Anti-vibration device for transformer or reactor union tube and testing method of anti-vibration device

Abstract

The invention relates to the technical field of transformers and electric reactors, and discloses an anti-vibration device for a transformer or electric reactor union tube and a testing method thereof. The anti-vibration device comprises a metal hose, a flange plate and a connecting pipe; the connecting pipes are connected in a sealed mode through flange plates or metal hoses, a plurality of supporting columns are arranged below the connecting pipes at intervals in the axial direction of the connecting pipes, and the tops of the supporting columns are detachably connected with the connecting pipes through U-shaped clamps. The testing method comprises the steps of working condition parameter calibration, structure detection, cold and hot circulation aging, composite vibration testing and failure judgment, and vibration acceleration and strain data are monitored through multi-dimensional sensing. According to the invention, through the composite metal hose and the optimized support layout design and in combination with full-flow test verification, the vibration resistance of the connection pipe connection is greatly improved, the service life is remarkably prolonged, and the occurrence rate of faults such as oil leakage and cracks caused by vibration of equipment is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transformers and reactors, and particularly relates to an anti-vibration device for a transformer or reactor manifold and a testing method thereof. BACKGROUND

[0002] In a power system, transformers and reactors as key equipment need to be stably operated for a long time. However, under the long-term operation condition, the manifold connection position is subjected to a large vibration force due to the combined action of electromagnetic vibration, equipment impact and other complex factors. If the manifold connection mode is not firm enough, when subjected to continuous vibration force, the connection part is prone to local resonance. Local resonance will continuously increase the vibration amplitude of the position, aggravating the fatigue loss of the material. With the passage of time, micro cracks will gradually appear at the connection part, and these cracks will continuously expand under the action of continuous vibration stress, eventually leading to the rupture of the manifold system and oil leakage, seriously affecting the operation safety and reliability of the equipment.

[0003] Therefore, in order to improve the anti-vibration performance of the transformer or reactor manifold connection position and reduce the failure rate, it is urgent to optimize the connection mode and establish a perfect test method to scientifically evaluate the anti-vibration performance, so as to improve the product quality of the transformer or reactor. SUMMARY

[0004] In view of the defects of the prior art, the present application provides an anti-vibration device for a transformer or reactor manifold and a testing method thereof, aiming to solve the problems of poor anti-vibration performance and easy fatigue failure of the existing manifold connection, and to ensure the anti-vibration performance of the anti-vibration device through the testing method.

[0005] In order to solve the technical problem, the technical scheme adopted by the present application is as follows: an anti-vibration device for a transformer or reactor manifold, comprising a metal hose, a flange plate and a manifold, the manifold of the vibration stress concentration area is connected through the metal hose and the flange plate, and the other manifolds are connected through the flange plate; a plurality of support columns are arranged below the manifold along the axial direction of the manifold, one end of the support column is detachably connected to the manifold through a clamp, and the other end of the support column is connected to the body of the transformer or reactor; the metal hose comprises a corrugated section, a woven wire mesh and a clamp, the woven wire mesh is wrapped outside the corrugated section, and the clamp is sleeved on both ends of the woven wire mesh and is in close contact with the end of the corrugated section. In the device, the metal hose realizes flexible connection between the manifolds, the support column and the body of the transformer / reactor are rigidly connected, and the components cooperatively realize the dual functions of "flexible compensation + rigid support". The metal hose forms a composite protection structure of "corrugated section-woven wire mesh-clamp", and the composite structure can absorb vibration displacement.

[0006] Further, the corrugated section is a ring-shaped stainless steel corrugated pipe, the corrugated depth D and the pipe diameter d satisfy the relationship D = 0.15 * d + 1 mm, the corrugated number N and the pipe diameter d satisfy the relationship N = d / 10 + 2, N is an integer.

[0007] Further, the woven wire mesh is woven by stainless steel wires, the weaving angle is 45° ± 5°, the weaving density is 4.7-7.1 D / cm, and the wire mesh thickness is 0.8-1.5 mm.

[0008] Further, the hoop is a stainless steel semicircular structure with a thickness of 2-4 mm, the inner wall of the hoop is attached to the woven wire mesh, and the two ends of the hoop are respectively sealed and welded to the end of the corrugated section and the edge of the flange plate by argon arc welding.

[0009] Further, the support column is rigidly connected to the transformer or the reactor body at the bottom through bolts, and a threaded hole is arranged at the top; the end of the clamp is provided with an external thread, and the depth of the external thread screwed into the threaded hole at the top of the support column is ≥20 mm.

[0010] Further, the distance between the support columns is 15-25 times the pipe diameter, and at least 2 support columns are arranged for the pipe with a length of ≥1 m, and the number of support columns increases by 1 for every increase of 1.5 m in the length of the pipe.

[0011] Further, a rubber buffer layer is arranged at the contact position of the clamp and the pipe.

[0012] The method also discloses a test method, and the method is used for testing the vibration performance of the anti-vibration device, and includes the following steps: S01, determining the vibration characteristic parameters of the transformer or the reactor pipe caused by electromagnetic force and equipment impact in real operation through field measurement, and taking the vibration characteristic parameters as test input criteria; S02, performing ultrasonic flaw detection and air tightness test on the to-be-tested metal hose to ensure that the to-be-tested metal hose is in a crack-free and un-fused state and the air tightness meets the requirements before vibration test; S03, placing the to-be-tested metal hose in a sealed environment, then performing cold and hot cycle aging test on the to-be-tested metal hose, and detecting the air tightness of the to-be-tested metal hose after the cold and hot cycle aging test is completed; S04, assembling the metal hose after the cold and hot cycle aging test into the anti-vibration device, and fixing the anti-vibration device to a vibration test tool table, wherein the tool table is rigidly connected to the multi-degree-of-freedom vibration table; S05, arranging three-axis acceleration sensors at the middle of the metal hose, the middle of the pipe, the root of the flange, the contact position of the clamp and the pipe, and the tail end of the pipe, and pasting strain gauges at the welding seam of the metal hose and the wave peak position of the corrugated section, wherein the three-axis acceleration sensors are used for detecting the stress state of the anti-vibration device, and the strain gauges are used for detecting the vibration response of the anti-vibration device. S06, the multi-degree-of-freedom vibration table sends out vibration, and the anti-vibration device sequentially carries out random vibration test, sine sweep vibration test, impact vibration test and fatigue vibration test; S07, real-time monitoring is carried out through a data acquisition system, and any one of the following conditions is judged as failure: visible cracks occur in the metal hose or the pipe joint, medium leakage occurs; internal defect extension of more than 2mm is found in the weld flaw detection; the strain amplitude of the corrugated joint exceeds 80% of the material yield strain.

[0013] Further, the cold-heat cycle aging test is one cycle at-10 DEG C, room temperature, 70 DEG C and room temperature, 6h at-10 DEG C, 1h transition from-10 DEG C to room temperature, 6h at 70 DEG C, 1h transition from 70 DEG C to room temperature, and 3 cycles are completed to complete the cold-heat cycle aging test.

[0014] Further, the random vibration test adopts the spectrum density signal and vibration acceleration matched with step S01, the frequency range is 50-400Hz, the vibration lasts for N1 hours, and the vibration acceleration amplitude is recorded synchronously; the sine sweep vibration test sweeps in the range of 50-400Hz at a rate of 1oct / min, the acceleration peak value is the acceleration peak value in the vibration characteristic parameter recorded in step S01, each frequency point lasts for N2 minutes, and the resonance frequency is identified; the impact vibration test adopts a half-sine impact waveform, the acceleration peak value is the upper half value of the acceleration peak value in the vibration characteristic parameter recorded in step S01, the duration is N3 milliseconds, the impact times are M times, and the start-stop or fault impact of the simulation equipment is simulated; the vibration amplitude of the fatigue vibration test is set according to historical experience data of similar products, the excitation frequency is based on the frequency measured in step S01, and the vibration duration is not less than N4 hours.

[0015] The beneficial effects of the present application are as follows: the anti-vibration performance is greatly improved, the maximum vibration amplitude of the sample is 35.6m / s² under the working condition of 1000kV electric reactor, which is only 11.4% of the traditional structure, the anti-vibration performance is improved by about 7.8 times, the average strain value is 178-210με, which is far lower than the traditional 652-720με, and the early fatigue of the material is avoided. The reliability and adaptability are strong, no cracks and leakage are found after 100h fatigue test, the device can be adapted to 10-1000kV equipment, the parameters can be dynamically adjusted to cope with different working conditions; the test is scientific, covers aging and composite vibration test, and multiple dimensions are monitored to provide accurate data for product optimization, and effectively reduce the oil leakage and crack failure of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the anti-vibration device; Figure 2 It is a structural schematic diagram of the metal hose; Figure 3A schematic diagram showing the vibration damping device fixed to the vibration test fixture. Figure 4 This is a schematic diagram of the arrangement of the three-dimensional accelerometer sensors; In the diagram: 1. Metal hose, 2. Flange, 3. Connecting pipe, 4. Clamp, 5. Support column, 6. Vibration test fixture, 7. Corrugated pipe, 8. Braided wire mesh, 9. Clamp. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1 This embodiment discloses an anti-vibration device for transformer or reactor couplings, such as... Figure 1 As shown, the system includes a flexible metal hose 1, a flange 2, and a connecting pipe 3. Connecting pipe 3 in the vibration stress concentration area is connected to flange 2 via flexible metal hose 1, while other connecting pipes are connected via flange 2. In this embodiment, the vibration stress concentration area is the connection point between the vertical and horizontal connecting pipes. A flexible metal hose is installed 100mm to the left of the vertical connecting pipe. Multiple support columns 5 are spaced apart along the axial direction of connecting pipe 3 below it. One end of each support column 5 is detachably connected to connecting pipe 3 via a U-shaped clamp 4, and the other end is connected to the transformer or reactor body. Figure 2 As shown, the flexible metal hose 1 includes a corrugated section 7, a braided wire mesh 8, and a clamp 9. The braided wire mesh 8 wraps around the outside of the corrugated section 7, and the clamp 9 is fitted onto both ends of the braided wire mesh 8 and fits snugly against the ends of the corrugated section 7. In this device, the flexible metal hose 1 provides a flexible connection between the connecting pipes 3, while the support column 5 is rigidly connected to the transformer / reactor body. The components work together to achieve the dual functions of "flexible compensation + rigid support." The flexible metal hose 1 forms a composite protective structure of "corrugated section-braided wire mesh-clamp," which can absorb vibration displacement.

[0019] The corrugated section 7 is a ring-shaped stainless steel corrugated pipe, the corrugated depth D and the pipe diameter d satisfy the relationship D = 0.15 * d + 1 mm, the corrugated number N and the pipe diameter d satisfy the relationship N = d / 10 + 2, N is an integer. Specifically, the corrugated depth is 5-15 mm, and the corrugated number is 8-15. The core function of the corrugated pipe 7 is to absorb displacement by corrugated deformation, and the flexibility is positively correlated with the corrugated depth (the greater the corrugated depth, the smaller the stiffness, and the better the flexibility; however, when the corrugated depth is large, the material forming limit is exceeded, and uneven wall thickness reduction, cracking or wrinkling occurs). To ensure that the corrugated depth is proportional to the pipe diameter, and to avoid insufficient wave depth of large-diameter pipes and excessive wave depth of small-diameter pipes, based on past experience, the formula: corrugated depth (D) = 0.15 * pipe diameter (d) + 1 mm is formed; the constant term of 1 mm is the "minimum effective wave depth" of the corrugated pipe, which can ensure the integrity of the corrugated structure even when the pipe diameter is extremely small, and avoid the sudden change in stiffness caused by excessive proximity of wave peaks and valleys. The axial stiffness of the corrugated pipe 7 is approximately inversely proportional to the number of corrugations (under the same pipe diameter and corrugated depth, the more the number of waves, the smaller the stiffness, and the stronger the flexibility). Based on past experience, the formula: corrugated number (N) = pipe diameter (d) / 10 + 2 (N is an integer) is formed; the coefficient of d / 10 is an empirical value based on "unit length wave number adaptation", for example, when d = 60 mm, N = 8, and when d = 130 mm, N = 15. This ratio can make large-diameter pipes offset the increase in stiffness caused by the increase in pipe diameter by increasing the number of waves, and small-diameter pipes avoid insufficient stiffness by reducing the number of waves. The constant term +2 sets the minimum wave number bottom line. The corrugated pipe achieves precise balance between flexibility and strength through parameter matching.

[0020] The woven wire mesh 8 is woven from stainless steel wire, the weaving angle is 45°±5°, the weaving density is 4.7-7.1 ends / cm, and the wire mesh thickness is 0.8-1.5 mm. The hoop 9 is a stainless steel semicircular structure with a thickness of 2-4 mm, the inner wall of the hoop 9 is in close contact with the woven wire mesh 8, and the two ends of the hoop 9 are respectively sealed and welded with the end of the corrugated section 7 and the edge of the flange plate 2 by argon arc welding. The corrugated section 7, the woven wire mesh 8 and the hoop 9 are made of 316 stainless steel, which makes the overall structure have excellent corrosion resistance and fatigue resistance, and is suitable for the complex operating environment of transformers and reactors.

[0021] The support columns 5 are arranged along the pipe axis at intervals, and the radial vibration of the pipe 3 is limited by the U-shaped clamp 4, so that the natural frequency of the support system avoids the equipment vibration frequency band of 50-400 Hz. The support column 5 is made of low-alloy high-strength steel, the bottom is rigidly connected to the transformer or reactor body by bolts, and the top is provided with a threaded hole; the end of the clamp 4 is provided with an external thread, and the depth of the external thread screwed into the threaded hole at the top of the support column 5 is ≥20 mm.

[0022] The distance between the support columns 5 is 15-25 times the diameter of the manifold 3, and at least two support columns are arranged for each section of the manifold 3 with a length of greater than or equal to 1 m. The number of support columns 5 is increased by one for each increase of 1.5 m in the length of the manifold 3, and the vibration stress is dispersed by the reasonable arrangement of the support columns 5.

[0023] In this embodiment, the manifold 3 is made of ordinary carbon steel Q235B, with an outer diameter of 60 mm, a wall thickness of 4 mm, and a total length of 2920 mm. The manifold 3 is an oil-filled pressure pipeline with a design working pressure of 0.6 MPa. The end of the manifold 3 is fixed to the flange plate 2 by argon arc welding, and the welded joint is qualified after ultrasonic flaw detection. The corrugated section 7 is a 316 stainless steel annular thin-walled corrugated pipe with a thickness of 0.4 mm. According to the diameter of the manifold 60 mm and the relationship formula, the corrugation depth D = 0.15 x 60 + 1 mm = 10 mm, and the number of corrugations N = 60 / 10 + 2 = 8, which meets the requirements of a depth of 5-15 mm and a number of 8-15. The woven wire mesh 8 is made of 316 stainless steel wire, with a weaving angle of 45°, a weaving density of 15 gauge / inch (5.9 gauge / cm), and a wire mesh thickness of 1.2 mm, which is tightly wrapped outside the corrugated section 7. The clamp 9 is a 316 stainless steel semicircular structure with a thickness of 3 mm, and the inner wall is attached to the woven wire mesh 8. The two ends are respectively sealed and welded to the end of the corrugated section 7 and the edge of the flange plate 2 by argon arc welding, with a weld width of greater than or equal to 5 mm and no undercut defects. The flange plate 2 is made of 316 stainless steel, with a diameter of 160 mm and a thickness of 18 mm. It is connected to the manifold end flange and the metal hose clamp by four M20 bolts, with a bolt pretightening torque controlled at 250 N·m. An oil-resistant rubber gasket is installed at the connection to achieve sealing. The support column 5 is made of low-alloy high-strength steel Q345B, with a height of 510 mm, an outer diameter of 48 mm, and a wall thickness of 3.5 mm. The bottom is rigidly connected to the reactor body by four M16 bolts, with a bolt screw-in depth of greater than or equal to 30 mm. The U-shaped clamp 4 is made of low-alloy high-strength steel Q345B, with an M14 external thread at the end. The clamp 4 is screwed into the top threaded hole of the support column 5 with a screwing depth of 25 mm. A rubber buffer layer is installed on the inner side of the clamp 4 to avoid rigid contact with the manifold. After assembly, the clamping force of the clamp 4 on the manifold is greater than or equal to 5 kN. Through the above structural design, the flexible compensation amount of the metal hose 1 can reach ±10 mm, and the natural frequency of the support system avoids the equipment vibration frequency band of 50-400 Hz. While meeting the flexible connection requirements of the pipeline, the vibration transmission is effectively weakened, and the fatigue loss of the connection part is reduced.

[0024] In other embodiments, the parameters of the woven layer of the metal hose 1, the specifications of the clamp 9, and the number and distance of the support columns 5 can be dynamically adjusted according to the diameter of the manifold, the medium pressure (0.1-1.0 MPa), and the vibration working condition, to adapt to different capacity levels of transformers and reactors.

[0025] Example 2 This embodiment discloses a test method for testing the test performance of the metal hose and the anti-vibration device formed by the metal hose described in Example 1. Specifically, the metal hose used in a certain 1000kV reactor header is taken as the test object, and a comparative test is carried out with a traditional metal corrugated pipe connection structure. The specific process is as follows: Step 1: Test working condition parameter calibration: Through field measurement, the vibration characteristic parameters (including X, Y, Z three-direction vibration frequency direction and size, wherein the frequency range is 50-400Hz, and the acceleration peak value is 0.1g-5g) caused by electromagnetic force and equipment impact in the actual operation of the transformer or reactor header are determined as the test input reference parameters, to ensure the consistency of the test and the actual working condition.

[0026] In this embodiment, through in-situ measurement of a certain 1000kV reactor factory, it is determined that the X direction of the reactor header is the main vibration direction, the vibration frequency is 100Hz, the maximum peak acceleration of the tank cover is 3g, and the power spectral density signal is 4.49 g² / Hz, which is taken as the test input reference.

[0027] Step 2: Structure detection: 100% ultrasonic flaw detection is performed on the weld of the metal hose, the detection sensitivity is ≥2mm, and no cracks, incomplete fusion and other defects are ensured; air tightness test is performed on the weld of the header and the flange, 0.2MPa compressed air is filled and pressure is maintained for 10min, and the pressure drop ≤5% is qualified.

[0028] For a 1000kV reactor, 100% ultrasonic flaw detection is performed on the weld of the metal hose according to GB / T 11345-2013 standard, the detection sensitivity is 2mm, and no defects are found; 0.2MPa compressed air is filled at the weld of the header flange, and the pressure is maintained for 10min, the pressure drop is 2%, and it is determined to be qualified.

[0029] Step 3: Cold and hot cycle aging test: in a sealed state, -10℃ (soaking for 6h), room temperature (transition for 1h), 70℃ (soaking for 6h), and room temperature (transition for 1h) are taken as one cycle, and a total of 3 cycles are completed, to simulate the seasonal temperature difference aging effect of the equipment. After the test, the air tightness test of step 2 is repeated, and the pressure drop is all ≤3%, without leakage.

[0030] Step 4: Test system construction and environment control: as Figure 3As shown, the flexible connection structure after the cold and hot cycle test is fixed as a whole on the vibration test tooling table 6, and the tooling table 6 is rigidly connected with the multi-degree-of-freedom vibration table through 8 M20 bolts; the test environment temperature is controlled at 10-40°C, and the humidity is controlled at 40-80%, simulating the equipment operating environment. The pipe system is filled with insulating oil to 0.6MPa rated pressure to simulate the operating state. In this embodiment, the test environment temperature is 25°C, the humidity is 60%, and the atmospheric pressure is 101kPa, which meets the control range of 10-40°C and 40-80%.

[0031] Step 5: Multi-dimensional sensing system arrangement: three-axis acceleration sensors are arranged in the middle of the metal hose (channel 1), the middle of the pipe (channel 2), the root of the flange (channel 3), the contact between the U-shaped clamp and the pipe (channel 4), and the tail end of the pipe (channel 5), with a sampling frequency of not less than 20kHz; strain gauges are pasted at the welds and wave peak positions of the metal hose, with an accuracy level of ≥0.1 level; synchronous monitoring of vibration response and stress state is realized.

[0032] As shown in Figure 4 In this embodiment, 2 groups of pipes are provided on the tooling table 6, and each group of pipes is provided with 5 three-axis acceleration sensor arrangement points (shown as red dots in the figure), which cover different positions and can reflect the stress state of the anti-vibration device when receiving vibration, and the sampling frequency of the three-axis acceleration sensor is 20kHz. Four 0.1 level strain gauges are pasted at the welds and wave peak positions of the metal hose, numbered S1-S4, of which S1 and S2 are pasted at the wave peak positions, and S3 and S4 are pasted at the weld heat-affected zone.

[0033] Step 6: Composite vibration test, including: 6.1 Random vibration test: the power spectral density and acceleration value obtained in step 1 are used, the frequency range is 50-400Hz, the vibration lasts for 24 hours, and the vibration acceleration amplitude is recorded synchronously. In this embodiment, the acceleration peak value of each measuring point of the sample is ≤35m / s², and the acceleration peak value of the traditional sample is ≤80m / s².

[0034] 6.2 Sine sweep vibration test: sweep at a rate of 1oct / min in the range of 50-400Hz, with an acceleration peak value of 0.1g, and each frequency point lasts for 30 minutes. The resonance frequency of the sample in this embodiment is identified as 140Hz (avoiding the operating frequency band), and the resonance frequency of the traditional sample is 110Hz (in the operating frequency band).

[0035] 6.3 Impact vibration test: A half-sine impact waveform is used, with an acceleration peak of 2-5g, a duration of 10-50ms, and 10-50 impacts to simulate the start-stop or failure impact of the device. In this embodiment, the acceleration peak is 5g, the duration is 30ms, and the number of impacts is 30. The strain amplitude of the sample of the present application is 60% of the yield strain of the material, and the strain amplitude of the traditional sample is 75%.

[0036] 6.4 Fatigue vibration test: The vibration amplitude of the fatigue vibration test is set according to the historical experience data of similar products, the excitation frequency is based on the frequency measured in step 1, and the vibration duration is not less than 100 hours to ensure that the material can withstand countless cycles without failure under this stress level. In this embodiment, the loading frequency is 100Hz, the acceleration peak is 3g, and the duration is 100h (cycle number is about 1.1x10 7

[0037] Step 7: Real-time monitoring by the data acquisition system, and any of the following conditions is considered as failure: visible cracks or medium leakage in the metal hose or pipe; internal defect extension ≥2mm found by weld inspection; strain amplitude of the corrugated section exceeding 80% of the yield strain of the material (316 stainless steel yield strain 1500με).

[0038] After the fatigue test, the final monitoring data of each strain gauge is shown in the following table (in the table, "strain value" is the arithmetic mean value within 10min in the stable stage of the test, and "fluctuation amplitude" is the difference between the maximum and minimum values within the same period): Test surface: The maximum vibration amplitude of the sample of the present application (35.6m / s²) is only 11.4% of that of the traditional sample (313.5m / s²), and the anti-vibration performance is improved by about 7.8 times, and the acceleration distribution of each channel is more uniform (the fluctuation range of the sample of the present application is 28.3-40.8m / s²; the fluctuation range of the traditional sample is 36.8-313.5m / s², and there is a significant vibration concentration phenomenon).

[0039] The average strain of the traditional sample is 652-720με, and the maximum value is 686-760με, which is close to 50% of the yield strain of the material, and fatigue cracks are easily generated during long-term operation. The average strain of the sample of the present application is 178-210με, and the maximum value is 190-224με, which is only 15% of the yield strain of 316 stainless steel (1500με), which is far below the failure threshold of strain amplitude exceeding 80% of the yield strain of the material, and the anti-vibration performance is greatly improved. ​

[0040] The flexible connection mode of the application can maintain excellent anti-vibration performance and structural stability under the high-voltage and strong-vibration working condition of the 1000kV electric reactor, can meet the long-term operation requirement of the 1000kV extra-high voltage power equipment, and can reduce the operation and maintenance cost of the equipment.

[0041] Finally, it should be noted that the above examples are only specific embodiments of the application, which are used to illustrate the technical solutions of the application, but not to limit it. The protection scope of the application is not limited to this. Those skilled in the art should understand that any person skilled in the art can modify or easily think of changes to the technical solutions recorded in the foregoing examples within the technical range disclosed by the application, or make equivalent replacement to some technical features. The modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application, and should be covered in the protection scope of the application.

Claims

1. A vibration-damping device for transformer or reactor couplings, characterized in that: It includes metal hoses, flanges, and connecting pipes. Connecting pipes in areas of vibration stress concentration are connected by metal hoses and flanges, while other connecting pipes are connected by flanges. Multiple support columns are arranged at intervals along the axial direction of the connecting pipes. One end of the support column is detachably connected to the connecting pipe by a clamp, and the other end of the support column is connected to the transformer or reactor body. The metal hose includes a corrugated joint, a braided wire mesh, and a clamp. The braided wire mesh is wrapped around the outside of the corrugated joint, and the clamp is fitted on both ends of the braided wire mesh and fits against the ends of the corrugated joint.

2. The vibration-damping device for transformer or reactor couplings according to claim 1, characterized in that: The corrugated joint is an annular stainless steel corrugated pipe. The corrugation depth D and the connecting pipe diameter d satisfy the relationship D=0.15×d+1mm. The number of corrugations N and the connecting pipe diameter d satisfy the relationship N=d / 10+2, where N is an integer.

3. The vibration-damping device for transformer or reactor couplings according to claim 1, characterized in that: The woven wire mesh is made of stainless steel wire with a weaving angle of 45°±5°, a weaving density of 4.7-7.1 mesh / cm, and a wire mesh thickness of 0.8-1.5mm.

4. The vibration-damping device for transformer or reactor couplings according to claim 1, characterized in that: The clamp is a semi-circular stainless steel structure with a thickness of 2-4mm. The inner wall of the clamp is fitted with woven wire mesh, and the two ends of the clamp are sealed to the end of the corrugated section and the edge of the flange by argon arc welding.

5. The vibration-damping device for transformer or reactor couplings according to claim 1, characterized in that: The bottom of the support column is rigidly connected to the transformer or reactor body by bolts, and the top is provided with a threaded hole; the end of the clamp is provided with an external thread, and the external thread is screwed into the threaded hole at the top of the support column to a depth of ≥20mm.

6. The vibration-damping device for transformer or reactor couplings according to claim 1, characterized in that: The spacing between the support columns is 15-25 times the diameter of the connecting pipe. Each connecting pipe with a length of ≥1m should be equipped with at least 2 support columns. The number of support columns increases by 1 for every 1.5m increase in the length of the connecting pipe.

7. The vibration-damping device for transformer or reactor couplings according to claim 1, characterized in that: A rubber buffer layer is provided at the contact point between the clamp and the connecting pipe.

8. A testing method, characterized in that: This method is used to test the vibration performance of the vibration damping device according to any one of claims 1-7, and includes the following steps: S01. Determine the vibration characteristic parameters of the transformer or reactor coupling caused by electromagnetic force and equipment impact during actual operation through on-site measurement, and use the vibration characteristic parameters as the test input benchmark. S02. Perform ultrasonic flaw detection and air tightness test on the metal hose to be tested to ensure that the metal hose to be tested is in a crack-free, unfused state and meets the air tightness requirements before the vibration test. S03. Place the metal hose to be tested in a sealed environment, and then conduct a thermal cycling aging test on the metal hose to be tested. After the thermal cycling aging test is completed, test the air tightness of the metal hose to be tested. S04. The metal hoses after the cold and hot cycle aging test are assembled into a vibration-resistant device. The vibration-resistant device is fixed to the vibration test fixture, and the fixture is rigidly connected to the multi-degree-of-freedom vibration table. S05. Triaxial accelerometers are installed in the middle of the metal hose, the middle of the connecting pipe, the root of the flange, the contact point between the clamp and the connecting pipe, and the tail end of the connecting pipe. Strain gauges are attached to the weld seam of the metal hose and the crest of the corrugated joint. The triaxial accelerometers are used to detect the stress state of the vibration damping device, and the strain gauges are used to detect the vibration response of the vibration damping device. S06. The multi-degree-of-freedom vibration table emits vibrations, and random vibration test, sinusoidal sweep frequency vibration test, impact vibration test and fatigue vibration test are carried out in sequence on the anti-vibration device. S07. Real-time monitoring through the data acquisition system shall determine failure if any of the following conditions occur: visible cracks appear in the metal hose or connecting pipe, or medium leakage occurs; internal defects are found to extend ≥2mm during weld inspection; or the strain amplitude of the corrugated joint exceeds 80% of the material's yield strain.

9. The test method according to claim 8, characterized in that: The thermal cycling aging test consists of three cycles: -10℃, room temperature, 70℃, and room temperature. The test involves holding the temperature at -10℃ for 6 hours, followed by a 1-hour transition from -10℃ to room temperature, holding the temperature at 70℃ for 6 hours, and then a 1-hour transition from 70℃ to room temperature. The thermal cycling aging test is completed after a total of 3 cycles.

10. The test method according to claim 8, characterized in that: The random vibration test uses a spectral density signal and vibration acceleration matched to step S01, with a frequency range of 50-400Hz and continuous vibration for N1 hours, while simultaneously recording the vibration acceleration amplitude. The sinusoidal sweep vibration test sweeps the frequency within the 50-400Hz range at a rate of 1 oct / min, with the acceleration peak value being the acceleration peak value in the vibration characteristic parameters recorded in step S01. Each frequency point is continuously vibrated for N2 minutes to identify the resonant frequency. The impact vibration test uses a half-sine impact waveform, with the acceleration peak value being the upper half of the acceleration peak value in the vibration characteristic parameters recorded in step S01, a duration of N3 milliseconds, and M impacts, simulating equipment start-up, shutdown, or fault impacts. The vibration amplitude of the fatigue vibration test is set based on historical experience data of similar products, with the excitation frequency based on the frequency measured in step S01, and the vibration duration is no less than N4 hours.

Images