Utilization of CFD to Reduce NOx, Improve Efficiency and Reliability of a PC Boiler

Ferrybridge “C” Power station is owned by SSE and has 2,000 MWe of generating capacity and utilizes pulverized coal as its fuel source. Originally commissioned in 1966, it was designed to burn local Yorkshire coal, but currently uses a varied supply from South African to Russian coals. In order to meet the Large Combustion Plant Directive (LCPD) emission requirements, starting in the late 1990’s, the plant was first retrofit with low NOx burners and later with a Boosted Over Fire Air (BOFA) system. These modifications allowed the plant to achieve compliant NOx operation of 500 mg/Nm³, but had the unintended side effects of high unburned carbon in the fly ash (CIA) and operational problems. This paper discusses some of the site investigations, analysis and modifications that were accomplished on the plant to address these issues. In the process of attending to these issues, NOx emissions of less than 300 mg/Nm³ have been demonstrated, on the Unit, a significant reduction from 500 mg/Nm³. With the Industrial Emissions Directive (IED) regulations looming, and a further reduction to 200mg/Nm³ required, these reductions improve the options the plant has in maintaining compliant operations.