Carnot
Cycle::
- This cycle was proposed in 1824 by a German
engineer “SADI CARNOT”.
- It is a hypothetical cycle which is used to compare other
cycle.
- It consists of four reversible process.
Assumptions
of Carnot Cycle::
- Working substances is a perfect
gas.
- There is no friction between
the cylinder and piston.
- Walls of cylinder and piston
are considered as perfect heat insulator.
- Transfer of heat does not
affect the temperature of source or sink.
Processes of Carnot Cycle::
Process 1-2 (Isothermal
Heat Addition):
- Reversible isothermal heat addition at high
temperature.
- The gas is allowed to expand isothermally by receiving
heat (QH) from a hot reservoir.
 |
| Process 1-2: Isothermal Heat Addition |
Process
2-3 (Adiabatic Expansion):
- Reversible adiabatic expansion from high
temperature to low temperature.
- The cylinder now is insulated
and the gas is allowed to expand adiabatically and thus doing work on the
surrounding.
- The gas temperature decreases
from TH to TL.
 |
| Process 2-3: Adiabatic Expansion |
Process 3-4 (Isothermal
Heat Rejection):
- Reversible isothermal heat rejection at low
temperature.
- The insulation is removed and the gas is compressed isothermally by rejecting heat (QL) to a cold
reservoir.
 |
| Process 3-4: Isothermal Heat Rejection |
Process
4-1 (Adiabatic Compression):
- Reversible adiabatic compression from low
temperature to high temperature.
- The cylinder is insulated again
and the gas is compressed adiabatically to state 1, raising its
temperature from TL to TH.
 |
| Process 4-1: Adiabatic Compression |
P-V & T-S diagram of
Carnot Cycle:
 |
| T-S & P-V diagram of Carnot cycle |
Efficiency of a Carnot Cycle:
 |
| Efficiency of Carnot cycle |
No comments:
Post a Comment