Start-Up
After 8 Hours of Shutdown ( Hot start-UP)
Unit
condition
Sequence
|
00' |
Drum
Pr=75
ksc |
Take
4 guns in AB elevation |
|
Start
APH soot Blowing prior to firing |
|
|
MST:
415-430 |
Open
Drain Before BSVs |
|
|
|
|
|
Open
BSV IBvs |
|
MS
strainer drain to SDFT, UFT, CRH drain pot, Open |
|
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Open
BSvs |
|
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|
Open
Warm-up Of HPBP and then HPBP and LPBP |
|
HRH
Pr=2 ksc, Close CRH Drain pot |
|
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Start
PA fan & seal air fans |
|
Ensure
FG & air Damper of PAPH Open Prior PA Fans |
|
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|
Line-Up
Milling system |
|
Open
CAG/CAD of at least 3 mills before PA Fan start |
|
40' |
MS=
85/485 |
Take
1st Mill |
|
Make
Ready SH/RH spray |
|
|
HR=12/440 |
Charge
ESP fields |
|
Ensure
Ash Handling System Ready |
|
|
|
Cut
in 2nd Mill |
|
Peg
Deaerator with CRH (Pr=2 ksc) |
|
|
|
Reset
turbine |
|
Bring
Starting
Device to 0,
Put TG LO TCV on auto-45
Deg |
|
50' |
MS=85/500 |
Open
Turbine
SGC seq/Switch
ON/Select
Start-up |
|
105-Starting
Device (42
%)
109-
Tracking Device ON |
|
|
HR=12/450 |
Raise
Starting Device to 100% once ESVs Opened |
|
110-Speeder
Gear goes 100 %(If LT100%) |
|
|
Bypass
flow BLI
= 360 TPH |
Hold
for 5 minutes at 360 rpm |
|
112-
Turbine Speed 360
rpm
command |
|
52' |
|
Raise
Turbine speed to 3000 rpm |
|
116-Turbine
speed 3000
rpm
command |
|
|
|
(Rate
of Acceleration b/w 600-850 rpm2) |
|
(OFF
: Turning gear=240 rpm, JOP=540 rpm ) |
|
|
|
Switch
Off ATRS Program (After 116) |
|
Monitor-Bearing
Temp/Pedestal-shaft Vibration ,TSI |
|
56' |
|
Put
AVR on auto |
|
Ensure
AOP: Off
|
|
|
|
Close
Field Breaker |
|
Check
starting
GT cooling Fans |
|
|
|
Select
GCB from ECP, put sync-ON |
|
|
|
|
|
Select
Auto-synchronizer made ON |
|
Load
Ref=50 MW . Pr Max=75 MW |
|
|
|
Synchronize
Generator with Grid |
|
Speed
set point raised by 8rpm
and 20
MW
load will come |
|
|
|
Raise
speed SP by small pulse |
|
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|
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|
Put
HPBP in Auto with increased SP |
|
|
|
60' |
Load=60
MW |
Cut
in LPH-2,3 |
|
Change-Over
of ST
to UT
|
|
|
MS=85
/500 |
Cutout
Heating system from PRDS to Deaerator |
|
|
|
|
HRH=16/470 |
Raise
D/A Pr from 2 ksc to 4ksc |
|
|
|
|
|
Cut
in all Controllers |
|
|
|
65' |
Load=150
MW |
Charge
PRDS from CRH |
|
|
|
|
MS=100/500 |
Cut
in HP Heaters |
|
|
|
|
HRH=20/480 |
Start
2nd CEP, 1st
TDBFP
at Load=170 MW |
|
|
|
|
BLI=
600 TPH |
Control
MS/HRH Temp by spray (If Required) |
|
|
|
|
Trim
Dev : Off |
Change
D/A Pegging from CRH to Extraction |
|
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|
|
|
Cut
in 3rd Mill |
|
|
|
70' |
Load=230
MW |
Cut
in 4th Mill |
|
|
|
|
MS=120/500 |
Cut
off Oil Support |
|
Ensure
Healthiness of Scanners |
|
|
HRH=25/495 |
Cut
in 5th Mill |
|
|
|
|
BLI=820
TPH |
Start
2nd TDBFP and Switch off MDBFP |
|
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|
Cut
in 6th Mill |
|
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|
86' |
Load=500
MW |
Ensure all
controllers in auto |
|
|
|
|
MS=170/500 |
|
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HRH=40/500 |
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BLI=1620 TPH |
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|
135' |
Load=500
MW |
MS=170/535,
HRH=45/535 |
|
|
Emergency
Instructions:
220
V DC Failure
Unit
condition
- DCDB section-1 & 2 under voltage alarm in LVS-5
- All HT/LT Breakers Indication Becomes Bad
- Boiler will Trip on MFT ( after 2 Sec)
- Turbine will Trip on MFT
- Generator will not Trip as GCB Protection will not act
- Generator will run as Synchronous Motor
- HP/IP/LP Casing Exhaust Temperature will start increasing
- 400 KV Breakers can be Operable
- Feeders of Mill will Trip on MFT
- Fans(ID, FD, PA), Mills, BCW Pumps etc will continue to run
- DC Drives can not come in service
Actions
- Sequence to Trip Drives:
- PA fan
- Mills
- One set ID/FD
- Another set of ID/FD
- BCW Pumps
- MDFP
- CEP
- SG ECW
- TG ECW
- Air compressors
- CW Pumps
- Start DG set
- Start AOP-1, SOP-1, AOP-1 of TDBFPs, PW-1
- Trip Normal Incomer breaker from unit service Board to Emergency board from Switchgear
- Close DG set incomer breaker to emergency Board from Switchgear
- Start AOP-2, SOP-2, AOP-2 of TDBFPs, PW-2
- Trip 400 KV Main/Tie GCB from CCR/Switchyard
- Trip Station Transformer after shifting critical equipments
- This will result in Total Power Failure with Emergency Board in charged condition
Furnace
Air Tightness Test
- Scope- Boiler Furnace, Air and FG Duct upto ID Fan Inlet
- Why- To test Tightness of Furnace wrt Environment not for Strength
- Ensure- All PTWs of BMD( PP, Rotary, Mills, Ash handling) cancelled and Clearance Available
-
S.No
Area/system
Status ReqActual Status1Bottom Ash Hopper / CG Manholes
2Seal Trough
3APH & Eco hopper Flushing Apparatus
4ESP / ESP Duct Manholes
5Mill/Scrapper Manhole
6Boiler Manholes/ Peep Holes
7SADC
8Feeders Doors ( front, Rear)
9SA/ PA duct Manholes/Drains
- Start SAPH-A/B &PAPH-A/B Main Motors
- Start one Set of ID/FD fans. Slowly raise Airflow and Furnace Pressure . Start AC Scanner
- Start another Set of ID/FD fans increase Pressure further
- Start Both PA fans, Slowly raise PA Header Pr to 800 mmWC. Start Seal air fan also
- Keep Furnace Pressure to +120 mmWC
- For Identification of any leakage, Local round to be taken with Maintenance Person. Following area to be visted :-
- Boiler 1st Pass, 2nd Pass, APH Flue Gas duct, ESP i/l and o/l ducts, ESP Passes, Secondary Air duct, Hot & Cold Primary duct, Mill HAG/HAD/CAG/CAD
- APH guide and support Bearing area
- Dead Zone chamber in s-Panel & Reheater Goose Neck Area
- Boiler Pent House
- Slowly reduce Furnace Pressure to Normal and Stop PA/FD/ID Fans
- FATT Completed.
DG
Load Trial and Regular checks
Requirements:
-
1
Inform & Ensure availability of TMD/EMD/C&I
2
SG/TG/BOP source-2 AC Power Supply Interruption. Inform C&I for Standby chargers
3
Ensure DG Set Tank Oil Level Adequate
4
Evacuate and Isolate Boiler Passenger, Service Building Lift and Isolate. Inform EMD(temporary supply )
5
Arrange 3 Walky Talky : 1-CR 2-DG board 3-DG Set room
6
Note Down Initial Parameters of DG Set
Status
of Unit:
-
1
TG on Barring
2
Generator Depressurized(H2/CO2 Purged out)
3
Seal Oil system in Service
4
All Drives in DG Bus in available condition( Plan within 1-2 days of Unit shut down)
5
DG Board charged from Normal Incomer Breaker from Unit Service Board
Sequence:
- Start all drives on DG Bus from other standby source(other board)
Ex-
SOP-2 to Sop-1, FD/ID/PA Lop-2 to LOP-1
- Start Main DG set & Note Down: Volatge, RPM, Tank Level, LO Pr/Temp, Battery Voltage
- Trip Normal Incomer from USS and Close DG set Incoming breaker to charge DG Bus
- Start Loading Drives by starting them which are on DG Bus
- Continue Test run fro ½ -1 Hour.
Normalisation:
- Start all drives on DG Bus from other standby source(other board)
- Trip DG Set Incoming Breaker and Close Normal Incomer From USS
- Switch Off DG Set
Regular
checks:
- DG Set Fuel Tank Level Normal
- DG Set engine Oil Level Normal
- Battery charger OK
- Engine Coolant level is OK
- DG Set Incomers to DG Bus Healthy
UPS
Failure
Condition
- All LVS, OWS will not be available
- Scanner Supply Off. Hence Scanner sense NO flame
- Boiler will trip on Flame failure. Turbine on MFT. Generator on Low Forward Power Protection
- LLD High Level Switch will act
- ID Fans : VFD will trip
- APH Air motor will take Auto start
- MDBFP Scoop will be Inoperative from Remote
- All Drives vibration/Turbine Vibration Data will not Available
Actions:
Instrument
Air supply Failure
Reasons
of Failure:
- Failure of control supply of compressor
- Loss of Cooling Water (SG ECW Pump Trip)
- Massive leakage in IA supply Header
- One Unit Under Overhaul. Unit Aux Board/ Station Aux board got Tripped of that Unit
- Total Black Out of any stage
Problems/Actions:
- No Oil guns can be taken in service: Oil/steam Valves remain Inoperative. Igniter Will not advance
- If Unit on only Oil guns: Boiler will Trip. (HOTV/LOTV will close)
- Stay Put :
- HAG/HAD/CAG/CAD. No mill can be taken in service.
- SADC,
- Burner tilt (if leakage the it will go Up),
- SH/RH spray control valves( close due to leakage),
- Seal Air Fan discharge /damper,
- Scanner air fain Discharge Damper
- D/A Level controllers ( close if Air Leakage)- Maintain Level through Motorized Bypass Valve
- TDBFP Seal steam supply/dump –Maintain through Bypass motorized valve
- FRS 30%(FDV-14) if Open (Close on leakage)- control Drum through Scoop, TDBFP Scoop may Increase or Decrease, Open High Range FRs 100 % line
- Close:
- SH/RH spray Block .Open SH/RH block v/v manually if Temperature is running high
- Vacuum Pump inlet v/v will start closing(vacuum will fall)
- HP/LP Heaters normal Drip
- Open:
- Running BFPs Recirculation Valve ( Start MDBFP or Reduce Load)
- CEP recirculation – start Standby CEP to maintain H/W, D/A OR Reduce Load
- GSC Recirculation will Open: Reduce condensate to D/A- Close its Manual valve
- Normal Make-Up –maintain level through Bypass valve OR through Manual valve
- HP/LP Heaters emergency Drip
- Deaerator Overflow valve
- Open PAC-IAC Interconnection.
- Isolate Plant Air Supply to boiler of both Units.
- Inform other stage to run Additional IAC and Open Interconnection b/w stages
- C&I should periodically check the healthiness of the lock out relay for maintaining stay put condition and maintain records of such checking.
Important
Points at IAC Failure:
- Steam Temperature
- Condenser Vacuum
- Drum Level
- Deaerator & Hotwell Level
Main
Equipments Tripped
|
S.No
|
Fault
|
Consequence
|
Actions
|
|
1
|
1
mill Tripped out of 6
|
|
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|
2
|
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3
|
Any one ID Fan
Trips |
|
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|
4
|
Both ID Fans
Tripped |
|
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5
|
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4
|
Both FD Fans
Tripped |
|
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5
|
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4
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5
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6
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7
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8
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9
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10
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11
|
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12
|
Both TDBFP
trips |
|
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13
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14
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15
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IBT
Outage
Consequences
on Stage-2 ( Station Transformer Tripped)
- 132 KV Switchyard dead results in tripping of -Station Transformers, Construction Transformer, Misc Transformer
- All colony power( Lighting,Water supply) will get interrupted
- Power Supply to DM Plant, HFO Pump house, PTCW Pump house, Offsite Board, ADPH,
- Following Board will get dead:
- OBA,OBB,OBC,OBD (11 KV station Board)
- OCA,OCB (3.3 KV Station aux Board), ADPH MCC, CHP Transformers
- DMPT, CWST, WTPT,BTST,ODA,ODB(Station Service), ODC(FW Pump House),ODD ( Offsite ): 3.3 KV
- OQA,OQB(St. Serv),3SA,4SA(Air Washer MCC),3TA,4TA(Unit Ventilation MCC),OTA(HVAC ) : 415 V
- OSA(SW MCC), OTB(Serv Bldg Ventilation MCC), FOPH : 415 V
- Following Equipments will Trip ( If running)
- MDBFP
- ECW pump (TG)-C, PAC-1, PAC-2, IAC-3
- DM Make-up Pumps, Boiler Fill Pumps, CW BFV OSU, MOT Centrifuge,
- Electric Hydrant/Spray Pumps, Service Water Pumps, APH Wash Pump, Ash Water Make-up Pumps,
- HFO/LDO Pumps , Raw Water Pumps, HVAC Make-up Pumps,
- Clarified Water Pumps, SW Tank Make-up Valve
- Unit-3: ACW pumps-B,C | Unit-4 : ACW Pumps-A,C
- HVAC Equipments ( Air Washers, Chilled Pump, Condensate Pump etc)
- Actions:
- Charge IBT asap after informing EMD, if cannot be revived go For Safe Shut own Or otherwise follow
- Stage-3 IAC Interconnection : Open
- Stop soot Blowing
- ACW-3A and ACW-4B will keep on running, Start 4th CW pump if not running
- Observe Hotwell level, if decreasing Reduce load
- Close PRDS Supply from Unit to reduce water consumption
- If IBT cannot be revived, Before Tripping Unit, Start DG Set, Start AOP-1, SOP-1, PW-1 and then close DG incomer braeker of DG board and shift essential drives on this bus after tripping normal incomer from unit
- As IBT revives, Charge ST, SATs, SSTs and run drives essential for normal condition of unit
Cold
start-up
Points
to Remember
- maximum of HP casing and HP shaft is less than 150C(more than 5 days)
- It requires soaking of Turbine at 360 rpm with steam(40ksc,360 Deg)
- An upper limit of 200 C/hr. saturation temp gradients can be allowed, i.e. approximately the boiler pressure can be brought to 20 Kg/ Cm2 within an hour of cold start up
- But actual temp gradient is limited by the thick walled Y piece provided in the main steam and HRH lines
- maximum differential temp allowed between inner (98%) and mid wall temp (50%) is ±40C
- Start only two CC pumps in order to minimize flashing in down comers (and subsequent vibration) when the boiler water is in the range of 85 to 125 C
- third pump should be started before drum pressure reaches 7 Kg/Cm2 to minimize the temperature transients experienced by the pump casing ( this is to avoid fast load out back on the boiler in the event of any CC pump tripping).
- To get the rolling parameters, normally two elevation oil guns are taken with approx. 70 to 80 t/hr. flow through HP-LP bypass. At that time MS parameters would be 40 Kg/Cm2 and 360 C.
- As soon as the turbine loading has started, HP/LP by pass closes
- First mill is put into operation around 10% of generator load
- Second mill is put into operation around 25%
- Third mill at 40% of generator load
- Fourth and fifth mills are put into operation at 60% and 80% of generator load respectively
- Sixth mill is taken to reach full generator load
- During loading the RH outlet steam temperature has to be kept as close as possible to SH outlet steam temp. Burner tilt, SH spray, RH-spray controls have to be adjusted accordingly
Procedure
|
SNo
|
Time
|
Condition
|
Action
|
Follow-up
|
Status
|
|
1 |
|
0
ksc |
Charge
PRDS from other Units (14ksc,>260 Deg) |
Open
drains at PRDS,TG Floor,8.5 m |
|
|
|
|
|
Charge
Atomizing steam(Pr 6.5 ksc) |
Open
drains at 4 elevation |
|
|
Fill
Water upto +200 mm
One
CEP i/s
LPH,HPH
charged from FW side
Deaerator
Level =175 mm
Hotwel
b/w -100 to -200 mm
FRS
30 % to fill Drum /load upto 180 MW |
Drum,
SH, RH Vents , SH Drains : Open
LPD
: Drains Closed
BSV
: closed
Drain
Before BSV :Closed
MS
strainer drains UFT/SDFT: Open
HRH
strainer Drain UFT/SDFT : Open
ECO
Recirculation E20 Manual : Open |
|
|||
|
Charge
LDO upto HOTV |
|
|
|||
|
ESP
ready in charge Condition |
Open
i/l, o/l damper of passes |
|
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Bottom
Hopper & Seal Trough Lined-up |
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EAST,
Excitation panel, GRP Panel Ready |
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Generator
gas Pr= 3.5 ksc |
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H2
cooler,PW system Ready |
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Start
one CC pump |
Drum
>+200 mm, Vents B3,B4,B5,B6 Closed |
|
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|
Start
second CC Pump |
Drum
normal =+50 mm, B3, B4,B5,B6 Closed |
|
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Start
Scanner Fan |
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Start
Both SAPH |
Air
Motor availability to be checked
FG/Air
Inlet/Outlet Dampers Open |
|
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Start
Both PAPH |
Air
Motor availability to be checked
Air
Inlet/Outlet Dampers Open
FG
Inlet/Outlet Dampers closed |
|
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Start
one set ID/FD, Air>30% (600 TPH) |
SADC
100 % (auto) |
|
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|
Charge
SCAPH for Running FD Fan |
Check
for Increase in Air Temp at SAPH i/l |
|
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|
Start
Purge (Duration : 5 min) |
HOTV,
LOTV got reset
SADC
will released from 100 % in auto |
|
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|
Machine
on Barring |
LO
Temp=45 Deg, Speed=80-100 rpm
JOP
Header Pr=140 ksc
Start
MOT Centrifuge
HPCF
Charged, Temp=55 Deg |
|
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|
Boiler
Ready & turbine on Barring
|
Start
4 guns in AB elevation
After
30', Start 4 guns in CD elevation
To
match Drum MTM Raise 2 Deg/Min |
LDO
control Pressure =9 ksc
Start
: Pair AB 1/3 and after 7 sec AB 2/4
Check
scanner Intensity / Local Verfied
Start
: Pair CD 1/3 and after 7 sec CD 2/4
Open
E20 R/C valve, if MDBFP not feeding in Drum
Check
Drum Level/ Open CBD
Check
D/A Level & H/W level |
|
|
Start
GSC Exhauster fan
Charge
Seal steam upto Supply Motorized v/v of GS supply station
Start
Vacuum Pumps one by one |
Open
dtain before NRV
Steam
Temp >250 Deg
Drain
Casing of Pumps,
Fill
Receiver tank >80 % in VG |
|
|||
|
At
-0.2 ksc, charge seal steam |
By
bringing controller from 50 % towards zero
Build
Vacuum upto -0.9 ksc |
|
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Open
HPBP Warm-Up drains |
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Switch
on SLC Drains |
Verify:
Manual v/v Opened |
|
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3 |
60' |
Drum
Pr= 2ksc |
Close
SH/RH Header Vents
Close
SH Header drains at Dr Pr =10 ksc
Open
BSV Bypass Lines |
|
|
|
4 |
100' |
Drum
Pr= 5ksc |
Open
LP Bypass 10%
Open
BSVs
Open
HPBP by 10% at Dr Pr=7 ksc
Start
3rd CC pumps at Dr Pr=9 ksc
Take
Additional EF gun ( If Required)
Close
HPBP Warm-up valves |
Open
1st HPBP Warm-up valves
Close
CRH drain Pot at TG 0m |
|
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|
Rolling
through SGC |
|
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|
5 |
150' |
MS
=15 ksc/
180-200
Deg
HRH=8
ksc
|
Switch
On start-up Sequence of SGC-turbine
|
TSE
Influence comes ON
|
|
|
6 |
300' |
MS
=50 ksc/
350
Deg
HRH=8
ksc/350 Deg
Turbine
Ready to Roll
|
Turbine
Speed raised to 360 rpm through SGC sequence |
Ensure
LO TCV on auto with SP=45 Deg
Gas
Controller on auto
PW
controller on auto
Ensure
closure of Barring valve at 240 rpm
Monitor
TG Vibrations, TSI, Bearing Temp
MS
Pressure/Temp to be maintained upto load 50 MW
|
|
|
7 |
360' |
MS
=50 ksc/
350
Deg
Turbine
at 360 rpm
|
Turbine
Speed raised to 3000 rpm through SGC sequence |
Check
X6 criteria
Ensure
Tripping of JOP at 540 rpm
Ensure
Tripping of AOP at 2950 rpm
|
|
|
8 |
370' |
MS
=50 ksc/
350
Deg
Turbine
at 3000rpm
|
Switch
Off SGC Program
Put
AVR on auto
Close
Field Breaker
Select
Main GCB
Switch
on Synchroscope after select Check
Synchronise
unit through synchroscope from OWS
Raise
Speed SP by 15 rpm
Close
MAL drains and other HE drains |
Check
X7 criteria
GT
Cooler Fan starts on auto/ Verify
Load
Ref=50 MW . Pr Max=75 MW
Turbine
Speed will Decrease |
|
|
9 |
390' |
Load=55
Mw
MS
Pr=54 ksc/350 Deg
HRH=12
/340 Deg
|
Start
PA Fan, Seal air Fans starts in auto
Take
1st Mill
Start
2nd set of ID/FD Fans
Cut
in LPH-2, 3
Cut
out Deaerator steam from PRDS
Peg
Deaerator form CRH =2 ksc
Cut
in all controllers |
Open
PAPH FG/Air inlet/outlet Damper Open
PA
Header Pr=800 mmWC,
SA
Disch Hdr=1500 mmWC
|
|
|
10 |
420' |
Load=
110
MW
MS=70ksc/370
Deg
|
Charge
PRDS from CRH
Peg
D/A upto 4ksc( gradually)
Cut
in 2nd Mill
Start
withdrawing Oil support
Control
MS/HRH Temp with Burner Tilt and spray(if Required)
|
Ensure
energizing of Trim Device at 100 MW load
|
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11 |
440' |
Load=
160
MW
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Hydrogen
Purging:
- SLC AS SOP Off, SLC DC SOP Off, SLC H2 SOP Off
- Suppy of DC SOP Off
- Start one AC SOP ( DP=1.5 ksc)
- Dew Point Air=<-10 Deg, clearance from Chemist
- H2 (Isolated Position), CO2(Isolated Position), Air Inlet(Open), Casing vent ( Closed)
- Fill and Pressurise upto 0.5 ksc
- After that, cut out Air supply and Detach Hose of air to Filter
- CO2 cylinders in rack, CO2 Flash Evaporator On(SLc made ON), Hot Water Lined up to Filling room, Pour water on cylinder
- Maintain Manifold Pr=50 ksc
- Filling CO2: H2 (Vent Position), CO2(Inlet Position), Air Inlet(Close), Manitain Co2 (0.3-0.8 ksc) by Casing vent
- Continue Till purity of Co2 comes more than, 99%, Purge other Drier by changeover, Purge LLD, clearance from Chemist(25-35 Cylinders)
- CO2 supply Out: CO2 (Vent Position), H2 (inlet position), Air inlet(Close), mainatain b/w 0.3 t0 o.8 ksc Pressure by Casing Vent
- Continue Till purity of H2 comes more than, 99%, Purge other Drier by changeover, Purge LLD, clearance from Chemist: (90-100 Cylinders)
- Pressurization: Co2 (Isolated), H2 (Inlet Position), Air( Closed Position), Casing Vent( Close ): (50-70 cylinders)
- Start H2 SOP when As SOP reaches 4.5 ksc,SLC AS SOP, SLC H2 SOP, DC SOP to be normalised
- Build Pressure of H2 upto 3.35 ksc, cut out H2 supply
- H2(ISolated), CO2(Isolated), AIr(Close), Casing Vent ( Close)
Important
Procedures
Vacuum
Pulling
: Procedure:
- Close RH Vents, CRH, HRH UFT drains
- Close Vacuum Breaker
- Open 8.5 m steam Manual valve full Both (100%), Temp> 250 Deg ( Open
- Start GSC Exhauster Fan
- Start Both Vacuum pumps ( Casing Empty, Receiver tank Level adeq)
- At -0.2 ksc charge steam gradually ( lower Controller from 50% 0 %)
- Build Vacuum upto -0.9 ksc
Vacuum
Killing
: Procedure:
- Stop Vacuum Pumps
- Open Vacuum Breaker at -0.3 ksc Vacuum
- At -0.2 ksc, Close steam supply from Controller(50%), Closing Manual valve at 8.5 m(Both)
- Stop GSC Fans
- Open chimney Vents to Atmosphere
Turbine
Fast cooling:
Procedure:
- Gag Test valves of ESVs and IVs, CRH, close IPCV Sec Oil Pressure line(8.5 m)
- Open MAL Drains with their Manuals
- HP Casing Temp<= 300 Deg, Turbine on Barring
- Start Vacuum pumps (Maintain vacuum b/w -0.2 to -0.3 ksc)
- Switch Off RTS Supply, Reset Turbine(SD=0%)
- Close EHG sec Oil Supply to CV by Manually isolating at Gov Rack
- Open ESVs at SD=40%
- Open HPCVs at 55% (According to cooling rate : 5-6 Deg/hour)
- Observe TSI: DE, SE, CE
- Stop Fast cooling & Close Barring when HP Casing reaches 110 Deg
Boiler
Forced Cooling:
Procedure:
- Boiler Tripped, one set of ID/FD Running after Purging, BCWs Running
- Keep Running FD fan till APH FG inlet comes 205 Deg
- After that Trip FD Fan, Keep Running ID Fan in VFD Min position
- At Boiler Water Temp (s/c manifold temp 93 Deg), Trip all BCW Pumps
- Boiler washing to be done after that
Air/Co2/H2
Pressurizing in Generator:
Procedure:
- Start AC SOP
- Keep SLC DC SOP Off/ DC SOP Module Off. Keep SLC AC AOP Off
- Start filling Air after measuring Dew point (Preferably <-10deg)
- Fill Air Upto 0/5 ksc
- Then Fill Co2 and vent Air through casing vent. Purity>99% . Vary(0.25-0.75 ksc)
- Purge CO2 with H2 (0.25-0.75 ksc), vent through H2 Casing vent. Purity>98% (at least two continuous ample)
- Pressurize H2 upto 3.5 ksc
- While Pressurising , start H2 seal oil pump at 4.5 ksc AS SOP Pressure. SLC As SOP On/DC SOP Module ON/DC SOP On
- Take Trial o0f DC SOP/other As SOP too
Centrifuge
: Operation
- Drain anti-Flood Tank
- Start Separator
- At speed nearly constant , Charge sealing water,
- After 1 minute, Close seal water inlet valve
- Open Suction valve of Centrifuge
- Check flow through rotameter
Reheater
Metal Temperature
- Depends on: Total air Flow, Burner tilt, Mill combination, Total coal/PA Flow, Reheater spray etc
- RH Tube Leakge : Causes- Coal Ash Corrosion for Tubing, Uneven Temp distribution across Boiler
- Coal Ash Corrosion: Tube temp Higher than ash-fusion temperature. Liquid slag deposition. Oxidizes the metal at rate many times than normal rate of 0.001”-0.002” /Year
- Uneven Tmperature Distribution: Rupture due to Creep.
- FG Temp Distribution Across Furnace:
Div
SH (900)Final
SH(850)Reheater(750)LTSH(550)Eco
outlet(390)
Turbine
Governing system
Key
Points
- Governing- Regulation of Turbine Speed under No Load and Varying Load
- Others Works: CV Actuation/ Initial Run-up & Synchronization/ Load Variation to meet Grid Freq
- 500 MW KWU: Throttle Governed Machine
- 2 Governors , EHC and HG connected in Parallel: Only One at a time through Hyd Minimum slection
- CVs Open according to Secondary oil Pressure
- Between 100 MW to 525 MW , Load variation done by HPCV throttling
Hydraulic
Governor
- Only one control Loop: Speed controller
- Machine Speed: measured & Indicated by Primary Oil Pressure
- Range of Speed Control : 2800-3210 rpm
- Speed Regulation Range( Droop) of HG= 7%
- HG acts as a Back-up to EHG
- HG Cannot be isolated Mechanically
- HG is the Primary Governor of KWU turbine
Electro-Hydraulic
Governor
- EHG has 3 control loops for speed, Load, Pressure
- EHG enhance Turbine life by TSE
- Faster Response and Precise Frequency control
- Actual Speed Measured by Hall Probes
- Range of speed Control : 0-3210 rpm
- Speed Regulation( Droop) can be changed from 2.5% to 8% in step of 0.5% on Load, Usual setting: 5%
- EHG Can be mechanically isolated by closing secondary oil from local
RTS:
- Running condition: De-energized(Drain : closed), Tripping condition: Energized( Drain : Open)
- Running: Control Oil To Trip Gear
- Tripped Condition: Control Oil Path Locked & Trip oil from Trip Gear Drained through Drain Port
- 02 in Nos in Series
Turbine
Trip Gear
- Main Protection Mechanism | 02 in Nos
- Control OilRTSControl OilTrip Gear spool Spool MovementTrip Oil (from top) & Aux Trip Oil ( From Bottom)
- Aux Trip Oil Keeps Spool in Lifted Position
- Aux Trip Oil is connected to hydraulic Safety Devices: Over-speed, Low Vacuum & Thrust Bearing Trip Devices
SLLD
- Resets Turbine after Tripping
- Opens : SVs and Release CVs for Opening
- AT 0% starting Device:
Bellows
compressed ( CVs Closed)
Aux
start up Oil Resets Trip Devices
Start
up oil Resets SVs ( ESVs & IVs)
- Raising starting Device:
Start-up
Oil & aux start-up Oil circuits drained
ESV
Opens at 42% and IVs open at 56%
Speeder
Gear
- Bellow + Spring
- Bellow compression controlled by
Starting
Device Position
Speeder
Gear Position ( alerts Spring Tension)
Primary
Oil Pressure
- Draining /closing of oil drains happens through Aux FUP connected through link with speeder Gear
Test
Valves
- HP/IP SVs receive Trip Oil Through their Test valves
- Port Opening for start-up oil and Trip Oil
- Resets SVs after Turbine Tripping
- Test valve can be operated with Handwheel
Working
of Governing system
Control
OilStarting
DeviceAux
Start-Up oil Trip
GearHydraulic
Protection Devices
Start-Up
oil Trip
GearESVs
(Speeder
Gear linked with Starting Device)
Trip
Oil Aux
FUP(movement according to SG)Aux
secondary Oil
Input to Hydraulic Converter
Control
Oil + Aux Sec OilHydraulic
converter(trip
oil FUPs)HP/IP
Secondary oil to CVs
Switchyard
Breaker arrangement:
Stage-I
GT#1
1-52 Main (GCB to Bus Bar-1)
2-52 (Tie-GCB to bus Bar-2)
3-52(IBT-1 i/c)
GT#2
7-52Main (GCB to Bus Bar-2)
8-52((Tie-GCB to bus Bar-1)
Bus
bar-1
4-52 (H1)
5-52(Tie H1-S2)
6-52(S2)
Bus Bar-2
Bus
bar-2
10-52 (S1)
11-52(Tie S1-H2)
12-52(H2)
Bus Bar-1
Bus-1
13-52(Bus-coupler-1)
Bus-3
Bus-2
14-52(Bus-coupler-2)
Bus-4
Stage-II
GT#3
15-52 Main (GCB to Bus Bar-3)
16-52 ( Tie-GCB to bus Bar-4)
17-52(IBT-2 i/c)
GT#4
21-52 Main (GCB to Bus Bar-2)
22-52 ((Tie-GCB to bus Bar-1)
Bus
Bar-318-5219-52(Tie)20-52(A1)Bus
Bar-4
Bus
Bar-318-5219-52(Tie)20-52(A1)Bus
Bar-4
Bus
Bar-424-52(A2)25-52(Tie)Bus
Bar-3
IBT
(132 KV)
IBT-1(Transformer)LT
of IBT-1(12-52)
(12-89 Isolator-Bus-1 & 12-89A Isolator to bus
-2)]12-89Bus-1ST-1(10-52),
ST-3(3-52)
IBT-2(Transformer)LT
of IBT-2(13-52)
(13-89 Isolator-Bus-1 & 13-89A Isolator to bus
-2)]13-89ABus-2ST-2(7-52),St-4(14-52)
Bus-15-895-52(Bus-Coupler)5-89ABus-2
4-52(Miscellaneous
Transformer)
6-52(Overhead
Transformer)
Check
List (Light-Up)
Unit:
Date:
|
S.No
|
Activity
|
Status
|
Remark
|
|
1
|
Drum
Level, RH Protection Bypass |
|
|
|
2
|
Seal
Trough charged & Bottom Hopper filled |
|
|
|
3
|
ESP
field Ready & Off |
|
|
|
4
|
SADC
In auto |
|
|
|
5
|
LPD
close, Drum SH Vents Open, SH drains Open, Eco-Recirculation Open |
|
|
|
6
|
APH
blowing Lined-up |
|
|
|
7
|
All
3 BCW Running |
|
|
|
8
|
CBD
Manual Open, EBD Auto close Bypass |
|
|
|
9
|
LP
dosing & Both CPU i/s |
|
|
|
10
|
FG
& Air path OK/ PAPH-A/B FG outlet Damper closed |
|
|
|
11
|
All
Mills & Feeders Ready |
|
|
|
12
|
Hotwell
& Deaerator Normal |
|
|
|
13
|
SH/RH/HPBP
spray Manual closed(Turbine Side) |
|
|
|
14
|
MAL
Drains/SDFT/UFT Manual Open |
|
|
|
15
|
MS/HRH
strainers drain to UFT,SDFT Open |
|
|
|
16
|
Vacuum
Pulled,TDBFPs on Barring/Rolled upto 1000 rpm through PRDS |
|
|
|
A
|
Light-UP |
|
|
|
1
|
Note
Boiler Light-up Time ( 1st
gun I/s) |
|
Time
of BLU: |
|
2
|
Feed
Drum through 30% line by TDBFP(Maintain DP>10 ksc) Or MDBFP |
|
|
|
3
|
Close
Drum/SH Vents at 2 ksc Drum Pressure |
|
|
|
4
|
BSV
Open at 5ksc Drum Pressure |
|
|
|
5
|
HPBP/LPBP
Open at 8 ksc Drum Pressure |
|
|
|
6
|
Start-up
vents Close after HPBP/LPBP Charging |
|
|
|
7
|
Close
SH Drains at 10 ksc Drum Pressure |
|
|
|
B
|
Before
Rolling |
|
Time
Before rolling: |
|
1
|
Before
PA Fan start,Open 2 Mills CAG/CAD, start PA Fan,Open PAPH FG o/l |
|
|
|
2
|
Ensure
only one Seal air Fan Running |
|
|
|
3
|
One
Mill A/C to be taken i/s as per HP Casing Metal Temp |
|
|
|
4
|
Bring
Rolling Parameter, Note Time Before rolling |
|
|
|
5
|
Turbine
EHTC Normal from Local |
|
|
|
6
|
HP
ESV/IV/CV /CRH gagging Removed |
|
|
|
7
|
Decrease
TG LO SP to 45 Deg |
|
|
|
8
|
Turbine
LP Mode, Load Ref 50 MW, Pr Max 75 MW, Th Pr SP=30 Ksc |
|
|
|
C
|
Before
Synchronization |
|
|
|
1
|
GT
Isolators from s/Y Closed |
|
|
|
2
|
GRP
relays Reset |
|
|
|
3
|
One
Mill i/s and Other Warmed-up(Hot Air charged) |
|
|
|
4
|
HPBP
spray Manual Open when Downstream Temp crosses 330 Deg |
|
|
|
D
|
After
Synchronization |
|
Time
Of sync:
|
|
1
|
SH/RH
sprays from turbine Side Normalized. Monitor MS/HRH Temp |
|
|
|
2
|
PW/CG
Controller on auto |
|
|
|
3
|
LPH/Deaerator
charged |
|
|
|
4
|
MAL/SDFT/UFT
Manual drains closed |
|
|
|
5
|
ST/UT
Change-over at 100 MW |
|
|
|
6
|
FRS
High Range at 180 MW from 30 % line change-Over |
|
|
|
7
|
Oil
guns taken out (>5 Mills i/s: scanner Healthy), Note time of
Oil w/d |
|
|
|
8
|
ESP
field charging after Oil guns taken out |
|
|
|
9
|
Boiler
silica to be monitored Before Load Increase |
|
|
-
Checked ByName
Sign
Designation
Rolling
of TDBFP: Turbine
Points
to Remember:
- AT Load 100/150/200/250 MW, Single TD rolled, Steam available for TDBFP=20/25/30/38 TPH
(CRH
Extraction(0-250MW), IPT(250-300)
- AT Load 100/150/200/250 MW, Both TD rolled, Steam available for TDBFPs=15/18/22/25TPH
- Design Parameers: 7.2 ksc /300 Deg/ 0.12 ksc /5325 rpm/
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