Research Of Vibration Characteristics Of Pipeline Conveying Gas-Liquid Two-Phase Flow

In this paper, gas-liquid two-phase flow parameters and flow pattern classification methods are briefly described. Based on the methods of theoretical calculations, numerical solution and vibration test, the vibration characteristics of pipeline conveying gas-liquid two-phase flow are analyzed and researched with different flow parameters.Firstly, with hinged beam model, the free vibration equation of two-phase flow pipe is established and the instability critical velocity and the natural frequency are solved. The effect of structure physical parameters and flow parameters to the natural frequency is analyzed. Secondly, the natural frequency and mode shapes of typical pipes are calculated by using FEA software. The results show that the effect of fluid-structure interaction can be ignored to modal shape, but it may reduce the natural frequency. Besides, the displacement and stress under different importing pressure are calculated. To horizontal bend, the displacement of axial and horizontal direction is larger than vertical direction. The displacement of pipe is mainly caused by the impact of two-phase flow. The angle of elbow is smaller, the displacement and stress are smaller. The vibration protection measures of two-phase flow pipeline are provided. Lastly, with air and water as media, many vibration experiments are carried out. When adding liquid to the single-phase gas, the frequency range of vibration spectrum becomes wider and the vibration energy values become larger; the vibration characteristics of horizontal straight pipe and undulating pipe are analyzed detailedly; and under different flow patterns, the characteristics of the vibration signal are also different. Some useful exploration of flow pattern distinction has been done.