Nikola Tesla - Results of heat transfer
calculation
Dr. Storm / Dipl.-Ing. Erkol
Babcock Borsig Steinmüller GmbH
Belgrade, 15.08.2014
Page 2
Heat calculation:
Assumptions
Babcock Borsig Steinmüller GmbH
Not depending on load:
1.
Boiler A3 and A4 are identical in construction (without regard to RH1 surface).
2.
Behavior of boiler A4 corresponds to
boiler A3 “without low-NOx modification” and “with change of RH1 surface”.
3.
Amount of cold reheat taken from cyclic process (delivered by customer) and
rechecked by heat balance of Biflux.
4.
Baselinetest coal (25.06.2014) taken from customers analysis, elementary
analysis of coal defined by statistical method acc. to FDBR.
5.
Cleanliness of heating surfaces kept constant when changing from calibration
model to low-NOx model.
6.
Change of relative burner position considered in low-NOx-model
7.
6% Burnout in OF2 (experience value taken from other boiler)
Depending on load:
1.
O
2
-Values / Excess air linearly interpolated
2.
HP-Injection: 5%, RH-Injection:0%
3.
HP outlet pressure kept constant at about ~180 bar a
Page 4
Heat calculation:
Fuel characteristics
Babcock Borsig Steinmüller GmbH
Fuel
Unit
Baselinetest:
Fuel sample
taken 25.06.
Design coal
Best coal
Worst coal
LHV
kJ/kg
8198
6700
8800
6280
Water
Ma-%
47,30
52,00
48,00
52,50
Ash
Ma-%
16,10
18,00
14,50
17,50
C
Ma-%
24,26
19,21
25,86
19,20
H
Ma-%
2,11
1,78
2,10
1,80
N
Ma-%
0,40
0,38
0,43
0,40
O
Ma-%
9,59
8,11
8,61
8,10
S
Ma-%
0,24
0,52
0,50
0,50
Page 5
Heat calculation:
Guaranteed values
Babcock Borsig Steinmüller GmbH
Fresh steam flow through the boiler
960 t/h
920 t/h
650 t/h
Pressure before the STOP valve at the HP turbine
-
177,5 bar
177,5 bar
Superheat steam temp. at the boiler outlet (SH6)
-
543 °C
543 °C
Reheat steam temp. at the boiler outlet (RH2)
-
543 °C
543 °C
Мinimum mill capacity
-
88 t/h
/
Boiler efficiency
-
≥ 88,11%
≥ 87,7%
Furnace outlet temperature (маx.)
-
1050 °C
1050 °C
NOx emission limit value (ELV)
-
*<200
mg/Nm
3
*<200
mg/Nm
3
СО NOx emission limit value (ELV)
-
*250
mg/Nm
3
*250 mg/Nm
3
Page 7
Heat calculation:
Calibration of model 2
Babcock Borsig Steinmüller GmbH
Benennung
Designation
-
Measurement:
25.06.2014
Calibration of model
Brennstoff
Fuel
-
-
Analysis taken
25.06.2014
Kessellast
(bezogen auf 920 t/h)
Boiler load (related to 920 t/h)
%
100%
100%
SpW-Temp. Kesseleintritt
Boiler feedwater temperature
°C
248
248
SpW-Temp. nach Eco1
FW temperature ECO1
°C
286
286
SpW-Temp. nach Eco2
FW temperature ECO2
°C
322
322
HD-Temp. Nach Spirale
Temperature evaporator outlet
°C
372
374
HD-Temp. nach HD1 / Wand
Temperature SH1 outlet
°C
-
373
HD-Temp. nach HD2 / Tragrohr
Temperature SH2 outlet
°C
-
375
HD-Temp. nach Einspritzung1
Temperature SH3 inlet (after injection1)
°C
376
374
HD-Temp. nach HD3
Temperature SH3 outlet
°C
409
409
HD-Temp. nach Biflux
Temperature Biflux outlet
°C
394
390
HD-Temp. nach HD4
Temperature SH4 outlet
°C
451
451
HD-Temp. nach Einspritzung2
Temperature SH5 inlet (after injection2)
°C
441
440
HD-Temp. nach HD5
Temperature SH5 outlet
°C
486
486
HD-Temp. nach Einspritzung3
Temperature SH6 inlet (after injection3)
°C
465
464
HD-Temp. nach HD6
Temperature SH6 outlet
°C
539
540
ZD-Temp. Eintritt
Temperature cold reheat
°C
326
326
ZD-Temp. nach Biflux
Temperature RH Biflux outlet
°C
368
368
ZD-Temp. nach ZD1
Temperature RH1 outlet
°C
442
442
ZD-Temp. nach Einspritzung
Temperature RH2 inlet (after injection)
°C
442
442
ZD-Temp. nach ZD2
Temperature RH2 outlet
°C
527
527
Einspritzmenge HD
Mass flow injection cooler
t/h
47
47
Einspritzmenge ZD
Mass flow RH injection cooler
t/h
0
0
