Research on Leakage Localization in Gaseous CO2 Pipelines Using the Acoustic Emission Method

In the CCUS industrial chain, the pipeline transportation of CO2 is a crucial link that connects the upstream and downstream. However, currently, there is still no reliable, stable, and efficient method for detecting pipeline leaks. Based on the time difference in arrival (TDOA) localization method within the acoustic emission technique, this study conducted preliminary experiments on air pipeline leak localization and experiments on gaseous CO2 pipeline leak localization, thereby establishing the applicability of acoustic emission technology for leak detection in gaseous CO2 pipelines. In the preliminary experiment on air pipeline leak location, the SNR (signal-to-noise ratio) of the CEEMDAN denoising algorithm is greater than that of the EEMD denoising algorithm. The larger the SNR, the smaller the signal interference, which proves the superiority of the CEEMDAN denoising algorithm. In the experiment on gaseous CO2 pipeline leak location, the CEEMDAN denoising algorithm was adopted. Five time-delay estimation methods, namely GCC, Roth weighting, PHAT weighting, ML weighting, and SCOT weighting, were used for location calculations. The positioning accuracies were 10.6%, 6.9%, 6.9%, 8.6%, and 8.6% respectively, all meeting the engineering accuracy requirements. Combining the results of the preliminary experiment on air pipeline leak location, the Roth weighting time-delay estimation method is recommended. The results show that: Acoustic emission technology can be used for the leak location of gaseous CO2 pipelines.