Viessmann Vitobloc 200 EM-50/81 Operating Instructions Manual page 11

Preparations
Gas quality
WARNING
Natural gas and the combustion air
must not contain any phosphorus, ar-
senic, heavy metals or dust, and halo-
gens only in quantities up to the limits
stipulated.
The natural gas must be technically
free from mist, dust and liquids and
must not contain any substantial quan-
tities of corrosive components. The
methane number and the calorific val-
ue of the biogas must remain constant.
PLEASE NOTE
The methane number (not to be con-
fused with the methane content) is a
measurement for the knock susceptibil-
ity of the type of gas concerned. A too
low methane number will result in
knocking combustion and thus damage
the engine. We would like to point out
that the methane number will consider-
ably drop, especially if a liquid gas mix-
ture (propane/air and butane/air) is
added. We therefore recommend verifi-
cation with the local gas supplier that
this is not done so.
INSTRUCTION
As for the rest, please observe the
instructions in the chapter „Gas
connection" of the assembly
instructions as well as the directives
contained in worksheet G 260 or G 261,
respectively, issued by the Deutsche
Vereinigung des Gas- und
Wasserfaches e.V. (DVGW).
VITOBLOC 200 Operating instructions for the natural gas-fuelled CHP module
Fuel values to be observed
parameter
calorific value H
i,N
1)
methane number MZ
minimum flow pressure in the
controlled system for the gas
maximum flow pressure in the
controlled system for the gas
maximum gas pressure varia-
tions (short variations due to
control activities)
maximum changing speed of
3)
the gas pressure
relative humidity 
Temperature of gas mixture
downstream of gas/air mixer T
chlorine content Cl
fluorine content F
total chlorine/fluorine Σ(CI,F)
dust content < 5 m
oil vapour
silicon content Si
sulphur content S
hydrogen sulfide H S
2
ammonia content NH
3
Table 3 Fuel values during the operation of a CHP module
1) Operations with a lower methane number might be possible
after the CHP module manufacturer has examined the
circumstances.
2) For the Vitobloc 200 EM-401/549 and EM-530/660
modules, the minimum flow pressure is 30 mbar.
Flow pressure in the module's control system for the gas.
3)
value
3
> 5 kWh/Nm
> 80
2)
20 mbar
50 mbar
± 3 mbar
3 mbar/min
< 60 %
10 °C < T < 30 °C
G
G
3
< 80 mg / Nm
CH4
3
< 40 mg / Nm
CH4
3
< 100 mg / Nm
CH4
3
< 10 mg / Nm
CH4
3
< 400 mg / Nm
CH4
3
< 2 mg / Nm
CH4
3
< 200 mg / Nm
< 150 ppm
< 228 mg / Nm³
< 40 ppm
< 30 mg / Nm³
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