This document summarizes the Carnot cycle, which is considered the most efficient thermodynamic cycle. It was proposed by Nicolas Léonard Sadi Carnot in 1824 and establishes the theoretical maximum efficiency possible for a heat engine operating between two heat reservoirs. The Carnot cycle consists of two isothermal and two adiabatic processes. While ideal, it establishes the theoretical limit of efficiency that real heat engines strive to approach.

2. CARNOT CYCLE
The Most Efficient Ever But Ideal

3. GROUP MEMBERS:
 MUHAMMAD OMER (2015-EE-468)
 WALEED TARIQ (2015-EE-406)
 ZAIN-UL-ABIDIN (2015-EE-456)
 RIDA FATIMA (2015-EE-462)
 USAMA BUTT (2015-EE-492)

4. CONTENTS
 INTRODUCTION
 HISTORY
 ASSUMPTIONS
 P-V DIAGRAM
 EFFICIENCY
 LIMITATIONS
 CONCLUSIONS

5. INTRODUCTION
 The most powerful and efficient heat cycle
consisting of two isothermal and two
adiabatic processes.
 This actually is the idealization because in
order to approach it’s efficiency the
processes involved must be reversible and
involves no change in entropy.
 A system undergoing carnot cycle is called
“Carnot Engine”.

6. HISTORY
 Proposed by Nicolas Léonard Sadi Carnot in
1824.
 He was a French Engineer.
 Founder of the science of thermodynamics.
 First one to recognize the relationship
between work and heat.
1796-1832

7. COMMON ASSUMPTIONS OF CARNOT
CYCLE
 Isothermal expansions and compressions
are considered quasi-equilibrium.
 No heat losses in pipes and other
components.
 The cycles do not have any friction. Thus,
no pressure drops in the working fluid.
 Changes in kinetic and potential energies
are negligible.

8. P-V DIAGRAM
Processes:-
 Isothermal Expansion
(1-2)
 Adiabatic Expansion
(2-3)
 Isothermal
Compression
(3-4)
 Adiabatic
Compression
(4-1)

9. 4 STEPS
OF
CARNOT
CYCLE

10. ELABORATION
 The fig. shows the schematic and
accompanying P-V diagram of a carnot cycle
executed by water steadily circulating
through a simple vapor power plant.
 The steam exiting the boiler expands
adiabatically through the turbine and the
work is developed . The steam temperature
decreases from TH To TL.
 Two phases mixture flows through condenser
where heat rejection occurs at constant
temperature TL.

11. ELABORATION
 The mixture (liquid-vapour) enters the
pump (or compressor) and its pressure
increases.This is an adiabatic process and
requires input work.
 The saturated liquid at high temperature
enters the boiler,where change of phase
occurs at constant temperature TH.

12. CARNOT THEOREM
• No real engine can be more efficient than
a Carnot Engine operating between same
two reservoirs.
• All Carnot Engines operating between
reservoirs at the same temperature have
the same efficiency.

13. PROOF OF CARNOT THEOREM

14.  An impossible situation.
 A heat engine cannot drive a less efficient
heat engine.
 Voilation of 2nd Law of Thermodynamics.
 If ŋM > ŋL, then the net heat flow would be
backwards, i.e., into the hot reservoir.

15. PROOF OF CARNOT THEOREM FOR:
 Reversible Engines :
“ All reversible engines that operate between
the same two heat reservoirs have the same
efficiency.”
 Irreversible Engines:
“ No irreversible engine is more efficient
than the Carnot engine operating between the
same two reservoirs.”

16. EFFICIENCY OF CARNOT CYCLE
 Thermal efficiency of the Carnot cycle can
be calculated from:
th=1-(QL/QH)=1-(TL/TH).
So called the Carnot efficiency.
 The higher the temperature of the low-
temperature sink, the more difficult for a
heat engine to transfer heat into it.Thus,
lower thermal efficiency also.

17. LIMITATIONS OF CARNOT CYCLE
 The isentropic process 1-2 is practically not
achievable,as it is difficult to handle two
phase system.
 If the steam quality is poor then process
3-4 is difficult to carry out.

18. CONCLUSIONS
 We can say that Carnot Engine is one of the
most efficient one but it’s ideal one.
 Let assume for a moment that it’s not an
ideal cycle then what would happen??
 I think there will be no other engines
Because after this gorgeous thing there is
no need   