DEVELOPMENT OF A NOVEL STEAM TURBINE LOW PRESSURE SECTION FOR VARIABLE SPEED APPLICATION

Low Pressure (LP) stage design characteristics play a key role in Steam Turbine (ST) product line as they typically set limits to the maximum turbine flow and rotating speed and have a strong influence on the overall turbine efficiency. LP stages design presents a combination of structural and aerodynamics challenges that obliges the manufacturers to develop and test the design well in advance with respect to the turbine design schedule. For the same reason (development complexity) an LP stages design is usually scaled to cover a wide range of rotating speed and annulus area. The set of scaled LP stage is referred to as LP stage family. The author's company has started the design of a new family of LP stages for power generation and mechanical drive application. The initial phase of the development has focused on the design of the master size, development of the entire family and manufacturing process qualification. This paper will present a comprehensive review of all the phases of development with the intent to share an OEM perspective of the key technical aspects involved in the development of these components.