Acoustic source characteristics of built-in acoustic emission sensor in storage tank

On-line acoustic emission detection technology for large crude oil storage tanks is affected by the larger diameter of tank bottom, and the attenuation of acoustic source signal in the central area is obvious. It is difficult to obtain the complete acoustic source signal of tank bottom corrosion by traditional detection methods. In this paper, a wide-area acoustic emission detection method associated with the built-in sensor array and the peripheral sensor array of tank wall is proposed. The difference of arrival time of acoustic source signal can be more accurately obtained by the full-phase multiple cross-correlation algorithm, and the accurate localization of the whole-area acoustic source signal of tank floor corrosion can be achieved by combining the three-dimensional overdetermined localization algorithm. The validation experiment is carried out in the simulated vertical tank. The experimental results show that the three-dimensional overdetermined location method based on all-phase multi-correlation can be effectively used to locate the sound source with mixed arrangement inside and outside the sensor, and the location accuracy is higher than that of the traditional detection method sticking to the outer wall multiple cross-correlation.