5
! Important warning:
The stated thermal technical parameters vary in dependence on the sort, quality and moisture of the used
fuel. Therefore some corrections might be necessary when setting the stoking cycle (time for fuel feed
versus time for fuel afterburning). For example if unburned fuel slivers appear on the grate and in the ash-
pan it stands to reason that stoking is faster than burning and the stoking cycle must be reduced – see
parameters description (chap. 6.2.3).
Parameters of the prescribed fuel – fuel used for tests in SZÚ:
•
water content
max. 12 % (pellets) max. 20 % (lignite)
•
volatile combustible content
28 – 40 %
•
ash deformation by melting temperature > 1150 °C
•
low sintering capacity
•
small moisture expansion
Tab.
№
. 4
Specified fuel - pellets
Fuel
Pellets
Fuel class
C1
Granularity
[mm]
6 - 8
Fuel value [MJ.kg
-1
]
15 – 19
Pellets must conform at least to one of following directives or standards:
Directive no. 14-2000 MŽP
Č
R
DIN 517 31
ÖNORM M 7135
Specified granularity of pellets
6 to 8 mm
Water content in fuel
max. 12 %
Ash content
max. 1,5 %
Tab.
№
. 5
Specified fuel - lignite
Fuel
Screened lignite – nub 2
Fuel class
b
Granularity
[mm]
10 - 25
Fuel value [MJ.kg
-1
]
16.5 – 19.5
Ash content [%]
9,8 (in anhydrous condition)
water content [%]
max. 20
sulphur content [%]
0.77
Specific sulphur content [g/MJ]
0.44
Tar content in dry matter [%]
15.1
Tar content in combustible matter [%]
15.71
ATTENTION! Low fuel quality can significantly affect the boiler output and emission parameters.
The boiler is operated at a negative pressure at the flue gas outlet.
The boiler operates at conditions without condensation.
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0
0,5
1
1,5
2
2,5
Q [dm
3.
s
-1
]
p
z
[P
a
]
Fig.
№
. 1
Boiler hydraulic loss
