mime4220 power plant engg hanout sem 2 2013-14(1)

8/21/2019 MIME4220 Power Plant Engg Hanout Sem 2 2013-14(1)

1/87

MINISTRY OF MANPOWERDIRECTORATE OF TECHNOLOGICAL EDUCATION

HIGHER COLLEGE OF

TECHNOLOGY

ENGINEERING DEPARTMENT

MECHANICAL ENGINEERING SECTION

Specialization: Mechanical EngineeringLevel: Baccalaureate

Course Name: Power Plant Engineering

Course Code: MIME 4!

Semester: II "!#$%#4&

Student Name

Student I' No(

Name o) the *acult+: Kuppuraju Bommannan

MIME4220 Power Plant Engineering Page 1


2/87

Contents

Chapter ,itle Pages

# Energ+ -esources and Energ+ Conversion Methods ,o ProduceElectric Power in .man

/%#$

1.1 Oil Reserves and Production 6

1.2 Enhanced Oil Recovery Proects. !

1." #atural $as Reserves and Production... %

1.4 &i'ue(ied #atural $as 11

1.) Electricity Production. 11

1.6 Energy *onversion +ethods 12

Modern -an0ine c+cle #4%$#

2.1 Introduction.. 14

2.2 *lassi(ication o( Power Plant *ycles.. 14

2." ,i+-le Ranine cycle 1)

2.4 Ranine cycle with su-er heat..... 1/

2.) Ranine cycle with Reheat.. 20

2.6 Ranine cycle with Regeneration 2)

2.! Ranine cycle with irreversiility.. 2/

$1eat -ate2 *an2 *lame ,emperature and Com3ustion ir-e5uirements

$%4!

".1 Introduction... "2

".2 eat Rate.. "2

"." 3an. "4

".4 3la+e e+-erature. ")

".) *o+ustion 5ir Re'uire+ents.. "6

4 ,u3e -e5uirements to Condenser and *eed 6ater 1eater4#%44

4.1 Introduction.. 41

4.2 *ondenser... 41

4." 3eed ater eater.................................. 41

4.4 ue and Pi-e Re'uire+ents .. 41

7 Blade Shape and 6or0 .utput Calculations 47%7!

).1 Introduction.. 4)



3/87

).2 #o+enclature o( aero(oil cross section 4)

)." urine ,tages .. 46

).4 *lassi(ication o( stea+ turine ..... 46

).) or out-ut o( single turine stage.. 4!

/ 8as ,ur3ine 7#%/!

6.1 Introduction... )1

6.2 O-en *ycle $as urine... )1

6." *losed *ycle $as urine. )2

6.4 Per(or+ance 5nalysis. )2

6.) $as urine with Reheat and Regeneration.. ))

6.6 *o+ined *ycle Power Plants. )!

6.! $eneral 5s-ects.. )%

9 1+dro Power and 6ind Power ,ur3ines /#%/4

!.1 Introduction.. 61

!.2*lassi(ication o( ydro Powerurines...

61

!." *lassi(ication o( ind Power urines.... 62

Power 8eneration )rom -enewa3le 1eat Sources ; lternate *uels /7%/ilowatthours )E>wh+ of eletriity while onsumin$ 13.3 E>wh. Oman hopes to e8pand eletri$eneratin$ apaity in the future to support risin$ domesti demand and industrial $rowth. The$overnment has set a $oal to privati?e all state,owned ompanies in the power setor by 200!#and the ountry has ourted international investors to finane new independent power pro=ets



13/87

*ha-ter 1

)4&&+ to help raise $eneration apaity. Omans %inistry of Aousin$# -letriity# and Iater)%A-I+ has primary re$ulatory authority in the power setor and is responsible for eletriitydistribution throu$hout the ountry.

i$ 1."

-letriity eneration and 9onsumption1* Energy conversion methods

1*1 $as Power Plants

%a=ority of power produed at Oman are throu$h onventional ener$y soures# in partiular $as.The $as power plants are wor>in$ on Erayton yle# whih is very ompat and noiseless. Thewor> ratio of $as power plant is low. To improve wor> ratio and the overall thermal effiieny ofa $as power plant a steam power plant an be ombined with the $as power plant. This is alledombined yle power plant. or further details refer hapter ".1*! +olar Power Plants

:ultanate of Oman is reeivin$ a more intensified solar ray amon$ all 99 ountries. :o a lear

possibility is in si$ht to improve its eletriity prodution throu$h solar. This is still inoneptual level# soon this will $ain momentum and bi$ establishments would ome up tosupport the $rowin$ demand of eletriity in this ountry.1*" ,ind Power Plants

The oast of Oman is one of the lon$est and in this re$ion. The potential of wind ener$y isappreiable. Aene a lot of wind turbine both on and off shore an be installed to support theeletriity prodution.

MIME4220 Power Plant Engineering Page 1"


14/87

*ha-ter 1

Re(erences

1. Oil G as Journal# January 200.

2. -4 Catural as %onthly# u$ust 200".

3. -4 4nternational -ner$y Journal.200(.

(. -4 4nternational -ner$y Journal# 200(



15/87

Chapter !

Modern Ran-ine Cycle

!1 .ntroduction

thermal power station wor>s on the basi priniple that heat liberated by burnin$ fuel is

onverted into mehanial wor> by means of a suitable wor>in$ fluid. The mehanial wor> isonverted into eletri ener$y by usin$ $enerators. wor>in$ fluid $oes throu$h a repetitive yli han$e and this yli han$e involvin$ heatand wor> is >nown as the thermodynami yle. Thus a thermodynami yle is a series ofoperations# involvin$ a heat soure# a heat reeiver# a mahine or utili?e between the soure andthe reeiver and a wor>in$ substane.4n a steam power station# heat is released by burnin$ fuelL this heat is ta>en up by water whihwor>s as the wor>in$ fluid. Iater is onverted into steam as it reeives heat in boiler. The steamthen e8pands in a turbine produin$ mehanial wor> whih is then onverted into eletrialener$y throu$h a $enerator. The e8haust steam from the turbine is then ondensed in a ondenserand ondensate thereafter pumped to the boiler where it a$ain reeives heat and the yle is

repeated.!! Classi(ication o( Power Plant Cycles

Thermal power plants may wor> on vapour yles or $as power yles.

Mapour &ower 9yles

a. Ranine cycle

. Reheat cycle

c. Regenerative cycle

d. 7inary va-our cycle

as &ower 9yles

a. Otto cycle

. ;iesel cycle

c. ;ual co+ustion cycle

d. $as turine cycle

i. O-en cycle

ii. *losed cycle

MIME4220 Power Plant Engineering Page 1)


16/87

*ha-ter 2

!" +imple Ran-ine cycle

The yles have two harateristis1. The wor>in$ fluid is ondensable vapour whih is in li/uid phase durin$ part of the yle2. The yle onsists of steady flow proesses,speially desi$ned omponents ,open systems

i$ 2.1 Dayout of a simple an>ine yle

&roess 1,2 eversible adiabati e8pansion in the turbine

&roess 2,3 9onstant pressure heat re=etion in the ondenser

&roess 3,( eversible adiabati pumpin$ proess in the feed pump

&roess (,1 9onstant pressure heat supplied in the boiler

9onsiderin$ 1 >$ of fluidN

a. 3or oiler ?5 @ h1

?5 @ h1 h(4 .eqn 2.1

. 3or turine


17/87

*ha-ter 2

h1 @ > h2

@ h1 h2 .eqn 2.2

c. 3or condenser

h2 @ ?R > h("

?R @ h2 h(" .eqn 2.3

d. 3or the (eed -u+-

h(" > P @ h(4

P @ h(4 h(" .eqn 2.4

The terms related to the analysis are

Cet Ior> output9yle effiieny ,,,,,,,,,,,,,,,,,,,,,,,,

Aeat supplied PPP.eqn 2.5

Cet wor> output ITH I&Ior> ratio ,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,

ross wor> output IT.eqn 2.6

:peifi steam onsumption mass of steam re/uired per unit power output 1 >$ ::9 ,,,,,,,,,,,,,,,,,, 8 3"00 ,,,,,,,,,,, Ior>TH Ior>& >I H hr

.eqn 2.7

MIME4220 Power Plant Engineering Page 1!


18/87

*ha-ter 2

Pro/lem !1

9alulate the yle effiieny# wor> ratio and steam onsumption of the an>ine yle wor>in$between the pressures of 30 bar and 0.0( bar. ssume the steam is dry saturated at the inlet ofturbine.

i$ 2.2 T,s dia$ram of a simple an>ine yle

rom steam tables at 30 bar ) 3%&a+ the orrespondin$ saturation temperature T 1 233.!Q9h1 h$1 260(.2 >J*>$s1 s$1 ".16"! >J*>$ ;

The proesses 1,2 and 3,( are isentropi :1:2 G :3:(t ondenser pressure 0.0( bar ) ( >&a+

T2 T3 26.!"Q9hf2 121.(" >J*>$ sf2 0.(22" >J*>$ ;

MIME4220 Power Plant Engineering Page 1%

T

:

1

23

(


19/87

*ha-ter 2

hf$2 2(32.! >J*>$ sf$2 6.0520 >J*>$ ;h$2 255(.( >J*>$ s$2 6.((" >J*>$ ;

and the dryness fration at state 2 is R2 0.2h3 hf3 121.(" >J*>$h2 hf2 S R2 . hf$2

121.(" S )0.2+ 2(32.! 163.15 >J*>$Therefore# Ior> of turbine IT h1H h2

260(.2 H 163.15 !31 >J*>$ Ior> of pump I&vf )p(H p3+ 0.001 )3000 H (+

2.!" 3 >J*>$ h( h3S I& 121.(2 S 2.!" 12(.(2 >J*>$

Aeat supplied h1H h( 260(.2 H 12(.(2 2"!.6 >J*>$

Ior>TH Ior>& !31 H 39yle effiieny ,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,, R 100 3(."2 7 Aeat supplied 2"!.6

Ior>TH Ior>& !31 , 3Ior> atio ,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,, 0.!!" Ior>T !31

1 1:peifi :team 9onsumption ,,,,,,,,,,,,,,,,,,, R 3"00 ,,,,,,,,,, R 3"00

Ior>TH Ior>& !31 H 3

3.6 >$ * >I H hr

MIME4220 Power Plant Engineering Page 1/


20/87

*ha-ter 2

!% Ran-ine cycle with super0heated steam

4n atual power plants various modifiations are usually inorporated to improve overallperformane. :uperheatin$ the steam is one suh modifiation.Ie are not limited to havin$ saturated vapour at the turbine inletL further ener$y an be added by

heat transfer to the steam# brin$in$ it to a superheated vapour ondition at the turbine inlet.This is aomplished in a separate heat e8han$er alled a super heater. The ombination ofboiler and super heater is referred to as a steam $enerator.ll the e8pressions $iven earlier are suitable for this modifiation.The T: dia$ram inorporates the modifiation as follows.

i$ 2.3 T,s dia$ram of a an>ine yle with superheated steam entry to turbine

4t is evident from the T: dia$ram the enthalpy and entropy at inlet of the turbine are at

superheated state.

The values an be obtained from superheated steam tables.


T

:

2

1

(

3

p1

p2


21/87

*ha-ter 2

!) Ran-ine cycle with Re0heat

4n the ideal reheat yle# the steam does not e8pand to the ondenser pressure in a sin$le sta$e.The steam e8pands throu$h a first sta$e turbine )proess 1,2+ to some pressure between thesteam $enerator and ondenser pressures. The steam is then reheated in the steam $enerator

)proess 2,3+. 4deally# there would be no pressure drop as the steam is reheated. fter reheatin$#the steam e8pands in a seond sta$e turbine to the ondenser pressure )proess 3,(+. Theprinipal advanta$e of reheat is to inrease the /uality of the steam at the turbine e8haust.Ihen omputin$ the thermal effiieny of a reheat yle# it is neessary to aount for the wor>output of both turbine sta$es as well as the total heat addition ourrin$ in thevapouri?ation*superheatin$ and reheatin$ proesses.

i$ 2.( T,s dia$ram of a eheated an>ine yle

The han$es in the e8pression are as followsN

Aeat addition )h1 , h"+ S )h3H h2+ PPP.eqn 2.8Aeat re=eted )h(H h5+ PPP.eqn 2.9Ior> of turbine )h1H h2+ S )h3H h(+ PPP.eqn 2.10Ior> of pump )h"H h5+ PPP.eqn 2.11

Pro/lem !!

steam plant wor>s on the an>ine yle with reheat. :team enters the turbine at 35 bar# 350Q9#and e8pands to 10 bar# where it passes throu$h a reheater# emer$in$ at 350Q9. 4t then e8pands tothe ondenser pressure of 35 >&a. or an ideal yle# ompute

)a+ wor>done in A& and D& turbines)b+ heat added in the reheater)+ pump wor>


T

:

1

2

3

(

-1

p2

p3


22/87

*ha-ter 2

)d+ effiieny)e+ heat added in the boiler

t point 1 for 35 bar# 350Q9 from superheated steam tables#h1 310( >J*>$ s1 "."5! >J*>$ ;

t point 2 10 bart point 3 10 bar# 350Q9h3 315. >J*>$ s3 .3011 >J*>$ ;

t point( 35 >&at point 2 from saturated steam tables#Tsat2 1!.!1 Q9

hf2 "2.61 >J*>$ sf2 2.136 >J*>$ ;hf$2 2015.3 >J*>$ sf$2 (.((6 >J*>$ ;h$2 26.1 >J*>$ s$2 ".56"5 >J*>$ ;

t point ( from saturated steam tables#hf( 303.(05 >J*>$ sf( 0.!6(! >J*>$ ;

hf$( 232."5 >J*>$ sf$( ".3(( >J*>$ ;h$( 2"31.05 >J*>$ s$( .1!3 >J*>$ ;Ey assumin$ steam is wet at point 2

s1 s2 sf2 S R2 sf$26.6)!/@ 2.1"%! > A2 J*>$:imilary# assumin$ steam is wet at point (

s3 s( sf(S R(sf$(.3011 0.!6(! S R()".3((+R( 0.!( U 1 so# steam is wet at point (.h( hf(S R(hf$(

303.(05 S )0.!(+ 232."5 2(!1.( >J*>$

I A& h1H h2 2!2.!2 >J*>$I D& h3H h( """.3 >J*>$

B eheat h3H h2 3("."2 >J*>$



23/87

*ha-ter 2

I &ump )p1H p2+ vf )35,0.35+ 8 100 8 0.001 3.("5 >J*>$h" h5 S I &ump

hf( S I &ump 303.(05 S 3.("5 30".6 >J*>$

B Eoiler h1H h" 310( H 30".6 2!.13 >J*>$

B :upplied B Eoiler S B eheat 2!.13 S 3("."2 31(3.602 >J*>$

I Cet I Turbine, I &ump )2!2.!2 S """.3+ H 3.("5 !55.60 >J*>$ I Cet

-ffiieny ,,,,,,,,,,,,,,,, B :upplied

0.30(0 30.( 7



24/87

*ha-ter 2

Pro/lem !"

two sta$e steam turbine with one re,heater wor>s under a boiler pressure of 15 %&a and re,heater pressure of %&a. The steam temperature at the outlet of boiler is (00Q9 and at the outletof re,heater is 350Q9. The net power developed by the plant is13!!5 >I.

@etermine mass flow rate of water supplied to the boiler# if the pump onsumes 1(.! >J*>$. lsofind the ratio of heat supplied at the re,heater to the boiler.

p1 15 %&ap3 %&aT1 (00Q9T3 350Q9

Cet &ower m s)IT,I&+ 13!!5 >II& 1(.! >J*>$

%ass flow rate of water to boiler ) wm + V

Aeat supplied at reheater

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, VAeat supplied at boiler

t point 1 for 15 %&a# (00Q9 from superheated steam tables#h1 2!5.5 >J*>$ s1 5.6611 >J*>$ ;

t point 3# p3 p2 %&a# 350Q9 from superheated steam tables#h3 301".0 >J*>$ s3 ".2263 >J*>$ ;I& )p1H p(+vf1(.! )15000,p(+ 0.001

122 -Pa

t point 2# p2 %&a from saturated steam tables#

Tsat2 265.66 Q9hf2 12".0 >J*>$ sf2 3.1211 >J*>$ ;hf$2 1505.1 >J*>$ sf$2 2."!22 >J*>$ ;h$2 22.1 >J*>$ s$2 5.6133 >J*>$ ;Ey assumin$ steam is wet at point 2

s1 s2 sf2S R2sf$2 5.6611 3.1211 S R2)2."!22+

R2 1.03 1 so# steam is superheated at point 2.

s1 s2 s$2S 9psln

+

+

23.15

23.15sup

satT

T

5.6611 5.6133 S )2.1+ ln

+

+23.1565.662

23.15supT

Tsup2 30(.22Q9



25/87

*ha-ter 2

Aene# h2 h$2S 9ps )TsupH Tsat+h2 222.1 S 2.1)30(.22 H 265.66+

2610."1 >J*>$

t point (# p( 100 >&a 0.1 %&a from saturated steam tables#

Tsat( !!."3 Q9 hf( (1.(" >J*>$ sf( 1.302" >J*>$ ;hf$( 2256.0 >J*>$ sf$( ".05"6 >J*>$ ;h$( 2"5.5 >J*>$ s$( .35!( >J*>$ ;

Ey assumin$ steam is wet at point (s3 s( sf(S R(sf$(".2263 1.302" S R()".05"6+ R( 0.61 U 1 so# steam is wet at point ( h( hf(S R(. hf$(

(1.(" S )0.61+ 2256.0 22(".(( >J*>$

IT )h1,h2+ S )h3,h(+ )2!5.5 H 2610."1+ S )301".0 H 22(".((+ !3(.(5 >J*>$

m s)IT,I&+ 13!!5 >I m s 13!!5 * )!3(.(5 H 1(.!+

15.22 >$*se mass flow rate of water to the boiler m w

h5 hf5 (1.(" >J*>$h" h5S I& (1.(" S 1(.! (32.(" >J*>$

Aeat supplied at boiler BEoiler h1,h" 2!5.5 H (32.3" 25(3.1( >J*>$

Aeat supplied at re,heater Be,heater h3,h2 301".0 H 2610."1 205.3! >J*>$

205.3!atio of heat supplied at re,heater to boiler ,,,,,,,,,,,,,,

25(3.1(

0.061



26/87

*ha-ter 2

!* Ran-ine cycle with Re0generation

4t is one of the ommonly used methods to inrease thermal effiieny of vapour power plants. 4tis also alled regenerative (eed water heating. part of the steam is e8trated or bled from turbine sta$es and fed into an feed water heater

operatin$ at the e8tration pressure.The rest of the steam e8pands throu$h the seond sta$e turbine to state 3. This portion of thetotal flow is ondensed to saturated li/uid# state (# and introdued into the feed water heater atthe same state. sin$le mi8ed stream e8its the feed water heater at state 5. The li/uid at state 5is then pumped to the steam $enerator pressure and enters the steam $enerator at state ".

i$ 2.5 Dayout of a an>ine yle with re$eneration

4f one >$ of steam is fed into the turbine and some m >$ is bled out at state 2. Then the remainin$)1,m+ >$ of steam is ontinue to e8pand until ondenser pressure.Aene# the wor> of the turbine is

Ior> of Turbine )h1,h2+ S )1,m+ )h2,h3+

PPP.eqn 2.12To $et the /uantity of bled steam out of 1 >$ of steam supplied to turbine# a heat balane analysisan be adopted aross re$enerator.Thus the amount of heat $ettin$ in and $oin$ out of re$enerator is same.

m h2 S )1,m+ h( h5 PPP.eqn 2.13

Pro/lem !%

turbine with one re$enerator is admitted with steam havin$ enthalpy of 3200 >J*>$ at "0 bar. 4tis then e8hausted to ondenser at an enthalpy of 2200 >J*>$. The ideal re$enerative feed waterheater is fed with 11350 >$*hr of steam at 3.5 bar and with an enthalpy of 2"00 >J*>$. Theondensate from ondenser is enterin$ heater at 13( >J*>$. 4t leaves the heater dry saturated at3.5 bar. @etermine the power developed by the turbine and wor> ratio.


1

23

(5

"

Eoiler Turbine

9ondensere$enerator

eed &ump


27/87

*ha-ter 2

iven @atah1 3200 >J*>$

h2 2"00 >J*>$

h3 2200 >J*>$

h( 13( >J*>$p1 "0 bar

p2 3.5 bar

m 11350 >$*hr

s>ed @ata

&ower VIor> atio V

:olution

rom :aturated :team Tables for 3.5 bar 0.35 %&a

h5 56(.33 >J*>$

Ior> of the pump )9han$e in pressure+ W vf

)"000 H 350+ 0.001

5."5 >J*>$

h" h5S Ip

56(.33 S 5."5

56!.!6 >J*>$

pplyin$ ener$y balane aross re,$enerator# from e/n 2.13

m h2 S )1,m+ h( h5

m 2"00S )1,m+ 13( 56(.33

m 0.162" >$* >$ of steam supplied to turbine

This is $iven as 11350 >$*hr 3.15 >$*se in the problem

Therefore mass of steam supplied to turbine 3.15*0.162"

1.25 >$*se



28/87

*ha-ter 2

Therefore from e/n 2.12

Ior> of Turbine )h1,h2+ S )1,m+ )h2,h3+

)3200 H 2"00+ S )1,0.162"+ )2"00 H 2200+

!2".!" >J*>$

Therefore#

&ower mass of steam supplied to turbine 8 IT

1.25 8 !2".!"

15!!0 >I

Ior> of Turbine , Ior> of pump

Ior> atio ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Ior> of Turbine

!2".!" H 5."5

,,,,,,,,,,,,,,,,,,,,,,,,,,,,

!2".!"

0.!!

Pro/lem !) steam turbine operates on re,$enerative vapour power yle# with one losed feed water heaterreeives some /uantity of steam at intermediate pressure# and develops a net power of 32000>I. The steam $enerator supplies ((.06 >$*se of steam at %&a and (50Q9. The ondenserfuntions at a vauum pressure of 0.03 %&a. The turbine produes 31.6! >J of wor> per >$ ofsteam. The isentropi effiienies of turbine and pump are 627 and 65 7 respetively.@etermine the fration of steam supplied to feed water heater.

Cet &ower m s)IT,I&+ 32000 >I

%ass of steam supplied to turbine )m s+ ((.06 >$*se

p1 %&aT1 (50Q9p3 0.03 %&aIT 31.6! >J*>$XT 627X& 657

rational mass of steam to heater )m+ V



29/87

*ha-ter 2

m s)IT ,I&+ 32000 >I ((.06 )31.6! , I&+ 32000

I& 5.!( >J*>$

9onsiderin$# X& 6574deal I& 5.!( 8 0.65 5 >J*>$9onsiderin$ XT 627

4deal IT 31.6! * 0.62 6!2.5 >J*>$I& )p1H p2+vf )000,p2+ 0.001 5 >J*>$p2 2000 >&a 2 %&a

t point 1 for %&a# (50Q9 from superheated steam tables#h1 326.1 >J*>$ s1 "."32 >J*>$ ;

t point 2# p2 2 %&a from saturated steam tables#

Tsat2 212.(2 Q9hf2 !06.! >J*>$ sf2 2.((( >J*>$ ;hf$2 16!0. >J*>$ sf$2 3.6!35 >J*>$ ;h$2 2!!.5 >J*>$ s$2 ".3(0! >J*>$ ;

t point 3# p2 30 >&a from saturated steam tables#Tsat3 "!.10 Q9

hf3 26!.23 >J*>$ sf3 0.!(3! >J*>$ ;hf$3 233".1 >J*>$ sf$3 ".62( >J*>$ ;h$3 2"25.3 >J*>$ s$3 ."6" >J*>$ ;

Ey assumin$ steam is wet at point 2s1 s2 sf2S R2sf$2

"."32 2.(((S R2)3.6!35+R2 1.0 1 so# steam is superheated at point 2.

s1 s2 s$2S 9psln

+

+

23.15

23.15

sat

sup

T

T

"."32 ".3(0! S )2.1+ ln

+

+

23.15(2.212

23.15supT

Tsup 26(.6Q9

Aene# h2 h$2S 9ps )TsupH Tsat+h2 2!!.5 S 2.1)26(.6 H 212.(2+

2!51.5 >J*>$:imilarly by assumin$ steam is wet at point 3

s1 s3 sf3S R3sf$3 "."32 0.!(3! S R3)".62(+



30/87

*ha-ter 2

R3 0.63

h3 hf3S R3hf$3 26!.23 S )0.63+ 233".1 2226.1! >J*>$

h( hf3 26!.23 >J*>$h5 hf2 !06.! >J*>$

4n re$eneration yle applyin$ ener$y balane aross feed water heaterm h2 S )1,m+ h( 1 8 h5

:ubstitutin$ enthalpy values#m )2!51.5+ S )1,m+ )26!.23+ 1 8 !06.!

m 0.23 >$ * >$ of steam supplied to turbine

!3 Ran-ine cycle with irreversi/ility

eversible proesses are not possible to obtain in pratie. Eut for onepts we assume suh

proesses# in an>ine yle the e8pansion and pumpin$ proesses are ta>en as isentropiproesses. 4sentropi proess means the heat transfer is ?ero and the han$e in entropy is also?ero# whih is not possible to obtain in pratie. Aene to ma>e the alulation lose to real weta>en up effiienies alled isentropi effiieny for both e8pansion and pumpin$ proesses.The atual /uantities an be obtained by usin$ the followin$ e8pressions

isen

actT

W

W= PPP.eqn 2.14

act

isenPump

W

W= PPP.eqn 2.15

4n the above e8pressions the effiienies are isentropi effiienies# the isentropi wor> is withsuffi8 isen. tual wor> an be determined from the e8pression whih is the atual wor> ofe8pansion and pumpin$ an be e8peted at the real power plants.Pro/lem !*

9alulate the /uantities as as>ed in &roblem 2.1# if the isentropi effiienies of the e8pansionand ompression proesses are 607 )0.6+

isen

actT

W

W=

!316.0 act

W=

kgkJWact *6.((=

:imilarly#act

isenPump

W

W=

actW

36.0 =

kgkJWact

*5.3=

nd hene# Ior> atio 0.!!5 ::9 (.61 >$ * >I,hr

MIME4220 Power Plant Engineering Page "0


31/87

*ha-ter 2

E4ercises

E4 #o 1

:team at a pressure of 20 bar and 250Q9 is e8panded throu$h a turbine at first to a pressure of (bar. 4t is then reheated at onstant to the initial temperature of 250Q9 and is finally e8panded to

0.1 bar.-stimate the wor> done per >$ of steam flowin$ throu$h the turbine and amount of heat supplieddurin$ the proess of reheat.9ompare the wor> output when the e8pansion is diret from 20 bar to 0.1 bar without reheat.ssume all the pressures are absolute and all e8pansion proesses to be isentropi.

E4 #o !

4n a sin$le,heater re$enerative yle the steam enters the turbine at 50 bar and (50Q9 and thee8haust pressure is 0.2 bar. The feed water is a diret ontat type# whih operates at bar. ind

)a+ the effiieny and steam rate of the yle# if turbine develops 20 %I.)b+ the inrease in effiieny as ompared to the an>ine yle without

re,$eneration. &ump wor> may be ne$leted.E4#o"

reheat an>ine yle turbine reeives steam at 6 %&a# 300Q9. 4t is then e8panded to reheaterpressure. There it is reheated to 2!"0. >J*>$ at 300Q9. Then it is further e8panded to ondenserpressure of 0.5 bar. fter pumpin$ water enters boiler at 100Q9# determine effiieny and ratio ofheat supplied at boiler to reheater.



32/87

*ha-ter 2

Re(erences

1. %.%.-l Ia>il# &ower &lant Tehnolo$y# %raw Aill# Cew Yor># 1!65.

2. .;.a=put# te8t boo> of &ower &lant -n$ineerin$# 3rdedition# Da8mi&ubliations )&+ Dtd.#Cew @elhi #200". 4:EC 61,006,"52,3

3. ;.;.amalin$am# &ower &lant -n$ineerin$# :94T-9A# 9hennai# 2002. 4:EC

61,6326,,0

5dditional Te4t Boo- Re(erence

1. -astop G %9on>ey# pplied Thermodynamis for -n$ineerin$Tehnolo$ists 5thedition# &earson &rentie Aall# -n$land# 2002.

4:EC !6,0,562,0!1!3,1 )vailable in the olle$e library+

2. J.Ieisman and .->art# %odern &ower &lant -n$ineerin$# &rentie Aall of

4ndia# Cew @elhi# 1!65.

3. %.%.-4 Ia>il# &ower &lant Tehnolo$y# %raw Aill# Cew Yor># 1!65.



33/87

*ha-ter "

Chapter "6eat Rate7 8an7 8lame Temperature and Com/ustion 5ir Re'uirements

"1 .ntroduction

4n the previous hapter the fundamental thermodynami onepts were disussed. To stream

line a thermal power plant in perfet operation some pratial aspets should also be ta>en are.ew of them are the amount of heat re/uired by the boiler to produe steam must be met. Tomaintain the furnae with $ood operatin$ pressure a fan must be inluded. The flametemperature must be at the appropriate level to sustain the ombustion. inally the amount of airre/uired by the fuel has to be supplied with allowable veloity. 4n this hapter these small butimportant aspets would be onversed."! 6eat Rate

Aeat ate is the amount of heat transferred to water to produe the re/uired /uantity of steam. 4t

is also alled steamin$ rate.

4t is e8pressed in >J*:e.

The steamin$ rate is used to refer the apaity of boiler. The amount of power produed in the

turbine is based on the /uantity of steam supplied by the boiler. :o# heat rate is one of the

important parameters influenin$ performane of a thermal power plant.

Aeat ate 9apaity of boiler W :peifi enthalpy of steam at the re/uired /uality.

)or+

tual -vaporation

A maW hs PPP.e/n 3.1

)>J*:e+ )>$*:e+ )>J*>$+

MIME4220 Power Plant Engineering Page ""


34/87

*ha-ter "

Pro/lem "1

@etermine the heat rate to produe 200 >$ of dry and saturated steam per hour at 10 bar.

iven N

ma 200 >$*hr 200*3"00 0.055 >$*se

p 10 bar

:olution

Aeat ate maR hs.

rom steam tables for p 10 bar )1 %&a+# the saturated enthalpy 26.1 >J*>$

Therefore#

A 0.055 R 26.1

152.60 >J*se

Pro/lem "!

9alulate the amount of heat to be supplied to $enerate 2 >$*se of steam at 100 bar and 350Q9.

rom superheated steam tables at the $iven pressure and temperature

hs2!23.( >J*>$

A 2 8 2!23.( 56(".5 >J*:e.



35/87

*ha-ter "

"" 8an

""1 Chimney 9raught

The small pressure differene whih auses a flow of $as to ta>e plae is termed as a drau$ht.The funtion of drau$ht is to fore air to the fire and to arry away the $aseous produts ofombustion. 4n a boiler furnae proper ombustion ta>es plae only when suffiient /uantity ofair is supplied to the burnin$ fuel.The drau$ht may be lassified as )i+ Catural and )ii+ rtifiial drau$htFnder artifiial drau$ht either fored or indued drau$ht fans are used.""! 8orced 9raught

4n this system a blower or fan is installed near or at the base of the boiler to fore the air throu$hthe ool bed and other passa$es throu$h the furnae. 4t is a positive pressure drau$ht.""" .nduced 9raught

4n this system a blower or fan is loated at or near the base of the himney. The pressure over thefuel bed is redued below that of the atmosphere. Ey reatin$ a partial vauum in the furnae andflues# the produts of ombustion are drawn from the main flue and they pass up the himney.This drau$ht is used usually when eonomi?ers and air pre heaters are inorporated in the

system.""% 8an Power Consumption

The ideal power onsumption of a fan )without losses+ an be e8pressed as

&i dp . / PPP.e/n 3.2

Ihere#

Pi ideal power onsumption )I+

dp total pressure inrease in the fan )&a+

q air volume flow delivered by the fan )m3*s+

The ideal power onsumptions for fans at different air volumes and pressure inreases are

e8pressed in the hart belowN

MIME4220 Power Plant Engineering Page ")


36/87

*ha-ter "

:oure N www.en$ineerin$ toolbo8.om

i$ 3.1 &ower hart for industrial fans

"") 8an E((iciency

The fan effiieny is the ratio between power transferred to the airflow and the power used by

the fan. The fan effiieny is in $eneral independent of the air density and an be

e8pressed asN

Zf dp / * & PPP.e/n 3.3

where

Zf fan effiieny )values between 0 , 1+

dp total pressure )&a+

/ air volume delivered by the fan )m3*s+

& power used by the fan )I# Cm*s+

The power used by the fan an be e8pressed asN

& dp / * Zf PPP.e/n 3.(

"% 8lame Temperature

The temperature of flame varies dependin$ on

)i+ the substane bein$ ombusted

)ii+ the e8tent to whih the fuel and o8idi?er have been pre,mi8ed

)iii+ the flow is laminar or turbulent.



37/87

*ha-ter "

One of the lowest temperature of flame is the safety flame of a Eunsen burner# to demonstrate

it is on \ about 300 Q9 # while the hottest is arbon sub,nitride burnin$ in pure o8y$en# with a

temperature of (!6 Q9# almost as hot as the surfae of the :un. The nulear flame that heats

the :un is not a hemial flame at all# but it does have an e8tremely hi$h temperature \ the

temperature of flame at the :un's ore is estimated at over 13#000#000 Q9.

Ihen the fuel and o8idi?er are mi8ed well# the temperature of flame is hi$her# as the reation

proeeds more /ui>ly and $enerates more heat.

Ihen the fuel and o8idi?er are not mi8ed at all prior to ombustion# the reation ours

imperfetly# $eneratin$ less total heat.

The olor of a flame is often related to its temperature# althou$h the moleule bein$ burned is

relevant as well.

Di$ht resultin$ =ust from temperature is alled bla>body radiation# and ran$es from

red , 1000 ;

oran$e*yellow , 3000 ;

white or li$ht blue , 5000 ;

lames an be divided into ( ate$oriesNa. laminar# premi8ed

b. laminar# diffusion

. turbulent# premi8ed H followed in boilers# air and fuel are premi8ed in burner

d. turbulent# diffusion

") Com/ustion 5ir Re'uirements

uels that are used in boiler are $enerally hydro,arbons. They an be in any of the three states.

The amount of air re/uired to ompletely ombust the fuel is one of the >ey elements to deide

the performane of thermal power plant.

MIME4220 Power Plant Engineering Page "!


38/87

*ha-ter "

tually ombustion of fuel means o8idation that is addin$ o8y$en with the moleules present in

fuel and onvertin$ them into different ompounds# bein$ e8othermi reations they liberate

hu$e /uantity of heat.

or e8ample 9 present in fuel an either beome 9O2or 9O. 4f enou$h o8y$en is supplied 9

produes 9O2# if not it produes 9O.

The ombustion trian$le ontains three elements re/uired for ombustion to ta>e plae. These

elements areN fuel# heat )i$nition+ and air. The re/uirement for fuel is obvious. The re/uirement

for i$nition is e/ually obvious. The re/uirement for air is somewhat less obvious and too often

i$nored beause it is freely available. 4f one of these three elements is removed# the ombustion

proess stops and the ombustion trian$le ollapse.

Ihen boilers are installed in a onfined spae suh as a boiler room# two openin$s

ommuniatin$ diretly with the outside are re/uired. One openin$ is loated hi$h in the outside

wall. The seond openin$ is loated lose to the floor. 4f the boiler room is loated partially or

entirely below $rate# a dut is provided from the lower openin$ terminatin$ at a point e/ual to

the depth of the dut above the floor )i$ 3.2+.

i$ 3.2 Eoiler oom

The most important elements of fuel are arbon and hydro$en# and sometimes a small amount ofsulphur. 4n addition they ontain some o8y$en and a small /uantity of inombustibles )-8N watervapour# nitro$en# or ash+n aurate hemial analysis by mass of the important elements in the fuel is alled the:&T.M5TE 5#5&;+.+.

MIME4220 Power Plant Engineering Page "%

T- @F9T

DOFM-

EO4D- OO%DOO


39/87

*ha-ter "

The followin$ table indiates different types of oal that are ommonly used in thermal powerplants.

Table 3.1

Type Car/on 6ydrogen O4ygen #itrogen 5sh

1.nthraite !0.2 3.00 02.32 1.(( 2.!2.Eituminous 9oal 61.!3 (.6 05.!6 2.32 (.!0

3.Di$nite 5".52 5.2 31.6! 1."2 (.25

(.&eat (3.0 ".(2 ((.3" 1.52 (.00

100 O2%inimum air re/uired per >$ of solid fuel ,,,,,,,, [ 11.5 9 S 3(.5 )A2, ,,,,,+ S(.3:]

23 6 PPP.e/n

3.5)or+

100 6 O2%inimum air re/uired per >$ of solid fuel ,,,,,,,, [ ,,,,,, 9 S 6)A2, ,,,,,+ S:]

23 3 6PPP.e/n 3."

MIME4220 Power Plant Engineering Page "/


40/87

*ha-ter "

E4ercises

E4 #o 1

9alulate the amount of heat to be supplied to $enerate 10 >$*se of steam at 12 %&aand (00Q9 from water at 115Q9.

E4 #o !

Irite the hemial e/uations to find out the amount of O2re/uired to ombust the $iven

perenta$e of 9# A2and : present in fuel.

E4 #o "

@etermine the minimum amount of air re/uired to ombust 1 >$ of fuel with the followin$

onstituents

9 H 607L A2 37 L : 0.(7 and the rest is O 2.



41/87

*ha-ter "

Re(erences


2. .;.a=put# te8t boo> of &ower &lant -n$ineerin$# 3rdedition# Da8mi

&ubliations )&+ Dtd.#Cew @elhi #200". 4:EC 61,006,"52,3


61,6326,,0






42/87

*ha-ter 4

Chapter %

Tu/e Re'uirements to Condenser and 8eed ,ater 6eater

%1 .ntroduction

thermal power plant involves many numbers of heat e8han$ers. Eut dependin$ upon the

need# purpose and ativity they arry different name. 9ondenser and feed water heater are twosuh heat e8han$ers. s the name implies ondenser onverts the steam omin$ out of turbineinto water thus removin$ the latent heat of steam# whih would be sent ba> to boiler. eed waterheater is preheatin$ the water before enterin$ boiler# thus minimi?in$ the amount of sensible heatto be supplied at boiler. The oolin$ soure at ondenser is waterL the heatin$ soure at feedwater heater is the flue $as omin$ out of furnae.-very heat e8han$er omprises of tubes# in this hapter the re/uirements of suh tubes toondenser and feed water heater will be disussed.%! Condenser

4n a thermal power plant# a ondenser unit is attahed to the e8it of the steam turbine and thepressure in this unit is maintained to be far below that of atmosphere. This partial vauum is

maintained by a powerful vauum pump. Ey this means the steam an e8pand in the turbine fromthe boiler pressure to a pressure lower than that of atmosphere. Ey this $reater e8tend ofe8pansion# the steam produes more power [3].%" 8eed ,ater 6eater

eed water heater is a heat e8han$er whih uses the waste heat from the e8haust $ases to heatthe feed water before its entry into the boiler. The supply of preheated water redues the amountof heat to be added in the boiler for onvertin$ the same into steam. &reheated water supply alsoredues the thermal stresses whih will be indued due to the variations in the temperature ofwater in the drum.The provision of feed water heater inreases the effiieny of the boiler onsiderably. The steam$enerator effiieny rises about 17 for eah 5Q9 rise in feed water temperature [3].4n the feed

water heater the heatin$ surfae is built of a number of tubes arran$ed in $roups. The number oftubes in eah row# the len$th of the tubes# and the number of $roups depend on the performanere/uired. 4n feed water heater the water flow throu$h the feed water heater tubes and the hot$ases flow over the tubes. These tubes are usually sta$$ered in a sinuous form.%% Tu/e and Pipe Re'uirements

The pipin$ system in steam power plant is divided into four ate$ories)i+ :T-% &4&4C

)ii+ IT- &4&4C

)iii+ EDOI,O &4&4C

)iv+ OTA-:

%%1 Re'uirements o( steam piping system

)a+ %a8imum reliability

)b+ :hould be of neessary si?e

)+ %ust withstand the pressure to whih it is sub=eted



43/87

*ha-ter 4

)d+ 4t should be possible to arry out inspetion at any point without shut,down the entire

system

)e+ &ipes should be made in lon$est possible len$th to redue the number of =oints

)f+ :hould be able to withstand the temperature and e8pansion aused due to the

temperature han$es

)$+ &ipe should run as diret and strai$ht as possible

)h+ &ipin$ system should ensure an effiient draina$e of all pipes

%%! Materials (or tu/es in Condenser and 8eed ,ater 6eatereup the e8pansion strain in tubes.


:anned ima$e from ef[2]


45/87

*ha-ter 4

Re(erences





61,6326,,0






46/87

Chapter )

Blade +hape and ,or- Output Calculations

)1 .ntroduction

The most si$nifiant part of a thermal power station desi$nin$ is the turbine blade. The shape of

a turbine blade is often termed as +AEROFOIL,. This is the shape whih offer very less entry aswell as e8it loss to the fluid flow# thus transformin$ ma8imum ener$y from fluid into mehanialener$y. The followin$ dia$ram desribes a sin$le turbine blade. The two main omponents areblade ross setion and blade hei$ht.

i$ 5.1 :in$le Turbine Elade

)! #omenclature o( aero(oil cross section

i$ 5.2 erofoil 9ross :etion

The above dia$ram mentions some of the basi nomenlature of an aerofoil setion.


Elade ross setion

Elade hei$ht

9hord Den$th

9amper Dine


47/87

*ha-ter )

)" Tur/ine +tages

4n atual turbine two types of blades are in use. One is fi8ed blade )no??le+ and another ismovin$ blade. i8ed blade onverts the potential ener$y of steam into >ineti ener$y. %ovin$blade transforms that >ineti ener$y into mehanial ener$y. One set of fi8ed and movin$ bladeis alled a turbine sta$e.

@ependin$ upon the pressure differene between the boiler and ondenser as muh as 2( sta$eshad been pratied.

i$ 5.3 One Turbine :ta$e

:et of blade often termed rin$. :imilar >ind of sets $ives additional turbine sta$es.

)% Classi(ication o( steam tur/ine

There are several ways in whih the steam turbines may be lassified. The most important andommon division bein$ with respet to the action o( the steamas

a. I+-ulse

. Reaction

c. *o+ination o( I+-ulse and Reaction

Other areordin$ to the number of sta$es ):in$le,sta$e and %ulti,sta$e+ and diretion of steam flow)8ial or adial+ et.#


i8ed Elade in$

%ovin$ Elade in$


48/87

*ha-ter )

)) ,or- output o( a single tur/ine stage

i$ 5.( Meloity dia$ram for movin$ blade

The above dia$ram shows the veloity dia$ram of a sin$le sta$e impulse turbine

9bl Dinear veloity of movin$ blade )m*s+91 bsolute veloity of steam enterin$ movin$ blade )m*s+90 bsolute veloity of steam leavin$ movin$ blade )m*s+9w1 Ihirl veloity at the entrane of movin$ blade9w0 Ihirl veloity at the e8it of movin$ blade9f1 low veloity at entrane of movin$ blade

9f0 low veloity at e8it of movin$ blade9r1 elative veloity of steam at entrane of movin$ blade9r0 elative veloity of steam at e8it of movin$ blade

^ Co??le n$le at entry_ Co??le n$le at e8it` Elade an$le at entry of movin$ blade Elade an$le at e8it of movin$ blade


91

9r1

9f1

9bl

9w1

9bl

9w0

90

9r

09

f0

9bl

^ `

_

9ro


49/87

*ha-ter )

The wor> output of a sin$le blade may be found out from the han$e of momentum of the steam=et durin$ its flow over the blade. 4t is only the veloity of whirl whih performs wor> on theblade sine it ats in its )blade+ diretion of motion.rom Cewtons seond law of motionore )tan$ential+ on the wheel mass of steam 8 aeleration

mass of steam*se 8 han$e of veloity s)9w1H 9w0+ PPP.eqn 5.1

T%e $alue of C-.is a!(uall" #ega(i$e as (%e s(ea) is 'is!%arge' i# (%e o&&osi(e 'ire!(io# (o (%e

bla'e )o(io#/ (%erefore/ 'ue !o#si'era(io# s%oul' be gi$e# (o (%e fa!( (%a( (%e $alues of C-0a#' C-.are (o be a''e' -%ile 'oi#g (%e solu(io# of (%e &roble)*

Ior> done on blades * se ore 8 distane travelled * se s)9w1S 9w0+ 8 9bl PPP.eqn 5.2

&ower per wheel s)9w1S 9w0+ 8 9bls9w9bl

,,,,,,,,,,,,,, >I PPP.eqn 5.3

1000



50/87

*ha-ter )

E4ercises

E4 #o 1

turbine blade reeives fluid at 1( m*se and leaves at ! m*se absolute veloities. The no??le

inlet and outlet an$les are 1!Q and 21Q. @etermine the wor> developed by the blade per

unit flow rate in >I# if the wheel diameter is (0m and spins at 2( rps.

E4 #o !

Aow to alulate the whirl and flow veloitiesV

MIME4220 Power Plant Engineering Page )0


51/87

*ha-ter )

Re(erences


2. .;.a=put# te8t boo> of &ower &lant -n$ineerin$# 3rdedition# Da8mi &ubliations )&+

Dtd.#Cew @elhi #200". 4:EC 61,006,"52,3

3. ;.;.amalin$am# &ower &lant -n$ineerin$# :94T-9A# 9hennai# 2002. 4:EC 61,6326,,0


1. J.Ieisman and .->art# %odern &ower &lant -n$ineerin$# &rentie Aall of 4ndia# Cew

@elhi# 1!65.



52/87

Chapter *

$as Tur/ine

*1 .ntroduction

The $as turbine is the most satisfatory way of produin$ very lar$e /uantities of power in a self,

ontained and ompat unit. 4t omprises of a ompressor# a ombustion hamber and a $asturbine unit. To improve the thermal effiieny of a $as turbine unit a heat e8han$er an beinluded. The thermal effiieny of a $as turbine unit alone is 20 to 307# whih is low omparedwith that of a modern steam plant 36 to (07. 4t is possible to onstrut ombined plants whereeffiienies are (57 or more.*! Open cycle $as Tur/ine

The fundamental $as turbine unit operatin$ on the open yle has a ompressor and a turbinemounted on a ommon shaft. ir is drawn into the ompressor and after ompression passes to aombustion hamber. -ner$y is supplied in the ombustion hamber by sprayin$ fuel into the airstream# and the resultin$ hot $ases e8pand throu$h the turbine to the atmosphere. 4n order toahieve networ> output from the unit# the turbine must develop more $ross wor> output than is

re/uired to drive the ompressor and to overome mehanial losses in the drive.

i$ ".1 Open yle $as turbine

The produts of ombustion omin$ out from the turbine are e8hausted to the atmosphere as theyannot be used further. The wor>in$ fluid )air and fuel+ must be replaed ontinuously as theye8hausted into the atmosphere.


9 T

992 3

(

1


53/87

-

v

2

,

2

"

4

*ha-ter 6

*" Closed cycle $as Tur/ine

i$ ".2 9losed yle $as turbine

The above fi$ure shows a $as turbine operatin$ on a onstant pressure yle in whih the losed

system onsists of air behavin$ as an ideal $as. heat e8han$er or otherwise >nown as ooler isused to ool the e8haust fluid from $as turbine and reyle the same to the ompressor. :o# thewor> input ta>en by the ompressor redues# thus improves the overall thermal effiieny as wellas the net wor> output of the $as turbine unit.*% Per(ormance 5nalysis

i$ ".3 pv and T: dia$ram

-ffiieny )+ edeat,u--li

6or.done#et

in?

netor

in

?out

?in

? PPP.eqn 6.1

MIME4220 Power Plant Engineering Page )"

1

9 T

992 3

(


54/87

*ha-ter 6

Aeat is supplied durin$ onstant pressure proess 2 H 3Bin 9p)T3H T2+ PPP.eqn 6.2

Aeat is re=eted durin$ onstant pressure proess (, 1

Bout 9p)T(H T1+ PPP.eqn 6.3

:ubstitutin$ the above values of heat supplied and heat re=eted in the effiieny e/n".1

-ffiieny )+ in

?out

?in

?

( ) ( )

( )2"-

14-2"-

*

**

( ) ( )

( )2"142"

1 ( )

( )2"

14

1

1

1

2

"2

1

41

PPP.eqn 6.4

&roesses 1,2 and 3,( are isentropi&roesses 2,3 and (,1 are isobariAene p2 p3and p( p1the pMT relationship for isentropi proess yields

b1b

=

1-

2-

1

2

b1b

=

4-

"-

4

"

:ine# p2 p3and p( p1

=

=

b1b

1-

2-

1

2

=

b1b

4-

"-

4

"

:o# 12

4"

On ross multipliation

1

4

2

"

PPP.eqn 6.5

:ubstitutin$ e/n ".5 in e/n ".(



55/87

*ha-ter 6

1 2

1

PPP.eqn 6.6

1 b1b

2-1-

1

( ) b

1b

-r

1PPP.eqn 6.7

Pro/lem *1

$as turbine unit has a pressure ratio of "N1 and ma8imum yle temperature of "10Q9.9alulate the power output in >I of an eletri $enerator $eared to the turbine when the airenters the ompressor at 15Q9 at the rate of 1" >$*se.

p2* p1 "T3 "10Q9 663 ;

T1 15 Q9 266 ; + 1" >$*se

or isentropi proess

1

=

1

2

1

2

-

-

( ) 1.411.4

1

2 62%%

=

T2 (61 ;

:imilarly for the turbine T( 52!.2 ;

Ior> of the ompressor )I9+ + 9p)T2H T1+ 1" 8 1.005 )(61 H 266+ 3103.(( >I

Ior> of the turbine )IT+ + 9p)T3H T(+ 1" 8 1.005 )663 H 52!.2+ 5"6!.1 >I

Cet wor> output IT, I9 2565.""( >I

Pro/lem *!

hi$h speed $as turbine power plant reeives $as at 1500 ;# produes 100 %I. Theompressor wor>s with a pressure ratio of 12. The atmospheri onditions are 101 >&a and (0Q9.@etermine#

)i+ The mass flow rate of air.)ii+ The thermal effiieny of the power plant.

MIME4220 Power Plant Engineering Page ))


56/87

*ha-ter 6

&ower 100 %IT3 1500 ; T1 (0 Q9 313 ; p1 101 >&a

p2* p1 12

T2 "3"."2 ;

T( 3.(! ;

Bin 9p)T3H T2+ 1.005 ) 1500 H "3"."2+ 6".0 >J*>$

0.51

Inet -ffiieny 8 heat input 0.51 8 6". ((2. 52 >J*>$

&ower mass flow rate 8 Inet100 8 103 mass flow rate 8 ((2.52

%ass flow rate 225.! >$*se

*) $as Tur/ine with Reheat and Regeneration

eheat and e$eneration are employed with simple Erayton yle to inrease the speifi outputand thermal effiieny of the plant.*)1 Reheatine 9yle at the bottom.

This is harateri?ed by hi$h inlet temperature and low e8haust temperature and hene hi$heffiieny of around (57.

i$ "." 9ombined 9yle &lant

The as Turbine Fnit in a ombined yle is li>e that in a simple $as turbine plant. Aowever thee8haust is not wasted into atmosphere. The heat is reovered in a Aeat eovery :teamenerator and the steam so $enerated is supplied to the :team enerator Fnit.

The omparisons of effiieny for different types are as follows.Table ".1

Comparison o( E((iciency

Type E((iciency

an>ine 35

:imple Erayton 20

9ombined (5

MIME4220 Power Plant Engineering Page )%


59/87

*ha-ter 6

*3 $eneral aspects*31 5pplications

%a=or fields of appliation of $as turbines area. 5viation

. Power $eneration

c. Oil and gas industry

d. Marine -ro-ulsion

*3! 5dvantages

a. ,el( contained

. &ight weight

c. #o cooling water re'uired (or o-en cycle -lant

d. &ow installation cost

e. ?uic starting

*3" 9is0advantages

a. #ot sel(starting

. &ow e((iciencies at -art loads

c. #on irreversiility

d. igher rotor s-eeds

e. &ow overall -lant e((iciency

MIME4220 Power Plant Engineering Page )/


60/87

*ha-ter 6

E4ercises

E4 #o 1

ir enters the ompressor of a $as turbine plant operatin$ on Erayton yle at 101.325 >&a#2Q9. The pressure ratio in the yle is ". 9alulate the ma8imum temperature in the yle andthe yle effiieny.ssume IT 2.5 I9# where ITand Iare the turbine and ompressor wor> respetively.Ta>e 1.(nswer T3 1251 ; L X (07IT 2.5 IE4 #o !

5n isentro-ic air turine is used to su--ly 0.1 gBsec o( air at 0.1 M#B+2and at 2%) C toa cain. he -ressure at inlet to the turine is 0.4 M#B+2. ;eter+ine the te+-erature at

turine inlet and the -ower develo-ed y the turine.5ssu+e *-@ 1.0 DBg C.5nswer "@ 42".) C P @ 1".%) . F int G @ *- < "H 4= E4 #o "

5ir enters the co+-ressor at 1.0 ar and 20J*. he -ressure o( air leaving theco+-ressor is ".) ar and the te+-erature at turine inlet is 600J*. ;eter+ine -er g o(air G


61/87

*ha-ter 6

Re(erences


2. .;.a=put# te8t boo> of &ower &lant -n$ineerin$# 3rdedition# Da8mi&ubliations )&+ Dtd.#Cew @elhi #200". 4:EC 61,006,"52,3


61,6326,,0


1. J.Ieisman and .->art# %odern &ower &lant -n$ineerin$# &rentie Aall of4ndia# Cew @elhi# 1!65.



62/87

*ha-ter !

Chapter 3

6ydro Power and ,ind Power Tur/ines31 .ntroduction

hydro power turbine onverts the potential ener$y of water into mehanial ener$y whih inturn is utili?ed to run an eletri $enerator to $et eletri ener$y. :imilarly wind power turbine

onverts the >ineti ener$y of wind into mehanial ener$y whih in turn is used to run aneletri $enerator to $et eletri ener$y. The eletri ener$y produed by hydro power turbinewould be 9 and the same with wind power turbine would be mostly @9.3! Classi(ication o( 6ydro Power Tur/ines

a 5ccording to the head and 'uantity o( water availa/le

)i+ 4mpulse turbine H Ai$h head and low /uantity of water)ii+ eation turbine H Dow head and hi$h /uantity of water

/ 5ccording to the #ame o( the Originator

)i+ &elton turbine H 4mpulse turbine)ii+ ranis turbine H eation turbine )medium head and medium /uantity of

water+

)iii+ ;aplan turbine H eation turbine )Dow head and hi$h /uantity of water+c 5ccording to action o( water on the moving /lades

)i+ 4mpulse turbine H &elton turbine)ii+ eation turbine H ranis turbine G ;aplan turbine

d 5ccording to direction o( (low o( water in the runner /lades

)i+ Tan$ential flow turbine )&elton turbine+)ii+ adial flow turbine)iii+ 8ial flow turbine );aplan turbine+)iv+ %i8ed flow turbine )ranis turbine+ both radial and a8ial flow turbine

e 5ccording to the disposition o( sha(t

)i+ Aori?ontal shaft

)ii+ Mertial shaft( 5ccording to speci(ic speed =#s>

)i+ &elton turbine H 10 to 35 rpm)ii+ ranis turbine H "0 to 300 rpm)iii+ ;aplan turbine H 120 to 1000 rpm

S&e!ifi! s&ee' of s%af( is 'efi#e' as (%e s&ee' of a geo)e(ri!all" si)ilar (urbi#e (%a(

-oul' 'e$elo& o#e bra1e %orse &o-er u#'er (%e %ea' of 0)*

All geo)e(ri!all" si)ilar (urbi#es 2irres&e!(i$e of (%eir sies3 -ill %a$e (%e sa)e

s&e!ifi! s&ee' -%e# o&era(i#g u#'er (%e sa)e !o#'i(io#s of %ea' a#' flo-*



63/87

*ha-ter !

3" Classi(ication o( ,ind Power Tur/ines

i$ .1 -ner$y onversions in a typial Iind Turbine.9ourtesy N www.Aow:tuffIor>s.om

;ineti ener$y of the onomin$ air stri>es the rotor blades# turnin$ them# and hene the a8ial>ineti ener$y is turned into mehanial ener$y of the rotatin$ blades.:ome of this mehanial ener$y is lost in the ontrol mehanism# onsistin$ of the $ear bo8 andbra>e to re$ulate the speed and math it with that of the $enerator. :ome ener$y losses areenountered due to frition.The shaft turnin$ with the remainin$ ener$y will rotate in turn the $eneratorL hene onvertin$its the output into eletrial ener$y )i.e.# mehanial to eletrial ener$y+.

:ome losses are dissipated throu$h the mehanial onnetions between the turbine and theeletrial $enerator.%ahines usin$ rotors as wind ener$y olletors may be lassified in terms of the orientation oftheir a8is of rotation# relative to the wind,stream.

)i+ Aori?ontal,a8is rotors , for whih the a8is of rotation is hori?ontal and parallel to thewind

)ii+ Mertial,a8is rotors , for whih the a8is of rotation is vertial and perpendiular to the windIind turbines an also be lassified aordin$ to their si?es.



64/87

*ha-ter !

)a+ +mall ,ind Tur/inesN Dess than 12 meters in diameter with ma8imum power outputs ofbetween 50 I and 50 >I. These are used as stand,alone systems for water pumpin$# batteryhar$in$ or small,sale power $eneration appliations.)b+ Medium0si?ed ,ind Tur/inesN Fp to about (0 meters in diameter with ma8imum poweroutputs of up to 50 >I. These are used for eletrial power $eneration appliations and usually

onneted to a main $rid.)+ &arge ,ind Tur/inesN reater than about (0 meters in diameter and have been built as lar$eas 100 meters in diameter. The lar$est an provide power outputs of up to 5 %I.Eoth medium and lar$e si?e wind turbines an be $rouped to$ether in wind farms.



65/87

*ha-ter !

E4ercises

1. Ihih turbine is preferred for low head and low flow rate and whyV

2. Aow to lassify hydrauli turbines based on the pressure headV

3. -numerate the use of draft tube.

Re(erences





61,6326,,0






66/87

Chapter @

Power $eneration (rom Renewa/le 6eat +ources

and

5lternate 8uels

@1 .ntroduction

:ome of the renewable heat soures are eothermal# Oean thermal# :olar thermal power plants.

lternate fuels are Eio fuels and :yntheti fuels.

@! $eothermal Energy Conversion

The earth rust is in hot ondition. The heat ener$y is available there in earths rust and it is

easily aessible upto a depth of 10 >m. The term $eothermal is defined as all the heat

stored in the earths rust above 15Q9 to a depth of 10 >m.

The hot molten ro> alled ma$maK usually present at a depth of 25 to (0 >m. The ma$ma also

present lose to the surfae of the earth in some plaes due to $eolo$ial onditions.

Aene this heat ener$y an be tapped artifiially to $enerate steam. The total amount of heat

ener$y available upto a depth of 10>m is far $reater than the heat obtained from

ombustion of fossil fuels. Only small portion of this heat is tapped so far and there is

sope to use $eothermal ener$y.

The earths surfae is lassified into three broad $roups. They are

)i+ Con thermal areas )10Q to (0Q 9 per >m depth+

)ii+ :emi thermal areas ) 0Q9 per >m depth+

)iii+ Ayper thermal areas

)a+ Iet fields H produes wet steam# small fration of that steam splashed into

steam and a ma=or portion remains as hot water.

)b+ @ry fields H produes dry saturated and super heated steam at a pressure

above atmospheri.



67/87

*ha-ter %

:oure N httpN**visual.merriam,webster.omi$ 6.1 eothermal &ower &lant

5dvantages

1. Mersatile and heaper ompared to onventional power plants.2. Deast pollutin$ ompared to onventional power plants.

3. Ai$hest load fator.

(. Ai$h ener$y density.

9isadvantages

1. Dow overall effiieny.

2. :team and water from the earth may ontain harmful A2:# 9o2# CA3and other $ases.

3. @rillin$ of earth reates lot of noise.

(. Dar$e area is re/uired.



68/87

*ha-ter %

@" Ocean Thermal Energy Conversion

The first system this >ind was proposed by the renh physiist Ja/uesdrsonval in the year

1661. This OT-9 is another form of utili?in$ the solar ener$y indiretly.

The basi priniple behind this ener$y onversion system is utili?in$ the temperature $radient

e8istin$ between the surfae level sea water and the deep water.

The surfae sea water whih is e8posed to the :unli$ht is in warm ondition. The deep water is

in old ondition. There is a temperature differene of the order of 20 H 25; is e8istin$.

The warm water an be used to vapori?e some low boilin$ or$ani fluids. Then the

vapour an run a turbine oupled with $enerator to produe power. The e8it vapour from

the turbine is ondensed usin$ the old water from the deeper re$ions. The amount of

ener$y available for the $eneration of oean thermal power is enormous.

Two methods normally adopted are

)i+ Open yle OT-9 system )9laude yle+

)ii+ 9losed yle OT-9 system )nderson yle+

@% +olar Thermal Power plant throu$h the reeiver# where it is at 5"5 o9 andthen to a hot stora$e tan>. The hot salt is pumped to a steam $eneratin$ system that produessuperheated steam for a onventionalRa#1i#e !"!le (urbi#e ge#era(or s"s(e).4n this system several heliostats are loated on the $round level. heliostat is a nearly flat mirrorwith the provision to tra> the sun in two planes. The refleted rays are pointed towards a 9entraleeiver mounted on a tall tower. -ah heliostat has its own tra>in$ system. lar$e entral reeiver power plant is usually built with modular onept. -ah power plant mayhave 2 to 10 modules. -ah module may be rated for 10 %I to 100 %I.

@) Bio 8uelsin$.Eiofuel industries are e8pandin$ in -urope#siaand meria.eent tehnolo$y developed atDos lamos Cational Dab even allows for the onversion of pollution into renewable bio fuel.$rofuels are biofuels whih are produed from speifi rops# rather than from waste proessessuh as landfill off,$assin$ or reyled ve$etable oil.

http://en.wikipedia.org/wiki/Petroleum#formationhttp://en.wikipedia.org/wiki/Europehttp://en.wikipedia.org/wiki/Europehttp://en.wikipedia.org/wiki/Asiahttp://en.wikipedia.org/wiki/Americashttp://en.wikipedia.org/wiki/Americashttp://en.wikipedia.org/wiki/Europehttp://en.wikipedia.org/wiki/Asiahttp://en.wikipedia.org/wiki/Americashttp://en.wikipedia.org/wiki/Petroleum#formation


69/87

*ha-ter %

There are two ommon strate$ies of produin$ li/uid and $aseous a$rofuels. One is to $rowrops hi$h in su$ar )su$ar ane# su$ar beet# and sweet sor$humor starh)orn*mai?e+# and thenuse yeast fermentation to produe ethyl alohol )ethanol+. The seond is to $row plants thatontain hi$h amounts ofve$etable oil#suh as oil palm#soybean# al$ae#=atropha# orpon$amiapinnata.Ihen these oils are heated# their visosityis redued# and they an be burned diretly in

adiesel en$ine# or they an be hemially proessed to produe fuels suh as biodiesel. Ioodand its byproduts an also be onverted into biofuels suh as wood$as# methanol or ethanolfuel.

@* +ynthetic 8uels

:yntheti fuel is a li/uid fuel obtained from oal# natural $as# or biomass. 4t may also refer tofuels derived from other solids suh as plastis or rubber waste# or from the fermentation of bio,matter.:yntheti fuels are lassified based on what feedsto> was used to reate them. Ey far# the threemost prominent proesses are 9oal,To,Di/uids )9TD+# as,To,Di/uids )TD+ and Eiomass,To,Di/uids )ETD+.

The widest used form of syntheti fuel is li/uefied oal and its derivatives. The isher,Tropsh&roess# developed by Ca?i ermany and used by :asol in :outh fria today is one of the mostused for onvertin$ oal# as well as biomass or natural $as# into syntheti fuels.@*1 +teps to produce synthetic (uel

1. 9onvert the fuel into arbon mono8ide and hydro$en $as# in natural $ases li>e

methane# this re/uires partial ombustion.

2. or oal or biomass# $asifiation is neessary# whih means ombinin$ the material

with water and o8y$en or air at hi$h temperatures.

3. The arbon in the oal ombines with o8y$en in the water to reate arbon mono8ide#

whih the leftover hydro$en atoms reate hydro$en $as.

(. This produes a substane alled :yn$as# whih an itself by used as a fuel# or further

proessed into diesel or another derivative.

http://en.wikipedia.org/wiki/Sugar_canehttp://en.wikipedia.org/wiki/Sugar_beethttp://en.wikipedia.org/wiki/Sweet_sorghumhttp://en.wikipedia.org/wiki/Starchhttp://en.wikipedia.org/wiki/Maizehttp://en.wikipedia.org/wiki/Maizehttp://en.wikipedia.org/wiki/Yeasthttp://en.wikipedia.org/wiki/Ethanol_fermentationhttp://en.wikipedia.org/wiki/Ethanol_fermentationhttp://en.wikipedia.org/wiki/Ethanolhttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Oil_palmhttp://en.wikipedia.org/wiki/Oil_palmhttp://en.wikipedia.org/wiki/Oil_palmhttp://en.wikipedia.org/wiki/Soybeanhttp://en.wikipedia.org/wiki/Algaehttp://en.wikipedia.org/wiki/Jatrophahttp://en.wikipedia.org/wiki/Pongamia_pinnatahttp://en.wikipedia.org/wiki/Pongamia_pinnatahttp://en.wikipedia.org/wiki/Pongamia_pinnatahttp://en.wikipedia.org/wiki/Pongamia_pinnatahttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Biodieselhttp://en.wikipedia.org/wiki/Woodgashttp://en.wikipedia.org/wiki/Methanolhttp://en.wikipedia.org/wiki/Methanolhttp://en.wikipedia.org/wiki/Methanolhttp://en.wikipedia.org/wiki/Ethanol_fuelhttp://en.wikipedia.org/wiki/Ethanol_fuelhttp://en.wikipedia.org/wiki/Sugar_canehttp://en.wikipedia.org/wiki/Sugar_beethttp://en.wikipedia.org/wiki/Sweet_sorghumhttp://en.wikipedia.org/wiki/Starchhttp://en.wikipedia.org/wiki/Maizehttp://en.wikipedia.org/wiki/Maizehttp://en.wikipedia.org/wiki/Yeasthttp://en.wikipedia.org/wiki/Ethanol_fermentationhttp://en.wikipedia.org/wiki/Ethanolhttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Oil_palmhttp://en.wikipedia.org/wiki/Soybeanhttp://en.wikipedia.org/wiki/Algaehttp://en.wikipedia.org/wiki/Jatrophahttp://en.wikipedia.org/wiki/Pongamia_pinnatahttp://en.wikipedia.org/wiki/Pongamia_pinnatahttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Biodieselhttp://en.wikipedia.org/wiki/Woodgashttp://en.wikipedia.org/wiki/Methanolhttp://en.wikipedia.org/wiki/Ethanol_fuelhttp://en.wikipedia.org/wiki/Ethanol_fuel


70/87

*ha-ter %

E4ercises

1. 9ompare the positive aspets of $eothermal power plant over OT-9.

2. Ihat is the strate$y suitable to Oman to produe bio,fuelV Justify your answer.

3. Dist the advanta$es of syntheti fuel onversion.

Re(erences



Dtd.#Cew @elhi #200". 4:EC 61,006,"52,3

3. :.ao and @r.E.E.&arule>ar# -ner$y Tehnolo$y#3rdedition# ;hanna &ubliations#Cew

@elhi# 1!!!. 4:EC 61,(0!,0(0,1


1. J.Ieisman and .->art# %odern &ower &lant -n$ineerin$# &rentie Aall of 4ndia# Cew

@elhi# 1!65.

MIME4220 Power Plant Engineering Page !0


71/87

Chapter A

9irect Electric Power Conversion +ystemsA1 .ntroduction

The diret eletri power onversion systems are possessin$ overall thermal effiieny of morethan "07 sine they do not have mehanial ener$y onversion from primary soure in their

ener$y route. They do not reate noise pollution as well. :o# they an be utili?ed for small saleappliations.Eut the disadvanta$e is the initial investment over the e/uipment is enormous# in addition thesi?e is also bi$.:ome of the ommonly used diret eletri power onversion systems are solar photovoltai#thermioni# and fuel ell devies.

A! +olar Photovoltaic Cell

The :olar &hoto,Moltai ells )&M ells+ onvert the inident solar li$ht ener$y diretly toeletrial ener$y in @9 form. sin$le ell has a rated volta$e of about 0.5 M and rated power ofabout 0.3 I.

4n the 1!50s# merian en$ineers sou$ht a method to power F.:. spae satellites. They found itin an e8istin$ proess that used ener$y from the sun alled photo,voltais )&M+. Ie still usephoto,voltais to ener$i?e orbitin$ satellites# spae stations# and the Aubble telesope. Ea> onthe earth# &M is widely used for everythin$ from roadside all bo8es to lar$e power plants.4n photovoltais# photons of sunli$ht reat with speially desi$ned materials in a proess thatresults in eletriity. &hoto means li$ht# and voltai refers to the eletrial urrent. The smallestunit is a photovoltai ell# made of wafer,thin layers that reat to sunli$ht to reate eletriity.The most ommon material in use today is silion# either in rystalline form or thin films# butother materials are bein$ investi$ated. :olar ells are wired to$ether to ma>e modules# andmodules are ombined to$ether to ma>e up a solar panel. $roup of solar panels are olletively>nown as a &M array and an provide enou$h eletriity for a household.



72/87

*ha-ter /

A" Thermionic Converter

thermioni onverter# in priniple# onsists of two metals or eletrodes with different wor>funtions sealed into an evauated vessel. The eletrode with a lar$e wor> funtion is maintainedat a hi$her temperature than one with the smaller wor> funtion. Ior> funtion is te ene!g"!equi!ed t# e$t!act an e%ect!#n &!#m te meta%. 4t is measured in e%ect!#n '#%ts. The value of

wor> funtion varies with the natu!e #& meta% and its su!&ace c#nditi#n.

i$ !.1 Thermioni onverter

thermioni onverter omprises a heated athode )eletron emitter+ and an anode )eletronolletor+ separated by vauum# the eletrial output iruit bein$ onneted between the two asshown in i$ !.1 The heat whih is supplied to the athode raises the ener$y of its eletrons to

suh a level that it enables them to esape from the surfae and flow to the anode. t the anodethe ener$y of eletrons appears partially as heat# removed by oolin$ and partially as eletrialener$y delivered to the iruit. lthou$h the distane between anode and athode is only aboutone millimeter# the ne$ative spae har$e with suh an arran$ement hinder the passa$e of theeletrons and must be redued# this an be ahieved by introduin$ positive ions into the inter,eletrode spae# esium vapour bein$ valuable soure of suh ions.

A% 8uel cells

fuel ell is an eletrohemial devie in whih the hemial ener$y of a onventional fuel isonverted diretly and effiiently into low volta$e# diret,urrent eletrial ener$y. This devie isoften desribed as a primary battery in whih the fuel and o8idi?er are stored e8ternal to thebattery and fed to it as needed.The i$ !.2 shows a shemati dia$ram of a fuel ell. The fuel $as diffuses throu$h the anodeand is o8idi?ed# thus releasin$ eletrons to the e8ternal iruitL the o8idi?er diffuses throu$h theathode and is redued by the eletrons that have ome from the anode by way of the e8ternaliruit.The fuel ell is a devie that >eeps the fuel moleules from mi8in$ with the o8idi?er moleules#permittin$# however# the transfer of eletrons by a metalli path that may ontain a load.


node

*athode

-vauated Messel

Aeat in ut

[email protected]

9oolant -letrons


73/87

*ha-ter /

Of the available fuels# hydro$en has so far $ive the most promisin$ results# althou$h ellsonsumin$ oal# oil or natural $as would be eonomially muh more useful for lar$e saleappliations.

E&E*RI*5&

&O5;

E&E*RO&KE

*5O;E5#O;E

i$ !.2 :hemati of fuel ell

E4ercises

1.Ihat are the available forms of silion to produe solar ellV :tate the advanta$es of eah

ate$ory.

2. Ihy do we need an evauated vessel to perform thermioni onversionV

3. Aow the o8idi?er diffusion happens in fuel ellV

Re(erences




MIME4220 Power Plant Engineering Page !"


74/87

*ha-ter /


61,6326,,0

(. :.ao and @r.E.E.&arule>ar# -ner$y Tehnolo$y#3rdedition# ;hanna

&ubliations#Cew @elhi# 1!!!. 4:EC 61,(0!,0(05dditional Te4t Boo- Re(erence





75/87

Chapter 12

Control o( Major Pollutants (rom 8ossil 8uel Power Plants121 .ntroduction

(#ssi% (ue% )#m*usti#n results in emission of pollutants and heat into the environment. ir#water and land are adversely affeted by various emissions fromP#we! P%ants and +ndust!ies.

The prinipal emission produts )pollutants+ from fossil fuel power plants are)i+ 9O )ii+ 9O2

)iii+ :O2 )iv+ COR)v+ @ust )vi+ ly ash)vii+ &artiulate matter

12! E((ect o( pollutants

easons for 9O# CORemission are inomplete ombustion. That means insuffiient supply ofo8y$en.9O2is very harmful to atmosphere# whih ould turn fertile lands into desserts.:O2is assoiated with deterioration of the surfaes of leaves or needles due to the destrution of

hlorophyll.They also need to aidi rain# :O2 ontributes "07# COR ontributes 357 and 9O2 alsoontributes.

12" Control o( pollutants

%ethods to ontrol emission of :O2N1. @e,sulphurisation of fuels

2. Fse of low sulphur fuels

3. Fse of tall sta>es )9himneys+

(. 9leanin$ of flue $ases

%ethods to ontrol emission of CO2N1. edue the temperature in ombustion ?one

2. edue residene time in ombustion ?one

3. 4nrease the e/uivalene ratio in ombustion ?one

MIME4220 Power Plant Engineering Page !)


76/87

%ethods to ontrol &artiulate matter1. abri filter # Ea$ house H heap to remove partiles of 2 to 3 mirons

2. -letrostati preipitator H ostly# to remove up to 1 miron

3. 9ylone separator H moderate ost# usin$ entrifu$al priniple

ly ash an be removed usin$ fly ash srubber# it is similar to a mehanial ash olletor# but has a

flowin$ water film on its inner walls. t present# this fly ash is used to ma>e hollow,blo>s and bri>s.Aene# the disposal volume an be redued.12% Electrostatic Precipitator

i$ 10.1 &riniple of -:& ,ource G htt-GBBwww.ha+onresearchcottrell.co+BtechLes-(unda+entals


&artiles suspended in a $asenter the preipitator and passthrou$h ioni?ed ?ones aroundthe hi$h volta$e dishar$eeletrodes. The eletrodes#throu$h a orona effet emitne$atively har$ed ions into the$as.

The ne$atively har$ed$as field around eaheletrode har$es the

partiles ausin$ them tomi$rate to the eletrodesof opposite polarity# i.e.the olletin$ eletrodes.

The har$ed partiles $atheron the $rounded olletin$

plates. appers dislod$e thea$$lomerated partiulate#whih falls into theolletion hoppers forremoval.


77/87

E4ercises

1. &erform a flue $as analysis and list the ompositions of $ases omin$ out vehiles. :u$$est

suitable methods to ontrol the pollutants.

2. Ihat is use of fly ashV

Re(erences



Dtd.#

Cew @elhi #200". 4:EC 61,006,"52,3

3. ;.;.amalin$am# &ower &lant -n$ineerin$# :94T-9A# 9hennai# 2002. 4:EC 61,6326,,0

(. :.ao and @r.E.E.&arule>ar# -ner$y Tehnolo$y#

3rdedition# ;hanna publiations# Cew@elhi#1!!!. 4:EC 61,(0!,0(0

MIME4220 Power Plant Engineering Page !!


78/87

MIME4220 Power Plant Engineering Page !%


79/87

MIME4220 Power Plant Engineering Page !/


80/87

MIME4220 Power Plant Engineering Page %0


81/87



82/87



83/87

MIME4220 Power Plant Engineering Page %"


84/87



85/87

MIME4220 Power Plant Engineering Page %)


86/87



87/87

mime4220 power plant engg hanout sem 2 2013-14(1)

Documents