CN217113823U - Device for efficiently absorbing multiple harmonic noises radiated by electrical equipment - Google Patents
Device for efficiently absorbing multiple harmonic noises radiated by electrical equipment Download PDFInfo
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- CN217113823U CN217113823U CN202220411122.XU CN202220411122U CN217113823U CN 217113823 U CN217113823 U CN 217113823U CN 202220411122 U CN202220411122 U CN 202220411122U CN 217113823 U CN217113823 U CN 217113823U
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Abstract
The utility model discloses a device of many times of harmonic noise of high-efficient absorption power equipment radiation, the device is formed at the spatial arrangement combination by one or more different sound absorption units, the device includes 100Hz sound absorption unit, 100Hz sound absorption unit is including the first panel and the first maze layer of laminating mutually. The first labyrinth layer comprises a first frame, the interior of the first frame is divided by a first partition plate to form a first convolution type labyrinth passage, and a first through hole is formed in the middle of the first panel. The utility model discloses there is great gradient in labyrinth passageway entrance sound pressure level and its terminal department sound pressure level, because the vibration velocity u of air particle and the gradient of sound pressure p are directly proportional, consequently the air vibration velocity in the convolution labyrinth passageway will sharply increase. Considering that the air has the loss of hot viscosity near the wall surface of the channel, the strong air vibration can cause the acoustic energy which is locally positioned in the convoluted labyrinth channel to be converted into the heat energy to be lost, thereby realizing the quasi-perfect sound absorption.
Description
Technical Field
The utility model relates to a noise control field, concretely relates to high-efficient device that absorbs many times of harmonic noise of power equipment radiation.
Background
With the rapid development of economic society of China, the power load is continuously increased, the total number of transformers in transformer substations in different voltage grades and in terminal residential areas of power systems is accumulated to reach tens of millions, and the noise level in the transformer substations is higher.
Research shows that the body noise of power equipment such as a transformer mainly comes from magnetostrictive and electrostrictive noise, the body noise presents obvious low-frequency tonal characteristics, and the sound energy at harmonic frequencies of 2 times and 4 times (100Hz and 200Hz) of 50Hz accounts for more than 90% of the total radiation sound energy. In order to reduce the noise in the transformer room and the power distribution room of the indoor transformer substation, the sound absorption technology can be adopted to reduce the indoor reflected sound, such as using porous sound absorption materials (such as glass wool, rock wool and the like) and resonance sound absorption structures (such as thin plates, thin film resonance sound absorption structures and the like).
The porous sound absorption material is suitable for absorbing medium and high frequency noise, the sound absorption coefficient of low frequency sound is very low, the resonance sound absorption structure is suitable for absorbing medium and low frequency noise, and the sound absorption coefficient of 100Hz and 200Hz noise with lower frequency is still lower.
Further, patent specification CN111785520A discloses a noise reduction device suitable for a power capacitor, in which a totally enclosed vibration-damping housing is provided, and a sponge layer and a vacuum tube are provided in the housing to reduce noise radiation noise. Patent specification CN110767446A discloses a noise reduction device and a noise reduction method for a power filter capacitor, which includes a sound insulation cover mounted on the top of a capacitor housing and a sound absorption cavity structure mounted on the bottom of the capacitor housing. The sound absorption coefficients of the two schemes are still lower for the 100Hz and 200Hz noises with lower frequencies.
Therefore, there is a need to develop a device for absorbing 100Hz and 200Hz low-frequency noise in a power distribution room with high efficiency, so as to reduce noise pollution in the power distribution room.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a device of many times of harmonic noise of high-efficient absorption power equipment radiation. The device can efficiently absorb low-frequency noise radiated by power equipment, particularly the noise with the acoustic energy of 100Hz and 200 Hz.
A device for efficiently absorbing multiple harmonic noises radiated by electric equipment is formed by arranging and combining one or more different sound absorption units in space, and comprises a 100Hz sound absorption unit, wherein the 100Hz sound absorption unit comprises a first panel and a first labyrinth layer which are attached to each other; the first labyrinth layer comprises a first frame, the interior of the first frame is divided by a first partition plate to form a first convoluted labyrinth passage, and a first through hole is formed in the middle of the first panel.
Preferably, the thickness of the first labyrinth layer is 32mm +/-5 mm; the diameter of the first through hole is 3mm +/-1 mm; the turning angles of the first rotary labyrinth passage are right angles, the length of the central line of the first rotary labyrinth passage is 680mm +/-50 mm, and the width of the first rotary labyrinth passage is 13mm +/-3 mm.
Preferably, the device further comprises a 200Hz sound absorption unit, wherein the 200Hz sound absorption unit comprises a second panel and a second labyrinth layer which are attached to each other; the second labyrinth layer comprises a second frame, the interior of the second frame is divided by a second partition plate to form a second convolution type labyrinth passage, and a second through hole is formed in the middle of the second panel;
the thickness of the second labyrinth layer is 20mm +/-4 mm; the diameter of the second through hole is 3mm +/-1 mm; the turning angles of the second convolution type labyrinth passage are right angles, the length of the central line of the second convolution type labyrinth passage is 320mm +/-30 mm, and the width of the second convolution type labyrinth passage is 13mm +/-3 mm.
Simulation calculation results show that at 100Hz, the 100Hz sound absorption unit has normalized surface acoustic impedance Im (Z) s /Z 0 ) Normalized surface to 0Acoustic resistance Re (Z) s /Z 0 ) Approaching 1, indicating that the acoustic impedance of the structure matches that of air, and that most of the acoustic energy enters the interior of the structure. At the above-mentioned 100Hz frequency, the acoustic energy entering the interior of the 100Hz sound-absorbing unit will concentrate in the corresponding channel and create FP resonance. At 200Hz, the 200Hz sound absorption unit normalizes the surface acoustic impedance Im (Z) s /Z 0 ) Trend to 0, normalized surface acoustic resistance Re (Z) s /Z 0 ) Approaching 1, indicating that the acoustic impedance of the structure matches that of air, and that most of the acoustic energy enters the interior of the structure. At the above-mentioned 200Hz frequency, the acoustic energy entering the interior of the 200Hz sound-absorbing unit will concentrate in the corresponding channel and create FP resonance.
In order to clarify the sound energy dissipation mechanism of the structure FP resonance, the sound pressure level and the air particle velocity distribution in the labyrinth channel at 100Hz and 200Hz are further simulated and calculated, at the sound absorption peak of the sound absorption unit at 100Hz and 200Hz, the sound energy is respectively localized in the channel, and the sound pressure level at the inlet of the corresponding labyrinth channel and the sound pressure level at the tail end of the labyrinth channel have larger gradients. Since the vibration velocity u of the air particle is proportional to the gradient of the sound pressure p, i.e.
The air vibration speed in the corresponding channel will increase sharply. Considering that the air has thermal viscosity loss near the wall surface of the channel, the strong air vibration can cause the acoustic energy in the channel to be converted into heat energy to be lost, thereby realizing quasi-perfect sound absorption.
The loss factor of the system is changed by changing the structural parameters of the height of the labyrinth layer, the width of the labyrinth passage and the like
And leakage factor
The balance of (a), and the sound absorption performance of the structure is influenced, wherein the thickness of the first labyrinth layer of the 100Hz sound absorption unit is preferably 32mm +/-5 mm, and the clear width of the channel is preferably 13mm +/-3 mm; the thickness of the second labyrinth layer of the 200Hz sound absorption unit is preferably 20mm +/-4 mm, and the clear width of the channelPreferably 13mm +/-3 mm, the structure is close to the critical coupling state, and the sound absorption performance is optimal.
Preferably, every two adjacent 100Hz sound absorption units are paired, every two adjacent 200Hz sound absorption units are paired, or every two adjacent 100Hz sound absorption units and 200Hz sound absorption units are paired, the paired sound absorption units are communicated through a through hole in a frame at the tail end of the rotary labyrinth channel, and the maximum width of the cross section of the through hole is not more than 30% of the width of the rotary labyrinth channel.
A through hole is formed between the frames corresponding to the tail end of the rotary labyrinth-shaped channel to cause the acoustic impedance at the tail end of the channel to change, and the maximum width of the cross section of the through hole is controlled to be less than 30% of the net width of the channel, so that most of acoustic energy is reflected, and a small part of acoustic energy can be transmitted into the labyrinth-shaped channel of the matched sound absorption unit. The transmission sound enters the matched sound absorption units through the through holes, the channel length is equivalently prolonged, the low-frequency sound absorption capacity below 100Hz or 200Hz is improved, and the sound absorption frequency band is widened while the sound absorption effects of 100Hz and 200Hz are ensured.
Preferably, the device further comprises a Helmholtz resonance sound absorption unit, and the Helmholtz resonance sound absorption unit comprises a first perforated plate and a cavity layer which are attached to each other. The resonance frequency of the Helmholtz resonator is below 500Hz, so that the sound absorption frequency band is widened, and the sound absorption coefficient is improved.
Preferably, the device further comprises a resistive sound absorption unit, wherein the resistive sound absorption unit comprises a second perforated plate and a porous sound absorption material layer which are attached to each other. The porous sound absorption material layer utilizes work loss sound energy such as viscous resistance of air in pores, friction between the air and pore walls and the like, and has good medium-high frequency sound absorption performance and wide sound absorption frequency band, so that medium-high frequency sound absorption coefficient is improved, and the sound absorption frequency band is widened.
Preferably, the resistive sound absorbing unit is located in the same plane as or directly above the 100Hz sound absorbing unit, the 200Hz sound absorbing unit and the helmholtz resonance sound absorbing unit.
Preferably, the 100Hz sound absorption unit, the 200Hz sound absorption unit, the helmholtz resonance sound absorption unit and the resistive sound absorption unit respectively comprise a bottom plate which is respectively attached to the first labyrinth layer, the second labyrinth layer, the cavity layer and the porous sound absorption material layer.
Preferably, the cross sections of the 100Hz sound absorption unit, the 200Hz sound absorption unit, the Helmholtz resonance sound absorption unit and the resistive sound absorption unit are rectangular.
The utility model has the advantages that:
the utility model discloses a device of high-efficient multiple harmonic noise of absorbing power equipment radiation, integrated 100Hz sound absorption unit, 200Hz sound absorption unit, Helmholtz resonance sound absorption unit and hindering nature sound absorption unit in sound absorbing device, when guaranteeing to absorb 100Hz or 200Hz high efficiency (be close perfect sound absorption), realize the wide band sound absorption.
Drawings
Fig. 1 is a schematic structural diagram of embodiment 1 of the present invention;
fig. 2 is a schematic structural view of a first labyrinth layer in embodiment 1 of the present invention;
FIG. 3 is a side view of the 100Hz sound absorption unit of the present invention;
FIG. 4 is a schematic structural view of the 100Hz sound absorption unit of the present invention;
FIG. 5 is a schematic structural view of a first labyrinth layer of the 100Hz sound absorption unit of the present invention;
FIG. 6 is a top view of a first labyrinth layer of the 100Hz sound absorption unit of the present invention;
FIG. 7 is a schematic diagram of the simulation calculation result of sound absorption coefficient of the 100Hz sound absorption unit of the present invention;
fig. 8 is a schematic structural view of embodiment 2 of the present invention;
fig. 9 is a schematic structural view of a second labyrinth layer according to embodiment 2 of the present invention;
FIG. 10 is a side view of a 200Hz sound absorption unit of the present invention;
FIG. 11 is a schematic view of the 200Hz sound absorption unit of the present invention;
FIG. 12 is a schematic structural view of a second labyrinth layer of the 200Hz sound absorption unit of the present invention;
FIG. 13 is a top view of a second labyrinth layer of the 200Hz sound absorbing unit of the present invention;
FIG. 14 is a schematic diagram showing the result of the sound absorption coefficient simulation calculation of the 200Hz sound absorption unit of the present invention;
fig. 15 is a schematic structural view of embodiment 3 of the present invention;
fig. 16 is a schematic structural view of embodiment 4 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
Example 1
As shown in fig. 1 and 2, an apparatus for efficiently absorbing multiple harmonic noises radiated from electric power equipment is formed by arranging 16 100Hz sound-absorbing units 1.
As shown in fig. 3 to 6, the 100Hz sound absorption unit 1 is a sandwich plate structure, and is composed of a first panel 11, a first labyrinth layer 12 and a first bottom plate 13 which are sequentially attached, wherein the first bottom plate 13 is optional. The cross section of the 100Hz sound absorption unit 1 is square; the thickness D1 of the first labyrinth layer 12 is 32mm +/-5 mm; the first panel 11 faces the sound incidence side, and is provided with 1 hole p1 in the middle and with a diameter
Is 3mm plus or minus 1 mm; the first labyrinth layer 12 comprises a first frame 121, the inside of the first frame 121 is divided by a first partition plate 122 to form a first revolving labyrinth channel, the turning angles of the channel are right angles, the central line length of the channel is 680mm +/-50 mm, and the clear width r1 of the channel is 13mm +/-3 mm.
Every two adjacent 100Hz sound absorption units 1 are paired, a through hole S1 is arranged between the frames corresponding to the tail ends of the labyrinth-shaped channels of the paired sound absorption units, and the maximum width of the cross section of the through hole S1 accounts for less than 30% of the net width of the channel. The through hole S1 causes the acoustic impedance at the end of the channel to change, and the maximum width of the cross section of the through hole S1 is controlled to be less than 30% of the net width of the channel, so that most of the sound energy is reflected, and a small part of the sound energy is transmitted into the matched sound absorption unit. The transmission sound enters the matched sound absorption units through the through holes, the channel length is equivalently prolonged, the low-frequency sound absorption capacity below 100Hz is improved, and the sound absorption frequency band is widened while the sound absorption effect of 100Hz is ensured.
In order to verify the sound absorption performance of the sound absorption unit, simulation calculation is carried out on the 100Hz sound absorption unit 1 by adopting COMSOL, and the calculation result is shown in figure 7. As can be seen from fig. 7, the 100Hz sound absorption unit 1 has good sound absorption performance in the medium and low frequency range, has a high sound absorption coefficient near 100Hz, and the sound absorption coefficient is greater than 0.95, so that the sound absorption unit has a very good sound absorption effect at 100 Hz.
Example 2
As shown in fig. 8 and 9, an apparatus for efficiently absorbing multiple harmonic noises radiated from electric power equipment is formed by arranging 16 sound-absorbing units 2 of 200 Hz.
As shown in fig. 10 to 13, the 200Hz sound absorption unit 2 is a sandwich plate structure, and is composed of a second panel 21, a second labyrinth layer 22 and a second bottom plate 23 which are sequentially attached, wherein the second bottom plate 23 is optional. The cross section of the 200Hz sound absorption unit 2 is square; the thickness D2 of the second labyrinth layer 12 is 20mm +/-4 mm; the second panel 21 faces the sound incidence side, and is provided with 1 hole p2 in the middle and the diameter of the hole
Is 3mm plus or minus 1 mm; the second labyrinth layer 22 comprises a second frame 221, the inside of the second frame 221 is divided by a second partition 222 to form a second convoluted labyrinth passage, the passage turning angles are right angles, the length of the central line of the passage is 320mm +/-30 mm, and the clear width r2 of the passage is 13mm +/-3 mm.
Every two adjacent 200Hz sound absorption units 2 are paired, a through hole S2 is arranged between the frames corresponding to the tail ends of the labyrinth-shaped channels of the paired sound absorption units, and the maximum width of the cross section of the through hole S2 accounts for less than 30% of the net width of the channel. The through hole S2 causes the acoustic impedance at the end of the channel to change, and the maximum width of the cross section of the through hole S2 is controlled to be less than 30% of the net width of the channel, so that most of the sound energy is reflected, and a small part of the sound energy is transmitted into the matched sound absorption unit. The transmission sound enters the matched sound absorption units through the through holes, the channel length is equivalently prolonged, the low-frequency sound absorption capacity below 200Hz is improved, and the sound absorption frequency band is widened while the sound absorption effect of 200Hz is ensured.
In order to verify the sound absorption performance of the sound absorption unit, simulation calculation is carried out on the 200Hz sound absorption unit 2 by adopting COMSOL, and the calculation result is shown in figure 14. As can be seen from fig. 14, the 200Hz sound absorption unit 2 has good sound absorption performance in the medium and low frequency range, has a high sound absorption coefficient near 200Hz, and the sound absorption coefficient is greater than 0.95, so that the sound absorption unit has a very good sound absorption effect at 200 Hz.
Example 3
As shown in fig. 15, an apparatus for efficiently absorbing multiple harmonic noises radiated from electric power equipment is composed of 18 sound-absorbing units 1 of 100Hz, 18 sound-absorbing units 2 of 200Hz, and 18 helmholtz sound-absorbing units 3.
The 100Hz sound absorption unit 1 is matched with the 200Hz sound absorption unit 2, and the transmission sound enters the matched sound absorption unit through the through hole, so that the channel length is equivalently prolonged, the low-frequency sound absorption is improved, and the sound absorption frequency band is widened while the sound absorption effects of 100Hz and 200Hz are ensured.
Helmholtz resonance sound absorption unit 3 comprises first perforated plate, cavity layer and the bottom plate of laminating in proper order, and Helmholtz resonator resonant frequency is below 500Hz to widen the sound absorption frequency band, improve the sound absorption coefficient.
Example 4
This embodiment has increased resistive sound absorption unit 4 on embodiment 3's basis, and resistive sound absorption unit 4 is the sandwich panel structure, comprises the second perforated plate, porous sound absorbing material layer and the bottom plate that laminate in proper order, and resistive sound absorption unit 4 is folded and is executed on 100Hz sound absorption unit 1, 200Hz sound absorption unit 2 and Helmholtz resonance sound absorption unit 3 to improve medium-high frequency sound absorption coefficient, widen the sound absorption frequency band.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalent changes and modifications may be made to some of the technical features of the embodiments, and any modifications, equivalent changes and modifications made within the spirit and principles of the present invention should be included in the protection of the present invention.
Claims (10)
1. The device for efficiently absorbing multiple harmonic noises radiated by electric equipment is characterized by being formed by arranging and combining one or more different sound absorption units in space, wherein the device comprises a 100Hz sound absorption unit, and the 100Hz sound absorption unit comprises a first panel and a first labyrinth layer which are attached to each other; the first labyrinth layer comprises a first frame, the interior of the first frame is divided by a first partition plate to form a first convolution type labyrinth passage, and a first through hole is formed in the middle of the first panel.
2. The device according to claim 1, characterized in that the thickness of the first labyrinth layer is 32mm ± 5 mm; the diameter of the first through hole is 3mm +/-1 mm; the turning angles of the first rotary labyrinth passage are right angles, the length of the central line of the first rotary labyrinth passage is 680mm +/-50 mm, and the width of the first rotary labyrinth passage is 13mm +/-3 mm.
3. The apparatus of claim 2, wherein adjacent 100Hz sound absorption units are paired two by two, and the paired 100Hz sound absorption units are communicated through a through hole on a frame at the end of the convoluted labyrinth passage, and the maximum width of the cross section of the through hole is not more than 30% of the width of the convoluted labyrinth passage.
4. The apparatus of any of claims 1-3, further comprising a 200Hz sound absorbing unit, wherein the 200Hz sound absorbing unit comprises a second facing sheet and a second labyrinth layer which are attached to each other; the second labyrinth layer comprises a second frame, the interior of the second frame is divided by a second partition plate to form a second convolution type labyrinth passage, and a second through hole is formed in the middle of the second panel;
the thickness of the second labyrinth layer is 20mm +/-4 mm; the diameter of the second through hole is 3mm +/-1 mm; the turning angles of the second convolution type labyrinth passage are right angles, the length of the central line of the second convolution type labyrinth passage is 320mm +/-30 mm, and the width of the second convolution type labyrinth passage is 13mm +/-3 mm.
5. The device as claimed in claim 4, wherein the 200Hz sound absorption units and the 100Hz sound absorption units are adjacent to each other or the 200Hz sound absorption units are adjacent to each other in pairs, the 200Hz sound absorption units and the 100Hz sound absorption units or the 200Hz sound absorption units are matched to each other and are communicated with each other through a through hole on a frame at the tail end of the convoluted labyrinth passage, and the maximum width of the cross section of the through hole is not more than 30% of the width of the convoluted labyrinth passage.
6. The apparatus of claim 4, further comprising a Helmholtz resonance sound absorbing unit comprising a first perforated panel and a layer of cavities in abutting relationship.
7. The device of claim 6, further comprising a resistive sound absorbing unit comprising a second perforated panel and a layer of porous sound absorbing material attached together.
8. The apparatus of claim 7, wherein the resistive sound absorbing unit is in the same plane as or directly above the 100Hz sound absorbing unit, the 200Hz sound absorbing unit, and the helmholtz resonant sound absorbing unit.
9. The apparatus of claim 7, wherein the 100Hz sound absorbing unit, the 200Hz sound absorbing unit, the helmholtz resonance sound absorbing unit, and the resistive sound absorbing unit each comprise a base plate attached to the first labyrinth layer, the second labyrinth layer, the cavity layer, and the porous sound absorbing material layer, respectively.
10. The apparatus of claim 7, wherein the 100Hz sound absorbing unit, the 200Hz sound absorbing unit, the helmholtz resonance sound absorbing unit, and the resistive sound absorbing unit are each rectangular in cross-section.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202220411122.XU CN217113823U (en) | 2022-02-28 | 2022-02-28 | Device for efficiently absorbing multiple harmonic noises radiated by electrical equipment |
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| CN202220411122.XU CN217113823U (en) | 2022-02-28 | 2022-02-28 | Device for efficiently absorbing multiple harmonic noises radiated by electrical equipment |
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