This document presents information on gas turbine cycles. It discusses open and closed cycle gas turbines, with open cycle directly discharging exhaust to the atmosphere and closed cycle recirculating working medium. It also describes how intercooling, reheating, and regeneration can increase the net work output of gas turbine cycles by reducing compressor work and increasing turbine work. A T-S diagram is included to illustrate an ideal gas turbine cycle with these modifications.

1. PRESENTATION
ON
“GAS TURBINE CYCLES”
POWER PLANT ENGINEERING
SUBMITTED BY:
HIMANSHI GUPTA (140120119057)/ ME/A1
GUIDED BY:
PROF. NIMESH GAJJAR
(2171910)
GANDHINAGAR INSTITUTE OF TECHNOLOGY

2. INTRODUCTION
• Gas turbine engines derive their power from burning fuel in a
combustion chamber and using the fast flowing combustion
gases to drive a turbine
• A simple gas turbine is comprised of three main sections a
compressor, a combustor, and a power turbine
• The gas-turbine operates on the principle of the Brayton cycle,
where compressed air is mixed with fuel, and burned under
constant pressure conditions
• The resulting hot gas is allowed to expand through a turbine to
perform work

3. OPEN CYCLE GAS TURBINE
• In this cycle, air from the ambient atmosphere is compressed
to a higher pressure and temperature by the compressor
• In the combustion chamber, air is heated further by burning
the fuel-air mixture in the air flow
• Combustion products and gases expand in the turbine either to
near atmospheric pressure (engines producing mechanical
energy or electrical energy) or to a pressure required by the jet
engines
• The open gas turbine cycle means that the gases are
discharged directly into the atmosphere

4. OPEN CYCLE GAS TURBINE

5. CLOSED CYCLE GAS TURBINE
• In a closed Brayton cycle, working medium recirculates in the
loop and the gas expelled from the turbine is reintroduced into
the compressor.
• In these turbines, a heat exchanger (external combustion) is
usually used and only clean medium with no combustion
products travels through the power turbine.

6. GAS TURBINE CYCLE WITH
INTERCOOLING, REHEATING,
AND REGENERATION

7. • The net work output of the cycle can be increased by reducing the work
input to the compressor and/or by increasing the work output from
turbine (or both).
• Using multi-stage compression with intercooling reduces the work input
the compressor.
• Likewise utilizing multistage expansion with reheat will increase the
work produced by turbines.
• When intercooling and reheating are used, regeneration becomes more
attractive since a greater potential for regeneration exists.
• The back work ratio of a gas-turbine improves as a result of intercooling
and reheating.
• However, intercooling and reheating decreases thermal efficiency unless
they are accompanied with regeneration.
• This is because intercooling decreases the average temperature at which
heat is added, and reheating increases the average temperature at which
heat is rejected.

9. • For minimizing work
input to compressor
and maximizing work
output from the
turbine:
T-S DIAGRAM FOR AN IDEAL GAS-TURBINE
CYCLE WITH INTERCOOLING, REHEATING,
AND REGENERATION
and

10. THANK YOU