Composite heat dissipation device, its preparation method and application

Abstract

This application provides a composite heat dissipation device, including an electromagnetic radiation heat dissipation structure. The electromagnetic radiation heat dissipation structure includes a polarized material, which is composed of multiple polarized material units. Each polarized material unit has an optical phonon. The polarized material can interact with solar radiation and thermal radiation. The solar radiation interacts with the surface of the polarized material unit to produce diffuse reflection. The thermal radiation interacts with the optical phonon, and the optical phonon amplifies the energy intensity of the thermal radiation.

Description

Technical Field

[0001] This application relates to the fields of materials and heat dissipation, and in particular to a composite heat dissipation device that combines multiple heat transfer methods, its preparation method, and its application. Background Technology

[0002] As extreme weather events intensify globally and global temperatures reach new highs, various cooling devices have become a major source of global energy consumption. However, the process of consuming energy also emits carbon dioxide, which further exacerbates global warming.

[0003] Heat transfer occurs in three ways: conduction, convection, and radiation. When convection or conduction is obstructed, radiation becomes the primary mode of heat transfer. Conversely, when radiation is obstructed, convection or conduction becomes the main mode of heat transfer. Both conduction and radiation transfer heat in all directions; conversely, convection typically transfers heat upwards.

[0004] Existing heat dissipation devices often only consider one heat transfer method. This application proposes a radiation composite heat dissipation device that uses highly durable materials and a simple manufacturing process that can be mass-produced. It can combine multiple heat transfer schemes, including radiation cooling. In addition to effectively reducing the absorption of solar radiation energy by objects and effectively increasing the thermal radiation energy of objects, this composite heat dissipation device can help target objects effectively dissipate excess heat even under strong solar radiation during the day. It also incorporates a heat dissipation device scheme optimized by combining the formation of heat conduction. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a composite heat dissipation device that uses highly durable materials and a simple manufacturing process that can be mass-produced, reduces the absorption of solar radiation energy by an object and increases the thermal radiation energy of the object, and has low thermal resistance characteristics, so that the composite heat dissipation device can help the target object effectively dissipate excess heat even under strong solar radiation during the day.

[0006] To achieve the above objectives, this application provides a composite heat dissipation device, including an electromagnetic radiation heat dissipation structure. The electromagnetic radiation heat dissipation structure includes a polarized material, which is composed of multiple polarized material units. Each polarized material unit has an optical phonon. The polarized material can interact with solar radiation and thermal radiation. The solar radiation interacts with the surface of the polarized material unit to produce diffuse reflection. The thermal radiation interacts with the optical phonon, and the optical phonon amplifies the energy intensity of the thermal radiation.

[0007] Preferably, the polarization material unit is a subwavelength structure.

[0008] Preferably, the subwavelength structures are stacked in an interleaved manner to form a self-supporting structure.

[0009] Preferably, the subwavelength structures are stacked in an alternating manner to form a porous structure containing multiple pores through which solar radiation interacts with the surface of the polarized material unit.

[0010] Preferably, the subwavelength structure is nanometer-sized particles.

[0011] Preferably, the subwavelength structure is a fibrous structure with a diameter of nanometers.

[0012] Preferably, the subwavelength structure consists of multiple nanometer-sized particles attached to a fibrous structure.

[0013] Preferably, the polarized material unit further comprises a plurality of acoustic phonons, which can transfer energy to each other.

[0014] Preferably, it also includes a heat conduction interface located between the electromagnetic radiation heat dissipation structure and a heat source body, the heat source body providing thermal energy to be transferred to the polarization material through the heat conduction interface.

[0015] Preferably, the thermal energy is transferred in the acoustic phonons and coupled to the optical phonons, which are used to increase the intensity of the thermal radiation energy.

[0016] This application provides a composite heat dissipation device, including an electromagnetic radiation heat dissipation structure. The electromagnetic radiation heat dissipation structure includes a polarized material, which is composed of a plurality of first polarized material units and a plurality of second polarized material units. Each first polarized material unit has a first optical phonon, and each second polarized material unit has a second optical phonon. The first optical phonon and the second optical phonon have different resonant frequencies. The polarized material can interact with solar radiation, a first thermal radiation, and a second thermal radiation. The solar radiation will produce diffuse reflection on the surfaces of the first polarized material units and the second polarized material units. The first thermal radiation and the second thermal radiation will interact with the first optical phonon and the second optical phonon, respectively. The first optical phonon increases the energy intensity of the first thermal radiation, and the second optical phonon increases the energy intensity of the second thermal radiation.

[0017] Preferably, the first polarization material unit and the second polarization material unit are subwavelength structures.

[0018] Preferably, the subwavelength structures are stacked in an interleaved manner to form a self-supporting structure.

[0019] Preferably, the subwavelength structures are stacked in an alternating manner to form a porous structure containing multiple pores, through which solar radiation directly interacts with the first polarization material units and the second polarization material units.

[0020] This application provides a method for preparing a composite heat dissipation device, which involves providing a polarized material, uniformly grinding the polarized material units, and then firing them at a temperature lower than the melting point of the polarized material units to form a self-supporting structure.

[0021] This application provides a method for modulating the blackbody radiation spectrum band using a composite heat dissipation device. It provides polarized material units with optical phonons of different resonance frequencies located in the blackbody radiation spectrum band. These polarized materials can interact with thermal radiation located in the blackbody radiation spectrum band. The solar radiation will produce diffuse reflection on the surfaces of the first polarized material unit and the second polarized material unit. These polarized material units with optical phonons of different resonance frequencies will respectively increase the intensity of the thermal radiation energy.

[0022] The composite heat dissipation device, its preparation method, and its application disclosed in this application have high reflectivity to solar radiation energy, high emissivity to thermal radiation, and low thermal insulation coefficient.

[0023] The other effects and embodiments of this application are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a cross-sectional schematic diagram of a composite heat dissipation device according to an embodiment of this application;

[0026] Figure 2 This is a schematic diagram of a polarization material unit according to an embodiment of this application;

[0027] Figure 3 This is a schematic diagram of a composite heat dissipation device according to another embodiment of this application;

[0028] Figure 4 This is a schematic diagram of a first polarization material unit and a second polarization material unit according to an embodiment of this application;

[0029] Figure 5 The graph shows a comparison of the radiative power of boron nitride and silicon dioxide at different temperatures.

[0030] Figure 6 The graph shows a comparison of the absorption rates of boron nitride, silicon dioxide, and their mixtures at different wavelengths.

[0031] Figure 7 The graph shows a comparison of the radiative power of silicon nitride and calcium sulfate at different temperatures;

[0032] Figure 8 The graph shows a comparison of the absorption rates of silicon nitride, calcium sulfate, and their mixtures at different wavelengths.

[0033] Figure 9 The diagram shown is a cross-sectional view of a composite heat dissipation device according to another embodiment of this application.

[0034] Symbol Explanation

[0035] 1, 2, 3 Composite heat dissipation device

[0036] 11, 21 Electromagnetic radiation heat dissipation structure

[0037] 111 and 211 polarization materials

[0038] 112 Polarized Material Unit

[0039] 212 First Polarization Material Unit

[0040] 213 Second Polarization Material Unit

[0041] 1121 Optical Phonon

[0042] 2121 First Optical Phonon

[0043] 2131 Second Optical Phonon

[0044] 1123 Acoustic phonons

[0045] 2123 First acoustic phonon

[0046] 2133 Second acoustic phonon

[0047] 14, 24 Main heat source

[0048] 13, 23 Thermal conduction interface

[0049] 15. Thermally conductive materials

[0050] λ solar Solar radiation

[0051] λ IR thermal radiation

[0052] λ IR1 First thermal radiation

[0053] λ IR2 Second thermal radiation

[0054] P radRadiated power Detailed Implementation

[0055] To more clearly illustrate the technical solutions of this application, detailed descriptions will be provided below through various embodiments and accompanying drawings. However, it should be understood that this is not intended to limit this application to the specific embodiments described. On the contrary, modifications, equivalents, and substitutions of the various embodiments, as long as they conform to the spirit of this application, fall within the scope of the claims of this application. Furthermore, the terminology used in this application is merely exemplary and not restrictive. For example, the terms "first" and "second" used in this application are used to distinguish different objects and are not intended to limit a specific order.

[0056] This application relates to electromagnetic radiation of different wavelengths. "Solar radiation" refers to any electromagnetic radiation whose wavelength falls within the "solar radiation spectrum band," which primarily refers to wavelengths from approximately 0.3 μm to 4 μm. "Thermal radiation" refers to any electromagnetic radiation whose wavelength falls within the "blackbody radiation spectrum band," which primarily refers to wavelengths from approximately 4 μm to 25 μm. "Atmospheric transparency window band" primarily refers to wavelengths from approximately 8 μm to 13 μm. However, it should be understood that the above representations of wavelengths are merely exemplary and not restrictive. Distinguishing between different radiation wavelengths is currently used to explain the principles and effects of the technical features of this application, and its purpose is not to strictly limit this application to the specific wavelengths described.

[0057] The term "diffuse reflectance" used in this application to refer to materials or structures is a fraction of any incident electromagnetic radiation diffusely reflected from a surface. A perfect reflector is defined as having a diffuse reflectance of 100%. High diffuse reflectance, as used in this application, means that the material or structure has a diffuse reflectance greater than about 60% within a specified range; a better diffuse reflectance can reach 80% or more; and an optimal diffuse reflectance can reach 95% or more.

[0058] In this application, the term "emissivity" as used with respect to materials or structures refers to the effectiveness of emitting electromagnetic radiation energy. A perfect blackbody emitter is defined as having 100% emissivity. High emissivity, as used in this application, means that the material or structure has an emissivity greater than approximately 70% within a specified range; a better emissivity can reach over 80%; and an optimal emissivity can reach over 95%.

[0059] In this application, the term "transmittance" as used with respect to materials or structures refers to the ratio of electromagnetic waves that pass through the material or structure within a specified wavelength range. A perfectly transmissive material or structure is defined as having 100% transmittance. High transmittance, as used in this application, means that the material or structure has a transmittance greater than approximately 60% within a specified range; preferred transmittance in this application can reach 80% or more; and optimal transmittance can reach 95% or more.

[0060] In this application, the term "subwavelength structure" as used with respect to materials or structures refers to a material or structure containing particles of any shape whose size in at least one direction is smaller than the wavelength of the electromagnetic radiation being compared. Examples include particles of any shape whose size in at least one direction is close to or smaller than the wavelength of the maximum blackbody radiation intensity of the material, or structures composed of fibers of any shape whose diameter is smaller than the wavelength of the maximum blackbody radiation intensity of the material. The wavelength of the maximum blackbody radiation intensity of the material can be calculated using Wien's displacement law with respect to the material temperature.

[0061] The term "polarizing material" in this application refers to materials with a high bandgap that absorb very little radiation in the solar radiation spectrum, such as, but not limited to, various oxides (Al2O3, ZnO, MgO, TiO2, SiO2, HfO2, ZrO2, etc.), nitrides (AlN, hBN, cBN, Si3N4, GaN, etc.), SiC, metal fluorides (CaF2, MgF2, BaF2), and carbonates (CaCO3, CaMg(CO3)2, etc. containing CO32-). 2- Compounds), sulfates (such as BaSO4, CaSO4, etc. containing SO42-), and sulfates (such as BaSO4, CaSO4, etc.). 2- Compounds), phosphates (containing PO4) 3- Any one of the compounds, etc.

[0062] In this application, "optical phonons" refer to the collective oscillations of atoms in a crystal, specifically the quantization of excitation modes. If two or more types of atoms in a crystal lattice possess different charge distributions, the dipoles generated between these atoms interact with the incident electromagnetic wave, altering the relative positions of the atoms within the lattice. The resulting phonon modes are called optical phonons. Optical phonons occurring in the blackbody radiation spectrum of a material significantly enhance the emissivity of the material's electromagnetic radiation energy. Acoustic phonons refer to the overall translational vibrations of the crystal lattice, where the relative positions of the atoms within remain unchanged. For polarized materials with a crystalline structure, acoustic phonon modes facilitate the propagation of heat from the interior of the polarized material to the surface, thereby increasing the intensity of the material's electromagnetic radiation energy.

[0063] Please refer to Figure 1 and Figure 2 , Figure 1 This is a cross-sectional schematic diagram of a composite heat dissipation device 1 according to an embodiment of this application. Figure 2 This is a schematic diagram of a polarized material unit 112 according to an embodiment of this application. The composite heat dissipation device 1 includes an electromagnetic radiation heat dissipation structure 11, which can be respectively connected to a solar radiation λ. solar and thermal radiation λ IRDue to the interaction, the electromagnetic radiation heat dissipation structure 11 exhibits different optical properties in different electromagnetic radiation bands. The composite heat dissipation device 1 has high diffuse reflectivity in the solar radiation spectrum and high emissivity in the blackbody radiation spectrum. The electromagnetic radiation heat dissipation structure 11 includes a polarization material 111, which is composed of multiple polarization material units 112, wherein the surface of the polarization material unit 112 interacts with solar radiation λ. solar The interaction produces diffuse reflection. The polarized material unit 112 possesses an optical phonon 1121. The optical phonon 1121 and thermal radiation λ... IR The interaction gain of this thermal radiation λ IR Energy intensity.

[0064] In this embodiment, the polarizing material 111 is a porous structure composed of multiple polarizing material units 112 stacked in an alternating manner. The pores or voids formed in the porous structure allow solar radiation λ. solar Solar radiation λ passes through it solar Scattering occurs on the surface of polarized material unit 112. Solar radiation λ solar Entering from one side of the composite heat dissipation device 1, the solar radiation comes into contact with the surface of the polarized material unit 112 and is scattered on the surface of the polarized material unit 112. Since the scattering occurs in different directions, the scattered solar radiation λ solar It can then generate multiple scatterings with the surface of multiple polarization material units 112. The porous structure of the polarization material 111 in this application can achieve the effect of scattering incident solar radiation λ. solar The effect of producing high diffuse reflectance. Understandably, a porous structure composed of multiple polarized material units 112 stacked in an alternating manner, wherein the alternating stacking of polarized material units 112 can be regular or irregular, as long as it can form a porous structure with pores or holes and produce high diffuse reflectance, is within the scope of the spirit of this application.

[0065] In this embodiment, the pores in the pore structure can absorb incident solar radiation λ. solar In addition to generating high diffuse reflectance, the air within the pores can also modulate the overall equivalent optical constant of the polarization material 111. A slight increase in the porosity of the pore structure helps to dilute the overall equivalent optical constant of the polarization material 111. By reducing the particle density adjustment and porosity of the staggered stack, the thermal radiation λ is enhanced. IR The emissivity. It is understood that, in other embodiments, to achieve the above objective, the pores of the porous structure may also be filled with a substance with a refractive index lower than that of the polarization material unit 112, so as to achieve the purpose of controlling the overall equivalent optical constant of the polarization material 11.

[0066] The polarization material unit 112 of this application has a subwavelength structure. The subwavelength structure can be an arbitrary-shaped particle with a scale in at least one direction close to or smaller than the wavelength of the comparative electromagnetic radiation, or an arbitrary-shaped fiber structure with a diameter close to or smaller than the wavelength of the comparative electromagnetic radiation. If the wavelength of the comparative electromagnetic radiation is the wavelength of the maximum blackbody radiation intensity of the material, the subwavelength structure can be, for example, but not limited to, nanometer-sized particles with diameters distributed between 50 nm and 8000 nm, more preferably between 100 nm and 2000 nm. It is understood that in other embodiments, the polarization material unit 112 is a fibrous structure with a diameter of nanometers, or multiple nanometer-sized particles attached to a fibrous structure. This application does not require all polarization material units 112 to be exactly the same size; as long as the polarization material 111 includes a certain number of polarization material units 112 with subwavelength structural characteristics, it falls within the scope of this application.

[0067] Figure 2 The diagram shows polarized material unit 112 and solar radiation λ. solar and thermal radiation λ IR A schematic diagram of the interaction. Solar radiation λ solar After incident on the surface of the polarization material unit 112, it scatters in all directions. The polarization material unit 112 of this application is a high bandgap material, which absorbs very little solar radiation in the solar radiation spectrum band, resulting in high diffuse reflectivity. The polarization material unit 112 with a sublongal structure described in this application has an optical phonon 1121. The optical phonon 1121 refers to the phenomenon where, when the atoms constituting the material lattice vibrate, their relative positions change, and the dipoles generated between different atoms couple and resonate with electromagnetic waves of a specific frequency. This helps to extract photons containing that energy range from the resonant wavelength range. The phonon mode at this time is called the optical phonon 1121, and the optical phonon 1121 can enhance the emissivity of electromagnetic waves. In this embodiment, when the optical phonon 1121 and the thermal radiation λ of a specific frequency... IR The interaction produces resonance, and the optical phonon 1121 can amplify the thermal radiation λ at that specific frequency. IR The emission energy intensity. Compared to polymers, the polarization material unit 112 of this application contains a higher energy state density of optical phonons 1121, which is more effective for thermal radiation at a specific frequency λ. IR The emission energy intensity of the material will be greater than that of the polymer.

[0068] Please refer to the following: Figure 2The polarization material unit 112 of this application also possesses acoustic phonons 1123. Acoustic phonons 1123 refer to the overall translational vibration of the material's crystal lattice, where the relative positions of the atoms within remain unchanged. Acoustic phonons 1123 can interact with thermal energy, meaning that heat transfer can also occur efficiently between different polarization material units 112. The acoustic phonons 1123 of the polarization material unit 112 with its sub-long structure in this application enhance heat transfer efficiency, reducing the overall thermal resistance of the polarization material 111. The heat transferred to the polarization material unit 112 can then be further amplified by optical phonons 1121, radiating thermal radiation λ in the resonant wavelength range. IR Extracting emitted thermal radiation with a specific frequency gain λ IR The intensity of the emitted energy.

[0069] Please refer to this again. Figure 1 This diagram illustrates a composite heat dissipation device 1 mounted on a heat source body 14. A heat conduction interface 13 is located between the electromagnetic radiation heat dissipation structure 11 and the heat source body 14. The heat energy of the heat source body 14 can be transferred to the electromagnetic radiation heat dissipation structure 11 via the heat conduction interface 13. Specifically, some polarized material units 112 of the polarized material 111 are in direct contact with the heat conduction interface 13, and heat energy is directly transferred to the polarized material unit 112 through the heat conduction interface 13. The heat energy received by the polarized material unit 112 can be further transferred to other polarized material units 112 by acoustic phonons 1123. Due to the heat transfer by the acoustic phonons 1123, the overall thermal resistance of the polarized material 111 is minimized, and the temperature difference between the two surfaces of the polarized material 111 is reduced. The polarized material unit 112 emits thermal radiation λ through optical phonons 1121. IR The method of extracting and emitting thermal radiation at a specific frequency λ is used to gain a specific frequency. IR Energy intensity. The polarization material 111 of this application reduces the overall thermal resistance through the heat transfer of acoustic phonons 1123 and increases thermal radiation λ through optical phonons 1121. IR The increased emission intensity enhances the radiative cooling power of the polarized material 111, thus aiding in the heat dissipation of the heat source body 14. Therefore, the composite heat dissipation device 1 of this application can achieve effective heat transfer and radiative cooling.

[0070] Please refer to Figure 3 This is a schematic diagram of a composite heat dissipation device 2 according to another embodiment of this application. The composite heat dissipation device 2 includes an electromagnetic radiation heat dissipation structure 21. The electromagnetic radiation heat dissipation structure 21 includes a polarization material 211, which includes a plurality of first polarization material units 212 and a plurality of second polarization material units 213. The electromagnetic radiation heat dissipation structure 21 can be respectively connected to a solar radiation λ. solar First thermal radiation λ IR1 and a second thermal radiation λ IR2Interaction, in which the first thermal radiation λ IR1 Second thermal radiation λ IR2 Electromagnetic radiation heat dissipation structure 21 has different wavelengths and is resistant to solar radiation λ. solar With high diffuse reflectivity, the electromagnetic radiation heat dissipation structure 21 supports the first thermal radiation λ. IR1 Second thermal radiation λ IR2 It has a high emissivity.

[0071] The parts of this embodiment that are the same as those in the previous embodiments will only be briefly described, while the differences will be described in detail. In this embodiment, the polarization material 211 is a porous and self-supporting structure, which is composed of multiple first polarization material units 212 and multiple second polarization material units 213 stacked alternately. Solar radiation λ solar The electromagnetic radiation enters from one side of the heat dissipation structure 21 and is scattered on the surface of the first polarized material unit 212 or the second polarized material unit 213, resulting in solar radiation λ. solar It can interact with the surfaces of multiple first polarization material units 212 and / or second polarization material units 213 to produce multiple scattering, thereby enabling the polarization material 211 to scatter solar radiation λ. solar It has high diffuse reflectance. Similarly, it can be understood that the porous structure composed of multiple first polarized material units 212 and second polarized material units 213 stacked alternately, the first polarized material units 212 and second polarized material units 213 can be arranged in a regular or irregular alternating stack, as long as a porous structure with pores can be formed to produce high diffuse reflectance, it is within the scope of the spirit of this application.

[0072] Figure 4 The first polarization material unit 212 and the second polarization material unit 213 in the above embodiments are respectively coupled with solar radiation λ. solar First thermal radiation λ IR1 Second thermal radiation λ IR2 A schematic diagram of the interaction. The first polarization material unit 212 has a first optical phonon 2121, and the second polarization material unit 213 has a second optical phonon 2131. The first optical phonon 2121 and the second optical phonon 2131 can couple and resonate with electromagnetic waves of different frequencies. In this application, the first optical phonon 2121 and the second optical phonon 2131 respectively interact with the first thermal radiation λ. IR1 Second thermal radiation λ IR2 The interaction produces resonance, and the first optical phonon 2121 and the second optical phonon 2131 can amplify the first thermal radiation λ with different frequencies. IR1 Second thermal radiation λ IR2 The intensity of the emitted energy.

[0073] The first polarization material unit 212 further includes a first acoustic phonon 2123, and the second polarization material unit 213 further includes a second acoustic phonon 2133. The first acoustic phonon 2123 and the second acoustic phonon 2133 can interact with thermal energy. In this embodiment, thermal energy can be effectively transferred between the first acoustic phonon 2123 of the first polarization material unit 212 with a sub-long structure and the second acoustic phonon 2133 of the second polarization material unit 213. When energy is effectively transferred to the first polarization material unit 212 and the second polarization material unit 213, the first optical phonon 2121 and the second optical phonon 2131 in the first polarization material unit 212 and the second polarization material unit 213 can transmit the first thermal radiation λ in the resonant band range. IR1 Second thermal radiation λ IR2 The extracted emission, with a gain of a specific frequency, produces a first thermal radiation λ. IR1 Second thermal radiation λ IR2 The intensity of the emitted energy.

[0074] Please refer to this again. Figure 3 This is a schematic diagram of a composite heat dissipation device 2 assembled on a heat source body 24. A heat conduction interface 23 is located between the electromagnetic radiation heat dissipation structure 21 and the heat source body 24. The heat energy of the heat source body 24 can be transferred to the electromagnetic radiation heat dissipation structure 21 via the heat conduction interface 23. Specifically, some of the first polarized material units 212 and some of the second polarized material units 213 of the polarized material 211 are in direct contact with the heat conduction interface 23, and the heat energy is transferred to the first polarized material units 212 and the second polarized material units 213 through the heat conduction interface 23. The heat energy received by the first polarized material units 212 and the second polarized material units 213 can be transferred to other first polarized material units 212 and second polarized material units 213 by the first acoustic phonons 2123 and the second acoustic phonons 2133. Because the first acoustic phonons 2123 and the second acoustic phonons 2133 can effectively increase the heat transfer efficiency, the overall thermal resistance of the polarized material 211 will be minimized, and the temperature difference between the two surfaces of the polarized material 211 will be reduced. The first polarization material unit 212 and the second polarization material unit 213 are then amplified by the first optical phonon 2121 and the second optical phonon 2131 to a specific frequency of first thermal radiation λ. IR1 Second thermal radiation λ IR2 The emitted energy intensity. The polarization material 211 of this application reduces the overall thermal resistance through heat transfer from the first acoustic phonon 2123 and the second acoustic phonon 2133, and increases the first thermal radiation λ through the first optical phonon 2121 and the second optical phonon 2131. IR1 Second thermal radiation λ IR2 The emission intensity increases the radiation cooling power of the polarization material 211, effectively helping the heat source body 23 dissipate heat.

[0075] The composite heat dissipation device 2 of this application includes multiple first polarization material units 212 and multiple second polarization material units 213. Its advantage lies in the ability to select polarization materials with specific optical phonon resonance bands, which helps in the controllability of the spectrum, and it is still possible to create a wide-band high-emissivity cooling body by combining multiple polarization materials with different optical phonon resonance bands. Compared to the various bond vibration modes generated by functional groups composed of elements such as carbon, hydrogen, and oxygen in existing polymer technologies, the characteristic peak wavelengths of these functional groups are often very close, causing them to overlap in the infrared band to form absorption peaks with a large half-width, resulting in a wide-band radiator that is difficult to modulate in the high-emissivity band.

[0076] According to one embodiment of this application, the combination of the first polarization material unit 212 and the second polarization material unit 213 of the composite heat dissipation device 2 is as follows, and the combination of materials that can be used, but is not limited to, is as follows: the first polarization material unit 212 is boron nitride, and the second polarization material unit 213 is silicon dioxide. Figure 5 The figure shows the radiative power P of a broadband high-emissivity cooling body fabricated from boron nitride and silicon dioxide at different temperatures (330 K, 330 K, and 373 K) in a 1:1 mixing ratio with a porosity of 0.3. rad A comparison chart. Figure 6 The diagram shows a comparison of the absorbance of boron nitride, silicon dioxide, and their mixtures at wavelengths of 4-25 μm. Due to the inherent properties of the materials, boron nitride exhibits absorbance troughs at 6-8 μm and 12-13 μm, while silicon dioxide shows troughs at 8-10 μm and beyond 20 μm. However, if the two are uniformly mixed at a volume ratio of 1:1, and considering the porosity present in the self-supporting structure, calculations based on the equivalent medium theory show that the mixed polarized material can significantly mitigate the troughs in the absorption spectra of the first polarized material unit 212 and the second polarized material unit 213, respectively, and this is clearly reflected in the material's radiation capacity. Considering that this application can assist in the dissipation of heat from a self-generated heat source, the radiation power of the material at high temperatures can be calculated using the absorption spectra. The radiation power of boron nitride and silicon dioxide at 373 K is 860.14 W / m², respectively. 2 and 830.59W / m 2 However, if the two are uniformly mixed in a 1:1 volume ratio to form a broadband high-radiation cooling body, the radiation power will significantly increase to 917.93 W / m². 2 .

[0077] In another embodiment of this application, the combination of the first polarization material unit 212 and the second polarization material unit 213 of the composite heat dissipation device 2 is as follows, and the combination of materials that can be used, but is not limited to, is as follows: the first polarization material unit 212 is silicon nitride, and the second polarization material unit 213 is calcium sulfate. Figure 7The figure shows the radiative power P of a broadband high-emissivity cooling body fabricated from silicon nitride and calcium sulfate at different temperatures (330 K, 330 K, and 373 K) in a 1:1 mixing ratio and with a porosity of 0.3. rad A comparison chart. Figure 8 The diagram shows a comparison of the absorbance of silicon nitride, calcium sulfate, and their mixtures at wavelengths of 4–25 μm. Due to the inherent properties of the materials, silicon nitride exhibits absorbance troughs at 6–7 μm and 10–14 μm, while calcium sulfate shows troughs at 8–9 μm and beyond 16–18 μm. Assuming a 1:1 volume ratio of homogeneous mixing and considering porosity in the self-supporting structure, the radiant power of the materials at 373 K is calculated using absorption spectra. The radiant power of silicon nitride and calcium sulfate at 373 K is 758.00 W / m². 2 and 852.22W / m 2 If the two are uniformly mixed in a 1:1 volume ratio to form a broadband high-radiation cooling body, the radiation power will significantly increase to 902.36 W / m². 2 .

[0078] Figure 9 The diagram shown is a cross-sectional view of a composite heat dissipation device 3 according to another embodiment of this application, and Figure 1 The difference lies in the inclusion of a thermally conductive material 15 located above the heat source body 14. The thermally conductive material 15 can fill the gaps between the polarization material 111 and the heat source body 14, as well as between some of the polarization material units 112, improving heat transfer efficiency and reducing interfacial thermal resistance. The thermally conductive material 15 has a high thermal conductivity coefficient, and its viscosity, flowability, coating extensibility, and other properties can be adjusted according to the application. Types of thermally conductive materials 15 include, but are not limited to, potting compounds, silicone paste, silicone grease, thermal putty, silicone sheets, thermally conductive silicone cloth, thermal oil, thermally conductive coatings, plastics, thermally conductive films, insulating materials, interface materials, double-sided tape, thermally conductive substrates, phase change materials, heat dissipation films, mica sheets, gaskets, tapes, liquid metal thermally conductive sheets, etc. The thickness of the thermally conductive material 15 is less than the thickness of the polarization material 111, ensuring that the outer surface of the polarization material 111 has sufficient thermal radiation emission area. Understandably, in other implementations, this material with a high thermal conductivity can also be used to fill the gaps, thereby improving heat transfer efficiency and reducing interfacial thermal resistance.

[0079] In this embodiment, the polarizing material is a self-supporting structure composed of multiple polarizing material units stacked in an alternating manner. It is prepared by firing at a temperature not exceeding the melting point of each polarizing material unit. The polarizing material prepared in this application does not require a supporting substrate, allowing it to directly contact the object to be cooled, thus achieving higher cooling efficiency. The preparation method of the polarizing material in this application may include, but is not limited to, the following steps: providing one or more polarizing materials with subwavelength granular form and uniformly grinding them, then selectively applying pressure to form the material, and firing the formed material at high temperature for a period of time to increase stability. For example, but not limited to: providing zinc oxide (median diameter 559 nm), silicon dioxide (median diameter 542 nm), and aluminum oxide (median diameter 776 nm) particles, uniformly mixing them in a mortar, placing them in a metal mold with a diameter of one inch (2.54 cm), and pressing the powder in the mold at a pressure of 80 kg / cm³ for 2 minutes. After pressing and forming, demolding is performed, and the formed ingot is bisque-fired at 700–800°C for 1–2 hours to increase stability. The thickness of the ingot ranges from several hundred micrometers to several millimeters, with the optimal thickness likely falling between 100-1000 μm. The polarized material of this application possesses a high melting point, allowing the material produced through this process to withstand high temperatures for extended periods while maintaining a stable supply of radiative cooling power. It is understood that the dimensions listed above are merely illustrative and not intended to be strictly limited to the given figures.

[0080] The thermal resistance characteristics of the polarization material in this application will be expressed in terms of the material's "thermal insulation coefficient" (SI unit: m). 2 *K / W) quantitative. The physical meaning of the thermal insulation coefficient is the temperature difference between the two ends of an object when a unit of heat passes through a unit area of ​​material per unit time. It can be obtained by dividing the material thickness by the material's thermal conductivity (SI unit: W / m*K). Generally, the thermal insulation coefficient of insulating materials is greater than 0.1m. 2 *K / W; The thermal insulation coefficient of commonly used metallic materials is between 1*10⁻⁶. -4 ~1*10 -5 m 2 The polarization material in this application is selected from a complex number of polarization material units stacked alternately to form a self-supporting structure. Its thermal conductivity ranges from approximately 0.5 to 10.0 W / m*K, and its thermal insulation coefficient can be less than 5*10. -3 m 2 *K / W.

[0081] The composite heat dissipation device of this application includes a polarized material, which is composed of multiple polarized material units with a sub-long structure. The polarized material units of this application possess both optical phonons and acoustic phonons. The advantage of this application in radiative cooling applications lies in controlling the emissivity band of a single or composite material by selecting optical phonons that fall within the blackbody radiation band, thereby achieving selective narrow-band or wide-band radiators suitable for cooling needs in different situations. Furthermore, the polarized material can provide higher mechanical properties, ultraviolet light stability, and heat resistance, thus overcoming the bottlenecks in the application of polymer radiative cooling materials. The difference between the polarized material of this application and existing polymer materials is that polymers typically absorb ultraviolet light (290-350nm) or near-infrared light (1500-2500nm). Besides failing to effectively reduce solar absorption, polymers also have poor weather resistance; prolonged outdoor use may lead to yellowing or deterioration of mechanical properties due to ultraviolet exposure. Additionally, polymers are not heat-resistant (<300 degrees Celsius) and lack flame-retardant properties, making them unsuitable for building applications. The polarization material of this application has the technical advantages of being able to be mass-produced over a large area, having mature technology, being easy to shape, being lightweight, and being inexpensive.

[0082] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of this application, and are not intended to limit the implementation methods of the technology of this application in any way. Any person skilled in the art may make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in this application, but these should still be regarded as the technology or embodiments that are substantially the same as those of this application.

Claims

1. A composite heat dissipating device, characterized by comprising: The electromagnetic radiation heat dissipation structure comprises a polarized material, the polarized material is composed of a plurality of polarized material units, wherein the polarized material can interact with a solar radiation, the solar radiation interacts with the surface of the polarized material units to produce diffuse reflection, the polarized material units have an optical phonon, the optical phonon can interact with a thermal radiation, and the optical phonon increases the energy intensity of the thermal radiation.

2. The composite heat sink of claim 1, wherein The polarized material units are sub-wavelength structures.

3. The composite heat sink of claim 2, wherein The polarized material units are sub-wavelength structures. The sub-wavelength structures are staggered to form a self-supporting structure.

4. The composite heat sink of claim 2, wherein The sub-wavelength structures are staggered to form a porous structure, the porous structure comprises a plurality of pores, and the solar radiation passes through the pores and interacts with the surface of the polarized material units.

5. The composite heat sink of claim 2, wherein The sub-wavelength structures are nano-sized particles.

6. The composite heat sink of any one of claims 1 to 5, wherein, The polarized material units further comprise a plurality of acoustic phonons, and the plurality of acoustic phonons can transfer energy to each other.

7. The composite heat sink of claim 6, wherein A heat conduction interface is further provided between the electromagnetic radiation heat dissipation structure and a heat source body, and the heat source body provides a thermal energy to the polarized material through the heat conduction interface.

8. The composite heat sink of claim 7, wherein, The thermal energy is transferred in the acoustic phonons and coupled to the optical phonon, and the optical phonon is used to increase the energy intensity of the thermal radiation.

9. A composite heat dissipating device, characterized by comprising: The electromagnetic radiation heat dissipation structure comprises a polarized material, the polarized material is composed of a plurality of first polarized material units and a plurality of second polarized material units, the first polarized material units have a first optical phonon, the second polarized material units have a second optical phonon, the first optical phonon and the second optical phonon have different resonance frequencies, wherein the polarized material can interact with a solar radiation, a first thermal radiation and a second thermal radiation, the solar radiation produces diffuse reflection on the surface of the first polarized material units and the second polarized material units, the first thermal radiation and the second thermal radiation respectively interact with the first optical phonon and the second optical phonon, the first optical phonon increases the energy intensity of the first thermal radiation, and the second optical phonon increases the energy intensity of the second thermal radiation.

10. The composite heat sink of claim 9, wherein The first polarized material units and the second polarized material units are sub-wavelength structures.

11. The composite heat sink of claim 10, wherein The sub-wavelength structures are staggered to form a self-supporting structure.

12. The composite heat sink of claim 10, wherein The sub-wavelength structures are staggered to form a porous structure, the porous structure comprises a plurality of pores, and the solar radiation passes through the pores and directly interacts with the first polarized material units and the second polarized material units.

13. A method of making a composite heat dissipating device as claimed in any one of claims 1 to 8, characterized in that, The polarized material is provided, the polarized material units are uniformly ground, and then sintered below the melting point temperature of the polarized material units to form a self-supporting structure.

14. A method of modulating a broadband radiation spectrum using the composite heat spreader of any one of claims 9 to 12, wherein, The first polarized material units and the second polarized material units are provided in the blackbody radiation spectral band and have different resonance frequencies, and the overall absorption rate of the composite heat dissipation device in the blackbody radiation spectral band is greater than the absorption rate of the first polarized material units and the second polarized material units in the blackbody radiation spectral band.

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