Boiler optimization

1. we focus on your process
Unburned Carbon
In the fly ash
UBC versus CO2 Emission

2. we focus on your process
Coal bin
Mill
Precipitator
Air preheater
Burner
Air fan
Intermediate
storage tank
Pulverized
fuel
-
Air
Flue gas
Fly ash
Secondary
air
Primary
air
Coal
UBC
Air
Steam Generator
Heat Input:
•Coal
Losses:
•Flue gas heat loss
•Gaseous LOI (CO)
•Unburned Carbon
•Radiation
•Ash Heat Loss

3. we focus on your process
Combustion Heat Loss
Boiler radiation
heat loss
Unburned carbon
in ash
Sensible ash
heat loss
Power Station Basis Data (example):
Mean continuous load (Basis: steam production) 100 %
Full-load (100% MCR) operating hours per year 6 000 [hrs]
Coal mass flow (100% load) 300 [shtn/h]
Excess air ratio (100% load) 1.25 –
Gross heat input (calculated for 100 % load) 7 109 [BTU/hr · 106]
Gross electric power output (100% load) 750 [MWel]
Net power efficiency 36 [%]
5.5%
1.11%
CO
Flue gas heat loss Other
losses

4. we focus on your process
Sources of Improvement
CO
Carbon
in ash
Flue gas heat
loss improvement
(0.43 % absolute)
Other
improvements
(0.13 % absolute)
Goals of good combustion practice:
Reduction of excess air 5 [%-points]
Reduction of fly ash carbon content 1 [%-points]
Reduction of CO 80 [ppmdv]

5. we focus on your process
Total boiler losses
6 % (absolute)
reduction in flue gas heat loss
reduction in solid LOI (carbon in ash)
reduction in gaseous LOI (CO)
total fuel heat
savings = 0.57 %
Savings in CO2 emissions: 26 493 shtn/a  CO2 emission credit
Assumed market price within intern. CO2 emission trading system:
5 $ per ton  132 000 $ per year
0.43%
0.04%
0.10%
reduced CO2 emission
Fuel savings: 10,000 shtn/yr at 30 US$ per shtn:
300 000 US$ per year

6. we focus on your process
Coal bin
Mill
Precipitator
Air preheater
Burner
Air fan
Intermediate
storage tank
Pulverized
fuel
-
Air
Flue gas
Fly ash
Secondary
air
Primary
air
Coal
UBC
Air
Steam Generator
Heat Input:
•Coal mass flow & CV
Losses:
•Flue gas temperature & O2
•CO
•Unburned Carbon in Fly Ash
Coal analysis (Ash Content)
•Ash Temperature

7. we focus on your process
MECONTROL
UBC Sensor
Screw Measuring
Chamber
Drive
Shaft

8. we focus on your process
Dielectric constant of fly ash is a function of the carbon
content. Measuring the shift of frequency in a
resonator ( f) the carbon content can be calculated.
MECONTROL UBC Measurement Principle
UBC = A + B   f
A and B are the
calibration coefficients
we focus on your process

9. we focus on your process
Measurement Data of MECONTROL UBC
Wedel
0
100
200
300
400
500
600
700
800
900
1000
18.07.2001
00:00
20.07.2001
00:00
22.07.2001
00:00
24.07.2001
00:00
26.07.2001
00:00
28.07.2001
00:00
Rest-C
[0,01%]
0
100
200
300
400
500
600
700
800
900
1000
Kanal 2
Kanal 3
Temperatur Kanal 2
Temperatur Kanal 3
we focus on your process

10. we focus on your process
Trial run at BEWAG "Reuter West" power plant
170
165
160
155
150
145
140
135
130
125
06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00
Time
Secondary
Air
x
1000
(inverted)
[m³/h]
STP
1
2
3
4
5
6
7
8
9
10
UBC
[%]
Secondary Air (MECONTROL Air)
UBC ETG 17 (MECONTROL UBC)
UBC ETG 18 (MECONTROL UBC)
Remark: Listed values of secondary air
amount are only for one burner plane.
 1 % O2
Result of SA Reduction Trial Run

11. we focus on your process
Result of SA Reduction Trial Run
we focus on your process
Boiler Optimization Program
0
2
4
6
8
10
12
14
16
18
7:00 7:30 8:00 8:30 9:00 9:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00
Time
UBC
[%];
CO
x10
[mg/m³]
STP
0
0,5
1
1.5
2
2.5
3
3.5
4
4.5
O
2
[%]
UBC Fly ash (MECONTROL UBC)
UBC Fly ash (Lab analysis)
CO Stack
O2 Boiler / DeNOx outlet
Trial run at BEWAG "Reuter West" power plant

12. we focus on your process
Parameters for Efficiency Improvement
we focus on your process
Boiler Optimization Program
UBC
at 7.2 % gA
General calculation example with parameter variation
Basis: 5 % UBC in fly ash; 4.3 % O2 in flue gas
0.00%
0.05%
0.10%
0.15%
0.20%
0.25%
0.30%
0.35%
0.40%
0.45%
0% 1% 2% 3% 4% 5% 6%
UBC in fly ash
Increase
in
efficiency*
h
*) Without power savings of fans
at 3.6 % gA
UBC
O2
Excess air reduction
most efficient !
O2-content of flue gas; UBC in fly ash

13. we focus on your process
we focus on your process
Boiler / Mill Optimization by UBC Monitoring
Excess air: nabs= 7.6 %-pts
h = 0.5 %-pts
2
3
4
5
6
7
8
Time
UBC
[wt.-%];
O
2
[vol.-%]
200
220
240
260
280
300
320
340
360
380
400
Secondary
air
x
1000
[m³/hr]
STP
O2 right duct
UBC Basis: gash = 3.6 %
Secondary airBasis: n = 1.259
O2 left duct
Trial run at “Wedel” power plant
UBC: Cabs = -2 %-pts
h = -0.08 %-pts
Resulting efficiency increase:
0.42 %-pts !
Excess Air Reduction

14. we focus on your process
we focus on your process
Boiler / Mill Optimization by UBC Monitoring
Datteln
0
2
4
6
8
10
12
14
16
18
20
09.08.
00:00
11.08.
00:00
13.08.
00:00
15.08.
00:00
17.08.
00:00
19.08.
00:00
21.08.
00:00
23.08.
00:00
25.08.
00:00
27.08.
00:00
29.08.
00:00
Rest-C
[%]
Kanal 0 geglättet
Mittelwert Kanal 0
Coal type change

15. we focus on your process
we focus on your process
Power Station Farge, Power Utility E-on
2
2,5
3
3,5
4
4,5
5
10:00 11:12 12:24 13:36 14:48 16:00 17:12
O
2
[Vol.-%]
500
520
540
560
580
600
620
NOx
[mg/m³]
O2 boiler out NOx before Kat.
SA2 TA
SA1+CA

16. we focus on your process
we focus on your process
Boiler Optimization Program
750 MW units Germany
Amonia savings
15%
Fuel Savings
36%
CO2 sales
27%
Ash
benefication ?
22%
savings potential

17. we focus on your process
we focus on your process
savings potential
Boiler Optimization Program
750 MW units USA
NOx credits
55%
Fuel Savings
22%
CO2 sales
17%
Ash
benefication ?
6%

18. we focus on your process
we focus on your process
savings potential
Boiler Optimization Program
$0,000
$50,000
$100,000
$150,000
$200,000
$250,000
$300,000
$350,000
$400,000
$450,000
$500,000
Nox credits/Amonia Fuel Savings CO2 sales Ash benefication ?
Savings pa 750 MW unit
US
Germany

19. we focus on your process
we focus on your process
 Determine the O2/UBC, O2/CO and O2/NOx
impact due to different air admission (Secondary air,
Tertiary air, Overfire air, etc.)
 Change overall O2-level on the back pass with
favorable excess air supply
 Run boiler with optimized O2-settings
Action Items for UBC Control
Boiler Optimization Program