Development of a Low-Pressure Section for Industrial Power Generation Application

The Low Pressure (LP) stages are critical components in any steam turbine product line, as their contribution has a significant impact on overall expansion and their specific operability design limits may pose restriction to the turbine operation. The authors’ company designed a new family of LP stages for power generation applications aimed at improving the efficiency and the overall design of the existing low-pressure sections for 50 Hz and 60 Hz industrial power generation applications of a comparable annulus area. Industrial power generation comprises a wide range of applications for fixed speed 50 Hz and 60 Hz LP stages, especially in Waste to Energy plants, Concentrated Solar Power plant, Geothermal plants, Combined Cycles plants, Captive Power plants and more recently, energy transition process power plants (e.g. green hydrogen production). This wide application mix establishes an ample set of requirements in terms, among the others, of off design performances, frequent start up, high exhaust pressure capability and capability to sustain operation in low load and erosion promoting conditions which poses a specific challenge in the definition of a single optimal design. This paper will present a broad review of the typical operational and design requirements dictated by the various industrial power generation applications along with the summary of the all the phases of the design with focus on the technology related aspects of the different components developed, including exhaust system.