• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a device for reducing pure sound noise belonging to a low frequency band, and more specifically, to a low frequency band noise of less than 1 kHz, a Helmholtz resonance type device is installed in a sealed space to reduce pure sound noise. It relates to a type noise reduction device. In the present invention, a transformer or the like as a noise source is installed inside, and surrounded by a sealed box for preventing the internal noise from spreading to the outside around the outer circumference, and the inner wall of the sealed box has a resonance phenomenon in the sealed space. The Helmholtz resonator type device is installed by placing a predetermined interval on the inner wall so that the main noise source of the pure sound type generated by the noise source is extinguished from the inner wall so as not to be discharged to the outside. The deformed device includes a porous plate 110 in which a plurality of holes 111 having a diameter of a predetermined size are regularly drilled; By the grid for fixing the porous plate 110 to the inner wall of the soundproof wall to be installed so as to maintain a gap to form the air layer of the soundproof wall inner surface and a predetermined interval, the porous plate is a pomax of 3mm thick It is characterized in that the (foamex) plate has a diameter of 5mm and a pitch of 30mm and maintains a distance of 40mm from the inner surface of the soundproof wall to reduce low frequency band noise of 480Hz.
    公开号:KR20010010290A
    申请号:KR1019990029093
    申请日:1999-07-19
    公开日:2001-02-05
    发明作者:이현；김연환；이준신
    申请人:이종훈；한국전력공사；
    IPC主号:
    专利说明:

    Resonance type noise reduction device for transformer closed structure {Cavity resonance type reduction instrument for Enclosurer of Transformer Noise}
    The present invention relates to a device for reducing pure sound noise belonging to a low frequency band, and more specifically, to a low frequency band noise of less than 1 kHz, a Helmholtz resonance type device is installed in a sealed space to reduce pure sound noise. It relates to a type noise reduction device.
    In general, the method of controlling pure noise type is divided into passive noise control and active noise control. Active noise control (ANC), which is of recent interest, is a method to reduce the sound pressure level of noise by generating and superimposing artificial sounds having the same amplitude and opposite phase to the noise to be reduced by using a secondary sound source. It is suitable for controlling pure low frequency noise of 120Hz, which is small in a space such as a car and low in frequency. However, when the space to be controlled and the frequency are large, such as a power plant or a substation, the number of speakers and microphones required for the control becomes uneconomical.
    Therefore, the noise control for noise sources such as transformers located in a large space such as a power plant is a passive method of absorbing and blocking the noise generated by treating sound absorbing materials together with sealed boxes and soundproof walls. Especially, the method of fundamentally isolating the target noise source in the closed box is used as an effective control method.
    However, due to the sound field resonance characteristic of the space between the sound source and the sealed box, there is a problem that there is no sealing effect due to the characteristic frequency and resonance of the noise source.
    In order to solve such a problem, in the present invention, a Helmholtz resonator type device is installed in a sealed box to extinguish the main noise source of the pure sound type generated from the noise source in accordance with the pure sound component transmitted by the resonance phenomenon of the sealed space from the inner wall surface. It is an object of the present invention to provide a resonance type noise reduction device for a transformer hermetic structure to prevent the emission to the outside to compensate for the blocking performance of the sealing device.
    1 is a schematic configuration perspective view of a sealed box as an embodiment of the present invention.
    2 is a configuration of a panel-type Helmholtz resonance noise reduction device applied to the present invention,
    (a) is a front view and (b) is a side sectional view.
    3 is a schematic configuration diagram of a transformer sealing structure simulation apparatus for achieving the present invention.
    Figure 4 shows the simulation results of the transformer closed structure,
    (a) is the graph of analysis result and (b) is the graph of experiment result.
    Figure 5 is a cross-sectional view of the installation state of the transformer 480Hz noise reduction device.
    Figure 6 is a graph of noise transmission before and after the installation of the noise reduction device in a sealed box.
    <Explanation of symbols for main parts of drawing>
    100: Helmholtz resonator device 110: porous plate
    111 hole 120 grid
    200: sealed box 300: noise source
    In order to achieve the above object, in the present invention, a transformer, such as a noise source, is installed therein, and is surrounded by an airtight box for preventing the internal noise from spreading to the outside around the outside, but the inner wall of the sealed box. The Helmholtz resonator type device is installed at a predetermined interval on the inner wall so that the main noise source of pure sound type generated from the noise source is extinguished from the inner wall so as not to be emitted to the outside in accordance with the pure sound component transmitted by the resonance phenomenon in the closed space. It is characterized by the configuration.
    In addition, the Helmholtz resonator device includes a porous plate in which a plurality of holes regularly having a diameter of a predetermined size; The perforated plate is installed by a lattice for fixing the perforated plate to the inner surface of the soundproof wall so as to maintain an interval so as to form an air layer having a predetermined interval with the inner surface of the soundproof wall, wherein the perforated plate has a diameter of a 3 mm thick fomaxx plate. 5mm, pitch 30mm and 40mm distance to the inner surface of the soundproof wall is characterized by reducing the low frequency band noise of the 480Hz band.
    Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
    1 is a perspective view schematically showing a sealed box 200 applied to block noise generated from a noise source 300 such as a transformer as an embodiment of the present invention.
    Helmholtz resonator type device 100 is installed on the inner wall surface of the sealed box 200 so that the main noise source of the pure sound type generated from the noise source in accordance with the pure sound component transmitted by the resonance phenomenon of the sealed space inside the sealed box 200. It is extinguished from the inner wall to prevent it from being released to the outside
    Noise sources such as transformers are installed and operated outside the power plant, so when the residential area is close, there is no choice but to block the noise as a closed structure, but there are two problems in this method.
    One is the cooling problem of the transformer, the perfect sealed structure is practically impossible, and the other is that even if the perfect sealed structure is achieved, some characteristics of the harmonic wave of the noise source and the sound field resonance of the internal space can occur.
    Therefore, in the present invention, by installing the panel-type noise reduction device 100 shown in FIG. 2 as a way to overcome such a realistic problem, the acoustic characteristics of the inner wall of the closed box 200 are appropriately changed to amplify the noise of the component that is amplified and transmitted. By preventing the transmission to the outside to control the environmental noise components to the outside.
    The device of the present invention is made of a Helmholtz resonator structure, which is widely used for noise control, to seal the inner wall of the sealed structure so that the resonance frequency is matched to the target component so that the noise disappears from the inner wall and is not emitted to the outside. . The Helmholtz resonator device includes a porous plate (110) in which a plurality of holes (111) having a diameter of a predetermined size is regularly drilled; The porous plate 110 is fixed by a grating 120 for fixing the inner surface of the soundproof wall, so that the porous plate 110 is spaced apart from the inner surface of the soundproof wall to form an air layer having a predetermined interval.
    Figure 3 is a schematic view showing a simulated apparatus for simulating the closed structure of the present invention to install a speaker on one side to act as a noise source, and to form a porous plate and an expansion space as shown on the other side.
    In this case, the resonant structure absorbs noise of the same frequency generated in the internal space by creating a resonance frequency as shown in the following equation.
    The resonant frequency of the resonator is low frequency Is obtained by substituting
    (One)
    Where effective length Is the inlet length If the inlet cross-sectional area is small compared to the wavelength, the following correction relationship is used.
    According to Equation (1) induced by numerical analysis, a panel-type Helmholtz resonator that reduces the noise of pure sound component (480Hz) is to be installed. do.
    The table below summarizes the dimensions of each section and the natural frequencies of the resonators.
    Table 1. Main dimensions of closed structure simulation test apparatus, mm
    Wave Guide PartHelmholtz resonance Length. LOpen gap lengthCross section, SPanel thickness, l H1 Opening ratio, S H2 / S H1 Expansion chamber length, l H2 Natural frequency, f 11,42020200 * 200348.340.0478 Hz
    4 is a result obtained by analyzing the sound pressure ratio at the opening to the unit input with or without the resonator in the simulation device. Analytically, it is expressed as the ratio of sound pressure to the speed of the speaker, and the comparison between the analytical and experimental values is compared with the overall trend instead of the absolute value. Even in the experimental condition, the noise reduction was more than 15dB at around 480Hz, the natural frequency of the simulator.
    The target noise reduction device for 480Hz noise reduction is as shown in FIG. 5.
    The resonance noise reduction structure for the target noise of 480Hz is to weld the square pipe (20 × 40) to the H-beam in lattice form in order to eliminate the effect of irregularities (bending) of the closed box, and the size of the lattice is perforated It was installed in accordance with the size of to keep the air layer 40mm accurately. A 1t galvanized steel sheet was mounted on the square pipe so that the properties of the sealed box did not interfere with the sound absorbing device. The porous plate is shown in FIG. 5 and designed to be manufactured with a diameter of 5 mm and a pitch of 30 mm on a 3 mm thick fomaxx plate to reduce the 480 Hz.
    By installing the noise reduction device according to the present invention as described above, the component of 480Hz showed a reduction result of 14dB as shown in Table 2 below.
    360 Hz480 Hz600 Hz Before installation72.077.068.0 after installing66.063.061.0 Damping6.014.07.0
    In Example 2 of the present invention, as a countermeasure against 480Hz pure voice noise, the 480Hz component is significantly reduced as shown in Table 2 as a result of performing the installation in an actual sealed box based on the results and experimental values based on sound field theory. This result shows that it can be used as a useful method for pure noise reduction. This method can be usefully used for reducing the pure voice noise of only 500 Hz caused by the excitation frequency of the fan and the resonance of the duct among the duct noise of the air conditioner.
    权利要求:
    Claims (3)
    [1" claim-type="Currently amended] Install a transformer, etc., as a noise source inside, to be surrounded by an airtight box to prevent the noise from spreading to the outside by blocking the noise inside.
    The inner wall of the sealed box 200 is disposed on the inner wall so that the main noise source of the pure sound type generated in the noise source 300 is extinguished from the inner wall surface so as not to be discharged to the outside in accordance with the pure sound component transmitted by the resonance phenomenon in the sealed space. Resonance-type noise reduction device for transformer hermetic structure, characterized in that by installing a predetermined interval Helmholtz resonator device 100 is configured.
    [2" claim-type="Currently amended] The method of claim 1,
    The Helmholtz resonator device 100 includes a porous plate 110 in which a plurality of holes 111 having a diameter of a predetermined size are regularly drilled;
    Resonance type for transformer hermetic structure characterized in that the porous plate 110 is installed by maintaining a gap to form an air layer of a predetermined interval with the inner surface of the soundproof wall by a grating 120 for fixing the porous plate 110 to the inner surface of the soundproof wall Noise reduction device.
    [3" claim-type="Currently amended] The method of claim 2,
    The perforated plate 110 has a diameter of 5mm, pitch 30mm on a 3 mm thick fomax plate, and maintains a 40 mm gap with the inner wall of the soundproof wall to reduce the low frequency band noise of 480 Hz. Structural resonance type noise reduction device.
    类似技术:
    公开号 | 公开日 | 专利标题
    Fry2013|Noise Control in Building Services: Sound Research Laboratories Ltd
    US7398855B2|2008-07-15|Compressor sound attenuation enclosure
    US8459407B2|2013-06-11|Sound attenuation systems and methods
    US5942736A|1999-08-24|Antinoise barrier with transparent panels, provided with acoustic insulation and acoustic absorption characteristics
    US20010053232A1|2001-12-20|Lay-in ceiling speaker
    US20030136101A1|2003-07-24|Gas turbine exhaust passage and damper system for same
    DK166104B|1993-03-08|Sound attenuating box
    CN203160760U|2013-08-28|Noise abatement machine room
    EP2205952B1|2011-11-23|Vibration absorber
    US4100993A|1978-07-18|Acoustic liner
    JP3615172B2|2005-01-26|Noise reduction apparatus and filter coefficient setting method thereof
    EP0636267A1|1995-02-01|Extended frequency range helmholtz resonators
    Kang et al.2005|Feasibility of applying micro-perforated absorbers in acoustic window systems
    US20030048910A1|2003-03-13|Sound masking system
    CN202167759U|2012-03-14|Acoustical enclosure for transformer of large power station
    AU2015225964B2|2020-06-25|High and low frequency sound absorption assembly
    CN101033702B|2013-02-27|Active silencer for an exhaust system
    WO2005086864A3|2009-04-02|Power trailer structural elements for air flow, sound attenuation and fire supression
    RU110675U1|2011-11-27|Sound-protecting casing
    WO2016020511A2|2016-02-11|Method for reducing the comprehensibility of speech signals, and separating component for influencing sound transmission
    US8893851B2|2014-11-25|Soundproofing plate which does not obstruct airflow
    KR101750957B1|2017-06-26|Acoustic panel and soundproof wall equipment
    CN104727452B|2017-12-08|A kind of composite sound isolating material and the sound-proof wall body structure based on the material
    DE10134539A1|2003-02-13|Screening booth
    Bao et al.1997|Experimental study of different approaches for active control of sound transmission through double walls
    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1999-07-19|Application filed by 이종훈, 한국전력공사
    1999-07-19|Priority to KR1019990029093A
    2001-02-05|Publication of KR20010010290A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019990029093A|KR20010010290A|1999-07-19|1999-07-19|Cavity resonance type reduction instrument for Enclosurer of Transformer Noise|
    [返回顶部]