STUDY TOPIC: STEAM PLANT Reference: Chapter 8 in the unit Text Book. Previously, you learned the basics of thermodynamics including basic definition, first and second laws of thermodynamics heat engine cycles. From these study, we know that the most efficient cycle (for heat engine) is the Cornot cycle for given temperatures of source and sink. If the wet vapour is used as working fluid, the Carnot cycle is shown in a T-S diagram below. Figure 1.1 Its essential features is: Process 4 −>1: heat is supplied at constant temperature and pressure. Process 1 −>2: the vapour expands isentropically. In doing so it does work, which is the purpose of the cycle. Process 2 −>3: the wet vapour at state 2 has to be cooled to point isothermally. Process 3 −>4: the rich wet vapour at state 3 returns to its original state at 4 by isentropic compression. Key points of this chapter • The simplest form of saturated Rankine cycle has a high work ratio but a disappointingly low thermal efficiency. • The thermal efficiency can be improved, in theory, by making the cycle more like a Carnot cycle, and by increasing the maximum temperature of the cycle.
has intentionally blurred sections.
Sign up to view the full version.