Influence of flow conditions on the distribution of thermal stresses in the waterwall tubes connected by fins

Abstract

In this study are presented results of numerical analysis of the thermal conditions of smooth waterwall tubes connected by fins and heated with equal heat flux. Inside tubes flows the water at supercritical parameters. The thermodynamic parameters at the inlet to each tube are similar but the mass flow of the fluid differs in each tube. Numerical model used for analysis allows to determine the temperature distribution, in online mode, in every control element of the analysed tubes and in the finite elements of the working fluid depending on the current thermodynamic parameters of the fluid and tubes. After calculation of the temperature distribution field, it can be used to determine the thermal stresses distribution in tubes and fins and determine the parts of elements, where the maximum values of the thermal stresses occur. The presented analysis was carried out for comparison of the thermal stresses distribution in small fragment of the combustion chamber wall in case of changing the fluid mass flows in neighbouring waterwall tubes.