Voidage measurement of gas-liquid two-phase flow based on Capacitively Coupled Contact less Conductivity Detection

Based on Capacitively Coupled Contactless Conductivity Detection (CID) technique, a new method for the voidage measurement of conductive gas-liquid two-phase flow is proposed. 15 Conductance signals, which reflect voidage distribution of gas-liquid two-phase flow, are obtained by a six-electrode (CD)-D-4 sensor. With the conductance signals, the flow pattern of gas-liquid two-phase flow is identified by flow pattern classifiers and then the voidage measurement is implemented by a corresponding voidage measurement model (for each typical flow pattern, a corresponding voidage measurement model is developed). The conductance measurement of the six-electrode (CD)-D-4 sensor is implemented by phase sensitivity demodulation (PSD) method. The flow pattern classifiers and the voidage measurement models are developed by partial least squares (PLS) technique and least squares support vector machine (LS-SVM) technique. Static voidage measurement experiments and dynamic voidage measurement experiments show that the proposed voidage measurement method is effective, the developed six-electrode CID sensor is successful and the measurement accuracy is satisfactory. (C) 2014 Elsevier Ltd. All rights reserved.