Simulation Research On Acoustic Emission Signal Of Tank Corrosion

With the rapid development of national economiesèeach country is growing demand for energy. And, fossil energy is a major position in the energy supply. Large-scale atmospheric energy storage tank is essential for these devices, therefore, the use of tank safety issues related to the whole energy. More related to the country's political, economic, environmental and other major life issues. A few years ago, the tank needs to use off-line testing. This method not only takes a long time, but requires a lot of manpower and financial resources. Acoustic emission testing is a new type of dynamic non-destructive testing methods, can be implemented online testing, is a great potential for development of detection methods.This paper describes the principles of acoustic emission signal, based on this study due to tank corrosion and acoustic emission signals. Because the use of tanks for a long time, many have not closed tightly. This is likely to cause the water outside go into the tank, and the water density is light than the oil, most of the water deposited on the bottom, this will generate electrochemical corrosion. Therefore for the tank, the bottom of the tank is the most serious part of the corrosion. This part is main focus on the corrosion research of the oil tank bottom.This paper studies through the application of large finite element physics simulation software COMSOL simulation of coupled the propagation of acoustic emission signals within the tank. Acoustic emission signal is a form of elastic waves, is a kind of mechanical waves. Therefore, the theory of acoustic emission signals can follow the elastic wave propagation in solids and liquids in the propagation theory. Simulation is divided into two-dimensional and three-dimensional simulation. The end of Oil tank is two-dimensional simulation, the entire tank is three-dimensional simulation. Through modeling, meshing, solving and post processing, the simulation graph of the acoustic emission signals distribution inside the tank can be result. Two-dimensional simulate different kinds of situations , the point source strength are the same with different positions, and the same point source position with different intensity, Three-dimensional simulate many kinds of situations, different point source with the same medium inside the tank, the same medium with different point source and the same point source with different intensity. The propagation of acoustic emission has a greater relationship with dissemination of media, the point source position, and the different interfaces. Under certain media, signal is transmit along the circle, sensors can be arranged around the wall, and with some distance from the bottom of the tank, this allows simultaneous detection the defects in the tank bottom and wall.