Nested structure carbon / carbon composite material thermal insulation assembly and preparation method thereof

Abstract

The invention discloses a nested structure carbon / carbon composite material thermal insulation assembly and a preparation method thereof. The heat preservation assembly comprises an inner cylinder, an outer cylinder, an upper connecting ring, a lower connecting ring and a core body, the outer cylinder is arranged on the outer side of the inner cylinder in a sleeving mode, the outer cylinder and the inner cylinder are connected with the upper connecting ring and the lower connecting ring through bolts, a closed isolation cavity is formed among the inner cylinder, the outer cylinder, the upper connecting ring and the lower connecting ring, and the core body is arranged in the isolation cavity; the inner cylinder, the outer cylinder, the upper connecting ring, the lower connecting ring and the bolt are all made of a carbon / carbon composite material; and the core body is formed by laminating a plurality of layers of carbon fiber soft felts and a plurality of layers of graphite paper. According to the heat preservation assembly, the erosion effect of heat and erosion gas on the core body can be effectively avoided, the heat insulation effect is better, the actual thickness of the heat insulation functional layer can be effectively reduced, and the use amount of heat preservation materials is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of carbon fiber composite materials, and in particular to a nested structure carbon / carbon composite material thermal insulation component and a preparation method thereof. Background Art

[0002] The single crystal silicon pulling furnace is the core equipment for producing single crystal silicon by the Czochralski method. Its working principle is to place polycrystalline silicon material in the thermal field of the single crystal silicon Czochralski furnace, heat it to 1400℃~1500℃ under the protection of inert gas to melt the polycrystalline silicon material, and the seed crystal grows under traction to form a single crystal silicon rod.

[0003] The thermal insulation component is one of the core thermal field components in the single crystal silicon direct pulling furnace. During the operation of the single crystal furnace, the thermal insulation component mainly plays the role of thermal insulation and supporting other components of the entire thermal field. The traditional thermal insulation component is a single-layer graphite insulation tube or a carbon / carbon insulation tube with multiple layers of insulation material (carbon felt) wrapped around the outside. During the use of the existing thermal insulation components, silicon vapor will corrode the insulation material, causing the insulation material to infiltrate silicon, pulverize, increase the thermal conductivity, and significantly reduce the insulation performance. In addition, after a period of use, the existing thermal insulation components will also deform due to reasons such as surface siliconization, and the roundness error will increase, resulting in uneven heating of the thermal field at the same diameter position at the same height of the axis, affecting crystal pulling.

[0004] Chinese patent CN117989417A discloses a carbon / carbon composite spliced ​​insulation cylinder and its production process, including an insulation unit and a fixing unit, the insulation unit includes an insulation board group, the insulation board group includes a first insulation board, a second insulation board, a third insulation board and a fourth insulation board, the insulation boards in the insulation board group are all arc-shaped structures, the insulation unit also includes a connecting component, and the insulation boards in the insulation board group are spliced ​​through the connecting component to form the side wall of the insulation cylinder. This patent has the problems of many types of spliced ​​carbon / carbon parts, complex insulation board structure design, high processing cost, long labor hours in the splicing process, and the splicing seams may diffuse hot field gas, increase corrosion and heat loss.

[0005] Chinese patent CN112479731A discloses a method for preparing a carbon fiber sewing hardened thermal insulation material, wherein the preform after forming is impregnated as a whole and chemical vapor deposition is performed. After impregnation and chemical vapor deposition, the soft carbon felt that plays a role in thermal insulation is hardened and densified, so that the thermal conductivity coefficient increases sharply and the thermal conductivity is significantly improved. The thermal insulation layer needs to be thickened to achieve the thermal insulation effect required by the working conditions. Therefore, the application scenario of this structural combination scheme is relatively narrow; in addition, the thermal insulation felt and the carbon fiber preform are integrated after sewing, and the failure time of the two in the thermal field is different. The high-density carbon / carbon material after the carbon fiber preform is composited has a long service life in the thermal field. Although the composite soft carbon felt has certain strength and rigidity, its porosity is much higher than that of the carbon / carbon material after the carbon fiber preform is composited. It is easy to oxidize and pulverize and fail. It is a consumable material that needs to be replaced periodically. However, the thermal insulation device after sewing and composite is integrated, with good integrity, which is not conducive to partial disassembly and can only be scrapped as a whole, which increases the cost of use.

[0006] To sum up, the existing thermal insulation components do not achieve more effective isolation and protection for insulation materials. During use, gas will penetrate into the insulation felt, resulting in increased thermal conductivity, corrosion and powdering of the insulation material, and premature failure of the insulation. Therefore, developing a thermal insulation component with stable thermal conductivity and which can reduce the impact of furnace gas on the thermal insulation performance of the insulation material is still a key technical issue in this field. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a nested structure carbon / carbon composite material thermal insulation component and a preparation method thereof.

[0008] The technical solution adopted by the present invention is: A nested carbon / carbon composite material thermal insulation component comprises: an inner tube, an outer tube, an upper connecting ring, a lower connecting ring and a core body, wherein the outer tube is sleeved on the outer side of the inner tube, the outer tube and the inner tube are connected to the upper connecting ring and the lower connecting ring by bolts, a closed insulating cavity is formed among the inner tube, the outer tube, the upper connecting ring and the lower connecting ring, and the core body is arranged in the insulating cavity; the inner tube, the outer tube, the upper connecting ring, the lower connecting ring and the bolts are all made of carbon / carbon composite materials; the core body is made of a plurality of layers of carbon fiber soft felt and a plurality of layers of graphite paper laminated.

[0009] Furthermore, the density of the inner tube is not less than 1.2 g / cm³.

[0010] Furthermore, the density of the inner side of the inner tube is 1.5 to 2 times that of the outer side.

[0011] Furthermore, the density of the outer cylinder is not less than 1.1 g / cm³.

[0012] Furthermore, the density of the upper connecting ring and the lower connecting ring is not less than 1.2 g / cm³.

[0013] Furthermore, the density of the bolt is not less than 1.5 g / cm³.

[0014] Furthermore, the ash content of the carbon fiber soft felt is 50-500 ppm, the thickness of a single-layer carbon fiber soft felt is 5-15 mm, and the density is 0.15-0.2 g / cm³.

[0015] Furthermore, the core body includes, from the inside to the outside, 2 to 3 layers of graphite paper, 7 to 8 layers of carbon fiber soft felt, 2 to 5 layers of graphite paper and 2 to 4 layers of carbon fiber soft felt.

[0016] The method for preparing any one of the above-mentioned nested structure carbon / carbon composite material insulation components comprises the following steps: (1) preparing an inner cylinder, using an inner cylinder carbon fiber preform, subjecting it to a vapor deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment process in sequence, to form a carbon / carbon composite inner cylinder, then machining the inner and outer cylindrical surfaces and two end surfaces of the inner cylinder, performing a pyrolytic carbon coating treatment after machining, and radially setting bolt through holes at both ends of the inner mold surface of the cylinder; (2) preparing an outer cylinder, using an outer cylinder carbon fiber preform, subjecting it to vapor deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment in sequence to form a carbon / carbon composite outer cylinder, and then machining the inner and outer cylindrical surfaces and two end faces of the outer cylinder, performing pyrolytic carbon coating treatment after machining, and axially setting bolt holes on both end faces of the cylinder; (3) preparing an upper connecting ring and a lower connecting ring, using an upper connecting ring carbon fiber preform and a lower connecting ring carbon fiber preform, respectively, and subjecting them to gas phase deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment processes in sequence to form a carbon / carbon composite upper ring and a lower ring, and then machining the upper and lower ring surfaces and the inner and outer cylindrical sides of the upper ring and the lower ring, and processing step surfaces on the outer cylindrical sides of the upper ring and the lower ring, respectively, and then radially arranging threaded holes that match the threaded through holes of the inner cylinder on the inner side surfaces of the upper ring and the lower ring, and axially arranging bolt through holes that match the bolt holes of the outer cylinder on the outer side surfaces; (4) preparing bolts by using a sheet carbon fiber preform, subjecting it to a vapor deposition densification, a liquid phase resin impregnation densification, a carbonization treatment, and a graphitization treatment process in sequence to form a carbon / carbon composite sheet, which is then machined to form bolts; (5) preparing a core body, alternately winding graphite paper and carbon fiber soft felt on a cylindrical mold, and tying and binding with a carbon rope after winding to obtain a core body; (6) Assembly: (6.1) Fastening the inner cylinder prepared in step (1) and the lower connecting ring prepared in step (3) with the bolts prepared in step (4); (6.2) The outer cylinder prepared in step (2) is mounted on the inner cylinder prepared in step (6.1), and the outer cylinder is fastened to the lower connecting ring of step (6.1) by means of the bolts prepared in step (4), so as to form a semi-enclosed cylindrical cavity; (6.3) placing the core prepared in step (5) in the cylindrical cavity prepared in step (6.2); (6.4) The upper connecting ring prepared in step (3) is fastened to the inner tube and the outer tube of step (6.3) by means of the bolts prepared in step (4) to form a nested structure carbon / carbon composite material insulation component.

[0017] Beneficial effects of the present invention: 1. The insulation component adopts a combined structure. By combining the carbon / carbon outer shell formed by the inner tube and the outer tube with the insulation core, the heat conduction path can be effectively cut off, the heat dissipation can be reduced, and the reactive power of the equipment can be reduced; 2. The core uses high thermal conductivity graphite paper to reflect heat radiation, and uses low thermal conductivity carbon fiber soft felt for heat insulation. The combination of heat insulation and reflected heat radiation insulation has better insulation effect than the traditional insulation method that only uses insulation materials. It can effectively reduce the actual thickness of the insulation function layer and reduce the amount of insulation materials used. 3. The outer jacket adopts a double-layer carbon / carbon supported insulation tube cavity structure, which can effectively prevent the erosion of heat and corrosive gas on the core and increase the service life of the insulation component; 4. The outer shell structure of the double-layer carbon / carbon cylinder is stable, and it is not easy to deform the cylinder due to long-term use of the traditional single-layer insulation cylinder; 5. The thermal insulation jacket adopts a split design. The materials of the inner and outer tubes can be designed separately according to needs, which can reduce the overall material cost and processing cost, and is conducive to large-scale production; 6. The insulation shell is made of hard carbon / carbon composite inner and outer tubes. It has a simple structure, is easy to disassemble and assemble, and is convenient for overall lifting. Compared with the traditional soft felt shell, it can effectively avoid mechanical damage to the soft felt when dismantling the furnace, installing and repairing parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the overall structural diagram of the thermal insulation component of the present invention.

[0019] Figure 2 for Figure 1 Cross-sectional view of .

[0020] Figure 3 It is a schematic diagram of the principle of reducing heat dissipation of the thermal insulation component of the present invention.

[0021] Figure 4 It is a schematic diagram of the density gradient distribution of the inner cylinder preform of the present invention.

[0022] Figure 5 A flow chart for preparing the thermal insulation assembly of the present invention.

[0023] 1. Upper connecting ring; 2. Inner cylinder; 3. Core body; 3-301 inner layer of graphite paper; 3-302 carbon fiber soft felt; 3-303 outer layer of graphite paper; 4. Bolt; 5. Outer cylinder; 6. Lower connecting ring. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and a preferred implementation manner.

[0025] See also Figure 1-Figure 5 The present invention provides a nested structure carbon / carbon composite material insulation component, comprising: an inner tube 2, an outer tube 5, an upper connecting ring 1, a lower connecting ring 6 and a core body 3, the outer tube 5 is sleeved on the outside of the inner tube 2, the outer tube 5 and the inner tube 2 are connected to the upper connecting ring 1 and the lower connecting ring 6 by bolts 4, the inner tube 2, the outer tube 5, the upper connecting ring 1 and the lower connecting ring 6 form a double-layer outer jacket, a closed isolation cavity is formed between the inner tube 2, the outer tube 5, the upper connecting ring 1 and the lower connecting ring 6, and the core body 3 is arranged in the isolation cavity.

[0026] Preferably, the height of the inner cylinder 2 is the height of the heat preservation assembly, and the height of the outer cylinder 5 is less than the height of the inner cylinder 2. Notches are machined on the outer sides of the upper connecting ring 1 and the lower connecting ring 6, and the upper connecting ring 1 and the lower connecting ring 6 with the notched parts cut off form a circular annular protrusion, which can just be inserted between the inner cylinder 2 and the outer cylinder 5, and the notched part can just cover the inner cylinder 2. After the two ends of the inner cylinder 2 are radially connected to the upper connecting ring 1 and the lower connecting ring 6 by bolts 4, and the two ends of the outer cylinder 5 are axially connected to the upper connecting ring 1 and the lower connecting ring 6 by bolts 4 to form a heat preservation assembly, there is no seam on the inner side of the inner cylinder 2, which can better prevent the erosion of silicon vapor, and this structure also makes the connection structure of the inner cylinder 2, the outer cylinder 5, the upper connecting ring 1 and the lower connecting ring 6 simpler.

[0027] The density of the inner cylinder is not less than 1.2g / cm³. The inner cylinder carbon fiber preform is used, and it is subjected to vapor deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment processes in sequence to form a carbon / carbon composite inner cylinder.

[0028] The density of the preferred inner tube carbon fiber preform is designed with a gradient along the thickness direction. By adjusting the mesh ratio and the needle-punching density, the density of the preform is reduced from the inside to the outside, and the density range is 0.35 to 0.55 g / cm³. The specific number of gradients can be freely designed according to demand. For example, in this embodiment, the density of the inner 1 / 2 part of the wall thickness is 0.5 to 0.55 g / cm³, and the density of the outer 1 / 2 part of the wall thickness is 0.35 to 0.4 g / cm³, and the inner density is 1.5 to 2 times the outer density. The density gradient preform used in the manufacture of the carbon / carbon inner tube has a high density on the inside and a low density on the outside in the thickness direction after isothermal and isobaric vapor deposition densification and subsequent composite processes. The reason for this design is that the inner and outer cylindrical surfaces of the carbon / carbon inner tube have different functional requirements. The inner profile requires corrosion resistance and support for thermal field load, and the outer cylindrical surface requires low thermal conductivity and thermal insulation, so a low-density, high-porosity preform is required. During the composite process, the preform with a density gradient design is easier to achieve a composite effect with high density on one side of the inner wall than the preform without a gradient design. This effect enables the inner tube, which serves as an atmosphere isolation and support, to achieve both functions. That is, the low-density design on the outer side in the thickness direction has a good thermal insulation effect, and the high-density design on the inner side in the thickness direction can better meet the stringent working conditions and support strength requirements of direct contact with the corrosive gas and high-temperature environment in the single crystal furnace.

[0029] The density of the outer cylinder is not less than 1.1g / cm³. The outer cylinder carbon fiber preform is used, and it is subjected to vapor deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment processes in sequence to form a carbon / carbon composite outer cylinder.

[0030] The density of the upper connecting ring and the lower connecting ring is not less than 1.2 g / cm³. The upper connecting ring carbon fiber preform and the lower connecting ring carbon fiber preform are respectively subjected to vapor deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment processes in sequence to form a carbon / carbon composite upper ring and lower ring.

[0031] The density of the bolt is not less than 1.5g / cm³. The carbon fiber preform of the plate is used, and it is subjected to vapor deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment processes in sequence to form a carbon / carbon composite plate, and then the bolt is formed by machining.

[0032] The core body includes 2 to 3 layers of graphite paper, 7 to 8 layers of carbon fiber soft felt, 2 to 5 layers of graphite paper and 2 to 4 layers of carbon fiber soft felt from the inside to the outside. Preferably, the ash content of the carbon fiber soft felt is 50 to 500 ppm, the thickness of a single layer of carbon fiber soft felt is 5 to 15 mm, and the density is 0.15 to 0.2 g / cm³. By distributing the graphite paper and the carbon fiber soft felt at intervals, such as Figure 2As shown, the inner and outer layers of graphite paper are used to isolate the corrosion of silicon vapor inside and outside the carbon fiber felt, and the heat reflection performance of the graphite paper can be used for effective heat insulation, thereby improving the thermal insulation performance of the thermal insulation material. The carbon fiber felt is arranged outside the outer layer of graphite paper because the graphite paper is thin, weak, and easy to break during assembly. The outer layer of tough carbon fiber felt can reduce the breakage of the graphite paper. Carbon fiber felt is arranged between the graphite papers, and the low thermal conductivity of the carbon fiber felt is used to further improve the thermal insulation performance of the thermal insulation material. By combining the two thermal insulation design concepts of heat insulation and reflective heat radiation, the thermal insulation effect can be improved, the actual thickness of the thermal insulation functional layer can be effectively reduced, and the amount of thermal insulation material used can be reduced.

[0033] See also Figure 5 The preparation method of the thermal insulation assembly of the present invention is described below using two preferred embodiments as examples. Example

[0034] 1. Coat preparation: (1.1) The inner cylinder preform with a density of 0.40g / cm³ was subjected to vapor deposition to increase the density to 1.10 g / cm³; then liquid phase impregnation with resin and carbonization treatment were performed to increase the density to 1.30g / cm³; followed by high-temperature graphitization treatment at a graphitization temperature of 2100℃ for 2 hours. After the composite was completed, the inner and outer cylindrical surfaces and the two end faces of the embryo were machined, and after machining, a 30-hour pyrolytic carbon coating treatment (CVD) was performed. Twelve 12mm through holes were made circumferentially evenly distributed at a position of 10mm from the two end faces on the inner mold surface of the cylinder.

[0035] (1.2) The outer cylinder preform with a density of 0.35g / cm³ is subjected to vapor deposition to increase the density to 0.9g / cm³; then liquid phase resin is impregnated and carbonized to increase the density to 1.20g / cm³; then high-temperature graphitization is performed at a graphitization temperature of 2100℃ and kept warm for 2h. After the composite is completed, the inner and outer cylindrical surfaces and two end faces are machined, and M10 threaded holes are evenly distributed at the center of the thickness of the two end faces of the cylinder.

[0036] (1.3) The upper and lower connecting ring preforms with a density of 0.40g / cm³ were subjected to vapor deposition to increase the density to 1.10g / cm³; then liquid phase impregnation with resin and carbonization treatment were performed to increase the density to 1.30g / cm³; followed by high-temperature graphitization treatment at a graphitization temperature of 2100℃ for 2h. After the composite was completed, the upper and lower ring surfaces, the inner cylindrical side surface and the outer step surface were processed, and 12 evenly distributed M10 threaded holes were made at the center of the thickness of the inner side surface of the connecting ring, and a concave stop was processed on the outer side, and 12 evenly distributed φ12mm through holes were made on the thin edge of the concave stop.

[0037] (1.4) The carbon / carbon bolt sheet preform with a density of 0.45 was gas-phase densified to 1.4 g / cm³; liquid-phase impregnation with resin and carbonization treatment was performed to increase the density to 1.60 g / cm³, and then high-temperature graphitization treatment was performed at a graphitization temperature of 2100°C for 2 hours. Then it was processed into M10 bolts.

[0038] 2. Core preparation: (2.1) Wrapping three layers of graphite paper on a cylindrical mold, wherein the diameter of the cylindrical mold is 4 mm larger than the outer diameter of the inner cylinder; (2.2) Wrap 8 layers of 10 mm thick carbon fiber felt on the graphite paper in step (2.1); (2.3) Wrap 2 layers of graphite paper on the carbon fiber felt prepared in step (2.2); (2.4) Wrap 2 layers of carbon felt on the graphite paper in step (2.3); (2.5) The winding materials of steps (2.1), (2.2), (2.3), and (2.4) are of equal width and have neat end surfaces after winding, thereby forming a core thermal insulation functional structure; (2.6) Use a 6mm twisted carbon rope to tie and bind. Wrap the carbon rope around the core of step (2.5) twice, and arrange three groups of tying and binding: upper, middle and lower.

[0039] 3. Overall assembly of insulation components: (3.1) Align the inner cylinder through hole prepared in step (1.1) and the threaded hole on the inner side of the lower connecting ring prepared in step (1.3), and use the M10 bolts prepared in step (1.4) to connect and tighten; (3.2) Align the threaded hole on the end face of the outer cylinder prepared in step (1.2) with the through hole on the outer edge of the lower connecting ring prepared in step (1.3), and use the M10 bolts prepared in step (1.4) to connect and tighten; (3.3) placing the core prepared in step 2 into the semi-enclosed structure assembled in step (3.2); (3.4) Align the threaded hole on the inner side of the upper connecting ring prepared in step (1.3) with the through hole at the other end of the inner tube in the semi-enclosed structure prepared in step (3.3), and use the M10 bolts prepared in step (1.4) to connect and tighten. Then align the threaded hole on the other end of the outer tube prepared in step (1.2) with the through hole on the outer edge of the upper connecting ring prepared in step (1.3). Use the M10 bolts prepared in step (1.4) to connect and tighten. A closed carbon / carbon composite material insulation component with a nested structure is formed. Example

[0040] 1. Coat preparation: (1.1) The inner cylinder preform with a density of 0.45g / cm³ is subjected to vapor deposition to increase the density to 1.2g / cm³; then it is impregnated with liquid resin and carbonized to increase the density to 1.35g / cm³; followed by high-temperature graphitization treatment at a graphitization temperature of 2200℃ for 2h. After the composite is completed, the inner and outer cylindrical surfaces and the two end faces of the embryo are machined, and after machining, a 50h pyrolytic carbon coating treatment (CVD) is performed. 12 φ12mm through holes are evenly distributed in the annular direction at a position 10mm away from the two end faces of the inner mold surface of the cylinder. Finally, it is purified with chloroform to reduce the ash content to less than 50ppm.

[0041] (1.2) The outer cylinder preform with a density of 0.40g / cm³ is subjected to vapor deposition to increase the density to 1.00g / cm³; then liquid phase resin is impregnated and carbonized to increase the density to 1.25g / cm³; then high-temperature graphitization is performed at a graphitization temperature of 2200℃ and kept warm for 2h. After the composite is completed, the inner and outer cylindrical surfaces and two end faces are machined, and M10 threaded holes are evenly distributed at the center of the thickness of the two end faces of the cylinder.

[0042] (1.3) The upper and lower connecting ring preforms with a density of 0.45g / cm³ were subjected to vapor deposition to increase the density to 1.15g / cm³; then liquid phase impregnation with resin and carbonization treatment were performed to increase the density to 1.35g / cm³; followed by high-temperature graphitization treatment at a graphitization temperature of 2200℃ for 2 hours. After the composite was completed, the upper and lower ring surfaces, the inner cylindrical side surface and the outer step surface were processed, and a 12-M10 threaded hole was made at the center of the thickness of the inner side surface of the connecting ring, and a concave stop was processed on the outer side, and 12 φ12mm through holes were evenly distributed on the thin edge of the concave stop.

[0043] (1.4) The carbon / carbon bolt plate preform with a density of 0.50 is gas-phase densified to 1.5g / cm³; liquid-phase impregnation with resin and carbonization treatment are performed to increase the density to 1.65g / cm³; high-temperature graphitization treatment is then performed at a graphitization temperature of 2100°C and kept at this temperature for 2 hours. Finally, it is processed into M10 bolts.

[0044] 2. The steps of core preparation are as follows: (2.1) Wrapping two layers of graphite paper on a cylindrical mold, wherein the diameter of the cylindrical mold is 6 mm larger than the outer diameter of the inner cylinder; (2.2) Wrap 7 layers of 10 mm thick carbon fiber felt on the graphite paper in step (2.1); (2.3) Wrap 4 layers of graphite paper on the carbon fiber felt prepared in step (2.2); (2.4) Wrap 3 layers of carbon felt on the graphite paper in step (2.3); (2.5) The winding materials of steps (2.1), (2.2), (2.3), and (2.4) are of equal width and have neat end surfaces after winding, thereby forming a core thermal insulation functional structure; (2.6) Use a 6mm twisted carbon rope to tie and bind. Wrap the carbon rope around the core of step (2.5) twice, and arrange three groups of tying and binding: upper, middle and lower.

[0045] 3. The overall assembly of the insulation component is the same as implementation 1.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also within the protection scope of the present invention.

Claims

1. A nested carbon / carbon composite material insulation component, characterized in that: include: An inner cylinder (2), an outer cylinder (5), an upper connecting ring (1), a lower connecting ring (6) and a core body (3), wherein the outer cylinder (5) is sleeved on the outer side of the inner cylinder (2), the outer cylinder (5) and the inner cylinder (2) are connected to the upper connecting ring (1) and the lower connecting ring (6) by bolts (4), and a closed isolation cavity is formed between the inner cylinder (2), the outer cylinder (5), the upper connecting ring (1) and the lower connecting ring (6), and the core body (3) is arranged in the isolation cavity; The inner cylinder (2), the outer cylinder (5), the upper connecting ring (1), the lower connecting ring (6) and the bolt (4) are all made of a carbon / carbon composite material; The core (3) is made of a plurality of layers of carbon fiber soft felt and a plurality of layers of graphite paper.

2. A nested structure carbon / carbon composite material insulation component according to claim 1, characterized in that: The density of the inner tube (2) is not less than 1.2 g / cm³.

3. A nested structure carbon / carbon composite material insulation component according to claim 2, characterized in that: The density of the inner side of the inner tube (2) is 1.5 to 2 times that of the outer side.

4. The nested structure carbon / carbon composite material insulation component according to claim 1, characterized in that: The density of the outer cylinder (2) is not less than 1.1 g / cm³.

5. The nested structure carbon / carbon composite material insulation component according to claim 1, characterized in that: The density of the upper connecting ring (1) and the lower connecting ring (6) is not less than 1.2 g / cm³.

6. The nested structure carbon / carbon composite material insulation component according to claim 1, characterized in that: The density of the bolt (4) is not less than 1.5 g / cm³.

7. The nested structure carbon / carbon composite material insulation component according to claim 1, characterized in that: The ash content of carbon fiber soft felt is 50-500ppm, the thickness of single-layer carbon fiber soft felt is 5-15mm, and the density is 0.15-0.2g / cm³.

8. The nested structure carbon / carbon composite material insulation component according to claim 1, characterized in that: The core body (3) comprises, from the inside to the outside, 2 to 3 layers of graphite paper, 7 to 8 layers of carbon fiber soft felt, 2 to 5 layers of graphite paper and 2 to 4 layers of carbon fiber soft felt.

9. A method for preparing a nested structure carbon / carbon composite material thermal insulation component according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) preparing an inner cylinder (2), using an inner cylinder carbon fiber preform, subjecting it to a vapor deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment process in sequence, to form a carbon / carbon composite inner cylinder, then machining the inner and outer cylindrical surfaces and two end faces of the inner cylinder, performing a pyrolytic carbon coating treatment after machining, and radially setting bolt through holes at both ends of the inner profile of the cylinder; (2) preparing an outer cylinder (5), using an outer cylinder carbon fiber preform, subjecting it to a vapor deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment process in sequence, to form a carbon / carbon composite outer cylinder, and then machining the inner and outer cylindrical surfaces and two end faces of the outer cylinder, performing a pyrolytic carbon coating treatment after machining, and axially setting bolt holes on both end faces of the cylinder; (3) preparing an upper connecting ring (1) and a lower connecting ring (6), using an upper connecting ring carbon fiber preform and a lower connecting ring carbon fiber preform, respectively, and subjecting them to gas phase deposition densification, liquid phase impregnation resin densification, carbonization treatment, and graphitization treatment processes in sequence to form a carbon / carbon composite upper ring and lower ring, and then machining the upper and lower ring surfaces and the inner and outer cylindrical sides of the upper and lower rings, and machining step surfaces on the outer cylindrical sides of the upper and lower rings, respectively, and then radially arranging threaded holes that match the threaded through holes of the inner cylinder on the inner side surfaces of the upper and lower rings, respectively, and axially arranging bolt through holes that match the bolt holes of the outer cylinder on the outer side surfaces; (4) preparing bolts (4), using a sheet carbon fiber preform, subjecting it to a vapor deposition densification, a liquid phase resin impregnation densification, a carbonization treatment, and a graphitization treatment process in sequence to form a carbon / carbon composite sheet, and then forming a bolt by machining; (5) preparing a core body (3), alternately winding graphite paper and carbon fiber soft felt on a cylindrical mold, and tying and binding with a carbon rope after winding to obtain a core body; (6) Assembly: (6.1) Fastening the inner cylinder prepared in step (1) and the lower connecting ring prepared in step (3) with the bolts prepared in step (4); (6.2) The outer cylinder prepared in step (2) is mounted on the inner cylinder prepared in step (6.1), and the outer cylinder is fastened to the lower connecting ring of step (6.1) by means of the bolts prepared in step (4), so as to form a semi-enclosed cylindrical cavity; (6.3) placing the core prepared in step (5) in the cylindrical cavity prepared in step (6.2); (6.4) The upper connecting ring prepared in step (3) is fastened to the inner tube and the outer tube of step (6.3) by means of the bolts prepared in step (4) to form a nested structure carbon / carbon composite material insulation component.

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