Research On Slow Leak Detection And Location Method Based On Of Signal Downsampling And Virtual Acoustic Signal

A slow leak is a leak with a slowly decreasing pressure.A gradual increase in the leaking aperture or a gradual slack in the outer covering of the leak is the root cause of a slow leak.The amount of leakage corresponding to a slow leak is not necessarily small,but the signal-to-noise ratio must be low when the leak signal propagates to the sensor mounting position due to propagation attenuation.Since the amount of leakage caused by slow leakage is not small but the signal-to-noise ratio is relatively low,such leakage is difficult to detect,and the resulting damage is also greater.Research and exploration of accurate and sensitive detection methods for slow leakage can effectively reduce the false negatives and improve the accuracy and reliability of leak detection,thus ensuring the safe operation of pipeline transportation and avoiding the occurrence of major accidents.It has important theoretical significance and application value.By analyzing and comparing the time-domain characteristics of the sudden leak pressure signal and the slow leak pressure signal,this paper proposes a signal enhancement method for the slow leak pressure signal:using signal downsampling and signal period compression method to effectively increase the pressure of the slow leak pressure signal.Decline rate;combined with virtual sound wave technology,the pressure signal is converted into a virtual sound wave signal,effectively realizing the signal enhancement of the slow leak signal.The method can effectively improve the detection capability of the system for slow leakage pressure signals without changing the leakage detection method of the original leakage monitoring system,and has good portability and achievability.Aiming at the problem that the time resolution of the above-mentioned virtual acoustic wave signal is compressed to different degrees,which affects the accuracy of leakage positioning,a method for improving the leakage positioning accuracy based on signal interpolation reconstruction is proposed,which effectively improves the accuracy of slow leakage positioning.The time domain characteristics of virtual acoustic wave signals under normal pipeline operation and pipeline leakage are analyzed and compared.A virtual acoustic wave anomaly signal extraction method based on kurtosis threshold is proposed.The one-to-one delay cross-correlation calculation is combined to realize the accurate positioning of slow leakage.The method proposed in this paper is tested by the actual pressure data collected at the site.The test results show that the proposed method of slow leakage signal enhancement and leak detection and detection is accurate and reliable for slow leak detection,accurate positioning,and negative pressure wave method.The acoustic wave method has a greater technical advantage.