PWHT Simulation In FEA For Nozzle With Bulls Eye Method And Circumferential Approach

Abstract

A nuclear power plant is a power generation station using the heat source from a nuclear reactor. In nuclear power plant steam generators are used to convert water into steam from heat produced in nuclear reactor core. Here we take feed water nozzle a small part of nuclear steam generator.in this study post weld heat treatment simulation (PWHT) is performed of nuclear steam generator. In the industry, PWHT is necessary to eliminate residual stresses at the welded area of the components after the welding process. Reheating welded material lowers the critical temperature through a regulated process known as PWHT. The temperature is nearest to 600◦c. The implementation of PWHT techniques on a nozzle weld is explored in this simulation research. The bulls eye method and a circumference approach are two different approaches that are discussed. The efficiency of each PWHT technique in lowering residual stresses and improving the nozzle’s structural integrity is evaluated by analyzing temperature profiles, stresses, and deformation. This study gives in-depth knowledge and compares these two approaches. A study analyzes the deformation & stresses generated at the nozzle and handling lug area. By taking different cases in both approaches the analysis is performed. Temperature mapping with respect to time is also performed in this analysis. This study is performed by using modeling software CATIA, finite element analysis tool ANSYS and meshing tool HYPERMESH. A study is performed with WRC-452 guideline. Size of soaking band, heating band and gradient control band is taking as per requirement and guidelines. The attachment nearest to nozzle like handling lug is also heated. The Boundary conditions and loadings are given to surface area as per requirement. Saddle supports are considered to perform analysis. A study helps to improve PWHT performance in pressure vessels and other industries. The detailed analysis contributes to PWHT in mechanical industries.