Study On The Volume Fraction Measurement Of Oil/Water Two-Phase Flow Based On Conductance Sensor

The flow patterns of oil/water two-phase flow in vertical upward pipes werecharacterized by the analysis of symbolic time series based on the conductancefluctuating signals. The study showed that the symbolic sequence temporalirreversibility T_fb and chi-square χ² statistics had little changes with oil-in-water flowpattern variations for water cut ( K_w) ranging from 61% to 91% and irregular suddenchanges to transitional flow pattern variations of 51%. When distinguishing thetransitional flow pattern from oil-in-water, the symbolic time series analysis methodpresents more unique characteristic and is a useful assistant diagnostic tool for theidentification of oil/water two-phase flow patterns.The volume fraction is an important parameter of the two-phase flowmeasurement. The methods of the volume fraction measurement were summarizedand the vertical multi-electrode sensor measurement theory was analyzed in this paper.The measurement system of vertical multi-electrode sensor was established. The threeway signals of multi-electrode sensor are acquired by use of the dynamic signalacquisition device and LabVIEW. We did the exerperiments in the laboratory andachieved ideal results.The soft measurement method was applied to predict the volume fraction ofoil/water two-phase flow. The characteristics of time domain and frequency domainact as the inputs of artificial neural network. Several traditional statistics represent thetime domain characteristics. The frequency domain characteristics are obtained by thelinear prediction method. The transition time of the correlation electrodes also acts asthe input characteristic. The prediction results indicate that the soft measurementtechnique may be used to predict the volume fraction of oil/water two-phase flow.