CHAPTER 1 - The steam turbine

Abstract

A turbine requires a suitable working fluid, a source of high-grade energy, and a sink for low-grade energy to function. When the fluid flows through the turbine, part of the energy content is continuously extracted and converted into useful mechanical work. Steam and gas turbines use heat energy while water turbines use pressure energy. The main objectives of the turbine designer are to ensure that this process is carried out with maximum efficiency by means of a plant having maximum reliability at minimum cost. The plant should also require minimum supervision and minimum starting time. This chapter focuses on the modern power station practice as implemented by UK turbine makers. It also explains the reasons behind every facet of turbine development. For turbines driving electrical generators, the limit of a single-cylinder turbine is around 100 MW, depending on the design concepts, the initial steam conditions whether or not a reheat cycle is used, the exhaust conditions, and the speed of rotation. The chapter discusses the thermodynamics and economics of the steam cycle and describes the applications of turbine.