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Show Diagnostics The BERL will take advantage of recent advances in laser diagnostics and, therefore, it is designed for maximum flexibility in optical access, providing standardized panels with window configurations suited to the diagnostic need. Initial panels will include a range of optical access from small projection pons to full windows. Five levels of diagnostics are defined below which are intended for use in the BERL. These cover the range from conventional diagnostics at Level 1 to exotic planar spectroscopic methcxis at Level 5. Levell This includes conventional diagnostics such as gas analyzers for measuring the concentration of various emission products and thermocouples for wall temperatures and average combustion temperatures. The remaining levels of diagnostics are optical and non-intrusive. A conventional flue gas monitoring system will be used to routinely monitor the composition of the furnace exhaust. This infonnation will be used in many aspects of the system, including combustion efficiency, NOx emissions, and verification of the combustion stoichiometry. A sampling probe will be placed in the furnace exhaust upstream of the watercooled damper. A heated sample line will convey the gas to a sample conditioning The continuous emissions monitoring system will consist of 02, C02, CO, N20, HC and NO/NOx analyzers. The analyzers will have both on-line digital readouts and serial. pons connected to the data acquisition system. Level 2 This includes imaging techniques such as self-light and schlieren photography and cinematography to provide a qualitative measure of the flame structure and behavior. Self-light photography highlights regions of high flame luminosity (usually resulting from soot radiation) and schlieren photography highlights regions of high thennal gradient. Level 3 This includes standard optical point 8 measurements such as Laser Anemometry (LA) for gas velocity measurement and Rayleigh scattering for gas density measurement. Level 3 also includes planar imaging of light scattered from tracer panicles in the flow. The tracer particles identify the reaction interface either by forming at the reaction interface (e.g., using titanium tetrachloride), or disappearing at the reaction interface (e.g., using silicon oil droplets). If the particles are inen and are added to either the fuel or oxidizer flow stream, they can be employed to measure mixing. Level 4 Diagnostics at this level are point measurements involving spectroscopy, including spontaneous Raman scattering, laser induced fluorescence (LIF), multi-photon ionization (MPI), degenerate four-wave mixing (DFWM), and coherent anti-Stokes Raman scattering (CARS). These techniques can provide non-intrusive, spatially and temporally resol ved gas temperatures and species concentration infonnation. LevelS These diagnostics are planar spectroscopic measurements, and include planar laser induced fluorescence and planar Raman scattering. Program Status Construction and installation of the BERL is now complete and the verification phase of the program is underway. The furnace has been fired to 1 MMB tu/h using a generic IFRFdesign movable-block variable-swirl burner. Diagnostics evaluation activities have included the following: • • • • Verification of the data acquisition system and interface with process monitors and exhaust gas analyzers Cold flow and burner testing of twocomponent laser anemometry Self-light and Schlieren imaging of the flame zone Time-averaged and instantaneous planar mie scattering in the flame zone |
