Analysis And Control Of Vibration Coupling Characteristics Of Gas Pipeline

With the development of industrialization in our country,environmental pollution has become increasingly intensified,and using clean energy will be obtained more and more attention.Compared with coal and petroleum,natural gas has the advantages of Secure use,high calorific value,and cleanliness.Today,with more emphasis on environmental protection,it has been greatly reduced that with the using of coal and natural gas has become an important energy source.At present,a large number of pipeline vibrations occur during the extraction and transportation of shale gas and natural gas,causing pipeline damage,gas leakage,and huge economic losses.Therefore,it is necessary to study the gas-structure coupled vibration problem of gas pipelines.In this paper,finite element method and finite volume method are used.ANSYS Workbench finite element simulation platform widely to study fluid-structure coupled vibration analysis is used.The gas-solid coupling pipeline is taken as the research object,and the dynamic model of the gas-solid coupling pipeline is established.The solid coupled vibration model simulates and analyzes the empty pipe and the gas-solid coupling pipe and obtains corresponding vibration characteristics.Firstly,the mathematical model of the gas-solid coupling vibration of the elbow was deduced.The dynamic model of the elbow was established.The modal analysis mathematical model of the empty pipe was solved by the Rayleigh method.The equation is established the vibration of the gas-solid coupling pipeline by using of the free vibration motion of the pipe.Then the ANSYS Workbench finite element simulation platform was used to perform modal analysis on the pipeline,and the bend-type pipeline was selected to study the natural frequencies and modes of different wall thicknesses,different supports of the empty pipe and the gas-solid coupling pipeline.The results show that the natural frequency of the bend-type hollow pipe is increased for the increase of the wall thickness,and the vibration mode is also increased;the more constraints the support,the greater the natural frequency of the bend pipe,and the change of the vibration mode with the increase of the constraint,the period of change of the mode shape is become shorter,and the mode shape also is increased.It will be increased the natural frequency of the bend pipe and increased the mode shape by the gas-solid coupling.However,when the wall thickness is small,the low-order natural frequency of the bend-type gas-solid coupling pipe is smaller than the low-order natural frequency of the same-stage bend-type hollow tube.Finally,the natural frequencies and mode shapes of elbows and gas-solid coupling elbows under different elbow angles are studied.The results show that with the increase of elbow angles,the natural frequency and mode shape change are not obvious,and only the higher order comparison occurs.