Research on Immersion-Type Acoustic Emission Detection and Location Method for Large Tank Bottom

When the acoustic emission technology is used to detect the corrosion of the large tank bottom plate, it is not easy to collect information in the central area of the floor due to the attenuation of the corrosion acoustic emission signal, and the detection blind zone is formed. Immersion acoustic detection technology is an effective method to solve the above problem. By using the detector to carry several immersion acoustic sensors into the tank from the manhole, the tank bottom plate is detected in different regions according to the preset route, so as to realize the global detection of the large tank bottom plate. The location of the corrosion source of the tank floor is a key technology when using immersion acoustic testing. To this end, sound source passive positioning method based on time delay estimation, combined with the characteristics of tank bottom immersion acoustic detection, a planar small array unit acoustic positioning method is established. By simulating the tank bottom plate positioning experiment, it can be known that the error of the positioning method in the direction finding accuracy and the ranging accuracy meets the requirements. Using the experimental data, the maximum effective radius R of the immersed acoustic detection unit was determined. According to the large-scale tank immersion acoustic detection method, a prototype of the tank bottom plate acoustic detector was designed.