Temperature measurement of gas turbine swirling flames using tomographic imaging techniques

This paper presents the 3-D (three-dimensional) temperature measurement of swirling flames of a well-characterized tangential swirl burner using a RGB (red, green and blue) CMOS (Complementary metal-oxide-semiconductor) camera associated with four flexible imaging fiber bundles for flame image acquisition. Optical tomographic algorithms were used to reconstruct the 3-D model of grey-level intensity of the flame and the two-color pyrometric technique was applied for computing the flame temperature based on the reconstructed 3-D model. Three R-type thermocouples were also employed to measure the flame temperature which was then used as a reference for validating the temperature derived from the flame images. Experimental results obtained show that the proposed technique is capable of determining flame temperature profiles, and consequently can be an effective means of characterizing the 3-D swirling flame behaviors, including stability limits such as flame blow-off/flashback, thus reducing the event probability by changing inlet conditions.