ABSTRACT
This chapter covers the basic principles governing design, analysis and operation of large steam turbines used in gas turbine combined cycle power plants. It starts with a brief look into combined cycle steam turbine types with the help of product portfolios of major original equipment manufacturers (OEMs). Two fundamental steam path design principles, impulse and reaction, are explained in detail using fundamental aerothermodynamic principles. The linkage between cycle thermodynamics and hardware design is illustrated. The low-pressure (LP) turbine and its last stage with the largest flow annulus (i.e., longest rotor blade) are the most important components of the steam turbine, and their coverage in this chapter is comprehensive. Basic performance calculation methods are introduced with a numerical example.
