门洞对变压器声屏障声学性能影响分析

Analysis of the Influence of Doorway on the Acoustic Performance of Transformer Sound Barriers

门洞有利于变压器声屏障的通风等,但是对屏障声学性能的影响程度却不得而知。以某500 kV变电站主变及其高压侧声屏障(设3.2 m×3.2 m门洞)为对象,开展现场试验和模型预测。试验结果表明,受声点距离屏体越近,声屏障效果越好。声屏障在门洞全开、半开、关闭状态下,可使屏体外8m范围内的噪声L_(Aeq)平均降低3.1dB(A)、6.9dB(A)、10.7 dB(A),站内道路处的噪声SIL平均降低3.7 dB、9.1 dB、13.4 dB。门洞从全开状态转换到半开状态时,屏体外噪声频谱的变化主要集中于中高频,而从半开状态转换到关闭状态时频谱变化分布相对较广。变电站厂界噪声频谱随门洞状态调整的变化也呈现出相似规律。采用通透门洞法可以较好模拟门洞对声屏障的影响,模型预测值与实测值较接近。研究成果可为门洞在变压器声屏障中的应用提供数据支撑。

Doorways are beneficial for the ventilation of sound barriers around transformers,but their effect on the acoustic performance of the barriers is unknown.In this paper,the main transformers of a 500 kV substation and the sound barriers on their high voltage side with 3.2 m×3.2 m doorways are studied with field tests and model predictions.The test results show that the closer the sound receiving point to the barrier,the better the insulation effect of the sound barrier.When the doorway of the sound barrier is fully opened,half opened or closed,the L_(Aeq) within 8 m outside the sound barrier is reduced by 3.1 dB(A),6.9 dB(A)and 10.7 dB(A)in average,respectively,and the SIL on the road inside the substation is reduced by 3.7 dB,9.1 dB and 13.4 dB in average,respectively.When the state of doorway changes from fully opened to half opened,the spectrum change of noise outside the sound barrier is mainly in middle and high frequency ranges.However,when the doorway changes from half opened to closed,the spectrum change covers a relatively wider range.The spectrum of noise at substation boundary varies with the change of doorway state and displays a similar pattern also.The method of empty doorway can better simulate the influence of doorway on the sound barrier,and the results of model predictions are closer to the tested values.The results of this work may provide a data support for the applications of doorways in transformer sound barriers.