特高压装备Box-in结构的腔内声学参数与隔声性能研究

Study on Acoustic Parameters and Sound Insulation Performanceof Box-in Structures of UHV Equipment

特高压变电站、换流站内常见的噪声治理手段是装设声屏障、Box-in隔声罩等被动吸隔声结构,主要用在辐射声功率较大的换流变、特高压并联电抗器等设备的近场以及噪声敏感点厂界处。此类噪声治理工程的实际效果除与隔声结构的布局有关以外,还与所选结构隔声性能,甚至与设备声场的动力耦合密切相关。比如,Box-in的隔声量与壁面材质、结构型式、室内声场分布、辐射噪声的谱特性都有关联。然而,以往研究多侧重于材料、结构设计,而对罩内声源、声场特性的关注较少。针对隔声罩内声场以及换流变的声源特征,研究某特高压换流站Box-in内的空间声场分布,从声模态的角度解释Box-in隔声量的差异。给出Box-in闭空间声学参数的现场测定方案,获取典型特高压换流站Box-in腔体的混响时间、插入损失等声学参数。基于上述研究,提出一种从空腔内声场调控的角度提高隔声罩相对隔声量的方法。

The common measures of noise control and management in UHV substations and converter stations are the installation of passive acoustic insulation structures such as sound barriers and Box-in enclosures,which are mainly used in the near field of equipment such as converter and UHV shunt reactors with high radiation sound power,as well as at noise sensitive points at the plant boundary.The actual effect of such noise management projects,in addition to the layout of the sound insulation structure,is also related to the selected structure sound insulation performance,and even closely related to the dynamic coupling of the equipment sound field.For example,the sound insulation of the Box-in is related to the wall material,the structure type,the distribution of the sound field in the room and the spectral characteristics of the radiation noise.However,previous studies have mostly focused on material and structural design,while less attention has been paid to the sound source and sound field characteristics inside the isolation hood.In this paper,the spatial sound field distribution inside the Box-in of a UHV converter station is investigated to obtain the sound field inside the enclosure and the sound source characteristics of the converter,and the difference in the Box-in sound insulation is explained from the perspective of sound modality.A field measurement scheme for the acoustic parameters of the Box-in closed space is given,and the acoustic parameters such as reverberation time and insertion loss of the Box-in cavity in a typical UHV converter station are obtained.Based on the above study,a method is proposed to improve the relative sound insulation capacity of the Box-in cavity based on sound field modulation in the cavity.