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GBZ38251-2019 English PDF

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US$679.00 · In stock
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GBZ38251-2019: Acoustics - Calculation of sound attenuation during propagation for electrical converter station - Engineering method
Status: Valid

Standard ID	USD	BUY PDF	Lead-Days	Standard Title (Description)	Status
GB/Z 38251-2019	679	Add to Cart	7 days	Acoustics - Calculation of sound attenuation during propagation for electrical converter station - Engineering method	Valid

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Basic data

Standard ID: GB/Z 38251-2019 (GB/Z38251-2019)
Description (Translated English): Acoustics - Calculation of sound attenuation during propagation for electrical converter station - Engineering method
Sector / Industry: National Standard
Classification of Chinese Standard: A59
Classification of International Standard: 17.140
Word Count Estimation: 34,338
Date of Issue: 2019-10-18
Date of Implementation: 2020-05-01
Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration

GBZ38251-2019: Acoustics - Calculation of sound attenuation during propagation for electrical converter station - Engineering method

---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
GB /Z 38251-2019 Acoustics-Calculation of sound attenuation during propagation for electrical converter station-Engineering method ICS 17.140 A59 National Standardization Technical Document of the People's Republic of China Calculation method for acoustic propagation attenuation of acoustic converter stations Published on October 18,.2019 2020-05-01 implementation State Administration of Market Supervision Published by China National Standardization Administration

Foreword III Introduction IV 1 Scope 1 2 Normative references 1 3 Terms, definitions and symbols 1 3.1 Terms and definitions 1 3.2 Symbol 3 4 Calculation process 4 5 Expression of sound source 6 5.1 Overview 6 5.2 Simplification of incoherent sound sources 7 5.3 Calculation of sound source coherence 7 6 Meteorological conditions 14 7 Calculation of noise contribution at prediction point 14 7.1 Calculation of sound pressure level attenuation 14 7.2 Calculation of total sound pressure level 15 Appendix A (informative) Sound power levels and frequency spectrum of some converter noise equipment 16 Appendix B (informative) Method for measuring the directivity of power capacitor towers 18 Appendix C (informative) Example of calculation of noise contribution value of capacitor tower of converter station 19 References 28

Foreword

This guiding technical document was drafted in accordance with the rules given in GB/T 1.1-2009. This instructional technical document is proposed by the Chinese Academy of Sciences. This instructional technical document is under the jurisdiction of the National Technical Committee for Acoustic Standardization (SAC/TC17). Drafting organization of this guiding technical document. Hefei University of Technology, China Southern Power Grid Co., Ltd., Shenzhen Zhongya Mechanical and Electrical Industry Co., Ltd. Company, Tongji University, Zhejiang University, Institute of Acoustics, Chinese Academy of Sciences, Shanghai Shenhua Acoustics Equipment Co., Ltd., State Grid Tianjin Electric Power Company Electric Power Research Institute, Shanghai Jiaotong University, Beijing Institute of Labor Protection Science, Zhejiang University of Science and Technology. The main drafters of this guiding technical document. Wei Haozheng, Huang Ying, Lu Yimin, Fang Qingchuan, Yu Wuzhou, Mao Dongxing, Zhai Guoqing, Cheng Mingkun, Lv Yadong, Li Xiaokuan, Zhang Mingfa, Yu Jinshan, Zhao Peng, Li Zhengguang, Jiang Weikang, Xu Xin, Zhang Zuan, Zheng Zhongyuan, Yin Song, Li Zhiyuan.

Introduction

The converter station contains converter transformers, capacitors, reactors and other equipment.The noise radiated by these equipment contains multiple significant pure-tone components. The surrounding sound field is coherent, resulting in uneven spatial distribution of sound pressure on its propagation path, and the sound pressure levels in different directions vary widely, sometimes different More than 10dB. Therefore, coherence should be considered in the calculation of acoustic propagation attenuation in converter stations. The main basis for the calculation of outdoor sound propagation attenuation GB/T 17247, this standard is calculated based on the energy superposition of incoherent sound waves, without considering the coherence of the sound waves. Based on the principle of coherent and non-coherent superposition of sound waves, this instructional technical document gives a calculation method for attenuation of sound propagation in converter stations. Correct There are a large number of capacitors in the converter station, which are arranged in an array in space. The coherent sound of the capacitors in the converter station is established using the principle of acoustic coherent superposition. Field calculation model to calculate the propagation attenuation of the coherent sound; for other devices with insignificant and uncertain coherent sound in the converter station, the non-coherent sound is used. Perform equivalent calculations. The calculation results of the two are superimposed to calculate the noise source of the modulated noise with coherent characteristics in the noise propagation of the converter station. Environmental noise level around the plant boundary. In order to meet the applicability of engineering applications, this guidance technical document is equivalent to and related to the sound source model. The algorithm has been simplified accordingly. For other equipment with significant coherence in the converter station, the calculation of the sound attenuation of the capacitor can be performed with reference to the calculation method of the coherent sound of the capacitor. This guidance technical document provides a calculation method for sound propagation attenuation based on the coherence of the sound source of the converter station, which can regulate the sound transmission of the converter station Attenuation calculation, and provides a basis for optimizing the layout of the sound source of coherent equipment and the overall noise control of the converter station. Calculation method for acoustic propagation attenuation of acoustic converter stations

1 Scope

This instructional technical document proposes a calculation process for calculating the acoustic propagation attenuation of a converter station, and gives a method of expressing sound sources in a converter station (including (Including simplified method of incoherent sound, directivity calculation of single capacitor tower and three-phase capacitor tower group, and sound power correction method) and prediction Method for calculating the total contribution of point noise. Note. This guidance technical document mainly provides the calculation method for the propagation attenuation of coherent sound sources.The propagation attenuation of non-coherent sound sources is calculated according to GB/T 17247. This instructional technical document is applicable to the calculation of sound propagation attenuation of converter stations with coherent sound sources. An area that is more than twice as large. For other coherent sound source propagation attenuation calculations, please refer to this guidance technical document.

2 Normative references

The following documents are essential for the application of this document. For dated references, only the dated version applies to this article Pieces. For undated references, the latest version (including all amendments) applies to this document. GB/T 3222.1 Description, measurement and evaluation of acoustic environmental noise-Part 1. Basic parameters and evaluation methods GB/T 3222.2-2009 Description, measurement and evaluation of acoustic environmental noise-Part 2. Determination of environmental noise level GB/T 3947 Acoustics terminology GB/T 17247 (all parts) Acoustics Attenuation of outdoor sound propagation GB/T 17247.2 Acoustics. Attenuation of outdoor sound propagation. Part 2. General calculation methods GB/T 32524.1-2016 Acoustic sound pressure method for determination of sound power level and directivity characteristics of power capacitor units-Part 1. Half Anechoic Chamber Precision 3 terms, definitions and symbols 3.1 Terms and definitions The terms and definitions defined in GB/T 3947 and the following apply to this document. 3.1.1 Noise People don't need, audible sound in the frequency range of 20Hz ~ 20,000Hz. 3.1.2 Pointsource A sound source with a wavelength longer than the radius of the sound source. 3.1.3 Linesource The wavelength of the sound wave is much shorter than the length of the sound source. 3.1.4 Area source The wavelength of the sound wave is much smaller than that of the long and short sides of a planar sound source. ......

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Tips & Frequently Asked Questions:

Question 1: How long will the true-PDF of GBZ38251-2019_English be delivered?

Answer: Upon your order, we will start to translate GBZ38251-2019_English as soon as possible, and keep you informed of the progress. The lead time is typically 4 ~ 7 working days. The lengthier the document the longer the lead time.

Question 2: Can I share the purchased PDF of GBZ38251-2019_English with my colleagues?

Answer: Yes. The purchased PDF of GBZ38251-2019_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.

Question 3: Does the price include tax/VAT?

Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countries

Question 4: Do you accept my currency other than USD?

Answer: Yes. If you need your currency to be printed on the invoice, please write an email to Sales@ChineseStandard.net. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.