Numerical Prediction of Erosion in Coal Burner of 210 MW Boiler Through Computational Fluid Dynamics Modeling

Abstract

The splitter plates of coal burners in Indian thermal plants are subjected to severe erosion and erosioncorrosion conditions owing to the combined effect of abrasive nature of coal and elevated service temperature environment. During service, tilting of splitter plates is adopted to achieve the desired final steam outlet temperature which shifts the fireball location and heat release area in the combustion zone. The tilt condition gives rise to a change in the incidence angle of the coal particle as well as the change in flow profile. The erosion life of these plates is predominantly affected by the coal particle velocity, impact angle, particle size and steady state metal temperature during service. The sensitivity of burner tilt angle on the erosion life requires an understanding of primary air with coal particle flow phenomenon within the burners. The effect of burner tilt angle on the erosion of presently used SS310 grade splitter material was studied through computational fluid dynamics. The erosion sensitive velocity exponent was calculated based on the laboratory simulated erosion tests at elevated temperatures upto 700°C. The life of the splitter plates was calculated based on the predicted erosion rate intensity.