On the Formation of Nitrogen Oxides During the Combustion of ...

5.3 Influence of Ambient Preheating
the initial glowing points of each pair of SiC fibers shift outwards with an increase
of Ψ. This indicates a broader width of the spreading flame front due
to a further developed fuel vapor layer around the droplet array [208].
5.3 Influence of Ambient Preheating
In order to complement the results of Chapter 5.2, this section isolates the
impact of ambient preheating on droplet vaporization and combustion, and
furthermore on NO x formation. Particularly Figures 5.15 and 5.16 provide a
more detailed insight into the counteracting parameters of pre-vaporization
and preheating within the field of NO x formation. The curves of temperature
with T ∞ = 500K are identical to the ones in Figure 5.3 (i.e. the case “with heat
extraction”). The temperature levels of 600 and 700 K are plotted in addition
here. The results were obtained by numerical simulation.
6.0
g kg −1
Emission index of NOx EINOx
4.0
2.0
T ∞ = 500 K
T ∞ = 600 K
T ∞ = 700 K
0.0
0.0 0.2 0.4 0.6 0.8 1.0
Pre-vaporization rate Ψ
Figure 5.15: Impact of Ambient Preheating on NO x Abatement Potential due to Pre-
Vaporization by Referring to the Initial Droplet Mass. The positions of heat
introduction and extraction are set to the constant values of r m,in = 0.8×10 −3 m
and r m,ex = 1.4×10 −3 m (cf. Fig. 5.3).
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