Duct noise reduction rectifier and duct flow metering system

Abstract

The application relates to the technical field of pipeline flow metering equipment, and discloses a pipeline noise reduction rectifying device and a pipeline flow metering system. The pipeline noise reduction rectifying device comprises a shell, an air inlet arranged at the front end of the shell, and an air outlet arranged at the rear end of the shell. The shell comprises a diameter expansion part and a steady flow noise reduction part arranged in sequence from front to rear. The inner diameter of the diameter expansion part gradually increases from the air inlet to the downstream. The inner diameter of the steady flow noise reduction part is greater than that of the air inlet. A front rectifying net is arranged on one side of the steady flow noise reduction part close to the air inlet. A steady flow ball is fixedly arranged on the steady flow noise reduction part and located on the rear side of the front rectifying net. The rear end of the steady flow ball is opposite to the air outlet. The pipeline noise reduction rectifying device can perform noise reduction and rectification on the airflow in the pipeline, create a stable measurement environment for the ultrasonic flow meter on the pipeline, and indirectly improve the measurement accuracy of the flow.

Description

Technical Field

[0001] This invention relates to the field of pipeline flow metering equipment technology, specifically to a pipeline noise reduction and rectification device and a pipeline flow metering system. Background Technology

[0002] During long-distance transmission, the gas flow is prone to instability due to terrain variations, pipe diameter changes, and the influence of valves, elbows, tees, and other fittings along the route. During natural gas transportation, pressure and flow rates fluctuate with changes in user demand and the operational status of the pipeline system. These pressure and flow rate variations lead to gas flow instability, causing difficulties in metering.

[0003] Some rectifiers do not provide ideal rectification, making it difficult to fully integrate airflow into a uniform and stable state. For example, ultrasonic flow meters using ordinary rectifier plates may not be able to completely eliminate airflow rotation and irregular movement, affecting signal acquisition and measurement accuracy. Summary of the Invention

[0004] This invention is made to solve the above-mentioned technical problems. One of its objectives is to provide a pipeline noise reduction and rectification device that can perform noise reduction and rectification on the airflow in the pipeline, creating a stable measurement environment for the ultrasonic flow meter on the pipeline, and indirectly improving the accuracy of flow measurement.

[0005] Another objective of this invention is to provide a pipeline flow metering system capable of accurately measuring the flow rate of gas within a pipeline.

[0006] According to one embodiment of the present invention, a pipeline noise reduction and rectification device is provided, comprising: a housing having an air inlet at the front end and an air outlet at the rear end, including an expansion section and a flow stabilization and noise reduction section arranged sequentially from front to back, wherein the inner diameter of the expansion section gradually increases from the air inlet downstream, and the inner diameter of the flow stabilization and noise reduction section is larger than the inner diameter of the air inlet; a front rectification net disposed on the side of the flow stabilization and noise reduction section near the air inlet; and a flow stabilization ball fixedly disposed on the flow stabilization and noise reduction section, located behind the front rectification net, with its rear end opposite to the air outlet.

[0007] As one implementation, the front rectifier mesh is provided with a flow stabilizing cavity at a position opposite to the air inlet. The outer periphery of the flow stabilizing cavity is a flame arrestor mesh. The flow stabilizing cavity includes several tubes arranged side by side. The end of the flow stabilizing cavity near the air inlet forms a concave arc surface, and the end of the flow stabilizing cavity away from the air inlet is closed.

[0008] As one embodiment, the front rectifier mesh also includes a fixing base disposed between the current stabilizing socket and the flame arrestor mesh, and the front end of the current stabilizing ball is connected to the fixing base.

[0009] As one implementation, the diameter of the flow stabilizing socket is 0.85-1.15 times the inner diameter of the air inlet.

[0010] As one embodiment, the housing further includes an airflow straightening section disposed downstream of the flow stabilization and noise reduction section. The airflow straightening section is a cylinder with one end connected to the air outlet and the other end extending into the flow stabilization and noise reduction section. The inner diameter of the cylinder is smaller than the inner diameter of the flow stabilization and noise reduction section.

[0011] As one embodiment, the pipeline noise reduction and rectification device further includes: a rear rectification net, which is disposed in the airflow rectification section and has a mesh structure; and a flow stabilizing tube bundle, which is disposed downstream of the rear rectification net and consists of several tubes filling the airflow rectification section, with the tubes arranged along the length of the airflow rectification section.

[0012] As one implementation, a preset distance is provided between the rear rectifier grid and the current stabilizing tube bundle.

[0013] As one implementation, the rear diameter of the flow stabilization and noise reduction section gradually decreases and is connected to the outer periphery of the airflow straightening section.

[0014] As one implementation, the diameter of the flow stabilizing ball is 1-1.5 times the inner diameter of the air inlet.

[0015] According to one embodiment of the present invention, a pipeline flow metering system is provided, comprising: an ultrasonic flow meter; and a pipeline noise reduction and rectification device as described above, disposed at a predetermined distance upstream of the pipeline where the ultrasonic flow meter is located.

[0016] Based on the above description and practical application, the duct noise reduction and rectification device of this invention incorporates a front rectifier and a flow stabilizing sphere within the housing through which the airflow passes. The airflow first enters the expansion section from the inlet, where its high-speed velocity decreases, reducing noise energy and intensity. The airflow then enters the flow stabilization and noise reduction section, where the front rectifier, with its mesh structure, initially adjusts the chaotic airflow, making it more stable. A gap exists between the flow stabilizing sphere and the front rectifier, allowing the airflow to form vortices. As the airflow velocity decreases, it fully contacts the surface of the flow stabilizing sphere, bringing the airflow in the vortex section close to a stationary state and dispersing it beyond the rectifier's range. Molecules in the high-speed airflow interact with molecules in the stationary airflow, exchanging momentum and homogenizing the overall airflow velocity, thus reducing the speed of the high-speed airflow. When the high-speed airflow flows in, the velocity gradient decreases, the turbulence intensity weakens, and the airflow becomes relatively stable. In this flow stabilization and noise reduction section, the airflow channel is enlarged, resulting in a more uniform airflow velocity distribution. This reduces turbulence and eddies, decreasing the velocity gradient and turbulence within the airflow, thus lowering noise caused by airflow instability. The reduced airflow velocity also decreases the impact force between the airflow and the inner wall of the casing, consequently reducing friction and vibration, further lowering noise levels.

[0017] This pipeline noise reduction and rectification device can reduce noise and rectify the airflow in the pipeline, creating a stable measurement environment for the ultrasonic flow meter on the pipeline and indirectly improving the accuracy of flow measurement. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal structure of a pipeline noise reduction and rectification device according to one embodiment of the present invention.

[0019] Figure 2a and Figure 2b This is a simulation diagram of the pipeline noise reduction and rectification device in operation according to one embodiment of the present invention, with an internal gas flow velocity of 0.75m. 3 / h.

[0020] Figure 3a and Figure 3b This is a simulation diagram of the pipeline noise reduction and rectification device in operation according to one embodiment of the present invention, wherein the internal gas flow velocity is 6m. 3 / h.

[0021] Figure 4a and Figure 4b This is a simulation diagram of the pipeline noise reduction and rectification device in operation according to one embodiment of the present invention, wherein the internal gas flow velocity is 30m. 3 / h.

[0022] The attached figures are labeled as follows:

[0023] 1. Shell; 11. Inlet; 12. Outlet; 13. Expansion section; 14. Flow stabilization and noise reduction section; 15. Airflow sorting section; 2. Front rectifier mesh; 21. Flow stabilization recess; 22. Flame arrestor mesh; 23. Mounting base; 3. Flow stabilization ball; 4. Rear rectifier mesh; 5. Flow stabilization tube bundle; 6. Flow stabilization baffle; 7. Cylinder; 81. Position of front airflow vortex; 82. Position of middle airflow vortex; 83. Position of rear airflow vortex. Detailed Implementation

[0024] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0025] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. It should be noted that in this disclosure, the terms "comprising," "configured with," and "set in" are used to indicate an open-ended inclusion, meaning that additional elements / components / etc. may exist besides those listed; the terms "first," "second," etc., are used only as labels and are not intended to limit the number or order of objects; the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., 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 the invention 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 the invention.

[0026] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] During gas transportation, the airflow becomes turbulent and generates supersonic sound waves after passing through various transmission pipes, which can cause the ultrasonic flow meter installed on the pipeline to fail to measure accurately. This embodiment discloses a pipeline noise reduction and rectification device, installed in front of the ultrasonic flow meter on the gas transportation pipeline. This device stabilizes the airflow, reduces the intensity of the supersonic sound waves in the airflow, and rectifyes the airflow, eliminating airflow rotation and irregular movement, thus ensuring stable and accurate measurement by the ultrasonic flow meter.

[0028] like Figure 1 As shown, the pipeline noise reduction and rectification device includes a housing 1, a front rectification net 2, and a flow stabilizing ball 3. The housing 1 has an air inlet 11 at its front end and an air outlet 12 at its rear end. The main body of the housing 1 includes an expanding diameter section 13 and a flow stabilizing and noise reduction section 14 arranged sequentially from front to back. The inner diameter of the expanding diameter section 13 gradually increases downstream from the air inlet 11, and the inner diameter of the flow stabilizing and noise reduction section 14 is larger than the inner diameter of the air inlet 11.

[0029] The front rectifier mesh 2 is located on the side of the flow stabilization and noise reduction section 14 near the air inlet 11. Its main body is a mesh structure, which can divide the airflow and initially adjust the chaotic airflow to make the airflow more stable. When the front rectifier mesh 2 is a metal structure, it can also prevent the propagation of flames of a certain intensity and speed, increasing the safety performance of the device. The flow stabilizing ball 3 is fixedly installed in the flow stabilization and noise reduction section 14, located behind the front rectifier mesh 2, with the rear end of the flow stabilizing ball 3 opposite to the air outlet 12.

[0030] After the pipeline noise reduction and rectification device is installed on the gas delivery pipeline, the airflow first enters the expansion section 13 from the inlet 11. The high-speed airflow slows down in the expansion section 13, reducing the noise energy and intensity generated by the airflow. The airflow then enters the stabilization and noise reduction section 14, where the front rectifier mesh 2, with its mesh structure, can initially adjust the chaotic airflow, making it more stable. There is a gap between the stabilizing sphere 3 and the front rectifier mesh 2, allowing the airflow to form a medium-speed vortex. After the airflow speed decreases, it fully contacts the surface of the stabilizing sphere 3, making the airflow in the medium-speed vortex section nearly still, dispersing the airflow beyond the rectifier sphere's range. Molecules in the high-speed airflow interact with molecules in the still airflow, exchanging momentum and making the overall airflow speed more uniform, thus reducing the speed of the high-speed airflow. When the high-speed airflow flows in, the velocity gradient decreases, the turbulence intensity weakens, and the airflow becomes relatively stable. In the flow stabilization and noise reduction section 14, the airflow channel is enlarged, the airflow velocity distribution is more uniform, and the turbulence and eddies of the airflow are reduced, decreasing the velocity gradient and turbulence within the airflow, thereby reducing noise caused by airflow instability. With the reduced airflow velocity, the impact force between the airflow and the inner wall of the casing 1 decreases, and the friction and vibration between them are correspondingly reduced, further lowering the noise.

[0031] This pipeline noise reduction and rectification device can reduce noise and rectify the airflow in the pipeline, creating a stable measurement environment for the ultrasonic flow meter on the pipeline and indirectly improving the accuracy of flow measurement.

[0032] Furthermore, in this embodiment, a flow stabilizing recess 21 is provided at the position opposite to the air inlet 11 on the front rectifier mesh 2. The outer periphery of the flow stabilizing recess 21 is a flame-retardant mesh 22, i.e., a mesh structure made of metal. The flow stabilizing recess 21 includes several tubes arranged side by side. The end of the flow stabilizing recess 21 near the air inlet 11 forms a concave arc surface, and the end of the flow stabilizing recess 21 away from the air inlet 11 is closed.

[0033] After the gas enters the device, it faces the stabilizing cavity 21. Due to the special structure of the cavity 21, the airflow forms a forward airflow vortex at this location. As the airflow passes through tubes of varying lengths, it is scattered. This scattering changes the direction of sound wave propagation, dispersing the originally concentrated sound wave energy in space, thereby reducing the noise intensity in a specific direction. Furthermore, during scattering, sound waves are reflected and refracted between different interfaces, consuming some sound energy. At the forward airflow vortex position 81, the airflow speed decreases from a high speed to a low speed, or even to zero. This process further rectifyes and reduces noise from the airflow.

[0034] In this embodiment, the front rectifier mesh 2 further includes a fixing base 23 disposed between the current stabilizing socket 21 and the flame arrestor mesh 22, and the front end of the current stabilizing ball 3 is connected to the fixing base 23. Figure 1 As shown, one side of the fixed base 23 has an annular groove. Each tube constituting the flow stabilizing cavity 21 is axially fixed in this groove. The length of each tube gradually decreases from the outer circle to the inner circle of the groove, forming an inwardly concave arc surface on the left side. This arc surface is opposite to the air inlet 11 and serves to guide the airflow to form a front airflow vortex. The outer periphery of the flame arrestor mesh 22 is fixedly connected to the inner wall of the housing 1, and the inner side of the flame arrestor mesh 22 is fixedly connected to the fixed base 23. The front end of the flow stabilizing ball 3 is fixedly connected to the fixed base 23 by bolts.

[0035] By setting the fixing base 23, the flow stabilizing socket 21, the flame arresting net 22 and the flow stabilizing ball 3 can be fixed in the housing 1. During the process of conveying airflow, the three can work stably and are not prone to loosening. They can also avoid noise caused by their own vibration.

[0036] The diameter of the flow stabilizing recess 21 is 0.85-1.15 times the inner diameter of the air inlet 11. While ensuring smooth airflow through the device, it also guides the airflow to form a forward airflow vortex, reducing noise during gas delivery and making the gas delivery process more stable. In this embodiment, the diameter of the flow stabilizing recess 21 is the same as the inner diameter of the air inlet 11. In other embodiments, the diameter of the flow stabilizing recess 21 can be adjusted within the above-mentioned range, for example, set to 0.85 times, 0.9 times, 0.95 times, 1.05 times, 1.1 times, or 1.15 times the inner diameter of the air inlet 11. All of these adjustments can achieve the same effect: ensuring smooth airflow through the device while guiding the airflow to form a forward airflow vortex, reducing noise during gas delivery, and making the gas delivery process more stable.

[0037] Furthermore, in this embodiment, the housing 1 also includes an airflow straightening section 15 disposed downstream of the flow stabilization and noise reduction section 14. The airflow straightening section 15 is a cylinder 7 in the flow stabilization and noise reduction section 14 with one end connected to the air outlet 12 and the other end extending into the cylinder 7. The inner diameter of the cylinder 7 is smaller than the inner diameter of the flow stabilization and noise reduction section 14.

[0038] like Figure 1 As shown, the left end of the cylinder 7 constituting the airflow conditioning section 15 extends into the flow stabilization and noise reduction section 14, and the right end of the cylinder 7 is connected to the air outlet 12. The airflow processed by the flow stabilization and noise reduction section 14 is finally conveyed backward through the cylindrical airflow conditioning section 15. Since the inner diameter of the cylinder 7 is smaller than the inner diameter of the flow stabilization and noise reduction section 14, the airflow velocity and pressure level will return to a level close to that before the expansion after the airflow enters this section. At the same time, the airflow can still maintain a certain stability after entering the airflow conditioning section 15, which has a diameter close to that of the air inlet 11.

[0039] Furthermore, in this embodiment, the pipeline noise reduction and rectification device also includes a rear rectifier mesh 4 and a flow stabilizing tube bundle 5. For example... Figure 1 As shown, the rear rectifier mesh 4 is located in the airflow straightening section 15 and has a mesh structure; the flow stabilizing tube bundle 5 is located downstream of the rear rectifier mesh 4 and consists of several tubes filling the airflow straightening section 15, with the tubes arranged along the length of the airflow straightening section 15.

[0040] Similar to the front rectifier mesh 2, the rear rectifier mesh 4 can divide the airflow and further adjust it to make the airflow more stable. After the airflow has undergone a series of treatments, the flow stabilizing tube bundle 5, through its own structure, divides the airflow into multiple small channels, guiding the airflow to flow in a specific direction, thereby making the airflow more evenly distributed across the cross-section. It plays a role in rectifying and stabilizing the airflow, reducing airflow fluctuations and turbulence, allowing the airflow to flow in a stable state, and finally enter the downstream ultrasonic flow meter for stable measurement. In this embodiment, the rear rectifier mesh 4 is a metal structure, which also has a certain flame-retardant function.

[0041] Furthermore, in this embodiment, a preset distance is provided between the rear rectifier mesh 4 and the flow stabilizing tube bundle 5, forming a flow stabilizing cavity 6 between them. Due to the presence of this flow stabilizing cavity 6, the flame needs to travel a longer path from the rear rectifier mesh 4 to the flow stabilizing tube bundle 5, which enhances the flame-stopping effect and extends the flame propagation path. When the flame propagates within the flow stabilizing cavity 6, it continuously exchanges heat with the cavity wall, absorbing a large amount of heat and gradually lowering the temperature, thereby reducing the flame propagation speed and increasing the success rate of the rear rectifier mesh 4 in preventing the flame from passing through.

[0042] In addition, the flow stabilizing cavity 6 can buffer airflow fluctuations, allowing the airflow to be temporarily stabilized and adjusted within it, reducing the impact of the airflow on the flow stabilizing tube bundle 5, and helping the flow stabilizing tube bundle 5 to better perform its rectification function, so that the airflow passes through more evenly and stably. The flow stabilizing cavity 6 can guide the airflow to flow more evenly towards the flow stabilizing tube bundle 5, reducing the possibility of airflow deviation and improving the stability and efficiency of gas transportation in the entire pipeline. When the airflow passes through the rectification net 4 and the flow stabilizing tube bundle 5, it will generate some noise. The flow stabilizing cavity 6 can play a certain role in sound insulation, absorbing and blocking some of the noise, reducing the noise level of the device during operation, and improving the working environment.

[0043] Furthermore, in this embodiment, the rear end diameter of the flow stabilization and noise reduction section 14 gradually decreases and is connected to the outer periphery of the airflow straightening section 15. For example... Figure 1 As shown, the entire housing 1 has a shape with smaller diameters at both ends and a larger size in the middle. Because the diameter of the rear end of the flow stabilization and noise reduction section 14 gradually decreases and the left end of the airflow conditioning section 15 extends to the flow stabilization and noise reduction section 14, and because a flow stabilizing ball 3 is provided in the housing 1, a rear airflow vortex is formed between the outer periphery of the flow stabilizing ball 3, the rear end of the flow stabilization and noise reduction section 14, and the cylinder 7 constituting the airflow conditioning section 15. Similar to the front and middle airflow vortices, the rear airflow vortex can reduce airflow noise and decrease speed. Specifically, in Figure 1 The image shows the position of the front airflow vortex 81, the position of the middle airflow vortex 82, and the position of the rear airflow vortex 83.

[0044] Before passing through the rectifier mesh, the airflow undergoes a reduction in diameter at the rear end of the flow stabilization and noise reduction section 14, restoring the airflow velocity and pressure levels to near those before the expansion. The airflow maintains a certain degree of stability after entering the airflow straightening section 15, which has a diameter similar to that of the inlet 11.

[0045] Furthermore, the diameter of the flow stabilizer 3 is 1-1.5 times the inner diameter of the air inlet 11. The distance between the flow stabilizer 3 and the airflow regulating section 15 should not be too low; it is advisable to ensure that the gas flow behind the flow stabilizer 3 is not less than the gas flow at the air outlet 12. Specifically, this distance should not be less than 0.7 times the inner diameter of the air outlet 12. This structural form, while ensuring smooth airflow through the device, can also guide the airflow to form medium-airflow vortices within the housing 1, reducing noise during gas delivery and making the gas delivery process more stable.

[0046] In this embodiment, the diameter of the flow stabilizing ball 3 is 1.25 times the inner diameter of the air inlet 11, and the distance between the flow stabilizing ball 3 and the airflow regulating section 15 is 0.8 times the inner diameter of the air outlet. In other embodiments, the diameter of the flow stabilizing ball 3 can also be adjusted within the above-mentioned numerical range, for example, set to 1, 1.05, 1.1, 1.15, 1.2, or 1.25 times the inner diameter of the air inlet 11. All of these can ensure that the airflow passes smoothly through the device, while also guiding the airflow to form medium-airflow vortices within the housing 1, reducing noise during gas delivery and making the gas delivery process more stable.

[0047] In this embodiment, the flow stabilizing ball 3 is made of stainless steel or other high-temperature resistant materials, which has good fire resistance and wear resistance, and higher safety and stability.

[0048] In this embodiment, the front rectifier mesh 2 and the rear rectifier mesh 4 can achieve the effect of flame arrest and enhance heat dissipation. Specifically, the distance between the two rectifier meshes is increased, and a flow stabilizing ball 3 is set to form a larger cavity, which is conducive to heat dissipation. After the flame passes through the front rectifier mesh 2, the part that is not completely extinguished enters the cavity. Due to the increased space, heat can be exchanged more fully with the surrounding air, and the temperature is further reduced, thereby improving the flame arrest success rate of the rear rectifier mesh 4.

[0049] The duct noise reduction and rectification device is internally equipped with a metal front rectifier mesh 2 and a rear rectifier mesh 4. When a flame of a certain intensity and speed propagates, the rectifier mesh decomposes the flame through the wall effect and heat exchange effect, achieving a flame-stopping effect. Its small mesh size causes the flame to stretch and deform, while heat is absorbed and rapidly dissipated by the rectifier mesh, resulting in a decrease in flame temperature. Between the front rectifier mesh 2 and the rear rectifier mesh 4, there is a reasonably designed enlarged rear chamber. This increased space allows for more efficient heat exchange with the surrounding air, further reducing the temperature and improving the flame-stopping success rate of the rear rectifier mesh 4.

[0050] The expansion treatment at the front end of the housing 1 in this pipeline noise reduction and rectification device minimizes noise and velocity of the transported gas within the expanded chamber. As the airflow passes through this chamber, a relatively still airflow layer forms near the flow stabilizing sphere 3. Here, the high-speed and still airflows merge, causing the airflow to slow down. This reduction in velocity also reduces noise to some extent. After passing through the flow stabilizing tube bundle 5, the airflow flows uniformly, serving to rectify and stabilize the airflow. This prevents downstream ultrasonic flow meters and other instruments based on velocity measurement principles from experiencing measurement errors due to instantaneous changes in flow velocity.

[0051] In the field of gas applications, this pipeline noise reduction and rectification device, while rectifying and reducing airflow noise, also adds a flame-retardant effect, ensuring both accurate metering and safety performance. Combining these two functions into one device saves costs and installation space while ensuring accurate flow measurement, representing a breakthrough in the field of gas metering safety. It also reduces mechanical impact and wear on metering equipment caused by unstable airflow, extending the service life of the metering equipment.

[0052] like Figures 2a to 4b As shown, in this embodiment, the pipeline noise reduction and rectification device is simulated using SolidWorks Flow Simulation, and the solution calculation is performed using the finite volume method (FVM). The calculation conditions are as follows:

[0053] Boundary conditions: wall roughness 200 μm; initial conditions: inlet volumetric flow rate set to a constant value; outlet constant pressure set to 0.4 MPa. The gas flow velocity is 0.75 m / s². 3 / h、6m 3 / h and 30m 3 / h.

[0054] As shown in the figure, after the airflow enters the expansion section 13, the airflow velocity is almost zero at the front airflow vortex generated by the stabilizing hole 21, and then enters the expansion rear chamber after passing through the front rectifier mesh 2. The high-speed airflow decreases in velocity after expansion, which reduces the noise energy generated by the airflow and weakens the noise intensity. At the same time, the airflow channel becomes larger, and the airflow velocity distribution becomes more uniform. As can be seen from the simulation diagram, the airflow velocity in the expansion rear chamber decreases and is evenly distributed. While the airflow velocity decreases, the noise also decreases. The airflow velocity between the stabilizing ball 3 and the front rectifier mesh 2 decreases and comes into contact with the surface of the stabilizing ball 3, forming a middle airflow vortex at this point, where the flow velocity is close to a stationary state. The airflow disperses in the shell 1 to the outer periphery of the stabilizing ball 3. The airflow forms a rear airflow vortex between the outer periphery of the stabilizing ball 3, the rear end of the flow stabilization and noise reduction section 14, and the cylinder 7 constituting the airflow sorting section 15. Similar to the front and middle airflow vortices, this reduces the noise and velocity of the airflow. When the airflow enters the airflow sorting section 15, the airflow velocity and pressure level will return to levels close to those before expansion while still maintaining a certain degree of stability.

[0055] As can be seen from the simulation diagram, the airflow velocity at the front, middle and rear airflow vortices is almost 0. The airflow velocity in the airflow straightening section 15 is basically stable, and the velocity after passing through the flow stabilizing tube bundle 5 is maintained at the velocity when the airflow enters the device.

[0056] In addition, this embodiment also discloses a pipeline flow metering system, which includes an ultrasonic flow meter and the aforementioned pipeline noise reduction and rectification device. Both are installed on a gas delivery pipeline, with the pipeline noise reduction and rectification device located at a predetermined distance upstream of the ultrasonic flow meter. This pipeline flow metering system, through the upstream pipeline noise reduction and rectification device, can reduce noise in the pipeline, making the airflow more stable and creating a stable measurement environment for the downstream ultrasonic flow meter, ultimately improving the accuracy of flow metering.

[0057] It's important to note that the intensity of aerodynamic noise generated by high-speed gas flow within a pipeline is directly proportional to the square of the flow velocity. As the gas velocity increases, the noise sound pressure level increases exponentially by the square of the velocity. For example, doubling the flow velocity will increase the noise sound pressure level by approximately 6 decibels. This relationship is crucial in practical engineering. For instance, when designing natural gas pipeline systems, it's essential to carefully control the gas flow velocity to avoid excessive noise and minimize its impact on the surrounding environment and equipment. Furthermore, for pipeline systems already experiencing noise issues, reducing the flow velocity can effectively lower the noise intensity. As the flow rate increases, the fluid's flow state within the pipeline changes, eventually leading to complex flow phenomena such as turbulence. Turbulence causes internal pressure fluctuations in the fluid, generating noise. This noise is an irregular, broadband sound wave signal, potentially covering multiple frequency bands from low to high frequencies, and may also contain components similar to ultrasonic frequencies. As a sound wave, noise can superimpose with ultrasonic waves as it propagates through the medium. Due to the irregularity of noise, it alters the properties of the medium through which ultrasound propagates, causing localized, random fluctuations in parameters such as density and elastic modulus. This leads to scattering and absorption of ultrasound waves during propagation, resulting in signal attenuation. In ultrasonic flow measurement, flow rate is typically calculated by measuring the time difference or phase difference of ultrasound waves propagating in the fluid. When noise is present, it can interfere with the echo signal. On one hand, noise may distort the waveform of the echo signal, making it no longer a regular sine wave or other standard waveform, increasing the difficulty of signal processing and identification. On the other hand, noise may superimpose on the echo signal, causing random changes in the amplitude and phase of the echo signal.

[0058] In existing technology, the ultrasonic flow meter with model AS-40-500BA / 5N-YG incorporates a noise reducer. This noise reducer lowers noise in the pipeline, thereby improving the measurement accuracy of the ultrasonic flow meter. The main internal structure of this noise reducer is a cylindrical filter element, arranged axially. Its end near the air inlet is conical and closed. Gas enters the filter element through a multi-layered mesh structure on the sidewall and continues to be delivered downstream. After prolonged use, the filter element is prone to clogging, affecting gas delivery and requiring periodic replacement. However, because the cylindrical filter element is made of a multi-layered mesh structure and has a large area, different filter elements are prone to shape differences during manufacturing, resulting in poor consistency. Furthermore, the mesh structure is susceptible to deformation during subsequent transportation and storage. Therefore, when replacing the noise reducer, the specific structures of the old and new filter elements often differ, leading to measurement errors in the downstream ultrasonic flow meter. To resolve this error, the newly replaced noise rectifier and ultrasonic flow meter need to be calibrated. Calibration often requires returning to the original manufacturer, impacting gas delivery efficiency and increasing operating costs. In other words, the noise rectifier included with this model of ultrasonic flow meter has poor interchangeability.

[0059] The pipeline noise reduction and rectification device in this application has the advantage of good interchangeability. Specifically, in this pipeline noise reduction and rectification device, the mesh structure only involves the flame arrestor mesh 22 and the post-rectifier mesh 4, and both are significantly smaller in size than the filter elements in the prior art. Furthermore, both are single-layer structures, making it easier to control consistency during manufacturing and reducing deformation during transportation and storage. Other components, such as the flow stabilizing socket 21, the flow stabilizing ball 3, and the flow stabilizing tube bundle 5, do not have the problem of easy deformation, and components of the same specification and size exhibit good consistency during manufacturing. Therefore, when the pipeline noise reduction and rectification device becomes blocked and needs to be replaced, the metering characteristics of the new pipeline noise reduction and rectification device remain consistent with the old one, without affecting the measurement accuracy of the downstream ultrasonic flow meter. Thus, the pipeline noise reduction and rectification device in this application has good interchangeability.

[0060] In this embodiment, the interchangeability of the pipeline noise reduction and rectification device in the pipeline flow metering system was tested. During the test, three pipeline noise reduction and rectification devices of the same specification were installed successively on a DN40 diameter pipeline. When different preset flow rates of gas were transported in the pipeline, the ultrasonic flow meter in the system was used to measure the repeatability of the three pipeline noise reduction and rectification devices of the same specification. The specific test method refers to the metrological verification procedure JJG1030-2007, and the relevant test data is shown in Table 1. The repeatability of the three pipeline noise reduction and rectification devices of the same specification all meet the numerical range specified in the metrological verification procedure, proving that the pipeline noise reduction and rectification device in this application has good repeatability. When the old pipeline noise reduction and rectification device becomes blocked after use, the new pipeline noise reduction and rectification device can be directly replaced without recalibration, thus reducing the cost of use.

[0061] Table 1:

[0062]

[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A pipeline noise reduction and rectification device, characterized in that, include: The housing has an air inlet at the front end and an air outlet at the rear end. It includes an expanding section and a flow stabilizing and noise reduction section arranged sequentially from front to back. The inner diameter of the expanding section gradually increases from the air inlet downstream. The inner diameter of the flow stabilizing and noise reduction section is larger than the inner diameter of the air inlet. The housing also includes an airflow regulating section located downstream of the flow stabilizing and noise reduction section. The airflow regulating section is a cylindrical body with one end connected to the air outlet and the other end extending into the flow stabilizing and noise reduction section. The inner diameter of the cylindrical body is smaller than the inner diameter of the flow stabilizing and noise reduction section. A front rectifier mesh is located on the side of the flow stabilization and noise reduction section near the air inlet; a flow stabilization recess is provided on the front rectifier mesh opposite to the air inlet, and the outer periphery of the flow stabilization recess is a flame arrestor mesh. The flow stabilization recess includes several tubes arranged side by side. The end of the flow stabilization recess near the air inlet forms a concave arc surface, and the end of the flow stabilization recess away from the air inlet is closed. A flow stabilizing ball is fixedly installed in the flow stabilizing and noise reduction section, located behind the front rectifier mesh, with its rear end facing the air outlet; The rear rectifier mesh, located in the airflow straightening section, has a mesh structure; A flow stabilizing tube bundle, located downstream of the rear rectifier mesh, consists of several tubes filling the airflow straightening section, with the tubes arranged along the length of the airflow straightening section; a preset distance is provided between the rear rectifier mesh and the flow stabilizing tube bundle. When the gas enters the pipeline noise reduction and rectification device, it faces the flow stabilizing hole. Due to the structure of the flow stabilizing hole, the airflow will form a front airflow vortex here. There is a gap between the flow stabilizing ball and the front rectification net, where the airflow can form a middle airflow vortex. The airflow forms a rear airflow vortex between the outer periphery of the flow stabilizing ball, the rear end of the flow stabilizing and noise reduction part, and the cylinder.

2. The pipeline noise reduction and rectification device as described in claim 1, characterized in that, The front rectifier mesh also includes a fixed base disposed between the stabilizing socket and the flame arrestor mesh, and the front end of the stabilizing ball is connected to the fixed base.

3. The pipeline noise reduction and rectification device as described in claim 1, characterized in that, The diameter of the flow stabilizing socket is 0.85-1.15 times the inner diameter of the air inlet.

4. The pipeline noise reduction and rectification device as described in claim 1, characterized in that, The rear diameter of the flow stabilization and noise reduction section gradually decreases and is connected to the outer periphery of the airflow sorting section.

5. The pipeline noise reduction and rectification device as described in any one of claims 1 to 4, characterized in that, The diameter of the flow stabilizing ball is 1-1.5 times the inner diameter of the air inlet.

6. A pipeline flow metering system, characterized in that, include: Ultrasonic flow meter; The pipeline noise reduction and rectification device as described in any one of claims 1 to 5 is located at a predetermined distance upstream of the pipeline where the ultrasonic flow meter is located.

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