The influence of oxygen-enhanced combustion methods on NOx emissions, in-flame temperatures and heat flux distribution

abstrakt

angličtina

The present work is aimed at experimental investigation and comparison of characteristics of three various oxygen-enhanced combustion (OEC) methods, namely premix enrichment (PE), air-oxy/fuel combustion (AO) and oxygen lancing (OL). The combustion tests are carried out with an experimental two-staged gas burner at a large-scale burners testing facility. As for the PE method, the high-purity oxygen is injected into the incoming combustion air stream through the diffuser inserted in the air supply duct before entering the burner, while in the AO and OL methods the oxygen is injected directly into the flame through oxygen nozzle heads inserted in the center burner pipe and near secondary gas nozzles, respectively. The total oxygen concentration is varied from 21 % to 38 % which corresponds to the flow rate of oxygen in the range from 0 Nm3/h to 100 Nm3/h (N denotes the normal conditions, i.e. 0 Celsius degrees, 101.325 kPa). All tests are carried out at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged fuel combustion. The target oxygen concentration in dry flue gas is kept around 3 % by volume. The characteristics of OEC methods such as the concentration of nitrogen oxides in flue gas, flue gas temperature, heat flux to the combustion chamber wall, in-flame temperatures distribution in the horizontal symmetry plane of the combustion chamber, and the stability of flame are investigated.

Oxygen-enhanced combustion, staged combustion, nitrogen oxides, heat flux, in-flame temperatures

BĚLOHRADSKÝ, P.; SKRYJA, P.; HUDÁK, I.

3. 8. 2014

San Francisco

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