On-line Voidage Measurement of Two-phase Flow Based on Ant System Algorithm

Abstract

Based on Ant System Algorithm (ASA) and 12-electrode Electrical Capacitance Tomography (ECT) system, a new method is proposed for the on-line voidage measurement of oil-gas two-phase flow. The ASA is adopted to select the effective capacitance set (the capacitances in this set make significant contributions to the voidage measurement) from 66 measurement capacitances obtained from the ECT system and determine its contribution weight vector. The practical voidage measurement process includes three steps. Firstly, 66 measurement capacitances are obtained and the real-time flow pattern of the oil-gas two-phase flow is identified. Secondly, the effective capacitance set and its contribution weight vector are determined by using the ASA, and an appropriate voidage measurement model is chosen according to the flow pattern identification result. Finally, the measurement voidage value is calculated. Experimental results show that the proposed voidage measurement method is effective. The real-time performance and measurement accuracy are satisfactory.