Lightweight PV / T hot water-air composite module

Abstract

The present invention discloses a lightweight PV / T hot water-air composite component, which belongs to the field of comprehensive utilization of solar photovoltaic and thermal energy, and comprises a non-glass transparent cover plate, a photovoltaic cell, a hot melt adhesive film, a transparent back plate, a heat-absorbing metal plate, a metal tube, a wavy perforated heat-conducting sheet, a heat-insulating back plate and a heat-insulating frame; a plurality of photovoltaic cells are arranged in a matrix array; the non-glass transparent cover plate and the transparent back plate are respectively arranged at the upper and lower ends of the photovoltaic cell to form a photovoltaic component; the wavy perforated heat-conducting sheet and a plurality of metal tubes are arranged on the back of the heat-absorbing metal plate to form a heat-absorbing plate core; the photovoltaic component is arranged on the front of the heat-absorbing metal plate to form a photovoltaic-thermal integrated component; the photovoltaic-thermal integrated component is packaged with the heat-insulating back plate and the heat-insulating frame; the present invention can significantly reduce the weight of the component and reduce the difficulty of installation; enhance the multifunctional characteristics of the PV / T technology and expand its applicable scenarios; improve the heating efficiency of the air and the cooling efficiency of the photovoltaic cell.

Description

Technical Field

[0001] The invention belongs to the field of solar photovoltaic and thermal comprehensive utilization, in particular to a lightweight PV / T hot water-air composite component. Background Art

[0002] Driven by current issues such as global warming, energy shortages, and rising fossil fuel prices, renewable energy technologies, especially photovoltaics, have developed rapidly. However, photovoltaic technology still faces a key challenge, that is, up to 70-80% of solar energy is either reflected or converted into heat energy during the process of converting solar energy into electricity, causing the temperature of photovoltaic cells to rise, greatly limiting their performance. In order to improve the photovoltaic efficiency of photovoltaic cells, the excess heat must be effectively handled. Wolf proposed a solution that combines photovoltaics and thermal energy collection, defined as a PV / T module. This module can generate electricity and collect thermal energy at the same time, realizing the comprehensive utilization of solar photovoltaics and thermal energy. This technology is expected to solve the problems of photovoltaic cell efficiency and thermal energy recovery, thereby promoting the wider application of renewable energy.

[0003] Traditional PV / T modules usually use bulky transparent glass covers, which makes installation complicated and puts higher requirements on the load-bearing performance of building structures. In addition, glass is not transparent to infrared light and has poor heat dissipation effect, but its transmittance to ultraviolet rays is as high as 40% to 50%, which cannot effectively resist the damage of ultraviolet rays to photovoltaic cells and packaging materials, seriously reducing the overall performance of PV / T modules. Water-collecting PV / T modules also have difficulties in effectively raising water temperature and easy freezing in cold areas with low winter temperatures, which limits their application in the area. However, in winter in such areas, there is usually a demand for indoor building heating, and the use of heat-collecting air-type PV / T modules can be considered to meet the heating needs. However, in summer, this part of the heat cannot be effectively utilized. In addition, due to the poor thermal conductivity of air, it is difficult to effectively take away the heat accumulated by the metal collector plate. As a result, the thermal energy utilization rate of air-type PV / T modules is low. At the same time, it is difficult for the upper high-temperature air to effectively transfer heat to the lower air, thereby affecting the cooling effect and power generation efficiency of photovoltaic modules. This results in a low thermal energy utilization rate of the heat-collecting air-type PV / T modules, and affects the cooling effect and power generation efficiency of the photovoltaic modules. Summary of the invention

[0004] The purpose of the present invention is to provide a lightweight PV / T hot water-air composite component, which firstly solves the problem that the traditional PV / T component has a large weight base and is difficult to install. Secondly, it solves the problem that the traditional PV / T component has a single heat collection mode and cannot effectively utilize solar thermal energy throughout the year. Thirdly, it solves the problem that the traditional heat collection air-type PV / T component has low thermal energy utilization rate and poor cooling effect of photovoltaic cells. The PV / T component has the characteristics of lightweight, diversified functions and high efficiency of air heat collection.

[0005] The technical solution to achieve the purpose of the present invention is:

[0006] A lightweight PV / T hot water-air composite assembly, comprising a non-glass transparent cover plate, a photovoltaic cell, a hot melt adhesive film, a transparent back plate, a heat absorbing metal plate, a metal pipe, a corrugated perforated heat conducting sheet, a heat insulating back plate and a heat insulating frame;

[0007] A plurality of photovoltaic cells are arranged in a matrix array; a non-glass transparent cover plate and a transparent back plate are respectively arranged at the upper and lower ends of the photovoltaic cells to form a photovoltaic module; the non-glass transparent cover plate is used to block ultraviolet rays and pass infrared light;

[0008] The wavy perforated heat conductive sheet and a plurality of metal tubes are arranged on the back of the heat absorbing metal plate to form a heat absorbing plate core; the wavy perforated heat conductive sheet is used to mix the air of the upper and lower layers and increase the heat exchange area and retention time of the air in the flow channel, thereby enhancing the heat exchange effect;

[0009] The photovoltaic assembly is arranged on the front of the heat-absorbing metal plate to form a photovoltaic and thermal integrated component;

[0010] The photovoltaic and thermal integrated component is packaged with the thermal insulation back plate and the thermal insulation frame, the flow medium in the cavity is air, and the flow medium in the metal tube is liquid working fluid;

[0011] The insulation back plate and insulation frame are provided with air valves, and the metal pipes are connected to the heat collecting pipes;

[0012] The number of the metal tubes is the same as the number of columns of the photovoltaic cell array, and one metal tube is located at the lower side of a column of photovoltaic cells; the metal tube is located at the crest position of the wavy perforated heat conductive sheet, and the trough of the wavy perforated heat conductive sheet is located between the gaps of each column of the photovoltaic cell array.

[0013] Compared with the prior art, the present invention has the following significant advantages:

[0014] (1) The present invention adopts a lightweight PV / T hot water-air composite module design to solve the problem that the traditional PV / T module is heavy and difficult to install. The lightweight non-glass transparent cover plate used in the present invention is lighter and thinner, and can reduce the weight of 6 to 8 kg / m compared to the traditional PV / T module using a 3.2 mm thick glass cover plate. 2, reducing the difficulty of component installation and the load-bearing requirements for building structures, improving the safety and reliability of the structure, expanding the scope of application, and also making transportation and installation more convenient. In addition, traditional glass cover plates do not have the ability to transmit infrared light, resulting in poor heat dissipation and a high ultraviolet transmittance (about 40% to 50%). In contrast, the outer layer of the lightweight non-glass transparent cover plate used in the present invention is compounded with a polytrifluoroethylene (PVF) film, which can transmit mid-infrared radiation while blocking the transmission of ultraviolet rays, so as to reduce the damage of ultraviolet rays to photovoltaic cells and packaging materials, and improve the life and stability of photovoltaic cells.

[0015] (2) The design of the present invention can realize the flexible heating function of solar hot water supply or solar heating. Traditional water-collecting PV / T components can produce low-temperature hot water in summer for family showers and other needs in extremely cold areas, but in winter, there are problems such as difficulty in effectively raising the water temperature and easy freezing. Although traditional air-collecting PV / T components can meet the needs of indoor heating in winter, this part of heat cannot be effectively utilized in summer. The lightweight PV / T hot water-air composite component designed in the present invention provides a flexible heating function, which can not only enhance the multifunctional characteristics of PV / T technology, but also expand its adaptability to application scenarios.

[0016] (3) The design of the present invention can solve the problems of low thermal energy utilization rate and poor cooling effect of photovoltaic cells in traditional heat-collecting air-type PV / T modules. By introducing a wave-shaped perforated high thermal conductivity sheet, the contact area and heat transfer coefficient between the air and the heat-absorbing plate are effectively increased; the air temperature can be increased and the uniformity of the air temperature in the upper and lower layers can be ensured, while the photovoltaic cells can also be effectively cooled; in general, the component can significantly improve the comprehensive utilization efficiency of solar energy photovoltaic and thermal energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention.

[0018] Figure 2 It is a top perspective view of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0020] Combination Figure 1 , Figure 2A lightweight PV / T hot water-air composite component of this embodiment includes a lightweight non-glass transparent cover plate 11, a photovoltaic cell 9, a hot melt adhesive film (6, 8, 10), a transparent back plate 7, a heat-absorbing metal plate 5, a metal tube 4, a wavy perforated heat conductive sheet 3, a heat-insulating back plate and a heat-insulating frame 1, etc. Among them, a plurality of photovoltaic cells 9 are arranged in a matrix array, and the lightweight non-glass transparent cover plate 11 and the transparent back plate 7 are laminated with a plurality of photovoltaic cells through hot melt adhesive films (8, 10) to combine them into a photovoltaic component. A plurality of metal tubes 4 are arranged in parallel, and the number of metal tubes 4 is the same as the number of columns of the photovoltaic cell 9 array, and one metal tube 4 is located at the lower side of a column of photovoltaic cells 9;

[0021] The wavy perforated heat conductive sheet 3 and a plurality of metal tubes 4 and the heat absorbing metal plate 5 form a heat absorbing plate core. The upper surface of the heat absorbing metal plate 5 is covered with a solar selective absorption coating, such as a black nickel or black chrome solar selective absorption coating, which has a high absorption rate (0.93-0.95) in the solar spectrum band (0.3-2.5μm) and a low emissivity (0.04-0.12) in the mid-infrared band (2.5-20μm), thereby showing a higher light-to-heat conversion efficiency. The metal tube 4 and the wavy perforated heat conductive sheet 3 are welded to the back of the heat absorbing metal plate 5. The metal tube 4 is located at the crest position of the wavy perforated heat conductive sheet 3, and the trough of the wavy perforated heat conductive sheet 3 is located between each column gap of the photovoltaic cell 9 array (such as Figure 2 Position A in the middle). Finally, the photovoltaic module is laminated on the front of the heat-absorbing metal plate 5 by a hot melt adhesive film 6, and the photovoltaic module is connected to the heat-absorbing plate core to form a photovoltaic and thermal integration component. The main function of the thermal insulation backboard and the thermal insulation frame 1 is to provide support and insulation. At the same time, they are packaged into a cavity together with the photovoltaic and thermal integration components to form a solar photovoltaic and thermal integration module. The flow medium in the cavity is air, and the flow medium in the metal tube 4 is water or other liquid working fluids. The metal tube 4 is connected to the heat collecting tube 12. A flange air outlet 13 is provided on the thermal insulation backboard and the thermal insulation frame 1 for installing an air valve.

[0022] First, a lightweight non-glass transparent cover plate 11 and a transparent back plate 7 are laminated with a photovoltaic cell 9 to form a photovoltaic module; then a wavy perforated heat conductive sheet 3 and a plurality of metal tubes 4 are welded to the back of a heat absorbing metal plate 5, wherein the plurality of metal tubes 4 are arranged in parallel at equal intervals; finally, the photovoltaic module is laminated on the heat absorbing metal plate 5, so that the heat absorbing metal plate 5, the wavy perforated heat conductive sheet 3, the metal tube 4 and the photovoltaic module are composited into a whole, and the whole is encapsulated in the upper part of the cavity 2 of the heat-insulating back plate and the heat-insulating frame 1. The cavity 2 of the heat-insulating back plate and the heat-insulating frame 1 is provided with an air valve.

[0023] The PV / T module technology uses a low-density, lightweight, non-glass transparent cover 11 (about 1400kg / m 3 ), compared to the traditional PV / T modules using a higher density glass cover (about 2500kg / m 3), can reduce weight by 6-8kg / m 2 , reducing the difficulty of installation and the load-bearing requirements for the building structure. In addition, the outer layer of the lightweight non-glass transparent cover plate 11 is a PVF film. Compared with hydrophilic glass, it is easier to remove dirt on its surface through rainwater scouring and simple cleaning, and it can also dissipate heat through infrared. Overall, the use of lightweight non-glass transparent cover plates can make the module lighter, easier to clean and have better heat dissipation effect. In addition to realizing the comprehensive utilization of photovoltaic light and heat, the lightweight PV / T hot water-air composite component proposed in this design also has two working modes: "photovoltaic + hot water collection" and "photovoltaic + air heat collection". The specific working principles are as follows: (a) "Photovoltaic + hot water collection" working mode: by closing the air valve connected to the cavity 2; at the same time, opening the water valve connected to the heat collection pipe 12; the water flow can flow through the metal pipe 4 and take away the heat absorbed by the heat-absorbing metal plate 5 for family showers, kitchen hot water and swimming pool heating, etc. (b) "Photovoltaic + air heat collection" working mode: by opening the air valve connected to the cavity 2; at the same time, closing the water valve connected to the heat collection pipe 12; air is introduced into the cavity 2. In this process, the air can take away the heat absorbed by the heat-absorbing metal plate 5 and the corrugated perforated heat conductive sheet 3, which can be used for passive heating of buildings, industrial drying, etc. In addition, the use of the corrugated perforated heat conductive sheet 3 not only increases the contact area and heat transfer coefficient of the air, but also strengthens the mixing of the upper and lower layers of air, thereby improving the heating efficiency of the air and the cooling efficiency of the photovoltaic cells. Users can choose between the two working modes of "photovoltaic + water collection" and "photovoltaic + air heat collection" according to climate and needs to flexibly meet the needs of solar water heating or solar heating. This unique design not only enhances the multifunctional characteristics of PV / T technology, but also expands its applicable scenarios. This design is expected to further promote the application of PV / T technology.

[0024] Sunlight irradiates the photovoltaic cell 9 through the lightweight transparent non-glass cover plate 11, and part of the energy is converted into electrical energy for photovoltaic use. The unconverted solar energy is absorbed by the heat-absorbing metal plate 5 together with the solar energy directly irradiated on the heat-absorbing metal plate 5 through the transparent cover plate 11, forming thermal energy. This part of thermal energy can be flexibly selected between heating the flowing air in the cavity or the flowing medium in the heat collecting tube according to climate adaptability and different needs, so as to realize the comprehensive utilization of solar photovoltaic and thermal energy. Among them, the wavy perforated heat conductive sheet 3 can effectively increase the contact area and heat transfer coefficient between the air and the heat-absorbing metal plate 5. At the same time, the air can mix the upper and lower layers of air of the wavy perforated heat conductive sheet 3 through the perforations, and can also effectively cool the photovoltaic cell, thereby enhancing the heat exchange effect. In particular, the lightweight non-glass transparent cover plate used in this design is lighter and thinner, and can reduce the weight by 6 to 8 kg / m compared with traditional PV / T components. 2, reducing the difficulty of installation and the load-bearing requirements for building structures, improving the safety and reliability of the structure, expanding the scope of application, and making transportation and installation more convenient. It is not easy to produce mud spots and water stains and is easier to clean. In addition, the lightweight non-glass transparent cover is not easy to transmit ultraviolet rays, which contributes to the long-term stability of the battery cells and packaging materials. The combination of the collector tube and the air cavity makes the heating function of the component flexible, which can not only enhance the multifunctional characteristics of PV / T technology, but also expand its adaptability to application scenarios. Moreover, the combination of infrared radiation heat dissipation of the lightweight non-glass transparent cover and the heat absorbing plate core enhances the cooling effect of the photovoltaic cell, improves the power generation efficiency, and the utilization rate of thermal energy.

Claims

1. A lightweight PV / T hot water-air composite assembly, characterized in that: It includes non-glass transparent cover plate, photovoltaic cell, hot melt adhesive film, transparent back plate, heat absorbing metal plate, metal tube, corrugated perforated heat conducting sheet, heat insulation back plate and heat insulation frame; A plurality of photovoltaic cells are arranged in a matrix array; a non-glass transparent cover plate and a transparent back plate are respectively arranged at the upper and lower ends of the photovoltaic cells to form a photovoltaic module; the non-glass transparent cover plate is used to block ultraviolet rays and pass infrared light; The wavy perforated heat conductive sheet and a plurality of metal tubes are arranged on the back of the heat absorbing metal plate to form a heat absorbing plate core; the surface of the heat absorbing metal plate is provided with a selective absorption coating that can absorb the solar spectrum in the 0.3-2.5μm band at a high level and reflect the 2.5-20μm band at a low level, wherein the absorption rate is 0.93-0.95 and the reflectivity is 0.04-0.12; the wavy perforated heat conductive sheet is used to mix the air in the upper and lower layers and increase the heat exchange area and residence time of the air in the flow channel, thereby enhancing the heat exchange effect; The photovoltaic assembly is arranged on the front of the heat-absorbing metal plate to form a photovoltaic and thermal integrated component; The photovoltaic and thermal integrated component is packaged with the thermal insulation back plate and the thermal insulation frame, the flow medium in the cavity is air, and the flow medium in the metal tube is liquid working fluid; The insulation back plate and insulation frame are provided with air valves, and the metal pipes are connected to the heat collecting pipes; The number of the metal tubes is the same as the number of columns of the photovoltaic cell array, and one metal tube is located at the lower side of a column of photovoltaic cells; the metal tube is located at the crest position of the wavy perforated heat conductive sheet, and the trough of the wavy perforated heat conductive sheet is located between the gaps of each column of the photovoltaic cell array.

2. The lightweight PV / T hot water-air composite assembly according to claim 1, characterized in that: It has two working modes: "PV + water collection" and "PV + air collection". (a) "PV + water collection" working mode: by closing the air valve connected to the heat collection pipe and opening the water valve connected to the heat collection pipe at the same time, water can flow through the metal pipe and take away the heat absorbed by the heat-absorbing metal plate. (b) "PV + air collection" working mode: by opening the air valve and closing the water valve connected to the heat collection pipe at the same time, air is introduced into the cavity of the insulation back plate and the insulation frame.

3. The lightweight PV / T hot water-air composite assembly according to claim 1, characterized in that: The non-glass transparent cover plate and the transparent back plate are laminated with the photovoltaic cells through a hot-melt adhesive film.

4. The lightweight PV / T hot water-air composite assembly according to claim 1, characterized in that: The photovoltaic module is laminated on the front side of the heat-absorbing metal plate through a hot-melt adhesive film.

5. The lightweight PV / T hot water-air composite assembly according to claim 1, characterized in that: The thermal insulation back plate and the thermal insulation frame are provided with flange air outlets for installing air valves.

6. The lightweight PV / T hot water-air composite assembly according to claim 1, characterized in that: The outer layer of the non-glass transparent cover plate is composited with a PVF film.

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