Stage 1 NTPC Dadri : H2 purging

PPE metrix : NTPC dadri

Dadri stage-1 start up tables

 

TURBINE START UP TABLES(210 MW)

 

Dadri stage-1 start up & shutdown Checklist

 

Unit Shutdown Checklist

Dadri stage-1 Hot start up

 

After shut down

 

Dadri stage-1 Light up Preparation

 

LIST OF ACTIVITIES AFTER UNIT LIGHT UP

(WARM/HOT START UP AFTER TUBE LEAKAGE)

Dadri stage-1 after Light up checklist

 

LIST OF ACTIVITIES AFTER UNIT LIGHT UP

(WARM/HOT START UP AFTER TUBE LEAKAGE)

Dadri stage-1 After shutdown Work

 

ACTIVITIES AFTER UNIT SHUTDOWN (SHORT SHUTDOWN 8Hrs TO 72 Hrs) STAGE-1

1.       After closing MS-1 & 2, isolate electrical supply.

Dadri Stage-1 Start up Write-up

 

SOP to avoid unit disturbance/tripping during litup/turbine rolling/unit synchronization

1.    APH oil carryover probe to be checked hourly during light up. Oil gun having poor flame to be removed. APH soot blowing to  continue till oil guns in service. CBD to be opened after boiler litup and closed as per chemistry clearance. SCAPH charging &Dearator heating / pegging to be done . Condensate dumping to be done.

Dadri stage-1 Turbine Interlock & Protection

 Dadri stage-1 Turbine Interlock & Protection

• Lub Oil Pr: Alarm=2.0 ksc. Trip=1.88 ksc Effect: Turbine Trips, Barring gear Protection Close,Vacuum Breaker Opens

ATT-200 MW

 

Dadri U-1 functional Loocation /Job Card Help

 

Functional loc. 1011-S1U01 Valid From 20.08.17
Description STAGE-1 UNIT-1

HP Bypass . LP Bypass Operation

Dadri stage-1 Reserve Shut down Procedure

 PROCEDURE FOR RESERVE SHUT DOWN OF STAGE-1 UNITS

PREPARATIONS

Dadri stage-1 : ST-1, ST-2 Both tripping

 In case of both station transformer tripping following disturbance will be observed

SOP for Mills Operation along with Bio Mass

 1) Mill Operating Parameters and Operation procedure:

Work Instructions

Start-Up After 8 Hours of Shutdown ( Hot start-UP)

Unit condition

1	At least 2 BCW pump in Serrvice
2	Both SAPH and PAPH Running
3	Turbine : On Barring (AOP,JOP,SOP, HPCF in service)
4	Generator: PW system, Seal Oil system, Gas system

TDBFP LOP protection and Auto Start

1. LOP A running if trips, LOP B takes start

2. LOP A running and LO dis Hdr manifold pr  LT 8.4 ka, LOP takes start

3. LOP A running and LO dis pr at brg inlet LT 1.8 ka, LOP B takes start

4. If LO dis Pr at Brg inlet LT 1 ka, DCEOP starts

SCED Features

SCED Features

• NLDC has opened a separate bank account called ‘National Pool Account (SCED)’. All payments to/from the generators and to the Discoms on account of SCED flow to/from the said National Pool Account (SCED)

Power Terminology

Power Terminology

• 100MW for 24 Hrs = 2.4 MU (Million Units)
• Ancillary services refer to functions that help grid operators maintain a reliable electricity system.
• Ancillary services maintain the proper flow and direction of electricity, address imbalances between supply and demand, and help the system recover after a power system event

RH Metal Temp Optimization

RH Metal Temp Optimization

• Causes of Rh Tube Fail:  

(a) COAL ASH CORROSION FOR TUBING
(b) UNEVEN TEMPERATURE DISTRIBUTION ACROSS THE BOILER

Dry Ash system : 500 MW

Dry Ash system : 500 MW

• Ash is oxidised form of the mineral matters present in coal
• Typical ash composition : SiO2, Al2O3, Fe2O3, CaO, MgO etc
• Coal with more SiO2 & Al2O3, Ash MP > 1400ºC

NTPC Rihand Shift Rota : Year 2020

Shut-Down Procedure: 500 MW (Planned Shutdown)

Shut-Down Procedure: 500 MW

• Reduce load from 500 MW to 400 MW
• Gradualy Reduce Pr SP from 170 ksc to 130 ksc, Load is still 400 MW
• Take unit of TFM

New Regulation: Real Time Market Power Trading

Hydrogen Purging

Pre-Purging checklist:

1. The generator may be on barring gear or at standstill. Preferably be on barring speed of around 50-80rpm (without condenser vacuum).
 At least 60 CO2 filled cylinders should be available in the unit where purging is to be done.
 Arrangement for filling hot water on CO2 cylinder / lines (to avoid freezing) is to be ready.

Loss of Instrument Air

Loss of Instrument Air
Anticipated Problems:

1. No oil burner can be taken in service. Oil guns, oil/steam valves will remain inoperative.
The igniter will not get advance.

Vacuum Pulling Process

Vacuum Pulling Process
1 Ensure permit cancellation on Vacuum pump/Flash Tank related MOV/Condensate system & Clearance for vacuum pulling.

Mill Fire

Mill Fire
a) Fire in mill under shut down:
 Isolate the mill totally from air side by closing cold/hot air dampers & gates and mill seal air valves.

Shutdown Instructions

Shutdown Instructions
1 Ensure UT change over before tripping of boiler/ turbine.
2 Ensure 400 KV breaker are opened after unit tripping.

UPS Failure

UPS Failure

CONSEQUENCES OF 240 VOLT UPS SUPPLY FAILURE:-

 All LVS supplies from main UPS will not be available but from mini UPS supply will be
available for around 2 hours .

Boiler forced Cooling

Boiler Forced Cooling

1 In case of Tube leakage

1.1 After Tripping the boiler ,stop FD fan and keep ID fan running at
minimum load and ensure furnace pressure negative inside boiler.

CC(BCW) Pump Isolation & Purging

CC(BCW) Pump Isolation & Purging

1. ISOLATION OF CC PUMP REMARKS

1.1 Remove from Stand by mode if it is in auto
1.2 Stop CC pump if running

Bunker fire : Prevention

Bunker fire

PREVENTION OF BUNKER FIRE

 Ensure Feeder outlet gate closes on auto when Feeder stopped/tripped. Otherwise give
a close command for closing.

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

Check List (Light-Up)

Unit:

Date:

Switchyard Breaker arrangement: Rihand

Stage-I

GT#1  à 1-52  Main (GCB to Bus Bar-1) à 2-52 (Tie-GCB to bus Bar-2) à 3-52(IBT-1 i/c)

GT#2 à 7-52Main (GCB to Bus Bar-2) à 8-52((Tie-GCB to bus Bar-1)

Bus bar-1 à 4-52 (H1) à 5-52(Tie H1-S2) à 6-52(S2) à Bus Bar-2

Bus bar-2 à 10-52 (S1) à 11-52(Tie S1-H2) à 12-52(H2) à Bus Bar-1

Bus-1  ß13-52(Bus-coupler-1) à Bus-3

Bus-2  ß14-52(Bus-coupler-2) à Bus-4

Turbine Governing system

Key Points

Ø  Governing- Regulation of Turbine Speed under No Load and Varying Load

Ø  Others Works: CV Actuation/ Initial Run-up & Synchronization/ Load Variation to meet Grid Freq

Ø  500 MW KWU: Throttle Governed Machine

Ø  2 Governors , EHC and HG connected in Parallel: Only One at a time through Hyd Minimum slection

Ø  CVs Open according to Secondary oil Pressure

Ø  Between 100 MW  to 525 MW , Load variation done by HPCV throttling

Important Procedures

Vacuum Pulling : Procedure:

Ø  Close RH Vents, CRH, HRH UFT drains

Ø  Close Vacuum Breaker

Ø  Open 8.5 m steam Manual valve full Both (100%), Temp> 250 Deg ( Open

Ø  Start GSC Exhauster Fan

Ø  Start Both Vacuum pumps ( Casing Empty, Receiver tank Level adeq)

Ø  At -0.2 ksc charge steam gradually ( lower Controller from 50% à 0 %)

Ø  Build Vacuum upto -0.9 ksc