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TRAINING REPORT

ON

GENERATION OF ELECTRICAL

ENERGY

AT

KANTI BIJLEE UTPADAN NIGAM LIMITED

(A joint venture of NTPC Ltd. &BSEB)

MUZAFFARPUR THERMAL POWER STATION, KANTI, MUZAFFARPUR,

BIHAR

Submitted for the partial fulfilment of the Requirement of

BACHELOR IN ELECTRICAL ENGINEERING

DURATION : 30.05.2011 to 26.06.2011

Under the guidance of :-

1. Mr. J. Bhattacharya

DGM

2. Mr. A. K. Jena

3. Mr. N. D. Nayak

SUBMITTED BY:-

Md.

SHARIQUE AFZAL

COLLEGE: AL INSTITUTE OF TECHNOLOGY, ICHCHHANATH, SURAT-

395007(GUJARAT), INDIA

COURSE : B. TECH. (ELECTRICAL ENGG.)

YEAR : 3nd year (6th Sem. )


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ADMISSION NUMBER : U09EE567

ACKNOWLEDGMENT

This report pertains to take vocational training which was undertaken

under KANTI BIJLEE UTPADAN NIGAM LIMITED, KANTI,

MUZAFFARPUR, BIHAR ( A joint venture of NTPC & BSEB ) in

partial fulfilment of the requirement for the BACHELOR IN

ELECTRICAL ENGINEERING from SARDAR VALLABHBHAI

NATIONAL INTITUTE OF TECHNOLOGY, ICHCHHANATH, SURAT-

395007,GUJARAT. The main purpose of the training was to acquaint

myself with practical experience of actual work condition in which we

are required to work in future. I learnt a lot from the practical

experience of the engineering & other personals under whom I was

placed for training. This helped me to develop the habit of analysis

critically various aspects of problem at the time of decision making.

I would like to acknowledge to Mr. J. Bhattacharya, Mr.

A.K.Jena, Mr.N. D. Nayak, during training period whogive me clear details & guidelines for the power station .

Finally; I would like to express my thanks to all of the technical & non

technical persons for the co- operation & valuable guidance duringmy training period.


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INTRODUCTION ABOUT THE

PLANT

KBUNL (Kanti Bijlee Utpadan Nigam Limited) which was formerly

known as Vaishali Power Generating Company Ltd(VPGCL) is situated

in kanti which is 12 km away from main town muzaffarpur.

It is totally coal fired Thermal power station.

There are two units of each 110MW installed capacity.

RECENT DEVELOPMENT

NTPC has opted for joint venture(jv) with BSEB. The main feature of

this jv is as follows:

KANTI BIJLEE UTPADAN NIGAM LIMITEDThis jv was incorporated on with Bihar State Electricity Board, a State run

Electricity Board in the State of Bihar with NTPC, engaged in generation,transmission and distribution of electricity.

OBJECTIVE: To take over Muzaffarpur Thermal Power station(2*110MW),a coal based power station at kanti , for carrying ourrestoration ,R&M and supplying power mainly to state ofBihar.

PROMOTERS EQUITY

NTPC: 51-74%BSEB: 49-26%


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ABSTRACT

Any thermal power plant is converting the chemical energy of fossil

fuel (coal) into electrical energy. The process involved for this

conversion is based upon the modified Rankin cycle. The major

components that are used to accomplish the modified Rankin cycle

are:

Boiler feed pump,

The steam generator water walls (evaporator),

Steam generator super heaters,

Steam turbine,

Reheater,

Condenser,

Regenerative feed heaters etc.

All components of a power generating cycle are vital and critical in

operation. In Modified Rankin cycle, the two most important aspects

that is added are reheating & regenerative heating. By reheating we

used to send the steam coming from exhaust of the turbine back to

the reheater of the boiler so that its enthalpy increases and more

work can be done by this steam the other purpose is to make steam

dry so that no harm will be done to the blades of turbine.


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In MTPS Kanti, we have three turbines in Tandem coupling namely

one H.P Turbine, one I.P Turbine & one L.P Turbine coupled with the

generator to which is synchronized with the grid to produce

electricity at 50Hz.

In all my modesty, i wish to record here that a sincere attempt has

been made for the presentation of this project report. I also trust that

this study will not only prove to be of academic interest but also will

be able to insight into the area of technical management.

CONTENT

SINO.

Description Page-No

01 An over view (NTPC) 0302 Plant introduction 04-0503 Schematic diagram of thermal power plant 0604 Working principle 0705 Process of generation of electricity 0806 Coal to steam 0907 Steam to mechanical 10-1108 Power Generation, Transmission &

Distribution12-13

09 Single line diagram of grid 1410 Transmission 15-1811 Light up process 1912 Main boiler components 19-2113 Cooling water circuit 2214 Types of fan 22-2315 Types of pump 23-24

16 Types of turbine 24-2517 Types of heater 25


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18 Unit control desk and panels 2519 References 26

An Overview

NTPC

NTPC was set up in 7th November 1975, the NAVRATNA power giant

today generates more than one fourth of the total power in the

country, ranked 5th largest power generating utility in the world, NTPC

is the second most efficient in capacity utilization among the top ten

thermal generating companies according to a survey conducted byData monitor, United Kingdom. In a short span of two decades, NTPC

has earn its prime status by setting up a total generating capacity of

22,249MW, with 19.14% of Indias operating capacity, the company

generates 26.7% of country electricity through its 13 coal & 7 gas

based power plants spread all over the country.

Today, country needs a 10% sustained growth in power generation to

ensure the momentum for a 7% overall growth in the economy.

Recognizing this, NTPC has committed itself to achieving the status of

a 30,000MW plus company by the year 2007 and 40,000MW pluscompany by the year 2012 and power generating capacity addition

programme of 51,000MW (including nuclear energy and non-

conventional sources of energy) for the tenth plan.

NEW TECHNOLOGY

Super critical technology at NTPC Sipat project (3*600MW) to

increase the efficiency of the cycle and to decrease the green house

gas emission,


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Closed cycle seawater cooling at Simhadri project for first time

in India

Introduction of IGCC (Integrated gasified combined cycle) for

clean and efficient utilization of coal.

ENVIROMENT MANAGEMENT

Liquid water treatment plants at Farakka and

Kahalgaon.

Ash water recycling system at Kahalgaon and korba to

reduce water requirement for ash disposal at these

stations.

PLANT INTRODUCTION

Salient Features Of Boiler Plant

1. General

Type of boiler Single drum tangential firing &reheat type (water tube)

Type of fuel used Pulverized coal (Main fuel), Heavy oil & L.D.O (for light up & flamestabilization)

No. Of Mills 06Type of Mills Pressurized type Bowl MillFurnace Balanced draught P.A Fans 02 (each 60% capacity)F.D Fans 02 (each 60% capacity)I.D Fans 03 (each 60% capacity, one

standby)Air heater 02Types of Air Heater Trisector regenerative

Electrostatic Precipitator 01


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2. M.C.R Parameter

M.C.R. Value

S.H. Outlet steam flow 375 T/HrR.H. stem flow 331 T/Hr Pressure at S.H. Outlet 141.5 AtaTemp. at S.H. Outlet 540cPressure at R.H. Inlet 37 AtaPressure at R.H Outlet 32.9 AtaTemp. at R.H. Inlet 369cTemp. at R.H Outlet 540cPressure in drum 148.69 Ata

Design pressure 158.0 kg/cmFlue gas temp. leavingEconomiser

350c

Flue gas temp. leaving AirHeater

142c

Feed Water Temp. beforeEconomizer

235c

Salient Features Of Turbine

1. General

Type Of Turbine Reheat No. Of Cylinders 3(HP,IP &LP)No. Of LP Heater 05No. Of HP Heater 02Deaerator 01(Variable pressure type)No. Of Extraction pump 03(one standby)No. Of BFP 02(one standby)

M.C.R. Parameter

M.C.R. Value

Rated output 110MW M.S. Pressure at H.P.turbine inlet

130 Ata

M.s. temp. at H.P. turbine

inlet

535c


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H.R.H. temp. at I.P.turbine inlet

535c

Turbine speed 3000 rpmCondenser Vacuum 0.1 kg/cm(abs)

No. Of Extraction 07Quality of cooling water 15,400 m/hrSalient Features Of Generator

Rating ContinuousActive Output 110 MW Rated Voltage 11000+/-5%V Rated Current 7220 APower Factor 0.8 lagging

Frequency 50 Hz Excitation System Static typeField current at ratedoutput

1335 A

Type of cooling system Hydrogen CooledHydrogen Pressure 2 AtaNo. Of H cooled elements

06

Cooling medium for H Soft water

WORKING PRINCIPLE

The working principle of thermal power plant is based on Rankin

cycle. A central steam station basically works on the Rankin cycle.

Steam is produced in the boiler , is expanded in the prime mover

(Turbine) and is condensed in a condenser to be fed into the boiIer.

PROCESS OF GENERATION OF

ELECTRICITY

MTPS Kanti is a Thermal Power Plant. The functioning of every

Thermal power plant is based on following process:-

1. Coal To Steam

2. Steam To Mechanical power


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3. Power Generation, Transmission & Distribution.

Coal To Steam

Coal and water are the primary inputs to a thermal power plant.This

process of conversion of water to steam by using heat energy

produced by burning of coal by producing heat takes place in boiler

and its auxiliaries. Coal burns in a furnace located at the bottom part

of the boiler. Feed water is supplied to the boiler drum by boiler feed

pumps, where water is heated and converted into saturated steam.

This is further superheated in the super heaters.

Steam To Mechanical Power

This is the most important process of a power plant. The superheated

steam produced in the boiler at high pressure and temperature is

feed to the turbine giving up heat energy, which is transformed into

mechanical energy on turbine shaft. Thus, mechanical power is

obtained from the turbine shaft.

Power Generation, Transmission & Distribution

Mechanical power produced at the shaft of the turbine is used to

rotate the rotor of an electrical generator that produces electricalpower. The electric power produced by the generator is boosted to a

high voltage by a generator transformer to reduce transmission

losses. This power at EHV i.e. 400 KV is transmitted and distributed

by EHV transmission lines.

Coal To Steam

We are taking coal from coal-yard as Wagon tippler load with the help

of motor on which the conveyer belt is mounted. As Wagon tippler

consist of rotor & pinion. The pinion use to rotate rotor. If in case

Wagon tippler not working then mechanically coal is transfer into

hopper to the belt. We supply coal in coal bunker watching the load

on control room connected Ammeter & Voltmeter. Feeder is used to

put coal on belt. Small motors are connected to belt for support. Coal

being passed through metal detector after passing through metal

detector it is passed through vibrating screen where coal of 5mm


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seperated from large coal ane fed to crusher then magnetic separator

to remove iron particle from coal. Then fed to crusher to coal bunker.

Metal detector placed over conveyer belt

From coal bunker coal is supplied, to pulverising mill. There are six

coal bunkers supplying coal to each mill and are located at top of the

mills to add in gravity feeding of coal. Each bunker store coal whichcan be used for 12 hrs. Coal is supplied to the mill by the four

barriers. With the help of primary air fan we feed coal to pulveriser

mill with high pressure of air. There are five pipes connected to mill

from on we feed coal to mill and from other four pipes coal dust

comes out from mill after pulverising. The coal is converted into

powered form in the mill. The mill is ball mill of MTPS power station.

With the help of primary air coal dust is feed into ignited boiler. The

coal which we are using for thermal power plant is of class c. In boiler

heat of coal is used to convert water into steam. Coal produces heat

of 330c and that of super heated stem is 535 c.

Steam To mechanical power

The steam which being produced in the boiler are collected in boiler

drum. This boiler drum is mounted on top of the boiler. From boiler

drum steam is passed through super heater. There are three super

heaters between boiler drum and high pressure turbine. Super


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heaters are used to remove moisture or water droplets from steam

which can decrease efficiency of turbine.

The stem passing through high pressure turbine again given to

reheater where steam is reheated and then used on intermediate

turbine from intermediate turbine steam is directly used on low

pressure turbine. The steam which is being used on low pressure

goes to condenser where it cools. The steam heated in reheater at

535c and fed to intermediate turbine of 20 kg/cm and then fed to

low pressure. And this produces mechanical power on shaft on

turbine. Where the turbine shaft is directly coupled with the

alternator rotor.

Turbine

Types of turbine

1. HP Turbine:-


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HP turbine is a single flow design with eight stages of blading. Each

stages compromises stationary and moving blades which are

positioned into the rotor mounted on the diaphragms, directs steam

into the rotor mounted on the moving blades. HP turbine is double

shell construction comprising inner and outer casing.

H.P steam enters the H.P turbine inner casing through inlet

connection are mounted on the top and bottom outer casing. The

steam exhausts through the two branches in the bottom half casing

and returns to the boiler to be reheated to increase the temperature

of the steam to 535c so that the efficiency increases.

2. I.P Turbine: -

Intermediate pressure turbine is a double flow design with seven

stages on blading on either side of central steam inlet. Each stage

comprises stationary and moving blades which are positioned so that

the stationary blades mounted on diaphragm, directs the steam into

rotor mounted moving blades. The inner casing , diaphragm carrier

ring and outer casing are made in halves bolted together in the

horizontal centre.

3. L.P Turbine:-L.P Turbine is a double flow design with six stages in each of its front

and rear flow paths. Each stage consists of number of stationary

blades incorporating in the diaphragm located in the casing and a set

of rotating blades mounted on the rotor disc.

Power Generation, Transmission &

Distribution

Mechanical power produced at the shaft of the turbine is used torotate rotor. where magnetic flux produced inside the stator

conductor cuts by rotor conductor an electro motive force will be

induced due to Faradays law of Electromagnetic induction and

produces electricity with the speed of 3000rpm and frequency of

50Hz. As generator consists of stator which consist of stator winding

and rotor consisting of rotor winding. And we have three phase

supply. For cooling purpose of generator we are using hydrogen

which is shielded with oil.


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GENERATOR

A generator consists of rotor which consists of carbon brushes. The

rotor rotates at 3000rpm in case of any fault if production of plants

stops then we have bearing motor which rotates shaft of turbine

continuously and rotor at 65rpm. This is because if shaft doesntrotates then due to load it may bend.

As generator produces 110MW or generates 11kv output. The output

of generator is step up to 220kv by using step up transformer or

generating transformer. Three phase is fed to station transformer.

There are two station transformer1 and 2 which is step down

transformer. Here 220kv is step down to 6.6kv for internal purpose.

This 6.6kv is step down to 415v for low rating motors. At generating

transformer we are using lighting arrestor which protects G.T from

lighting. This 220kv is given to grid substation. In grid substation we

are using some protective system before distribution we have Bus

isolator, SF6 breaker, Line isolator, CT, lightning arrestor. Similarly we

have two unit auxiliary transformer UAT-1 and UAT-2, which will step

down voltage from 11kv to 6.6kv and it will supply to unit auxiliary

board 1BA, 1BB.

Similarly station transformer will supply to station board 9BA, 9BB.

One unit is tie with other unit because during the failure of any one of

the unit other unit will able to supply.


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We are using web trap which changes the frequency 50Hz to 500Hz

can be used for communicate in power plant. As three phase fed to

station transformer (Auto transformer) by step up we fed to

switchyard where circuit breaker is closed, when terminal voltage and

frequency matched with the busbar conductor.

Transmission

The KBUNL has capacity to generate 220MW of electricity but only

one unit is working and the second unit is under R&M process. We are

generating 90Mw out of 110MW and giving to the substation. The

transmission is done through three phase, double circuit system. with

the help of transformer, we are converting 11kv to 220kv and fed to

substation. It is then step down to 132kv and feeded to BSEB and

local areas.

Equipments used in transmission of power:-

1. Sub- Station

A. Control Room

B. switchyard

Sub-Station:-

It is the place where power is changed, step down or step up and

transmitted to other places. It consists of various protection

equipments, switching circuits etc.

A substation consists of

a) Bus isolators

b) circuit breaker

c) Line isolator

d) Current transformer

e) CVT

f) Lightning arrestor

g) Wave trap


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A. Control Room:-

It is the brain of any sub-station. All the necessary steps about the

transmission, protection, charging etc. are carried out in the control

room.

Measuring instruments of the control room:-

a) Relay circuit

b) Fault locator

c) Switch gears

d) Voltmeters

e) Ammeters

f) Power meter

g) CRT screen

h) Battery room

a) Relay circuit:- A relay is a protective device that operates

during faulty condition and gives command to circuit breaker to tripcircuit.

Operating principle:-

1. Electromagnetic attraction

2. Electromagnetic induction

Components of electromagnetic relay:-

1. Shaded pole

2. Watt-hour meter

3. Induction cup

4. Single and double induction loop

b) Fault locator:- A simple beam relay would measure thecurrent seen by the relay with the voltage at the relaying point. By


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comparing these two quantities the relay measure the line

impedence (z=v/i) up to the point of fault.

c) Switch gear:- Switches are used in sub-station as a devicefor making or breaking the electric circuit in convenient way i.e just

by the simple motion of a knob or a handle to connect together or

disconnect two terminals to which cables are connected. There are

two types of switch gears Air switch and Oil switch.

d) Voltmeter:- It is an instrument, which measures the voltagealong the phase. It actually measures the potential difference

between the two points of the conductors.

e) Ammeter:- It is an instrument, which measures the currentacross the conductor. It is mounted on the panel board. Where staff

on duty can easily watch the readings.

f) Power meter:- These instruments are used to measure thepower in standard units i.e in MW. This instrument is also mounted on

the panel board for easy watch for the operating staff.

g) CRT screen:- It is a computer arrangement in which current

information about the transmission line is seen. The circuit diagramof switchyard and control room is stored in hard disk. It also displays

the current status of the transmission line.

h) Battery room:- This room consists of 3 units of batteriesand charged for emergency purpose. In each unit there are 110

batteries. When power failure is there, then power is supplied by the

battery to keep all the instrument or devices in on status. There are

two types of charger for charging battery 1)Float charger 2)Boost

charger. Float charger is mainly used for charging purpose.

B. Switch yard:-

It is systematic arrangement of various components, where all the

machines or equipments are connected with each other, looping, step

down, step up of transmission line are done here only.

A switchyard consists of following

equipments:-


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a) Transformer

b) Tower

c) Conductor

d) Insulator

e) Circuit breaker

a) Transformer:-A transformer is an electrical device whichworks on the principle of mutual induction. The

autotransformer used in power station. It has three windings

primary, secondary and tertiary. The 220kv voltage is fed as

input to primary by step down132kv fed MTPS as input.

b) Tower:- Tower is the an important part of transmission line. Astower consists of guard ring. it is located at the bottom of the tower

so that any unauthorised person or animal cannot climb upto the

tower.

We have suspension type tower called as A type tower. The peak

point angle is 0 to 2. In this type conductor is suspended with an

insulator.

B-type : angle lies between (2-15)

C-type : angle lies between (15-30)

D-type: angle lies between (30-60)


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C) Conductor:- A conductor is very essential equipment which isused for transmission of power. It is generally made of aluminium. It

is hanged on the tower with the help of insulators. Aluminium cost is

cheap and has good conductivity.

D) Insulator:- It is made up of porcelain material which is badconductor of electricity. For transmission purpose generally PIN-TYPE

insulators are used. The capacity of each disk is 20kv.

E) Circuit breaker:- These are mechanical devices designed toclose or open contact members thus closing or opening an electrical

circuit under normal or abnormal conditions. These circuit breakers

are equipped with trip coil connected to relay, design to open breaker

automatically.

Connection with grid to synchronisation:-

1. The terminal voltage of alternator must be equal to the bus-barvoltage.

2. The running speed frequency must be equal to the bus-bar

frequency.

(Ns=120f/P) => (f=PN/120)

Where, f= frequency

P= no. Of poles

N= speed of alternator

3. The terminal voltage of two conductors must be equal to the

two busbar terminal to place the external resistance to reduce the

voltage drop.

Light up process


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MTPS Kanti has direct firing system. In this system, a controlled

quantity of crushed coal is fed to each bowl mill (pulveriser) by its

respective feeders and primary air is supplied from the primary air

fans which drives the coal as it is being pulverized and transports the

pulverized coal through the coal piping system to the coal burners.

There are six pulverisers out of which four are used and two remains

in standby. The raw coal feeders supply 74TPH of coal to each mill.

The pulverized coal and air discharge from the coal burners is

directed towards the centre of furnace to form fire ball. There are 24

tilting, tangentially fired coal burners fitted at the four corners of the

boiler at elevations.

The secondary air heating system supplies secondary air for

combustion in the furnace around the pulverized coal burners and

through auxiliary air compartments directly adjacent to the coal

burner compartments. There are 12 air-atomizing ignitors per boiler,

which initially ignite the coal and air mixture.

Above a predictable minimum loading condition, the ignition becomes

self-sustaining. Combustion is completed as the gases spiral up in the

furnace.

MAIN BOILER COMPONENTS

Boiler is a closed vessel in which water is converted into steam.

There are two types of boilers

a) Fire tube boiler

b) Water tube boiler

The major accessories of a steam-generating unitare listed as follows:-

Furnace

Economiser

Boiler drum

Down comers

Water walls


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Riser tubes

Superheaters

Reheaters

De superheaters

Furnace:- A boiler furnace is the first pass of the boiler in whichfuel is burned and from which the combustion products pass to the

super heater and second pass of boiler. The combustion process is a

continuous process, which takes place in first pass of boiler and

controlled by fuel input through coal feeders. It is a radiant type and

water-cooled furnace and inclosure is made up of water walls.

The furnace is open at the bottom to allow ash/clinkers to fall freelyinto the furnace bottom ash hopper.

Economiser :- The function of an economiser in a steamgenerating plant is to absorb heat from flue gases and add this as

sensible heat to the feed water before the feed water enters the

evaporative circuit of boiler. This increases the efficiency of the

boiler.

The economiser is placed in the path of the flue gases leaving the

boiler rear gas pass below the rear super heater. The economiser is

continuous unfinned loop type and water flows in upward direction

and gas flows in downward directions.

Boiler drum:- It is a cylindrical pressure vessel withhemispherical ends. It contains two rows of cyclone separators, four

rows of driver boxes, a perforated feed water distribution pipe, and achemical dosing pipe.

The boiler drum is located on the upper front of the boiler, it is

suspended from roof steel work by two u-shaped slings.

It forms a part of the water circulating system of the boiler. The drum

serves mainly two functions.

The first and primary one is that it separates steam from the

mixture of the water and steam discharged into it and to reduce the

dissolved solid contents of the steam to below the prescribed limit of

1 ppm.


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Secondly, the drum houses all equipments used for purification

of steam after being separated from the water. These equipments are

known as drum internals.

Down comers:- Down comer provide a passage for water fromthe boiler drum to bottom ring header. From bottom ring header

water goes to water walls for heat absorption and conversion into

steam heating. To achive the circulation of water into water walls

boiler circulation pumps are provided in down comers.

Riser tubes:- A riser is a tube through which the mixture of waterand steam pass from an upper water wall header to the steam drum.

Cooling water circuit

A large quantity of cooling water is required to condense the steam in

condenser and in maintaining a low pressure in it. Cooling water may

be taken from the upper side of the river and after passing through

condenser ( where it is heated ).

Where adequate quantity is not available water coming out from the

condenser may be cooled either in cooling pound or cooling tower.

The cooling tower having fans which is rotated with the help of

motors. The blades of fen are set at an angle of 13 to 15. More

angle of blade cause more cooling and more current drop. The motorrotates at 1400rpm.

Cooling tower


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Types of fan :-

A fan is a device by which the air is made to flow at required velocity

and pressure in a defined path imparting K.E of its impellers to

air/flue gases. This pressure boost is used to create a draught in theair and flue gases system. Fans mainly perform two functions:

1. They supply air required for combustion in the furnace with

required pressure and flow.

2. They evacuate the product of combustion i.e. flue gases into

the atmosphere via chimney.

P.A fan:-

The primary air fan supplies heated air to the coal mills known as

primary air, to give dry and pulverized coal to the furnace for efficient

combustion. There are two P.A fans per boiler. The fan impeller is a

double inlet, centrifugal wheel with backward curved plate blades.

F.D fan:-

The forced draught fan system is provided to supply secondary air

required for pulverized coal combustion in the furnace, air for fuel oil

combustion and over fire air to minimize NOX production.

The F.D fan system comprises of two single stage axial flow, constant

speed, and auto variable pitch fans per boiler. These fans provide

pressurized atomospheric air to the boiler for combustion.

I.D fan:-

The induced draught fan system comprises of three centrifugal

double inlet fans per boiler, two operating and one standby. Each fan

unit consist of a backward curved plate bladed impeller, which is

driven by an electric motor through a variable speed hydraulic

coupling. The I.D fan serves the purpose of evacuating the products

of combustion or the flue gases in the atmosphere via chimney.

Types of pump :-

1.Condensate Extraction pump (CEP):-

The function of condensate extraction pumps is to pump out the

condensate to the deaerator through, L.P heaters. The steam fromthe L.P cylinders exhausts into the condenser shells where it is


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constrained to flow across the water tubes, through which cooling

water is circulated.

2.Air extraction pump (AEP):-

The function of air extraction pump is to raise and maintain the

vacuum conditions in the turbine main condensers, and to remove air

and other non-condensable gases vented to the condensers from the

various parts of the turbine and feedweater heating system.

3.Boiler feed pump (BFP):-

Boiler feed pump is the most critical component of a power plant. It is

a rotary machine, which is coupled to a motor through variable speed

coupling or turbo coupling. Under normal conditions two 50% boiler

feed water pump sets are run in parallel to undertake the complete

load of feeding the boiler, while the third 50% pump set is on standby

duty.

Types of turbine1. HP Turbine:-

HP turbine is a single flow design with eight stages of blading. Each

stages compromises stationary and moving blades which are

positioned into the rotor mounted on the diaphragms, directs steam

into the rotor mounted on the moving blades. HP turbine is double

shell construction comprising inner and outer casing. H.P steam

enters the H.P turbine inner casing through inlet connection are

mounted on the top and bottom outer casing. The steam exhausts

through the two branches in the bottom half casing and returns to

the boiler to be reheated to increase the temperature of the steam to

535c so that the efficiency increases.

I.P Turbine:-

Intermediate pressure turbine is a double flow design with seven

stages on blading on either side of central steam inlet. Each stage


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comprises stationary and moving blades which are positioned so that

the stationary blades mounted on diaphragm, directs the steam into

rotor mounted moving blades. The inner casing , diaphragm carrier

ring and outer casing are made in halves bolted together in the

horizontal centre.

3. L.P Turbine:-

L.P Turbine is a double flow design with six stages in each of its front

and rear flow paths. Each stage consists of number of stationary

blades incorporating in the diaphragm located in the casing and a set

of rotating blades mounted on the rotor disc.

Types of heater

1. High pressure heater (HPH):-In the water cycletemperature of feed water from BFP is increased to approx, 130c by

heating it in HP heater. As the heating of feed water in HP heater is

done by the extra steam coming out of the High Pressure Turbine(HPT) hence, it is named as High Pressure Heater (HPH).

2. Low pressure heater(LPH):-In the water cycle,temperature of condensate from CEP is raised to approx. 80c by

heating it in LP heater is done by the extra steam coming out of the

low pressure turbine(LPT) hence, it is known as low pressure heater.

Unit control desk and panel

The operation of each unit is envisaged from the central unit controlroom. It is located in the control bay at 9.0m TG floor. It is adequately

illuminated and is centrally air conditioned. For operation

convenience, the control room front wall has complete glass

panelling for TG hall view and the two double doors for entry from TG

hall.

The control board has a special profile with three sloping surfaces for

mounting a large facias, instruments and controls. The automatic

control station and drive control switches and indications are located

on the first sloping surface. The process indicators/recorders and


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ammeters are mounted on the second sloping surface and the alarm

annunciation window facias are mounted on the top i.e. third sloping

surface. The unit control board are arranged in logical operating

sequence from the left to right starting with a) air and flue gas, b)

fuel oil, c) ball mills, d) steam & feed water, e) regenerative system,f) turbine and g) generator

Power distribution in KBUNL for

main plant and off-site area

There are two types of power distribution in KBUNL for plant

and its auxiliaries

1. HT System(6.6kv)

2. LT system (415v)

3. DC system(220 V)


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HT System (6.6kv)

HT power used is of 6.6 kV .there are 2 no. Unit board per unit and 2

no. Station board per unit.

As given in the network drawing .these boards are

Unit-1

1. Unit board 1BA -6.6kv,1250 A.

2. Unit board 1BB-6.6kv, 1250 A

3. Station board9BA-6.6 kv , 1600 A

4. Station board9BB-6.6 kv , 1600 A

Unit-2

1. Unit board 2BA -6.6kv,1250 A

2. Unit board 2BB-6.6kv,1250 A

3. Station board 9BC-6.6 kv , 1600 A

4. Station board 9BD-6.6 kv , 1600 A

Station board

The purpose of this board are to import power to the powerhouse for

its auxiliary supply.Intially power taken from grid 220 kv bus through

station transformer -1 and charged station board 9BA and

9BB.Similarly power taken from grid through station transformer -2

and charged station board 9BC and 9BD

There is provision for coupling of station board 9BA to 9BC and 9BB

to 9BD through Tie breakers at both ends. These board supply power


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initially to Unit board as well as the areas which are common to both

the units &Off-site areas .

Important feeders are:

1. Station service transformer

2. Cooling tower transformer

3. DM plant transformer

4. ASH handling transformer

5. CHP -6.6kV board through cables

6. FIRE hydrant pump

7. Mulisifyer pump

8. CW pump -3

9. HP Ash water pump A,B,C

Unit Boards

Before running the unit auxiliary power is required for different

activity in power plant so respective unit are charged through bus

coupler as per the drawing

1. 1BA charged through 9BA

2. 1BB charged through 9BB

3. 2BA charged through 9BC

4. 2BB charged through 9BD

After synchronisation of unit Normal Incomer from AUT taken into

service and station bus coupler taken out. Every board has I/C Bkr. ,

Bus PT and outgoing feeders for HT drive and transformers

Important feeders in units board of respective unit

1. BFP


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2. PA FAN

3. ID FAN

4. FD FAN

5. COAL MILLS

6. CEP

7. Unit service transformer

8. ESP transformer

Breaker used in KBUNL6.6 kv system

BHEL- Make

MOCB - Breaker

LT system (415v)

Main plant

There are two types of LT supply system. One is station service whichis common for both the unit and other is for respective units service.

Station service switchgear(415v)

It has two section charged through station service transformer having

with LT breakers in each section.

Bus coupler provision is there.


1. ACW pump-1 and 2

2. Outgoing feeder to compressor MCC

3. Outgoing feeder to station emergency board

4. Station lightning


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Unit service switch gear(415v)

It has two section each section charged through unit service

transformer having with LT breaker in and bus coupler.

1. Important feeder

2. Outgoing feeder to boiler MCC section a and b

3. Outgoing feeder to turbine MCC section a and b

4. Unit lightning

Boiler MCC

It has two section A and B having with bus coupler mainly it provides

power control to all the LT drive in boiler area.

Important drives are:

1. Mill seal air fan A and B

2. Air preheater lub oil A and B

3. Hydrazine dosing pump A and B

4. Ammonia dosing pump A and B

5. Phosphate dosing pump A and B

Turbine MCC

It has two section having with bus coupler mainly it provides power

control to turbine aux.


1. BCW pump A,B,C

2. Starting oil pump A and B

3. Drip pump A and B

4. Oil centrifuge

5. Chimney exhaust fan-A and B

Station emergency board


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It has two sections A and B having with bus coupler. Each section

having with one normal I/C from Stn. Service PCC and one DG set.

Normally the board is charged through the normal I/C in case of

power failure in station DG set started and the board charged

through DG I/C breaker.


1. Outgoing feeder to respective unit emergency board

2. Battery charger

3. Inst. Compressor-4

Unit emergency board

It has two I/C one from Unit PCC and other from Stn. Emergency

board. Initially it charged through Unit PCC, in case of power failure

automatically it changes over to emergency supply system.


1. AC seal oil pump

2. AC EOP

3. AC JOP

4. Turbine barring gear

5. AC scanner fan

6. Unit emergency lighting

Turbine v/v and damper MCC

It has two source one from Turbine MCC and other from Unit

Emergency board having with auto change over ckt. Mainly supply

power to all the valve control in turbine areas.

Boiler v/v and damper MCC


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It has two source one from Boiler MCC and other from Unit

Emergency board having with auto change over ckt. Mainly supply

power to all the valve and damper control in boiler areas.

DC system

There are common DCDB of 220V dc system having with two set of

unit batteries and two charger one main and other standby.


1. DC seal oil pump

2. DC JOP

3. DC EOP

4. DC scanner fan

5. DC lighting

6. DC supply to all HT /LT sw.gr for controlled and protection

system .

Like main plant in all the offsite area there are LT SG. Gear .They are

charged through their respective transformer to provide power toelectric drives of that area

Offsite areas are:

1. DM PLANT

2. RAW WATER

3. COOLING TOWER

4. ASH HANDLING PLANT

5. FUEL OIL PUMP HOUSE

6. COMPRESSOR

7. COAL HANDLING PLANT


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GENERATOR

125MVA, 110KW, 11KV, 6050A, 0.88PF ,3000RPM,50HZ

Hydrogen cooled, with static excitation used in KBUNL

BHEL Make.

Initially power taken from grid for unit light-up process started. After

parameter of steam like pr. and temp. reached turbine rolling started

.After attaining 3000 RPM. Exitation field breaker made on when

generate output voltage attain then generator synchronised with

grid. the AVR system controlled the generator o/p voltage as per the

load. The generating power at 11kv is step-up by G.T. to220kv with

same power and export to the grid through 220kv bus in switchyard.

Switchyard

There are two 220kv and 132kv bus system in switch yard they are

coupled with 02 nos. IBT. KBUNL takes power from grid through

220kv line and export power through both 220kv and 132kv line

Details of MOCB at KBUNL:

For station incomer / Tie breaker

Voltage 7.2kv


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Frequency 50hz

Normal current 1600A

RVM Breaking capacity 40kA

Short time current 40KA

Duration 3sec

Making capacity 102KAP

RF withstand 35kv

Impulse 75kvp

Shunt trip coil 220VDC

Spring release coil 220VDC

Type LM12/16J

SR.NO. 9026558

Division BHOPAL

Year 1983

For station feeder/station transformer

Voltage 7.2kv

Frequency 50hz

Normal current 630A



Duration 3sec


RF withstand 35kv


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Impulse 75kvp



Type LM12/6J

SR.NO. 9026564

Division BHOPAL

Year 1983

For unit incomer/ Bus coupler breaker

Voltage 7.2kv

Frequency 50 hz

Normal current 1250A



Duration 3sec


RF withstand 35kv

Impulse 75kvp



Type LM12/12J

SR.NO. 9026598

Division BHOPAL

Year 1983


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training repor1

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