A pipeline vibration reduction design method based on the coupling of viscous damping and particle damping

Abstract

The present invention discloses a pipeline vibration reduction design method based on the coupling of viscous damping and particle damping, including: performing vibration test on the pipeline to be optimized, extracting vibration frequency characteristics, establishing a discrete element-finite element coupling analysis model, matching the vibration reduction frequency bands corresponding to the viscous damping vibration absorber and the particle damping vibration absorber, and determining their various configuration parameters; performing static analysis mode calculation on the optimized new pipeline, obtaining the new pipeline model and the stress distribution diagram of the new pipeline model, comparing the maximum stress value in the stress distribution diagram with the fatigue limit value of the pipeline, so that the maximum stress value of the new pipeline model is less than the fatigue limit value of the pipeline. The present invention utilizes the vibration reduction characteristics of the viscous damping vibration absorber and the particle damping vibration absorber, matches them with the discrete element-finite element coupling analysis model of the pipeline to be optimized, and can specifically reduce vibration and noise in each vibration frequency band of the pipeline, realize vibration control of the full frequency range of the pipeline, and has good vibration reduction and noise reduction effects.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline vibration reduction, and in particular to a pipeline vibration reduction design method based on the coupling of viscous damping and particle damping. Background Art

[0002] Pipeline vibration is a common phenomenon in the petrochemical industry. Pipeline vibration can be caused by a variety of reasons, such as the opening and closing of valves in pipelines, the transportation of fluids in pipelines, and mechanical vibration transmission. Pipeline vibration has many hazards. Severe vibration can even cause fatigue failure of pipeline structures, leading to structural damage to pipelines, causing pipeline ruptures, and causing serious safety accidents such as container ruptures and explosions. Therefore, pipeline vibration reduction has attracted much attention.

[0003] Pipeline vibration is a relatively complex systemic problem. Special structures such as valves, tees, elbows, etc. are set on the pipeline. The vibration characteristics at different positions on the pipeline are different, the vibration causes are also different, and the frequency components are relatively complex. The pipeline vibration absorbers currently on the market have limitations in their vibration reduction frequency bands. For example, the viscous damping vibration absorber is a velocity-type vibration absorber, which has a good vibration reduction effect on low-frequency vibrations, but a poor vibration reduction effect on high-frequency vibrations. For example, the particle damping vibration absorber is an acceleration-type vibration absorber, which has an insignificant vibration reduction effect on low-frequency vibrations below 100Hz, but has a very obvious vibration reduction effect on high-frequency vibrations above 100Hz. Summary of the invention

[0004] The purpose of the present invention is to provide a pipeline vibration reduction design method based on the coupling of viscous damping and particle damping, so as to carry out targeted vibration reduction design for each vibration frequency band of the pipeline.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A pipeline vibration reduction design method based on the coupling of viscous damping and particle damping is provided, wherein a viscous damping vibration absorber and a particle damping vibration absorber are arranged on the outer periphery of the pipeline to reduce vibration, and the method comprises the following steps:

[0007] S1. Perform a vibration test on the pipeline to be optimized in operation, extract the vibration frequency characteristics of the pipeline to be optimized, and establish a discrete element-finite element coupling analysis model of the pipeline to be optimized;

[0008] S2. According to the vibration frequency characteristics of the pipeline and the discrete element-finite element coupling analysis model, the vibration damping frequency bands corresponding to the viscous damping damper and the particle damping damper are matched, and the configuration parameters of the viscous damping damper and the particle damping damper are determined;

[0009] S3. Perform static analysis mode calculation on the optimized new pipeline configured with the viscous damping vibration absorber and the particle damping vibration absorber to obtain the optimized new pipeline model and the stress distribution diagram of the new pipeline model;

[0010] S4. Compare the maximum stress value in the stress distribution diagram with the fatigue limit value of the pipeline. If the maximum stress value is less than the fatigue limit value, the obtained new pipeline model meets the equipment operation conditions; if the maximum stress value is greater than or equal to the fatigue limit value, the obtained new pipeline model does not meet the equipment operation conditions, and it is necessary to repeat steps S2 and S3 to re-optimize the pipeline until the maximum stress value of the obtained new pipeline model is less than the fatigue limit value of the pipeline.

[0011] Furthermore, the method further includes step S5. Performing dynamic analysis on the optimized new pipeline model to obtain the vibration response curve of the pipeline before and after adding the viscous damping shock absorber and the particle damping shock absorber, and comparing the vibration response curve with relevant standards.

[0012] Furthermore, when performing dynamic analysis on the new pipeline model, it is necessary to perform modal calculation on the new pipeline model, the order of the modal calculation is at least 12 or more, and the number of iterative calculations is at least 11 times.

[0013] Furthermore, in step S2, when matching the viscous damping vibration absorber and the particle damping vibration absorber, the vibration reduction performance of each viscous damping vibration absorber and the particle damping vibration absorber is evaluated in each vibration reduction frequency band according to a one-tenth octave frequency band.

[0014] Furthermore, in step S1, a test system is used to perform a vibration test on the pipeline to be optimized, and the test system includes an acceleration sensor, a vibration data collector and a data analysis platform. The measurement frequency range of the acceleration sensor is 0.5Hz-12000Hz, and the data analysis platform is used for Fourier analysis and wavelet analysis.

[0015] Furthermore, in step S1, the steps of establishing a discrete element-finite element coupling analysis model of the pipeline to be optimized are as follows:

[0016] S11. Select the unit time step;

[0017] S12. Calculate the damping coefficients of the particle damping shock absorber corresponding to each damping frequency band using the discrete element method; calculate the damping coefficients of the viscous damping shock absorber corresponding to each damping frequency band using the finite element method;

[0018] S13. The static and dynamic responses of the pipeline after the additional damping coefficient is calculated using the finite element method;

[0019] S14. Iterate the next time step;

[0020] S15. Repeat steps S11-S14 until convergence.

[0021] Furthermore, in step S3, the number of calculation iterations of the static analysis mode calculation is 1-45 times.

[0022] The present invention has the following beneficial effects:

[0023] 1. By utilizing the vibration reduction characteristics of the viscous damping vibration absorber and the particle damping vibration absorber and matching them with the discrete element-finite element coupling analysis model of the pipeline to be optimized, it is possible to specifically reduce vibration and noise in each vibration frequency band of the already operating pipeline, realize vibration control of the full frequency range of the pipeline, and achieve good vibration reduction and noise reduction effects.

[0024] 2. By comparing the maximum stress value of the new pipeline model with the fatigue limit value of the pipeline, the optimized new pipeline model can be directly tested, which is simple and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the pipeline structure.

[0026] Figure 2 This is a schematic diagram of the pipeline vibration data spectrum.

[0027] Figure 3 Schematic diagram of the pipeline finite element model.

[0028] Figure 4 This is one of the schematic diagrams of the connection between the viscous damping shock absorber and the pipeline.

[0029] Figure 5 This is one of the schematic diagrams of the connection between the viscous damping shock absorber and the pipeline.

[0030] Figure 6 This is one of the schematic diagrams of the connection between the viscous damping shock absorber and the pipeline.

[0031] Figure 7 Schematic diagram of the connection between particle damping vibration absorber and pipeline.

[0032] Figure 8 Schematic diagram of the installation position of viscous damping shock absorber and particle damping shock absorber.

[0033] Explanation of main component symbols: 1. Pipe; 11. Elbow 1; 12. Elbow 2; 13. Elbow 3; 14. Elbow 4; 15. Tee; 2. Viscous damping shock absorber; 3. Particle damping shock absorber. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0035] The present invention discloses a pipeline vibration reduction design method based on the coupling of viscous damping and particle damping, which is designed by arranging a viscous damping vibration absorber 2 and a particle damping vibration absorber 3 on the periphery of a pipeline 1 to reduce vibration, and includes the following steps:

[0036] S1. Perform a vibration test on the pipeline 1 to be optimized in operation, extract the vibration frequency characteristics of the pipeline 1 to be optimized, and establish a discrete element-finite element coupling analysis model of the pipeline 1 to be optimized.

[0037] The vibration test is carried out using a test system when pipeline 1 is working. The test system includes an acceleration sensor, a vibration data collector and a data analysis platform. The measurement frequency range of the acceleration sensor is 0.5Hz-12000Hz, and the data analysis platform is used for Fourier analysis and wavelet analysis.

[0038] When establishing the discrete element-finite element coupling analysis model of the pipeline 1 to be optimized, the specific steps are as follows:

[0039] S11. Select the unit time step;

[0040] S12. The damping coefficients of the particle damping shock absorber 3 corresponding to each damping frequency band are calculated using the discrete element method; the damping coefficients of the viscous damping shock absorber 2 corresponding to each damping frequency band are calculated using the finite element method;

[0041] S13. The static and dynamic responses of pipeline 1 after obtaining the additional damping coefficient by using the finite element method;

[0042] S14. Iterate the next time step;

[0043] S15. Repeat steps S11-S14 until convergence.

[0044] S2. According to the vibration frequency characteristics of the pipeline 1 and the discrete element-finite element coupling analysis model, the vibration damping frequency bands corresponding to the viscous damping vibration absorber 2 and the particle damping vibration absorber 3 are matched, and various configuration parameters of the viscous damping vibration absorber 2 and the particle damping vibration absorber 3 are determined. When matching the viscous damping vibration absorber 2 and the particle damping vibration absorber 3, the vibration damping performance of each viscous damping vibration absorber 2 and the particle damping vibration absorber 3 is evaluated in each vibration damping frequency band according to one-tenth of an octave.

[0045] S3. Perform static analysis mode calculation on the optimized new pipeline 1 equipped with the viscous damping vibration absorber 2 and the particle damping vibration absorber 3 to obtain the optimized new pipeline model and the stress distribution diagram of the new pipeline model. The number of calculation iterations of the static analysis mode calculation is 1-45 times.

[0046] S4. Compare the maximum stress value in the stress distribution diagram with the fatigue limit value of pipeline 1. If the maximum stress value is less than the fatigue limit value, the obtained new pipeline model meets the equipment operation conditions; if the maximum stress value is greater than or equal to the fatigue limit value, the obtained new pipeline model does not meet the equipment operation conditions, and it is necessary to repeat steps S2 and S3 to re-optimize and calculate pipeline 1 until the maximum stress value of the obtained new pipeline model is less than the fatigue limit value of pipeline 1.

[0047] S5. Perform dynamic analysis on the optimized new pipeline model to obtain the vibration response curve of the pipeline 1 before and after adding the viscous damping shock absorber 2 and the particle damping shock absorber 3, and compare the vibration response curve with the relevant standards. When performing dynamic analysis on the new pipeline model, it is first necessary to perform modal calculation on the new pipeline model, and the order of the modal calculation is at least 12 orders, and the number of iterative calculations is at least 11 times.

[0048] like Figure 1 As shown, taking the vibration reduction design of the outlet pipe 1 of the propylene refrigeration compressor K-601 as an example, after the pipe 1 is connected to the compressor, it passes through a straight pipe section and an elbow 11 and then connects to a tee 15. The other two ends of the tee 15 pass through an elbow 2 12 and then climb upward through a vertical straight pipe section. A normally closed overflow valve is set on the top of the straight pipe section. The other end passes through elbows 3 13 and 4 14 and then is connected to the gas storage tank through a horizontal long straight pipe section. A throttling flowmeter is set in the long straight pipe 1. In response to the problem of excessive vibration of the pipe 1:

[0049] (1) The vibration of the pipeline 1 to be optimized is tested and analyzed using a test system, and the vibration curve of the pipeline 1 is obtained as follows: Figure 2 as shown in .

[0050] By comparing the theoretical calculation and the frequency spectrum of the field sampling data, it can be obtained that: a. The vibration acceleration, velocity and radiated noise of pipeline 1 all have peak values ​​at a frequency of 130Hz, and the vibration and noise influence show periodic fluctuation characteristics; b. In the analysis and calculation of the pipeline 1 mode, it is found that in the 131Hz frequency range, the structure of the middle section of the bend of pipeline 1 is prone to produce large strains, forming a strong resonance effect in the local structure; c. After the tee 15, after the pipeline passes through the elbow 2 12, there is an extremely high straight pipe air column, which makes the compressor pulsation energy accumulate again and difficult to release.

[0051] (2) Establish a discrete element-finite element coupling analysis model of the pipeline 1 to be optimized, match the vibration damping frequency bands corresponding to the viscous damper 2 and the particle damper 3, match the corresponding dampers from the designed viscous damper 2 and particle damper 3 databases, and determine their various configuration parameters. The finite element model of the pipeline 1 is as follows: Figure 3 as shown in .

[0052] The vibration reduction performance of each viscous damping vibration absorber 2 and particle damping vibration absorber 3 is evaluated in each vibration reduction frequency band according to one-tenth octave frequency band. Among them, the vibration reduction frequency band of the viscous damping vibration absorber 2 is 1.6Hz, 3.15Hz, 6.3Hz, 12.5Hz, 25Hz, 50Hz, and 100Hz; the vibration reduction frequency band of the particle damping vibration absorber 3 is 200Hz, 400Hz, 800Hz, 1600Hz, 3200Hz, 6400Hz, and 12800Hz. The damping coefficients corresponding to each vibration reduction frequency band are as follows:

[0053]

[0054] The viscous damping shock absorber 2 can reduce the vibration of the structure by using the friction energy dissipation of the viscous damping fluid, and has the characteristics of good durability, high reliability, and insensitivity to temperature changes. When applied to the pipeline 1, since the pipeline 1 generates a large vibration displacement under the pulsation excitation of the high-pressure gas, the viscous damping shock absorber 2 can effectively control the vibration displacement of the pipeline 1. Figure 4-6 As shown therein, a seat-type three-dimensional viscous damping shock absorber is used to reduce the vibration of the pipeline 1. Since the damping force of the viscous damping shock absorber 2 is proportional to the vibration velocity, in order to maximize its effect, it is set in the area with the largest amplitude of the pipeline 1, that is, the peak point in the vibration waveform, to obtain the maximum possible damping load.

[0055] The particle damping vibration isolator is suitable for multi-excitation and wide-frequency vibration environments. It can be used in two important links: the vibration source and the transmission path. It can greatly increase the vibration and noise attenuation without changing the system structure and effectively suppress the resonance peak within the range of 6000Hz.

[0056] According to the vibration test results of the pipeline 1, the pipeline 1 generates periodic vibration at a frequency of 131 Hz and produces relatively high noise. By comparing the vibration spectrum curve and the on-site vibration spectrum curve and combining the modal vibration shape of the pipeline 1 at a frequency of 131.72 Hz, it can be determined that the frequency of 131 Hz is generated by the resonance of the pipeline 1. Therefore, particle damping vibration isolators 3 are installed at the elbows of the pipeline 1 and the tee 15 where the vibration is severe. Figure 7 As shown in FIG. 1 , the particle damping vibration absorber 3 used is an external particle damping vibration absorber 3. The new pipeline 1 equipped with the viscous damping vibration absorber 2 and the particle damping vibration absorber 3 is as shown in FIG. Figure 8 as shown in .

[0057] (3) A static analysis mode calculation is performed on the optimized new pipeline 1 equipped with the viscous damping vibration absorber 2 and the particle damping vibration absorber 3 to obtain an optimized new pipeline model and a stress distribution diagram of the new pipeline model.

[0058] (4) Compare the maximum stress value in the stress distribution diagram with the fatigue limit value of pipeline 1 to ensure that the maximum stress value of the new pipeline model obtained is less than the fatigue limit value of pipeline 1.

[0059] (5) Finally, a dynamic analysis is performed on the optimized new pipeline model to obtain the vibration response curve of the pipeline 1 before and after adding the viscous damping shock absorber 2 and the particle damping shock absorber 3, and the vibration response curve is compared with the relevant standards.

[0060] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A pipeline vibration reduction design method based on the coupling of viscous damping and particle damping, which is characterized by: The following steps are involved: S1. Perform a vibration test on the pipeline to be optimized in operation, extract the vibration frequency characteristics of the pipeline to be optimized, and establish a discrete element-finite element coupling analysis model of the pipeline to be optimized; the steps of establishing the discrete element-finite element coupling analysis model of the pipeline to be optimized are as follows: S11. Select the unit time step; S12. Calculate the damping coefficients of the particle damping shock absorber corresponding to each damping frequency band using the discrete element method; calculate the damping coefficients of the viscous damping shock absorber corresponding to each damping frequency band using the finite element method; S13. The static and dynamic responses of the pipeline after the additional damping coefficient is calculated using the finite element method; S14. Iterate the next time step; S15. Repeat steps S11-S14 until convergence; S2. According to the vibration frequency characteristics of the pipeline and the discrete element-finite element coupling analysis model, the vibration damping frequency bands corresponding to the viscous damping damper and the particle damping damper are matched, and the configuration parameters of the viscous damping damper and the particle damping damper are determined; S3. Perform static analysis mode calculation on the optimized new pipeline configured with the viscous damping vibration absorber and the particle damping vibration absorber to obtain the optimized new pipeline model and the stress distribution diagram of the new pipeline model; S4. Compare the maximum stress value in the stress distribution diagram with the fatigue limit value of the pipeline. If the maximum stress value is less than the fatigue limit value, the obtained new pipeline model meets the equipment operation conditions; if the maximum stress value is greater than or equal to the fatigue limit value, the obtained new pipeline model does not meet the equipment operation conditions, and it is necessary to repeat steps S2 and S3 to re-optimize the pipeline until the maximum stress value of the obtained new pipeline model is less than the fatigue limit value of the pipeline.

2. The pipeline vibration reduction design method based on the coupling of viscous damping and particle damping as claimed in claim 1, characterized in that: The method also includes step S5. Dynamic analysis is performed on the optimized new pipeline model to obtain the vibration response curve of the pipeline before and after the viscous damping shock absorber and the particle damping shock absorber are added, and the vibration response curve is compared with relevant standards.

3. The pipeline vibration reduction design method based on the coupling of viscous damping and particle damping as claimed in claim 2, characterized in that: When performing dynamic analysis on a new pipeline model, it is necessary to perform modal calculation on the new pipeline model. The order of the modal calculation should be at least 12, and the number of iterative calculations should be at least 11.

4. The pipeline vibration reduction design method based on the coupling of viscous damping and particle damping according to claim 1, characterized in that: In step S2, when matching the viscous damping vibration absorber and the particle damping vibration absorber, the vibration reduction performance of each viscous damping vibration absorber and the particle damping vibration absorber is evaluated in each vibration reduction frequency band according to a one-tenth octave frequency band.

5. The pipeline vibration reduction design method based on the coupling of viscous damping and particle damping according to claim 1, characterized in that: In step S1, a test system is used to perform a vibration test on the pipeline to be optimized. The test system includes an acceleration sensor, a vibration data collector and a data analysis platform. The measurement frequency range of the acceleration sensor is 0.5Hz-12000Hz, and the data analysis platform is used for Fourier analysis and wavelet analysis.

6. The pipeline vibration reduction design method based on the coupling of viscous damping and particle damping according to claim 1, characterized in that: In step S3, the number of calculation iterations of the static analysis mode calculation is 1-45 times.

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