共查询到19条相似文献,搜索用时 203 毫秒
1.
科学识别和获取特高压换流站内主要噪声源特性,在此基础上对换流站噪声影响进行分析预测,用于换流站噪声评价、设计和防护。在复杂声场环境条件下,通过现场录波、噪声与振动同步测试等方法,结合噪声理论知识,识别出换流变压器的优势谱点为400 Hz,该点占整个频谱噪声贡献值90%以上,同时识别出交流滤波器场电抗器特征频率点与电抗器所滤除的谐波频率相一致,且换流变压器和交流滤波器场电抗器的声压与振动优势频点具有较强的相关性。根据噪声源特性,对其计算模型进行相应的改进,可提高换流站噪声预测结果的准确性。 相似文献
2.
目前,国内通常采用的城市环境噪声普查方法是网格布点、大样本一次性测量。南京市自1980年开始开展这项工作,按规范以500×500米网格城区布设测点205个,每年各测点昼,夜分别监测一次约8分钟,计算各测点等效连续A声级的算术平均值(以下简称网格平均声级Leq)。鉴于噪声传播的随机性、局限性,各测点的监测数据反映的仅是测点附近某一时段的噪声状况,而并非该网络0.25km~2的年度噪声水平,因而普查结果所表明的主要是全市环境噪声总体统计结果及分布规律。然而这些信息又是城市环境质量评价、管理、各城市间宏观声环境的比较所必不可少的,环境部门必须定期耗费大量人力物力完成此项工作。 相似文献
3.
4.
5.
关于厂界噪声监测若干问题的思考 总被引:1,自引:1,他引:0
陈宏观 《环境监测管理与技术》2000,(Z1)
在执行GB 1 2 349- 90《工业企业厂界噪声测定方法》(以下简称《方法》)的过程中 ,碰到了一些问题 ,现提出讨论和建议 ,以期加强对《方法》的研究 ,克服噪声监测的随意性和盲目性 ,切实提高噪声监测质量。1 厂界噪声测点的布设《方法》2 6条中规定 :“测点应选在法定厂界外1m ,高度 1 2m以上的噪声敏感处。”据此 ,测点位置应符合两个基本条件 :一、法定厂界外 ;二、噪声敏感处。何为“噪声敏感处” ,《方法》未明确规定。根据《中华人民共和国噪声污染防治法》第二条第二款“本法所称环境噪声污染 ,是指所产生的环境噪声超过国家规… 相似文献
6.
待兴建的厂房在投入生产运行时,厂房内设备、机器将产生噪声影响周围环境,其噪声影响值为Lp.正确预测Lp值是环境影响评价工作中的主要内容.本文阐述了Lp值的预测方法;通过测算待建厂房内的各种机器,设备声源的声功率级,掌握待建厂房的建筑构造和构件材料组成以及机器、设备在该厂房内的空间布局,然后,就可以运用声扩散、传播的数学处理方法,预测出厂房内声源机器、设备对环境的噪声影响声级值Lp.单个或多个机器、设备被设置在厂房内确定的空间位置上,当机器、设备运行时,厂房 相似文献
7.
8.
9.
10.
高速公路交通噪声经验预测模式探讨 总被引:1,自引:0,他引:1
通过对浙江省内各高速公路交通噪声实测数据的分析,总结和探讨较为简便的高速公路交通噪声经验预测模式,主要讨论车流量、受声点离公路距离和噪声等效声级的相关性,为高速公路交通噪声环境影响预测与评价提供参考。 相似文献
11.
Mohsen Aliabadi Rostam Golmohammadi Muharram Mansoorizadeh 《Environmental monitoring and assessment》2014,186(3):1855-1864
It is highly important to analyze the acoustic properties of workrooms in order to identify best noise control measures from the standpoint of noise exposure limits. Due to the fact that sound pressure is dependent upon environments, it cannot be a suitable parameter for determining the share of workroom acoustic characteristics in producing noise pollution. This paper aims to empirically analyze noise source characteristics and acoustic properties of noisy embroidery workrooms based on special parameters. In this regard, reverberation time as the special room acoustic parameter in 30 workrooms was measured based on ISO 3382-2. Sound power quantity of embroidery machines was also determined based on ISO 9614-3. Multiple linear regression was employed for predicting reverberation time based on acoustic features of the workrooms using MATLAB software. The results showed that the measured reverberation times in most of the workrooms were approximately within the ranges recommended by ISO 11690-1. Similarity between reverberation time values calculated by the Sabine formula and measured values was relatively poor (R 2?=?0.39). This can be due to the inaccurate estimation of the acoustic influence of furniture and formula preconditions. Therefore, this value cannot be considered representative of an actual acoustic room. However, the prediction performance of the regression method with root mean square error (RMSE)?=?0.23 s and R 2?=?0.69 is relatively acceptable. Because the sound power of the embroidery machines was relatively high, these sources get the highest priority when it comes to applying noise controls. Finally, an objective approach for the determination of the share of workroom acoustic characteristics in producing noise could facilitate the identification of cost-effective noise controls. 相似文献
12.
The authors have developed the Activity Accounting Technique for predicting far field noise levels due to operation of specific set of mining machinery. The technique is based on the breaking down of the mining operations into a number of activities and establishing their duration and average location. By estimating the noise levels due to these activities, the overall noise field near a surface mine can be predicted. Experiments were undertaken at a quarry to validate the model developed based on this technique. Results of these experiments are discussed in this paper. The Activity Accounting Technique has the scope of elaborate application for prediction of environmental noise near mining sites. In a system where the activities involved and their duration can be estimated one can develop a noise quality prediction model based on near field spectrum of the sound pressure levels due to the activities. However, this method will be more useful if an acoustic database can be evolved for all the possible activities for different alternative equipment system. 相似文献
13.
以移动通信基站轴向功率密度计算公式为基础,根据非轴向方向上实际监测点位和轴向方向的相对位置,对轴向功率密度计算公式参数进行系列修正,从而建立一种简单适用的移动通信基站非轴向方向上功率密度预测模式. 相似文献
14.
以北京市某典型区域作为研究对象,在收集大量相关资料与实测历史噪声数据的基础上,对研究区域内的声环境质量影响因素进行灰色关联度分析,并运用灰色理论建立GM(1,1)模型进行预测。结果表明,影响城市区域声环境质量因素从大到小的排序依次为:机动车辆﹥常住人口数量﹥平均车流量﹥地区生产总值﹥城市道路桥梁﹥基础设施投资﹥治理噪声环保投资;以研究区域内噪声污染实测历史数据建立的GM(1,1)模型精度符合要求标准,根据GM(1,1)模型预测北京市“十二五”期间声环境质量达标且有轻微下降趋势。 相似文献
15.
针对我国当前广泛使用的2种高速公路噪声预测模型《06规范》预测模型与《09导则》预测模型在预测时比较研究,重点利用环境现状监测数据分别对2种模型验证与对比分析.结果表明,2种模型预测值与实测值相差3dB ~5dB,车流量> 300辆/h,《09导则》更接近实测值;在夜间车流量<300辆/h,《06规范》更接近实测值,2种模型结合采用《06规范》计算的车速,距离衰减考虑车流量的大小,在此基础上应用《09导则》,预测结果与实测值更为接近. 相似文献
16.
17.
18.
19.
Can A Van Renterghem T Rademaker M Dauwe S Thomas P De Baets B Botteldooren D 《Journal of environmental monitoring : JEM》2011,13(10):2710-2719
Requirements for static (prediction of L(den) and diurnal averaged noise pattern) and dynamic (prediction of 15 min and 60 min evolution of L(Aeq) and statistical levels L(A90,)L(A50) and L(A10)) noise level monitoring are investigated in this paper. Noise levels are measured for 72 consecutive days at 5 neighboring streets in an inner-city noise measurement network in Gent, Flanders, Belgium. We present a method to make predictions based on a fixed monitoring station, combined with short-term sampling at temporary stations. It is shown that relying on a fixed station improves the estimation of L(den) at other locations, and allows for the reduction of the number of samples needed and their duration; L(den) is estimated with an error that does not exceed 1.5 dB(A) to 3.4 dB(A) according to the location, for 90% of the 3 × 15 min samples. Also the diurnal averaged noise pattern can be estimated with a good accuracy in this way. It was shown that there is an optimal location for the fixed station which can be found by short-term measurements only. Short-term level predictions were shown to be more difficult; 7 day samples were needed to build models able to estimate the evolution of L(Aeq,60min) with a RMSE ranging between 1.4 dB(A) and 3.7 dB(A). These higher values can be explained by the very pronounced short-term variations appearing in typical streets, which are not correlated between locations. On the other hand, moderately accurate predictions can be achieved, even based on short-term sampling (a 3 × 15 minute sampling duration seems to be sufficient for many of the accuracy goals set related to static and dynamic monitoring). Finally, the method proposed also allows for the prediction of the evolution of statistical indicators. 相似文献