Theoretical study and experimental study on leak detection for natural gas pipelines based on acoustic method

In order to study the fundamentals and research methods of leak detection for natural gas pipelines based on acoustic method,the simulation model and experiment model are established.First the aero-acoustics generation mechanism is researched when leak occurs to find out the fundamentals of leak detection for gas pipelines based on acoustic method.And then the simulation model is established on CFD software by which the flow field and the sound field are aquired to analyze acoustic signal characteristics.Thirdly,based on acoustic leak detection method, a complete set of high-pressure gas pipeline leak experimental device and acoustic data acquisition system is designed and the experiment is accomplished based on the consequences of simulation.The paper analyzes the data acquired by experiment and concludes the acoustic signal characteristics which are used to correct the characteristics concluded by simulation method.Finally the paper compares the experimental method with simulation method under variable conditions and find out the law between the different conditions and pressure perturbations which provides a theoretical basis for the engineering applications of leak detection for gas pipelines based on acoustic method.The results indicate:it is the quadrupoles and the dipoles generated by turbulent fluctuations that causes the leak-acoustics;both the simulation method and the experimental method can be applied to study acoustic leak detection method. Conclusions can be drawn that acoustic leak detection method has many advantages such as high sensitivity and less detection time so it can be used in natural gas pipelines better.