Long Distance Pipeline Leak Detection and Location Based on Center Frequency Method

In recent years, the condition monitoring of underground transportation pipelines has garnered significant attention from various sectors, as their condition directly impacts daily operational efficiency. This paper proposes an acoustic detection method and introduces a long-distance pipeline leak detection and localization strategy based on the center frequency method. Hydrophones are placed upstream and downstream of external valves along long-distance transportation pipelines to receive leak signals. The coherence function and cross-spectral density between upstream and downstream signals are calculated to identify similar frequency bands where the leak signals are concentrated. The signals are then pre-filtered to remove most environmental noise, and the long signals are segmented. Using the Variational Mode Decomposition (VMD) method, the signals are decomposed to a certain level where the center frequencies of each mode are close. Kurtosis is calculated for the mode components to construct high Signal-to-Noise Ratio (SNR), robust signals. Finally, cross-correlation analysis of the reconstructed signal is performed to obtain the time delay and calculate the leak location. Simulation experiments with multiple sets of measured data demonstrate that the proposed method has a minimal error percentage compared to the actual leak location(2.5%), showcasing its practical value.