sammi kapco report(electrical )

7/25/2019 Sammi Kapco Report(electrical )

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Abstract

Samman sammi

03475070922

The report is about my internship tenure which made me learn the basics of a combined cycle power

plant. There are ten Gas turbines and 10 HRSGs and 5 steam turbines (one steam turbine with every two

as turbines! thus successfully followin enery economy policy. The au"iliary systems with the main

units are e"tremely efficient at #$%&'.$ very passionate manaement a hihly s)illed and disciplined

man power and most importantly their mutual coordination ma)es #$%&' )nown all


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*

Samman sammi

03475070922

Acknowledgement

Than)s to Almighty ALLAH +H' ave me the strenth and will to o out in search of )nowlede and

+H' is always our reatest well wisher.

, would than) Engr !ahmood "ahim # Engr Ari$ !ahmood who has assisted me throuhout my

internship tenure. -esides his enineerin s)ills and )nowlede they are thorouhly a well disciplined

personality. , would always remember their ditch efforts to ma)e me and my fellows entanled in

discussions that ultimately proved to be very fruitful .,t was a real feast bein with him.

, am very oblied to all the personalities who were always there whenever , as)ed for help. ,t was really

a very ood e"perience to be at %A&'(


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%A&'() A* +*,"(-.',+(*

/achinin $n ,ntroduction

%ower %lant Technoloy

Samman sammi

03475070922

TABLE OF CONTENTS

'(!/+*E- '0'LE &(1E" &LA*,

,ntroduction

unctional 2escription

2AS ,."/+*E # +,S 1("%+*2 &"+*'+&LE

/ain components of as turbine +or)in

%rinciple (-R$3T'4 &3&6!

,."/+*E 1ASH+*2

General 2escription

%re washin

+ashin

S,EA! ,."/+*E A*- +,S 1("%+*2 &"+*'+&LE

FUELING OF THE PLANT


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7

Samman sammi

03475070922

/ain &omponents of a Steam Turbine cycle

L./"+'A,+(* SS,E!


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5

Samman sammi

03475070922

KAPCO: AN INTRODUCTION

Kot Addu Power Compan L!m!ted "KAPCO#

On June 27, 1996, following international competitive bidding by

the Privatization ommi!!ion "overnment of Pa#i!tan $the

%Privatization ommi!!ion%&, the management of '(PO wa!

tran!ferred to )ational Power $now *nternational Power& of the

+nited 'ingdom, which acting through it! !ub!idiary )ational

Power $'ot (ddu& imited $%)P'(%&, bought !hare!repre!enting a 26- !ta#e in '(PO. ater, )P'( bought a

further 1/- !hareholding in '(PO increa!ing it! total

!hareholding to 06-.

'ot (ddu Power Plant $the %Power Plant%& wa! built by the Pa#i!tan ater and Power evelopment

(uthority $%(P(%& in five pha!e! between 1934 and 1996 at it! pre!ent location in 'ot (ddu, i!trict

5uzaffargarh, Punab. *n (pril 1996, 'ot (ddu Power ompany imited $%'(PO%& wa! incorporated a!

a public limited company under the ompanie! Ordinance, 193 with the obective of ac8uiring the

Power Plant from (P(. he principal activitie! of '(PO include the owner!hip, operation and

maintenance of the Power Plant.

S$are$o%d!n& Stru'ture:

:ollowing the !ucce!!ful completion of the Offer for ;ale by the Privatization ommi!!ion $on behalf of

(P(& in :ebruary 2//4, 13- of '(PO


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A Lead!n& Power Generat!on Compan

Lo'at!on

he Power Plant i! !ituated in i!trict 5uzaffargarh, Punab, 9/ '.5. north we!t of 5ultan onthe left ban# of the ?iver *ndu! at a di!tance of 16 '.5. from aun!a @arrage. he area i!

!urrounded by agricultural land on the north and we!t !ide of 'ot (ddu.

Samman sammi

03475070922

PO(ER PLANT TECHNOLOG)

'ot (ddu Power ompany imited $%'(PO%& wa! incorporated in 1996 with the purpo!e to

contribute economical power to the national grid. '(PO ha! !hown e>ceptional re!ult! in thearea of plant maintenance, availability, 8uality !tandard! and financial performance. *n (pril

2//4 '(PO wa! formally li!ted on all the three ;toc# =>change! of Pa#i!tan. '(PO i!

committed to contributing to Pa#i!tan

continuou!ly improving it! performance through efficient !y!tem!, capable wor#force and good

governance.

he Power Plant i! a multiAfuel ga!Aturbine power plant with the capability of u!ing 0 different

fuel! to generate electricity, namelyB )atural "a!, ow ;ulphur :urnace Oil and Cigh ;peed ie!el to

generate electricity. he Power Plant i! al!o the only maor plant in Pa#i!tan with the ability to !elf !tart

in ca!e of a country wide blac#out.

'(PO i! Pa#i!tan

5. he Power Plant compri!e! of 1/ multi fuel fired ga! turbine! and 4 !team turbine! in!talled in 4pha!e! between 1934 and 1996. he!e turbine! are divided into 0 energy @loc#! with each @loc#

having a combination of ga! and !team turbine!. he Power Plant

'(PO to u!e the wa!te heat from the ga! turbine e>hau!t to produce !team in the Ceat ?ecovery

;team "enerator, which in turn i! u!ed to run the !team turbine! thereby re!ulting in fuel co!t efficiency

and minimum wa!tage.


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&LA*, E*E"AL 'HA"A',E"+S,+'S

/lock

GT 1:* and ST ;:10

/anufacturer Siemens Germany

&apacity of Gas turbine *s

Samman sammi

03475070922


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?

,n a combined cycle power

plant (&&%%!: or combined

cycle as turbine (&&GT!plant: a as turbine enerator enerates electricity and the waste heat is used to ma)e steam to enerate

additional electricity via a steam turbine@ this last step enhances the efficiency of electricity eneration. ,n

a thermal power plant: hihAtemperature heat as input to the power plant: usually from burnin of fuel: is

converted to electricity as one of the outputs and lowAtemperature heat as another output. $s a rule: in

Samman sammi

03475070922

1/

1/

4

16//5

1415

1045

106/5

6 > 102 'D

6 > 22/ 'D

04,6675h

G$S TBR-,46S

HRSGs

ST6$/ TBR-,46S ,4ST$62

&$%$&,T3 /$C. '$2

G646R$T,'4

'$2 $&& T' ,2& T6ST (1;;8! '$2

$&& T' $2& T6ST (*007! 4B/-6R '

6626RS

/$C G646R$T,'4 ,4 '46 2$3

'ombined cycle &ower &lant

+*,"(-.',+(*)

$ combined cycle is characteristic of a power producin enine or plant that employs more than one

thermodynamic cycle. Heat enines are only able to use a portion of the enery their fuel enerates

(usually less than 50D!. The remainin heat (e.. hot e"haust fumes! from combustion is enerally

wasted. &ombinin two or more EcyclesE

/",(* ''LE

"A*%+*E ''LE


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;

order to achieve hih efficiency: the temperature difference between the input and output heat levels

should be as hih as possible. This is achieved by combinin the Ran)ine (steam! and -rayton

1orkingrincile o$ acombinedcycle owerlant

Samman sammi

03475070922

$n open circuit as turbine cycle has a compressor: a combustor and a turbine. ,n this type of cycle: the

input temperature to the turbine (the firin temperature!: is relatively hih (;00 to 1:700 0c!. The output

temperature of the flue as is also hih (750 to 850 0c!. This is therefore hih enouh to provide heat for

a second cycle which uses steam as the wor)in fluid@ (a Ran)ine cycle!.

,n a combined cycle power plant: the heat of the as turbineFs e"haust is used to enerate steam by

passin it throuh a heat recovery steam enerator (HR5G! with a live steam temperature between 7*0

and 5?0 0c. The condenser of the Ran)ine cycle is usually cooled by water from a la)e: river: sea or

coolin towers. This temperature can be as low as 15 &.

&ombined cycle plants are usually powered by natural as: althouh fuel oil: synthesis as: urnace 'il:

Hih speed 2iesel or other fuels can be used. The supplementary fuel may be natural as: fuel oil:


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'(!/+*E

''LE AS

,."/+*E

2AS

,."/+*E

Samman sammi

03475070922

,n a thermal power station water is the wor)in medium. Hih pressure steam reuires stron: bul)y

components. Hih temperatures reuire e"pensive alloys made from nic)el or cobalt:rather than

ine"pensive steel. These alloys limit practical steam temperatures to 855 '( while the lower temperature

of a steam plant is fi"ed by the boilin point of water. +ith these limits: a steam plant has a fi"ed upper

efficiency of 5 to 7*D.

-+66E"E*'E /E,1EE* (&E* A*- '(!/+*E- ''LE)


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$ as turbine also called a combustion turbine is a rotary enine that e"tracts enery from a flow of

combustion as. ,t has an upstream compressor coupled to a downstream turbine: and a combustion

chamber inAbetween. 8as trbine may also refer to Iust the turbine element.!

6nery is added to the as stream in the combustor: where air is mi"ed with fuel and inited. &ombustion

increases the temperature: velocity and volume of the as flow. This is directed throuh a noJJle over the

turbine blades spinnin the turbine and powerin the compressor.

6nery is e"tracted in the form of shaft power compressed air and thrust in any combination

and used to power enerators

.

Samman sammi

03475070922


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1*

!A+* '(!&(*E*,S (6 A 2AS ,."/+*E

+ntake Air 6ilters

These provide clean: filtered and dust free air to

the compressor inlet.

'omressor

$ir is drawn in and compressed when passin throuh rows of rotatin blades and stationary

vanes. There are total 18 staes in compressor. $t the end of the compressor: before reachin the

combustion chamber: the air is compressed to about 10 bar and has been heated to about 10& by

compression.

'ombstor : 'ombstion 'hamber

The combustor or combustion chamber is the heart of the enine@ here the combustible mi"ture of

compressed air and fuel is burnt. The hot as output temperature becomes 10000& to 100&@ its volume

becomes more than doubled by the temperature rise where as pressure remains constant.

&ompressed air havin about 10 bars pressure and 50& temperature. The pressuriJed air that

delivered by the compressor flows around the hot as path and outer casin paths. &ooled air: which

came from compressor: cooled down the inner casin of combustion chamber. &ompressed air serves as a

heat e"chaner of the combustion chamber.

-oth combustion chambers have eiht separate burners. These burners may euip aseous: liuid

or dual fuel operation. The oil burners desined on reverse flow principle without any movin parts. Hih

temperature combustion is provided with refractory linins on its upper portion. These combustion

chambers are very easy to assemble and disassemble: so they are easy for inspection and they have ood

accessibility for all components. ,n case of as :it has two modes of combustion.

K0 2,BS,'4 /'26 in which burner has a lon flame burnin.

K1 %R6/,C /'26 in which burner has a cattle shape flame burnin.

Samman sammi

03475070922


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,rbine

The turbine section converts the thermal and )inetic enery of the combustion ases into

rotational mechanical enery. Gas turbines li)e steam turbines have three or four staes of rotatin and

stationary blades. However@ because as turbines wor) with lower initial inlet pressures: they have fewer

staes and less chane in blade heiht from inlet to e"haust. Turbines normally consist of combination of

impulse and reaction types. The as turbine also differs from the steam turbine in@

K0 the type of bladin material used

K1 the lower ratio of blade lenth to wheel diameter

K* less number of turbine staes

lue ases flow to the turbine with a very hih velocity v of about ?0 mjs (*?? )mhr!. ,t means it

has hih )inetic enery. The )inetic enery of flue ases is converted to mechanical enery when flue as

is e"panded in the staes of turbine transferrin its enery to the turbine rotor.

The volume of flue ases is increased by e"pansion and thus temperature is decreased and at the e"haust

it is about 500&

The turbine parts which are mechanically stressed are at the same time subIect to very hih

temperature: so that these parts are desined with special material and coolin paths are provided for

coolin air to flow.

E;hast di$$ser

,t diverts the deAeneriJed (but still hot! flue ases into the ambience to complete the cycle. ,t is

fitted with filter and silencer.

/earings)

-earin are used to lift the shaft: to ma)e the vibration of rotor as small as possible and to ma)e

the friction durin the movement of the shaft. $s shaft is connected with bearin: this shaft is lifted by oil

flowin in the bearin. The main purpose of usin oil in these bearins is coolin of bearins which are

heated because of runnin of the shaft. riction is also reduced when we use oil in the bearin.

Samman sammi

03475070922


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Samman sammi

03475070922

.

,."/+*E 1ASH+*2

1hy is it necessary to 7 hors the wheel space temperature reaches 50 '

K7 This time limit is usually for summers and for winters this time is comparatively less.

1ASH+*)

K0 Then Turbine is iven Crank start at crank speed of 475 rm with the help of startin motor.

K1 Then Washing Pump is started simultaneously.

K* Hot water at a temperature of ?0c is used to wash turbine blades


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1. +$SH,4G ,S &$RR,62 'BT 'R *5 minutes.

*. The Turbine rotor is brouht at Jero rpm after 25 min washin.

. 2urin this time the temperature of wheel space is about =0 &. $t this temperature Thermal stresses

are avoided and sain is thus avoided.7. Then 40 min are iven without any operation while rotor remains at Jero rpm.

5. Then after 70 mins turbine is iven cran) speed with the help of startin motor and washin is aain

carried out for *5 mins.

8. rom now onwards machines are started normally.

9. The whole Turbine washin is to be ta)en out within 1* hours and machine must be made available

within this time.

Samman sammi

03475070922


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S,EA! ,."/+*E

Samman sammi

03475070922

.

E*E"AL -ES'"+&,+(*)

$ Steam turbine is a turbine that wor)s with the help of superheated steam that has no moisture. +e need

moisture free steam because of certain reasons. or e"ample the moisture may cause rust and the surface

of blades corrodes. The blades of a turbine are very e"pensive and there replacement causes wastae of

hue sum of money and time which increase cost of enery production and this renders a hue loss to the

company.

$ combined cycleemploys as and steam turbines. ,ts called a combined cycle because the e"haust ases

obtained by utiliJin as in the as turbine after its combustion in the combustion chamber. Thetemperature of these hot e"haust ases is very hih ranin from about 480 to 510 &. ,nstead of

wastin such a hue amount of enery into the atmosphere this enery of e"haust ases are used in steam

turbine to produce superheated steam to run a steam turbine.

$t %A&'( a steam turbine is installed with every two as turbines. The e"haust ases of each as

turbine are utiliJed in HEA, "E'(?E" S,EA! E*E"A,(" 8H"S) which is a nonA

conventional boiler. $ complete description of HRSG is discussed later.

Two HRSG boilers produce superheated steam that runs a steam turbine. The efficiency of combined

cycle is hiher than a closed cycle. ,ts about 35 @ to 40 D.whereas the efficiency of a as turbine is

25 D to 30 D.$lthouh the efficiencies may vary dependin upon the desins of particular as turbines

and steam Turbines. Here these 6fficiencies are for S+E!E*S as turbine and steam turbine. S,6/64S

is Turbine manufacturer based in ermany.

+hen a sinle Gas Turbine is functionin then only one HRSG system wor)s for that as turbine and

therefore load of steam turbine is halved.


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S'HE!A,+' -+A"A! (6S,EA! ,."/+*E

Samman sammi

03475070922

/ain components of a steam Turbine are discussed as below


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1?

Samman sammi

03475070922

!ain 'omonents o$ a Steam ,rbine cycle)

K0 -oiler(HRSG!

K1 Turbine

K* &ondenser

K %ump

4ow they are discussed in detail separately alon with their au"iliaries and other components

/(+LE" 8H"S)

The e"haust ases of a as turbine are at a hih temperature and such hot ases are utiliJed in Heat

Recovery Steam Generator (HRSG! . The efficiency of HRSG is relatively hiher than conventional

boilers i.e. 40@ to 45 D whereas the efficiency of conventional boilers is about 35 0(0 and that of

-urners -oiler is 32@ to 40 D.

The HRSG has the capacity of about *00 tons of

steam production in it. There are different staes

of a HRSG.There are enerally four staes

1.L& EBaorator

2H& EconomiCer

3H& EBaorator

4Serheater

L& EBaarator)

The % 6vaporator is basically a Heat 6"chaner (

parallel flow ! consistin of a bundle of tubes

confined in a lare shell or cylinder.


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Samman sammi

03475070922

The hot water comin from hot well passes throuh these tubes.The hot water at a temperature of about

25 ' to 30 ' from feed water tan) at low pressure than atmospheric pressure flow throuh these

tubes.The water flows trouh these tubes with the help of ow %ressure %umps at eed +ater %umps

-uildin where these pumps pic) hot water from feed water tan) and ma)e it flow throuh % 6vaporator

tubes by first brinin it in L& -".! that is connected with % 6vaparator.% 2rum maintains low

pressure saturated steam in it ..The % 6vaporator is the top most stae a of vertically desined HRSG.The e"haust ases of a as

turbine reach % 6vaporator at the last when the temperature of these ases has been utiliJed in first three

staes. The temperature of these ases at this stae is about =0 &.+hen these ases passes across the

water containin tubes it oes throuh a phase chane where water is converted into steam with a little

increase in temperature. ,he Latent heat is added in water due to which it is converted in steam by

maintainin its temperature.

$bout :5th volume of water in % 2rum is converted into saturated steam and rest of the water )eep

flowin in cycle throuh tubes or % 6vaporator until it is also converted into saturated steam.The level

of % 2rum is maintained at certain level which is controlled throuh automatic level detectors. These

send electrical sinals to &entral &ontrol Room where the readins are viewed on computer screen.

4ow the low pressure saturated steam produced in % 6vaporator oin throuh % 2rum that is used for

the purpose of 2earation in -EA"A,("

-EA"A,(" # its 6nction)

26$R$T'R is drum mounted Iust below eed +ater tan) ($s shown in the fi!. The purpose of

2earator is to deAair the hot water at a temperature of 1*5 & to 1; & comin from the Hot+el1. $

2earator has two inlets. 'ne form hot well and the other from % 2rum.The hot water comin from the

Hot +ell is showeed in the dearator and low pressure saturated steam is blown throuh this showered

water. $s air becomes lihter by heatin therefore by mi"in steam with this showered water the

temperature of air available in hot water increases and it rises and finally it is drained out from 2earator

top. The hot water collected at the bottom of 2earator drum is airAfree and is then used convert into steam

in HRSG.


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*0

Samman sammi

03475070922

2 H& E'(*(!+DE")

Hih %ressure (H%! 6conomiJer is also a heat e"chaner (counter flow! consistin of a bundle of tubes.

Hih %ressure eed water %umps placed in the eed +ater %umps -uildin ta)e water from eed +ater

Tan) placed below 2earator and ma)e it flow throuh H% 6conomiJer. Hih pressure is developed with

the help of Hih %ressure eed %umps. Here at steam turbines 11 L 1* impeller type &entrifual pumps

are bein used for this purpose(%ump has been viewed in detail!. Hih pressure is developed so that

ma"imum heat can be absorbed in the economiJer by water at hiher pressure (The boilin point of a

liuid increase with an increase in pressure!.

The flue ases e"chane heat to hot water in the tubes of H% 6conomiJer and raise its temperature to

about 170 &$t this heat e"chaner there is a sensible heat addition where there is an increase in

temperature of water in the tubes instead of phase chane (steam!. This hih temperature water flows

down to H% 2rum.

3 H& E?A&("A,(")Hih %ressure 6vaporator is also another heat e"chaner (%arallel low! consistin of a bundle of tubes

throuh which hot water comin from second stae of the HRSG flows at hih pressure.

$s discussed before that water comes in H% 2rum from 6conomiJer. Then this hih temperature water

from H% 2rum is ta)en from suction pump and made flown throuh H% 6vaporator where there is atent

Heat $ddition into the water.

The water is converted into hih pressure saturated steam. This steam then oes aain in H% 2rum where

it maintains hih pressure in which hih pressure steam is present over a certain level of water. This H%

steam whose temperature is about *90 & flows throuh the last stae of HRSG called superheater whereaswater that has not been converted into steam in the H% 6vaporator is brouht aain into H% 2rum by

Reciprocatin %ump.

.


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*1

Samman sammi

03475070922

4 S.&E"HEA,E")

Superheater is another type of heat e"chaner (counter flow! consistin of a bundle of thin walled tubes

for the ma"imum rate of heat e"chane. This part of the HRSG is located directly in front of the e"haust

section where flue ases at a temperature ranin from 7?0 & to 500 & are comin out. Superheater

utiliJes the ma"imum temperature of hot flue ases and there is a sensible heat addition in the saturated

steam comin from H% 2rum@ thus increasin temperature of steam in the tubes and ma)in saturatedsteam superheated and moisture free. The temperature of this superheated steam is about 7?0 & to 500 &.

This superheated steam at pressure of about 5 -ars then runs the steam turbine

'(*-E*SE")

E*E"AL A""A*E!E*,)

The &ondenser consists of a hotwell and a shell of rectanular shape: on which is placed a pyramidal

nec) which is connected to the turbine e"haust hood by means of the e"pansion Ioint and the rectanular

nec).

The condenser is placed directly on concrete foundations with no fle"ible suspensions ( or sprins! or

counter reaction devices.

&onnection between the condenser hotwell and the condensate e"traction pumps is provided by means of

pipins. 6ach of the four tube bundles is fed throuh an inlet and outlet waterbo" which is bolted toether

to the tube sheet. The water bo"es are specially desined to uniformly distribute the coolin water flow in

all tubes. The four tube -undles are identical.

The followin main circuits are placed in the condenser shell

2rain issuin from the flash tan)

$ir and 4onAcondensable ases e"traction device.

/a)eAup water.

/ain &omponents%arts

K +ater -o"es

K -undles

K Tube -undles

K $ir coolers

K Tube sheets

K 6"haust 4ec)

K 5ower 6"haust 4ec)

K Bpper e"haust nec)

K Stainless steel e"pansion Ioint installation

K Supports and $nchorin.

6.EL+*2 (6 &LA*,


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**

Samman sammi

03475070922


23/26

*

Samman sammi

03475070922

Since the plants at )apco run on combined cycle which utiliJes basically two types of fuels i.e. Liid L

aseos

The liuid fuels are

K urnace oil

K Hih Speed 2iesel 'il (HS2!

+hile Gaseous uel is purely the *atral

as 'btainin of the fuel

iuid uel is obtained from two sources

i &akistan State (il 8&S(

%a)istan State 'il is the maIor contractor for providin ow Sulphur urnace 'il (S'! to #apco.

This ' is ntreated and raw form. The oil reaches the plant throuh two ways

*. %ipe ine from /ahmood #ot 'il 2epot.

. 'il Tan)ers

1hy LS6( is sed at %A&'(

sammi kapco report(electrical )

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