Modernizing the boiler installation for unit no. 3 at the Kashirskaya GRÉS to reduce nitrogen oxide emissions

• Published in: Power technology and engineering 2008-03, Vol.42 (2), p.93-99
• Main Authors: Smyshlyaev, A. A., Evdokimov, S. A., Dubovitskaya, L. G., Kochetkov, I. A., Verbovetskii, É. Kh
• Format: Article
• Language: English
• Subjects: 01 COAL, LIGNITE, AND PEAT; 03 NATURAL GAS; AIR POLLUTION ABATEMENT; AMMONIA; BOILERS; BURNERS; COAL; Combustion; Electrical Machines and Networks; EMISSION; Emissions control; Energy; Energy Systems; Foundations; Fuels; Geoengineering; Hydraulics; Liquids; Natural gas; NITROGEN OXIDES; NOZZLES; Power Electronics; PULVERIZED FUELS; RECYCLING; REDUCING AGENTS; REDUCTION; Renewable and Green Energy; RETROFITTING; RUSSIAN FEDERATION; SLAGS; STAGED COMBUSTION; Thermal Electric Power Stations
• ISSN: 1570-145X; 1570-1468
• DOI: 10.1007/s10749-008-0018-7

The purpose of modernizing the Pp-1050-25-545 KGZh (P-50R) boiler is to reduce the emissions of nitrogen oxides (NO x ) to levels consistent with modern requirements. The following engineering steps were taken, with liquid slag removal from the boiler, to attain NO x levels of 700–750 mg/m 3 for operation with coal and 125 mg/m 3 for operation with natural gas — three-stage combustion with natural gas as the reducing fuel (∼15% thermal) burning in the recirculating gases; and — use of low-emission coal-dust burners with dust feed at high concentrations, overflow burners, and tertiary draft nozzles to lower the amount of excess air in the active combustion zone. The NO x level was further reduced to 570 g/m 3 (just for operation with coal) by using a selective noncatalytic nitrogen oxide reduction system with injection of ammonia (NH 3 ) vapor into the boiler in a zone with temperatures of 950°C.