Research Of Vibration Characteristics Of Pipeline Conveying Gas-liquid Two-phase Flow

Wet gas flow occurs widely in many industrial processes, such as nuclear, petroleum, chemical and power equipment industries. Flow regime greatly affects flow characteristics, heat transfer characteristic and flow parameter metering accuracy of wet gas flow, in addition, it also affects the stability and safety of related equipment. Flow regime identification, therefore, is always an fundamental and important topic in the study of wet gas flow.Fluid-structure interaction can induce pipeline vibration, and the vibration signal frequency characteristic vary with the flow regime for wet gas, based on this, this paper presents noninvasive approach to identifying flow regime based on flow-induced pipeline vibration and empirical mode decomposition.The research work consists of two parts:The first part is mainly the analysis of experimental about vibration characteristics of Pipeline Conveying gas-liquid two-phase Flow. The vibration signals were collected by a transducer installed on external wall of pipeline. Firstly, Empirical mode decomposition(EMD) is used to decompose the vibration signal into so-called intrinsic mode functions(IMF), the energy and the kurtosis of vibration signal in different frequency bands vary with the flow regime, so extract normalized IMF energy features and the kurtosis features of various flow regimes, and the IMF energy features vector and the kurtosis features vectors are input to the support vector machine(SVM) separately in order to identify three typical flow regimes including stratified/stratified wavy flow, annular/annular mist flow and slug flow for wet gas flow. The experimental results of flow regimes identification for wet gas flow in horizontal pipeline show that the proposed approach can identify flow regimes effectively, and the identification rate is over 93.4%.The second part is the simulation analysis of gas-liquid two-phase flow, in order to research the flow characteristics and the vibration characteristic of pipeline. Fluent is used to analyze the characteristics of gas-liquid two-phase flow. The influence of the change of flow rate on flow regime is analyzed, and the results of the simulation are in accordance with Mandhane flow regime map. The total pressure characteristics of inner wall of pipeline for gas-liquid two-phase flow is analyzed. The results show that the energy distribution and energy stage of the power spectrums of the total pressure vary with flow regimes, providing the basis for the force analysis of pipeline based on fluid-solid coupling for gas-liquid two-phase flow. Fluid-Structure coupling approach is used to study the vibration characteristics of pipeline in this paper based on ANSYS. So far, this paper has established fluid-structure coupling model.