Design And Application Of Experimental Device For Sound Pressure Signal Detection Of Urban Gas Pipeline Leakage

With the increasing popularity of urban gas use and the continuous expansion of the scale of the pipeline network,gas leakage incidents have occurred,which has caused important harm and impact on urban social public safety.Gas pipeline leakage detection is gradually receiving widespread attention as an important means to ensure pipeline safety and reduce accident hazards.Based on the sound pressure signal leakage detection technology,this paper designs and develops a gas pipeline leak detection experimental device,and uses the experimental device to carry out the experimental research work on the gas pipeline leakage judgment and positioning.The main research contents are as follows:1.Through the literature and on-site investigation,combined with the general conditions of daily operation of urban gas pipelines and national standard specifications,the research determines the structural type and main technical indicators of the experimental pipeline,and uses this as the geometric condition,based on the sound pressure detection mechanism and the city gas pipeline.The leakage characteristics of the experimental pipeline were constructed by FLUENT software.The simulation analysis of the sound field and pressure field of the pipeline leakage was carried out.The variation of flow velocity,sound pressure level,sound power level and pressure field was recognized.The experimental device design and development and leak detection research laid the foundation.2.Through the system design method,after the calculation and comparison and selection,the overall structural design,operation flow design,main equipment and data acquisition system selection design of the gas pipeline leakage sound pressure signal detection experimental device,and the LabVIEW virtual instrument platform were carried out.The core program was developed twice,and the experimental device system was set up in the field.By controlling the leakage amount,the effects of different leakage conditions such as micro hole and small hole leakage and the detection effect of leakage sound pressure signal under different pipeline conditions are realized.After the debugging operation of the device,the sound field and pressure field of the pipeline leakage are further verified.Change laws and signal characteristics.3.By designing the pipeline testing experimental scheme of unleaked working conditions and leakage working conditions,the experimental device was used to carry out the experimental research on the sound pressure signal detection and leakage identification of the simulated gas pipeline,and the wavelet transform processing method was adopted for the collected signals.The time point of the sudden change of the sound pressure signal of the pipeline leakage signal under the experimental conditions is taken as the time point of the pipeline leakage,and the time domain characteristic amplitude,noise energy interval and pressure signal frequency domain of the acoustic signal are found.The magnitude of the power spectrum serves as a basis for interactively identifying leaks in the pipeline.4.The experimental scheme of pipeline leakage point location was designed by changing the pressure and sensor arrangement.The experimental application of simulated gas pipeline leakage location was carried out by using experimental equipment.Combined with the twopoint positioning model of acoustic signal and cross-correlation positioning method,the experimental data was used to calculate the signal delay.Time and pipe leak point locations provide a reference for quickly finding leaks.