Abstract: Disclosed is a method for detecting leakage of a full-capacity liquefied natural gas (LNG) storage tank by acoustic emission. The method includes: detecting an amplitude of system noise by an acoustic sensor, and determining a signal acquisition threshold; acquiring an amplitude of ambient noise; acquiring an amplitude of the acoustic signal excited by the analog sound source at the distance of 0.1 m from the acoustic sensor and an amplitude of the acoustic signal excited by the analog sound source at the distance of x m from the acoustic sensor, and calculating, an attenuation coefficient of an acoustic signal passing through the outer wall of the storage tank; determining a maximum detection range of the acoustic sensor; and continuously moving the acoustic sensor on the outer wall of the storage tank in a step smaller than the maximum detection range, to perform an LNG leakage detection.

Abstract: An acoustic emission internal testing method and device for detecting corrosion of a large liquid-carrying storage tank bottom plate. An acoustic emission sensor is configured to collect an acoustic emission signal generated by an underwater acoustic transducer, and to calculate an attenuation coefficient of the acoustic emission signal when propagated by the underwater acoustic transducer through a medium, thereby determining a step distance of the storage tank robot. After the storage tank robot travels every step distance on a storage tank bottom plate, the acoustic emission sensor collects an acoustic emission signal generated by the storage tank bottom plate. Finally, the position where the storage tank bottom plate is corroded and the corrosion degree are determined according to intensity characteristic parameters and activity characteristic parameters of the acoustic emission signal collected after the storage tank robot travels every step distance.

Abstract: An apparatus and method for testing sensitivity consistency of an acoustic emission sensor are provided. The apparatus uses a cylindrical polymethyl methacrylate (PMMA) rod as a test bench. A clamping seat, a clamping block, and a mounting cylinder are mounted on one end of the test bench in cooperation. Under an action of a pressure spring, an end face of a tested sensor keeps pressure-stable coupling contact with an end face of the test bench. A bracket is mounted on another end face of the test bench, and keeps, together with a fixing seat and the clamping seat, the test bench horizontally placed on a desktop. By adjusting a width and an amplitude of a pulse excitation signal of a signal generator, and according to sensitivity distribution and aggregation between tested sensors, a consistency calculation method is used to screen out tested sensors with first, second, and third sensitivity consistency.