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A Training Report

For Partial Fulfillment B.E Electrical Engineering from

MSIT, Janakpuri

ONNational Fertilizers limited,Panipat Unit

Presented By - Underguidance of:-


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Harshal Kumar Mr.Johnson OramB.Tech (EEE)00315004911

Acknowledgement

It is a matter of great pleasure for me

acknowledging me with profound sense of

gratitude, the invaluable help & worth

guidance rendered by my project guide Mr.

Johnson Oram .Their innumerable suggestions

which served as the material source & the

motivational force for the successfulcompletion of the training.

At last, I am thankful to all those who helped

me in any way, in achieving my goal of

successful completion of the training.

It is my pleasure to thank my fatherMr.R.K.Sonkar for his constant

encouragement and valuable advice during

the whole training period.

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Harshal Kumar

COMPANY PROFILE

[3]
http://www.nationalfertilizers.com/panipat_plant.htm


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National Fertilizers Limited was established in August, 1974 to set

up two fuel oil based plants at Bathinda (Punjab) and Panipat

(Haryana). Both of them were commissioned in 1979. The Nangal

Fertilizer plant of Fertilizer Corporation of India (F.C.I) has been

merged with National Fertilizer Limited (NFL) in 1978 on thereorganization of FCI and NFL group of companies. Later, NFL

executed its gas based plant at Vijaypur (Madhya Pradesh) on HBJ

gas pipe line. Vijaypur plant had gone in commercial production

in July, 1988.

The National Fertilizers Limited is now operating three fuel based

plants located at Nangal, Bathinda and Panipat and a gas based

plant at Vijaypur. The of three fuel based plants is 900 TPD of

ammonia, 1000 TPD of urea at Nangal and 1550 TPD of urea at

Bathinda and Panipat. The capacity of gas based plant at Vijaypur

is 700 TPD of Ammonia and 400 TPD of Urea with the addition of

the gas based plant in the family of National Fertilizers Limited,

the Company now occupies the position of largest producer of

nitrogenous fertilizers in the country.

PLANTS AND CAPACITIES

CAPTIVE POWER PLANT 2X15MWH

AMMONIA PLANT 900MT/DAY

UREA PLANT 1550MT/DAY

SULPHUR RECOVERY PLANT 26.5MT/DAY

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STEAM GENERATION PLANT 3X150MT/DAY

COAL HANDLING PLANT 150&250MT/HR

DM WATER PLANT 400MT/HR

RAW WATER PLANT 2400M

Training Report

CAPTIVE POWER PLANT

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Captivepower plant has been installed to meet the total

power requirement of the plant. The turbo generators of

15MW each generate power at 11KV. Power plant can be

run in parallel and in isolation with the grid. Boiler of

210T/hr has been provided to supply stream to turbo

generators. Boiler is designed to operate on coal with

support of oil and or fully on fuel oil.

It was commissioned in 1988 with the basic purpose of

serving Panipat unit independent from HSEB grid so that

performance does not have any adverse effect.

Three main actions of plant are:-

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Steam generation plant

Turbo generator set

Transformer

STEAM GENERATION PLANT

Coal from material handling plant is taken to six bunkers

through conveyer belts. Coal from six bunkers are fed to

3 ball mills through six coal feeder for controlling the flow

of controlling the flow of coal according to the boiler

demand. Each ball mill is connected to two coal feeders

through six coal crusher.

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Major sections of SGP are:- Boiler

Super heater

Economiser

Air preheater

Electrostatic precipitator Forced shaft fans &induced shaft fans

BOILER:

Boiler in the CPP is multi relay RX type from fixed boiler.

Normal capacity of boiler is 210T/hr. Boiler is designed torun on pulverized coal supported by oil. Plant can take

full load on any type of fuel.

SUPER HEATER:

Basic function of super heater is to raise the temperature of steam above

the boiling point of water which increases the overall efficiency of the

plant. It consists of groups made up of several alloy steels such aschromium molybdenum. There are three types of super heaters namely:

radiant, convection, and separately fired. Super heaters increase the

efficiency of the steam engine, and were widely adopted. Steam which

has been superheated is logically known as superheated steam; non-

superheated steam is called saturated steam or wet steam. Super heaters

[8]
http://en.wikipedia.org/wiki/Saturated_steamhttp://en.wikipedia.org/wiki/Saturated_steam


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were applied to steam locomotives in quantity from the early 20th

century, to most steam vehicles, and to stationary steam engines. This

equipment is still an integral part of power generating stations

throughout the world.

ECONOMISER:

It heats the feed water on its way to boiler. It consists of

large number of closely spaced large parallel tubes

connected by the header of the drum. Economizers are

commonly used as part of a heat recovery steam

generator in a combined cycle power plant. A common

application of economizers in steam power plants is to

capture the waste heat from boiler stack gases (flue gas)

and transfer it to the boiler feed water. This raises the

temperature of the boiler feed water thus lowering the

needed energy input, in turn reducing the firing rates to

accomplish the rated boiler output.

AIR PREHEATER:Heat absorbed from flue gas is transferred to incoming

cold air by means of continuously rotating heat transfer

elements of specially formed metal plates. An air

preheater or air heater is a general term to describe

any device designed to heat air before another process

(for example, combustion in a boiler) with the primary

objective of increasing the thermal efficiency of the

process. 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 useful

heat lost in the flue gas.

[9]
http://en.wikipedia.org/wiki/Heat_recovery_steam_generatorhttp://en.wikipedia.org/wiki/Heat_recovery_steam_generatorhttp://en.wikipedia.org/wiki/Combined_cyclehttp://en.wikipedia.org/wiki/Boilerhttp://en.wikipedia.org/wiki/Flue_gashttp://en.wikipedia.org/wiki/Airhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Boilerhttp://en.wikipedia.org/wiki/Flue_gashttp://en.wikipedia.org/wiki/Heat_recovery_steam_generatorhttp://en.wikipedia.org/wiki/Heat_recovery_steam_generatorhttp://en.wikipedia.org/wiki/Combined_cyclehttp://en.wikipedia.org/wiki/Boilerhttp://en.wikipedia.org/wiki/Flue_gashttp://en.wikipedia.org/wiki/Airhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Boilerhttp://en.wikipedia.org/wiki/Flue_gas


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ELECTROSTATIC PRECIPITATOR:

Its basic function is to free the gas from ash and

minimize the pollution. Each ESP has 10 electrodes and

18 plates. 60 KV (DC) is fed by the help of transformer

and rectifier assembly. Following is the process taking

place in the electrostatic precipitator:-

Dust laden flue gases from the boiler passes

between rows of two electrodes.

Neutral gas molecules get ionized due to theprocess of electronic field.

Positively charged ions travel towards emitting

electrodes and negatively charged ions getattached to dust particles.

Dust particles get electrically charged anddeposited on collecting electrodes.

TURBO GENERATOR SET

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Fig. Turbo generator

SPECIFICATION:

NUMBER 2

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OUTPUT 18750KVA,

15MW

RATED POWER FACTOR 0.8

RATED VOLTAGE 11000V

RATED FREQUENCY 50Hz

SPEED 3000RPM

DEGREE OF PROTECTION IP-54

INSULATION CLASS STATOR-F

ROTOR-F

TEMPRATURE STATOR-B

ROTOR-B

EXCITATION CHARACTERISTICS:

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AT NO LOAD I=276A,

V=55V

AT MAXIMUM RATED CURRENT I=580A,

V=163V

AT 125% MAX RATED CURRENT I=672A,

V=189V

EFFICIENCY AT POWER FACTOR 0.8:

100% LOAD 97.53%

75% LOAD 97.25%

50% LOAD 96.49%

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DESCRIPTION

GENERAL:

Three phase alternator set has:-

Totally enclosed self ventilated with two lateral air to

water cooling.

Horizontal shaft

Two enshield sleeve bearing with forced lubrication.

Six stator leads consisting of copper bars arranged

vertically at the bottom frame.

Rated output is given for continuous running at 50 Hz

frequency, power factor 0.8, 36C inlet temperature

of fresh cooling water and altitude above sea level

exceeding 1000m.

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STATOR CONSTRUCTION:

FRAME: The frame has parallelepiped form. It is madeof welded steel and designed to ensure the best

mechanical holding.

CORE: The core is built of low losses electrical sheetlamination insulated in accordance with insulation

process and can be clamped between two plates; thewhole is divided in to elementary stacks separated by

steel insulation which form ventilation canal for cooling of

coil.

STATOR WINDING: Stator wedge consist of identical

coils. The alternator is insulated in accordance with ourepoxy process which is an insulating system based on

mica tape with paper or Dacron support and wrapped in

multiple layer around the coil. After impregnation the

complete stator is subjected to heat treatment that

allows a compact homogeneous supervious insulated

structure to be obtained.

TERMINALS: The six main leads which consist ofcopper strip are arranged vertically at the bottom of

frame.

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SPACE HEATER: One space heater is located at thebase of stator to avoid humidity when the generator is

running.

ROTOR CONSTRUCTION:

SHAFT: Shaft end and rotor bodies are integrally forgedof high mechanical quality steel that has undergone a no.

of tests.

ROTOR WINDING: Wedge is made of cold drawnrectangular of high conductivity. The turns are framed on

mandrel and lead into the slots. The turns are stratified

glass fiber insulation.

RETAINING RING: These are fixed to the rotor body.In this way the shaft end are free to bend without

touching the retaining ring. The rings have great number

of radial holes which permits evacuation of the end

turned air.

VENTILATION: The ventilation system is designed toprovide maximum efficiency and prevents hot spots. The

art is drawn at each end of the generator by the two

helicoidally fans. After cooling the active parts of the

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machine, the air is discharged at the periphery of the

stator core and then in the coolers located on either side

of the frame.

COOLERS:The two air to water coolers are located ineither side of frame. They are formed by the nest of

round cupronickel tubes on which aluminum cooling fins

are fixed.

EXCITERDESCRIPTION: Total enclosed cooled with cold airsupplied by the main generator inverted alternators with

stationery field and rotating armature. It feeds the

generator through a rectifier mounted on shaft

connection between the rectifier bridge and main

generator field are made by hole drilled in shaft.

ROTATING ARMATURE: The lamination cut in onepiece insulated after puncturing. The slots are scrunch on

the rim that has to be keyed on the shaft. The armature

winding is installed in the open slots, secured in position

and connected to the rotatingrectifier bridge.

STATOR: The frame consist of laminated magnetic ringon which the main hole cores are bolted. The field coils

are secured on the hole cores.

RECTIFIER BRIDGE: The rectifier bridges aremounted in GRAETZ Bridge and are two types of cells.

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Each arm of the bridge uses 3 cells in parallel and

elementary rectifier bridge is protected by fuses. The size

of cells and their charge to avoid all the possibility of

overload or over voltage when the alternator is runningin following conditions:-

Three phase fault at the generator terminals.

Over voltage of the network.

None synchronized running.

GENERATOR EXCITATION:-

In both automatic and manual operation with excitation

by taping the generator must be started until a voltage of

0.1Un is reached. The stator is cut off by a voltage

threshold relay which they release the controller. In

automatic operation the generator is excited so that

rated voltage is reached immediately a variation of du

being then possible by external control.

OVERLOADING:-

When load current increases, generator speeddecreases, now reading increases.

Signal sent to control panel from where it is sent to

governing valve that in turn governs the steam inflow of the turbine.

Valve opens accordingly and steam in flowincreases.

Collaterally, now reading goes to neutral.

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DE-EXCITATION:

Whether manual or following activation of a protectiondevice, de-excitation occurs after the coupling circuit

breaker has opened following the rapid cut off of the

excitation current, the transformer/thruster set will

operate as inverter. On a de-excitation order, thruster

clock pulses are locked in the minimum position (inverter

mode) excitation contactor being then de-energized.

GENERATOR PROTECTION:

1. FREQUENCY RELAY

Solid state frequency relay with high accuracy and

stability are used:-

(a) For splitting up a grid system openingtransmission lines to prevent complete systemcollapse.

(b) For isolating small systems having their owngeneration from the main system.

(c) For the protection of generators and auxiliarywhere frequency suppression can avoid damage toturbines and auxiliary drives.

2. ACTIVE OR REACTIVE POWER RELAYS

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The WTG 7100 relays have been developed in order to

provide a static solution to the various problems of

protection requiring real measure of active power (as

well as energy flow direction supervision), a solutionoffering the following advantage:-

Unbalanced power in case of 3-wire,3-phase

networks, measured by two wattmeter method.

Great directional stability.

Active power relay is totally unaffected by current

and voltage harmonics.

Operating threshold continuously adjustable.

Low burden on current and voltage transformer.

3. OVER CURRENT PROTECTION RELAY

The ITG relay of the 7200, 7300, 7400 series provides a

complete range of phase or earth fault protection relays

inverse time extremely inverse time type with or without

instantaneous high set units. The ITG relay of the 7200,

7300, 7400 series have specifically designed or the

protection of the networks and substations against faultbetween phases or from phase to earth.

4. ALTERNATOR LOSS OF FIELD PROTECTION

RELAY

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The YTM 7111 is an admittance relay, specifically

designed for the detection by using the electrical

quantities available in its stator circuit of the loss of field

of an alternator connected to a network. To perform thisdetection, the relay is supplied from two phase circuit

and corresponding phase to phase voltage.

If the field current of alternator is interrupted either

by a short circuit or by accidental opening of the rotor

circuit, after a short period the machine will loose

synchronism. The rotor will accelerate slighter and the

alternator will operate as asynchronous generatorcontinuing to supply active power required for its

magnetization from the network to which it is connected.

The rotor motor may go above nominal due to

reactive power absorbed and low frequency currents are

induced in the damper winding and on rotor surface

causing abnormal heating of the later if asynchronous

operation continuous for too long period.

5. ROTOR EARTH FAULT RELAY

The first fault should however be first eliminated without

delay, because it allowed to remain a second fault of the

same type that would immediately put the machine out

of service and could cause very serious damage to rotor.

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The object of TTE 7015 and TTE 7017 is to detect

immediately any fault on the rotor winding of a

synchronous machine in order to give an alarm and if

required to separate the machine from network.

TRANSFORMER

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RATING

MVA 31.25/24

FREQUENCY 50 Hz

TYPE OF COOLING ONAF/ONAN

VOLTAGE AT NO LOAD

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H.V. 132KV

(STAR)

L.V. 11KV

(STAR)

T.V. 6.6KV

(DELTA)

NORMAL AMPERES AT 31.5 MVA BASE

H.V. 137.8

A

L.V. 1653.3

A

INSULATION LEVEL

H.V.

650KVP

L.V.

75KVP

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H.V.NEUTRAL

95KVP

DESCRIPTION OF TRANSFORMER

GENERAL:

The transformer is oil immersed with double rating of

31.5 MVA and 24 MVA under oil natural air forced and oil

natural air natural type of cooling respectively. The

transformer is the most convenient and economical

device for transfer of power from one voltage to another

voltage(low or high) at the same frequency. It works on

the principle of electromagnetic induction. There is

hardly any installation without a transformer. Due to thisequipment, it has been possible to transmit bulk power to

load centers from far off power houses and to various

machineries and switchgears of the power plant.

Transformers are of two types:-

STEP-UP TRANSFORMER: The transformer which

steps up the voltage at the secondary side is calledstep-up transformer.

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STEP-DOWN TRANSFORMER: The transformerwhich step down the voltage at secondary side arecalled step-down transformer.

MAIN PARTS OF POWER TRANSFORMER:

Primary winding

Secondary winding

Oil tank

Conservator

Breather

Explosion vent

Temperature gauge

Tap changer

Tubes for cooling

Transformer oil

Earth point

Primary terminals

Secondary terminals

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ACCESSORIES OF TRANSFORMER

1.OIL CONSERVATOR:

Oil conservator is a short of drum mounted on the top of

transformer. A level indicator is fixed to it, which gives

alarm at low level. Conservator is connected through a

pipe to the transformer tank containing oil. This oil

expands or contracts depending upon the heat produced

and so the oil level in conservator is left open to theatmosphere through the breather so that the extra air

may go out or come in.

2. BREATHER:

The breather is a box containing calcium chloride or

silica gel to absorb moisture that entering theconservator. Silica gel is having a property absorbing the

moisture or humidity, so it is used as breather. It is well

known fact that the insulating property of the

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transformers oil is lost if a small amount of moisture

enter in it, so dry air is passed through the breather.

3. EXPLOSION VENT:

It is also a safety device of the transformer which

protects the transformer tank from gases induced by and

any type of short circuit in the transformer. This consists

of a vertical pipe closed by diaphragm made of thin

Bakelite sheet. This diaphragm bursts or slides out in

case of abnormal pressure inside the tank.

4. TEMPRATURE INDICATOR:

It is also a protective device fitted to the transformer to

indicate temperature of transformer oil. For measuring

temperature of the oil, bulb of the vapour pressure type

thermometer is placed in the hot oil and dial of the

thermometer is mounted outside the tank. Two indicating

pointers black and red are provided. Alarm contacts are

also provided which come into action when

predetermined permissible higher temperature is

reached under abnormal operating conditions.

Temperature indicator indicates the temperature of both

i.e. the winding temperature as well as of oil

temperature.

5. BUSHINGS:

The bushing serves as supports and insulation of the bus

bars and transformer terminal. The bushing consist of

porcelain shell body, upper and lower locating washer

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used for fixing the position of bush bar and mounting

flange with the hole drilled for fixing bolt and it is

supplied with an earthing bolt.

Fig. Bushing

7. MAGNETIC OIL GAUGE:

The magnetic oil gauge supervises the level of oil in the

conservator tank. The oil level gauge is provided on the

transformer are of dial type with minimum and maximum

level marking and pointer which indicate the level of oilin the conservator. Sometimes the scale is also

graduated for oil temperature on the basis of its level

8. TAP CHANGER:

The voltage control of transmission and distributionsystem is obtained by tap changer. Tap changer are

either on load or off load tap changer. Tap changer is

fitted with transformer for adjusting secondary voltage.

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The voltage control of the range of 16% can be

achieved by tap changing transformers.

MAIN RECEIVING SUBSTATION

Total factory load is around 23.5 MW, 2 lines from HSEB

(Haryana State Electricity Board) and 2 lines from CPP

are taken to receiving towers with the help of insulator

arrangement. For the protection of switchyard, shielding

wires are also provided on receiving towers. 3

transformers step down 132KV to 11KV.

Normally 3 kinds of supply are available:

NORMAL SUPPLY :

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It is given by generator and grid. Supply levels of

132KV, 11KV, 3.3KV and 415V are available.

EMERGANCY SUPPLY :

It gets operated when there is failure of normal supply.

It is given from DG set. Generally it comes in act after

2 minutes of failure of normal supply.

CRITICAL SUPPLY :

It gives to those motor operated valves, whose non

functioning could result in blockage of pipelinescarrying poisonous gases which could lead to serious

accidents.

The protective equipments present in 132KV

switchyard are:-

LIGHTNING ARRESTOR:

They are used to protect the electrical system againstdirect lightning strokes. It conducts the high voltagesurges on the power system to the ground. Eachlightning arrestor is connected in parallel to one phasewire.

ISOLATOR:

Isolator opens a circuit under no load. The main purposeof an isolator is to isolate one portion of circuit from otherand is not intended to open while current is flowing in the

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line. They are used in both sides of the circuit breaker inorder that repair work can be performed on circuitbreaker without any damage.

CIRCUIT BREAKER:It can open a circuit under any condition i.e. under loadas well as no load conditions. It is so designed that it canbe operated manually under normal condition andautomatically under faulty condition with the help of therelay circuit. They are used to open circuit or break thecircuit. Minimum Oil Circuit Breaker (MOCB) are used inthe switchyard.

CURRENT TRANSFORMER:

They are used to measure the current flowing in thesystem. They are connected in series with each phasewire. In case of overcurrent they operate a relay which inturn disconnects all the links to faulty area.

POTENTIAL TRANSFORMER:

They are used to measure the voltage through thesystem. They are also connected in parallel to eachphase wire, in case of overvoltage they operate acorresponding relay which in turn send signal todisconnect link to the faulty area.

RATING OF SYNCHRONOUS GENERATOR AT

CPP

OUTPUT

18750KVA

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VOLTAGE

11000V

CURRENT 984A

R.P.M. 3000

P.F. 0.8

EXCITATION VOLTAGE 163V

EXCITATION CURRENT 580A

RATING OF DIFFERENT THREE PHASE

INDUCTION MOTORS INSTALLED AT CPP

1. ASH HANDLING MOTOR

VOLTAGE 3300V

KW 180

RPM 1486

PF 0.82

FREQUENCY 50 Hz

INSULATION CLASS F

2. ASH WATER PUMP-A

VOLTAGE 3300V

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KW 250

RPM 1488

FREQUNCY 50 HzP.F. 0.86

IP 55

HP 340

INSULATION CLASS B

3. ASH WATER PUMP

VOLTAGE 3300V

KW 200V

RPM 1486

CURRENT 45A

HP 270

INSULATION CLASS F

Bibliography

From Daily Dairy

From engineeringfundamentals.com

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From electric M\c by J.B Gupta.

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