An efficient heat insulation / high-sensitivity integrated heat storage and release "sandwich" thermal protection structure for spacecraft

Abstract

The present invention belongs to the field of spacecraft heat insulation protection and functional material structure design, and relates to an efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure. It includes an intermediate heat insulation layer and inner and outer heat storage and release layers. The heat storage and release layer is composed of a heat conduction component and a phase change component. The heat conduction component is used as a shaping matrix, and the phase change component is uniformly adsorbed into the pores of the heat conduction component by the vacuum impregnation method. The heat insulation layer is composed of a heat insulation component. The present invention has a comprehensive thermal protection effect of efficient heat insulation / high-sensitivity heat storage and release, can effectively block the external space heat flux of the spacecraft, quickly absorb the power consumption fluctuation of the spacecraft, ensure the stability of the internal thermal environment temperature of the spacecraft, and meet the application requirements of spacecraft thermal protection.

Description

Technical Field

[0001] The present invention belongs to the field of spacecraft thermal insulation protection and functional material structure design, and relates to a high-efficiency thermal insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure. Background Art

[0002] Thermal disturbances within spacecraft systems and fluctuations in heat fluxes outside space severely interfere with gravitational wave detection. To maintain the spacecraft within a suitable temperature range and mitigate the interference of temperature fluctuations on gravitational wave detection, it is necessary to minimize heat exchange between the spacecraft's internal temperature environment and the external space thermal environment to ensure a stable internal thermal environment. However, traditional one-way passive thermal protection structures, primarily composed of a single low-thermal conductivity insulation material, cannot dynamically adjust the spacecraft's internal thermal environment, making it difficult to absorb thermal disturbances within the spacecraft system and fluctuations in heat flux outside space, thus failing to meet the thermal protection requirements of spacecraft for gravitational wave detection.

[0003] Phase change materials can store / release a large amount of latent heat during the phase change process of melting / solidification, and are reusable. Therefore, thermal protection structures combined with phase change materials can not only effectively block the transfer of heat flow from outside space to the interior of the spacecraft system, but also the heat storage and release characteristics of phase change materials can realize the self-stabilization regulation of the thermal environment inside the spacecraft. However, there are still certain problems in the practical application of phase change composite thermal protection structures. (1) Solid-liquid phase change materials have the advantages of high energy storage density and large phase change latent heat. However, solid-liquid phase change materials will produce liquid leakage during the phase change process, which reduces the storage capacity of phase change materials. (2) Traditional thermal protection structures are mainly composed of thermal insulation materials. However, thermal insulation materials have low thermal diffusivity and slow thermal response speed, which is not conducive to the rapid transfer of external thermal disturbances to phase change materials, and it is difficult to quickly absorb the power consumption fluctuations of spacecraft. (3) In order to improve the heat storage and release rate of the phase change composite thermal protection structure, it is necessary to improve its thermal conductivity to reduce the thermal response time of the external thermal disturbance transmitted to the phase change material. However, the thermal protection structure with high thermal conductivity is difficult to effectively block the heat flow outside the spacecraft, and cannot have the functions of high sensitivity heat storage and release and high efficiency heat insulation. Summary of the Invention

[0004] In response to the above-mentioned problems, the present invention proposes an integrated "sandwich" spacecraft thermal protection structure with high efficiency insulation and high sensitivity heat storage and release, which can effectively block the heat flow in the space outside the spacecraft, quickly absorb the power consumption fluctuations of the spacecraft, and ensure the stability of the thermal environment temperature inside the spacecraft.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure, including an intermediate heat insulation layer and inner and outer heat storage and release layers. The heat storage and release layer is composed of a heat-conducting component and a phase-change component. The heat-conducting component is used as a shaping matrix, and then the phase-change component is uniformly adsorbed into the pores of the heat-conducting component. The heat insulation layer is composed of a heat-insulating component.

[0007] Preferably, the heat-conducting component is a carbon-based porous material, specifically expanded graphite or three-dimensional graphene.

[0008] Preferably, the phase-change component is a paraffin-based solid-liquid phase-change material, and the main component is an organic straight-chain alkane, which is any one or a combination of two or more of n-tetradecane, n-hexadecane, n-octadecane, n-eicosane, and n-docosane. The phase-change temperatures are 5.5°C, 16.7°C, 28°C, 36.7°C, and 44°C respectively, and the phase-change latent heats are 225.7 J / kg, 236.8 J / kg, 242.4 J / kg, 247.3 J / kg, and 249 J / kg respectively.

[0009] Preferably, the heat-insulating component is an aerogel heat-insulating material, which is formed by silica nanoparticles interconnected to form a three-dimensional spatial network structure.

[0010] Preferably, the heat storage and release rate of the heat storage and release layer is not less than 0.2 J / kg·s, and the thermal conductivity of the heat insulation layer 2 is not higher than 0.04 W / m·K.

[0011] An efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure, and the thermal protection principle is as follows:

[0012] The external space heat flux of the spacecraft is transferred to the outer heat storage and release layer. When the solid-liquid phase-change material in the phase-change component reaches the phase-change temperature range, it absorbs heat through the melting phase-change process, absorbs the fluctuations of the external heat flux in space. When the phase-change component absorbs the external heat load to saturation, the external space heat flux continues to be transferred to the intermediate heat insulation layer. The heat-insulating component is silica aerogel, and its extremely low thermal conductivity can prevent further heat transfer and diffusion, effectively blocking the external space heat flux of the spacecraft.

[0013] When there are fluctuations in the heat source generated inside the spacecraft system, the heat-conducting component in the inner heat storage and release layer enables the heat source disturbance inside the system to be quickly transferred to the phase-change component. The solid-liquid phase-change material that reaches the phase-change temperature can store and release a large amount of latent heat during the melting / solidification phase-change process, quickly absorbing the heat source disturbance inside the spacecraft system.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. An efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure disclosed by the present invention. The heat-conducting component in the heat storage and release layer is a carbon-based porous material, and its internal structure has a large number of micro / nano pores. The capillary action and confinement effect generated can effectively adsorb the phase change component, improve the shape stability of the phase change component, prevent liquid leakage of the phase change material during the molten heat storage process, and improve the energy storage density of the heat storage and release layer.

[0016] 2. An efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure disclosed by the present invention. The heat-conducting component in the heat storage and release layer has a continuous three-dimensional porous network structure, and the continuous heat-conducting network channels formed inside can enhance the transient heat response ability of the heat storage and release layer. Accelerate the transfer of external heat disturbances to the phase change component and quickly absorb the power consumption fluctuations of the spacecraft.

[0017] 3. An efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure disclosed by the present invention. By combining the heat storage and release layer and the heat insulation layer to design the "sandwich" spacecraft thermal protection structure, it can not only effectively block the external space heat flow of the spacecraft, but also quickly absorb the power consumption fluctuations of the spacecraft, overcoming the contradiction between high-sensitivity heat storage and release and high-efficiency heat insulation characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention.

[0019] In the drawings:

[0020] Figure 1 It is a schematic diagram of the composition of the efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" thermal protection structure of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The following is a description of the preferred embodiments of the present invention with reference to the drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0022] Embodiment:

[0023] Referring to the attached Figure 1 , an efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure includes an intermediate heat insulation layer 2 and inner and outer heat storage and release layers 1. The heat storage and release layer 1 is composed of a heat-conducting component 3 and a phase change component 4, and the heat insulation layer 2 is composed of a heat insulation component 5.

[0024] The heat-conducting component 3 is a carbon-based porous material, which has the characteristics of low density, high porosity, and high specific surface area. Its internal structure has a large number of micro / nano-sized pores, which can effectively adsorb the phase change component through capillary action, increasing the storage amount of the phase change component 4 in the porous material carrier. Moreover, the confinement effect generated by the porous structure can improve the shape stability of the phase change component 4, prevent the liquid leakage of the phase change material during the molten heat storage process, and increase the energy storage density of the heat storage and release layer 1. The carbon-based porous material has a high intrinsic thermal conductivity, and the continuous heat-conducting network channels formed by the porous structure can accelerate heat transfer and enhance the transient temperature response ability of the heat storage and release layer 1.

[0025] The carbon-based porous material is expanded graphite or three-dimensional graphene. Expanded graphite is a worm-like porous carbon material obtained by treating natural graphite through intercalation and high-temperature expansion. The thermal conductivity of a single expanded graphite strip is 335.6 ± 27.4 W / m·K. Three-dimensional graphene is a nanoporous material formed by physically constraining, adsorbing, and chemically bonding single-layer graphene sheets in three-dimensional space, which has a continuous three-dimensional heat-conducting network. The thermal conductivity of a single-layer graphene sheet is 5300 W / m·K.

[0026] The phase change component 4 is a paraffin-based solid-liquid phase change material, which stores / releases heat through the phase change process of melting / solidification within the phase change temperature range, and absorbs the heat source disturbance and the external heat flux fluctuation in the spacecraft system.

[0027] The phase change component 4 is a paraffin-based solid-liquid phase change material, which is a mixture of organic hydrocarbons, with a large phase change latent heat, stable chemical properties, small volume change during the phase change process, and being safe and non-toxic.

[0028] The main component of the paraffin-based solid-liquid phase change material is an organic straight-chain alkane, which is any one or a combination of two or more of n-tetradecane, n-hexadecane, n-octadecane, n-eicosane, and n-docosane. Their phase change temperatures are 5.5 °C, 16.7 °C, 28 °C, 36.7 °C, and 44 °C respectively, and the phase change latent heats are 225.7 J / kg, 236.8 J / kg, 242.4 J / kg, 247.3 J / kg, and 249 J / kg.

[0029] The heat storage and release layer 1 is a paraffin-carbon-based shaped phase change composite material composed of a carbon-based porous material and a paraffin-based solid-liquid phase change material. Taking the carbon-based porous material as the shaping matrix, the liquid paraffin-based phase change material is evenly adsorbed into the pores of the carbon-based porous material through the vacuum impregnation method. The capillary action and surface tension of its micro-nano pore structure can effectively encapsulate the paraffin-based solid-liquid phase change material.

[0030] The heat insulation component 5 is an aerogel heat insulation material, which can effectively block the transfer of external heat flux into the spacecraft system. The heat insulation component 5 is an aerogel heat insulation material with low density and low thermal conductivity, having a continuous three-dimensional nano-porous network structure, and its nano-scale porous framework and pore diameter can significantly block the transfer and transport of heat.

[0031] The aerogel heat insulation material is silica aerogel, which is formed by the interconnected silica nanoparticles to form a three-dimensional spatial network structure, with a thermal conductivity of 0.01 - 0.02 W / m·K and a density of 0.003 - 0.15 g / cm 3 .

[0032] The specific preparation process of the silica aerogel: By mixing a silicon source, water and a catalyst, the silicon source undergoes hydrolysis and polycondensation to obtain a sol mainly composed of silicon-oxygen bonds, and then through the gelation and aging processes to obtain a wet gel with a three-dimensional network structure, and finally through drying to prepare a silica aerogel with a three-dimensional nano-porous structure.

[0033] The heat storage and release rate of the heat storage and release layer 1 is not less than 0.2 J / kg·s, and the thermal conductivity of the heat insulation layer 2 is not higher than 0.04 W / m·K.

[0034] A high-efficiency heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure, and the thermal protection principle is:

[0035] The external space heat flux of the spacecraft is transferred to the outer heat storage and release layer 1. When the solid-liquid phase change material in the phase change component 4 reaches the phase change temperature range, it absorbs heat through the melting phase change process to absorb the fluctuations of the external space heat flux. When the phase change component 4 absorbs the external heat load to saturation, the external space heat flux continues to be transferred to the middle heat insulation layer 2. The heat insulation component 5 is silica aerogel, and its extremely low thermal conductivity can prevent the further transfer and diffusion of heat, effectively blocking the external space heat flux of the spacecraft.

[0036] When there are fluctuations in the heat source generated inside the spacecraft system, the self-stabilizing regulation of the internal thermal environment of the spacecraft is realized through the inner heat storage and release layer 1. The heat conduction component 3 is a carbon-based porous material with high heat diffusivity characteristics. The heat conduction component 3 in the inner heat storage and release layer 1 enables the rapid transfer of the heat source disturbance inside the system to the phase change component 4. The solid-liquid phase change material reaching the phase change temperature can store and release a large amount of latent heat during the melting / solidification phase change process, quickly absorbing the heat source disturbance inside the spacecraft system.

[0037] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure, characterized in that: It includes an intermediate heat insulation layer (2) and inner and outer heat storage and release layers (1). The heat storage and release layer (1) is composed of a heat-conducting component (3) and a phase-change component (4). The heat-conducting component (3) is used as a shaping matrix, and then the phase-change component (4) is uniformly adsorbed into the pores of the heat-conducting component (3). The heat insulation layer (2) is composed of a heat insulation component (5). The heat-conducting component (3) is a carbon-based porous material, specifically expanded graphite or three-dimensional graphene. The phase-change component (4) is a paraffin-based solid-liquid phase-change material, and its main component is an organic straight-chain alkane, which is any one or a combination of two or more of n-tetradecane, n-hexadecane, n-octadecane, n-eicosane, and n-docosane. The phase-change temperatures are 5.5°C, 16.7°C, 28°C, 36.7°C, and 44°C respectively, and the latent heats of phase change are 225.7 J / kg, 236.8 J / kg, 242.4 J / kg, 247.3 J / kg, and 249 J / kg respectively. The heat storage and release rate of the heat storage and release layer (1) is not less than 0.2 J / kg·s, and the thermal conductivity of the heat insulation layer (2) is not higher than 0.04 W / m·K.

2. An efficient heat insulation / high-sensitivity heat storage and release integrated "sandwich" spacecraft thermal protection structure according to claim 1, characterized in that: The heat insulation component (5) is an aerogel heat insulation material, which is formed by silica nanoparticles interconnected to form a three-dimensional space network structure.

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