Composite thermal insulation board and preparation method thereof

Abstract

The invention provides a composite thermal insulation board and a preparation method thereof. Ceramic fibers, carbon nanotubes, organic or inorganic silicon, glass beads, a heat reflecting agent and other materials are used as raw materials, and the composite material is prepared through compression molding. The high-temperature heat conductivity coefficient is high, the melting point is high, all temperature zone wave bands of heat radiation can be shielded, heat convection and heat transfer are blocked, the A1-level fireproof standard is achieved, the preparation technology is simple, batch production can be achieved, and the material is widely applied to industrial and building heat insulation scenes.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation materials technology, specifically to a composite thermal insulation board and its preparation method. Background Technology

[0002] With the escalating global energy crisis and environmental degradation, energy conservation and environmental protection have become a major concern, leading to increasingly higher demands on thermal insulation technology. In recent years, thermal insulation materials have developed rapidly. Currently, commonly used thermal insulation materials can be mainly divided into three categories based on their composition: organic thermal insulation materials, inorganic thermal insulation materials, and composite thermal insulation materials. They differ in performance and advantages.

[0003] Organic insulation materials, such as common polystyrene boards and polyurethane foam, are lightweight, dense, waterproof, moisture-resistant, and easy to process, resulting in low overall cost and widespread use. However, they have certain drawbacks, such as poor aging resistance and flammability, which, once ignited, produce smoke and toxic gases, posing a threat to the environment and human health.

[0004] Inorganic insulation materials, such as rock wool, glass wool, and aerogel felt, are seeing their usage increase year by year due to their non-combustibility, high temperature resistance, and stable performance. However, they are heavy, have high thermal conductivity, high water absorption, high production costs, complex processes, and difficult construction, and are prone to generating dust, fine fibers, and other substances.

[0005] Both organic and inorganic thermal insulation materials have certain drawbacks. In order to overcome the shortcomings of thermal insulation materials, it is of great significance to develop green composite thermal insulation materials with high safety performance, fire resistance and flame retardancy, and thermal insulation properties. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a composite thermal insulation board and its preparation method. This board has a high thermal conductivity and a high melting point, which can shield all temperature bands of heat radiation, block heat convection and heat transfer, achieve good fire resistance and thermal insulation performance, meet the A1 fire resistance standard, and has a simple preparation process that can be mass-produced.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a composite thermal insulation board, comprising a hot panel, an insulation core material, a nano panel, and a cold panel, wherein the hot panel is located on the external fire-facing side of the composite thermal insulation board, the cold panel is located on the external un-fire-facing side of the composite thermal insulation board, the insulation core material and the nano panel are located inside the composite thermal insulation board, the insulation core material is adjacent to the hot panel, and the nano panel is adjacent to the cold panel.

[0008] Furthermore, the raw materials for the hot panel and the cold panel are alumina (45% aluminum), aluminum nitride, or silicon dioxide (98% silicon) ceramic fibers.

[0009] Furthermore, the diameter of the ceramic fiber is 2-4 mm.

[0010] Furthermore, the thermal insulation core material has a porous structure, and its raw materials, by weight, include: 10-15 parts vitrified microspheres, 3-5 parts organosiloxane, 10-20 parts inorganic silicon, 5-12 parts organosilanol, 1-5 parts silazane, 15-25 parts glass microspheres (particle size 2-20 μm), 10-15 parts closed-cell microspheres (particle size 30-150 mesh), 2-5 parts Fe2O3, 2-5 parts TiO2, 1-3 parts SiC, 1-3 parts potassium silicate, 30-50 parts gypsum, 10-20 parts cement, 0.2-3 parts ceramic fiber, 0.1-1 part glass fiber, 0.1-3 parts basalt fiber, 0.5-5 parts aluminum silicate fiber, 5-10 parts flaky expanded vermiculite, and 20-50 parts deionized water.

[0011] Furthermore, the raw materials of the nanoplate, by weight, include: 45-65% nano-scale inorganic heat insulation material, 35-45% fumed silica, 15-25% heat reflective protective agent, 3-8% fiber, 2-7% sericite or talc powder, and 5-30% binder.

[0012] Furthermore, the raw materials of the nanoplate, by weight, include: 35-65% nano-scale inorganic heat insulation material, 15-25% heat reflective protective agent, 3-8% fiber, 2-7% sericite or talc powder, 5-30% binder, and 2-10% carbon nanotubes.

[0013] Furthermore, the nanoscale inorganic thermal insulation material is one or a combination of two of fumed alumina nanopowder and fumed silica nanopowder.

[0014] Furthermore, the heat-reflective protective agent is one or a combination of two of silicon carbide, Fe3O4, TiO2, and cesium tungsten oxide.

[0015] Furthermore, the fiber is one or a combination of two of glass fiber, ceramic fiber, and alumina fiber.

[0016] Furthermore, the adhesive is polyamide (PI).

[0017] Furthermore, the composite thermal insulation board also includes a protective layer, which is sprayed onto the surface of the thermal panel.

[0018] Furthermore, the raw materials of the protective layer, by weight, include: 20-35 parts of inorganic resin, 5-15 parts of silazane resin, 5-15 parts of siloxane resin, 1-5 parts of nano alumina, 1-5 parts of mica, 2-8 parts of nano zirconium oxide, 10-20 parts of ethanol, 3-5 parts of deionized water, 0.5-2 parts of wetting agent, and 2-5 parts of nano dispersant.

[0019] Furthermore, the wetting agent is one or a combination of two of fatty alcohol polyoxyethylene ether, polyoxyethylene siloxane, sodium alkylbenzene sulfonate, and sodium dodecyl sulfate.

[0020] Furthermore, the nano-dispersant is one or a combination of two of sodium carboxymethyl cellulose and polyvinylpyrrolidone.

[0021] Secondly, the present invention provides a method for preparing the composite thermal insulation board, comprising the following steps: Step 1, Preparation of nanoplates Weigh the raw materials for the nanoplates according to the formula, mix them evenly, dry them at 50-120℃ for 5-60 min, hot press them at 100-250℃ and 50-200t, let them stand for 1-5 min, cool them to room temperature and pressure, and set them aside for use. Step 2: Preparation of thermal insulation core material Weigh the raw materials of the thermal insulation core material according to the formula, disperse them evenly, pour them into the pre-made mold, and demold them after solidification to obtain the blank material. Place the blank material into the curing rack, push it into the steam curing chamber, and cure it at 40~80℃ for 24~72 hours. Then, let it air dry or dry it at 40~80℃ for one week before use. Step 3: Compression molding Nanoboard, thermal insulation core material, hot panel material and cold panel material are sequentially placed into a pre-made mold, molded and cured, to obtain a composite thermal insulation board blank for later use. Step 4: Applying the protective layer Weigh the protective layer raw materials according to the ratio, grind them with a nano-grinding machine to obtain a slurry, spray the slurry onto the surface of the composite thermal insulation board blank, and cure it at room temperature to obtain a composite thermal insulation board.

[0022] The technical solution of this invention has the following advantages: This invention provides a composite thermal insulation board using fumed silica and aluminum dioxide. Silica has a thermal emissivity of 0.95-0.98, while aluminum has a thermal emissivity of 0.02-0.40, effectively blocking heat radiation transfer at high temperatures. The addition of a heat-reflective protective agent effectively shields all temperature bands of heat radiation, further blocking heat radiation transfer at high temperatures and improving the board's high-temperature impact resistance. Simultaneously, the inclusion of carbon nanotubes and polyamide (PI) provides excellent heat resistance and low thermal conductivity, maintaining a low thermal conductivity even at high temperatures. This further reduces the thermal conductivity of the nano-insulation board and also provides reinforcement and support, enhancing compressive strength and toughness.

[0023] The composite thermal insulation board of this invention is prepared by compression molding, which is simple and can be mass-produced. It is widely used in industrial and building thermal insulation applications. Attached Figure Description

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

[0025] Figure 1 This is a schematic diagram of the structure of the composite thermal insulation board provided in the embodiment of the present invention.

[0026] In the picture 1. Hot panel; 2. Insulation core material; 3. Nanoplate; 4. Cold panel. Figure 2 This is a cross-sectional view of the composite thermal insulation board product provided in the embodiment of the present invention. Figure 3 This is a thermal image of the composite thermal insulation board product provided in an embodiment of the present invention. Figure 4 This is a cold-side view of the composite thermal insulation board product provided in an embodiment of the present invention. Detailed Implementation

[0027] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0028] Where specific experimental steps or conditions are not specified in the embodiments, they can be performed according to the conventional experimental steps or conditions described in the literature in this field. All raw materials or instruments used are commercially available conventional products, including but not limited to those used in the embodiments of this application.

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The following will provide a detailed description, with reference to the accompanying drawings, of a composite thermal insulation board and its preparation method provided by an embodiment of this application.

[0030] Please see Figure 1 This document provides a structural schematic diagram of a composite thermal insulation board as an embodiment of this application. To address the shortcomings of organic insulation materials, such as flammability and the release of toxic fumes and gases upon contact with fire, and inorganic insulation materials, such as high construction difficulty and dust generation, this document provides a composite thermal insulation board with high thermal conductivity and high melting point, capable of shielding various temperature bands of heat radiation, blocking heat convection and heat transfer, achieving excellent fire resistance and thermal insulation performance, and meeting the A1 fire resistance standard. Figure 1 As shown in the figure, this application provides a composite thermal insulation board with a four-layer composite structure, including: a hot panel 1, an insulation core material 2, a nano-board 3, and a cold panel 4. The hot panel 1 and the cold panel 4 are located on the outside of the composite thermal insulation board, respectively on the fire-facing side and the un-fired side of the composite thermal insulation board. The insulation core material 2 and the nano-board 3 are located inside the composite thermal insulation board, with the insulation core material 2 adjacent to the hot panel 1 and the nano-board 3 adjacent to the cold panel 4.

[0031] Specifically, the raw materials for hot panel 1 and cold panel 4 are alumina (45% aluminum), aluminum nitride or silicon dioxide (98% silicon) ceramic fibers, with a diameter of 2-4 mm.

[0032] Specifically, the thermal insulation core material 2 has a porous structure, and its raw materials, by weight, include: 10-15 parts vitrified microspheres, 3-5 parts organosiloxane, 10-20 parts inorganic silicon, 5-12 parts organosilanol, 1-5 parts silazane, 15-25 parts glass microspheres (particle size 2-20μm), 10-15 parts closed-cell microspheres (particle size 30-150 mesh), 2-5 parts Fe2O3, 2-5 parts TiO2, 1-3 parts SiC, 1-3 parts potassium silicate, 30-50 parts gypsum, 10-20 parts cement, 0.2-3 parts ceramic fiber, 0.1-1 part glass fiber, 0.1-3 parts basalt fiber, 0.5-5 parts aluminum silicate fiber, 5-10 parts flaky expanded vermiculite, and 20-50 parts deionized water.

[0033] Specifically, the raw materials of nanoplate 3, by weight, include: 45-65% nano-level inorganic heat insulation material, 35-45% fumed silica, 15-25% heat reflective protective agent, 3-8% fiber, 2-7% sericite or talc, and 5-30% binder; or, include: 35-65% nano-level inorganic heat insulation material, 15-25% heat reflective protective agent, 3-8% fiber, 2-7% sericite or talc, 5-30% binder, and 2-10% carbon nanotubes.

[0034] Specifically, the nanoscale inorganic thermal insulation material is one or a combination of two of fumed alumina nanopowder and fumed silica nanopowder; the heat reflective protective agent is one or a combination of two of silicon carbide, Fe3O4, TiO2, and cesium tungsten oxide; the fiber is one or a combination of two of glass fiber, ceramic fiber, and alumina fiber; and the binder is polyamide (PI).

[0035] Furthermore, the composite thermal insulation board provided in this application embodiment also includes a protective layer, which is sprayed onto the surface of the heat-insulating panel 1.

[0036] Specifically, the raw materials of the protective layer, by weight, include: 20-35 parts inorganic resin, 5-15 parts silazane resin, 5-15 parts siloxane resin, 1-5 parts nano alumina, 1-5 parts mica, 2-8 parts nano zirconium oxide, 10-20 parts ethanol, 3-5 parts deionized water, 0.5-2 parts wetting agent, and 2-5 parts nano dispersant.

[0037] Furthermore, the wetting agent is one or a combination of two of fatty alcohol polyoxyethylene ether, polyoxyethylene siloxane, sodium alkylbenzene sulfonate, and sodium dodecyl sulfate; the nano-dispersant is one or a combination of two of sodium carboxymethyl cellulose and polyvinylpyrrolidone.

[0038] The method for preparing the composite thermal insulation board provided in this application includes the following steps: Step 1, Preparation of nanoplates Weigh the raw materials for the nanoplates according to the formula, mix them evenly, dry them at 50-120℃ for 5-60 min, hot press them at 100-250℃ and 50-200t, let them stand for 1-5 min, cool them to room temperature and pressure, and set them aside for use. Step 2: Preparation of thermal insulation core material Weigh the raw materials of the thermal insulation core material according to the formula, disperse them evenly, pour them into the pre-made mold, and demold them after solidification to obtain the blank material. Place the blank material into the curing rack, push it into the steam curing chamber, and cure it at 40~80℃ for 24~72 hours. Then, let it air dry or dry it at 40~80℃ for one week before use. Step 3: Compression molding Nanoboard, thermal insulation core material, hot panel material and cold panel material are sequentially placed into a pre-made mold, molded and cured, to obtain a composite thermal insulation board blank for later use. Step 4: Applying the protective layer Weigh the protective layer raw materials according to the ratio, grind them with a nano-grinding machine to obtain a slurry, spray the slurry onto the surface of the composite thermal insulation board blank, and cure it at room temperature to obtain a composite thermal insulation board.

[0039] Example 1 This embodiment provides a composite thermal insulation board with a four-layer composite structure, including: a thermal panel 1, a thermal insulation core material 2, a nano panel 3, and a cold panel 4.

[0040] The raw material for hot panel 1 and cold panel 4 is alumina (45% aluminum) ceramic fiber with a diameter of 2 mm.

[0041] The raw materials of the thermal insulation core material 2, by weight, include: 10 parts vitrified microspheres, 3 parts organosiloxane, 10 parts inorganic silicon, 5 parts organosilanol, 1 part silazane, 15 parts glass microspheres (particle size 10 μm), 10 parts closed-cell microspheres (particle size 80 mesh), 2 parts Fe2O3, 2 parts TiO2, 1 part SiC, 1 part potassium silicate, 30 parts gypsum, 10 parts cement, 1 part ceramic fiber, 1 part glass fiber, 1 part basalt fiber, 2 parts aluminum silicate fiber, 5 parts flaky expanded vermiculite, and 50 parts deionized water.

[0042] The raw materials of nanoplate 3, by weight, include: 45% fumed alumina nanopowder, 35% fumed silica, 15% silicon carbide, 3% alumina fiber, 5% sericite, 10% polyamide (PI), and 10% carbon nanotubes.

[0043] The composite thermal insulation board provided in this application embodiment also includes a protective layer, which is sprayed onto the surface of the heat-insulating panel 1. The raw materials, by weight, include: 20 parts of inorganic resin, 5 parts of silazane resin, 5 parts of siloxane resin, 1 part of nano alumina, 1 part of mica, 2 parts of nano zirconium oxide, 10 parts of ethanol, 5 parts of deionized water, 1 part of polyoxyethylene siloxane, and 2 parts of sodium carboxymethyl cellulose nanopowder.

[0044] The method for preparing the composite thermal insulation board provided in this embodiment includes: Step 1, Preparation of nanoplates Weigh the raw materials for the nanoplates according to the formula, mix them evenly, dry them at 100℃ for 30 min, hot press them at 150℃ and 200t, let them stand for 5 min, cool them down to room temperature and pressure, and set them aside for use. Step 2: Preparation of thermal insulation core material Weigh the raw materials of the thermal insulation core material according to the proportion, disperse them evenly, inject them into the pre-made mold, and demold them after solidification to obtain the blank material. Place the blank material into the curing rack, push it into the steam curing chamber, cure it at 60°C for 48 hours, and then air dry it or dry it at 60°C for one week before use. Step 3: Compression molding Nanoboard, thermal insulation core material, hot panel material and cold panel material are sequentially placed into a pre-made mold, molded and cured, to obtain a composite thermal insulation board blank for later use. Step 4: Applying the protective layer Weigh the protective layer raw materials according to the ratio, grind them with a nano-grinding machine to obtain a slurry, spray the slurry onto the surface of the composite thermal insulation board blank, and cure it at room temperature to obtain a composite thermal insulation board.

[0045] Example 2 This embodiment provides a composite thermal insulation board with a four-layer composite structure, including: a thermal panel 1, a thermal insulation core material 2, a nano panel 3, and a cold panel 4.

[0046] The hot panel 1 and the cold panel 4 are made of aluminum nitride ceramic fibers with a diameter of 2 mm.

[0047] The raw materials of the thermal insulation core material 2, by weight, include: 15 parts vitrified microspheres, 5 parts organosiloxane, 10 parts inorganic silicon, 10 parts organosilanol, 3 parts silazane, 20 parts glass microspheres (particle size 10 μm), 20 parts closed-cell microspheres (particle size 80 mesh), 2 parts Fe2O3, 2 parts TiO2, 1 part SiC, 1 part potassium silicate, 30 parts gypsum, 10 parts cement, 1 part ceramic fiber, 1 part glass fiber, 1 part basalt fiber, 2 parts aluminum silicate fiber, 5 parts flaky expanded vermiculite, and 50 parts deionized water.

[0048] The raw materials of nanoplate 3, by weight, include: 45% fumed alumina nanopowder, 35% fumed silica, 15% silicon carbide, 3% alumina fiber, 5% sericite, 10% polyamide (PI), and 10% carbon nanotubes.

[0049] The composite thermal insulation board provided in this application embodiment also includes a protective layer, which is sprayed onto the surface of the heat-insulating panel 1. The raw materials, by weight, include: 20 parts of inorganic resin, 5 parts of silazane resin, 5 parts of siloxane resin, 1 part of nano alumina, 1 part of mica, 2 parts of nano zirconium oxide, 10 parts of ethanol, 5 parts of deionized water, 1 part of polyoxyethylene siloxane, and 2 parts of sodium carboxymethyl cellulose nanopowder.

[0050] The preparation method of the composite thermal insulation board provided in this embodiment can be found in Embodiment 1.

[0051] Example 3 This embodiment provides a composite thermal insulation board with a four-layer composite structure, including: a thermal panel 1, a thermal insulation core material 2, a nano panel 3, and a cold panel 4.

[0052] The hot panel 1 and the cold panel 4 are made of silicon dioxide (98% silicon) ceramic fibers with a diameter of 2 mm.

[0053] The raw materials of the thermal insulation core material 2, by weight, include: 15 parts vitrified microspheres, 5 parts organosiloxane, 10 parts inorganic silicon, 10 parts organosilanol, 5 parts silazane, 20 parts glass microspheres (particle size 10 μm), 20 parts closed-cell microspheres (particle size 80 mesh), 5 parts Fe2O3, 5 parts TiO2, 3 parts SiC, 1 part potassium silicate, 30 parts gypsum, 10 parts cement, 1 part ceramic fiber, 1 part glass fiber, 1 part basalt fiber, 2 parts aluminum silicate fiber, 5 parts flaky expanded vermiculite, and 50 parts deionized water.

[0054] The raw materials of nanoplate 3, by weight, include: 65% fumed alumina nanopowder, 45% fumed silica, 25% silicon carbide, 3% alumina fiber, 5% sericite, 10% polyamide (PI), and 10% carbon nanotubes.

[0055] The composite thermal insulation board provided in this application embodiment also includes a protective layer, which is sprayed onto the surface of the heat-insulating panel 1. The raw materials, by weight, include: 20 parts of inorganic resin, 5 parts of silazane resin, 5 parts of siloxane resin, 1 part of nano alumina, 1 part of mica, 2 parts of nano zirconium oxide, 10 parts of ethanol, 5 parts of deionized water, 1 part of polyoxyethylene siloxane, and 2 parts of sodium carboxymethyl cellulose nanopowder.

[0056] Experimental Example 1 The thermal conductivity of the composite thermal insulation board prepared according to the embodiments of the present invention was tested.

[0057] Thermal conductivity measurement method: The test was conducted using an intelligent flat plate thermal conductivity meter (model DRH-ZD-600). The procedure followed GB10294-2008 (Determination of steady-state thermal resistance and related properties of thermal insulation materials...protective hot plate method). Prepare two to six composite thermal insulation board samples each, prepared in Examples 1-3 of this invention, each 40 mm thick and 300 mm x 300 mm in size. Place the test samples into the meter, turn on the device computer, run the testing software, and conduct the test for 4 hours.

[0058] Measurement results: See Table 1.

[0059] Table 1. Thermal conductivity results of composite thermal insulation boards

[0060] Referring to Table 1, the composite thermal insulation board of the present invention has a low high-temperature thermal conductivity, with an average thermal conductivity of no more than 0.045 w / m∙k. It has excellent resistance to flames and thermal shock at temperatures above 1000℃, and meets the A1 fire protection standard.

[0061] Experiment Example 2 The fire resistance time of the composite thermal insulation board prepared in Example 3 of the present invention was tested.

[0062] Measurement method: The test was conducted according to the UL-263 fire resistance test standard for building structures and materials. The composite thermal insulation board samples prepared in Example 3 were installed on the designated test equipment according to the actual usage method (e.g., adhesive, mechanical fixing) to form standard test specimens. In this test, the thicknesses of the samples were 30 mm, 40 mm, 50 mm, and 100 mm, and the dimensions were all 300 mm * 300 mm.

[0063] Test results: See Table 2.

[0064] Table 2 Fire resistance time test results

[0065] Referring to Table 2, the composite thermal insulation board of this invention has a fire resistance time of 2 hours when the board thickness is 30-40 mm and 4 hours when the thickness is 50-100 mm. Its fire resistance increases with the increase of thickness. It has excellent resistance to flames and thermal shock at temperatures above 1000℃, achieving the A1 fire resistance standard.

[0066] In summary, this invention provides a composite thermal insulation board using fumed silica and aluminum dioxide. Silica has a thermal emissivity of 0.95-0.98, while aluminum has a thermal emissivity of 0.02-0.40, effectively blocking heat radiation transfer at high temperatures. The addition of a heat-reflective protective agent effectively shields all temperature bands of heat radiation, further blocking heat radiation transfer at high temperatures and improving the board's high-temperature impact resistance. Simultaneously, the addition of carbon nanotubes and polyamide (PI) provides excellent heat resistance and low thermal conductivity, maintaining a low thermal conductivity even at high temperatures, further reducing the thermal conductivity of the nano-insulation board. This also provides reinforcement and support, enhancing compressive strength and toughness. The board is manufactured using compression molding, a simple process that allows for mass production and wide application in industrial and building thermal insulation applications.

[0067] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A composite thermal insulation board, characterized in that, The composite thermal insulation board includes a hot panel, an insulation core material, a nano panel, and a cold panel. The hot panel is located on the fire-facing side of the composite thermal insulation board, the cold panel is located on the fire-resistant side of the composite thermal insulation board, the insulation core material and the nano panel are located inside the composite thermal insulation board, the insulation core material is adjacent to the hot panel, and the nano panel is adjacent to the cold panel.

2. The composite thermal insulation board according to claim 1, characterized in that, The raw materials for the hot panel and the cold panel are alumina (45% aluminum) ceramic fibers, aluminum nitride ceramic fibers, or silicon dioxide (98% silicon) ceramic fibers, and the diameter of the ceramic fibers is 2-4 mm.

3. The composite thermal insulation board according to claim 1, characterized in that, The thermal insulation core material has a porous structure, and its raw materials, by weight, include: 10-15 parts vitrified microspheres, 3-5 parts organosiloxane, 10-20 parts inorganic silicon, 5-12 parts organosilanol, 1-5 parts silazane, 15-25 parts glass microspheres (particle size 2-20 μm), 10-15 parts closed-cell microspheres (particle size 30-150 mesh), 2-5 parts Fe2O3, 2-5 parts TiO2, 1-3 parts SiC, 1-3 parts potassium silicate, 30-50 parts gypsum, 10-20 parts cement, 0.2-3 parts ceramic fiber, 0.1-1 part glass fiber, 0.1-3 parts basalt fiber, 0.5-5 parts aluminum silicate fiber, 5-10 parts flaky expanded vermiculite, and 20-50 parts deionized water.

4. The composite thermal insulation board according to claim 1, characterized in that, The raw materials of the nanoplate, by weight, include: 45-65% nano-scale inorganic heat insulation material, 35-45% fumed silica, 15-25% heat reflective protective agent, 3-8% fiber, 2-7% sericite or talc powder, and 5-30% binder.

5. The composite thermal insulation board according to claim 1, characterized in that, The raw materials of the nanoplate, by weight, include: 35-65% nano-scale inorganic heat insulation material, 15-25% heat reflective protective agent, 3-8% fiber, 2-7% sericite or talc powder, 5-30% binder, and 2-10% carbon nanotubes.

6. The composite thermal insulation board according to claim 1, 4, or 5, characterized in that, The nanoscale inorganic thermal insulation material is one or a combination of two of fumed alumina nanopowder and fumed silica nanopowder; the heat reflective protective agent is one or a combination of two of silicon carbide, Fe3O4, TiO2, and cesium tungsten oxide; the fiber is one or a combination of two of glass fiber, ceramic fiber, and alumina fiber; and the binder is polyamide (PI).

7. The composite thermal insulation board according to claim 1, characterized in that, It also includes a protective layer, which is sprayed onto the surface of the heated panel.

8. The composite thermal insulation board according to claim 7, characterized in that, The raw materials of the protective layer, by weight, include: 20-35 parts of inorganic resin, 5-15 parts of silazane resin, 5-15 parts of siloxane resin, 1-5 parts of nano alumina, 1-5 parts of mica, 2-8 parts of nano zirconium oxide, 10-20 parts of ethanol, 3-5 parts of deionized water, 0.5-2 parts of wetting agent, and 2-5 parts of nano dispersant.

9. The composite thermal insulation board according to claim 8, characterized in that, The wetting agent is one or a combination of two of fatty alcohol polyoxyethylene ether, polyoxyethylene siloxane, sodium alkylbenzene sulfonate, and sodium dodecyl sulfate; the nano-dispersant is one or a combination of two of sodium carboxymethyl cellulose and polyvinylpyrrolidone.

10. The method for preparing the composite thermal insulation board according to any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1, Preparation of nanoplates Weigh the raw materials for the nanoplates according to the formula, mix them evenly, dry them at 50-120℃ for 5-60 min, hot press them at 100-250℃ and 50-200t, let them stand for 1-5 min, cool them to room temperature and pressure, and set them aside for use. Step 2: Preparation of thermal insulation core material Weigh the raw materials of the thermal insulation core material according to the formula, disperse them evenly, pour them into the pre-made mold, and demold them after solidification to obtain the blank material. Place the blank material into the curing rack, push it into the steam curing chamber, and cure it at 40~80℃ for 24~72 hours. Then, let it air dry or dry it at 40~80℃ for one week before use. Step 3: Compression molding Nanoboard, thermal insulation core material, hot panel material and cold panel material are sequentially placed into a pre-made mold, molded and cured, to obtain a composite thermal insulation board blank for later use. Step 4: Applying the protective layer Weigh the protective layer raw materials according to the ratio, grind them with a nano-grinding machine to obtain a slurry, spray the slurry onto the surface of the composite thermal insulation board blank, and cure it at room temperature to obtain a composite thermal insulation board.

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