Research On Safety Operation Of Two-Phase Flowing Pipeline Based On Vibration Test

Based on the theory of pipeline vibration subjected to single-phase flow, the vibration characteristics of two-phase pipeline were analyzed based on test in this paper. Comparative research was done combined with theoretical calculations and test results, and the risk status of the pipeline system was determined by risk assessment of pipeline.Firstly, two-phase flow was introduced and theoretical analysis of two-phase pipeline was completed .The main reason was given out, including two-phase flow pressure pulsation, the status of flowing pipe and the imbalance of the power machinery. All kinds of measures and means to reduce vibration were summzrized, such as adjusting the natural frequency and changing the stiffness of the pipe system.Secondly, straight pipe model and siphon model of pipline system were built based on the theory of finite element. Modal analysis and harmonic analysis were carried out, and the natural frequencies of the pipeline were calculated by software of ANSYS. The harmonic response analysis was carried out under specific circumstances and some methods of vibration protection were proposed.After that, the basic theory of vibration and the components of tesing system were introduced. According to the above theory, the vibration test of horizontal and rolling pipe of the two-phase flow were carried out. By the methods of spectrum and energy analyzing, the vibration law of two-phase flow pipe under different gas-liquid ratios and different rolling angles was showed. Combined with theoretical analysis of finite element and analog computation, and analyzing vibration state under diffent measure conditions, essential vibration reducing measures were carried out, according to the analysis results.Finally, main factors of risk management were pointed out by the method of risk index of pipeline (also known as EST), including the third-party destroying, corrosion reasons, design reasons and operation reasons. Evaluation standard of various factors was given out, and risk assessment of the two-phase pipeline system was carrided out combined with the above standard, and risk control measures were proposed.