Dual-phase-change-material-based photovoltaic-thermoelectric system used in winter and summer

Abstract

The invention discloses a dual-phase-change-material-based photovoltaic-thermoelectric system for winter and summer, and relates to the technical field of solar photovoltaic power generation, a photovoltaic cell, a first phase change layer, a thermoelectric power generation sheet and a second phase change layer are sequentially arranged from top to bottom, a phase change material in the first phase change layer can absorb and transfer heat generated by the photovoltaic cell, and the phase change material in the second phase change layer can absorb and transfer heat generated by the thermoelectric power generation sheet. A second phase change layer is arranged at the lower end of the thermoelectric power generation sheet, and a phase change material in the second phase change layer stores and dissipates waste heat into the environment through absorption, convection and radiation heat dissipation, so that the cold end temperature of the thermoelectric power generation sheet is controlled, and continuous thermoelectric conversion is maintained; two phase change materials with different phase change temperatures are filled in the container and used for temperature adjustment in winter and summer, the winter and summer dual-purpose effect of the power generation system is achieved, efficient energy utilization of the winter and summer dual-purpose is achieved, and meanwhile the power generation efficiency of a photovoltaic-thermoelectric system is remarkably improved by combining multiple energy utilization of photoelectricity, photothermal and thermoelectricity.

Description

Technical Field

[0001] The present invention belongs to the technical fields of solar photovoltaic power generation, semiconductor temperature difference power generation, and phase change heat storage, and specifically relates to a winter-summer dual-use photovoltaic-thermoelectric system based on dual-phase change materials. Background Art

[0002] Under the dual pressures of global climate change and resource depletion, countries are accelerating the transformation of their energy structures, aiming to shift from reliance on fossil fuels to cleaner, more sustainable energy systems. As one of the most abundant renewable energy sources on Earth, solar energy offers advantages such as widespread distribution, zero pollution, and inexhaustibility, making it an ideal alternative to traditional energy sources.

[0003] Utilizing the photoelectric effect of photovoltaic cells to achieve light-to-electricity conversion is a current research hotspot in the field of solar energy utilization and a key development direction for solar energy utilization in my country. In practical photovoltaic applications, over 80% of solar radiation is converted into heat within the photovoltaic cell, causing the cell temperature to rise, resulting in reduced efficiency and wasteful heat. Thermoelectric cells can convert this waste heat into electricity, so coupling photovoltaic cells with thermoelectric cells is considered an effective way to improve photovoltaic cell efficiency.

[0004] However, despite significant progress in improving energy efficiency with photovoltaic-thermoelectric coupled systems, energy demand varies significantly across regions and seasons. Solar energy utilization is significantly affected by factors such as season and weather, particularly in winter, when sunshine duration is short and intensity is weak. Traditional photovoltaic-thermoelectric coupled system integration approaches often struggle to flexibly address these seasonal demand fluctuations, making thermal energy management a major challenge. This can lead to significant energy efficiency losses and resource waste when the system operates at suboptimal operating temperatures, posing a significant challenge to the effective use of solar energy. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and provide a winter-summer dual-purpose photovoltaic-thermoelectric system based on dual phase change materials to overcome the undesirable integration mode between existing photovoltaic-thermoelectric coupling systems. Through clever component separation and heat source management design, the temperature of the photovoltaic cell surface is reasonably managed, thereby achieving efficient energy utilization in both winter and summer.

[0006] The present invention adopts the following technical solutions: A dual-phase change material-based photovoltaic-thermoelectric system for both winter and summer use, comprising a photovoltaic cell and a thermoelectric sheet, wherein a first phase change layer is disposed between the photovoltaic cell and the thermoelectric sheet, and a second phase change layer is connected to the bottom surface of the thermoelectric sheet; The photovoltaic cell and the first phase change layer, and the thermoelectric power generation sheet and the second phase change layer are connected by heat conductive materials; The first phase change layer and the second phase change layer each include a phase change container, wherein the phase change container contains a phase change material.

[0007] Furthermore, the photovoltaic cell is a single crystal silicon photovoltaic cell.

[0008] Furthermore, the bottom area of the photovoltaic cell is the same as the area of the phase change container.

[0009] Furthermore, the top surface area of the thermoelectric power generation sheet is the same as the area of the phase change container.

[0010] Furthermore, the thermoelectric power generation sheet includes two ceramic layers, and an electrode sheet and a thermoelectric pin are provided between the two ceramic layers.

[0011] Furthermore, the electrode sheet is bonded to the ceramic layer, and the thermoelectric pin is arranged between the two electrode sheets.

[0012] Furthermore, the electrode sheet is a copper electrode sheet.

[0013] Furthermore, the phase change container is made of aluminum alloy.

[0014] Furthermore, the heat-conducting material is thermally conductive glue or thermally conductive silicone grease.

[0015] Furthermore, the phase change material is paraffin.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: The present invention provides a dual-phase change material-based winter-summer dual-purpose photovoltaic-thermoelectric system, comprising a photovoltaic cell, a first phase change layer, a thermoelectric power generation sheet and a second phase change layer. The structures are arranged in sequence from top to bottom. The phase change material in the first phase change layer can absorb and transfer the heat generated by the photovoltaic cell, thereby managing the surface temperature of the photovoltaic cell and improving its power generation efficiency. The second phase change layer is arranged at the lower end of the thermoelectric power generation sheet, in which the phase change material stores and dissipates the waste heat into the environment through absorption, convection and radiation heat dissipation, controls the cold end temperature of the thermoelectric power generation sheet, and maintains the continuous thermoelectric conversion. The present invention achieves the winter-summer dual-purpose effect of the power generation system by filling a container with two phase change materials with different phase change temperatures for temperature regulation in winter and summer, thereby realizing efficient energy utilization for both winter and summer, and at the same time combining multiple energy utilizations of photovoltaic, solar thermal and thermoelectricity to significantly improve the power generation efficiency of the photovoltaic-thermoelectric system.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a winter-summer dual-purpose photovoltaic-thermoelectric system based on dual phase change materials according to the present invention; Figure 2 This is a schematic diagram of the summer working mode; Figure 3 This is a schematic diagram of the winter working mode.

[0019] Among them: 1. Photovoltaic cell; 2. Phase change container; 3. Ceramic layer; 4. Thermoelectric pin; 5. Electrode sheet; 6. Phase change container. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "one side," "one end," and "one side" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, in the description of the present invention, unless otherwise specified, "a plurality" means two or more.

[0022] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0023] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0024] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0026] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0027] The present invention provides a winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials, such as Figure 1 As shown, it includes a photovoltaic cell 1, a first phase change layer 2 is provided at the lower end of the photovoltaic cell 1, the first phase change layer 2 includes a first phase change container, a first phase change material is installed in the first phase change container, the first phase change material is used to absorb and transfer the heat energy generated by the photovoltaic cell 1, a thermoelectric power generation sheet is provided at the bottom of the first phase change container, the bottom end of the thermoelectric power generation sheet is connected to the second phase change layer 6, the second phase change layer 6 includes a second phase change container, a second phase change material is installed in the second phase change container, during the whole process, the second phase change material in the second phase change container absorbs and transfers the heat generated in the photovoltaic cell 1, the first phase change material or the second phase change material selects different phase change temperatures according to winter and summer, reasonably manages the surface temperature of the photovoltaic cell 1, and improves its power generation efficiency; The first phase change container is fixed to the hot end of the photovoltaic cell 1 and the thermoelectric power generation sheet, wherein the hot end of the photovoltaic cell 1 is the lower surface of the photovoltaic cell 1, and the hot end of the thermoelectric power generation sheet is the upper end of the thermoelectric power generation sheet. The photovoltaic cell 1 and the thermoelectric power generation sheet are both tightly connected to the first phase change container using thermal conductive glue or thermal conductive silicone grease. The second phase change container is fixed to the cold end of the thermoelectric power generation sheet, and the second phase change container and the bottom surface of the thermoelectric power generation sheet are tightly connected using thermal conductive silicone grease. The side connection surface of the first phase change container connected to the photovoltaic cell 1 has the same light-receiving area as the photovoltaic cell 1. The area of the side connection surface of the first phase change container connected to the hot end of the thermoelectric power generation sheet is not limited and can be determined according to actual conditions. In this embodiment, the side connection surface has the same light-receiving area as the photovoltaic cell 1. Photovoltaic cell 1 is a commercial monocrystalline silicon photovoltaic cell. Monocrystalline silicon material has relatively stable photoelectric conversion performance in low-temperature environments and can adapt to working conditions in extremely cold regions. Its light-receiving surface is a rectangular structure. The lower surface (non-light-receiving surface) of photovoltaic cell 1 serves as the hot end and is tightly connected to the upper side of the first phase change layer 2 via thermally conductive adhesive to ensure efficient heat transfer. The first phase change container is a container for carrying phase change material. The phase change material in the first phase change container can be paraffin wax. The material of the first phase change container is aluminum alloy. The thermoelectric power generation sheet includes two upper and lower ceramic layers 3 and thermoelectric pins 4. The ceramic layer 3 is made of aluminum oxide, the electrode sheet 5 is made of copper, and the thermoelectric pins 4 are made of bismuth telluride. The second phase change container is tightly connected to the cold end of the thermoelectric power generation sheet using thermally conductive adhesive. The connection area of the second phase change container is the same as that of the thermoelectric power generation sheet. The material of the second phase change container is aluminum alloy. The materials of the first phase change container and the second phase change container are both aluminum alloy. Aluminum material has excellent thermal conductivity and can quickly transfer the heat generated by the photovoltaic cell 1 to the phase change material.

[0028] The thermoelectric power generation chip consists of two layers of alumina ceramic layers 3, with bismuth telluride-based thermoelectric pins 4 and electrode sheets 5 installed in the middle. The electrode sheets 5 are bonded to the inner side of the ceramic layer 3 through a high-temperature sintering process.

[0029] The quantity and specifications of the photovoltaic cells 1, phase change layers, and thermoelectric power generation sheets can be determined according to actual needs and are not limited to this example.

[0030] This invention discloses a dual-phase-change material-based photovoltaic-thermoelectric system for both winter and summer use. This system relates to the field of solar photovoltaic power generation technology. The coupled power generation system comprises, arranged in order from top to bottom, a photovoltaic cell, a container containing a phase-change material (PCM1), a thermoelectric generator, and a container containing a phase-change material (PCM2). This invention achieves dual-use in both winter and summer by filling the container with two phase-change materials with different phase-change temperatures for temperature regulation in winter and summer. In summer, the phase-change material (PCM1) is placed between the photovoltaic cell and the thermoelectric generator, lowering the cell's temperature and providing heat to the thermoelectric generator's hot end. The phase-change material (PCM2) maintains continuous thermoelectric power generation by controlling the temperature of the thermoelectric generator's cold end. In winter, the phase-change material (PCM2) is placed between the photovoltaic cell and the thermoelectric generator, raising the cell's temperature and providing heat to the thermoelectric generator's hot end. The phase-change material (PCM1) maintains continuous thermoelectric power generation by controlling the temperature of the thermoelectric generator's cold end. Realize the efficient use of photovoltaic cells and thermoelectric panels in both winter and summer, and combine the use of multiple energies such as photovoltaic, solar thermal and thermoelectric to significantly improve the power generation efficiency of the photovoltaic-thermoelectric system.

[0031] The working method or principle of the winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials of the present invention is as follows: The photovoltaic cell 1 absorbs sunlight and converts part of it into electrical energy for external output. The other part is converted into heat energy, which is used by the first phase change layer 2 and transferred to the thermoelectric power generation sheet, providing a heat source for the input end of the thermoelectric power generation sheet, driving the thermoelectric power generation sheet to generate electricity by temperature difference and output electrical energy. The first phase change layer 2 stores and dissipates this part of waste heat into the environment through absorption, convection and radiation.

[0032] For details, please refer to the attached Figure 2 In the present invention, during the summer sunshine period, the photovoltaic cell 1 faces the sunlight, and the sunlight is incident on the upper surface of the photovoltaic cell 1. Part of the incident light is converted into electrical energy by the photovoltaic cell 1 in the dual phase change material photovoltaic-thermoelectric system, and the other part of the incident light is transmitted through the photovoltaic cell 1 and transmitted to the first phase change layer 2. The PCM1 in the first phase change layer 2 absorbs and utilizes this part of the energy and undergoes a phase change. At the same time, the energy of the first phase change layer 2 is transferred to the connection between the first phase change layer 2 and the hot end of the thermoelectric power generation sheet, driving the thermoelectric power generation sheet to perform thermoelectric power generation and output electrical energy to the outside; the residual heat from the thermoelectric power generation sheet is transferred to the second phase change layer 6; the PCM2 in the second phase change layer 6 dissipates this part of the residual heat into the environment through absorption, convection and radiation heat dissipation, controls the cold end temperature of the thermoelectric power generation sheet, and maintains the continuous thermoelectric conversion.

[0033] During this process, the PCM1 of the first phase change layer 2 absorbs, utilizes and transfers the heat generated in the photovoltaic cell 1 to achieve the effect of temperature control, thereby reducing the surface temperature of the photovoltaic cell 1 and improving its power generation efficiency.

[0034] For details, please refer to the attached Figure 3 In the present invention, during the winter sunshine period, the photovoltaic cell 1 faces the sunlight, and the sunlight is incident on the upper surface of the photovoltaic cell 1. Part of the incident light is converted into electrical energy by the photovoltaic cell 1 in the dual phase change material photovoltaic-thermoelectric system, and the other part of the incident light is transmitted through the photovoltaic cell 1 and transmitted to the first phase change layer 2. The PCM2 in the first phase change layer 2 absorbs and transmits this part of the energy to the connection between the first phase change layer 2 and the hot end of the thermoelectric power generation sheet, driving the thermoelectric power generation sheet to perform thermoelectric power generation and output electrical energy to the outside; the remaining heat from the thermoelectric power generation sheet is transferred to the second phase change layer 6; the PCM1 in the second phase change layer 6 controls the cold end temperature of the thermoelectric power generation sheet by absorbing the remaining energy, thereby maintaining the continuous thermoelectric conversion.

[0035] During this process, since the temperature of the photovoltaic panel itself is relatively low during winter, the PCM2 of the first phase change layer 2 has not reached the phase change range. The PCM2 transfers the heat generated in the photovoltaic cell 1 while reducing the heat loss of the photovoltaic cell, achieving the effect of heat preservation, increasing the surface temperature of the photovoltaic cell, making it closer to the optimal operating temperature range, and improving its power generation efficiency.

[0036] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A dual-phase change material-based photovoltaic-thermoelectric system for winter and summer use, characterized in that: It comprises a photovoltaic cell (1) and a thermoelectric power generation sheet, wherein a first phase change layer (2) is provided between the photovoltaic cell (1) and the thermoelectric power generation sheet, and a second phase change layer (6) is connected to the bottom surface of the thermoelectric power generation sheet; The photovoltaic cell (1) and the first phase change layer (2), and the thermoelectric power generation sheet and the second phase change layer (6) are all connected via heat-conducting materials; The first phase change layer (2) and the second phase change layer (6) both comprise a phase change container, wherein the phase change container is filled with a phase change material.

2. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 1, characterized in that: The photovoltaic cell (1) is a single crystal silicon photovoltaic cell.

3. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 1, characterized in that: The bottom surface area of the photovoltaic cell (1) is the same as the area of the phase change container.

4. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 1, characterized in that: The top surface area of the thermoelectric power generation sheet is the same as the area of the phase change container.

5. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 1, characterized in that: The thermoelectric power generation sheet comprises two ceramic layers (3), with an electrode sheet (5) and a thermoelectric pin (4) provided between the two ceramic layers (3).

6. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 5, characterized in that: The electrode sheet (5) is bonded to the ceramic layer (3), and the thermoelectric pin (4) is arranged between the two electrode sheets (5).

7. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 5, characterized in that: The electrode sheet (5) is a copper electrode sheet.

8. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 1, characterized in that: The phase change container is made of aluminum alloy.

9. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 8, characterized in that: The heat-conducting material is heat-conducting glue or heat-conducting silicone grease.

10. The winter-summer dual-use photovoltaic-thermoelectric system based on dual phase change materials according to claim 1, characterized in that: The phase change material is paraffin.

Images