IR imaging for stability analysis of industrial burner

In this paper, a new diagnostic tool is presented to spatially characterize combustion fluctuations. This tool based on FAst IR Imaging of flames was applied on two different types of gas turbine burners and on two traditional industrial burners varying the fluid dynamic conditions. Both GT burners evidenced oscillation at low frequencies around 25 Hz, 100 Hz and at higher frequencies up to several kHz. Typical frequencies bias toward combustion were identified. The investigations also evidenced that the typical frequencies shift up while increasing AFR. The FAIRI technique allowed to identify higher frequencies (up to several kHz) in the 2D dimensions. The extension of the technique to a practical Lean Premixed gas turbine gave good results either for frequency analysis of fluctuations, either for the location of the phenomenon of humming. Regarding industrial boiler combustion the FAIRI technique allowed to identify on both gas and coal combustion the proper location of the flame root and its better performance in stability. Further information have to be collected on air/fuel mixing and local flame temperature. The technique came out as an interesting tool for further development and investigations.