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Tanjung Jati B TrainingAIR HEATERS

Tanjung Jati B Training

OPERATIONSAIR HEATERS


Boiler Precipitator FGD Absorber

2 x 660MW (net)

P.T. Central Java PowerTanjung Jati B Units 1 & 2

Tri-Sector Air HeaterFunction

Two (2) 50% capacity Ljungstrom Tri-Sector Air Heaterstransfer heat from the flue gas leaving the boiler to theincoming cold primary and secondary air.


Secondary Air System

FD Fan

FD Fan

SCAH

SCAH

Tri-SectorAir Heater

Tri-SectorAir Heater

N


Tri-Sector Air HeaterSections

The Air Heater is divided into three (3) sections

Flue Gas Side

Secondary Air Side (~4/5 of air side)

Primary Air Side (~1/5 of air side)



Tri-Sector Air HeaterOrientation

AIR HEATER A AIR HEATER B

ROTATION ROTATION

GAS SIDE GAS SIDE

SECONDARYAIR SIDE

SECONDARYAIR SIDE

PRIMARYAIR SIDE

Tri-Sector Air HeaterAir Heater Components

Terms to remember

Rotor & Rotor DriveEmergency Air (Rotor) DriveHeating Elements or BasketsGuide & Support BearingsOil Circulating SystemsSector Plates & SealsThermocouple Temperature Monitoring PanelSootblowerWater Washing


Tri-Sector Air HeaterFlow Paths


FLUE GAS IN

PRIMARYAIR OUT

SECONDARYAIR OUT

Tri-Sector Air HeaterHeating Elements (Baskets)


Baskets, which contain a multitude of corrugatedsteel plate, absorb the heat from the flue gas stream.

HOT ENDLAYER

(42)

HOTINTERMEDIATE

LAYER(12)

COLD ENDLAYER

(10)


Tri-Sector Air HeaterHeating Elements (Baskets)

CORRUGATED PLATE DESIGN


Tri-Sector Air HeaterRotor Drive

The Air Heater Rotor Drive consists of the followingmajor components

30 HP, 380 VAC MotorSpeed ReducerFluid CouplingPinion Gear & Hub


Tri-Sector Air HeaterRotor Drive

43.5 LITER


Tri-Sector Air HeaterEmergency Air (Rotor) Drive

If the electric motor should lose power, an EmergencyAir Drive is used to insure the continuous operation ofthe Air Heater.


Tri-Sector Air HeaterEmergency Air (Rotor) Drive

SOLENOID VALVEFAILS OPEN UPONLOSS OF POWER


Tri-Sector Air HeaterBearings

The Air Heater has two (2) main bearings, oneGuide Bearing & one Support Gearing.

The Guide Bearing is located at the top portionof the rotor assembly, while the Support Bearingis near the bottom.


Tri-Sector Air HeaterBearings

GUIDEBEARING

SUPPORTBEARING


Tri-Sector Air HeaterGuide Bearing

Due to the Guide Bearing being located in a hotenvironment, an Integral Oil Circulating System is provided to maintain oil viscosity and provide a bath of clean oil.Cooling water is from the CCCW System.


The Integral Oil Circulating System has thefollowing components

Oil PumpDual Oil FiltersOil Pressure GaugeDifferential Pressure Gauge with SwitchOil-Water Heat ExchangerPressure Relief Valve (set @ 75 psig)Thermometer ProbeAdjustable Temperature Controller (set @ 38oC)

Tri-Sector Air HeaterIntegral Oil Circulating System(Guide Bearing)


OIL REQUIREMENT:~43.5 LITERS



Due to the potential for oil to leak and get underthe casing and insulation, there is always a potential for fires to start.

It is recommended that an operator periodicallycheck the oil system.

Tri-Sector Air HeaterIntegral Oil Circulating System(FIRE Potential)


Tri-Sector Air HeaterSupport Bearing

The Support Bearing is equipped with an Oil CirculationSystem. The bearing itself is submerged in an oil bathrequiring approximately 185.5 liters.


Tri-Sector Air HeaterExternal Oil Circulation System(Support Bearing)

Unlike the Integral Oil Circulating System for theGuide Bearing, the Support Bearing has what iscalled an External Oil Circulating System.

This system is similar but has no Oil-Water HeatExchanger.


The External Oil Circulating System has thefollowing components

Oil PumpMicro-Klean FilterPressure GaugeThermometerPressure Relief Valve (set @ 50 psig)Filter Differential Pressure Switch



Tri-Sector Air HeaterSector Plates & Seals

The sealing systems are comprised of the followseals

RadialCircumferentialAxialRotor


Tri-Sector Air HeaterSector Plates & Seals

Our discussion will focus on the Radial Seals.

The hot and cold sides of the air heater have theseseals which run from the center of the air heater toits outer circumference.

Radial Seals, along with Sector Plates minimize AirHeater Leakage


Tri-Sector Air HeaterSector Plates & Radial Seals

RADIAL SEALS(HOT END)


Tri-Sector Air HeaterSector Plates & Radial Seals(Leakage)

Leakage occurs between the following Air andGas streams

Primary Air stream to the Flue Gas streamPrimary Air stream to the Secondary Air streamSecondary Air stream to the Flue Gas stream

Flue Gas In

Flue Gas Out Pri. AirIn

Sec AirIn

Pri. AirOut

Sec. AirOut

Leakage occurs because the pressure onthe air side is greater than the pressure onthe gas side. Also, Primary Air pressure isgreater than Secondary Air Pressure.


Tri-Sector Air HeaterLeakage



Sector Plates are also located on both the Hot andCold End of the Air Heater. The Sector Plates are essentially pie-shaped plates and are adjustableon the Hot Side and stationary on the cold side.

Sector Plates are used to set the gap between thePlate and the Radial Seals.



1 of 3 SECTOR PLATES

RADIAL SEAL


Tri-Sector Air HeaterSector Plates - Numbering

1 2

3

Top View of Air Heater B(Mirror Image for Air Heater A)

GAS SIDE

PRIMARYAIR SIDE

SECONDARYAIR SIDE



The Hot Side Sector Plates, which are adjustable,incorporate an automatic system which checksand sets the gap between the plate and the RadialSeals. A Rotor Position Sensor is utilized for thistask.

The Rotor Position Sensor Assembly and Sector PlateDrive Assembly are located at the ends of the SectorPlate.



The Sector Plate position can also be set manually.Each Sector Plate, numbered 1, 2 & 3, has itsown Local Control Panel to perform this function.

CAUTION! An experienced operator or technicianshould be the only one to adjust the Sector Platesvia the Local Panel, otherwise Radial Seal damagecan occur.


Tri-Sector Air HeaterSector Plates Drive Location

AIR HEATER A AIR HEATER B

ROTATION ROTATION

GAS SIDE GAS SIDE

SECONDARYAIR SIDE

SECONDARYAIR SIDE

PRIMARYAIR SIDE

112 2

33


Tri-Sector Air HeaterSector Plate Local Panel


Tri-Sector Air HeaterThermocouple Temperature Monitoring Device

The Thermocouple Temperature MonitoringDevice (TTMD), is designed to measure the airtemperature leaving the Air Heater.

The TTMD will alarm if a thermocouple detects anunexpectedly high local air outlet temperature.

A high outlet air temperature could be an indicationof a FIRE internal to the Air Heater.

Each Air Heater has one TTMD Panel.



The TTMD utilizes the following Thermocouples

One (1) for Air Inlet Temperature

One (1) for Gas Inlet Temperature

Fourteen (14) for Air Outlet Temperature



The 14 Thermocouples are located internally alongthe radius of the rotor with a spacing of approximatelyone foot (305 mm) and as close as possible tothe heat transfer surface (baskets).

All Thermocouple readings are routed to the TTMDPanel for evaluation or comparison.

The TTMD panel will send an alarm signal to the DCSand alarm locally as well.


T/C #1 th

ru #14

CUTAWAY OFROTOR SECTION


THERMOCOUPLESLOCATED IN THE

AIR OUTLET STREAM


Tri-Sector Air HeaterTTMD Panel Alarm Potential Fire

When the TTMD Panel has a High TemperatureAlarm, immediate attention should be given toit by an operator and I&C technician.

First, push the alarm acknowledge button andsee if the alarm clears or resets.

If not, check to see if the Thermocouple is functioningproperly, for example, the thermocouple has notfailed (infinite resistance).



At first evidence of a fire from temperature indicationor otherwise, inspection of the Air Heater should bemade.

If the temperature continues to rise or if a fire isvisible, the fans should be shut down and water shouldbe admitted to the Air Heater in sufficient quantitiesto quench the fire.



If it is possible to isolate the area of the fire, then stopthe Air Heater so that the water can be directed atthe fire.

On the other hand, if the fire is burning in several areas,continue to rotate the Rotor as long as it will turn.

Note: If the fire has progressed to the metal HeatingElements, temperatures could range from 1093oC to2204oC.



DO NOT CONSERVE ON WATER!!

GET AS MUCH WATER AS POSSIBLE ON THE FIRE!!


Tri-Sector Air HeaterOut of Service Water Washing

Over time, Air Heater air and gas pressure differentialmay increase. Air heater inspection and water washingmay be necessary.

A Water Wash system with wash nozzles is providedto serve this task.

Flue Gas In

Flue Gas Out Pri. AirIn

Sec AirIn

Pri. AirOut

Sec. AirOut

Pressure DifferenceAcross ElementsPin - Pout

Pressure DifferenceAcross ElementsPin - Pout

Tri-Sector Air HeaterOut of Service Water Washing(Pressure Drop)



Tri-Sector Air HeaterSootblower

The extendable lance sootblower is used tominimize the buildup of combustion byproductson the Air Heaters heat transfer elements.

It also minimizes No. 2 fuel and fuel ash depositionduring relatively cold start-up conditions.

Tri-Sector Air HeaterTypical Sootblower Arrangement



Tri-Sector Air HeaterPlugged Heating Elements



Since there is no auxiliary boiler, and if both unitsare cold, compressed air is used. Service AirCompressors provide this air.

Steam which is generally more economical, shouldbe used when auxiliary steam is available.



During boiler start-up, the Air Heater Sootblowershould be operated on a continuous basis. Thisis due to the greater potential for the accumulationof No. 2 Oil combustion byproducts and oil itself.

Once the Boiler is up and operating, the sootbloweris used periodically (typically once per shift).


Tri-Sector Air HeaterStart-Up & Shutdown

The Air Heater is started prior to firing theBoiler and the sootblower is operated on acontinuous basis.

During normal operation, periodically checkthe operation of the Air Heater and be surethe Emergency Air Drive air isolation valveis open.


Tri-Sector Air HeaterStart-Up & Shutdown

During normal operation, check for unusualnoises. A periodic or repetitive noise can bea sign of excessive rubbing between the RadialSeals and the Sector Plate(s).

When shutting down the Boiler, the sootblowershould be operated continuously prior toextinguishing the fires.


Tri-Sector Air HeaterLoss of Air Heater during Unit Operation

Most often, the reason for an Air Heater tostop during Unit Operation is due to electricaloverload of the Main Drive Motor.

This is generally due to excessive rubbingbetween the Radial Seals and the Hot EndSector Plates.



If this should occur, the Emergency Air MotorDrive will not be able to rotate the Air Heateras well.

Provisions should be made to reduce Unit Loadas quickly as possible so that the Air Heater canbe isolated from the incoming Flue Gas, if thisshould become necessary.



At the time of Air Heater Rotor Stoppage, theOperator should immediately go to the Air Heaterand Retract all three (3) Sector Plates by wayof the Local Control Panel.

Once this is done, try to restart the Air HeaterDrive Motor.



If the Main Drive Motor is successfully restarted,continue to operate the Air Heater with the SectorPlates in the retracted position.

Once the Unit is stable at the reduced Unit Load,the Sector Plates can be extended by automaticcontrol.



If the Main Drive Motor will not restart, andwhen Unit Load permits, close all IsolationDampers to isolate the Air Heater.

The main reason for retracting the Sector Platesas soon as possible is to avoid damage of theRadial Seals.



All Operators should thoroughly familiar withthe Air Heater operating instructions found inthe Operations & Maintenance Manual.

High LeakageIncreases fan power requirementsPossible load curtailmentReduced thermal performanceNegative effects on precipitators and scrubbers

High Pressure DropIncreases fan power requirements

Low Thermal PerformanceHigh gas outlet temperatureLow air outlet temperatureLowers unit efficiencyIncreases leakage

Tri-Sector Air HeaterPerformance


Build up and blockage of heating surface flow paths by ash and corrosion productsEffects

Increases pressure dropIncreases leakageReduces thermal performance and effects boiler operationShortens element lifeLimits unit capacity

ControlSootblowingWater washingCold end temperature control



Surface PluggingIneffective sootblowingLow cold end metal temperatureIncomplete water washingAsh carryover

High LeakageDeteriorated sealsIncorrect seal adjustmentImproper operationsRotor or sector plate problems




OPERATIONSAIR HEATERS

(END)

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