Transcript Thermal Power Plant

CERTIFICATE
This is to certify that the project work entitled
“Different Power Plants“
Is being submitted by
Name of the student :
Patel Akshaykumar V
Shaikh Shahrukh
Tiwari Brijesh
Pandey Nitesh
Enroll no.:
130330111026
130330111043
130330111048
130330111025
For fulfillment of requirements of semester-III of the degree
Bachelor of Engineering ELECTRONICS AND COMMUNICATION at
GUJARAT TECHNOLOGICAL UNIVERSITY
For academic year 2014-15


Thermal Power Plants
Steam Power Plants
THERMAL POWER PLANT



A Thermal Power Plant converts the heat energy of coal
into electrical energy. Coal is burnt in a boiler which
converts water into steam. The expansion of steam in
turbine produces mechanical power which drives the
alternator coupled to the turbine.Thermal Power Plants
contribute maximum to the generation of Power for any
country
Thermal Power Plants constitute 75.43% of the total
installed captive and non-captive power generation in
India
In thermal generating stations coal, oil, natural gas
etc. are employed as primary sources of energy.












Coal handling plant
Pulverizing plant
Draft fans
Boiler
Ash handling plant
Turbine
Condenser
Cooling towers and ponds
Feed water heater
Economizer
Superheated and Reheated
Air preheated
Coal Handling Plant
Raw Coal Wagon- Coal is brought to the site through a
Wagon as per requirement.
Wagon tippler-The coal is unloaded from the Wagon
and is transported to crushers and for
storage place through conveyor.
Junction tower- JT’s are used where the conveyor has
any angular deviation.
Rejected- The
stones and
unwanted coal
is rejected
Primary Crusher-The Raw coal is crushed into fine
pieces to 45mm grit). Primary crusher is also
called Rotary Breaker since the coal is
crushed by a rotating plate.
Secondary Crusher-The fine pieces of coal is crushed to
powder (to 25mm grit)
Two way conveyor
Junction Tower
Stacker & Reclaimer- It is
used to store the powdered
coal for emergency purpose
Mill Bunker-The 25mm grit coal is crushed into very fine
powder for feeding the boiler. We will have a spare
Bunker for each Boiler.
BOILER
Atmospheric air (Through
FD fan)
The boiler is fed with HFO and LDO initially to ignite the coal in the Boiler.
Types of boilers:
1. Water tube Boiler: A boiler in which water circulates in tubes heated externally by the fire.
2. Fire tube Boiler: Water is present in the drum inside the boiler and Hot air is circulated around maintain
the temperature.
Fuel
HFO,LDO & Coal
Air
Boiler
Fuel
HFO,LDO & Coal
Air
Dryer
•The fuel and air are feed from 2
increase the efficiency
directions to
Air compressor
FD Fan
Atmospheric Air

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.
2.
Natural draft
Mechanical draft
Flue Gases
The Ash from the boiler is collected in two forms:
1. Bottom Ash(Slurry):It’s a waste which is dumped into a Ash Pond
2. Fly ash: Fly ash is separated from Flue Gases in ESP(Electro static
Precipitator).
Economizer : Reduces the temperature
Boiler
Bottom
ash(wet ash)
Ash Pond
Fly Ash
& Flue
Gases
Chimney
Economizer
Flue Gases
ESP
Fly ash
Cylo
Cement Factory
In a Thermal Power Plant generally 3 turbines are used to increase the efficiency.
 High Pressure Turbine(HPT): The superheated steam is directly fed to this turbine to
rotate it.
 Intermediate Pressure Turbine(IPT): The out put from the HPT is reheated in a
reheated(RH) and used to rotate IPT .
 Low Pressure Turbine(LPT): The Exhausted steam from the IPT is directly fed to
rotate the shaft of LPT.
*All the turbines are connected to a single shaft which is connected
to the Generator.
Super
Heater
Steam
Shaft
HPT
RH
IPT
LPT
Steam
Condenser
Generator

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.
o
o
o
o
o
o
A condenser needs huge quantity of water to
condense the steam .
Typically a 2000MW plant needs about 1500MGallon
of water.
Most plants use a closed cooling system where warm
water coming from condenser is cooled and reused
Small plants use spray ponds and medium and large
plants use cooling towers.
Cooling tower is a steel or concrete hyperbolic
structure having a reservoir at the base for storage of
cooled water
Height of the cooling tower may be 150 m or so and
diameter at the

Advantages of heating water before feeding back to the
boiler:-
Feed water heating improves overall plant efficiency.
b) The dissolved oxygen and carbon dioxide which would
otherwise cause boiler corrosion are removed in feed
water heater
c) Thermal stresses due to cold water entering the boiler
drum are avoided.
d) Quantity of steam produced by the boiler is increased.
e) Some other impurities carried by the steam and
condensate, due to corrosion of boiler and condenser are
precipitated outside the boiler
a)
Water in a Power Plant is used for
1. Production of Steam- for rotating turbine.
2. Cooling Purpose- For cooling of various equipment .
Water is recycled and used for various purpose:
Raw
Water
Conden
ser
Steam
Purified
DM
water
For
cooling
purpose
3% of water is wasted during this process. Appx 4
cubic mt water is lost /day/MW
Water Cycle
Reservoir
Water Clarification
Chlorification
&
Filtration
DM Plant
(Demineralized Plant)
Auxiliary cooling
Water (ACW)
DMCW Demineralized
cooling Water
Various Equipment
Various Equipment
Boiler
Steam
DMCWP
Condenser
PHE
water
25D  35D
CT
Cooling Water
25D  20D
D-Degrees
CWP-cooling water Pump
PHE-Pre heat
Exchange
Cooling Tower
CT
Hot water
CWP
CWP
CWP
Cool water
Dearator
Hot Well








The coal is brought and crushed to powder. This is feed to Boiler for producing heat
In Boiler the water is converted to steam.
In Super heater the moisture content is removed from the steam and that steam is called
super heated steam
The superheated steam rotates the shaft of the High pressure turbine
The Exhausted steam is sent to preheater and the steam then rotates the Intermediate
pressure(IP) Turbine
The steam from the IP turbine is then feed to low pressure turbine.
The turbine shaft is connected to the Generator, which produces Electric Power.
The power generated is then Transmitted.
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
.
UAT
20Kv to 6.KV
Bus Duct
SYNCHRONOUS
GENERATOR
Generator Transformer
20KV to 400KV
Unit Auxiliary Transformer: This transformer is used to step down the produced
voltage and use for Auxiliary purpose.
Steam Power Plant


mechanical power is produced by a heat
engine that transforms thermal energy (from
combustion of a fuel) into rotational energy
heat (generated in the furnace) is transmitted
to the boiler where water forced into the
boiler by the feed pump is converted into
steam

steam drives turbine blades
shaft

the efficiency of a steam turbine is limited by
the maximum temperature of the steam
produced and is not directly a function of the
fuel used (for the same steam conditions,
coal, nuclear and gas power plants all have
the same theoretical efficiency)






Operating pressure
Boiler efficiency
Steaming hours
Heating surface
Generating surface
Superheated steam


Operating pressure – the pressure at which
the boiler is operated in service
Boiler efficiency -the ratio between the
thermal energy actually absorbed by water
and the thermal energy available in fuel (80 –
90 %)


Steaming hours -the time during which the
boiler generates steam
Heating surface -the total surface of all parts
exposed to combustion gases (tubes,
superheater, economiser)


Generating surface - a part of the surface in
which water is heated and steam is generated
(tubes, drum)
Superheated steam = saturated steam +
more heat at constant pressure –> dry steam
(to avoid damage to tubine blades)





FURNACE
BOILER
SUPERHEATER
TURBINE
CONDENSER