ptps project 1(1)

7/28/2019 PTPS Project 1(1)

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INTRODUCTION

1.1 THERMAL POWER STATION:-

A generating station which converts heat energy of coal

combustion into electrical energy is known as thermal power station.

A steam power station basically works on the RANKINECYCLE. Steam is produced in the boiler by utilizing the heat of coal combustion. The steam is then expanded in the prime mover (i.e., steam turbine) and is condensed in condenser to be fed in tothe boiler again. The steam turbine drives the alternator whichconverts mechanical energy of turbine into electrical energy.

1.2 POWER TO PROGRESS:-

Energy provides the power to progress. The naturalresources of a country may be large but they can be turned intowealth if they are developed, used and exchanged for the other goods. This cannot be achieved without energy. Availability of

available energy and its proper use in any country can result in its people rising from substantial level to the highest standard of living.

It has been found that countries whose national output ismainly agricultural and whose population lives mostly in ruralcommunities enjoy low per capita growth of energy consumption.Another factor on which the growth of energy consumption isdependent is the extent to which industrial activity forms a part of gross domestic product. As a country develops, the pattern of itsenergy usage undergoes a distinct change. Once energy is madeavailable in excess of domestic needs, it has been found that it is notused solely as a consumer good but becomes a factor of growth.

1.3 DEMAND OF ELECTRICITY:-1


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A large proportion of energy is being met all over theworld by electricity. This trend will further be stimulated because of increasing availability of clean electricity. This applies especially todeveloping countries because their industrial progress is based onmodern technologies, which require electricity.

1.4 ESTABLISHMENT OF POWER PLANT:-

To meet the above mentioned demand of electricity; BADARPUR THERMAL POWER STATION wasestablished in 1975 by GOVERNMENT OF INDIA. It has aninstalled capacity of 720 MW with a derated capacity of 705 MW.The water source for this plant is agra canal. It has 3 units of 95MW and 2 units of 210 MW. The first 3 units of 95 MW werecommissioned on july 1973, august 1974 and march 1975respectively. Later on 2 units of 210 MW were commissioned onDecember 1978 and December 1981. Ownership of BTPS wastransferred to NTPC with effect from 01.06.2006 through GOIsGazette notification.

1.5 CLIMATIC CONDITIONS:-

The site is situated in the zone of humid climate. Someimportant meteorological data are:

Maximum ambient temperature is 46 C.

Average annual wet bulb temp. is 23.2 C.

Maximum humidity is 87%.

Average annual rainfall is 50 inches.

Mostly the wind direction is western and north western.

1.6 COMMON FACILITIES:-2


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(8) Ash fusion temp. = 1350 C

SALIENT DATA

MAIN GENERATOR

MAIN TURBINE DATA

4

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 V

Rated 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)


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BHEL UNITS

Boilers

Manufacturer/Supplier BHEL Teruchirapalli, Tamil NaduRadiant drum water type, Dry bottom,

Pulverized Coal fired boilers.

Rated output 380 tonnes/hr.

Working pressure 139 atm.

Feed water temp. - 240CSuperheated steam temp. - 540C 5C

Steam turbineManufacturer BHEL, Hyderabad

Type - Three casing, condensing steam with reheating5

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 to receptor 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 inton/hour

68,645,652,662

3.Rated pressure at exhaust of LP turbinein mm of Hg

19.9,55.5,65.4,67.7


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Rated speed 3000 rpm

Rated steam temp. - 535C

Rated cooling water temp. - 30C

Manufacture by Bharat heavy electrical Limited (BHEL)

Rating of 95 MW Generator

Capacity - 117500 KVAVoltage - 10500V

Speed - 3000 rpmHydrogen - 2.5 Kg/cm2Power factor - 0.85 (lagging)Stator current - 6475 AFrequency - 50 HzStator wdg connection - 3 phase

Rating of 210 MW Generator

Capacity - 247000 KVAVoltage (stator) - 15750 VCurrent (stator) - 9050 AVoltage (rotor) - 310 VCurrent (rotor) - 2600 VSpeed - 3000 rpmPower factor - 0.85Frequency - 50 HzHydrogen - 3.5 Kg/cm2Stator wdg connection - 3 phase star connectionInsulation class - B

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IN the thermal power plant steam is the first necessarysource to generate the Electricity. Equipment used for the

production of steam is boiler. In boiler water is heated up to certaintemperature to get steam. Steam thus generated by boiler passesthrough super heaters, and from there to turbine, it again sent in tothe boiler in case of re-heater boiler

BOILER DISTRIBUTION AT B.T.P.S:-

PART I

RUSSIAN UNIT

PHASE I PHASE II

For 50 MW units For 100 MW units

Unit number 1 4 Unit number 5 & 6

4 x 1=4 boiler 2 x 1=2 boilers

One boiler for each Two boilers for each

50 MW units 100 MW units

Total number of boilers in Russian unit = 8

PART II

INDIAN UNIT

For 110 MW units

Unit number 7 107


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4 x 1 = 4 boilers

One boiler for each 110 MW units

Total number of boilers in Indian unit = 4

MAIN PARTS OF BOILER

1. BOILER DRUM:-It is stock of water which is situated at the top of the

furnace. The shape of the boiler is spherical and dimensionsused in P.T.P.S are:-

Length : 15000 mm

Diameter : 1800 mm

Capacity of drum : 70 tonnes/hr.

Thickness : 97 mm

(1) WATER WALLS:- Inside the furnace there is a large number of verticaltubes for the production of steam. All the tubes are connectedwith bottom header by which water is filled inside the tubeand very nearer to each other when water is heated, steam iscollected in the upper part of the tubes and through the upper header steam is ejected.

(3) FURNACE CHAMBER: -Furnace chamber is a closedvessel inside the chamber fire bents. There is provision for entry

of coal oil through the pipes inside the chamber for burning.(4) ECONOMISER: -Economizer is used to preheat the feedwater. The furnace chamber economizer is situated in the way of exhaust flue gases. When flue gases pass through that area, theeconomizer is also heated which in turn heats the feed water flowing through it.

(5) AIR PREHEATER: -Air pre-heater is an equipment used for 8


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heating the passing air before reaching the boiler furnace.

(6) SUPER HEATER: -By the super heaters, we getsuperheated steam with very high temperatures.Superheaters are placed in the boiler before the steam inlet

into the turbine.

(7)BURNERS: -Burners are used for firing into the furnacechamber.

(8)REHEATERS: -Reheaters are used to raise the temperatureof steam. Reheaters are connected into the furnace chamber.Through reheater, the steam pipe is injected and after passingsteam, temperature of steam is raised.

AUXILARIES:-

1. P.A FAN (Primary Air Fan):- It is used for carrying pulverized coal dust from p.c.feeder. Two primary fans areused for each unit at P.T.P.S.

2. CYCLONE SEPARATOR: -It is connected with the

ceiling inside the furnace. Inside the cyclone separator, themoisture of steam and water be massed and throughseparator steam be taken with steam raise.

3. INDUCED DRAUGHT FAN: -Induced draught fan is usedfor evacuating flue gases through the chimney.

4. FORCED DRAUGHT FAN: -Forced draught fan is used

for the supply of air inside the furnace for burning.5. CONDENSATE PUMP: -It is used for pumping the hot

condensate back to the boiler.

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6. BOILER FEED PUMP: -It is used for water supply to the boiler. In P.T.P.S, 2 feed pumps are used (One is reservedand the other is working).

7. CIRCULATING WATER PUMP: -By the use of

circulating water pump, we pass the cold water which isused to cool the hydrogen gas present in the turbine.

8. COAL FEEDERS:- It is used for feeding the pulverizedcoal inside the furnace. In P.T.P.S, three coal feeder fansare used for each unit.

Capacity = 27 tonnes/hr.

BOILER SPECIFICATIONS:-

1. FOR 50 MW UNITS:-

Rated output 220 tonnes/hr.

Working pressure in boiler drum 115 atm.Working pressure at main valve outlet 100 atm.

Feed water temperature - 215C

Superheated steam temperature - 540C

Place of boiler- 32 m

2. FOR 110 MW UNITS:-Rated output 375 tonnes /hr.

Working pressure in boiler drum 146kg/m2

Working pressure at main valve outlet 139 atm.10


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Feed water temperature - 240C (after HPH 1)

Superheated steam temperature - 540C

Place of boiler- 40 m

OTHER DIMENSIONS:-

1. Internal dimension of furnace chamber 7160 X 9792 mm2. Water tube dimensions Dia. 60 X 5 mm3. Internal diameter of boiler drum 1600 mm, pitch 64 mm

4. Diameter of furnace chamber 8.26 m

Tubes made of steel sheets of 22k grade, 89 mm thickness.

TYPES OF SUPERHEATERS USED:-

1. Ceiling super heater I2. Ceiling super heater II3. Platen super heater 4. Convective super heater I5. Convective super heater II6. Wall super heater 7. Aux. Injector 5

TUBE LEAKAGE PROBLEMS:-

It is the main problem in the boiler arising due to the followingfactors:-

1. High temperature inside the furnace.2. Chocking due to salt accumulation.3. High slaging factor.

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4. Furnace explosion.5. Furnace draft high/low

Nos. of equipment in each boiler:-

1. ID fans 2 Nos.

2. FD fans 2 Nos.

3. P.A. fans 2 Nos.

4. Ball mills 3 Nos.

5. Vapour fans 3 Nos.

6. P.C. feeders 16 Nos.

7. R.C. feeders 3 Nos.

8. Slag crusher 4 Nos.

INTERLOCK AND PROTECTION OF BOILER

Boiler will trip off :-

1. Both FD fans trip

2. Furnace draft reaches 40 mm wc

3. Boiler drum high level (+ 200 mm)

4. Boiler drum level low (- 200 mm)5. Both ID fans trip

6. If turbine trips

7. If generator trips

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Boiler should be tripped off:-

1. If all PC feeders trip

2. If both PA fans trip

3. If there is no fire in furnace

Fig 1:- External view of Fig 2: Internal view of

( BOILER) ( BOILER)

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STEAM TURBINE ( RUSSIAN & INDIAN UNIT )

The 110 MW condensing steam turbine is designeddirectly coupling with Hydrogen cooled generator. The steamturbine is designated for operation with live steam at 36 kg. pressureand 535-540C temperature as measured before the entry into theturbine emergency stop valve. The steam turbine has three cylinder mixed blades with a wheel as the governing stage and so pressurestage. The turbine is divided into three parts:-

1. H.P High pressure2. M.P Medium pressure3. L.P Low pressureAfter each pressure section in the steam turbine, bearings areconnected. Due to this movement of the rotor, the turbine is easy tooperate.

PRINCIPLE:- There are two parts of a turbine:-

1. Stator part2. Rotor part

The blades of the turbine make some angle with the shaft.Due to injection of steam, rotor is rotating and a generator is directlycoupled with the steam turbine shaft. Rotational energy of the

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turbine shaft is directly transferred to the rotor of generator and after rotation, electricity is produced in P.T.P.S.

WORKING:-

At the starting position, steam is firstly injected in themedium pressure cylinder of the turbine. Before this operation, bythe bearing gear, we give some rotation (approx. 63 rpm), which isoperated electrically. Due to injection we raise the speed of turbinerotor blades up to 500 rpm. After this operation, main steam linestop valve is opened which is operated at the H.P. Cylinder, side,after rotation, the steam pressure is constant but temperaturedecreases. So again the extracted is sent to boiler for reheatingsteam and is in to M.P. Cylinder. Before again injecting after thisoperation, steam is injected to L.P. cylinder section.

Turbine is flexible one with having following criticalspeed

H.P. turbine- 2355rpm

M.P. turbine- 1900-2200rpm

L.P. turbine- 1900-2200rpm

STEAM EXTRACTION:-

The steam turbine has five outlet steam extraction pipefor the extraction of steam. Pipes are insulated with thermosettingmaterials. For feed water heating up to 218C in L.P. heater, steamup to 25 tonnes/hr. is extracted from 1 st, 2nd and 3 rd extraction line.Besides steam up to 7 tonnes/hr. is used for heating up deaerator from 2 nd or 3 rd extraction line steam pipes.

110 BHEL UNITS

BASIC PARAMETERS:-

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1. Rated output measured at the terminals for the generator as

Per cms. 080030-110 MW

2. Economical output = 95 MW

3. Rated speed = 3000 rpm4. Rate pressure of steam just before stop valve = 130 atm.

5. Rated temperature of steam just before stop valve = 535C

6. Max. pressure of steam just before the stop valve = 146 atm.

7. Max. temp. of steam just before the stop valve = 545C

8. Rated pressure before medium pressure casing = 27.4 atm.

9. Rated temp. before medium pressure casing = 535C

10. Max. pressure before M.P casing = 35 atm.

11. Max. temp. before M.P casing = 545C

SYSTEM OF THE TURBINE (110 MW)

a) 4 control valve + 2 interceptor valves

b) H.P. cylinder:-2 rows of curtis wheel + 8 action wheel

c) Medium pressure cylinder:-2 action wheels.

d) Weight of M.P. cylinder:-11000 kg. (approx.)

e) Low pressure cylinder:-4 action wheel of double flow

directionf) Weight of low pressure cylinder:-24000 kg.

g) Looking from the front the front bearing pedestal: - clockwise

h) Rotors rotate at 62 rpm on bearing gears.

i) Number of non-regulated extractions = 816


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GOVERNING

REGULATING AND SAFETY EQUIPMENT OF THETURBINE

The quantity of steam entering the turbine is regulated bymeans of four governing valves (GV) on the inlet to the H.P part an

by two interceptor valves (IV) on the M.P part. The amount of opening at any instant of these valves is given by the pressure of secondary oil, which is indirectly dependent on the primary oil

pressure and directly dependent upon the spring force in thetransformer. The pressure of the primary oil is directly dependentupon the speed of the set through the speed-sensing element. Thetension of the spring in the transformer can be varied by the speedchanger and by that it is possible to vary the speed beforesynchronizing and to vary the load after synchronizing the alternator of the grid.

The non-uniformity of the regulation can be changedcontinuously in the range of 3 to 5.5% by the means of non-uniformly changer (NUC) and by that the proportion of change of output of the set can be influenced with respect to the other machines connected to the common grid when there is a change onloading on grid.

INTERLOCK & PROTECTION OF TURBINE:-

Turbine will trip automatically if:-

1. Condenser vacuum drops to(-)0.5 kg/cm2

2. Control oil pressure drops to 7.0 kg/cm 2

3. Lub. Oil pressure drops to 0.08 kg/cm 2

4. Axial shift becomes 0.065mm

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5. Primary oil pressure becomes 3.05 kg/ cm 2

6. If boiler trips

7. If generator trips

Turbine should be tripped if:-

a. There is sudden increase of high vibration or some metallicsound

b. Sudden entering of water in turbine resulting cooling of someturbine parts

c. Return bearing oil temperature reaches 70C

d. Temperature of bearing Babbitt metal reaches 85 C

e. If all condensate pumps trip

f. If all C.W. pumps trip

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INTRODUCTION:-Alternators (A.C generator) are also known as synchronousgenerator. Its main function is to convert mechanical power from a

prime mover to electric power at a specific voltage and frequency.Large generators are used to generate bulk power at thermal,hydroelectric and nuclear power stations.

A. STATOR:- Stationary part, comes the armature winding inwhich voltage is generated i.e. output is taken from stator.

YOKE (frame): Cast iron for small machine and welded steel for large machine.

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CORE: Assembled with high grade silicon content steel laminationto reduce iron losses.

STATOR WINDING: A 3-phase winding puts in the slot in star connection.

B. ROTOR:-

*salient pole rotor *cylindrical rotor

Rotor is a rotating part, which produces the main field flux in whichsupply is given through d.c. Generator is excited. In PTPScylindrical rotor is used.

1. Slots are at regular intervals & parallel to the shaft on whichd.c. field winding occurs2. Rotor is smoother machine, makes less winding losses & the

operation is less noisy (due to uniform air gap).3. Cylindrical rotor is two or four pole type alternator, which

provides greater mechanical strength & permits more accurate balancing.

4. It is driven by steam or gas turbine i.e. turbo generator or turbo.

D.C.EXCITER:- Excitation means production of flux by passingcurrent in the field winding (rotor) from d.c. generator. As a rotor has no more residual magnetism, so first of all to make itelectromagnetic i.e. dc is supplied to the rotor through brushes andslip ring. Brushes excite in which to eliminate the use of brushes &slip ring.

PRINCIPLE-VOLTAGE GENERATION:- A prime mover (machine) supplies the mechanical energy input to the alternator i.esteam gas turbine-turbine. Actually, armature conductor on thestator, the field flux the armature conductors, voltage is generated.

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AVR(Automatic Voltage Regulated):-

It controls the system voltage with alternators.If any fault in the system-to increase the excitation for maximumsynchronizing.To prevent, if sudden loss of load on the system i.e. (EVR-Electronic Voltage Regulator).

Scheme Diagram:-

Automatic Voltage Regulator

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AVR

Exciter

FB

SB

FWR


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DC Generator

Field Breaker

Slip Ring Brushes

Alternator

FWR=Field winding of rotor

SYNCHRONISM CASE:-

i. Frequency- supply frequency & grid frequency should bematched

ii. Voltage- generated voltage & that voltage should be matched

iii. Phase sequence- matching phase sequence(i.e positive phasesequence) it should be at 60deg. either lagging or leading.

PROTECTION(ELECTRICAL):-

I. Negative phase sequence relayII. Phase to phase fault.

III. Phase to earth.IV. A) over fluxing B) over current C) over load & over balanced load

V. Loss of excitation under power.VI. Anti-motoring (Failure of Prime Mover).

MOTORING :-

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i. Prime Mover

ii. AVR

iii. Generator Breaker.

INUCTION MOTOR:- If Prime Mover & remaining three willfunction.

1. Prime mover(turbine fails)- trip

2. Excitation-zero(field breaker trip)

3. Generator breaker ON

Then the Generator will act as Induction motor. In case asmotoring.

SYNCHRONOUS MOTOR:- Only generator beaker fails &remaining three is function.

A. Prime mover(turbine fails)- trip

B. Excitation-zero(field breaker trip)

C. Generator breaker ON

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Transformer is a static device, which transfers electrical power fromone circuit to another circuit at constant power and frequency.

There are two types of transformer:-

1. Step up transformer-low voltage to high voltage

2. Step down transformer- high voltage to low voltage

There are mainly two parts of transformer :-

1. External parts

2. Internal parts

OBSERVATION:-

TRANSFORMER

a)Parts b)interconnection c)Damage d)Protectione)Application

Internal External

A)Internal parts:-

i. Coil(winding)

ii. Core(silicon steel sheet)

iii. Oil(mineral oil/porcelain oil)i. Coil:-In the power transformer there are two types of

winding(wire)

a. Round winding:-For small transformer

b. Flatted winding:-(copper) for large transformer 24


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In the winding there are two types of connection:-

Star connected secondary side

Delta connection primary side

In actual winding are:-Single winding- Auto transformer

Double winding- Double magnetic circuits

Three winding- Three phase transformer

ii.Core:-

It is made of silicon steel sheet laminated with insulation(mica, porcelain oil etc,)

iv.Oil:-

In the transformer mineral oil is filled in the oil tank. Its mainfunction

Cooling of winding due to movement of oil

Insulating

B).EXTERNAL PARTS:-

i. Oil tanker (trans, body)

ii. Conservator

iii. Radiator (oil pump fan)

iv. Breather (lungs)

v. Explosion vent or PRV (pressure release valve)

vi. Tap changer

vii. Bushing (LV, HV, MV)25


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viii. Bucholze relay

ix. Thermo signalizer

x. CT & PT

xi. Aux. Transformer xii. Earthing bus bar

i) Oil tanker:- Body of the transformer (ferro-magnetic material) inwhich mineral oil is filled up.

ii) Conservator:- Conservator is cylindrical hollow tank & it isconnected with transformer body. It acts on oil reservoir to maintain

the level of oil in the transformer. When it is on LOAD and NOLOAD in either case.

iii) Radiator:- Radiator is used for natural cooling of oil. For coupling of radiator internal fan and oil pump is used to circulatesthe oil & distribution in different section of radiator to keep cool.

iv) Breather:- It is connected to conservator. Its main function is to

remove moisture in air ingress through pump. Oil layer is goes up &down during this incident making a chance of introduction moistureair in oil, which is harmful to insulator & transformer oil (Acidic). Itcontains silica gel.

v) Explosion vent (Whistle):- It is connected over the transformer,it forms high gas. If it gets no way to exit, it will come out withexplosion i.e., to gets blast and break the Bakelite foil, it has

diaphragm made up of Bakelite foil or aluminium foil.

Nowadays instead of explosion vent, PRV (pressurerelease valve) is used i.e. to release gas as pressure increases.

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vi) Tap changer:- Tap changer is connected to secondary windingtransformer. It contains no. of contact points (winding) of differentvoltage and operated manually.

In the P.T.P.S. 9, 5, 17 steps tap changer are used to

maintain the voltage level of transformer. Tap changer may work indifferent modes i.e. on load, off load & auto load.

vii) Bushing:- Bushing is a type of insulator situated at the top of transformer body. Its main function is to introduce flux or electricalconnection from power transformer to switch yard.

VIII) Bucholze Relay:- It is a gas detector relay used to protect

transformer from minor fault and heavy fault. Any types of fault or short circuited or sudden damage in insulator, oil of the tank getsover heated and gases formed it is connected.

It is used for alarm. The up $ down in oil level disturbsthe equilibrium of the gas flouts no mercury will come in firstcontact and a signal arrived in the control room either an alarm or aglowing bulb.

Further it large volume of gas generated againequilibrium will disturb will disturb and mercury comes in secondcontact i.e. closed and transformer will trip.

IX) Thermo Signalizer:- It is used for measuring temperature. Itcontains

Steam :- methyl chloride gas is filled.

Capillary tube :- It is covered by PVC. In capillary tube methylchloride gas also filled it is made of copper. It has combination of four small size bulbs. Its and needle pointers, when tempt willincrease contact their no signalizer make contact at 65 C andtripped the transformer.

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In the upper piping of the transformer. The ups and down in theoil level due to formation of gas. Disturbs the mercury equilibriumin the relay and the 1 st enunciation (alarm) comes.

X) CT and PT:- both are instruments. CT are used to measure

current at rated voltage. It is used in switched yard. For one phaseone CT is used. It is also used as protective device.

PT is used to measure voltage at rated current. It is used in plantnear the connection and generator and bus bar i.e. situated at bus

bar.

XI) Auxiliary Transformer:- Two aux. transformer of rating

(7.5MVA) are connected to provide power supply in unit.XII) Earth (Grounding):- Two purpose of earth

a) To earth, electrical leakage goes to ground (zero potential) otherwise current will conduct in all body of transformer and a chance shock.

b) Helps in phase test.

XIII) Bus bar:- it is solid material made of copper. It is aluminumsize 10mm (large for HV). It helps in connecting switches and other equipment of power transmission.

# Main bus bar measuring instrument, relay etc. associatedwith it.

# Transfer bus (aux.bus) used for connecting feeder or

equipment (selector or transfer switch)

b) Interconnection:- Star connection (secondary side)

Delta connection (primary side)

c) Damage :-

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1) Due to movement in oil it will be heated and damage theinsulating material.

2) Up & Down in oil level in the conservator, a moisture air isintroduced and makes oil acidic.

d) Protection:-

1) Winding should be insulated.

2) Cooling of winding is necessary.

3) Output should be taken with help of bushing.

4) Earth is necessary otherwise shocked.

5) Fan & oil pump is used to keep cool radiator.

6) Foil in diaphragm is of bakelite (should be blasted)

e) Application:-

c) Use in communication and electronic system (Transformer will amplifier)

d) Generator transformer used in plant.

e) Distribution of transformer used for industrial used.

f) To match source and load for maximum power transfer.

Rating of transformer

No load voltage (hv) - 229 KVNo load Voltage (lv) -10.5 KVLine current (hv) - 315.2 ALine current (lv) - 873.2 ATemp rise - 45 CelsiusOil quantity -40180 litWeight of oil -34985 Kg

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Total weight - 147725 KgCore & winding - 84325 KgPhase - 3Frequency - 50 Hz

Fig 5: Transformer 60 MVA

The main function of the switch yard is :-

It makes available the generator power at plant to the people.

Power generated transmitted via switch-yard

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To protect the plant due to sudden damage happening

Outside the plant Switch yard scheme (in PTPS)

1 to 10 units PTPS 132KV Hatia

1 to 4-50 MW HatiaRussian

5 to 6-10 MW PTPS220KV hatia-1

7 to 10-110MW- Indian (BHEL) ..Hatia-2

PTPS (Outgoing feeders)

P.T.P.S (OUTGOING FEEDER)

1. a) 132KV Ramgarh (D.V.C) 5C

b) 132KV BASL (jindal) 6C

2. a) 132KV Hatia-I grid 8C

b) 132KV Hatia-I grid 9C

(Line Hatia-1)

3. a) 220KV Hatia-1 grid 1b

(Line Hatia-1)

b) 220KV Hatia-1 grid 2b

4. 400KV TTPS (TVNL) P.T.P.S

In the PTPS switch yard the main equipment ininstalled are

As.

LA Lighting arrester

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CT Current transformer

PT Potential transformer

Autotransformer

Insulator Bus

Bushing

Wave trap

1) Lighting arrester (LA):-

As overload voltage is enclosed transmission linedue to

Lightening, so the main function of LA is to divert theincoming

High voltage for round i.e., earthed this HV , the HV is due tolashing thundering sky.

2) CT:-

It is the protective device, which measures the current atrated voltage.

It has one turn of primary winding i.e., the conductor of the

Ckt. It self formed the primary of the CT.

Rating of CT is very small i.e. 15VA and more exists to30VA. the heavy current is used to be measured without breakingthe ckt.with the help of CT.

Few data of CT used at PTPS:-

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Turn ratio 1200/1 A

Frequency 50Hz

Voltage 240KV

Capacity 26.4KVA3) PT (Potential Transformer):-

It is also protective device used to measure thevoltage.

Used for voltages above 380V .

It has more turns is primary and less turns in secondary sothat potential is reduced to measure the voltage by using lowcapacity volt meter.

Each phase of the system has different PT

one such data of PT at P.T.P.S:-

Rated Burden 400/600VA

Voltage ratio 220KV/110V (measurement)

4) Auto Transformer:-

a) There are two auto transformer used in switch yard

(Auto T1, AutoT2)

b) Main function it primary side generation is low and demand

on secondary is high . then autotransformer will maintainfrom other side generation with no loss of power and vice-versa. Rating- 150MVA ,120MW

5) Circuit Breaker:- there are four types of CB in PTPS

a) OCB (Oil Circuit Breaker)33


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b) VCB (Vacuum Circuit Breaker)

c) ABCD(Air Blast ckt Breaker)

d) SF6(Sulfur hexa fluoride gas ckt Breaker)

CB is the protective device act as switch but the maindifference between breaker and switch, switch having noany protection i.e. manually on/off but in case of CB ithas a protection device like Relay.

FUNCTIONS:-

To make &break the normal operating current.

To open & closed on load.

PRINCIPAL:-

It has coils namely closing coal and tripping coal andspring charging mechanism which may either be charged by motor (spring charging motor) or manually by manual operating handle.

By charging closing coil (Electrical supply in given tocoil), the breaker may be mode ON by local/remote switchsimilarly by emerging tripping coil (Electric supply given to coil)we may make the breaker OFF by local/remote switch or the

breaker may trip on Protection such as earth fault/over current in thetransmission line by itself.

Current coil made up of copper.

SF6-SF gas is used to burn off the spark.

ABCD Air used to burn off arc extinguisher.

OBC Oil used to burn off the sparking ,takes place due to

heating Oil .

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6) Isolator :- It is a disconnection switch and to be operated onload not (When circuit break closed position). It is necessaryto facilitate manual work on transmission line &circuit

breaker.

7) BUS:- Bus is a system , with help in transmission of voltageas per availability and requirement.

At PATRATU THERMAL POWER STATION in33KV switch-yard two buses are used to charge the stationtransformer and also used to supply the power to the Patratuthermal power station.

In 132 KV switch-yard three buses is used for same purpose.

8) Bushing:- It is a type of insulator and design above2000amp.

Through it terminal should be taken out for transmission i.e. protect to shock.

9) Wave Trap:- Wave trap is an equipment installed in switch-yard for telecommunication on line.

It has coupling capacitor i.e. trap the communicationamong P.T.P.S grid and substation connected to it.

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Fig 6: Switch yard

Fig 7: Air Blast Circuit Breaker

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There are present widespread belt conveyor systems to feed the raw

coal bunkers of the various boilers. The entire plant consists of threewagon trippler, two crusher houses and a system of conveyor belts.The plant constructed with extension stage I and II provided onewagon trippler and a crusher house having two crushers of capacity600 tonnes/hr. each. The plant had to be extended with another wagon trippler and a crusher house and an additional conveyor system for the 2 x 110 MW units constructed in stage III extension.

This plant is being further extended by provision of another wagontrippler and conveyor system for 2 x 110 MW units under installation in stage IV extension.

Coal received in rail wagon is straight way uploaded onthe wagon triples and transferred to R.C. Bunkers through a seriesof conveyor belts. There is also provision to upload coal on truck hoppers and then to feed by blade feeders as well as by bulldozing

coal to conveyor system in case of non-availability of wagon triples.ASH DISPOSAL PUMP HOUSE:-

There are four ash disposal pumps that have beeninstalled at each ash disposal pump house. They are working onreserve and repair combined with hydraulic removal of product of combustion that is slag and under boilers and E.S.P. These house to

slag and ash dump which are crested through three pipelines of diameter 400 mm. One pipeline is on working, the second one isreserve. In addition, three flush away from under E.S.P are present.Here slag is framed to crusher from the ferapent conveyor, small

pieces of slag(less than 25 mm.) go through the holes of screen and big pieces of slag go to drum with tooth. The drum rotates and

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catches pieces of slag passing between the drum andcrushing. The pieces are grinded.

COAL DELIVERY EQUIPMENT:-

Coal delivery equipment is one of the major components of plantcost.

Coal handling consists of the following steps:-

I) Coal deliveryII) UnloadingIII) PreparationIV) Transfer (Conveyor)

V) Storage (Yard)VI) Implant handlingVII) Crushing and pulverizingVIII) Weighing and measuringIX) Feeding the coal into furnace

The coal storage capacity of the plant is 3,00,000 tones and thefeeding capacity is 5oo tones/hr. The source of coal is Khalari andBarkakana.

QUALITY OF COAL:-

1. Grade of Coal E &F

2. Calorific value of coal 4000 Kcal/kg

3. Ash content of coal: 41%

EQUIPMEMTS USED:-

1. Wagon Tripler:- Unloading capacity is 500 tones/hr.

2. Swing feeder

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4. Reclaim hopper

5. Vibrator feeder

6. Magnetic drum

7. Belt scales8. Belt feeders

9. Crushers

10. Bunker hopper

11. R C Bunker

Power supplied to conveyor : 0.4KV/440V

Material Used : Nylon (6 ply)

Width : 1200mm

Top cover : 3.15mm

Bottom cover : 1.50mm

Grade : m 24

For the generation of steam , we used coal is large amount. It isfossil fuels. Coal is classified as:-

*Peat

*Lignite*Bituminous and

*Anthracite

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The main features of coal handling are:-

1. Russian 400MW,Indian 440 MW

2. To know the calorific value (required fired as steam is used)

3. To crush large size Raw Coal in to small size (25 mm)4. To remove impurities & provide good flame to boiler

MAIN PARTS:-

1. Wagon Trippler:- It is a set of motor, gearbox, railway bogey. It helps in unloading.

2. Bunker hopper:- In which there are square holes, so thatlarge size coal dont pass to conveyor.

3. B.F. (Belt Feeder):- Help to carry this coal.

4. Conveyor:- Set of belt of different sizes. It is used to carrycoal from one place to another place.

5. Crusher:- To crush or break the coal in to 25mm size.

6. RCH (Reclaim Hopper) + Swing Feeder(SF):- To sendcoal to yard to swing feeder with the help of bulldozer.

Fixed Trippler A&B

Plough Feeder

Blade Feeder(BF)

2. Travelling trippler:- For every conveyor two trippler give bunker coal on both side as requirement.

RC Bunker:- Raw coal bunker

TST (telescopic tube):- Yard

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OPERATIONS INVOLVED IN COAL HANDLING:-

1. Loading coal with the help of cranes in the wagon machine2. By wagon pusher it is brought on the railway track, near the

wagon trippler.3. Bulb off means the bucket is completely tilted and coal is

filled into the bunker hopper.4. From bunker hopper coal is carried with the help of

conveyors. It may be underground or aboveground.5. Through conveyors at crushers. The crushers the coal into 20

mm. size.6. From crushers, it carries on the ball milling and from ball

milling in the form of dust it goes to storing bunker in powder form.

7. From storing bunker, through conveyors, it goes to furnace,where from other side ash comes out through conveyors.

BELT CONVEYORS:- Consists of an endless belt made of rubber,canvas or balata. The belt conveyors are successfully used oninclination up to 20 to the horizontal.

Average speed:- 60 100 m/min.

Load carrying capacity:- 50 100 tonnes/hr. over a distance of 400meters.

PROTECTION:-

a) At the time of bringing in wagon trippler, few water ismixed/sprayed in to coal, so that the dust may be absorbed.

b) Do wait till bulb gets OFF, otherwise coal will be remains in

boggy.c) Grease & Oil should be given in bearing properly.

Advantages:-

1. Economical

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2. Rate of coal transfer can be easily varied by just varying thespeed of belt.

3. Repair and maintenance costs are minimum.

4. Coal can be easily protected from rain by overhead.

5. Power consumption is minimum.

Disadvantages:- on the drum and crushing. The pieces are grinded

1. Not suitable for short distances and greater heights.

2. Cannot be used if inclination is more than 20.

Fig 8 :- Wagon Trippler

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Fig 9 :- Conveyor Belt

Fig 10:- Bunker Hopper

WATER TREATMENT PLANT

Water is an essential part of any power house for electricitygeneration. In the Thermal Plant, steam is produced by heating of water and steam passed through turbine to move the generator for the production of electricity.

To produce steam, pure water is required. But the water availablecontain many impurities, which are :-

1. Un-dissolved and suspended solid materials like mud,sediment, sand, sodium and potassium salts, etc. Sometimesiron, manganese or silica are also present.

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2. Dissolved salts and impurities which include carbonates, bicarbonates, sulphates and chlorides of calcium andmagnesium.

3. Dissolved gases such as carbon dioxide and bicarbonates.

4. Other materials such as oil, acid, etc.

The above impurities damage the boiler and turbine to a greatextent. Thus it is required to check the water and make specialtreatment before using it in the power plant.

In Patratu Thermal Power Station, water is treated in twostages :-

1. At the source (Filtration Plant)

2. At the plant.

1. AT THE SOURCE :- In the filtration plant water is treated inthree stages to remove solid particles by mixing alum, chlorideand bleaching powder.

a) USE OF ALUM:- Firstly water is stored in the water tank.Water contains muddy particles. When the alum is dissolvedthe muddy particles being heavy settle at the bottom and thefresh water is collected.

b) BY USE OF BLEACHING POWDER:- After collection of the fresh water, bleaching powder is used for the extraction of

bacteria.

c) BY USE OF CHLORINE: -Water is passed through thechlorine layer which results in removal of oil or acidic

particles.

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Hardness Nil

Silica Less than 0.02 ppm

Conductivity Less than 1 /cm.

PH value 7

Fig 11 :- Water treatment plant

INTRODUCTION:-

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The C&I plays important role in industry and plant in theform of control record and gives information to all part of the plantabout its running position &condition.

1) Control system:- In PTPS the control system is divided in

to three types :-a) Manual control:-Oil type control system i.e., not

suitable for fast controlling system.

b) Remote control:-It uses valves and dampness operated by electrical motor, controlling from UCB.

c) Automatic control:- Latest technology , uses electronics

regulator or pneumatic regulator.

2) Instrumentation measuring:- In PTPS instrumentation isdivided in to four sections.

a) Manometric lab:-

Pressure Flow Level

b) Temperatures labc) Auto-protection lab

SECTION:-

a) Pressure:-

DIRECT MOUNTING INSTRUMENT:-

A. Pressure Gauge:- It is used as primary instrumentin control system employing electronics controller. Itemploys to measures pressure of steam, water, oiland gas.

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B. Pressure measuring transducer:- It consist Burdentube-hollow (alloy steel) metallic part (plunger) Nonmetallic material which oscillate within inductioncoil according to tension in burden tube,

C. Induction coil:- Two winding PW &SW in whichinduced voltage is different.

Protection:-

Tripping of boiler and turbines:-

1. Drum level very high and very low+/-200mm.

2. Furnace drought very high and low +/- 50m3. Both F.D fans trip.

4. 6.6KV is dead

5. Push button for M.F.R is passed

6. Turbine lub. Oil pressure is very low 0.6 kg/cm 2

7. Primary oil pressure is very high 3.05kg/ cm2

8. Distribution oil pressure is low 7kg/ cm 2

9. Axial shift (mech.) is high +0.66mm.

10. Vacuum is very low (-)ve 0.5kg / cm 2

11. Push button for turbine trip is passed.

12. M.F.R trips d. Amplifier- To amplify the signal.

e. Motor- single phase reversible motor rating- 50 Hz, 0.14,

127V , 30.7rpm.

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f . Inductor (metering instruments)

PRINCIPLES:-

Burden tubes, through which pressure is supplied, it starts toexpand and in the way compress the iron core of induction coil andso the E.M.F Change takes place to the amplifier, amplify (current)feed to a synchronous motor that turns the pointer of the metering toappropriate reading.

Damage:-

Circuit problem

Mechanical fault (line leakage) Burnt diode resistance.

Hole in pipe-pressure high (6kg/cm 2) i.e. tension becomes highand so unbearable case.

INDIRECT MOUNTING INSTRUMENTS:-

It uses transmitter or transducer, which convert mechanical pulse to electrical pulse. It was observed on the suitable calibratedscale (metering scale) corresponding to the pressure, which producethe electrical pulse.

1) DPT (Differential Pressure Transducer):- If is anelectronics transmitter which operates on the force balancing

principle and provide a UMA to 20ma output signal proportional to the measured condition.

DPT is an instrument used to measure the pressuredifference of two pipe and a signal reading (mean value). Ithas two inlets.

Blow drum (Base)

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Middle

It consist of following parts:-

I) Hollow, pipe:- Inside it plunger is vertical placed.II) Seal hollow plate:- Linked by horizontally.

III) Induction coil.

DAMAGE:-

Flow should be jammed (Stop).

Null Point adjustment necessary.

USES:-

Deaerator

Condenser level.

Feed water flow.

Air pressure.

SECTION- B:- TEMPRATURE:-

Direct measurement:-

1. Thermometer:- It is a calibrated glass tube in whichmercury filled as heating (hot) . It stars to rise i.e.measuring temperature of the spot.

a. Thermo signalizer:- used to measure low temperaturelow temperature range but not accurate reading.

2. Consist:-

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There three type of RT:-

a) PRT- The resistance is 100 at 0C

b) PRT-The resistance of the material (platinum) is 46 at0C.

c) CRT- 53 the copper resistance transducer resistance53ohm at 0C

PRINCIPLE:- The measuring circuit is balanced by variableresistance element (RT) in one of the arms. Any change of RTcauses and unbalanced resulting in an AC error voltage. This isamplified as feed to the control winding of the balancing meter, the

reference winding being permanently supplied from a transformer.The pointer and pen are cinematically linked to the motor shaft,indicating linked to the motor shaft, indicating and recording themeasured variable on a calibrated scale and chart paper.

SECTION-C GATE VALVE

There are three types of valve:-

a) Isolating valve: - Its main function to put in service or isolated it. It is either shut off the valve or opens widely thevalve.

b) Pneumatic valve : - works on air to shut off or regulate.

c) Regulating valve : - Operation valve which are regulated indial from 0% through out to 100% and also has reversible

function.

Above are guided by three phase motor, starter switches,comparators, twist switch RCC cables, position indicators andsignalizing system.

SECTION-D:-AUTO PROFECTION:-52


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Fig 12:- Control Switches

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Fig 13: Control Switch of Motor & Pump

MOTOR MAINTENANCE

Three phase induction motor i.e. AC motor is based onelectromagnetic induction principle. It is used for industrial dragsdue to having good speed regulation and high starting torque.

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A motor is a machine which converts electrical energy intomechanical energy. It is robust, cheap, efficient and requires littlemaintenance.

Principle:-

A current carrying conductor placed in a slot of armature, aforced acted upon by the magnetic field from a north pole to themotor; from Flemings left hand rule, the conductor has a tendencyto move to the left hand side, tangential force acts to the rotor, atorque is developed on the rotor, rotor is free to move so startsrotating in the anticlockwise direction.

Characteristics:- Torque Vs. Armature current

Speed Vs. Armature current

Speed Vs. Torque

There are many types of motors used in P.T.P.S for various works:-

in motor feeding pumps, I-D fan, Ball mill, Cooling tower, etc.

MOTOR

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A.C. Motor D.C. MotorUniversal Motor

Three phase Single phase Series ShuntCompound Motor(IM) (IM) WoundWound

Squirrel cage motor Slip ring motor

There are mainly two parts of a motor:-

a. Stator

b. Rotor

Faults in stator:-

1. Breakdown of shaft:- Friction will take place and damage it.

2. Overload:- If during the time of tripping care is not taken, thestator gets heated and damaged due to overheating.

3. If anyone phase found to be fault that means high voltage from phase sue to which it gets heated or damaged.

4. Faults in rotor:-

Faults in rotor:-

1. Faults in rotor:-

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2. o shear the shaft and the chance of breaking, if any type of joint takes place in shaft, temperature variation takes place andthere are chances of damage.

Protection:-

1. Joints should be welded or silver blazed.2. Material should be perfect.3. For cooling F.D.Fan, vent in stator and rotor is necessary.Uses:-

1. Used in water feeding pumps.2. In ball mill.3. In cooling tower.

Fig 14 :- Motor Rotor MOTOR STATOR

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Fig 15:- Motor Rotor

Fig 16:- Feed Pump Motor

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Introduction: - It is the device used for the removal of dust and ash

particle carried with exhaust flue gases of thermal power plant.Performance: - The performance of the precipitator depends on the

physical and chemical properties of the gases and particles treated.Its design and performance are strongly dependent on the propertiesof the coal burnt in the furnace.

The fly ash from low sulphur coal has electrical resistivity and isdifficult to precipitate. Theory and experience indicates that whenthe dust resistivity exceed a critical value of 1010cm. The

precipitator operating voltage is limited which in turn reduces the precipitator efficiency. The loss in performance increases quiterapidly for resistivity greater than 1010 cm; hence resistivity is amajor factor in precipitator technology.

Parts of ESP: -

1. Casing -The outer structure of ESP in which all the parts of ESP resides.

2. Electrodes It is of two types-a) Collecting Electrode

b) Emitting electrodes.

3. Electricity .

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WORKING PROCEDURE: - When a unidirectional high voltageis applied to the three emitting electrodes and earthed, the dust of flue gas from boiler passes between the row of collecting andemitting electrodes. The high voltage induces the ionization of gasmolecules adjacent to the ve electrodes and negative chargetowards the collecting electrodes. On the wall of the collectingelectrodes ve charge gets deposited. In the presence of the highelectric fields between the electrodes, the charged dust particlesexperience a force which causes the particle to attach through thecollecting electrodes and finally get deposited in the hopper. Aminor portion of the dust particle gets deposited on emittingelectrode.

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Hydrogen is used as a coolant in generator. It is also used for sealing of shaft of generator.

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Fan type cooling towers are installed at PTPS. The purpose of cooling tower is to cool the circulating water, which is heated incondensers by exhaust steam of turbines.

One cooling tower (1-4) is designed for unit rate of 50 MW capacity

and cooling tower number 5 and 6 are designed for 100 MWcapacity units.

Cooling towers are equipped with fans of induced type, designatedfor operation under conditions of tropical climate. Fans give air steam by means of which the circulating water is cooled. For better contact of air with water and for more effective heat transfer, water coming from condensers of steam turbine is distributed uniformly incross-section of cooling tower, sprayed by means of special devicesand flows down to basin in separate small jets.

Between fan and level of water of supply water to be cooled, thereare wooden nets, which change the direction of air steam andconsiderable carryover of water drops by air steam. Evaporation of water in cooling tower is about 2% of the water flow of closedcirculating system condenser cooling tower. Carryover of water from cooling tower is approx. equal to 1% of water flow of theabove system.

Area of spraying of one cooling tower 1200 m 2

Capacity of one cooling tower - 7730 m 3 /hr.

Temperature drop 9.8C

Density of spraying 6.45 M/V

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INTRODUCTION: - As we all know that oil is one of theimportant sources of power production, so we have to supply pureand filtered oil to the furnace chamber at satisfactory pressure. Oilsections deal with all of the work which is done on LDO & FO

Main equipments used in oil section are: 1) Unloading Header 2) Unloading feeder 3) General Filters and Course Filters4)Unloading Pump 5)Storage Tanks 6)Transfer Pump

Line Diagram of Oil Section:

Wagon Header Filter Unloading pump

Transfer pump Oil tan Supply channel

Course filter Supply pump Steam heater

Boiler surface Filter

NOTE: 1. In circulation of LDO, we dont need any heat of steam.

3. if oil is more than the supplied oil to the furnace then it is sent back to the storage tank.

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SOURCES OF FIRE : The main source of fire in any industry areelectricity, smoking, friction, overheating of material, hot surfaces,

burner flame ignition, cutting and welding, mechanical spark, staticspark and other sources of exposure. The ex tent to which theindustrial fires are caused by these sources are as under: -

SOURCE %age

Electricity 32%

Smoking 09%

Friction 10%

Hot surfaces 15%

Burner flame 06%

Spontaneous ignition 05%

Cutting and welding 09%

Mechanical spark 02%

Static spark 02%

Others 10%

Total 100%

Causes of fire:

1. cutting and welding

2. heat/ over heat

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3. Elec. Spark or short ckt.

4. Metal spark

5. Local spark

6. Mechanical fault7. Spontaneous combustion

8. Static electricity

9. Improper quenching

10. Friction

11. Open Flame

12. Others

Important fire hazards in thermal power plant:

a) Boiler

i) Accumulation of coal dust

ii) Air pre heaters

iii) Fuel oil

iv)Rejected coal from coal mills

b) Turbine

i) Oil leakages from bearing

ii) Oil leakages from sealings

iii) Oil leakages from governing system

iv)Oil leakages from jacking system etc.

c) Generator

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i) Leakage of hydrogen

ii) Exciter slip rings

d) Oil facility

i) Fuel oil in tanksii) Oil splashes near oil transfer pump & motors

iii) Oil splashes in tunnels

e) Coal handling plants

i) Spontaneous fire in coal heaps

ii) Coal dust

iii) Conveyor belts

iv)Movable equipments

f) Hydrogen plant : Electric equipment

g) Switch yard

i) Transformers

ii) Breakers

iii) CT/PT

h) Transformers/Breakers/Cables

i) Generator transformers

ii) Unit Aux. Transformers

iii) Switch gear rooms THANKU Cablegalleries

FIRE PROTECTION

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Fire protection is a planned approach to the provision of adequatestructural safe guard against the possibility of fire spread and theavailability of fixed and portable appliances which will be readilyavailable in emergency.

FIRE PROTECTION SYSTEM

1. Active System: These are operated automatically incase of fire. Itincludes: Sprinkler System, CO 2 injection system, Smoke detectionSystem, Fire Resisting Coating for HT cables etc.

2. Passive System: These are operated manually incase of fire. Itincludes: Smoke detection System, Heat Detectors, Booster Pump

System, Landing Valves, Hydrant System, First Aid Fire FightingEquipment etc.

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ptps project 1(1)

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