Method for synchronously observing low-temperature accelerated degradation and surface crack of sealing element

Abstract

The invention discloses a method for synchronously observing low-temperature accelerated degradation and surface cracks of a sealing element. The method comprises the following steps: 1, integrally placing the device in a container comprising a high-definition window; placing a test sample between an upper clamp and a lower clamp of the device, wherein the lower clamp is fixed at the bottom of the container through a bracket base; step 2, placing the surface crack synchronous observation device on the outer side of a container of the experiment device, after the experiment is started, keeping the relative position of the surface crack synchronous observation device and the test sample unchanged, performing pixel-level difference on images shot at different times by adopting an image difference method, and determining the aging degree of the sealing element by adjusting important factors of aging of the sealing element. Performing low-temperature accelerated degradation of the sealing element; the sample surface crack development process is recorded. The device can realize local stress reinforcement and local temperature difference control, and has the characteristic of synchronous observation of surface microcracks.

Description

Technical Field

[0001] This invention relates to the field of sealing technology for low-temperature power equipment, specifically to a method for simultaneous observation of accelerated low-temperature degradation and surface cracks in sealing components. Background Technology

[0002] Rubber seals are commonly used at the connection points of high-voltage oil-filled and gas-filled electrical equipment. Because the rubber seals are tightly connected to the equipment casing, the temperature of the rubber seals is close to the ambient temperature when the equipment is operating in low-temperature environments. In the plateau and northeastern regions of my country, the lowest temperatures can reach below -50℃, causing cracks to appear on the surface of commonly used rubber seals. These seals gradually deteriorate and fail, leading to oil and gas leaks into the equipment. External gases, moisture, and other impurities can then enter the equipment, causing malfunctions or even complete failure.

[0003] When seals are used in low-temperature environments, they are subjected to the combined effects of mechanical pressure, temperature, and media, causing microcracks to form on the surface and continuously develop, leading to the overall deterioration of the seal's performance. To investigate the performance degradation of seals caused by low temperatures and to quickly assess the suitability and reliability of seals in low-temperature environments, it is necessary to conduct accelerated aging and surface crack testing on the seals specifically designed for low temperatures.

[0004] Existing performance evaluation methods for rubber seals in power equipment all involve independent testing of single macroscopic properties, which cannot simultaneously detect parameters during accelerated degradation and do not address the generation and development of surface cracks. To address this need, this invention provides a novel method. Summary of the Invention

[0005] In order to overcome the defects of the existing technology, the present invention provides a method for simultaneous observation of low-temperature accelerated deterioration of sealing components and surface cracks, which can realize local stress strengthening and local temperature difference control, and has the feature of simultaneous observation of surface microcracks.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for simultaneous observation of accelerated low-temperature degradation and surface cracks in sealing components includes the following steps:

[0008] Step 1: Place the entire low-temperature accelerated degradation device inside the container containing the high-definition viewing window, and then place the test sample between the upper and lower clamps of the low-temperature accelerated degradation device. The lower clamp is fixed to the bottom of the container by the support base.

[0009] Step 2: Place the surface crack synchronous observation device outside the container of the experimental setup. After the experiment begins, keep the relative positions of the surface crack synchronous observation device and the test sample unchanged. Use the image difference method to perform pixel-level difference analysis on images taken at different times. By adjusting key factors of seal aging, accelerate the low-temperature degradation of the seal; thus, record the surface crack development process of the sample. By performing pixel-level difference analysis on images taken at different times using the image difference method, and by controlling key factors of seal aging to conduct a low-temperature accelerated degradation experiment of the seal, dynamic recording of the surface crack development process of the sample can be achieved.

[0010] In step 1, the upper and lower clamps are hollow annular heat-conducting metals, and are connected and fixed by bolts. The test sample is located between the upper and lower clamps. The test sample is axially compressed by controlling the clamp distance to apply axial pressure, which is used to simulate the normal use pressure and pressure enhancement during the installation and use of the sealing ring.

[0011] In step 1, the distance between the upper and lower clamps is controlled by tightening the bolts, and the sample is compressed to 99% to 50% of its original size, thereby achieving axial compression and pressure application. The upper and lower clamps can axially compress the sample to 1% to 50% of its original size.

[0012] The test sample is a ring-shaped experimental sample. A radial stress support is used at a position parallel to the center of the ring-shaped experimental sample to provide radial local pressure reinforcement. The radial pressure enhancement simulates the local stress concentration during the installation of the sealing ring.

[0013] The radial stress support is in the shape of a "I", "+", or "M" and its dimensions are adjustable in all directions. The elongation is controlled by threads and can achieve an elongation of 1% to 45%, providing 1% to 45% radial deformation stress concentration. The radial stress support is installed between the upper and lower clamps, parallel to the center of the test sample. By adjusting the size of the radial stress support relative to the test sample, radial stress is applied to provide radial local pressure reinforcement.

[0014] The upper clamp is detachable and has a temperature control function. The temperature control function is achieved by installing a liquid circulation pipe inside the clamp and circulating it with an external compression and temperature system.

[0015] The circulation pipeline is connected to an external compression and temperature control system. Temperature control is achieved through the circulation of water, oil, and refrigerant. The temperature control system simulates the temperature conditions of the sealing ring in extremely cold and normal working environments. The temperature control range is from -65℃ to 85℃, and the temperature control accuracy is ±0.5℃.

[0016] The circulation pipeline is arranged in a spiral shape, and the external compression system is a turbine compressor. Temperature sensors are arranged in the cavity between the circulation pipeline and the upper clamp. The temperature sensors test the temperature of the upper clamp. The temperature sensors and the external compressor use PI closed-loop control to achieve temperature regulation and stabilization.

[0017] The container is cylindrical or rectangular with a high-definition viewing window, and is transparent. It is made of heat-resistant glass or acrylic and is resistant to insulating oil and water.

[0018] The lower clamp is coaxial with the upper clamp, and the lower clamp is connected and fixed to the bottom of the container; the upper clamp and the lower clamp are coaxially installed, with an inner diameter of 10mm-150mm and an outer diameter of 100mm-300mm, and are matched with a radial stress control bracket with a size of 10-300mm.

[0019] In step 2, the surface crack synchronous observation device includes an image processing device, a lens, an optical magnifying lens, and a CCD electronic magnifying lens.

[0020] The optical magnifying lens has an adjustable magnification of ×1 to ×40, and the CCD electronic magnifying lens has an adjustable magnification of ×1 to ×10. The optical and CCD electronic magnifying lenses are coaxially mounted to collect data on surface crack changes of the test sample. The light source is an LED cold light source, coaxially mounted with the optical and CCD electronic magnifying lenses to provide illumination for image acquisition. The lens acquires images in real time, enabling automatic shooting and storage at intervals of 5s to 1800s for recording the crack development process on the sample surface. The lens transmits the acquired information to an image processing device.

[0021] In step 2, the axial pressure of the test sample is controlled by adjusting the distance between the upper and lower clamps; radial stress is applied to the test sample by adjusting the radial length of the radial stress support; the low-temperature accelerated aging temperature of the test sample is controlled by adjusting the internal circulation conduit of the clamp; the solvent environment of the test sample is controlled by changing the solvent in the container; and the low-temperature accelerated deterioration of the seal is achieved by controlling the axial and radial stress, low temperature, and solvent.

[0022] The image processing device controls image acquisition through a timing program, and can automatically capture images at intervals of 5s to 1800s by setting a delay program. By keeping the detection distance, light, and lens magnification constant, the resolution and size of images captured for the same sample and the same degradation experiment stage remain consistent. Using image color threshold settings (e.g., threshold set to 125, values ​​greater than 125 become 255, and others become 0), images with the same resolution and size are binarized. The changes and distribution of data after binarization in images from different degradation experiment stages are compared to analyze the changes in surface cracks.

[0023] The beneficial effects of this invention are:

[0024] This application simulates the temperature, stress, and solvent conditions encountered in the actual application of rubber seals. The upper and lower clamps simulate axial stress, while the radial stress support simulates concentrated axial forces caused by installation and equipment vibration. It features temperature simulation capabilities, capable of simulating both extremely cold and normal operating environments for the rubber seals. The container can be filled with oil and other solvents that can cause aging of the rubber seals. Combined with a camera with magnification, a light source, and a data processor, it enables real-time acquisition of images showing changes on the seal surface during accelerated degradation. The data processor uses image difference analysis to compare image pixels, achieving simultaneous detection of crack changes and aging time. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings.

[0027] like Figure 1 As shown, a device for simultaneous observation of low-temperature accelerated deterioration and surface cracks of sealing components is provided. The annular experimental sample is placed between the upper clamp 1 and the lower clamp 2 of the device. The upper clamp 1 and the lower clamp 2 are hollow annular heat-conducting metals, which are connected and fixed by bolts 5 and axial pressure is applied by controlling the dimensions.

[0028] The lower clamp 2 and the support base are fixed to the bottom of the container 3. The upper clamp 1 is detachable and has a temperature control function. The radial stress support 7 is installed between the upper clamp 1 and the lower clamp 2, and is installed in a position parallel to the center part of the annular experimental sample. The radial local pressure is strengthened by adjusting the size of the support.

[0029] An optical magnifying lens and a CCD electronic magnifying lens are coaxially mounted to collect changes in cracks on the sample surface.

[0030] Light source 9 is an LED cold light source, which is coaxially mounted with the lens to provide illumination for image acquisition;

[0031] Lens 9 acquires images in real time, enabling automatic shooting and storage at intervals of 5s to 1800s, for recording the crack development process on the sample surface.

[0032] Compression and temperature control system: used for temperature acquisition and control;

[0033] Temperature control liquid circulation pipeline 6: used for the circulation of liquids such as water, oil, and refrigerant to achieve sample temperature control;

[0034] Transparent container 3: Used to fix clamps and hold experimental apparatus;

[0035] Upper fixture 1 and lower fixture 2: Used to place the sample, provide temperature control and axial pressure;

[0036] Bolt 5: Used to control the distance between the upper fixture 1 and the lower fixture 2 and control the axial pressure applied to the sample;

[0037] Radial stress bracket 7: Used to apply radial stress to the sample;

[0038] Light source 9: Used for stable control of illumination for image acquisition;

[0039] Magnifying lens: Includes an optical magnifying lens and a CCD magnifying lens, used for image acquisition;

[0040] Image processor 8: Compared with the above picture, used for storage and crack development analysis.

[0041] Embodiment:

[0042] The solvent can be: transformer oil, silicone grease, water, silicone oil, alkylbenzene, etc.;

[0043] Temperature: Mainly focus on room temperature to -60°C, extremely cold usage environment;

[0044] Pressure: Compress the sample to 99% to 50% of its original size to achieve axial compression and pressure application: The upper fixture 1 and the lower fixture 2 can axially compress the sample to 1% to 50% of its original size;

[0045] The radial stress bracket 7 is in the shape of "one", "cross", or "rice", and the dimensions in each direction are adjustable. The dimensions are controlled by threads to achieve elongation, and 1% to 45% elongation can be achieved, providing 1% to 45% of radial deformation stress concentration;

[0046] For example: To simulate the deterioration of the low-temperature transformer seal ring, use transformer oil, 25% axial compression, low temperature of -50°C, and use the "one" - shaped bracket with 10% elongation; <​​​​​​​​​​​​​Step 2: Place the surface crack synchronous observation device outside container 3 of the experimental apparatus. After the experiment starts, keep the relative positions of the surface crack synchronous observation device and the test sample 4 unchanged. Use the image difference method to perform pixel-level difference on the images taken at different times to record the development process of surface cracks on the sample.

[0052] Program implementation:

[0053] Python programming language

[0054] Image acquisition:

[0055]

[0056]

[0057]

Claims

1. A method for simultaneous observation of low-temperature accelerated deterioration and surface cracks in sealing components, characterized in that, It includes the following steps; Step 1: Place the whole low-temperature accelerated deterioration device inside a container (3) including a high-definition window; then place the test sample (4) between the upper fixture (1) and the lower fixture (2) of the low-temperature accelerated deterioration device, and the lower fixture (2) is fixed to the bottom of the container (3) through a bracket base; Step 2: Place the surface crack synchronous observation device outside the container (3) of the experimental device. After the experiment starts, keep the relative positions of the surface crack synchronous observation device and the test sample (4) unchanged. Adopt the image difference method to perform pixel-level difference on the images taken at different times, and perform low-temperature accelerated deterioration of the seal by adjusting the important factors of seal aging; Record the development process of the surface crack of the sample.

2. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 1, characterized in that, In the above Step 1, the upper fixture (I) and the lower fixture (2) are hollow annular heat-conducting metals. The upper fixture (I) and the lower fixture (2) are connected and fixed by bolts (5). The test sample (4) is located between the upper fixture (I) and the lower fixture (2). Axial compression of the test sample is carried out by controlling the distance between the fixtures to apply axial pressure to simulate the normal use pressure condition and the pressure strengthening condition during the installation and use of the sealing ring.

3. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 2, characterized in that, In the above Step 1, the distance between the upper fixture (I) and the lower fixture (2) is controlled by tightening the bolts (5) to compress the test sample (4) to 99% to 50% of its original size, realizing axial compression and pressure application: the upper fixture (I) and the lower fixture (2) can axially compress the sample to 1% - 50% of its original size.

4. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 1, characterized in that, The test sample (4) is an annular experimental sample, and a radial stress bracket (7) provides radial local pressure strengthening at a position parallel to the central part of the annular experimental sample. The radial pressure strengthening simulates the local stress concentration situation during the installation of the sealing ring; The radial stress bracket (7) is in the shape of "one", "cross", or "rice". The dimensions in each direction are adjustable. The dimensions are controlled by threads to extend, realizing 1% - 45% elongation and providing 1% to 45% radial deformation stress concentration; the radial stress bracket (7) is installed between the upper fixture (I) and the lower fixture (2), and is installed at a position parallel to the central part of the test sample (4). By adjusting the dimensions of the radial stress bracket (7) relative to the test sample (4), radial stress is applied to provide radial local pressure strengthening.

5. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 1, characterized in that, A liquid circulation pipeline (6) is installed inside the upper fixture (I), and temperature control is achieved through external compression and temperature system circulation; the upper fixture (I) is detachable and has a temperature control function; The circulation pipeline (6) is connected to an external compression and temperature control system (10), and temperature control is achieved through the circulation of water, oil, and refrigerant. The temperature control system (10) simulates the temperature conditions of the sealing ring in extremely cold and normal working environments. The temperature control range is from -65°C to 85°C, and the temperature control accuracy is within ±0.5°C for the internal temperature control device.

6. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 5, characterized in that, The circulation pipe (6) is arranged in a spiral shape, and the external compression system is a turbine compressor. A temperature sensor is arranged in the cavity between the circulation pipe (6) and the upper clamp (1). The temperature sensor measures the temperature of the upper clamp (1). The temperature sensor and the external compressor are controlled by PI closed loop to achieve temperature regulation and stabilization.

7. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 1, characterized in that, The upper clamp (1) and lower clamp (2) are coaxially mounted, with an inner diameter of 10mm-150mm and an outer diameter of 100mm-300mm. They are matched with a radial stress support (7) with a size of 10-300mm.

8. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 1, characterized in that, In step 2, the surface crack synchronous observation device includes an image processing device (8), a lens (9), an optical magnifying lens, and a CCD electronic magnifying lens; The magnification of the optical magnifying lens is adjustable from ×1 to ×40, and the magnification of the CCD electronic magnifying lens is adjustable from ×1 to ×10. The optical magnifying lens and the CCD electronic magnifying lens are coaxially mounted to collect the surface crack changes of the test sample (4). The light source (9) is an LED cold light source, which is coaxially mounted with the optical magnifying lens and the CCD electronic magnifying lens to provide illumination for image acquisition. The lens (9) acquires images in real time and can automatically capture and store images at intervals of 5s to 1800s for recording the development process of surface cracks on the sample. The lens (9) transmits the acquired information to the image processing device (8).

9. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 8, characterized in that, In step 2, the axial pressure of the test sample (4) is controlled by adjusting the distance between the upper clamp (1) and the lower clamp (2); the radial stress is applied to the test sample 4 by adjusting the radial length of the radial stress support (7); the low-temperature accelerated aging temperature of the test sample is controlled by adjusting the internal circulation conduit (6) of the clamp (1); the solvent environment of the test sample (4) is controlled by changing the solvent in the container (3); and the low-temperature accelerated deterioration of the seal is achieved by controlling the axial and radial stress, low temperature, and solvent.

10. The method for simultaneous observation of low-temperature accelerated deterioration and surface cracks of a sealing component according to claim 8, characterized in that, The image processing device (8) controls the image acquisition of the lens (9) through a timing program. Automatic shooting at intervals of 5s to 1800s can be achieved by setting a delay program. The resolution and size of the images taken for the same sample and the same degradation experiment stage remain consistent after the detection distance, light and lens magnification are set. The images with the same resolution and size are binarized by setting the image color threshold. The changes and distribution of the data after binarization in the images of different degradation experiment stages are compared to analyze the changes in surface cracks.

Images