湿式自然通风冷却塔噪声控制的试验研究

Experimental researches on noise control of wet-style natural-ventilation coolingtower

淋水噪声是湿式自然通风冷却塔的主要噪声源,噪声频谱表现为中高频特性。在试验装置上进行了冷却塔噪声模拟试验,试验装置较好地模拟了火电厂湿式自然通风冷却塔的中高频噪声特性。在此装置上,采用两层尼龙网之间夹一层聚氨酯泡沫塑料的降噪方案,可使噪声降低10.5 dB。两网之间、下层网与集水池水面之间合适的距离为10～20 cm;增加聚氨酯泡沫层厚度,降噪效果并没有明显提高。

The water-spouting noise is the dominant noise source of the wet-style natural-ventilation cooling tower. The noise mainly ranges in the middle and high frequencies. The middle and high-frequency noise of the wet-style natural-ventilation cooling tower is simulated by test rig in tab. With a layer of PU foam in the middle of two layers of nylon nets, the noises can be reduced by 10.5 dB. The distances between the two nets and between the lower net and water surface of the catch pond are both 10-20 cm. With further increase of PU foam thickness, the noise reduction is not obvious.