| Fuel and Combustion |
| S. |
Description |
Symbol |
Formula |
Example |
| No. |
|
|
|
|
|
|
|
|
| 1 |
Gross calorific value |
GCV |
|
|
80.8 * C + 22.45 * S + 339.53 * H – 35.89 * O |
|
C |
70.86 |
|
|
kcal/kg-fuel |
|
|
|
|
S |
0.58 |
|
|
|
|
C |
Carbon content in fuel, wt% |
|
H |
3.87 |
|
|
|
|
S |
Sulphur content in fuel, wt% |
|
O |
6.08 |
|
|
|
|
H |
Hydrogen content in fuel, wt% |
|
GCV |
6834 |
|
|
|
|
N |
Nitrogen content in fuel, wt% |
|
Target |
– |
| 2 |
Net calorific value |
NCV |
|
|
GCV – 52.53 * H – 6 * m |
|
GCV |
6007 |
|
|
kcal/kg-fuel |
|
|
|
|
H |
3.2 |
|
|
|
|
GCV |
Gross calorific value of fuel, kcal/kg-fuel |
|
m |
1.3 |
|
|
|
|
H |
Hydrogen content in fuel, wt% |
|
NCV |
5831 |
|
|
|
|
m |
Moisture content in fuel, wt% |
|
Target |
– |
| 3 |
Useful heat value |
UHV |
|
|
8900 – 138 * ( Ash + m ) |
|
Ash |
14.99 |
|
|
kcal/kg-fuel |
|
Ash |
Ash content in fuel, wt% |
|
m |
1.93 |
|
|
|
|
m |
Moisture content in fuel, wt% |
|
UHV |
6565 |
|
|
|
|
|
|
|
Target |
– |
| 4 |
Standard coal factor |
SCF |
|
|
( 1 – m / 100 ) * NCV / 7000 |
|
m |
1.93 |
|
|
– |
|
m |
Moisture content in fuel, wt% |
|
NCV |
6500 |
|
|
|
|
NCV |
Net calorific value of fuel, kcal/kg-fuel |
|
SCF |
0.911 |
|
|
|
|
|
|
|
Target |
– |
| 5 |
Stoichiometric Combustion |
SCA |
Formula-1 |
|
NCV |
6500 |
|
Air |
kg/s |
|
|
NCV * F |
|
F |
11000 |
|
or |
|
|
|
709 * 3600 |
|
SCA |
28.01 |
|
Minimum Combustion |
|
|
NCV |
Net calorific value of fuel, kcal/kg-fuel |
|
Target |
– |
|
Air |
|
|
F |
Fuel rate in kiln, kg/hr |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Formula-2 |
|
C |
70.78 |
|
|
|
|
|
[ 0.11594 * C + 0.34783 * ( H – O / 8 ) + 0.04348 * S ] * F |
|
H |
3.46 |
|
|
|
|
|
3600 |
|
O |
5.12 |
|
|
|
|
C |
Weight% of Carbon in fuel |
|
S |
0.71 |
|
|
|
|
H |
Weight% of Hydrogen in fuel |
|
F |
11000 |
|
|
|
|
O |
Weight% of Oxygen in fuel |
|
SCA |
28.17 |
|
|
|
|
S |
Weight% of Sulphur in fuel |
|
Target |
– |
|
|
|
|
F |
Fuel rate in kiln, kg/hr |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Formula-3 |
|
m |
1.9 |
|
|
|
|
|
10.478 * ( 100 – m ) * GCV * F |
|
GCV |
6700 |
|
|
|
|
|
100 * 7000 * 3600 |
|
F |
10500 |
|
|
|
|
m |
Weight% of Moisture in fuel |
|
SCA |
28.70 |
|
|
|
|
GCV |
Gross calorific value of fuel, kcal/kg-fuel |
|
Target |
– |
|
|
|
|
F |
Fuel rate in kiln, kg/hr |
|
|
|
| 6 |
Specific Stoichiometric |
SSCA |
Formula-1 |
|
NCV |
6500 |
|
Combustion Air |
kg/kg-fuel |
|
|
NCV |
|
SSCA |
9.17 |
|
or |
|
|
|
709 |
|
Target |
– |
|
Specific Minimum |
|
|
NCV |
Net calorific value of fuel, kcal/kg-fuel |
|
|
|
|
Combustion Air |
|
|
|
|
|
|
|
|
|
|
Formula-2 |
|
C |
70.78 |
|
|
|
|
|
0.11594 * C + 0.34783 * ( H – O / 8 ) + 0.04348 * S |
|
H |
3.46 |
|
|
|
|
C |
Weight% of Carbon in fuel |
|
O |
5.12 |
|
|
|
|
H |
Weight% of Hydrogen in fuel |
|
S |
0.71 |
|
|
|
|
O |
Weight% of Oxygen in fuel |
|
SSCA |
9.22 |
|
|
|
|
S |
Weight% of Sulphur in fuel |
|
Target |
– |
|
|
|
|
|
|
|
|
|
|
|
|
Formula-3 |
|
m |
1.9 |
|
|
|
|
|
10.478 * ( 100 – m ) * GCV |
|
GCV |
6700 |
|
|
|
|
|
100 * 7000 |
|
SSCA |
9.84 |
|
|
|
|
m |
Weight% of Moisture in fuel |
|
Target |
– |
|
|
|
|
GCV |
Gross calorific value of fuel, kcal/kg-fuel |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Formula-4 |
|
SCF |
0.925 |
|
|
|
|
|
10.478 * SCF |
|
SSCA |
9.69 |
|
|
|
|
SCF |
Standard coal factor, – |
|
Target |
– |
| 7 |
Theoretical Flame Temperature |
TFT |
|
|
3.107 * NCV |
|
NCV |
6500 |
|
|
deg.C |
|
|
SCA |
|
SSCA |
9.28 |
|
|
|
|
NCV |
Net calorific value of fuel, kcal/kg-fuel |
|
TFT |
2176 |
|
|
|
|
SSCA |
Specific stoichiometric combustion air, kg/kg-fuel |
|
Target |
– |
| 8 |
True CO2 in kiln exit gas |
TCO2 |
|
|
100 * ( CO2 + CO ) |
|
CO2 |
36.5 |
|
|
vol% |
|
|
100 + ( 1.89 * CO ) – ( 4.78 * O2 ) |
|
CO |
0.002 |
|
|
|
|
CO2 |
Kiln exit gas CO2, vol% |
|
O2 |
4.2 |
|
|
|
|
CO2 |
Kiln exit gas CO, vol% |
|
TCO2 |
45.7 |
|
|
|
|
O2 |
Kiln exit gas O2, vol% |
|
Target |
– |
| 9 |
Burner Tip Velocity |
BTV |
|
|
4 * Ps 0.5 |
|
Ps |
1800 |
|
|
m/s |
|
Ps |
Static pressure in duct, mmWG |
|
BTV |
170 |
|
|
|
|
|
|
|
Target |
– |
| 10 |
%Primary Air |
%PA |
|
|
PA * 100 |
|
PA |
2.05 |
|
|
% |
|
|
SCA |
|
SCA |
27.24 |
|
|
|
|
PA |
Primary air, kg/s |
|
%PA |
7.53 |
|
|
|
|
SCA |
Stoichiometric combustion air, kg/s |
|
Target |
– |
| 11 |
Flame Momentum |
FM |
|
|
%PA * BTV |
|
%PA |
11.2 |
|
or |
%.m/s |
|
%PA |
%Primary air, % |
|
BTV |
150 |
|
Relative Impulse |
|
|
BTV |
Burner tip velocity, m/s |
|
FM |
1680 |
|
(Source : F.L. Smidth) |
|
|
|
|
|
Target |
1000-2000
|
