Study On Acoustic Intensity And Location Of Inner Pipe Leakage In Jacketed Structure

In the chemical industry,the jacket structure is used widely.Its main body usually contains high temperature and high corrosive medium.Undoubtely,long period service will cause the inner body to crack,or reduce and lastly leak.Because of its special structure,the leakage of the inner tube of jacketed structure is concealed,so often causes serious accidents.Therefore,it is urgent to develop a real-time leak monitoring method to ensure the safe operation of jacket equipment.Acoustic emission technology is suitable for on-line monitoring of such structures because of its real-time and high sensitivity.Therefore,on the basis of theoretical research and numerical analysis,it is the key point to determine the vibration response of the outer pipe when inner pipe leaking and locate the vibration source.In this technical plan,the main work of this paper is as follows:1.A numerical model of two-dimensional jacket structure is established with GAMBIT,then the FLUENT software is used to simulate the leakage flow field.And the sound field simulation is carried out on the basis of flow field simulation in order to obtain the relationship between leakage state and sound intensity of leakage;2.The main reason of the vibration response in the outer wall of jacket structure is revealed,and the response law of the sensor is obtained,which is generated by the sound pressure and the fluid turbulent drag;3.On the basis of theoretical research and numerical analysis,an experimental system of inner tube leakage for jacket structure is established.Firstly,the frequency characteristics of the experimental system are obtained by LMS vibration and modal test,and the main acoustic source of the sensor response is determined.And the inner tube leakage process is monitored by the sensor array arranged on the outer wall of the jacket structure,and the basic law of the acoustic response is obtained;4.Through the analysis of acoustic emission waveform,the appropriate wavelet function is selected to obtain the main acoustic characteristic features,and the relationship is obtained between the acoustic features and the propagation distance;5.Through acoustic emission line location analysis,it is concluded that the leakage of inner tube of jacket structure belongs to multi sound source regoin.And the location of leakage can be effectively determined by cross-correlation location analysis.