Date of Award
Master of Science (MS)
Chemical-looping combustion (CLC) is a next generation carbon capture technology with high efficiency and low cost. To assess the potential of this technology for industrial scale power plants, thousands of laboratory scale and many pilot-scale plants have been designed and tested. In recent years, to obtain a thorough understanding of the hydrodynamic behavior inside the reactors and chemical looping combustion process, high-fidelity numerical simulation using Computational Fluid Dynamics(CFD) have been performed. However, CFD simulations in the literature have been limited reported compared to the laboratory scale experiments.
In this thesis, cold flow simulations of a CLC fuel reactor are performed corresponding to the pilot-scale experiment of a dual fluidized bed CLC system. By employing the dense discrete phase model (DDPM) with hydrodynamics, the fluidization behavior is captured in the simulations, which also shows stable circulation in the reactor. Comparisons of captured static pressures and volume fractions in the reactor show excellent agreement with the experimental data. To further verify this computational model, different bed materials are employed in the simulations and again satisfactory results are obtained.
In a second project, cold flow simulations of a cross-flow moving bed in an air reactor are performed corresponding to a laboratory-scale experiment. Because of the requirement of high accuracy in these simulations, discrete element method (DEM) is employed. The simulation results for the particle behavior and pressure drop are in satisfactory agreement with the experiment. Time varied particle velocity distributions are obtained and a dual-vortex formation is observed. Again, simulations achieved stable circulation inside the reactor. This work has provided important insight into controlling the pressure gradient and recirculation in the moving bed reactor.
Dr. Ramesh K. Agarwal
Dr. Swami Karunamoorthy Dr. Qiulin Qu