POTENTIAL OF TWIN-SCREW COMPRESSOR AS VIBRATION SOURCE FOR ENERGY HARVESTING APPLICATIONS

The paper presents the vibrational behaviour of a twin-screw compressor at various functioning regimes. The speed is varied by means of a 250 kW electric driving motor, via a frequency converter. The compressor can supply pressurized air up to ~16 bar into a buffer tank. The air is used for testing various equipment on test bench, such as expanders, pneumatic starters for gas turbine engines, or other compressors and blowers used for compressing air starting from a pressure higher than the atmospheric pressure. Like all other industrial equipment, compressors experience inherent vibrations in operation. The pulsatory effects of the air within the compressor also give birth to harmonics. The study herein involves gathering vibration data and represent it as vibration spectra. Raw vibration signals, employed for assessing the condition of the machinery, may not always be clear in the frequency spectrum for vibration analysis, thus being required to apply Fast Fourier Transform for converting the time waveform into frequency spectrum. The study herein pursues a future application of energy harvesting from vibrations, and outlines that the spectral analysis of the compressor is convenient for piezoelectric cantilever harvesters in terms of vibration frequency and amplitude.