Monitoring And Research, Based On A Long Pipeline Of The Negative Pressure Wave Leakage

With the unique advantage of transmitting gas, liquid and slurry, pipeline has become the fifth important conveyance after railway, highway, waterway and voyage. Because of inevitably pipeline aging, erodibility, stiletto steal and so on, leakage accident happends frequently. It interferes in natural production badly, brings enormous economic losing and pollutes the environment. So the research and application of the leak detecting and locating system of transporting-oil pipeline becomes an urgent problem. Advanced research of leakage detection and location of pipeline can find the leakage of pipeline and take action quickly. It may reduce the happening of steal case, avoid the pollution of environment, reduce the interprise's economic losing and improve the level of interprise's automatic management.This dissertation compares and analyzes some kinds of leak detecting technologies of pipeline, and then proposes some methods based negative pressure wave to finish pipeline leak detection and location depending on runtime situations. In order to decrease noise at the wave curves of negative pressure, this dissertation compares the advantages and disadvantages of gliding window average filter, medium and mean filter zp.d wavelet analysis method, and finally selects one-dimension wavelet anyli sis method as the main decreasing noise filter. After filtering noise, this dissertation studies the propagation process of instantaneous negative pressure wave caused by leak of crude petroleum transported pipeline and then uses a phased accumulative algorithm to distinguish the features of pressure wave. This dissertation proposes a new instantaneous negative pressure wave detecting method based statistical method. After distilling layered waves' characters, this dissertation proposes a new mothod of detecting pipeline leaks with application to analyzing the negative pressure wave using structural pattern recognition.