2. CONTENTS
About the company
Introduction
General layout
Components
Coal cycle
Condensation cycle
Steam cycle
Power cycle
Ash treatment
exhaust
3. About The Company
• Damodar valley corporation, popularly known
as DVC , came into being on July 7, 1948.this
was first multi-purpose river valley project of
independent India.
• CTPS: chandrapura thermal power station is
situated in Bokaro district of Jharkhand. This
has a installed capacity of 1600 MW.
4. MISSION VISION
• To generate adequate and • To be the best power utility
reliable power most in the country and one of
economically , efficiently the best in the world.
and eco-friendly.
• To spearhead accelerated
power development by
planning and implementing
new power projects
5. INTRODUCTION
• A thermal power plant converts the heat
energy of coal into electrical energy. Coal is
burned in a boiler which converts water into
steam. The expansion of steam produces
mechanical power drives alternator coupled
to turbine
7. COMPONENTS
main auxiliary
Coal mill • FD fan
Boiler • ID fan
• Safety valve
Turbine
• Gauge valve
Generator • Conveyer
Condenser • Transmission lines
super heater • Air pre-heater
• De-aerator
• Reheater
• ESPs
9. Coal Handling Plant
Wagon unloading system
Crushing system
Conveying system
Unload the coal from wagon for standardization and
selection and then the coal is stored in STOCK YARD.
Through conveyer system , the coal is sent in hopper.
Hopper allows to pass coal pieces<200 mm
From it coal falls on vibrator which is supported by
roller
11. Crushing System
• The gear box: contains worm wheel and worm
gear which moves the wheel.
• Motor: this provides energy for both worm gear
and exhaust fan to move.
• Exhaust fan: it sucks the coal dust , mixes it with
pre-heated air (to maintain coal temperature)
and send it through pipes in to boiler.
• One coal mill unit sends 8 pipes into boiler.
• Grinding roll fixed with mill body as shown in fig.
brings coal to 20 mm size.
12. Coal + Air Supply
Atmospheric air
Combustion intake
Air pre heater
Fd fan
Coal pulveriser
Coal +air
Burner floor Primary superheater
13. Air Supply
DRAFT SYSTEM
Natural
Mechanical
In mechanical systems fans are used to create
draft .
At CTPS balanced draft system is used in
which both FD and ID fans are used
14. • FD fan-forced draft fan , this creates a negative
pressure in the boiler and via this pressure
difference atmospheric air is drawn in the boiler
• ID fan-this sucks the treated flue gas out and
ejects it through chimney.the mechanical draft is
created by fan
• Now the pre heated air goes into coal pulverizer
and then sent into burner floor of boiler where
through corner firing system(CFS) fire balls are
made , which burn the coal laden air stream
coming from below. Thus producing required
heat for super heating.
15. Air Pre-heater
• This is a general term to describe any device
designed to heat air before another
process(for ex. Combustion in a boiler). The air
comes through combustion intake pipeline,
assisted by FD fan.
16. CONDENSATE CYCLE
L.P. turbine River water
Surface condenser reservoir
Cooling tower Alum house sump
Condensate pump Water treatment
De-aerator Pure water
Feed water heater Condensate pump
Feed water pump
economizer
17. Water Supply
• Majority of water supply for steam generation
is condensed water. The steam fromL.P.
turbine is sent into surface condenser which
• Changes the phase from steam to water.
• Now, this water is sent to cooling towers
which are evaporative coolers used for cooling
water. these evaporate some part of
condensed water to reject heat. At CTPS
cooling towers are of hyperboloid structure
19. DE-aerator Feed water heater
• Device for air removal and • This is used to pre heat
corrosive dissolved gases water delivered to a steam
because corrosion can generating boiler, improving
render pipe networks efficiency. Feed water
heaters allow the water to
useless and rusty be brought upto saturatiuon
temperature very gradually.
This reduces costs and help
prevent thermal shocks to
boiler material.
•
20. • Feed water pump: these pumps are high
pressure units that overcome steam pressure
to force water into the boiler drum.
• ECONOMIZER :in boilers, these are heat
exchangers that heat fluids usually water, upto
its saturation point, they use the energy from
the heat of flue gas and thus reduce heat in
put and costs. It is placed in the passage of
flue gas between outlet and chimney
21. Make Up Water
• This is additional water added in feed water
stream . but before that it Is treated in water
treatment plant
• At CTPS, there are 4 treatment units
• 1)dirty water from reservoir. Sedimentation
removes majority suspensions particles:
trough perforations clean water drips into well
2)
23. • (2) alum is mixed in 2)with water coming from
1) micelle formation and this micelle is
removed by mechanical arrangement; by
forcing this trough a slope.
• 3)clean water comes from 2) into (3) via
perforations.
• This treated water is sent into feed stream ,
where it mixes with condensed water, to form
“final water”.
24. STEAM CYCLE
• fe Feed water Gauge valve
Primary super
heater
Secondary super
economizer Ceiling tube
heater
Platen
Boiler drum Boiler drum
superheater
Ring header Riser tube
turbine
Water valve Input header
26. Boiler Operations
The feed water enters into economizer reaches upto saturation point.
It is sent into boiler steam drum
BOILER STEAM DRUM
It is reservoir
of water/steam at the top end of the water tubes in the water-tube
boiler. They store the steam generated in the water tubes and act as
a
phase separator for the steam/water mixture. The difference in
densities between hot and cold water helps in the accumulation of
the
“hotter”-water/and saturated –steam into steam drum.
27. • The
• separated steam is drawn out from the top section of the drum.
• Saturated steam is drawn off the top of the drum. The steam will reenter
• the furnace in through a super heater, while the saturated water
• at the bottom of steam drum flows down to the mud- drum /feed water
• drum by down comer tubes accessories include a safety valve, water
• level indicator and fuse plug. A steam drum is used in the company of
• a mud-drum/feed water drum which is located at a lower level. So that
• it acts as a sump for the sludge or sediments which have a tendency to go
to bottom
29. Super Heater Tubes
• At CTPS types of super heater are :
• Primary -straight pipes
• Secondary- U shaped
• Platen - BENT shaped
• This all tubing has same function to super
heat water: to heat the steam extracted from
drum, increasing it’s thermal energy and
decreasing the likelihood that it will condense
in pipe network or in turbine section
30. • The superheated steam is sent into high pressure turbine, at 540 degree
celcius and 145 kg per square cm
• And the thin ash particles are collected by ESP and thick ash fall into ash
hopper below.
• Turbine section:
• A steam turbine is a device that extracts thermal energy from
pressurized steam and used it to do mechanical work on a
rotary output shaft. this is a form of heat engine that derives
much of its improvement in thermodynamic efficiency
through the use of multi stagesin expansion of steam
32. • There are three turbines:
• High pressure – 5 stages
• Intermediate pressure-12 stages
• Low pressure -9 stages
• Turbine types:(based on stages)
• Impulse turbine: stage is set of moving blade behind the nozzle.
• Reaction turbine: each row of blades is called a stage.
• Blades:
• in H.P., the blading used is impulse blading because it extracts more work
from high pressure steam than reaction blading.
33. • Impulse blading:it is in shape of half moon. As steam impact the
moving blade, it pushes the blade forward. this causes steam to lose
velocity without losing pressure.
• The steam coming out from the H.P. turbine gas into reheater through
inlet and comes back trough outlet attaining thermal energy can be
extracted in I.P. turbine and L.P. turbine.
• I.P. and L.P. turbines: the steam at low pressure and
temperature enter into this turbine pair respectively: so
reaction blading is used
34. • REACTION BLADING: works on same concept as a jet engine.
A jet engine is designed to take in air. Each moving reaction
blade is designed to act as a nozzle.as the steam passes
trough a reaction blade it causes the reaction blade to be
propelled forward , resulting in rotation of L.P. turbine rotor
• Intercept valve: this is in H.P. turbine and governs the the
steam flow amount.
• There is a surface condenser below L.P. turbine, explained in
water supply previously.
• all the three turbines are mechanically linked trough a rotor
and the generator is coupled at the end of the system. At
CTPS it is hydrogen cooled.
35. Ash Treatment Plant
• ESP: electro static precipitator is a particulate device that removes particles
from a flowing gas, using force of an induced electrical charge.automatic
rapping systems and hopper evacuation system remove the collected
particulate matter while in line allowing esps to stay in operation for years at a
time.
• From the hoppers these are collected in the collector tank.
• this collector tank has wet line trough which water comes.both ash and water
are mixed and sent into collector tank. the hydrovactor is vaccum creating
machine, that creates vaccum by removing water and air ,thus ensuring
necessary pressure difference.
• A VACCUM BREAKER is like a plate, it maintains and releases vaccum as
and when required.
• The slury is sent into sump from where it is carried 4 km away from CTPS
using suitable pumps and pipe network.
37. • There is air washer in conjunction with hydrovactor,
that cleans air of its dust and susrensions, etc.
• For thick ash, metal or stones which are falling in ash
hopper below,where they are crushed using grinde.
Using grinder. Using a power cylinder to open the
gate and remove the pulverized debris with water
into sump tank and discharged.
39. exhaust
• The dust and ash are taken into ash treatment
plant as mentioned earlier.
• The rest flue gas moves through flue gas stack
which is a type of chimney, a vertical pipe or
channel for the exhaust gas outlet.