隔声屏障-不能治理冷却塔噪声（英文）

Acoustic barrier – not a total solution to reducing cooling towers' noise

现时中国大陆城市急速发展,做成大量环境噪声问题。某室外空调机房配备了六台冷却塔,与附近最近的居民楼距离只有15 m,测得的噪声比国标的规定高出了25 d B(A)。传统的噪声治理是利用隔声屏障去阻挡冷却塔的噪声,可是效果不显着,而使用隔声罩与消声器则可能会影响冷却塔运作。此项工程最大的挑战除了要做到高消声效果外,还要解决消声器的压降与进出风短路问题。作者提供了一个整体的降噪治理和解决进出风短路的方案,最终把居民楼的噪声由75 d B(A)降至49 d B(A)。此系统和产品设计非常值得讨论。

Rapid urban development in China has created many environmental noise issues. Six large cooling towers were located at 15 m away from a residential building and the measured noise level at the noise receiver had exceeded the national environmental standard by 25 d B（A）. Traditional noise control measures by erecting acoustic barrier was not effective while acoustic enclosure with silencers might affect the cooling performance of the cooling towers. The challenge of this project is not only the high demand on noise attenuation but also the minimization of pressure drop and elimination of air ventilation short circuit problem. The authors provided a total solution to the noise and air circulation problems. Acoustic enclosure with 3 m and 1.8 m long silencers for air intake and discharge was designed and built to reduce the noise level at the NSR from 75 d B（A） to 49 d B（A）. The system and product designs to improve the acoustic and aerodynamic performance are worth for discussion.