AUX BLR

Station: NTPC- Simhadri BHEL Ref No.PS-DC-186-500-0030NTPC Ref no SIM/1/TS/3/ 30

Sheet 1 of 28

Plant area: BOILERPROCEDURE FOR COMMISSIONING OF AUXILIARY BOILER

SLNO

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

LIST OF CONTENTS

PLANT DETAILS

OBJECTIVE

PROPOSAL

SERVICES REQUIRED

SAFETY PERECAUTIONS

EMERGENCY PROCEDURE

STATE OF THE PLANT

METHOD

COMPLETION CRITERIA

APPENDICES

a) DRAWING

Station: NTPC- Simhadri BHEL Ref No.PS-DC-186-500-0030NTPC Ref no SIM/1/TS/3/30

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SL.NO

1.0 PLANT DETAILS:

GENERAL DESCRIPTION

The Steam generator is of natural circulation water tube design. arranged for pressurized firing. Basically it is a two drum vertical bent tube arrangement with water cooled furnace walls combined with the convective boiler bank surface. The complete steam generator is of the bottom supported design resting on concrete pedestals

The upper and lower drums are connected by the bank tubes. The steam drum is provided with efficient internals for steam separation. The unheated downcomers are located in the rear half of boiler side wall ensures adequate circulation in the boiler.

The boiler bank tubes are arranged in line for the best heat absorption minimum draft loss and easy tube inspection and cleaning. Required accessibility is provided at the side of the boiler bank convective surface. Adequate peep holes are provided to watch the flame.

Feedwater is fed into the upper drum and circulation is maintained in the boiler bank through the downcomers. From the bottom drum water flows through the heat absorbing furnace tubes and back into the steam drum. After separation of moisture in the internals, the saturated steam flows through superheaters and to SH outlet steam collecting header from where the main steam is tapped off.

STATUS

Signatures

NTPC BHEL


Sheet 3 of 28


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The main fuels are Heavy Fuel Oil and Light Diesel Oil. The firing system consists of one no oil burner with register located in the front wall to carry MCR capacity with either of the fuels. The luel oil is steam atomized; light oil is air atomised. High Energy Arc (HEA) ignitor is used for lighting up the burner. A flame scanning system is provided to monitor the flame condition in the furnace.

The HFO system consists of HFO day tank, 2 x 100% fuel oil pressurizing pumps with heaters, controls, piping, valves and fittings. The LDO system consists of LDO day tank with 1 x 100% LDO pressurizing pump with required controls piping valves and fittings.

The boiler is equipped with a deaerator and feed pumps to supply deaerated feed water at 105 Deg. C to the boiler.

Blow down system with blow down tank, HP and LP chemical dosing system comprising tanks, pumps, piping, valves and fitting are also provided.

The boiler is equipped with two Radial FD fans (2x60%) with electric motor drive.

The boiler and auxilaries will be complete with the required accessories associated equipment, fittings and valves, integral piping systems etc.

Complete air and flue gas ducting upto and including steel chimney will be provided along with the required expansion joints, damper and supporting steel work,

Refractory and thermal insulation, outer and inner casing materials will be provided as required.

STATUS

Signatures

NTPC BHEL


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1.1 MECHANICAL SYSTEM CONSISTS OF THE FOLLOWING:

Boiler drums with internals

Complete system including down comers, boiler bank tubes etc

Complete superheater system including headers. connecting pipes etc.

Boiler integral piping, valves and fittings including drain, vent and safety valves with exhaust piping, startup vent, silencers for spring loaded safety valve at SH outlet and startup vent and sample coolers along with piping.

Main steam piping from SH outlet header to isolation valve in MS line.

Soot blowing system consisting of soot blowers for Boiler bank (4 Nos.)

Heavy fuel oil system with 2 x 100% pumping and heating unit strainers piping to burner including valves and fittings.

LDO system with 1 x 100% pumping unit including strainer piping valves and fittings.

Atomising steam piping, tracing piping to burners with valves and fittings from boiler front.

STATUS

Signatures

NTPC BHEL


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Atomising air piping for LDO atomization.

Fuel oil burner - 1 No

Flame scanner - 1 No

High energy Arc ignitor - 1 No

Boiler refractory and insulating material alongwith the required fixing materials for the equipment as required.

Boiler inner casing wherever necessary.

Aluminium sheet outer casing for boiler, air and gas ducts and integral piping.

Complete air and gas duct work with necessary expansion joints dampers and support steel work.

Boiler mounting including access / inspection doors

Structural steels, foundation bolts and anchor channels for all equipment supplied.

Platforms and walkways as required access and staircase for the boiler with gratings.

Boiler roof structure columns and roof covering

One number thermal deaerator with feed water tank and pneumatically operated control valves for deaerator level control and steam pressure reduction.

STATUS

Signatures

NTPC BHEL


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DM water line to deaerator from DM water storage tank.

Boiler feed piping from deaerator to feed pump and feed pump to boiler.

Blow down system consisting of one no blow down tank blow down valve and line to tank

Two (2) number boiler feed pumps (1 working + 1 standby) with electric motor drives and accessories.

Feed control valve

HP chemical dosing system with one mixing cum metering tank (mild steel rubber lined) and two pumps (1 working + 1 standby) and piping.

LP dosing system consisting of one mixing cum metering tank (mild steel rubber lined) and two pumps (1 working + 1 standby) and piping.

Cooling water instrument air and service air supply to equipments requiring the utilities.

Two no forced draft fans (2 x 60%) with electric drive silencer and coupling.

STATUS

Signatures

NTPC BHEL


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1.2

1.2.1

1.2.2

ELECTRICALS, CONTRIOLS AND INSTRUMENTATION SYSTEM CONSISTS OF THE FOLLOWING :

Electricals

LT motors for boiler auxiliaries

Electric actuators for various valves and open-close dampers as per schemes

Pheumatic actuators for valves and FD fan damper control as per schemes.

Controls

Burner Management System (microprocessor based)

Auto Control system (microprocessor based) comprising of:

Coombustion control system (Master steam pressure control system Fuel flow control system and Air flow control system).Drum level control systemDeaerator storage tank level control systemDeaerator steam pressure control system.

Local pneumatic control system for Sootblowing steam drain temperation control system. Atomising steam pressure control system. HFO heater outlet temperature control system and LFO pressure control system. Atomising steam pressure control system and Furnace to windbox differential pressure control system.

STATUS

Signatures

NTPC BHEL


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1.2.3

1.2.4

Panels, Cublcles and Local Control Boxes

Boiler control / Instrumentation panel.

Soot blower local starter box.

Boiler LT Motor Control center.

Instrumentation

Temperature tappings and test pockets on pressure parts as per schemes.

Level, Flow and Pressure tappings and pressure test pockets on pressure parts as per schemes.

Pressure. Temperature and Draft tappings and test pockets on pressure parts as per schemes.

Combustion air flow measuring element.

Local Pressure, temperature and differential pressure gauges as per schemes.

Pressure switches temperature switches and flow switches as per schemes

Flowmeter for HFO flow measurement.

Two direct water level gauge at drum floor.

Field transmitter and temperature elements for remote instruments/auto controls as per schemes.

STATUS

Signatures

NTPC BHEL


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1.2.5

1.3

Flue gas Oxygen analyzer.

Cables

Special cables for flame scanner.

LP Power and control cable.

T wisted pair instrumentation cable.

Compensating cable.

Predicted performance

a) Flow (TPH) Superheated steam 55.0

Combustion air 61.0

Flue gas 65.0

b) Pressure kg/cm2 (g)

Feed water pressure at feed check valve line 25.5

Drum operating pressure 21.4

Drum design pressure 25.0

Steam pressure @ SHO outlet 18.0

STATUS

Signatures

NTPC BHEL


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C) Temperature Deg C

Feed water temperature 105

Steam temp @ SHO 215

Gas temp entering SH 1247

Gas temp entering BB 1192

Gas temp entering stack 316

d ) Burners No of burners 1

Location Front wall

Fuel HO/LSHS/HPS/LDO

Atomising medium Air – LDO Steam Other fuels

e) Ignltors & Seanners No of Ignitors / burners 1

Type HEA

No of scanners / burners 1 Type Visible Light Self Checking.

STATUS

Signatures

NTPC BHEL


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1.4

1.5

f) Draft system

No of forced draft fans 2

Air volume (Design) m3/sec 10.15

Head developed (Design) mmwc 562

Motor rating & speed KW/rpm 110/1480

Fuels

LDO (as per IS 1460 – 1974)

HFO (as per IS 1593-1971)/ lshs/hps.

Safety Valves Data Sheet

STATUS

Sl.No LOCATIONVALVE TAG NO

VALVE SET PRESSURE KSC %

BLOWDOWNREMARK

%OPEN CLOSE

1) DRUM SV1 25.0 24.0 4.0

2) DRUM SV2 25.8 24.7 4.3

3) SH SV3 20.5 19.6 4.4

NOTE: Percentage blow down to be within 3% -5% of value lifting pressure

Signatures

NTPC BHEL


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2.0 OBJECTIVE:

The objective of the procedure is to commission the Auxiliary Boiler and make it available for Pre-commissing and commissioning activities of main Boiler.

STATUS

Signatures

NTPC BHEL


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3.0

3.1

3.2

3.3

3.4

3.5

3.6

3.7

PROPOSALS:

Auxiliary Boiler will be commissioned through the following proposals.

Air Blowing and oil flushing of LFO system.

Gas Tightness test of Boiler (Either with FD fan or suitable temporary blower)

Pre-Boiler Feed water System flushing.

Chemical cleaning of Boiler – Refer TS No: BHEL PS-DC-186-500-0015

Steam blowing and oil flushing of HFO system.

Steam Blowing & Safety valve floating.

Commissioning of soot Blowing System.

STATUS

Signatures

NTPC BHEL


Sheet 14 of 28


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4.0

4.1

4.2

4.3

4.4

4.5

4.6

SERVICES REQUIRED:

Availability of DM water.

Availability of Service Air / Industrument Air.

Availability of LFO / HFO oil.

Availability LT Power supply.

Availability communication and lighting facility at Auxiliary Boiler area, steam blowing areas.

Availability of operating personnel / working manpower with required tools and tackles.

STATUS

Signatures

NTPC BHEL


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5.0

5.1

5.2

5.3

5.4

5.5

5.6

SAFETY PRECAUTIONS:

Required quantities of safety gears such as helmets, Asbestos hand gloves, Ear Mufflers etc are available.

First aid kit box available in control room

Service water shall be made available near the activity area.

Required stair cases or platform or approaches etc with hand rails are made available.

Required barricades to be made to prevent personal from coming into contract with temporary piping.

Required number of sign boards to be put into position at selected locations to indicate the ongoing process of steam blowing.

STATUS

Signatures

NTPC BHEL


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6.0

6.1

6.2

6.3

EMERGENCY PROCEDURES:

The group consisting of NTPC and BHEL, which is carrying out steam Blowing should be aware of procedures to be followed in case of accidents involving injury to personnel.

The group should be aware of operating procedures of portable fire extinguishers to be used for quenching minor fires.

The group should be aware that if any abnormality is observed in the permanent and temporary system during the steam blowing operation, the operation should be immediately terminated and appropriate action taken to address the emergency.

STATUS

Signatures

NTPC BHEL


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SL.NO7.0

7.1

7.2

STATE OF THE PLANT:

Erection of the following are completed.

a) Auxiliary Boiler proper and all its mounting.

b) Steam line from Auxiliary Boiler to Pumping & Heating Unit & F.O. Heating System.

c) Steam line from Auxiliary Boiler to LOW temperature APRDS.

d) FD Fans

e) BFPS and its associated piping with all supports.

f) Deaerator cum FST

g) LFO / HFO Pumps at F.O Pump House.

h) LFO/HFO pipe lines from Day Tank to Auxiliary Boiler including (F.O lines up to oil burner with all supports.

i) Soot Blowers and its steam line from Main steam line.

j) LP/HP dosing system and connected pipe lines upto deaerator / Drum respectively.

k) Temporary blower of sufficient capacity is available for Gas tightness test.

Hydraulic test of the following are completed.

a) Auxiliary Boiler and its main steam line including soot Blower steam line.

STATUS

Signatures

NTPC BHEL


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7.3

7.4

7.5

7.6

7.7

7.8

7.9

7.10

7.11

b) Steam line from Auxiliary Boiler to F.O Pumping and heating System and up to low temperature APRDS.

A ‘U’ tube Manometer is made available at a suitable location for pressure measurement.

Temporary blower connection with boiler to a suitable point by temporary duct. (This arrangement may not be required when the test is conducted by using FD fans)

Insulation of Boiler not done till the gas tightness test is completed.

A suitable dummy is provided at Boiler outlet for conducting the gas tightness test (This dummy removed after the completion of test).

All thermo wells are in removed condition and these will be erected only after completing steam blowing.

Trip valves control valves, flow elements are not erected in HFO lines and spool pieces are erected at these places.

Insulation of Boiler, F.O lines, FW lines & Steam lines are completed where ever applicable, before Boiler light up.

Permanent piping to be suitably used or temporary piping erected with required supports at steam blowing points.

Safety valves (2 Nos in Drum and 1 No in MSL) are erected with its exhaust pipe line and supports. Silencer (for MSL SV) is also erected.

STATUS

Signatures

NTPC BHEL


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7.12

7.13

7.14

7.15

7.16

7.17

All vents and drains of the boiler including F.O. System are properly routed and supported.

Suitable temporary line connection is given for steam blowing.

a) HFO lines from Boiler to F.O pump house

b) Deaerator Pegging/Heating line

c) Steam line to low temperature APRDS at APRDS end.

Steam heating arrangements for HFO system are available.

Atomising air system is completed and all the air leaks attended.

DM inlet lines to FST is available. Required flushing of this line is completed before connecting to DE inlet.

Remote operation / control and Indications of the following are available.

a) BFP and its control

b) FD Fan and its control

c) Burner operation through Burner Management System

d) Operation of Soot Blowers

e) LP/HP dosing system (local only)

STATUS

Signatures

NTPC BHEL


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7.18

7.19

7.20

7.21

f) Deaerator Level

g) Furnace Pressure

h) Drum Level

i) Drum pressure / MSL Pressure / MS temperature.

j) Secondary Air Pressure

k) F.O pressure / Atomising Air & Steam Pressure

l) Start up vent valve and boiler outlet valve.

(List of controls and Instrumentation to be finalized at site)

Calibrated pressure gauges (2 Nos) of suitable range (Preferably 0-50 KSC with Least court of 0.5 KSC) is made available for safety valve floating.

Manual operation of sootblowers are checked for free operation. Electrical operation at local and remote is made available. This is to be done under boiler stutdown condition.

DM water inlet to dosing system completed and flushed sufficiently before taking in to service.

Dosing system tanks are clean and electrical operation of the pump is made through.

STATUS

Signatures

NTPC BHEL


Sheet 21 of 28


SL.NO8.0

8.1

8.1.1

8.1.2

8.1.3

8.1.4

8.1.5

8.1.6

8.1.7

8.2

8.2.1

METHOD:

Air Blowing and oil flushing of LFO system (Refer drg. No.)

4:PS:TSX:0051:00 Dated 15.05.2001

The LFO system from LFO Day Tank to Auxiliary Boiler is cleaned by pressurizing and card board bursting method.

A suitable air entry to be selected and either service air or portable compressor is used for this cleaning.

The line dummied with card board at suitable location, air filled, pressurized and card board burst till clear air blows. (Visual only)

After completing air blowing, the lines are normalized.

LFO is charged in to the system by gravity and checked for any leakage.

LFO pump started and flushing carried out for 1-2 hour from LFO Day tank – Suction line LFO Pump LFO discharge – up to Auxiliary boiler – temporary loop at suitable location with HFO return – HFO return line back to HFO Day tank.

After LFO flushing, the LFO system connected to Auxiliary Boiler is normalized for regular operation.

Gas Tightness Test of Boiler (Refer drg. No)

4:PS:TSX:0052:00 Dated 15.05.2001

This test can be done either with a) FD Fan or with b) Temporary blower

STATUS

Signatures

NTPC BHEL


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8.2.2

8.2.3

8.2.4

8.2.5

8.3

8.3.1

8.3.2

8.3.3

8.3.4

8.3.5

8.4

Start FD Fan / Blower and gradually load the fan to achieve a positive pressure of 100 mm WC.

Check externally the entire boiler for leakages physically / by applying soap solution to all welded area and attend them.

Repeat the test till all the leaks are attended.

After the completion of test, the boiler is normalized and released for light up (Removal of dummy / temporary duct connected to boiler and completion of insulation shall be done after the completion of gas tightness test.

Pre-Boiler Feed water System Flushing. (Refer Drg. No 4 TSX :0053:00 Dated 15.05.2001

Fill the Deaerator cum Feed storage tank with clarified water once and drain fully.

Fill the system again, now with DM water

Commission the Boiler feed pumps and complete trial run for 8 Hrs on re-circulation.

Charge the feed line gradually up to E1 valve and flush the line through a suitable drain / vent line (E1 and E2 valve closed)

Keeping E1 and E2 open, flush the feed line in to Boiler drum and drain the flushed water through Boiler drain.

Chemical cleaning of Auxiliary Boiler

Refer to procedure (BHEL Ref: ) PS –DC-186-500-0015 (NTPC Ref: ) SIM/1/TS/1/011

STATUS

Signatures

NTPC BHEL


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8.5

8.5.1

8.5.2

8.5.3

8.5.4

8.5.5

8.5.6

8.6

8.6.1

Steam Blowing and Oil flushing of HFO system (Refer drg No) 4:PS:TSX:0055:00 Dated 15.05.2001

Auxiliary Boiler is lighted up as per start up procedure using LFO fuel and Boiler pressure raised to 10.0 KSC.

Steam to Pumping and heating unit charged and through a suitable temporary looping, HFO line from pump house to Auxiliary Boiler is charged and Steam blown for 20-30 minutes continoussly for 3 times with a time gap of 1 Hr between the blowing.

HFO return line also to be steam blown as above.

After steam blowing completion, the lines are normalized.

HFO system designated for Auxiliary Boiler is charged and circulation established bypassing heating unit up to Auxiliary Boiler and back to Day tank through return line.

HFO circulation is carried out for a duration of 8 Hrs and the system released for light up of Auxiliary Boiler on HFO fuel.

Steam Blowing and Safety Valve floating

This steam blowing activity is carried out through 2 stages (Refer drg. No 4:PS:TSX:0054:00 Dated 15.05.2001

a) Steam blowing of Steam lines of Auxiliary Boiler, Fuel oil Heating System and Pumping and Heating Unit.

b) Steam Blowing of Steam lines from Auxiliary Boiler to low temperature APRDS.

STATUS

Signatures

NTPC BHEL


Sheet 24 of 28


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8.6.2

8.6.3

8.6.4

8.6.5

8.6.6

8.6.7

8.6.8

Start Auxiliary Boiler and raise the pressure to 10.0 KSC. Start up vent and fuel firing to be used for controlling the pressure during steam blowing.

Keeping the valve AS-48 in closed condition, charge the steam lines and blow the circuit as given in 8.6.1.

a) for 20-30 minutes. Totally 3 blows are required to be given with time gap of 1 Hour between the blows.

Isolate the circuit of F.O Heating System and Pumping and Heating Unit. Keeping the auxiliary boiler in Service as above, charge slowly the steam line leading to low temperature APRDS.

Allow sufficient warming up of line and charge further by opening the valve (Either valve As-56 AS – 48 can be operated for charging and steam blowing keeping the other valve in fully open condition.

Steam blowing of steam line up to low temperature APRDS is done by continous method for a duration of 20-30 minutes at 10.0 KSC at Auxiliary boiler outlet. Fuel firing or regulation of start up vent or valves AS-48/AS-%^ to be made use off to achieve the above steam blowing.

Totally about 3-4 blows will be required with time gap of 1 hour between each blow.

Safety valve floating

After completing the steam blowing, valve AS-56 to be closed to prepare the boiler for safety valve floating.

STATUS

Signatures

NTPC BHEL


Sheet 25 of 28


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8.6.10

8.6.11

8.6.12

8.6.13

8.6.14

8.6.15

8.7

Boiler pressure is gradually raised nearer to floating value of SV-2 (Floating value is 25.8 KSC). Boiler overall expansion is noted down and verified that the boiler expansion is in order. Boiler start up vent valve S-13 is used for boiler pressure raising.

Raise the pressure further gradually and allow the safety valve to float. Note down the set pressure at which valve actually floated. Immediately after floating of the valve, open the start up vent fastly and reduce rate of fuel firing and effect reduction in boiler pressure. Note down the pressure at which the valve resets.

Verify the set pressure, Reset pressure and blow down percentage with data sheet. (Section 10) The valve to be refloated again after effecting the reguired adjustments for pressure and blowdown (O & M for safety valve to be referred for safety valve adjustment) till the safety valve floating are set as per data sheet.

The other safety valves are floated on similar lines as explained above in steps 8.6.11 & 8.6.12

Floating of Safety Valve is done from the valve with higher set pressure to the lower one. Ie from SV2 – SV1-SV3

while floating SV1 or SV2, the other two valves are to be gagged and while floating SV3, gagging of other two valves not needed.

Soot Blowing System

Start auxiliary boiler and raise the pressure near to MCR valve.

STATUS

Signatures

NTPC BHEL


Sheet 26 of 28


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8.7.2

8.7.3

8.7.4

8.7.5

Keeping the steam line of Sootblower in disconnected condition from the soot blower, sufficiently steam blow the lines by the charging the line through the valve SB-6. Drains are kept open to the required amount for continous warming up of the line.

After normalizing the Steam line with soot blower, steam line charged and through local operation, pressure setting of the soot blower is done one by one. (For arrangements such as condensing Loop etc, refer the respective O & M for soot Blower)

Operation of soot blowers from remote also checked without steam under shutdown condition and with steam under boiler running condition.

With the completion of all the above activities, auxiliary boiler released for regular operation.

STATUS

Signatures

NTPC BHEL


Sheet 27 of 28


SL.NO

9.0

9.2

9.3

9.4

9.5

9.6.

COMPLETION CRITERIA

a) Air blowing of LFO system: Air blowing by card board bursting done till clear air blows (Visual)

b) LFO flushing for 1-2 hours from LFO Day tank to HFO Day tank Concludes LFO flushing

Gas tightnes test at 100 mmwc conducted till all the leaks are attended

Pre-boiler feed water system flushing completed by gravity filling & draining and flushing through the line by running BFP till clear water conditions are achieved:

Chemical clearing of Boiler: As given in the referred procedure.

Steam blowing and HFO flushing:

a) Steam blowing 20 - 30 minutes – 3blows- 1hr time gap BETWEEN THE BLOWS – Boiler pressure during the blowing at 10.0 KSC.

b) HFO flushing conduded after 8 Hrs of oil flushing

Steam blowing & Safety value floating.

a) Steam blowing for 20-30 minutes –3blows – 1Hr time gap between blows – Boiler pressure at 10 KSC

b) Set values of Safety value floating as given in Section 1.0.

STATUS

Signatures

NTPC BHEL

PROCEDURE FOR COMMISSIONING OF AUXILIARY BOILER

Documents

AUX BLR