Thermal Stress Analysis Of Surge Line By Finite Element

Reactor coolant system pressure boundary is a key power plant safety barrier, its structural integrity must be guaranteed. The surge line connected to the main channel of the reactor coolant system and regulator, belongs to the reactor coolant system pressure boundary. In this paper, ANSYS finite element software was used to carry out the thermal-structure coupling analysis, modal analysis, fluid-solid coupling analysis, and fluid-solid-thermal coupling analysis for the pressurizer surge line of the nuclear power plant.In normal condition, the surge line works under high temperature and high pressure environment. High temperature and high pressure may result in a greater thermal stress in the wall of surge line. A ANSYS finite element software is used to carry out a thermal-structure coupling analysis for a surge line. It is found that the maximum equivalent stress and large stress gradient occur at the two ends of the surge line in either a normal or an accident working condition, while the maximum displacement deformation locates near the central part of the surge line in the two working conditions. These facts should be a reason that results in the bending deformation and thermal fatigue of a surge line.The flow field, thermal field and structure interaction might cause stress, thermal stress and thermal fatigue of hot leg piping in a reactor. In this paper a finite element software of CFD is used to study the coupling properties of hot leg piping section in the fluid, temperature, and stress fields in normal work conditions. It is found that the wall of hot leg piping suffers large stress by the fluid-solid-thermal coupling. The stress arising from fluid- solid-thermal coupling is three folds in magnitude as the stress produced by only fluid- solid coupling, while almost little change of velocity in fluid field is found for the two types of coupling methods.