Turbine Start up
CHECK BEFORE START UP
Ensure availability of A C W and compressed air.
Switch ON all instruments
Check oil level in all oil tanks .
Start lube oil system and fill overhead oil tank.
Start JOP and put machine on TURNING GEAR and check machine speed is 4.5rpm.
Ensure that eccentricity is less than 0.03mm above initial value
start BFP to maintain boiler drum level
Check the levels in condenser storage tank
Start CEP on Recirculation and put level control in auto mode.
Start HP & LP bypass oil system and open main steam & reheat line drains.
Charge main steam line and auxiliary PRDS.
Start EH – FRF Oil System.
ØThen Raise vacuum in air cooled condenser.
Put HP & LP Bypass systems in service.
Check protections and interlocks.
Modes of Start Up.
Cold start up ≤150°C
Warm startup 150 °C ~ 300 °C
Hot start up 300°C ~ 400°C
Very hot start up ≥ 400 °C
These temperatures are metal temperatures at upper half regulating stage of HP Inner casing
Ensure that all Turbine extraction drain valves before NRV are open.
Start pre-warming of HIP casing and Main steam & Reheat steam pipes.
Rise the Main steam pressure up to 15 Kg/cm2 and Temperature up to 300°C
Start steam admission and ensure that Turning Gear disengages automatically.
Øut the inter layer heating in operation
Øpeed up the turbine to 500rpm and check systems within five minutes.
Go to 1100rpm & warm-up the turbine for ten minutes.
Check the Bearing vibration which is to be less than 0.03mm
Increase speed to 2500rpm and perform high speed warm up for 10 minutes.
JOP has to stop automatically at 1200rpm and starts when the speed comes down below 1200rpm.
After high speed warm up increase the speed to 3000rpm
Perform No Load turbine warm up for 30 Minutes at 3000 rpm.
Exhaust hood temperature should be less than 85°C and vacuum should be more than -0.7kg/cm2.
Synchronize the Unit
For conducting over speed test unit has to run at 20% load for 3 hours.
Charge LP heaters at 30% of unit load and HP heaters at 60% of Unit Load
Close HP,IP & LP drains at 10,20, & 30 % load
START UP PARAMETER
Warm start up
Main steam pressure 16 kg/cm2
Reheat steam Temperature 330°C
Rate of speed rise is 150 rpm/min.
Hot start up Very Hot start up
Steam pressure 36 Kg/cm2 45 kg/cm2
Temperature 440°C 510°C
Reheat Temp 410°C 480°C
Rate of speed rise is 250 rpm/min.