Research And Application Of Accurate Location And Detection Method For Leakage Points In Gas Pipelines

With the rapid development of the national economy,the social demand for gas is increasing year by year,and the scale of gas pipeline network is increasing.In recent years,gas pipeline leakage incidents have occurred from time to time due to disrepair.Gas pipeline leakage not only causes economic losses and environmental damage,but also poses a huge threat to social safety.It is found that the leakage detection technology of urban gas pipeline has not been popularized and applied on a large scale.This technology has a broad market,and the single leakage detection technology used in urban gas pipeline has some limitations,such as the accuracy needs to be improved.This thesis studies a technology and device based on the interaction of acoustic wave and pressure wave to detect the leakage point and achieve accurate positioning.The main work and conclusions are as follows :(1)Through characteristic analysis and pipeline leakage point algorithm research,a pipeline leakage point detection method based on acoustic pressure interactive recognition method is proposed.The distance calculation formula between the leakage point and the sensor installation point is obtained.Theoretical derivation proves that the method is more accurate than the single pressure wave detection method and the acoustic wave detection method.(2)The CFD fluid software is used to construct the leakage flow field simulation model of the gas pipeline,and the flow field changes before and after the leakage point are simulated and analyzed.Based on the wavelet transform method,the acoustic signal and pressure wave signal generated by gas leakage are denoised to obtain the eigenvalues of the pipeline leakage sound pressure wave signal.(3)The sound pressure wave acquisition device of urban gas pipeline is designed and developed.It is confirmed that the sound pressure interactive detection method has better performance than the single pressure wave detection method and the sound wave detection method in the experimental test field with a length of 100 m.The accuracy of the sound pressure interaction detection method is 100 % when the leakage is greater than 10 %,and the relative error is 0.07%,which meets the actual needs.