(461a) CFD Simulations of Tangentially Fired Coal Boiler Under Various Loads

Tangentially fired boilers are widely used in coal power plants. The pulverized coal particles and air form a fireball in the center of boiler with intense concentric swirling turbulent mixing. The nation's generating assets are changing as more electricity being generated from intermittent renewable capacity such as wind and solar power plant. Coal-fired power plants optimized as baseload resources are being increasingly operated in partial load situations. Existing coal power plants are being operated in ways that are suboptimal from the perspective of efficiency and capacity utilization. In an effort to address these challenges by identifying and developing technologies that increase coal-fired power plant efficiency, improve unit reliability and availability, and enhance unit capability for flexible operations (e.g. “cycling”), a CFD model using ANSYS-FLUENT is developed to simulate the industrial scale coal boiler.

The Discrete Phase Models is used to track particles. The Discrete Ordinates (DO) radiation model, realizable k-ε turbulence model, gas phase chemical reaction, coal devolatilization, char combustion are included in the heat transfer. Eddy-dissipation is used as the turbulence-chemistry interaction model. The CFD model is first validated with the available data which had been collected from Tri-State’s Escalante coal power plant. After the CFD model is validated with experimental results, then a much wider range of operational parameters such as the pulverize air, secondary air and coal particle flowrates are simulated and their effect on combustion, temperature distribution, flow field are analyzed and discussed.