Study of the influence of water vapour and carbon dioxide dilution on flame structure of swirled methane/oxygen-enriched air flames
Résumé
In this work, the effect of dilution with water vapour H2O and carbon dioxide CO2 on the structure and stability of a methane/enriched air premix flame, confined and swirled at atmospheric pressure was studied. Measurements were carried out at constant adiabatic temperature (1773, 1873, 1973 and 2073 K), from air to oxycombustion (enrichment OI ranging from 21 to 100%), for two inlet temperatures (T0 = 373 K and 473 K), at constant equivalence ratio maintained at 0.91 and inlet aerodynamic conditions maintained constant: average inlet velocity at 30 m·s−1 and geometric swirl number at Sn = 0.90. The experimental setup is a burner used consisting of a swirled stainless steel single injector, mounted in a combustion chamber operating at atmospheric pressure. The flames were visualized by CH* chemiluminescence. From instantaneous images, the flame contour, detected with a Matlab® processing, was determined. From this flame contour, flame height (Hf) and lift-off height (Hlo) were extracted by measuring respectively the maximum height of the flame top and the minimum height of the bottom flame. The evolution of the mean macrostructure of the flame was then studied. The results of the steam dilution were detailed and compared with those obtained with carbon dioxide. Links between the laminar flame speed and the flame structure and stability were clearly established.
Origine | Fichiers produits par l'(les) auteur(s) |
---|