Automatic shape optimization of the first step labyrinth seal of a geothermal steam turbine

Miguel Tamayo Soto; Ángel Cerriteño Sánchez; Heriberto Arias Rojas; Sergio Galvan; Francisco Javier Domínguez Mota; Nicólas-David Herrera Sandoval

doi:10.15649/2346075X.4996

Authors

Miguel Tamayo Soto Universidad Michoacana de San Nicolás de Hidalgo, Facultad de ingeniería Mecánica, Morelia, México. https://orcid.org/0009-0000-8485-6321
Ángel Cerriteño Sánchez Universidad Michoacana de San Nicolás de Hidalgo, Facultad de ingeniería Mecánica, Morelia, México https://orcid.org/0000-0001-7925-0237
Heriberto Arias Rojas Universidad Michoacana de San Nicolás de Hidalgo, Facultad de Ciencias Físico-Matemáticas, Morelia, México https://orcid.org/0000-0002-7641-8310
Sergio Galvan Universidad Michoacana de San Nicolás de Hidalgo, Facultad de ingeniería Mecánica, Morelia, México. https://orcid.org/0000-0002-6925-707X
Francisco Javier Domínguez Mota Universidad Michoacana de San Nicolás de Hidalgo, Facultad de Ciencias Físico-Matemáticas, Morelia, México https://orcid.org/0000-0001-6837-172X
Nicólas-David Herrera Sandoval Tecnológico Nacional de México, Campus Morelia, Morelia, México. https://orcid.org/0009-0007-6057-5470

DOI:

https://doi.org/10.15649/2346075X.4996

Keywords:

Labyrinth seal, Steam Turbine, Numerical Optimization, Genetic Algorithms

Abstract

Introduction. The design of straight labyrinth seals for a steam turbine has had little progress concerning their geometry. As an auxiliary system, its current shape causes a significant loss of efficiency in this machine. Objective. This study aims to evaluate the use of an automatic optimization process to define a more suitable seal profile that increases the pressure ratio at the first stage of a steam turbine installed in a geothermal field in México. Materials and Methods. Multidisciplinary software, controlled by a PowerShell script, were coupled to optimize the seal shape in response to the flow and pressure field given by a computationally cheap CFD model of the first step of the labyrinth seal. Results and Discussion. By parameterizing the seal geometry, the leading edge was automatically manipulated with the numerical algorithm, obtaining an angle tendency towards 45°. This new leading edge decreased the outlet pressure of the seal system by 1.2%, which, for a total of 5 stages in the turbine with the same seals, would result in a 6% pressure reduction. Conclusions. It is inferred that this practical methodology could easily update the seal design during the turbine re-powering operations.

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