Analýza vedení tepla a degradace palivové stěny kotle

Abstract

The diploma thesis deals with the analysis of physical processes taking place at the weld joint of the heat exchanger. The purpose is to obtain information about the temperature field in the region of the pressure fins and beyond, depending on the dew point of the flue gas. The first part describes the exposed part of the device, defines the boundary conditions according to which the results used in other simulations of heat conduction are subsequently calculated. The second part is focused on the theory of degradation processes taking place in the reducing environment of the wood fuel tank. Degradation, corrosion is mainly influenced by the chemical composition of the flue gas, the humidity of the fuel, the amount of air. This dependence is described by the method of dimensional analysis, where the resulting dimensionless criteria are determined. In the next part geometry for the numerical model of the pressure rib and the wall of the fuel tank is described. Microsoft Excel was used for numerical calculation using the mesh method. For comparison were also created dimensionally shaped models. The results are clearly graphically compared and shown. A non-stationary temperature model can be created by using a finite element simulation program with usage of the previously obtained values in this work. The resulting model is similarly analyzed with more accurate results. Both methods are then compared and evaluated in the final part, where the reader should get a comprehensive overview of the issue, results and subjects for other follow-up subjects.