Noise and Vibration Characteristic Studies of Twin Screw Compressor in Different Operating Conditions

摘要

The tonal noise or vibration of air-cooled or water-cooled chillers with rotary twin screw compressors is crucial forrnenvironmental concerns. This work aims to perform the receiver tests regarding the radiated noise and structuralrnvibration due to the compressor in different operating conditions. The sound pressure near the compressor isrnrecorded by the one-third octave and narrow band frequency analyzers, respectively. For environmental concern, thernone-third octave band spectrum is frequently adopted to evaluate the radiated noise, while the narrow band spectrumrncan be used to characterize the noise sources. The axial, vertical and horizontal accelerations on the compressor shellrnat the motor and oil-injection locations are also monitored to correlate the structure-borne noise. Other than therncomparison of spectral content between radiated noise and compressor shell vibration, the frequency responsernfunctions and the coherence functions are examined to further characterize the relation between noise and vibration.rnThis work lays out the general steps and measurement procedures for noise and vibration evaluation in primary stagernfor receiver tests considering different load capacities. The vibration energy transmission path tests as well as thernrefrigerant pulsation effects on the compressor noise and vibration can then be carried out accordingly.