Experimental Analysis of Screw Compressor Noise and Vibration

Very few reports have been presented to date on the noise and vibrational characteristics of oil injected screw compressors. This time. a series of extensive experimental analysis is performed. It includes the measurements and analysis of compressor casing vibrations. rotor shafts vibrations, torsional <rotational) vibrations. suction and discharge gas pulsations. pressure trans~ ient in one thread of rotors ana compressor noise. These experiments are done mainly with R-22 gas, and the operating speed of compressor continuously varied up to 4400 RPM in some test conditions. The tested compressors are mainly 1SOL<163mm ,long rotor). Analyzed results of these experiments help to explain the major noise and 'vibrational characteristics of standard oil injected screw compressors. Nomenclature Fo = fundamental screw frequency, Hz Fm male rotor operating frequency, Hz Ff female rotor operating frequency, Hz k specific heat ratio n operating speed. RPM Pd = discharge pressure. Pa Ps suction pressure. Pa Vi bUilt-in volume ratio Pi built-in pressure ratio= Vik(adiabatic change) Zm male tooth number Zf female tooth number D rotor diameter. mm L rotor length. mm