Investigation on leakage detection and localization in gas-liquid stratified flow pipelines based on acoustic method

Abstract

Leakage detection technology is of vital importance to the safe operation and flow insurance of multiphase flow pipelines. This paper for the first time applies acoustic based leakage detection method to stratified flow pipelines and verifies the feasibility of this method in multiphase flow pipelines. Gas-liquid stratified flow pipeline leakage detection and localization experiment is conducted to investigate the effectiveness of different filtering methods when calculating the time difference (delay) between arrival times of leakage acoustic signals at different sensors using cross-correlation algorithm. Propagation characteristics of the leakage acoustic wave in stratified flow are also investigated. The results show that the 5-level Symlets wavelet filter can effectively improve the accuracy of time delay estimation. Moreover, the value of sound speed can be set as 346 m/s when carrying out leakage localization in stratified flow pipelines, which is nearly irrelevant with pressure, void fraction, superficial velocity of gas phase and the structure of pipe. The research in this paper lays a foundation for the application of acoustic based leakage detection technology in multiphase flow pipelines.