Study & Analysis of Carnot’s Model for Ideal Machine

1. Study & Analysis of Carnot’s Model for Ideal Machine P M V Subbarao Professor Mechanical Engineering Department IIT Delhi A True Concept of Blue Printing…….

2. expansion Heat Addition Heat Removal A Mathematical Model for (James Watt’s) Steam Engine

3. Carnot Power Cycle Goal: To generate Mechanical Power through from heat input !!! Question: What is the Upper Limit of Engine Performance? Can You Predict? Is it essential to try and find out using only on the field Test?

4. Carnot’s Model for Power Cycle

5. Carnot’s Model for Power Cycle s 1 – 2 : Compressor : Isentropic Compression : s2 = s1 2 – 3 : Boiler: Isothermal Heating : T3 = T2 3 – 4 : Turbines : Isentropic Expansion : s4 = s3 4 – 1 : Condenser: Isothermal Cooling : T1 = T4

6. Compressor : Isentropic Process SSSF: Conservation of mass First Law : No heat transfer, change in kinetic and potential energies are negligible Assuming a single fluid entering and leaving…

7. Use the combined first and Second law statement for a reversible process. Reversible Adiabatic Process:

8. 2 – 3 : Boiler: Isothermal Heating : T3 = T2 No work transfer, change in kinetic and potential energies are negligible QCV 3 2 Assuming a single fluid entering and leaving…

9. For reversible constant Pressure & Temperature Process (change of phase)

10. Turbine : Isentropic Process :s4=s3 3 T 4 No heat transfer. Change in kinetic and potential energies are negligible Assuming a single fluid entering and leaving…

11. 4 – 1 : Condenser : Isothermal Cooling : T3 = T2 QCV 4 1 No work transfer, change in kinetic and potential energies are negligible Assuming a single fluid entering and leaving…

12. Analysis of Cycle First law for a cycle:

13. Work done per unit volume of the engine: Mean Effective Pressure

14. Carnot

15. Use of Carnot Model for Optimization of Power Plant Minimize the capital & running costs. Compact and efficient.

16. A Major Crossroad Confusion: How to go from <6% to 75% Efficiency ???????

17. Rankine, William John Macquorn(1820-1872)

18. A MANUAL of the STEAM ENGINE and other PRIME MOVERS 1859 Rankine • The conventional name work of the thermodynamics by Rankine. • Rankine is the largest meritorious person who in addition raises the technology of the steam engine to science, the word, " energy " is something due to him. • Harmony meaning of this work becomes " the manual of the steam engine and the other motive for action machines “. • The chapter " of thermodynamics " advocated the cyclic process which is called Rankine cycle. • This was related to the policy of researching the steam engine theoretically, brought the progress of the steam engine.

19. Rankine, William John Macquorn(1820-1872) • Rankine was born in Edinburgh and trained as a civil engineer.From 1855 he was professor at Glasgow. • In 1849 he delivered two papers on the subject of heat, and in 1849 he showed the further modifications required to French physicist Sadi Carnot's theory of thermodynamics. • In A Manual of the Steam Engine and other Prime Movers 1859, Rankine described a thermodynamic cycle of events (the Rankine cycle). • This came to be used as a standard for the performance of steam-power installations where a considerable vapour provides the working fluid. • Rankine here explained how a liquid in the boiler vaporized by the addition of heat converts part of this energy into mechanical energy when the vapour expands in an engine. • As the exhaust vapour is condensed by a cooling medium such as water, heat is lost from the cycle. • The condensed liquid is pumped back into the boiler.