A NEW METHOD OF MEASURING TWO-PHASE MASS FLOW RATES IN A VENTURI

The metering of the individual flow rates of gas and liquid in a multi-component flow is of great importance for the oil industry. A convenient, non-intrusive way of measuring these is the registration and analyzing of pressure drops over parts of a venturi. The commercially available venturi-based measuring equipment is costly since they additionally measure the void fraction. This paper presents a method to deduce the individual mass flow rates of air and water from pressure drop ratios and fluctuations in pressure drops. Not one but two pressure drops are used and not only time-averaged values of pressure drops are utilized. As a proof-of-principle, prediction results for a horizontal venturi are compared with measurements for void fractions up to 80 %. Residual errors are quantified and the effect of variation of equipment and of slip correlation is shown to be negligible. At relatively low cost a good predictive capacity of individual mass flow rates is obtained.