CESC Report

.
REPORT ON VOCATIONAL TRAINING
4TH
JULY,2016 TO 16TH
JULY,2016
Prepared by:
DEBOKTI GHOSH
3RD
YEAR,
ELECTRONICS & COMMUNICATION ENGINEERING,
ACADEMY OF TECHNOLOGY,
HOOGHLY.
UNIVERSITY ROLL NO:16900313038.
Submitted in partial fulfillment of the requirements for the degree of:
Bachelor of Technology.
CALCUTTA ELECTRICAL SUPPLY CORPORATION
(A flagship company of the RP-Sanjiv Goenka Group)
TITAGARH GENERATING STATION

2 | VOCATIONAL TRAINING, SUMMER 2016, TITAGARH GENGERATING STATION
ACKNOWLEDGEMENT:
This Training cum project report is not just mine. It is a collective effort of many people
who helped me a lot to successfully complete this project report and without the support of
whom this project report would not have been implemented. I thank, Mr.Hirak Das (HRD) for
providing me with important data , description of the whole process and assisting us throughout
the training.
I would also thank Mr. Monotosh Chowdhury (Asst.Manager, HRD) of CESC LTD
for allowing me to have training under his careful supervision at TGS.
I am also grateful to Mr. Debdutta Maitra (GM,HR), Mr. D Basak (Station
Manager), for providing me with important data, description of the whole process and assisting
us throughout the training.
I would also thank all the employees of Instrumentation Maintenance Department for
explaining the operation details of the instruments at TGS.
Lastly I would like to thank the entire staff at TGS for their support. It has been a
privilege to have them by my side throughout the training period from 07.07.2014 to 19.07.2014.
Their tireless guidance, co-operation has led me to successful completion of this
vacational training.
15 July 2016. DEBOKTI GHOSH
ACADEMY OF TECHNOLOGY

Table of Contents:
1.About CESC
2.About Titagarh Generating Station
3.Thermal Power Plants
4.Rankine Cycle
5.Cycles in a power plant
6.Coal Handling Plant
7.Water Treatment Plant
8.FAN(PA,FD & ID)
9.Boiler and its auxiliaries
10.Distributed Control System(DCS)
11.Conclusion
12.Bibliography

ABOUT CESC:
 CESC is India’s first fully integrated electrical utility company and CESC has been
on an epic ride ever since 1897 in generating and distributing power in Kolkata and
Howrah.
 CESC have private participation in generation, transmission and distribution of
electrical power.
 CESC are the sole distributor of electricity within an area of 567sq km in the state
capital and serve 2.9 million consumers which include domestic, industrial and
commercial users.
 CESC own & operate three thermal power plants generating 1125 MW of power. These
are: Budge Budge Generating Station (750 MW), Southern Generating Station (135
MW), & Titagarh Generating Station (240 MW)
 From these three generating stations, CESC accomplishes 88% of their customer’s
electricity requirement and remaining 12% is achieved by purchase of electricity from
third parties.
 More than 50% of coal is sourced from captive mines for generation of electricity in
their generating stations.
 The Transmission and Distribution system comprises of 474 km circuit of transmission
lines linking the company’s generating & receiving stations with 105 distribution
stations, 8,211 circuit km of HT lines further linking distribution stations with LT
substations, large industrial consumers and 12,269 circuit km of LT lines connecting the
LT substations to LT consumers.

ABOUT TITAGARH GENERATING STATION(TGS).:
 TGS is one of the oldest generating station & is the first pulverized fuel
thermal station of CESC situated on B.T. road, Titagarh.
 It has total installed capacity of 240 MW comprising four units each rated 60
MW.
 Its generating voltage is 10.5 KV. The plant started commercial generation since
1983, when the first unit started operating. Subsequently the other three units
started in the years 1983, 1984 & 1985.
 TGS is committed to ensuring required power supply to the CESC’s distribution
network in line with the varying level of electricity demand.
 In TGS the generating voltage 10.5 KV is stepped up by generating transformer to
33KV. This 33 KV supply is again stepped up to 132KV in the receiving station
& is sent to distribution station & stepped down to 11KV. Thereafter it is again
stepped down to 6 KV, 415 V for distributing to consumers.
 Operation & maintenance of the plant is part of the business activity of TGS.
 CESC central Turbine Maintenance department (CTM) is responsible for
Turbo-Alternator sets while, testing & calibration of protection metering
equipment are done by company’s test department.
 Boiler specifications: ABL make (Front fired PF)
Steam O/L pr. 91.4 kg/sq.cm.
 Turbo Alternator: NEI Parsons, U.K.
Impulse Reaction, Condensing, Non-reheat
 Generator: Air Cooled
Stator Voltage: 10.5kV
Stator Current: 3881A.
Performance parameters:
Year 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15
Target
Generation(MU)
1858.1900 1926.7100 1864.0400 1868.0000 1689.0000 1755.0000 1683.0000 1573.0000
Units
Generated(MU)
1942.6251 1933.6849 1888.7906 1866.0116 1716.6021 01549.5400 1776.0090 1684.2202
Aux.Power
Consumption(%)
8.79 8.49 8.32 8.17 8.35 8.23 8.25 8.43
Plant Load
Factor(%)
92.15 91.98 89.84 88.75 81.38 78.46 84.48 80.11
Plant
Availability (%)
95.80 96.29 96.32 96.75 96.15 87.08 96.59 96.25
Coal Fig.(Gen) 0.605 0.630 0.652 0.664 0.636 0.631 0.644 0.660
Oil Fig(Gen) 0.940 0.850 1.63 1.09 1.17 0.78 0.76 0.92

THERMAL POWER PLANTS-An Overview:
A thermal power station is a power plant in which the prime
mover is steam driven. Water is heated, turns into steam and spins a steam turbine
which drives an electrical generator. After it passes through the turbine, the steam is
condensed in a condenser; this is known as a Rankine cycle. The greatest variation in
the design of thermal power stations is due to the different fuel sources. Some prefer
to use the term energy center because such facilities convert forms of heat energy into
electrical energy. However, power plant is the most common term in Asia Pacific, while
power station prevails in many Commonwealth countries and especially
in the United Kingdom, almost all coal, nuclear, geothermal, solar thermal electric,
and waste incineration plants, as well as many natural gas power plants are thermal.
Natural gas is frequently combusted in gas turbines as well as boilers. The waste heat
from a gas turbine can be used to raise steam, in a combined cycle plant that improves
overall efficiency. Such power stations are most usually constructed on a very large
scale and designed for continuous operation.
History -reciprocating steam engines have been used for mechanical power sources since
the 18th Century, with notable improvements being made by James Watt. The very first
commercial central electrical generating stations in New York and London, in 1882, also
used reciprocating steam engines. As generator sizes increased, eventually turbines took
over due to higher efficiency and lower cost of construction. By the 1920s any central
station larger than a few thousand kilowatts would use a turbine prime mover. Efficiency -
The electric efficiency of a conventional thermal power station, considered as saleable
energy produced at the plant bus bars compared with the heating value of the fuel consumed,
is typically 33 to 48% efficient, limited as all heat engines are by the laws of
thermodynamics (See: Carnot cycle). The rest of the energy must leave the plant in the
form of heat. This waste heat can be disposed of with cooling water or in cooling towers.
If the waste heat is instead utilized for e.g. district heating, it is
called cogeneration. An important class of thermal power station are associated with
desalination facilities; these are typically found in desert countries with large
supplies of natural gas and in these plants, freshwater production and electricity are
equally important co-products.
Since the efficiency of the plant is fundamentally limited by the ratio of the absolute
temperatures of the steam at turbine input and output, efficiency improvements
require use of higher temperature, and therefore higher pressure, steam. Historically,
other working fluids such as mercury have been experimentally used in a mercury
vapour turbine power plant, since these can attain higher temperatures than water at
lower working pressures. However, the obvious hazards of toxicity, and poor heat
transfer properties, have ruled out. mercury as a working fluid.

Schematic of Coal Fired Power Plant
What a power plant looks like

RANKINE CYCLE:
The Rankine cycle is a model that is used to predict the performance of steam turbine systems. The Rankine
cycle is an idealized thermodynamic cycle of a heat engine that converts heat into mechanical work. The heat is
supplied externally to a closed loop, which usually uses water as the working fluid. It is named after William
John Macquorn Rankine, a Scottish polymath and Glasgow University professor. The Rankine cycle closely
describes the process by which steam-operated heat engines commonly found in thermal power generation
plants generate power. The heat sources used in these power plants are usually nuclear fission or the
combustion of fossil fuels such as coal, natural gas, and oil.
The efficiency of the Rankine cycle is limited by the high heat of vaporization of the working fluid. Also,
unless the pressure and temperature reach super critical levels in the steam boiler, the temperature range
the cycle can operate over is quite small: steam turbine entry temperatures are typically around 565°C and
steam condenser temperatures are around 30°C. This gives a theoretical maximum Carnot efficiency for
the steam turbine alone of about 63% compared with an actual overall thermal efficiency of up to 42% for
a modern coal-fired power station. This low steam turbine entry temperature (compared to a gas turbine)
is why the Rankine (steam) cycle is often used as a bottoming cycle to recover otherwise rejected heat
in combined-cycle gas turbine power stations.
The working fluid in a Rankine cycle follows a closed loop and is reused constantly. The
water vapor with condensed droplets often seen billowing from power stations is created by the cooling
systems (not directly from the closed-loop Rankine power cycle) and represents the means for (low
temperature) waste heat to exit the system, allowing for the addition of (higher temperature) heat that can
then be converted to useful work (power). This 'exhaust' heat is represented by the "Qout" flowing out of
the lower side of the cycle shown in the T/s diagram below. Cooling towers operate as large heat
exchangers by absorbing the latent heat of vaporization of the working fluid and simultaneously
evaporating cooling water to the atmosphere. While many substances could be used as the working fluid
in the Rankine cycle, water is usually the fluid of choice due to its favorable properties, such as its non-
toxic and unreactive chemistry, abundance, and low cost, as well as its thermodynamic properties. By
condensing the working steam vapor to a liquid the pressure at the turbine outlet is lowered and the
energy required by the feed pump consumes only 1% to 3% of the turbine output power and these factors
contribute to a higher efficiency for the cycle. The benefit of this is offset by the low temperatures of
steam admitted to the turbine(s). Gas turbines, for instance, have turbine entry temperatures approaching
1500°C. However, the thermal efficiencies of actual large steam power stations and large modern gas
turbine stations are similar.
Physical layout of the four main devices used in the Rankine cycle

There are four processes in the Rankine cycle. These states are identified by numbers (in brown) in the
above T-s diagram.
 Process 1-2: The working fluid is pumped from low to high pressure. As the fluid is a liquid at this
stage, the pump requires little input energy.
 Process 2-3: The high pressure liquid enters a boiler where it is heated at constant pressure by an
external heat source to become a dry saturated vapour. The input energy required can be easily
calculated graphically, using an enthalpy-entropy chart (aka h-s chart or Mollier diagram), or
numerically, using steam tables.
 Process 3-4: The dry saturated vapour expands through a turbine, generating power. This decreases
the temperature and pressure of the vapour, and some condensation may occur. The output in this
process can be easily calculated using the chart or tables noted above.
 Process 4-1: The wet vapour then enters a condenser where it is condensed at a constant pressure to
become a saturated liquid.
In an ideal Rankine cycle the pump and turbine would be isentropic, i.e., the pump and turbine would
generate no entropy and hence maximize the net work output. Processes 1-2 and 3-4 would be represented
by vertical lines on the T-s diagram and more closely resemble that of the Carnot cycle. The Rankine
cycle shown here prevents the vapor ending up in the superheat region after the expansion in the
turbine, [1]
which reduces the energy removed by the condensers.
The actual vapor power cycle differs from the ideal Rankine cycle because of irreversibilities in the
inherent components caused by fluid friction and heat loss to the surroundings; fluid friction causes
pressure drops in the boiler, the condenser, and the piping between the components, and as a result the
steam leaves the boiler at a lower pressure; heat loss reduces the net work output, thus heat addition to the
steam in the boiler is required to maintain the same level of net work output.
T-s diagram of a typical Rankine cycle operating between pressures of 0.06bar and 50bar

FOUR BASIC CYCLES ON WHICH A POWER
GENERATING PLANT OPERATES
Any COAL FIRED Power Generating Plant operates on the following four basic
cycles:
1. Coal & Ash cycle
2. Air & Flue Gas cycle
3. Water & Steam cycle
4. Cooling Water cycle
Of all the above four mentioned cycles, the fist two i.e. COAL & ASH CYCLE &
AIR & FLUE GAS CYCLE are called OPEN CYCLES.
The next i.e. WATER & STEAM CYCLE is a CLOSED CYCLE.
The fourth and the last mentioned cycle i.e. THE COOLING WATER CYCLE occurs
in the condenser.
COAL ASH CYCLE
Raw coal is fed into the Coal Handling Plant (CHP) after which it is sent to the coal
bunker.Then through the coal feeder the coal is fed into the pulveriser/ crusher where
the coal (50mm dia.) is pulverized. After that the pulverized coal is fed through the
24(6x4) coal burners by primary air fans into the boiler furnace. After proper
combustion (determined by the 3-Ts : Temperature, Time and Turbulence) ash is
formed. This ash is of two types. The heavier variety is called the Bottom Ash while
the lighter variety passes out as flue gas into the Economiser. From the Economiser
also bottom ash is obtained. The bottom ash is obtained as clinkers which are crushed
into powder form by the scrapper-clinker grinder conveyer. Then the bottom ash thus
obtained is converted to slurry by water through the ash water pumps. The flue gas
from the furnace is fed to the economiser and the Air Preheaters (APH).Then from the
Electrostatic Precipitator (ESP) the flue gas is vent out into the atmosphere by ID fans
through the chimney. The ESP collects all the suspended ash particles by high voltage
discharge. The ash thus obtained is the second variety of ash and is called Fly Ash.
This fly ash, as the bottom ash, is converted into slurry. The slurry (of bottom ash +
fly ash) is collected in the Ash Slurry Sump. The slurry from the sump by a set of
three ash slurry pumps is sent to the Ash Pond .This ash is used in several applications
like cement industry, manufacture of bricks, etc.
AIR-FLUE GAS CYCLE
AIR CIRCUIT:

The air requirement of the boiler is met by two forced draft fans (FD FANS). The
forced draft fans supply the necessary primary and secondary air. About 80% of the
total air which is the secondary air goes directly to the furnace wind box and 20% of
the air goes to the mill via primary air fans. This air is known as the primary air. The
air before it goes into the furnace or to the mill it is pre heated in the air pre heaters.
The air pre heater installed is a tubular type heat exchanger in which the heat
exchanger takes place between flue gas and air. The flue gas flows through the tubes
and air flows over the tubes. The air heater serves to recovers the useful heat in the
outgoing flue gas (after recovery in the economizer) and thus improves the efficiency
of the boiler. At the air heater cold end the outgoing flue gas contains constituents like
sulpher dioxide. If the operating temperature goes below the dew point of the vapours
then the vapours get condensed and react with sulpher dioxide and sulphuric acid is
former which is corrosive in nature. The possibility of cold and corrosion is more
during lighting up of the boiler and at low load. To avoid this corrosion problem the
flue gas bearing the air is to be maintained at a higher temperature. This is
accomplished by passing the Air Pre-heater during lighting up and low load condition
when flue gas temperature is low. The primary air is supplied to the five mills by the
five primary air fans. The primary air is used in the mill to dry the pulverized coal and
to carry it into the furnace. To ensure drying of coal a portion primary air is taken after
passing through the air pre-heater. A cold air line is also connected to the hot primary
air line before it enters into the mills. The temperature of the coal air mixture at the
mill outlet is controlled by admitting the cold and hot primary air proportionately.
FLUE GAS CIRCUIT:
The flue gases move upward in the furnace and through the rear gas pass in a
downward direction to the air pre-heaters. The flue gas leaving the air preheater pass
through the electrostatic precipitators and then the induced draft fan (ID FAN) sucks
and forces the flue gas through the stack. The flue gas leaving the boiler furnace
carries with it particles like ash, unburnt carbon etc. The quantity of these matters is
small when oil is fired but it becomes quite considerable when coal is fired,
particularly when high ash content coal is fired. The ESP helps in minimizing the dust
concentration of flue gas thus reducing the erosion of ID FAN impellers, ducting and
the atmospheric pollution.
AIR FLUE PATH
WATER & STEAM CYCLE
Feed water is supplied to the boiler drum from economiser outlet header through

economiser links and these two links at the point of entering the drum have been
divided into 4 branch pipes. Altogether there are 8 downcomers from boiler drum, out
of which two downcomer pipes termed as ‘short loop’ (water platen) divided into 4
branches before entering the boiler and ultimately water flows to the drum through
these 4 water platen outlet headers. The front & the rear wall inlet headers feed the
front and rear furnace wall tubes. The furnace side walls are fed by two side wall inlet
headers. The water in the furnace sidewall, water wall platen and the extended side
wall absorb heat from the furnace.The resultant mixture of water and steam is
collected in the outlet headers and discharged into the steam drum through a series of
riser tubes. Steam generated in the front and the rear walls is supplied directly into the
drum. In the drum separation of water and steam takes place. The boiler water mixes
with the incoming water. The saturated steam is led to the roof radiant inlet header
and from there to the final SH outlet header via LTSH and platen superheater stages.
The steam is superheated to the designed temperature and from the superheater outlet
header the steam is led to the turbine via the main steam line.
COOLING WATER CYCLE
There are NINE cooling tower fans each of voltage rating: 415 V. They are
of ID fan type. All of them are controlled by MCC block.
SCHEMATIC DIAGRAMS:

->Air flue Gas cycle

COAL HANDLING PLANT
Coal is a primary fuel. Source of coal varies from thermal power plants of
CESC as per design parameters of individual boiler. Much coal is supplied by ECL
from Rani gaunge and Mugma fields, BCCL from Barakar and Kusunda areas and by
ICML. Coal is transported through railway linkages from respective fields to
generating stations. Requirement of coal at TGS is about TGS is about 3000 tones per
day.There are some properties of coals which are used in TGS.
 SWELLING INDEX: Some types of coal during and after release of volatile
matter become soft and pasty and form agglomerates called caking coals.
 GRINDABILITY: This property is measured by grindability index.
 WEATHERABILITY: It is a measure of how coal can be stockpiled for long
periods of time without crumbling to pieces.
 SULPHER CONTENT: Sulpher content in coal is combustible but the product
after combustion i.e.SO2 is a major source of atmospheric pollution.
 HEATING VALUE: The coal used in TGS has4000-5000 kcal/kg of heating
value.
PROCESS: First the coal is coming in the station .then with the help of tipplers or
bull dozer, coal from wagon or reclaim hopper is dropped to vibrating feeder through
a 30mm mesh. Any large coal chunk is broken manually and then fed. The first
conveyer belt starts below the ground and with an angle of 18 deg. with the ground. It
comes out and discharges the coal to another conveyer belt. This also with an angle of
18 deg. makes the coal reach the crusher. But before the crusher, impurities like iron
parts, which get carried so far, are separated by a magnetic separator which is oriented
in cross way. The coal is then dropped to the vibrating screen. The coal chunks are
already less then 20mm and go to stock. In the crusher, solid metallic, non ferrous
crushing wheels are used to crush the coals to 20 mm. From the crusher, coal goes to
the bunkers. From these bunkers they are dropped in ball & race mill. Here, huge solid
metallic balls are used to pulverize the coal to 75 micro meters. Then the coal is fed to
furnace. By primary air coal is dried from any moisture and also carries the pulverized
coal to furnace. At the starting of combustion, oil is required. The volatile matter in
coal starts to burn at a temp. near about 400 deg.C. This is temperature is attained by
burning oil which is LDO for industrial purposes. Sometimes oil is also required to
fire the furnace when the quality of coal is not up to mark or when there is high
moisture content in the coal. The main function of the Coal Handling Plant (CHP) is
to feed crushed coal up to the bunker. In the 4th Unit of DTPS there are 6 nos. of

bunkers as well as coal mills.
The CHP is divided into three zones:
ZONE 1 --- Unload uncrushed coal from wagon tippler up to UNCRUSHED
COAL YARD. Equipments: WAGON TIPPLER, VIBRATOR, CONVEYER BELT.
ZONE 2 --- Taking uncrushed coal from yard for crushing and send it to crushed yard.
Equipments: BELT, SCREEN, CRUSHER, VIBRATOR, DISCHARGE BELT.
ZONE 3 --- Taking crushed coal from yard through reclaim hopper (7, 8, 9 and 10)
and send it to the bunker. Equipments: BELT, VIBRATOR, TIPPER CAR.
COMPONENTS OF DIRECT FIRING SYSTEM ARE AS FOLLOWS:
1.Raw coal feeders.
2. Source to supply hot primary air to the pulverizer for drying the coal.
3. Pulverizer fan, also known as primary air fan arranged as a blower.
4. Pulverizer arranged to operate under pressure.
5. Burners.
TRANSMISSION OF COAL:(Coal yard to furnace)
1. Coal is brought by rail wagons, which the Indian Railways deliver till the coal yard
of TGS. From there, six to eight wagons are separated and are pulled to the Wagon
Tripler where there are unloaded one by one.
2. Wagon Tripler is a device by which the wagon is tripled to unload the coal to the
bunker. The Wagon Tripler consists of a moveable platform, which also acts as a
Computerized Weight Bridge A single wagon is first brought to the platform.
Then by a pulley and weight arrangement Powered by an electric motor, the
platform is tilted towards the bunker by 140 degree while a support from the top
catches the wagon and tilts it which causes the coal to fall down to the bunker. While
the unloading is done, water is sprayed on the coal to avoid spreading of coal dust.
3. From the coal bunker, the different varieties of coal. May be mixed by Dozers and
the coal from there is sent to the crusher.
4. In the crusher, coal is broken into small pieces of sizes not exceeding 20 mm in
diameter. From there by conveyor belt, the coal is taken through the chute and sent to
the top of. the main building
5. The coal is then dumped into an area from where it is fed into by conveyor belts to
the coal trolley which gathers the coal, decides which bunker requires coal, then it
rolls over to the of that bunker and pours the required amount of coal in it.

6. From the bunker, the coal comes down through the Hopper to the Besta Feeder.
7. The Besta Feeder controls the rate of the amount of coal to be fed tot the
pulverizer.Besta Feeder is a device consisting of a conveyor belt, which transfers the
coal from the hopper to the mouth of the pulverizer. The transfer rate of coal is
controlled from the controlled room by monitoring the speed of the Besta feeder. This
is because as the coal is grounded in the pulverizer, it becomes explosive in nature and
cannot be stored.
8. The coal is sent to the Pulverizer to get crushed into the size of 200 micron in
diameter.The Pulverizer consists of an enclosing cylinder with a channel comprising
of large Steel balls. These balls are rotated under pressure and coal is fed into this
channel where due to movement of these balls, it gets grounded. This procedure is
taken to achieve complete combustion of coal, better control of furnace temperature
and increasing the efficiency of the boiler.
9. From the Pulveriser the coal dust and air mixture is blown to the furnace by
PRIMARY AIR FAN.
COAL PULVERIZATION
Coal is pulverized in order to increase it’s surface its surface exposure thus promoting
rapid combustion without using large quantities of excess air. In modern power plants,
lump coal, crushed to uniform size is continuously supplied to the pulverized hopper
from where it is fed into the pulverized through a feeder arrangement. Combustion
rate is controlled by varying the feeder speed thereby controlling the rate of coal being
fed to the pulverizer. It is swept out from the mill and floated to the burner located in
the furnace wall by admitting enough of the combustion air at the pulverinizer to
accomplish air bone transportation. This air is called primary air as it is varied from as
little as 10% to almost the entire combustion air requirements, depending upon load.
SOME SPRECIFICATION ABOUT FHP
RH1------------------------ ECL
RH2------------------------- ICML, ECL
RH3------------------------- ICML
CRUSHER HOUSE SPECIFICATION
The no of convert belt----------------------- 18
It’s area---------------------------------------- Wagon tippler to bunker
Crusher speed--------------------------------- 750rpm

Shaft per crasher------------------------------ 4
The no of hammers inside the shaft-------- 18
The no of Gates------------------------------- 19
BUNKER SPECIFICATION
The no of bunker per unit-------------------- 5
The no of wagon per bunker----------------- 5
The height of bunker-------------------------- 60
Timing of to fill up a bunker----------------- 30 to 45 min
Bunker division-------------------------------- 1 ECL coal Bunker
4 ICML coal Bunker
Ability of supply of coal in a bunker--------- 14-15 hrs
Time require for transport of coal from
Wagon tippler to bunker--------- 5-6min
A typical coal handling plant
Belt Conveyor:

Layout of CHP:
A wagon tippler, crusher house, a bowl
mill.(Clockwise)

WATER TREATMENT PLANT & ITS OPERATION
The river water contains suspended matter with colloidal particles and some of
organic and inorganic impurities which make it necessary for chemical and
mechanical treatment in WT plant before being used as clarified and filtered water.
The impurities in water are of two kinds, volatile and non-volatile. Volatile impurities
can be expelled from water to a very great extent by it in fine streams or droplets into
the atmosphere. By this means foul gases dissolved in it are removed. By the Cascade
Type, 5 Stage Aerator the iron dissolved in water also is oxidised and thus
precipitates, enabling easy removal by filtration. The pH value of the water is often
increased due to aeration owing to the removal of CO2 from it. Lime dosing is done to
promote the coagulation efficiency. It also helps to maintain the pH value around 7.4
during coagulation. The non-volatile impurities like clay, vegetable matter, colouring
matter and bacteria being minute escape through filters. Hence alum is added to
sedimentation and hence, filtration. In the clariflocculator mechanical agitation is
created and the mixture is allowed to fall into a trough below for integrate mixing with
the chemicals used, creating violent turbulence. The flocculated water is admitted into
the clarifier tank from the bottom of the flocculator tank in a continuous rotary upward
movement that enhances the rate of deposition of sludge on the floor of the tank. This
sludge is removed by continuous sweeping through a desludging valve. The clarified
water is then collected in the gravity filter beds where they are filtered through a layer
of sand and gravel by the effect of gravity. Now to clean the pores in the filter bed,
backwashing is done. This process of backwashing involves flushing by compressed
air and water from beneath the filter bed and simultaneous drainage of the turbid
water. The filtered water thus is collected in the filtered water sump from where
through colony filter pumps this water is supplied to the colony. Through plant filter
pumps the clarified water is supplied to the DM plant & the Bearing Cooling Water
(BCW) sump or the non-dm plant.
DEMINIRELIZED WATER PLANT
Water is required for industrial process. From the Ganges the water is taken. The
water is first processed to deminarilize in DM plant. However natural water contains
dissolved salts, alkaline salts such as bicarbonates & carbonates of Ca, Na& mg. there
are also other dissolved impurities such as sulphates, chlorides & nitrates of Ca, Mg &
Na. Silica, dissolved CO2 and metals like Fe, Mn & organic matters are also present.
Ion exchange resins are porous materials that contain inert base attached to which
are free ions & can be free to move about within the resin structure. At first water is
taken from Ganges is taken to main water bus and is sent to water chamber where
alum is mixed. By clarifoculator system and flushing of air the alum gets mixed
properly in water and all the mud, algae etc. settles down.Uper portion of the water is
collected in reservoir which is divided into two sections. One portion goes for
treatment & other is for cooling of machines, coal yard & other services. There are
three types of pump. Clarified water pump, drinking water pump, service water pump.
PROCESS:
The clarified water is fed to pressure sand filter (PSF). There are three
numbers of PSF (A, B, C) & used to remove sand, mud etc. From PSF the water is fed
to the activated carbon filter (ACF). In the ACF it absorbs

any chlorine. There are 3 no.s of ACF (A, B, C) & used to remove the small particles
& bacteria. From ACF the water is moved to Strong Acid Cation (SAC) which are
three in no. (A, B, C). In SAC the cation exchange resin causes removal of the cation
& in their place hydrogen ions are released in the
solutions.
REGENERATION: While supply of exchangeable ions within the resin is
exhausted, the quality of treated water from the resin deteriorates & the resin requires
regeneration.
SAC:
 RNa + HCl ->RH + NaCl
 R2Mg + H2SO4 -> 2RH + MgSO4
SBA:
 RCl + NaOH -> ROH + NaCl
WBA:
 RHCl + NaOH -> R + H2O + H2O
The other part of the water goes to the non-dmplant from the clarifloculator. Now
from this the water is pumped out by service water pump & drinking water pump. The
water from the service water pump goes to clarified water pump the water of which is
used as heat absorber in case of ID,FD,PAF,generator air compressor etc. & this water
is cooled by raw ganga water tapped from the condenser. The water from service
water pump is also used as heat exchanger for ash water system bearing & rotary
unloader bearing. Now the water from drinking watrer pump goes to bathroom etc.&
the etc. part goes to the drain from the drain the water goes to the ETP1(effluent
treatment plant). The water then passes through ETP2,ETP3,&ETP4 & then it goes to
the circular reservoir after passing through the oil scheamer. While passing through
ETP3 chemical dodging was done. Finally the water from circular reservoir the water
goes to the non-dmplant. When the water flooded in ETP then to extract this extra
flooded water a tapping was done which is connected directly to the ganga & when it
returns to its normal condition then again it get back to the tapping line of condenser.
Again from the sump where water comesby tapping raw ganga water; the water goes
to the ash water pump & by creating a slury the ashes goes to the hydrabin & then to
the EADA(ash pond) from which the water goes to the ETP1 & ETP2. Now water
from demineralised water tank goes to CST(condensate storage tank). From which it
goes to the RFW(reserve feed water tank) by which the level of hot well is
maintained. The warter from CST also goes for deareator cold filling, boiler cold
filling & condensate emergency filling. Thus we can explain the full water treatment
cycle in a power plant.
SPECIFICATIONS:
In lower tower there are 9 IM PUMP used.
It’s voltage-------- 415v, speed-------- 2920rpm, current---------- 31amp………
There are used three type of pumps:
1. Service water pump---------------- 3
2. Drinking water pump--------------- 2
3. Clarified water pump---------------- 4
There is Oil skinning station where removes oil from the water.
Outer premises of D.M plant

2 tanks are used. 1 tank is full& the other tank is empty. A rotating device is attached
on top& it rotates slowly along the tanks boundary.
Inner premises of D.M plant
Effluent recircular system
The no of PSF( pressure sand filter) vessel------------------------ 2
The no of ACF (Activated charcoal filter) vessel------------------ 2{[A]---2kg/cm.sq
[B]---2.4kg/cm.sq
The no of SAC (SULPHURIC acidic cation) vessel -------------------3{[A] ---off,[B]--
0.5kg/cm.sq
,[C]---2kg/cm.sq
DEGASSED WATER PUMPS
Pump3 ------------1kg/cm.sq
Pump 4------------1kg/cm.sq
Pump1-----------------5kg/cm.sq.
MB air blasts: Not running-----------2, mixed bed===== 3, pressure-----6kg/cm.sq
Strong base anion (SBA) basin------------- 3
Weak base anion (WBA) basin----------------3
Each of pressure----------------------------------2kg/cm.sq
WBA(Weak Base Anion)

SAC(Strong Acid Cation)
SBA(Strong Base Anion)

ACF(Activated Carbon Filter)
MBA(Mixed Bed Anion)

PSF (Pressurized Sand Filter)
Clarifoculator

Addition Of Chlorine

FAN
PRIMARY AIR FAN: It is used for pulverized system. Primary air has two
functions. First one is dozing coal & transportation the coal to furnace.
No of fan per boiler 5
Motor type 3 phase AC 50 HZ IM
Rating(KW/HP) 235/315
Rated voltage 6.6 KV
P.F. at full load 0.87
Rated speed 1490 RPM
INDUCED DRAFT FAN: It is used only in balanced draft units to stuck the
gasses out of the furnace & throw them into the stack.
No of fans per boiler 2
Motor rating(KW/HP) 450/603
Rated speed 740RPM
FORCED DRAFT FAN: It is used to take air from atmosphere at ambient
temperature to supply essentially all the combustion air. It can either be sized to
overcome all the boiler losses (pressurized system) or just put the air in furnace
(balanced draft units).
FD FAN SPECIFICATION
No of fans per boiler 2
Motor rating (KW/HP) 270/362
Rated speed 985 RPM
PRIMARY AIR FAN

Induced Draft Fan
Forced Draft Fan

BOILER & THEIR AUXILLIARIES
Boiler is a steam raising unit of single radiant furnace type with auxiliary designated
to generate 272 kg/hr. at 91.4 kg/sq. cm pressure. The unit burns pulverized coal and
is equipped with oil burners. This plant is designated to operate at a 475m above sea
level .the ambient temperature is 40
0
C with a humidity of 70%. Furnace consists of
walls, tangent bare water tubes. Rear water tubes from a cavity for the pendant super
heater. A boiler or steam generator is a device used creates steam by applying heat
energy to water. Although the definitions are somewhat flexible, it can be said that
older steam generators were commonly termed boilers and worked at low to medium
pressure
(1–300 psi/0.069–20.684 bar; 6.895–2,068.427 KPa), but at pressures above this it is
more usual to speak of a steam generator. A boiler or steam generator is used
wherever a source of steam is required. Here in T.G.S steam is generated 318ton/hour
at 89.5kg/cm.sq. pressure and 515 °C in boiler.
Steam generator (component of prime mover)
The steam generator or boiler is an integral component of a steam engine when
considered as a prime mover; however it needs be treated separately, as to some
extent a variety of generator types can be combined with a variety of engine
units. A boiler incorporates a firebox or engine units. A boiler incorporates
a firebox orfurnace in order to burn the fuel and generate heat; the heat is
initially transferred to water to make steam; this produces saturated
steam at ebullition temperature saturated steam which can vary according to the
pressure above the boiling water. The higher the furnace temperature, the faster
the steam production. The saturated steam thus produced can then either be
used immediately to produce power via a turbine and alternator, or else may be
further superheated to a higher temperature; this notably reduces suspended
water content making a given volume of steam produce more work and creates a
greater temperature gradient in order to counter tendency to condensation due
to pressure and heat drop resulting from work plus contact with the cooler walls
of the steam passages and cylinders and wire-drawing effect from strangulation
at the regulator. Any remaining heat in the combustion gases can then either be
evacuated or made to pass through an economizers, the role of which is to warm
the feed water before it reaches the boiler.
DESIGN DATA:
Steam pressure --------------------------------91.4 kg/sq.cm.
Steam temperature ----------------------------515 deg.C
Furnace volume--------------------------------- 1558 m3
Drum:
Length-------------------------------------------- 12.97 m
Pressure-------------------------------------------- 102.7 kg/cm
2
Temperature---------------------------------------- 312 deg. C
Pulvarizer:
Type --------------------------------------------------Ball & race

Capacity----------------------------------------------- 15 T/hr * 5 Nos.
Speed ---------------------------------------------------49 rpm
Required power----------------------------------------- 100 KW
Feeder:
Type------------------------------------------------------- Drag Link
Control Device- ------------------------------------------- Thyristor
Technicial data of T.G.S drum:
Length=12.93Mtr
Weight=56tons
O.D=1724mm
DESIGN press=102.7Kg/cm.sq.
Shell thickness=105mm
Design temp= 312
0
c
Head thickness=90mm
Types of firing: a> perfect mixing of air & fuel
b> for complete combustion the optimum fuel &air ratio is maintained.
c> continuous and reliable ignition of fuel.
d>adequate control over point of formation& accumulation of ash when coal is fuel.
DIAGRAM SHOWING LOCATION OF FANS

STEAM DRUM:
The steam drum is made up of high cast steel so that its thermal stress is very high.
There is a safety valve in the drum, which may be explored if the temperature and the
pressure of the steam are beyond to a set value.
The boiler drum has the following purpose:
1. It stores and supplies water to the furnace wall headers and the generating tubes.
2. It as the collecting space for the steam produced.
3. The separation of water and steam tube place here.
4. Any necessary blow down for reduction of boiler water concentration is done from
the drum.
RISER AND DOWN COMERS:
Boiler is a closed vessel in which water is converted into the steam by the application
of the thermal energy. Several tubes coming out from the boiler drum and make the
water wall around the furnace. Outside the water wall there is a thermal insulation
such that the heat is not lost in the surroundings. Some of the tubes of the water wall
known as the ‘down comer’, which carries the cold water to the furnace and some of
other known as the ‘riser comer’, which take the steam in the upward direction. At the
different load riser and the down comers may change their property. There is a natural
circulation of water in the riser and the down comers due to different densities of the
water and the steam water mixture. As the heat is supplied, the steam is generated in
the risers due to this density of the steam water mixture is greater in the riser then in
the down comer and the continuous flow of water takes place. Down comer connected
to the ‘mud drum’, which accumulates the mud and the water. When the plant takes
shut down the mud drum is allowed to clean manually.
BURNERS:
15 Y jet sprayers are provided for lighting up and PF flame stabilization of 15
numbers burners. There is a provision for firing both the heavy fuel oil and light diesel
oil. The oil firing is done initially during the starting up and when the coal used in
TGS is of poor quality, then the plant is allowed to run on oil support. In TGS light
diesel oil (LDO) is used for the initiation for ignition of the pulverized coal. The LDO
charged into the furnace through the oil burners. It increases the burning capacity of
the pulverized coal. Heavy fuel oil passes through the pumping and heating unit to
reduce the viscosity as required for firing. For LDO no heating is required. Separate
oil pumps are provided for LDO. For both the type of oil, the oil pump discharge a
pressure is 14 kg cm². Constant steam pressure 10.5 kg cm² is maintained for oil
atomization and oil heating. P 34 gas igniters are provided for ignition.
SUPER HEATER: The super heater rises the temperature of the steam above its
Saturation point and there are two reasons for doing this:
FIRST- There is a thermodynamic gain in the efficiency.
SECOND- The super heated steam has fewer tendencies to condense in the last stages
of the turbine. It is composed of four sections, a platen section, pendant section, rear
horizontal section and steam cooled wall and roof radiant section. The platen section
is located directly above the furnace in front of the furnace arch. it is composed of 29
assemblies spaced at 457.2mm centers from across the width of the furnace. The
pendant section is located in the back of the screen wall tubes. It is composed of 119
assemblies at 1114mm centers across the furnace width. The horizontal section of the

superheater is located in the rear vertical gas pass above the economizer. Itis
composed of 134 assemblies spaced at 102 mm centers across furnace width. The
steam cooled wall section from the side front and rear walls and the roof of the
vertical gas pass. The superheater works like coils on an air conditioning unit,
however to a different end. The steam piping (with steam flowing through it) is
directed through the flue gas path in the boiler furnace. This area typically is between
1,300–1,600 degree Celsius (2,372–2,912 °F). Some superheaters are radiant type
(absorb heat by thermal radiation), others are convection type (absorb heat via a fluid
i.e. gas) and some are a combination of the two. So whether by convection or
radiation the extreme heat in the boiler furnace/flue gas path will also heat the
superheater steam piping and the steam within as well. It is important to note that
while the temperature of the steam in the superheater is raised, the pressure of the
steam is not: theturbine or moving pistons offer a "continuously expanding space" and
the pressure remains the same as that of the boiler.
The process of superheating steam is most importantly designed to remove all droplets
entrained in the steam to prevent damage to the turbine blading and/or associated
piping. Superheating the steam expands the volume of steam, which allows a given
quantity (by weight) of steam to generate more power. When the totality of the
droplets are eliminated, the steam is said to be in a superheated state.
Water tube boiler: Another way to rapidly produce steam is to feed the water under
pressure into a tube or tubes surrounded by the combustion gases. The earliest
example of this was developed by Goldsworthy Gurney in the late 1820s for use in
steam road carriages. This boiler was ultra-compact and light in weight and this
arrangement has since become the norm for marine and stationary applications. The
tubes frequently have a large number of bends and sometimes fins to maximize the
surface area. This type of boiler is generally preferred in high pressure applications
since the high pressure water/steam is contained within narrow pipes which can
contain the pressure with a thinner wall. It can however be susceptible to damage by
vibration in surface transport appliances. In a iron sectional boiler, sometimes called a
"pork chop boiler" the water is contained inside cast iron sections. These sections are
mechanically assembled on site to create the finished boiler. High pressure water tube
boilers generate steam rapidly at high temperatures that can be increased by
lengthening the tubes.

STEAM DRUM
BURNER
RISERS AND DOWNCOMERS
BOILER FAILURE:

1. overpressurisation of the boiler.
2. insufficient water in the boiler causing overheating and vessel failure.
3. pressure vessel failure of the boiler due to inadequate construction or maintenance.
FUEL PREPARATION SYSTEM:
In coal-fired power stations, the raw feed coal from the coal storage area is first
crushed into small pieces and then conveyed to the coal feed hoppers at the boilers.
The coal is next pulverized into a very fine powder. The pulverizers may be ball mills,
rotating drum grinders, or other types of grinders. Some power stations burn fuel
oil rather than coal. The oil must kept warm (above its pour point) in the fuel oil
storage tanks to prevent the oil from congealing and becoming unpumpable. The oil is
usually heated to about 100 °C before being pumped through the furnace fuel oil spray
nozzles.
Boilers in some power stations use processed natural gas as their main fuel. Other
power stations may use processed natural gas as auxiliary fuel in the event that their
main fuel supply (coal or oil) is interrupted. In such cases, separate gas burners are
provided on the boiler furnaces.
Air path: External fans are provided to give sufficient air for combustion. The
forced draft fan takes air from the atmosphere and, first warming it in the air preheater
for better combustion, injects it via the air nozzles on the furnace wall.The induced
draft fan assists the FD fan by drawing out combustible gases from the furnace,
maintaining a slightly negative pressure in the furnace to avoid backfiring through any
opening.
AUXILIARY SYSTEMS:
Fly ash collection: Fly ash is captured and removed from the flue gas by electrostatic
precipitators or fabric bag filters (or sometimes both) located at the outlet of the
furnace and before the induced draft fan. The fly ash is periodically removed from the
collection hoppers below the precipitators or bag filters. Generally, the fly ash is
pneumatically transported to storage silos for subsequent transport by trucks or
railroad cars.
Bottom ash collection and disposal:
At the bottom of the furnace, there is a hopper for collection of bottom ash. This
hopper is always filled with water to quench the ash and clinkers falling down from
the furnace. Some arrangement is included to crush the clinkers and for conveying the
crushed clinkers and bottom ash to a storage site.

ECONOMISER:
The heat of the flue gas is utilized to heat the boiler feed
water. During the start up
when no feed water goes inside the boiler water could stagnate
and over heat in the
economizer. To avoid this economizer re circulation is provided
from the boiler drum
to the economizer inlet.
AIR HEATER OR AIR PREHEATER:
The air heater is placed after the economizer in the path of the boiler flue gases and
preheats the air for combustion and further economy. There are 3 types of air pre
heaters: Tubular type, rotary type and plate type.Tubular type of air heater is used in
TGS. Hot air makes the combustion process more efficient making it more stable and
reducing the energy loss due to incomplete combustion and unburnt carbon. The air is
sucked by FD fan heated by the flue gas leaving the economizer. The preheated air is
sent to coal mill as primary air where coal is pulverized. The air sucked is heated to a
temp. of 240-280°C. The primary air transports the pulverized coal through three
burners at TGS after drying in the mill.
SPRAY ATTEMPERATOR:- In order to deliver a constant steam temperature

over a range of load, a steam generating unit (Boiler) may incorporate a spray
attemperator. It reduces the steam temperature by spraying controlled amount of water
into the super heated steam the steam is cooled by evaporating and super heating the
spray water. The spray nozzle is situated at the entrance to a restricted venture
sections and introduces water into the steam. A thermal sleeve linear protects the
steam line from sudden temperature shock due to impingement of the spray droplets
on the pipe walls.
The spray attemperator is located in between the primary super heater outlet and the
secondary super heater inlet. Except on recommendation of the boiler manufacturer
the spray water flow rate must never exceed the flow specified for maximum designed
boiler rating. Excessive attemperation may cause over heating of the super heater
tubes preceding the attemperator, since the steam generated by evaporation of spray
water and it does not pass through the tubes. Care must also be taken not to introduce
so much that the unevaporated water enters the secondary stage of the super heater.

SPRAYATTEMPERATOR
ELECTROSTATIC PRECIPITATOR: It is a device that separates fly ash
from outgoing flue gas before it discharged to the stack. There are four steps in
precipitation.
 Ionization of gases and charging of dust particles.
 Migration of particle to the collector.
 Deposition of charged particles on collecting surface.
 Dislodging of particles from the collecting surface.
By the electrostatic discharge the ash particles are charged due to high voltage(56KV)
between two electrodes. Generally maximum amount of ash particles are collected in
the form of dry ash, stored inside the SILO. Rest amount of ash(minimum) are
collected in the form of bottom ash and stored under the water inside HYDROBIN.
Factors affect the dust removal by an ESP:
a) Particle size:- 0.01μ or less
b) Particle resistivity:- 104 to 1010 ohm-cm
Both low and high resistivity beyond the stipulated value is detrimental to ESP
performances because high resitivity leads to ‘back corona’ causing re-entrainment
of deposited particle back to gas stream from the collecting electrode whereas dust
particles of low resitivity (below 108 ohm-cm) get neutralized so fast as soon as they
reach the +ve plates that particles still remain residual momentum that bounced
them of the collecting plates and caused re-entrainment.
c) Field strength,
d) Corona Characteristic,
e) Flue gas velocity :-1.5 to 2.5 meter /sec.,
f) Area of collecting surface,
g) Rapping frequency.
h) Presence sulfur, carbon particles, moisture, affects the performances of the ESP
i) Flue gas temperature should be within 140 to 1600 C

SAFETY VALVE: A safety valve is a valve mechanism for the automatic release of
a gas from a boiler, pressure vessel, or other system when the pressure or temperature
exceeds preset limits. It is part of a bigger set named Pressure Safety Valves (PSV) or
Pressure Relief Valves (PRV). The other parts of the set are named relief valves,
safety relief valves, pilot operated safety relief valves, low pressure safety valves,
vacuum pressure safety valves. Safety valves were first used on steam boilers during
the industrial revolution. Early boilers without them were prone to accidental
explosion when the operator allowed the pressure to become too high, either
deliberately or through incompetence.

BOILER LOSSES
FEEDWATER HEATER:
In the case of a conventional steam-electric power plant
utilizing a drum boiler, the surface condenser removes the latent heat of vaporization
from the steam as it changes states from vapour to liquid. The heat content
(joules or Btu) in the steam is referred to as enthalpy. The condensate pump then
pumps the condensate water through a feedwater heater. The feedwater heating
equipment then raises the temperature of the water by utilizing extraction steam from
various stages of the turbine. Preheating the feedwater reduces the irreversibilities
involved in steam generation and therefore improves thethermodynamic efficiency of
the system. This reduces plant operating costs and also helps to avoid thermal shock to
the boiler metal when the feedwater is introduced back into the steam cycle.

CONDENSER:
The surface condenser is a shell and tube heat exchanger in which cooling water is
circulated through the tubes. The exhaust steam from the low pressure turbine enters
the shell where it is cooled and converted to condensate (water) by flowing over the
tubes as shown in the adjacent diagram. Such condensers use steam ejectors or rotary
motor-driven exhausters for continuous removal of air and gases from the steam side
to maintain vacuum. For best efficiency, the temperature in the condenser must be
kept as low as practical in order to achieve the lowest possible pressure in the
condensing steam. Since the condenser temperature can almost always be kept
significantly below 100 °C where the vapor pressure of water is much less than
atmospheric pressure, the condenser generally works under vacuum. Thus leaks of
non-condensable air into the closed loop must be prevented. Plants operating in hot
climates may have to reduce output if their source of condenser cooling water
becomes warmer; unfortunately this usually coincides with periods of high electrical
demand for air conditioning. The condenser generally uses either circulating cooling
water from a cooling tower to reject waste heat to the atmosphere, or once-through
water from a river.

DEAERATOR:
A steam generating boiler requires that the boiler feed water should be devoid of air
and other dissolved gases, particularly corrosive ones, in order to avoid corrosion of
the metal. Generally, power stations use adeaerator to provide for the removal of air
and other dissolved gases from the boiler feed water. A deaerator typically includes a
vertical, domed deaeration section mounted on top of a horizontal cylindrical vessel
which serves as the deaerated boiler feedwater storage tank. There are many different
designs for a deaerator and the designs will vary from one manufacturer to another.
The adjacent diagram depicts a typical conventional trayed deaerator. If operated
properly, most deaerator manufacturers will guarantee that oxygen in the deaerated
water will not exceed 7 ppb by weight (0.005 cm³/L).

BOILER FEED PUMP
A boiler feedwater pump is a specific type of pump used to pump feedwater into
a steam boiler. The water may be freshly supplied or returning condensate produced as
a result of the condensation of the steam produced by the boiler. These pumps are
normally high pressure units that take suction from a condensate return system and
can be of the centrifugal pump type or positive displacement type. Feedwater pumps
range in size up to many horsepower and the electric motor is usually separated from
the pump body by some form of mechanical coupling. Large industrialcondensate
pumps may also serve as the feedwater pump. In either case, to force the water into
the boiler, the pump must generate sufficient pressure to overcome the steam pressure
developed by the boiler. This is usually accomplished through the use of a centrifugal
pump. Feedwater pumps sometimes run intermittently and are controlled by a float
switch or other similar level-sensing device energizing the pump when it detects a
lowered liquid level in the boiler. The pump then runs until the level of liquid in the
boiler is substantially increased. Some pumps contain a two-stage switch. As liquid
lowers to the trigger point of the first stage, the pump is activated. If the liquid
continues to drop (perhaps because the pump has failed, its supply has been cut off or
exhausted, or its discharge is blocked), the second stage will be triggered. This stage
may switch off the boiler equipment (preventing the boiler from running dry and
overheating), trigger an alarm, or both.

TURBINE SECTION
Turbine is a rotating device which converts heat energy of steam into mechanical
energy. It is a two cylinder machine of impulse reaction type comprising a single flow
high pressure turbine and a double flow low pressure turbine. The H.P. turbine shaft
and the generator are all rigidly coupled together, the assembly being located axially
by a thrust bearing at the inlet end of H.P. turbine. The turbine receives high pressure
steam from the boiler via two steam chests. The H.P. turbine cylinder has its steam
inlets at the end adjacent to the no. one bearing block, the steam flow towards the
generator. Exhaust steam passes through twin over-head pipes to the L.P. turbine inlet
belt where the steam flows in both directions through the L.P. turbine where it
exhausts into under slung condenser. Steam is extracted from both the H.P. & L.P.
turbine at various expansion stages & fed into four feedwater heaters.
DESIGN DATA:
Economical and max. continuous rating------------------------------- 60 MW
Steam pressure at emergency stop valve------------------------------- 89kg./sqr.cm.
Steam temp. at emergency stop valve ------------------------------------510°C
Absolute pressure at exhaust------------------------------------------------ 0.088kg./sq.cm
Rotational speed---------------------------------------------------------------- 3000 r.p.m
Tripping speed-------------------------------------------------------------------- 3375r.p.m
ALTERNATOR:
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form
ofalternating current.[2]
For reasons of cost and simplicity, most alternators use a rotating magnetic
field with a stationary armature.[3]
Occasionally, a linear alternator or a rotating armature with a stationary
magnetic field is used. In principle, any AC electrical generator can be called an alternator, but usually the
term refers to small rotating machines driven by automotive and other internal combustion engines. An
alternator that uses apermanent magnet for its magnetic field is called a magneto. Alternators in power
stations driven by steam turbines are called turbo-alternators. Large 50 or 60 Hz three phase alternators in
power plants generate most of the world's electric power, which is distributed by electric power grids
A conductor moving relative to a magnetic field develops an electromotive force (EMF) in it (Faraday's
Law). This emf reverses its polarity when it moves under magnetic poles of opposite polarity. Typically, a
rotating magnet, called the rotor turns within a stationary set of conductors wound in coils on an iron core,
called the stator. The field cuts across the conductors, generating an induced EMF (electromotive force),
as the mechanical input causes the rotor to turn.
The rotating magnetic field induces an AC voltage in the stator windings. Since the currents in the stator
windings vary in step with the position of the rotor, an alternator is a synchronous generator.[3]
The rotor's magnetic field may be produced by permanent magnets, or by a field coil electromagnet.
Automotive alternators use a rotor winding which allows control of the alternator's generated voltage by
varying the current in the rotor field winding. Permanent magnet machines avoid the loss due to
magnetizing current in the rotor, but are restricted in size, due to the cost of the magnet material. Since the
permanent magnet field is constant, the terminal voltage varies directly with the speed of the generator.
Brushless AC generators are usually larger than those used in automotive applications.

An automatic voltage control device controls the field current to keep output voltage constant. If the
output voltage from the stationary armature coils drops due to an increase in demand, more current is fed
into the rotating field coils through the voltage regulator (VR). This increases the magnetic field around
the field coils which induces a greater voltage in the armature coils. Thus, the output voltage is brought
back up to its original value.
Alternators used in central power stations also control the field current to regulate reactive power and to
help stabilize the power system against the effects of momentary faults. Often there are three sets of stator
windings, physically offset so that the rotating magnetic field produces a three phase current, displaced by
one-third of a period with respect to each other.

ALTERNATOR SPECIFICATIONS:
Maximum continuous rating 60 MW output
Maximum continuous rating 70.59 MVA o/p
Rated power factor 0.85 lagging
Rated terminal voltage 10500 volts
Rated phase current 3881 amps
Rated speed 3000 rpm
Frequency 50Hz
Number of phases 3
Number of poles 2
Short circuit ratio 0.6
Anti-condensation heater rating 6off-1KW,415V,3ph,4wires 50Hz

EXCITATION SYSTEM:
Main Exciter:
Pilot Exciter:
Number of phase 1
Rated peak voltage 130V rms
Power factor peak 0.9 Y - Connection
Number of poles 8
Maximum continuous rating 207KW
Rated terminal volt at rectifier DC term 225V
Rated current at rectifier 920A
Frequency 150Hz
Rated speed 3300 rpm
Number of poles 6

DISTRIBUTED CONTROL SYSTEM(DCS):
Distributed control systems (DCSs) are dedicated systems used to control manufacturing processes that
are continuous or batch-oriented, such as oil refining, petrochemicals, central station power generation,
fertilizers, pharmaceuticals, food and beverage manufacturing, cement production, steelmaking, and
papermaking. DCSs are connected to sensors and actuators and use setpoint control to control the flow of
material through the plant. The most common example is a setpoint control loop consisting of a pressure
sensor, controller, and control valve. Pressure or flow measurements are transmitted to the controller,
usually through the aid of a signal conditioning input/output (I/O) device. When the measured variable
reaches a certain point, the controller instructs a valve or actuation device to open or close until the fluidic
flow process reaches the desired setpoint. Large oil refineries have many thousands of I/O points and
employ very large DCSs. Processes are not limited to fluidic flow through pipes, however, and can also
include things like paper machines and their associated quality controls (see quality control system
QCS), variable speed drivesand motor control centers, cement kilns, mining operations, ore
processing facilities, and many others.
A typical DCS consists of functionally and/or geographically distributed digital controllers capable of
executing from regulatory control loops in one control box. The input/output devices (I/O) can be integral
with the controller or located remotely via a field network. Today’s controllers have extensive
computational capabilities and, in addition to proportional, integral, and derivative (PID) control, can
generally perform logic and sequential control. Modern DCSs also support neural
networks and fuzzyapplication. Recent research focuses on the synthesis of optimal distributed
controllers, which optimizes a certain H-infinity or H-2 criterion.[1][2]
DCSs are usually designed with redundant processors to enhance the reliability of the control system.
Most systems come with displays and configuration software that enable the end-user to configure the
control system without the need for performing low-level programming, allowing the user also to better
focus on the application rather than the equipment. However, considerable system knowledge and skill is
required to properly deploy the hardware, software, and applications. Many plants have dedicated
personnel who focus on these tasks, augmented by vendor support that may include maintenance support
contracts.
DCSs may employ one or more workstations and can be configured at the workstation or by an off-line
personal computer. Local communication is handled by a control network with transmission over twisted
-pair, coaxial, or fiber-optic cable. A server and/or applications processor may be included in the system
for extra computational, data collection, and reporting capability.

FOXVIEWTM
DCS OUTPUT

INSTRUMENTS REQUIRED:
RESISTANCE TEMPERATURE DETECTOR(RTD)
THERMOCOUPLE
SMART TRANSDUCER

ORIFICE PLATE
DEAD WEIGHT TESTER

CONCLUSION
From the above stated facts, we can get an in depth view of what a Power plant is, what it
looks like, the various components in a power plant, etc. This was organized by CESC, Kolkata
and its Subsidiary, Titagarh Generating Station, Titagarh, North 24 Parganas, Kolkata-700 119.
This training comprised of hourly time bound classes as well as visits to the sites
corresponding to the theoretical facts provided. The faculty members have been extremely
helpful in explaining and clarifying our issues.
CESC’s environmental management system focuses on continuous improvement and
upgradation with state-of-the-art principles and equipment, setting high targets and reviewing its
performances. CESC recognizes its responsibility towards protecting the ecology, health and
safety of the employees and consumers.
This training thus has been extremely helpful to me and I would cordially thank everyone
involved with me concerning the training.

BIBLIOGRAPHY/WEBLIOGRAPHY/REFERENCES:
For completion of this report, a handful of resources has been helpful to me. Some of
them are mentioned here:
 https://www.cesc.co.in/?page_id=532
 https://www.cesc.co.in/?page_id=509
 https://en.wikipedia.org/wiki/Thermal_power_station
 Power Plant Engineering Paperback – 14 Aug 2007-by PK Nag
 Steam Power Plant Engineering- by Gebhardt, George Frederick

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