TURBINE COLD

START UP
PROCEDURE
 Initial Condition of Turbine

Turbine is under Cold condition

HP & IP starting probe temp is less than
1500C
AOP,JOP & OVEF in service
TG Rotor on Turning Gear
Speed = 19
Ensure all related work permits are returned
Ensure TG rotor is on Barring Gear (in auto) &
all oil pumps in auto
Ensure sufficient CST level & keep one hot well
make up in service with recirculation
Ensure adequate level in condenser Hot well.
(About 650mm)
Ensure Deaerator at adequate level (About
2500mm)
Ensure one CW pump is running
Ensure one TCW booster pump & CCW pump
in service with one PHE
Ensure Turbine Lube oil cooler water valves in
open condition
Ensure all the Turbine drain valves (MAL-
12,13,14,22,23&24) & MST,CRH and HRH line
drains MOV & GV in full open condition
Ensure drain before Boiler Main Stop valve in
open condition (MOV & GV)
Ensure drain before MST to AST PRDS in open
(MOV & GV)
Ensure AST header atmosphere drain in open
Ensure Main Ejector PCV in Auto & in Full open
condition (Pr. Set at 15 Bar)
Ensure opening of Steam trap GV & Bypass valve
in Seam of Main Ejectors & open one of the Main
Ejectors steam valve
Ensure full opening of drain before HP Bypass
valves. (Steam trap GV & Bypass valve)
Ensure opening of Stem trap GV & its Bypass
valves in the seal steam header drain line.
Ensure charging of BFPs & charge the feed line
through gravity by opening the discharge valve
& release the air
Ensure charging of CEPs
Start one Boiler Feed Pump & charge the Feed
Water circuit including HP Heaters & keep
another BFP in standby
Start one CEP & charge condensate circuit
including LP Heaters
Start The TV camera pump after venting
Start second CW pump
Open Bypass valve of Boiler Main Stop Valve
Start warming up of MST to AST PRDS
Ensure running of one Oil pump in HP Bypass
OSU & check for Oil leak at HP & LP Bypass
valves
Commission MST to AST PRDS & put AST
Pressure & Temperature control in Auto (set at
15 Bar & 3000C). Maintain AST header
pressure above 15 Bar.
Warm up the Boiler & FOPH steam line from
AST header
Warm up Deaerator preheating line & start
preheat the Deaerator tank (Keep Deaerator
motorized vents full open)
Warm up AST to Pilot Ejector & Seal Steam
system
Open the Main Valves at AST header for Boiler
& FOPH Steam lines
Ensure AST header pressure above 15 Bar &
Temp above 2500C
Commission AST pegging steam to Deaerator
& gradually raise the Deaerator pressure to
1 Bar
Prepare the system for Condenser Vacuum
raising (For Turbine Seal steam admission
minimum 500C super heat is necessary)
Ensure Main Ejectors siphon filling line is in
Open Condition
Start Vacuum pulling through Pilot Ejector
(Before raising vacuum ensure TG Rotor on
Barring Gear and Re-Heater drains & vents at
Boiler side closed)
When the vacuum is about 0.2 Bar (a), open
the Boiler Main Stop Valve (Take care of Drum
Level)
Close Drain Valve before Boiler Stop Valve
Ensure full vacuum is reached
Commission the HP & LP Bypass system and
keep in Auto
Ensure minimum super heat of 500C for HP B/P
opening
Ensure initial opening of HP B/P valves always
above 20% (Take care of Drum Level)
Close Steam Trap B/P valve in the drain line
before HP B/P valves
Ensure LP B/P pressure set at 7 Bar in full Auto
& check for opening of LP B/P valves
Ensure opening of HP & LP Bypass valves
above 20% (Check for temp pick up at the
Turbine)
Commission one Main Ejector when Main
Ejector steam pressure at 15 Bar & Temp is
above 2500C and close Pilot Ejector air valve
Maintain Main Ejector shell level by 250mm
(Observe for any vacuum drop)
Open CRH to Deaerator pegging steam valve
and maintain Deaerator pressure above 1 Bar
Ensure all the Turbine drain valves (MAL Valves) &
MS,CRH & HRH line drains valves in open condition
Prepare the system for Turbine reset
When MS Pressure >35 Bar & Temp above 3000C
RESET the Turbine for Opening of HP&IP stop valves.
(Ensure minimum Superheat of 500C)
Confirm of HP&IP stop valves opening at local
Ensure no speed rising on operation of Stop valves
Open LP Heaters & Deaerator steam extraction valves
(MOVs & Extn. NRVs)
Ensure Condensate to LP Heaters are made through
Ensure LP Heaters drain condensate valves are in
Auto
Raise the MST Pressure gradually to 45 Bar
Ensure the Steam temp is not dropping below
3200C
Check for HP & IP stop valves metal temp
pickup
Keep the Pegging Steam to Deaerator in Auto
(AST & CRH)
 Turbine Rolling Parameters

1. MST Pressure = 45/50 Bar

2. MST Temperature = 3700C
3. HRH Pressure = 7 Bar
4. HRH Temperature = 3500C

Ensure HRH Temp is always less than MST

Temp by 200C
Ensure Turbine Drain valves open
(Choke MS line drain by 50%)
Record Rolling parameters, Turbine metal Temps and
supervisory readings
Switch ON Turbine RSE
Start Turbine Rolling (Target Speed 501 rpm &
Acceleration 5%)
Ensure Turning Gear got disengaged on Rolling
Check the Turbine supervisory readings and observe
HP & LP De, Axial Shift, Shaft vibration & Bearing
metal Temp
At 500 rpm warm up the Turbine for 30 min (Turbine
soaking for 30 min)
Keep steam parameters steady
Check for HP&IP starting probe temp pick up
Start further Speed rising of Turbine (Target
speed 3000 rpm & Acceleration 5%)
Check the Turbine supervisory readings and
observe HP & LP DE, Axial Shift, Shaft
Vibration & Bearing metal temp
Record Maximum vibration during speed rising
(In the critical speed range, Auto acceleration is
10%)
Check for Opening of LP Exhaust hood spray
at 1500 rpm
Check the Lube Oil Temp (about 450C)
Observe Turbine Stress Margin
Observe HP Turbine exhaust temp & should
not exceed 4500C
Ensure stoppage of Auxiliary Oil Pump and
jacking Oil Pump at 2700 rpm & observe the
Lube Oil header pressure
Ensure Turbine RSE is ON & Enabled
On Synchronizing check the control valve open
demand rises by 5% for initial load pick up &
check for the load rising
Close MS line drain valves fully
Slowly raise the load till HP & LP Bypass valve
closure
If HP/LP Turbine stress margin is dropping, DO
NOT raise the load (Take care of Drum Level)
Hold 10/20 min. at this load depending on
Turbine Stress Margin
Ensure Closing of LP exhaust hood spray at
10% load
Ensure closure of Turbine drain valves, HRH &
CRH drain valves at 15% Load on Auto (Close
the GV of MOV if necessary)
Ensure turbine Follow Mode is selected
automatically on full closing of HP & LP Bypass
valves and ensure HP Bypass pressure set on
full Auto
Slowly close the Pilot Ejector steam valve
Close Deaerator Start up vents
Close steam trap bypass valve in the seal
steam header drain line
 Check Turbine Stress Margin for Parameter
raising (Margin must always be above 1%)
 Observe HP & LP DE for any abnormality
 Rate of parameter raising.
 Load :1.5 MW/min
 MS pressure : 0.2 bar/min (up to 70 bar)
 MS pressure : 1.2 bar/min. (above 70bar)
 MS Temp : 1 0C/min. (Up to 490 0C)
 MS Temp : 1.5 0C/min. (above 490 0C)
(Take care of Turbine thermal stress)
 Ensure take over of Turbine self-sealing and
open CRH steam to seal header MOV
 Charge CRH to AST PRDS
 Raise MS pressure gradually depending upon the
Steam Purity and Silica value (MS & Condensate
silica must be less than 20 ppb)
 Load the Turbine slowly on observing HP & LP
DE and Stress margin
 LOAD : 70 MW
 MS pressure : 60 70 bar.
 MS & HRH Temp : 450 OC.
(*** Ensure the Turbine control valves not opening full,
while raising the load ***)
 Start charging of HP heaters on steam side at a
load of 70 MW (Ensure FW to HP Heaters are made
through)
 Start one LP drain pump at a load of 90-100 MW
Start second BFP
Commission CRH to AST PRDS and set the
pressure at 15bar.Reduce MS to AST PRDS set
to 14 bar and ensure take over of CRH to AST
PRDS
LOAD : 90 MW
MS pressure : 70  80 bar.
MS & HRH Temp : 480 0C.
(If the silica value is high DONOT raise the load &
the pressure)
 LOAD : 110 MW
 MS pressure : 90 100 bar.
MS & HRH Temp : 500 0C.
LOAD : 140 MW
MS pressure : 110 120 bar
MS & HRH Temp : 520 0C

LOAD : 160 170 MW

MS pressure : 130 bar
MS & HRH Temp : 535 0C

LOAD : 210 MW
MS pressure : 146bar
MS & HRH Temp : 535 0C
 Put CMC mode into service& enable Frequency
influence.
 TURBINE START UP PARAMETER
ESV & ISV Warm Up
HPT – Turbine Rolling Min Load
for 10 min
Sl. RSE after
No Probe SH3 O/L RH2 O/L Acc Holding synchronize
MS Pr & HRH Pr
Temp Pr & Pr & Rate Time at & Hold Time
Temp & Temp
Temp Temp % 500 rpm

Below 30 Bar 7 Bar 45-50 Bar 7 Bar 20 MW

1 5 30 min
1500C 3000C 2500C 3700C 3500C 10 min

1500C 40 Bar 7 Bar 20 MW

7 Bar 50-60 Bar
2 to 325 - 350 - 7 20 min
3000C 4000C 10 min
2500C 3500C 3750C
2500C 60-70 Bar 7 Bar 70-80 Bar 7 Bar 20 MW
3 to 375 - 350 - 400 - 350 - 10 10 min
3500C 4500C 4250C 4500C 4250C 10 min

3500C 80 Bar 7 Bar 80-100 Bar 7 Bar

30 MW
4 to 450 - 400 - 450 - 450 - 10 5 min
5 min
4500C 4800C 4800C 5000C 5000C
4500C 100 Bar 7 Bar 40 MW
100 Bar 7 Bar Direct
5 and 500 - 500 - 10
5000C 5000C 3000 rpm 5 min
above 5200C 5200C
 Start Up Limiting Factors
Thermal Stress
 Non steady state operation such as start up,
shutdown & load changes give rise to Thermal
Stresses
Vibration
 Excessive vibration affecting a machine can be
originated by improperly balanced or bowed Rotor
Differential Expansion
 Sudden loading & Unloading can give raise to
excessive temp differences between Rotor &
Casing. This is due to differences existing between
Mass & Surface area of the parts concerned
 Turning Gear Operation
Its very important that Turbine shaft is turned by
the turning gear for a sufficient period of time
before a start-up is initiated, even if the turbo-
group is in cold condition.
Turning Gear times are:

Shaft Stand still Min. Turning Gear Time

Less than 1 day 2 Hours
Up to 7 days 6 Hours
From 7 to 30 days 12 Hours
Over 30 days 24 Hours
 Critical Speed Range
Speed up must never be stopped when in
the range of following critical speeds

Critical speed range:

0800 – 0900 RPM
1560 – 1700 RPM
2000 – 2450 RPM
 Differential Expansion
Differential Expansion should be watched
during load increase as well as load
decrease
Positive Expansion (+ve) mean the Rotor
Shaft is longer than Cylinder Body (During
Loading)
Negative Expansion (-ve) mean the Rotor
Shaft is shorter than Cylinder Body
(During Unloading)
Temperature at the HP Steam Exhaust
The HP exhaust steam temp limiter provides for
limiting the exhaust steam temp by acting on
both MST & RH control valves
Moreover during a load rise when coming fron
no-load or low load condition, care shall be
exercised that no allowable cooling down
gradients occur at the HP exhaust steam outlet
Allowable values given below:
 Sudden Temp change :500C
 Temperature gradient :1.30C/min
Under normal condition this is governed by the
HP cooling down limiter
 LPT Ventilation Safety
On No-Load/Low Load operation for a certain
time length & concurrent bad vacuum he
turbine temp can become to high through the
ventilation

Values for Spray Water Exhaust Hood system

 >750C : Opening Spray valve

Boundary value for LP blading temp

 >1800C : Alarm
 >2000C : Tripping
THANK YOU