Design of Transformer Substation Low Frequency Sound Absorber and Test Study on Sound Absorption Property

2013 ◽  
Vol 468 ◽  
pp. 134-140 ◽  
Author(s):  
Xia Zhang ◽  
Shu Ning Duan ◽  
Mei Gen Cao ◽  
Juan Mo ◽  
Yu Han Sun ◽  
...  
Keyword(s):  
Sound Absorption ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Frequency Sound ◽  
Sound Absorber ◽  
Test Study ◽  
Transformer Substation ◽  
Cavity Thickness ◽  
Standing Wave Tube

In allusion to the characteristic that transformer noise is mainly low-frequency noise, firstly the sound absorber is studied and analyzed on aspect of materials, sound absorption structure cavity thickness and punching rate etc in standing wave tube laboratory, secondly transformer substation low-frequency sound absorber is presented, and finally sound absorption properties of absorber is verified through random incidence Test. The analyses and study indicates that: compared with thin plate resonance absorber and micropunching sound absorber, the sound absorption band width of transformer substation low-frequency sound absorber has been improved under unchanged sound absorption effect and transformer low-frequency noise may be effectively absorbed.

scholarly journals Low Frequency Sound Absorption by Optimal Combination Structure of Porous Metal and Microperforated Panel

2019 ◽  
Vol 9 (7) ◽  
pp. 1507 ◽  
Author(s):  
Xinmin Shen ◽  
Panfeng Bai ◽  
Xiaocui Yang ◽  
Xiaonan Zhang ◽  
Sandy To
Keyword(s):  
Finite Element ◽  
Sound Absorption ◽  
Search Algorithm ◽  
Low Frequency ◽  
Porous Metal ◽  
Cuckoo Search ◽  
Element Model ◽  
Frequency Sound ◽  
Sound Absorber ◽  
Standing Wave Tube

The combination structure of a porous metal and microperforated panel was optimized to develop a low frequency sound absorber. Theoretical models were constructed by the transfer matrix method based on the Johnson—Champoux—Allard model and Maa’s theory. Parameter optimizations of the sound absorbers were conducted by Cuckoo search algorithm. The sound absorption coefficients of the combination structures were verified by finite element simulation and validated by standing wave tube measurement. The experimental data was consistent with the theoretical and simulation data, which proved the efficiency, reliability, and accuracy of the constructed theoretical sound absorption model and finite element model. The actual average sound absorption coefficient of the microperforated panel + cavity + porous metal + cavity sound absorber in the 100–1800 Hz range reached 62.9615% and 73.5923%, respectively, when the limited total thickness was 30 mm and 50 mm. The excellent low frequency sound absorbers obtained can be used in the fields of acoustic environmental protection and industrial noise reduction.

scholarly journals Sound Absorption Performance of Aluminum Silicate Fiber for Noise and Vibration Reduction of Distribution Transformer

2022 ◽  
Vol 2152 (1) ◽  
pp. 012037
Author(s):  
Qunli Chen ◽  
Wengeng Wu ◽  
Xu Gao ◽  
Yibiao Huang ◽  
Xiangwen Chen ◽  
...  
Keyword(s):  
Sound Absorption ◽  
Plate Thickness ◽  
Low Frequency ◽  
Unit Weight ◽  
Aluminum Silicate ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Absorption Performance ◽  
Cavity Thickness ◽  
Noise And Vibration Reduction

Abstract In view of the low-frequency noise problem in urban substation, the sound absorption (SA) properties of aluminum silicate fibers (ASF) with different materials, unit weight, plate thickness and cavity thickness were tested in this paper. It was found that the high-purity ASF with larger unit weight, plate thickness and cavity thickness had larger low-frequency SA coefficient, which provided technical support for the development of new low-frequency noise reduction materials for substation.

scholarly journals Improved Sound Absorption Properties in Polyurethane Foams by the Inclusion of Al2O3 Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Binxia Yuan ◽  
Xinyi Fang ◽  
Jianben Liu ◽  
Yan Liu ◽  
Rui Zhu
Keyword(s):  
Energy Dissipation ◽  
Absorption Coefficient ◽  
Sound Absorption ◽  
Low Frequency ◽  
Acoustic Energy ◽  
Sound Absorption Coefficient ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Dissipation Process ◽  
Single Hole

At present, the scale of China’s power grid is becoming larger and larger, and the control of low-frequency noise in substations (especially for transformers) is very important. The sound-absorbing materials have become one of the important ways to control low-frequency noise. The single polyurethane material cannot satisfy the requirements for reducing low-frequency noise, so it is very necessary to study its composite with other materials. In the paper, the flexible polyurethane foam and Al2O3 nanoparticle composites were obtained by the impregnation method. The method was simple, safe, and easy to control. The morphology and sound absorption coefficient of the foam materials before and after filling were analyzed. Single-hole acoustic cavity models of PU and Al2O3-PU composite were established through the finite element. The absorption and dissipation process of sound pressure for single hole was studied to understand the energy dissipation process. Meanwhile, through studying acoustic energy storage and acoustic energy dissipation, the loss factor of a single hole was obtained, which can predict the change rule of the sound absorption coefficient for PU foam and Al2O3-PU.

Low Frequency Noise Considerations for Combustion Turbine Projects

1997 ◽  
Author(s):  
Lisa A. Beeson ◽  
George A. Schott
Keyword(s):  
Noise Control ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Pressure Pulsations ◽  
Relative Difficulty ◽  
Low Frequencies ◽  
Sound Energy ◽  
Frequency Sound ◽  
Human Ear

Combustion turbine projects have become a popular choice for providing a clean and efficient source of electricity. However, since combustion turbines generally produce low frequency sound energy, special siting considerations should be evaluated to minimize the potential for impacts on sensitive receptors, such as residences, churches, hospitals, and schools. For successful siting of combustion turbine projects near sensitive receptors, it is necessary to incorporate noise control features into plant designs to reduce not only audible noise but also noise at frequencies which are even lower than the human ear can perceive. These extremely low frequencies can rattle walls and windows, causing pressure pulsations which may be perceived by some people, or vibration of small objects inside houses and other structures. Even “quiet” plants which include extensive noise control features may still result in perceptible low frequency noise due to the relative difficulty of attenuating low frequency sound energy. Noise attenuation options are discussed, including active, passive, and reactive technologies, along with the impacts associated with each type of design. Guidelines for siting combustion turbine power generation facilities near sensitive receptors are presented, to enable development of projects which not only meet applicable noise requirements, but also reduce the potential for community complaints.

scholarly journals Investigation of Acoustic Properties on Wideband Sound-Absorber Composed of Hollow Perforated Spherical Structure with Extended Tubes and Porous Materials

2020 ◽  
Vol 10 (24) ◽  
pp. 8978
Author(s):  
Dengke Li ◽  
Zhongcheng Jiang ◽  
Lin Li ◽  
Xiaobo Liu ◽  
Xianfeng Wang ◽  
...  
Keyword(s):  
Sound Absorption ◽  
Three Dimensional ◽  
Low Frequency ◽  
Acoustic Properties ◽  
Low Frequencies ◽  
Frequency Sound ◽  
Sound Absorber ◽  
Spherical Structure ◽  
Absorption Performance ◽  
Melamine Foam

Traditional porous media such as melamine foam absorb sound due to their three-dimensional porous struts. However, the acoustic properties at low frequencies are greatly related to its thickness. In this paper, a novel type of thin and lightweight sound absorber composed of melamine foam and hollow perforated spherical structure with extended tubes (HPSET) is introduced to enhance the sound absorption performance at low frequencies. A theoretical model for the normal absorption coefficient of the HPSET with melamine foam is established. Good agreements are observed between the simulated and the experimental results. Compared with the virgin melamine foam, the proposed absorber can greatly improve the low-frequency sound absorption and retain the mid- to high-frequency sound absorption, while the thickness of the proposed absorber is less than 1/28 of the wavelength.

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