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Show The host boiler is a 300-MWe opposed-wall, coal-fired, wet-bottom (slagging) boiler firing a high volatile Ukrainian bituminous coal, a Siberian brown (lignite) coal, or various blends. A n opposed-wall-fired, natural gas reburn system was designed and subsequently installed in the summer of 1992. Parametric testing was carried out during the remainder of 1992. Initial parametric test results from this boiler show average N O x reductions of approximately 50 percent from a baseline pre-retrofit level of 600 ppm* (0.82 lb NOx/106 Btu**). During this testing, variations in boiler operation and conditions resulted in a range of N O x reductions of 40-60 percent. Additional testing and analysis is currently in progress to define the results further and to optimize system performance. Optimization testing will continue through September 1993. Preliminary results also indicate that boiler thermal performance and slag tapping with the reburn system in operation are within acceptable ranges for normal boiler operation. The reburn system has been in continuous use since September 1992. Based on the favorable performance results thus far, reburn systems will be installed on other units at the Ladyzhin Power Station as soon as capital financing is available. This paper presents the design of the reburn system as well as the results of these initial parametric tests. Background A joint U.S./U.S.S.R committee for cooperation in the field of environmental protection has sponsored meetings of a working group on stationary source air pollution control technology over the past 15 years. This cooperation is continuing with U.S., Russian, and Ukrainian team involvement. The EPA's Air and Energy Engineering Research Laboratory (AEERL) has been responsible for technical information exchange activities under this program and, as of the Eleventh Working Group meeting in Moscow, in November 1988, has sponsored the first major joint U.S./Russian/Ukrainian air pollution control research project with the objective of implementing N O x control technology on a large coal-fired boiler in the Ukraine. Generally speaking, baseline NOx emissions from wet-bottom wall-fired units typically range between 370 and 730 p p m (0.5 and 1.0 lb/106Btu), depending on the unit configuration and coal type fired. The joint U.S./Russian/Ukrainian program called for the U.S. team (ABB Power Plant Laboratories, under contract to the EPA) to provide the Russian/Ukrainian team with a preliminary design for an in-furnace N O x control system for a specific Ukrainian boiler in anticipation of meeting impending N O x legislation. The Russian and Ukrainian *AII p p m N O x measurements in this paper are given corrected to 3 % O r "Readers more familiar with metric units m a y use the factors listed in the Appendix to convert lo metric units. |