W E L C O M EP M G V SRINIVASSUPDT (Operation)PRESENTATION ON BOILERS & AUXILIARIES

STAGE # 1 BOILER DRUMDOWN COMERSWATER WALLECONOMIZERSUPER HEARTER PRIMARY SH PLATEN SH PENDENT SHREHEATERBURNERS LFO HFO COAL

Boiler AuxiliariesID FANFD FANAPHMILLS & LUB OIL PUMPSPA FANS & FLOPFEEDERS COCSEAL AIR FANSCANNER AIR FANLPDOSING PUMPSHP DOSING PUMPSESPSCAPHBOTTOM ASH HOPPERCLINKER GRINDERSSOOT BLOWERS WATER WALL (24) LRSB (8) APH (4)

WATER AND STEAM CIRCUIT POWER PLANT SCHEMESAIR AND FLUE GAS CIRCUIT FUEL CIRCUIT COOLING WATER CIRCUITASH WATER CIRCUIT

CRH FROMHPTMS TO HPTHRH TO IPTDRUMPLATEN SH1PRI. SHECONOMISERECONOMISER

BOILER DRUM AND CONNECTIONS Designed Pressure :182 KscDesigned temperature:3560CLength :21344 MM.Thickness:110 MM.Material:AM6O situated at 46.4 MT elevation NO. SET PR.RELIEVING CAPACITY1 l82Ksc 148.3T/H2. l84Ksc 149.1T/H3.l86Ksc212.1T/H

FD FANVolume Flow Rate at MCR 96.5 NM3/Sec.Total PR. (MMWC)675Fan Efficiency %78.7Motor Rating KW1400Rated Speed RPM740Type of CouplingCLAW Type of BearingSleeve OilMethod of LubricationRing

REGULAR CHEKS:

1)Oil levels of all bearings. 2)Cooling water flow to the bearing jackets.Air supply to IGV, discharge damper, tempering air damper.4)Pressurised air leakage if any. 5)Oil leakages from bearings.6)Abnormal sound from fan, motor and bearings.7)Motor hot air temp. & earth strip connection

CHECKS BEFORE START:

1)Emergency Push Button (EPB) should be in released condition.2)IGV should be in closed condition.3)Discharge damper should be in closed condition.4) Bearings Temperatures should be normal.All man holes in the air duct should be in closed condition.

EMERGENCY

When any FD fan trips the closure of the discharge damper of tripped fan should be ensured at local.

INDUCED DRAFT FAN Volume flow rate (NM3/Sec.)107.5Total PR. (MMWC)210Fan Efficiency % 78.5Motor Rating KW1200Rated Speed RPM 720 Type of Coupling CLAW Type of Bearing Sleeve Oil

REGULAR CHECKS:

1)Oil levels of all bearings.Cooling water flow to the bearing jackets and oil cooler.3) Scoop oil temp. & pr. (normal values are 400C & 0.4 ksc)4) Flue gas leakage if any.5) Oil leakages from bearings.6) Abnormal sound from fan, motor and bearings. 7) Motor hot air temp. & earth strip connection

CHECKS BEFORE START:

1)EPB should be in released condition.2) IGV should be in minimum position.3) Scoop oil temp. & pr. should be adequate.All man holes in the flue gas duct should be in closed condition.

3.4 EMERGENCY

When any ID fan trips corresponding FD fan also trips, hence closure of discharge damper of tripped FD fan is to be ensured at local.

COAL MILLSREGULAR CHECKS:- Lighting & cleanliness in surroundings.- Loading system oil & Gas pressures, multipliers plunger position. loading oil tank level, loading oil pump healthiness loading cylinder oil leakages, loading cylinders cotter pins position. nitrogen gas cylinders position. -Lube oil pressure before and after filter. oil leakages. gearbox oil level & quality. -PF leakages if any from mill body, seal, salient blocks, classifier, PF v/vs, PF pipes etc. -Hot air leakages if any. from PA inlet duct inspection doors, expansion bellow, mill inspection doors and reject chutes.-

Abnormal sound from mill, gearbox, motor if any.- Mill seal air damper position, seal air differential pressures.- Lube oil coolers water & oil leakages.- Checking the readiness of the standby mill

NORMAL OPERATIONS:

1.Loading system pressurisation when gas pressure is low. Ensure close position of other mills regulator valves. - Open manual isolating v/v of Nitrogen cyl. discharge line.- Open regulator v/v then open precharge v/v.- Ensure pressure gauges v/vs open position.- Ensure open position of v/v to cylinders.- Open Nitrogen v/v to cylinder slowly and keep a precharge gas pressure of 40 Ksc for a few minutes so that nitrogen gas pressure is maintained around 36 ksc.- Close Nitrogen cyl. outlet v/v and discharge line manual v/v.- Close precharge v/v and regulator v/v.- Pressurise the loading oil system by pumping the loading oil pump to maintain a pressure of 7 ksc more than gas pressure.

If Multiplier plunger is out, operated loading oil pump to push the plunger inSupervision of reject gates operation and rejects removal once in an hour.3.Lube oil filter changing over on as per requirement (when after filter pressure is low or before filter pressure is high) with concurrence from UCB.4.Making standby mill ready- Ensure boxing up of Mill.- Check Reject Gate operation and close reject chambers doors.- Ensure loading gas pressure of 36 ksc and oil pressure of 43 ksc.

- Mill oil coolers water lines should be in charged condition.- Open seal air valves.- Ensure C&I whether the connections are through or not.- Ensure Healthiness of all gauges.- Release EPB of mill & LOP and inform UCB. 5.Doing local run of mill when required.6. Giving necessary feed backs to the UCB engineer when mill is taken in to service (Like PF valves position, lube oil pressures, abnormal sounds, PF/air leakages, reject passage healthiness etc).

START / STOP FROM UCB.

1.For taking milling system into service. - Take oil support in associated burners (HFO/LFO) - Start PA fan and load it to 40 t/h. - Raise the mill outlet temperature to 800 C (by regulating CAD/HAD position). - Start Mill. - Start feeder and load it upto 15 t/h with corresponding increase in PA flow (PA flow = 21+coal flow in t/h). - Cut out oil gun pairs one by one after establishing PF auto indication and flame scanner readings are O.K. - Mill loading can be raised to required value with corresponding raise in air flow

FOR STOPPING THE MILL-Reduce feeder speed to minimum gradually, with a corresponding reduction in air flow in mill. -Keep the mill outlet temp. setting to slightly lower value than normal.-Ensure healthiness of flame scanner readings in other mills.- Stop feeder and maintain an air flow of 40 t/h. Allow the mill to get empty which is indicated by reduction in mill current and mill outlet temperature rise. Stop mill after reducing air flow to minimum.- Stop PA fan and keep PF valves closed.-Close isolating damper of PA fan (if neccessary) only after fan comes to stand still.

SAFETY:- Fire fighting equipment readiness is to be checked and ensured before permitting any gas cutting or welding work.- If smoke is observed from reject chamber, clear the reject passages immediately to avoid fire.- Oil/PF/hot air leakages are to be arrested on priority as these may pose fire hazard & pollute the area.- Coal accumulated (reject coal mill local run coal etc.) near mill should be transported to identified place.- All safety precautions to be taken before doing local run of mill to avoid accidents.- personal protection equipment (helmet, safety shoes dust mask etc.) are to be used religiously by all personnel working in mills area.

EMERGENCIES: Abnormal sound from mill /gear box Stop the milling system and get it attended. Both reject passages chocked Stop the milling system and get the reject passages cleared (if there is no fire or any other abnormality, mill can be run for a few hours with both reject passages chocked) Reject passage fire Keep the reject gate and door open for a few minutes to flush out clinkers from passage. If fire is not getting off, milling system is to be stopped and reject passage to be cleared. Fire inside running mill - Reduce or cut off the air flow to mill and dump the mill with coal by increasing the feeder speed. Loading system pressures not maintaining due to leakages

PA FANType of PA fan : Radial Flow, centrifugal type Motor : 6.6 KV (HT) - 400 KWShaft speed: 1480 RPMDesign capacity: 12.9 NM3 /SECVolume flow Rate : 10.3 NM3/SECTotal pressure : 1130 MMWCFan Efficiency : 80%

REGULAR CHECKS:

1.Return oil flow from fan bearings.2. Cooling water flow to the bearing jackets.3. Hot air leakage from fan and duct. 4. Oil leakage from the bearings.5.Abnormal sound from motor, fan and bearings.6. Forced lub oil tank level.7.Air Supply to IGV.

CHECKS BEFORE START:

1.EPB should be in released condition.2.Mill PF valves should be in closed condition.FLOP should be running and LOP dish pressure should not be more than 1.0 KSC to avoid oil spillage from bearings.4.All bearings temperature should be normal.5.All manholes in the hot air duct upto mill should be in closed condition.

BO1TOM ASH HOPPER SPECIFICATIONS:

1)Hopper Capacity : 160 tons2) Hydro ejector capacity : 60 T/HR.3) Frequency of deashing: 4 hrs.4)Ash water ratio: 1:45)Water pressure required : 8 ksc6)Bottom hopper flushing duration : 40 Mm.Cap. of BA HP pumps: 600 M3 /hr at 7.5ksc

CLINKER GRINDER SPECIFICATIONS:

Capacity of grinder60 T/HRSpeed of grinder 55 RPMDia of roller 318 MMNo. of grinders 4 Nos.Type of grinders Double rollerWeight of grinder170 kgs.Seal water quantity2 M3 /hr/grinderClinker grinder motor rating 7.5 KWFuse rating32 AmpsPower supply source Boiler MCCClinker grinders A&C Module No.R5.3 & R 5.4Clinker grinder B&D Module No. F11.3 & F 9.4

BOTTOM ASHING PROCEDURE:1) Open the line discharge valves of corresponding grinders (AD or BC)2) Open corresponding ejector HP water valves.3) Get the bottom ash HP pump started from UCB.4) Check the water pressure (Normally 7/8 Ksc.)5) Fill the hydro-pneumatic tank with water.6) Check the control air pressure is normal and charge the hydro- pneumatic tank by opening air valve.7)Start the clinker grinders.8)Open hopper gate fully by opening water valve at hydro tank outlet.9) Check the pressure in discharge line located after disch. Valve.10) To ensure ash evacuation open the sample valve which is located in disch. Line (Mixture of ash and water should come.)

Monitor evacuation of ash by viewing through side, front & rear view glasses.12) When hopper is empty air suction takes from grinder overflow line. Then open hopper flushing valves in pairs starting from top to bottom (one in each pair).13).Ensure that no accumulation of ash on hopper slope portion by viewing through view glasses. After ensuring hopper is clear stop the flushing.14) Close both hopper gates by changing the air valve position 15) Open grinder flushing valve and wait for overflow to come from overflow line, then close and stop both grinders.16)Open both hopper filling valves and close both ejector valves.17) Close the filling valves after ensuring overflow hopper overflow line (Note Before closing filling valve keep open atleast one ejector valve18)Inform to UCB about the bottom ashing details.

ROUTINE CHECKS:

Ensure both ash hoppers with full of water (slight overflow should always come from over flow line.) 2)Seal trough level to be ensured by ensuring over flow from seal trough over flow line.3)Ensure all 4 hopper gates are in closed condition.4)Ensure correct oil level of CG fluid coupling .5)Monitor bottom ash pit level. If level is more dewatering to be done. 6)Keep refractory cooling water crack open to avoid over heating.7)Ensure adequate lighting at bottom ash hopper area.

ELECTROSTATIC PRECIPITATOR FUNCTION OF DIFFERENT AUXILIARIES:

GD SCREEN : It is a perforated steel plate for uniform gas distribution across the ESP.

HOPPER HEATER : To prevent any dampening of the ash inside the hopper.

COLLECTOR RAPPER : To dislodge ash accumulated on the collector plates.

EMITTER RAPPER : To dislodge ash accumulated on the emitters.

AIR FLUSHING FAN :

1. To supply warm air to heat the insulator and prevent possible condensation to avoid flash over and consequent damage to the insulators.2. To supply air with light pressure inside insulator to creat air barrier against the dirty gas crossing the precipitator AIR HEATERS : To maintain temp of air coming from air flushing fan.

ROTARY FEEDERS : As maximum ash collection is in the zero and 1st fields, hoppers are provided with the rotary feeders. Ash is mixed with water and through open channel sent to ash slurry pump house. Ash is fed from hoppers by gravity / vibrator.

SPECIFICATIONS:

1.Manufacturer Flakt Italiana SPA2.SP Collecting plate Area (SQ M2/M3/SEC) 147.683.Total power consumption 370 KW4.Efficiency without anyone field in service 98.16%Hopper storage capacity (Ash den. 750 /M3) 8/80/250/700 Hrs.6.Ash collection rates with 4 fields in service1- 84%2- 10.5%3- 3.3%4- 1.2%

TAKING ESP INTO SERVICE :

1.Check that coal firing is started in the boiler and ash handling system is taken into service.2.Switch on heater for the shaft and support insulators. Check up current drawn by heating elements from meters on aux panel.3.Ensure that LT switchgear is charged.4.Rapping mechanism for emitting and collecting electrodes is to be taken into service after starting ID fan.5.The high voltage switch is to be put in 'ON' position.6.Check that all interlocking keys are kept in normal condition.

7. Put LT main switch in 'ON' position.

8.Switch on the breaker in control cubicle.Set the selector switch in manual position. The manual control should be kept at minimum.10.Switch on the rectifier unit by pressing start push button on rectifier control cubicle.11.Increase the manual setting gradually so that working current is reached. Take care to see that spark rate is min.12.Voltmeter and ammeter should show steady readings.13.Put the selector switch on auto.

SHUTTING DOWN OF ESP :

Make sure that coal firing is stopped and boiler is being shutdown.2.Switch off high voltage for all rectifies. 3.Switch off LT motor main switch.4.Put the high voltage disconnecting switch in 'OFF' position.5.Keep rapping, vibration and heating systems in service for 12 hours.6.After 12 hours switch off all the rapping motors and heating elements

ROUTINE CHECKS:

ZERO METER LEVEL :

1.ESP and economiser hopper chockages.2.Healthiness of rotary feeders. 3.HP/LP pressure.4.Ash leakages.5.Channels free of ash 6.Mixing chamber water overflow to be ensured 7.Carbon particles in ash scale.8.Collector and emitter rapper healthiness.9.Ash trench water nozzle healthiness

ESP CONTROL ROOM:

1.Air conditioner healthiness.2.All fields primary and sec voltages and currents. 3.Chattering in any relay. For all fields whether all rappers are starting and stopping as per sequence or not.5.No rapper motor should be continuously kept on or off.

ESP PASS ISOLATION

Close inlet and outlet dampers of the particular pass.2.Switch off HT for all fields of the pass.3.Keep aux in service till the PTW is issued.Keep Outlet damper open by 10-15% along with 2-3 manholes for cooling the pass.5.Keep step all auxiliaries.6.Issue P&W after isolating electrical supplies and cooling of ESP elements.

AIR PREHEATER ROUTINE ACTIVITIES:

1.Check the oil levels in the top & bottom bearings through the guage glasses.2. Checking coIling water supply to both bearings. 3. Check oil level in the drive gear box of main motor & auxiliary motor.4.Check the gas inlet, air outlet & air bypass dampers position.5.Check whether air receiver is charged, drain the condensate of air receiver & check the line up of solenoid valve for air motor. The air pr. required is 6 Ksc.6.Check the line up of APH Soot blowing steam either from main steam or from aux. steam. 7.Follow up APH soot blowing &ensuring proper draining of condensate from soot blowing steam circuit during blowing. 8.Check whether bearing temp. & vibration are normal.9.Visual inspection of the air - preheater through view glass at the bottom with the help of light inside.

EMERGENCY ACTIVITIES:

1.In case of air - preheater tripping ensure full closure of air outler & gas inlet dampers.2.In case of total power failure ensure starting of air motor. In case air motor fails to operate, the air - heater is to be rotated manually with the help of a handle.3.In case of fire in the air - heater ensure full closure of air outlet & gas inlet dampers. After stopping of ID & FD fans send water through fire fighting line until the fire is extinguished & rotor is cooled completely

SCANNER AIR BOOSTER FAN START UP CHECKS:

1.Both suction filters should be in charged condition. 2.Fan suction damper is the open condition. 3.Fan discharge damper is in close condition.4.Discharge damper air connection is through. 5.Emergency push button is in released condition.

ROUTINE CHECKS:

1.Both suction filters are incharged condition. 2. Running fan discharge damper is in fully open condition. 3. Standby fan EPB is in released condition.4. Scanner fan discharge header pr. is normal. 5. Standby fan discharge damper is in closed condition. 6. All individual scanners cooling air isolating valves are in open condition

BURNER FRONT

Operation:

On clearance for Boiler light up, initially igniters will be taken into service by giving on command to oil guns at UCB. Sequence of operations as follows.1.steam purge v/v closes, 2.Guns insert,3.Igniters insert,4.Igniter v/vs open,5.Initiation of spark by spark rods.200 MW boiler is a front fired boiler having 24 burner assemblies i.e. 6 burner assemblies at 4 different elevations

DESIGN VALUESCalorific Values.Coal 4300 Kcal/kg. Oil 11000 Kcal/kg.Maximum consumption. Coal. 115T/hrs. (Good coal), 131T/hr (worst coal)

Capacity of oil guns:

HFO 0.5 kl/Gunhour. at 7 kg/cm2LFO 0.8 kl/Gunhour.)

REGULAR CHECK UPS AND ROUTINE ACTIVITIES - Check all air registers are open for running mills- Check igniters and oil guns are in retracted position for all running mills. - Check steam purge valve open for all burners except for oil guns which are in service.- If any oil leakage observed close the individual valves and inform to UCB.- Check coal and steam leakages if any and inform UCB.- Replace oil guns with cleaned oil guns as per schedule to maintain free oil flow.- Check availability of fire protection system located at Burner floor.- Ensure Good House keeping.- Ensure pipe sampling points checking for coal pipe chokage verification:

DOs & DONTs

Dos :- Before operating any oil or steam valves it is to be confirmed from UCB.- Personal protection equipment should be used while working at Burner front. - Check regularly fire fighting Apparatus readiness.

Donts - Do not allow gas cutting and welding without fire fighting equipment availability. - Do not allow any maintenance persons without work permit

SEAL AIR FAN STARTUP CHECKS:

1.Check that bearings of the fan are greased.2.Check that oil level in the bearing sump is normal.3.Check that discharge damper is in closed condition.4.Check that discharge damper is in auto position & air connection to the damper is through.5.Check that stop push button of the fan is in released condition

ROUTINE CHECKS:

1.Check the bearing oil level.2.Check the bearing temperature of the fan & the motor bearing.3.Check for any abnormal sound in the fan or the motor.4.Check the discharge header pr. of seal air fan.5.Check for any leakage in the discharge line of seal air fan.

GRAVIMETRIC FEEDER START UP CHECKS:1.Check that oil level in the drive gear box of feeder & clean out conveyor is normal.2.Ensure that feeder is completely boxed up condition. 3.Ensure that bunker gate is fully opened condition.4.Check that seal air valve to the feeder is in open condition. 5.Check that feeder local / remote switch is in remote position & clean out conveyor is on position. 6.Ensure that clean out conveyor shearpin is in intact condition.7.Ensure that feeder view glass is in clean condition. 8.Ensure that light provided inside feeder is available.

SOOT BLOWING SYSTEM Group 1. 24 blowers Water wallsGroup 2. 8 blowers Final RH Group 3.8 blowers Final SHGroup 4.12 blowers Primary SHGroup 5 8 blowers Primary RHGroup 612 blowers EconomiserGroup 7.4 blowers Air Preheater

CHECKS AND PRECAUTIONS:

1.Ensure the steam flow from the drain at zero meter before starting the soot blowing 2.When blower does not retract UCB is to be informed and blower is to be retracted manually after ensuring supply isolation.3.In case blower is jammed steam valve is to be isolated.4.After wall blowing ensure that all blowers are retracted

CHEMICAL DOSING WHY CHEMICAL DOSING IS REOUIRED?

The water used in boilers for steam generation is deminaralised water, generated in DM plant. Corrosion in boiler tubes is caused by dissolved gases mainly O2 & CO2, these gases can be absorbed by water any time through, condenser tube leakages, feed water suction leaks and from makeup water. Various salts such as carbonates, sulphates and chlorides of calcium and Magnesium can enter into the steam and water cycle due to cooling water leakage in the condenser, and cause scale formation

LP DOSING

Hydrazine (N2H4) & Ammonia Solution will be pumped in to the deaerator. After mechanical deaeration the left out dissolved gases will be removed by adding hydrazine solution in deaerator with LP dozing pump. The chemical equation as follows. N2H4 +O2 ------------ N2 +2H2O

DAILY ROUTINE CHECK UPS:1)Check the pump gear box oil level ------------- If levelis low inform to UCB2)Check for any gland leakage -------------- If any glandleak inform to UCB3)Pump is not discharging ------------- Do the line flushingwith DM water to release line choke if any.4)Check the pump shear pin is intact ----------- If not informto UCB.5)Check for any abnormal sound from pump & motor ______ if any abnormal sound is observed inform to UCB, stop the pump and start spare pump if available.6)If dosing tank level is low ---------------- Transfer chemical solution from preparation tank to dosing tank.7)If preparation tank level is low Inform to UCB, inturn UCB will inform to DM plant for chemicals addition in preparation tank.

USAGE OF AUX. STEAM IN BOILER & TURBINE1. To SCAPH 2. To APH sootblowing 3. To HFO atomisation 4. To HFO tracing steam 5. To Turbine pre-heating 6. To Turbine Seal Steam 7. To Ejectors 8. To Deaerator Pre-heating & bleeding

ROUTINE ACTIVITIES AND CHECKS

1.Check for line up of APRDS steam side if it is available.2.Check for line up of spray water line.3.Check for line up of oil lines for all sulzer valves.4.Check for all drain lines are isolated & no passing of drain lines.5.Check for any steam or water leakage.6.Check for any oil leakage from the system.7.Check for any passing of safety valves.8.Check for line-up / isolation of aux. steam supply to different auxiliaries as per requirements.

ISOLATION OF APRDS STATION

1.Isolate the first valve at main steam side F001.2.Isolate manual valve F005 between APRDS station & aux. steam header.3.Isolate spray water line manual valves.4.Open all drain lines in the APRDS station.5.Isolate oil lines in the control valves if required.

CHARGING OF APRDS STATION :

1. Check that all control valves & Movs in APRDS station are in closed condition.2. Crack open drain lines in APRDS station.3. Crack open first isolating valve From main steam line F00l.4. Check for flow through drains & close all drain lines.5. Check for any leakages or abnormality, if nothing Open fully FOOl valve.6. Fully open F005 valve.7. Open spray water isolating valves.8. Open MOV F002 & manual valve after control valve F550, if closed.9. Check for line up of oil lines for all control valves. 10.Check for supply in OSU & oil pump is running