Dynamic vacuum insulation nondestructive testing tool

Abstract

The invention provides a dynamic vacuum insulation nondestructive testing tool which comprises a low-atomic-number shell, an elastic temperature-resistant layer is arranged on the inner side of the low-atomic-number shell, and a magnetic attraction fixing unit is embedded in the low-atomic-number shell; the internal supporting structure is arranged in a shell body of the carbon fiber shell and consists of at least two layers of V-shaped corrugated sheets which are orthogonally arranged and a nano-porous heat insulation composite material which is filled in gaps of the corrugated sheets; the dynamic vacuum system comprises a sealing valve and a vacuum pump, is provided with a multi-point extraction opening, a vacuum monitoring unit and a controller, and automatically adjusts the working state of the vacuum pump according to the change of the vacuum degree; dynamic vacuum on-demand control is adopted, rapid vacuumizing and pressure relief are achieved through cooperation of a magnetic suction type sealing valve and a vacuum pump, energy consumption is reduced, ray interference is reduced, and meanwhile it is ensured that the surface of the heat insulation plate is maintained within a certain range through the synergistic effect formed by combining a vacuum layer with an aerogel ceramic composite material; meanwhile, the orthogonal corrugated sheets and the point contact needle-shaped supports disperse stress, and the structural strength is enhanced.

Description

Technical Field

[0001] This invention relates to the field of non-destructive testing technology for thermal pipelines, and in particular to a dynamic vacuum insulation non-destructive testing fixture. Background Technology

[0002] When conducting online radiographic inspection of thermal pipelines, the insulation layer of the inspection area needs to be removed. However, the high temperature of the pipe wall can cause problems such as film performance damage, substrate deformation, and intensifying screen failure. Existing insulation devices are mostly made of materials with low thermal conductivity, have insufficient structural strength, and suffer from significant X-ray interference, making them unsuitable for direct use in the inspection area. Therefore, there is an urgent need for an insulation device that combines dynamic vacuum control, low X-ray interference, and high structural strength to improve the accuracy and safety of high-temperature pipeline inspection. Summary of the Invention

[0003] The purpose of this invention is to provide a thermal insulation device that combines dynamic vacuum control, low radiation interference, and high structural strength, thereby solving the problems of traditional thermal insulation devices such as difficulty in maintaining vacuum, significant high-temperature deformation, and high radiation absorption and scattering rate.

[0004] To achieve the above objectives, this invention proposes a dynamic vacuum thermal insulation non-destructive testing fixture, comprising: Low atomic number shell: The inner side is equipped with an elastic heat-resistant layer and a magnetic fixing unit is embedded in it; the use of carbon fiber low atomic number shell significantly reduces the problem of radiation absorption and scattering; Internal support structure: located inside the carbon fiber outer shell, it consists of at least two layers of orthogonally arranged V-shaped corrugated sheets and nanoporous thermal insulation composite material filling the gaps between the corrugated sheets; Dynamic vacuum system: includes sealing valve and vacuum pump, and is equipped with multi-point evacuation port, vacuum monitoring unit and controller, which automatically adjusts the working status of vacuum pump according to changes in vacuum level; The surface of the V-shaped corrugated sheet is coated with a high-temperature resistant coating; point contact support units are provided between the V-shaped corrugated sheets, and the cooperation of the orthogonal corrugated sheet point contact units achieves a balance between high structural strength and low thermal conductivity; the controller adjusts the pumping speed in real time according to the vacuum level.

[0005] Furthermore, the sealing valve is a magnetic sealing valve, and the vacuum pump is a portable vacuum pump. The magnetic sealing valve and the portable vacuum pump work together to achieve rapid vacuuming and depressurization, which greatly reduces energy consumption in high-temperature pipeline inspection.

[0006] Furthermore, the low atomic number shell is made of carbon fiber reinforced polymer-based material; the magnetic fixing unit is a neodymium iron boron magnet.

[0007] Furthermore, the nanoporous thermal insulation composite material is an aerogel-reinforced ceramic fiber composite material with a compressive strength ≥50MPa and a temperature resistance ≥1300℃.

[0008] Furthermore, the high-temperature resistant coating on the surface of the V-shaped corrugated sheet is a CrNbO4 coating with a temperature resistance of ≥300℃; the wave height of the V-shaped corrugated sheet is 10mm and the wave pitch is 15mm.

[0009] Furthermore, the point contact support unit is a bulbous needle-shaped support structure with a circular cross-section. It is connected to the corrugated sheet by high-temperature sintering, and the point contact area accounts for ≤0.5%. The design of minimizing the contact area greatly reduces the heat conduction path while maintaining the structural support strength.

[0010] Furthermore, the dynamic vacuum system has a pumping time of ≤10 minutes and maintains a vacuum level of ≤10-6 Pa.

[0011] Furthermore, the total absorption of the detection fixture for Ir-192 γ rays is ≤12%, and the low radiation absorption characteristics ensure that the film receives sufficient exposure, thereby improving the defect detection rate and imaging quality.

[0012] Furthermore, the sealing surface of the magnetic sealing valve is coated with CrNbO4, which has a temperature resistance of ≥300℃. The CrNbO4 coating has excellent high-temperature stability and sealing performance, and can maintain a long-term effective vacuum seal in a 300℃ steam pipeline testing environment.

[0013] Furthermore, the elastic heat-resistant layer is a silicone layer with a pre-cut V-groove. The groove depth is adapted to the minimum bending radius of the pipe. The design of the pre-cut V-groove enables the testing fixture (insulation plate) to fit tightly against the surface of pipes with different curvature radii, eliminating the thermal bridging effect caused by poor fit.

[0014] Furthermore, the vacuum monitoring unit is a thin-film vacuum gauge; the dynamic vacuum system integrates the thin-film vacuum gauge and adjusts the pumping rate in real time through the controller, automatically adjusting the pump working status according to the change in vacuum level, ensuring internal vacuum consistency, significantly reducing energy consumption and extending equipment life.

[0015] Compared with the prior art, the advantages of the present invention are: 1. Compared with the existing insulation device structure, the present invention adopts dynamic vacuum on-demand control, and uses a magnetic sealing valve and a portable pump to achieve rapid vacuuming and depressurization, reducing energy consumption and radiation interference, and reducing the scattering rate by 15% compared with the aluminum structure; in addition, the synergistic effect of the vacuum layer combined with the aerogel ceramic composite material makes the surface temperature of the insulation board ≤40℃; at the same time, the orthogonal corrugated sheet and the point contact needle support disperse stress and strengthen the structural strength.

[0016] 2. Compared to traditional insulation devices used in high-temperature steam pipeline inspection, which fail to effectively block heat conduction, leading to melting and deformation of the film substrate and malfunction of the intensifying screen, this invention utilizes the synergistic effect of a dynamic vacuum layer and nanoscale insulation materials to form a highly efficient thermal barrier in the detection area. The vacuum layer isolates the gas heat conduction path, and the aerogel composite filler blocks solid heat conduction, reducing the outer surface temperature of the insulation board, which is in close contact with the high-temperature pipe wall, to near room temperature, thus eliminating the damage to the detection element caused by heat at its source.

[0017] 3. Compared to existing metal-based insulation structures (such as aluminum corrugated sheets), which exhibit strong absorption and scattering effects on X-rays, leading to blurred imaging and missed defects, this invention employs an ultra-lightweight carbon fiber shell and a micro-contact support structure. The low atomic number carbon fiber significantly reduces the probability of X-ray collisions, and the orthogonal corrugated sheets combined with needle-tip support points compress the physical contact area to near its limit, ensuring that X-rays pass through the fixture with almost no interference, achieving film-level resolution in imaging clarity.

[0018] 4. Compared to traditional static vacuum devices where the vacuum level drops sharply within 30 minutes due to seal failure and material outgassing, this invention introduces a magnetically controlled dynamic vacuum system. The high-temperature resistant chromium-niobium-oxygen coated sealing valve maintains airtightness during thermal cycling, and the intelligent controller tracks the vacuum status in real time via a thin-film vacuum gauge (sensor), directing the portable pump to replenish pressure as needed. This significantly extends the vacuum maintenance time and solves the problem of not being able to stably maintain a high vacuum in high-temperature environments.

[0019] 5. Compared to traditional tooling used in high-temperature pipeline inspection, which often suffers from seal cracking or adhesion failure due to thermal expansion, this invention employs an innovative support structure design. The corrugated sheets utilize a special coating with a coefficient of thermal expansion matching that of the pipeline steel, while the needle-like supports achieve a rigid connection through high-temperature sintering, yet maintain a microscopically "flexible" contact. This allows the entire device to be stably fixed to the pipeline surface under 300℃ thermal shock, providing both pressure resistance and load-bearing capacity while also adapting to deformation.

[0020] 6. Compared to traditional insulation fittings that require disassembling pipe components during installation, which is time-consuming and dangerous, the pre-cut groove magnetic adhesion design of this invention allows the insulation board to fit tightly against pipe surfaces with different radii of curvature, eliminating thermal bridging effects caused by loose adhesion. Precise adsorption is achieved through a built-in magnet array, simplifying the complex process requiring skilled technicians into a highly efficient, standardized action. Attached Figure Description

[0021] Figure 1 Main view of the overall assembly of the dynamic vacuum insulation non-destructive testing fixture Figure 2 Side view of the overall assembly of the dynamic vacuum insulation non-destructive testing fixture Figure 3 Cross-sectional view of the overall assembly of the dynamic vacuum insulation non-destructive testing fixture Figure 4 Top view of the overall assembly of the dynamic vacuum insulation non-destructive testing fixture Figure 5 Axonometric view of a V-shaped corrugated sheet Figure 6 For V-shaped corrugated sheets Figure 5 Partial axonometric view at point A Figure 1-6 In the middle: 1-outer shell, 2-elastic heat-resistant layer, 3-magnetic fixing unit, 4-V-shaped corrugated sheet, 5-high temperature resistant coating, 6-point contact support unit, 7-nano porous thermal insulation composite material, 8-magnetic sealing valve, 9-extraction port, 10-thin film vacuum gauge. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described below.

[0023] This embodiment proposes a dynamic vacuum thermal insulation non-destructive testing fixture, such as... Figure 1-5 As shown, the tooling structure includes a low atomic number shell 1, an internal support structure, and a dynamic vacuum system.

[0024] The outer shell 1, with its low atomic number, is made of carbon fiber reinforced polymer-based material, reducing radiation absorption and scattering. Its inner side features a 0.5mm elastic heat-resistant layer 2, which is a silicone layer with pre-cut V-grooves. The groove depth is adapted to the minimum bending radius of the pipe. The pre-cut V-groove design allows the testing fixture (insulation plate) to fit tightly against pipe surfaces with different curvature radii, eliminating thermal bridging effects caused by poor fit. Simultaneously, the outer shell 1 also contains a neodymium iron boron magnet magnetic fixing unit 3.

[0025] In this embodiment, the internal support structure is located inside the carbon fiber outer shell 1. This support structure consists of two layers of orthogonally arranged V-shaped corrugated sheets 4 and nanoporous thermal insulation composite material 7 filling the gaps between the corrugated sheets, arranged as follows: Figure 5 and Figure 6As shown. The surface of the V-shaped corrugated sheet 4 is coated with a high-temperature resistant coating 5, and point-contact support units 6 are provided between the V-shaped corrugated sheets 4. The cooperation of the orthogonal corrugated sheet point-contact units achieves a balance between high structural strength and low thermal conductivity. In this embodiment, the nanoporous thermal insulation composite material 7 is an aerogel-reinforced ceramic fiber composite material with a compressive strength ≥50MPa and a temperature resistance ≥1300℃. The high-temperature resistant coating on the surface of the V-shaped corrugated sheet 4 is a CrNbO4 coating 5 with a temperature resistance ≥300℃; the wave height of the V-shaped corrugated sheet is 10mm and the wave spacing is 15mm. The point-contact support unit 6 is a bulbous needle-shaped support structure made of zirconia-reinforced ceramic. The needle-shaped structure has a circular cross-section and is connected to the corrugated sheet 4 by high-temperature sintering. The point contact area accounts for ≤0.5%, and the design of minimizing the contact area greatly reduces the heat conduction path while maintaining the structural support strength.

[0026] In addition, the dynamic vacuum system includes a magnetic sealing valve 8 and a portable vacuum pump, and is equipped with multi-point evacuation ports 9, a vacuum monitoring unit (diaphragm vacuum gauge 10), and a controller. The magnetic sealing valve 8 and the portable vacuum pump work together to achieve rapid vacuuming and depressurization, significantly reducing energy consumption in high-temperature pipeline inspection. The controller adjusts the evacuation rate in real time according to the vacuum level, that is, it automatically adjusts the working state of the vacuum pump based on the vacuum level changes measured in real time by the diaphragm vacuum gauge 10. The evacuation time is ≤10 minutes, and the vacuum level is maintained at ≤10⁻⁶ Pa. The sealing surface of the magnetic sealing valve 8 is coated with CrNbO₄ 5, which is ≥300℃. The CrNbO₄ coating 5 has excellent high-temperature stability and sealing performance, and can maintain a long-term effective vacuum seal in a 300℃ steam pipeline inspection environment. This dynamic vacuum system integrates the diaphragm vacuum gauge 10 and adjusts the evacuation rate in real time through the controller, automatically adjusting the pump working state according to the vacuum level changes, ensuring internal vacuum consistency, significantly reducing energy consumption, and extending equipment life.

[0027] In this embodiment, the total absorption of Ir-192γ rays by the detection fixture is ≤12%. The low radiation absorption characteristics ensure that the film receives sufficient exposure, thereby improving the defect detection rate and imaging quality.

[0028] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A dynamic vacuum thermal insulation non-destructive testing fixture, characterized in that, include: Low atomic number shell: The inner side is equipped with an elastic heat-resistant layer and has an embedded magnetic fixing unit; Internal support structure: located inside the carbon fiber outer shell, it consists of at least two layers of orthogonally arranged V-shaped corrugated sheets and nanoporous thermal insulation composite material filling the gaps between the corrugated sheets; Dynamic vacuum system: includes sealing valve and vacuum pump, and is equipped with multi-point evacuation port, vacuum monitoring unit and controller, which automatically adjusts the working status of vacuum pump according to changes in vacuum level; The surface of the V-shaped corrugated sheet is coated with a high-temperature resistant coating; point contact support units are provided between the V-shaped corrugated sheets; and the controller adjusts the pumping speed in real time according to the vacuum level.

2. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The low atomic number outer shell is made of carbon fiber reinforced polymer-based material; the magnetic fixing unit is a neodymium iron boron magnet.

3. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The nanoporous thermal insulation composite material is an aerogel-reinforced ceramic fiber composite material with a compressive strength ≥50MPa and a temperature resistance ≥1300℃.

4. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The high-temperature resistant coating on the surface of the V-shaped corrugated sheet is a CrNbO4 coating with a temperature resistance of ≥300℃; the wave height of the V-shaped corrugated sheet is 10mm and the wave pitch is 15mm.

5. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The point contact support unit is a bulbous needle-shaped support structure, which is connected to the corrugated sheet by high-temperature sintering, and the point contact area accounts for ≤0.5%.

6. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The dynamic vacuum system has a pumping time of ≤10 minutes and maintains a vacuum level of ≤10. -6 Pa.

7. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The total absorption of Ir-192γ rays by the detection fixture is ≤12%.

8. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The sealing surface of the magnetic sealing valve is coated with CrNbO4, which has a temperature resistance of ≥300℃.

9. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The elastic heat-resistant layer is a silicone layer with a pre-cut V-shaped groove, the groove depth of which is adapted to the minimum bending radius of the pipe.

10. The dynamic vacuum thermal insulation non-destructive testing fixture according to claim 1, characterized in that, The vacuum monitoring unit is a thin-film vacuum gauge; the dynamic vacuum system integrates the thin-film vacuum gauge and adjusts the pumping rate in real time through a controller, automatically adjusting the pump's operating status according to changes in vacuum level.

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