||ABB/Combusion Engineering, Inc., Windsor, CT. ;All-Russian Heat Engineering Inst., Moscow. ;Ladyzhin Power Station (Ukraine).;Environmental Protection Agency, Research Triangle Park, NC. Air and Energy Engineering Research Lab.
The paper gives results of a program to design, install, and test a natural-gas three-stage combustion (reburn) system on a 300-MWe, opposed-wall, wet-bottom (slagging) coal-fired utility boiler operating in the Ukraine. The U.S. EPA sponsored this program in support of a working group initially involving the EPA and (the former) Soviet Union, and now consisting of representatives from the EPA, Russia, and the Ukraine. The host boiler fires a high volatile Ukrainian bituminous coal, a Siberian brown (lignite) coal, or various blends. An opposed-wall, natural-gas reburn system was designed and 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 nitrogen oxide (NOx) reductions of about 50% from a baseline pre-retrofit level of 600 ppm, corrected to 3% oxygen (0.82 lb NOx/million Btu). During this testing, variations in boiler operation and conditions resulted in a range of NOx reductions of 40-60%. Additional testing and analysis is currently in progress to define the results further and to optimize system performance.