Exploring the Effects of Employing Different Scaling Criteria on Swirl Stabilised Pulverised Coal Burner Performance

Abstract

Abstract ABSTRACT–The effects of employing different scaling criteria on the performance of swirl stabilised pulverised coal burners are presented. Two burners were studied at 2.5MWthermal input. The burners were scaleddown from a SO MW1 reference case usingboth constantvelocityandconstant residence-time scaling criteria. Coal particle size distribution was maintained constant at 75% < 751lffi in both cases. Parametric studies were performed on each burner under baseline high NOx and aerodynamically air staged low NOx operation. Detailed in-flame measurements of temperature and gas composition were performed on both baseline flames. Results show that in the baseline firing mode, NOx emissions are consistently higher for the constant velocity burner. Employing aerodynamic air staging for NOx reduction by promoting penetration of the coal jet into the internal recirculation zone, resulted in significant NOx reduction in both burners. It was also observed that the normalised coal injector insertion distance ...