The Inner Wall State Monitoring Method For The Industrial Main Pipe

In engineering practice, the inner wall of many industrial main pipes operate in theenvironment of high temperature, high pressure, medium erosion for a long time. So thedamages and sheddings are prone to emerge in the inner wall of the device during use.However, currently quantitative analysis of the inner wall defects is lack during theindustrial production. These defects can’t be found easily in the detection of the inner wall,and these defects will become the safety risks. So it is very important to detect the locationand the severity of the inner wall defect accurately and in real-time. In order to ensure thesafely operation of the equipment, the detection of the inner wall defect has become anurgent practical problem. The equipments’ inner wall condition monitoring technology isconducted on the premise of not damaging the performance and condition of theequipment. The special evaluations on the quality and internal structure of the device areachieved through the analysis on the outer surface temperature distribution data of thedevice. This technology plays an important role in the on-line defect monitoring of theindustrial mains pipe device.In this paper, the inner wall defect monitoring theory of the industrial main pipeequipment is mainly researched and analyzed. The specific contents are as follows:Firstly, the three basic methods of heat transfer and the heat transfer laws areintroduced. The boundary conditions, the initial conditions, the definition andclassification of the steady and unsteady heat transfer in the heat conduction problem areanalyzed. The heat transfer laws of the industrial main pipe’s defect model are studied.Then the theories and the solution methods of the inverse heat conduction problem arefocused on the inner wall condition monitoring problems of the industrial main pipe.Secondly, the temperature field model, and the form description of the heatconduction differential equation in several typical coordinates are described. The boundaryconditions and the basic solution methods of the thermal differential equations areintroduced. Based on the analysis of the heat conduction theories, the MathematicalPhysics method is used to solve and analyze the industrial main pipe’s inner wall condition monitoring model. Then the inner wall condition monitoring model of theindustrial main pipe has been established.Finally, the finite element analysis software Comsol Multiphysics is used in thesolving process of the heat conduction problem. The methods and steps of this softwareare introduced, and the solution of the outer surface temperature with this software hasbeen achieved. At the same time the effect of many external factors to the outer surfacemaximum temperature difference has been analyzed. The resulted outer surfacetemperature distribution is taken as the boundary condition, and is substituted into theinner wall condition monitoring model. Then the identification of the industrial mainspipe’s inner wall geometry boundary is achieved. The recognition result of the inner wallboundary geometry is compared with the set boundaries, so that the feasibility of thismodel can be verified.