Effects of operating conditions on deNOx system efficiency in supercritical circulating fluidized bed boiler

Artur Błaszczuk, Wojciech Nowak, Szymon Jagodzik

Abstract


The purpose of this work was to determine the impact of a operating conditions on the deNOx system efficiency.in a 966MWth supercritical circulating fluidized bed boiler. Experimental tests were carried out on a full-scale DeNOx system installed in the world’s largest once through supercritical circulating fluidized bed boiler. In this work, the effects of the following parameters were studied: flue gas temperature inside the separators between 636°C and 845°C, relative ammonia mass flow over the range 0.22-1.00 and three relative values of O2 concentration (i.e. 0.94, 1.0 and 1.13). The efficiency of deNOx system increases (ca. 53%) with increasing relative ammonia mass flow. A maximum DeNOx system efficiency (ca. 70%) was achieved at flue gas temperature in the range from 720°C to 790°C. In the case of all unit loads, deNOx system efficiency from 36% to 70% was observed and performs a standard emissions relate to permissible concentration of NOx in the flue gas.

Keywords


supercritical CFB boiler, SNCR method, deNOx system efficiency, oxygen concentration, flue gas temperature

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References


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