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Summary: This paper presents a thermal power plant retrofitting approach focused on improvements in the operational flexibility of existing combined cycle power plants dedicated to providing thermal energy for medium and low‐temperature processes in copper mining facilities. The main motivation for this research was aimed at evaluating the operational flexibility of the electrical industry through sector coupling and its effect on solving the energy sector decarbonization issues. The research evaluates the advantages of hybridization systems for supporting the electrical and mining industries to better predict operations. The proposed approach is based on a dynamic simulation scheme that finds the optimal operating parameters of the combined heat and power (CHP) system, such as location, type, and arrangement of each component of the CHP system. The power plant dynamic simulation model was validated against data available in the literature; it was also characterized by real operational data of the San Isidro II power plant installed in Chile. Several alternatives for the cogeneration plant location, as well as the splitter system design, were investigated and then compared. A cogeneration plant design with two heating modules was selected based on the comparative study performed in this work and its CHP system was evaluated for a load reduction case study. The results were compared against a reference model. The proposed CHP system exhibited improved performance: a minimum of 15% of the exhaust gases are required to supply the thermal energy demand of the electrowinning process when a full load is considered. It was also found that an average decrease of 5% of the mechanical power at each steam turbine stage noted. Finally, the proposed CHP system's average thermodynamic efficiency is found to be 19% greater than the power plant average efficiency. Consequently, an average decrease of 32 500 tons of carbon dioxide emissions per year is predicted. [ABSTRACT FROM AUTHOR]

This paper presents a thermomechanical analysis of a first stage bucket during a gas turbine startup. This analysis uses two simulation techniques, computational fluid dynamics (CFD) for the conjugate heat transfer and flow analysis, and finite element analysis (FEA) for the thermostructural analysis. Computational three-dimensional models were developed using two commercial codes, including all elements of the real bucket to avoid geometric simplifications. An interface was developed to transfer the three-dimensional behavior of bucket temperatures during turbine startup from CFD analysis to subsequent FEA analysis, imposing them as a thermal load. This interface virtually integrates the computational models, although they have different grids. The results of this analysis include temperature evolution and related stresses, as well as the thermomechanical stresses and zones where they are present. These stresses are dominated by thermal mechanisms, so a new temperature startup curve is proposed where the maximum calculated stress decline around 100 MPa, and almost all stresses are lower throughout the transient analysis. The results are compared with experimental data reported in the literature obtaining acceptable approximation. [ABSTRACT FROM AUTHOR]

This article presents a numerical study of solid particle erosion (SPE) on the nozzle of the first stage steam turbine. The analysis consists of the application of Eulerian conservation equations to the continuous phase and the comparison of the DNV-Haugen, Neilson-Gilchrist, Tulsa-Ahlert, and Tabakoff-Wakeman erosion models to the discrete phase. This analysis is developed using computational fluid dynamics software based on the finite volume method. This study permits the selaction of the erosion model which presents the best numerical predictions to know the SPE influence on the blade surface, with variation of parameters such as steam mass flow rate, diameter, impact angle, velocity, and distribution of particles. These parameters were modified within a real operational turbine range. This study shows that the Tabakoff-Wakeman model predicts with greater accuracy the SPE in steam turbine blades and the particle diameter is the most critical parameter. [ABSTRACT FROM AUTHOR]