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Tab. no. 2a)Thermal technical parameters of the boiler during combustion of brown coal
Size 4 sect. 5 sect. 6 sect. 7 sect.
Nominal output kW 20 25 30 35
Regulated output kW 6 - 20 7,5 - 25 9 - 30 10,5 - 35
Fuel consumption at nominal output kg.h
4,5 5,6 6,65 7,65
Fuel consumption at minimum output kg.h
1,4 1,7 2,02 2,32
Fuel consumption in upkeep regime kg.h
0,1 0,1 0,1 0,1
Fuel value MJ.kg
19,17 19,17 19,17 19,17
Burning time at nominal output – small
reservoir h 36 h 15 min 29 h 10 min 24 h 30 min 21 h 15 min
Burning time at nominal output – large reservoir
h 71 h 30 min 57 h 20 min 48 h 15 min 42 h
Efficiency % up to 83,1 up to 85 up to 87 up to 89
Flue gas temperature °C 115 – 195 100 – 180 95 – 170 90 – 160
Flue gas mass flow at outlet kg.s
0,007 – 0,015
0,009 – 0,019
0,011 – 0,022
0,013 – 0,025
Tab. no. 2b)Thermal technical parameters of the boiler during combustion of black coal
Size 4 sect. 5 sect. 6 sect. 7 sect.
Nominal output kW 20 25 30 35
Regulated output kW 6 - 20 7,5 - 25 9 - 30 10,5 - 35
Fuel consumption at nominal output kg.h
3,4 4,21 5 5,8
Fuel consumption at minimum output kg.h
1,03 1,28 1,52 1,76
Fuel consumption in upkeep regime kg.h
0,13 0,13 0,13 0,13
Fuel value MJ.kg
25,1 25,1 25,1 25,1
Burning time at nominal output – small
reservoir h 45 h 10 min 36 h 30 min 30 h 35 min 26 h 25 min
Burning time at nominal output – large reservoir
h 88 h 40 min 71 h 35 min 60 h 15 min 52 h
Efficiency % up to 84,2 up to 85 up to 86 up to 87
Flue gas temperature °C 110 – 195 90 – 170 85 – 165 80 – 150
Flue gas mass flow at outlet kg.s
0,007 – 0,014
0,010 – 0,017
0,012 – 0,021
0,014 – 0,024
Tab. no. 2c)Thermal technical parameters of the boiler during combustion of wood pellets
Size 4 sect. 5 sect. 6 sect. 7 sect.
Nominal output kW 20 25 30 35
Regulated output kW 6 - 20 7,5 - 25 9 - 30 10,5 - 35
Fuel consumption at nominal output kg.h
4,85 6,06 7,26 8,47
Fuel consumption at minimum output kg.h
1,5 1,84 2,21 2,57
Fuel consumption in upkeep regime kg.h
0,35 0,35 0,35 0,35
Fuel value MJ.kg
17 17 17 17
Burning time at nominal output – small
reservoir h 27 h 10 min 21 h 45 min 18 h 10 min 15 h 30 min
Burning time at nominal output – large reservoir
h 53 h 20 min 42 h 40 min 35 h 35 min 30 h 30 min
Efficiency % up to 87,3 up to 87,4 up to 87,5 up to 87,5
Flue gas temperature °C 95 – 175 90 – 165 90 – 160 85 – 145
Flue gas mass flow at outlet kg.s
0,007 – 0,015
0,009 – 0,018
0,010 – 0,022
0,012 – 0,025
! Important notice:
The above mentioned values vary according to the type, quality and moisture of the fuel used.
Therefore there may be necessary corrections at setting of feeding time (proportion of fuel feeding
and fuel afterburning time). For example, if there occur the sliver parts of fuel on the fire grate and in
the ash pan, it is evident, that the speed of feeding is higher than the speed of afterburning, in this
case it is necessary to decrease the feeding cycle.
Specified fuel parameters – fuel which was tested by SZÚ:
•Water content max. 12 % (hard coal, wood pellets),
max. 20 % (lignite)
•Volatile combustible content 28 - 40 %
•Ash deformation temperature by melting > 1150 °C
•Low agglutinating power
•Low creeping
