A stacked solar spectrum step utilization and thermoelectric cogeneration device

Abstract

The utility model provides a kind of stacked sunlight spectrum step utilization and thermoelectricity collaborative device, including by upper to lower sequentially arranged Fresnel condensing layer, high-transparency packaging glass, translucent photovoltaic cell, heat collection layer and narrow band gap photovoltaic cell;Fresnel condensing layer, high-transparency packaging glass, translucent photovoltaic cell, heat collection layer and narrow band gap photovoltaic cell are respectively independently constructed or using layer-by-layer deposition or integrated packaging process to realize integrated manufacturing.The utility model in series by Fresnel condensing layer, high-transparency packaging glass, translucent photovoltaic cell, heat collection layer and narrow band gap photovoltaic cell vertical integration, realize solar spectrum step utilization, improve comprehensive efficiency.Heat collection layer recycles upper and lower layer photovoltaic waste heat, reduces cell temperature, enhances stability and life.System takes into account power generation and heating, output heat energy can satisfy multiple scene, compact structure adapts multiple deployment form, and manufacturing is compatible with existing process, cost is controllable, effectively solve the problem such as traditional system resource waste.

Description

Technical Field

[0001] This utility model relates to the field of solar energy utilization technology, and in particular to a device for the cascaded utilization of solar spectrum and thermoelectric synergy. Background Technology

[0002] Currently, solar energy utilization mainly includes two forms: photovoltaic (PV) power generation and solar thermal power generation. PV power generation directly converts solar radiation energy into electrical energy through solar cells, offering advantages such as simple system structure, short construction period, and strong adaptability. Solar thermal power generation, on the other hand, absorbs solar radiation heat energy for heating, steam supply, and steam-driven applications, making it particularly suitable for energy-intensive industrial processes and thermochemical conversions. However, traditional PV and solar thermal systems are typically deployed separately, leading to problems such as redundant resource allocation, redundant system structure, and low land utilization, making it difficult to simultaneously meet the dual demands of high power generation efficiency and high heat output. Furthermore, PV modules are prone to efficiency degradation under strong sunlight conditions due to excessive temperature rise (i.e., the temperature coefficient problem), hindering their stable operation in high-irradiance, hot climates.

[0003] In recent years, to improve the overall efficiency of solar energy utilization, researchers have gradually proposed photovoltaic-solar thermal synergistic utilization systems, attempting to integrate power generation and heat production functions into a single system. Existing PVT systems can be broadly categorized as follows:

[0004] Non-transparent PVT systems: Coolant channels or absorber plates are added to the back of traditional photovoltaic modules to collect waste heat. These systems have a relatively simple structure, but they cannot further utilize the transmission spectrum, and there are significant coupling losses in the thermoelectric conversion.

[0005] Transparent PVT system: This system uses semi-transparent photovoltaic modules, allowing some sunlight to pass through to the heat collection module below. This structure improves spectral utilization, but existing solutions mostly rely on simple transparent glass + water tank structures, failing to form a complete tiered spectral utilization mechanism, resulting in low heat collection efficiency and low overall system integration.

[0006] Tandem photovoltaic systems: These systems connect or stack multiple solar cells with different bandgap values ​​to construct high-efficiency photovoltaic tandem cells (such as perovskite / silicon tandem cells). Although this can improve photoelectric conversion efficiency, heat in the system is still emitted disorderly as a byproduct and is not fully recovered and utilized.

[0007] In addition, existing photovoltaic and solar thermal integrated systems generally suffer from the following problems: insufficient spectral utilization: a full-spectrum, specialized utilization path for sunlight from ultraviolet to near-infrared has not yet been formed; weak heat management capabilities: a lack of systematic guidance and recovery of heat from photovoltaic modules, limiting module stability; low structural integration: multiple functional units are scattered, resulting in large overall thickness and volume redundancy, making it difficult to meet the needs of building integration and distributed deployment; poor functional scalability: the system is generally limited to power supply or heating, making it difficult to meet higher-level energy utilization needs such as combined power generation and supply, and multi-functional coupling.

[0008] Therefore, there is an urgent need for a new type of photovoltaic-thermal coupling system with high integration, high efficiency, and thermoelectric synergistic output capability, which can realize multi-energy conversion of solar energy, energy cascade utilization, and intelligent system control within a limited space, thereby cooling and improving the efficiency of photovoltaic modules, while outputting high-quality thermal energy to provide clean energy support for building energy use, industrial heat and chemical conversion and other scenarios. Utility Model Content

[0009] The purpose of this invention is to provide a multilayer solar spectrum cascade utilization and thermoelectric synergy device that can realize the coordinated operation of photovoltaic power generation and photothermal collection, thereby improving the comprehensive utilization efficiency of solar energy.

[0010] According to one objective of this utility model, this utility model provides a stacked solar spectrum gradient utilization and thermoelectric synergy device, comprising a Fresnel concentrator layer, a semi-transparent photovoltaic cell, a heat collection layer, and a narrow bandgap photovoltaic cell arranged sequentially from top to bottom; the Fresnel concentrator layer adopts a focusing Fresnel lens array, and the Fresnel concentrator layer, the high-transparency encapsulation glass, the semi-transparent photovoltaic cell, the heat collection layer, and the narrow bandgap photovoltaic cell are constructed independently or integrated into a single unit using layer-by-layer deposition or integrated encapsulation processes.

[0011] Furthermore, it also includes high-transparency encapsulation glass, which is disposed on the upper surface of the semi-transparent photovoltaic cell.

[0012] Furthermore, the high-transparency encapsulation glass has a thickness between 1-10 mm and a light transmittance ≥92%.

[0013] Furthermore, the semi-transparent photovoltaic cell is a semi-transparent perovskite cell, CIGS, organic photovoltaic, or semi-transparent heterojunction silicon cell.

[0014] Furthermore, the heat collection layer is a closed flat plate hollow cavity structure, and the interior of the heat collection layer is filled with a transparent heat collection working fluid.

[0015] Furthermore, the upper and lower surfaces of the heat collection layer are sealed with high-transparency glass.

[0016] Furthermore, the heat-collecting working fluid is water, ethylene glycol, nanofluid, or photothermal conversion fluid.

[0017] Furthermore, the heat collection layer is provided with a miniature input / output fluid port, and the heat collection layer is connected to an external heat exchange system.

[0018] Furthermore, the heat collection layer absorbs the heat energy from the transmitted visible and infrared light, while also absorbing the heat emitted by the upper and lower photovoltaic cells during operation, and provides heat energy to the external heating system or drives the photothermal chemical reaction system.

[0019] Furthermore, the narrow bandgap photovoltaic cell is a monocrystalline silicon cell, CIGS, or other solar cell with high absorption capacity for red-near infrared light, and is directly attached to the bottom of the heat collection layer or co-encapsulated with the lower glass of the heat collection layer.

[0020] This utility model's technical solution achieves cascaded utilization of the solar spectrum and improves overall efficiency by vertically integrating a Fresnel concentrator layer, high-transparency encapsulation glass, semi-transparent photovoltaic cells, a heat collection layer, and narrow-bandgap photovoltaic cells. The heat collection layer recovers waste heat from the upper and lower photovoltaic layers, reducing cell temperature and enhancing stability and lifespan. The system combines power generation and heating, with output heat energy meeting diverse scenarios. Its compact structure adapts to multiple deployment forms, and its manufacturing is compatible with existing processes, keeping costs under control and effectively solving problems such as resource waste in traditional systems. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0023] Figure 2 This is a schematic diagram of the heat collection layer in an embodiment of the present invention;

[0024] In the diagram: 1. Fresnel concentrator layer; 2. High-transparency encapsulation glass; 3. Semi-transparent photovoltaic cell; 4. Heat collection layer; 5. Narrow bandgap photovoltaic cell; 6. High-transparency glass; 7. Heat-absorbing medium. Detailed Implementation

[0025] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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 connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Example 1

[0029] like Figure 1 and Figure 2 As shown, a stacked solar spectral gradient utilization and thermoelectric synergy device comprises, from top to bottom, a Fresnel concentrator layer 1, a high-transparency encapsulation glass 2, a semi-transparent photovoltaic cell 3, a heat collection layer 4, and a narrow bandgap photovoltaic cell 5; each functional layer can be constructed independently, or integrated manufacturing can be achieved using layer-by-layer deposition or integrated encapsulation processes; wherein:

[0030] The Fresnel focusing layer 1 uses a focusing Fresnel lens array and is made of polycarbonate, PMMA or quartz glass. It can be placed on the top layer of the system as a detachable external module or directly laminated to the surface of the encapsulation glass.

[0031] The high-transparency encapsulation glass 2 is a tempered low-iron glass with a thickness between 1.6-3.2mm, a light transmittance of ≥92%, and has anti-ultraviolet, anti-wind load, and anti-thermal shock properties.

[0032] The semi-transparent photovoltaic cell 3 preferably adopts a semi-transparent perovskite cell, but other semi-transparent solar cells with high visible light transmittance can also be used. The total thickness is about 0.8-1.5μm. By adjusting the thickness of the perovskite layer or the electrode design, an average visible light transmittance of 20-60% can be achieved. It mainly absorbs ultraviolet and some infrared light for photovoltaic power generation, and allows some visible and near-infrared light to be transmitted to the heat collection layer below.

[0033] The heat collection layer 4 has a hollow cavity structure with a thickness of 1-30cm. Both the top and bottom surfaces are sealed with high-transparency glass, and the sealing frame is made of stainless steel or a high-polymer heat-resistant colloid. The interior is filled with a transparent heat collection medium with a light transmittance ≥80% and high heat capacity and thermal conductivity. The heat collection layer is equipped with micro-input / output fluid ports for connection to an external heat exchange system, and the convective heat transfer effect can be enhanced through a microfluidic structure. The heat collection medium can be water, ethylene glycol, nanofluid, or photothermal conversion fluid.

[0034] The narrow bandgap photovoltaic cell 5 is preferably a crystalline silicon cell or other solar cell with high absorption capacity for red-near infrared light. It can be a flexible or rigid component, directly attached to the bottom of the heat collection layer, or co-encapsulated with the lower glass of the heat collection layer. It mainly absorbs the portion of visible and near-infrared light that has not been fully utilized by the upper cell and the heat collection layer for photovoltaic power generation.

[0035] The working principle of the stacked solar spectrum gradient utilization and thermoelectric synergy device in this embodiment is as follows:

[0036] Sunlight first strikes the Fresnel concentrator, which focuses the incident light onto the area below, increasing the local irradiance.

[0037] The light then passes through the high-transparency encapsulation glass and enters the semi-transparent photovoltaic cell layer, which absorbs ultraviolet and some infrared light to generate photovoltaic power, while allowing some visible and near-infrared light to be transmitted to the heat collection layer below.

[0038] The transparent heat-collecting working medium inside the heat-collecting layer absorbs the heat energy carried in the transmitted light and stores or transfers heat, and also absorbs the waste heat released by the upper and lower photovoltaic cells during operation.

[0039] The narrow-band photovoltaic cells below the heat collection layer absorb some of the visible and near-infrared light that has not yet been fully utilized by the upper layer, thus achieving multi-level utilization of the spectrum.

[0040] The beneficial effects of this utility model are as follows:

[0041] This system achieves tiered utilization of the solar spectrum, with synergistic photovoltaic and photothermal output. The system's spectral utilization rate can reach over 85%, far exceeding traditional single photovoltaic systems and non-transparent PVT systems. The heat collection layer effectively absorbs the waste heat from the upper and lower photovoltaic cells, reducing cell temperature and improving device stability and lifespan. The operating temperature of the upper perovskite photovoltaic module is reduced by approximately 15-20°C compared to systems without cooling measures. OC The voltage is increased by approximately 25-40mV, and the device performance stability is improved by more than 2 times. It achieves the coordinated output of electrical and thermal energy, and the heat collection layer can output thermal energy of 60-90℃, which can drive a variety of heat utilization scenarios and broaden the application range. The system structure of this utility model is highly integrated and modularly deployable, and the thickness can be controlled within the range of 50-100mm, making it suitable for various scenarios such as centralized and distributed systems. The materials and manufacturing methods of each layer are compatible with existing processes, the manufacturing cost is controllable, and it has good prospects for engineering promotion.

[0042] Example 2

[0043] like Figure 1 and Figure 2 As shown, the structure of this embodiment is basically the same as that of embodiment 1. The difference is that the stacked solar spectrum gradient utilization and thermoelectric synergy device in this embodiment includes, from top to bottom, a Fresnel concentrator layer 1, a high-transparency encapsulation glass 2, a semi-transparent photovoltaic cell 3, a heat collection layer 4, and a narrow bandgap photovoltaic cell 5.

[0044] In this embodiment, the Fresnel focusing layer 1 is a focusing Fresnel lens array made of PMMA material, which is placed on the top layer of the system as a detachable external module. The high-transmittance encapsulation glass 2 is tempered low-iron glass with a thickness of 2mm and a light transmittance of 93%.

[0045] The semi-transparent photovoltaic cell 3 is a semi-transparent perovskite cell with a total thickness of 1μm and an average visible light transmittance of 40%. The heat collection layer 4 is a 10cm thick hollow cavity, sealed on both the top and bottom with AR-coated low-iron glass, and the sealing frame is made of stainless steel. It is filled with CuO / H2O nanofluid and has micro-input / output fluid ports for connection to the external heat exchange system. The narrow bandgap photovoltaic cell 5 is a monocrystalline silicon cell, directly attached to the bottom of the heat collection layer 4.

[0046] When the system is working, sunlight is focused by Fresnel concentrator 1 and passes through high-transparency encapsulation glass 2 into semi-transparent photovoltaic cell 3. Semi-transparent photovoltaic cell 3 absorbs ultraviolet and some infrared light to generate electricity, while some visible and near-infrared light is transmitted to heat collection layer 4. Nanofluids in heat collection layer 4 absorb heat energy and absorb the residual heat of photovoltaic cells above and below. Finally, narrow bandgap photovoltaic cell 5 absorbs the remaining light to generate electricity.

[0047] This utility model embodiment realizes the cascade utilization of the solar spectrum and the synergistic output of photovoltaic and photothermal energy; utilizes the heat collection layer for bidirectional waste heat recovery to enhance overall thermal management performance; improves the stability and conversion efficiency of photovoltaic modules; possesses good integrability, scalability and multi-scenario adaptability; and provides an all-around coupling path, providing a platform foundation for integrated applications of "power generation + heating + chemical industry".

[0048] Compared with existing technologies, the stacked solar spectral gradient utilization and thermoelectric synergy device provided by this utility model has significant advantages in terms of structural integration, energy utilization efficiency, temperature control capability, and system adaptability through multi-layer structure integration and spectral gradient allocation mechanism. Specifically, these advantages are reflected in the following aspects:

[0049] 1. Achieve efficient cascade utilization of the solar spectrum, significantly improving overall energy conversion efficiency.

[0050] This invention utilizes a top-to-bottom arrangement of semi-transparent photovoltaic cells, a heat collection layer, and narrow-bandgap photovoltaic cells to achieve spectral absorption and layered utilization of ultraviolet, visible, and infrared light. Specifically, the semi-transparent perovskite photovoltaic cells primarily absorb ultraviolet and blue-green light in the 300-700 nm wavelength range, achieving a photoelectric conversion efficiency of 15-18%. The heat collection layer absorbs mid-to-far infrared light and heat in the 700-1100 nm wavelength range, achieving a heat collection efficiency of over 60% (using water as the heat collection medium, with a 20°C temperature difference between inlet and outlet water, and a flow rate of 0.1 L / min). The bottom silicon cells absorb the remaining wavelengths of light not utilized by the upper layers, achieving a conversion efficiency of 10-20%. System integration testing shows that the spectral utilization rate of this coupled system (defined as the proportion of unit incident light energy effectively converted to electricity / heat) can reach over 85%, significantly higher than traditional single photovoltaic systems (≤22%) and non-transparent PVT systems (≤50%).

[0051] 2. Significantly enhances the thermal management capabilities of photovoltaic cells, improving stability and lifespan.

[0052] In this invention, the heat collection layer is positioned between two photovoltaic layers, effectively absorbing the waste heat generated during operation and providing dynamic thermal coupling and active cooling. Tests show that under standard solar intensity (AM1.5, 1000 W / m²), the heat collection layer effectively absorbs the waste heat generated during operation. 2 Under these conditions, the operating temperature of the upper-layer perovskite photovoltaic module in the system decreases by approximately 15-20°C compared to without cooling measures. OC The voltage is increased by approximately 25-40 mV, and the device performance stability is improved by more than 2 times (the efficiency decay is less than 10% after 500 h under damp heat cycling conditions).

[0053] 3. Achieve coordinated output of electrical and thermal energy, expanding application scenarios.

[0054] Unlike traditional PVT systems primarily used for hot water output, this novel heat collection layer can be selectively filled with high specific heat media such as nanofluids and ethylene glycol, achieving an output heat temperature of 60–90℃. It possesses the capability to drive low-temperature steam systems and thermocatalytic reactions (such as hydrogen production and methanol synthesis). Simultaneously, the system output can achieve decoupled thermoelectric control, flexibly matching different energy usage scenarios, such as building-integrated power and heating systems, agricultural facility solar thermal combined systems, and industrial chemical thermal reaction systems.

[0055] 4. The system has a highly integrated structure, can be deployed modularly, and is highly adaptable.

[0056] This invention employs a vertically integrated encapsulation structure, combining multiple functions into a single structural unit. The system thickness can be controlled within the range of 50-100 mm, significantly lower than traditional multi-layered systems. This structure is not only suitable for centralized solar power plants but can also be integrated as a building component into distributed photovoltaic applications such as rooftops, curtain walls, and light canopies, enabling "BIPV + solar thermal integration" deployment.

[0057] 5. Possesses good compatibility with manufacturing processes and cost controllability.

[0058] The materials and manufacturing methods used in each layer are compatible with existing solar module manufacturing processes. For example, the semi-transparent photovoltaic layer can be manufactured using mature perovskite spin-coating or evaporation techniques; the heat collection cavity can be encapsulated using conventional glass hot-pressing or modular assembly; and the bottom silicon cells are commercially available standard components. Estimates indicate that the overall manufacturing cost of this system is controlled at 1.5-2.2 yuan / W (electricity + heat), demonstrating promising prospects for engineering application.

[0059] In summary, this utility model, through reasonable allocation of functional levels and compact integration of structure, maintains high photoelectric conversion efficiency while fully recovering heat energy and improving the thermal environment of the device, realizing the synergistic and efficient utilization of photovoltaic and photothermal technologies. It overcomes the problems of spectral waste, structural dispersion, and insufficient thermal management in existing technologies, and has significant technological progress and industrial application prospects.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A device for the stacked solar spectrum gradient utilization and thermoelectric synergy, characterized in that, It includes, from top to bottom, a Fresnel concentrator layer, a high-transparency encapsulation glass, a semi-transparent photovoltaic cell, a heat collection layer, and a narrow bandgap photovoltaic cell; the Fresnel concentrator layer adopts a focusing Fresnel lens array, and the Fresnel concentrator layer, the high-transparency encapsulation glass, the semi-transparent photovoltaic cell, the heat collection layer, and the narrow bandgap photovoltaic cell are either independently constructed or integrated into a single unit using a layer-by-layer deposition or integrated encapsulation process.

2. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 1, characterized in that, It also includes high-transparency encapsulation glass, which is disposed on the upper surface of the semi-transparent photovoltaic cell.

3. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 2, characterized in that, The high-transparency encapsulation glass has a thickness between 1-10 mm and a light transmittance of ≥92%.

4. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 1, characterized in that, The semi-transparent photovoltaic cell is a semi-transparent perovskite cell, CIGS, organic photovoltaic, or semi-transparent heterojunction silicon cell.

5. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 1, characterized in that, The heat collection layer is a closed flat plate hollow cavity structure, and the interior of the heat collection layer is filled with a transparent heat collection working fluid.

6. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 5, characterized in that, The heat collection layer is sealed with high-transparency glass on both the top and bottom surfaces.

7. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 5, characterized in that, The heat collection medium is water, ethylene glycol, nanofluid, or photothermal conversion fluid.

8. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 5, characterized in that, The heat collection layer is provided with a miniature input / output fluid port, and the heat collection layer is connected to an external heat exchange system.

9. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 5, characterized in that, The heat collection layer absorbs the heat energy from the transmitted visible and infrared light, while also absorbing the heat emitted by the upper and lower photovoltaic cells during operation, and providing heat energy to the external heating system or driving the photothermal chemical reaction system.

10. The stacked solar spectrum gradient utilization and thermoelectric synergy device according to claim 1, characterized in that, The narrow bandgap photovoltaic cell is a monocrystalline silicon cell, CIGS, or other solar cell with high absorption capacity for red-near infrared light, and is directly attached to the bottom of the heat collection layer or co-encapsulated with the lower glass of the heat collection layer.

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