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: A device and method for leakage detecting of a crude oil tank floor are provided, the leakage detection field of oil storage tank base plates is related to. The device comprises a control system, a detection robot and a plurality of acoustic signal receivers. The acoustic signal receivers and the control system are all arranged outside a crude oil tank. The control system is arranged outside the crude oil tank. The acoustic signal receivers are all connected with the control system. When the crude oil tank is detected, the detection robot is arranged in the crude oil tank. The detection robot comprises a moving mechanism, a positioning sonar and an array leakage detection sensor. The positioning sonar and the array leakage detection sensor are both arranged on the moving mechanism. The acoustic signal receivers are used for receiving sonar signals sent by the positioning sonar. The array leakage detection sensor is used for detecting a leakage point of the crude oil tank.

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.

Abstract: A magneto acoustic emission detection method for fatigue damage of ferromagnetic metal components: First, generating an excitation magnetic field by using a sine wave voltage signal, gradually increasing a loading voltage until a magneto acoustic emission signal of a bimodal envelope with an obvious tail peak is acquired, and taking a corresponding voltage peak value as a reference voltage; second, generating an excitation magnetic field by using a square wave voltage signal equal to or higher than a reference voltage, and acquiring a magneto acoustic emission signal with a T-shaped envelope; and third, calculating the average value of peak-to-peak values of the magneto acoustic emission signal in multiple periods to serve as a characteristic parameter, and enabling the characteristic parameter to have inflection point change along with the development of the initiation and expansion of the fatigue crack, and giving a timely early warning for the failure of the component.

Abstract: A magneto acoustic emission detection method for fatigue damage of ferromagnetic metal components: First, generating an excitation magnetic field by using a sine wave voltage signal, gradually increasing a loading voltage until a magneto acoustic emission signal of a bimodal envelope with an obvious tail peak is acquired, and taking a corresponding voltage peak value as a reference voltage; second, generating an excitation magnetic field by using a square wave voltage signal equal to or higher than a reference voltage, and acquiring a magneto acoustic emission signal with a T-shaped envelope; and third, calculating the average value of peak-to-peak values of the magneto acoustic emission signal in multiple periods to serve as a characteristic parameter, and enabling the characteristic parameter to have inflection point change along with the development of the initiation and expansion of the fatigue crack, and giving a timely early warning for the failure of the component.