A light-weight dot-matrix structure plate based on aerogel and heating wire combination and a thermal control design method

Abstract

This invention discloses a lightweight lattice structure plate based on aerogel and heating wire, and a thermal control design method, belonging to the field of aerospace technology. The structure plate includes: wall panels, a lattice structure, a piping structure, heating wires, and insulating aerogel; the lattice structure is placed between the wall panels, the piping structure is embedded in the lattice structure, and the heating wires and insulating aerogel are installed in the piping structure; wherein the wall panels, lattice structure, and piping structure are integrally formed. The structure plate proposed in this invention comprehensively considers load-bearing capacity, lightweight design, and integrated manufacturing, greatly simplifying the manufacturing process and time, eliminating the use of structural adhesives, and using lightweight aerogel for thermal insulation, significantly reducing the overall weight. Furthermore, the integral molding of the lattice structure ensures the overall mechanical properties of the structure plate compared to post-assembly.

Description

Technical Field

[0001] This invention relates to the field of aerospace technology, and more specifically to a lightweight lattice structure plate based on a combination of aerogel and heating wire, and a thermal control design method. Background Technology

[0002] In recent years, with the continuous development of aerospace technology and deep space exploration technology, new-generation satellites are moving towards intelligence, lightweighting, and integration. As a major component of various satellite models, structural plates are subject to higher requirements.

[0003] Traditional structural panels typically consist of upper and lower bottom skins, a honeycomb structure in the middle layer, and pre-embedded pipes embedded within the honeycomb structure. The honeycomb structure serves as the load-bearing structure, while the pre-embedded pipes are used for propellant and fuel / gas transport. In actual manufacturing, each component is processed and manufactured separately, and then assembled into the final structural panel. The honeycomb structure is fixedly connected to the upper and lower bottom skins with adhesive, and the pre-embedded pipes are embedded and fixed within the honeycomb structure with adhesive. Furthermore, to prevent the propellant and fuel / gas from solidifying in the extreme environment of deep space, the pipes are generally wrapped with specialized heating tape and insulated with multiple layers of heat-resistant tape.

[0004] The existing manufacturing technology of separate manufacturing followed by assembly has the following main problems:

[0005] (1) The manufacturing process is complex, the development cycle is long, and the development cost is high.

[0006] The overall manufacturing process mainly involves the manufacturing of each component and the final assembly. The manufacturing process of each component involves multiple assembly processes such as mold design, component processing, honeycomb structure post-processing, pipeline laying, and bonding. The process is complex, time-consuming, labor-intensive, and costly.

[0007] (2) The structural weight reduction effect is not obvious and the mechanical properties are insufficient.

[0008] The main weight reduction of the structural panel comes from the honeycomb structure in the middle, while the heating and insulation parts using traditional heating belts and insulation modules would add a significant amount of weight. At the same time, in order to ensure that the pipes are successfully embedded in the honeycomb structure, post-processing is required after the honeycomb structure is manufactured, which damages the original structure and affects its mechanical properties. In addition, the bonding process is affected by environmental corrosion and other factors, and will undergo aging and other behaviors during long-term service, affecting the overall mechanical properties of the structure.

[0009] (3) The insulation process is complex and lightweight design was not considered.

[0010] To ensure the normal flow of propellant and oil / gas in the embedded pipeline, it is generally necessary to wrap heating wires or heating belts around the outside for temperature control. At the same time, it is also necessary to cover the outside with a lot of heat insulation material to prevent heat loss. The entire heat insulation process is relatively complex and requires high skill from designers. In addition, the added weight is not conducive to lightweight design.

[0011] (4) Low design and manufacturing flexibility

[0012] Since the pipes are assembled into the honeycomb structure later, the direction of the pipes is restricted to a certain extent. They must be straight pipes; otherwise, they cannot be properly embedded into the honeycomb structure after assembly. This limits the flexibility of design and manufacturing to some extent.

[0013] Therefore, how to efficiently and effectively manufacture structural panels while meeting the requirements of lightweighting and thermal insulation is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0014] In view of this, the present invention provides a lightweight lattice structure plate and thermal control design method based on the combination of aerogel and heating wire. It comprehensively considers load-bearing, lightweight and integrated manufacturing, greatly simplifies the manufacturing process and manufacturing time, eliminates the use of structural adhesive, and uses lightweight aerogel for thermal insulation, which greatly reduces the overall weight. The integrated molding manufacturing of the lattice structure ensures the overall mechanical properties of the structure plate compared with post-assembly.

[0015] To achieve the above objectives, the present invention adopts the following technical solution:

[0016] On one hand, the present invention discloses a lightweight lattice structure plate based on the combination of aerogel and heating wire, comprising: wall panel, lattice structure, pipeline structure, heating wire and thermal insulation aerogel;

[0017] The dot matrix structure is placed between the wall panels, the pipeline structure is embedded in the dot matrix structure, and the pipeline structure wraps the heating wire and the thermal insulation aerogel from the inside to the outside in sequence;

[0018] The wall panel, dot matrix structure, and pipeline structure are integrally formed.

[0019] Preferably, the unit cell configuration of the lattice structure is a body-centered cubic octahedron structure.

[0020] Preferably, the pipeline structure includes an outer wall, an inner wall, and ribs;

[0021] The outer wall and the inner wall are connected by the ribs, and the space formed between the inner wall, the outer wall and the ribs is used for injecting thermal insulation aerogel.

[0022] The inner wall is provided with small holes for the heating wire to pass through.

[0023] Preferably, the rib plate has a hollow structure.

[0024] Preferably, the surface of the heating wire is coated with an insulating coating.

[0025] Preferably, the pipeline structure is a straight pipe or a curved pipe.

[0026] On the other hand, the present invention also discloses a thermal control design method for a lightweight lattice structure plate based on the combination of aerogel and heating wire, which is applied to the above-mentioned lightweight lattice structure plate. The method includes the following steps:

[0027] S1. Integrated manufacturing of wall panels, lattice structures, and pipeline structures to obtain integrated structural components;

[0028] S2. Post-processing of the integrated structural component: The integrated structural component is placed in metal powder and allowed to cool naturally. Then, the integrated structural component is removed from the powder tank and excess metal powder and impurities in the integrated structural component are removed.

[0029] S3. Winding of heating wire: The heating wire passes through all the small holes on the inner wall of the pipeline structure axially and is fixed.

[0030] S4. Preparation of aerogel stock solution and molding of thermal insulation aerogel: MXene or graphene and CNF are dispersed in an organic solvent and mixed evenly by magnetic stirring and cell disruption. The evenly mixed solvent is poured into the space formed by the inner wall, outer wall and ribs of the pipeline structure and freeze-dried to form thermal insulation aerogel.

[0031] Preferably, S1 includes:

[0032] The wall panel, lattice structure, and pipeline structure are modeled using 3D modeling software. After the model is built, the file is exported and saved in STL format. The saved 3D model is then imported into slicing software to continue slicing and layering. The scanning path is planned and converted into laser scanning information. The printer selectively performs single-layer laser sintering of metal powder based on the laser scanning information. After one layer is sintered, the forming stage descends by one layer thickness. The above steps are repeated until the integrated structural component is formed.

[0033] Preferably, in step S2, removing excess metal powder and impurities from the integrated structural component includes:

[0034] Use a brush to remove excess metal powder from the surface, and use compressed air to preliminarily clean the inside of the pipeline structure to remove excess metal powder.

[0035] Then, sandpaper is used to polish the surface of the integrated structural component. For the inside of the pipeline structure, abrasive flow process is used for polishing.

[0036] After polishing, the entire integrated structural component is cleaned with deionized water to remove excess impurities.

[0037] As can be seen from the above technical solution, the present invention discloses a lightweight lattice structure plate based on the combination of aerogel and heating wire and a thermal control design method, which has the following advantages compared with the prior art:

[0038] (1) Simplify the design method of structural panels to reduce production time and production costs.

[0039] Additive manufacturing was used to create integrated wall panels, lattice structures, and piping structures, replacing the traditional method of assembling individual components. This eliminated the cumbersome assembly process and greatly reduced manufacturing costs and time.

[0040] (2) Improved the stability of the mechanical properties of the structural plate.

[0041] The structural design fully considers heating and insulation measures, reserving dedicated space for the heating wire and aerogel. This effectively avoids damage to the intermediate lattice structure during traditional manufacturing processes, ensuring the overall mechanical performance of the structure. Simultaneously, it eliminates the need for adhesives and other materials, reducing the risk of environmental factors damaging the adhesives and thus affecting the overall structural performance.

[0042] (3) It has a strong lightweight design concept and the weight reduction effect is obvious.

[0043] By fully utilizing the ultra-lightweight properties of aerogel and replacing traditional insulation modules with aerogel, the overall structural weight is greatly reduced. At the same time, the internal ribs of the pipeline are designed with a hollow design, which also reduces the structural weight to a certain extent.

[0044] (4) The insulation process is simple and does not require processing of other modules.

[0045] Aerogels with excellent thermal insulation properties were manufactured by directly using a solution-pouring freeze-drying method, replacing the traditional complex winding insulation modules. The process is simple, and the module is relatively independent and will not affect other parts.

[0046] (5) Design flexibility has been greatly improved.

[0047] The pipeline can be customized according to actual needs. The pipeline structure is not limited to straight pipes. Curved pipes can be generated directly in one piece, which greatly improves the design flexibility. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of a lightweight lattice structure plate based on the combination of aerogel and heating wire.

[0050] Figure 2 This is a schematic diagram of the unit cell configuration of the lattice structure;

[0051] Figure 3 Detailed diagram of the piping structure;

[0052] Figure 4 This is an overall flowchart of a thermal control design method for a lightweight lattice structure plate based on the combination of aerogel and heating wire;

[0053] Figure 5(a) shows a schematic diagram of the heating wire being wound clockwise, and Figure 5(b) shows a schematic diagram of the heating wire being wound counterclockwise.

[0054] Figure 6 This is a scanning electron microscope (SEM) image of the thermal insulation aerogel.

[0055] In the figure, 1-wall panel, 2-lattice structure, 3-pipeline structure, 4-heating wire, 5-thermal insulation aerogel, 31-outer wall, 32-inner wall, 33-rib plate. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] The purpose of this invention is to provide a lightweight lattice structure plate based on the combination of aerogel and heating wire and a thermal control design method. It solves the problems of complex manufacturing process, long manufacturing cycle, insignificant weight reduction effect, insufficient mechanical properties, low design freedom and complex thermal control process of existing structural plates, and realizes rapid manufacturing of lattice structure and optimizes thermal control process.

[0058] On one hand, embodiments of the present invention disclose a lightweight lattice structure plate based on a combination of aerogel and heating wire, with the overall structure referring to... Figure 1 It includes wall panel 1, lattice structure 2, pipeline structure 3, heating wire 4, and thermal insulation aerogel 5.

[0059] The lattice structure 2 is placed between the wall panels 1, and the pipe structure 3 is embedded in the lattice structure 2. The pipe structure 3 wraps the heating wire 4 and the thermal insulation aerogel 5 from the inside to the outside.

[0060] The wall panel 1, the dot matrix structure 2, and the pipeline structure 3 are integrally formed, specifically manufactured by selective laser melting (SLM) technology. The selected materials are aluminum alloy and titanium alloy, with aluminum alloy being more preferred, and 7075 aluminum alloy being even more preferred.

[0061] The unit cell configuration of lattice structure 2 is a body-centered cubic (BCC) or face-centered cubic (FCC) structure, or a combination of both, more preferably a body-centered cubic structure, and even more preferably a body-centered cubic octahedral structure, such as... Figure 2 As shown.

[0062] The structure of pipeline structure 3 is as follows Figure 3 As shown, it includes an outer wall 31, an inner wall 32, and ribs 33. The outer wall 31 and the inner wall 32 are connected by ribs 33. In this embodiment, four ribs are used. The space formed between the inner wall 32, the outer wall 31, and the ribs 33 is used to inject aerogel stock solution to form the thermal insulation aerogel 5. The inner wall 32 has several small holes with a diameter of approximately 0.8-1.2 mm, preferably 1.0 mm, for the heating wire 4 to pass through. The ribs 33 are designed with a hollow structure (e.g.,...). Figure 3 (As shown in the middle part), to achieve lightweighting.

[0063] Heating wire 4 is used to heat the liquid within the inner wall 32 of the pipeline structure 3. The material of heating wire 4 is iron-chromium-aluminum alloy or nickel-chromium alloy, more preferably nickel-chromium alloy, and even more preferably Cr20Ni80 nickel-chromium alloy. The surface of heating wire 4 is coated with an insulating coating. The material of the insulating coating is more preferably high-temperature resistant ceramic insulating paint, and the coating technology is preferably plasma spraying.

[0064] The thermal insulation aerogel 5 exhibits excellent thermal insulation properties and is one of MXene / CNF aerogels or G / CNF aerogels, with MXene / CNF being more preferred. In this embodiment, the thermal insulation aerogel 5 is prepared by freeze-drying.

[0065] This invention also provides a thermal control design method for a lightweight lattice structure plate based on a combination of aerogel and heating wire. Specifically, using 7075 aluminum alloy powder as the printing raw material, Cr20Ni80 nickel-chromium alloy as the heating wire, and MXene / CNF as the insulating aerogel, the thermal control design method is illustrated. The overall manufacturing process is as follows: Figure 4 As shown. The specific steps are as follows:

[0066] S1. The wall panels, lattice structure and pipeline structure are manufactured in an integrated manner to obtain an integrated structural component.

[0067] Using 3D modeling software, a 3D model of the integrated structure consisting of wall panel 1, lattice structure 2, and pipeline structure 3 is created. After the model is built, the file is saved as an STL file. The saved 3D model is then imported into slicing software for slicing and layering. A laser scanning path is planned and converted into laser scanning information. The laser scanning information is then transmitted to the printer. Based on the laser scanning information, single-layer laser sintering of 7075 aluminum alloy powder is performed. After the first layer of sintering is completed, the forming stage descends by one layer thickness (0.035mm), and a new layer of powder is laid with the same thickness as the descending height of the forming stage. The above steps are repeated until the integrated structural panel is formed.

[0068] In this embodiment, the laser wavelength of the SLM is 700nm-900nm, the laser power is 250-350W, the scanning rate is 400-1200mm / s, more preferably 600-800mm / s, the scanning spacing is 0.12-0.18mm, more preferably 0.15mm, and the energy density is 50J / mm². 3 -90J / mm 3 The powder thickness is 0.035mm.

[0069] S2. Post-processing of integrated structural components: Place the integrated structural components in metal powder to cool naturally, then remove the integrated structural components from the powder tank and remove excess metal powder and impurities from the integrated structural components.

[0070] Specifically, after printing, the integrated structural component is first placed in metal powder to cool naturally for 5-7 hours, preferably 6 hours. Then, it is removed from the powder tank, and excess metal powder is brushed off the surface. Excess powder is initially cleaned from the interior of the pipe structure (including the space between the inner wall 32 and the outer wall 31, the internal cavity of the inner wall 32, and the small holes and channels on the inner wall 32) using compressed air. Next, the surface of the integrated structural component is sanded to improve its smoothness. For the interior of the pipe structure, an abrasive flow process is used to sand the inner surface to remove excess burrs. After sanding, the entire integrated structural component is rinsed with deionized water to remove any remaining impurities.

[0071] In this step, the abrasive used in the particle flow process is silicon carbide sand with a diameter between 0.005 and 1.5 mm, and the number of working cycles is 20-40.

[0072] S3. Winding of heating wire: The heating wire is wound axially through all the small holes on the inner wall of the pipeline structure in a clockwise (refer to Figure 5(a)) or counterclockwise (refer to Figure 5(b)) direction and fixed.

[0073] S4. Preparation of aerogel stock solution and molding of thermal insulation aerogel: MXene or graphene and CNF are dispersed in an organic solvent and mixed evenly by magnetic stirring and cell disruption. The evenly mixed solvent is poured into the space formed by the inner wall, outer wall and ribs of the pipeline structure and freeze-dried to form thermal insulation aerogel.

[0074] Weigh out 3 mg of MXene and 1 mg of CNF, and add them to 40 mL of DMF solution. Stir magnetically at 500 rpm for 2 hours at room temperature to ensure thorough dispersion and mixing. After dispersion, place the mixture in a cell disruptor and sonicate for 2 hours using a 20 mm diameter amplitude transformer at 80% power density to obtain a homogeneous MXene / CNF thermal insulation aerogel stock solution. Seal one end of the cavity between the inner wall 32 and the outer wall 31, then pour in the MXene / CNF thermal insulation aerogel stock solution. Pre-freeze the entire structure at -20℃ to -30℃ for at least 12 hours to solidify. Then, place the pre-frozen structure in a large vacuum freeze dryer and dry at -50℃ to -75℃ for at least 60 hours to remove the DMF solvent, thus obtaining the MXene / CNF thermal insulation aerogel.

[0075] The microstructure of the MXene / CNF thermal insulation aerogel prepared in this step is as follows: Figure 6 As shown, it is a porous structure with excellent thermal insulation performance.

[0076] The MXene in this step is prepared by etching the MAX phase in LiF / HCl. The specific preparation process is as follows:

[0077] First, LiF (m1g) was added to a polytetrafluoroethylene beaker containing 20ml of HCl (9M) and stirred at room temperature for 20min. Then, Ti3AlC2 powder (m1g) was slowly added to the etching solution, and the mixture was stirred continuously at 40℃ for 50h. The resulting suspension was washed repeatedly with deionized water until the pH of the supernatant reached approximately 6. Then, the bottom precipitate was dispersed in deionized water and sonicated in an ice bath for 60min, followed by centrifugation at 3500rpm for 60min to remove unpeeled Ti3C2T. x The uniformly dispersed supernatant was collected and dried in a freeze dryer for 72 hours to obtain Ti3C2T. x MXene powder.

[0078] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0079] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lightweight lattice structure plate based on a combination of aerogel and heating wire, characterized in that, include: Wall panel (1), lattice structure (2), pipeline structure (3), heating wire (4) and thermal insulation aerogel (5); The dot matrix structure (2) is placed between the wall panels (1), the pipeline structure (3) is embedded in the dot matrix structure (2), and the pipeline structure (3) wraps the heating wire (4) and the thermal insulation aerogel (5) from the inside to the outside. The wall panel (1), the dot matrix structure (2), and the pipeline structure (3) are integrally formed; The unit cell configuration of the lattice structure (2) is a body-centered cubic octahedron structure; The pipeline structure (3) includes an outer wall (31), an inner wall (32), and a rib plate (33); The outer wall (31) and the inner wall (32) are connected by the rib (33), and the space formed between the inner wall (32), the outer wall (31) and the rib (33) is used for injecting thermal insulation aerogel (5). The inner wall (32) is provided with small holes for the heating wire (4) to pass through. MXene or graphene is dispersed with CNF in an organic solvent and mixed evenly by magnetic stirring and cell disruption. The mixed solvent is then poured into the space formed by the inner wall, outer wall and ribs of the pipeline structure, and freeze-dried to form a thermally insulated aerogel.

2. The lightweight lattice structure plate based on aerogel and heating wire combination according to claim 1, characterized in that, The rib (33) has a hollow structure.

3. The lightweight lattice structure plate based on aerogel and heating wire combination according to claim 1, characterized in that, The heating wire (4) is coated with an insulating coating.

4. The lightweight lattice structure plate based on aerogel and heating wire combination according to claim 1, characterized in that, The pipeline structure (3) is a straight pipe or a curved pipe.

5. A thermal control design method for a lightweight lattice structure plate based on a combination of aerogel and heating wire, applied to the lightweight lattice structure plate described in claim 1, characterized in that, Includes the following steps: S1. Integrated manufacturing of wall panels, lattice structures, and pipeline structures to obtain integrated structural components; S2. Post-processing of the integrated structural component: The integrated structural component is placed in metal powder and allowed to cool naturally. Then, the integrated structural component is removed from the powder tank and excess metal powder and impurities in the integrated structural component are removed. S3. Winding of heating wire: The heating wire passes through all the small holes on the inner wall of the pipeline structure axially and is fixed. S4. Preparation of aerogel stock solution and molding of thermal insulation aerogel: MXene or graphene and CNF are dispersed in an organic solvent and mixed evenly by magnetic stirring and cell disruption. The evenly mixed solvent is poured into the space formed by the inner wall, outer wall and ribs of the pipeline structure and freeze-dried to form thermal insulation aerogel.

6. The thermal control design method for a lightweight lattice structure plate based on aerogel and heating wire combination according to claim 5, characterized in that, S1 includes: The wall panel, lattice structure, and pipeline structure are modeled using 3D modeling software. After the model is built, the file is exported and saved in STL format. The saved 3D model is then imported into slicing software to continue slicing and layering. The scanning path is planned and converted into laser scanning information. The printer selectively performs single-layer laser sintering of metal powder based on the laser scanning information. After one layer is sintered, the forming stage descends by one layer thickness. The above steps are repeated until the integrated structural component is formed.

7. The thermal control design method for a lightweight lattice structure plate based on aerogel and heating wire combination according to claim 5, characterized in that, In step S2, removing excess metal powder and impurities from the integrated structural component includes: Use a brush to remove excess metal powder from the surface, and use compressed air to preliminarily clean the inside of the pipeline structure to remove excess metal powder. Then, sandpaper is used to polish the surface of the integrated structural component. For the inside of the pipeline structure, abrasive flow process is used for polishing. After polishing, the entire integrated structural component is cleaned with deionized water to remove excess impurities.

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