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Continuous Combustion Management (CCM)
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J. Estrada, Progress EnergySt. Petersburg, FL
D. Earley, Combustion TechnologiesApex, NC
B. Kirkenir, Progress EnergyRaleigh, NC
Acknowledgements
Bob Sisson
Crystal River Plant Engineer
Crystal River Power Plant
Crystal River, FL
Ideal Furnace Combustion
� Proper and even burner stoichiometry leads to consistent flames in furnace
� Fuel:Air ratio distribution
� Emissions reduction and improved efficiency
� Low hanging fruit
� Potential alternative to post combustion emission equipment
Crystal River Unit 4
� B&W Opposed Fire Pulverized Coal 770 MW
� 6 MPS-89 Puvlerizers
� 9 Coal Outlets per Mill
� 54 B&W DRB-4Z Low NOx Burners
� 6 Compartmentalized Windboxes
� 3 x Front, 3 X Rear
� SCR, Cold Side ESP & Wet FGD
Continuous Combustion Management (CCM)
� Equipment Additions:
� Coal Flow Measurement & control valves
� Burner Secondary Air Flow Measurement & auto purge
� Burner Secondary Air Flow Adjustment
� Primary Air Measurement and Auto Purge
� CO measurement
� Equipment Modifications
� Relocation of O2 Probes
� New O2 equipment (probes and cabinets)
Coal Balancing� Problem: Uneven Coal distribution
� Solution: Online coal measurement + adjustment
Coal Out
Coal In
Pulverizer Discharge
Adjustable Coal Valves
Coal Flow Measurement
� Air Monitor Corporation
� Santa Rosa, CA
Coal Flow Balancing
Coal Flow Balancing
Burner Air:Fuel Ratios
Secondary Air Balance
Secondary Air
Secondary Air
•Problem: Uneven Secondary Air (SA) distribution
•Solution: Measure SA flow at each burner and adjust SA dampers
Windbox Air Dampers
Windbox Air Dampers
Secondary Air Measurement
� Wind Tunnel Testing at Air Monitor HQ
Why Automate SA Dampers?
� Dynamic windbox flow profiles
� Fluctuating windbox pressure
� Ash build-up
Burner1
Burner2
Burner3
Post-Combustion
� CO and O2 measurement accuracy is critical
� Grid configuration preferred
Op
tim
um
Zo
ne
Op
tim
um
Zo
ne Boiler Efficiency
Air Flow
Com
bust
ion
Par
amet
ers
CO
O2
NOx
LOI
Co
mfo
rt
Zon
e
Co
mfo
rt
Zon
eSlagging
Fireside Corrosion
Tube Leaks
O2 Probe Relocation
� Old location not representative of furnace O2 profile
Economizer
ECONOMIZER ASH
HOPPER
FLUE GAS
CASCADE ROOM
OLD O2
LOCATION
NEW O2
LOCATION 15'
40'
� New location proven to be more accurate through testing with B&W
� Significant distribution improvement realized due to new location
O2 Probe Standard Deviation
0
1
2
3
4
5
6
7
8
0 100 200 300 400 500 600 700 800 900
Sta
nar
d D
ev
iati
on
(Pro
be
s 2
& 7
Om
itte
d)
Gross Load (MW)
CR4 O2 Probe Standard Deviation
Pre-Outage
Pre-Tuning
Post Tuning
CRN O2 Distribution ComparisonsCR4 O2 Profiles
CR5 O2 Profiles
Note: Unit scales are different
CO Probe Augmentation
� CO is better diagnostic tool than O2 alone
� Air leakage impact on O2 probe
CCM Tuning
Remote Combustion Dashboard
New O2 Curve
� LOI benefit
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
6.0%
7.0%
8.0%
9.0%
10.0%
0 1000 2000 3000 4000 5000 6000
Ex
cess
O2
(%
)
Steam Flow (kpph)
Unit 4 O2 Curve
Old Curve
Manual Curve
New Curve
NOx Benefit
Project Results
� Boiler Efficiency Increase = 0.5%
� Annual fuel savings
� Combustion NOx Reduction
� 7% at full load, 15-25% at part load
� Annual Ammonia Reagent Usage Reduction
� SCR Catalyst Life Extension
� Fan Auxiliary Power Savings
Pre vs. Post CCM Boiler Efficiency Comparisons
Operational DescriptionBase -- Original OEM Predicted
Efficiency Pre CCM Test w/ 2.5 lb Sulfur Coal Post CCM Test w/ 2.5 lb Sulfur CoalPost CCM test w/ 2.5 lb Sulfur Coal &
optimized O2 Curve
Comments
Original predicted performance assumes 0.013 lbs moisture / lb of air (80˚F & 60% Humidity).
This test was run @ full load on 5/30/10 prior to placing the CCM project in service.
This test was run @ full load on 6/24/10 after initial balancing of the coal burner lines and placing the secondary air registers in automatic.
This test was run @ full load on 8/16/10 w/ stable O2 & CO parameters. The O2 curve had been adjusted down to optimize overall boiler efficiency.
Adjustments / VariablesExcess Air 20.0 16.0 15.0 11.0
Humidity 60% 80% 80% 80%Average Air Heater Exit Gas Temperature ˚F 262 317 319 315
Annual Capacity Factor 85% 71% 71% 71%% Dry Carbon in Refuse --- 4.00 2.70 3.20
Boiler Efficiency ParameterDry Gas Loss % 4.43 5.36 5.28 4.99
Water from Fuel Loss % 5.91 5.15 5.13 5.12Moisture in Air Loss % 0.11 0.21 0.20 0.19
Unburned Combustible Loss % 0.30 0.51 0.34 0.41Radiation Loss % 0.15 0.15 0.15 0.15
Unaccounted for Manuf Margin % 1.50 1.50 1.50 1.50
Total Losses % 12.40 12.88 12.61 12.36
Overall Boiler Efficiency % 87.60 87.12 87.39 87.64Input in Fuel (MKB/HR) 6581.00 6717.48 6690.00 6662.11Input in Fuel (MLB/HR) 639.80 584.13 581.74 579.31Wet Gas Wt (MLB/HR) 6579.00 6892.86 6821.53 6570.70Tot air to Burn Equip (MLB/HR) 5891.00 6324.39 6254.89 6008.25
Additional “Soft” Benefits
1. Reduced emissions
2. Reduced pulverizer wear
3. Reduced wear on Coal Yard equipment.
4. Reduced boiler tube & non-pressure part erosion due to lower flue gas velocities.
5. Improved ESP performance due to lower flue gas velocities.
6. Reduced potential for slagging and fouling events
7. Improved Pressure part life due to improved temperature profile
8. Reduced ash disposal costs
9. Reduced boiler tube failures due to reducing atmospheres
Contact
� Joe Estrada – [email protected]
� David Earley – [email protected]
� Bill Kirkenir – [email protected]
