steam turbine operation and maintenance

8/19/2019 Steam Turbine Operation and Maintenance

1/24

PROPULSION TURBINE

• Warming up depends on age and design ofturine! and t"pe of s#ip$

• A%% main &a%&es et'een oi%er and (P turineupto main 'arming &a%&es are opened '#i%eg%and steam! au)i%iar" #eating and manoeu&ring

&a%&es are s#ut$

• (eating rate s#ou%d e *ontro%%ed so t#at in%ettemperature of t#e LP turine rea*#es to +,o-after one #our$ If t#e turning gear 'as in uset#en no' it ma" e disengaged$

• G%and steam of pressure .$/,0.$, ar is used and&a*uum is raised rapid%"! turine ma" e turned a


2/24

PROPULSION TURBINE

• T#e 'arming t#roug# &a%&e is no' *%osed and a#eadmanoeu&ring &a%&es opened s%ig#t%"$ Turine s#ou%d

e turned under steam at t'o minutes inter&a%s for2, minutes$ 3a*uum s#ou%d e maintained at .$/4

ar$

• 5rainage is &er" important to a&oid distortion$ A%%

drains must e 6ept *%ear and s#ou%d not e *%osedunti% t#e turine #as een rotating for se&era%minutes$

•

Au)i%iar" e)#aust steam entering main *ondensers#ou%d e redu*ed to minimum at stand " periods$

• 5uring pro%onged astern running! LP turinee) ansion indi*ators s#ou%d e *%ose% 'at*#ed and


3/24

STARTING PRO-E5URE OF -OPT• -#e*6 t#e oi% %e&e% in sump! drain o9 an" 'ater$

• Start t#e priming %u oi% pump for turine$

• Turn t#e turine " #and using a %e&er$

• Start *oo%ing 'ater to *ondenser and %u oi%*oo%er$

• Start up t#e &a*uum t#roug# steam e:e*tors$

• -%ose t#e drains for *asing! e)#aust! and steamin%et &a%&e$


4/24

STARTING PRO-E5URE OF -OPT;-ONTINUE5<

• Open t#e g%and steam to a %o' pressure and

'arming up &a%&e$

• Start up *ondensate pump and maintain 'ater%e&e% $

• S'it*# on a%arm pane% and reset an" e)istinga%arm$

•

Tr" out %u oi% %o' pressure and #ig# a*6pressure trips and remote and %o*a% emergen*"stops$

• W#en turine #as su1*ient% 'armed u


5/24

STARTING PRO-E5URE OF -OPT;-ONTINUE5<

• Gradua%%" open t#e steam &a%&e unti% go&ernorta6es o&er *ontro%! open t#e steam &a%&e fu%%$

• (and o&er t#e *ontro%s to -argo -ontro% Room$

• Monitor steam *#est! e)#aust and g%and steam

and %u oi% pressures$

• Monitor turine earing and pump earingstemperatures$


6/24

GO3ERNING OF STEAM TURBINES

• T#e speed of t#eturine is *ontro%%edeit#er " &ar"ing t#esteam pressure or "

&ar"ing steam =o'$

• T#e speed of turinema" e *ontro%%ed "

• T#rott%ing is asso*iated" redu*tion of pressure

at *onstant ent#a%p"$

• T#e =o' of steam ma"e *ontro%%ed "

grouping of no>>%es andea*# group is *ontro%%ed" it7s &a%&e$

• ("rid *ontro% is a

*omination of t#rott%e&a%&e *ontro% andno>>%e &a%&e *ontro%$One no>>%e group is


7/24

;-ONTINUE5<

• B"pass *ontro% is usedfor otaining e)trapo'er '#en fu%%pressure is app%ied to

• T#e "pass &a%&e ta6essteam from ?rst stage

to t#e %ater stage '#erearea is %arge and e)trapo'er *an e otained$

• Steam pressure is*ontro%%ed from t#ego&ernor &a%&e$

• In t#e simp%est form t#e

turine ma" #a&e :ustone no>>%e$

• In e)treme *ase no>>%es


8/24

EPANSION OF STEAM TURBINES

• T#e e)pansion arrangement s#o'n ao&e is fora #ig# pressure turine$ T#is a%%o's t#e *asingto e)pand a)ia%%" from t#e gear o) end and


9/24

;-ONTINUE5<

• T'o s%iding f eet support e%o' t#e *asing*entre %ine #a&e a)ia% 6e"s for %o*ation$

• Four support pa%ms are pro&ided of '#i*# t'oaft do not permit a)ia% mo&ement '#ereas t'ofor'ard a%%o' a)ia% mo&ement and are*onne*ted to #ori>onta% e)tensions of t#e*asing :oints$

• Rotor position re%ati&e to *asing is *ontro%%ed "t#e t#rust earing at t#e for'ard end$

• Interna% rings *orre*t%" dimensioned and ?ttedin t#rust earing ensures no furt#erad:ustment$


10/24

• T#is &a%&e *%oses automati*a%%" and s#uts o9t#e steam supp%" to t#e turine in fo%%o'ing

*onditionsC

• Loss of %uri*ating oi% pressure

• Turine o&er speed

•

E)*essi&e a)ia% rotor tra&e%• Lo' *ondenser &a*uum

• T#is &a%&e *an e *%osed manua%%" "C

• (and'#ee%

• Emergen*" #and *ontro%

• 5e*6 manua% *ontro%

3AL3E ;-ONT5$<

SELF -LOSING EMERGEN-D STOP


11/24

SELF -LOSING EMERGEN-D STOP3AL3E


12/24

• To open t#is &a%&e! supp%" &a%&e %e&er is ?rstpressed fo%%o'ed " turning of #and '#ee%$

Supp%" &a%&e %e&er admits steam t#roug# a%%and supp%" &a%&e to t#e %eft side of t#e piston$

• Piston is %oose%" ?tted in *"%inder due to '#i*#steam a%so passes on t#e a*6 side of t#e pistonand 6eeps t#e piston a%an*ed under springfor*e$

• 3a%&e is #e%d in open position " a *at*# on

supp%" &a%&e %e&er$

• If oi% pressure or &a*uum drops! steam on t#ea*6 side of t#e piston 'i%% e drained resu%ting

3AL3E ;-ONT5$<


13/24

LOW 3A-UUM TRIP


14/24

LOW 3A-UUM TRIP

• To prote*t t#e *ondenser from o&er pressuret#is de&i*e is e@uipped$

• In*rease of pressure on t#e diap#ragm top dueto de*rease in &a*uum or #and re%ease fromde*6 *auses do'n'ard mo&ement$

• T#roug# t#e %in6age t#e &a%&e opens and %eadst#e steam to drain! '#i*# *%oses t#e emergen*"stop &a%&e$

• T#e gear 'or6s e@ua%%" 'e%% " re%easing oi%pressure and fun*tioning on t#e *ontro% &a%&e insimi%ar 'a" to ot#er oi% operated trips$


15/24

ME-(ANISM

O3ERSPEE5 AIAL MO3EMENT TRIP


16/24

O3ERSPEE5 AIAL MO3EMENT TRIPME-(ANISM

• In t#is position! oi% in annu%ar spa*e 5 is a%%o'edto dis*#arge t#roug# port and t#e steam &a%&es#uts$

•

Tripping speed *an e &aried " nut B$ To resett#e &a%&e! *at*# spind%e is pu%%ed " 6no $

• In *ase of e)*essi&e a)ia% mo&ement of rotor!*ontro% us# N mo&es 'it# rotor ut inde) us#

E remains in p%a*e$ Oi% trapped in annu%us G isre%eased t#roug# annu%us ( '#i*# stops t#eturine$


17/24

EMERGEN-D O3ERSPEE5 TRIP


18/24

EMERGEN-D O3ERSPEE5 TRIP;-ONTINUE5<

• Speed *ontro% go&ernor *onsists of a nonrotating oi% supp%" tue and rotating assem%"of *anti%e&er arms$

•

T#e *anti%e&er arms #o%d a a%% &a%&e at t#eirfree ends$

• As t#e speed in*reases! *anti%e&er arms mo&eradia%%" out'ards! opening t#e a%% &a%&e and

a%%o'ing oi% to es*ape and drain$

• T#is in turn redu*es oi% pressure '#i*# a*tsupon t#e ser&ome*#anism and 'ou%d *%ose t#e

GO3ERNOR SER3OMOTOR


19/24

GO3ERNOR SER3OMOTOR


20/24

;-ONTINUE5<

• W#en turine is not running! go&ernor output isma)imum and steam &a%&e #as fu%% opening 'it#ser&oCpiston *omp%ete%" up$

• As steam is admitted to turine! go&ernor startsrotating 'it# =" 'eig#ts mo&ing out'ardsresu%ting in up'ard a*tuator mo&ement$

• As pi%ot &a%&e is *onne*ted 'it# %in6age! it mo&esup and supp%ies oi% on top of ser&oCpiston$ Ser&oCpiston starts mo&ing do'n draining oi% from

ottom side and *%osing t#e steam &a%&esimu%taneous%"$

• W#en desired speed is a*#ie&ed! pi%ot &a%&e 'i%%%o*6 ot# oi% orts and maintain t#e desired

TURBINE -LEARAN-E GAUGES


21/24



22/24

;-ONTINUE5<

• For smoot# operation of turines! *%earan*es#a&e to e maintained 'it#in *%ose to%eran*es$

• Finger pie*e gauge a%ongC'it# fee%er gauge isused to measure t#e 'ear of t#rust earing'#i*# 'i%% e re=e*ted as t#e s#aft7s e)*essi&e

a)ia% mo&ement$ T#is is *#e*6ed '#en t#eturine is stopped$

• Po6er gauge a%so measures t#e 'ear of t#rustearing and e)*essi&e a)ia% mo&ement of s#aft$T#is *an e used '#en t#e turine is at rest anda%so '#en it is running$ T#e reading is gi&en ona ?)ed s*a%e$



23/24

TURBINE -LEARAN-E GAUGES;-ONTINUE5<

• -asing a)ia% position indi*ator des*ries aout

t#e e)pansion of *asing dire*t%" on a s*a%e$

• Bridge gauge is used to measure t#e 'ear of :ourna% earing or t#e drop of rotor$

• T#is is otained after remo&ing t#e upper #a%fof earing and p%a*ing t#e dept# gauge on topof rotor$

• Wear 'i%% e otained " *omparing presentreading 'it# origina% reading$

ENERGD LOSSES MET(O5S OF• Fo%%o'ing met#ods ma"


24/24

ENERGD LOSSES MET(O5S OFIMPRO3EMENT

• We *an see t#at on%"/8 #eat is a&ai%a%efor usefu% 'or6$

• Remaining JK goes as'aste! of '#i*# ,+goes in *ondenser and

g "e app%ied to redu*e%ossesC

• Use of *ross *ompoundturine p%ant$

• Use of *omp%e) *"*%e'it# regenerati&e feed

#eating and re#eating$

• S*oop inta6e of*ondenser -$W$

• Impro&ed automation!%eading to on%ine*ontro%$

steam turbine operation and maintenance

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