Pipeline vibration absorption device

Abstract

The invention discloses a pipeline vibration absorption device which aims at overcoming the defects of an existing pipeline vibration control means and achieving broadband vibration absorption. The device is composed of a passive vibration absorption part and an active vibration absorption part, a medium-high frequency vibration absorption unit of the passive vibration absorption part is filled with particle damping, and medium-high frequency vibration is absorbed through a pipe clamp connecting pipeline; the active vibration absorption part comprises a vibration sensor, an active vibration absorber, a controller and a power amplifier and is used for controlling low-frequency vibration. During working, medium-high frequency vibration is reduced through the medium-high frequency vibration absorption unit, and then low-frequency vibration is counteracted through the active vibration absorption part. The device effectively reduces the broadband vibration of the pipeline, optimizes the performance of a control system, simplifies the structure and reduces the cost.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration and noise control, and particularly to a vibration absorption device for pipelines. Background Art

[0002] In ship mechanical equipment, pipelines are one of the main vibration and noise transmission paths. Traditional means for controlling pipeline vibration and noise mainly include pipeline elastic supports and hangers, dynamic vibration absorbers, etc. Pipeline elastic supports and hangers have limitations in controlling pipeline vibration and noise. Pipeline elastic supports have a certain effect on broadband vibration transmission, but are not good at controlling low-frequency vibration; although dynamic vibration absorbers can effectively suppress vibration at specific frequencies, their followability to system frequency changes is poor, making it difficult to meet actual control requirements. Therefore, it is urgent to study new pipeline vibration transmission control technologies to solve the problems of pipeline vibration control in the low-frequency band and the medium-high frequency band. Summary of the Invention

[0003] The present invention aims to provide a pipeline vibration absorption device to solve the problems in the prior art that the means for controlling pipeline vibration have poor control effects on low-frequency vibration and insufficient followability to system frequency changes, and to achieve effective vibration absorption of high-frequency and low-frequency vibrations in the pipeline, meeting the requirements for broadband vibration control of the pipeline.

[0004] The composition of the pipeline vibration absorption device includes:

[0005] Passive vibration absorption part: mainly the medium-high frequency vibration absorption unit, which is internally provided with vibration absorption materials such as particle damping. It also includes pipe clamps, which are used on the one hand to transmit pipeline vibration to the medium-high frequency vibration absorption unit, and on the other hand to connect the active vibration absorption part to the pipeline, ensuring the stability of the connection between the entire device and the pipeline.

[0006] Active vibration absorption part: composed of a vibration sensor as the sensing unit, an active vibration absorber as the driving unit, a controller as the control unit, and a power amplifier. The vibration sensor is arranged downstream of the pipeline vibration transmission to pick up low-frequency vibration signals. The controller performs arithmetic processing on the signals, and the power amplifier converts the control signals output by the controller into driving currents to drive the active vibration absorber to work.

[0007] The working principle of the pipeline vibration absorption device:

[0008] The medium and high frequency vibration absorption unit of the passive vibration absorption part utilizes the characteristics of the vibration absorption material to convert the medium and high frequency vibration energy of the pipeline into other forms of energy such as heat energy for dissipation, thereby achieving the absorption of medium and high frequency vibration. The active vibration absorption part is based on the feedback control principle. The vibration sensor of the induction unit acquires the low frequency vibration signal, which is processed by the controller of the control unit through operation, and then converted by the power amplifier to generate a driving current, driving the active vibration absorber to generate a force with the same magnitude and opposite direction as the low frequency vibration, so as to cancel the low frequency vibration. At the same time, the absorption of medium and high frequency vibration by the passive vibration absorption part makes the main signals collected by the induction unit of the active vibration absorption part be low frequency signals, which is equivalent to achieving physical low-pass filtering, simplifying the design of the control unit of the active vibration absorption part and reducing the system delay.

[0009] The working process of the pipeline vibration absorption device:

[0010] The working process of passive vibration absorption: After the pipeline generates vibration, the vibration is transmitted to the medium and high frequency vibration absorption unit through the pipe clamp. The vibration absorption material in the medium and high frequency vibration absorption unit, such as particle damping, causes the internal particles to rub and collide with each other under the action of vibration, converting the medium and high frequency vibration energy into heat energy for consumption, effectively reducing the medium and high frequency vibration of the pipeline, so that the vibration transmitted to the downstream is mainly low frequency vibration.

[0011] The working process of active vibration absorption: The low frequency vibration processed by the medium and high frequency vibration absorption unit is transmitted to the vibration sensor of the induction unit downstream of the pipeline. The vibration sensor converts the picked-up low frequency vibration signal into an electrical signal and transmits it to the controller of the control unit through a connecting wire. The controller performs arithmetic processing on the signal to generate a corresponding control signal, and the control signal is converted by the power amplifier of the control unit into a driving current to drive the active vibration absorber to work. The force generated by the active vibration absorber is transmitted to the pipeline through the pipe clamp, and this force cancels out the low frequency vibration at the position of the vibration sensor downstream of the pipeline, achieving active control of the low frequency vibration of the pipeline.

[0012] Beneficial effects

[0013] Achieve broadband high-efficiency vibration reduction: Combining active and passive vibration absorption technologies, effectively control low frequency and medium and high frequency vibrations respectively, significantly reduce the broadband vibration of the pipeline, greatly improve the effect and range of pipeline vibration control, and meet the vibration reduction requirements under various complex working conditions.

[0014] Optimize the performance of the control system: The medium and high frequency vibration absorption unit realizes physical low-pass filtering, so that the control unit of the active vibration absorption part does not need to set a low-pass filter, which not only simplifies the system structure but also reduces the cost. At the same time, the system delay is greatly reduced, the response speed is accelerated, and the feedforward or feedback control algorithm can be flexibly used to accurately control the low frequency line spectrum and the broadband vibration in the low frequency band, improving the accuracy and reliability of vibration control. Description of the drawings

[0015] Figure 1 This is a schematic diagram of the composition of the present invention.

[0016] Figure 2 This is an installation schematic diagram of the present invention.

[0017] Figure 3 This is the control schematic diagram of the present invention.

[0018] Reference numerals: pipe clamp - 1, medium - high frequency vibration absorption unit - 2, vibration sensor - 3, active vibration absorber - 4, controller - 5, power amplifier - 6, pipeline - 7 Detailed implementation manners

[0019] Embodiment

[0020] A section of pipeline in a certain ship propulsion system is selected as the application object. When the pipeline is in operation, it is excited by the engine and other equipment, generating strong broadband vibration, which has an adverse impact on the stability and comfort of the ship. In view of this situation, the pipeline vibration absorption device of the present invention is installed for vibration reduction treatment.

[0021] (1) Composition and installation of the pipeline vibration absorption device

[0022] Passive vibration absorption part: The medium - high frequency vibration absorption unit 2 filled with particle damping inside is adopted. The particle damping selects metal particles with moderate hardness and large friction coefficient to enhance the vibration absorption effect. The medium - high frequency vibration absorption unit 2 is tightly connected to the pipeline 7 through a high - strength and high - elasticity rubber pipe clamp 1. The design of the pipe clamp 1 can not only ensure the efficient transmission of pipeline vibration to the medium - high frequency vibration absorption unit 2, but also, during the operation of the ship, due to the elastic buffer of the pipe clamp 1, avoid the generation of additional stress concentration between the device and the pipeline, ensuring the stability of the connection.

[0023] Active vibration absorption part: A piezoelectric vibration sensor 3 with high sensitivity and fast response speed is selected as the induction unit, which is installed on the surface of the pipeline 7 one meter downstream of the medium - high frequency vibration absorption unit 2 to ensure that the low - frequency vibration signal processed by the medium - high frequency vibration absorption unit 2 can be accurately picked up. The active vibration absorber 4 is used as the driving unit, and an electromagnetic active vibration absorber is selected, which is connected to the pipeline 7 through the pipe clamp 1 to ensure that the force generated by it can be effectively transmitted to the pipeline. The control unit adopts a controller 5 based on a digital signal processor (DSP), and an optimized adaptive filtering algorithm is installed inside it. The power amplifier 6 of the control unit selects a linear power amplifier with power matching and high conversion efficiency to convert the control signal output by the controller 5 to drive the active vibration absorber 4 to work. Each component is connected through a shielded connecting wire to reduce electromagnetic interference and ensure the accuracy of signal transmission.

[0024] (2) Working principle of the composition of the pipeline vibration absorption device

[0025] Principle of passive vibration absorption: When the pipeline 7 vibrates, the vibration energy is transmitted to the medium-high frequency vibration absorption unit 2 through the pipe clamp 1. Under the vibration excitation, the particle damping inside the medium-high frequency vibration absorption unit 2 causes strong friction and collision between the particles, converting the medium-high frequency vibration energy into heat energy and consuming it, thus achieving the absorption of medium-high frequency vibration.

[0026] Realization of the principle of active vibration absorption: The low-frequency vibration processed by the medium-high frequency vibration absorption unit 2 propagates to the vibration sensor 3 downstream of the vibration of the pipeline 7. The vibration sensor 3 converts the low-frequency vibration signal into an electrical signal. Based on the piezoelectric effect, the amplitude and frequency of this electrical signal are proportional to the intensity and frequency of the vibration. The electrical signal is transmitted to the controller 5 through a shielded connection line. The controller 5 uses the internal adaptive filtering algorithm to calculate a control signal that is equal in magnitude and opposite in direction to the low-frequency vibration according to the pre-set reference signal and the collected vibration signal. This control signal is converted by the power amplifier 6 and then drives the active vibration absorber 4 to work. The active vibration absorber 4 generates a force opposite to the low-frequency vibration based on the principle of electromagnetic induction and transmits it to the pipeline 7 through the pipe clamp 1 to achieve the cancellation of the low-frequency vibration.

[0027] (3) Implementation of the working process of the pipeline vibration absorption device:

[0028] Working process of passive vibration absorption: After the ship propulsion system is started, the pipeline 7 begins to vibrate. The vibration is transmitted along the pipeline 7 to the pipe clamp 1, thereby exciting the particle damping movement inside the medium-high frequency vibration absorption unit 2. The particles continuously friction and collide with each other. After a stable operation for a period of time (about 5 - 10 minutes), the downstream pipeline 7 of the medium-high frequency vibration absorption unit 2 is detected using a vibration spectrum analyzer, and it is found that the vibration amplitude in the medium-high frequency band (500 Hz - 5000 Hz) has decreased by 60% - 70%, proving that the medium-high frequency vibration absorption unit 2 effectively absorbs the medium-high frequency vibration, making the vibration transmitted to the downstream mainly low-frequency vibration.

[0029] Working process of active vibration absorption: The low-frequency vibration processed by the medium-high frequency vibration absorption unit 2 reaches the vibration sensor 3. The vibration sensor 3 converts the vibration signal into an electrical signal and transmits it to the controller 5 at a sampling frequency of 1000 times per second. The controller 5 completes the arithmetic processing within 1 millisecond after receiving the signal and generates a control signal. The control signal is converted by the power amplifier 6 and then drives the active vibration absorber 4 to generate a force. The force generated by the active vibration absorber 4 is transmitted to the pipeline 7 through the pipe clamp 1 and cancels out the low-frequency vibration at the position of the vibration sensor 3 downstream of the pipeline 7. During the operation of the ship, by continuously monitoring the signals collected by the vibration sensor 3 and the working state of the active vibration absorber 4, the parameters of the controller 5 are continuously adjusted to adapt to the low-frequency vibration changes under different working conditions. After debugging and optimization, the vibration amplitude in the low-frequency band (50 Hz - 500 Hz) has decreased by 80% - 90%, achieving effective control of the low-frequency vibration of the pipeline 7.

[0030] Through the implementation and application in the pipeline of the ship propulsion system, the pipeline vibration absorption device of the present invention exhibits good performance under actual working conditions. In terms of composition, reasonably selected components such as the medium-high frequency vibration absorption unit 2, pipe clamp 1, vibration sensor 3, active vibration absorber 4, controller 5, and power amplifier 6 ensure the reliability and effectiveness of the device. In terms of principle implementation, both the passive vibration absorption and active vibration absorption principles are effectively verified, and the conversion of medium-high frequency vibration energy and the cancellation effect of low-frequency vibration are significant. During the working process, whether it is the absorption of medium-high frequency vibration or the active control of low-frequency vibration, the expected goals are achieved, and the broadband vibration of the pipeline is greatly reduced.

Claims

1. A pipeline vibration absorbing device, characterized in that: include: The passive vibration absorbing part comprises a medium-high frequency vibration absorbing unit (2) and a pipe clamp (1); the medium-high frequency vibration absorbing unit (2) has vibration absorbing material arranged inside for absorbing medium-high frequency vibration of the pipeline; the pipe clamp (1) is used, on the one hand, to transmit the vibration of the pipeline (7) to the medium-high frequency vibration absorbing unit (2), and on the other hand, to connect the active vibration absorbing part (4) with the pipeline (7); The active vibration absorption part is composed of a vibration sensor (3) as a sensing unit, an active vibration absorber (4) as a driving unit, a controller (5) as a control unit, and a power amplifier (6); the vibration sensor (3) is arranged downstream of the vibration transmission of the pipeline (7) and is used to pick up low-frequency vibration signals, the controller (5) performs calculation processing on the signal, and the power amplifier (6) converts the control signal output by the controller into a driving current to drive the active vibration absorber (4) to work, so as to offset the low-frequency vibration of the pipeline.

2. The pipeline vibration absorbing device according to claim 1, characterized in that: The vibration absorbing material in the medium and high frequency vibration absorbing unit (2) is particle damping.

3. The pipeline vibration absorbing device according to claim 1, characterized in that: The vibration sensor (3) is a piezoelectric vibration sensor.

4. The pipeline vibration absorbing device according to claim 1, characterized in that: The active vibration absorber (4) is an electromagnetic active vibration absorber.

5. The pipeline vibration absorbing device according to claim 1, characterized in that: The controller (5) is based on a digital signal processor (DSP) and is internally equipped with an adaptive filtering algorithm.

6. The pipeline vibration absorbing device according to claim 1, characterized in that: The power amplifier (6) is a linear power amplifier.

7. The pipeline vibration absorbing device according to claim 1, its working process is as follows: When the pipeline (7) vibrates, the vibration is transmitted to the medium and high frequency vibration absorbing unit (2) through the pipe clamp (1), and the vibration absorbing material in the medium and high frequency vibration absorbing unit (2) converts the medium and high frequency vibration energy into heat energy, thereby reducing the medium and high frequency vibration, so that the downstream vibration is mainly low frequency vibration; The low-frequency vibration is transmitted to the vibration sensor (3), which converts it into an electrical signal and transmits it to the controller (5). The controller (5) generates a control signal after processing, which is converted into a driving current by the power amplifier (6) to drive the active vibration absorber (4) to generate a force, which is transmitted to the pipeline (7) through the pipe clamp (1) to offset the low-frequency vibration, thereby realizing active control of the low-frequency vibration.

8. The pipeline vibration absorbing device according to claim 7, characterized in that: In the passive vibration absorption process, the particle damping uses metal particles with moderate hardness and large friction coefficient, and the medium and high frequency vibration absorption unit (2) is tightly connected to the pipeline (7) through a high-strength and high-elasticity rubber pipe clamp (1). When the ship is running, the elastic buffer of the pipe clamp (1) can avoid the generation of additional stress concentration between the pipeline vibration absorption device and the pipeline (8).

9. The pipeline vibration absorbing device according to claim 7, characterized in that: During the active vibration absorption process, the piezoelectric vibration sensor (3) is installed on the surface of the pipeline (7) 1 meter downstream of the medium and high frequency vibration absorption unit (2), with a sampling frequency of 1000 times per second; the controller (5) completes the calculation processing within 1 millisecond after receiving the signal; the electromagnetic active vibration absorber (4) is connected to the pipeline through the pipe clamp (1), and the force generated by it can be effectively transmitted to the pipeline.

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