Cfd Analysis of Gas - Particle Interaction in a Circulating Fluidized Bed Riser

P.Ragothaman,[email protected] Dr.N.V.Mahalakshmi,[email protected] Institute for Energy Studies, Anna University, Chennai-25,Tamilnadu, India. P.sudhakar,[email protected] Abstract Circulating fluidized bed reactors are widely applied in industry for power generation in boilers and gasifier. Computational Fluid dynamics modeling of hydrodynamics and heat transfer can be an effective tool for optimizing the flow, improve the design of such systems significantly and can supplement the need for experimental analysis. Modeling and simulation of gas-solids two-phase flow is performed aiming to study the effects on flow hydrodynamics and heat transfer in the riser column of circulating fluidized bed. The modeling and simulations of circulating fluidized bed has been done by GAMBIT 2.0.4 and FLUENT 6.2 solver respectively. An Eulerian approach is considered for fluid and particulate phases. The gas phase and particulate phase turbulences are modeled using Kinetic Theory of Granular flow and K-Epsilon models respectively. User Defined codes are developed for solid phase velocity, volume fraction, Pressure drop, viscosity, drag coefficient and heat transfer co-efficient to analyze the above parameters inside the riser Column. Results are validated with experimental data published in the literature. There is a good agreement between measured and simulated profiles of solids axial velocity and solids volume fraction along the diameter of riser at 4.9m and pressure profile along riser column of 15.08 m.