Análisis técnico-económico de la sustitución del ciclo de vapor por uno de CO2 supercrítico en configuraciones de ciclo combinado.

Abstract

The present work analyzes the technical and economic viability of the supercritical CO2 cycles as substitutes of the steam cycle of a combined cycle. Its application as a waste heat recovery system is interesting not only in commercial power plants (200 to 400 MWe) but in gas microturbines, in order to analyze its profitability improvement. The first part of the project consists in the study of the parameters of the gas Brayton cycle (head cycle) to determine the entry conditions of the supercritical CO2 cycle (sCO2). After comparing different cases of secondary cycles applied to the gas cycle with microturbine, the most interesting alternative was considered. The study continues with the modeling of the simple Brayton with Industrial Gas Turbine (sT) and Central Turbine. of Combined Cycle (ccT). Of all the cases analyzed, one of the confirmations has been selected as the object of study. The project continues with the dimensioning of the exchangers and pipes of the cycle. Finally, an economic assessment of the combined cycle and a sensitivity analysis with different scenarios of natural gas prices and CO2 emission costs have been carried out and alternatives have been proposed to optimize the profitability in future studies.

The present work analyzes the technical and economic viability of the supercritical CO2 cycles as substitutes of the steam cycle of a combined cycle. Its application as a waste heat recovery system is interesting not only in commercial power plants (200 to 400 MWe) but in gas microturbines, in order to analyze its profitability improvement. The first part of the project consists of the study of the parameters of the gas Brayton cycle (head cycle) to determine the entry conditions of the supercritical CO2 cycle (sCO2). After comparing different cases of secondary cycles applied to the gas cycle with microturbine, the most interesting alternative was considered. The study continues with the modeling of the simple Brayton with Industrial Gas Turbine (sT) and Central Turbine. of Combined Cycle (ccT). Of all the cases analyzed, one of the confirmations has been selected as the object of study. The project continues with the dimensioning of the exchangers and pipes of the cycle. Finally, an economic assessment of the combined cycle and a sensitivity analysis with different scenarios of natural gas prices and CO2 emission costs have been carried out and alternatives have been proposed to optimize the profitability in future studies.