Piping noise reduction system

Abstract

The application relates to a pipeline noise reduction system, which comprises: an air pipe comprising a noise reduction pipe section; a power vibration absorption assembly arranged on the noise reduction pipe section and used for absorbing vibration energy of the noise reduction pipe section; a vibration pickup assembly used for detecting a sound field signal in the air pipe; and a control system in communication connection with the vibration pickup assembly, wherein the control system is configured to collect the sound field signal and calculate a vibration spectrum corresponding to the noise reduction pipe section based on the sound field signal and a preset sound vibration transfer function; and wherein the vibration absorption frequency band of the power vibration absorption assembly is adjustable according to a preset peak vibration frequency of the noise reduction section. Through the technical scheme, the problem that, in the related art, a pipeline silencer is arranged on an air conditioner system pipeline to absorb noise, the noise absorption capacity for medium and low frequency noise is insufficient, the medium and low frequency noise is easily propagated along the air conditioner pipeline to a cabin, and the comfort of passengers is affected can be solved.

Description

Technical Field

[0001] This application relates to the field of noise reduction devices, and in particular to pipeline noise reduction systems. Background Technology

[0002] The civil aviation industry has increasingly higher requirements for aircraft cabin comfort, as excessive cabin noise can reduce the passenger experience. Civil aircraft cabin noise originates from multiple sources, such as engines, turbulent boundary layers, environmental control systems, and electronic equipment. Among these, air conditioning noise from the environmental control system propagates along the air conditioning ducts into the cabin and persists throughout the entire process from start-up to shutdown, significantly impacting passenger comfort.

[0003] In related technologies, noise is absorbed by installing duct silencers in the air conditioning ducts. The duct silencer is usually an expansion cavity with sound-absorbing material inside. However, the sound-absorbing material has insufficient absorption capacity for mid- and low-frequency noise, which travels a long distance and can easily propagate along the air conditioning ducts into the cabin, affecting passenger comfort. Summary of the Invention

[0004] Therefore, it is necessary to provide a pipeline noise reduction system to address the problem that the absorption of low- and mid-frequency noise by installing pipeline silencers on the air conditioning system is insufficient, and that low- and mid-frequency noise can easily propagate along the air conditioning pipeline into the cabin, affecting passenger comfort.

[0005] A pipeline noise reduction system, comprising:

[0006] Air ducts, including noise reduction sections;

[0007] Dynamic vibration absorption components are installed on the noise reduction pipe section to absorb the vibration energy of the noise reduction pipe section;

[0008] Vibration pickup components are used to detect sound field signals inside the air duct;

[0009] The control system is connected in communication with the vibration pickup component. The control system is configured to acquire sound field signals and calculate the vibration spectrum of the noise reduction pipe section based on the sound field signals and the preset sound vibration transfer function.

[0010] The vibration absorption frequency band of the dynamic vibration absorption component is adjustable according to the preset peak vibration frequency of the noise reduction section.

[0011] In one embodiment, the sound field signal includes incident sound and reflected sound. The control system can process the acquired sound field signal, separate the incident sound, and calculate the vibration frequency range corresponding to the noise reduction pipe section caused by the incident sound based on the separated incident sound and a preset sound vibration transfer function.

[0012] In one embodiment, the control system includes:

[0013] The signal acquisition unit is communicatively connected to the vibration pickup component and is used to acquire sound field signals;

[0014] The signal analysis unit communicates with the signal acquisition unit. The signal analysis unit establishes and solves the sound pressure equation in the duct based on the acquired sound field signal, separates the incident sound and reflected sound from the sound pressure equation, and calculates the vibration spectrum of the noise reduction duct section caused by the incident sound based on the separated incident sound and the preset sound vibration transfer function.

[0015] In one embodiment, the vibration pickup component is used to detect the sound pressure at at least eight different spatial points in the duct and convert the sound pressure at each spatial point into a sound field signal. The at least eight spatial points are distributed at intervals along the airflow direction in the duct. Among the eight spatial points distributed at intervals along the airflow direction in the duct, the projections of any two spatial points on the first reference surface do not overlap, the projections on the second reference surface do not overlap, and the projections on the third reference surface do not overlap. The first reference surface, the second reference surface, and the third reference surface are perpendicular to each other.

[0016] In one embodiment, the vibration pickup component includes:

[0017] Eight microphone units are arranged spirally around the axis of the duct, and each microphone unit detects the sound pressure at the spatial point corresponding to its own position.

[0018] The signal conversion unit is communicatively connected to eight microphone units and is used to convert the sound pressure detected by the eight microphone units into a sound field signal.

[0019] In one embodiment, the vibration pickup component is disposed on a section of the duct that is used for noise reduction.

[0020] In one embodiment, the noise reduction duct section includes an air inlet and an air outlet disposed opposite to each other along the airflow direction, and the duct further includes:

[0021] The first connecting pipe section is located at the air inlet end and is connected to the noise reduction pipe section. The first connecting pipe section is made of viscoelastic material.

[0022] The second connecting pipe section is located at the air outlet and is connected to the noise reduction pipe section. The second connecting pipe section is made of viscoelastic material.

[0023] The vibration pickup assembly is installed on the first connecting pipe section and / or the second connecting pipe section.

[0024] In one embodiment, the control system is communicatively connected to the dynamic vibration absorption component. The control system is configured to be based on the vibration spectrum of the noise reduction pipe segment and to use the frequency of the preset peak value of the vibration spectrum of the noise reduction pipe segment as the natural angular frequency of the noise reduction pipe segment. The vibration absorption frequency band of the dynamic vibration absorption component is adjustable according to the natural angular frequency.

[0025] In one embodiment, the mass, stiffness, and damping rate of the dynamic vibration absorption component are all adjustable.

[0026] In one embodiment, the dynamic vibration damping component includes:

[0027] An elastomer is installed on the noise reduction pipe section; the stiffness and damping rate of the elastomer are adjustable.

[0028] The mass body is set on the elastic body, and the mass body's mass is adjustable.

[0029] In the aforementioned duct noise reduction system, airflow generates aerodynamic noise as it passes through the duct. Vibration pickup components detect the sound field signal within the duct. The control system calculates the vibration spectrum corresponding to the noise-reducing duct section based on the sound field signal and a preset acoustic transfer function. Accordingly, it adjusts the absorption frequency band of the dynamic vibration-absorbing component to match the vibration frequency range corresponding to the noise-reducing duct section. When the absorption frequency band of the dynamic vibration-absorbing component matches the vibration frequency range corresponding to the noise-reducing duct section, the dynamic vibration-absorbing component can resonate synchronously with the noise-reducing duct section as much as possible. This allows the vibration energy of the noise-reducing duct section to be transferred to the dynamic vibration-absorbing component as much as possible, thus improving the vibration reduction and noise reduction effect of the dynamic vibration-absorbing component. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the pipeline noise reduction system according to an embodiment of the present application.

[0031] Figure 2 This is a simplified diagram showing the working relationship between the control system and the dynamic vibration absorption component of a pipeline noise reduction system according to an embodiment of the present application.

[0032] Figure 3 This is a cross-sectional view of the noise reduction pipe section, elastomer, and mass body of a pipeline noise reduction system according to an embodiment of the present application.

[0033] Explanation of reference numerals in the attached figures:

[0034] 10. Air duct; 11. Noise reduction duct section; 1101. Air inlet; 1102. Air outlet; 12. First connecting duct section; 13. Second connecting duct section;

[0035] 20. Dynamic vibration damping assembly; 21. Elastomer; 22. Mass body;

[0036] 23. Mass adjustment device;

[0037] 24. Viscoelasticity regulating device; 241. Temperature and pressure control box; 242. Pressure detection element; 243. Pressure regulating element; 244. Temperature detection element; 245. Temperature regulating element; 246. Circulating pump;

[0038] 30. Vibration pickup assembly;

[0039] 40. Control system; 41. Signal acquisition unit; 42. Signal analysis unit; 43. Control unit. Detailed Implementation

[0040] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0041] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0042] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0043] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0046] See Figure 1 The pipeline noise reduction system includes a duct 10, a dynamic vibration absorption component 20, a vibration pickup component 30, and a control system 40. The duct 10 includes a noise reduction section 11. The dynamic vibration absorption component 20 is installed on the noise reduction section 11 to absorb its vibration energy. The vibration pickup component 30 detects the sound field signal within the duct 10. The control system 40 is communicatively connected to the vibration pickup component 30 and is configured to acquire the sound field signal and calculate the vibration frequency range of the noise reduction section 11 based on the sound field signal and a preset sound vibration transfer function. The vibration absorption frequency band of the dynamic vibration absorption component 20 is adjustable according to the preset peak vibration frequency of the noise reduction section 11. Figure 1 The direction of the dashed arrow indicates the airflow direction.

[0047] In the aforementioned duct noise reduction system, airflow generates aerodynamic noise as it passes through the duct 10. The vibration pickup component 30 detects the sound field signal within the duct 10, and the control system 40 calculates the vibration spectrum corresponding to the noise reduction duct section 11 based on the sound field signal and a preset acoustic transfer function. The control system then adjusts the absorption frequency band of the dynamic vibration absorption component 20 accordingly, ensuring that the absorption frequency band of the dynamic vibration absorption component 20 matches the vibration frequency range corresponding to the noise reduction duct section 11. When the absorption frequency band of the dynamic vibration absorption component 20 matches the vibration frequency range corresponding to the noise reduction duct section 11, the dynamic vibration absorption component 20 can resonate synchronously with the noise reduction duct section 11 as much as possible. This allows the vibration energy of the noise reduction duct section 11 to be transferred to the dynamic vibration absorption component 20 as much as possible, thus improving the vibration reduction and noise reduction effect of the dynamic vibration absorption component 20.

[0048] It is understandable that the acoustic transfer function is pre-calibrated and can characterize the mapping relationship between the sound field signal flowing through the duct 10 and the vibration frequency of the noise reduction pipe section 11. When the vibration pickup component 30 collects the sound field signal, it uses the sound field signal as the input quantity and converts it through the acoustic transfer function to obtain the vibration spectrum corresponding to the noise reduction pipe section 11.

[0049] It should be noted that the vibration spectrum can describe the amplitude and phase of the noise reduction tube segment 11 at different vibration frequencies. It includes the amplitude spectrum and the phase spectrum. For example, in the amplitude spectrum curve, the horizontal axis is the vibration frequency and the vertical axis is the amplitude. The preset peak vibration frequency refers to the frequency on the horizontal axis corresponding to the highest point on the vertical axis of the curve in the amplitude spectrum. By adjusting the vibration absorption frequency band of the dynamic vibration absorption component 20, its vibration absorption frequency band is matched or aligned with the preset frequency band where the preset peak frequency of the noise reduction tube segment 11 is located. When the vibration absorption frequency band of the dynamic vibration absorption component 20 matches the preset frequency band where the peak frequency of the noise reduction tube segment 11 is located, the vibration energy of the noise reduction tube segment 11 can be transferred to the dynamic vibration absorption component 20. The preset frequency band where the peak frequency is located refers to a continuous frequency range centered on the peak frequency and including one end of the peak frequency. It is specifically determined according to the actual working conditions. Within this preset frequency band range, the vibration amplitude is higher than the preset value. If the vibration frequency band of the dynamic vibration absorption component 20 is different from the frequency band of the peak frequency of the noise reduction tube section 11, the vibration energy of the noise reduction tube section 11 cannot be transferred to the dynamic vibration absorption component 20.

[0050] It should be noted that this solution can be applied to various duct systems with airflow, such as the air conditioning ducts of aircraft. It can absorb energy at a major vibration frequency point and a surrounding frequency band, reducing noise during airflow and thus reducing the noise level in the cabin.

[0051] In some embodiments, the sound field signal includes incident sound and reflected sound. Incident sound refers to sound that propagates from upstream to downstream along the airflow direction, while reflected sound is sound that propagates from downstream to upstream. The control system can process the acquired sound field signal, separate the incident sound, and calculate the vibration spectrum corresponding to the noise reduction pipe section caused by the incident sound based on the separated incident sound and a preset sound transfer function. It is understood that the incident sound is the main source of vibration and noise generation in the noise reduction pipe section 11. After separating the incident sound, the control system 40 calculates the vibration spectrum corresponding to the noise reduction pipe section 11 caused by the incident sound based on the spectral characteristics of the incident sound and the preset sound transfer function, avoiding interference from reflected sound and improving the calculation accuracy of the vibration spectrum of the noise reduction pipe section 11. This helps to improve the accuracy of matching the vibration absorption frequency band of the dynamic vibration absorption component 20 with the vibration frequency range of the noise reduction pipe section 11, thereby improving the noise reduction effect.

[0052] In some embodiments, the control system 40 includes a signal acquisition unit 41 and a signal analysis unit 42. The signal acquisition unit 41 is communicatively connected to the vibration pickup component 30 and is used to acquire sound field signals. The signal analysis unit 42 is communicatively connected to the signal acquisition unit 41. The signal analysis unit 42 establishes and solves the sound pressure equation within the duct 10 based on the acquired sound field signals, separates the incident sound and reflected sound from the sound pressure equation, and calculates the vibration spectrum of the noise-reducing pipe section 11 caused by the incident sound based on the separated incident sound and a preset sound vibration transfer function. When airflow passes through the duct 10, the vibration pickup component 30 detects the sound field signals within the duct 10. The signal acquisition unit 41 acquires the sound field signals and transmits them to the signal analysis unit 42. The signal analysis unit 42 establishes the sound pressure equation within the duct 10 based on the acquired sound field signals, separates the incident sound and reflected sound by solving the equation, and calculates the vibration spectrum of the noise-reducing pipe section 11 caused by the incident sound based on the spectral characteristics of the incident sound and a preset sound vibration transfer function.

[0053] In some embodiments, the vibration pickup component 30 is used to detect the sound pressure at at least eight different spatial points within the duct 10 and convert the sound pressure at each spatial point into a sound field signal. The at least eight spatial points are spaced apart along the airflow direction within the duct 10. Among these eight spatial points, the projections of any two spatial points on the first reference plane do not overlap, the projections on the second reference plane do not overlap, and the projections on the third reference plane do not overlap. The first, second, and third reference planes are mutually perpendicular. It should be noted that the sound field signal inside the duct 10 has spatiotemporal distribution characteristics. The sound pressure at each spatial point within the duct 10 is a function of time and spatial coordinates. By detecting the sound pressure at multiple spatial points within the duct 10 and converting it into a sound field signal using the vibration pickup component 30, the control system 40 can solve the sound pressure equation based on the sound field signal data detected at multiple spatial points. Simultaneously, the sound field at each spatial point within the duct 10 is mainly formed by the superposition of the sound component transmitted from upstream to downstream (i.e., incident sound) and the sound component reflected from downstream to upstream (i.e., reflected sound). Accordingly, the control system 40 can decompose the sound pressure equation and separate the incident sound from the reflected sound. By collecting sound pressure data from at least eight spatial points, sufficient spatial and temporal information can be provided, ensuring the uniqueness and accuracy of the solution to the sound pressure equation, which helps in separating the incident sound from the reflected sound.

[0054] In some embodiments, the vibration pickup assembly 30 includes eight microphone units and a signal conversion unit. The eight microphone units are spirally arranged around the axis of the duct 10, and each microphone unit detects the sound pressure at a spatial point corresponding to its respective position. The signal conversion unit is communicatively connected to the eight microphone units and is used to convert the sound pressure detected by the eight microphone units into a sound field signal. Exemplarily, all eight microphone units are disposed on the inner wall of the duct 10. This arrangement facilitates the placement of the eight microphone units.

[0055] In some embodiments, the vibration pickup component 30 is disposed on the portion of the duct 10 excluding the noise reduction section 11. In other words, the vibration pickup component 30 is not disposed on the noise reduction section 11. If the vibration pickup component 30 is disposed on the noise reduction section 11, it will increase the added mass of the noise reduction section 11, change the inherent vibration characteristics of the noise reduction section 11, affect the matching accuracy with the acoustic transfer function, and affect the accuracy of the vibration frequency detection of the noise reduction section 11.

[0056] In some embodiments, the noise-reducing duct section 11 includes an air inlet end 1101 and an air outlet end 1102 disposed opposite to each other along the airflow direction. The duct 10 also includes a first connecting duct section 12 and a second connecting duct section 13. The first connecting duct section 12 is disposed at the air inlet end 1101 and communicates with the noise-reducing duct section 11. The first connecting duct section 12 is made of a viscoelastic material. The second connecting duct section 13 is disposed at the air outlet end 1102 and communicates with the noise-reducing duct section 11. The second connecting duct section 13 is also made of a viscoelastic material. By providing the first connecting duct section 12 and the second connecting duct section 13, it is possible to help isolate the vibration transmission between the noise-reducing duct section 11 and other ducts.

[0057] For example, both the first connecting pipe section 12 and the second connecting pipe section 13 are made of rubber material.

[0058] In some embodiments, the first connecting pipe section 12, the noise reduction pipe section 11, and the second connecting pipe section 13 are connected sequentially along a first direction. The noise reduction pipe section 11 is made of a material with good flexibility, such as polyester plastic. This arrangement makes it easier for the noise reduction pipe section 11 to vibrate at the same frequency as the noise, and it is convenient to calculate the vibration frequency of the noise reduction pipe section 11 through the sound field signal.

[0059] In some embodiments, the vibration pickup component 30 is disposed on the first connecting pipe section 12 and / or the second connecting pipe section 13. Disposing the vibration pickup component 30 on the first connecting pipe section 12 or the second connecting pipe section 13 will not add extra mass to the noise reduction pipe section 11, improve the accuracy of matching with the acoustic vibration transfer function, and help reduce the error in detecting the vibration frequency of the noise reduction pipe section 11.

[0060] In some embodiments, the vibration pickup component 30 is disposed on the inner wall of the first connecting pipe section 12. For example, multiple microphone units are disposed on the inner wall of the first connecting pipe section 12 and used to detect the sound field signal within the first connecting pipe section 12. An acoustic transfer function establishes a correlation between the sound field signal within the first connecting pipe section 12 and the vibration frequency of the noise reduction pipe section 11. Furthermore, the control system 40 calculates the vibration spectrum of the noise reduction pipe section 11 based on the sound field signal within the first connecting pipe section 12 and the preset acoustic transfer function. The airflow sequentially passes through the first connecting pipe section 12, the noise reduction pipe section 11, and the second connecting pipe section 13. The vibration pickup component 30 is disposed on the first connecting pipe section 12, located upstream of the noise reduction pipe section 11. The sound field signal it acquires precedes the vibration response of the noise reduction pipe section 11, and the acquired sound field signal is not affected by the vibration of the noise reduction pipe section 11, thereby further improving the accuracy of detecting the vibration frequency of the noise reduction pipe section 11.

[0061] In some embodiments, the control system 40 is communicatively connected to the dynamic vibration absorption component 20. The control system 40 is configured to use the frequency of a preset peak value of the vibration spectrum corresponding to the noise reduction tube segment 11 as the natural angular frequency of the noise reduction tube segment 11, based on the vibration spectrum corresponding to the noise reduction tube segment 11. The vibration absorption frequency band of the dynamic vibration absorption component 20 is adjustable according to the natural angular frequency. For example, the mass, stiffness, and other parameters of the dynamic vibration absorption component 20 are calculated and adjusted according to the general design principles of the dynamic vibration absorption component 20 to achieve the optimal combination of parameters. Furthermore, according to the "fixed-point theorem" in the general design principles of the dynamic vibration absorption component 20, the two fixed points of the amplitude amplification coefficient of the noise reduction tube segment 11 are at the same height at the current natural angular frequency, and the optimal damping ratio of the dynamic vibration absorption component 20 is calculated and adjusted. Based on the optimal combination of the above parameters, the dynamic vibration absorption component 20 can absorb the vibration energy caused by the incident sound to the maximum extent.

[0062] In some embodiments, the mass, stiffness, and damping rate of the dynamic vibration absorption component 20 are all adjustable. By adjusting the mass, stiffness, and damping rate of the dynamic vibration absorption component 20, the vibration absorption frequency band of the dynamic vibration absorption component 20 can be adjusted to match the vibration frequency range of the noise reduction pipe section 11, so as to absorb the vibration of the noise reduction pipe section 11 as much as possible, thereby dissipating the sound energy in the duct 10.

[0063] For example, when the vibration spectrum of the noise reduction pipe section 11 reaches a certain stable state, the control system 40 adjusts the mass and stiffness of the dynamic vibration absorption component 20 to quickly match the vibration absorption requirements; when the vibration of the noise reduction pipe section 11 is largely absorbed by the dynamic vibration absorption component 20, the control system 40 adjusts the damping rate of the dynamic vibration absorption component 20 to further improve the vibration absorption effect.

[0064] See Figure 1 and Figure 3In some embodiments, the dynamic vibration absorption assembly 20 includes an elastic body 21 and a mass 22. The elastic body 21 is disposed on the noise reduction pipe section 11, and the stiffness and damping rate of the elastic body 21 are adjustable. The mass 22 is disposed on the elastic body 21, and the mass 22 is adjustable. Exemplarily, both the elastic body 21 and the mass 22 are annular. The elastic body 21 is fitted around the outer periphery of the noise reduction pipe section 11, and the mass 22 is fitted around the outer periphery of the elastic body 21. That is, the noise reduction pipe section 11, the elastic body 21, and the mass 22 are coaxially arranged from the inside to the outside. This arrangement allows the dynamic vibration absorption assembly 20 to uniformly apply vibration absorption to the circumference of the noise reduction pipe section 11, improving the uniformity of vibration suppression of the noise reduction pipe section 11 and enhancing the noise reduction effect.

[0065] See Figure 1 and Figure 2 In some embodiments, the mass body 22 is filled with liquid, and the dynamic vibration absorption assembly 20 also includes a mass adjustment device 23, which adjusts the volume of the liquid filling the mass body 22, thereby adjusting the mass body 22. The control system 40 also includes a control unit 43, which is communicatively connected to the signal analysis unit 42 and the mass adjustment device 23. Exemplarily, the mass adjustment device 23 includes a miniature hydraulic cylinder, which injects or extracts liquid into the mass body 22 to achieve continuous adjustment of the mass body 22's mass. Figure 1 and Figure 2 In the middle, the solid black arrows indicate communication connections.

[0066] In some embodiments, the elastomer 21 is filled with gas. The device also includes a viscoelasticity regulating device 24, which controls the temperature and pressure of the gas inside the elastomer 21, thereby adjusting the damping rate and stiffness of the elastomer 21. Exemplarily, the viscoelasticity regulating device 24 includes a temperature and pressure control box 241, a pressure detection element 242, a pressure regulating element 243, a temperature detection element 244, a temperature regulating element 245, and a circulation pump 246. The temperature and pressure control box 241 is connected to the interior of the elastomer 21 to form a gas circulation loop. The pressure detection element 242 detects the pressure inside the temperature and pressure control box, and the pressure regulating element 243 regulates the pressure of the gas inside the temperature and pressure control box, thereby regulating the pressure of the gas inside the elastomer 21. The temperature detection element 244 detects the temperature inside the temperature and pressure control box, and the temperature regulating element 245 regulates the temperature of the gas inside the temperature and pressure control box. The circulation pump 246 is disposed on the gas circulation loop to drive the continuous circulation of gas between the temperature and pressure control box 241 and the elastomer 21, ensuring uniform temperature and pressure distribution of the gas within the overall loop. The control unit 43 is communicatively connected to the pressure detection element 242, the pressure regulating element 243, the temperature detection element 244, and the temperature regulating element 245. By regulating the temperature and pressure of the gas filling the elastomer 21 through the viscoelastic regulating device 24, the mechanical properties of the elastomer 21 can be dynamically changed, achieving continuous adjustment of its damping rate and stiffness. Figure 2 In the image, the black arrows indicate the direction of fluid flow.

[0067] In summary, the noise reduction method of the pipeline noise reduction system in this solution includes the following steps:

[0068] Step S1: Obtain the acoustic vibration transfer function;

[0069] Step S2: The vibration pickup component 30 detects the sound field signal inside the air duct 10;

[0070] Step S3: The control system 40 calculates the vibration spectrum corresponding to the noise reduction pipe section 11 based on the sound field signal and the preset sound vibration transfer function;

[0071] Step S4: Adjust the mass, stiffness, and damping rate of the dynamic vibration absorption component 20 according to the vibration spectrum to achieve the best vibration absorption and noise reduction effect.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A pipeline noise reduction system, characterized in that, include: Air duct (10), including noise reduction duct section (11); A dynamic vibration absorption assembly (20) is disposed on the noise reduction pipe section (11) to absorb the vibration energy of the noise reduction pipe section (11); Vibration pickup assembly (30) is used to detect the sound field signal inside the air duct (10); The control system (40) is communicatively connected to the vibration pickup component (30). The control system (40) is configured to acquire the sound field signal and calculate the vibration spectrum of the noise reduction pipe section (11) based on the sound field signal and a preset sound vibration transfer function. The vibration absorption frequency band of the dynamic vibration absorption component (20) is adjustable according to the preset peak vibration frequency of the noise reduction tube section (11).

2. The pipeline noise reduction system according to claim 1, characterized in that, The sound field signal includes incident sound and reflected sound. The control system (40) can process the collected sound field signal, separate the incident sound from it, and calculate the vibration spectrum corresponding to the noise reduction pipe section (11) caused by the incident sound based on the separated incident sound and the preset sound vibration transfer function.

3. The pipeline noise reduction system according to claim 2, characterized in that, The control system (40) includes: The signal acquisition unit (41) is communicatively connected to the vibration pickup component (30) and is used to acquire the sound field signal; The signal analysis unit (42) is communicatively connected to the signal acquisition unit (41). The signal analysis unit (42) establishes and solves the sound pressure equation in the duct (10) based on the acquired sound field signal, separates the incident sound and the reflected sound from the sound pressure equation, and calculates the vibration spectrum of the noise reduction pipe section (11) caused by the incident sound based on the separated incident sound and the preset sound vibration transfer function.

4. The pipeline noise reduction system according to claim 3, characterized in that, The vibration pickup component (30) is used to detect the sound pressure of at least eight different spatial points in the duct (10) and convert the sound pressure of each spatial point into a sound field signal. The at least eight spatial points are distributed at intervals along the flow direction of the airflow in the duct (10). Among the eight spatial points distributed at intervals along the flow direction of the airflow in the duct (10), the projections of any two spatial points on the first reference surface do not overlap, the projections on the second reference surface do not overlap, and the projections on the third reference surface do not overlap. The first reference surface, the second reference surface, and the third reference surface are perpendicular to each other.

5. The pipeline noise reduction system according to claim 4, characterized in that, The vibration pickup component (30) includes: Eight microphone units are arranged spirally around the axis of the duct (10), and each microphone unit detects the sound pressure at a spatial point corresponding to its own position. The signal conversion unit is communicatively connected to the eight microphone units and is used to convert the sound pressure detected by the eight microphone units into a sound field signal.

6. The pipeline noise reduction system according to claim 1, characterized in that, The vibration pickup component (30) is disposed on the portion of the air duct (10) excluding the noise reduction section (11).

7. The pipeline noise reduction system according to claim 6, characterized in that, The noise reduction duct section (11) includes an air inlet (1101) and an air outlet (1102) arranged opposite to each other along the airflow direction. The duct (10) also includes: The first connecting pipe section (12) is provided at the air inlet end (1101) and is connected to the noise reduction pipe section (11). The first connecting pipe section (12) is made of viscoelastic material. The second connecting pipe section (13) is provided at the air outlet (1102) and is connected to the noise reduction pipe section (11). The second connecting pipe section (13) is made of viscoelastic material. The vibration pickup component (30) is disposed on the first connecting pipe section (12) and / or the second connecting pipe section (13).

8. The pipeline noise reduction system according to claim 1, characterized in that, The control system (40) is communicatively connected to the dynamic vibration absorption component (20). The control system (40) is configured to be based on the vibration spectrum of the noise reduction pipe section (11) and to use the frequency of the preset peak value of the vibration spectrum of the noise reduction pipe section (11) as the natural angular frequency of the noise reduction pipe section (11). The vibration absorption frequency band of the dynamic vibration absorption component (20) is adjustable according to the natural angular frequency.

9. The pipeline noise reduction system according to claim 7, characterized in that, The mass, stiffness, and damping rate of the dynamic vibration absorption component (20) are all adjustable.

10. The pipeline noise reduction system according to claim 9, characterized in that, The dynamic vibration absorption assembly (20) includes: An elastomer (21) is disposed on the noise reduction pipe section (11), and the stiffness and damping rate of the elastomer (21) are adjustable; A mass body (22) is disposed on the elastic body (21), and the mass body (22) is adjustable in mass.

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