Device for protecting a subject from damage

Abstract

An apparatus for protecting a subject from damage. The protection apparatus includes an outer protective enclosure comprising a thermal energy conducting element for conducting thermal energy through at least a portion of the outer protective enclosure and an internal component positioned adjacent to the outer protective enclosure, the internal component comprising a thermal energy transfer device adapted to transfer thermal energy to and / or from the thermal energy conducting element. The thermal energy conducting element comprises a graphitic-like material or a pyrolytic graphitic-like material and the thermal energy transfer device comprises a thermal energy transfer fluid.

Description

[0001] field

[0002] The present invention relates to a device for protecting a body from damage, particularly from external heat damage.

[0003] background

[0004] From circuit electronics in data centers to aerospace environments, thermal damage (such as heat) is a common problem in many different applications. Thermal management systems are designed to heat or cool affected devices to achieve smooth operation. These systems can use a variety of different cooling methods, but typically employ heat transfer methods based on fluid transfer or conduction. However, many existing thermal management systems are inefficient due to the use of materials that are difficult to dissipate heat effectively due to their insufficient thermal conductivity.

[0005] Furthermore, the most efficient thermal management systems are typically large and heavy, limiting their use in high-tech industries such as aerospace. For example, aerospace vehicles such as rockets and reentry vehicles have strict weight and size limitations. While some lightweight solutions exist in the electronics industry, these solutions have limited applicability to other industries. For instance, many cooling systems (such as heat sinks) exist in electronic devices, but these systems have limitations and, importantly, are impractical for use in outdoor or highly exposed environments. Instead, these cooling systems are designed for operation in precisely controlled environments where temperature fluctuations are within a relatively small window and where they are protected from physical damage. These cooling systems are also primarily designed to dissipate heat from the protected device, rather than protecting it from external heat generation.

[0006] Therefore, there is a need for an improved thermal management system that exhibits efficient heat transfer (e.g., heat dissipation).

[0007] Overview

[0008] A first aspect provides a device for protecting a subject from damage. The device includes an outer protective shield comprising a heat-conducting element for transferring heat energy through at least a portion of the outer protective shield; and an internal assembly adjacent to the outer protective shield comprising a heat-transfer device adapted to transfer heat energy to and / or from the heat-conducting element. The heat-conducting element comprises a graphite-like material or a pyrolytic graphite-like material (including graphite and pyrolytic graphite). The heat-transfer device includes a heat-transfer fluid adapted to transfer heat energy to and / or from the heat-conducting element.

[0009] Therefore, the implementation provides a thermal management device that can protect a subject (e.g., a device or component) from damage. This includes thermal damage (e.g., damage caused by heat or cold), but may also include physical damage, such as impact from an external object. An external protective shield is such a protective element adapted to protect internal components and / or the subject from damage, such as physical damage. It includes at least a heat-conducting element and may also include a protective layer. Thus, the heat-conducting element can transfer heat through the external protective shield (e.g., across the surface of the external protective shield or through the thickness of the external protective shield), thereby dissipating accumulated heat (e.g., hot spots). For example, this can prevent hot spots that could otherwise accumulate and damage the device and / or the subject and / or serve to transfer heat from the outer surface of the device to another part of the device.

[0010] Graphite-like or pyrolytic graphite-like materials (or graphitic or pyrolytic graphitic materials) are particularly effective at transferring heat, thus forming particularly efficient heat transfer materials. Furthermore, due to the anisotropic nature of these materials, heat transfer can be achieved in a single direction. When combined with secondary cooling mechanisms such as heat transfer devices, heat transfer can be particularly efficient. In particular, thermal energy can be transferred rapidly and efficiently between the external environment and the heat transfer device via heat conduction elements. This efficient heat transfer of these specific materials, and the transfer in a particular direction, allows for minimal loss to other parts of the device (and the body it protects), thereby reducing damage to these parts and improving the efficiency of heat transfer. In addition, these materials exhibit excellent stability, strength, wear resistance, and fatigue resistance. This makes them suitable for use in external protective layers because they are less susceptible to damage under harsh conditions, such as those experienced by aerospace vehicles.

[0011] Combined with a fluid (e.g., liquid) transfer device, this provides a highly efficient way to transfer heat to or from an area (e.g., the surface or body of an outer protective shield). Graphite-like or pyrolytic graphite-like materials provide highly efficient heat transfer over a portion of an outer protective shield, which, in combination with a fluid transfer device, further transfers thermal energy. This can be done, for example, over distances greater than that possible with graphite-like or pyrolytic graphite-like materials (considering cost and practicality).

[0012] "External" means that when assembled on or around a body, the protective cover is external relative to the heat transfer device and preferably relative to other components of the device. That is, the heat transfer device and optionally other components can be positioned inside the device. When assembled on the device, the protective cover is outside the heat transfer device (and the backing structure, if present). For example, if the device is a protective cover for a vehicle, the outer protective cover forms at least a portion of the outermost part of the device opposite the vehicle. Additional components may be disposed on the outside of the protective cover (e.g., an additional outer skin or covering layer may be present). Thus, adjacent internal components may be behind the outer protective cover.

[0013] Graphite-like materials refer to materials with a two-dimensional planar structure, comprising atoms arranged in a hexagonal (graphite-like or graphene-like) configuration. This includes six-membered rings with sp2-hybridized carbon atoms, but can include other structures, including six-membered rings with atoms other than carbon. For example, such materials can include at least one planar layer comprising hexagonal six-membered rings comprising carbon, boron, nitrogen, and combinations thereof (or substantially composed of carbon, boron, nitrogen, and combinations thereof). This can include graphene (e.g., graphene, functionalized graphene, graphene oxide), a two-dimensional allotrope of carbon, wherein a single layer of graphene comprises a single planar sheet of sp2-hybridized carbon atoms. This can also be graphite. Graphene comprises at least one atomic layer of graphene, and can be up to, for example, 10 or 15 atomic layers of graphene. Above this, graphene is referred to as graphite. In some implementations, this can be hexagonal boron nitride (also known as h-BN, α-BN, and graphitic boron nitride (g-BN)). These can be functionalized.

[0014] Pyrolytic graphite-like (or pyrolytic carbon-like) materials refer to materials having two-dimensional sheets comprising atoms arranged in a hexagonal (graphite-like or graphene-like) configuration, but with deformations that result in some covalent bonds between the sheets. This includes six-membered rings with sp2 hybridized carbon atoms, but can include other structures, including six-membered rings with atoms other than carbon. For example, such materials can include at least one planar layer comprising hexagonal six-membered rings comprising carbon, boron, nitrogen, and combinations thereof (or substantially composed of carbon, boron, nitrogen, and combinations thereof). Pyrolytic graphite has excellent thermal conductivity (compared to 400 W·m for copper). -1 .k -1 In comparison, at room temperature 1700 W·m -1 .k -1Examples of pyrolytic graphite-like materials include pyrolytic graphite. It is highly efficient for thermal diffusion in a range of heat transfer applications (heating and cooling), and is also very lightweight. Another example is pyrolytic hexagonal boron nitride. Other examples include pyrolytic graphite-boron compounds (e.g., pyrolytic graphite with <2% boron). These can be functionalized.

[0015] Therefore, in the embodiments, the graphite-like material or pyrolytic graphite-like material is selected from graphene, pyrolytic graphite, pyrolytic carbon, pyrolytic hexagonal boron nitride, or combinations thereof. In the embodiments, the graphite-like material or pyrolytic graphite-like material may be in the form of sheets, flakes, or other structures (e.g., fullerenes, nanotubes).

[0016] In implementation schemes, the heat transfer fluid includes nanofluids (i.e., heat transfer fluids comprising nanoparticle components). Nanofluids are an excellent alternative to traditional cooling fluids because the added nanomaterial component can significantly improve the fluid's thermal conductivity while having minimal impact on other properties such as the fluid's viscosity. One family of materials that has proven particularly well-suited for this field of thermal management is the 2D materials family. Nanomaterials can be broadly classified by the total number of their nanoscale dimensions: if all three dimensions of a material are nanoscale, then it will be called a 0D (zero-dimensional) material, more commonly referred to as nanoparticles. If two dimensions of a material are nanoscale, and the other dimension is much larger (much like a rope contracted to a tiny size), then it is a 1D material or 'nanotube / nanowire'. If only one dimension is nanoscale, then it will be a 2D material—similar to a large but very thin sheet.

[0017] In embodiments, the nanofluid comprises at least one of ZnO, hexagonal boron nitride, graphene, or diamond nanoparticles. These provide particularly effective nanofluids, as illustrated below. In a preferred embodiment, the nanofluid comprises hexagonal boron nitride and / or graphene nanoparticles. In a particularly preferred embodiment, the nanofluid comprises disordered hexagonal boron nitride and / or disordered graphene.

[0018] In implementations, the internal components also include a support structure. The support structure may be adapted to support the external protective shield and / or provide additional protection to the main body from damage. For example, the support structure may be a scaffold on which the external protective shield is formed. In implementations, the support structure includes an aerogel (e.g., the structure may include a layer comprising or composed of aerogel). Aerogels are a class of highly porous (typically nanoporous) solid materials with very low density and are very robust relative to their weight, making them suitable for use in composite materials. Aerogels are formed by generating a gel and subsequently drying the gel to remove the liquid component (e.g., using supercritical drying). This produces a unique structure that contributes to advantageous properties, including low density and the ability to effectively transfer and dissipate impact forces. Furthermore, they are particularly effective insulators, thus further aiding in thermal management and reducing the risk of component damage.

[0019] More specifically, the aerogel is an open-cell structure having a porosity of at least 50% (but preferably at least 95% air (e.g., 95% to 99.99%), optionally at least 99%), which is produced by forming a gel in solution and subsequently removing the liquid component of the gel using supercritical heating. As a result of the drying conditions, when the liquid component is removed, the solid portion of the gel retains its structure, thereby creating a porous bulk. The pores of the aerogel will typically have a pore size in the range of 0.1 nm to 100 nm, typically less than 20 nm. However, in embodiments, the aerogel may have a pore size in the range of 0.1 nm to 1000 nm, optionally 0.1 nm to 900 nm; 10 nm to 900 nm; 20 nm to 900 nm; 20 nm to 500 nm; or 20 nm to 100 nm. In some embodiments, the porosity and pore size distribution of the aerogel can be measured at 77 K using nitrogen adsorption and applying the Brunauer, Emmit, and Teller (BET) equations (see “Reporting Physisorption Data for Gas / Solid Systems” in Pure and Applied Chemistry, Vol. 57, p. 603, (1985)). Aerogels can be formed from a variety of materials, including silica, organic polymers (including polyimide, polystyrene, polyurethane, polyacrylate, epoxy resin), biologically present polymers (e.g., gelatin, pectin), carbon (including carbon nanotubes), some metal oxides (e.g., iron oxide or tin oxide), and some metals (e.g., copper or gold). In some embodiments, the aerogel is a cross-linked aerogel (e.g., the aerogel is formed from a cross-linked polymer such as cross-linked polyimide). Such aerogels are advantageously both flexible and robust. Aerogels provide enhanced impact absorption properties because they offer a much wider force dispersion cone than prior art composites, and therefore impact forces can be dispersed much faster and more widely. This is at least in part due to the ability of these layers to propagate impacts both within the plane of the layer and through its height. In particular, the “nano-stretched” structure of aerogels can provide them with shock-absorbing properties—nano-sized dendritic atomic structures propagate impact forces along these branches, thereby rapidly dissipating the impact.

[0020] In an embodiment, the support structure further includes a composite material comprising a first layer and a second layer, the first layer comprising an aerogel, and the second layer comprising a protective layer. The protective layer may have a higher tensile strength than any other material in the internal components. This layer may have a tensile strength of at least 200 MPa, at least 500 MPa, or at least 1000 MPa; for example, 250 MPa to 5000 MPa; or 1000 MPa to 5000 MPa. This can be measured, for example, by ASTM D7269 for fiber-based layers and ASTM D3039 for polymer-based materials. The protective layer may be arranged to absorb part of any impact on the outer protective layer and to provide structure and support for the device. Together with the aerogel layer acting as an impact-absorbing layer, this can reduce the forces transmitted through the structure. In an embodiment, the protective layer comprises a metal, alloy, polymer, and / or carbon-containing material, preferably a polymer and / or carbon-containing material. For example, the protective layer may comprise a high-tensile polymer and / or a carbon fiber-containing material. In another embodiment, the protective layer comprises a high-tensile material selected from the group consisting of aramid (aromatic polyamide) fibers, aromatic polyamide fibers, boron fibers, ultra-high molecular weight polyethylene (e.g., fibers or sheets), poly(p-phenylene-2,6-benzobisoxazole) (PBO), poly{2,6-diimidazo[4,5-b:4′,5′-e]–pyridyl-1,4(2,5-dihydroxy)phenylene} (PIPD), or combinations thereof. For example, in one embodiment, the protective layer is a UHMWPE textile with a weight between 100 gsm and 200 gsm, optionally between 140 gsm and 180 gsm. When fibers are used, the layer may include an adhesive, such as an epoxy resin. In embodiments, the protective layer has a thickness of 50 μm to 500 μm, optionally from 125 μm to 250 μm. In embodiments with multiple protective layers, each protective layer has a thickness of 50 μm to 500 μm, optionally 125 μm to 250 μm.

[0021] In this implementation, the outer protective cover includes a housing, and the heat-conducting elements are encapsulated within the housing. The housing may contain aluminum, copper, kapton, carbon fiber, or a copper-molybdenum alloy.

[0022] In the implementation, the device also includes a thermoelectric generator adapted to receive thermal energy from a heat-conducting element and convert it into electrical energy. A thermoelectric generator, or Seebeck generator, is a solid-state device that converts heat flux into electrical energy through a phenomenon known as the "Seebeck effect." This effect describes how a temperature gradient in a conductive material leads to heat flow; this results in the diffusion of charge carriers. The flow of charge carriers between hot and cold regions then generates a voltage difference. This is particularly advantageous because it allows the use of heat transferred through the device, which typically releases excess energy into the environment through a radiator / vent for utilization. For example, in aerospace vehicles (such as reentry vehicles or high-speed vehicles), heat can be used to power other components and thus reduce reliance on batteries, which are typically bulky and space-consuming / add to the profile.

[0023] The second aspect provides a device for protecting a subject from damage. The device includes an outer protective shield comprising a heat-conducting element for transferring heat through at least a portion of the outer protective shield; and an internal assembly adjacent to the outer protective shield. The internal assembly includes a heat-conducting device adapted to transfer heat to and / or from the heat-conducting element; and a support structure. The heat-conducting element comprises a graphite-like material or a pyrolytic graphite-like material (including graphite and pyrolytic graphite), and the support structure comprises an aerogel.

[0024] Therefore, the implementation provides an effective thermal control device, such as a device suitable for protecting the body from thermal damage. As described above, the materials described offer robust and effective protection, while graphite-like or pyrolytic graphite-like materials offer excellent heat transfer. This can be achieved using solid heat transfer devices (e.g., additional thermally conductive elements, such as thermal through-holes or thermal tracks).

[0025] In the implementation plan, the features of the second aspect are as described with respect to the first aspect. In other words, the specific implementation plan mentioned with respect to the first aspect also applies to the second implementation plan.

[0026] For example, in the implementation scheme, the graphite sample material or pyrolytic graphite sample material is selected from graphene, pyrolytic graphite, pyrolytic carbon, pyrolytic hexagonal boron nitride or a combination thereof.

[0027] In one embodiment, the heat transfer device includes a heat transfer fluid. As in the first aspect, in another embodiment, the heat transfer fluid includes a nanofluid. The nanofluid may include at least one of ZnO, hexagonal boron nitride, graphene, or diamond nanoparticles.

[0028] In one embodiment, the device further includes a thermoelectric generator adapted to receive thermal energy from a heat-conducting element and convert the thermal energy into electrical energy. Brief description of the attached diagram

[0030] Specific implementation schemes will now be discussed in detail with reference to the accompanying drawings, in which:

[0031] Figure 1 The graphite-like structure of a planar sheet of h-BN is shown;

[0032] Figure 2 The structure of the disordered h-BN is shown; and

[0033] Figure 3 A cross-sectional view according to an embodiment of the present invention is shown.

[0034] Detailed Explanation

[0035] As described above, a first aspect provides a device for protecting a subject from damage. The device includes an outer protective cover comprising a heat-conducting element for transferring heat through at least a portion of the cover, and an internal assembly positioned adjacent to (or behind) the outer protective cover, the internal assembly including a heat transfer device adapted to transfer heat to and / or from the heat-conducting element. The heat-conducting element comprises a graphite-like material or a pyrolytic graphite-like material, and the heat transfer device comprises a heat transfer fluid. A second aspect provides a device for protecting a subject from damage, comprising: an outer protective cover comprising a heat-conducting element for transferring heat through at least a portion of the cover; and an internal assembly adjacent to the outer protective cover (e.g., positioned behind the outer protective cover). The internal assembly includes a heat transfer device adapted to transfer heat to and / or from the heat-conducting element; and a support structure. The heat-conducting element comprises a graphite-like material or a pyrolytic graphite-like material; and the supporting structure therein comprises aerogel.

[0036] This device advantageously provides both protective and thermal management functions. It can protect a body (e.g., a device or component) from damage. For example, the device can serve as an outer shell or skin for a body, such as an aerospace vehicle. Thermal damage (e.g., damage due to heat or cold) can be transmitted across the surface of the enclosure or through its depth, or both. The enclosure also protects the body and internal components from physical damage, such as impacts from external objects.

[0037] Heat transfer element

[0038] An important aspect of this invention, in either the first or second aspect, is the use of graphite-like materials or pyrolytic graphite-like materials. These possess high thermal conductivity (graphene 600 W·m). -1 .k -1 ; Pyrolytic boron nitride 42W.m-1 .k -1 ; Pyrolytic graphite at RT 1700W.m -1 .k -1 At 150K 2800W.m -1 .k -1 These materials, while possessing certain advantages, also offer favorable properties. For example, some of their properties are anisotropic in the sense that they are directional. For instance, perpendicular to their 2D plane, they tend to be insulating (electrically and thermally), but in that plane they exhibit high conductivity (electrically and thermally). The insulating function can be used to re-radiate heat back into the atmosphere or to protect internal components from damage. The high conductivity can be used to rapidly transfer heat across the cover and through the device.

[0039] In one embodiment, the heat-conducting element comprises pyrolytic graphite. This is a man-made product, typically formed by pyrolyzing hydrocarbon gases to near their decomposition temperature, allowing graphite to crystallize (see Ratner, Buddy D. (2004)). Pyrolytic carbon. In Biomaterials science: an introduction to materials in medicine. Academic Press. pp. 171-180, which is incorporated herein by reference. The crystalline structure of pyrolytic carbon has a distorted lattice structure with randomly associated carbon atoms, unlike, for example, graphite. The morphology of pyrolytic graphite means that it is unaffected by extreme acceleration / deceleration, making it particularly advantageous for vehicles, especially in aerospace applications.

[0040] As described above, in the embodiments, the graphite-like material may include graphite, graphene, and hexagonal boron nitride. Other structures with varying amounts of carbon, boron, nitrogen, and combinations thereof are also embodiments (e.g., see "Syntheses and Structures of New Graphite-like Materials of Composition BCN(H) and BC3N(H)", Kawaguchi, Kawashima, and Nakajima, Chem. Mater. 1996, 8, 6, 1197–1201). The pyrolytic graphite-like material may be selected from pyrolytic graphite, pyrolytic carbon, pyrolytic hexagonal boron nitride, or combinations thereof. In the embodiments, the graphite-like material or pyrolytic graphite-like material may be in the form of sheets, flakes, or other structures (e.g., fullerenes, nanotubes).

[0041] The heat-conducting element can be a component formed purely of graphite-like material or pyrolytic graphite-like material, or it can be in the form of a composite material or a composition containing graphite-like material or pyrolytic graphite-like material. Alternatively, it can be in the form of annealed graphite-like material or pyrolytic graphite-like material. For example, annealed pyrolytic graphite (APG).

[0042] In some embodiments, graphite-like materials or pyrolytic graphite-like materials may be functionalized and / or doped. This can further affect the properties of the material and improve, for example, incorporation into other materials or matrices. Functionalization may involve treating the material to incorporate functional groups on the surface and / or edges of the graphite-like or pyrolytic graphite-like material. Exemplary functional groups include thiol groups, hydroxyl groups, carboxyl groups, epoxy groups, and / or carbonyl groups. This can be functionalization, for example, using plasma treatment. For example, in some embodiments, graphene may be functionalized using (additional) carboxyl groups. One example is plasma treatment for “oxygen” functionalization using the Haydale HDLPAS process, as described in WO 2010 / 142953 A1.

[0043] Nanofluids

[0044] As described above, in some embodiments, the device can use nanofluids as heat transfer fluids. These are excellent alternatives to traditional cooling fluids because the added nanomaterial component can increase the thermal conductivity of the fluid by up to 85% while having minimal impact on other properties such as the fluid's viscosity. Some exemplary nanoparticles used for heat transfer fluids, along with their properties, are shown in Table 1 below.

[0045]

[0046] Table 1 – Exemplary Nanoparticles and Nanofluids

[0047] In the embodiments, the nanoparticles are selected from graphite-like materials. Hexagonal boron nitride and graphene provide particularly effective nanoparticles. In a preferred embodiment, for graphite-like materials, the number of layers in the nanoparticles is less than 15, preferably less than 10. Thermal conductivity properties decrease with increasing number of layers. Phonon transport associated with thermal diffusion is disrupted by the presence of van der Waals bonds between the layers and between graphene, which contains three (although it is a 2D material) acoustic phonon modes: two in-plane and one perpendicular to the plane, with the perpendicular mode predominating at lower temperatures. Hexagonal boron nitride has similar problems with phonon transport, although these are less pronounced.

[0048] Hexagonal boron nitride (BN) is particularly advantageous in nanofluids because it is thermally stable (even up to 900°C in oxidizing atmospheres). The partially ionic structure of the BN layers in hexagonal BN reduces covalent bonding and conductivity, while increasing interlayer interactions, resulting in higher hardness relative to graphite. Hexagonal BN lubricants are especially useful when the conductivity (significantly reduced electrical properties) or chemical reactivity of graphite (an alternative lubricant) would be problematic. Furthermore, hexagonal BN does not require water or gas molecules to be trapped between layers for lubrication; therefore, h-BN lubricants can even be used in a vacuum. The interlayer registration of boron nitride sheets in the hexagonal BN form differs from that seen in the case of graphite. For example, due to their size differences, atoms are covered by nitrogen atoms, and boron atoms above the nitrogen atoms are masked. Figure 1 This shows what the structure looks like from above and highlights how different edge effects can be presented on a single sheet.

[0049] Particularly effective materials are disordered hexagonal boron nitride and disordered graphene. In one embodiment, the nanofluid comprises disordered hexagonal boron nitride and / or disordered graphene. In disordered h-BN and disordered graphene, the fundamental plane is shifted (see, for example...). Figure 2 In h-BN, the dimensional differences between boron and nitrogen atoms allow for easy displacement between the basic planes of the boron nitride sheets, resulting in a so-called disordered layer structure.

[0050] In some embodiments, the heat transfer fluid utilizes this disordered layer structure to maximize thermal properties. The large gaps between layers allow molecules to more easily insert between planar sheets of h-BN or graphene. In some embodiments, functionalization allows functional groups (e.g., OH and COOH groups) to insert into the structure. In some embodiments, additional functionalization may be possible through the use of low-temperature plasma processes, taking the form of chemically (covalently) bonding functional groups (e.g., OH molecules) to reactive sites on the edges of the plates and erroneous sites on the surface. This allows the functionalized material to be readily wetted in many continuous phases (e.g., water) and amplifies the effects of ultrasonic cavitation to break down the starting material into a stack of smaller planar structures. As illustrated above, this increases the thermal conductivity of the resulting nanofluid. Functionalizing the edges of the plates with molecules such as OH or COOH has the additional benefit of providing stabilization in the nanofluid. For example, OH functionalization provides active bonds into hydrogen-bonded water structures, and COOH allows bonding to hydrocarbon-based fluids. Hexagonal boron nitride is not readily wetted by deionized water, thus requiring surfactants to allow the formation of stable dispersions.

[0051] The covalent bonding of functional groups to the edges and surfaces of h-BN and graphene plates is advantageous for two reasons: 1) it stabilizes the particles in the resulting nanofluid, providing long-term protection against agglomeration and short-term protection against sedimentation. 2) the long-chain organic compounds used as surfactants suppress phonon transfer from the heat source to the hexagonal boron nitride plates—that is, the long-chain compounds insulate h-BN and graphene and prevent heat flow. The use of ultrashort groups, i.e., OH or COOH groups, minimizes this insulating effect.

[0052] Energy production

[0053] As explained above, the apparatus disclosed herein may also include a thermoelectric generator. This allows the use of any thermal energy received by the apparatus. This can be particularly advantageous in cases where a large amount of heat is input into the apparatus, such as thermal energy associated with reentry vehicles or high-speed vehicles. A thermoelectric generator, or Seebeck generator, is a solid-state device that converts heat flux into electrical energy through a phenomenon known as the Seebeck effect. This effect describes how a temperature gradient in a conductive material leads to heat flow; this results in the diffusion of charge carriers. The flow of charge carriers between hot and cold regions then generates a voltage difference. Thermocouples made of iron and copper wire, mounted in series, are called thermopile generators and can be used to generate a current when a temperature difference is applied. The generated voltage is proportional to the temperature difference.

[0054] Therefore, in this implementation, the heat transfer device can transfer heat energy (heat) from the external protective enclosure to the thermoelectric generator. This can be used to power components in the device and / or related main body, and / or the electrical energy can be stored in a storage device.

[0055] In the implementation, the thermoelectric generator incorporates graphene. Thermoelectric conversion requires excellent electrical conductivity and poor thermal conductivity to ensure that heat moves electrons. However, in most cases, the relationship between the thermal conductivity of electrons and the electrical conductivity of a material is fixed. However, in the case of graphene, because electrons reside in clouds above and below the atomic plane, electrons and atoms do not collide frequently, making the transfer of energy from electrons to phonons very efficient. However, electrons do collide with other electrons, resulting in a net charge flow (current) in one direction, while heat transfer is reduced through collisions between electrons. This provides high electrical conductivity but low thermal conductivity.

[0056] Specific implementation plan

[0057] exist Figure 3 An embodiment of the invention is illustrated. This embodiment shows a device in the form of an outer skin 100 according to the invention for protecting an aerospace vehicle (not shown) from thermal and physical damage. Figure 3A cross-section through the skin is shown. Although not shown, the skin forms a cylinder that is part of the forward section of an aerospace vehicle.

[0058] Skin 100 includes an outer protective shield 110 and internal components 120. The outer protective shield 110 forms the outer surface of the aerospace vehicle and is therefore exposed to the environment during transit. The outer layer is formed of a layer of tiles 112 containing graphite-like or pyrolytic graphene-like materials. The use of tiles allows for easier fabrication of pyrolytic graphene materials.

[0059] An internal component 120 is disposed on the inner surface of the outer protective casing 110 and includes a heat transfer device 130 in the form of a heat transfer layer comprising a fluid-based system. The heat transfer device 130 includes a plurality of semi-circular (cross-sectional) conduits 134 filled with a heat transfer fluid 132. The conduits 134 are held in place by insulating adhesive blocks 136. In this embodiment, the heat transfer fluid 132 comprises nanoparticles. The conduits 134 are arranged to contact the inner surface of the tile-like structure 112 and are adapted to absorb heat from the outer protective casing 110. The conduits 134 carry heat from the outer surface to a radiator (not shown) centrally located in the body of the aerospace vehicle. The internal component 120 also includes a support structure 150. The support structure 150 includes a monolithic aerogel 154, with protective layers 152, 156 disposed on either side of the monolithic aerogel 154. The support structure 150 acts as a bracket on which the outer protective cover 110 and the heat transfer device 130 are formed and supported. The support structure 150 also protects the vehicle and any internal components from external physical damage, and acts as an insulator to protect the rest of the vehicle from thermal damage.

[0060] The device 100 also includes a thermoelectric generator comprising a hot junction 162 located in a tile-like structure 112 of the outer protective cover 110 and a cold junction 164 located on the inner surface of the support structure. The aerogel monolith 154 also serves as an insulator between the hot junction and the cold junction.

[0061] In use, device 100 protects aerospace vehicles from thermal and physical damage. Due to the properties of the graphite-like / pyrolytic graphite-like material in preventing damage to the vehicle's internal components, the outer protective shield 110 acts as both a thermal and physical barrier. Hot spots are reduced by transferring heat across the outer surface of the outer protective shield 110 via tile-like structures 112. The heat transferred through the tile-like structures 112 is then transferred to another part of the vehicle using fluid conduits 134 and nanofluids (powered by a pump (not shown)), allowing the heat to dissipate in cooler sections of the vehicle, or the heat to be converted into electrical energy by a thermoelectric generator. The use of a thermoelectric generator will further dissipate heat and provide electrical energy to the vehicle, reducing reliance on batteries or other methods of generating electricity.

[0062] although Figure 3 The implementation relies on a fluid-based heat transfer system, but in an alternative implementation, this could be a solid-based heat transfer system. For example, internal components may include a series of through-holes or thermal tracks that guide heat away from the tile-like structure 112 and to a portion of the device where the heat can be dissipated.

[0063] By studying the accompanying drawings, this disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed embodiments in practicing the claimed invention. For example, in the example above:

[0064] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. The fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. A device for protecting a subject from damage, the device comprising: An external protective cover, the external protective cover including a heat conduction element for transferring heat energy through at least a portion of the external protective cover; and An internal component, adjacent to the external protective cover, includes a heat transfer device adapted to transfer heat to and / or from the heat conduction element. The heat-conducting element comprises a pyrolytic graphite-like material; The heat transfer device mentioned above includes a heat transfer fluid; and The heat transfer fluid includes a nanofluid, which comprises hexagonal boron nitride nanoparticles and / or graphene nanoparticles.

2. The apparatus according to claim 1, wherein the pyrolytic graphite sample material is selected from graphene, pyrolytic graphite, pyrolytic carbon, pyrolytic hexagonal boron nitride, or a combination thereof.

3. The apparatus according to any of the preceding claims, wherein the internal component further comprises a support structure arranged to support the external protective cover by providing a bracket, the external protective cover being formed on the bracket.

4. The device according to claim 3, wherein the support structure comprises aerogel.

5. The apparatus of claim 4, wherein the support structure further comprises a composite material comprising a first layer and a second layer, the first layer comprising the aerogel, and the second layer comprising a protective layer.

6. The apparatus according to any of the preceding claims, The external protective cover includes a housing; and The heat conduction element is encapsulated within the housing.

7. The apparatus according to any of the preceding claims further includes a thermoelectric generator, wherein the thermoelectric generator is adapted to receive thermal energy from the heat conduction element and convert the thermal energy into electrical energy.

8. The apparatus according to any one of claims 1 to 7, wherein the hexagonal boron nitride nanoparticles are randomized hexagonal boron nitride nanoparticles, and the graphene nanoparticles are randomized graphene nanoparticles.

9. The apparatus according to any one of claims 1 to 8, wherein the hexagonal boron nitride nanoparticles and / or the graphene nanoparticles are functionalized with OH and COOH functional groups.

10. The apparatus according to any one of claims 1 to 9, wherein the hexagonal boron nitride nanoparticles comprise less than 15 hexagonal boron nitride layers in each nanoparticle, and / or the graphene nanoparticles comprise less than 15 graphene layers in each nanoparticle.

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