The Renovation of Noise Reduction and Ventilation for Indoor Substations

2013 ◽  
Vol 732-733 ◽  
pp. 738-744
Author(s):  
Rui Xu ◽  
Ting Fang Yu
Keyword(s):  
Noise Reduction ◽  
Noise Level ◽  
Noise Source ◽  
Measurement Data ◽  
National Standard ◽  
Source Characteristics ◽  
Before And After ◽  
Visible Effect ◽  
Poor Ventilation ◽  
Excessive Noise

The noise reduction and ventilation cooling is contradictory each other for urban indoor substation. Our efforts were focused on the problems of the excessive noise and poor ventilation of indoor substation in this paper, the existing shortages of the primary ventilation cooling program and the noise source characteristics of the indoor substation were analyzed, and the renovation of noise reduction and ventilation cooling was proposed. The measurement data of before and after renovation demonstrated that this renovation on noise reduction and ventilation cooling has a visible effect in meeting the national standard for noise level of the substation surrounding as well as in improving the cooling effect significantly.

A Study of Traffic Noise Reduction Performance of Arc Pavement Roads and Traffic Flow

2006 ◽  
Author(s):  
Zheng Lou ◽  
Liming Dai
Keyword(s):  
Noise Reduction ◽  
Traffic Flow ◽  
Noise Level ◽  
Traffic Noise ◽  
Flow Conditions ◽  
Noise Levels ◽  
Flow Monitoring ◽  
Before And After ◽  
The Relationship ◽  
Rubber Concrete

Asphalt Rubber Concrete (ARC) pavement has shown an excellent performance of noise reduction in terns of reducing the power of air pumping, absorbing sound power, depressing carcass vibration and changing sound reflection geometry. This research is to investigate the traffic noise reduction performance of a segment of test highway with ARC pavement in Saskatchewan, Canada. Before and after the highway section was repaved, a series of traffic noise level measurements combining with traffic flow monitoring are conducted in order to compare the sound performance of ARC and conventional pavements. A relationship between the noise level and corresponding traffic flow conditions of ARC pavement is established. The energetic averaging method is employed to study the relationship between traffic noise level and traffic flow condition. The two noise levels of 24-hour's time averaged and Statistical Pass-By noise levels indicated that the ARC pavement has a better sound performance over that of conventional pavement in terms of traffic noise reduction. The traffic noise reduction applicability of ARC pavement under various traffic flow conditions is also performed in this research.

scholarly journals Workplace Noise Exposure After Modernisation of an Aluminium Processing Complex

2009 ◽  
Vol 60 (3) ◽  
pp. 343-348 ◽  
Author(s):  
Jagoda Doko-Jelinić ◽  
Jela Lukić ◽  
Ružica Udovičić ◽  
Eugenija Žuškin ◽  
Iskra Nola ◽  
...  
Keyword(s):  
Noise Level ◽  
Noise Exposure ◽  
Working Environment ◽  
Ingot Casting ◽  
Occupational Noise ◽  
Aluminium Production ◽  
Before And After ◽  
Production Complex ◽  
Workplace Noise ◽  
Excessive Noise

Workplace Noise Exposure After Modernisation of an Aluminium Processing ComplexThe aim of this study was to assess to which extent modernisation of an aluminium production complex reduced occupational noise hazard for jobs with the highest potential of exposure. Periodical measurements of noise level were taken at the same workplaces using the same method, before and after modernisation of all plants. The results were compared with the recommended standard. After modernisation, the noise was significantly reduced in all sections of all plants. The greatest reduction was measured in the foundry. After modernisation, the portion of workplaces with excessive noise level dropped significantly (chisquare=21.315; p<0.0001) from 78.4% to 13%. Noise remained a problem in ingot casting and dross skimming section. In the anode plant, noise remained a problem in the green mill section where noise intensities generated by mills and vibrocompactors varied from 95 dB(A) to 102 dB(A). In the electrolysis plant, the portion of workplaces with extensive noise dropped from 77.8% to 39.3% after modernisation (p=0.0019). Noise remains to be a problem at the anode covering section where levels rise up to 100 dB(A). The modernisation of the factory has considerably reduced the noise level in the working environment of all plants, but it can not be reduced completely.

scholarly journals Analysis of Noise Environment and Noise Reduction Measures in Urban 110kV Indoor Substations

2020 ◽  
Vol 145 ◽  
pp. 02066 ◽  
Author(s):  
Fengchun Liu ◽  
Shan Tu ◽  
Hanbing Yan ◽  
Xiufang Chen ◽  
Liqiang Guo
Keyword(s):  
Noise Reduction ◽  
Noise Source ◽  
Public Awareness ◽  
Rapid Development ◽  
Current Status ◽  
The Public ◽  
Noise Environment ◽  
Reduction Methods ◽  
Boundary Noise ◽  
Excessive Noise

With the rapid development of society and economy, the public awareness of environmental protection has gradually increased, and urban substation noise has become an environmental issue of concern to residents. In order to study the current status of the noise environment of urban substations, to guide the management of substation noise and the construction of transmission and transformation projects, this article selects 50 110kV indoor substations as objects, and measures their boundary noise. By analyzing the characteristics of the noise source of the substation with excessive noise and various noise reduction measures, the noise reduction methods suitable for urban indoor substations are summarized.

AN IMPROVED ARMORED VEHICLE KRAZ “FIONA” NOISE SILENCER

2019 ◽  
pp. 21-26
Author(s):  
Volodymyr Fedorov ◽  
Vasyl’ Yanovsky ◽  
Dmytro Kovalshuk
Keyword(s):  
Noise Reduction ◽  
Speed Of Sound ◽  
Acoustic Waves ◽  
Noise Level ◽  
Combustion Engine ◽  
Environmental Aspect ◽  
Exhaust Gases ◽  
Ecological Requirements ◽  
On The Road ◽  
Armored Vehicle

Ecological requirements for cars grow from year to year, both in the world as a whole, and in Ukraine in particular. This is especially true of noise pollution. Additionally, noise reduction becomes relevant, taking into account the conduct of military operations during the last 5 years on the territory of Ukraine. The war has caused a special need for military vehicles for which masking properties are vital. Noise is a serious disincentive factor. Therefore, its reduction for a military vehicle, apart from the environmental aspect, is of a purely military nature, that is, it is extremely important. The car has many sources of noise there are many ways to deal with them. One of the most powerful source of noise is the sleeping bag. This kind of noise is reduced by means of silencers of noise. The vast majority of silencer data in the basis of its design has a reactive (or resonant) muffler. To calculate the jet silencer you must know the speed of sound in the sleeping bags. In order to increase the acoustic efficiency of reactive and resonant mufflers of exhaust gases noise of the ICE of cars, an experimental method was proposed for determining the speed of sound in the sleighs. Implementation of the method is carried out by measuring the attenuation of acoustic waves. The noise level of the bedrooms is measured without silencer and silencer. Based on the data obtained, the noise reduction performance of the residual is established. From the well-known formula, based on the calculation of the efficiency of the silencing of a jet muffler, a formula is obtained for calculating the speed of sound in the sleeping quays. In this formula, all parameters are known: the level of silencer efficiency, the noise level of the sleeping, the ratio of areas of cross sections of the muffler and the inlet pipe and the length of the muffler. The sound speed thus established can continue to be used not only for engines of the type for which measurements and calculations were made, but also with a certain approximation for some other types of engines. This method provides high accuracy for determining the required parameter. In the given work on the example of the armored car KrAZ “Fiona” the calculation of efficiency increase of the reactive silencer is made due to the above-mentioned method. Also, the projected decrease in the external noise level of the KrAZ Armored Vehicle “Fiona” is considered by determining the speed of sound in the recesses on the trunk cycle on the road with acceleration up to speed of 50 km/h (75 km/h) and the movement with this speed, as well as when driving at a speed of 45 km/h. Keywords: transport, armored car, internal combustion engine, exhaust, exhaust gases, noise, source, acoustic efficiency, acoustic efficiency, speed of sound, jet muffler.

scholarly journals The optimum orientation of an absorbing barrier

2005 ◽  
Vol 461 (2060) ◽  
pp. 2369-2383 ◽  
Author(s):  
A.D Rawlins
Keyword(s):  
Noise Level ◽  
Noise Source ◽  
Shadow Region ◽  
Source Position ◽  
Absorbent Material ◽  
Noise Barrier ◽  
Receiver Point

In the following work, we solve the problem of the best orientation of a rigid noise barrier, which has one face lined with absorbent material, between a noise source and a receiver point in the shadow region of the barrier. By the ‘best orientation’, we mean that positioning of the barrier which yields the least noise level at the receiving point for a given barrier and source position.

Comparison of Noise Reduction Performance Evaluation Methods for Low-Noise Pavement in Korea- Part

2021 ◽  
Vol 263 (4) ◽  
pp. 2930-2939
Author(s):  
Byungchae Kim ◽  
Hyunjin Kim ◽  
Wonuk Kang
Keyword(s):  
Noise Reduction ◽  
Noise Level ◽  
Measurement Method ◽  
Road Traffic ◽  
Low Noise ◽  
Management Standards ◽  
Close Proximity ◽  
Porous Pavement ◽  
Reduction Effect ◽  
Measurement Location

In Korea, road noise is assessed as a measurement method of exterior noise emitted by road vehicle for management standards by the National Institute of Environmental Sciences. In this method, the noise felt at the actual pickup point is measured as LAeq (the roadside equivalent noise level). Recently, to clarify the standard for measuring noise on low-noise pavements, the CPX (ISO11819-2; Close-proximity method) was first introduced in the Porous Pavement Guidelines of the Ministry of Land, Infrastructure and Transport. According to ISO, the CPX adopts the side microphone as a mandatory measurement location, and the rear optional. The side location has been a mandatory due to its high correlation with SPB (ISO 11819-1, Statistical Pass-by method). However, according to our previous study on the correlation evaluation between L and CPX rear microphone noise level, both noise reduction effect was about 9-12 dB(A) showed a high correlation in Korea where heavy road traffic is common. The following study aims to show the consistent correlation between the L and CPX rear noise level. Furthermore, it is intended to be helpful in selecting the location of the CPX microphone that can most effectively represent the actual noise on the low-noise pavement in Korea.

Sign in / Sign up

Export Citation Format

Share Document