Impact of Burner Yaw and Tilt Angles on the NO Emissions and Slagging in a 330 MW Tangentially Fired Boiler Utilizing Zhundong Coal: A Numerical Study

Combustion of Zhundong coal in utility boilers is frequently challenged by ash-related issues (fouling/slagging) and stringent NO emission control requirements. This study conducted numerical simulations to investigate burner configuration effects, specifically yaw angle adjustments (modulating the imaginary tangential circle diameter, ITCD) and downward tilt angles, on the NO emissions and slagging propensity in a 330 MW subcritical tangentially fired boiler. The results reveal a compromise mechanism between NO emission control and furnace slagging mitigation. ITCD reduction via yaw angle optimization increases furnace exit NO concentrations by 1.5–3% but decreases total deposition rates by 1.3–2%. By altering the burner downward tilt angle to 15° and 25°, NO emissions increase by 8% and 19%, respectively, with about a 7% reduction in total particle deposition rate. An optimal burner yaw and tilt angle is identified to achieve a compromise between NO emission and furnace slagging control. The findings provide some guidance for the combustion optimization of Zhundong coal-fired boilers.