CT (Computed Tomography) detection system and detection method for sample characteristics under high-pressure tank and high hydrostatic pressure

Abstract

The invention discloses a high-pressure tank and high hydrostatic pressure sample characteristic CT detection system and method in the technical field of material detection, and the system comprises an outer tank which comprises a base, a window cylinder, a steel connecting ring, a knife edge sealing ring and a top sealing cover which are fixedly connected in sequence from bottom to top, and the outer tank is used for providing support for a lining; large deformation of the lining under high pressure is avoided; the window cylinder is used for ensuring that the X-rays can penetrate through the sample; the steel connecting ring is used for connecting and fixing the window cylinder and is connected with the knife edge sealing ring; the lining is attached to the base and the window cylinder to prevent the window cylinder from leaking under high pressure, the upper edge of the lining is installed in a clamping groove in the upper end of the steel connecting ring, and a sealing interface is formed between the lining and the sealing cover; the knife edge sealing ring is provided with a corrugated knife edge, so that a sealing interface is formed by the knife edge sealing ring and the upper edge of the lining at the lower part; and the sealing cover is fixedly installed at the top of the outer tank, and a sealing ring is arranged between the sealing cover and the knife edge sealing ring.

Description

Technical Field

[0001] The present invention relates to the technical field of material detection, and in particular to a high-pressure tank, a sample characteristic CT detection system under high hydrostatic pressure and a detection method. Background Art

[0002] Traditional materials have different structures inside, which give them extraordinary performance. However, as the external pressure increases, the internal structure of the above materials is easily destroyed, resulting in a serious decline in performance. Studying the change of internal structure with pressure is the basis for clarifying the change mechanism of materials and the support for the design of pressure-resistant structures. There is still a long way to go to achieve the goal of stable performance of materials in high-pressure environments.

[0003] At present, there is a lack of systematic research on the structural evolution mechanism of belt internal structural materials under hydrostatic pressure. Therefore, it is of great significance to explore the structural evolution mechanism of belt internal structural materials under hydrostatic pressure and characterize the geometric characteristics of the internal structure more intuitively and accurately, which is of great significance to the study of the characteristics of belt structural materials.

[0004] At present, there are few studies on the structural stability mechanism of band-structured materials under high pressure. According to the survey, no researchers have proposed a quantitative characterization method for band-structured materials to systematically study the structural change mechanism of materials under high pressure.

[0005] In recent years, CT technology has been widely used in various fields. Its characteristic is that it can non-destructively characterize the internal properties of samples, including material and structural characteristics. Therefore, with the help of CT technology, the changes and development process of material structural characteristics under high pressure can be characterized in situ, providing strong technical support for further exploring the influence of pressure on the internal structure of materials.

[0006] At present, the way to apply high pressure to material structures is to place the materials in a sealed high-pressure tank and pressurize them. The high-pressure tank needs to take into account the requirements of high-pressure watertightness, X-ray penetrability and high-pressure structural strength. If the high-pressure tank directly uses X-ray transparent window materials as a whole, it can meet the requirements of watertightness and X-ray penetrability, but the structural strength is low and it may break under high pressure. If a suitable X-ray transparent material is selected as the window and reinforced at both ends with high-strength materials, it has both X-ray penetrability and high-pressure structural strength requirements, but there will be watertightness problems at the interfaces of different materials.

[0007] In summary, existing high-pressure tanks cannot simultaneously meet the requirements of high-pressure water tightness, X-ray penetration and high-pressure structural strength. Summary of the invention

[0008] The purpose of the present invention is to provide a high-pressure tank, sample feature CT detection system and detection method under high hydrostatic pressure, so as to solve the technical problem that the high-pressure tank in the prior art cannot simultaneously take into account the requirements of high-pressure water tightness, X-ray penetration and high-pressure structural strength.

[0009] In order to solve the above technical problems, the present invention specifically provides a high-pressure tank for CT detection of sample characteristics under high hydrostatic pressure, comprising:

[0010] An outer tank, comprising a base, a window cylinder and a steel connecting ring fixedly connected in sequence from bottom to top, the outer tank is used to provide support for the inner liner to prevent the inner liner from deforming under high pressure;

[0011] The inner liner is arranged in the outer tank, used for placing the sample, and is fitted with the base and the window tube, and the upper edge of the inner liner is installed in the slot at the upper end of the steel connecting ring;

[0012] A sealing cover is fixedly mounted on the top of the outer tank, and a sealing ring is provided between the sealing cover and the inner liner to convert multiple sealing interfaces into one sealing interface between the inner liner and the sealing cover;

[0013] The window tube and the inner lining are both made of high X-ray penetrating materials to ensure that the X-rays can penetrate the sample.

[0014] As a preferred solution of the present invention, a corrugated blade is provided at the lower part of the sealing ring, and a threaded hole for connecting with the steel connecting ring is provided on the sealing ring, so that the corrugated blade forms a sealing interface with the liner under the action of the preload force;

[0015] An O-type rubber ring groove for placing an O-type rubber ring is arranged on the upper part of the sealing ring, and the sealing cover and the sealing ring are fixedly connected by screws.

[0016] As a preferred solution of the present invention, the window tube is inserted into the slot of the base, and threaded holes are arranged on the circumference of the side wall thereof so as to fix the base and the window tube together by screws;

[0017] The steel connecting ring sleeve is wrapped around the outer side of the top of the window tube, and threaded holes are arranged on the circumference of the side wall so as to fix the steel connecting ring and the window tube with screws.

[0018] As a preferred solution of the present invention, a sample positioning device is provided inside the high-pressure tank for fixing the sample on the axis of the high-pressure tank;

[0019] A high-pressure tank positioning device is provided at the bottom of the high-pressure tank, which is used to make the axis of the high-pressure pipe coincide with the rotation center of the motion control console, so that the high-pressure tank can rotate in situ under the drive of the motion control console.

[0020] As a preferred solution of the present invention, the sample positioning device comprises a self-positioning component and a sample positioning component installed together, and the sample positioning component is located above the self-positioning component;

[0021] The self-positioning assembly is used to fix the sample positioning assembly at the center of the high-pressure tank, and the sample positioning assembly is used to fix the sample at the center of the sample positioning assembly.

[0022] As a preferred solution of the present invention, the sample positioning assembly includes a sample positioning platform, a plurality of slideways are evenly arranged on the upper surface of the sample positioning platform, a positioning block and a tension spring are installed in each of the slideways, and the tension spring pulls the positioning block inward to fix the high-pressure tank at the center of the sample positioning platform;

[0023] The self-positioning assembly comprises a self-positioning platform, and a plurality of compression spring balancing devices are evenly arranged on the circumference of the self-positioning platform to make the center of the self-positioning platform coincide with the axis of the pressure tank;

[0024] The sample positioning platform has the same profile as the self-positioning platform, and the opposite sides of the sample positioning platform and the self-positioning platform are both arranged in positioning grooves, in which permanent magnets are inserted, so that the sample positioning platform and the self-positioning platform are aligned up and down.

[0025] As a preferred solution of the present invention, the high-pressure tank positioning device is a trapezoidal frustum, and the upper and lower ends of the trapezoidal frustum are coaxially engaged with the high-pressure tank and the motion control console respectively.

[0026] As a preferred solution of the present invention, the pressurizing hole on the sealing cover is connected to a hydraulic pump through a hydraulic valve to control the hydrostatic pressure in the tank body, and is connected to a hydraulic gauge through a three-way joint to display the pressure in the tank body.

[0027] The present invention further provides a CT detection system for sample characteristics under high hydrostatic pressure, comprising:

[0028] A motion control console, used for installing the high-pressure tank according to claim 8, capable of driving the high-pressure tank to rotate in situ and adjusting the geometric parameters before detection;

[0029] An X-ray data collector and an X-ray source generator are respectively arranged on two opposite sides of the high-pressure tank;

[0030] A data processor, connected to the X-ray data collector and the motion console, respectively, to obtain CT scan data and the high-pressure tank motion data, and post-process the data;

[0031] The CT control cabinet is connected to the X-ray source generator and is used to control the X-ray source generator.

[0032] The present invention further provides a CT detection method for sample characteristics under high hydrostatic pressure, using the above-mentioned CT detection system, comprising the following steps:

[0033] Adjust the distance between the object distance and the focal length of CT imaging to improve the clarity of the imaging effect, make the sample outline clear, and meet the imaging requirements of the sample (28);

[0034] Correcting the energy of the X-ray data collector (23) to eliminate the annular virtual shadow of the three-dimensional reconstructed slice image. This step needs to be performed before each CT scan;

[0035] The high-pressure tank (27) is pressurized, and when the pressure value meets the requirement, the system is allowed to stand still until the pressure value is stable to reduce the influence of the relaxation phenomenon of the sample (28) on the test, and the pressure pump is removed to perform a rotational CT scan;

[0036] The X-ray source generator (24) is started, and the X-ray collector receives the attenuated X-rays after passing through the sample (28), and converts the collected signals into raw CT data;

[0037] Processing the original CT data by a reconstruction algorithm to obtain three-dimensional data of the sample (28);

[0038] Slicing the three-dimensional data of the sample (28) to obtain CT slice grayscale data;

[0039] The CT slice grayscale data is cropped to reduce the data volume;

[0040] The grayscale data of the cropped frontal CT slices are de-noised by using a filtering algorithm;

[0041] The de-noised image is subjected to threshold segmentation through a convolutional neural network to obtain an accurate target segmentation image and accurately distinguish the air phase and solid phase in the deformed sample (28);

[0042] The voxel value of the image is calibrated according to the reference method, the volume of each pixel is calculated, the number of pixels of the air phase and the solid phase in the CT segmentation image is counted, and the overall volume of all layer slices (28) of the sample is obtained by the accumulation method to obtain the volume of the sample (28) under hydrostatic pressure;

[0043] The pressure value of the high-pressure tank (27) is changed, and the above experiment is repeated to obtain the volume of the sample (28) under different hydrostatic pressures, so as to comprehensively and accurately evaluate the changes of the elastic sample (28) under hydrostatic pressure.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The outer tank and the inner lining meet the requirements of X-ray penetrability at the same time. The outer tank with high structural strength provides strong support for the inner lining, enhances the reliability of the inner lining under high pressure, and makes the high-pressure tank meet the requirements of high-pressure structural strength. The inner lining converts the three sealing interfaces of the outer tank into one sealing interface, so that the high-pressure tank meets the requirements of high-pressure watertightness. That is, the outer tank takes into account high-pressure watertightness, X-ray penetrability and high-pressure structural strength at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0047] Figure 1 It is a schematic diagram of the three-dimensional structure of the high-pressure tank in an embodiment of the present invention;

[0048] Figure 2 It is a cross-sectional schematic diagram of a high-pressure tank in an embodiment of the present invention;

[0049] Figure 3 It is a schematic diagram of the structure of a sample positioning device in an embodiment of the present invention;

[0050] Figure 4 It is a structural schematic diagram of a trapezoidal frustum in an embodiment of the present invention;

[0051] Figure 5 It is a structural schematic diagram of pressurizing and measuring the pressure of a high-pressure tank in an embodiment of the present invention;

[0052] Figure 6 It is a structural schematic diagram of a detection system in an embodiment of the present invention;

[0053] Figure 7 This is a comparison diagram of the X-ray data collector before and after energy correction in an embodiment of the present invention;

[0054] Figure 8 This is a comparison diagram of sample cavities under different hydrostatic pressures in the embodiments of the present invention.

[0055] The numbers in the figure represent the following:

[0056] 1-base, 2-window tube, 3-steel connecting ring, 4-lining, 5-sealing cover, 6-sealing ring, 7-corrugated blade, 8-O-type rubber ring groove, 9-self-positioning assembly, 10-sample positioning assembly, 11-sample positioning platform, 12-positioning block, 13-tension spring, 14-self-positioning platform, 15-compression spring balancing device, 16-positioning groove, 17-trapezoidal table, 18-motion control console, 19-hydraulic valve, 20-hydraulic pump, 21-tee joint, 22-hydraulic gauge, 23-X-ray data collector, 24-X-ray source generator, 25-data processor, 26-CT control cabinet, 27-high-pressure tank, 28-sample. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] The present invention specifically provides a high-pressure tank 27 for CT detection of characteristics of a sample 28 under high hydrostatic pressure, comprising:

[0059] The outer tank comprises a base 1, a window tube 2 and a steel connection ring 3 which are fixedly connected in sequence from bottom to top, and the outer tank is used to provide support for the inner liner 4 to prevent the inner liner 4 from being deformed under high pressure;

[0060] The liner 4 is arranged in the outer tank, used for placing the sample 28, and is fitted with the base 1 and the window tube 2, and the upper edge of the liner 4 is installed in the slot at the upper end of the steel connecting ring 3;

[0061] A sealing cover 5 is fixedly mounted on the top of the outer tank, and a sealing ring 6 is provided between the sealing cover 5 and the inner liner 4 to convert multiple sealing interfaces into one sealing interface between the inner liner 4 and the sealing cover 5;

[0062] The window tube and the inner lining 4 are both made of high X-ray penetrating materials to ensure that the X-rays can penetrate the sample 28 .

[0063] The high-pressure tank 27 in the present invention utilizes a base 1, a window tube 2 and a steel connecting ring 3 that are fixedly connected in sequence from bottom to top to form an outer tank body, and a liner 4 is placed in the outer tank. During testing, a sample 28 is placed in the liner 4; the liner 4 and the window tube 2 are both X-ray high-penetration materials, which can meet the requirements of X-ray penetration; the upper and lower ends of the window tube 2 are reinforced by the base 1 and the steel connecting ring 3 respectively, so that the outer tank structure has high strength, the liner 4 fits with the base 1 and the window tube 2, and the outer tank with high structural strength provides strong support for the liner 4, thereby enhancing the reliability of the liner 4 under high pressure and meeting the requirements of high-pressure structural strength; at the same time, the upper edge of the liner 4 is installed in the slot at the upper end of the steel connecting ring 3, and the sealing problems between the base 1 and the window tube 2, the window tube 2 and the steel connecting ring 3, and the steel connecting ring 3 and the sealing cover 5 are converted into sealing problems between the liner 4 and the sealing cover 5, and the three sealing interfaces are converted into one sealing interface, which can meet the requirements of high-pressure watertightness.

[0064] In summary, the outer tank and the liner 4 simultaneously meet the requirements of X-ray penetrability. The outer tank with high structural strength provides strong support for the liner 4, enhances the reliability of the liner 4 under high pressure, and makes the high-pressure tank 27 meet the requirements of high-pressure structural strength. The liner 4 converts the three sealing interfaces of the outer tank into one sealing interface, so that the high-pressure tank 27 meets the requirements of high-pressure water tightness. That is, the outer tank takes into account high-pressure water tightness, X-ray penetrability and high-pressure structural strength at the same time.

[0065] Furthermore, a corrugated blade 7 is provided at the lower part of the sealing ring 6, and a threaded hole for connecting with the steel connecting ring 3 is provided on the sealing ring 6. By tightening the bolts, a pre-tightening force is applied to the sealing ring 6, and the sealing ring 6 is fastened to the upper edge of the liner 4, so that the corrugated blade 7 forms a sealing interface with the liner 4 under the action of the pre-tightening force;

[0066] An O-ring groove 8 for placing an O-ring is provided on the upper portion of the sealing ring 6, and the sealing cover 5 and the sealing ring 6 are fixedly connected by screws. The sealing cover 5 is fastened to the sealing ring 6 by screws so that the sealing cover 5 presses the O-ring to seal.

[0067] Furthermore, the window tube 2 is inserted into the slot of the base 1, and threaded holes are arranged on the circumference of the side wall thereof, so as to fix the base 1 and the window tube 2 together by screws;

[0068] The steel connecting ring 3 is wrapped around the outside of the top of the window tube 2, and threaded holes are arranged on the circumference of the side wall so that the steel connecting ring 3 and the window tube 2 can be fixedly connected by screws.

[0069] Furthermore, a sample positioning device is provided inside the high-pressure tank 27 for fixing the sample 28 on the axis of the high-pressure tank 27;

[0070] A high-pressure tank positioning device is provided at the bottom of the high-pressure tank 27 for aligning the axis of the high-pressure pipe with the rotation center of the motion control console 18 so that the high-pressure tank 27 can rotate in situ under the drive of the motion control console 18 .

[0071] The sample 28 is located at the center of the high-pressure tank 27, and the high-pressure tank 27 is located at the center of the motion control console 18. When performing CT detection, the motion control console 18 can drive the high-pressure tank 27 to rotate in situ, without moving the CT equipment, to measure the structural characteristics of the sample 28 in hydrostatic pressure, thereby reducing the displacement deviation of the sample. The present invention realizes the in-situ measurement of the structural characteristics of the sample 28 in hydrostatic pressure for the first time, and provides a new technical means for the subsequent performance research of underwater sound absorbing materials.

[0072] Further, the sample positioning device comprises a self-positioning component 9 and a sample 28 positioning component 10 installed together, and the sample 28 positioning component 10 is located above the self-positioning component 9;

[0073] The self-positioning assembly 9 is used to fix the sample 28 positioning assembly 10 at the center of the high-pressure tank 27 , and the sample 28 positioning assembly 10 is used to fix the sample 28 at the center of the sample 28 positioning assembly 10 .

[0074] Further, the sample 28 positioning assembly 10 includes a sample 28 positioning platform 11, a plurality of slideways are evenly arranged on the upper surface of the sample 28 positioning platform 11, a positioning block 12 and a tension spring 13 are installed in each slideway, and the tension spring 13 pulls the positioning block 12 inward to fix the high-pressure tank 27 at the center of the sample 28 positioning platform 11;

[0075] The self-positioning assembly 9 includes a self-positioning platform 14, and a plurality of compression spring balancing devices 15 are evenly arranged on the circumference of the self-positioning platform 14 to make the center of the self-positioning platform 14 coincide with the axis of the pressure tank;

[0076] The sample 28 positioning platform 11 has the same contour as the self-positioning platform 14 , and the opposite sides of the sample 28 positioning platform 11 and the self-positioning platform 14 are both arranged in the positioning groove 16 , and a permanent magnet is inserted in the positioning groove 16 to align the sample 28 positioning platform 11 and the self-positioning platform 14 up and down.

[0077] Furthermore, the high-pressure tank positioning device is a trapezoidal truncated cone 17 , and the upper and lower ends of the trapezoidal truncated cone 17 are coaxially engaged with the high-pressure tank 27 and the motion control console 18 , respectively.

[0078] Furthermore, the pressurizing hole on the sealing cover 5 is connected to a hydraulic pump 20 through a hydraulic valve 19 for controlling the hydrostatic pressure in the tank body, and is connected to a hydraulic gauge 22 through a three-way joint 21 for displaying the pressure in the tank body.

[0079] The present invention further provides a CT detection system for characteristics of a sample 28 under high hydrostatic pressure, comprising:

[0080] A motion control console 18, used for installing the high-pressure tank 27 of claim 8, capable of driving the high-pressure tank 27 to rotate in situ and adjusting geometric parameters before detection;

[0081] The X-ray data collector 23 and the X-ray source generator 24 are respectively arranged on opposite sides of the high-pressure tank 27;

[0082] The data processor 25 is connected to the X-ray data collector 23 and the motion console 18 respectively to obtain the CT scan data and the motion data of the high-pressure tank 27 and perform post-processing on the data;

[0083] The CT control cabinet 26 is connected to the X-ray source generator 24 and is used to control the X-ray source generator 24 .

[0084] The present invention further provides a CT detection method for the characteristics of the sample 28 under high hydrostatic pressure, using the above-mentioned CT detection system, comprising the following steps:

[0085] Adjust the distance between the object distance and the focal length of CT imaging to improve the clarity of the imaging effect, make the sample outline clear, and meet the imaging requirements of sample 28.

[0086] The energy of the X-ray data collector 23 is corrected to eliminate the annular virtual shadow of the 3D reconstructed slice image. This step needs to be performed before each CT scan. The results of CT reconstruction with and without energy correction are as follows: Figure 7 As shown in Figure 1, without correction and positioning, artifacts will appear in the CT slice image, affecting the accuracy of image processing, such as Figure 7 As shown in A, after correction and positioning, the image artifacts disappear. Figure 7 As shown in B.

[0087] The high-pressure tank 27 is pressurized. When the pressure value meets the requirement, the system is allowed to stand for a period of time to reduce the influence of the relaxation phenomenon of the sample 28 on the test. After the pressure value stabilizes, the pressure pump is removed and a rotational CT scan is performed.

[0088] The X-ray source generator 24 is started, and the X-ray collector receives the attenuated X-rays after passing through the sample 28. The data acquisition system of the CT machine converts the ray intensity into a digital signal to become projection data. The projection data is processed by the image processing system to obtain the original CT data.

[0089] The original CT data is processed by a reconstruction algorithm to obtain the three-dimensional data of sample 28;

[0090] Slice the three-dimensional data of sample 28 to obtain CT slice grayscale data;

[0091] The CT slice grayscale data is cropped to reduce the data volume;

[0092] The grayscale data of the cropped frontal CT slices are de-noised by using a filtering algorithm;

[0093] The de-noised image is subjected to threshold segmentation through a convolutional neural network to obtain an accurate target segmentation image, and the air phase and the solid phase in the deformed sample 28 are accurately distinguished. The specific segmentation method is as follows: the CT slice data is processed using an image enhancement algorithm, which can make the CT image look clearer and easier to accurately segment different materials in the CT image. Then, the slice data is made into a data set with image segmentation labels according to specific segmentation requirements. Finally, the image is segmented through a deep learning algorithm to obtain accurate pixel classification information after the sample changes, and the physical phase classification in the CT slice image is realized.

[0094] The voxel value of the image is calibrated according to the reference object method, the volume of each pixel is calculated, the number of pixels of the air phase and the solid phase in the CT segmented image is counted, and the overall volume of all layers of the sample 28 is obtained by the accumulation method, and the volume of the sample 28 under hydrostatic pressure is obtained; that is, a sample has many layers of CT slices, and the number of pixels of a certain material in each layer of the slice is calculated, and the number of pixels of all slices of the material is added up to obtain the volume of the material.

[0095] The pressure value of the high-pressure tank 27 is changed, and the above experiment is repeated to obtain the volume of the sample 28 under different hydrostatic pressures, so as to comprehensively and accurately evaluate the change of the elastic sample 28 under hydrostatic pressure.

[0096] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A high-pressure tank for CT detection of sample characteristics under high hydrostatic pressure, characterized in that: include: An outer tank, comprising a base (1), a window tube (2) and a steel connecting ring (3) which are fixedly connected in sequence from bottom to top, the outer tank being used to provide support for the knife liner (4) to prevent the liner (4) from deforming under high pressure; The inner liner (4) is arranged in the outer tank, used for placing the sample (28), and is fitted with the base (1) and the window tube (2), and the upper edge of the inner liner (4) is installed in the slot at the upper end of the steel connecting ring (3); A sealing cover (5) is fixedly mounted on the top of the outer tank, and a sealing ring (6) is provided between the sealing cover (5) and the inner liner (4) to convert multiple sealing interfaces into one sealing interface between the inner liner (4) and the sealing cover (5); The window tube and the inner lining (4) are both made of highly X-ray penetrating materials to ensure that the X-rays can penetrate the sample (28).

2. The high pressure tank according to claim 1, characterized in that: The sealing ring (6) is provided with a corrugated blade (7) at the bottom, and the sealing ring (6) is provided with a threaded hole for connecting with the steel connecting ring (3), so that the corrugated blade (7) forms a sealing interface with the liner (4) under the action of a pre-tightening force; An O-type rubber ring groove (8) for accommodating an O-type rubber ring is provided on the upper part of the sealing ring (6), and the sealing cover (5) and the sealing ring (6) are fixedly connected by screws.

3. The high pressure tank according to claim 1, characterized in that: The window tube (2) is inserted into the slot of the base (1), and threaded holes are arranged on the circumference of the side wall thereof so as to fix the base (1) and the window tube (2) together by screws; The steel connecting ring (3) is wrapped around the outside of the top of the window tube (2), and threaded holes are arranged on the circumference of its side wall so as to fix the steel connecting ring (3) and the window tube (2) with screws.

4. The high-pressure tank according to any one of claims 1 to 3, characterized in that: A sample positioning device is provided inside the high-pressure tank (27) for fixing the sample (28) on the axis of the high-pressure tank (27); A high-pressure tank positioning device is provided at the bottom of the high-pressure tank (27) for aligning the axis of the high-pressure pipe with the center of rotation of the motion control console (18), so that the high-pressure tank (27) can rotate in situ under the drive of the motion control console (18).

5. The high pressure tank according to claim 4, characterized in that: The sample positioning device comprises a self-positioning component (9) and a sample positioning component (10) installed together, wherein the sample positioning component (10) is located above the self-positioning component (9); The self-positioning component (9) is used to fix the sample positioning component (10) at the center of the high-pressure tank (27), and the sample positioning component (10) is used to fix the sample (28) at the center of the sample positioning component (10).

6. The high pressure tank according to claim 5, characterized in that: The sample positioning assembly (10) comprises a sample positioning platform (11), a plurality of slideways are evenly arranged on the upper surface of the sample positioning platform (11), a positioning block (12) and a tension spring (13) are installed in each of the slideways, and the tension spring (13) pulls the positioning block (12) inward to fix the high-pressure tank (27) at the center of the sample positioning platform (11); The self-positioning assembly (9) comprises a self-positioning platform (14), and a plurality of compression spring balancing devices (15) are evenly arranged on the circumference of the self-positioning platform (14) so ​​as to make the center of the self-positioning platform (14) coincide with the axis of the pressure tank; The sample positioning platform (11) and the self-positioning platform (14) have the same profile, and the opposite sides of the sample positioning platform (11) and the self-positioning platform (14) are both arranged in a positioning groove (16), and a permanent magnet is inserted in the positioning groove (16) so that the sample positioning platform (11) and the self-positioning platform (14) are aligned vertically.

7. The high pressure tank according to claim 4, characterized in that: The high-pressure tank positioning device is a trapezoidal truncated cone (17), and the upper and lower ends of the trapezoidal truncated cone (17) are coaxially engaged with the high-pressure tank (27) and the motion control console (18) respectively.

8. The high pressure tank according to claim 4, characterized in that: The pressure hole on the sealing cover (5) is connected to a hydraulic pump (20) via a hydraulic valve (19) for controlling the hydrostatic pressure in the tank body, and is also connected to a hydraulic gauge (22) via a three-way joint (21) for displaying the pressure in the tank body.

9. A CT detection system for sample characteristics under high hydrostatic pressure, characterized in that: include: A motion control console (18) for installing the high-pressure tank (27) according to claim 8, capable of driving the high-pressure tank (27) to rotate in situ and adjusting geometric parameters before detection; An X-ray data collector (23) and an X-ray source generator (24) are respectively arranged on two opposite sides of the high-pressure tank (27); A data processor (25) is connected to the X-ray data collector (23) and the motion control console (18) respectively to obtain CT scan data and motion data of the high-pressure tank (27), and to post-process the data; A CT control cabinet (26) is connected to the X-ray source generator (24) and is used to control the X-ray source generator (24).

10. A CT detection method for sample characteristics under high hydrostatic pressure, characterized in that: Using the CT detection system according to claim 9 comprises the following steps: Adjust the distance between the object distance and the focal length of CT imaging to improve the clarity of the imaging effect, make the sample outline clear, and meet the imaging requirements of the sample (28); Correcting the energy of the X-ray data collector (23) to eliminate the annular virtual shadow of the three-dimensional reconstructed slice image. This step needs to be performed before each CT scan; The high-pressure tank (27) is pressurized, and when the pressure value meets the requirement, the system is allowed to stand still until the pressure value is stable to reduce the influence of the relaxation phenomenon of the sample (28) on the test, and the pressure pump is removed to perform a rotational CT scan; The X-ray source generator (24) is started, and the X-ray collector receives the attenuated X-rays after passing through the sample (28), and converts the collected signals into raw CT data; Processing the original CT data by a reconstruction algorithm to obtain three-dimensional data of the sample (28); Slicing the three-dimensional data of the sample (28) to obtain CT slice grayscale data; The CT slice grayscale data is cropped to reduce the data volume; The grayscale data of the cropped frontal CT slices are de-noised by using a filtering algorithm; The de-noised image is subjected to threshold segmentation through a convolutional neural network to obtain an accurate target segmentation image and accurately distinguish the air phase and solid phase in the deformed sample (28); The voxel value of the image is calibrated according to the reference method, the volume of each pixel is calculated, the number of pixels of the air phase and the solid phase in the CT segmentation image is counted, and the overall volume of all layer slices (28) of the sample is obtained by the accumulation method to obtain the volume of the sample (28) under hydrostatic pressure; The pressure value of the high-pressure tank (27) is changed, and the above experiment is repeated to obtain the volume of the sample (28) under different hydrostatic pressures, so as to comprehensively and accurately evaluate the changes of the elastic sample (28) under hydrostatic pressure.

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