Análise numérica das variáveis do processo de soldagem em operação utilizando os programas Battelle e Ansys

Abstract

In-service welding is a procedure widely used in industry when you want to expand the pipeline network through derivations or to carry out repairs on components without the flow of internal fluids being interrupted. Repairing pipelines in operation, through the placement of gloves, using the welding process, is a common intervention and it is cost-effective. However, this type of intervention requires a thorough analysis to ensure the operational safety and high quality of the welds performed, since any unwanted leaks or perforations can represent serious accidents and cause personal and environmental damage. In general, these analyzes are theoretical studies with bench experimentation. In this context, numerical simulation plays a fundamental role in defining the experimental conditions under which the welding in operation will be carried out. Battelle is a simulation program that is recommended by standards and therefore widely used to support ongoing welding operations. However this is a program with a relatively small number of duct and fluid material types, restricting its application to situations that are covered in its library. In this context, aiming to fill this gap, Ansys Fluent program was used to simulate this welding process in operation, with greater possibility of combinations of fluids and materials for welding applications in operation. An ellipsoid mobile three-dimensional heat source was used to traverse the weld bead, from a fillet joint, between the full enveloping sleeve and the pressurized tube. Some combinations of welding parameters and pipeline operation were used, and evaluations of the thermal character results were carried out. In parallel, validation simulations were performed using the Battelle program. The simulation using the Ansys program was able to predict the thermal aspects of the welding process and, in comparison with the Battelle program, presented good approximations for the lowest welding energies, with errors from 2 to 5.7%, and regular approximations for the highest welding energies (1.13kJ/mm and 1.35kJ/mm), with errors from 11.3 to 21.3%.