Specification
6 720 645 817
(2010/09)
30
2.5
Boiler efficiency
The boiler efficiency
η
K
identifies the ratio of heat output
to heat input subject to the return temperature.
Fig. 16 Boiler efficiency subject to boiler return
temperature (average for this series of boilers)
η
K
Boiler efficiency
ϑ
Return temperature
1
Full load
2
Partial load
2.6
Standby loss
The standby loss q
B
is part of the rated heat input that
is required to achieve the specified boiler water
temperature. The cause of this loss is the cooling down
of the boiler through radiation and convection during the
standby time (burner idle time). Radiation and
convection result in part of the output being transferred
continuously from the boiler surface to the ambient air.
In addition to this surface loss, the boiler can also cool
down to a lesser degree through the chimney draught.
Fig. 17 Standby loss, relative to the rated heat input of
the boiler, subject to the average boiler water
temperature (average for this series of boilers)
q
B
Standby loss
ϑ
K
Average boiler water temperature
94
96
98
100
102
104
106
108
30
40
50
60
70
2
1
η
K
[%]
ϑ
[°C]
6 720 642 877-05.1il
0
0,1
0,2
30
40
50
60
70
q
B
[%]
ϑ
K
[°C]
6 720 642 877-06.1il
Содержание SUPRAPUR KBR 120-3 A
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