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NATIONAL THERMAL POWER COOPERATION
BADARPUR THERMAL POWER STATION
NEW DELHI
Submitted by:
Nisar Ansari
B.Tech 3rd Year
09ECS-54
Electronics and communication Engineering
JAMIA MILLIA ISLAMIA ,NEW DELHI-110025
Duration- 21/05/2012 to 30/06/2012
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ACKNOWLEDGEMENT
I would like to express a deep sense of gratitude and thanks to Mr AJEET KUMAR OJHA-
DGM(HR)without the wise counsel and able guidance, it would have been impossible to complete the
report
in this manner.
The help rendered by Mrs RACHANA SINGH BHAL, Sr. Manager, National Thermal
PowerCorporation for experimentation is greatly acknowledged.
I would also like to express gratitude to the HOD and other faculty members of department
of
Electronics and communication engineering, MNNIT for their intellectual supportthroughout the
course of this work.
Finally, I would like to thanks Er. SONIA SINGH and all other technical staff of B.T.P.S.for giving
helping me throughout the training period.
Nisar Ansari
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ECE-MNNIT ALLAHABD
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CONTENT
1. INTRODUCTION TO THE COMPANY
2. OPERATION OF POWER PLANT
3. VARIOUS CYCLE AT POWER STATION
4. CONTROL & INSTRUMENTATION
5. IT DEPARTMENT
6. REFERENCE
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. About The Company
. Vision
. Strategies
. Environmental Policy
. Evolution
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About The Company
NTPC, the largest power Company in India, was setup in 1975 to accelerate powerdevelopment in
the country. It is among the worlds largest and most efficient power generation companies.
InForbes list of Worlds 2000 Largest Companies for the year 2007, NTPC occupies 411th
place.
A View Of Badarpur Thermal Power Station, New-Delhi
NTPC has installed capacity of 29,394 MW. It has 15 coal based power stations (23,395
MW), 7 gasbased power stations (3,955 MW) and 4 power stations in Joint Ventures (1,794 MW). The
company has power generating facilities in all major regions of the country. It plans to be a
75,000
MW company by 2017.
Types Of Power Station
Number
Capacity(MW)
Coal Based Power Station
15
23,395
Gas Based Power Station
7
3,955
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Joint Venture
4
1,794
Total Capacity 29,394 MW
NTPC has gone beyond the thermal power generation. It has diversified into hydro power,
coalmining, power equipment manufacturing, oil & gas exploration, power trading &
distribution. NTPCis now in the entire power value chain and is poised to become an Integrated Power Major.
NTPC's share on 31 Mar 2008 in the total installed capacity of the country was 19.1% andit
contributed 28.50% of the total power generation of the country during 2007-08. NTPC has
set new benchmarks for the power industry both in the area of power plant construction and
operations. With its experience and expertise in the power sector, NTPC is extending
consultancyservices to various organizations in the power business. It provides consultancy in the area
of
power plant constructions and power generation to companies in India and abroad.
In November 2004, NTPC came out with its Initial Public Offering (IPO) consisting of
5.25% as fresh
issue and 5.25% as offer for sale by Government of India. NTPC thus became a listed
company with Government holding 89.5% of the equity share capital and rest held by
Institutional Investors and Public. The issue was a resounding success. NTPC is among the
largest five companies in India in terms of market capitalization.
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Growth Of NTPC Generation & PLF %
Recognizing its excellent performance and vast potential, Government of the India has
identified
NTPC as one of the jewels of Public Sector 'Navratnas'- a potential global giant. Inspired
by itsglorious past and vibrant present, NTPC is well on its way to realize its vision of being "A
world class
integrated power major, powering India's growth, with increasing global presence".
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VISION
Corporate vision: - A world class integrated power major, powering India's growthwith increasing global presence.
Mission :-Develop and provide reliable power related products and services at competitive
prices,
integrating multiple energy resources with innovative & Eco-friendly technologies andcontribution to the
society.
Core Values - BCOMIT
Business ethics
Customer Focus
Organizational & Professional Pride
Mutual Respect & Trust
Innovation & Speed
Total Quality for Excellence
A View Of Well Flourished Plant
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STRATEGIESSustainableDevelopmentMaintainsectorLeadershipFurther
EnchanceFuel SecurityExploitNewBusinessOpportunitiesTechnologyInitiativesNuturingHumanResource
STRATEGIES
Technological Initiatives
. Introduction of steam generators (boilers) of the size of 800 MW.
. Integrated Gasification Combined Cycle (IGCC) Technology.
. Launch of Energy Technology Center -A new initiative for development of technologieswith
focus on fundamental R&D.. The company sets aside up to 0.5% of the profits for R&D.
. Roadmap developed for adopting Clean Development.
. Mechanism to help get / earn Certified Emission Reduction.
Corporate Social Responsibility
. As a responsible corporate citizen NTPC has taken up number of CSR initiatives.
. NTPC Foundation formed to address Social issues at national level.
. NTPC has framed Corporate Social Responsibility Guidelines committing up to 0.5% ofnet
profit annually for Community Welfare Measures on perennial basis.
. The welfare of project affected persons and the local population around NTPC projectsare
taken care of through well drawn Rehabilitation and Resettlement policies.
. The company has also taken up distributed generation for remote rural areas.
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ENVIROMANTAL POLICY
NTPC is committed to the environment, generating power at minimal environmental costand
preserving the ecology in the vicinity of the plants. NTPC has undertaken massive a
forestation inthe vicinity of its plants. Plantations have increased forest area and reduced barren land.
The
massive a forestation by NTPC in and around its Ramagundam Power station (2600 MW)
havecontributed reducing the temperature in the areas by about 3c. NTPC has also taken
proactive
steps for ash utilization. In 1991, it set up Ash Utilization Division
A "Centre for Power Efficiency and Environment Protection- CENPEE" has been
established inNTPC with the assistance of United States Agency for International Development- USAID.
CENPEEP
is efficiency oriented, eco-friendly and eco-nurturing initiative - a symbol of NTPC'sconcern
towards environmental protection and continued commitment to sustainable power
development
in India.
As a responsible corporate citizen, NTPC is making constant efforts to improve the socio-
economicstatus of the people affected by its projects. Through its Rehabilitation and Resettlement
programmes, the company endeavors to improve the overall socio economic status Project
Affected Persons.
NTPC was among the first Public Sector Enterprises to enter into a Memorandum of
Understanding-
MOU with the Government in 1987-88. NTPC has been placed under the 'Excellentcategory' (the
best category) every year since the MOU system became operative.
Harmony between man and environment is the essence of healthy life and growth.
Therefore,maintenance of ecological balance and a pristine environment has been of utmost
importance to
NTPC. It has been taking various measures discussed below for mitigation of environment
pollution
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due to power generation.
NTPC is the second largest owner of trees in the country after the Forestdepartment.
Environment Policy & Environment Management System
Driven by its commitment for sustainable growth of power, NTPC has evolved a well
definedenvironment management policy and sound environment practices for minimizing
environmental
impact arising out of setting up of power plants and preserving the natural ecology.
NTPC Environment Policy
As early as in November 1995, NTPC brought out a comprehensive document entitled
"NTPCEnvironment Policy and Environment Management System". Amongst the guiding
principlesadopted in the document are company's proactive approach to environment, optimum
utilization
of equipment, adoption of latest technologies and continual environment improvement. Thepolicy
also envisages efficient utilization of resources, thereby minimizing waste, maximizing ash
utilization and providing green belt all around the plant for maintaining ecological balance.
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Environment Management, Occupational Health and Safety Systems:
NTPC has actively gone for adoption of best international practices on environment,
occupational
health and safety areas. The organization has pursued the Environmental ManagementSystem
(EMS) ISO 14001 and the Occupational Health and Safety Assessment System OHSAS
18001 at itsdifferent establishments. As a result of pursuing these practices, all NTPC power stations
have been
certified for ISO 14001 & OHSAS 18001 by reputed national and international Certifying
Agencies.
Pollution Control systems:
While deciding the appropriate technology for its projects, NTPC integrates manyenvironmental
provisions into the plant design. In order to ensure that NTPC comply with all thestipulated
environment norms, various state-of-the-art pollution control systems / devices as
discussed belowhave been installed to control air and water pollution.
Electrostatic Precipitators:
The ash left behind after combustion of coal is arrested in high efficiency Electrostatic
Precipitators
(ESPs) and particulate emission is controlled well within the stipulated norms. The ashcollected in
the ESPs is disposed to Ash Ponds in slurry form.
Flue Gas Stacks:
Tall Flue Gas Stacks have been provided for wide dispersion of the gaseous emissions
(SOX, NOXetc) into the atmosphere.
Low-NOX Burners:
In gas based NTPC power stations, NOx emissions are controlled by provision of Low-
NOx Burners(dry or wet type) and in coal fired stations, by adopting best combustion practices.
Neutralisation Pits:
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Neutralisation pits have been provided in the Water Treatment Plant (WTP) for pH
correction of the
effluents before discharge into Effluent Treatment Plant (ETP) for further treatment anduse.
Coal Settling Pits / Oil Settling Pits:
In these Pits, coal dust and oil are removed from the effluents emanating from the Coal
Handling
Plant (CHP), coal yard and Fuel Oil Handling areas before discharge into ETP.
DE & DS Systems:
Dust Extraction (DE) and Dust Suppression (DS) systems have been installed in all coal
fired powerstations in NTPC to contain and extract the fugitive dust released in the Coal Handling
Plant (CHP).
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Cooling Towers:
Cooling Towers have been provided for cooling the hot Condenser cooling water in closed
cycle
Condenser Cooling Water (CCW) Systems. This helps in reduction in thermal pollutionand
conservation of fresh water.
Ash Dykes & Ash Disposal systems:
Ash ponds have been provided at all coal based stations except Dadri where Dry Ash
DisposalSystem has been provided. Ash Ponds have been divided into lagoons and provided with
garlanding
arrangements for changeover of the ash slurry feed points for even filling of the pond and
foreffective settlement of the ash particles.
Ash in slurry form is discharged into the lagoons where ash particles get settled from the
slurry and
clear effluent water is discharged from the ash pond. The discharged effluents conform tostandards specified by CPCB and the same is regularly monitored.
At its Dadri Power Station, NTPC has set up a unique system for dry ash collection and
disposalfacility with Ash Mound formation. This has been envisaged for the first time in Asia
which has
resulted in progressive development of green belt besides far less requirement of land andless
water requirement as compared to the wet ash disposal system.
Ash Water Recycling System:
Further, in a number of NTPC stations, as a proactive measure, Ash Water Recycling
System (AWRS)has been provided. In the AWRS, the effluent from ash pond is circulated back to the
station for
further ash sluicing to the ash pond. This helps in savings of fresh water requirements fortransportation of ash from the plant.
The ash water recycling system has already been installed and is in operation atRamagundam,
Simhadri, Rihand, Talcher Kaniha, Talcher Thermal, Kahalgaon, Korba and Vindhyachal.
The scheme
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has helped stations to save huge quantity of fresh water required as make-up water for
disposal of
ash.
Dry Ash Extraction System (DAES):
Dry ash has much higher utilization potential in ash-based products (such as bricks, aerated
autoclaved concrete blocks, concrete, Portland pozzolana cement, etc.). DAES has been
installed atUnchahar, Dadri, Simhadri, Ramagundam, Singrauli, Kahalgaon, Farakka, Talcher
Thermal, Korba,
Vindhyachal, Talcher Kaniha and BTPS.
Liquid Waste Treatment Plants & Management System:
The objective of industrial liquid effluent treatment plant (ETP) is to discharge lesser and
cleanereffluent from the power plants to meet environmental regulations. After primary treatment
at the
source of their generation, the effluents are sent to the ETP for further treatment. Thecomposite
liquid effluent treatment plant has been designed to treat all liquid effluents which originate
within
the power station e.g. Water Treatment Plant (WTP), Condensate Polishing Unit (CPU)effluent,
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Coal Handling Plant (CHP) effluent, floor washings, service water drains etc. The scheme
involvescollection of various effluents and their appropriate treatment centrally and re-circulation of
the
treated effluent for various plant uses.
NTPC has implemented such systems in a number of its power stations such as
Ramagundam,Simhadri, Kayamkulam, Singrauli, Rihand, Vindhyachal, Korba, Jhanor Gandhar,
Faridabad, Farakka,
Kahalgaon and Talcher Kaniha. These plants have helped to control quality and quantity of
theeffluents discharged from the stations.
Sewage Treatment Plants & Facilities:
Sewage Treatment Plants (STPs) sewage treatment facilities have been provided at all
NTPC
stations to take care of Sewage Effluent from Plant and township areas. In a number ofNTPC
projects modern type STPs with Clarifloculators, Mechanical Agitators, sludge drying
beds, Gas
Collection Chambers etc have been provided to improve the effluent quality. The effluentquality is
monitored regularly and treated effluent conforming to the prescribed limit is discharged
from thestation. At several stations, treated effluents of STPs are being used for horticulture
purpose.
Environmental Institutional Set-up:
Realizing the importance of protection of the environment with speedy development of the
power
sector, the company has constituted different groups at project, regional and CorporateCentre
level to carry out specific environment related functions. The Environment Management
Group,Ash Utilisation Group and Centre for Power Efficiency & Environment Protection
(CENPEEP)
function from the Corporate Centre and initiate measures to mitigate the impact of power
project
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implementation on the environment and preserve ecology in the vicinity of the projects.
Environment Management and Ash Utilisation Groups established at each station, look
aftervarious environmental issues of the individual station.
Environment Reviews:
To maintain constant vigil on environmental compliance, Environmental Reviews are
carried out atall operating stations and remedial measures have been taken wherever necessary. As a
feedback
and follow-up of these Environmental Reviews, a number of retrofit and up-gradation
measureshave been undertaken at different stations.
Such periodic Environmental Reviews and extensive monitoring of the facilities carried out
at allstations have helped in compliance with the environmental norms and timely renewal of
the Airand Water Consents.
Waste Management
Various types of wastes such as Municipal or domestic wastes, hazardous wastes, Bio-
Medical
wastes get generated in power plant areas, plant hospital and the townships of projects. Thewastes generated are a number of solid and hazardous wastes like used oils & waste oils,
grease,
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lead acid batteries, other lead bearing wastes (such as garkets etc.), oil & clarifier sludge,
usedresin, used photo-chemicals, asbestos packing, e-waste, metal scrap, C&I wastes, electricial
scrap,
empty cylinders (refillable), paper, rubber products, canteen (bio-degradable) wastes,buidling
material wastes, silica gel, glass wool, fused lamps & tubes, fire resistant fluids etc. These
wastesfall either under hazardous wastes category or non-hazardous wastes category as per
classification
given in Government of Indias notification on Hazardous Wastes (Management and
Handling)Rules 1989 (as amended on 06.01.2000 & 20.05.2003). Handling and management of these
wastes
in NTPC stations have been discussed below.
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NTPC was set up in 1975 with 100%
ownership by the Government ofIndia. In the last 30 years, NTPC has
grown into the largest power utility in
India.1975In 1997, Government of India granted
NTPC status of Navratna"being one
of the nine jewels of India, enhancingthe powers to the Board of Directors.1997NTPC became a listed company with
majority Government ownership of
89.5%.
NTPC becomes 3rdlargest by MarketCapitalization of listed companies2004The company rechristened as NTPC
Limited in line with its changing
business portfolio and transforms
itself from a thermal power utility toan integrated power utility.
2005National Thermal Power Corporationis the largest power generation
company in India. Forbes Global 2000
for 2008 ranked it 411th in the world.2008EVOLUTION
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INTRODUCTION
BADARPUR THERMAL POWER STATION was established on 1973 and it was the part
of Central
Government. On 01/04/1978 is was given as No Loss No Profit Plant of NTPC.
Since then operating performance of NTPC has been considerably above the national
average. Theavailability factor for coal stations has increased from 85.03 % in 1997-98 to 90.09 % in
2006-07,
which compares favourably with international standards. The PLF has increased from
75.2% in1997-98 to 89.4% during the year 2006-07 which is the highest since the inception of
NTPC.
Capacity of BADARPUR THERMAL POWER STATION
Sr. No.
Capacity(MW)
Number
Total Capacity(MW)
1.
210
2
420
2.
95
3
285
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Overall Capacity- 705 MW
BASIC PRINCIPLE
As per FARADAYs Law- Whenever the amount of magnetic flux linked with a circuit
changes, an EMF is
produced in the circuit. Generator works on the principle of producing electricity. Tochange the flux in the
generator turbine is moved in a great speed with steam.
To produce steam, water is heated in the boilers by burning the coal. In a BadarpurThermal Power
Station, steam is produced and used to spin a turbine that operates a generator. Water is
heated,
turns into steam and spins a steam turbine which drives an electrical generator. After itpasses
through the turbine, the steam is condensed in a condenser; this is known as a Rankinecycle.
Shown here is a diagram of a conventional thermal power plant, which uses coal, oil, or
natural gasas fuel to boil water to produce the steam. The electricity generated at the plant is sent to
consumers through high-voltage power lines The Badarpur Thermal Power Plant has Steam
Turbine-Driven Generators which has a collective capacity of 705MW. The fuel being used
is Coalwhich is supplied from the Jharia Coal Field in Jharkhand. Water supply is given from the
Agra
Canal.
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Heat Enegrgy
SteamCoupling
Electricity from Coal
There are basically three main units of a thermal power plant:
1. Steam Generator or Boiler
2. Steam Turbine
3. Electric Generator
Basic Electricity Generation Chart
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Functioning of Thermal Power Plant
Typical Diagram of Coal Based Power Plant
Its various parts are listed below:-
1. Cooling tower
2. Cooling water pump
3. Transmission line (3-phase)
4. Unit transformer (3-phase)
5. Electric generator (3-phase)
6. Low pressure turbine
7. Condensate extraction pump
8. Condenser
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9. Intermediate pressure turbine
10. Steam governor valve
11. High pressure turbine
12. DE aerator
13. Feed heater
14. Coal conveyor
15. Coal hopper
16. Pulverised fuel mill
17. Boiler drum
18. Ash hopper
19. Super heater
20. Forced draught fan
21. Re heater
22. Air intake
23. Economiser
24. Air preheater
25. Precipitator
26. Induced draught fan
27. Fuel Gas Stack
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1. Cooling towers
Cooling Towers are evaporative coolers used for cooling water or other working mediumto near the
ambivalent web-bulb air temperature. Cooling tower use evaporation of water to reject heat
fromprocesses such as cooling the circulating water used in oil refineries, Chemical plants,
power plants
and building cooling, for example. The tower vary in size from small roof-top units to verylarge
hyperboloid structures that can be up to 200 meters tall and 100 meters in diameter, or
rectangular
structure that can be over 40 meters tall and 80 meters long. Smaller towers are normallyfactory
built, while larger ones are constructed on site.
The primary use of large , industrial cooling tower system is to remove the heat absorbed in
thecirculating cooling water systems used in power plants , petroleum refineries,
petrochemical andchemical plants, natural gas processing plants and other industrial facilities . The absorbed
heat is
rejected to the atmosphere by the evaporation of some of the cooling water in mechanicalforced-
draft or induced draft towers or in natural draft hyperbolic shaped cooling towers as seen at
most
nuclear power plants.
2. Cooling Water Pump
It pumps the water from the cooling tower which goes to the condenser.
3.Three phase transmission line
Three phase electric power is a common method of electric power transmission. It is a type
ofpolyphase system mainly used to power motors and many other devices. A Three phase
system uses
less conductor material to transmit electric power than equivalent single phase, two phase,or direct
current system at the same voltage. In a three phase system, three circuits reach their
instantaneouspeak values at different times. Taking one conductor as the reference, the other two current
are
delayed in time by one-third and two-third of one cycle of the electrical current. This delay
between
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phases has the effect of giving constant power transfer over each cycle of the current and
also
makes it possible to produce a rotating magnetic field in an electric motor.At the power station, an electric generator converts mechanical power into a set of electric
currents,
one from each electromagnetic coil or winding of the generator. The current are sinusoidalfunctions
of time, all at the same frequency but offset in time to give different phases. In a three
phase systemthe phases are spaced equally, giving a phase separation of one-third one cycle. Generators
output at
a voltage that ranges from hundreds of volts to 30,000 volts.
4. Unit transformer (3-phase)
At the power station, transformers: step-up this voltage to one more suitable for
transmission. Afternumerous further conversions in the transmission and distribution network the power is
finallytransformed to the standard mains voltage (i.e. the household voltage).
The power may already have been split into single phase at this point or it may still be three
phase.Where the step-down is 3 phase, the output of this transformer is usually star connected
with the
standard mains voltage being the phase-neutral voltage. Another system commonly seen in
NorthAmerica is to have a delta connected secondary with a center tap on one of the windings
supplying
the ground and neutral. This allows for 240 V three phase as well as three different singlephase
voltages( 120 V between two of the phases and neutral , 208 V between the third phase
( known as awild leg) and neutral and 240 V between any two phase) to be available from the same
supply.
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5. Electrical generator
An Electrical generator is a device that converts kinetic energy to electrical energy,generally using
electromagnetic induction. The task of converting the electrical energy into mechanical
energy isaccomplished by using a motor. The source of mechanical energy may be a reciprocating or
turbine
steam engine, , water falling through the turbine are made in a variety of sizes ranging fromsmall 1
hp (0.75 kW) units (rare) used as mechanical drives for pumps, compressors and other shaft
driven
equipment , to 2,000,000 hp(1,500,000 kW) turbines used to generate electricity. There areseveral
classifications for modern steam turbines.
Steam turbines are used in all of our major coal fired power stations to drive the generators
oralternators, which produce electricity. The turbines themselves are driven by steam
generated inBoilers. or steam generators. as they are sometimes called.
Electrical power station use large stem turbines driving electric generators to produce most
(about86%) of the world.s electricity. These centralized stations are of two types: fossil fuel
power plants
and nuclear power plants. The turbines used for electric power generation are most often
directlycoupled to their-generators .As the generators must rotate at constant synchronous speeds
according
to the frequency of the electric power system, the most common speeds are 3000 r/min for50 Hz
systems, and 3600 r/min for 60 Hz systems. Most large nuclear sets rotate at half those
speeds, andhave a 4-pole generator rather than the more common 2-pole one.
6. Low Pressure TurbineEnergy in the steam after it leaves the boiler is converted into rotational energy as it passes
through
the turbine. The turbine normally consists of several stage with each stages consisting of astationary
blade (or nozzle) and a rotating blade. Stationary blades convert the potential energy of the
steaminto kinetic energy into forces, caused by pressure drop, which results in the rotation of the
turbine
shaft. The turbine shaft is connected to a generator, which produces the electrical energy.
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Low Pressure Turbine (LPT) consist of 4x2 stages. After passing through Intermediate
Pressure
Turbine is is passed through LPT which is made up of two parts- LPC REAR & LPCFRONT. As
water gets cooler here it gathers into a HOTWELL placed in lower parts of Turbine.
7. Condensation Extraction PumpA Boiler feed water pump is a specific type of pump used to pump water into a steam
boiler. The
water may be freshly supplied or retuning condensation of the steam produced by theboiler. These
pumps are normally high pressure units that use suction from a condensate return system
and can be
of the centrifugal pump type or positive displacement type.Construction and operation
Feed water 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 industrial condensatepumps may
also serve as the feed water pump. In either case, to force the water into the boiler; thepump must
generate sufficient pressure to overcome the steam pressure developed by the boiler. This is
usuallyaccomplished through the use of a centrifugal pump.
Feed water pumps usually 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 theboiler is
substantially increased. Some pumps contain a two-stage switch. As liquid lowers to the
trigger pointof the first stage, the pump is activated. I f 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 secondstage will
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be triggered. This stage may switch off the boiler equipment (preventing the boiler from
running dryand overheating), trigger an alarm, or both.
8. Condenser
The steam coming out from the Low Pressure Turbine (a little above its boiling pump) is
brought
into thermal contact with cold water (pumped in from the cooling tower) in the condenser,
where itcondenses rapidly back into water, creating near
vacuum-like conditions inside the condenser chest.
9. Intermediate Pressure Turbine
Intermediate Pressure Turbine (IPT) consist of 11 stages. When the steam has been passedthrough
HPT it gets enter into IPT. IPT has two ends named as FRONT & REAR. Steam enters
through front
end and leaves from Rear end.
10. Steam Governor ValveSteam locomotives and the steam engines used on ships and stationary applications such as
power
plants also required feed water pumps. In this situation, though, the pump was oftenpowered using a
small steam engine that ran using the steam produced by the boiler. A means had to be
provided, of
course, to put the initial charge of water into the boiler(before steam power was available tooperate
the steam-powered feed water pump).the pump was often a positive displacement pump
that hadsteam valves and cylinders at one end and feed water cylinders at the other end; no
crankshaft was
required.In thermal plants, the primary purpose of surface condenser is to condense the exhaust
steam from a
steam turbine to obtain maximum efficiency and also to convert the turbine exhaust steam
into pure
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water so that it may be reused in the steam generator or boiler as boiler feed water. By
condensing
the exhaust steam of a turbine at a pressure below atmospheric pressure, the steam pressuredrop
between the inlet and exhaust of the turbine is increased, which increases the amount heat
availablefor conversion to mechanical power. Most of the heat liberated due to condensation of the
exhaust
steam is carried away by the cooling medium (water or air) used by the surface condenser.Control valves are valves used within industrial plants and elsewhere to control operating
conditions
such as temperature,pressure,flow,and liquid Level by fully partially opening or closing in
responseto signals received from controllers that compares a set point to a process variable
whose value
is provided by sensors that monitor changes in such conditions. The opening or closing of
controlvalves is done by means of electrical, hydraulic or pneumatic systems
11.High Pressure Turbine
Steam coming from Boiler directly feeds into HPT at a temperature of 540C and at a
pressure of136 kg/cm2. Here it passes through 12 different stages due to which its temperature goes
down to
329C and pressure as 27 kg/cm2. This line is also called as CRH COLD REHEAT
LINE.
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It is now passed to an REHEATER where its temperature rises to 540C and called as
HRH-HOTREHEATED LINE .
12. DeaeratorA Dearator is a device for air removal and used to remove dissolved gases (an alternate
would be the
use of water treatment chemicals) from boiler feed water to make it non-corrosive. Adearator
typically includes a vertical domed deaeration section as the deaeration boiler feed water
tank. A
Steam generating boiler requires that the circulating steam, condensate, and feed watershould be
devoid of dissolved gases, particularly corrosive ones and dissolved or suspended solids.
The gases
will give rise to corrosion of the metal. The solids will deposit on the heating surfacesgiving rise to
localized heating and tube ruptures due to overheating. Under some conditions it may giveto stress
corrosion cracking.
Deaerator level and pressure must be controlled by adjusting control valves- the level byregulating
condensate flow and the pressure by regulating steam flow. If operated properly, most
deaerator
vendors will guarantee that oxygen in the deaerated water will not exceed 7 ppb by weight(0.005
cm3/L)
13. Feed water heaterA Feed water heater is a power plant component used to pre-heat water delivered to a
steam
generating boiler. Preheating the feed water reduces the irreversible involved in steamgeneration and
therefore improves the thermodynamic efficiency of the system.[4] This reduces plant
operating
costs and also helps to avoid thermal shock to the boiler metal when the feed water isintroduces
back into the steam cycle.
In a steam power (usually modelled as a modified Ranking cycle), feed water heaters allowthe feed
water to be brought up to the saturation temperature very gradually. This minimizes the
inevitableirreversibility.s associated with heat transfer to the working fluid (water). A belt conveyor
consists of
two pulleys, with a continuous loop of material- the conveyor Belt that rotates about
them. The
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pulleys are powered, moving the belt and the material on the belt forward. Conveyor belts
are
extensively used to transport industrial and agricultural material, such as grain, coal, oresetc.
14. Coal conveyor
Coal conveyors are belts which are used to transfer coal from its storage place to Coal
Hopper.
15. Coal Hopper
Coal Hopper are the places which are used to feed coal to Fuel Mill. It also has the
arrangement of enteringof Hoy Air at 200C inside it which solves our two purposes:-
1. If our Coal has moisture content then it dries it so that a proper combustion takes place.
2. It raises the temperature of coal so that its temperature is more near to its IgniteTemperature so
that combustion is easy.
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16. Pulverised Fuel Mill
A pulveriser is a device for grinding coal for combustion in a furnace in a fossil fuel power
plant.
17. Boiler DrumSteam Drums are a regular feature of water tube boilers. 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 watertubes 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 steamdrum. Made
from high-grade steel (probably stainless) and its working involves temperatures 390.C and
pressure
well above 350psi (2.4MPa). The separated steam is drawn out from the top section of thedrum.
Saturated steam is drawn off the top of the drum. The steam will re-enter the furnace inthrough 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.
18. Ash Hopper
A steam drum is used in the company of a mud-drum/feed water drum which is located at alower
level. So that it acts as a sump for the sludge or sediments which have a tendency to the
bottom.19. Super Heater
A Super heater is a device in a steam engine that heats the steam generated by the boiler
again
increasing its thermal energy and decreasing the likelihood that it will condense inside theengine.
Super heaters increase the efficiency of the steam engine, and were widely adopted. Steam
which hasbeen superheated is logically known as superheated steam; non-superheated steam is called
saturated
steam or wet steam; Super heaters were applied to steam locomotives in quantity from theearly 20th
century, to most steam vehicles, and so stationary steam engines including power stations.
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20. Force Draught Fan
External fans are provided to give sufficient air for combustion. The forced draft fan takesair from
the atmosphere and, first warming it in the air preheater for better combustion, injects it via
the airnozzles on the furnace wall.
21. Reheater
Reheater are heaters which are used to raise the temperature of air which has been fallen
down due to
various process.
22. Air Intake
Air is taken from the environment by an air intake tower.
23. Economizers
Economizer, or in the UK economizer, are mechanical devices intended to reduce energy
consumption, or to perform another useful function like preheating a fluid. The termeconomizer is
used for other purposes as well. Boiler, power plant, and heating, ventilating and air
conditioning. In
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boilers, economizer are heat exchange devices that heat fluids , usually water, up to but not
normallybeyond the boiling point of the fluid. Economizers are so named because they can make
use of the
enthalpy and improving the boiler.s efficiency. They are a device fitted to a boiler whichsaves
energy by using the exhaust gases from the boiler to preheat the cold water used the fill it
(the feedwater). Modern day boilers, such as those in cold fired power stations, are still fitted with
economizer which is decedents of Green.s original design. In this context they are turbines
before it
is pumped to the boilers. A common application of economizer is steam power plants is tocapture
the waste hit from boiler stack gases (flue gas) and transfer thus it to the boiler feed water
thus
lowering the needed energy input , in turn reducing the firing rates to accomplish the ratedboiler
output . Economizer lower stack temperatures which may cause condensation of acidiccombustion
gases and serious equipment corrosion damage if care is not taken in their design and
materialselection.
24. Air Preheater
Air preheater is a general term to describe any device designed to heat air before another
process (forexample, combustion in a boiler). The purpose of the air preheater is to recover the heat
from the
boiler flue gas which increases the thermal efficiency of the boiler by reducing the usefulheat lost in
the fuel gas. As a consequence, the flue gases are also sent to the flue gas stack (or
chimney) at alower temperature allowing simplified design of the ducting and the flue gas stack. It also
allows
control over the temperature of gases leaving the stack.
25. PrecipitatorAn Electrostatic precipitator (ESP) or electrostatic air cleaner is a particulate device that
removes
particles from a flowing gas (such As air) using the force of an induced electrostaticcharge.
Electrostatic precipitators are highly efficient filtration devices, and can easily remove fine
particulate matter such as dust and smoke from the air steam.ESP.s continue to be excellent devices for control of many industrial particulate emissions,
including
smoke from electricity-generating utilities (coal and oil fired), salt cake collection from
black liquor
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boilers in pump mills, and catalyst collection from fluidized bed catalytic crackers from
several
hundred thousand ACFM in the largest coal-fired boiler application.The original parallel plate-Weighted wire design (described above) has evolved as more
efficient (
and robust) discharge electrode designs were developed, today focusing on rigid dischargeelectrodes
to which many sharpened spikes are attached , maximizing corona production. Transformer
rectifiersystems apply voltages of 50-100 Kilovolts at relatively high current densities. Modern
controls
minimize sparking and prevent arcing, avoiding damage to the components. Automatic
rappingsystems and hopper evacuation systems remove the collected particulate matter while on
line
allowing ESP.s to stay in operation for years at a time.
26. Induced Draught Fan
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. At
the furnace outlet, and before the furnace gases are handled by the ID fan, fine dust carriedby the
outlet gases is removed to avoid atmospheric pollution. This is an environmental limitation
prescribed by law, additionally minimizes erosion of the ID fan.
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27. Fuel gas stack
A Fuel gas stack is a type of chimney, a vertical pipe, channel or similar structure throughwhich combustion
product gases called fuel gases are exhausted to the outside air. Fuel gases are produced
when coal, oil,natural gas, wood or any other large combustion device. Fuel gas is usually composed of
carbon dioxide
(CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intakecombustion air. It
also contains a small percentage of pollutants such as particulates matter, carbon mono
oxide, nitrogen
oxides and sulfur oxides. The flue gas stacks are often quite tall, up to 400 meters (1300feet) or more, so as
to disperse the exhaust pollutants over a greater aria and thereby reduce the concentration
of the pollutants
to the levels required by governmental environmental policies and regulations.When the fuel gases exhausted from stoves, ovens, fireplaces or other small sources within
residentialabodes, restaurants , hotels or other stacks are referred to as chimneys.
OPERATION OF BOILER
The boiler is a rectangular furnace about 50 ft (15 m) on a side and 130 ft (40 m) tall. Its
walls are
made of a web of high pressure steel tubes about 2.3 inches (60 mm) in diameter.
Pulverized coal is air-blown into the furnace from fuel nozzles at the four corners and it
rapidly
burns, forming a large fireball at the center. The thermal radiation of the fireball heats thewater
that circulates through the boiler tubes near the boiler perimeter. The water circulation rate
in theboiler is three to four times the throughput and is typically driven by pumps. As the water
in the
boiler circulates it absorbs heat and changes into steam at 700 F (370 C) and 22.1 MPa. It
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separated from the water inside a drum at the top of the furnace. The saturated steam is
introduced into superheat pendant tubes that hang in the hottest part of the combustion
gases asthey exit the furnace. Here the steam is superheated to 1,000 F (540 C) to prepare it for
the
turbine.
The steam generating boiler has to produce steam at the high purity, pressure and
temperaturerequired for the steam turbine that drives the electrical generator. The generator includes
the
economizer, the steam drum, the chemical dosing equipment, and the furnace with its
steamgenerating tubes and the superheater coils. Necessary safety valves are located at suitable
pointsvto avoid excessive boiler pressure. The air and flue gas path equipment include:
forced draft
(FD) fan, air preheater (APH), boiler furnace, induced draft (ID) fan, fly ash collectors(electrostatic
precipitator or baghouse) and the flue gas stack.
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Schematic diagram of a coal-fired power plant steam generator
Boiler Furnace and Steam Drum
Once water inside the boiler or steam generator, the process of adding the latent heat of
vaporization or enthalpy is underway. The boiler transfers energy to the water by the
chemicalreaction of burning some type of fuel.
The water enters the boiler through a section in the convection pass called the economizer.
Fromthe economizer it passes to the steam drum. Once the water enters the steam drum it goes
downthe down comers to the lower inlet water wall headers. From the inlet headers the water
rises
through the water walls and is eventually turned into steam due to the heat being generatedby the
burners located on the front and rear water walls (typically). As the water is turned into
steam/vapour in the water walls, the steam/vapor once again enters the steam drum.
Fuel Preparation System
In coal-fired power stations, the raw feed coal from the coal storage area is first crushedinto 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 un-pumpable.
The oil is usually heated to about 100C before being pumped through the furnace fuel oil
spraynozzles.
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Fuel Firing System and Ignite System
From the pulverized coal bin, coal is blown by hot air through the furnace coal burners atan
angle which imparts a swirling motion to the powdered coal to enhance mixing of the coal
powder with the incoming preheated combustion air and thus to enhance the combustion.
To provide sufficient combustion temperature in the furnace before igniting the powdered
coal, the
furnace temperature is raised by first burning some light fuel oil or processed natural gas
(by usingauxiliary burners and igniters provide for that purpose).
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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 viathe 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 anyopening. At
the furnace outlet, and before the furnace gases are handled by the ID fan, fine dust carried
by the
outlet gases is removed to avoid atmospheric pollution. This is an environmental limitationprescribed by law, and additionally minimizes erosion of the ID fan.
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 orbag
filters. Generally, the fly ash is pneumatically transported to storage silos for subsequent
transportby trucks or railroad cars.
Bottom Ash Collection and Disposal
At the bottom of every boiler, a hopper has been provided for collection of the bottom ash
from
the bottom of the furnace. This hopper is always filled with water to quench the ash andclinkers
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.
Boiler Make-up Water Treatment Plant and Storage
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Since there is continuous withdrawal of steam and continuous return of condensate to the
boiler,
losses due to blow-down and leakages have to be made up for so as to maintain the desiredwater
level in the boiler steam drum. For this, continuous make-up water is added to the boiler
watersystem. The impurities in the raw water input to the plant generally consist of calcium and
magnesium salts which impart hardness to the water. Hardness in the make-up water to the
boilerwill form deposits on the tube water surfaces which will lead to overheating and failure of
the
tubes. Thus, the salts have to be removed from the water and that is done by a water
demineralising treatment plant (DM).
OPERATION OF TURBINE
Steam turbines are used in all of our major coal fired power stations to drive the generators
oralternators, which produce electricity. The turbines themselves are driven by steam
generated in
'Boilers' or 'Steam Generators' as they are sometimes called. Energy in the steam after it
leaves theboiler is converted into rotational energy as it passes through the turbine. The turbine
normally
consists of several stages with each stage consisting of a stationary blade (or nozzle) and arotating
blade. Stationary blades convert the potential energy of the steam (temperature and
pressure) intokinetic energy (velocity) and direct the flow onto the rotating blades. The rotating blades
convert
the kinetic energy into forces, caused by pressure drop, which results in the rotation of the
turbineshaft. The turbine shaft is connected to a generator, which produces the electrical energy.
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rotational speed is 3000 rpm for Indian System (50 Hz) systems and 3600 for American (60
Hz)systems.
In a typical larger power stations, the steam turbines are split into three separate stages, thefirst
being the High Pressure (HP), the second the Intermediate Pressure (IP) and the third the
LowPressure (LP) stage, where high, intermediate and low describe the pressure of the steam.
After
the steam has passed through the HP stage, it is returned to the boiler to be re-heated to its
original temperature although the pressure remains greatly reduced. The reheated steamthen
passes through the IP stage and finally to the LP stage of the turbine.
High-pressure oil is injected into the bearings to provide lubrication.
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VARIOUS CYCLES AT POWER
STATION
. COAL CYCLE
. CONDENSATE CYCLE
. FEED WATER CYCLE
. STEAM CYCLE
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Coal Stock
YardRC BunkerRC FeederMillFurnace
COAL CYCLE
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From LP
TurbinecondensorCondensatePumpEjectorGlandSteamLPH1LPH2LPH3Dearrator
Condensate Cycle
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Boiler Feed
PumpHPH5HPH6HPH7Feed WaterLineEconomizerBoiler
DrumDown
CornerWaterFFED WATER CYCLE
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From Boiler
DrumLT SuperHeaterFinal HeaterMain Steam
LineHP TurbineCold Reheat
LineReheaterHot ReheatLineLow pressure
LineTo
CondensorSTEAM CYCLE
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CONTROL & INSTRUMENTATION
. INTRODUCTION
. C&I LABS
. CONTROL & MONITORING MECHENISM
. PRESSURE MONITORING
. TEMPERATURE MONITORING
. FLOW MEASUREMENT
. CONTROL VALVES
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INTRODUCTION
This division basically calibrates various instruments and takes care of any faults occur in
any of the
auxiliaries in the plant.
Instrumentation can be well defined as a technology of using instruments to measure and
control the physical and chemical properties of a material.
C&I LABS
Control and Instrumentation Department has following labs:
1. Manometry Lab
2. Protection and Interlocks Lab
3. Automation Lab4. Electronics Lab
5. Water Treatment Plant6. Furnaces Safety Supervisory System Lab
OPERATION AND MAINTAINANCE
Control and Instrumentation Department has following Control Units:
1. Unit Control Board
2. Main Control Board
3. Analog & Digital Signal Control4. Current Signal Control
This department is the brain of the plant because from the relays to transmitters followed
by the
electronic computation chipsets and recorders and lastly the controlling circuitry, all fall
underthis.
A View of Control Room at BTPS
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1. Manometry Lab
TRANSMITTERS
It is used for pressure measurements of gases and liquids, its working principle is that theinput
pressure is converted into electrostatic capacitance and from there it is conditioned and
amplified. Itgives an output of 4-20 ma DC. It can be mounted on a pipe or a wall. For liquid or steam
measurement transmitters is mounted below main process piping and for gas measurement
transmitter is placed above pipe.
MANOMETER
Its a tube which is bent, in U shape. It is filled with a liquid. This device corresponds to a
differencein pressure across the two limbs.
BOURDEN PRESSURE GAUGE
Its an oval section tube. Its one end is fixed. It is provided with a pointer to indicate the
pressure
on a calibrated scale. It is of 2 types:
(a) Spiral type: for Low pressure measurement.
(b) Helical Type: for High pressure measurement.
While selecting Pressure Gauge these parameters should keep in mind-
1. Accuracy
2. Safety
3. Utility4. Price
ACCURACY
Higher Accuracy implies Larger Dial Size for accuracy of small and readable pressurescale
increments.
SAFETY
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While selecting Pressure Gauge it should consider that Gauge Construction Material should
bechemically compatible with the environment either inside or outside it.
UTILITY
It should keep it mind that range of the Gauge should be according to our need else
OverpressureFailure may occur resulting in damage of Gauge.
PRICE
Lager the Gauges Dial size larger would be our price. Better Gauges Construction
material also
increses the cost. So they must be chosen according to our need.
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2. Protection and Interlock Lab
INTERLOCKING
It is basically interconnecting two or more equipments so that if one equipment fails otherone can
perform the tasks. This type of interdependence is also created so that equipments
connectedtogether are started and shut down in the specific sequence to avoid damage. For protection
of
equipments tripping are provided for all the equipments. Tripping can be considered as the
seriesof instructions connected through OR GATE, which trips the circuit. The main equipments
of this lab
are relay and circuit breakers. Some of the instrument uses for protection are:.
RELAY
It is a protective device. It can detect wrong condition in electrical circuits by constantly
measuring
the electrical quantities flowing under normal and faulty conditions. Some of the electricalquantities are voltage, current, phase angle and velocity. 2. FUSES It is a short piece of
metal
inserted in the circuit, which melts when heavy current flows through it and thus breaks the
circuit.
Usually silver is used as a fuse material because:
a) The coefficient of expansion of silver is very small. As a result no critical fatigue occurs
and
thus the continuous full capacity normal current ratings are assured for the long time.b) The conductivity of the silver is unimpaired by the surges of the current that produces
temperatures just near the melting point.
c) Silver fusible elements can be raised from normal operating temperature to vaporization
quicker than any other material because of its comparatively low specific heat.
Miniature Circuit Breaker-
They are used with combination of the control circuits to.
a) Enable the staring of plant and distributors.
b) Protect the circuit in case of a fault. In consists of current carrying contacts, one movable
and other fixed. When a fault occurs the contacts separate and are is stuck between them.
There are three types of trips
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I. MANUAL TRIP
II. THERMAL TRIP
III. SHORT CIRCUIT TRIP.
Protection and Interlock System-
1. HIGH TENSION CONTROL CIRCUIT for high tension system the control system are
excited byseparate D.C supply. For starting the circuit conditions should be in series with the starting
coil of the equipment to energize it. Because if even a single condition is not true then
system will not start.
2. LOW TENSION CONTROL CIRCUIT For low tension system the control circuits aredirectly
excited from the 0.415 KV A.C supply.
The same circuit achieves both excitation and tripping. Hence the tripping coil is provided
foremergency tripping if the interconnection fails.
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3. AUTOMATION LAB
This lab deals in automating the existing equipment and feeding routes. Earlier, the old
technology
dealt with only (DAS) Data Acquisition System and came to be known as primary systems.The
modern technology or the secondary systems are coupled with (MIS) Management
InformationSystem. But this lab universally applies the pressure measuring instruments as the
controlling force.
However, the relays are also provided but they are used only for protection and interlocks.
4. PYROMETRY LAB
LIQUID IN GLASS THERMOMETER
Mercury in the glass thermometer boils at 340 C which limits the range of temperature
that canbe measured. It is L shaped thermometer which is designed to reach all inaccessible places.
1. ULTRA VIOLET CENSOR-
This device is used in furnace and it measures the intensity of ultra violet rays there and
according
to the wave generated which directly indicates the temperature in the furnace.
2, THERMOCOUPLES
This device is based on SEEBACK and PELTIER effect. It comprises of two junctions at
different
temperature. Then the emf is induced in the circuit due to the flow of electrons. This is animportant part in the plant.
3. RTD (RESISTANCE TEMPERATURE DETECTOR)
It performs the function of thermocouple basically but the difference is of a resistance. In
this due
to the change in the resistance the temperature difference is measured. In this lab, also themeasuring devices can be calibrated in the oil bath or just boiling water (for low range
devices) and
in small furnace (for high range devices).
5. FURNACE SAFETY AND SUPERVISORY SYSTEM LAB
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This lab has the responsibility of starting fire in the furnace to enable the burning of coal.
For first
stage coal burners are in the front and rear of the furnace and for the second and third stagecorner
firing is employed. Unburnt coal is removed using forced draft or induced draft fan. The
temperature inside the boiler is 1100C and its heights 18 to 40 m. It is made up of mildsteel. An
ultra violet sensor is employed in furnace to measure the intensity of ultra violet rays inside
thefurnace and according to it a signal in the same order of same mV is generated which
directly
indicates the temperature of the furnace. For firing the furnace a 10 KV spark plug is
operated forten seconds over a spray of diesel fuel and pre-heater air along each of the feeder-mills.
The
furnace has six feeder mills each separated by warm air pipes fed from forced draft fans. In
firststage indirect firing is employed that is feeder mills are not fed directly from coal but are
fed fromthree feeders but are fed from pulverized coalbunkers. The furnace can operate on the
minimum
feed from three feeders but under no circumstances should anyone be left out underoperation, to
prevent creation of pressure different with in the furnace, which threatens to blast it.
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6. ELECTRONICS LAB
This lab undertakes the calibration and testing of various cards. It houses various types of
analytical
instruments like oscilloscopes, integrated circuits, cards auto analyzers etc.Various processes undertaken in this lab are:
1. Transmitter converts mV to mA.
2. Auto analyzer purifies the sample before it is sent to electrodes. It extracts the magneticportion.
ANNUNCIATIN CARDSThey are used to keep any parameter like temperature etc. within limits. It gets a signal if
parameter goes beyond limit. It has a switching transistor connected to relay that helps in
alerting
the UCB.
CONTROL & MONITORING MECHANISMS
There are basically two types of Problems faced in a Power Plant
1. Metallurgical
2. Mechanical
Mechanical Problem can be related to Turbines that is the max speed permissible for a
turbine is
3000 rpm so speed should be monitored and maintained at that level.
Metallurgical Problem can be view as the max Inlet Temperature for Turbine is 1060 C so
temperature should be below the limit. Monitoring of all the parameters is necessary for thesafety
of both:
1. Employees2. Machines
So the Parameters to be monitored are:
1. Speed
2. Temperature
3. Current
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4. Voltage
5. Pressure
6. Eccentricity
7. Flow of Gases
8. Vacuum Pressure
9. Valves
10. Level
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11. Vibration
PRESSURE MONITORING
Pressure can be monitored by three types of basic mechanisms
1. Switches
2. Gauges
3. Transmitter type
For gauges we use Bourdon tubes. The Bourdon Tube is a non-liquid pressure
measurement device.It is widely used in applications where inexpensive static pressure measurements are
needed.
A typical Bourdon tube contains a curved tube that is open to external pressure input on
one end and is coupled mechanically to an indicating needle on the other end, as shown
schematically below.
Typical Bourdon Tube Pressure Gages
For Switches pressure switches are used and they can be used for digital means of
monitoring as
switch being ON is referred as high and being OFF is as low.
All the monitored data is converted to either Current or Voltage parameter.
The Plant standard for current and voltage are as under
Voltage : 0 10 Volts range
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Current : 4 20 milli-Amperes
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We use 4mA as the lower value so as to check for disturbances and wire breaks.
Accuracy of such systems is very high.
ACCURACY : 0.1 %
Programmable Logic Circuits (PLCs) are used in the process as they are the heart of
Instrumentation.
TEMPERATURE MONITORING
We can use Thermocouples or RTDs for temperature monitoring. Normally RTDs are usedfor low
temperatures.
Thermocouple selection depends upon two factors:
1. Temperature Range2. Accuracy Required
Normally used Thermocouple is K Type Thermocouple:
In this we use Chromel (Nickel-Chromium Alloy) / Alumel (Nickel-Aluminium Alloy) as
two metals.This is the most commonly used general purpose thermocouple. It is inexpensive and,
owing to its
popularity, available in a wide variety of probes. They are available in the-200C to+1200C range.
Sensitivity is approximately 41 V/C.
RTDs are also used but not in protection systems due to vibrational errors.
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We pass a constant current through the RTD. So that if R changes then the Voltage also
changes
RTDs used in Industries are Pt100 and Pt1000
Pt100 : 0C 100 O ( 1 O = 2.5 0C )
Pt1000 : 0C - 1000O
Pt1000 is used for higher accuracy.
The gauges used for Temperature measurements are mercury filled Temperature gauges.
For Analog medium thermocouples are used and for Digital medium Switches are used
which are
basically mercury switches.
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FLOW MEASUREMENT
Flow measurement does not signify much and is measured just for metering purposes and
for monitoring the processes
ROTAMETERS:
A Rotameter is a device that measures the flow rate of liquid or gas in a closed tube. It
isoccasionally misspelled as 'Rotometer'.
It belongs to a class of meters called variable area meters, which measure flow rate by
allowing the
cross sectional area the fluid travels through to vary, causing some measurable effect.
A rotameter consists of a tapered tube, typically made of glass, with a float inside that is
pushed up
by flow and pulled down by gravity. At a higher flow rate more area (between the float andthe
tube) is needed to accommodate the flow, so the float rises. Floats are made in many
differentshapes, with spheres and spherical ellipses being the most common. The float is shaped so
that it
rotates axially as the fluid passes. This allows you to tell if the float is stuck since it will
only rotate ifit is not.
For Digital measurements Flap system is used.
For Analog measurements we can use the following methods :
1. Flow meters
2. Venturimeters / Orifice meters
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3. Turbines
4. Mass flow meters ( oil level )
5. Ultrasonic Flow meters6. Magnetic Flow meter ( water level )
Selection of flow meter depends upon the purpose, accuracy and liquid to be measured sodifferent
types of meters used
.
TURBINE TYPE:
They are simplest of all. They work on the principle that on each rotation of the turbine apulse is
generated and that pulse is counted to get the flow rate.
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VENTURIMETERS :
Referring to the diagram, using Bernoulli's equation in the special case of incompressible
fluids (such as the approximation of a water jet), the theoretical pressure drop at the
constriction would be given by (./2)(v22 - v12).
And we know that rate of flow is given by:
Flow = k v (D.P)
Where DP is Differential Presure or the Pressure Drop.
CONTROL VALVES
A valve is a device that regulates the flow of substances (either gases, fluidized solids,slurries, or
liquids) by opening, closing, or partially obstructing various passageways. Valves are
technicallypipe fittings, but usually are discussed separately. Valves are used in a variety of
applications
including industrial, military, commercial, residential, transportation. Plumbing valves arethe most
obvious in everyday life, but many more are used.
Some valves are driven by pressure only, they are mainly used for safety purposes in steam
enginesand domestic heating or cooking appliances. Others are used in a controlled way, like in
Otto cycle
engines driven by a camshaft, where they play a major role in engine cycle control.
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Many valves are controlled manually with a handle attached to the valve stem. If the handle
is
turned a quarter of a full turn (90) between operating positions, the valve is called aquarter-turn
valve. Butterfly valves, ball valves, and plug valves are often quarter-turn valves. Valves
can also becontrolled by devices called actuators attached to the stem. They can be electromechanical
actuators such as an electric motor or solenoid, pneumatic actuators which are controlled
by airpressure, or hydraulic actuators which
are controlled by the pressure of a liquid such as oil or water. So there are basically three
types ofvalves that are used in power industries besides the handle valves.
They are :
PNEUMATIC VALVES They are air or gas controlled which is compressed to turn or
movethem
HYDRAULIC VALVES They utilize oil in place of Air as oil has better compression
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MOTORISED VALVES These valves are controlled by electric motors
FURNACE SAFEGUARD SUPERVISORY SYSTEM
FSSS is also called as Burner Management System (BMS). It is a microprocessor based
programmable logic controller of proven design incorporating all protection facilitiesrequired for
such system. Main objective of FSSS is to ensure safety of the boiler.
The 95 MW boilers are indirect type boilers. Fire takes place in front and in rear side.
Thats why its
called front and rear type boiler.
The 210 MW boilers are direct type boilers (which means that HSD is in direct contact
with coal)firing takes place from the corner. Thus it is also known as corner type boiler.
IGNITER SYSTEM
Igniter system is an automatic system, it takes the charge from 110kv and this spark isbrought in
front of the oil guns, which spray aerated HSD on the coal for coal combustion. There is a
5 minutedelay cycle before igniting, this is to evacuate or burn the HSD. This method is known as
PURGING.
PRESSURE SWITCH
Pressure switches are the devices that make or break a circuit. When pressure is applied,
the switch
under the switch gets pressed which is attached to a relay that makes or break the circuit.
Time delay can also be included in sensing the pressure with the help of pressure valves.
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Examples of pressure valves:
1. Manual valves (tap)
2. Motorized valves (actuator) works on motor action
3. Pneumatic valve (actuator) _ works due to pressure of compressed air
4. Hydraulic valve
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IT DEPARTMENT
. IT BTPS VISION
. IT ROLE & RESPONSIBLITIES @BTPS
. IT APPLICATION @BTPS
. BENEFITS OF IT INNOVATION @ BTPS
. VARIOUS E-SERVICES @BTPS
. SMS ALERT @ BTPS
. REWARDS & RECOGNITION
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BTPS IT VISION
. INTEGRATED IT ENABLEMENT OF BUSINESS PROCESSES FOR EFFICIENT
PLANT
MANAGEMENT. INFORMATION ANYTIME ANYWHERE
IT ROLE & RESPONSIBILITIES @ BTPS
1. Development, Implementation & Support for Local Applications
2. Procurement & Maintenance of IT Infrastructure ( PCs, Printers, Servers & Network
LAN,WAN
etc)
3. Support to users for ERP & modules to supplement ERP.
4. Customization & Implementation support for BTPS Applications to other projects.
IT APPLICATION @ BTPS
At BTPS, Information Technology has been used extensively to manage following business
processes-
1. Maintenance Management System
2. Materials Management System
3. Financial Accounting System4. Contracts Management System
5. Operations & ABT Monitoring System
6. Coal Monitoring & Accounting System7. Hospital Management System
8. HR, T/S & Training Management System
9. Office Automation & Communication System
10. E-Samadhan complaints monitoring system
Benefits of IT Innovations @ BTPS
1. OPERATIONS
Important & critical parameters of Power Plant operation are monitored online to enable
effective
control on operation of various equipments and reduce down time. Online load analysis &
Generation
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values are monitored to have optimum load balance of various units. Auxiliary power
consumption
monitored and controlled. Meritorial operation practicing enabled.
2. MAINTENANCE
Better control over maintenance cost by way of online information available through the
system.Based
on failure analysis and equipment history, modified maintenance strategy of Preventive,Predictive and
Risk Based maintenance is implemented. Equipment spares planning are streamlined by
way of Annual
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requirement, Vendor wise, linked to Equipment, Standardization of defects and repair
codes for easyfilling of Work Order Card, for future analysis.
3. MATERIALS
Material Planning and Procurement system streamlined, resulting in reduction in
Administrative leadTime. Further, procurement on Annual Rate Contract basis enabled through the system,
Ordering on
actual need basis (just in time). This further reduces lead time and Inventory carrying.
Detection of duplicate and obsolete items, standardization of material description and
specification,
Cleaning and Weeding of redundant data, resulting in overall system improvement and
functionalities,Availability of coal stock status online, reduction in demurrages paid to railways.
4. OFFICE AUTOMATION AND COMMUNICATION
With implementation of e-Desk/e-broadcast, e-alerts, auto mail and BTPS website,information is
available instantly to all and all time, resulting in tremendous reduction in paper
communication and
cost.
BTPS IT Applications Highlights
1. Single Login screen, Pass Word & Role based secured access .
2. G.U. Interface, Easy information retrieval/search facility.
3. Information captured once at source.4. Automation of routine activities.
A View of BTPS Login Page
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ERP/SAP MODULES IMPLEMENTED(ERP-ENTERPRISE RESOURCES PLANNING)
. Maintenance Management- PM
. Finance Management- FI
. Materials Management- MM
. Human Resource Management- HR
. Operations Management- OPN
. Employee Self Service- ESS
Maintenance Management system, Anurakshan @ BTPS
1. Permit to Work Issue with detailed feedback.
2. Daily Plant Meeting minutes generated online.3. Trends of defects priority wise /department wise for a period.
4. Equipment history with detailed feedback available.
5. Analysis of repeated equipment failure for corrective action.
6. Standardization of defects & repair codes.7. Interface with Materials Management System & CMS for WOC cost
MATERIAL & CONTRACT MANAGEMENT SYSTEM (CMS)
1. Initiation and approval of Contract Proposal.2. Preparation of Tender Documents and approvals.
3. Preparation and processing of Bills.
FINANANCIAL ACCOUNTING SYSTEM (FAS)
1. Status of Income Tax Details, PF slips, Leave, Accrued Interest, and Earning Cardavailable online.
2. Fund Flow Statements & other Reports for day to day functioning.
3. Bank Reconciliation.
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Coal Accounting System (CAS)
1. Online uploading of Wagon wise Weight from Wagon Tipplers.2. Coal and Rail Freight bill payments accounting & reconciliation.
3. Tariff Summary, coal accounting and MIS reports generated from the system.
HOSPITAL MANAGEMENT SYSTEM (HMS)
1. Online patient registration
2. Doctors prescription
3. Medicines issues/availability
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4. Investigation reports
5. Annual check-ups, patient history , referrals etc.
A View of Hospital Management System
HR/TRAINING MANAGEMENT SYSTEM
1. Computerized Attendance recording system.
2. Employee database to record/ update information of employees
3. Township/Quarter management system.
4. Performance Management analysis & evaluation system.
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E-SERVICES OFFICE
AUTOMATION &COMMUNICATIONKEY FOCUS AREATOWAREDS PAPERLESS
OFFICEE-Desk , E-Broadcast,
SMS & E-Mail as PrimaryCommunication &
Document Delivery
System.
A View of Tanning Management System
VARIOUS E-SERVICES @ BTPS
SMS ALERT @ BTPS
1. One more IT initiative for fast & convenient way to information sharing thru SMS2. Automatic SMS alert is already in use for plant load & unit Trip.
3. Send SMS instantly or scheduled date/time.
4. SMS to groups or individual numbers.
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Plant Load & Unit Trip SMS Alert
REWARDS & RECOGNITION
. Badarpur has achieved unique distinction of being; First site in NTPC, with independent
initiative of Development & Implementation of new Oracle based integrated online
Applications, with in house effort. This has been appreciated by NTPC higher
management.. BTPS Received Golden Peacock award for IT Innovation in 2004.
REFERENCE
. TRAINING REPORTS OF PAST YEARS AT NALANDA LIBRARY
. INTERNET
. DOCUMENTS OF IT DEPARTMENT
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