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.


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