variavel0=<b>Rafaela Frota Reinaldo</b> - rafaela@cet.ufsc.br Universidade Federal de Santa Catarina
<b>Antônio Carlos Ribeiro Nogueira</b> - nogueira@emc.ufsc.br Universidade Federal de Santa Catarina
<b>Edson Bazzo</b> - ebazzo@emc.ufsc.br Universidade Federal de Santa Catarina
<b>Gilson Atanásio</b> - gilson@sinmec.ufsc.br Universidade Federal de Santa Catarina
<b>Diego Guimarães Amorim de Oliveira</b> - diego@sinmec.ufsc.br Universidade Federal de Santa Catarina
<b>Abstract.</b> The thermal gradients along the tubes in the superheater and reheaters are known to cause failure by creep and are important factor determining the utility boiler unavailability of the power plant unity in the electric system. To evaluate the magnitude of thermal gradients and to estimate the residual life of tube bundles, we propose the use of a commercial package to calculate the heat transfer and models for the prediction of failure by creep. This work presents initial numerical results for the fluid flow simulation inside a 125MW utility boiler. Four different types of mesh refinement were used and their effects on the calculated flow field were accessed.
<b>Keywords.</b> steam generator unity, utility boilers, numerical simulation, mesh study.