Diagnostic flow metering using ultrasound tomography

Abstract

For an accurate flow metering without considering the influences of flow control devices such as valves and elbows in closed conduits, velocity distribution in the cross-sectional area must be integrated. However, most flow meters, including multi-path ultrasonic, electromagnetic or Coriolis mass flow meters, require assumptions on the fully-developed turbulent flows to calculate flow rates from physical quantities of their own concern. Therefore, a long straight pipe has been a necessary element for accurate flow metering because the straight pipe can reduce flow disturbances caused by flow control devices. To reduce costs due to the installation of long straight pipes, another flow metering technique is required. For example, flow rates can be estimated by integrating velocity distributions in the crosssection of conduits. In the present study, ultrasound tomography was used to find the velocity distribution in the cross-section of a closed conduit where flow was disturbed by a Coriolis mass flow meter or a butterfly valve. A commercial multi-path ultrasonic flow meter was installed in the pipeline to measure the line-averaged velocity distribution in the pipe flow. The ultrasonic flow meter was rotated 180° at intervals of 10° to construct line-averaged velocity distributions in Radon space. Flow images were reconstructed by using a backprojection algorithm (inverse Radon transform). Flow diagnostic parameters were defined by calculating statistical moments, i.e., average, standard deviation, skewness, and kurtosis, based on the normalized velocity distribution. The flow diagnostic parameters were applied to flow images to find whether the parameters could discern flow disturbances in the reconstructed velocity distribution.

Application of acoustic techniques to fluid-particle systems – A review

“…The frequency shift is predicted by the Doppler theory. This method is widely used in medicine (Chun et al, (2011), Sigel, (1998)); in multiphase flows it has been used to measure the velocity profiles of solid particles in dispersed solid-liquid flows (Meribout et al, (2020), Tomonori et al, (2013), Takeda. Y., ( 2013)) and bubble velocity profiles in bubbly flows (Aritomi et al, (2000)).…”

Computer methods for non-invasive measurement and control of two-phase flows: a review study

“…To reconstruct the velocity profile, the algorithm of filtered back-projection was implemented. Similarly, the same image reconstruction technique and the Ultrasound Tomography (UST) was used in [28] to imagine the flow from the line-averaged velocity distribution in Radon space. The method of ultrasonic pulse echo reflected from the pipe's internal wall is proposed in [82] for flow pattern identification in a horizontal pipe with gas-liquid TPF.…”

Application of ultrasound techniques in Solid-Liquid fluidized bed

“…The ultrasound techniques used here are based on the measurements of the sound attenuation and speed to characterise the voidage of the bed, of the Doppler effect to obtain the solids velocity profiles, and of the attenuation coefficient at different sound excitation frequencies to characterise the particle size distribution. The Doppler effect manifests itself as a change in the frequency of the sound wave when it impacts objects moving at a different velocity with respect to the sound source and is widely used in medicine (Chun et al, (2011), Sigel, (1998; in multiphase flows it has been used to obtain velocity profiles of solid particles in dispersed liquid-solid flows (Meribout et al, (2020), Tomonori et al, (2013), Takeda. Y., (2013) and of bubbles in bubbly flows (Aritomi et al, (2000)).…”