2. Introduction
• The gas turbine is the engine at the heart
of the power plant that produces electric
current. A gas turbine is a combustion
engine that can convert natural gas or
other liquid fuels to mechanical energy.
This energy then drives a generator that
produces electrical energy.
3. History of Gas Turbines
• 1791- In this year the first patent for gas turbine was proposed by John
Barber of United Kingdom.
• 1904- In this year the gas turbine project was done unsuccessfully by Franz
Stolze in Berlin.
• 1906- Gas turbine was developed by Armengaud Lemale in France which
comprises of centrifugal compressor and it is of no useful power.
• 1910- The first gas turbine featuring combustion was discovered of 150 KW
(const. volume combustion) by Holzwarth.
• 1923- First exhaust gas turbo charger was developed to increase the power of
diesel engine.
• 1939- World’s first gas turbine for power generation by Brown Boveri Company,
Neuchatel, Switzerland
4. Some of Gas
turbine power
generation
plants of India
:
Power station operator State (location)
Installed capacity
(MW)
IPGCL Gas Turbine
Power Station
IPGCL New Delhi 270
Pragati Gas Power
Station
PPCL NTC Delhi 330.40
Pampore Gas Turbine
Station II
J&K Govt Jammu & Kashmir 100.00
Dholpur Combined
Cycle Power Station
RVUNL Rajasthan 330.00
National Capital TPP NTPC Uttar Pradesh 817.00
Trombay Gas Power
Station
TATA Maharashtra 180.00
6. Two types of gas
turbine plants
• 1. Open cycle gas
turbine plants
• 2. Closed cycle gas
turbine plants
7. Working principle :
• The fundamental working
principle of a gas turbine
power plant is same as
that of a steam turbine
power plant. In the gas
turbine power plant air is
compressed in a
compressor. This
compressed air then
passes through a
combustion chamber
where the temperature of
the compressed air rises.
8. Air Compressor :
• The air compressor and turbine are mounted at either end
on a common shaft, with the combustion chamber between
them
• Gas turbines are not self starting. A starting motor is used
• The air compressor sucks in air and compresses it, thereby
increasing its pressure.
•
9. Some of Air
compressor
• The air compressor used in gas
turbines is of rotary type mainly
axial flow turbines. It
draws air from the atmosphere and
compressed to the required pressure.
This compressed air is then
transferred of
the air instantaneously. It increased
the pressure and temperature of
the air instantaneously
10. Combustion Chamber :
• → Combustion in the normal, open cycle, gas turbine is a continuous
process in which fuel is burned in the air supplied by the compressor; an
electric spark is required only for initiating the combustion process, and
thereafter the flame must be self-sustaining.
• → Combustion of a liquid fuel involves the mixing of a fine spray of
droplets with air, vaporization of the droplets, the breaking down of
heavy hydrocarbons into lighter fractions, the intimate mixing of
molecules of these hydrocarbons with oxygen molecules, and finally the
chemical reactions themselves.
• → A high temperature, such as is provided by the combustion of an
approximately stoichiometric mixture, is necessary if all these processes
are to occur sufficiently rapidly for combustion in a moving air stream to
be completed in a small space
12. Turbine
• The gas turbine is the engine at the
heart of the power plant that
produces electric current. A gas
turbine is a combustion engine that
can convert natural gas or other
liquid fuels to mechanical energy.
This energy then drives a generator
that produces electrical energy.
14. Advantage :
• • Gas turbines can be built relatively quicker.
• • Above 550 degree centigrade, the thermal efficiency of the gas plant
increases as fast the steam cycle efficiency.
• • Storage of fuel is much smaller.
• • Because of the low specific weight the gas turbines are particularly
suitable for aircrafts.
• • Cheaper fuels such as paraffine type, residue oils can be used as
compare to diesel power plants.
• • Gas turbines plants can be installed anywhere without any difficulty.
15. Site Selection :
• The site should be as near to the load centre as
possible so that the transmission costs and losses
are minimised
• The land should be available at cheap rate in
order to keep the capital cost of the plant
• The fuel should be easily available and at
reasonable rate.
• The transportation facilities should be available
16. Disadvantage :
• With wide operating speeds, the fuel control is comparatively difficult.
• Thermal efficiency of simple turbine cycle is low.
• The gas turbine blades need a special cooling system.
• For the same output the gas turbine produces 5 times the exhaust gases as
compare to the other thermal plant.
• Because of the prevalence of high temperature (1000k for blades and
2500k for combustion chamber) and centrifugal force, the life of the
combustion chamber and blades is short and small.
• Poor part load efficiency.
17. Applications :
• To drive generators and supply peak loads
in steam, diesel or hydroplants.
• To work as combination plants with
conventional steam boilers.
• To supply mechanical drive for
auxiliaries.
• Heat recovery feed water heating
combustion chamber.