Etude de la combustion de gaz de synthèse issus d'un processus de ...

Experimental set ups and diagnostics
CHAPTER 3
EXPERIMENTAL SET UPS AND DIAGNOSTICS
In order to characterize the combustion of typical syngas-air mixtures, various
experimental devices are required. Two static combustion chambers were used for
burning velocity measurements by constant pressure and constant volume methods. A
rapid compression machine (RCM) was also used for simulate the
compression/expansion events of an engine. In the following subsections all this
devices are described as well as the experimental procedures.
3.1. Experimental set ups
3.1.1. Syngas mixtures
tel-00623090, version 1 - 13 Sep 2011
The syngas-air mixtures were prepared using pressurized containers, vacuum pump
and pressure transducer by the partial pressure method. The purity of all used gases is
at least 99.9%.
The simplified chemical reaction that expresses the stoichiometric combustion of
syngas for syngas typical compositions is:
⎛ a b ⎞
aH2 + bCO + cCH4 + dCO2 + eN2 + ⎜ + + 2 c ⎟( O2 + 3.76 N2
) →
⎝ 2 2 ⎠
⎡ ⎛ a b ⎞⎤
( b + c + d ) CO + ( a + 2c ) H O + ⎢e + 3.76⎜
+ + 2c ⎟ N
2 2
⎥
⎣ ⎝ ⎠⎦
2 2 2
(3.1)
The partial pressure of each gas of the syngas-air mixture is given by:
n
a
P P P
H2
H
=
2 m
=
m
nm
a + b + c + d + e + 4.76( f φ)
nCO
b
P = P =
P
n a + b + c + d + e + 4.76( f φ )
CO m m
m
n
c
P P P
CH4
CH
=
4 m
=
m
nm
a + b + c + d + e + 4.76( f φ)
n
d
P P P
CO2
CO
=
2 m
=
m
nm
a + b + c + d + e + 4.76 ( f φ)
n
e
P P P
N2
N
=
2 m
=
m
nm
a + b + c + d + e + 4.76( f φ)
(3.2)
(3.3)
(3.4)
(3.5)
(3.6)
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