A heat engine is a system that converts heat or thermal energy into mechanical energy. It does this by bringing a working substance from a higher temperature state to a lower temperature state. There are four main heat engine cycles: the Carnot cycle, Rankine cycle, Otto cycle, and Diesel cycle. The Carnot cycle involves reversible, isothermal expansion and compression processes. The Rankine cycle models steam engines and involves reversible expansion of steam in a turbine and condensation of steam in a condenser. The Otto and Diesel cycles involve compression, constant volume heat addition, and expansion processes to model gasoline and diesel engines.

1. Present By
Riddhi Shah
180050119061

2. IND
EX
 HEAT ENGINES
 HEAT ENGINE
CYCLES
 CARNOT CYCLE
 RANKINE CYCLE
 OTTO CYCLE
 DIESEL CYCLE

3. A heat engine is a
system that converts
heat or thermal
energy and chemical
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.

4. 1) Carnot Cycle
2) Rankine Cycle
3) Otto Cycle
4) Diesel Cycle

5. CARNOT
CYCLE

6. 1. Working fluid is the perfect gas.
2. Piston cylinder arrangement is weightless and does not
produce friction during motion.
3. The walls of cylinder and piston are considered as
perfectly insulated .
4. Compression and expansion are reversible.
5. The transfer of heat does not change the temperature of
source or sink.

7.  Isothermal expansion (1-2)
 Adiabatic expansion (2-3)
 Isothermal compression (3-4)
 Adiabatic compression (4-1)

8.  efficiency (η) = 1 − TL / TH
 Where ,
TL = Max Temp. of Cycle
TH = Min Temp. of Cycle

9. RANKINE
CYCLE

10. 1. All the devices are teats as steady flow energy device.
2. Kinetic and potential energy changes are neglected.
3. Expansion in turbine and pump are assume as reversible
adiabatic process/ isentropic process.

11.  Reversible adiabatic expansion
0f steam in turbine (1-2)
 Heat rejection at p=C in
condenser (2-3)
 Reversible adiabatic expansion
of liquid in pump (3-4)
 Heat supplied at p=C in boiler
(4-1)

12.  efficiency (η) = h1 – h2 / h1 – h4

13. CYCLE

14.  Reversible adiabatic
compression (1-2)
 Heat supplied at V=C (2-3)
 Reversible adiabatic expansion
(3-4)
 Heat rejection at V=C in boiler
(4-1)

15.  Thermal Efficiency:

16. CYCLE

17.  Reversible adiabatic
compression (1-2)
 Heat supplied at V=C (2-3)
 Reversible adiabatic expansion
(3-4)
 Heat rejection at V=C in boiler
(4-1)

18.  Thermal Efficiency
Here, α- Cut-off Ratio

19. THANK
YOU