Enertech Bentone BG 450, Installation And Maintenance Instruction

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172 205 16 98-01
DETERMINATION OF GAS VOLUME FOR THE INSTALLATION
V = Gas volume Nm 3 /h
Q = Boiler output 120 kW
H
u
= Calorific value of the gas A. 37 144 kJ/Nm
3
, B. 10.3 kWh/Nm
3
η
= Expected efficiency 90%
Ex. A
Ex. B
If the barometer height, pressure and temperature of the gas deviate very much from the normal values this must be taken
into account as follows:
f =
t = Temperature of the gas at the gas meter (15°C)
B = Barometer height (945 mbar)
P
u
= Pressure of the gas at the gas meter (15,0 mbar)
f =
f
≈
1.11
The gas volume read on the gas meter actually reads 1,11 . 12,9 = 14,4 m 3 /h.
Net calorific value
Gas quality kWh/Nm 3 kJ/Nm 3 kcal/Nm 3
Natural gas 10.3 37 144 8 865
Propane 26.0 93 647 22 350
Butane 34.3 123 571 29 492
Town gas 4.9 17 653 4 213
Bio gas 7.0 25 219 6 019
Specifications on natural gas, town
gas and bio gas vary. For more exact
information please contact the gas
distributor.
EXAMPLE HOW TO CALCULATE THE GAS VOLUME (NATURAL GAS)
273+15
273
. 1013,25
945+15
V
=
120
10,3 · 0,90
≈
12,9 Nm 3 /h
B+P
u
273+t
273
. 1013,25
120 . 3 600
37 144 . 0,90
V =
Q .3 600
H
u
·
η
= ≈
12,9 Nm 3 /h