On differential pressure fluctuation signals of gas-liquid two-phase flow in small-size pipe

In recent years, miniaturization has become one of the important development directions of industrial equipment. More and more micro/mini industrial equipments are used in industrial and scientific research fields. Differential pressure is one of the most important parameters, and accurate acquisition of differential pressure information is of great significance for the flow characteristics analysis and flow state monitoring in these equipments. In the differential pressure acquisition system with small-size pipe, the transmission tube has an approximate geometric scale with the measured pipe. It is necessary to study the dynamic characteristics of differential pressure signals in small-size pipe. In this work, a differential pressure acquisition system is designed and the dynamic characteristics of differential pressure signals for gas-liquid two phase flow in the pipe with 4.0 mm inner diameter are analysed. Then the characteristic vectors are extracted by Empirical Mode Decomposition (EMD). And the flow regime identification is implemented by Support Vector Machines (SVM). The experimental results show that the differential pressure signals can reflect the flow state and can be used in flow regime identification effectively.