Experimental study on new leak location methods for natural gas pipelines based on dynamic pressure waves

Natural gas is a vital energy carrier that can serve as an energy source for domestic and commercial applications by supplying electricity and heating through pipeline systems. Natural gas pipelines are extremely vulnerable to leakages, and leaked gas clouds from gas pipeline leakages may be ignited with low energy. Although pipeline safety has increased in recent decades, incidents involving natural gas pipelines still result in fatalities and property damage annually. In order to reduce gas pipeline leakage and increase consumer safety, a leak detection and location method based on dynamic pressure waves (DPWs) was proposed and researched experimentally. Firstly, new leak location methods based on the improved WT method and the propagation model were proposed. An improved wavelet transform (WT) method was designed, and a theoretical propagation model of DPWs in gas was established. Once two key points were clarified, experimental facilities were established at a laboratory scale and experiments were carried out, through which, the time difference (TD) was calculated, the propagation model and the leak location methods were verified. The results indicate: the improved WT method is superior to the WT method in calculating the TDs for leak location; the method based on the amplitude propagation model can be achieved without TD calculation; the proposed methods are efficient in locating leakages in natural gas pipelines. Finally, the proposed methods were applied in the field. The maximum absolute values of the field leak location errors for the two methods were 0.725% and 0.735%. It is concluded that the new methods can protect and monitor natural gas pipelines.