摘要
某定频风冷冷水机组在半消声室进行整机噪声测试阶段,制冷模式下在机组左侧耳听有低频“嗡嗡声”,观察发现左系统储液罐与壳管的连接管出现振动“重影”现象,采集相关弯位的三向振动加速度响应,发现管路水平方向加速度响应为67.8 m/s2远超企标要求,首先识别管路的频响及相干函数获取了多个参考固有频率,初步判定管路在58 Hz处产生了共振,然后分别对原始管路及施加配重块的管路进行有限元模态分析获取其前四阶模态频率及振型,验证了配重块的移频效果,讨论了配重块位置对各阶模态频率的影响,最后识别施加配重块后的管路系统的频响函数,通过实验的方法确认加配重块后管路的一阶固有频率向低频移动了13.5 Hz,与仿真分析结果类似,最终测试了三种配重块布置方案下的管路振动加速度响应数据,对比确认了最终的减振方案采用方案2弯上侧一个配重块执行。
During the whole machine noise testing stage of a fixed frequency air-cooled chiller in a semi anechoic room,low frequency“buzzing sound”appeared on the left side of the unit in refrigeration mode.It was observed that there was a vibration“double shadow”phenomenon in the connecting pipe between the left system storage tank and the shell tube.Three directional vibration acceleration responses of relevant bends were collected,and it was found that the horizontal acceleration response of the pipeline was 67.8m/s2,far exceeding the enterprise standard requirements,firstly,the frequency response and coherence function of the pipeline were identified to obtain multiple reference natural frequencies.It was preliminarily determined that the pipeline had resonance at 58Hz,then,finite element modal analysis was performed on the original pipeline and the pipeline with counterweight blocks to obtain the four modal frequencies and vibration modes.The frequency shifting effect of the counterweight blocks was verified,and the influence of the counterweight block position on the modal frequencies of each order was discussed,Finally,the frequency response function of the pipeline system after the application of counterweight blocks was identified.Through experimental methods,it was confirmed that the first-order natural frequency of the pipeline after the addition of counterweight blocks shifted towards low frequencies by 13.5Hz,which was similar to the simulation analysis results.Finally,the vibration acceleration response data of the pipeline under three different counterweight block layout schemes were tested,and the final vibration reduction scheme was compared and confirmed to be executed using one counterweight block on the bending side of Scheme 2.
出处
《日用电器》
2024年第7期123-128,共6页
ELECTRICAL APPLIANCES
关键词
定频冷水机组
频响函数
固有频率
模态分析
fixed frequency chiller unit
frequency response function
natu ral frequency
modal analysis
