BOILER FEED PUMP INTRODUCTION: It sucks water from Deaerator storage tank at 22.5 mtrs. And feed it to the • economizer inlet either through HPHs or bypassing HPHs one or both. he pump internals are designed as cartridge which can be easily remo!ed for • maintenance without disturbing the suction and discharge piping work or the alignments of the pump and the hydraulic coupling. As "#P is handling the feed water of $%& degree '( so net positi!e suction head • re)uirement of "#P must be maintained. o meet *P+H ( "#P suction pressure is being increased by, • $. Placin Placing g Dearera Dearerator tor at at higher higher ele!a ele!atio tion. n. 2. Pressu Pressuriz rizing ing Deaer Deaerato atorr with peggi pegging ng steam. steam. -. sin sing g "oos "ooste terr pump pump.. CONTRUCTION: he "oiler feed Pump consists of the following main components/ Pump casing • Discharge co!er • +uction guide • 0ing section assembly • 0otating assembly • 1echanical seal • ournal 3 hrust bearing • Hydraulic balance • 'oupling • TECHNICAL SPECIFICATION: SPECIFICATION:
&$ 1ake 3 ype &2 Dire Direct ctio ion n of rota rotati tion on !iew !iewed ed from from dri!e end &- 0ated flow &; +hut off Head &5 Impeller type &% 1in. recirculation flow &= #eed water temperature &< +uction strainer &? *o *o. of stages $& +uction bore diameter8mm9 $$ Discharge bore diameter8mm9 $2 +peed8rpm9 $- Power absorbed8kw9 $; *P+H re)uired
14+ "H6 3 #7%D -&8"arrel 'asing9 Anti:'lock:wise -&5 PH $%2& mlc 0adial flow( +ingle suction <& m-4hr $%5.5 degree ' ++ +imple> basket( -$5 microns mesh size % 2&& $5& ;22& $--2 7@ $5 mlc
$5 $% $= $< $? 2& 2$
"#P leak off flow at rated speed *o. of pump bearing ype of balancing system 'oupling type "#P motor rating 1otor 0P1 "ooster pump type
22 22; 25 2%
*P+H re)uired at "ooster pump 0ated speed 80P19 of "ooster pump Power input at rated flow 8-&5m-4hrs9 Direction of rotation8from 1otor side9 ype of lubrication
$; m-4hrs 2 ournal B $ hrust bearing "alance drum #le>ible 2$&& 7@ $;<58%.% 7C9 +ingle stage( #A$"5% double !olute type with horizontal split casing and double suction impeller. -.; mlc $;<5 $$57@8"ooster pump9 Anti:clockwise8"ooster pump9 il lubrication
VOITH variable Speed Coupli!: he 1ain 'omponent of this type o coupling are/ • $. Input +haft 2. Eear and Pinion -. Primary shaft ;. hydro 'oupling primary wheel 5. Hydro coupling secondary wheel %. +coop tube =. @orking il46ube oil pump with spar and be!el gear <. Au>iliary 6ube il pump assembly. •
•
•
•
•
Input shaft o Hydraulic coupling is coupled with motor shaft 3 power transmitted to the gear through this shaft. Here Eear and Pinion has $;2 and -? nos. of teeth respecti!ely. +o( EA0 0AI is "#$%&' . #rom the pinion power transmitted to hydro coupling primary wheel through a shaft called primary shaft. hen power4tor)ue transmitted to secondary wheel by p ump 3 turbine action of primary and secondary wheel respecti!ely. A scoop arrangement control the speed of the secondary wheel by controlling )uantity of working oil in the coupling chamber between primary and secondary wheel.
OIL CICUIT: he same il is used as working and 6ube oil. @orking oil pump 8centrifugal9 and • main lube oil pump 8gear9 is combine to form a pump set dri!en by the input shaft of geared !ariable speed turbo coupling. he electric motor dri!en Au>iliary lube oil pump 8AP9 lubricate the unit during • start up( shut down and incase of interference.
(OR)IN* OIL CIRCUIT: Pump:::::::::::::: through the il circulation !al!e:::::::: 'oupling working chamber :::::::::+coop chamber 8due to centrifugal force( forms a oil ring 3 scoop tube position determines the thickness of oil ring in the scoop chamber and thus also the filling in working chamber9 ::::::::::: he scoop tube scoop up the warmed up working oil in working chamber:::::::::::::::::::: @orking oil cooler 8where oil cooled down9 :::::::::::: il circulation !al!e. Clo+e Cir,ui- ,o.ple-ed/ 000he oil circulation !al!e controls the working oil flow rate dependent on the accumulated power losses. Any e>cessi!e oil in the circuit is returned through the pressure relief !al!e into the tank.
FFF If the close circuit is interrupted and the geared !ariable speed turbo coupling oil temperature rises to $%& Degree '( the #+I"6 P6E blow due to a temporary thermal o!erloading of oil circuit i.e. due to cooler failure or o!erloading of coupling( the control beha!ior o the coupling changes slightly/ LUBE OIL CIRCUIT: 1ain 6ube oil pump:::::::::::::: *on return !al!e:::::::::::: Pressure relief !al!e::::::::: 6ube oil cooler ::::::::::::::::: Duple> filter ::::::::::::::: "earing points( pressure switches and gear wheel. he lube oil pressure set is appro> 2.5 kg4cm2. • o ensure the bearing is coated with an oil film during start up( shut down( failure( • they are supplied with oil by au>iliary oil pump before the dri!e motor is switched on and after it is switched off. Au>iliary oil pump:::::::::::: *on return !al!e::::::::: 6ube oil circuit. • 6ube oil for e>ternal unit 8e.g. Dri!e machine( dri!en machine or connecting • coupling9 are supplied from the same lube oil circuit and returned to the oil sump. SCOOP TUBE CONTROL: he scoop tube which regulates the amount of oil in the coupling is controlled by the • actuator turning the cam disc( positioning the scoo p tube accordingly. +P P +PD '*06/ he scoop tube mo!es away from the oil ring in the • coupling( the amount of oil scooped up decreases( the pressure in the circulating control !al!e drops( the pressure relief !al!e closes( the )uantity deli!ered by the working oil pump is also used to fill the working chamber.
BFP START UP PERMISSIVE SN
START PERMISSIVE
CONDITION
"
1otor @inding emp. not high.
$ &
ournal "rg. emp. not high 3 hrust "rg. emp. not high. +uction !al!e open
ournal G ?& deg. hrust G $&& deg. 6imit +witch.
#
6ube oil header pressure 7
&.< kg4cm2 for 5 sec.
1
"#P A is not tripped.
2
"reaker is in ser!ice.
3
"#P A is ##.
4
"#P condition stand by.
'
wo "#P not running.
"5
""
Deaerator le!el normal/ 82;5&mm9 High/ 2=&&mm High:High/2?5&mm 6ock out relay reset.
"$
"reaker not in test.
1''
"&
+witch Eear is not 0IPPD.
1''
"#
+coop position minimum.8259
1''
"#P A selected or #'C open 3 Dis. Cal!e close.
*o low switch acted.
1''
BFP TRIPPIN* LO*IC 6 VALUE
+*
Protection ype
+et Point Alarm ripping
'ondition
$
"reaker in est.
1''
2
1otor @inding emp. !ery High.
$2& deg.
$2% deg
-
"#P brg. emp. !ery high. 8ournalBhrust BH4' B motor9 Diff. temp. !ery high 3 +uction flow 6@.
?& deg.
$&$ deg.
5
@orking il temp. !ery high.
$$& deg
$-&.5 deg.
%
BFP +u,-io pre++ure ver7 lo8/
$= kg4cm2
$5.5 kg4cm2
+uction K $% kg4cm2
=
Lube Oil pre++ure ver7 lo8 6 BFP ON/
&.< kg4cm2
&.5 kg4cm2
6ube il press.K &.5 kg4cm2 for = sec.
<
+uction !al!e not open.
?
Deaerator le!el !ery low.
$?-5mm
55&mm
24- logic.
$&
"#P !ib. Cery high.
$$mm4sec
$<.5mm4sec8delay time/ 5 sec.9
$$
+witch Eear tripped.
1''
;
Diff. temp.J $5 deg for 2 sec. 3 suction flow $&& PH.
'A+ / After 1aor +4D
PREPARATION FOR STARTUP:
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• • •
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• • • •
• •
•
All permits are returned from all ser!ice agencies. 'heck that the compressed air and electrical supplies are a!ailable for the instruments leak off e)uipment and !al!es. 'heck that the booster pump and the feed pump drain !al!es are shut. 'heck that the recirculation !al!e and its isolating !al!es are open. 'heck that all the instruments tapping points and isolating !al!es are open and that all drain e)ualizing !al!es are shut. pen the feed pump dri!e end and non dri!e end mechanical seal cooler circulation water inlet and outlet isolating !al!es. 'heck that the pump discharge !al!e and its bypass is close and power on . 'rack open the pump suction side isolating !al!e. pen the booster stage air !ent !al!e and !ent any trapped air or gasses from the pump casing. +hut the booster pump air !ent !al!e when water issues freely from it. Cent the feed pump mechanical seals cooler and the oil coolers. #ully open the pump suction isolation !al!e. nsure that the clarified cooling water and the Au>iliary cooling water are a!ailable for the pump set. Prepare the hydraulic coupling and lube oil system for starting. 'heck that the au>iliary cooling water from the booster pump mechanical seals is flowing freely through the flow indicators 'heck that the au>iliary cooling water from the feed pump mechanical seal coolers is flowing freely through the flow indicators.
START UP: nsure that the hydraulic coupling au>iliary lube oil pump is running. • $. 6ube oil pressure at minimum of 2.5 bars and no leakage from any oint . 2. 'heck that the lube oil is flowing freely through the following flow indicators. "ooster pumps D and *D bearing drain flow. • "ooster pump side and hydraulic coupling side motor bearing • drain flow. #eed pump D and *D bearing drain flow. • 'heck that the deaerator is filled to normal working le!el J 2;5& mmwc . • All protections are in ser!ice •
+tart the boiler feed pump dri!ing motor. *ote the 'urrent on recirculation flow 4+uction flow 4Pump speed 4 Pump Discharge pr 4 All brg !ib and emp. 0un the pump for at least two hrs and keep close watch on all parameters • •
No-e: +imultaneously with the starting of the boiler feed pump open cooling water !al!e to supply water to dri!e motor air coolers.
RUNNIN* CONDITION:
@hen the pump set is running normally the recirculation !al!e ensures a minimum flow of $&& tph through the pump set. A scoop tube on the hydraulic coupling is controlled by a pneumatic actuator to automatically !ary the speed of the "#P according to the load re)uirement( from a different pressure transmitter across the feed regulating !al!e he au>iliary lube oil pump should be stopped.
ROUTINE CHEC)S: • • •
•
• • •
'heck that the dri!ing motor ammeter reading is normal. 'heck that all pressure and temperature readings are normal. 'heck that the lube oil is flowing through the following indicators $. "ooster pump D and *D bearing drain flow. 2. "ooster pump side and hydraulic coupling side dri!e motor bearing drain flow. -. #eed pump D and *D bearing drain flow. 'heck that the clarified cooling water from the booster pump mechanical seal is flowing freely through the flow indicators. 'heck for any undue noise or !ibration. 'heck for oints and !al!e glands for leakage. 'heck the security o all fastenings paying particular attention to the holding down bolts.
STANDB9 CONDITION:
@hen the pump set is re)uired or standby duty( it should be prepared as follows. $. +et the selector switch to Lauto conditionM. 2. pen the discharge !al!e. -. +tart the au>iliary lube oil pump. No-e: he scoop of the standby pump set will follow the scoop tube of running pump set.
TRIP CONDITION:
he operating feed pump set will trip when any of the following condition e>ists. $. Deaerator le!el low low. 2. 6ube oil pressure in common header low. -. Differential temperature rise between the discharge and suction of the feed pump( abo!e the preset !alue. ;. Hydraulic coupling temperature high. SHUTDO(N:
+top the dri!ing motor and position the circuit breaker in L##M position +hut the discharge !al!e
'lose the cooling water !al!e to the dri!ing motor air cooler and water cooler of the hydraulic coupling.
AUTO START UP SEUENCE/ S-ep "
AP start 3 6ube oil Header press J &.< kg4cm2.
S-ep $
"#P A 46 !al!e close command issue and check the close feedback.
S-ep #
"#P A 46 !al!e I"C close command issued and checks the close feedback. "#P recirculations Cal!e open command issued and checks the open feedback. "#P +coop is in min. condition( 8259 "#P A start command and discharge pressure 78$5& kg4cm29
S-ep 1
"#P A discharge !al!e I"C open command issued.
S-ep 2
"#P A discharge !al!e open command
S-ep 3
"#P A scoop A enable 8presently by passed (for first time operation9
S-ep 4
"#P discharge !al!e I"C close command issued.
S-ep &
SHUT DO(N SEUENCE S-ep "
"#P:A stop command "#P:A AP start command 8 #or $5 minutes protection on 9
S-ep $
"#P:A recirculation !al!e open command. "#P:A discharge !al!e I"C close command. "#P:A discharge !al!e close command. +H D@* se)uence complete
S-ep &
FAULTS: S9MPTOMS
POSSIBLE CAUSES Dri!e motor fails to start • Power supply fails • +eizure of pump set •
Pu.p ;ail+ -o +-ar-
Deaerator le!el low low • Pump set tripped •
S9MPTOMS
ACTIONS
Dri!e motor fault @rong rotation Hydraulic couple scoop tube actuator faulty "ooster pump faulty 0ecirculation !al!e faulty >cessi!e wear of pump internals
'heck motor 'heck motor connections 'heck operations of scoop tube actuator. 'heck booster pump 'heck booster !al!e Dismantle pump and inspect
POSSIBLE CAUSES
ACTIONS
• •
• • •
S9MPTOMS
6ube oil defect "earing worn out or misaligned Pump misaligned
•
Beari! over
•
•
S9MPTOMS Me,
S9MPTOMS
POSSIBLE CAUSES •
Insufficient cooling water
•
1echanical seal faulty
'heck lube oil >amine bearings 'heck bearings
ACTIONS 'heck cooling water to mechanical seals 'heck the seals.
POSSIBLE CAUSES
ACTIONS
1isalignment of pump set • "earing misalignment • Holding down bolts loose • >cessi!e clearance of pump internals • 0otating assembly out of
'heck alignment >amine bearing ighten holding down bolts 'heck clearance and o!erhaul 'heck dynamic balance
•
E=,e++ive oi+e or vibra-io
'heck motor 'heck supply Decouple and locate seizure. !erhaul if necessary. 'heck deaerator In!estigate cause. Arrest trip.
POSSIBLE CAUSES •
Per;or.a,e lo8
ACTIONS
balance