ACW pump house

Condenser : One Pass Isolation

1 Ensure the availability of both condenser de-watering pumps.
2 Decrease the load to 300 – 350 MW
3 Ensure that both CW interconnection valve are opened
4 Start Stand by Vacuum pump

Generator Air tightness Test

TEST PROCEDURE: -
1) Air Filling valve is to be opened for flushing of line & removal of moisture in atmosphere.
2) Chemistry is to take sample for dew point measurement. After chemistry clearance , Filling process
has to be continued.
3) Close the waste gas (vent) valves.

APH Hot Washing

1 Water washing of air heaters should be carried out in hot condition after boiler shutdown.Flue gas inlet temperature should be between 200 deg C to 150 deg C
2 Both FD/ID/PA fans should be in stopped condition
3 All APH flue gas outlet damper should be closed

Stopping one FD Fan

1 Reduce the load to 400 MW & then remove from CMC
2 Before Unloading FD Fan (to be stopped ),The following
Permissive & Protection to be kept bypassed :
“FD Fan ON & Discharge Gate close” permissive to be given
“FD Fan ON & Discharge gate auto open” to be bypassed.

Stopping one PA Fan

1 Reduce the load to 300 MW & then remove from CMC
2 Keep 4 consecutive Mills in service. If required , take oil guns in service

Stopping one ID Fan

1. Reduce Load to 300MW
2. Start Unloading corresponding FD fan & increase loading of other FD Fan through blade pitch.

Stopping one PAPH

• Reduce Load to 300MW
• Slowly close flue gas outlet damper for PAPH which has to be stopped

Stopping one SAPH

• Reduce Load to 300MW
• Slowly close flue gas outlet damper (2 in no. )for APH which has to be stopped
• Adjust other PAPH/SAPH flue gas outlet damper
• Close flue gas inlet damper
• Close SCAPH inlet , outlet & bypass damper. During Closing , Observe Air Flow.
• Close SAPH air outlet damper (2 in no.)
• Stop the SAPH motor once flue gas inlet temperature reduced below 150deg C
• Close Air motor main isolating valve & bypass isolating valve

LIGHT UP CHECK POINTS

BEFORE LIGHT UP ACTIVITIES

BOILER SIDE

• MAN ,MATERIAL REMOVED AND BOILER IS READY FOR LIGHT UP.
  

Water-chemistry: 500 MW

Recommended Parameter Values
1. Boiler Water – pH = 9.1-9.4
2. Boiler Water – Specific Conductivity < 20.0 μs/cm
3. Boiler Water – Silica < 100 ppb
4. Boiler Water - Phosphate = 1-2 ppm
5. Boiler Water - Chloride < 0.5 ppm