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

Chapter 3
In-cylinder volume during compression is reported in the figure 3.10. The volume is
determined thanks to a laser piston positioning sensor being the compression time
estimated on 44 ms. The piston velocity is comprised between 0 and 15 m/s, and it is
around 9.5 m/s on average. In order to avoid measurements uncertainties, another
laser piston position sensor was placed at TDC and the pressure and piston position
signals synchronized.
The same procedure was followed when working with compression-expansion strokes
without combustion (motored) being the pressure trace repetition verified in the figure
3.11.
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Pressure (bar)
25
20
15
10
5
0
Shot 1
Shot 2
Shot 3
90 100 110 120 130 140 150 160 170 180
Time (ms)
Figure 3.11 - Typical pressure trace for compression expansion of stoichiometric downdraft
syngas-air mixture in a RCM. Initial Conditions: P i = 1.0 bar; T i = 293 K.
A very good repetition of signals was found during compression expansion experiments
being the maximum difference between peak pressures around 0.4 bar (27 bar on
average) from one experiment to another. Notice the higher pressure peak (>2.0 bar,
8%) of the compression expansion strokes compared with single compression stroke of
the figure 3.9. To explain this difference the average piston displacement without
combustion during the compression stroke for both working modes are shown in the
figure 3.12.
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