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7/27/2019 Coal Fired GE Tobin
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CombustionOptimization for
Coal-Fired Boilers
2nd U.S.-China NOx WorkshopDalian, China
August 2005
James TobinNeil Widmer
GE Energy
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The problem
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3GE Energy
August 2005
Poor combustion result in many
performance issues.
Reduced
Througput (Load)
High Metal
Temperatures
Increased FEGT(Furnace Exit Gas Temperature)
Reduced
Efficiency
~Coal
Supply
CoalCrushe
r
Mill
CoalSilos
Boiler
AirHeater
Stack
IDFan
FDFan
Turbine Generator
Local Fouling
Increased
Steam Spray
Local Slagging
Local Hot Spots
Increased
Excess O2
High COHigh CO
Combustion profile as monitored
by Spatial Sensors
Economizer
O2 Imbalance
Local Corrosion
High Carbon in
Ash, eg. LOI(Loss on Ignition)
High NOx
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4GE Energy
August 2005
The major lost opportunities result from
poor combustion.Fleet-wide lost opportunity
cost can be over $80 MMper year.
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Boiler Fleet
AnnualLossOpportu
nityContribu
tions
Condensate System
Opacity
Controls Chemistry
Seasonal Derate
Feedwater System
Slag & Ash Removal
PRB Derate
Air Supply
Fuel Quality
Mill/Feeders
Turbine
Tube Leaks
Contributing Factors:
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5GE Energy
August 2005
Improved burner operation drives
performance gains.
Fuel Savings
Comfort
Zone
Initial A/FInitial A/F
FEGT
ImprovedImprovedA/FA/F
High CO Burners LimitPerformance
Emissions Credits
Availability & Peak Power
Output (Throughput)
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Solutions
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7GE Energy
August 2005
Zonal combustion control system
Combustion (O2/CO)Monitors
Output
NOx
AvailabilityBurnerAirflow
Controls
CombustionTuningControls
Efficiency
CombustionDiagnostic
ZonalFuel and AirOptimization
BurnerAdjustments
1
2
3
object
BurnerCoal FlowControls
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8GE Energy
August 2005
Combustion
Sensors
CombustionTuning Model
Burner AirflowControls
Coal Flow
Sensors
Coal FlowDampers
Components
Zonal Combustion
Controls
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9GE Energy
August 2005
Zonal combustion control system
how fuel & air controls work together.Zonal CO Trim - fine controlsfor combustion balancing :
> Trim furnace zonal air/fuelratios based on sensor grid
Balance CO
Reduce hot spots
Reduce delayedcombustion
Maintain burner flame Reduce LOI
Reduce excess O2
Zonal Fuel Trim - coarsecontrols for combustionshaping :
> Optimize wall-burner firing
Reduce impingement
> Reshape tangential fireball
Centered and round
> Tune furnace fueldistribution
Balance economizer O2 Divert heat loading from
peak FEGT & slag regions
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10GE Energy
August 2005
Fuel control can reduce temperature
and CO zones the precursors to slag.AfterBefore
CO Profile
Max = 2088 Max = 2023
Gas Temp. Profile
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11GE Energy
August 2005
Automatic Fuel Trim controls are
successful at tightening distribution.
-25%-20%
-15%
-10%
-5%
0%
5%
10%
15%
Burner CoalFlow Bias
As-Found Manual Automatic
Coal Distribution
Burner C1
Burner C2
Burner C3
Burner C4
Burner C5
First Demonstration August 2003
7/27/2019 Coal Fired GE Tobin
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12GE Energy
August 2005
Balanced and optimized coal flow
distribution reduced peak FEGT 60F.
2375
2400
2425
2450
2475
2500
2525
FurnaceExitGas
Tempera
ture(deg.
F)
Baseline Balanced OptimizedCoal Distribution
Ash FusionPoint
PeakFEGTReduction
10MWCapa
cityIncrease
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13GE Energy
August 2005
20F Peak FEGT limited boiler capacity
approximately 10MW.
2,150
2,200
2,250
2,300
2,350
2,400
2,450
2,500
2,550
2,600
2,650
2,700
220 240 260 280 300 320 340 360 380 400
Load, MWg
FurnaceExitGasTemperature,
degF
FEGT West
FEGT East
FEGT Average
Turbine Capacity
Boiler Limit
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14GE Energy
August 2005
Zonal combustion monitoring system
Interface Display
Modeling
(upgrade)
Flow and
Control PanelSensor Array
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15GE Energy
August 2005
Zonal combustion model-based
control system.Combustion Trim ModelMonitoring & Control Interface
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16GE Energy
August 2005
Zonal combustion tuning system
demonstration.
Burner
Tuning
CombustionSensors
Boiler Model
Initial CO
Tuned CO
Tunin
e
mo
gD
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17GE Energy
August 2005
0
100
200
300
400
500
600
700
800
900
1000
COLe
vel,ppm
CO#11
CO#6
CO#12
CO#7
CO#14
CO#13
CO#1
CO#9
CO#8
CO#10
CO#4
CO#15
CO#5
CO#2
CO#3
Combustion Sensors
Initial Tuned
0
0.5
1
1.5
2
2.5
3
3.5
Fly-As
hLOI,%
West Middle East
Flue Gas Duct
Initial Tuned
Systematic tuning balanced CO and
fly-ash LOI synergistic with Hg control.
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18GE Energy
August 2005
Zonal combustion control system
features:> Faster tuning experience
> One system for managing Zonal combustion
> Improves quality through systematic methods
> Advises burner adjustments> Stores preferred burner setting by operating
mode> Diagnoses combustion performance
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Benefits
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20GE Energy
August 2005
Combustion Optimization Case Study
Sunflower Electric 380 MW BoilerScope:> GE coal flow monitors & control
> GE combustion sensors> GE boiler tuning services
> GE control software
System Benefits:> Reduced peak FEGT 60F
Eliminated barrier to increasingoutput 10 MW worth $1M/yr
> Reduced high CO and temperaturezones
Avoid future slag outage 1weeks worth ~ $2.5M/yr
> Reduced NOx and Heat Rate
Furnace Combustion
Balancing
Burner Fuel/Air Flow
Sensors & Auto-Control
Coal
Flow
Sensor
Coal
Damper
Furnace
Combustion
Sensor Arrays
COSensor
Burner Air
Control
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21GE Energy
August 2005
Zonal combustion controls benefits:
9Reduce average and peak FEGT
9Reduce fuel rich (CO) zones
9Reduce corrosion
9Reduce slagging
9Reduce LOI
9Reduced NOx
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22GE Energy
August 2005
Good combustion provides significant
benefits.
0
500
1,0001,500
2,000
2,500
100 300 500 700 900
Boiler Load, MWe
A
nnua
lBene
fits
,k$/yr
Emissions Heat Rate
Peak Power Availability
Improvements :
> Excess O2: 0.5% reduction> Emissions (NOx): 15% reduction
> Heat Rate: 0.4% improvement
> Peak Power: 2.3% increase> Availability: 1 week avoided
outage
Economic assumptions provided in notes
Economic benefits are site-specific. Your plants benefits may vary.
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