Bentone BFG 1 H1, Installation And Maintenance Instruction

Page: 20 / 60

20 Bentone
T = Temperature of gas at the gas meter [°C]
B = Barometer reading [mbar]
P = Pressure of gas at the gas meter [mbar]
f = Factor calculated for multiplication with flow in Nm
3
/h to
arrive at actual flow in Nm 3 /h.
V = Actual flow [m
3
/h]
f =
273
·
B+P
273+T 1013.25
Example A
V
0A
= Q . 3600
=
50 · 3600
≈ 5.9 Nm 3 /h
H
u
·
η
34020 · 0.90
Example B
V
0B
= Q
≈
50
≈ 5.8 Nm
3
/h
H
u
·
η
9.5 · 0.90
Example C
V
0C
=
Q
=
50
≈ 5.9 Nm
3
/h
H
u
· 0,00116 ·
η
8126 · 0.00116 · 0.90
If the barometer reading (altitude), pressure and temperature of the gas
deviate significantly from normal values, this must be taken into account as
follows:
Calculation example:
Q = 50 kW
H
U
= Example A: 34020 MJ/Nm
3
Example B: 9.5 kWh/Nm
3
Example C: 8126 kcal/Nm 3
η =
90%
V
0
= Desired quantity of gas [Nm 3 /h]
Q = Boiler output [kW]
H
U
= Gas heat value [kWh/Nm 3 ] or [MJ/Nm 3 ] or [kcal/
Nm3]
η
=
Boiler efficiency [%]
4.3 Example of how to calculate the
gas quantity (natural gas G20):