VOLUME FLOW RATE MEASUREMENT IN VERTICAL OIL-IN-WATER PIPE FLOW USING ELECTRICAL IMPEDANCE TOMOGRAPHY AND A LOCAL PROBE

摘要

This paper presents the use of a high-performance dual-plane electrical impedance tomography (EIT) system and a local dual-sensor conductance probe to measure the vertical upward cocurrent oil-in-water pipe flows. Experiments were carried on a flow loop with a transparent 2.5-m-long, 80-mm inner diameter test section using kerosene and tap water. The flow conditions were predominantly of the dispersed type, with nonslip oil volume fractions of 9.1, 16.7, and 23.1%, respectively, and with two groups of different mixture velocities. A sensitivity coefficient back-projection algorithm was adopted to reconstruct the flow distributions from the EIT measurement data, and then the oil in situ volume fraction was calculated based on a Maxwell relationship with temperature compensation. The oil velocity distribution was obtained using a pixel-to-pixel cross-correlation method. A local intrusive conductance probe was adopted to supply a reference measurement of oil volume fraction and velocity profiles. The oil volume fraction and velocity distributions from the two techniques were compared and good agreement was found. A further calculation of the water velocity distributions and flow rates was implemented through the drift flux approach and the results were analyzed and discussed.