Thermal Engine & Carnot's Cycle and their Working Principle

2. -6
6

5.  In thermodynamics, a heat engine is a system
that converts heat or thermal energy to
mechanical energy, which can then be used to do
mechanical work. It does this by bringing a
working substance from a higher state
temperature to a lower state temperature.

6. Parts Of Heat Engine
Hot Body
(source of heat)
Q1
Cold Body
(absorbs heat)
Q2
W
Working
substance

7. Defination:
Carnot’s Engine: In order to express an
explanation of the convertion of heat into
work , Sadi Carnot imagines an idle heat engine
which is known as Carnot’s Engine.
Heat
source
sink
Heat
instractor
deck
Cylender With piston

8. Sadi Carnot was a French military
engineer and physicist.

9.  Carnot’s Cycle:
cycle in which the working substance starting a state of
certain temperature, pressure and volume is made to
undergo two successive expansions (isothermal &
adiabatic) and then two successive compressions and then
brought back finally to its initial state is called Carnot
cycle.

10.  Adiabatic process: The process in which a system neither
receives heat nor rejects heat is called adiabatic process.
In this process a gas undergoes changes in pressure,
volume and temperature under thermal isolation.
 IsoThermal Process: When a gas undergoes a change in
pressure and volume at constant temperature, the gas
is said to undergo an isothermal change, and the
process in which the change takes place is called
isothermal process.

11. • Carnot’s cycle consisting of four reversible processes(any substance):
 Reversible isothermal expansion
 Reversible adiabatic expansion
 Reversible isothermal compression
 Reversible adiabatic compression
1-2 2-3 3-4 4-1

12. Volume
Pressure
•
•
a
b
•
d
T1
Q1
Q2 T2•c
Q=0
Q=0
Graph

13. Volume
Pressure
•
•
a
b
•
d
T1
Q1
Q2 T2•c
Q=0
Q=0
Graph
W

15. 

17.  Isothermal process is possiable if it is very slow and
Adiabatic process is possiable if it is very fast. This
Alternate Combination of very fast very slow process is
not posiable to achieve in actual practice.