11. Power Gas Turbines

A gas turbine is a turbomachine composed of a compressor part, a part with heat supply to the compressed gas and a turbine part in which the hot gas expands. The present chapter discusses gas turbines for mechanical power ­generation. These are machines with an outgoing shaft, meant to drive a load. The largest market sector of such machines is electrical power generation, but machines for driving compressors and pumps in industrial plants and for driving large vehicles and ships also are examples. We discuss the working principles of the components of power gas turbines in the present chapter. As electric power generation is the largest sector of application, we choose components of such machines for illustrations. The main purpose of the chapter is the discussion of the overall performance of power gas turbines. Performance analysis is a matter of thermodynamic modelling and is not strongly linked to a particular application.