Highly heat-insulating composite carbon fiber thermal insulation material and preparation method thereof

Abstract

The present application relates to a kind of high thermal insulation composite carbon fiber thermal insulation material and its preparation method, composite carbon fiber thermal insulation material includes inner layer carbon fiber hard felt, intermediate layer carbon fiber hard felt and outer layer carbon fiber hard felt, and the density of inner layer carbon fiber hard felt>the density of outer layer carbon fiber hard felt>the apparent density of intermediate layer carbon fiber hard felt;Wherein, intermediate layer carbon fiber hard felt has multiple cavities;Prepared adhesive composite film is bonded between inner layer carbon fiber hard felt and intermediate layer carbon fiber hard felt, between intermediate layer carbon fiber hard felt and outer layer carbon fiber hard felt, and composite carbon fiber thermal insulation material is as a whole by heat pressing solidification and graphitization processing.The present application reduces the thermal conductivity of product, improves the thermal insulation performance of product by using density difference and cavity thermal radiation effect under the condition of guaranteeing important indexes such as service life, ash control unchanged.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber insulation materials technology, and in particular to a high thermal insulation composite carbon fiber insulation material and its preparation method. Background Technology

[0002] With the development of the photovoltaic and solar energy industries, the demand for thermal insulation materials is constantly increasing. Carbon fiber insulation materials possess excellent properties such as low thermal conductivity, low heat capacity, low density, low coefficient of linear expansion, high temperature resistance, strong thermal shock resistance, strong chemical corrosion resistance, and high purity without pollution, making them the most important thermal insulation material for high-temperature furnaces. However, currently available carbon fiber insulation materials generally adopt a low-density design to improve insulation performance, making them susceptible to the effects of heat radiation in high-temperature environments. This can lead to pulverization, flaking, and even residue falling into the products inside the furnace, directly affecting product quality. Furthermore, carbon fiber insulation materials are often used in conjunction with furnace support components, which can easily lead to wear and tear, thus reducing the service life of the carbon fiber insulation materials.

[0003] Currently, research on how to improve the thermal insulation performance of carbon fiber insulation materials is ongoing. For example, Chinese patent application CN111409321A discloses "a method for preparing carbon fiber rigid felt with density gradient." Based on the different density requirements of each layer in the carbon fiber rigid felt, the material and weight of the carbon fiber soft felt are selected. Then, the soft felt is sequentially impregnated with resin, dried, each layer is sprayed with a special adhesive, hot-pressed and cured, coated with a special surface treatment agent, and vacuum high-temperature sintered. Finally, a multi-layered material with different densities in the thickness direction, ranging from 0.12 g / cm³, is produced. 3 ~0.3g / cm 3A density-gradient, graphitized carbon fiber rigid felt is used. However, its production process is lengthy, energy-intensive, and involves organic solvent pollution and high costs. Chinese patent application CN108673969A discloses a "carbon fiber thermal insulation curing felt," comprising an inner felt layer, a middle felt layer, and an outer felt layer. The inner and outer felt layers are respectively attached to both sides of the middle felt layer. The density of the inner, middle, and outer felt layers decreases sequentially, while their thickness increases sequentially. The inner felt layer is made of a carbon / carbon composite board, while the middle and outer felt layers are made of carbon fiber rigid felt. The inner, middle, and outer felt layers of this carbon fiber curing felt are composited using resin and a carbon-based binder, increasing the amount of carbon-based binder and raising the density of the inner insulation felt. While increasing the binder increases density, it also increases the thermal conductivity of the carbon fiber insulation felt, affecting the product's insulation performance. Furthermore, a high binder content leads to high internal stress, causing cracking and warping in each layer. In one embodiment, the mating surface of the inner felt layer has a set of protrusions, which are evenly distributed on the inner felt layer and protrude outwards. The middle felt layer has a set of recessed holes adapted to the protrusions, with the positions of the recessed holes corresponding to the positions of the protrusions. The protrusions extend into the recessed holes. The outer felt layer has a set of connecting holes, with the positions of the connecting holes corresponding to the positions of the recessed holes. A connecting screw is provided in the connecting hole, with the tail end of the connecting screw extending outwards from the connecting hole. The protrusion has a positioning hole, and a connecting nut is provided in the positioning hole. The tail end of the connecting screw engages with the connecting nut, thus fixing the inner felt layer, middle felt layer, and outer felt layer together. However, this solution still has the problem that the thermal conductivity and insulation performance of the carbon / carbon composite board need to be further improved. Multiple sets of carbon-carbon bolts directly penetrate the insulation material. Since carbon is a good conductor of heat, it will transfer a large amount of heat to the outside of the furnace, causing a large amount of heat loss and increasing energy consumption. These factors will significantly reduce the overall insulation performance of the product. In addition, the cost of carbon-carbon board is relatively high.

[0004] Existing carbon fiber insulation materials have the following drawbacks:

[0005] 1) Currently, carbon fiber thermal insulation rigid felt sold on the market generally adopts a processing method of impregnating or spraying soft felt with glue and then bonding it layer by layer. When this structure is affected by heat radiation in a high-temperature environment, the carbon fiber thermal insulation rigid felt will peel off due to the large stress between the soft felt layer and the bonding layer. It may even cause the heater to ignite and pulverize due to the close proximity of the peeled layer to the heater, resulting in damage to the heater. The pulverized powder will fall onto the products in the furnace, which will directly reduce the quality of the products in the furnace.

[0006] 2) Existing carbon fiber rigid felts have all undergone curing and high-temperature carbonization. After a period of use, they are prone to internal corrosion, hollow collapse, delamination and other phenomena, which not only affect the quality of carbon fiber rigid felts, but may also change the thermal conductivity of carbon fiber rigid felts, thereby affecting the thermal insulation performance and service life of carbon fiber rigid felts.

[0007] 3) For carbon fiber insulation materials that are bonded layer by layer, the internal stress is high, they are prone to deformation, and it is difficult to make them into thin insulation layers (too thin will result in large deformation and bending). The problems are more prominent during use, increasing the risk of heater arcing and making the use risk high.

[0008] 4) Existing carbon fiber rigid felt materials are often impregnated with a large amount of binder, resulting in a relatively low fiber content in the material, which leads to unsatisfactory thermal insulation performance of the product.

[0009] In summary, existing carbon fiber insulation materials are prone to warping and delamination after curing, shaping, and high-temperature carbonization. This not only affects product quality but may also alter the thermal conductivity, thereby impacting the product's insulation performance and service life. Therefore, developing a novel carbon fiber insulation material that improves insulation performance, service life, and processing efficiency while reducing production costs has become a key research focus and challenge. Summary of the Invention

[0010] This invention provides a high-insulation composite carbon fiber thermal insulation material and its preparation method. While ensuring that important indicators such as service life and ash content control remain unchanged, it reduces the thermal conductivity of the product and improves its thermal insulation performance by utilizing density differences and the cavity thermal radiation effect. On the one hand, it sets up a density gradient structure to effectively reduce heat conduction while minimizing the impact of stress. On the other hand, it uses a cavity thermal insulation design through crystal growth thermal field simulation, and further improves the thermal insulation effect of the product by utilizing the principles of heat conduction and heat radiation.

[0011] To achieve the above objectives, the present invention employs the following technical solution:

[0012] A high-performance composite carbon fiber insulation material includes an inner carbon fiber rigid felt, a middle carbon fiber rigid felt, and an outer carbon fiber rigid felt, wherein the density of the inner carbon fiber rigid felt is greater than the density of the outer carbon fiber rigid felt, and the apparent density of the middle carbon fiber rigid felt is greater than that of the middle carbon fiber rigid felt; wherein the middle carbon fiber rigid felt has multiple cavities; the inner carbon fiber rigid felt and the middle carbon fiber rigid felt, as well as the middle carbon fiber rigid felt and the outer carbon fiber rigid felt, are bonded together using a pre-made adhesive composite film; the composite carbon fiber insulation material is subjected to hot-press curing and graphitization treatment.

[0013] The density of the inner carbon fiber rigid felt is 0.2–0.3 g / cm³. 3 The density of the intermediate carbon fiber rigid felt is 0.12–0.18 g / cm³. 3 The density of the outer carbon fiber rigid felt is 0.12–0.16 g / cm³. 3 .

[0014] The thickness of the inner carbon fiber rigid felt is 10-40 mm; the thickness of the middle carbon fiber rigid felt is 10-120 mm; and the thickness of the outer carbon fiber rigid felt is 10-40 mm.

[0015] Composite carbon fiber insulation materials are rectangular, circular, or ring-shaped.

[0016] The cavity can be a rectangular cavity, a fan-shaped cavity, or an arc-shaped cavity.

[0017] The cavity is either a vacuum or filled with an inert gas; or the cavity is filled with carbon fiber felt, the density of which is 0.07–0.1 g / cm³. 3 .

[0018] The thickness of the adhesive composite film is 400–1700 μm.

[0019] A method for preparing a composite carbon fiber insulation material with high thermal insulation performance includes the following steps:

[0020] 1) Cutting the inner carbon fiber hard felt, the middle carbon fiber hard felt and the outer carbon fiber hard felt: Cut the inner carbon fiber hard felt, the middle carbon fiber hard felt and the outer carbon fiber hard felt according to the set size and thickness.

[0021] 2) Preparation of adhesive composite membrane: The adhesive composite membrane is composed of adhesive, carbon fiber powder, vapor-deposited carbon particles, plasticizer and catalyst in a mass ratio of 30-60 parts: 10-40 parts: 5-30 parts: 3-10 parts: 2-20 parts; after the components are mixed evenly, they are thermoplasticized at 80-150℃ to form a film, and after cooling, the adhesive composite membrane is obtained.

[0022] 3) Cut the adhesive composite film according to the shape of the adhesive part;

[0023] 4) Curing and bonding: Place the inner carbon fiber rigid felt horizontally, place the lower adhesive composite film on it, place the middle carbon fiber rigid felt on the lower adhesive composite film, then place the upper adhesive composite film, and finally place the outer carbon fiber rigid felt on the upper adhesive composite film to form an assembly; place the assembly in a hot press and cure it at 150-280℃ for 30-150 minutes.

[0024] 5) Graphitization treatment: The hot-pressed and cured assembly is graphitized under an inert atmosphere or vacuum. The graphitization temperature is 1800-2400℃ and the treatment time is 2-6h to obtain composite carbon fiber insulation material.

[0025] The adhesive is one or more of phenolic resin, epoxy resin, polycarbonate, polyamide, polymethyl methacrylate, and asphalt; the plasticizer is one or more of tributyl citrate, acetylated tributyl citrate, diethylene glycol xylene ester, dipropylene glycol dibenzoate, epoxidized soybean oil, and epoxidized fatty acid octyl ester; the catalyst is one or more of ammonium bromide, ammonium carbonate, and ammonium bicarbonate.

[0026] The fiber length of the carbon fiber powder is 10–200 μm; the particle size of the vapor-deposited carbon particles is 10–100 μm.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1) The composite carbon fiber insulation material produced by this invention can effectively solve the problem of high interlayer stress, and will not deform, delaminate or crack, thereby avoiding heater sparking, reducing pulverization and other problems, which is conducive to improving the quality of products in the furnace.

[0029] 2) The composite carbon fiber insulation material produced by this invention has a high inner layer density and uniform porosity, and is not prone to internal corrosion, hollow collapse, delamination and other phenomena caused by infiltration. It has stable insulation performance and long service life.

[0030] 3) The composite carbon fiber insulation material produced by this invention uses a special adhesive with a relatively small amount of adhesive, resulting in low internal stress and reduced deformation, effectively avoiding the risk of heater arcing.

[0031] 4) The composite carbon fiber insulation material produced by this invention has a low binder content and a high fiber content, and is provided with cavities or low-density soft felt, which effectively improves the thermal insulation performance, achieves the purpose of energy saving and consumption reduction, and reduces the cost of use. Attached Figure Description

[0032] Figure 1 This is a three-dimensional structural diagram of the composite carbon fiber insulation material in Embodiment 1 of the present invention (excluding the inner insulation board).

[0033] Figure 1a yes Figure 1 The main view.

[0034] Figure 1b yes Figure 1a AA section view in the image.

[0035] Figure 2 This is a three-dimensional structural diagram of the composite carbon fiber thermal insulation material in Embodiment 2 of the present invention.

[0036] Figure 2a yes Figure 1 The main view.

[0037] Figure 2byes Figure 2a BB section view in the middle.

[0038] Figure 3 This is a three-dimensional structural diagram of the composite carbon fiber thermal insulation material in Embodiment 3 of the present invention.

[0039] Figure 3a yes Figure 3 The main view.

[0040] Figure 3b yes Figure 3a CC section view in the image.

[0041] In the diagram: 11. Outer insulation board; 12. Inner insulation board; 13. Longitudinal edge strip; 14. Transverse edge strip; 15. Longitudinal spacer; 16. Transverse spacer; 17. Rectangular cavity; 21. Outer insulation plate; 22. Inner insulation plate; 23. Circumferential edge strip; 24. Middle ring strip; 25. Radial spacer; 26. Fan-shaped cavity; 31. Outer insulation ring; 32. Inner insulation ring; 33. Annular outer edge strip; 34. Annular inner edge strip; 35. Radial short spacer; 36. Arc-shaped cavity. Detailed Implementation

[0042] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0043] like Figure 1 , Figure 2 , Figure 3 As shown, the high thermal insulation performance composite carbon fiber insulation material of the present invention includes an inner carbon fiber hard felt, a middle carbon fiber hard felt, and an outer carbon fiber hard felt, wherein the density of the inner carbon fiber hard felt is greater than the density of the outer carbon fiber hard felt and the apparent density of the middle carbon fiber hard felt; wherein, the middle carbon fiber hard felt has multiple cavities; the inner carbon fiber hard felt and the middle carbon fiber hard felt, as well as the middle carbon fiber hard felt and the outer carbon fiber hard felt, are bonded together by a pre-made adhesive composite film; the composite carbon fiber insulation material as a whole is subjected to hot pressing curing and graphitization treatment.

[0044] The density of the inner carbon fiber rigid felt is 0.2–0.3 g / cm³. 3 The density of the intermediate carbon fiber rigid felt is 0.12–0.18 g / cm³. 3 The density of the outer carbon fiber rigid felt is 0.12–0.16 g / cm³. 3 .

[0045] The thickness of the inner carbon fiber rigid felt is 10-40 mm; the thickness of the middle carbon fiber rigid felt is 10-120 mm; and the thickness of the outer carbon fiber rigid felt is 10-40 mm.

[0046] The composite carbon fiber insulation material is rectangular in shape (e.g., Figure 1 As shown), circular (as shown) Figure 2 (as shown) or circular (e.g.) Figure 3 (As shown).

[0047] The cavity is a rectangular cavity (e.g., Figure 1 As shown), sector-shaped cavity (as shown) Figure 2 (as shown) or arc-shaped cavity (such as) Figure 3 (As shown).

[0048] The cavity is either a vacuum or filled with an inert gas; or the cavity is filled with carbon fiber felt, the density of which is 0.07–0.1 g / cm³. 3 .

[0049] The thickness of the adhesive composite film is 400–1700 μm.

[0050] The preparation method of the high thermal insulation performance composite carbon fiber insulation material of the present invention includes the following steps:

[0051] 1) Cutting the inner carbon fiber hard felt, the middle carbon fiber hard felt and the outer carbon fiber hard felt: Cut the inner carbon fiber hard felt, the middle carbon fiber hard felt and the outer carbon fiber hard felt according to the set size and thickness.

[0052] 2) Preparation of adhesive composite membrane: The adhesive composite membrane is composed of adhesive, carbon fiber powder, vapor-deposited carbon particles, plasticizer and catalyst in a mass ratio of 30-60 parts: 10-40 parts: 5-30 parts: 3-10 parts: 2-20 parts; after the components are mixed evenly, they are thermoplasticized at 80-150℃ to form a film, and after cooling, the adhesive composite membrane is obtained.

[0053] 3) Cut the adhesive composite film according to the shape of the adhesive part;

[0054] 4) Curing and bonding: Place the inner carbon fiber rigid felt horizontally, place the lower adhesive composite film on it, place the middle carbon fiber rigid felt on the lower adhesive composite film, then place the upper adhesive composite film, and finally place the outer carbon fiber rigid felt on the upper adhesive composite film to form an assembly; place the assembly in a hot press and cure it at 150-280℃ for 30-150 minutes.

[0055] 5) Graphitization treatment: The hot-pressed and cured assembly is graphitized under an inert atmosphere or vacuum. The graphitization temperature is 1800-2400℃ and the treatment time is 2-6h to obtain composite carbon fiber insulation material.

[0056] The adhesive is one or more of phenolic resin, epoxy resin, polycarbonate, polyamide, polymethyl methacrylate, and asphalt; the plasticizer is one or more of tributyl citrate, acetylated tributyl citrate, diethylene glycol xylene ester, dipropylene glycol dibenzoate, epoxidized soybean oil, and epoxidized fatty acid octyl ester; the catalyst is one or more of ammonium bromide, ammonium carbonate, and ammonium bicarbonate.

[0057] The fiber length of the carbon fiber powder is 10–200 μm; the particle size of the vapor-deposited carbon particles is 10–100 μm.

[0058] The high thermal insulation composite carbon fiber insulation material of the present invention has a three-layer composite structure. All three structural layers are made of carbon fiber rigid felt. The middle layer of carbon fiber rigid felt has multiple cavities inside. The middle layer of carbon fiber rigid felt can be strip felt, which can be combined to form the required cavity shape, such as rectangular, fan-shaped or arc-shaped.

[0059] The inner and outer carbon fiber rigid felts are made of carbon fiber rigid felts of corresponding densities, cut and slit flat according to the required thickness, with the thickness preferably being 10-40mm.

[0060] The intermediate carbon fiber rigid felt is obtained by subtracting the thickness of the inner and outer carbon fiber rigid felts from the total thickness of the composite carbon fiber insulation material, with a preferred thickness of 10-120 mm. When made of strip felt, the preferred length of a single strip is 300-1500 mm and the width is 30-100 mm.

[0061] The adhesive composite film is prefabricated and then rolled up and stored after production. The adhesive composite film of the present invention has the advantages of being easy to store and convenient to use. On the one hand, it does not need to be dissolved with solvent before use, so it will not cause pollution to the environment. On the other hand, it eliminates the drying and curing process after lamination, reducing energy consumption and making it energy-saving and environmentally friendly.

[0062] When the intermediate carbon fiber rigid felt is made of strip felt, the adhesive composite film can be cut according to the size of the strip felt, that is, the cutting length is 300-1500mm and the width is 30-100mm.

[0063] like Figure 1 As shown, when the composite carbon fiber insulation material is a rectangular plate structure, the corresponding cavity is preferably a rectangular cavity, and the length and width of the rectangular cavity are preferably 200-600mm.

[0064] like Figure 2 As shown, when the composite carbon fiber insulation material has a circular disc structure, the corresponding cavity is preferably a fan-shaped cavity. The fan-shaped cavity is obtained by dividing the central angle into equal parts of 5° to 90°. The smaller the diameter, the larger the circumferential angle, and the larger the diameter, the smaller the circumferential angle.

[0065] like Figure 3 As shown, when the composite carbon fiber insulation material has a circular structure, the corresponding cavity is preferably an arc-shaped cavity. The arc-shaped cavity is obtained by dividing the central angle into equal parts of 5° to 90°. The smaller the diameter, the larger the circumferential angle, and the larger the diameter, the smaller the circumferential angle.

[0066] The high thermal insulation composite carbon fiber insulation material described in this invention has the following advantages:

[0067] 1) The inner carbon fiber rigid felt is made of high-density carbon fiber rigid felt. The cavity in the middle carbon fiber rigid felt is designed to be rectangular, fan-shaped or arc-shaped. During the manufacturing process, strips of carbon fiber rigid felt are bonded to the inner carbon fiber rigid felt to form cavities of the set shape. Then, a low-density outer carbon fiber rigid felt is bonded to the outside to finally obtain composite carbon fiber thermal insulation material. This can effectively solve the problems of easy delamination, deformation, powdering and flaking of existing carbon fiber rigid felt, and improve performance stability and service life.

[0068] 2) The composite carbon fiber insulation material of the present invention adopts a structural design with a density gradient in the thickness direction. The inner layer has a high density, while the middle and outer layers have low densities. This not only ensures the overall insulation performance, but also avoids the problem of poor thermal insulation performance caused by heat radiation in high-temperature environments when traditional surface fiber insulation materials adopt a low-density design. This effectively improves the thermal insulation performance of carbon fiber insulation materials.

[0069] 3) The middle layer of carbon fiber rigid felt adopts a cavity or soft felt filling structure design, which effectively reduces the overall weight of carbon fiber insulation material while enhancing its bonding force with the furnace support; the inner layer of carbon fiber rigid felt has a higher density, which helps to reduce wear and extend service life; by improving the curing and shaping process of carbon fiber insulation material, corrosion collapse and delamination are avoided, ensuring the quality of finished products.

[0070] 4) Through special structural design, the characteristics of the inner carbon fiber hard felt, the outer carbon fiber hard felt and the middle cavity structure are fully utilized, which effectively improves the high temperature resistance, thermal shock resistance and overall performance of the finished product; the composite carbon fiber insulation material has a low thermal conductivity and good thermal insulation, which is conducive to energy saving and consumption reduction.

[0071] 5) The intermediate carbon fiber hard felt and the filling soft felt can be made from the leftover materials after processing (such as strip or block leftover materials), which improves the utilization rate of materials, reduces production costs, and realizes the full utilization of resources.

[0072] 6) The adhesive composite film is easy to store and use. By adding a catalyst, the activation energy of the reaction is reduced, the reaction rate is increased, and the tensile strength and toughness of the adhesive composite film are improved. After carbonization, the residual carbon of the adhesive can be increased, and it also has certain flame retardant properties, which can prevent the adhesive from ablation and deterioration due to excessive temperature.

[0073] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0074]

Example 1

[0075] This embodiment produces a 60mm thick plate-shaped composite carbon fiber insulation material, which consists of an inner layer of carbon fiber rigid felt, a middle layer of carbon fiber rigid felt, and an outer layer of carbon fiber rigid felt.

[0076] The inner and outer carbon fiber rigid felts were cut from corresponding sealed carbon fiber rigid felts. The density of the inner carbon fiber rigid felt is 0.25 g / cm³. 3 The density of the outer carbon fiber rigid felt is 0.14 g / cm³. 3 After being flattened, the thickness of each layer is 20mm, and the overall dimensions are 1500mm (length) × 1200mm (width) × 20mm (thickness). The middle layer is made of carbon fiber rigid felt with a density of 0.17g / cm³. 3 Strips of felt spliced ​​together.

[0077] like Figure 1 , Figure 1a and Figure 1b As shown, in this embodiment, the outer carbon fiber rigid felt is the outer insulation board 11, and the inner carbon fiber rigid felt is the inner insulation board 12. The longitudinal edges of the outer insulation board 11 and the inner insulation board 12 are closed by longitudinal edge strips 13, and the transverse edges are closed by transverse edge strips 14. Ten rectangular cavities 17 are divided within the rectangular space enclosed by the longitudinal edge strips 13 and the transverse edge strips 14 by one longitudinal partition strip 15 and four transverse partition strips 16. The longitudinal edge strip 13, the transverse edge strips 14, the longitudinal partition strip 15, and the transverse partition strips 16 together constitute the middle carbon fiber rigid felt.

[0078] In this embodiment, the preparation process of the composite carbon fiber thermal insulation material is as follows:

[0079] (1) Cut the inner carbon fiber hard felt, the middle carbon fiber hard felt, and the outer carbon fiber hard felt for later use: Cut the inner carbon fiber hard felt and the outer carbon fiber hard felt according to the set dimensions; based on the total thickness of the composite carbon fiber insulation material, subtract the thickness of the inner carbon fiber hard felt and the outer carbon fiber hard felt to obtain a thickness of 20mm for the middle carbon fiber hard felt. The width of the strip felt (including longitudinal edge strips 13, transverse edge strips 14, longitudinal spacers 15, and transverse spacers 16) is 50mm. The strip felt is cut into 3 specifications, of which: 6 strips of 1100mm (length) × 50mm (width) × 20mm (thickness) are used as transverse edge strips 14 and transverse spacers 16; 5 strips of 300mm (length) × 50mm (width) × 20mm (thickness) are used as segmented longitudinal spacers 15; 2 strips of 1500mm (length) × 50mm (width) × 20mm (thickness) are used as longitudinal edge strips 13. Along the longitudinal direction of the composite carbon fiber insulation material, the spacing between the strips is 300mm, and along the transverse direction of the composite carbon fiber insulation material, the spacing between the strips is 600mm, ultimately forming 10 rectangular cavities 17.

[0080] (2) Preparation of adhesive composite film: 50 parts of phenolic resin (adhesive), 30 parts of carbon fiber powder with a fiber length of 50 μm, 20 parts of vapor-deposited carbon particles with a particle size of 50 μm, 5 parts of tributyl citrate (plasticizer) and 7 parts of ammonium bromide (catalyst) are mixed evenly and thermoplasticized at 100℃ to form a film. After cooling, an adhesive composite film with a thickness of 690 μm is obtained and rolled up for storage.

[0081] (3) Cut adhesive composite film: Cut adhesive composite film in three specifications, including 12 strips of 1100mm (length) × 50mm (width), 10 strips of 300mm (length) × 50mm (width), and 4 strips of 1500mm (length) × 50mm (width).

[0082] (4) Curing and bonding: Place the inner carbon fiber hard felt horizontally, place the lower adhesive composite film on it, place the middle carbon fiber hard felt on the lower adhesive composite film, place the upper adhesive composite film, and finally place the outer carbon fiber hard felt on the upper adhesive composite film to form an assembly; place the assembly in a hot press and cure it at 220°C for 120 minutes.

[0083] (5) Graphitization treatment: The hot-pressed and cured assembly is graphitized under an inert atmosphere or vacuum. The graphitization treatment temperature is 2000℃ and the treatment time is 3h to obtain composite carbon fiber insulation material.

[0084] In this embodiment, the thermal conductivity of the composite carbon fiber insulation material is 0.121 W / (m·K). After 100 cycles in a vacuum furnace, no delamination, warping, peeling, or powdering occurred. Compared with commercially available conventional carbon fiber insulation materials, it saves 30% of energy consumption, demonstrating significant energy-saving and consumption-reducing effects.

[0085]

Example 2

[0086] This embodiment produces a disc-shaped composite carbon fiber insulation material with a thickness of 80mm, which consists of an inner layer of carbon fiber rigid felt, a middle layer of carbon fiber rigid felt, and an outer layer of carbon fiber rigid felt.

[0087] The inner and outer carbon fiber rigid felts were cut from corresponding sealed carbon fiber rigid felts. The density of the inner carbon fiber rigid felt is 0.26 g / cm³. 3 The density of the outer carbon fiber rigid felt is 0.15 g / cm³. 3 The thickness after flattening is 20mm, and the external dimensions are... The intermediate layer of carbon fiber rigid felt has a density of 0.16 g / cm³. 3 Strips of felt spliced ​​together.

[0088] like Figure 2 , Figure 2a and Figure 2b As shown, in this embodiment, the outer carbon fiber rigid felt is the outer insulation plate 21, and the inner carbon fiber rigid felt is the inner insulation plate 22. The circumferential edges of the outer insulation plate 21 and the inner insulation plate 22 are closed by circumferential edge strips 23. The intermediate ring strip 24 is coaxially arranged with the circumferential edge strip 23, and the intermediate ring strip 24 and the circumferential edge strip 23 are separated into eight fan-shaped cavities 26 by eight radial spacers 25. The sector angle of each fan-shaped cavity 26 is 45°. The circumferential edge strip 23, the intermediate edge strip 24, and the radial spacers 25 together constitute the intermediate carbon fiber rigid felt.

[0089] In this embodiment, the preparation process of the composite carbon fiber thermal insulation material is as follows:

[0090] (1) Cut the inner layer carbon fiber hard felt, the middle layer carbon fiber hard felt, and the outer layer carbon fiber hard felt for later use: Cut the inner layer carbon fiber hard felt and the outer layer carbon fiber hard felt according to the set dimensions; based on the total thickness of the composite carbon fiber insulation material, subtract the thickness of the inner layer carbon fiber hard felt and the outer layer carbon fiber hard felt to obtain a thickness of 40mm for the middle layer carbon fiber hard felt. The width of the strip felt (including circumferential edge strips 23, middle ring strips 24, and radial spacers 25) is 40mm. The strip felt is cut into 3 specifications, of which: 6 arc strips with an outer arc length of 525mm, a width of 40mm, and a thickness of 40mm are used as circumferential edge strips 23; One small round plate is used as the middle ring 24; eight strips measuring 622mm (length) × 40mm (width) × 40mm (thickness) are used as radial spacers 25.

[0091] (2) Preparation of adhesive composite film: 35 parts asphalt (adhesive), 35 parts carbon fiber powder with a fiber length of 60 μm, 15 parts vapor-deposited carbon particles with a particle size of 55 μm, 10 parts diethylene glycol xylene ester (plasticizer), and 12 parts ammonium bicarbonate (catalyst) are mixed evenly and thermoplasticized at 120℃ to form a film. After cooling, an adhesive composite film with a thickness of 920 μm is obtained and rolled up for storage.

[0092] (3) Cutting the adhesive composite film: Cut the adhesive composite film into three specifications, including the outer diameter. inner diameter Two ring-shaped parts, two circular parts with a diameter of 200mm, and 16 strip-shaped parts with a length of 622mm and a width of 40mm.

[0093] (4) Curing and bonding: Place the inner carbon fiber hard felt horizontally, place the lower adhesive composite film on it, place the middle carbon fiber hard felt on the lower adhesive composite film, place the upper adhesive composite film, and finally place the outer carbon fiber hard felt on the upper adhesive composite film to form an assembly; place the assembly in a hot press and cure it at 240°C for 70 minutes.

[0094] (5) Graphitization treatment: The hot-pressed and cured assembly is graphitized under an inert atmosphere or vacuum. The graphitization treatment temperature is 2000℃ and the treatment time is 4h to obtain composite carbon fiber insulation material.

[0095] In this embodiment, the thermal conductivity of the composite carbon fiber insulation material is 0.116 W / (m·K). After 120 cycles in a vacuum furnace, no delamination, warping, peeling, or powdering occurred. Compared with commercially available conventional carbon fiber insulation materials, it saves 32% of energy consumption, demonstrating significant energy-saving and consumption-reducing effects.

[0096]

Example 3

[0097] This embodiment produces a 100mm thick annular composite carbon fiber insulation material, which consists of an inner carbon fiber rigid felt, a middle carbon fiber rigid felt, and an outer carbon fiber rigid felt.

[0098] The inner and outer carbon fiber rigid felts were cut from corresponding sealed carbon fiber rigid felts. The density of the inner carbon fiber rigid felt is 0.25 g / cm³. 3 The density of the outer carbon fiber rigid felt is 0.14 g / cm³. 3 The thickness after flattening is 20mm, and the external dimensions are... The intermediate layer of carbon fiber rigid felt has a density of 0.16 g / cm³. 3 Strips of felt spliced ​​together.

[0099] like Figure 3 , Figure 3a and Figure 3b As shown, in this embodiment, the outer carbon fiber rigid felt is the outer insulation ring 31, and the inner carbon fiber rigid felt is the inner insulation ring 32. The outer circumferential edges of the outer insulation ring 31 and the inner insulation ring 32 are closed by annular outer edge strips 33, and the inner circumferential edges are closed by annular inner edge strips 34. The annular outer edge strips 33 and annular inner edge strips 34 are coaxially arranged. The annular space between the annular inner edge strips 34 and the annular outer edge strips 33 is divided into eight arc-shaped cavities 36 by eight radial short spacers 35. The sector angle of each arc-shaped cavity 36 is 45°. The annular outer edge strips 33, the annular inner edge strips 34, and the radial short spacers 35 together constitute the middle layer of carbon fiber rigid felt.

[0100] In this embodiment, the preparation process of the composite carbon fiber thermal insulation material is as follows:

[0101] (1) Cut the inner carbon fiber hard felt, the middle carbon fiber hard felt, and the outer carbon fiber hard felt for later use: Cut the inner carbon fiber hard felt and the outer carbon fiber hard felt according to the set dimensions; after subtracting the thickness of the inner carbon fiber hard felt and the outer carbon fiber hard felt from the total thickness of the composite carbon fiber insulation material, the thickness of the middle carbon fiber hard felt is 60mm. The width of the strip felt (including the outer ring strip 33, the inner ring strip 34, and the radial short spacer strip 35) is 60mm. The strip felt is cut into 3 specifications, of which: 8 arc strips with an outer arc length of 505mm, a width of 60mm, and a thickness of 60mm are used as the outer ring strip 33; 8 arc strips with an inner arc length of 380mm, a width of 60mm, and a thickness of 60mm are used as the inner ring strip 34; 8 strips with a length of 220mm × a width of 60mm × a thickness of 60mm are used as the radial short spacer strip 35.

[0102] (2) Preparation of adhesive composite film: 60 parts of epoxy resin (adhesive), 25 parts of carbon fiber powder with a fiber length of 60 μm, 25 parts of vapor-deposited carbon particles with a particle size of 55 μm, 7 parts of epoxidized soybean oil (plasticizer), and 16 parts of ammonium carbonate (catalyst) are mixed evenly and thermoplasticized at 110℃ to form a film. After cooling, an adhesive composite film with a thickness of 1150 μm is obtained and wound up for storage.

[0103] (3) Cutting the adhesive composite film: Cut the adhesive composite film into three specifications, including the outer diameter. inner diameter Two ring-shaped parts, outer diameter inner diameter Two ring-shaped parts and 16 strip-shaped parts measuring 220mm (length) × 60mm (width);

[0104] (4) Curing and bonding: Place the inner carbon fiber hard felt horizontally, place the lower adhesive composite film on it, place the middle carbon fiber hard felt on the lower adhesive composite film, place the upper adhesive composite film, and finally place the outer carbon fiber hard felt on the upper adhesive composite film to form an assembly; place the assembly in a hot press and cure it at 230°C for 100 minutes.

[0105] (5) Graphitization treatment: The hot-pressed and cured assembly is graphitized under an inert atmosphere or vacuum. The graphitization treatment temperature is 2000℃ and the treatment time is 5h to obtain composite carbon fiber insulation material.

[0106] In this embodiment, the thermal conductivity of the composite carbon fiber insulation material is 0.132 W / (m·K). After 140 cycles in a vacuum furnace, no delamination, warping, peeling, or powdering occurred. Compared with commercially available conventional carbon fiber insulation materials, it saves 24% of energy consumption, demonstrating significant energy-saving and consumption-reducing effects.

[0107] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A composite carbon fiber insulation material with high thermal insulation performance, characterized in that, It includes an inner layer of carbon fiber rigid felt, a middle layer of carbon fiber rigid felt, and an outer layer of carbon fiber rigid felt, with the density of the inner layer of carbon fiber rigid felt being greater than that of the outer layer of carbon fiber rigid felt, which in turn is greater than that of the middle layer of carbon fiber rigid felt. The middle layer of carbon fiber rigid felt has multiple cavities. The inner and middle layers of carbon fiber rigid felt, as well as the middle and outer layers of carbon fiber rigid felt, are bonded together using a pre-made adhesive composite film. The composite carbon fiber insulation material is subjected to hot-press curing and graphitization treatment. The hot-press curing temperature is 150–280℃, and the time is 30–150 min. The density of the inner carbon fiber rigid felt is 0.2–0.3 g / cm³. 3 The density of the intermediate carbon fiber rigid felt is 0.12–0.18 g / cm³. 3 The density of the outer carbon fiber rigid felt is 0.12–0.16 g / cm³. 3 ; The adhesive composite film is composed of adhesive, carbon fiber powder, vapor-deposited carbon particles, plasticizer and catalyst in a mass ratio of 30-60 parts: 10-40 parts: 5-30 parts: 3-10 parts: 2-20 parts; after the components are mixed evenly, they are thermoplasticized at 80-150°C to form a film, and after cooling, the adhesive composite film is obtained. The binder is one or more of phenolic resin, epoxy resin, polycarbonate, polyamide, polymethyl methacrylate, and asphalt; the plasticizer is one or more of tributyl citrate, acetylated tributyl citrate, diethylene glycol xylene ester, dipropylene glycol dibenzoate, epoxidized soybean oil, and epoxidized fatty acid octyl ester; the catalyst is one or more of ammonium bromide, ammonium carbonate, and ammonium bicarbonate.

2. The high thermal insulation performance composite carbon fiber insulation material according to claim 1, characterized in that, The thickness of the inner carbon fiber rigid felt is 10-40 mm; the thickness of the middle carbon fiber rigid felt is 10-120 mm; and the thickness of the outer carbon fiber rigid felt is 10-40 mm.

3. The high thermal insulation performance composite carbon fiber insulation material according to claim 1, characterized in that, Composite carbon fiber insulation materials are rectangular, circular, or ring-shaped.

4. The high thermal insulation performance composite carbon fiber insulation material according to claim 1, characterized in that, The cavity is a rectangular cavity or an arc-shaped cavity.

5. The high thermal insulation performance composite carbon fiber insulation material according to claim 1, characterized in that, The cavity is either a vacuum or filled with an inert gas; or the cavity is filled with carbon fiber felt, the density of which is 0.07–0.1 g / cm³. 3 .

6. The high thermal insulation performance composite carbon fiber insulation material according to claim 1, characterized in that, The thickness of the adhesive composite film is 400–1700 μm.

7. A method for preparing a composite carbon fiber insulation material with high thermal insulation performance as described in any one of claims 1 to 6, characterized in that, Includes the following steps: 1) Cutting the inner carbon fiber hard felt, the middle carbon fiber hard felt and the outer carbon fiber hard felt: Cut the inner carbon fiber hard felt, the middle carbon fiber hard felt and the outer carbon fiber hard felt according to the set size and thickness. 2) Preparation of adhesive composite membrane: The adhesive composite membrane is composed of adhesive, carbon fiber powder, vapor-deposited carbon particles, plasticizer and catalyst in a mass ratio of 30-60 parts: 10-40 parts: 5-30 parts: 3-10 parts: 2-20 parts; after the components are mixed evenly, they are thermoplasticized at 80-150℃ to form a film, and after cooling, the adhesive composite membrane is obtained. 3) Cut the adhesive composite film according to the shape of the adhesive part; 4) Curing and bonding: Place the inner carbon fiber rigid felt horizontally, place the lower adhesive composite film on it, place the middle carbon fiber rigid felt on the lower adhesive composite film, then place the upper adhesive composite film, and finally place the outer carbon fiber rigid felt on the upper adhesive composite film to form an assembly; place the assembly in a hot press and cure it at 150-280℃ for 30-150 minutes. 5) Graphitization treatment: The hot-pressed and cured assembly is graphitized under an inert atmosphere or vacuum. The graphitization treatment temperature is 1800-2400℃ and the treatment time is 2-6h to obtain composite carbon fiber insulation material.

8. The method for preparing a high-thermal-insulation composite carbon fiber insulation material according to claim 7, characterized in that, The fiber length of the carbon fiber powder is 10–200 μm; the particle size of the vapor-deposited carbon particles is 10–100 μm.

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