TOWARDS IMPROVEMENTS IN STABILITY, EFFICIENCY AND EMISSIONS REDUCTION OF COMBUSTION PROCESSES BY USING A STRONG CYCLONIC RECIRCULATION

A challenging strategy to stabilize the oxidation process in novel combustion technologies is the exhaust gas recirculation. In such systems the mass and sensible enthalpy ratio of recycled exhausted gas represents a key parameter to promote and stabilize the oxidation process. The chemical/thermodynamic features of the oxidation process were investigated by means of a numerical analysis. The process was schematized as a CSTR where part of the exhausted gas was recirculated back to the reactor. The stability of the process was investigated as a function of the pre-heating temperature and of the dilution level of propane/oxygen/nitrogen mixtures for a fixed recirculation ratio. On the other hand experimental tests were realized in a small size burner characterized by a strong internal recirculation ratio, induced by a cyclonic fluid-dynamic pattern obtained with the geometrical configuration of the reactor and of the feeding system. The experimental results suggest that the cyclonic configuration represents a challenging choice to stabilize the oxidation process in small-size applications, extending the burner operability conditions.