离心式压缩机噪声源定位分析及降噪方法

针对制氧厂离心式压缩机的噪声问题,联合频谱分析、声成像分析和模态分析三种方法,定位离心式压缩机的主要噪声源。以离心式压缩机机组为研究对象,通过Norsonic150声振测试频谱分析,发现离心式压缩机噪声呈宽频带特性,以2.5 kHz为中心频率的排气管口噪声声压级最高,可达100.80 dB,进气管口与排气管口的噪声频率特性有一致性。结合主要部件的基频分析,发现噪声峰值频率1190.26 Hz、2380.43 Hz产生于离心式压缩机叶轮的基频及倍频;利用Norsonic848声成像分析,发现离心式压缩机排气管口产生的噪声最大,进气管口次之,这与声振测试频谱分析的结果一致;通过LMS声学软件对离心式压缩机机组箱、壳体进行模态分析,发现齿轮箱为低频特性噪声的激励源。根据离心式压缩机的噪声特性和吸隔、消声的基本理论,设计吸隔型隔声罩与阻抗复合式消声器相结合的降噪方法,可为离心式压缩机的噪声控制提供参考。

Noise Source Location Analysis and Noise Reduction Method of Centrifugal Compressors

In view of solving the noise problem of the centrifugal compressors in an oxygen production factory,the main noise source location of the centrifugal compressor is studied with spectrum analysis,acoustic imaging analysis and modal analysis.A centrifugal compressor set is taken as the research object.Through the spectrum analysis by means of the Norsonic150 acoustic vibration testing,it is shown that the noise of the centrifugal compressor has the characteristics of wide frequency band.At the center frequency of 2.5 kHz,the noise pressure level of the exhaust pipe is the highest,which can reach 100.80 dB.And the noise frequency characteristics of the intake port and the exhaust port are consistent.According to the basic frequency analysis of the main components,it is found that the peak frequencies of noise are 1190.26 Hz and 2380.43 Hz which are generated from the basic frequency and frequency multiplication of the impeller of the centrifugal compressor.Using the acoustic imaging analysis of Norsonic848,it is shown that the noise produced by the exhaust pipe orifice of the centrifugal compressor is the largest,and followed by the intake pipe orifice,which is consistent with the result of the acoustic vibration test.And the analysis method is verified.The modal analysis of the box and the shell of the centrifugal compressor unit are carried out by LMS acoustic software.It is found that the gearbox is the excitation source of low-frequency characteristic noise.Finally,according to the noise characteristics of the centrifugal compressor and the basic theory of sound absorption and silencing,a noise reduction method combining the absorption and isolation sound insulation cover and the impedance compound muffler is designed.This study provides a reference for noise control of centrifugal compressors.