CHAPTER 1
INTRODUCTION 1.1 1.1 About About NTPC NTPC NTPC Limited (also known as National Thermal Power Corporation Indian Central Central Public Sector Undertaking (CPSU) under the Limited) is an Indian Ministry of Power, Governent of India, engaged in the business of generation of electricity and allied activities! It is a co"any incor"orated under the Co"anies #ct $%&' and a Governent Co"any within the eaning of the act! he head*uarters of the co"any is situated at +ew elhi! +PC-s core business is generation and sale of electricity to state. owned "ower distribution co"anies and State /lectricity 0oards in India! he co"any also undertake undertakes s consultancy consultancy and turnkey turnkey "ro1ect "ro1ect contracts contracts that involve engineering, "ro1ect anageent, construction anageent and o"eration and anageent of "ower "lants! he co"any has also ventured into oil and gas e2"loration and coal ining activities! It is the largest "ower co"any in India with an electric "ower generating ca"acity of 34,564 M7 ! #lthough the co"any has a""ro2! $58 of the total national ca"acity it contributes to over 9:8 of total "ower generation due to its focus on o"erating its "ower "lants at higher e;ciency levels (a""ro2! 548 against the national P<= P<= rate rate of :58)! It was founded by Governent of India in India in $%:&, which now holds :68 of its e*uity shares on $4 May 96$&! In May 96$6, +PC was conferred Maharatna Maharatna status status by the Union Governent of India! It is ranked 393th in in the =orbes Global 9666 for 9666 for 96$3 he co"any has set a target target to to have an installed "ower "ower generating generating ca"acity of $,95,666 M7 by the year 9649! he ca"acity will have a diversi>ed fuel i2 co"rising &'8 coal, $'8 Gas, $$8 +uclear and $:8 ?enewable /nergy Sources(?/S) including hydro! 0y 9649, non.fossil fuel based generation ca"acity shall ake u" nearly 958 of +PC@s "ortfolio!
Page A $
i! 1.1 " PL #$ %ear !raph
1.& 'trate!i 'trate!ie$ e$ o( NTPC
i! 1.& ) 'trate!ie$ o( NTPC
Page A 9
i! 1.1 " PL #$ %ear !raph
1.& 'trate!i 'trate!ie$ e$ o( NTPC
i! 1.& ) 'trate!ie$ o( NTPC
Page A 9
1.* 1.* +i$io i$ion n Bo be the worlds largest and best "ower "roducer, "owering Indias growthD
1., -i$$ion Bevelo" and "rovide reliable "ower, related "roducts and services at co"etitive "rices, integrating ulti"le energy sources with innovative and eco.friendly technologies and contribute to societyD
1. Core +alue$ / E C O I T T E D
0usiness /thics /nvironentally E /conoically Sustainable Custoer =ocus Frganiational E Professional Pride Mutual ?es"ect E rust Motivating Self E others Innovation E S"eed otal otal Huality Huality for /2cellence /2cellence rans"ar rans"arent ent E ?es"ected ?es"ected Frganiatio Frganiation n /nter"rising evoted
1.0 In$talled Capait2 TA/LE 1.1 ) In$talled Capait2 o( NTPC Pro3et$ No. o( Commi$$ione Pro3et$ d Capait2 4-56 NTPC O5NED COAL 1, &&7*8 9A':LI;. UEL <0 *78 TOTAL &1 &=7*< O5NED /% >+C$ Coal * *1, 9a$:LI;. UEL 1 0,< 9RAND TOTAL & &07,<,
TA/LE 1.& ) Coal /a$ed Plant$ Page A 4
Coal ba$ed
'tate
1!
'in!rauli
&! *.
?orba Rama!undam
,. .
ara@@a +indh2ahal
=.
Rihand
0. .
?ahal!aon NTCPP
8.
Talher?anih a Unhahar
Uttar Prade$h Chhatti$!arh Andhra Prade$h 5e$t /en!al -adh2a Prade$h Uttar Prade$h /ihar Uttar Prade$h Ori$$a
1 <. 1 Talher 1. Thermal 1 'imhadri &. 1 Tanda *. 1 /adarpur ,. Total 4Coal6
Commi$$ioned Capait2 4-56 &7<<< &71<< &7=<< 17=<< *7&=< &7<<< 17*,< ,< *7<<<
Uttar Prade$h Ori$$a
17<<
Andhra Prade$h Uttar Prade$h Delhi
17<<<
,=<
,,< 0< &&7*8
TA/LE 1.* ) 9a$ /a$ed Plant$ 'tate
Commi$$ion ed Capa Capai it2 t2 4-56
1 Anta
Ra3a$than
,1*
& Aurai2a
Uttar Prade$h
=&
* ?awa$
9u3arat
=,
, Dadri
Uttar Prade$h
10
>hanor"
9u3arat
=,
9a$ ba$ed
Page A 3
9andhar Ra3i# 9andhi = CCPP ?a2am@ulam
?erala
*<
0 aridabad
Har2ana
,*<
Total 49a$6
*78
TA/LE 1., ) Pro3et$ Under Implementation
Coal : H2dro
'tate
uel
Addition Additional al Capait2 Capait2 Under Implementation 4-56
1.
?ahal!aon 'ta!e II 4Pha$e I6 4Pha$e II6
/ihar
Coal
<< <<
&.
'ipat 4'ta!e I6 4'ta!e II6
Chhatti$!ar Coal h
18< 1<<<
/ihar
18<
*. /arh
Chhatti$!ar Coal h
<<
. ?orba orba 4'ta 4'ta!e !e III6 III6
Chhatti$!ar Coal h
<<
=. ara@@a 4'ta!e III6
5e$t /en!al Coal
<<
0. NCTP NCTPP P 4'ta 4'ta!e !e II6 II6
Uttar Prade$h
Coal
8<
. 'imh 'imhad adri ri 4't 4'ta! a!e e II6 II6
Andhra Prade$h
Coal
1<<<
8. ?old oldam 4HEPP6 EPP6
Himahal Prade$h
H2dro
<<
1< Uttara@han Loharina! Pala 4HEPP6 . d
H2dro
=<<
11 Tapo#an+i$hnu!ad . 4HEPP6
H2dro
&<
,.
/hilai 4EBp. Power Pro3et">+ with 'AIL6
Coal
Uttara@han d
Page A &
Total 4Coal H2dro6
117*=<
TA/LE 1. ) Power Plant$ with >oint +enture$ Coal 'tate /a$ed
uel
Commi$$ione d Capait2 4-56
1
Dur!a 5e$t /en!al pur
Coal
1&<
&
Rour@ Ori$$a ela
Coal
1&<
*
/hilai
,
R9PPL
Chhatti$!arh Coal -ahara$tra
0,
Naptha:L 0,< N9
Total4>+6
1<,
9rand Total 4Coal 9a$ >+6
&07,<,
1.0 5or@in! Priniple # coal based "ower"lant basically works on ?ankine Cycle! Stea is "roduced in boiler is e2"orted in "rie over and is condensed in condenser to be fed into the boiler again! In "ractice of good nuber of odi>cations are aected so as to have heat econoy and to increase the theral e;ciency of "lant! Many of the i"racticalities associated with the Carnot cycle can be eliinated by su"erheating the stea in the boiler and condensing it co"letely in the condenser! he cycle that results is the Ran@ine 2le, which is the ideal cycle for va"or "ower "lants! he ideal ?ankine cycle does not involve any internal irreversibility-s ! $ 9 4 3
J J J J
9 4 3 &
0=P work Keating of water to convert it >nally to su"erheated stea in boiler /2"ansion in KP turbine ?eheating Page A '
&J' 'J$
/2"ansion in IP and
i! 1.* ) Ran@ine C2le 4with reheat6
1. About NTPC Dadri National Capital Power 'tation 4NCP'6 Fr NTPC Dadri, is the "ower "ro1ect to eet the "ower deand of +ational Ca"ital ?egion (India)! It has a huge coal.>red theral "ower "lant and a gas.>red "lant and has a sall townshi" located in Uttar Pradesh, India for its e"loyees!
+PC adri is a uni*ue "ower "lant of +PC grou" which has both coal based theral "lant and gas based theral "lant of $596 M7 and 5$: M7 res"ectively and & M7 solar "lant totaling 9'39 M7
1..1 In$talled Capait2 Coal based Page A :
he coal.based station ainly eets "ower re*uireents of the +ational Ca"ital ?egion L+C? , and the northern grid ! 7ith the 7orld 0ank funding co"onent , the ca"ital cost of the units is ?s! $'!'% billion ! here are four 9$6 M7 coal based units and two 3%6M7 coal based units! he units have a coal.>red boiler and a stea turbine each ! he boiler design is also suitable for $668 o"erations with heavy furnace oil >ring ! =or this , three storage tanks , each of ca"acity $&,666 k< , enough for $6 days continuous oil >ring re*uireents have been "rovided for the boilers !
#0
'ta!e
$st
9nd Total
Unit Number
In$talled Capait2 4-56
Date o( Commi$$ionin!
$
9$6
$%%$ Fctober
9
9$6
$%%9 eceber
4
9$6
$%%4 March
3
9$6
$%%3 March
&
3%6
96$6 Nanuary
'
3%6
96$6 Nuly
Si2
1&<
#0
'ta !e
Unit Numbe r
$st
Total
In$talled Capait2 4-56
Date o( Commi$$ioni n!
9T : 'T
$
$46!
%$$%%9 March
G
9
$46!
%$$%%9 May
G
4
$46!
%$$%%9 Nune
G
3
$46!
%$$%%9 +oveber
G
&
$&3!&$
$%%4 =ebruary
S
'
$&3!&$
$%%4 March
S
Si2
&8.0
Grand otal ca"acity is &=*0 -5!
1..& Loation It is located in Gauta 0udh +agar district of Uttar Pradesh about 9& k fro Ghaiabad and about % k froadri! It is nearly 35 k fro +ew elhi towards Ka"ur! he townshi" has an area of about &66 acres over all! +PC adri is a branch of +ational heral Power Cor"oration , which is a "ublic sector now! It is about 96k fro Ghaiabad via 0adal"ur, Mahawar, 0aabawar, and #kil"ur Nagir!
1..* Coal 'oure he coal is trans"orted fro the Pi"arwar block of ines of the +orth Oaran"ura Coal>elds of Nharkhand , over a distance of about $,966 ks! , by the Indian ?ailways botto discharge , and 0o2 -+- ty"e of wagons ! he coal re*uireent for the si2 units is about 9&666M!! each day! he station has its- own $3 ks!
1.., 5ater 'oure U""er Ganga Canal ehra Keadworks, uring closure of UGC through network of tube wells! he consu"tion of cooling water is &6 cusecs ($3$&!5& litressec)! Page A %
CHAPTER &
COAL C%CLE &.1 Coal 'upplied at NTPC Dadri Coal is su""lied to +PC, adri by Pi"arwar coal ines! he ty"e of coal is 0ituinous and Sei 0ituinous with following s"eci>cationsQ. Moisture. less than 58 Rolatile atter.$:8 to $%8 #sh. 4&8 . 368 Calori>c Ralue. 3&66 to &466 Ocalkg Coal is received in railway bo2 rakes containing &6.'6 wagons in each rake! Ca"acity of each bo2 wagon is about && ton! he 0F.+ ty"e wagons are "laced on 9 wagon ti""ler (one for Stage.I and other for Stage.II) he 0F0? ty"e wagons are e"tied on track ho""ers • • • • •
• •
•
&.& Dierent Component$ o( Coal C2le • • • • • • • • • •
7agon i""ler rack Ko""er Paddle =eeder Conveyer 0elts Crusher Kouse Stacker cu ?eclaier Coal Tard Coal 0unker Coal =eeder Coal Mills Page A $6
•
=urnace
i! &.1 ) Coal C2le
&.&.1 5a!on Tippler 7agon fro coal yard coe to the ti""ler and e"tied here! here are 9 wagon ti""lers! he ti""ler is tilted to about $4& so that coal fro the wagon is e"tied into the ho""er! /lli"tics "addle feeders are used to ove the coal fro ho""ers to conveyer belts! In this it takes &9 sec to raise a wagon, $6 sec to e"ty the wagon co"letely E then again &9 sec to bring the ti""ler down! # seicircular huge 7 gear is used to run the ti""ler! Protocol caeras have been installed for safety to ensure that no oving creature or ob1ect is near the wagon which is on the ti""ler!
&.&.& Tra@ Hopper Coal in 0F0? (0o2 F"en 0otto ?elease) was unloaded on the track ho""ers! he track ho""ers are shown as follows! he Coal is stored in the ho""ers fro where it is "assed on to the conveyer belts by "addle feeders, towards the crusher house!
Page A $$
i! &.& ) 5a!on Tippler Hopper$
i! &.* ) Tra@
&.&.* Paddle eeder hese are ovable elli"tical feeders with "addle like structures so as to ove the coal fro the botto of the track ho""ers to the conveyer belts! here are 3 "addle feeders which can ove along the botto of the track ho""er at dierent "ositions!
&.&., Con#e2er /elt$ # belt conveyor consists of two "ulleys, with a continuous loo" of aterial. the conveyor 0elt J that rotates about the! he "ulleys are "owered, oving the belt and the aterial on the belt forward! Conveyer belts are used in the CKP to transfer coal fro one "lace to other as re*uired in a convenient E safe way! #ll the belts are nubered accordingly so that their function can be easily dearcated! hese belts are ade of rubber E ove with a s"eed of 9&6.466 in!
&.&. 'a(et2 'withe$ in Con#e2er$ here are certain switches which are used for safe o"eration of th conveyers used throughout the "lant! /elt 'wa2 'with hese are the switches which are o"erated when there is sway in the conveyer belt, i!e! the belt ove in a "articular direction outside its >2ed "ath! hese are located on both the sides of the belt! In case there is a sway in the belt, the switch gets activated and sto" the conveyer so as to avoid accidents Pull Cord 'with
Page A $9
hese are the switches which are installed at every $6 ga" in a conveyer belt to ensure the safety of otors running the conveyer belts! If at any tie soe accident ha""ens or the conveyer belt is needed to be sto""ed iediately, then the cord is "ulled which activates the switch and sto"s the conveyer! ero 'peed 'with It is used as a safety device for the otor i!e! when the belt is not oving but the "ulley is rotating! his switch checks the s"eed of the belt E switches o the otor when s"eed of the belt is ero!
&.&.= Cru$her Hou$e #fter the coal is unloaded in the wagon ti""lers and track ho""er (sie of coalV.9&6), it is conveyed to the crusher house for reducing the sie of the coal u"to .96 which is the o"tiu sie for transfer via conveyers! Table &.1 ) Cru$her Hou$e No. and -a@e o( Cru$her T2pe and 'iFe -ain Cru$her Capait2 -otor Ratin! Power 'uppl2 RP-
7 Penn$2l#enia7 U'A Rin! 9ranulator$7 T??9N",<8* 0 tonne$:hr <
i! &., ) Coal 'iFe$
&.&.0 'ta@er um Relaimer
Page A $4
It is used for stacking (storage) of the e2cess coal in the coal yards! 7hen there is a re*uireent of the stored coal, reclaiing "rocess starts and the coal is sent to the coal bunkers through conveyer belts! here are 4 Stacker ?eclaiers at +PC adri with stacking ca"acity of $366t"h and reclaiing ca"acity of $366t"h with boo conveyer s"eed of 4s
i! &. ) 'ta@er um Relaimer
&.&. Coal %ard 7henever the coal bunkers are >lled and there is e2cess crushed coal in the "lant, it is stored in the coal yard! Ca"acity . 3& days coal of stagel re*uireent, &66666 4 of coal a""ro2! +o! of coal "iles in stockyard J '
ciency of coal at a "articular tie •
• •
&.&.8 Coal /un@er #fter the coal is crushed in the crusher house, it is either sent to the coal yards or directly to the coal bunkers! hese are very large coal storage Page A $3
containers which are "laced above the coal ills (where the coal is ground >nely)! hese are cylindrical in sha"e with conical cu hy"erbolic ho""er at botto and ade u" of 5 M!S! "late Stage I J ' Coal 0unkers "er unit Stage II J % Coal 0unkers "er Unit • •
i! &.= ) Coal /un@er$ 4in %ellow6
&.&.1< Coal eeder It is situated 1ust below the coal bunkers! It is used to send calculated aount of coal fro the coal bunkers to the coal ills as "er the re*uireent of the furnace! he *uantity of coal fed is controlled by controlling the s"eed of the conveyer inside it! Ma2iu and iniu ca"acity of the feeder is '6Mhr and 'Mhr res"ectively
&.&.11 Coal -ill he coal ills are situated 1ust below the raw coal feeders! Its ain function is to "ulverie the coal fro .9& sie to 966esh sie! In +PC adri there is a bowl ty"e coal ill in which there is a bowl and three rollers at $96 to each other! he bowl rotates at &6r" and the rollers rotate about their own a2is! he rollers are "ressed against the bowl using s"rings so as to facilitate the grinding of coal! Page A $&
he coal coes in the coal ill fro the to" fro the coal feeder through a single "i"e! #fter the coal is "ulveried it is carried by the "riary air (which enters the ill fro botto towards the to") to the furnace through 3 "i"es! hese four "i"es carry the coal to the 3 corners of the furnace!
Table &.& ) Coal -ill -a@e
/HEL
No. per boiler = T2pe RP * Capait2 ,8 T:hr Coal $iFe"inlet & mm " outlet 0< throu!h &<< me$h 9rindin! roll material Ni "Hard 9r II
Page A $'
i! &.0 ) Coal -ill$ 4Pul#eri$er6 Coal -ill
i! &. ) Roller$ o(
&.&.1& URNACE =urnace is "riary "art of the boiler where the cheical energy available in the fuel is converted into theral energy by cobustion! =urnace is designed for e;cient and co"lete cobustion! Ma1or factors that assist for e;cient cobustion are the te"erature inside the furnace and Page A $:
turbulence, which causes ra"id i2ing of fuel and air! In odern boilers, water.cooled furnaces are used! he boiler fuel >ring syste is tangentially >ring syste in which the fuel is introduced fro wind nole located in the four corners inside the boiler! he crushed coal fro the coal crusher is transferred into the unit coalbunkers where the coal is stored for feeding into "ulveriing ill through rotary feeder! he rotary feeders feed the coal to "ulverie ill at a de>nite rate! hen coal burners are e"loyed to >re the "ulveried coal along with "riary air into furnace! hese burners are "laced in the corners of the furnace and they send horiontal streas of air and fuel tangent to an iaginary circle in the centre of the furnace ! Table &.* ) urnae $peiJation$ T2pe /ottom urnae pro3eted area uel heat input Re$idene time (or (uel partile$ in (urnae Eeti#e #olume u$ed to alulate the re$idene time Dra(t urnae width urnae depth urnae hei!ht 4Rin! header to (urnae roo(6 4#iii6 urnae #olume
u$ion welded wall$ Dr2 *&0 m& 18.* -? Cal:hr *.1, $e ,&<< m* /alaned 1*.= m 1<.8& m ,*.1*= m 0< m*
CHAPTER *
5ATER C%CLE
Page A $5
i! *.1 ) 5ater C2le
*.1 De"-ineraliFed 5ater:'team C2le • • •
Condensate Cycle =eed 7ater Cycle Stea Cycle
*.& Conden$ate C2le ierent Co"onents of Condensate Cycle Kot 7ell Condensate /2traction Pu"
*.&.1 Hot 5ell #fter the stea is condensed in the condenser, it gets collected in the hotwell so that the water can be recirculated in the syste!
*.&.& Conden$ate EBtration Pump Page A
%$ his "u" is used to e2tract the condensed water fro the hotwell to the deaerater through the low "ressure heaters Table *.1 ) Conden$ate EBtration Pump $peiJation$ -anu(atuer /HEL No. o( pump$ K apait2 &B1<< T2pe NE'>1,OD 4&$ha(t67 #ertial entri(u!al onni$ter t2pe No. o( $ta!e$ Di$har!e apait2 = m*:hr Di. head 18< ml Input power to pump ,&& @w Temperature o( medium ,=.*< RP1, Eien2 o( pump 08.
*.&.* eed 5ater Heater # =eed water heater is a "ower "lant co"onent used to "re.heat water delivered to a stea generating boiler! Preheating the feed water reduces the irreversibility involved in stea generation and therefore i"roves the therodynaic e;ciency of the syste! his reduces "lant o"erating costs and also hel"s to avoid theral shock to the boiler etal when the feed water is introduced back into the stea cycle! In a stea "ower "lant, feed water heaters allow the feed water to be brought u" to the saturation te"erature very gradually! his iniies the inevitable irreversibility associated with heat transfer to the working Wuid! he water here is heated by the stea which is e2tracted fro the dierent stages of the turbine hese are of two ty"es Low Pre$$ure Heater hese are called as low "ressure heaters as they e2tract stea fro the stages of low "ressure turbine
Page A 96
i! *.& ) Low Pre$$ure Heater Pre$$ure Heater
i! *.* ) Hi!h
*.&., Deaerater # eaerator is a device for air reoval and used to reove dissolved gases (ainly F9 and CF9) fro boiler feed water to ake it noncorrosive! # Stea generating boiler re*uires that the circulating stea, condensate, and feed water should be devoid of dissolved gases, "articularly corrosive ones and dissolved or sus"ended solids! he gases will give rise to corrosion of the etal! he solids will de"osit on the heating surfaces giving rise to localied heating and tube ru"tures due to overheating! Under soe conditions it ay give rise to stress corrosion cracking eaerator is a ty"e of o"en feed water heater in which feedwater coes in direct contact with the stea e2tracted fro C?K line and IP e2haust! hese are of three ty"es S"ray ty"e eaerator ray ty"e eaerator S"ray Cu ray ty"e eaerator • • •
Page A 9$
In +PC adri, a s"ray cu tray ty"e eaerator is used! In this feedwater is >rst s"rayed and then ade to cascade down a series of trays and bled stea Wows u"wards! ue to this water gets heated and scrubbed to release the dissolved gases! ! If o"erated "ro"erly, the deaerator will guarantee that o2ygen in the deaerated water will not e2ceed : ""b by weight (6!66& c 4<)
*.&. eed 'tora!e Tan@ #fter the water is deaerated it is stored in the feed storage tank 1ust below the deaerater! =eed Storage tank acts as the inlet for the 0oiler =eed Pu"! So it is ke"t about 9& above the 0=P so as to aintain a net "ositive suction head for the 0=P so as to avoid cavitation!
i! *., ) Deaerator 4upper 2linder6 and eed 'tora!e Tan@ 4lower 2linder6
*.* eed 5ater C2le ierent Co"onents of =eed 7ater Cycle 0oiler =eed Pu" Kigh Pressure Keater =eed ?egulating Station /conoiser 0oiler ru 0oiler • • • • • •
*.*.1 /oiler eed Pump # 0oiler feed water "u" is a s"eci>c ty"e of "u" used to "u" water into a stea boiler! he water ay be freshly su""lied or returning condensation of the stea "roduced by the boiler! hese "u"s are Page A 99
norally high "ressure units that use suction fro a condensate return syste and can be of the centrifugal "u" ty"e or "ositive dis"laceent ty"e! Construction and o"erationQ =eed water "u"s range in sie u" to any horse"ower and the electric otor is usually se"arated fro the "u" body by soe for of echanical cou"ling! rst stage, the "u" is activated! If the li*uid continues to dro", ("erha"s because the "u" has failed, its su""ly has been cut o or e2hausted, or its discharge is blocked) the second stage will be triggered! his stage ay switch o the boiler e*ui"ent ("reventing the boiler fro running dry and overheating), trigger an alar, or both Table *.& ) /oiler eed /oo$ter Pump $peiJation$ /OILER EED /OO'TER PU-P Pump t2pe A 1/ = LiMuid pumped 'ution temperature Dierential head low rate Eien2 'peed Power NP'H7 reMuired
/oiler (eed water 1=<.0< 1<
Table *.* ) /oiler eed Pump $peiJation$ /OILER EED PU-P No and Capai2 * B < -a@e Pump t2pe No. o( $ta!e$ LiMuid pumped Dierential head De$i!n ow rate
/HEL7 H2derabad ? = D *< = /oiler (eed water &1&*m ,< m* : hr Page A 94
-inimum reirulation ow Eien2 'peed Power NP'H reMuired
11< m* : hr 1 1< rpm. &811 @w &,.< ml
i! *. ) /oiler eed Pump
*.*.& eed Re!ulatin! 'tation It is the station which is used to regulate the aount of feed water into the econoiser! Kere there are two lines 468
*.*.* Eonomi$er /conoiser is a echanical device intended to reduce energy consu"tion, or to "erfor another useful function like "reheating a Wuid! hey are devices >tted to a boiler which save energy by using the e2haust gases fro the boiler to "reheat the cold water used to >ll it (the feed water)! # coon a""lication of econoier in stea "ower "lants is to ca"ture the waste heat fro boiler stack gases (Wue gas) and transfer thus it to the boiler feed water thus lowering the needed energy in"ut , in turn reducing the >ring rates to acco"lish the rated boiler out"ut ! Table *., ) Eonomi$er 'peiJation$ T2pe Plain7 drainable7 non" $teamin! Tube -aterial 'A&1< 9rA1 OD o( Tube7 mm ,,. Atual Thi@ne$$ o( Tube$7 mm ,. Page A 93
Len!th o( Tube$7 mm Tube pith7 mm a6 Parallel to !a$ path b6 Aro$$ !a$ path 5ater $ide eeti#e heatin! area7 m& 9a$ $ide eeti#e heatin! area7 m& 9a$ ow path area7 m& De$i!n Pre$$ure o( tube$7 @!:m&
*&1<< 1*< 8= *< =10 =&. 1=1.<
*.*., /oiler Drum Stea rus are a regular feature of water tube boilers! It is reservoir of waterstea at the to" end of the water tubes in the water.tube boiler! hey store the stea generated in the water tubes and act as a "hase se"arator for the steawater i2ture! he dierence in densities between hot and cold water hel"s in the accuulation of the hotter water and saturated stea in dru! he se"arated stea is drawn out fro the to" section of the dru! he stea will re.enter the furnace in through a su"er heater, while the saturated water at the botto of stea dru Wows down through downcoers to the ring header fro where the water sent to the boiler Table *. ) /oiler Drum $peiJation$ Con$trution u$ion welded -aterial $peiJation De$i!n pre$$ure7 @!:m& ab$. -aB. operatin! pre$$ure7 @!:m& ab$. De$i!n temperature7
'A"&88 10=., 1=0.& *,.< 1&&<< &<* 100 = &< mm below drum entreline.
Page A 9&
i! *.= ) /oiler Drum
*.*. /oiler 0oiler is an enclosed vessel in which water is heated and circulated until the water is turned in to stea at the re*uired "ressure! Coal is burned inside the cobustion chaber of boiler! he "roducts of cobustion are nothing but gases! hese gases which are at high te"erature coe in contact with dierent heat e2changers and va"orie the water inside the to stea! his stea is further heated in a su"er heater as higher the stea "ressure and te"erature the greater e;ciency the "ower"lant will have in converting the heat in stea in to echanical work! his stea at high "ressure and te"erature is used directly as a heating ediu, or as the working Wuid in a "rie over (turbine) to convert theral energy to echanical work, which in turn is converted to electrical energy! 0oilers are classi>ed ainly into two categories as followingQ ire Tube /oiler In this ty"e the "roducts of cobustion "ass through the tubes which are surrounded by water! hese are econoical for low "ressure only! 5ater Tube /oiler •
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In this ty"e of boiler water Wows inside the tubes and hot gases Wow outside the tubes! hese tubes are interconnected to coon water channels and to stea outlet! #t +PC adri there is a water tube boiler in both stage I and stage II Table *.= ) /oiler 'peiJation$ -anu(aturer /HEL 4C.E. de$i!n6 T2pe Natural irulation7 balaned dra(t7 $mooth tube double pa$$7 $in!le drum7 $in!le reheat diret pul#eri$ed oal:oil Jred7dr2 bottom t2pe. Capait2 0<
*., 'team C2le ierent Co"onents of Stea Cycle 0oiler ru Su"erheater
• • •
• •
• •
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• •
*.,.1 'uperheater # Su"er heater is a device in a stea engine that heats the stea generated by the boiler again increasing its theral energy! Su"er heaters increase the e;ciency of the "ower "lant, and are widely ado"ted! Kere the te"erature of the stea is raised above the saturated te"erature of the stea so that even after isentro"ic e2"ansion in the turbine the wetness of stea reains in the desired region In +PC adri, the boiler has in total $3 su"erheater headers located at various "ositions in the boiler! Su"erheaters are of three ty"es
Table *.0 ) 'uperheater $peiJation$ LT'H Pendant HoriFontal T2pe Con#etion Diretion o( ow Counter Eeti#e heatin! $ur(ae *0<< area7 m& 9a$ ow path area7 m& 0* Total no. o( tube$ ,< O.D.7 mm ,,. Eeti#e len!th7 mm &=,== 9ro$$ len!th7 m *,0<< No. o( ele#:$etion , Tube pith 4a6 Parallel o( !a$ 8= ow7mm 11,.* 4b6 Aro$$ !a$ ow7 mm
Platen '.H. Radiant Parallel 1<80
inal '.H. Con#etion Parallel 1,*
1*.8 &<* ,0.=* 8<< 1<1<< 0
0& &* ,,. *=< 80=< &
0 ,0.&
8:8= 11,.*
*.,.& Reheater ?eheater is a heater which is used to raise the te"erature of stea which has fallen after the e2"ansion in Kigh Pressure urbine! his is done so as to increase the e;ciency of the "ower "lant and to aintain the dryness fraction of the stea within the desired liit! Table *. ) Reheater 'peiJation$ T2pe -aB. operatin! pre$$ure7@!:m& De$i!n pre$$ure7 @!:m& Total irum(erential heatin! $u(ae7
'paed7 $in!le $ta!e ,&.
m& 9a$ ow path area7 m& 'pae between two ban@$ in diretion o( !a$ ow7 mm -ean eeti#e len!th per one tube7 mm 9ro$$ len!th per tube7 mm Total no. o( tube$ Autal tube thi@ne$$ O.D.7 mm Tube material Tube pith 4a6 Parallel to !a$ ow7 mm 4b6 Aro$$ !a$ ow7 mm -ethod o( 3oinin! lon! tube$
11 8<< &<.<<< &&7<<< *, ,0.=*:,.<< 'A &1< 9r A17 'A &1*T117 T && 1<1.= &&.= /utt welded
*.,.* 'team Line$ -ain 'team Line It is the "i"eline which carries the su"erheated stea fro the >nal su"erheater to the KP Cold Reheat Line It is the "i"eline which carries the outlet stea of the KP to the reheaters in the boiler where the te" of the stea is again brought back to &36C at the sae "ressure Hot Reheat Line It is the "i"eline which carries the reheated stea fro the reheaters to the IP
*.,., Conden$er hese condensers are heat e2changers which convert e2haust stea fro its gaseous to its li*uid state at a "ressure below atos"heric "ressure! his is done because handling of the stea is ore di;cult and re*uires ore "ower as co"ared to that for condensed water! he condenser used is a shell and tube ty"e condenser in which stea is in the shell while cooling water is in the tubes! #fter condensing the stea, the cooling water gets heated u" and is sent to the cooling towers to cool it and use it again S"eci>cations of the condenser used in +PC adri is as follows Table *.8 ) Conden$er 'peiJation$ T2pe 'ur(ae t2pe7 double pa$$ with di#ided water boB on$trution. De$i!n .w. ow &&7<< m*:hr Page A 9%
*&<
De$i!n old wate temp. De$i!n ba@ pre$$ure No. o( tube$ Tube O.D. B thi@ne$$7 Tube material
0= mm o( H! 4ab$6 1**< no$. &., B <.0 thi@
'ur(ae area C.5. #eloit2 Pre$$ure drop C.5. $ide C.5. temp ri$e
'tainle$$ $teel welded A'T- A &,8 TP *<, 1*0&0 -& 1.* m:$ ,.1 mw 1<.<
i! *.0 " Conden$er
*. Coolin! 5ater C2le Page A 46
ierent Co"onents of Cooling 7ater Cycle ?aw 7ater ?eservoir 7ater Softening Plant e.ineralied 7ater Plant =orebay Circulating 7ater Pu" Kouse Condenser Cooling ower Intake Channel • • • • • • • •
*..1 Raw 5ater Re$er#oir 7ater is brought to the "lant through sall canal which is further connected to the U""er Ganga Canal! his water is stored te"orarily in a water reservoir before sending it to the water treatent "lant! his water is called raw water and is sent to 7P through ?aw 7ater "u" house
*..& De"-ineraliFin! Plant he "rinci"le "roble in high "ressure boiler is to control corrosion and stea *uality! Internal corrosion costs "ower station crores of ru"ees in re"air without strict control i"urities in stea also for de"osit over turbine blades and noles! he i"urities "resent in water are as follows Q. • • • • • • • • • • •
Un.dissolved and sus"ended solid aterials! issolved slats and inerals! issolved gases Fther inerals ( oil, acid etc!) urbidity E Sedient! Silica! Micro 0iological! Sodiu E Potassiu Salt! issolved Sales Minerals! F9 gas! CF9 gas!
he water treatent "lant is divided in to two "artsQ Page A 4$
•
•
5ater 'o(tenin! Plant 7ater Softening Plant deals with reoving larger solid i"urities by sedientation and by coagulation and Wocculation, and de.infection of water through aeration! Kere, #lu and Chlorine dosing is done so as to reove the hardness "resent in the water! #fter this the water is sent to de.ineraliing "lant and also serves as the drinking water for the +PC townshi" The De"-ineraliFation plant. 4D- plant6 In this "lant all the dissolved inerals are reoved fro the water! he water fro water softening "lant is "assed through S#C (strong acid cation) which contains acidic resins and reove dissolved cations such as Mg, Ca, +a etc! It is then "assed through degasser tower to force out the dissolved carbon dio2ide gas and carbonate ions! hen the water is "assed through the S0# chaber which contains strong basic resins which reove chlorine and sul"hate ions! =ro S0# the water is "assed through M0 (i2ed bed) chaber which reoves both cationic and anionic i"urities , if any, and the water is then sent to M storage tank, fro where it is trans"orted for various uses!
*..* oreba2 #fter the water is cooled in the cooling tower, it goes to the C7 Pu" house through forebay! It connects water fro all the four cooling towers in a single channel which >nally becoes the intake of C7 Pu" house!
*.., Coolin! 5ater Pump Hou$e It circulates the cooling water coing out of the cooling tower to the condenser! It consists of 5 vertical francis, single stage "u"s which take inlet fro the forebay
*.. Coolin! Tower Cooling towers are heat reoval devices used to transfer "rocess waste heat to the atos"here! Cooling towers ay either use the eva"oration of water to reove "rocess heat and cool the working Wuid to near the wet. bulb air te"erature or in the case of closed circuit dry cooling towers rely solely on air to cool the working Wuid to near the dry.bulb air te"erature! In theral "ower "lant, it is used to cool the circulation water which coes out of the condenser! he towers vary in sie fro sall roof.to" units to very large hy"erboloid structures that can be u" to 966 eters tall and $66 eters in diaeter, or rectangular structures that can be over 36 eters tall and 56 eters long! Page A 49
here are two ty"es of cooling towers +atural raught Cooling ower =orced raught Cooling ower In +PC adri, both natural and forced draught cooling towers are used +atural raft is used in Coal 0ased Unit while =orced raft is used in Gas based units • •
Table *.1< ) Coolin! Tower 'peiJation$ T2pe Natural dra(t t2pe No. ,7 1 (or eah unit Con$trution t2pe Rein(ore onrete7 h2perboli7 double ur#ature $hell with a bi! beam at the ba$e $upported on ro@er olumn$ Total hei!ht 110 m /a$e diameter 0.8 m Throat diameter ,=.0 m ,8.00 m Top diameter low &7<<< m*:hr Ran!e o( oolin! 11< Reooled water temp. *&< Ambient wet bulb temp. &0< De$i!n relati#e humidit2 < Approah. <
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i! *. ) Natural Dra(t Coolin! Tower$ Tower (rom in$ide
i! *.8 ) Coolin!
CK#P/? 3
TUR/INE AND 9ENERATOR Page A 43
,.1 Turbine # turbine, is a rotary echanical device that e2tracts energy fro a Wuid Wow and converts it into useful work! # turbine is a turboachine with at least one oving "art called a rotor assebly, which is a shaft or dru with blades attached! Moving Wuid acts on the blades so that they ove and i"art rotational energy to the rotor! he turbine norally consists of several stages with each stages consisting of a stationary blade (or nole) and a rotating blade! Stationary blades convert the "otential energy of the stea into kinetic energy and direct the Wow onto the rotating blades! he rotating blades convert the kinetic energy into i"ulse and reaction forces, caused by "ressure dro", which results in the rotation of the turbine shaft! he turbine shaft is connected to a generator, which "roduces the electrical energy! Kere in heral Power Plant Su"erheated Stea is used as the Wuid to run the turbine
,.1.1 Hi!h pre$$ure Turbine Stea coing fro 0oiler directly feeds into KP at a te"erature of &36C and at a "ressure of $&' kgc9! his turbine is a single Wow 9& stage reaction turbine! #fter e2"ansion the te"erature goes down to 4&9C and "ressure as 36!3 kgc 9! he outlet of the KP is taken back to the reheaters in the boiler through C?K lines where the stea is again heated to &36C at sae constant "ressure!
i! ,.1 ) Hi!h Pre$$ure Turbine
,.1.& Intermediate Pre$$ure turbine Page A 4&
Interediate Pressure urbine (IP) is a 96 2 9 stages, double Wow reaction turbine! #fter coing out of the reheaters, the stea is brought to the IP through K?K lines at &36C te"erature and 4' kgc9 "ressure! he stea is sent in the iddle of the IP fro where it e2"ands in both the directions!
i! ,.& ) Intermediate Pre$$ure Turbine
,.1.* Low Pre$$ure Turbine
i! ,.*) Low Pre$$ure Turbine Page A 4'
Table ,.1 ) Turbine 'peiJation$ -a@e /HEL7 ?RAT5ER? UNION DE'I9N T2pe Tandem ompound7 re!enerati#e7 reheat7 onden$in!7 three 2linder ha#in! $in!le ow HP turbine7 double ow IP K LP turbine. No o( $ta!e$ HP & no. IP &< B & no. LP B & no. T2pe o( HP:IP:LP turbine HPT"Reation7 barrel $in!le ow t2pe LPT"Reation7 double ow aBiall2 $plit t2pe LPT"Reation7 double ow three $hell de$i!n Nominal ratin! &1< -5 Pea@ loadin! &&8 -5 -aB.:-in. $peed *<8<:&< rpm 4,0. to 1. H6 Permi$$ible (or a maBimum o( & hour$ operation durin! the li(e o( the LP bladin! $peed below ,0. H K $peed abo#e 1.H. 5ei!ht o( turbine ,0 tonne 4approB.6
Hei!ht o( Jr$t $ta!e mo#in! blade -ean dia. o( Jr$t $ta!e mo#in! blade Hei!ht o( la$t $ta!e mo#in! blade -ean dia. o( la$t $ta!e mo#in! blade O#erall len!th O#erall width 4with ro$$ around pipe$6 Total eBhau$t area 4LP Turbine6
HPT ,*
IPT ==
LPT 0
=,*
0=
1,0*.
8
1<<
==.
=8
1<,1
&1,,.A
1=.80m 1<. 4approB.6 & B m&
,.& Eletriit2 C2le ierent Co"onents of #ir Cycle Generator /2citer ransforer Unit ransforer Unit #u2iliary ransforer Switch Tard • • •
• •
•
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• •
Interconnecting ransforer Futgoing =eeder
,.* 9enerator he generator works on the "rinci"le of electroagnetic induction! here are two co"onents stator and rotor! he rotor is the oving "art and the stator is the stationary "art! he rotor, which has a >eld winding, is given a e2citation through a set of 4666r" to give the re*uired fre*uency of KX! he rotor is cooled by Kydrogen gas, which has high heat carrying ca"acity of low density! If o2ygen and hydrogen get i2ed then they will for very high e2"losive and to "revent their cobining in any way there is seal oil syste! he stator cooling is done by de.ineralied (M) water through hollow conductors! 7ater is fed by one end by eWon tube! # boiler and a turbine are cou"led to electric generators! Stea fro the boiler is fed to the turbine through the connecting "i"e! Stea drives the turbine rotor! he turbine rotor drives the generator rotor which turns the electroagnet within the coil of wire conductors! Kydrogen gas is used to cool down the rotor! ed water in cooling tower is used to cool down the hydrogen gas! • • • • • •
•
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i! ,., ) 9enerator 4Red6 and Turbine 49reen6
Ratin! o( 9enerator$ u$ed Stage I J 9$6M7 Satge II J 3%6M7 • •
Table ,.& ) 'ta!e I 4&1<-56 9enerator $peiJation$ -a@e /HEL T2pe TH5 " &<1"& Two pole7 2lindrial7 $team turbine dri#en Coolin! 'tator windin! Diretl2 water ooled 'tator ore and Rotor Diretl2 h2dro!en ooled -5 ratin! &1< Rated terminal #olta!e 1=. @# Rated terminal urrent 7=, A Rated power (ator <. la! Rated $peed:(reMuen2 *<<< rpm:< H Eien2 at -C Condition 8. Pha$e onnetion Double $tar
he 9$6 M7 generates $'!& OR three "hase electricity! he voltage is ste""ed u" to 996 OR with the hel" of station transforer and is connected to the switch yard! his electricity is further ste""ed u" to 366OR and then su""lied to the grid Soe of the electricity is ste""ed down to '!'OR with the hel" of Unit #u2iliary ransforer to drive the dierent au2iliaries in the "lant!
,., Tran$(ormer It is a static achine which increases or decreases the #C voltage without changing the fre*uency of the su""ly! It is a device thatQ Page A 4%
ransfer electric "ower fro one circuit to another! It acco"lishes this by electroagnetic induction! In this the two electric circuits are in utual inductive inWuence of each other! It works on =aradays
i! ,. ) 'tation Tran$(ormer
,. 'with %ard #s we know that electrical energy can@t be stored like cells, so what we generate should be consued instantaneously! 0ut as the load is not constants therefore we generate electricity according to need i!e! the generation de"ends u"on load! he switchyard is the "lace fro where the electricity is send outside to the grid! Its ain function is to convert the electricity in the re*uired for and connect to the grid to su""ly this electricity!
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i! ,.= ) 'with %ard
,..1 Ciruit /rea@er Circuit breaker is an arrangeent by which we can break the circuit or Wow of current! # circuit breaker in station serves the sae "ur"ose as switch but it has any added and co"le2 features! he basic construction of any circuit breaker re*uires the se"aration of contact in an insulating Wuid that servers two functionsQ e2tinguishes the arc drawn between the contacts when circuit breaker o"ens! It "rovides ade*uate insulation between the contacts and fro each contact to earth! •
•
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CHAPTER
AIR AND LUE 9A' C%CLE .1 Air C2le ierent Co"onents of #ir Cycle =ans Priary #ir =an =orced raft =an Induced raft =an Seal #ir =an Scanner #ir =an #ir Preheter Cold #ir uct Kot #ir uct 7ind 0o2 •
• • • • •
• • • •
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i! .1 ) lue 9a$ C2le
.& an$ .&.1 Primar2 Air an 4PA an6 It is the fan which is used to carry "ulveried coal fro the coal ills to the furnace! he P# =an takes suction fro the = fan outlet fro where the air is sent to the air "reheaters! =ro #PK, the heated air is sent to the coal ills! Keating of "riary air is done so as to reove the oisture content fro the coal so as to facilitate the cobustion "rocess! Table .1 ) PA an $peiJation$ -anu(aturer /HEL No. per boiler T2pe
-edium handled Loation
Two ND+ 18 HER?ALE' ABial double $ution radial di$har!e $impl2 $upported Clean air (rom D (an di$har!e 9round mounted on onrete oor Page A 34
Orientation Capait2 Total head de#eloped Temp. o( medium 'peed
Top deli#er2 with , < inlined $ution hamber. 00., u.m:$e. 8*1 mmw *< 1,< rpm
.&.& ored Dra(t an 4D an6 It is the e2ternal fan "rovided to give su;cient air for cobustion! he forced draught fan takes air fro the atos"here and, wars it in the air "reheater for better cobustion and in1ects it via the air noles on the furnace wall! his air is called secondary air! Table .& ) D an $peiJation$ -anu(aturer /HEL No. per boiler T2pe -edium handled Loation Orientation Capait2 Total head de#eloped Temp. o( medium 'peed
Two AP1"18:11 Clean air 9round mounted on onrete oor HoriFontal aBi$ 1,,.0 u.m:$e **, mmw. << 1,< rpm
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i! .& ) ored Dra(t an 4bottom le(t6 and Primar2 Air an 4bottom ri!ht6
.&.* Indued Dra(t an 4ID an6 he induced draft fan assists the = fan by drawing out cobustible gases fro the furnace, aintaining a slightly negative "ressure in the furnace to avoid back>ring through any o"ening! #t the furnace outlet and before the furnace gases are handled by the I fan, >ne ash "articles carried by the outlet gases are reoved by /SP to avoid atos"heric "ollution! Table .* ) ID an $peiJation$ -anu(aturer /HEL No. per boiler Two T2pe ND+ *1 'IDOR ABial double $ution radial di$har!e -edium handled lue !a$ Loation 9round mounted Orientation /ottom deli#er2 with ,< inlined $ution Capit2 &&& u.m:$e Total head ,1 mmw de#eloped Temp. o( medium 1,< 'peed 0,< rpm
i! .* ) Indued Dra(t an
.* lue 9a$ C2le Page A 3&
ierent Co"onents of =lue Gas Cycle =urnace Su"erheater ?eheater /conoiser #ir Preheater /lectrostatic Preci"itator Induced raft =an Chiney • • • • • • • •
.*.1 Air Preheater #ir "reheater is a general ter to describe any device designed to heat air before another "rocess (for e2a"le, cobustion in a boiler)! he "ur"ose of the air "reheater is to recover the heat fro the boiler Wue gas which increases the theral e;ciency of the boiler by reducing the useful heat lost in the Wue gas! #s a conse*uence, the Wue gases are also sent to the Wue gas stack (or chiney) at a lower te"erature allowing si"li>ed design of the ducting and the Wue gas stack! here are two ty"es of #ir Preheaters $! ?ecu"erative #ir Preheater 9! ?egenerative #ir Preheater In +PC adri, a regenerative air "reheater is used! /very unit consists of two air "reheaters! It is of two ty"es 0isector #ir Preheater risector Preheater Kere, a trisector ty"e "reheater is used! In this the whole circular area is divided into three sectors of $56 (for Wue gas), $96 (for secondary air) and '6 (for "riary air) • •
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i! ., ) Air Preheater
.*.& Eletro$tati Preipitator #n /lectrostatic "reci"itator (/SP) or electrostatic air cleaner is a "articulate device that reoves "articles fro a Wowing gas (such as air) using the force of an induced electrostatic charge! /lectrostatic "reci"itators are highly e;cient >ltration devices, and can easily reove >ne "articulate atter such as dust and soke fro the air stea ! Kere /SP is used to se"arate ash "articles fro the Wue gases! # C current of :& OR is "assed through the electrodes which ionies the ash "articles! hese "articles then get de"osited on the collecting electrodes! #utoatic ra""ing systes and ho""er evacuation systes reove the collected "articulate atter while on line allowing /SPs to stay in o"eration for years at a tie Table ., ) Eletro$tati Preipitator -anu(aturer T2pe 9a$ ow rate Temperature No. o(!a$ path$ per boiler No. o( Jeld$ in $erie$ in eah !a$ pa$$ Treatment time +eloti2 o( !a$ at eletrode Fone on total area 9uarantee o( olletion eien2 (or de$i!n ondition$ Power on$umption No. o( row$ o( olletin! eletrode$ per Jeld
$peiJation$ /HEL AA"=B,"=81*"& *1&.0 u.m : $e 1*=< our 'iB *&.1 $eond$ <.*8 m:$e 88.8 < @w &,
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No. o( olletin! eletrode plate$ per Jeld total no7 o( olletin! plate$ per boiler Nominal hei!ht o( olletin! plate Nominal len!th o( olletin! plate 'peiJ olletin! area 4with one Jeld out o( $er#ie6 T2pe o( emmitin! eletrode$ 'iFe o( emmitin! eletrode$ No. o( emmitin! eletrode$ in the (rame (ormin! one row No. o( emittin! eletrode$ in eah Jeld Total no. o( emittin! eletrode$ per boiler Total len!th o( emittin! eletrode per Jeld
1,, *,= 1*. m 0< mm &1,., $M.m:u.m:$e 'piral with hoo@$ Dia &.0 mm , Jeld$ 1&,& &8< =8=0.=& m.
i! . ) Eletro$tati Preipitator
.*.* Chimne2 # =lue gas stack is a ty"e of chiney, a vertical "i"e, channel or siilar structure through which cobustion "roduct gases called Wue gases are e2hausted to the outside air! =lue gases are "roduced when coal or oil is burnt in the furnace! =lue gas is usually co"osed of carbon dio2ide (CF9) and water va"our as well as nitrogen and e2cess o2ygen reaining fro Page A 35
the intake cobustion air! It also contains a sall "ercentage of "ollutants such as "articulates atter, carbon ono o2ide, nitrogen o2ides and sul"hur o2ides! he Wue gas stacks are often *uite tall so as to dis"erse the e2haust "ollutants over a greater area and thereby reduce the concentration of the "ollutants to the levels re*uired by governent-s environental "olicies and regulations! Table . ) Chimne2 'peiJation$ No. o( (uel , NO. 5ind $hield material Rein(ored onerete ue material 'teel Chimne2 hei!ht &&< m Chimne2 ba$e diameter *&.80 Chimne2 ra(t diameter ,*.1&< m lue diameter ,. m
i! .= ) Chimne2
Page A 3%
., A$h Handlin! Plant #sh handling refers to the ethod of collection, conveying, interi storage and load out of various ty"es of ash residue left over fro solid fuel cobustion "rocesses! he ost coon ty"es of ash include botto ash, Wy ash and ash clinkers resulting fro the cobustion of coal! #sh handling systes ay e"loy "neuatic ash conveying or echanical ash conveyors! # ty"ical "neuatic ash handling syste will e"loy vacuu "neuatic ash collection and ash conveying fro several ash "ick u" stations with delivery to an ash storage silo for interi holding "rior to load out and trans"ort! Pressuried "neuatic ash conveying ay also be e"loyed! Coarse ash aterial such as botto ash is ost often crushed in clinker grinders (crushers) "rior to being trans"orted in the ash conveyor syste! Rery >nely sied Wy ash often accounts for the a1or "ortion of the aterial conveyed in an ash handling syste! It is collected fro baghouse ty"e dust collectors, electrostatic "reci"itators and other a""aratus in the Wue gas "rocessing strea! here are two ty"es of ash in a Power PlantQ /ottom A$h! It refers to "art of the non.cobustible residues of cobustion! In an industrial conte2t, it usually refers to coal cobustion and co"rises traces of cobustibles ebedded in foring clinkers and sticking to hot side walls of a coal.burning furnace during its o"eration! he "ortion of the ash that esca"es u" the chiney or stack is, however, referred to as Wy ash! he clinkers fall by theselves into the water or soeties by "oking anually, and get cooled! l2 A$h It is one of the residues generated in cobustion, and co"rises the >ne "articles that rise with the Wue gases! In an industrial conte2t, Wy ash usually refers to ash "roduced during cobustion of coal! =ly ash is generally ca"tured by electrostatic "reci"itators or other "article >ltration e*ui"ents before the Wue gases reach the chineys of coal. >red "ower "lants! •
here are basically 9 ty"es of ash handling "rocesses undertaken by #KPQ ry ash syste #sh slurry syste • •
Dr2 A$h '2$tem ry ash is re*uired in ceent factories as it can be directly added to ceent! Kence the dry ash collected in the /SP ho""er is directly dis"osed Page A &6
to silos using "ressure "u"s! he dry ash fro these silos is trans"orted to the re*uired destination! A$h 'lurr2 '2$tem #sh fro boiler is trans"orted to ash du" areas by eans of sluicing ty"e hydraulic syste which consists of two ty"es of systesQ /ottom a$h $2$tem In this syste, the ash slag discharged fro the furnace is collected in water i"ounded scra"er installed below botto ash ho""er! he ash collected is trans"orted to clinkers by chain conveyors! he clinker grinders churn ash which is then i2ed with water to for slurry! A$h water $2$tem In this syste, the ash collected in /SP ho""er is "assed to Wushing syste! Kere low "ressure water is a""lied through nole directing tangentially to the section of "i"e to create turbulence and "ro"er i2ing of ash with water to for slurry! Slurry fored in above "rocesses is trans"orted to ash slurry su"! Kere e2tra water is added to slurry if re*uired and then is "u"ed to the du" area
i! .0 ) H2drobin$
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i! . ) Dr2 A$h 'ilo$
CONCLU'ION he industrial training has "roved to be *uiet fruitful! It "rovided an o""ortunity for encounter with such huge achines! he architecture of the "ower "lant the way various units are link and the way working of whole "lant is controlled ake the student realie that engineering is not 1ust learning the structure descri"tion and working of various achines, but the greater "art is of "lanning "ro"er anageent! he "ractical e2"erience that I have gathered during the overview training of theral "ower "lant having a large ca"acity of 9'4: M7 in 3& days will be very useful and a ste""ing stone in building bright "rofessional career in future life! It gave e large s"ectru to utilie the theoretical knowledge and to "ut it into "ractice! he trouble shooting activities in o"eration and decision aking in case of crisis ade e ore con>dent to work in the industrial atos"here! Moreover, this overview training has also given a self.realiation E hands.on e2"erience in develo"ing the "ersonality, inter"ersonal relationshi" with the "rofessional e2ecutives, stas and to develo" the leadershi" ability in industry dealing with workers of all categories! I would like to thank everybody who has been a "art of this "ro1ect, without who this "ro1ect would never be co"leted with such ease!
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