ATRS Rolling: 500 MW

CHECKLIST FOR ROLLING THROUGH ATRS (HOT start up)

PRESENT CONDITION:

• M/C on barring
• MS temp :  >480 Deg /Pressure : 90 ksc
• HRH temp : >460 Deg /pressure : 9 ksc
• Lube oil temperature : 55 deg
• CF temperature : > 50 deg
• PW/CG/CF temperature control valves in auto
• Speed controller active

CHECK LIST

• Turbine in Reset condition ( Trip oil pressure : > 8 ksc)
• Starting device:  0% / Speeder gear : 99%
• HP & IP CVs showing : 0%
• Turbine throttle pressure set point 0 ksc
• MAL 11 & MAL 12 in open condition/ all MAL drains manual valve open /SLC drains ON
• Load contol On / Limit pressure mode selected
• MS 109 / MS 110 & HRH 105/106 valves open feedback
• Load refrence (PR) set point to be 70 MW/ PRmax 120 MW
• Trim device to be made off
• Check TSC margins &TSC influence on
• Plunger coil not off
• check X1 &X2 criteria for opening of STOP valves
• Temperature curves X3,X4& X5 for control valve opening and upto 360 rpm
• Reset all relays in the GRP panel
• Lube oil temperature set point to be kept at 45 deg.

PROCEDURE OF STARTING ATRS

• Check all start permissives are coming
• Ensure normal mode is displayed in ATRS mimic

Raising speed upto 360 RPM

• Select A/M from SGC turbine tile
• To start the programme press startup from the tile
• Check for closing of MAL 11 & MAL 12 in STEP 3
• Observe starting device raise command in STEP no 5 and stop valve opening( SD > 42%)
• Observe in STEP -8 that MAL 11 & 12 control goes to auto
• Step no.9 TRACKING DEVICE gets ON followed by opening of IP stop valves ( SD >56%)
• Check that in STEP -11 MAL 11& 12 opens in manual mode
• Check in step no-12 turbine speed set point increasing upto 360 RPM and accordingly the actual speed .
• Hold the programme in step no 12 if required (criteria not satisfied) by pressing A/M from SGC turbine tile.
• Ensure closing of barring valve at 240 rpm otherwise close it manually.Mot level will increase
• Soaking time for Hot start up 180 sec
• Check for closing of MAL 11 & 12 .

RAISING SPEED UPTO 3000 RPM

• Check TSC margin >30
• Check X6 criteria is satisfied (Ensure opening of MAL 11& 12 in manual )
• Check speed margin (600 mw/min)
• Sufficient margin in HP bypass
• Switch on the ATRS programme (Auto) & start
• Speed set point will increase upto 3000 rpm in STEP -16 and actual speed will raise accordingly
• Switch OFF the programme once speed set point reaches 3000 rpm
• Observe JOP stopping at 540 rpm & AOP at 2850 rpm
• Check vibration /Brg temperatures & other TSI parameters
• Change the lube oil filter if required
• LPBP in Auto with pr setpoint around 8 KSC.
• Check for HP (below 95 deg ) / IP casing DT before synch(below 40 deg)

BEFORE SYNCHRONISATION

• Check X7 criteria
• Close the field breaker & made excitation On (one AVR will come in auto)
• After excitation ON observe voltage build up 90% of 21kv (19kv)
• Slowly voltage raise up to 21kv & Adjust the generator terminal voltage

SYNCHRONISATION IN AUTO FROM ELECTRICAL VERTICAL PANNEL

• Select the GCB
• Switch ON the synchroscope
• Select the mode to ATRS by selection key
• Switch on the AUTO synchronizer from the vertical panel
• GCB closes in auto at 12 o clock
• Observe speed setpoint raises by 15 rpm as per logic other wise give one raise pulse to speed set point so that unit comes to block load .
• Unit is synchronised

Immediately after Synchronization

• Increase the Speed reference and maintain the unit load around 50 MW
• After ensuring all parameters are normal increase the load set point to 70 -75 MW by increasing the load reference.
• Change over the Turbine control from Speed to Load by increasing the load reference.
• While changing the control from speed to load always ensure that LP bypass is in auto, No hunting in IP Control valves, and increase the load set point in such a way that the IPCV opening to 100%.
• After IPCVs full open increase the load set point further and slowly close the HP bypass.
• After closing the HP bypass close the LP .
• After unit load more than 150 MW only keep machine in pressure control, if required.
• Charge the LP & HP heaters.