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Show Rather than use the chemiluminescence emission as a diagnostic measurement, the intent of this research is to develop a semi-quantitative indicator of stability or pollutant emissions for use in active control of the combustion process. This paper describes the measurements and initial analyses conducted toward that end. APPROACH In order to determine the ability of flame chemiluminescence or pressure fluctuations to predict stability limits and pollutant emissions, full emissions and operability mappings were conducted for a well characterized burner system. The model burner and test facility have been described previously (Miyasato and Samuelsen, 1994). Emissions data were collected over the stability range for two different fuel injection geometries: co-swirling fuel and counter-swirling fuel. A schematic of the burner, emissions sampling train, and placement of the fiber optic collection light guide are shown in Figure 1. Filters and PMT j_5£3_f|tBia3i \ Figure 1: Experimental Setup The fiber was placed at the back-end of the burner, viewing up through the "windbox" to the burner throat. This location was selected with the intent of capturing the reaction initiation region and simulate the most likely location of a typical, industrial flame scanner. The collimated measurement represents an integrated, line-of-sight measurement of the radical emissions. The light is directed along the fiber to a collimating lens, two beam splitters, and then through the appropriate filters to photomultiplier tubes (PMTs). Line filters were used for O H and C H , while a broadband filter was used for C 0 2 ; the wavelengths employed were outlined in Table 1. C 2 was not collected due to previous experiments which demonstrated weak signal strengths. A schematic of the optical layout is provided in Figure 2. Photographs of the fiber placement and field-of-view are provided in Figure 3; the red spot shown at the throat is from a H e N e laser directed through the throat fiber to display the measurement location. . |
