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Show development of ultra-low NOx burners. REGULATORY DRIVERS Many states in the U.S. are presently implementing plans to comply with federal Clean Air Act requirements for ozone non-attainment. These plans generally require the application of Reasonably Achievable Control Technologies (RACT) for the reduction of NO x and VOCs [1,3,4]. In extreme ozone non-attainment areas, such as the California South Coast Basin, advanced control technologies may be required [5]. The decision process for industry leaders faced with reducing NOx emissions are also more involved today with regional emissions credit trading programs such as the SCAQMD RECLAIM program and the EPA's proposed open market trading rule [6]. Today an industry representati ve faced with emissions compliance may either: 1) look to the open market for emission credits, 2) apply the minimum technology to meet current regulations, or 3) apply advanced controls and trade the surplus emission credits. The first and last approach are encouraged by SCAQMD and EPA emissions trading programs. Because of these incentives in emission credit trading, a market may be established for advanced control technologies. Many emission regulations are tied to the capability of control technologies either through RACT, MACT or BACT which represent Reasonably Available, Maximum Achievable or Best Available Control Technologies, respectively. Regulatory definitions for these terms are available either through the U.S. EPA, or in many cases are defined by regional and local air pollution control authorities. In addition, any new source in an ozone non-attainment area is required to meet the lowest achievable emission rate (LAER) and offset up to 50 percent of the new sources emissions from their other sources. Emissions trading incentives and stricter New Source Pollution Standards (NSPS), can lead to wider application of ultra-low NOx technologies. It is therefore important to investigate NOx formation in burners in order to develop ultra-low emission technologies that meet the pollution control needs of the future. This paper illustrates the use of advanced diagnostics in evaluating burner performance and NOx formation characteristics that are critical to the continued development of ultra-low NOx control technologies. EXPERIMENTAL In this program we studied a specially modified version of the Selas K988 wall-mounted radial flame burner with an aim to evaluate the overall burner characteristics and identify operating conditions and designs which could lead to ultra-low NOx burner perfonnance. The burner tested had a maximum firing rate of 0.8 MMBtulhr as an inspirated burner. This burner combines a premixed fuel/air approach with advanced fuel staging. The burner (Figure I) consists of a fuel/air injector inserted through a burner tile SECONDARY ./" COMBUSTION ~ PORTS ....--- PRIMARY COMBUSTION PORT TERTIARY AIR PRIMARY AIR Figure 1. Illustration of the Selas K988 radial flame burner. The burner operates with two premixed air and fuel streams supplied through the primary and secondary registers. Additional combustion air, if needed, is supplied through the tertiary air register. 3 |
