Thermo-structural FEM analyses of upgraded components in an industrial gas turbine

This thesis is a result of a partnership between Politecnico di Torino and Ethos Energy Group. The main project is based on the improvement of TG20 B7/8 (gas turbine produced by Ethos Energy Group) to a new upgrade called “TG20 B7/8 UG3”. The aims of this improvement are to increase efficiency and the net produced power and furthermore to decrease the NOx emission. This work is one of the parts of the entire project and it is regarding the analyses of the thermal and structural loads that are applied in the turbine. This is done to ensure that innovations applied to the engine do not endanger the gas turbine’s life. Initially, analyses are done for the standard version of the gas turbine, to create a base of comparison for the upgraded version. This evaluation is computed in three phases: thermal analysis, structural and thermal analysis and the creep and Low cycle fatigue (LCF) analyses. These three parts are done separately for each of the stage of the turbine. The combined load and the life analysis are computed for the disks. After that, the study moves to the improved design of the turbine (UG3), by considering all the modifications, a new analysis is done, and an evaluation of the results is made to understand the feasibility of the modifications. For all these analyses, a computation of the different heat transfer coefficients is needed, also because they are different from the first studied configurations. Finally, the LCF and the creep life are studied to verify that the new turbine reaches the targets imposed by the company in terms of life and to understand if a modification is needed.