The influence of the combustion operation parameters in the process burners on the formation of NOX and heat fluxes

article in a collection out of WoS and Scopus

English

The paper deals with the experimental investigation of combustion operating parameters and burner’s constructional parameters on the formation of nitrogen oxides and heat fluxes. The tests were carried out at BUT burners testing facility, which enables testing burners up to the capacity of 1.8 MW. Combustion tests were performed using a fuel stage burner and a fuel stage burner with integrated internal flue gas recirculation. Both prototypes have a maximum power of 1.5 MW and similar geometry. During the testing, several configurations were examined including various geometries of nozzles and numerous geometries of socalled swirl generator. The observed parameters included NOx and CO emissions, flame stability, air temperature, turndown ratio, heat transfer from hot flue gas to the combustion chamber’s shell and the distribution of in-flame temperatures measured in the horizontal symmetry plane of the chamber. The results showed that the area with the temperature peak for the fuel stage burner was not as large as for the burner with recirculation. Furthermore in close distance of a burner tile higher temperatures were observed while using the orifice with a larger diameter at burner with recirculation. The obtained shape of the heat flux curves was similar for all investigated settings. In general, the highest heat fluxes were reached in the distance 1.5 m from the burner, whereas the lowest heat fluxes were achieved in the distance 3.5 m from the burner for all three settings. In the section furthest from the burner, the heat fluxes were almost independent on combustion air temperature (ca. 25 kW∙m2 for all settings). With higher combustion air temperature, the heat flux is higher due to a higher amount of heat energy supplied to the combustion chamber.

combustion, preheated combustion air, flue gas analysis, NOx formation

SKRYJA, P.; ŠIMEČEK, R.; HUDÁK, I.; BOJANOVSKÝ, J.

14. 4. 2019

Instituto Superior Técnico, University of Lisboa, Portugal

Lisbon, Portugal

1732

1738

6