Thermal management system and preparation method of phase change material

Abstract

The invention relates to the technical field of photovoltaic thermal management, in particular to a thermal management system and a preparation method of a phase change material.The system is used for conducting thermal management on heat generated by a photovoltaic module, the thermal management system comprises a heat exchange module, the heat exchange module is connected to the photovoltaic module, and the heat exchange module is provided with a working medium cavity; the working medium cavity is internally provided with a phase change material, and the phase change material is configured to perform heat exchange with the photovoltaic module. According to the thermal management system, the heat exchange assembly is connected with the photovoltaic assembly, and the phase change material in the working medium cavity of the heat exchange assembly can absorb the heat of the photovoltaic assembly when the photovoltaic assembly is subjected to photoelectric conversion and the temperature rises, so that the photovoltaic assembly is cooled, and the technical problem that the power generation efficiency is reduced due to the temperature rise of the photovoltaic assembly is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic thermal management, and in particular to a thermal management system and a method for preparing a phase change material. Background Art

[0002] With the development of science and technology and the consumption of non-renewable energy, many countries have listed renewable energy as a long-term energy development goal. Among them, solar energy, as an important component of renewable energy, is widely used in various fields. Photovoltaic cells in photovoltaic modules can convert solar energy into high-quality electrical energy, but the photoelectric conversion rate of photovoltaic cells is limited, and photovoltaic cells will generate heat during use. The remaining heat accumulates inside the photovoltaic cells, causing the temperature of the photovoltaic cells to rise. At the same time, the power generation efficiency of photovoltaic cells is restricted by their operating temperature. The higher the operating temperature, the lower the power generation efficiency. Therefore, how to effectively reduce the damage of high temperature to photovoltaic modules to improve the power generation efficiency of photovoltaic modules is one of the research hotspots in this field. Summary of the invention

[0003] The embodiments of the present invention provide a thermal management system and a method for preparing a phase change material to solve the technical problem that the power generation efficiency of existing photovoltaic modules decreases due to the increase of temperature during photoelectric conversion.

[0004] A thermal management system provided in an embodiment of the present invention is used to perform thermal management on heat generated by a photovoltaic module. The thermal management system includes:

[0005] A heat exchange component is connected to the photovoltaic component. The heat exchange component has a working fluid cavity. The working fluid cavity has a phase change material. The phase change material is configured to perform heat exchange with the photovoltaic component.

[0006] Preferably, the heat exchange assembly comprises a plurality of columnar bodies arranged at intervals, the cross section of the columnar body is a "C"-shaped ring structure, and a cavity structure is formed between the inner wall and the outer wall of the columnar body to form the working medium cavity;

[0007] The columnar body is connected to the photovoltaic component, and the opening of the "C"-shaped ring structure faces the photovoltaic component to exchange heat with the photovoltaic component.

[0008] Preferably, the working medium cavity has a plurality of heat dissipation fins, which are arranged at intervals along the bending direction of the inner side wall or the outer side wall of the columnar body, and the heat dissipation fins are arranged at an angle to the inner side wall or the outer side wall of the columnar body;

[0009] And / or, the inner side wall of the columnar body forms a through groove with a "C"-shaped cross section, and both ends of the through groove are open and connected to the external environment;

[0010] And / or, the thermal management system further comprises a metal plate, and the heat exchange component is connected to the photovoltaic component via the metal plate; one surface of the metal plate is fixed to the photovoltaic component, and the other surface is fixed to the heat exchange component.

[0011] Preferably, the phase change material is a boron nitride-based phase change material.

[0012] Preferably, the boron nitride-based phase change material is mainly composed of paraffin wax and boron nitride nanotubes uniformly distributed inside the paraffin wax.

[0013] An embodiment of the present invention provides a thermal management system, which has the following beneficial effects: a heat exchange component with a phase change material in a working fluid cavity is connected to a photovoltaic component. The photovoltaic component will generate a large amount of heat when performing photoelectric conversion, causing the temperature to rise, thereby reducing the power generation efficiency of the photovoltaic component. The phase change material in the working fluid cavity of the heat exchange component connected to the photovoltaic component will exchange heat with the photovoltaic component, absorb the heat generated by the photovoltaic component in the photoelectric conversion process, and avoid the technical problem of the photovoltaic component having too high a temperature, resulting in reduced power generation efficiency. When the temperature of the photovoltaic component is low and does not need to be cooled, the phase change material will release heat and restore its original physical state for reuse.

[0014] The embodiment of the present invention further provides a method for preparing a phase change material, which is used to prepare the above-mentioned boron nitride-based phase change material. The preparation method comprises:

[0015] S100, adding boron nitride nanotubes into melted paraffin and stirring to obtain an intermediate mixture;

[0016] S200, subjecting the intermediate mixture to ultrasonic treatment and cooling to obtain a boron nitride-based phase change material.

[0017] Preferably, the step S100 includes:

[0018] S110, adding boron nitride nanotubes to the melted paraffin and stirring to obtain an intermediate mixed solution;

[0019] S120, adding a surfactant to the intermediate mixed solution to induce self-assembly of the intermediate mixed solution, and stirring to obtain an intermediate mixture.

[0020] Preferably, before step 110, the preparation method further comprises:

[0021] S102, placing the boron nitride nanotubes in a strong acid solution and performing ultrasonic treatment;

[0022] S104, washing the boron nitride nanotubes after ultrasonic treatment with deionized water;

[0023] S106, drying the cleaned boron nitride nanotubes.

[0024] Preferably, in step S102, the strong acid solution includes, by volume, a sulfuric acid solution and a nitric acid solution, the ratio of the sulfuric acid solution to the nitric acid solution is (2.5-3.5) / (0.5-1.5), the concentration range of the sulfuric acid solution is 0.5 mol / L-3 mol / L, the concentration range of the nitric acid solution is 0.5 mol / L-3 mol / L, the temperature range of the ultrasonic treatment is 58°C-62°C, and the ultrasonic treatment time range is: 2h-3h;

[0025] In the step S106, the process temperature range of drying is 77° C. to 83° C., and the process time range of drying is 24 hours to 26 hours.

[0026] Preferably, in step 200, the frequency range of ultrasonic treatment is 19kHz to 21kHz, the amplitude range of ultrasonic treatment is 40μm-100μm, the duration range of ultrasonic treatment is 40min to 45min, and the temperature range after cooling is 15°C to 20°C;

[0027] In the step S110, paraffin is melted in a hot water bath at 62° C. to 67° C., boron nitride nanotubes are added to the melted paraffin, and a magnetic stirrer is operated at 480 rpm to 520 rpm at 62° C. to 67° C. for 2.5 h to 3 h to disperse the particles to obtain a uniform intermediate mixed solution;

[0028] In the step S120, the surfactant is mainly composed of sodium dodecylbenzene sulfonate, and the stirring time ranges from 30 minutes to 35 minutes; by weight, the boron nitride nanotubes are 1 part to 5 parts, the paraffin is 90 parts to 98 parts, and the sodium dodecylbenzene sulfonate is 1 part to 5 parts.

[0029] An embodiment of the present invention provides a method for preparing a phase change material, and the beneficial effects of the preparation method are as follows: paraffin is selected as the main component of a boron nitride-based phase change material, the paraffin is melted and boron nitride nanotubes are added thereto and stirred to obtain an intermediate mixture, and the intermediate mixture is ultrasonically treated and cooled to obtain a boron nitride-based phase change material, wherein the paraffin in the obtained boron nitride-based phase change material has a higher phase change latent heat, and can absorb more heat generated by photovoltaic components during the phase change process, the paraffin with boron nitride nanotubes added has a high thermal conductivity, which is convenient for improving the efficiency of paraffin in absorbing the heat generated by photovoltaic components, and stirring and ultrasonic treatment are performed during the process of adding boron nitride nanotubes, so that the boron nitride nanotubes are more evenly dispersed in the paraffin, further improving the thermal conductivity of the boron nitride-based phase change material, and the boron nitride-based phase change material prepared from boron nitride nanotubes and paraffin can ensure the heat dissipation capacity of photovoltaic components while ensuring high thermal conductivity. For details, see the beneficial effects of the above-mentioned thermal management system, which will not be repeated here.

[0030] Other features and advantages of the embodiments of the present invention will be described in the following description, or some features and advantages can be inferred or determined without doubt from the description, or can be learned by implementing the above-mentioned techniques of the embodiments of the present invention.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the three-dimensional structure of a thermal management system provided by an embodiment of the present invention.

[0034] Figure 2 Schematic diagram of the internal three-dimensional structure of a thermal management system provided by an embodiment of the present invention

[0035] Figure 3 A schematic diagram of the three-dimensional structure of a heat exchange component in a thermal management system provided by an embodiment of the present invention.

[0036] Figure 4 A schematic flow chart of a method for preparing a phase change material provided in an embodiment of the present invention.

[0037] Figure 5This is a front view of a thermal management system provided by an embodiment of the present invention.

[0038] Figure 6 A bottom view of a thermal management system provided by an embodiment of the present invention.

[0039] Figure 7 This is a left view of a thermal management system provided by an embodiment of the present invention.

[0040] Description of reference numerals:

[0041] 1-heat exchange component; 2-photovoltaic component; 3-working fluid chamber; 4-heat dissipation fins; 5-metal plate. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The present invention is further described in detail below through specific implementation examples in conjunction with the accompanying drawings.

[0044] The embodiment of the present invention provides a thermal management system, such as Figure 1 As shown, the thermal management system is used to perform thermal management on the heat generated by the photovoltaic module, and includes: a heat exchange component 1, the heat exchange component 1 is connected to the photovoltaic module 2, the heat exchange component 1 has a working fluid cavity 3, the working fluid cavity 3 has a phase change material, and the phase change material is configured to perform heat exchange with the photovoltaic module 2.

[0045] When using the thermal management system provided by the embodiment of the present invention, a heat exchange component with a phase change material (PCM) in the working fluid cavity is connected to a photovoltaic component. The photovoltaic component will generate a large amount of heat during photoelectric conversion, causing the temperature to rise, thereby reducing the power generation efficiency of the photovoltaic component. The phase change material in the working fluid cavity of the heat exchange component connected to the photovoltaic component will exchange heat with the photovoltaic component, absorb the heat generated by the photovoltaic component during the photoelectric conversion process, and avoid the technical problem of reduced power generation efficiency due to excessive temperature of the photovoltaic component. The demand for improving the power generation efficiency of the photovoltaic component can be met, and when the temperature of the photovoltaic component is low and does not need to be cooled, the phase change material will release heat and restore its original physical state for reuse.

[0046] In the embodiment of the present invention, Figure 1As shown, the heat exchange component 1 includes a plurality of parallel and spaced columnar bodies, the cross-section of the columnar body is a "C"-shaped ring structure, the inner wall and the outer wall of the columnar body are a cavity structure and form a working fluid cavity 3; the columnar body is connected to the photovoltaic component 2, and the opening of the "C"-shaped ring structure faces the photovoltaic component 2 to exchange heat with the photovoltaic component 2.

[0047] The columnar body of the heat exchange component 1 can be made of metal copper with good thermal conductivity, which can enable the heat of the photovoltaic component 2 in the photoelectric conversion process to be transferred to the working fluid chamber 3 more quickly for absorption by the phase change material. During use, the columnar body of the heat exchange component 1 only needs to attach its rectangular side to the photovoltaic component 2 to achieve heat exchange with the photovoltaic component 2. The thermal management system is easy to install and has low cost.

[0048] In the embodiment of the present invention, Figure 2 and Figure 3 As shown, there are multiple heat dissipation fins 4 in the working fluid chamber 3, and they are arranged at intervals along the bending direction of the inner wall or the outer wall of the columnar body. The heat dissipation fins 4 are arranged at an angle to the inner wall or the outer wall of the columnar body. Specifically, the heat dissipation fins 4 are located in the working fluid chamber and are arranged on the inner wall. The material for making them can be copper. The arrangement of the heat dissipation fins 4 can increase the heat exchange area, increase the thermal conductivity, increase the melting rate of the phase change material, and promote the phase change of the phase change material.

[0049] The inner wall of the columnar body forms a through groove with a "C"-shaped cross-section, and both ends of the through groove are open and connected to the external environment. Specifically, the through groove with a "C"-shaped cross-section formed on the inner wall of the columnar body serves as an air channel for air circulation, which can form a passive cooling, namely air cooling, for the photovoltaic component 2. The working fluid cavity 3 is in direct contact with the air and can also be cooled by air. The phase change material in the working fluid cavity 3 is combined with the air cooling to reduce the heat of the photovoltaic component 2, thereby further improving the cooling effect on the photovoltaic component 2. There is no need to set up additional external air cooling resources to cool the photovoltaic component 2, and no additional maintenance is required, thereby ensuring the low cost of the thermal management system.

[0050] The thermal management system also includes a metal plate 5, through which the heat exchange component 1 is connected to the photovoltaic component 2. One surface of the metal plate 5 is fixed to the photovoltaic component 2, and the other surface is fixed to the heat exchange component 1. Specifically, the material of the metal plate 5 can be copper, such as Figure 1 As shown, one side of the opposite surface of the metal plate 5 is fixed to the photovoltaic component 2, and the other side is fixed to the heat exchange component 1. The metal plate 5 is arranged so that the heat of the photovoltaic component 2 is first transferred to the metal plate 5, and the metal plate 5 transfers the heat to the air and the heat exchange component 1. The arrangement of the metal plate 5 can also enhance thermal conductivity and accelerate heat transfer.

[0051] In the embodiment of the present invention, the phase change material may be a boron nitride-based phase change material. Specifically, the boron nitride-based phase change material has good thermal conductivity and can absorb the heat generated by the photovoltaic module 2 more quickly.

[0052] In the embodiment of the present invention, the boron nitride-based phase change material is mainly composed of paraffin and boron nitride nanotubes uniformly distributed inside the paraffin. Specifically, the phase change temperature range of paraffin from solid to liquid is 47-64°C, and paraffin is non-corrosive, non-toxic, has high chemical stability, and has the ability to store heat. At the same time, paraffin has a high phase change latent heat, that is, phase change enthalpy, and can absorb more heat generated by the photovoltaic module 2 during the process of physical state transformation. Boron nitride nanotubes are a synthetic material with the same number of boron atoms and nitrogen atoms, high thermal conductivity and electrical insulation, and its thermal conductivity is about 200-600W / m·K. Uniformly distributing boron nitride nanotubes inside the paraffin is beneficial to improving the thermal conductivity, heat transfer rate and stability of the paraffin.

[0053] The embodiment of the present invention also provides a method for preparing a phase change material, which is used to prepare the boron nitride-based phase change material. Figure 4 As shown, the steps include:

[0054] S100, adding boron nitride nanotubes into melted paraffin and stirring to obtain an intermediate mixture;

[0055] S200, subjecting the intermediate mixture to ultrasonic treatment and cooling to obtain a boron nitride-based phase change material.

[0056] In the preparation method of the phase change material provided in the embodiment of the present invention, paraffin is selected as the main component of the boron nitride-based phase change material, the paraffin is melted and boron nitride nanotubes are added thereto and stirred to obtain an intermediate mixture, and the intermediate mixture is ultrasonically treated and cooled to obtain a boron nitride-based phase change material, wherein the paraffin in the obtained boron nitride-based phase change material has a higher phase change latent heat, and can absorb more heat generated by the photovoltaic module during the phase change process. The boron nitride nanotubes added to the paraffin have high thermal conductivity and electrical insulation, which is convenient for improving the efficiency of the paraffin in absorbing the heat generated by the photovoltaic module, ensuring the stability of the boron nitride-based phase change material during use, and stirring and ultrasonic treatment are performed during the addition of the boron nitride nanotubes, so that the boron nitride nanotubes are more evenly dispersed in the paraffin, further improving the thermal conductivity of the boron nitride-based phase change material, and the boron nitride-based phase change material prepared by the boron nitride nanotubes and paraffin can ensure the heat dissipation capacity of the photovoltaic module while ensuring high thermal conductivity. For details, see the beneficial effects of the above-mentioned thermal management system, which will not be repeated here.

[0057] In the embodiment of the present invention, step S100 includes:

[0058] S110, adding boron nitride nanotubes to the melted paraffin and stirring to obtain an intermediate mixed solution;

[0059] S120, adding a surfactant to the intermediate mixed solution to induce self-assembly of the intermediate mixed solution, and stirring to obtain an intermediate mixture;

[0060] In the above steps, paraffin is melted, and boron nitride nanotubes are added and stirred to make the boron nitride nanotubes more evenly distributed in the paraffin. A surfactant is added to the intermediate mixed solution and stirred to induce self-assembly of the intermediate mixed solution to avoid precipitation of boron nitride nanotubes in the intermediate mixed solution, thereby ensuring the high thermal conductivity and stability of the subsequently prepared boron nitride-based phase change material.

[0061] In the embodiment of the present invention, before step 110, the preparation method further includes:

[0062] S102, placing the boron nitride nanotubes in a strong acid solution and performing ultrasonic treatment;

[0063] S104, washing the boron nitride nanotubes after ultrasonic treatment with deionized water;

[0064] S106, drying the cleaned boron nitride nanotubes;

[0065] In the above steps, the boron nitride nanotubes are placed in a strong acid solution for ultrasonic treatment, which effectively introduces carboxyl functional groups on the surface of the boron nitride nanotubes, so that the boron nitride nanotubes are more dispersed in the paraffin. The supernatant is removed and the boron nitride nanotubes after ultrasonic treatment are washed with deionized water to remove the acidic solution on the surface. Finally, the washed boron nitride nanotubes are dried for subsequent preparation of phase change materials.

[0066] In the embodiment of the present invention, in step S102, the strong acid solution includes, by volume, a sulfuric acid solution and a nitric acid solution, the ratio of the sulfuric acid solution to the nitric acid solution is (2.5-3.5) / (0.5-1.5), the concentration range of the sulfuric acid solution is 0.5 mol / L-3 mol / L, the concentration range of the nitric acid solution is 0.5 mol / L-3 mol / L, the temperature range of the ultrasonic treatment is 58°C-62°C, and the ultrasonic treatment time range is: 2h-3h;

[0067] In the above steps, a strong acid solution is prepared by mixing a sulfuric acid solution and a nitric acid solution, and the boron nitride nanotubes are acid-treated and functionalized, wherein the ratio of the sulfuric acid solution to the nitric acid solution is specifically a volume ratio, and the volume ratio is preferably 3 / 1, the concentration of the sulfuric acid solution is preferably 2 mol / L, the concentration of the nitric acid solution is preferably 1 mol / L, the temperature of the ultrasonic treatment is preferably 60°C, and the ultrasonic treatment time is preferably 2 hours.

[0068] In step S106, the drying process temperature ranges from 77°C to 83°C, and the drying process time ranges from 24h to 26h. Specifically, the drying process temperature is preferably 80°C, and the drying process time is preferably 24h.

[0069] In an embodiment of the present invention, in step 200, the frequency range of ultrasonic treatment is 19kHz to 21kHz, the amplitude range of ultrasonic treatment is 40μm-100μm, the duration range of ultrasonic treatment is 40min to 45min, and the temperature range after cooling is 15℃ to 20℃. Specifically, the ultrasonic treatment can be performed using a probe ultrasonic instrument, wherein the frequency of ultrasonic treatment is preferably 20kHz, the amplitude of ultrasonic treatment is preferably 70μm, the duration of ultrasonic treatment is preferably 40min, and the temperature after cooling is preferably 20℃.

[0070] In step S110, paraffin is melted in a hot water bath at 62°C to 67°C, boron nitride nanotubes are added to the melted paraffin, and a magnetic stirrer is used to operate at 480rpm to 520rpm at 62°C to 67°C for 2.5h to 3h to disperse the particles to obtain a uniform intermediate mixed solution. Specifically, it is preferred to melt paraffin in a hot water bath at 65°C, add boron nitride nanotubes to the melted paraffin, and use a magnetic stirrer to operate at 500rpm at 65°C for 2.5h.

[0071] In step S120, the surfactant is mainly composed of sodium dodecylbenzene sulfonate, and the stirring time ranges from 30 minutes to 35 minutes; by weight, 1 to 5 parts of boron nitride nanotubes, 90 to 98 parts of paraffin, and 1 to 5 parts of sodium dodecylbenzene sulfonate are used. Specifically, the stirring time is preferably 30 minutes. By weight, boron nitride nanotubes are preferably 3 parts, paraffin is preferably 94 parts, and sodium dodecylbenzene sulfonate is preferably 3 parts.

[0072] The working principle or use method of the embodiment of the present invention is further described below with reference to specific examples.

[0073] In this example, a thermal management system is provided, such as Figure 5 , Figure 6 and Figure 7As shown, there is a heat exchange component 1, including multiple columnar bodies, the columnar bodies are made of metallic copper, the cross-section of the columnar bodies is a "C"-shaped ring structure, i.e., a semicircular ring, and a cavity structure is between the inner wall and the outer wall as a working fluid chamber 3, the working fluid chamber 3 has a phase change material and is provided with multiple heat dissipation fins 4, the heat dissipation fins 4 are made of metallic copper, the multiple heat dissipation fins 4 are spaced along the bending direction of the inner wall of the columnar body, and each heat dissipation fin 4 is perpendicular to the tangent of the intersection with the inner wall, the multiple columnar bodies are spaced on one side of a metal plate 5, the metal plate 5 is made of metallic copper, and a "C"-shaped through groove is provided between the metal plate 5 as an air channel, and the other side of the metal plate 5 is attached to the photovoltaic component 2 (i.e., photovoltaic cell).

[0074] In this example, during the heat transfer process of the thermal management system, the heat generated by the photovoltaic module 2 during the photoelectric conversion process is first transferred to the metal plate 5 through heat conduction, and then part of the heat of the metal plate 5 is transferred to the phase change material in the working fluid chamber 3, and part of the heat is transferred to the air. According to the heat transfer process, the energy balance equation of the metal plate 5 is established as follows:

[0075] (T pv -T b ) / R b,pv +h p,1f (T 1f -T b )+h p,2f (T 2f -T b )=0,

[0076] Among them, R b,pv is the thermal resistance between the metal plate and the photovoltaic module; T pv is the temperature of the photovoltaic module; T b is the temperature of the metal plate; h p,1f h is the convection heat transfer coefficient of air between the metal plate and the air channel; p,2f is the convective heat transfer coefficient between the metal plate and the outside air; T 2f is the temperature of the outside air; T 1f is the temperature of the air in the air channel.

[0077] The heat of the metal plate 5 is conducted to the phase change material in the working medium chamber 3 through the part in contact with the heat exchange component 1. The heat in the air flow isolated between the air channel and the metal plate 5 is transferred to the phase change material through convection. Based on the heat absorbed by the phase change material from the air in the air channel through convection and the heat absorbed from the metal plate 5 through heat conduction, the energy equation of the phase change process of the phase change material is established:

[0078] δQ PCM =WL[h PCM,1f (T 1f -TPCM )+h PCM,2f (T 2f -T PCM )+(T b -T PCM ) / R b,pv ]δt,

[0079] Wherein, δ is the thickness of the phase change material layer; Q PCM is the real-time heat flux inside the phase change material layer; W is the radius of the air channel; L is the length of the air channel; T 2f is the temperature of the outside air; T 1f is the temperature of the air in the air channel; h PCM,2f is the convective heat transfer coefficient between the phase change material and the outside air, T PCM is the temperature of the phase change material; h PCM,1f is the convective heat transfer coefficient between the phase change material and the air in the air channel; t is the phase change time.

[0080] In addition, considering that the air flow flows through the air channel and transfers the heat of the phase change material to the atmosphere, based on this, the energy balance equation of the air is established:

[0081]

[0082] Where m is the air mass flow rate; c is the air thermal conductivity; W is the radius of the air channel; x is the unit length of the air channel; T 2f is the temperature of the outside air; h PCM,2f is the convective heat transfer coefficient between the phase change material and the outside air, T PCM is the temperature of the phase change material.

[0083] The thermal management system provided in this example includes a metal plate 5, one side of the metal plate 5 is attached to the photovoltaic component 1, and the opposite side is provided with a heat exchange component 1, wherein the heat exchange component 1 has a working fluid cavity 3, the working fluid cavity 3 is filled with phase change material and is provided with heat dissipation fins 4, the heat exchange component 1 is a plurality of parallel and spaced columnar bodies arranged on the metal plate 5, and each columnar body and the metal plate 5 have a "C"-shaped through groove as an air channel, and the heat conduction is enhanced by attaching the metal plate 5 to the photovoltaic component 1, and the heat of the photovoltaic component 1 during photoelectric conversion is absorbed, and the heat exchange component 1 arranged on the metal plate 5 cannot completely cover one side of the metal plate 5, and the spaced portion between the columnar bodies allows the metal plate 5 to contact with the air, and There is also air in the air channel, and the phase change material encapsulated in the heat exchange component 1 cooperates with the air to cool the metal plate, and the heat dissipation fins 4 arranged in the working fluid cavity 3 increase the heat exchange area and enhance the heat conduction effect, thereby realizing the cooling of the photovoltaic component 2. The thermal management system has a simple structure, low manufacturing cost, easy installation, good cooling effect, and does not require additional external air cooling resources and additional maintenance. At the same time, the heat exchange component 1 and the metal plate 5, and the metal plate 5 and the photovoltaic component 2 in the thermal management system are tightly attached, so that the thermal management system has sufficient stability, ensures the static performance of the thermal management system, can be widely used in engineering and life, and can improve the power generation efficiency of the photovoltaic component 1.

[0084] This example also provides a phase change material prepared by the preparation method of the above phase change material, which can be specifically implemented with reference to the following embodiments:

[0085] S300, placing the boron nitride nanotubes in a strong acid solution for ultrasonic treatment at a temperature of 60° C. for two hours, wherein the strong acid solution is a mixture of a sulfuric acid solution and a nitric acid solution, and the volume of the sulfuric acid solution in the strong acid solution is 3:1: the volume of the nitric acid solution, and the concentration of the sulfuric acid solution is 2 mol / L, and the concentration of the nitric acid solution is 1 mol / L;

[0086] S302, removing the supernatant, washing the sonicated boron nitride nanotubes with deionized water to neutralize the strong acid solution on the surface thereof, and drying the washed boron nitride nanotubes in a vacuum oven at 80° C. for 24 hours. The finally dried boron nitride nanotubes can be called new boron nitride nanotubes, which have good stability;

[0087] S304, melting paraffin in a hot water bath at 65° C., then adding the novel boron nitride nanotubes to the melted paraffin, and stirring for 2.5 hours to obtain an intermediate mixed liquid, so that the particles of the novel boron nitride nanotubes are evenly distributed in the paraffin, thereby improving the thermal conductivity of the paraffin;

[0088] S306, adding sodium dodecylbenzene sulfonate to the intermediate mixed solution, and stirring the intermediate mixture with a magnetic stirrer at 500 rpm for 30 minutes to obtain an intermediate mixture, wherein the sodium dodecylbenzene sulfonate is added to the intermediate mixed solution to induce self-assembly of the intermediate mixed solution to prevent precipitation of the novel boron nitride nanotubes;

[0089] S308, using a probe ultrasonicator to perform ultrasonic treatment on the intermediate mixture at a frequency of 20 kHz and an amplitude of 70 μm for 40 minutes to obtain a boron nitride-based phase change material, and cooling the boron nitride-based phase change material to 20° C. for subsequent use, and improving the dispersion and uniformity of the boron nitride nanotubes in the intermediate mixture by performing ultrasonic treatment.

[0090] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "horizontal", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0091] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "installation" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thermal management system, characterized in that: Used to perform thermal management on the heat generated by photovoltaic modules, the thermal management system comprises: A heat exchange component (1), the heat exchange component (1) is connected to the photovoltaic component (2), the heat exchange component (1) has a working fluid chamber (3), the working fluid chamber (3) has a phase change material, and the phase change material is configured to perform heat exchange with the photovoltaic component (2).

2. The thermal management system according to claim 1, characterized in that: The heat exchange assembly (1) comprises a plurality of columnar bodies arranged at intervals, the cross section of the columnar body being a "C"-shaped ring structure, and a cavity structure being formed between the inner wall and the outer wall of the columnar body to form the working fluid cavity (3); The columnar body is connected to the photovoltaic component (2), and the opening of the "C"-shaped annular structure faces the photovoltaic component (2) to exchange heat with the photovoltaic component (2).

3. The thermal management system according to claim 2, characterized in that: The working medium cavity (3) has a plurality of heat dissipation fins (4) arranged at intervals along the bending direction of the inner side wall or the outer side wall of the columnar body, and the heat dissipation fins (4) are arranged at an angle to the inner side wall or the outer side wall of the columnar body; And / or, the inner side wall of the columnar body forms a through groove with a "C"-shaped cross section, and both ends of the through groove are open and connected to the external environment; And / or, the thermal management system further comprises a metal plate (5), and the heat exchange component (1) is connected to the photovoltaic component (2) via the metal plate (5); one surface of the metal plate (5) is fixed to the photovoltaic component (2), and the other surface is fixed to the heat exchange component (1).

4. The thermal management system according to any one of claims 1 to 3, characterized in that: The phase change material is a boron nitride-based phase change material.

5. The thermal management system according to claim 4, characterized in that: The boron nitride-based phase change material mainly consists of paraffin wax and boron nitride nanotubes uniformly distributed inside the paraffin wax.

6. A method for preparing a phase change material, characterized in that: For preparing the boron nitride-based phase change material according to any one of claims 4 to 5, the preparation method comprises: S100, adding boron nitride nanotubes into melted paraffin and stirring to obtain an intermediate mixture; S200, subjecting the intermediate mixture to ultrasonic treatment and cooling to obtain a boron nitride-based phase change material.

7. The preparation method according to claim 6, characterized in that: The step S100 includes: S110, adding boron nitride nanotubes to the melted paraffin and stirring to obtain an intermediate mixed solution; S120, adding a surfactant to the intermediate mixed solution to induce self-assembly of the intermediate mixed solution, and stirring to obtain an intermediate mixture.

8. The preparation method according to claim 7, characterized in that: Before step 110, the preparation method further includes: S102, placing the boron nitride nanotubes in a strong acid solution and performing ultrasonic treatment; S104, washing the boron nitride nanotubes after ultrasonic treatment with deionized water; S106, drying the cleaned boron nitride nanotubes.

9. The preparation method according to claim 8, characterized in that: In step S102, the strong acid solution includes, by volume, a sulfuric acid solution and a nitric acid solution, the ratio of the sulfuric acid solution to the nitric acid solution is (2.5-3.5) / (0.5-1.5), the concentration range of the sulfuric acid solution is 0.5 mol / L-3 mol / L, the concentration range of the nitric acid solution is 0.5 mol / L-3 mol / L, the temperature range of the ultrasonic treatment is 58° C.-62° C., and the ultrasonic treatment time range is: 2 h-3 h; In the step S106, the process temperature range of drying is 77° C. to 83° C., and the process time range of drying is 24 hours to 26 hours.

10. The preparation method according to any one of claims 7 to 9, characterized in that: In step 200, the frequency range of ultrasonic treatment is 19kHz to 21kHz, the amplitude range of ultrasonic treatment is 40μm-100μm, the duration range of ultrasonic treatment is 40min to 45min, and the temperature range after cooling is 15°C to 20°C; In the step S110, paraffin is melted in a hot water bath at 62° C. to 67° C., boron nitride nanotubes are added to the melted paraffin, and a magnetic stirrer is operated at 480 rpm to 520 rpm at 62° C. to 67° C. for 2.5 h to 3 h to disperse the particles to obtain a uniform intermediate mixed solution; In the step S120, the surfactant is mainly composed of sodium dodecylbenzene sulfonate, and the stirring time ranges from 30 minutes to 35 minutes; by weight, the boron nitride nanotubes are 1 part to 5 parts, the paraffin is 90 parts to 98 parts, and the sodium dodecylbenzene sulfonate is 1 part to 5 parts.

Images