Characterization of a wet gas flow sensor based on the propagation of low frequency acoustic signals

Abstract

The interest of the oil and gas industry in evaluating and analyzing the behavior of the flare gas flow shows that there are technical and economic problems to be solved. One of the factors that makes flow measurement in this system problematic is the occurrence of moisture dispersed in the gas, and this moisture can manifest itself in the form of dispersed droplets, with or without the presence of liquid films close to the pipe walls. Conventional intrusive and invasive flow meters, such as orifice plate, inverted cone or turbine, disturb the flow, causing pressure loss and decreasing the efficiency of the system, in addition to being affected to a greater or lesser degree by the presence of the liquid. Thus, it is proposed to study a non-intrusive technique for measuring the flow of a two-phase gas-liquid flow dominated by the gas in the pipeline, based on the propagation of acoustic signals generated by a variable frequency sound source. However, external agents, such as structural vibrations, the noise generated by equipment and the flow turbulence and the noise present in the environment can significantly affect the analysis of the sound signals. Therefore, seeking to minimize the experimental uncertainty of the technique, it is proposed to use methods of analysis and digital processing of signals in the domain of time and frequency, such as the Fourier transform, spectral power density, digital noise filtering techniques and signal coherence analysis. To this end, the measurement of the flow of gas-liquid flow will be carried out at the Laboratory of Industrial Multiphase Flow (LEMI) of EESC-USP. The research aims to evaluate an alternative technique to improve the efficiency of measuring the flow of wet gases in flare gas pipelines in the oil and gas industry. (AU)