Friday, September 5, 2025

DSI SOP

STANDARD OPERATING

PRACTICE (DSI)

NTPC DADRI

STAGE I – 4X210 MW

DRY SORBENT INJECTION SYSTEM

DSI EQUIPMENTS

1. Instrument air compressor

2. Viper mill

3. Oil pump viper mill

4. Blower ( injection and unloading )

5. Dehumidifier ( injection and unloading )

6. Heat Exchanger ( injection and unloading )

7. SBC silo

8. Weigh hopper

9. Rotary air lock ( RAL )( Injection and unloading )

10. Rotary vane feeder ( RVF )

11. Jumbo bag hopper

12. Splitter

INSTRUMENT AIR FAILURE
NCPS Stage-2 (2X490 MW)

Dadri-1: Mill c/o guidelines

Mill starting procedure :

· Clearance from local operator is to be recorded before starting mill.

· Ensure feeder coal on belt is established.

· Ensure ignition permit is available.

· Open bunker outlet & feeder inlet gate.

· Start Mill LOP and observe lub oil pressure , temperature and flow.

· Open CAG ( CADshould be closed), monitor PA header pressure.

· Start Mill and monitor its current (60-65 Amp normal current).

· Open feeder seal air valve & feeder outletgate.

· Open HAG,( HAD should be closed), monitor PA header pressure.

· Observe boiler flame intensity during mill operation.

Dadri: biomass Operating Procedure

1) Mill Operating Parameters and Operation procedure: -

Ø Maintain Mill outlet temperature-> 55 C

Ø Mill inlet temperature -> not more than 180 C

Ø Observe all 4 coal pipe temperature of Mills with biomass regularly. In case of any deviation from rest of the pipes (any abrupt rise or fall), stop the mill and give PTW for inspection.

Ø Pre start and post shutdown purging of mill is mandatory.

Ø Continuous monitoring of mill parameters most importantly mills inlet air temperature, mill outlet temperature, mill current and mill DP.

Ø Mill inlet temperature should not be more than 180 C in any case

Ø Mill reject system to be kept under observation continuously

Ø Operator should be deployed at local for monitoring in wake of fire hazard.

Ø In case of fire, mill should be tripped and steam inerting should be done immediately by opening steam interting motorized valve, keeping watch on furnace pressure. Fire tender may also be used if required.

Ø Clinkering and slagging tendency to be observed from local as well as from rise in SH zone FG temperature. Soot blowing and LRSB to be done accordingly.

Dadri-1: Boiler Safety valve float data

BOILER SAFETY VALVES FLOATING PROTOCOL.

UNIT DATE:

S.NO.	VALVE NO.	DESIGN PR.(KSC)		ACTUAL PR.(KSC)
		OPERATING PR.	RESET PR.	OPERATING PR.	RESET PR.
1	SV-1	176	169.3
2	SV-2	179.9	170.9
3	SV-3	181.7	172.6
4	SV-4	163	158.1
5	SV-5(ERV-1)	161.4	158
6	SV-6(ERV-2)	161.4	158
7	SV-7	49	46.6
8	SV-8	46.3	44.0
9	SV-9	46.66	44
10	SV-10	48.42	46.0
11	SV-11(ERV-3)	45.8	44.9
12	SV-12(ERV-4)	45.8	44.9

Dadri-1: DOR

DOR OF HT/LT MOTORS

CONVENTION:

DOR TAKEN FROM NDE SIDE OF MOTOR

C: CLOCKWISE A: ANTI CLOCKWISE

HT MOTORS

ID A/B	A	MILL A/B/C/D/E/F	C	PA A	C
FD A /B	A	ECW A/B/C	C	PA B	A
CEP A/B	C	BFP A//B/C	C	CW A/B	A
				TAC A/B	C

LT MOTORS

1. BOILER

ID LOP-A/B	C	FEEDER MAIN MTR	C
ID AOP A/B	C	FEEDER COC MTR	C
FD LOP A/B	C	SCANNER FAN AC	C
PA LOP A/B	C	SCANNER FAN DC	C
PA AOP A/B	C	SEAL AIR FAN A/B	A
MILL LOPA/B	C	APH A MAIN MTR	A
APH GB LOP A/B	C	APH A S/B MTR	A
APH SB LOP A/B	C	APH B MAIN MTR	C
		APH B S/B MTR	C

Dadri-1: after Shutdown Activities

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

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

2. Before killing Vacuum,

a) open MS & HRH line drains to IBD

b) close all drains to flash box and condenser

c) Open HPBP line drain lines at 8.5 M.

d) MS line is depressurized.

Dadri -1: Reserve Shutdown Procedure

PROCEDURE FOR RESERVE SHUT DOWN OF STAGE-1 UNITS

PREPARATIONS

1. Open the seal steam drain v/v, MAL-81 and ensure the temp. above 230 deg before seal steam controller,

2. Put the oil guns of AB & CD elevation in scavenge.

3. Open the manual isolating v/v of CBD line at 19 M & 3.5 M.

4. Get the reqd. protections bypassed by C&I engr.

5. Close the Aux. PRDS if in service. (Close As-11, AS-12).

6. Close HT hdr isolating valve at Deaerator floor.

7. Inform CHP , AHP & Switchyard c/r regarding shut down plan.

8. Note down the HFO counter reading.

Dadri-1: Pre-lightup checklist

Light up preparation Checklist

BOILER SIDE

1. Deployment of CISF person(IOM & information to CISF)(one person for Blr & Tur. Each)

2. Ensure opening of manual isolating v/v of following

a. CBD

b. IBD

c. MS-203 MS-204

d. HRH-203,HRH-204

e. IBD side drains of MS & HRH LINE

f. Boiler vents

g. SH vents

h. SH Hdr. drains

i. Isolating valves of ERV’s

j. Boiler startup vent

Dadri: Raw Water Distribution scheme

Dadri stage-1 start up tables

TURBINE START UP TABLES(210 MW)

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

Friday, October 13, 2023

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

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

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

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

Causes of Rh Tube Fail:

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

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

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

Friday, September 5, 2025

Wednesday, September 3, 2025

Wednesday, February 28, 2024

Tuesday, January 30, 2024

Unit Shutdown Checklist

Friday, October 13, 2023

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

Wednesday, July 12, 2023

Friday, May 26, 2023

Tuesday, October 11, 2022

Thursday, July 30, 2020

Monday, June 1, 2020

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