Investigation of a thermal-stress state of a heated radiochemical apparatus

Features of the formation of a nonuniform temperature field and the appearance of thermal stresses in linked elements of structures that are washed with media at substantially different temperatures were studied on a radiochemical apparatus. The level and dynamics of changes in temperature stresses in the body of the studied apparatus were found from solution of a static boundary-value problem of thermal elasticity in an axially symmetric formulation by the finite-element method. To specify one of the boundary conditions necessary for solving this problem, the temperature field on the apparatus’s exterior surface was determined experimentally with a NEC Thermo Tracer TH-9100 thermal imager. Other boundary conditions were determined from the results of physical modeling and from approximate analytical solutions. It has been established that the maximum thermal stresses arise during the initial short period when the apparatus is heated by overheated steam supplied into it.