DVC Mejia Thermal Power StationReport

8/16/2019 DVC Mejia Thermal Power StationReport

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A REPORT OF THE VOCATIONAL

TRAININGat

MEJIA THERMAL POWER STATION

P.O. MEJIA, DIST. BANKURAWEST BENGAL-7221!OF

DAMODAR VALLE"CORPORATION

#D.V.C.$


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ACKNOWLEDGEMENT

The dissertation has been prepared based on the vocational training

undergone in a highly esteemed organisation of Eastern region, a pioneer in

Generation Transmission & Distribution of power, one of the mosttechnically

advanced & largest thermal power stations in India , the Mejia Thermal

ower !tation "M#T##!$, under D%#

I would li'e to e(press my heartfelt gratitude to the authorities of Mejia Thermal ower !tation for providing us such an

opportunity to undergo training in the thermal power plant of D%, MT!#

I would also li'e to than' the Engineers, highly e(perienced without whom

such type of concept building in respect of thermal power plant would not

have been possible# !ome of them are)

*$ Mr# arimal +umar Dubey

$ G -andesu


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INTRODUCTION


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Damodar %alley orporation was established on .th /uly*012#It is the most reputed company in the eastern 3one ofIndia# D% in established on the Damodar 4iver# Italsoconsists of the Durgapur Thermal ower lant inDurgapur# The MT! under the D% is the second largestthermal plant in 5est 6engal# Mejia Thermal ower !tationalso 'nown as MT! is located in the outs'irts of 4aniganj in6an'ura District# It is one of the 7 Thermal ower !tationsof Damodar %alley orporation in the state of 5est 6engal# The total power plant campus area is surrounded by

boundary walls and is basically divided into two majorparts, 8rst the ower lant area itself and the second is theolony area for the residence and other facilities for MT!s employees#


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TECHNICAL

SPECIFICATION OF MTPS

• I-!T9::ED 99IT;) <

• *$ Total number of =nits ) < 1 > *? M5"unit * to 1$ with

6rush Type Generators, > 7?

• M5"unit 7 and @$ with 6rush less Type Generators, A7??M5"unit . and 2$ Generators#

• $ Total Energy Generation) < B1? M5

•

B$ !ource of 5ater) < Damodar 4iver• 1$ !ources of oal) < 6###: and E##:, also imported from

Indonesia


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In a Thermal ower generating unit, combustion of fossilfuel "coal, oil natural gas$ in 6oiler generates heat energy# This heat energy transforms water stea at high pressureand temperature# This steam is utilised to generatemechanical energy in a Turbine# This mechanical energy, inturn is converted into electrical energy with thehelp of an9lternator coupled with the Turbine# The production ofelectric energy utilising heat energy is 'nown as thermalpower generation#

The heat energy changes into mechanical energyfollowing the principle of 4an'ine reheat


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OVERVIEW OF ATHERMAL POWER PLANT


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. . ) .,. Unit t"n'-o%e (&)#*"'e+. . Ele/ti/ gene"to (&)#*"'e+.0. Low #e''$e t$ine. 2. Con3en'"te

e4t"/tion #$%#.5. Con3en'e. 6. Inte%e3i"te #e''$et$ine. 17. Ste"% go8eno 8"l8e. 11.Hig* #e''$et$ine. 1!. De)"e"to. 1&. Fee3*e"te. 1,. Co"l /on8e9o. 1. Co"l*o##e. 10. P$l8ei'e3 -$el

%ill. 12. :oile 3$%'. 15. A'* *o##e.16. S$#e *e"te. !7. Fo/e3 3"$g*t-"n. !1. Re)*e"te.!!. Ai int";e. !&. E/ono%i'e. !,. Ai

#e *e"te. !. Pe/i#it"to. !0.


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ME9-I9: FE49TIF-


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COAL HANDLING PLANT

Generally most of the thermal power plants uses lowgrades bituminous coal# Theconveyer belt systemtransports the coal from the coal storage area to thecoal mill# -ow the C"Cuel andling lant$ department

is responsible for converting the coal converting it into8ne granular dust by grinding process# The coal fromthe coal bun'ers#oal is the principal energy sourcebecause of its large deposits and availability# oal canbe recovered from dierent mining techniHues li'e)<

shallow seams by removing the over burnt e(posethe coal seam

underground mining#


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The coal handling plant is used to store, transport and distribute coal which comes

from the mine# The coal is delivered either through a conveyor belt system or by

rail

or road transport# The bul' storage of coal at the power station is important for the

continues supply of fuel# =sually the stoc'piles are divided into three main

categories#

live storage

emergency storage

long term compacted stoc'pile# The 8gure below shows the schematic representation of the coal handling plant#

Cirstly the coal gets deposited into the trac' hopper from the wagon and then via

the

paddle feeder it goes to the conveyer beltJ*9# !econdly via the transfer port thecoal

goes to another conveyer beltJ6 and then to the crusher house# The coal afterbeing

crushed goes to the stac'er via the conveyer beltJB for being stac'ed or reclaimed

and 8nally to the desired unit# I:M! is the inline magnetic separator where all the

magnetic particles associated with coal get separated#


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COAL HANDLING PLANT PROCEDURE


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PLANT

R"w w"te '$##l9<

4aw water received at the thermal power plant is passed through 5ater

Treatment lantto separate suspended impurities and dissolved gases including organic

substance and then through De


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C*loin"tion<

-eutral organic matter is very heterogeneous i#e# it contains many classes of high

molecular weight organic compounds# umic substances constitute a major portion of

the dissolved organic carbon from surface waters# They are comple( mi(tures oforganic compounds with relatively un'nown structures and chemical composition


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DM (De%ine"li'e3 W"te+ Pl"nt

In De


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:OILER S=STEM5or'ing principle of 6oiler "!team Generator$) In 6oiler, steam is generated from

deminerali3ed water by the addition of heat# The heat added has two parts)sensible heat and latent heat# The sensible heat raises the temperature and

pressure of water as well as steam# The latent heat converts water into steam

"phase change$# This conversion is also 'nown as boiling of water, which isdependent on pressure and corresponding temperature# Thermodynamically,

boiling is a process of heat addition to water at constant pressure &temperature# The Huantity of latent heat decreases with increase in pressure of

water and it becomes 3ero at *#?@ bars# This pressure is termed as criticalpressure# The steam generators are designated as sub


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I%#ot"nt #"t' o- :oile > t*ei-$n/tion'<

E/ono%i?e< Ceed water enters into the boiler through economi3er# Its function is to

recover

residual heat of Kue gas before leaving boiler to preheat feed water priorto its entryinto boiler drum The drum water is passed through down


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S$#e*e"te< !uperheaters "!$ are meant for elevating the steam temperature above

the saturation temperature in phases so that ma(imum wor' can bee(tracted from high energy "enthalpy$ steam and after e(pansion in

Turbine, the dryness fraction does not reach below 2?N, for avoiding Turbine blade erosionLdamage and attaining ma(imum Turbine internaleOciency# !team from 6oiler Drum passes through primary superheaterplaced in the convective 3one of the furnace, then through platensuperheater placed in the radiant 3one of furnace and thereafter, through8nal superheater placed in the convective 3one# The superheated steam

at reHuisite pressure and temperature is ta'en out of boiler to rotateturbo


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Te/*ni/"l 3"t" o- t*e :oile


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ASH HANDLING PLANT

9 large Huantity of ash is, produced in steam power plants using coal#

9sh produced in about *? to ?N of the total coal burnt in the furnace#andling of

ash is a problem because ash coming out of the furnace is too hot, it isdusty and

irritating to handle and is accompanied by some poisonous gases# It isdesirable to

Huench the ash before handling due to following reasons)

*# Puenching reduces the temperature of ash#

# It reduces the corrosive action of ash#

B# 9sh forms clin'ers by fusing in large lumps and by Huenching clin'erswill

disintegrate#

1# Puenching reduces the dust accompanying the ash#

Cly ash is collected with an electrostatic precipitator"E!$

PRECIPITATOR


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PRECIPITATOR

The principal components of an E! are sets of electrodes insulatedfrom each other# Cirst set of rows are electrically grounded verticalplates called collecting electrodes while the second set consists ofwires called discharge electrodes# the negatively charged Ky ashparticles are driven towards the collecting plate and the positive ionstravel to the negatively charged wire electrodes# ollected particulate

matter is removed from the collecting plates by a mechanicalhammer scra in s stem#


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- +


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-"n+<

Corced draft represents Kow of air or products of combustion at a pressureabove atmosphere# The air for combustion is carried under forced draftconditions and the fan used for this purpose is called Corced Draft "CD$ fan#It is a(ial type fan and is used to ta'e air from atmosphere at ambienttemperature to supply air for combustion, which ta'es entry to boiler

through wind bo(# In all units e(cept Durgapur T! =nit J1, this fan alsosupplies hot Lcold air to the coal mills#


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Pi%"9 "i -"n (PA -"n+ oE4*"$'te -"n<


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oal mill or pulveriser)Most eOcient way of utili3ing coal for steam generation is to burn it in pulverised

form# The coal is pulveri3ed in coal mill or pulveriser to 8neness such that .?


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TEAM TUR:INE


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TEAM TUR:INE

9 steam turbine is a prime mover which continuously converts the energy of high

pressure, high temperature steam supplied by the boiler into shaft wor' with low

pressure, low temperature steam e(hausted to a condenser#


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Cooling toweooling towers cool the warm water discharged from the condenser and

feed the cooled water bac'to the condenser# They thus reduce the

cooling water demand in the power plants# 5et coolingtowers could bemechanically draught or natural draught# In M#T##! the cooling towers

are I#D#type for units *


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CHIMNE= 9 chimney may be considered as a cylindrical hollow tower made of bric'sor steel# In MT! the chimneys of eight units are made of bric's# himneysare used to release the e(haust gases"coming from the furnace of theboiler$high up in the atmosphere# !o, the height of the chimneys are madehigh#

*0

CO C S O


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CONCLUSION The practical e(perience that I have gathered during the overview training of

large thermal power plant having a large capacity of B1? M5 for =nitJ I to

%III in three wee's will be very useful as a stepping stone in building bright

professional career in future life# It gave me large spectrum to utili3e the

theoretical 'nowledge and to put it into practice# The trouble shooting

activities in operation and decision ma'ing in case of crisis made me more

con8dent to wor' in the industrial atmosphere#

Moreover, this overview training has also given a self reali3ation & hands

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DVC Mejia Thermal Power StationReport