containing a volume fraction of corrosion inhibitors / antifreeze additives ≤20%), silicone-based organic coolants (such as polydimethylsiloxane, phenyl-modified silicone oil, or mixtures thereof), or fluorine-based organic coolants (such as hydrofluoroethers, perfluoropolyethers, or perfluorocarbon liquids), and there is no limitation on this.

[0061] Example 2

[0062] This application also provides a method for manufacturing a photovoltaic-thermal integrated module, comprising the following steps:

[0063] S100, a photothermal film 113 capable of absorbing ultraviolet and near-infrared wavelengths in sunlight is provided on the inner surface of the first transparent substrate 111.

[0064] For example, when the photothermal film 113 is placed on the first transparent substrate 111, it can absorb ultraviolet and near-infrared wavelengths from sunlight, while the unabsorbed visible light passes through the second transparent substrate 112 to irradiate the photovoltaic layer 13, where it is absorbed and converted into electrical energy. In other words, the photothermal film 113 absorbs most of the thermal radiation from sunlight to heat the heat transfer medium layer 12, and carries away the heat as the heat transfer medium layer 12 flows, thus allowing the photovoltaic layer 13 to operate at a temperature not exceeding the ambient temperature, thereby improving the photoelectric conversion efficiency.

[0065] Furthermore, the photothermal thin film 113 can be disposed on the first transparent substrate using at least one of the following methods, including but not limited to: solution coating (e.g., blade coating, roller coating, slot / slit coating, gravure / flexible coating, spraying, spin coating, dip coating, or inkjet printing), physical vapor deposition (e.g., magnetron sputtering, vacuum evaporation, ion plating), and chemical film-forming techniques (e.g., sol-gel, chemical bath deposition, spray pyrolysis, atomized chemical vapor deposition, or plasma-enhanced chemical vapor deposition). It should be noted that the above-mentioned solution coating, physical vapor deposition, and chemical film-forming techniques are all prior art and will not be elaborated upon here.

[0066] S200, the second transparent substrate 112 is stacked below the photothermal film 113, and the first transparent substrate 111 is supported by the spacer structure, so that the first transparent substrate 111, the second transparent substrate 112 and the spacer structure together define a flow cavity for containing the heat conduction medium, and then a flowable heat conduction medium is introduced into the flow cavity to form a heat medium layer 12.

[0067] For example, the first transparent substrate 111 and the second transparent substrate 112 are spaced apart by an interleaved structure, so that a flow cavity can be formed between the first transparent substrate 111 and the photothermal film 113. Then, a flowing heat-conducting medium is introduced into the flow cavity. At this time, the photothermal film 113 absorbs the heat radiation of solar energy and heats the heat-conducting medium in the flow cavity. The absorbed heat is carried away with the flow of the heat-conducting medium for use. At the same time, the photovoltaic layer 13 can be kept in an environment where the temperature is not higher than the ambient temperature, which is beneficial to improving the photoelectric conversion efficiency.

[0068] S300: The solar cell 132 and the backsheet 131 are laminated using an encapsulating film to form a photovoltaic layer 13, and the photovoltaic layer 13 is disposed on the side of the second transparent substrate 112 away from the photothermal film 113.

[0069] In practical applications, the first transparent substrate 111 and the second transparent substrate 112 can be made of transparent glass. The photovoltaic layer 13 is a combination of a backsheet 131 and a solar cell 132. First, the solar cell 132 and the backsheet 131 are laminated together using an encapsulating film to form the photovoltaic layer 13. Then, the photovoltaic layer 13 is fixed to the side of the second transparent substrate 112 facing away from the photothermal film 113, thus completing the placement of the photovoltaic layer 13 on the second transparent substrate 112. It should be noted that the backsheet 131 and the second transparent substrate 112 can be fixed tightly together by physical fixing (e.g., adhesive bonding) to avoid internal misalignment of the module caused by vibration and temperature differences during long-term use.

[0070] S400, the first transparent substrate 111, the second transparent substrate 112 and the photovoltaic layer 13 are sealed and laminated as a whole to obtain a photovoltaic-thermal integrated module 10.

[0071] The manufacturing method of the photovoltaic-thermal integrated module in this embodiment firstly involves setting a photothermal film 113 on the inner side of a first transparent substrate 111. Then, a second transparent substrate 112 is stacked below the photothermal film 113, and a spacer structure supports the first transparent substrate 111. The first transparent substrate 111, the second transparent substrate 112, and the spacer structure together define a flow cavity, allowing a flowing heat transfer medium to pass through. Next, a photovoltaic layer 13 is formed by laminating the solar cell 132 and the backsheet 131 using an encapsulating film. The photovoltaic layer 13 is then fixed to the side of the second transparent substrate 112 facing away from the photothermal film 113. Finally, the first transparent substrate 111, the second transparent substrate 112, and the photovoltaic layer 13 are sealed and laminated together to obtain the photovoltaic-thermal integrated module. In other words, the photovoltaic-thermal integrated module 10 manufactured by this embodiment achieves selective absorption and utilization of solar light in different wavelengths through the photothermal film 113 and the photovoltaic layer 13, effectively utilizing the entire spectrum and achieving efficient solar energy conversion while avoiding energy waste.

[0072] The step of coating the side of the first transparent substrate 111 facing the back plate with a photothermal coating to form a photothermal film 113 includes: mixing cesium tungsten bronze powder with ethanol at a mass ratio of 1:(5-15), and ball milling the mixture for 1-2 hours to form a stable dispersion; mixing the dispersion with acrylic resin at a mass ratio of 1:(0.25-2) to prepare a coating; uniformly coating the coating onto the side of the first transparent substrate facing the back plate, and after coating, drying it in a drying oven at 80-85°C for 1-1.5 hours to allow the coating to cure and form the photothermal film. It should be noted that the acrylic resin used is specifically BASF SE Joncryl 581, with a solid content of 100% and a molecular weight of 13,000-16,000.

[0073] Preferably, cesium tungsten bronze powder and ethanol are mixed at a mass ratio of 1:10 and ball-milled for 1.5 hours to fully disperse the photothermal material particles to the nanoscale, forming a stable dispersion without agglomeration or sedimentation. This ensures that the photothermal material can be uniformly distributed on the first transparent substrate after the coating is applied, avoiding dead zones in light absorption due to local aggregation and improving the absorption of ultraviolet and near-ultraviolet wavelengths in sunlight. Then, the dispersion is mixed with acrylic resin at a mass ratio of 1:0.5 to prepare a coating, so that the coating has both suitable fluidity and film-forming properties. This facilitates uniform coating and ensures the formation of a continuous film layer after curing.

[0074] Example 3

[0075] Please refer to Figure 1 and Figure 3This application also provides a seawater desalination device, which includes a seawater pretreatment mechanism 20, a heat exchange mechanism 40, a distillation mechanism 50, and the photovoltaic-thermal integrated module 10 of Embodiment 1 above. The seawater pretreatment mechanism 20 is used to pretreat seawater. The heat exchange mechanism 40 includes a first heat exchanger 42 and a second heat exchanger 41. The outlet of the seawater pretreatment mechanism 20 is connected to the cold end inlet of the first heat exchanger 42, and the hot end outlet of the first heat exchanger 42 is connected to the cold end inlet of the second heat exchanger 41. The steam end of the distillation mechanism 50 is connected to the hot end inlet of the second heat exchanger 41, and the liquid end of the distillation mechanism 50 is connected to the hot end inlet of the first heat exchanger 42. The cold end outlet of the second heat exchanger 41 is connected to the liquid inlet pipe of the photovoltaic-thermal integrated module 10, and the liquid outlet pipe of the photovoltaic-thermal integrated module 10 is connected to the feed inlet of the distillation mechanism 50.

[0076] This seawater desalination device first treats the seawater using a pretreatment mechanism to remove sand and impurities. The seawater is then fed into a first heat exchanger 42, where steam introduced by the distillation mechanism 50 exchanges heat with the seawater, raising its temperature (e.g., to 25°C). Next, the seawater is fed into a second heat exchanger 41, where it exchanges heat with the liquid introduced by the distillation mechanism 50, raising its temperature to maintain the operating temperature of the solar cells (e.g., 35°C). The seawater is then fed into a flow chamber, where it is heated by the heat radiation absorbed by the photothermal film 113, raising its temperature to the distillation temperature (e.g., 60°C). Finally, the seawater flowing from the outlet pipe is fed back into the distillation mechanism 50 for use, thus achieving both desalination and heat recovery. If the seawater temperature does not reach the distillation temperature, other heating devices, such as electric heaters, can be used to ensure the seawater reaches the required distillation temperature. Furthermore, in the distillation unit 50, heated seawater is converted into steam. As the steam rises, it encounters a condensation structure and condenses into fresh water. The remaining high-salinity concentrated seawater is discharged from the brine outlet of the distillation unit. It is worth noting that while the photovoltaic-thermal integrated module 10 provides heat energy for seawater desalination, the electricity it generates can also be connected via cables to the control system, pumps, valves, and other electrical components of the seawater desalination plant, achieving energy self-sufficiency and reducing dependence on the external power grid.

[0077] In one embodiment, the seawater desalination device further includes a centrifugal pump 30, which is located between the seawater pretreatment mechanism 20 and the first heat exchanger 42, for pumping pretreated seawater into the first heat exchanger 42. The inlet of the tank 60 is connected to the cold end outlet of the first heat exchanger 42, for storing pure water formed after steam condensation. A vacuum pump 70 is connected to the interior of the tank 60 via a connecting pipe.

[0078] For example, centrifugal pump 30 is used to provide the power required to transport seawater from seawater pretreatment unit 20 to first heat exchanger 42. For this purpose, centrifugal pump 30 can be a power pump commonly used in seawater pumping in the prior art, and is not limited thereto. Since the steam generated by distillation unit 50 is introduced into the first heat exchanger 42, the steam condenses into water under the cooling effect of the seawater entering the first heat exchanger 42, and then is introduced into tank 60 for storage. Furthermore, vacuum pump 70 is connected to the inside of tank 60 via connecting pipes to perform vacuuming, so that tank 60, first heat exchanger 42, and distillation unit 50 are all in a vacuum state.

[0079] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A photovoltaic-thermal integrated module, characterized in that, It includes a photothermal layer, a heat transfer medium layer, and a photovoltaic layer; The photothermal layer includes a first transparent substrate, a second transparent substrate, and a photothermal film for absorbing ultraviolet and near-infrared wavelengths in sunlight. The first transparent substrate and the second transparent substrate are stacked together, and the photothermal film is disposed between the first transparent substrate and the second transparent substrate. The photothermal film is disposed on the surface of the first transparent substrate facing the second transparent substrate. The heat transfer medium layer includes a heat-conducting medium, which is flowably disposed between the photothermal film and the second transparent substrate; a flow cavity is provided between the second transparent substrate and the photothermal film, through which the heat-conducting medium can flow. The photovoltaic layer is disposed on the second transparent substrate and is located on the side of the second transparent substrate away from the photothermal film. It is used to absorb visible light transmitted through the photothermal layer and convert it into electrical energy. The photovoltaic layer includes a backsheet and a solar cell. The backsheet and the second transparent substrate are stacked opposite each other along the light propagation direction. The solar cell is encapsulated between the backsheet and the second transparent substrate to absorb visible light transmitted through the photothermal film and convert it into electrical energy. The heat conduction medium flows between the second transparent substrate and the photothermal film to absorb the heat energy converted by the photothermal film and reduce the operating temperature of the solar cell. The thickness of the photothermal film is 1μm to 100μm, the thickness of the heat medium layer is 0.1cm to 5cm, and the flow velocity of the heat conduction medium is 0.1mm / s to 10mm / s; the dimensions of the flow cavity are 100-200mm in length, 50-100mm in width, and 0.1cm to 5cm in height.

2. The photovoltaic-thermal integrated module according to claim 1, characterized in that, It also includes a spacer structure disposed between the second transparent substrate and the photothermal film, which can form the flow cavity between the second transparent substrate and the photothermal film, and the heat conduction medium can flow through the flow cavity.

3. The photovoltaic-thermal integrated module according to claim 2, characterized in that, The photovoltaic-thermal integrated module also includes an outer frame. The first transparent substrate and the back plate are respectively disposed on the front and rear sides of the outer frame to define an installation space. The second transparent substrate, the photothermal film and the battery cell are located within the installation space. The side wall of the outer frame is provided with an inlet pipe and an outlet pipe that communicate with the flow cavity and are located on the same side to introduce a flowable heat conduction medium into the flow cavity, thereby forming a flowable heat medium layer.

4. The photovoltaic-thermal integrated module according to claim 1, characterized in that, An anti-reflective layer is provided on the surface of the first transparent substrate facing away from the heat transfer medium layer.

5. The photovoltaic-thermal integrated module according to claim 1, characterized in that, The heat-conducting medium is a transparent medium with high transmittance to visible light; wherein, at 25°C, the average transmittance of the heat-conducting medium to visible light in the 400nm~780nm wavelength band is ≥85%.

6. A method for manufacturing a photovoltaic-thermal integrated module as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S100: A photothermal film capable of absorbing ultraviolet and near-infrared wavelengths in sunlight is provided on the inner side of the first transparent substrate, and an anti-reflection layer is provided on the outer side of the first transparent substrate. S200. A second transparent substrate is stacked below the photothermal film, and a spacer structure is provided on one side of the photothermal film so that the first transparent substrate, the second transparent substrate and the spacer structure together define a flow cavity for containing a heat-conducting medium. Then, a flowable heat-conducting medium is introduced into the flow cavity to form a heat medium layer. S300: A photovoltaic layer is formed by laminating the battery cell and backsheet using an encapsulating film, and the photovoltaic layer is placed on the side of the second transparent substrate away from the photothermal film. S400: The first transparent substrate, the second transparent substrate, and the photovoltaic layer are sealed and laminated as a whole to obtain a photovoltaic-thermal integrated module.

7. The manufacturing method according to claim 6, characterized in that, The step of forming a photothermal film capable of absorbing ultraviolet and near-infrared wavelengths in sunlight on the inner surface of the second transparent substrate includes: The photothermal material was mixed with ethanol at a mass ratio of 1:(5-15) and ball-milled for 2-2.5 hours to form a stable dispersion. The dispersion and acrylic resin were mixed at a mass ratio of 1:(0.25~2) to prepare a coating. The coating is uniformly applied to the inner surface of the first transparent substrate, and after coating, it is placed in a drying oven at 80℃~85℃ for 1h~1.5h to allow the coating to cure and form the photothermal film.

8. A seawater desalination device, characterized in that, include: Seawater pretreatment facilities are used to pretreat seawater. The heat exchange mechanism includes a first heat exchanger and a second heat exchanger. The outlet of the seawater pretreatment mechanism is connected to the cold end inlet of the first heat exchanger, and the hot end outlet of the first heat exchanger is connected to the cold end inlet of the second heat exchanger. The distillation mechanism has its vapor end connected to the hot end inlet of the second heat exchanger, and its liquid end connected to the hot end inlet of the first heat exchanger. In the photovoltaic-thermal integrated module as described in any one of claims 1 to 5, the cold end outlet of the second heat exchanger is connected to the liquid inlet pipe of the photovoltaic-thermal integrated module, and the liquid outlet pipe of the photovoltaic-thermal integrated module is connected to the feed inlet of the distillation mechanism.

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