Natural gas pipeline noise control system and method

Abstract

The invention relates to the technical field of noise control, in particular to a natural gas pipeline noise control system and method.The noise control system comprises two sound pressure sensors, a silencer and a controller, the two sound pressure sensors are installed at the two axial ends of the inner wall of a pipeline respectively, and the silencer is installed between the two axial ends of the inner wall of the pipeline; the silencing device comprises a resonance silencing assembly, a diffusion silencing assembly, a blade angle adjusting mechanism and a sound absorption layer silencing assembly. The resonance noise reduction assembly comprises a plurality of straight pipe noise reduction cylinders which are coaxially arranged in a sleeving mode, the diffusion noise reduction assembly comprises a plurality of conical noise reduction cylinders with the inner diameters gradually expanding in the natural gas flowing direction, the conical noise reduction cylinders are connected through sound absorption layers, and the sound absorption layer noise reduction assembly comprises a sound absorption layer and an opening degree adjustable mechanism; parameters of all the silencing assemblies are adjusted in real time through the blade angle adjusting mechanism and the opening degree adjusting mechanism, and full-band noise is effectively restrained under variable working conditions.

Description

Technical Field

[0001] The present application relates to the technical field of noise control, and in particular to a natural gas pipeline noise control system and method. Background Art

[0002] Pressure regulators are critical equipment in natural gas stations, used to reduce and stabilize the pressure of high-pressure natural gas before transporting it to downstream pipelines. However, this process, due to the throttling effect of valves and the turbulence caused by high-speed airflow within the pipeline, can cause significant noise. This noise primarily consists of two components: low- and medium-frequency noise generated by the throttling effect, and high-frequency noise caused by high-speed airflow turbulence. This noise from pressure regulating stations not only disrupts the lives of nearby residents but can also pose safety risks such as equipment fatigue and seal failure due to long-term vibration or sonic shock.

[0003] Currently, common muffler technologies are categorized into two main types: resistive and reactive. Resistive mufflers attenuate high-frequency noise through porous sound-absorbing materials (such as glass wool and metal fibers), but are less effective against mid- and low-frequency noise. Reactive mufflers, based on the principles of sound wave reflection and interference, are adept at suppressing mid- and low-frequency noise, but are less effective at attenuating high-frequency components. However, both types of mufflers have inherent drawbacks: their noise reduction characteristics are fixed upon installation and cannot dynamically adapt to changes in the noise spectrum caused by variations in natural gas flow rates.

[0004] Specifically, natural gas flow rate directly affects the frequency distribution of noise: as the flow rate increases, the proportion of high-frequency noise increases. In this case, if the number of resistive silencers is insufficient, high-frequency noise reduction will be insufficient. Conversely, as the flow rate decreases, medium- and low-frequency noise becomes dominant, and a fixed resistive silencer configuration may lead to reduced noise reduction effectiveness. Existing noise reduction systems lack real-time adjustment capabilities, making it difficult to match the changes in the noise spectrum caused by flow rate fluctuations. This leads to unstable overall noise reduction performance and may even trigger environmental complaints or safety accidents due to excessive noise levels. Summary of the Invention

[0005] In response to the above problems, the present application provides a natural gas pipeline noise control system and method, which adjusts the parameters of the silencer component in real time through the blade angle adjustment mechanism and the adjustable opening mechanism to achieve suppression of full-band noise under variable working conditions.

[0006] To achieve the purpose of the present invention, this application provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a natural gas pipeline noise control system, comprising: a first sound pressure sensor, a second sound pressure sensor, a silencer, and a controller, wherein the first sound pressure sensor and the second sound pressure sensor are mounted at two axial ends of an inner wall of a pipeline, and the silencer is mounted between the two axial ends of the inner wall of the pipeline, the first sound pressure sensor and the second sound pressure sensor are used to collect sound pressure signals before and after the silencer, and the silencer comprises a resonance silencer component, a diffusion silencer component, a blade angle adjustment mechanism, and a sound absorption layer silencer component;

[0008] The resonance silencer assembly includes a plurality of coaxially sleeved straight tube silencers, each of which is connected to a tube wall of the straight tube silencer with a plurality of first guide vane groups arranged in the axial direction, each of which includes an even number of first blade units evenly distributed along the circumference of the tube wall, the first blade unit including a first inner arc blade and a first outer arc blade that are symmetrically curved in opposite directions, the first inner arc blade being connected to the inner tube wall of the straight tube silencer, the second outer arc blade being connected to the outer tube wall of the straight tube silencer, the concave surfaces of the first inner arc blade and the first outer arc blade both facing the incoming direction of the natural gas flow, the curved section of the first inner arc blade extending toward the central axis of the straight tube silencer, the straight ends of the first inner arc blade and the first outer arc blade overlapping, and being rotatably connected to the tube wall of the straight tube silencer through the blade angle adjustment mechanism;

[0009] The diffusion silencer assembly includes a plurality of conical silencers whose inner diameters gradually expand along the natural gas flow direction, and the conical silencers are connected by a sound-absorbing layer; the conical silencers are connected to the cylinder wall with a plurality of groups of second guide vanes arranged in the axial direction, and each group of the second guide vanes includes a plurality of second blade units evenly spaced along the circumferential direction of the inner cylinder wall and the outer cylinder wall of the conical silencer, and each second blade unit includes a first curved blade and a second curved blade that are symmetrically curved in opposite directions, the concave surfaces of the first curved blade and the second curved blade both facing the natural gas flow direction, the curved sections of the first curved blade and the second curved blade both conform to the cylinder wall, the straight ends of the first curved blade and the second curved blade coincide, and the blade angle adjustment mechanism is used to rotationally connect the first curved blade and the second curved blade to the cylinder wall of the conical silencer;

[0010] The sound-absorbing layer silencer assembly includes a sound-absorbing layer and an adjustable opening mechanism. A plurality of grooves are evenly formed on a surface of the sound-absorbing layer facing the natural gas flow direction. The adjustable opening mechanism is provided in each groove. The adjustable opening mechanism is used to adjust the effective sound-absorbing area of ​​the sound-absorbing layer at the rear end of the groove.

[0011] The controller is communicatively connected with the first sound pressure sensor, the second sound pressure sensor, the blade angle adjustment mechanism and the opening adjustable mechanism respectively.

[0012] In some embodiments, the blade angle adjustment mechanism includes a first rotating shaft, a second rotating shaft, a plurality of connecting rods, a synchronous connecting rod mechanism, a first muffler net, a first right-angle bending rod and a first propulsion motor;

[0013] The straight ends of the first inner arc blade and the first outer arc blade are connected to the wall of the straight pipe silencer through the first rotating shaft, the first connecting rod is sequentially connected in series with the first inner arc blades arranged in the axial direction, and the second connecting rod is sequentially connected in series with the first outer arc blades arranged in the axial direction. The backs of the first inner arc blade and the first outer arc blade at the end are connected to the first silencer net through a synchronous connecting rod mechanism;

[0014] The straight ends of the first curved blade and the second curved blade are connected to the wall of the conical silencer through the second rotating shaft. The third connecting rod is sequentially connected in series with the first curved blade arranged axially on the outer wall of the conical silencer. The fourth connecting rod is sequentially connected in series with the second curved blade arranged axially on the outer wall of the conical silencer. The fifth connecting rod is sequentially connected in series with the first curved blade arranged axially on the inner wall of the conical silencer. The sixth connecting rod is sequentially connected in series with the second curved blade arranged axially on the inner wall of the conical silencer. The backs of the first curved blade and the second curved blade at the end are connected to the first silencer net through a synchronous connecting rod mechanism.

[0015] An opening is formed in the axial direction of the side wall of the pipe, and the first propulsion motor located outside the pipe is connected to the first silencer net via a first right-angle bent rod;

[0016] When the first propulsion motor drives the first muffler net to move axially along the pipeline, it can simultaneously drive all the arc-shaped blades to rotate around the corresponding rotation axis, thereby adjusting the gaps between the relative arc-shaped blades.

[0017] In some embodiments, the adjustable opening mechanism includes two cover plates, a third rotating shaft, a seventh connecting rod, an eighth connecting rod, a synchronous connecting rod mechanism, a second silencer net and a second pushing motor. The two cover plates are flatly laid to cover the groove, and the adjacent ends of the two cover plates are connected to the third rotating shaft. The two ends of the third rotating shaft are connected to the sound-absorbing layers on both sides of the groove. The backs of the two cover plates are respectively connected to one end of the seventh connecting rod and the eighth connecting rod, and the other ends of the seventh connecting rod and the eighth connecting rod are respectively connected to the second silencer net through a synchronous connecting rod assembly.

[0018] The side wall of the pipe is provided with an opening in the axial direction, and the second propulsion motor located outside the pipe is connected to the second silencer net via a second right-angle bent rod;

[0019] When the second propulsion motor drives the second silencer net to move axially along the pipe, it drives the cover plate to rotate around the third rotation axis, thereby adjusting the angle between the two cover plates and changing the effective sound absorption area of ​​the sound absorption layer at the rear end of the groove.

[0020] In some embodiments, the synchronous linkage mechanism includes a disc, an active rod, and a driven rod. An arc-shaped guide groove is opened on the surface of the disc along the circumferential direction. The first end of the active rod is connected to the silencer net, and the second end of the active rod is slidably connected to the arc-shaped guide groove of the disc via a slider. One end of the two driven rods is symmetrically hinged to the two sides of the second end of the active rod, and the other ends of the two driven rods are respectively hinged to the back of the first inner arc blade and the first outer arc blade at the end, the back of the first arc blade and the second arc blade at the end, or the back of the two cover plates.

[0021] When the motor drives the silencer net to move axially, the second end of the active rod slides along the arc guide groove, driving the angle between the two driven rods to change, thereby adjusting the angle between the first inner arc blade and the first outer arc blade, the angle between the first arc blade and the second arc blade, or the angle between the two cover plates.

[0022] In some embodiments, along the direction of natural gas flow, the pipeline is sequentially provided with the resonance silencer assembly and the diffusion silencer assembly, the axes of the resonance silencer assembly and the diffusion silencer assembly are parallel to the axis of the pipeline, and the sound absorbing layer silencer assembly is connected to the inner wall of the pipeline and is also provided at the rear end of the diffusion silencer assembly.

[0023] In some embodiments, the invention further comprises an acoustic-to-electrical conversion mechanism installed at the rear end of the conical silencer, the acoustic-to-electrical conversion mechanism comprising a connecting rod, an acoustic energy collection component, and the acoustic-to-electrical conversion mechanism, the acoustic energy collection component being connected to one end of the connecting rod, and the other end of the connecting rod being connected to the sound absorbing layer of the sound absorbing layer silencer assembly;

[0024] The acoustic energy collection component consists of a piezoelectric quartz crystal arranged to face the natural gas flow and an insulating bracket covering its non-working surface; the acoustic-to-electric conversion mechanism includes an acoustic-to-electric transducer, a battery and a noise monitor arranged outside the pipeline. The acoustic energy collection component, the acoustic-to-electric transducer and the battery are connected in series in sequence. The battery is electrically connected to the noise monitor for powering the noise monitor.

[0025] In a second aspect, an embodiment of the present application provides a natural gas pipeline noise control method, the method comprising:

[0026] The first sound pressure sensor and the second sound pressure sensor respectively collect sound pressure signals before and after silencing;

[0027] Analyzing and processing the sound pressure signal to obtain an energy attenuation rate of the noise reduction device for each characteristic frequency band, and determining whether the energy attenuation rate is below an attenuation rate threshold range, wherein the characteristic frequency band includes a low-mid frequency band and a high frequency band. The energy attenuation rate is used to quantify the noise suppression effect of the noise reduction device;

[0028] When the attenuation rate of the noise in the medium and low frequency bands is lower than the attenuation rate threshold range, the blade angle adjustment mechanism is controlled to drive the arc blades to deflect so as to increase the gap between the relative arc blades until the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipeline is ≤85dB;

[0029] When the attenuation rate of high-frequency noise is lower than the attenuation rate threshold, the opening of the adjustable opening mechanism is adjusted to increase the effective sound absorption area of ​​the sound absorption layer at the rear end of the groove until the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipe is ≤85dB.

[0030] In some embodiments, analyzing and processing the sound pressure signal to obtain the energy attenuation rate of the noise cancellation device for each characteristic frequency band and determining whether the energy attenuation rate is lower than an attenuation rate threshold range further includes:

[0031] Performing Fourier transform processing on the collected sound pressure signals to obtain corresponding time-frequency spectra, and extracting energy values ​​of the low-frequency band and the high-frequency band from the time-frequency spectra;

[0032] Calculating the energy attenuation rate of the muffler device for noise in the mid-low frequency band and the high frequency band based on the energy values ​​of the mid-low frequency band and the high frequency band corresponding to the first sound pressure sensor and the energy values ​​of the mid-low frequency band and the high frequency band corresponding to the second sound pressure sensor;

[0033] The calculated energy attenuation rate of each characteristic frequency band is compared with the preset attenuation rate threshold to determine whether the resonance silencer component and the diffusion silencer component are insufficiently effective in suppressing noise in the medium and low frequency bands, and whether the sound absorption layer silencer component is insufficiently effective in suppressing noise in the high frequency bands.

[0034] In some embodiments, the method further comprises:

[0035] Recording in real time and building a database based on the natural gas flow rate, the optimal blade deflection angle, and the optimal opening, wherein the optimal blade deflection angle and the optimal opening are, respectively, the angle of the curved blade and the opening of the cover plate when the energy attenuation rate is within the attenuation rate threshold range or the noise level measured at one meter from the pipeline is ≤85dB;

[0036] The real-time collected flow rate data is compared with the natural gas flow rate recorded in the database. When the flow rate data corresponds to the natural gas flow rate recorded in the database, the silencer is adjusted to an optimal blade deflection angle and an optimal opening corresponding to the natural gas flow rate, wherein the natural gas flow rate in the pipeline is collected by a flow meter.

[0037] The embodiments of this application utilize the synergy of reactive and resistive muffler components to construct a full-band noise suppression control system. The reactive muffler structure formed by the resonant and diffuse muffler components targets the fluctuation characteristics of low- and medium-frequency noise, utilizing the principles of acoustic interference and the expansion effect of the flow channel to effectively suppress low- and medium-frequency noise without significantly increasing flow resistance. The sound-absorbing layer muffler, on the other hand, utilizes the viscous dissipation of porous materials to specifically absorb broadband noise in the high-frequency band. This ensures that noise in each frequency band can find its corresponding muffler path while avoiding the frequency band limitations associated with a single muffler method, achieving both broadband noise reduction performance and fluid permeability. At the same time, the silencer device of the embodiment of the present application can also be adjusted according to the proportion of noise frequency bands, that is, when the flow rate is low and the proportion of medium and low frequency noise increases, the resonance silencer component and the diffusion silencer component have insufficient ability to suppress medium and low frequency noise energy, and the blade angle adjustment mechanism is used to increase the gap between the relative blades to achieve flow channel expansion and speed reduction silencer. When the natural gas flow rate increases and the proportion of high frequency noise increases, the sound absorption layer silencer component has insufficient ability to suppress high frequency noise energy, and the opening adjustable mechanism is used to increase the area of ​​the sound absorption layer to enhance the resistive silencer. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application.

[0039] Figure 1 A schematic cross-sectional view of a natural gas pipeline noise control system according to an embodiment of the present application;

[0040] Figure 2 A schematic diagram of the structure of a straight tube silencer provided in an embodiment of the present application;

[0041] Figure 3 A schematic structural diagram of a conical silencer provided in an embodiment of the present application;

[0042] Figure 4 A schematic diagram of the structure of the sound-to-electricity conversion mechanism provided in an embodiment of the present application;

[0043] Figure 5 A schematic structural diagram of a synchronous linkage mechanism provided in an embodiment of the present application;

[0044] Figure 6 A flow chart of a natural gas pipeline noise control method provided in an embodiment of the present application;

[0045] Illustrations: 100, resonance silencer assembly; 110, straight tube silencer; 111, first inner arc-shaped blade; 112, first outer arc-shaped blade; 200, diffusion silencer assembly; 210, conical silencer; 211, first arc-shaped blade; 212, second arc-shaped blade; 213, relative arc-shaped blade; 300, sound absorption layer silencer assembly; 310, sound absorption layer; 400, sound-to-electric conversion mechanism; 410, connecting rod; 420, sound energy collection assembly; 421, piezoelectric quartz crystal; 422, insulating bracket; 500, pipe; 600, synchronous connecting rod mechanism; 610, disc; 620, arc-shaped guide groove; 630, active rod; 640, driven rod. DETAILED DESCRIPTION

[0046] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0047] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features indicated. Thus, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; and in the description of this application, unless otherwise specified, "plurality" means two or more.

[0048] Traditional fixed silencers are unable to adapt to the shifting noise spectrum in real time, resulting in fluctuating noise reduction efficiency. Specifically, at high flow rates, insufficient resistive silencers result in excessive high-frequency residual noise. At low flow rates, mismatched reactive silencer structures lead to insufficient suppression of mid- and low-frequency noise. Simply increasing the number of silencers results in a significant number of them operating suboptimally for extended periods of time, often requiring replacement of still-useful silencers during maintenance, a waste of resources and increased costs.

[0049] In order to solve the above technical problems, the present invention proposes the following technical solutions and corresponding embodiments.

[0050] like Figure 1 A schematic cross-sectional view of a natural gas pipeline noise control system according to an embodiment of the present application; Figure 2 A schematic diagram of the structure of a straight tube silencer provided in an embodiment of the present application; Figure 3 A schematic structural diagram of a conical silencer provided in an embodiment of the present application; Figure 4 A schematic diagram of the structure of the sound-to-electricity conversion mechanism provided in an embodiment of the present application; Figure 5A schematic structural diagram of a synchronous linkage mechanism provided in an embodiment of the present application; Figure 6 This is a flow chart of a natural gas pipeline noise control method provided in an embodiment of the present application.

[0051] like Figure 1-Figure 3 As shown, an embodiment of the present application provides a natural gas pipeline noise control system, including a first sound pressure sensor, a second sound pressure sensor, a silencer and a controller.

[0052] Among them, the first sound pressure sensor and the second sound pressure sensor are installed at the axial ends of the inner wall of the pipe 500, and a silencer is installed between the axial ends of the inner wall of the pipe 500. The first sound pressure sensor and the second sound pressure sensor are used to collect sound pressure signals before and after the silencer. The silencer includes a resonance silencer component 100, a diffusion silencer component 200, a blade angle adjustment mechanism and a sound absorption layer silencer component 300.

[0053] In some embodiments, the resonance silencer assembly 100 of the silencer device includes a plurality of coaxially sleeved straight tube silencers, and the wall of each straight tube silencer is connected to a plurality of first guide vane groups arranged axially, and each first guide vane group includes an even number of first blade units evenly distributed along the circumference of the wall, and the first blade unit includes a first inner arc blade 111 and a first outer arc blade 112 that are reversely curved and symmetrical. The first inner arc blade 111 is connected to the inner wall of the straight tube silencer, and the second outer arc blade is connected to the outer wall of the straight tube silencer. The concave surfaces of the first inner arc blade 111 and the first outer arc blade 112 both face the direction of the incoming natural gas flow, and the curved section of the first inner arc blade 111 extends toward the central axis of the straight tube silencer. The straight ends of the first inner arc blade 111 and the first outer arc blade 112 coincide and are rotatably connected to the wall of the straight tube silencer through a blade angle adjustment mechanism.

[0054] Each of the curved blades in the present embodiment includes two opposing straight ends and two opposing curved ends. The projection of the chords of the curved ends of the first inner curved blade 111 and the first outer curved blade 112 onto the bottom surface of the straight silencer tube coincides with the radial direction of the tube. Furthermore, along the direction of natural gas flow, the roots of the first inner curved blade 111 and the first outer curved blade 112 are both forward and the tips are both backward.

[0055] In the resonance silencer assembly 100, the first inner arc blades 111 of the straight tube silencer with the smallest inner diameter, the first outer arc blades 112 of the straight tube silencer with the smallest inner diameter or other straight tube silencers, and the first inner arc blades 111 of the straight tube silencer sleeved thereon, are defined as relative arc blades in the resonance silencer assembly 100. A sound wave interference field is formed between the multiple pairs of relative arc blades arranged axially. When the medium and low frequency noise sound waves generated by the flow of natural gas pass through, the surfaces of the two relative arc blades reflect the incident sound waves and modulate them into sine waves and cosine waves with opposite phases to each other. After these two waves collide in the gap between the arc blades, the sound wave energy is offset, thereby achieving a silencer effect, and the escaping sound waves enter the next pair again to continue silencer.

[0056] Furthermore, during the above-mentioned interference silencing process, if the natural gas flow rate entering the pipeline 500 decreases, the proportion of medium and low-frequency sound waves generated by the natural gas flow increases. While consuming sound energy through sound wave interference, this embodiment can also adjust the deflection angles of the first inner curved blade 111 and the first outer curved blade 112 through the blade angle adjustment mechanism, specifically by deflecting them in a direction closer to the cylinder wall to expand the gap between the opposing curved blades. The larger the gap, the more expanded the natural gas flow channel, the passively reduced natural gas flow rate, and thus the smaller the noise generated.

[0057] In some embodiments, the diffusion silencer assembly 200 of the silencer device includes a plurality of conical silencers 210 whose inner diameters gradually expand along the direction of natural gas flow, and each conical silencer 210 is connected by a sound-absorbing layer; the wall of the conical silencer 210 is provided with a plurality of groups of second guide vane groups arranged along the axial direction, and each group of second guide vane groups includes a plurality of second blade units evenly spaced along the circumferential direction of the inner and outer walls of the conical silencer 210, each second blade unit includes a first curved blade 211 and a second curved blade 212 that are symmetrical and curved in opposite directions, the concave surfaces of the first curved blade 211 and the second curved blade 212 both face the direction of the natural gas flow, the curved sections of the first curved blade 211 and the second curved blade 212 are both close to the wall, the straight ends of the first curved blade 211 and the second curved blade 212 coincide, and are rotatably connected to the wall of the conical silencer 210 through a blade angle adjustment mechanism. It should be noted that, along the natural gas flow direction, the roots of the first and second curved blades 211, 212 are both forward and the tips are both backward. The curved sections of the first and second curved blades 211, 212 are close to the cylinder wall, for example, fitting closely to the cylinder wall, and movement tolerances are retained in actual assembly.

[0058] In the diffusion silencer assembly 200, the first curved blade 211 of a second blade unit on the inner wall or outer wall of the conical silencer 210 and the second curved blade 212 of another second blade unit adjacent to the second blade unit are defined as the relative curved blades 213 of the diffusion silencer assembly 200. The multiple relative curved blades 213 arranged along the axial direction form a sound wave interference field. When the medium and low frequency noise sound waves generated by the flow of natural gas pass through, the two relative curved blade surfaces (i.e., concave surfaces) reflect the incident sound waves and modulate them into sine waves and cosine waves with opposite phases. These two waves collide in the gap between the relative curved blades 213 to offset the sound wave energy and achieve a silencer effect. The escaping sound waves enter the next pair of relative curved blades 213 to continue silencer.

[0059] Furthermore, during the above-mentioned interference silencing process, if the natural gas flow rate entering the pipeline 500 decreases, the proportion of medium and low-frequency sound waves generated by the natural gas flow increases. The current diffusion silencing assembly 200 has insufficient noise attenuation capability under this working condition. In this embodiment, the deflection angles of the first curved blade 211 and the second curved blade 212 can be adjusted by a blade angle adjustment mechanism. Specifically, the blades are deflected in the direction of the natural gas flow to increase the gap between the two opposing curved blades. The larger the gap, the more expanded the natural gas flow channel, the passively reduced natural gas flow rate, and thus the smaller the noise generated.

[0060] In some embodiments, the blade angle adjustment mechanisms of the resonance silencer assembly 100 and the diffusion silencer assembly 200 are independently arranged, and the blade angle adjustment mechanisms include a first rotating shaft, a second rotating shaft, multiple connecting rods, a synchronous connecting rod mechanism 600, a first silencer net, a first right-angle bending rod and a first driving motor.

[0061] The straight ends of the first inner arc blade 111 and the first outer arc blade 112 are connected to the wall of the straight pipe silencer through the first rotating shaft. The first connecting rod is connected in series with the first inner arc blade 111 arranged axially, and the second connecting rod is connected in series with the first outer arc blade 112 arranged axially. The back sides of the first inner arc blade 111 and the first outer arc blade 112 at the end are connected to the first silencer net through a synchronous connecting rod mechanism 600.

[0062] The straight ends of the first curved blade 211 and the second curved blade 212 are connected to the wall of the conical silencer 210 via a second rotating shaft. The third connecting rod is connected in series with the first curved blade 211 arranged axially on the outer wall of the conical silencer 210. The fourth connecting rod is connected in series with the second curved blade 212 arranged axially on the outer wall of the conical silencer 210. The fifth connecting rod is connected in series with the first curved blade 211 arranged axially on the inner wall of the conical silencer 210. The sixth connecting rod is connected in series with the second curved blade 212 arranged axially on the inner wall of the conical silencer 210. The backs of the first curved blade 211 and the second curved blade 212 at the end are connected to the first silencer net via a synchronous connecting rod mechanism 600. An opening is provided in the axial side wall of the pipe 500. The first propulsion motor located outside the pipe 500 is connected to the first silencer net via a first right-angled bend rod.

[0063] When the first propulsion motor drives the first muffler screen to move axially along the pipeline 500, it simultaneously drives all of the curved blades to rotate about their corresponding rotation axes, thereby adjusting the gaps between the relative curved blades. For example, when the telescopic end of the first propulsion motor moves in the direction of natural gas flow, the curved blades rotate toward the cylinder wall, thereby increasing the gaps between the relative curved blades.

[0064] It should be noted that to ensure smooth rotation of the curved blades around the shaft, a blade root is provided at one end of the curved blade, with a blade root channel mateable with the shaft. A first shaft sequentially passes through the blade root channel of the first inner curved blade 111 and the blade root channel of the first outer curved blade 112, and both ends of the first shaft are rotatably connected to the wall of the straight tube silencer. A second shaft passes through the wall of the conical silencer 210, and the second shafts located on the inner and outer sides of the wall respectively pass through the blade root channels of the curved blades in the second blade unit.

[0065] It should be noted that since the natural gas in the pipeline is in a turbulent state, the relationship between the turbulent noise power Lw and the natural gas flow velocity v is expressed as:

[0066] Lw∝10log10(v n ), n=5-8,

[0067] When the natural gas flow rate doubles, the noise level increases by 6-10dB. Therefore, reducing the flow rate helps to reduce the turbulent noise power level, thereby reducing noise.

[0068] Therefore, in this embodiment, the telescopic rod of the driving motor is pushed in the direction of natural gas flow, and the angle between the first inner curved blade 111 and the first outer curved blade 112 included in the first blade unit is reduced, and the angle between the first curved blade 211 and the second curved blade 212 included in the second blade unit is reduced, so that the gap between the relative curved blades is increased, thereby expanding the natural gas flow channel and passively reducing the natural gas flow rate, thereby achieving the effect of reducing the flow rate by expanding the flow channel and thus consuming sound energy.

[0069] Due to the different ways in which the arc-shaped blades in the resonance silencer assembly 100 and the diffusion silencer assembly 200 are arranged, when the two are used in combination, sound waves, reflected sound waves and eddy current noise in different propagation directions can all find corresponding interference paths, thereby forming a more complete sound energy attenuation mechanism in the medium and low wide frequency range.

[0070] In some embodiments, the sound-absorbing layer sound-absorbing assembly of the sound-absorbing device includes a sound-absorbing layer and an adjustable opening mechanism. The sound-absorbing layer is evenly provided with multiple grooves on the side facing the natural gas flow direction, and an adjustable opening mechanism is provided in each groove. The adjustable opening mechanism is used to adjust the effective sound-absorbing area of ​​the sound-absorbing layer at the rear end of the groove.

[0071] The adjustable opening mechanism includes two cover plates, a third rotating shaft, a seventh connecting rod, an eighth connecting rod, a synchronous linkage mechanism 600, a second sound-absorbing screen, and a second propulsion motor. The two cover plates are flatly arranged over the groove. Adjacent ends of the two cover plates are connected to the third rotating shaft, the ends of which are connected to the absorption layer 310 on either side of the groove. The backs of the two cover plates are connected to one end of the seventh and eighth connecting rods, respectively. The other ends of the seventh and eighth connecting rods are connected to the second sound-absorbing screen via a synchronous linkage assembly. An opening is axially defined in the sidewall of the pipe 500. A second propulsion motor, located outside the pipe 500, is connected to the second sound-absorbing screen via a second right-angled bend. When the second propulsion motor drives the second sound-absorbing screen axially along the pipe 500, it rotates the cover plates about the third rotating shaft, thereby adjusting the angle between the two cover plates and changing the effective sound-absorbing area of ​​the absorption layer 310 at the rear end of the groove. For example, the telescopic end of the second propulsion motor moves in the direction of natural gas flow, causing the two cover plates to open to the sides. This reduces the angle between the two cover plates and increases the area of ​​the sound-absorbing layer.

[0072] In some embodiments, when the natural gas flow rate increases, the proportion of high-frequency noise generated by the natural gas flow increases, and the telescopic rod of the second propulsion motor moves along the direction of the natural gas flow, driving the second silencer net to move axially along the pipeline 500, so that the angle between the two cover plates becomes smaller, the exposed area of ​​the sound-absorbing layer increases, and the absorption effect of the high-frequency noise is enhanced.

[0073] In some embodiments, the blade angle adjustment mechanism corresponding to the resonance silencer assembly 100 and the blade angle adjustment mechanism corresponding to the diffusion silencer assembly 200 are independently set, and the synchronous connecting rod assembly in the blade angle adjustment mechanism and the adjustable opening mechanism adopts a unified structural design, including a disc 610, an active rod 630 and a driven rod 640. An arc guide groove 620 is opened on the surface of the disc 610 along the circumferential direction. The first end of the active rod 630 is connected to the silencer net, and the second end of the active rod 630 is slidingly connected to the arc guide groove 620 of the disc 610 through a slider. One end of the two driven rods 640 is symmetrically hinged to the two sides of the second end of the active rod 630, and the other ends of the two driven rods 640 are hinged to the back of the first inner arc blade 111 and the first outer arc blade 112 at the end, the back of the first arc blade 211 and the second arc blade 212 at the end, or the back of the two cover plates.

[0074] When the motor drives the silencing screen to axially displace, the second end of the active rod 630 slides along the arcuate guide slot 620, causing the angle between the two driven rods 640 to change, thereby adjusting the angle between the first inner arcuate blade 111 and the first outer arcuate blade 112, the angle between the first arcuate blade 211 and the second arcuate blade 212, or the angle between the two cover plates. A slider is provided at the second end of the active rod 630, which is slidably connected to the arcuate guide slot 620.

[0075] It should be noted that the first propulsion motor and the second propulsion motor are both explosion-proof linear drive motors. Based on the above embodiments, a shell is sealed around the opening of the pipeline 500, and the shell covers the telescopic rod, the right-angle bent rod and the opening of the pipeline 500 of the propulsion motor. The telescopic rod is sleeved with a packing seal ring to fill the gap between the axial direction of the telescopic rod and the inner wall of the shell. The ports of the outer wall of the shell and the packing seal ring are fastened by tightening nuts. In this way, the movement of the blade angle adjustment mechanism and the adjustable opening mechanism can be ensured while avoiding the leakage of natural gas in the pipeline 500.

[0076] In some embodiments, in order to realize the rotation of the arc-shaped blades or cover plates, the driving motors of the blade adjustable mechanism and the opening adjustable mechanism can also be arranged in the pipe. Among them, in order to realize the rotation of the arc-shaped blades in the resonance silencer assembly and the diffusion silencer assembly, this embodiment provides another method: the straight ends of the first inner arc-shaped blade 111 and the first outer arc-shaped blade 112 are connected to the wall of the straight pipe silencer through the first rotating shaft, and the straight ends of the first arc-shaped blade 211 and the second arc-shaped blade 212 are connected to the wall of the conical silencer 210 through the second rotating shaft. The back of each arc-shaped blade is respectively connected to the telescopic rod of the driving motor, and the driving motor drives the arc-shaped blade to rotate around the rotating shaft.

[0077] In some embodiments, the adjustable opening mechanism can also be set as two cover plates, a rotating shaft and a pushing motor. The two cover plates are laid flat to cover the grooves. The two cover plates are respectively installed with rotating shafts at one end close to the sound-absorbing layer. The two ends of the rotating shafts are connected to the sound-absorbing layers on both sides of the grooves. The backs of the two cover plates are respectively connected to two pushing motors. To ensure that the cover plate rotates around the rotating shaft, the angle between the cover plate and the pushing motor is set to be less than 90°. The pushing motor drives the cover plate to rotate synchronously around the third rotating shaft to adjust the size of the opening between the two cover plates.

[0078] In some embodiments, along the direction of natural gas flow, the pipeline 500 is sequentially provided with a resonance silencer assembly 100 and a diffusion silencer assembly 200, the axes of the resonance silencer assembly 100 and the diffusion silencer assembly 200 are parallel to the axis of the pipeline 500, and the sound absorption layer silencer assembly 300 is connected to the inner wall of the pipeline 500 and is also provided at the rear end of the diffusion silencer assembly 200.

[0079] The present embodiment of the present invention utilizes the synergy of reactive and resistive muffler components to construct a full-band noise suppression control system. Specifically, the reactive muffler structure formed by the resonant muffler component 100 and the diffuse muffler component 200 effectively suppresses mid- and low-frequency noise without significantly increasing flow resistance, targeting the fluctuation characteristics of mid- and low-frequency noise. The muffler utilizes the principles of acoustic interference and the expansion effect of the flow channel, effectively suppressing mid- and low-frequency noise without significantly increasing flow resistance. The sound-absorbing layer muffler component 300, on the other hand, utilizes the viscous dissipation of porous materials to specifically absorb high-frequency, broadband noise. This ensures that noise in each frequency band can find its corresponding muffler path, while avoiding the frequency band limitations associated with a single muffler method, achieving both broadband noise reduction performance and fluid permeability. At the same time, the silencer device of the embodiment of the present application can also be adjusted according to the proportion of noise frequency bands, that is, when the flow rate is low and the proportion of medium and low frequency noise increases, the resonance silencer component 100 and the diffusion silencer component 200 have insufficient ability to suppress medium and low frequency noise energy, and the gap between the relative blades is correspondingly increased through the blade angle adjustment mechanism to achieve flow channel expansion and speed reduction silencer. When the natural gas flow rate increases and the proportion of high frequency noise increases, the sound absorption layer silencer component 300 has insufficient ability to suppress high frequency noise energy, and the opening adjustable mechanism is used to increase the area of ​​the sound absorption layer to enhance the resistive silencer.

[0080] In some embodiments, the natural gas pipeline noise control system further includes angle sensors, each mounted on the inner curved blade, the outer curved blade, and the back of the cover plate. The angle sensors are communicatively connected to a controller. The angle sensors are configured to detect the current angles of the inner curved blade, the outer curved blade, and the cover plate. The controller collects the angles and calculates the gap between the two opposing blades and the degree of opening between the two cover plates.

[0081] In some embodiments, the natural gas pipeline noise control system further includes an acoustic-to-electrical conversion mechanism 400 installed at the rear end of the conical silencer 210. The acoustic-to-electrical conversion mechanism 400 includes a connecting rod 410, an acoustic energy collection component 420, and the acoustic-to-electrical conversion mechanism 400. The acoustic energy collection component 420 is connected to one end of the connecting rod 410, and the other end of the connecting rod 410 is connected to the attraction layer 310 of the sound-absorbing layer silencer assembly 300. Each connecting rod 410 coincides with the central axis of each conical silencer 210; the acoustic energy collection component 420 is composed of a piezoelectric quartz crystal 421 arranged to face the natural gas flow and an insulating bracket 422 covering its non-working surface; the acoustic-to-electrical conversion mechanism 400 includes an acoustic-to-electric transducer, a battery, and a noise monitor arranged outside the pipeline 500. The acoustic energy collection component 420, the acoustic-to-electric transducer, and the battery are connected in series in sequence. The battery is electrically connected to the noise monitor for powering the noise monitor.

[0082] The acoustic-to-electric conversion mechanism 400 converts the dissipated acoustic energy into usable electrical energy. The piezoelectric quartz crystal 421 in the acoustic energy collection assembly 420, positioned facing the airflow, maximizes the capture of residual acoustic vibrations after the noise reduction process. The converted electrical energy provides a continuous and stable power source for the noise monitor. The noise monitor is used to detect noise one meter away from the pipeline 500.

[0083] In some embodiments, cavities are reserved between the inlet and outlet ends of the pipe 500 and the muffler. The inlet cavity smoothly guides incoming flow noise into the muffler, preventing abrupt boundary changes from inducing secondary noise. The outlet cavity acts as a buffer for acoustic energy release, effectively eliminating pressure pulsations in the wake of the muffler assembly. The length of the pipe 500 also affects the muffler's effectiveness. If the pressure regulating point is approximated as a point source noise, the sound pressure level attenuation of the point source noise is expressed as:

[0084] ΔL p =20log10(r2 / r1),

[0085] Among them, L p is the noise attenuation value, r1 and r2 are the distances from the point sound source, ΔL p That is, the sound pressure level attenuation from the distance r1 to r2. From this relationship, it can be seen that the silencing effect can be enhanced by increasing the length of the pipe where the silencing system is installed. In this embodiment, the length of the pipe is set to 5-8 times the pipe diameter.

[0086] In some embodiments, along the direction of natural gas flow, the noise control system includes a perforated plate circumferentially fitted to the inner wall of the pipeline 500, a resistive silencer mesh, at least two sets of resonance silencer components 100, a combination of a diffusion silencer component 200 and a sound-absorbing layer silencer component, and an acoustic-to-electrical conversion mechanism 400.

[0087] For example, the straight tube muffler, tapered muffler 210, cover plate, rotating shaft, connecting rod, and synchronous connecting rod assembly in the above embodiment are all made of nitrided stainless steel, and the curved blades are all made of stainless steel with hard alloy overlay, ensuring the wear resistance, corrosion resistance, strength, and service life of each component. The sound-absorbing layer and sound-absorbing mesh are made of stainless steel fiber and stainless steel micro-perforated sound-absorbing panels.

[0088] In some embodiments, the controller is communicatively connected to the first sound pressure sensor, the second sound pressure sensor, the blade angle adjustment mechanism, and the opening adjustable mechanism, respectively.

[0089] The controller is configured to receive sound pressure signals collected by the first and second sound pressure sensors before and after silencing, respectively; analyze and process the sound pressure signals to determine the energy attenuation rate of the silencing device for noise in each characteristic frequency band and determine whether the energy attenuation rate is below a threshold attenuation rate range. The characteristic frequency bands include mid-low and high frequency bands. The energy attenuation rate is used to quantify the noise suppression effectiveness of the silencing device; and, when the attenuation rate of noise in the mid-low frequency band is below the threshold attenuation rate range, control the blade angle adjustment mechanism to drive the curved blades to deflect, increasing the gap between the opposing curved blades until the energy attenuation rate falls within the threshold attenuation rate range or the noise level measured at one meter from the pipe is ≤85dB. When the attenuation rate of noise in the high frequency band is below the threshold attenuation rate range, control the opening of the adjustable opening mechanism to increase the effective sound absorption area of ​​the sound absorption layer at the rear end of the groove until the energy attenuation rate falls within the threshold attenuation rate range or the noise level measured at one meter from the pipe is ≤85dB. The opening of the adjustable opening mechanism quantifies the effective sound absorption area of ​​the suction layer at the rear end of the groove; a larger opening indicates a larger effective sound absorption area.

[0090] The controller is further used to perform Fourier transform processing on the collected sound pressure signals respectively to obtain corresponding time-frequency spectra, and extract energy values ​​of the mid-low frequency bands and high frequency bands from the time-frequency spectra; based on the energy values ​​of the mid-low frequency bands and high frequency bands corresponding to the first sound pressure sensor and the energy values ​​of the mid-low frequency bands and high frequency bands corresponding to the second sound pressure sensor, calculate the energy attenuation rate of the silencer for the mid-low frequency bands and high frequency bands; compare the calculated energy attenuation rate of each characteristic frequency band with a preset attenuation rate threshold to determine whether the resonance silencer component and the diffusion silencer component have insufficient suppression effect on the mid-low frequency band noise, and whether the sound absorption layer silencer component has insufficient suppression effect on the high frequency band noise.

[0091] The controller is further used to record in real time and build a database based on the natural gas flow rate, the optimal blade deflection angle and the optimal opening, wherein the optimal blade deflection angle and the optimal opening are the angle of the curved blade and the opening of the cover plate, respectively, when the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipeline is ≤85dB; the flow rate data collected by the flow meter is compared with the natural gas flow rate recorded in the database, and when the flow rate data corresponds to the natural gas flow rate recorded in the database, the silencer is adjusted to the optimal blade deflection angle and the optimal opening corresponding to the natural gas flow rate, wherein the natural gas flow rate in the pipeline is collected by the flow meter.

[0092] In some embodiments, a natural gas pipeline noise control method is also provided, comprising the following steps:

[0093] The first sound pressure sensor and the second sound pressure sensor respectively collect sound pressure signals before and after silencing;

[0094] Analyze and process the sound pressure signal to obtain the energy attenuation rate of the noise in each characteristic frequency band of the silencer and determine whether the energy attenuation rate is below the attenuation rate threshold range. The characteristic frequency bands include mid-low frequency bands and high frequency bands. The energy attenuation rate is used to quantify the noise suppression effect of the silencer;

[0095] When the attenuation rate of noise in the medium and low frequency bands is lower than the attenuation rate threshold range, the blade angle adjustment mechanism is controlled to drive the arc blades to deflect so that the gap between the relative arc blades increases until the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipe is ≤85dB; when the attenuation rate of noise in the high frequency band is lower than the attenuation rate threshold, the opening of the adjustable opening mechanism is controlled to increase the effective sound absorption area of ​​the sound absorption layer at the rear end of the groove until the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipe is ≤85dB.

[0096] In some embodiments, a natural gas pipeline noise control method is also provided, comprising the following steps:

[0097] S100 collects sound pressure signals before and after silencing respectively through the first sound pressure sensor and the second sound pressure sensor;

[0098] S200 performs Fourier transform processing on the collected sound pressure signals to obtain corresponding time-frequency spectra, and extracts energy values ​​of the low- and medium-frequency bands and high-frequency bands from the time-frequency spectra. In this embodiment, the low- and medium-frequency bands are exemplarily proposed to be in the range of 100 Hz to 2500 Hz, and the high-frequency band is in the range of >2500 Hz.

[0099] S300 calculates, based on energy values ​​of the mid-low frequency band and the high frequency band corresponding to the first sound pressure sensor and energy values ​​of the mid-low frequency band and the high frequency band corresponding to the second sound pressure sensor, an energy attenuation rate of the muffler device for noise in the mid-low frequency band and the high frequency band, wherein the energy attenuation rate is used to quantify the noise suppression effect of the muffler device;

[0100] S400 compares the calculated energy attenuation rate of each characteristic frequency band with a preset attenuation rate threshold to determine whether the resonance muffler component and the diffusion muffler component are insufficiently effective in suppressing mid- and low-frequency noise, and whether the sound absorption layer muffler component is insufficiently effective in suppressing high-frequency noise.

[0101] When the attenuation rate of noise in the medium and low frequency bands of the S500 is lower than the attenuation rate threshold range, the blade angle adjustment mechanism is controlled to drive the curved blades to deflect, thereby increasing the gap between the opposing curved blades until the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipeline is ≤85dB;

[0102] When the attenuation rate of high-frequency noise is lower than the attenuation rate threshold, the opening of the adjustable opening mechanism is controlled to increase the effective sound absorption area of ​​the sound absorption layer at the rear end of the groove until the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipe is ≤85dB.

[0103] Based on the above embodiment, a natural gas pipeline control method further includes the following steps:

[0104] A database is constructed based on real-time recording of natural gas flow rate, optimal blade deflection angle, and optimal opening. The optimal blade deflection angle and optimal opening are the angle of the curved blade and the opening of the cover plate, respectively, when the energy decay rate is within the decay rate threshold range or when the noise level measured at one meter from the pipeline is ≤85dB. These angles are measured using angle sensors mounted on the curved blades and cover plate, respectively. The flow rate data collected by the flow meter is compared with the natural gas flow rate recorded in the database. When the flow rate data matches the natural gas flow rate recorded in the database, the silencer is adjusted to the optimal blade deflection angle and opening corresponding to the natural gas flow rate. The natural gas flow rate in the pipeline is collected by the flow meter.

[0105] The natural gas pipeline noise control method provided in this embodiment uses real-time noise data monitoring from dual sound pressure sensors and Fourier transform to accurately identify noise spectrum characteristics, thereby evaluating energy attenuation across the entire frequency band. Specifically, the method includes: first, independently calculating the energy attenuation rate by frequency band, diagnosing whether the noise suppression effects of the reactive silencer components (resonant silencer components and diffuse silencer components) in the low- and medium-frequency bands (100Hz-2500Hz) and the resistive components (sound-absorbing layer silencer components) in the high-frequency band (>2500Hz) meet expectations. If the effects do not meet expectations, the noise suppression component parameters corresponding to the corresponding frequency bands are dynamically adjusted to ensure that the noise attenuation rates in each frequency band continue to meet the standards. Furthermore, by recording the optimal blade angle and opening parameters, a noise reduction database for different operating conditions is constructed. Under complex operating conditions with variable flow rates, the noise control system automatically adjusts according to the optimal blade angle and opening parameters provided by the noise reduction database.

[0106] The above embodiments are intended only to illustrate the technical solutions of the present application and are not intended to limit them. The present application is not limited to the precise structures described above and illustrated in the accompanying drawings, and it cannot be assumed that the specific implementation of the present application is limited to these descriptions. For those skilled in the art of the present application, any changes and modifications made without departing from the concept of the present application should be deemed to fall within the scope of protection of the present application.

Claims

1. A natural gas pipeline noise control system, characterized in that: include: a first sound pressure sensor, a second sound pressure sensor, a silencer, and a controller, wherein the first sound pressure sensor and the second sound pressure sensor are mounted at both axial ends of the inner wall of the pipe, the silencer is mounted between the two axial ends of the inner wall of the pipe, the first sound pressure sensor and the second sound pressure sensor are used to collect sound pressure signals before and after the silencer, and the silencer includes a resonance silencer component, a diffusion silencer component, a blade angle adjustment mechanism, and a sound absorption layer silencer component; The resonance silencer assembly includes a plurality of coaxially sleeved straight tube silencers, each of which is connected to a tube wall of the straight tube silencer with a plurality of first guide vane groups arranged in the axial direction, each of which includes an even number of first blade units evenly distributed along the circumference of the tube wall, the first blade unit including a first inner arc blade and a first outer arc blade that are symmetrically curved in opposite directions, the first inner arc blade being connected to the inner tube wall of the straight tube silencer, the second outer arc blade being connected to the outer tube wall of the straight tube silencer, the concave surfaces of the first inner arc blade and the first outer arc blade both facing the incoming direction of the natural gas flow, the curved section of the first inner arc blade extending toward the central axis of the straight tube silencer, the straight ends of the first inner arc blade and the first outer arc blade overlapping, and being rotatably connected to the tube wall of the straight tube silencer through the blade angle adjustment mechanism; The diffusion silencer assembly includes a plurality of conical silencers whose inner diameters gradually expand along the natural gas flow direction, and the conical silencers are connected by a sound-absorbing layer; the conical silencers are connected to the cylinder wall with a plurality of groups of second guide vanes arranged in the axial direction, and each group of the second guide vanes includes a plurality of second blade units evenly spaced along the circumferential direction of the inner cylinder wall and the outer cylinder wall of the conical silencer, and each second blade unit includes a first curved blade and a second curved blade that are symmetrically curved in opposite directions, the concave surfaces of the first curved blade and the second curved blade both facing the natural gas flow direction, the curved sections of the first curved blade and the second curved blade both conform to the cylinder wall, the straight ends of the first curved blade and the second curved blade coincide, and the blade angle adjustment mechanism is used to rotationally connect the first curved blade and the second curved blade to the cylinder wall of the conical silencer; The sound-absorbing layer silencer assembly includes a sound-absorbing layer and an adjustable opening mechanism. A plurality of grooves are evenly formed on a surface of the sound-absorbing layer facing the natural gas flow direction. The adjustable opening mechanism is provided in each groove. The adjustable opening mechanism is used to adjust the effective sound-absorbing area of ​​the sound-absorbing layer at the rear end of the groove. The controller is communicatively connected with the first sound pressure sensor, the second sound pressure sensor, the blade angle adjustment mechanism and the opening adjustable mechanism respectively.

2. The natural gas pipeline noise control system according to claim 1, characterized in that: The blade angle adjustment mechanism includes a first rotating shaft, a second rotating shaft, a connecting rod, a synchronous connecting rod mechanism, a first silencer net, a first right-angle bending rod and a first driving motor; The straight ends of the first inner arc blade and the first outer arc blade are connected to the wall of the straight pipe silencer through a first rotating shaft. The first connecting rod is sequentially connected in series with the first inner arc blades arranged in the axial direction. The second connecting rod is sequentially connected in series with the first outer arc blades arranged in the axial direction. The backs of the first inner arc blade and the first outer arc blade at the end are connected to the first silencer net through a synchronous connecting rod mechanism. The straight ends of the first curved blade and the second curved blade are connected to the wall of the conical silencer through the second rotating shaft. The third connecting rod is sequentially connected in series with the first curved blade arranged axially on the outer wall of the conical silencer. The fourth connecting rod is sequentially connected in series with the second curved blade arranged axially on the outer wall of the conical silencer. The fifth connecting rod is sequentially connected in series with the first curved blade arranged axially on the inner wall of the conical silencer. The sixth connecting rod is sequentially connected in series with the second curved blade arranged axially on the inner wall of the conical silencer. The backs of the first curved blade and the second curved blade at the end are connected to the first silencer net through a synchronous connecting rod mechanism. The side wall of the pipe is provided with an opening in the axial direction, and the first propulsion motor located outside the pipe is connected to the first silencer net via a first right-angle bent rod; When the first propulsion motor drives the first muffler net to move axially along the pipeline, it can simultaneously drive all the arc-shaped blades to rotate around the corresponding rotation axis, thereby adjusting the gaps between the relative arc-shaped blades.

3. The natural gas pipeline noise control system according to claim 2, characterized in that: The adjustable opening mechanism includes two cover plates, a third rotating shaft, a seventh connecting rod, an eighth connecting rod, a synchronous connecting rod mechanism, a second silencer net and a second pushing motor. The two cover plates are flatly laid to cover the groove, and the adjacent ends of the two cover plates are connected to the third rotating shaft. The two ends of the third rotating shaft are connected to the sound-absorbing layers on both sides of the groove. The backs of the two cover plates are respectively connected to one end of the seventh connecting rod and the eighth connecting rod, and the other ends of the seventh connecting rod and the eighth connecting rod are respectively connected to the second silencer net through the synchronous connecting rod assembly. The side wall of the pipe is provided with an opening in the axial direction, and the second propulsion motor located outside the pipe is connected to the second silencer net via a second right-angle bent rod; When the second propulsion motor drives the second silencer net to move axially along the pipe, it drives the cover plate to rotate around the third rotation axis, thereby adjusting the angle between the two cover plates and changing the effective sound absorption area of ​​the sound absorption layer at the rear end of the groove.

4. The natural gas pipeline noise control system according to claim 3, characterized in that: The synchronous linkage mechanism includes a disc, an active rod and a driven rod. An arc-shaped guide groove is opened on the surface of the disc along the circumferential direction. The first end of the active rod is connected to the silencer net, and the second end of the active rod is slidably connected to the arc-shaped guide groove of the disc via a slider. One end of the two driven rods is symmetrically hinged to the two sides of the second end of the active rod, and the other ends of the two driven rods are respectively hinged to the back of the first inner curved blade and the first outer curved blade at the end, the back of the first curved blade and the second curved blade at the end, or the back of the two cover plates; When the motor drives the silencer net to move axially, the second end of the active rod slides along the arc guide groove, driving the angle between the two driven rods to change, thereby adjusting the angle between the first inner arc blade and the first outer arc blade, the angle between the first arc blade and the second arc blade, or the angle between the two cover plates.

5. The natural gas pipeline noise control system according to claim 1, characterized in that: Along the flow direction of natural gas, the pipeline is sequentially provided with the resonance silencer component and the diffusion silencer component, the axes of the resonance silencer component and the diffusion silencer component are parallel to the axis of the pipeline, and the sound absorption layer silencer component is connected to the inner wall of the pipeline and is also provided at the rear end of the diffusion silencer component.

6. The natural gas pipeline noise control system according to claim 1, characterized in that: The invention also includes an acoustic-to-electric conversion mechanism installed at the rear end of the conical silencer, the acoustic-to-electric conversion mechanism including a connecting rod, an acoustic energy collection component and the acoustic-to-electric conversion mechanism, the acoustic energy collection component is connected to one end of the connecting rod, and the other end of the connecting rod is connected to the sound absorbing layer of the sound absorbing layer silencer assembly; The acoustic energy collection component consists of a piezoelectric quartz crystal arranged to face the natural gas flow and an insulating bracket covering its non-working surface; the acoustic-to-electric conversion mechanism includes an acoustic-to-electric transducer, a battery and a noise monitor arranged outside the pipeline. The acoustic energy collection component, the acoustic-to-electric transducer and the battery are connected in series in sequence. The battery is electrically connected to the noise monitor for powering the noise monitor.

7. A natural gas pipeline noise control method, characterized in that: The method is implemented based on the natural gas pipeline noise control system according to any one of claims 1 to 6, and includes: The first sound pressure sensor and the second sound pressure sensor respectively collect sound pressure signals before and after silencing; Analyzing and processing the sound pressure signal to obtain an energy attenuation rate of the noise reduction device for each characteristic frequency band, and determining whether the energy attenuation rate is below an attenuation rate threshold range, wherein the characteristic frequency band includes a low-mid frequency band and a high frequency band. The energy attenuation rate is used to quantify the noise suppression effect of the noise reduction device; When the attenuation rate of the noise in the medium and low frequency bands is lower than the attenuation rate threshold range, the blade angle adjustment mechanism is controlled to drive the arc blades to deflect so as to increase the gap between the relative arc blades until the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipeline is ≤85dB; When the attenuation rate of high-frequency noise is lower than the attenuation rate threshold, the opening of the adjustable opening mechanism is adjusted to increase the effective sound absorption area of ​​the sound absorption layer at the rear end of the groove until the energy attenuation rate is within the attenuation rate threshold range or the noise measured at one meter away from the pipe is ≤85dB.

8. The natural gas pipeline noise control method according to claim 7, characterized in that: The analyzing and processing the sound pressure signal to obtain the energy attenuation rate of the noise at each characteristic frequency band by the muffler device and determining whether the energy attenuation rate is lower than the attenuation rate threshold range further includes: Performing Fourier transform processing on the collected sound pressure signals to obtain corresponding time-frequency spectra, and extracting energy values ​​of the low-frequency band and the high-frequency band from the time-frequency spectra; Calculating the energy attenuation rate of the muffler device for noise in the mid-low frequency band and the high frequency band based on the energy values ​​of the mid-low frequency band and the high frequency band corresponding to the first sound pressure sensor and the energy values ​​of the mid-low frequency band and the high frequency band corresponding to the second sound pressure sensor; The calculated energy attenuation rate of each characteristic frequency band is compared with the preset attenuation rate threshold to determine whether the resonance silencer component and the diffusion silencer component are insufficiently effective in suppressing noise in the medium and low frequency bands, and whether the sound absorption layer silencer component is insufficiently effective in suppressing noise in the high frequency bands.

9. The natural gas pipeline noise control method according to claim 8, characterized in that: The method further comprises: Recording in real time and building a database based on the natural gas flow rate, the optimal blade deflection angle, and the optimal opening, wherein the optimal blade deflection angle and the optimal opening are, respectively, the angle of the curved blade and the opening of the cover plate when the energy attenuation rate is within the attenuation rate threshold range or the noise level measured at one meter from the pipeline is ≤85dB; The real-time collected flow rate data is compared with the natural gas flow rate recorded in the database. When the flow rate data corresponds to the natural gas flow rate recorded in the database, the silencer is adjusted to an optimal blade deflection angle and an optimal opening corresponding to the natural gas flow rate, wherein the natural gas flow rate in the pipeline is collected by a flow meter.

Images