Thermodynamic analysis of steam turbines for ultracritical, supercritical, subcritical and geothermal cycles

Abstract

This paper presents the thermodynamics analysis of the power generation plants that use ultracritical, supercritical, subcritical regenerative steam cycle configurations and geothermal systems with two and three flash steam. This analysis is mainly carried out on the steam turbines to analyze the energy transformation and degradation in each of the expansion stages as function of the degree of overheating and the generated irreversibilities. The greater exergetic efficiencies are obtained in the stages of expansion of intermediate pressure that are done after the first and second reheat. However, for the case of the supercritical cycle the maximum efficiency occurs in the second stage of expansion of the high-pressure section. Geothermal systems have the lowest efficiencies due to their low enthalpy condition, although the availability of energy is used in 42%.