Summer Vocational Trainin1

8/8/2019 Summer Vocational Trainin1

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INDEX

PREFACE

ACKNOWLEDGEMENT

ABOUT NTPC

POWER PLANT CYCLE

POWER STATIONS IN INDIA

NTPC BADARPUR

AN OVERVIEW ON POWER PRODUCTION

BOILER MAINTENANACE DEPARTMENT (BMD)

PLANT AUXILLARY MAINTENANCE (PAM)

TUBINE MAINTENEANCE DEPARTMENT (TMD)

MAINTENANCE & PLANING DIVISION (MPD)


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PREFACE

This report contains the principle of power generation, machines and itsworking. Different departments of the power plant such as boiler maintenancedepartment, plant auxiliary department, turbine maintenance department andmaintenance and planning department. Different part such as boiler,superheater, reheater, different types of pumps, condenser, compressor, andtheir way of there maintenance.

In this report the working, its working condition, rating etc. are described for the machine. The mechanism and specifications are also included in it.


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ACKNOWLEDGEMENT

I am very grateful to Mr. Manmohan Singh (Sr. Manager) for giving me achance to get training at NTPC, BADARPUR. It is very encouraging to see andlearn about the working process of the plant .

I would like to thank officers and employees who help me to understand the process and its working principles. The employees here are very caring and co-operative, help me in sorting my problems and doubts.

ANIMESH JAIN


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C E

This is to certify


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NTPC NTPC is the largest thermal power generating company of India. A public

sector company incorporated in the year 1975 for power development in thecountry as a wholly owned company of the government of India. At presentgovernment of India holds 89.5% of the total equality shares of company andthe balance 10.5% is held by FIIs, Domestic banks, public and others. With in aspan of 30 years, NTPC has emerged as a truly NATIONAL POWER COMPANY with power generation facilities is all the major regions of thecountry. NTPC is one of the NAVARATNA comprises of the public sector. Itis the 6 th largest thermal power company in the world. It supplies one-fourth of the power produced to the country. It is now taking up the project using non-conventional source of energy also.

Environment Policy & Environment Management System

Driven by its commitment for sustainable growth of power, NTPC has evolveda well defined environment management policy and sound environment

practices for minimizing environmental impact arising out of setting up of power plants and preserving the natural ecology.

National Environment Policy:

At the national level, the Ministry of Environment and Forests had prepared adraft Environment Policy (NEP) and the Ministry of Power along with NTPCactively participated in the deliberations of the draft NEP. The NEP 2006 hassince been approved by the Union Cabinet in May 2006. NTPC Environment

Policy:

As early as in November 1995, NTPC brought out a comprehensive documententitled "NTPC Environment Policy and Environment Management System".Amongst the guiding principles adopted in the document are company's

proactive approach to environment, optimum utilization of equipment, adoption


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of latest technologies and continual environment improvement. The policy alsoenvisages efficient utilization of resources, thereby minimizing waste,maximizing ash utilization and providing green belt all around the plant for maintaining ecological balance NTPC has actively gone for adoption of bestorganization has purs international practices on environment, occupationalhealth and

Environment Management, Occupational Health andSafety Systems :

ued the Environmental Management System (EMS) ISO 14001 and theOccupational 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 reputednational and international Certifying Agencies .

Pollution Control systems:

While deciding the appropriate technology for its projects, NTPC integratesmany environmental provisions into the plant design. In order to ensure that

NTPC comply with all the stipulated environment norms, various state-of-the-art pollution control systems / devices as discussed below have been installed tocontrol air and water pollution .

Electrostatic Precipitators :

The ash left behind after combustion of coal is arrested in high efficiencyElectrostatic Precipitators (ESPs) and particulate emission is controlled well

within the stipulated norms. The ash collected in the ESPs is disposed to AshPonds in slurry form .

Flue Gas Stacks:


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Tall Flue Gas Stacks have been provided for wide dispersion of the gaseousemissions (SOX, NOX etc) into the atmosphere.

Low-NOXBurners :

In gas based NTPC power stations, NOx emissions are controlled by provisionof Low-NOx Burners (dry or wet type) and in coal fired stations, by adopting

best combustion practices .

Neutralisation Pits:

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 and use.

Coal Settling Pits / Oil Settling Pits:

In these Pits, coal dust and oil are removed from the effluents emanating fromthe 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 installedin all coal fired power stations in NTPC to contain and extract the fugitive dustreleased in the Coal Handling Plant (CHP).

Cooling Towers:

Cooling Towers have been provided for cooling the hot Condenser coolingwater in closed cycle Condenser Cooling Water (CCW) Systems. This helps inreduction in thermal pollution and conservation of fresh water .

Ash Dykes & Ash Disposal systems:


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Ash ponds have been provided at all coal based stations except Dadri whereDry Ash Disposal System has been provided. Ash Ponds have been divided intolagoons and provided with garlanding arrangements for change over of the ashslurry feed points for even filling of the pond and for effective settlement of theash particles. Ash in slurry form is discharged into the lagoons where ash

particles get settled from the slurry and clear effluent water is discharged fromthe ash pond. The discharged effluents conform to standards specified by CPCBand the same is regularly monitored. At its Dadri Power Station, NTPC has setup a unique system for dry ash collection and disposal facility with Ash Moundformation. This has been envisaged for the first time in Asia which has resultedin progressive development of green belt besides far less requirement of land

and less 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 fromash pond is circulated back to the station for further ash sluicing to the ash

pond. This helps in savings of fresh water requirements for transportation of ash from the plant. The ash water recycling system has already been installedand is in operation at Ramagundam, Simhadri, Rihand, Talcher Kaniha, Talcher Thermal, Kahalgaon, Korba and Vindhyachal. The scheme has helped stationsto save huge quantity of fresh water required as make-up water for disposal of

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 pozzolanacement, etc.). DAES has been installed at Unchahar, Dadri, Simhadri,Ramagundam, Singrauli, Kahalgaon, Farakka, Talcher Thermal, Korba,Vindhyachal, Talcher Kaniha and BTPS.

Liquid Waste Treatment Plants & Management System:


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The objective of industrial liquid effluent treatment plant (ETP) is to dischargelesser and cleaner effluent from the power plants to meet environmentalregulations. After primary treatment at the source of their generation, theeffluents are sent to the ETP for further treatment. The composite liquideffluent treatment plant has been designed to treat all liquid effluents whichoriginate within the power station e.g. Water Treatment Plant (WTP),Condensate Polishing Unit (CPU) effluent, 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 hasimplemented 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 the effluents dischargedfrom 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 andtownship areas. In a number of NTPC projects modern type STPs withClarifloculators, Mechanical Agitators, sludge drying beds, Gas CollectionChambers etc have been provided to improve the effluent quality. The effluentquality is monitored regularly and treated effluent conforming to the prescribedlimit is discharged from the station. 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 speedydevelopment of the power sector, the company has constituted different groupsat project, regional and Corporate Centre level to carry out specificenvironment related functions. The Environment Management Group, AshUtilisation Group and Centre for Power Efficiency & Environment Protection


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(CENPEEP) function from the Corporate Centre and initiate measures tomitigate the impact of power project implementation on the environment and

preserve ecology in the vicinity of the projects. Environment Management andAsh Utilisation Groups established at each station, look after variousenvironmental issues of the individual station.

Environment Reviews :

To maintain constant vigil on environmental compliance, EnvironmentalReviews are carried out at all operating stations and remedial measures have

been taken wherever necessary. As a feedback and follow-up of theseEnvironmental Reviews, a number of retrofit and up-gradation measures have

been undertaken at different stations. Such periodic Environmental Reviewsand extensive monitoring of the facilities carried out at all stations have helpedin compliance with the environmental norms and timely renewal of the Air andWater Consents.

Waste Up gradation & retrofitting of Pollution Control Systems:Management

Various types of wastes such as Municipal or domestic wastes, hazardouswastes, Bio-Medical wastes get generated in power plant areas, plant hospitaland the townships of projects. The wastes generated are a number of solid andhazardous wastes like used oils & waste oils, grease, lead acid batteries, other lead bearing wastes (such as garkets etc.), oil & clarifier sludge, used resin,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 wastes fall either under hazardouswastes category or non-hazardous wastes category as per classification given inGovernment of Indias notification on Hazardous Wastes (Management andHandling) Rules 1989 (as amended on 06.01.2000 & 20.05.2003). Handlingand management of these wastes in NTPC stations have been discussed below.

Advanced / Eco-friendly Technologies


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NTPC has gained expertise in operation and management of 200 MW and 500MW Units installed at different Stations all over the country and is lookingahead for higher capacity Unit sizes with super critical steam parameters for higher efficiencies and for associated environmental gains. At Sipat, higher capacity Units of size of 660 MW and advanced Steam Generators employingsuper critical steam parameters have already been implemented as a green field

project. Higher efficiency Combined Cycle Gas Power Plants are already under operation at all gas-based power projects in NTPC. Advanced clean coaltechnologies such as Integrated Gasification Combined Cycle (IGCC) havehigher efficiencies of the order of 45% as compared to about 38% for conventional plants. NTPC has initiated a techno-economic study under USDOE / USAID for setting up a commercial scale demonstration power plant

by using IGCC technology. These plants can use low-grade coals and havehigher efficiency as compared to conventional plants. With the massiveexpansion of power generation, there is also growing awareness among allconcerned to keep the pollution under control and preserve the health andquality of the natural environment in the vicinity of the power stations. NTPC iscommitted to provide affordable and sustainable power in increasingly larger quantity. NTPC is conscious of its role in the national endeavour of mitigatingenergy poverty, heralding economic prosperity and thereby contributing

towards Indias emergence as a major global economy.


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Lay out of Employees Overall Power Generation

The table below shows the detailed operational performance of coal basedstations over the years.

The energy conservation parameters like specific oil consumption and auxiliary

power consumption have also shown considerable improvement over the years.

Unit 1997-98 2006-07 % of increaseInstalled Capacity MW 16,847 26,350 56.40Generation MUs 97,609 1,88,674 93.29

No. of employees No. 23,585 24,375 3.34Generation/employee MUs 4.14 7.74 86.95

OPERATIONAL PERFORMANCE OF COAL BASED NTPC

STATIONSUnit 97-98

98-99

99-00

00-01

01-02 02-03 03-04 04-05 05-06 06-07

Generation BU 106.2109.5118.7130.1133.2140.86149.16 159.11 170.88 188.67PLF % 75.2076.6080.3981.8 81.1 83.6 84.4 87.51 87.54 89.43AvailabilityFactor % 85.0389.3690.0688.5481.8 88.7 88.8 91.20 89.91 90.09


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POWER PLANT CYCLE

The thermal power plants are based on Rankine cycle (modern). This ideal

cycle is more suitable as a creation for actual steam cycle than Carnot cycle.


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POWER STATIONS IN INDIA

COAL POWER PLANTS

Sno. Place State Installed capacity01 Singrauli Uttar Pradesh 2000MW

02 Karba Madhya Pradesh 2100MW

03 Ramaquandam Andhra Pradesh 2100MW

04 Farakka West Bengal 1600MW

06 Vindhyachal Madhya Pradesh 2260MW

07 Rihand Uttar Pradesh 1000MW

08 Kahalgaon Bihar 840MW

09 Dadri Uttar Pradesh 840MW

10 Talchar kaniha Orissa 3000MW

11 Unchahar Uttar Pradesh 840MW

12 Sinhadri Andhra Pradesh 1000MW

13 Tanda Uttar Pradesh 440MW


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GAS AND LIQUID FUEL PLANT

Sno. Place State Installed capacity01 Anta Rajasthan 413MW

02 Auraiya Uttar Pradesh 653MW

03 Kawas Gujarat 645MW

04 Jhanar Gandhar Gujarat 648MW

05 Dadri Uttar Pradesh 817MW

06 Kayankulam Kerala 400MW

07 Faridabad Haryana 400MW

POWER STATION MANAGED BY NTPC

Sno. Place State Installed capacity01 Badarpur New Delhi 705MW

02 Balco Power Madhya Pradesh 270MW


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NTPC BADARPUR

I was assigned to do training in operation division from 18th June 2007 to 23rdJune 2007ELECTRICITY FROM COAL Coal from the coal wagons is unloaded withthe help of wagon tipplers in the C.H.P. this coal is taken to the raw coal

bunkers with the help of conveyor belts. Coal is then transported to bowl mills by coal feeders where it is pulverized and ground in the powered form. Thiscrushed coal is taken away to the furnace through coal pipes with the help of hot and cold mixture P.A fan. This fan takes atmospheric air, a part of which issent to pre heaters while a part goes to the mill for temperature control.Atmospheric air from F.D fan in the air heaters and sent to the furnace ascombustion air. Water from boiler feed pump passes through economizer andreaches the boiler drum . Water from the drum passes through the down comersand goes to the bottom ring header. Water from the bottom ring header isdivided to all the four sides of the furnace. Due to heat density difference thewater rises up in the water wall tubes. This steam and water mixture is againtaken to the boiler drum where the steam is sent to super heaters for super heating. The super heaters are located inside the furnace and the steam is super

heated (540 degree Celsius) and finally it goes to the turbine. Fuel gases fromthe furnace are extracted from the induced draft fan, which maintains balancedraft in the furnace with F.D fan. These fuel gases heat energy to the varioussuper heaters and finally through air pre heaters and goes to electrostatic

precipitators where the ash particles are extracted. This ash is mixed with thewater to from slurry is pumped to ash period. The steam from boiler isconveyed to turbine through the steam pipes and through stop valve and controlvalve that automatically regulate the supply of steam to the turbine. Stop valves

and controls valves are located in steam chest and governor driven from mainturbine shaft operates the control valves the amount used. Steam fromcontrolled valves enter high pressure cylinder of turbines, where it passesthrough the ring of blades fixed to the cylinder wall. These act as nozzles anddirect the steam into a second ring of moving blades mounted on the disc


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MAIN GENERATOR DATA

MAIN TURBINE DATA

Maximum continuous KVA rating 24700KVAMaximum continuous KW 210000KWRated terminal voltage 15750VRated Stator current 9050 ARated Power Factor 0.85 lagExcitation current at MCR Condition 2600 ASlip-ring Voltage at MCR Condition 310 VRated Speed 3000 rpmRated Frequency 50 HzShort circuit ratio 0.49Efficiency at MCR Condition 98.4%

Direction of rotation viewed Anti ClockwisePhase Connection Double Star

Number of terminals brought out 9( 6 neutral and 3 phase)

Rated output of Turbine 210 MWRated speed of turbine 3000 rpmRated pressure of steam before emergency 130 kg/cm^2Stop valve rated live steam temperature 535 degree CelsiusRated steam temperature after reheat at inlet toreceptor valve 535 degree Celsius

Steam flow at valve wide open condition 670 tons/hour Rated quantity of circulating water throughcondenser 27000 cm/hour

1. For cooling water temperature (degreeCelsius) 24,27,30,33

1.Reheated steam pressure at inlet of interceptor valve in kg/cm^2 ABS

23,99,24,21,24,49,24.82

2.Steam flow required for 210 MW in ton/hour68,645,652,6623.Rated pressure at exhaust of LP turbine in 19.9,55.5,65.4,67


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Installed Capacity 720 MW

Location New Delhi

Coal Source Jharia Coal Fields

Water Source Agra CanalBeneficiary States Delhi

Unit Sizes 3X95 MW2X210 MW

Units Commissioned Unit I- 95 MW - July 1973Unit II- 95 MW August 1974Unit III- 95 MW March 1975Unit IV - 210 MW December 1978Unit V - 210 MW - December 1981

Transfer of BTPS to NTPC Ownership of BTPS was transferred to NTPC witheffect from 01.06.2006 through GOIs Gazette Notification.


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AN OVERVIEW ON POWERPRO DUCTION

Today electricity is a need of everyones life. Without it one cannot even think about work. We use the electrical utensils pretty easily but dont think about theway and procedure of production of power. It is a difficult process to produceelectricity but an interesting and important from engineering point of view. The

procedure of production is described in short below.

The main divisions of any thermal power plant are boiler division, turbine and plant auxiliary division. Starting with boiler division, raw coal is crushed andtransferred to the raw coal bunker (R C Bunker) , which is at a height of 30m-40m above the ground level, with the help of conveyors. This crushed coal isfeed into raw coal feeder (R C Feeder) which feeds the required amount of coal to the pulverize mill i.e. ball mill (for 100MW) or bowl mill (for 210MW). These mills pulverize the coal and are ready for the input in thefurnace.

Fans like force draft fans (F D Fan) , induced draft fans (I D Fan) and

primary air fans (P A Fan) are used for air flow, which is also a transportingmedium. P A Fan sucks the atmospheric air and sends it to air preheater for heating. It is then comes to pulverized mill form where it carries the coal

particles to the furnace for its combustion. This air which is delivered by P AFan is also called primary air. F D Fan delivers the required air for combustion. It is also called secondary air which is hot enough for thecombustion.

The burned coal which converted into ash dropped in scraper conveyor due togravity. This ash is cooled with the help of water and dumped in the water where it forms slurry. The rest of the ash is carried to electrostatic precipitator(ESP) with the help of air. This flow of air is due to I D Fan which drafts theair form furnace to the chimney . In ESP ash sticks to the electrodes due toelectric field produced by the electrodes. The ash collected in the plates is putdown by roller hammers . This ash is mixed with water to make slurry and


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dumped along with the slurry produced at scraper conveyor . The ash removed by the ESP is about 99% and the rest is passed to atmosphere via chimney .

Now starting the water cycle from boiler drum , there is hot water is collectedin the boiler drum . This water is supplied to the tubes placed in furnace, wherewater converted to and move above in the furnace in superheater . Here steamget superheated to a temperature of 535C at a high pressure and then injectedto turbine. The low pressure steam at the outlet it send to condenser where itcondenses with the help of cold water running in small (in diameter) tubes. Thiswater is supplied by cooling water pump (C W Pump) . This condensate is

pumped to deareator placed 18m above the ground wit the help of condensatepump . This may be called as a temporary storage tank. From here the water is

pumped to the boiler for regeneration of steam by boiler feed pumps (BFP) placed at ground level. The condensate goes through economizer and reheaterto the boiler drum .

The cooling water n water for other purpose is provided by the high pressurepump (H P Pump) ; low pressure pumps (L P Pump) etc. Water is pumpedfrom Agra canal which is filtered properly to make it suitable for the usage.


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BOILER

MAINTENANCE

DEPARTMENT

(BMD)


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BMD I, II & III

BOILERS

A part of power plant, which is concerned with heat generation from burning of fuel and with transfer of heat to the water to convert it into superheated steam.Boilers are broadly classified as:-

Fire tube type Boiler Water tube type Boiler

If hot combustion gases are confined inside the tubes, and the tubes aresurrounded with water, the boiler is called Fire tube boiler .If water is inside the tubes and hot gases outside the tube makes it a Watertube boiler .

BOILER DRUM

The boiler drum contains both steam and water, the former being trapped fromthe top of the drum where the highest concentration of dry steam exists.Modern boiler drums are usually provided with effective arrangement for separation of water from steam, so that the outlet of steam is as dry as possible,the quantity of dryness being over 99.5%.

METHODS OF COAL FIRING

There are two general ways of firing unpulverized coal in combustion furnace,viz. hand firing and stoker or mechanical firing .


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Hand firing is simple but can be used only in small installation as theuniformity of combustion is difficult to control with this type of firing. It is alsotiring and need close supervision.Stoker firing permits feeding and burning of large quantity of fuel with greatuniformity, and easier control of combustion. It achieves greater efficiencythrough less manual effort.

BURNER

Burners are used to focus the flame so as to burn the coal. There are 24 burners placed among 4 corners from 18-26m height.

OIL GUN

It is used to indicate and sustain the flame which is necessary for burning coal.Oil gun is used to provide oil to the burners and is placed between two burners.

SOOT BLOWER

Soot blowers are placed at the surface of furnace so as to blow the soot or deposits along the water tubes. The soot reduces the efficiency of the transfer of heat to the water from the heat produced by the burning of coal. Soot blowers

are placed on all sides of furnace at different elevations. They produce a jet of air which blows away the soot.


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SUPERHEATER

Superheaters are used to superheating steam to the desired temperature. Theseare made of coils of tubes forming parallel tube circuits connected betweenheaders. The superheater tubes are made of high temperature strength specialalloy steels such as chromium-molybdenum.Superheater system consists of four basic stages or sections, namely a platansuperheater, a pendent superheater, a rear horizontal superheater and the steamcooled wall and roof superheaters.

REHEATER

The function of reheater is to reheat the steam coming out from high pressureturbine to a temperature of 540C. Reheater composed of two sections: thefront pendant section and rear pendant section. The rear pendant section islocated above the furnace arc and the rear water wall and front pendant sectionis located between water hanger tubes and the superheater platen section.

ECONOMIZER

The purpose of the economizer is to preheat the boiler feed water before it isintroduced into the steam drum, and to recover some of the heat from the fluegases leaving the boiler.

AIR PREHEATER

Since the heat of the exit gases cannot be fully extracted through theeconomizers, air preheaters are employed o recover some of the heat escapingin these gases. If the gases can be cooled by 19C to 22C due to preheating of air, the plant efficiency is increased by about 1%.


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SCRAPER CONVEYOR

Scraper conveyor is machine placed directly below the furnace or combustionchamber. Its work is to clear the ash formed by the combustion of coal. As theash particles may combine together to form a big clinker, these clinkers are

break down with the help of clinker grinder. Clinker grinder is cylindrical inshape with spikes on the curved surface.

Ash which is collected in scraper conveyor is mixed with water to bring itstemperature down and then dump in the water, flowing at a very high velocity.This mixture of ash and water, which is called slurry, then dumping it at wasteland with the help of pumps, where it is used for making bids, bricks etc.

ELECTROSTATIC PRECEPITATOR

This dust collector employs an electrostatic field between two sets of electrodesother and between which the flue gases are made to pass. The dust particles are

joined as the gases passes through the electric field, and are attracted by the

collecting electrode which is grounded. Then the roller hammers, which areoperated with the help of motors, strike the electrode simultaneously to bringthe ash down to the hoppers. Ash collected in hoppers is then mixed with water and mixed with the slurry coming through scrapper conveyor. The efficiency of ESP is 90% in dust collection.

CHIMNEY

Chimney is a tall tower through which the hot flue gases and remaining ashescapes in air. Normally the height of chimney is about 150 meters.


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RAW COAL BUNKER (RC BUNKER)

RC Bunker is a place where raw coal is placed (and collected) with the help of conveyor belts. From here the coal is feed into the combustion chamber.Another advantage is that pulverizing operation can be done at a constant rateso that the fuel is kept in the bunkers.

RAW COAL FEEDER (RC FEEDER)

The raw crushed coal is delivered from the bunker to the feeders, which in turnfeed the coal at the controlled rate to the bowl mill each feeder supplying anindividual bowl mill.Hot air is admitted into the feeder through a slot in the lower part of the feedroll core. The air aids in drying of coal and keeps it from clogging between thefeed roller blades. The speed of feeder is varied depending on the feed raterequired.

Some specifications of RC Feeder: No. of feeders per boiler 6

Capacity Maximum 38 T/hr Rated speed 955 RPMSpeed ratio 1:6 (2.64:16 RPM)Motor rated power 2.2KW

BOWL MILL

In bowl mill the smooth rollers move in a rotating bowl and acts as a grindingtool. These three rollers are placed at 120 apart with a separation of 1mm fromthe surface of the bowl. To save the interior of the bowl from the wearingaction a hardened metal ring is fitted on the inside periphery. Adjustment of rollers with respect to the grinding ring ensures proper size of product.


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Bowl mill is basically used for 210MW unit. Some of its specifications are asfollows:

No. of Bowl mills per boiler 6Type Medium speed Bowl Mill pressurized type

No. of grinding rollers per mill 3Rated RPM 990Rated output 320KW

BALL MILL

A ball mill is a type of grinder used to grind materials into extremely fine

powder for use in paints, pyrotechnics, and ceramics.

Ball mill

A ball mill, a type of grinder , is a cylindrical device used in grinding (or mixing) materials like ores , chemicals, ceramic raw materials and paints. Ballmills rotate around a horizontal axis, partially filled with the material to beground plus the grinding medium. Different materials are used as media,including ceramic balls, flint pebbles and stainless steel balls. An internalcascading effect reduces the material to a fine powder. Industrial ball mills can

operate continuously, fed at one end and discharged at the other end. Large tomedium-sized ball mills are mechanically rotated on their axis, but small onesnormally consist of a cylindrical capped container that sits on two drive shafts( pulleys and belts are used to transmit rotary motion). A rock tumbler functionson the same principle. Ball mills are also used in pyrotechnics and themanufacture of black powder , but cannot be used in the preparation of some

pyrotechnic mixtures such as flash powder because of their sensitivity to
http://en.wikipedia.org/wiki/Grinder_(milling)http://en.wikipedia.org/wiki/Grinder_(milling)http://en.wikipedia.org/wiki/Oreshttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/w/index.php?title=Flint_pebbles&action=edit&redlink=1http://en.wikipedia.org/wiki/Stainless_steelhttp://en.wikipedia.org/wiki/Pulleyshttp://en.wikipedia.org/wiki/Rock_tumblerhttp://en.wikipedia.org/wiki/Pyrotechnicshttp://en.wikipedia.org/wiki/Black_powderhttp://en.wikipedia.org/wiki/Flash_powderhttp://en.wikipedia.org/wiki/Image:Ball_mill.gifhttp://en.wikipedia.org/wiki/Grinder_(milling)http://en.wikipedia.org/wiki/Grinder_(milling)http://en.wikipedia.org/wiki/Oreshttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/w/index.php?title=Flint_pebbles&action=edit&redlink=1http://en.wikipedia.org/wiki/Stainless_steelhttp://en.wikipedia.org/wiki/Pulleyshttp://en.wikipedia.org/wiki/Rock_tumblerhttp://en.wikipedia.org/wiki/Pyrotechnicshttp://en.wikipedia.org/wiki/Black_powderhttp://en.wikipedia.org/wiki/Flash_powder


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impact. High-quality ball mills are potentially expensive and can grind mixture particles to as small as 0.0001 mm, enormously increasing surface area andreaction rates. Ball Mills works on principle of critical speed.

INDUCED DRAFT FAN (I D FANS)

I D fans is used to extract flue gases from the combustion chamber. Each fan iscapable of delivering 936,000 m 3/hour flue gas from the furnace for subsequentevacuation through the chimney. Each 210MW boiler is provided with two I Dfans.

Some specifications of I D Fans: No. of fans per Boiler TwoFan capacity 936000 m 3/hr Speed 990 RPMRating 1100KWVoltage 6.6KV 3-phase star connected

Rated current 116.5ATemperature at full load 90CBearing Sleeve bearingMade by BHEL Bhopal, India

FORCE DRAFT FAN (F D FANS)

F.D.fan supplies air for combustion process by taking directly atmospheric air.The secondary air after preheating in the air heaters mixes with the primary air and coal dust in the manner to shape the flame and promote rapid mixing for

proper combustion.


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Some specifications of F D Fans: No. of fans per Boiler TwoFan capacity 406800 m 3/hr Speed 1400 RPMRating 800KWVoltage 6.6KV 3-phase star connectedRated current 84.5ATemperature at full load 90CBearing Ball bearing, Roller BearingMade by BHEL Bhopal, India

PRIMARY AIR FANS (P A FANS)

This fan handles the clean atmospheric air which then preheated in preheater.The hot primary air which comes out of the preheater scavenges the bowl milland carries the coal particle to the burners.A part of the primary cold air is used to sealing the R C Feeder, coal dust linesat the discharge end of bowl mill seal air ring header of mill.A part of primary cold air is used for regulating temperature of the hot air entering the bowl mill.

Some specifications of PA Fans: No. of fans per Boiler TwoFan capacity 254880 m 3/hr Speed 1485 RPMRating 1250KWVoltage 6.6KV 3-phase star connected

Rated current 112.2ATemperature at full load 90CBearing Ball bearing, Roller BearingMade by BHEL Bhopal, India


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PLANT

AUXILARY

MAINTENANCE

(PAM)


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WATER IN POWER PLANT

Water plays a very important role in power plant. Water is basically used for two purposes viz. cooling and for making steam. Therefore, a power plant

should have a water source for this purpose.The major problem for water is not quantity but quality. Water used for steamcycle should be treated well before sending it to boiler for steam cycle. Therequirement of water for steam cycle is 3-4 tones/hr/MW and makeup quantityis 2-3% of the same. For condensation purpose the amount of water required isapproximately 20000m3/hr/100MW. A small proportion is required for cooling


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of generator and other machinery. This amount can be fulfilled by canal or even by tube well.

As the quantity of water doesnt matter, it is the quality of water that matters.The water should undergo various water treatments such as hardness testing,caustic embritillment, ion exchange method, and deoxidization etc.

In NTPC Badarpur, water is supplied through Agra canal which came fromYamuna River. This water is filtered first to make it free from dirt, and then it is

pumped via different pumps to there respective destination where it is used inits required form. The waste water is again feed to the river via different path.


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COMPRESSOR HOUSE

In power plant, compressors are used to provide the required compressed gaswhich is used for opening and closing of valves which are out of reach of worker or where manual operation is difficult. It is also used for cooling of various air cooling machines.

There are mainly four types of compressor which are functioning in compressor house they are:

1. Reciprocating Compressor 2. Electric Screw Air Compressor 3. Blaster Compressor 4. Mechnofore Compressor

Reciprocating Compressor

Reciprocating compressor is actually double acting reciprocating compressor. Itconsists of a cylinder, a piston which compresses the air in both direction of itsmotion.

Some of its specifications are as follows:

Bore -LP Cylinder 380mm-HP Cylinder 245mm

Stroke 125mmCompressor speed 980RPMPiston displacement 27.54m 3/minFree Air Delivery (FAD) at 8Kg/cm 3 g 18 m 3/minMotor KW 120KW

Net weight of compressor 2900Kg (approx)Lubricating oil 25LCompressor Lubricating oil pressure 2.5 to 4Kg/cm 2 gCooling water flow rate 180L/min


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Electric Screw Air Compressor

A screw compressor consists of two rotors, one male and other female. Theserotors have symmetric profile lobes encircling the rotor in the form of thread.The male rotors have 4-lobes while female have 6.

Some specifications of screw compressor:

Types of compressor SES520 SES770 SES1000 SES1500Free Air Delivery (FAD) 520cfm 770cfm 1000cfm 1500cfm

(in m 3/min) 14.7 21.8 28.3 42.5

Working pressure 100psig 100psig 100psig 100psig7Kg/cm 2g 7Kg/cm 2g 7Kg/cm 2g 7Kg/cm 2g

Motor power (HP/KW) 125/93 180/132 250/187 350/258

Speed of motor (RPM) 3000 3000 3000 3000

*1m3/min=35.37 cfm

**1KW=1.344 HP


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ASH CONTROL PUMP HOUSE

The basic function of ash control pump house is as its name suggests is to dumpthe slurry i.e. mixture of water and ash to a place far away from the residential

place, so that it cannot harm any living organism.

For this purpose pumps are working. They suck the slurry and discharge itthrough the pipelines.

In NTPC Badarpur, there four pumps serving this purpose. They suck the slurryand discharge it through the pipelines to a place 8Km south east near YamunaRiver. There this slurry dries up and they are used for making bids, bricks etc.

CONTROL STUCTURE PUMP HOUSE

This pump house is very necessary for the plant. It supplies the water needed bythe power plant. It provides water for cooling purpose, cleaning purpose and of course for the boiler. Water for boiler doesnt directly feed to boiler; it is first

send for water treatment to purify and dematerialization.

It consists of four different types of pump such as HP Pump, LP Pump, CRWPump, and FS Pump. All of these pumps are used for different purposes like LPPumps are used for boiler water; HP Pumps are used for cleaning water purposeetc.

In NTPC Badarpur water is taken from Agra canal which is first filtered

properly and then it supplies water for required usage. Here 6HP Pumps, 3 LPPumps, 3 CRW Pumps and 2 FS Pumps are installed. The cooling water issupplied to the plant through underground water tunnel which is about 20mdeep. Hence it is a very important part of the power plant.


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TURBINE

MAINTENANCE

DEPARTMENT

(TMD)


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BOILER FEED PUMP (BFP)

During normal running of the unit, the feed pump has to handle hot water received from feed water storage tank of deaerator through its booster pumpenhancing the positive suction pressure and has to deliver the hot water under high pressure to boiler drum, through high pressure heaters and economizers for steam generation. Te feed pump may be treated as the heart of unit and,therefore, full attention is paid during its startup, shutting down and normalrunning.

In 210MW units the boiler feed pumps are coupled to motor by hydrauliccoupling. The hydraulic coupling serves the purpose of controlling the speed of feed pump for maintaining a definite delivery head and delivered quantity of the pump as per requirement of the boiler.

CONDENSATE PUMP

Condensate pump takes suction from condenser and delivers condensate water

to deaerator through main ejector, gland steam coolers and L.P Heaters.Condensate water discharged by the condensate pump is also utilized for thefollowing purposes:

1. Sealing of valve with gland seals.2. For PRDS and DSS temperature control of main steam lines and hot

reheats lines respectively.3. For filling siphons of ejectors and 15m siphon drain expander.4. For cooling down the steam dumped in steam throw off device built in

both condensers.


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COOLING WATER PUMP (CW PUMP)

CW Pumps are required for the cooling purpose i.e. for cooling the hot, low pressure steam. These pumps are single suction single discharge type whichdischarge water at a pressure of 0.4Kg/cm 2. The pump rotates at 450 RPM andhas a length of 14m.

CW Pump pumps cooling water which flows through the tubes of smalldiameter in the condenser. Here steam is all around the tubes looses energy andcondenses. The point is to be note is that steam condenses but still it is at atemperature of 160C because it is not cooled, so that its pressure shouldincrease.

The make up water is provide by the DM Tank i.e. De Mineralized water Tank where extra water is stored. When extra make up water is supplied then theextra water is automatically transferred to the Unit Drain Tank (UDT). Fromhere UDT Pump pumps the water for make up.

There is another pump in this category called sub pump. It is used basically for cleaning purpose. It is used to pump waste water split on the ground and

collected in a pit. Sub pump pumps this water out of the pit.

MAIN TURBINE

The steam turbine is a condensing tandem compound, three cylinders (HP, IP,and LP) horizontal, disc, and diaphragm type with nozzle governing and

regenerative feed water heating. The LP turbine is a double flow type whichincorporates a multi-exhaust in each flow.

The complete turbine assembly is mounted on pedestals and sole plates, whichare designed to ensure that the components are free to expand, whistle correctalignment is maintained under all conditions.


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The three rotors are supported on five bearings HP and IP rotor have common bearing which is a combined journal and radial thrust bearing.

Some specifications of turbine:

Rated output of turbine 210MWRated speed 3000RPMRated live steam temperature 535CRated pressure of steam before emergency stop valve 130Kg/cm 2 absRated pressure at the exhaust of LP turbine 45.2mm of HgCRated quantity of circulating water to condenser 27000m 3/hr


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MAINTENANCE

ANDPLANNING

DIVISION


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Oil analysis: Incase of oil analysis the sample of lubrication oil coming out of the machine is tested. According to the report it is clear that is there a contact

between bearing and shaft exists or not.

Motor current: Using method the maintenance of electrical appliances is done.

There are standard readings of every part of every machine which are feed inthe testing device. Therefore only by checking the machine the device tells thecondition and status of part and it become easier to localize the failure inmachine. It also increases the life, running time and condition of machine.

PLANNING SECTION

Along with maintenance, this department also does the planning work. Sometimes it is required to shut down the unit so before shutting down the unit thetime required is calculated and according to the time limit the work done per day is planned so that the repair work should take minimum time and the unitstart working soon.

DESIGN SECTION

This department also does the design work with the help of software likeAutoCAD. This is a very effective step to improve the working of the machine.These designs are available on the LAN and can be used or seen by any officer

easily at any time.


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Summer Vocational Trainin1

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