吸声蜗壳在离心风机降噪中的应用研究

Application Study of Noise Reduction of Sound-absorption Volute for Centrifugal Fan

在标准进气风管测试装置上,对某离心风机及在风机蜗壳周向板、前盖板、后盖板等部位分别加装吸声材料后,测试了不同结构形式下风机性能和噪声特性。试验结果表明:相比原风机,蜗壳周向板与后盖板同时加装吸声材料效果最好,设计工况下A声级能够降低7.2dB(A),在小流量工况下,吸声蜗壳的降噪效果变差;根据风机噪声频谱,穿孔板加玻璃棉吸声蜗壳的吸声性能中高频好于低频,风机基频噪声在设计点能够降低12.5dB(A);加装吸声材料后风机气动性能会略有下降,压力和效率都有不同程度的降低。

This paper uses the intake duct blower test platform to give an experimental tests for the aerodynamic performance and noise.The influence of the centrifugal fan absorption material in its scroll plate,front cover,back cover on the noise reduction of the sound-absorption volute is analyzed.Experimental results show that A-weighted sound pressure level can be reduced by 7.2 dB(A),comparing the fan with the absorption material to the original fan.The sound absorption property of the volute is decreased at smaller flow rate.According to the fan noise spectrum,the sound absorption property of the volute at the high-frequency is better than that at the low-frequency,and the blade passing frequency level of the modified fan is decreased by about 12.5 dB(A)at the design point.The aerodynamic performance of the modified fan is decreased slightly,compared with that of the original fan.The pressure and efficiency are decreased with varying degrees.