特高压换流站冷却塔可听噪声测试与分析

Measurement and Analysis of Valve Outside Cooling Tower's Audible Noise in UHVDC Converter Station

换流站中阀冷却系统外冷设备是产生噪声的主要设备之一,为了获得其噪声特性,文中以特高压换流站为研究对象,利用声级计和PULSE音频分析仪,采用声压法对其4组水冷却塔的可听噪声进行了现场测试与分析,获得了冷却塔的声压级以及噪声的频谱分布。测试与分析结果表明:每组冷却塔各测点的A计权声压级大约分布在75~85 d B之间,不同冷却塔组的声压分布非常接近,且风机所在面声压级明显大于其他面;冷却塔噪声频带宽,频率成分丰富,Z计权的噪声频率窄带谱中声压幅值最大值出现在20~50 Hz,A计权的1/3倍频程频谱中声压最大幅值所在频带的中心频率为1 600 Hz。相关研究成果为阀外冷设备的噪声控制技术研究提供了基础数据支持,对高压直流输电工程实践具有指导意义。

One of the main noise-generated equipments in the UHVDC （ultra high voltage direct current） con- verter station is valve outside cooling equipment. To obtain the noise characteristics of the equipment, this paper systematically measured and analyzed the audible noise of four water cooling towers outside valve in an UHVDC converter station using sound level meter and PULSE audio analyzer. The sound pressure level and noise spectrum of the cooling towers are obtained. According to the test and analysis results the following conclusions can be drawn： the sound pressure level with A weighting of measuring points distributed about 75 dB to 85 dB, the sound pressure level distribution of different cooling tower groups are very similar and the side where the fan installed is significantly greater than the other ones. The audible noise is a broadband noise which frequency component is rich. The maximum amplitude of the sound pressure appear at a frequency from 20 Hz to 50 Hz in noise frequency narrowband spectrum with Z-weighted and the maximum amplitude in 1/3 octave spectrum with A-weighted is reached at the frequency band with a center frequency of 1 600 Hz. The paper provides basis and guidance for con- verter station noise control technology.