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Title	The Application of Combustion Diagnostic Techniques in Boiler Tuning for NOx Control
Creator	Thompson, R.; Aufdencamp, T.; Davey, T.
Publisher	Digitized by J. Willard Marriott Library, University of Utah
Date	1994
Spatial Coverage	presented at Maui, Hawaii
Abstract	Field test programs to characterize the NOx emissions from coal-fired utility boilers have become an increasingly important effort as utilities comply with the Clean Air Act Amendment requirements. Since NOx emissions are so strongly dependent on furnace combustion conditions, diagnostic techniques and test protocols have been developed to aid in evaluating the boiler combustion process. The evaluation of combustion uniformity in the burner zone is one of the most critical, but difficult and time consuming, tasks in a NOx emissions test program. The use of diagnostic techniques has become increasingly important in all phases of NOx emissions compliance testing including: • obtaining representative baseline NOx emissions (e.g., for Phase II units); • making a preliminary assessment of the NOx reduction potential of combustion modifications (e.g., simulated OFA); • identifying equipment related operating constraints that impact combustion uniformity and NOx emissions (applicable to post-retrofit tuning and warranty tests). The paper presents a very practical, problem-solving approach to identifying regions of non-uniform combustion and NOx emissions. A checklist of common operational problems and associated diagnostic test procedures is provided based on experience from a variety of boiler field test programs. The paper emphasizes the benefits of using advanced diagnostic instrumentation such as a multi-point O2 analyzer, a HOT FOIL LOI analyzer, and an acoustic pyrometry gas temperature measurement system to identify problems and tune combustion conditions. The discussion of combustion diagnostic techniques is illustrated with field test data from several wall-fired and tangentially-fired units where "as-found" non-uniform combustion conditions in the furnace were reflected in significant NOx and/or LOI gradients. The causes of these gradients are discussed along with the maintenance and/or changes in firing practice changes that were implemented to achieve uniform combustion and NOx emissions.
Type	Text
Format	application/pdf
Language	eng
Rights	This material may be protected by copyright. Permission required for use in any form. For further information please contact the American Flame Research Committee.
Conversion Specifications	Original scanned with Canon EOS-1Ds Mark II, 16.7 megapixel digital camera and saved as 400 ppi uncompressed TIFF, 16 bit depth.
Scanning Technician	Cliodhna Davis
ARK	ark:/87278/s6222xb7
Setname	uu_afrc
ID	10114
Reference URL	https://collections.lib.utah.edu/ark:/87278/s6222xb7

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Title	Page 13
Format	application/pdf
OCR Text	Show 13 furnace exit is more difficult. Another very important combustion diagnostic parameter is the furnace exit gas temperature. Fossil Energy Research has evaluated several different techniques for real time measurement of furnace exit gas temperature and one of the most promising is acoustic pyrometry. This nonintrusive technique determines flue gas temperature by measuring the speed of sound along an unobstructed line-of-sight through the gas at the furnace exit plane. The use of two transducers will yield the average gas temperature along the path between them but the use of several transducers on three or four walls, as shown in Figure 12, will yield a two dimensional profile (see Figure 13). These data can be very valuable in identifying and correcting burner problems, slagging problems, and high exit gas temperatures due to sootblower problems or a change in boiler firing practices. All of these problems can have serious NOx emission implications. Acoustic pyrometry and real time monitOring of furnace exit gas temperature can also be used to optimize sootblowing cycles. It is antiCipated that the need for accurate real time FEGT measurements will develop as maintaining optimum combustion performance becomes more critical in achieving NOx emissions compliance. References 1. Giovanni, D.V., et aI., "Coal Quality Field Test at New England Power Company's Salem Harbor Unit 3," EPRI Conference on the Effects of Coal Quality on Power Plants, September 19-21, 1990, St. Louis, Missouri. 2. Frompovicz, Z.J. and Sanyal, A., "Application of Development of Techniques to Solve Combustion Related Problems in Power Plants," EPRI Conference on the Effects of Coal Quality on Power Plants, August 25-27, 1992, San Diego, California. 3. Thompson, R.E. and Giovanni, D.V., "Measuring the Impact of Coal Quality on Boiler Operation and Performance, tt EPRI Conference on the Effects of Coal Quality on Power Plants, August 25-27, 1992, San Diego, California. 4. Salem Harbor CO Field Test Report, Project Final Report for EPRI RP 1891-4, to be published Summer 1994.
Setname	uu_afrc
ID	10106
Reference URL	https://collections.lib.utah.edu/ark:/87278/s6222xb7/10106