Extraction of transferred charge signal of gas-solid two-phase flow based on nonlinear time domain analysis

—When the particles are in the gas-solid two-phase flow, the transferred charge will be generated. The transferred signal obtained by using the inner flush-mounted electrostatic sensor is rich in flow information, which can provide important support for studying the flow law of gas-solid two-phase flow. In this paper, the nonlinear time-domain analysis method based on embedded empirical mode decomposition (EEMD) and largest Lyapunov exponent (LLE) is proposed to extract the transferred charge signal of gas-solid two-phase flow. Firstly, the electrostatic signal is decomposed and the induced charge signal is removed by the combination of EEMD and autocorrelation function correlation coefficient index. Then, the LLE of the remaining intrinsic mode function (IMF) components is calculated, and the corresponding IMF is selected to reconstruct into the transferred charge signal according to the condition that LLE>0. The results show that the LLE of transferred charge signal increases with the increase of the superficial gas velocity and decreases with the increase of solid gas mass ratio. The root mean square (RMS) and standard deviation (STD) of the transferred charge signal increase with the increase of the superficial gas velocity, increase with the increase of the solid gas mass ratio, and slow down at high solid gas mass ratio.