A photovoltaic and thermal integrated component based on directional heat-conducting phase change material

Abstract

The present invention discloses a photovoltaic-thermal integrated assembly based on a directional heat-conducting phase-change material. The assembly comprises a glass cover layer, a photovoltaic panel layer, a heat-absorbing layer, and a directional heat-conducting phase-change material layer, arranged sequentially from top to bottom. The directional heat-conducting phase-change material is prepared by electrochemical and stress-inducing methods. The glass cover layer, the photovoltaic panel layer, the heat-absorbing layer, and the directional heat-conducting phase-change material layer are laminated to form a plate-shaped assembly, which is encased in a metal housing frame. A heat-exchange metal coil is disposed within the directional heat-conducting phase-change material layer, and the heat-exchange medium inlet and outlet of the heat-exchange metal coil extend out of the metal housing frame. By utilizing the high energy storage density and temperature-invariant phase-change material phase-change material phase-change process during phase change, the present invention effectively controls the operating temperature of the photovoltaic panel, improves the photoelectric conversion efficiency, and significantly enhances the heat storage capacity of the assembly, thus meeting users' increased domestic hot water needs.

Description

Technical Field

[0001] The present invention relates to the technical field of solar energy utilization, and in particular to a photovoltaic-thermal integrated component based on a directional heat-conducting phase-change material. Background Art

[0002] Solar photovoltaic and solar thermal integrated modules integrate two forms of solar energy utilization: photovoltaic power generation and solar thermal utilization, greatly improving the efficiency of solar energy utilization. With the cost reduction brought about by the upgrading of the photovoltaic industry, photovoltaic and solar thermal integrated modules have gradually become one of the mainstream solar energy utilization devices and are used in various building energy supply systems. The design and operation control of photovoltaic and solar thermal integrated modules mainly focus on balancing the two opposing temperature requirements of low photovoltaic panel surface temperature under the demand for high photoelectric conversion efficiency and high water supply temperature at the outlet to meet user needs. Photovoltaic and solar thermal integrated modules usually use water cooling to cool photovoltaic panels. Because the surface temperature of photovoltaic panels is too high under normal working conditions, the circulating water temperature used for cooling is relatively low. The outlet water temperature after cooling cannot meet the user's hot water demand, and an additional heat pump system is required for further heating, which increases energy consumption. Summary of the Invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a photovoltaic-thermal integrated component based on directional heat-conducting phase change material that can stably control the operating temperature of photovoltaic panels and provide hot water to users without the need for an additional heat pump system.

[0004] Technical solution: The photovoltaic and thermal integrated component based on directional heat-conducting phase change material described in the present invention includes a glass cover layer, a photovoltaic panel layer, a heat-absorbing layer and a directional heat-conducting phase change material layer arranged in sequence from top to bottom, and the directional heat-conducting phase change material is prepared by electrochemical method and stress induction method; the glass cover layer, the photovoltaic panel layer, the heat-absorbing layer and the directional heat-conducting phase change material layer are formed into a plate-like component by lamination, and the plate-like component is covered by a metal shell frame; a heat-exchange metal coil is arranged in the directional heat-conducting phase change material layer, and the heat-exchange medium inlet and the heat-exchange medium outlet of the heat-exchange metal coil extend out of the metal shell frame.

[0005] Furthermore, the directional thermal conductive phase change material is prepared by an electrochemical method and a stress induction method, including: using an electrolytic cell to apply a directional current to the metal powder in the electrolyte, controlling the current magnitude so that the vertical deposition rate remains constant, and forming a metal thermal conductive skeleton with a regular layered stacking form; filling the metal thermal conductive skeleton with a phase change energy storage material, and changing the structure of the thermal conductive filler in the phase change energy storage material through stress induction, so that the microstructural arrangement direction of the thermal conductive filler is consistent with the heat flow transfer direction, forming a parallel-like structure, reducing the equivalent thermal resistance, and reducing the thermal resistance of the phase change material.

[0006] The prepared directional thermal conductive phase change material can overcome the problem that directly adding thermal conductive fillers is difficult to balance the thermal conductivity and energy storage density of the composite material. The preparation operation is relatively easy and has the potential for large-scale production and application.

[0007] Furthermore, evenly distributed metal fins are provided at the bottom of the heat absorption layer, and the metal fins can improve the heat exchange effect between the heat absorption layer and the directional heat conducting phase change material layer.

[0008] Furthermore, the heat absorption layer is made of borosilicate nanoshell material, and is electroplated with a black chromium coating, black nickel coating, or black cobalt coating that selectively absorbs the spectrum. Using excellent heat absorption layer materials and coatings can enhance the spectral absorption capacity of sunlight.

[0009] Furthermore, the metal shell frame is a hollow sandwich structure, corrugated metal plates for support are arranged in the hollow sandwich structure, and thermal insulation materials are filled between the corrugated metal plates.

[0010] Furthermore, the thermal insulation material is made of one or more of rubber-plastic cotton, polyester cotton, polyurethane cotton, and polystyrene cotton.

[0011] Furthermore, foam metal fins are arranged on the outer circumferential surface of the heat exchange metal coil.

[0012] Furthermore, the distribution of the foam metal fins is dense at the top and sparse at the bottom. Each foam metal fin has a fractal short rib at an angle of 90 degrees at the end, and the fractal short rib forms an angle of 45 degrees with the base rib.

[0013] The heat exchange coils utilize non-uniformly distributed foam metal fins. This arrangement addresses the heat accumulation effect at the top of the phase-change material caused by gravity-induced heat convection during low-temperature heat transfer. This arrangement accelerates the heat transfer rate of the phase-change material at the top, while the fractal structure at the ends further enhances heat transfer at the edges of the tubes, thereby reducing the reduction in power generation efficiency caused by heat accumulation.

[0014] Furthermore, the foam metal fins are directly fired and fixed to the heat exchange metal coil, and this fixing method can effectively reduce the problem of large contact thermal resistance existing in welding.

[0015] Furthermore, the porosity of the foam metal fins is greater than or equal to 90%, which can reduce the volume occupied by the fins and increase the overall energy storage density.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0017] The present invention prepares a directional heat-conducting phase change material through an electrochemical method and a stress-induction method. The internal heat-conducting filler is consistent with the direction of heat flow transfer. From a microscopic perspective, it can be equivalent to a parallel form of a stack of thermal resistors, thereby greatly reducing the thermal resistance of the phase change material, having higher thermal conductivity and better heat storage capacity. The phase change material has a fixed temperature during phase change. The use of a directional heat-conducting phase change material for photovoltaic panel temperature control can keep the surface temperature of the photovoltaic panel constant under high heat flow transfer, thereby improving the photoelectric conversion efficiency. In addition, the high heat storage capacity of the directional heat-conducting phase change material can further increase the outlet water temperature, and the outlet water temperature can also be maintained constant under low sunlight intensity, meeting the user's demand for more domestic hot water, reducing the user's building energy consumption, and improving the operational stability of the photovoltaic thermal integration system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic cross-sectional view of a photovoltaic-thermal integrated assembly based on a directional heat-conducting phase change material provided by an embodiment of the present invention;

[0019] Figure 2 2 is a schematic top view of a directional heat-conducting phase change material layer according to an embodiment of the present invention;

[0020] Figure 3 Schematic diagram of the foam metal fin structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Attachment Figures 1 to 3 The reference numerals in the figures are as follows:

[0023] 1. Glass cover layer; 2. Photovoltaic panel layer; 3. Heat absorption layer; 4. Directional heat conduction phase change material layer; 5. Metal shell frame; 6. Thermal insulation material; 7. Metal fins; 8. Heat exchange metal coil; 9. Foam metal fins; 10. Heat exchange medium inlet; 11. Heat exchange medium outlet.

[0024] like Figures 1 to 3 As shown, an embodiment of the present invention provides a photovoltaic and thermal integration component based on a directional heat-conducting phase change material, comprising a glass cover layer 1, a photovoltaic panel layer 2, a heat absorption layer 3 and a directional heat-conducting phase change material layer 4 arranged in sequence from top to bottom.

[0025] The bottom of the heat absorption layer 3 is provided with evenly distributed metal fins 7. The heat absorption layer 3 is made of a borosilicate nanoshell material and is electroplated with a spectrally selective black chromium, black nickel, or black cobalt coating. These coatings offer excellent spectral selectivity, thermal stability, and high-temperature resistance, making them suitable for solar thermal utilization in high-temperature conditions.

[0026] Directional thermal conductive phase change materials have directional thermal conductivity and are prepared by electrochemical and stress-induced methods, including:

[0027] An electrolytic cell is used to apply a directional current to the metal powder in the electrolyte, and the current size is controlled to keep the vertical deposition rate at 20μm / s, forming a metal thermal conductive skeleton with a regular layered stacking form; phase change energy storage material is filled into the metal thermal conductive skeleton, and the structure of the thermal conductive filler in the phase change energy storage material is changed through stress induction, so that the microstructural arrangement direction of the thermal conductive filler is consistent with the direction of heat flow transfer, forming a parallel structure, reducing the equivalent thermal resistance, and lowering the thermal resistance of the phase change material.

[0028] This directional thermal conductive phase change material can overcome the problem that directly adding thermal conductive fillers is difficult to balance the thermal conductivity and energy storage density of the composite material. It is also easy to prepare and has the potential for large-scale production and application.

[0029] The glass cover layer 1, photovoltaic panel layer 2, heat absorption layer 3, and directional heat-conducting phase-change material layer 4 are laminated to form a plate-like assembly, which is then enclosed by a metal housing frame 5. Heat-exchange metal coils 8 are located within the directional heat-conducting phase-change material layer 4, with the heat exchange medium inlet 10 and outlet 11 of the heat exchange metal coils 8 extending beyond the metal housing frame 5.

[0030] The metal housing frame 5 is a hollow sandwich structure, within which corrugated metal sheets are provided for support. The spaces between the corrugated metal sheets are filled with insulation material 6. The corrugated metal sheets reduce the weight and cost of the housing while providing space for insulation material 6. Insulation material 6 can be made of one or more of rubber-plastic wadding, polyester wadding, polyurethane wadding, and polystyrene wadding.

[0031] The heat exchange metal coil 8 is in the shape of a serpentine coil. The material of the heat exchange metal coil 8 is preferably copper with high thermal conductivity.

[0032] Foam metal fins 9 are arranged on the outer circumferential surface of the heat exchange metal coil 8. The foam metal fins 9 are directly fired and fixed to the heat exchange metal coil 8, which can effectively reduce the problem of large contact thermal resistance existing in welding.

[0033] The foam metal fins 9 are distributed densely at the top and sparsely at the bottom, with fins arranged every 30° in the upper half and every 45° in the lower half. Each foam metal fin 9 ends with a fractal short rib at a 90° angle, which forms a 45° angle with the base rib. This arrangement addresses the heat accumulation effect at the top of the phase change material during heat transfer with low-temperature heat exchange media, where gravity causes heat convection. This arrangement accelerates the heat transfer rate of the phase change material at the top, while the fractal structure at the end further enhances the heat transfer capacity at the end of the pipe, thereby reducing the reduction in power generation efficiency caused by heat accumulation.

[0034] The porosity of the foam metal fins 9 is greater than or equal to 90%, which can reduce the volume occupied by the fins and increase the overall energy storage density of the component.

[0035] In actual operation, a temperature detection device can be used to monitor the inlet and outlet temperatures of the heat exchange metal coil 8, and a variable frequency water pump can be used to adjust the heat exchange medium flow rate to further control the temperature of the photovoltaic panel assembly. An adjustable bracket can also be installed at the bottom of the assembly to adjust the slope of the photovoltaic assembly according to the sun's angle, thereby improving the solar energy utilization rate of the photovoltaic thermal integrated assembly.

[0036] The present invention utilizes heat energy by exchanging heat between the heat exchange medium flowing within the heat exchange metal coil 8 and the heat-storing directional heat-conducting phase change material layer 4. Combining the photovoltaic panel's photoelectric and photothermal conversion effects, and utilizing the directional heat-conducting phase change material for energy storage and release, this system achieves cascaded utilization of the full solar spectrum, improving the panel's overall energy storage capacity, reducing heat exchange resistance, enhancing the panel's heat exchange efficiency, controlling the panel's temperature, and improving photovoltaic power generation efficiency. Consequently, this system possesses excellent technical effectiveness and application value.

Claims

1. A photovoltaic-thermal integrated component based on directional heat-conducting phase change material, characterized in that: The invention comprises a glass cover layer (1), a photovoltaic layer (2), a heat absorption layer (3) and a directional heat-conducting phase change material layer (4) arranged in sequence from top to bottom, wherein the directional heat-conducting phase change material is prepared by an electrochemical method and a stress-inducing method; the glass cover layer (1), the photovoltaic layer (2), the heat absorption layer (3) and the directional heat-conducting phase change material layer (4) are laminated to form a plate-shaped component, and the plate-shaped component is covered by a metal shell frame (5); a heat-exchanging metal coil (8) is arranged in the directional heat-conducting phase change material layer (4), and a heat-exchanging medium inlet (10) and a heat-exchanging medium outlet (11) of the heat-exchanging metal coil (8) extend out of the metal shell frame (5); The directional heat-conducting phase change material is prepared by an electrochemical method and a stress-inducing method, including: applying a directional current to metal powder in an electrolyte using an electrolytic cell, controlling the current magnitude to keep a constant vertical deposition rate, and forming a metal heat-conducting skeleton with a regular layered stacking form; Phase change energy storage material is filled into the metal heat-conducting skeleton, and the structure of the heat-conducting filler in the phase change energy storage material is changed by stress induction, so that the microstructure arrangement direction of the heat-conducting filler is consistent with the heat flow transfer direction, forming a parallel structure; foam metal fins (9) are arranged on the outer circumferential surface of the heat exchange metal coil (8).

2. The photovoltaic-thermal integrated assembly according to claim 1, characterized in that: Evenly distributed metal fins (7) are provided at the bottom of the heat absorption layer (3).

3. The photovoltaic-thermal integrated assembly according to claim 1, characterized in that: The heat absorption layer (3) is made of a silicon boride nanoshell material, and the heat absorption layer (3) is electroplated with a black chromium coating, a black nickel coating or a black cobalt coating that selectively absorbs the spectrum.

4. The photovoltaic-thermal integrated assembly according to claim 1, characterized in that: The metal shell frame (5) is a hollow sandwich structure, wherein corrugated metal plates for support are arranged in the hollow sandwich structure, and thermal insulation material (6) is filled between the corrugated metal plates.

5. The photovoltaic-thermal integrated assembly according to claim 4, characterized in that: The material of the thermal insulation material (6) is one or more of rubber-plastic cotton, polyester cotton, polyurethane cotton, and polystyrene cotton.

6. The photovoltaic-thermal integrated assembly according to claim 1, characterized in that: The distribution form of the foam metal fins (9) is dense at the top and sparse at the bottom. The end of each foam metal fin (9) has a fractal short rib with a 90° angle, and the fractal short rib and the base rib have a 45° angle.

7. The photovoltaic-thermal integrated assembly according to claim 6, characterized in that: The foam metal fins (9) are directly fired and fixed to the heat exchange metal coil (8).

8. The photovoltaic-thermal integrated assembly according to claim 6, characterized in that: The porosity of the foam metal fin (9) is greater than or equal to 90%.

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