2. o NTPC sipat has total installed capacity : 2980 MW
o Stage 1 = 3 X 660 MW
o Stage 2 = 2 X 500 MW
o Stage 2 is based on "Super Critical Boiler
Technology "
3. o COAL SOURCE
> Dipika Mines of South Eastern Coalfields
Limited
o WATER SOURCE
> Hasdeo barrage
4. o “Supercritical” is the thermodynamic state where there
is no clear distinction between the Water and Steam
phase in the Ranking Cycle.
o Water reaches to steam state at a critical pressure
above 22.1 MPa at 374 °C.
o This "critical point" is at the apex of the saturation line
on T-s coordinates.
o Above this pressure, the physical properties (density,
compressibility, and Viscosity) change continuously
from those of a liquid to those of a vapor.
5.
6. Higher unit cycle efficiency (40 - 42%).
Lower heat rate and electricity generation cost is lower.
Lower water losses because no continuous blow down.
Reduced auxiliary power consumption.
Reduce carbon dioxide (CO2) emissions and provides
carbon credit within the Rankine cycle.
7.
8. 1. Coal handling plant
2. Pulverizing plant
3. Draft fans
4. Boiler
5. Ash handling plant
6. Turbine
7. Condenser
8. Cooling towers and ponds
9. Feed water heater
10. Economizer
11. Superheater and Reheater
12. Air preheater
10. Train (coal) Track hopper
Conveyer
belt
Mill
Conveye
r belt
Pulverisation
process
Coal Coal Coal
small piece
of coal
small piece of coal
powderEd
coalboiler
steam
TurbineGeneratorElectricity
Tiscon pipe
with basalt
cutters
Ash dyke
Water dyke
Condensation
process
Cooling
tower
Storage
tank
Demineralisatio
n process
steam
Water
Water
Water
Water
Water
Water
ash + hot water
ash + hot water
Ventilator
turbine
dry ash
dry ash
Wind
pipes
ChimneyAtmosphere
dry ashdry ash
Shaft
11. A thermal power plant burns enormous amounts of coal.
A 200MW plant may require around 2000 tons of coal daily
The function of coal handling plant is automatic feeding of coal
to the boiler furnace.
12. In modern thermal power
plant , coal is pulverised i.e.
ground to dust like size and
carried to the furnace in a
stream of hot air. Pulverising
is a means of exposing a large
surface area to the action of
oxygen and consequently
helping combustion.
Pulverising mills are further
classified as:
1. Contact mill
2. Ball mill
3. Impact mill
13. • The circulation of air is caused by
a difference in pressure, known as
Draft.
• Draft is a differential pressure b/w
atmosphere and inside the boiler.
• It is necessary to cause the flow of
gases through boiler setting
• It may be –
1. Natural draft
2. Mechanical draft
14. • A boiler or steam generator
is a closed vessel in which
water under pressure, is
converted into steam.
• It is one of the major
components of a thermal
power plant
• Always designed to absorb
maximum amount of heat
released in the process of
combustion
Boilers are of two types-
1. Fire tube boiler
2. Water tube boiler
15. Wherever coal is burned it is necessary to have an efficient ash handling system,
especially in a coal-fired power station environment where large quantities of
pulverized fuel ash (PFA) are created
The various systems involved in the ash handling system are:
Bottom ash handling system
Fly ash handling system (both wet & dry)
Slurry handling system from slurry pump house to ash dyke
Ash water system
Ash water recirculation system
Basically, two types of ash are generated:
Fly ash (approx 80%)
Bottom ash (approx 20%)
16. oAsh collected in hoppers is grinded by grinders and mixed
with water and then sent to ash slurry house by using jet pumps.
oWhere it is collected in ASH PIT, from where it is pumped to ASH
POND.
oHere there is also an auxiliary pump which is used for FLUSHING
OFF blockages.
17. A steam turbine converts heat energy of
steam into mechanical energy and drives
the generator. It uses the principle that
steam when issuing from a small
opening attains a high velocity. This
velocity attained during expansion
depends on the initial and final heat
content of the steam. This difference b/w
initial and final heat content repesents
the heat energy converted into kinetic
energy.
These are of two types :-
Impulse turbine
Reaction turbine
18. Steam after rotating steam turbine comes to condenser.
Condenser refers here to the shell and tube heat exchanger (or
surface condenser) installed at the outlet of every steam turbine
in Thermal power stations of utility companies generally.
These condensers are heat exchangers which convert steam
from its gaseous to its liquid state, also known as phase
transition.
The purpose is to condense the outlet (or exhaust) steam
from steam turbine to obtain maximum efficiency and also to get
the condensed steam in the form of pure water, otherwise known
as condensate, back to steam generator or (boiler) as boiler feed
water.
19.
20. o A condenser needs huge quantity of water to condense the steam .
o Typically a 2000MW plant needs about 1500MGallon of water.
oMost plants use a closed cooling system where warm water coming from
condenser is cooled and reused
oSmall plants use spray ponds and medium and large plants use cooling
towers.
oCooling tower is a steel or concrete hyperbolic structure having a reservoir
at the base for storage of cooled water
oHeight of the cooling tower may be 150 m or so and diameter at the base is
150 m
21. The exhaust gases contain
large amount of smoke and
dust, which are being
emitted into atmosphere.
This possess a real threat to
the mankind as a health
hazards. Hence it has
become necessary to free
the exhaust gases from
smoke and dust. The
Electrostatic precipitator
utilizes electrostatic forces
to separate the dust particle
form the gas to be cleaned.
22. Flue gases coming out of the boiler carry lot of heat. An
economiser extracts a part of this heat from flue gases and uses
it for heating feed water. This use of economiser results in saving
coal consumption and higher boiler efficiency
23. After flue gases leave economiser,
some further heat can be extracted
from them and used to heat incoming
heat. Cooling of flue gases by 20
degree centigrade increases the plant
efficiency by 1%.
Air preheaters may be of three types
Plate type
Tubular type
Regenerative type
24. S u p erh eater is a comp on ent of a steam -gen eratin g u n it
in wh ic h steam, after it h as left th e b oiler d ru m, is
heated above its saturation temperature. The super
h eater may con sist of on e or more stages of tu b e b an ks
arran ged to effec tively tran sfer h eat from th e p rod u c ts
of comb u stion . S u p er h eaters are c lassified as
convec tion , rad iant or comb in ation of th ese.
25. The Synchronous Generator is used to Generate power by
connecting the shaft of the Turbine to the shaft of the generator
which cuts the magnetic flux producing Emf.
The Generated Voltage will generally 11KV to 20 KV max.
The Generated Voltage is stepped up by connecting Step up
transformer and is transmitted and is also used for Auxiliary
purposes.
26. Super critical power plants are
the efficient plants to produce
greater out put although it has
some drawbacks……