Exploring mono-fractal characteristics of dynamic pressure at exit of centrifugal compressor based on EWT

Abstract

This paper studies the dynamic pressure at the outlet of the 800 kW centrifugal compressor. It uses the single-fractal method and the empirical wavelet transform to analyze the nonlinear characteristics of the centrifugal compressor under different working conditions. First, it analyzes the characteristics of the dynamic pressure waveform when the centrifugal compressor enters the surge state from the steady state through the transition process. It also uses the empirical wavelet transform to extract the modal components of the pressure waveform, which is reconstructed according to the correlation coefficient. Second, it studies the characteristics of the autocorrelation function of the reconstructed signal under different numbers of hysteresis points k. Finally, it studies the Hurst parameters of the original signal and the reconstructed signal to identify the working state of the centrifugal compressor. The results show that the autocorrelation function of the reconstructed signal can effectively reflect the working state of the centrifugal compressor. Compared with the original signal, it is easier for the Hurst parameter of the reconstructed signal to identify the surge state of the centrifugal compressor.