Basic calculations
dreizler A 3001 E - 18.12.2015 | A 2048 - 1.12 | EN - 09.11.2012
163
50.7 Mathematical determination of air requirement / waste gas volume in gas power
burners
From these, the air requirements and waste gas volume can be determined:
L
W
= L
min
*
* H
iB
* D = (m
3
/kW * kW/m
3
* m
3
/h) = m
3
/h
V
W
= V
min
*
* H
iB
* D = (m
3
/h * kW/m
3
* m
3
/h) = m
3
/h
Calculation example for natural gas:
H
iB
= 9kW, D = 60m
3
/h, CO
2max
= 11.8%, CO
2 measured
= 10%
L
W
= 11.8/10 * 9 * 60 = 810m
3
/h Air requirement, V
W
= 1.43 * 1.18 * 9 * 60 = 915m
3
/h Waste gas volume
Terms:
L
min
= Air requirement in m
3
/h with
= 1 or CO
2max
H
i
= Lower heating value for combustion gas in kcal/m
n
3
and kW/m
n
3
H
iB
= Net heating value in kcal/m
3
and kW/m
3
with reduction factor f
V
fmin
= Waste gas volume, moist, in m
3
/h with
= 1 or CO
2max
CO
2max
= CO
2
value with air surplus = 0 (
= 1)
= CO
2max
/ CO
2 measured
= Air surplus value
L
W
= Actual air flow requirement with air surplus in m
3
/h
V
W
= Actual waste air volume with air surplus in m
3
/h
D
= Gas flow rate in m
3
/h
Gas type
Air requirement L
min
in terms of H
i
Waste air volume V
fmin
in terms of H
i
m
3
/1000 kcal
m
3
/kW
m
3
/1000 kcal
m
3
/kW
Natural gas
1,1
1,28
1,23
1,43
Propane
1,07
1,24
1,15
1,22