Noise reduction device and centrifugal compressor

Abstract

The invention discloses a noise reduction device and a centrifugal compressor, relates to the technical field of compressor equipment, and mainly aims to absorb high-energy noise generated by rotation of an impeller and at double and double blade passing frequencies, reduce the intensity of noise transmitted outwards by an air inlet pipeline and an air outlet pipeline of the centrifugal compressor and improve the noise reduction efficiency. And noise pollution to the surrounding environment and on-site workers in the operation process of the centrifugal compressor is reduced. According to the main technical scheme, the noise reduction device comprises a sound absorption pipeline, a first sound absorption module and a second sound absorption module are sequentially arranged in the sound absorption pipeline in the overflowing direction, the first sound absorption module comprises a first perforated plate, the first perforated plate is used for absorbing noise within a first frequency range, and the second perforated plate is used for absorbing noise within a second frequency range. The second sound absorption module comprises a second perforated plate and a third perforated plate, the third perforated plate is arranged on the radial outer side of the second perforated plate, and the third perforated plate and the second perforated plate are used for absorbing noise in a second frequency range.

Description

Technical Field

[0001] The present application belongs to the technical field of compressor equipment, and in particular relates to a noise reduction device and a centrifugal compressor. Background Art

[0002] In the fields of petrochemical, natural gas storage and transportation, electricity and other fields that have a key impact on the national economy, large centrifugal compressor units play an important role as core power equipment. However, when the units are running, they will generate a lot of aerodynamic noise, which will radiate outward through the intake and exhaust pipes, causing serious noise pollution. This pollution not only endangers the physical and mental health of on-site workers, but also has a great adverse impact on the surrounding living environment.

[0003] At present, the aerodynamic noise generated by large centrifugal compressors mainly consists of discrete noise and broadband noise. Among them, the discrete noise generated by dynamic and static interference dominates the overall noise, especially the noise of one and two times the blade passing frequency caused by the rotation of the impeller, whose sound energy is at the highest level among all noise components. Summary of the invention

[0004] In view of this, the present application provides a noise reduction device and a centrifugal compressor. The main purpose of the noise reduction device is to absorb the high-energy noise generated by the rotation of the impeller at one and two times the blade passing frequency, reduce the noise intensity propagated outward from the inlet and exhaust pipes of the centrifugal compressor, and reduce the noise pollution to the surrounding environment and on-site workers during the operation of the centrifugal compressor.

[0005] In order to achieve the above objectives, this application mainly provides the following technical solutions:

[0006] In a first aspect of the present application, a noise reduction device is provided, comprising a sound absorbing pipe, wherein a first sound absorbing module and a second sound absorbing module are sequentially arranged in the sound absorbing pipe along a flow direction, wherein the first sound absorbing module comprises a first perforated plate, wherein the first perforated plate is used to absorb noise in a first frequency range, and the second sound absorbing module comprises a second perforated plate and a third perforated plate, wherein the third perforated plate is arranged radially outside the second perforated plate, and the third perforated plate and the second perforated plate are used to absorb noise in a second frequency range.

[0007] Optionally, the thickness of the first perforated plate is 0.5 mm to 1.5 mm, and the perforation rate of the first perforated plate is 3% to 15%;

[0008] The thickness of the second perforated plate is 1 mm to 2.5 mm, and the perforation rate of the second perforated plate is 3% to 15%;

[0009] The thickness of the third perforated plate is 0.5 mm to 1.5 mm, and the perforation rate of the third perforated plate is 1% to 5%.

[0010] Optionally, the first perforated plate is provided with a plurality of first sound absorbing holes, the diameter of the first sound absorbing holes is 1 mm to 2.5 mm, and the interval between two adjacent first sound absorbing holes is 11 mm;

[0011] The second perforated plate is provided with a plurality of second sound absorbing holes, the diameter of the second sound absorbing holes is 1 mm to 2.5 mm, and the interval between two adjacent second sound absorbing holes is 12 mm;

[0012] The third perforated plate is provided with a plurality of third sound absorbing holes, the diameter of the third sound absorbing holes is 0.5 mm to 1.5 mm, and the interval between two adjacent third sound absorbing holes is 13 mm.

[0013] Optionally, a plurality of the first sound absorption holes, a plurality of the second sound absorption holes and a plurality of the third sound absorption holes are distributed in an equilateral triangle.

[0014] Optionally, the first sound absorbing module further includes a first honeycomb core and an annular back plate, wherein the first honeycomb core is arranged radially outside the first perforated plate, and the annular back plate is arranged between the outer wall of the first honeycomb core and the inner wall of the sound absorbing pipe.

[0015] Optionally, the thickness of the first honeycomb core is 11 mm to 61 mm, and the basic unit shape of the first honeycomb core is a regular hexagon.

[0016] Optionally, the second sound absorbing module further includes a second honeycomb core and an annular rib plate, the second honeycomb core is arranged between the second perforated plate and the third perforated plate, and the annular rib plate is arranged between the outer wall of the third perforated plate and the inner wall of the sound absorbing pipe.

[0017] Optionally, the basic unit shape of the second honeycomb core is also a regular hexagon, and the thickness of the second honeycomb core and the annular rib plate is 5 mm to 30 mm.

[0018] Optionally, the noise reduction device further includes a docking flange, and the docking flange is arranged at the end of the sound absorbing pipe.

[0019] A second aspect of the present application provides a centrifugal compressor comprising any one of the noise reduction devices described above.

[0020] By means of the above technical solution, the present application has at least the following beneficial effects:

[0021] An embodiment of the present application provides a noise reduction device and a centrifugal compressor. The noise reduction device can absorb noise in a first frequency range and a second frequency range respectively by setting a first sound absorption module and a second sound absorption module, so as to achieve continuous processing of high-energy noise at one and two times the blade passing frequency generated by the rotation of the impeller of the centrifugal compressor during the propagation process, thereby reducing the noise intensity radiated outward by the centrifugal compressor and reducing noise pollution to the surrounding environment and on-site workers during the operation of the centrifugal compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of a noise reduction device according to an optional embodiment of the present application;

[0023] Figure 2 for Figure 1 A partial enlarged view of the first perforated plate in the noise reduction device shown;

[0024] Figure 3 A schematic structural diagram of a first perforated plate of an optional embodiment of the present application;

[0025] Figure 4 for Figure 1 A partial enlarged view of the first honeycomb core in the noise reduction device shown;

[0026] Figure 5 This is a schematic structural diagram of a first honeycomb core of an optional embodiment of the present application;

[0027] Figure 6 for Figure 1 A partial enlarged view of the second perforated plate in the noise reduction device shown;

[0028] Figure 7 A schematic structural diagram of a second perforated plate of an optional embodiment of the present application;

[0029] Figure 8 for Figure 1 A partial enlarged view of the third perforated plate in the noise reduction device shown;

[0030] Fig. 9 A schematic structural diagram of a third perforated plate of an optional embodiment of the present application;

[0031] Fig.10 for Figure 1 A partial enlarged view of the second honeycomb core in the noise reduction device shown;

[0032] Fig.11 This is a schematic structural diagram of a second honeycomb core according to an optional embodiment of the present application.

[0033] The reference numerals are as follows:

[0034] 1. Sound absorbing pipe; 2. First sound absorbing module; 21. First perforated plate; 211. First sound absorbing hole; 22. First honeycomb core; 23. Annular back plate; 3. Second sound absorbing module; 31. Second perforated plate; 311. Second sound absorbing hole; 32. Third perforated plate; 321. Third sound absorbing hole; 33. Second honeycomb core; 34. Annular rib plate; 4. Connecting flange. DETAILED DESCRIPTION

[0035] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application and are not used to limit the present application.

[0039] The embodiment of the first aspect of the present application provides a noise reduction device, and the embodiment of the second aspect of the present application provides a centrifugal compressor.

[0040] Among them, the noise reduction device is used for centrifugal compressors.

[0041] Specifically, the noise reduction device is arranged on the inlet and exhaust pipes of the centrifugal compressor, aiming to effectively control the noise generated during the operation of the centrifugal compressor from the source. It is understandable that when the centrifugal compressor is working, the inlet and exhaust pipes are the main pathways for the propagation of aerodynamic noise, especially the high-energy noise at one and two times the blade passing frequency caused by the rotation of the impeller, which will propagate in the pipe with the airflow and radiate to the outside. The above-mentioned noise reduction device is installed on the inlet and exhaust pipes, and can directly act on the noise, effectively intercept and absorb the energy of the passing noise waves, thereby reducing the noise intensity radiated outward from the inlet and exhaust pipes, thereby effectively alleviating the noise pollution problem caused by the centrifugal compressor to the surrounding environment and on-site workers, and ensuring the comfort and safety of the working environment.

[0042] Here, combined with reference Figures 1 to 11 As shown, the noise reduction device provided by the embodiment of the first aspect of the present application includes a sound absorbing pipe 1, in which a first sound absorbing module 2 and a second sound absorbing module 3 are sequentially arranged along the flow direction, the first sound absorbing module 2 includes a first perforated plate 21, and the first perforated plate 21 is used to absorb noise in a first frequency range, the second sound absorbing module 3 includes a second perforated plate 31 and a third perforated plate 32, the third perforated plate 32 is arranged on the radial outside of the second perforated plate 31, and the third perforated plate 32 and the second perforated plate 31 are used to absorb noise in a second frequency range.

[0043] In this embodiment, the noise reduction device can absorb noise in the first frequency range and the second frequency range respectively by setting the first sound absorption module 2 and the second sound absorption module 3, so as to realize continuous processing of the high-energy noise at one and two times the blade passing frequency generated by the rotation of the impeller of the centrifugal compressor during the propagation process, thereby reducing the noise intensity radiated outward by the centrifugal compressor and reducing the noise pollution to the surrounding environment and on-site workers during the operation of the centrifugal compressor.

[0044] The sound absorbing pipe 1 is the basic structure of the entire noise reduction device, and provides a specific space for noise processing. Specifically, the first sound absorbing module 2 and the second sound absorbing module 3 can be arranged in the sound absorbing pipe 1 to realize the noise reduction function. In practical applications, when the noise passes through the sound absorbing pipe 1, it will fully contact the first sound absorbing module 2 and the second sound absorbing module 3 inside the sound absorbing pipe 1, so that the first sound absorbing module 2 and the second sound absorbing module 3 can effectively process the noise.

[0045] Among them, the first sound absorption module 2 includes a first perforated plate 21, the first perforated plate 21 is a ring structure, and a plurality of first sound absorption holes 211 are distributed on the first perforated plate 21. In the process of noise reduction, when the noise propagates to the first sound absorption module 2 in the form of sound waves, the following phenomenon will occur: part of the sound waves will enter the space formed by the outer wall of the first perforated plate 21 and the inner wall of the sound absorption channel through the first sound absorption holes 211, and will experience multiple reflections here. It can be understood that during the reflection process, the energy form of the sound wave changes, and the sound energy is gradually converted into other forms of energy, such as heat energy. In this way, effective absorption of noise in the first frequency range is achieved, thereby reducing the energy intensity of the noise in this frequency band during the entire propagation process, and contributing to the overall noise reduction effect.

[0046] Specifically, the noise in the first frequency range may be high-energy noise generated by the rotation of the impeller of the centrifugal compressor at a frequency that is one times the blade passing frequency.

[0047] Among them, the second sound absorption module 3 includes a second perforated plate 31 and a third perforated plate 32, both of which are annular structures, and the second perforated plate 31 and the third perforated plate 32 are radially distributed. In this embodiment, a plurality of second sound absorption holes 311 are distributed on the second perforated plate 31, and a plurality of third sound absorption holes 321 are distributed on the third perforated plate 32, and the third perforated plate 32 is located radially outside the second perforated plate 31. In the noise reduction process, when the noise propagates to the second sound absorption module 3 in the form of sound waves, it first interacts with the second perforated plate 31. Similar to the sound absorption principle of the first perforated plate 21, the second perforated plate 31 will guide part of the sound waves into the second sound absorption holes 311. In this process, a part of the sound energy is absorbed through a series of physical processes such as air vibration, friction and reflection. At this time, the third perforated plate 32 located radially outside the second perforated plate 31 can further enhance the absorption capacity of the noise in the second frequency range. Specifically, the third perforated plate 32 can change the propagation path of the sound wave near the second perforated plate 31, so that the sound wave is reflected and refracted multiple times between the second perforated plate 31 and the third perforated plate 32. As a result, the contact time and number of times of the sound wave and the second sound absorbing module 3 are increased, so that the noise in the second frequency range can be absorbed more comprehensively and fully, and the absorption effect of the entire second sound absorbing module 3 on the noise in the frequency range is effectively improved.

[0048] Specifically, the noise in the second frequency range may be high-energy noise generated by the rotation of the impeller of the centrifugal compressor at twice the blade passing frequency.

[0049] It should be noted that, in this embodiment, the first sound absorption module 2 is a single-layer first perforated plate 21, and the principle of noise absorption is based on that after the sound wave enters the first sound absorption hole 211, it is reflected multiple times between the outer wall of the first perforated plate 21 and the inner wall of the sound absorption channel to achieve energy conversion. This structure is more effective for absorbing noise of lower frequencies, because the wavelength of low-frequency noise is longer, and there is enough space and time for energy conversion processes such as reflection in a relatively simple structure. The second sound absorption module 3 is a double-layer structure composed of a second perforated plate 31 and a third perforated plate 32, and is radially distributed. This double-layer structure can change the propagation path of the sound wave, so that the sound wave is reflected and refracted multiple times between the second and third perforated plates 32. Since the wavelength of high-frequency noise is shorter, it is easier to interact with the above structure in this double-layer structure. For example, high-frequency sound waves can be reflected multiple times within a short distance between the double-layer perforated plates, which increases the chance of sound energy loss and is conducive to absorbing high-frequency noise.

[0050] In some possible embodiments disclosed in the present application, the thickness of the first perforated plate 21 is 0.5 mm to 1.5 mm, and the perforation rate of the first perforated plate 21 is 3% to 15%; the thickness of the second perforated plate 31 is 1 mm to 2.5 mm, and the perforation rate of the second perforated plate 31 is 3% to 15%; the thickness of the third perforated plate 32 is 0.5 mm to 1.5 mm, and the perforation rate of the third perforated plate 32 is 1% to 5%.

[0051] The thickness of the first perforated plate 21 is in the range of 0.5 mm to 1.5 mm. It should be noted that a thinner first perforated plate 21 (such as 0.5 mm) is better for absorbing low-frequency noise. Because the wavelength of low-frequency noise is longer, the thinner first perforated plate 21 is relatively easier to vibrate under the action of sound waves, and can better couple with low-frequency sound waves, thereby effectively absorbing low-frequency noise.

[0052] Specifically, the perforation rate of the first perforated plate 21 is between 3% and 15%. A lower perforation rate (such as 3%) means that there are relatively fewer first sound absorbing holes 211 on the first perforated plate 21. In this case, when the sound wave reaches the first perforated plate 21, the proportion of the sound wave entering the first sound absorbing hole 211 is smaller, and more sound waves will be reflected on the outer wall of the first perforated plate 21. This is more beneficial for absorbing low-frequency noise, because the energy of low-frequency noise is mainly concentrated in a larger spatial range, and fewer first sound absorbing holes 211 can make the sound wave have more sufficient reflection between the outer wall of the first perforated plate 21 and the inner wall of the sound absorption channel, thereby converting the sound energy into other forms of energy.

[0053] Among them, the thickness of the second perforated plate 31 is between 1 mm and 2.5 mm. It should be noted that the relatively thick range makes the second perforated plate 31 more advantageous for absorbing higher frequency noise. The wavelength of high-frequency noise is shorter, and the thicker second perforated plate 31 can provide more reflection interfaces. When the high-frequency sound wave enters the second sound absorbing hole 311, it will experience more reflections and refractions on the thicker second perforated plate 31, increasing the loss of sound energy. Moreover, when the thicker second perforated plate 31 cooperates with the third perforated plate 32, the propagation path of the sound wave between the two can be better controlled, which is beneficial to the absorption of high-frequency noise.

[0054] Specifically, the perforation rate of the second perforated plate 31 is also between 3% and 15%. The second perforated plate 31 is mainly used to absorb higher frequency noise. The lower perforation rate (3%) can make the high-frequency sound waves entering the second sound absorbing holes 311 have stronger reflection and vibration in the second sound absorbing holes 311, because the relatively small number of second sound absorbing holes 311 can make the air in each second sound absorbing hole 311 vibrate more violently, thereby increasing the loss of sound energy.

[0055] The thickness of the third perforated plate 32 is 0.5 mm to 1.5 mm. It should be noted that the third perforated plate 32 in this thickness range can work in conjunction with the second perforated plate 31 without affecting the compactness of the overall structure of the noise reduction device. The thinner part (0.5 mm) can produce a sensitive response to high-frequency noise because it is relatively light and is easy to vibrate under the action of high-frequency sound waves, thereby increasing the sound energy loss.

[0056] Specifically, the perforation rate of the third perforated plate 32 is 1% to 5%. The lower perforation rate allows the third perforated plate 32 to mainly play the role of changing the propagation path of the sound wave. Fewer third sound absorbing holes 321 can guide the sound waves to be reflected and refracted multiple times in the space between the second perforated plate 31 and the third perforated plate 32, rather than a large number of sound waves directly passing through the third sound absorbing holes 321. Thus, the space between the double-layer perforated plates can be fully utilized to absorb high-frequency noise, thereby enhancing the absorption capacity of the second sound absorbing module 3 for noise in the second frequency range.

[0057] In some possible embodiments disclosed in the present application, the diameter of the first sound absorption hole 211 is 1 mm to 2.5 mm, and the distance between two adjacent first sound absorption holes 211 is 11 mm; the diameter of the second sound absorption hole 311 is 1 mm to 2.5 mm, and the distance between two adjacent second sound absorption holes 311 is 12 mm; the diameter of the third sound absorption hole 321 is 0.5 mm to 1.5 mm, and the distance between two adjacent third sound absorption holes 321 is 13 mm.

[0058] The diameter of the first sound absorbing hole 211 is between 1 mm and 2.5 mm. When sound waves enter the first sound absorbing hole 211 with a smaller diameter, it will cause the air in the first sound absorbing hole 211 to vibrate violently. High-frequency noise is more likely to resonate with the air column in such a small space, thereby converting sound energy into other forms of energy such as heat energy.

[0059] Specifically, the interval between two adjacent first sound absorbing holes 211 is 11 mm, which can control the sound absorption performance of the first perforated plate 21, and ensure that when the first perforated plate 21 absorbs noise in the first frequency range, the sound waves have a suitable reflection and propagation path between the outer wall of the first perforated plate 21 and the inner wall of the sound absorption channel. If the interval is too small, the sound waves may interfere with each other between adjacent first sound absorbing holes 211, affecting the sound absorption effect; if the interval is too large, the chance of sound waves entering the first sound absorbing holes 211 may be reduced, reducing the sound absorption efficiency.

[0060] The diameter of the second sound absorbing hole 311 is also 1 mm to 2.5 mm. For absorbing noise in the second frequency range (relatively high frequency), the second sound absorbing hole 311 with a smaller diameter (1 mm) can enhance the absorption of high frequency components. After entering the second sound absorbing hole 311, high frequency sound waves will produce complex reflections and vibrations in the second sound absorbing hole 311, increasing sound energy loss.

[0061] Specifically, two adjacent second sound absorbing holes 311 are spaced 12 mm apart. For the second perforated plate 31 to absorb noise in the second frequency range, this spacing distance can optimize the propagation of high-frequency sound waves on the second perforated plate 31. Compared with the spacing of the first sound absorbing holes 211, a slightly larger spacing distance can allow high-frequency sound waves to have more space to reflect and propagate on the surface of the second perforated plate 31, and better interact with the second sound absorbing holes 311, thereby more effectively absorbing high-frequency noise.

[0062] Among them, the diameter of the third sound absorption hole 321 is between 0.5mm and 1.5mm. The smaller diameter range makes the third sound absorption hole 321 more targeted in absorbing high-frequency noise. After the high-frequency sound wave enters the third sound absorption hole 321, due to the smaller space of the third sound absorption hole 321, the vibration of the air column is more intense, and the sound energy loss is more obvious. This smaller diameter third sound absorption hole 321 combined with the lower perforation rate of the third perforated plate 32 can effectively guide the high-frequency sound waves to be reflected and refracted multiple times in the space between the second perforated plate 31 and the third perforated plate 32, thereby enhancing the absorption effect of high-frequency noise.

[0063] Specifically, two adjacent third sound absorbing holes 321 are spaced 13 mm apart. This relatively large spacing distance can enable the third perforated plate 32 to better play its role in changing the propagation path of sound waves. Under the premise of ensuring a certain density of the third sound absorbing holes 321, the larger spacing distance can guide high-frequency sound waves to be more fully reflected and refracted in the space between the second perforated plate 31 and the third perforated plate 32, avoiding the sound waves from passing through the third sound absorbing holes 321 too concentratedly, thereby enhancing the absorption effect of high-frequency noise in the second frequency range.

[0064] In the above embodiments, see Figure 3 , Figure 7 and Fig. 9 As shown, the plurality of first sound absorbing holes 211 , the plurality of second sound absorbing holes 311 , and the plurality of third sound absorbing holes 321 are all distributed in an equilateral triangle.

[0065] In this embodiment, when the first sound absorption hole 211, the second sound absorption hole 311 and the third sound absorption hole 321 are distributed in an equilateral triangle, a more uniform sound absorption hole layout can be achieved on the perforated plate. For the first sound absorption hole 211, this uniform distribution enables the first perforated plate 21 to absorb noise in the first frequency range, regardless of the direction from which the sound wave propagates, to enter the first sound absorption hole 211 more evenly. There will be no situation where some areas have excessive sound absorption and some areas have insufficient sound absorption due to the uneven distribution of the first sound absorption hole 211, thereby ensuring the uniformity and stability of the first perforated plate 21 in absorbing noise in the first frequency range. Similarly, for the second sound absorption hole 311 and the third sound absorption hole 321, the second perforated plate 31 and the third perforated plate 32 can also provide uniform sound absorption capacity on the entire second perforated plate 31 and the second perforated plate 31 when absorbing noise in the second frequency range. Especially for high-frequency noise, the evenly distributed second sound absorbing holes 311 and the third sound absorbing holes 321 can more effectively capture high-frequency sound waves from different directions, ensuring that the high-frequency noise can be effectively processed within the entire second sound absorbing module 3 .

[0066] Among them, when the sound absorbing holes are distributed in an equilateral triangle, from a geometric point of view, each sound absorbing hole is surrounded by six adjacent sound absorbing holes, and the distances between them are equal. Taking the first sound absorbing hole 211 as an example, on the first perforated plate 21, this distribution forms a regular and repeated pattern. The vertex of each equilateral triangle is the position of a first sound absorbing hole 211. Such a layout makes the first sound absorbing holes 211 distributed very evenly on the first perforated plate 21. The same is true for the second sound absorbing holes 311 and the third sound absorbing holes 321. On the second perforated plate 31 and the third perforated plate 32, this equilateral triangle distribution ensures that the spatial positions of the sound absorbing holes on their respective perforated plates are highly symmetrical. For example, when observing a local area, the distribution density and relative position relationship of the sound absorbing holes are the same regardless of the direction from which they are observed.

[0067] In some possible implementations disclosed in this application, see Figure 1 As shown, the first sound absorbing module 2 further includes a first honeycomb core 22 and an annular back plate 23 . The first honeycomb core 22 is arranged radially outside the first perforated plate 21 , and the annular back plate 23 is arranged between the outer wall of the first honeycomb core 22 and the inner wall of the sound absorbing pipe 1 .

[0068] In this embodiment, an additional propagation path and energy loss mechanism are provided for sound waves by setting the first honeycomb core 22. When sound waves act on the first sound absorbing module 2, part of the sound waves will enter the first honeycomb core 22 after passing through the first perforated plate 21. The first honeycomb core 22 is a honeycomb structure, and its internal space is limited and the shape is complex. In this case, the sound waves entering it will be constantly reflected back and forth in this honeycomb structure, and the energy of the sound waves will continue to decrease, thereby achieving a sound absorption effect. Furthermore, an annular back plate 23 is provided on the radial outer side of the first honeycomb core 22. When the sound waves are reflected in the first honeycomb core 22 and propagate outward, the annular back plate 23 will reflect the sound waves back to the inside of the honeycomb core, so that the sound waves are reflected again and energy is lost between the honeycomb core and the annular back plate 23. As a result, the propagation path of the sound waves in the first sound absorbing module 2 can be extended, and the contact time of the sound waves with the sound absorbing structure can be increased, thereby further improving the absorption efficiency of the noise in the first frequency range.

[0069] The first honeycomb core 22 is an annular structure. In practical applications, the first perforated plate 21, the first honeycomb core 22 and the annular back plate 23 are radially distributed.

[0070] Specifically, the first honeycomb core 22 is located radially outside the first perforated plate 21, and the annular back plate 23 is located outside the first honeycomb core 22. In this structure, the first perforated plate 21, the first honeycomb core 22 and the annular back plate 23 are connected into a whole by full brazing, which improves the overall strength of the first sound absorbing module 2, can meet the requirements of long-term safe and stable operation, and can avoid the aging problem of the first sound absorbing module 2 caused by long-term use of the noise reduction device.

[0071] In the above embodiments, see Figure 5 As shown, the thickness of the first honeycomb core 22 is 11 mm to 61 mm, and the basic unit shape of the first honeycomb core 22 is a regular hexagon.

[0072] The basic unit of the first honeycomb core 22 is the minimum repeating unit constituting the first honeycomb core 22. In this embodiment, by setting the basic unit of the first honeycomb core 22 to be a regular hexagon, the space of the first honeycomb core 22 can be utilized to the maximum extent, providing more reflection and propagation interfaces for sound waves. It should be noted that, compared with basic units of other shapes (such as squares or triangles), the regular hexagonal basic unit can provide more wall area for sound wave reflection under the same area, thereby improving the sound absorption efficiency.

[0073] In some possible implementations disclosed in this application, see Figure 1 As shown, the second sound absorption module 3 also includes a second honeycomb core 33 and an annular rib plate 34 . The second honeycomb core 33 is arranged between the second perforated plate 31 and the third perforated plate 32 . The annular rib plate 34 is arranged between the outer wall of the third perforated plate 32 and the inner wall of the sound absorption pipe 1 .

[0074] In this embodiment, the structure of the second honeycomb core 33 is similar to that of the first honeycomb core 22. When the sound wave enters the second honeycomb core 33 after passing through the second perforated plate 31, due to the complex spatial shape inside the second honeycomb core 33, the sound wave will frequently collide with the wall surface in the second honeycomb core 33, and each collision will convert part of the sound energy into heat energy, thereby effectively attenuating the sound energy gradually, thereby enhancing the absorption effect of the second sound absorbing module 3 on high-frequency noise.

[0075] The second honeycomb core 33 is also an annular structure. In practical applications, the second perforated plate 31, the second honeycomb core 33, the third perforated plate 32 and the annular rib plate 34 are radially distributed.

[0076] Specifically, the second honeycomb core 33 is located on the radial outer side of the second perforated plate 31, the third perforated plate 32 is located on the radial outer side of the second honeycomb core 33, and the annular rib plate 34 is located on the radial outer side of the third perforated plate 32. In this embodiment, a plurality of annular rib plates 34 can be provided, and the plurality of annular rib plates 34 are arranged at intervals along the axial direction. By providing the annular rib plates 34, the second honeycomb core 33 and the third perforated plate 32 can be supported to ensure the acoustic stability of the second sound absorption module 3. In addition, it should be noted that in this structure, the second perforated plate 31, the second honeycomb core 33, the third perforated plate 32 and the annular rib plate 34 are connected into a whole by full brazing, which improves the overall strength of the second sound absorption module 3, can meet the requirements of long-term safe and stable operation, and can avoid the aging problem of the second sound absorption module 3 caused by long-term use of the noise reduction device.

[0077] In the above embodiments, see Fig.11 As shown, the basic unit shape of the second honeycomb core 33 is also a regular hexagon, and the thickness of the second honeycomb core 33 and the annular rib plate 34 is 5 mm to 30 mm.

[0078] The basic unit of the second honeycomb core 33 is the smallest repeating unit constituting the second honeycomb core 33. In this embodiment, by setting the basic unit of the second honeycomb core 33 to be a regular hexagon, the space of the second honeycomb core 33 can be utilized to the maximum extent, providing more reflection and propagation interfaces for sound waves. It should be noted that, compared with basic units of other shapes (such as squares or triangles), the regular hexagonal basic unit can provide more wall area for sound wave reflection under the same area, thereby improving the sound absorption efficiency.

[0079] In some possible implementations disclosed in this application, see Figure 1 As shown, the noise reduction device also includes a butt flange, which is arranged at the end of the sound absorbing pipe 1.

[0080] In this embodiment, the connection between the sound absorbing pipe 1 and the inlet and outlet pipes of the centrifugal compressor is facilitated by providing a butt flange.

[0081] Among them, during the installation process, the butt flange can be connected to the corresponding flange of the intake and exhaust pipes by bolts and other connectors, which is simple and quick to operate. Moreover, when the noise reduction device needs to be repaired, replaced or modified, this flange connection method makes it easy to remove the noise reduction device from the intake and exhaust pipes, thereby improving work efficiency.

[0082] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0083] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A noise reduction device, characterized in that: The invention comprises a sound absorbing pipe (1), wherein a first sound absorbing module (2) and a second sound absorbing module (3) are sequentially arranged in the sound absorbing pipe (1) along a flow direction, wherein the first sound absorbing module (2) comprises a first perforated plate (21), wherein the first perforated plate (21) is used to absorb noise in a first frequency range, and the second sound absorbing module (3) comprises a second perforated plate (31) and a third perforated plate (32), wherein the third perforated plate (32) is arranged radially outside the second perforated plate (31), and the third perforated plate (32) and the second perforated plate (31) are used to absorb noise in a second frequency range.

2. The noise reduction device according to claim 1, characterized in that: The thickness of the first perforated plate (21) is 0.5 mm to 1.5 mm, and the perforation rate of the first perforated plate (21) is 3% to 15%; The thickness of the second perforated plate (31) is 1 mm to 2.5 mm, and the perforation rate of the second perforated plate (31) is 3% to 15%; The thickness of the third perforated plate (32) is 0.5 mm to 1.5 mm, and the perforation rate of the third perforated plate (32) is 1% to 5%.

3. The noise reduction device according to claim 1, characterized in that: The first perforated plate (21) is provided with a plurality of first sound absorbing holes (211), the diameter of the first sound absorbing holes (211) is 1 mm to 2.5 mm, and the interval between two adjacent first sound absorbing holes (211) is 11 mm; The second perforated plate (31) is provided with a plurality of second sound absorbing holes (311), the diameter of the second sound absorbing holes (311) is 1 mm to 2.5 mm, and the interval between two adjacent second sound absorbing holes (311) is 12 mm; The third perforated plate (32) is provided with a plurality of third sound absorbing holes (321), the diameter of the third sound absorbing holes (321) is 0.5 mm to 1.5 mm, and the interval between two adjacent third sound absorbing holes (321) is 13 mm.

4. The noise reduction device according to claim 3, characterized in that: The plurality of first sound absorption holes (211), the plurality of second sound absorption holes (311), and the plurality of third sound absorption holes (321) are all distributed in an equilateral triangle.

5. The noise reduction device according to claim 1, characterized in that: The first sound absorption module (2) further comprises a first honeycomb core (22) and an annular back plate (23), wherein the first honeycomb core (22) is arranged radially outside the first perforated plate (21), and the annular back plate (23) is arranged between the outer wall of the first honeycomb core (22) and the inner wall of the sound absorption pipe (1).

6. The noise reduction device according to claim 5, characterized in that: The thickness of the first honeycomb core (22) is 11 mm to 61 mm, and the basic unit shape of the first honeycomb core (22) is a regular hexagon.

7. The noise reduction device according to claim 1, characterized in that: The second sound absorption module (3) further comprises a second honeycomb core (33) and an annular rib plate (34); the second honeycomb core (33) is arranged between the second perforated plate (31) and the third perforated plate (32); and the annular rib plate (34) is arranged between the outer wall of the third perforated plate (32) and the inner wall of the sound absorption pipe (1).

8. The noise reduction device according to claim 7, characterized in that: The basic unit shape of the second honeycomb core (33) is also a regular hexagon, and the thickness of the second honeycomb core (33) and the annular rib plate (34) is 5 mm to 30 mm.

9. The noise reduction device according to claim 1, characterized in that: It also comprises a butt joint flange, which is arranged at the end of the sound absorbing pipe (1).

10. A centrifugal compressor, characterized in that: The method comprises the noise reduction device as described in any one of claims 1 to 9.

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