Integrated fluid dynamics-process modelling of a coal-fired power plant with carbon capture

Abstract

a b s t r a c tOxyfuel combustion, where the fuel is combusted in a mixture of pure oxygen and recycled flue gases instead of air, is one of the leading options for carbon capture from coal-fired power plants. Accurate simulation of the operation of such plants is critical for successful development of the technology. A major challenge of such a simulation is how to account for the fundamental differences in gaseous physical and thermal properties; in particular the radiative and convective heat transfer coefficients.In this paper a combined CFD-process approach is developed whereby a detailed CFD model is utilised to represent the complex gas-phase combustion and radiative heat transfer to the furnace walls and the radiant section of the boiler. This is then combined with a full plant process simulation which includes modifications to the heat transfer components to account for differing gas compositions.The novel integrated calculations have been completed for air-firing and for oxyfuel under a range of conditions and a comparison reveals that there is a possible 'working range' of oxygen concentrations/ recycle ratios under which the distribution of heat transfer in the system is similar to air firing and hence the steam conditions can be controlled to set-point temperatures and flows.

A numerical study on biomass fast pyrolysis process: A comparison between full lumped modeling and hybrid modeling combined with CFD

“…This empirical metamodel can resolve the complex geometry of the chosen catalyst and give better computational fidelity when it is applied to the full system level simulation. For a boiler of coal power plant, heat flux is calculated using CFD and 3D heat flux data is regressed to 1D function of boiler height (Edge et al, 2013). Then, this heat flux model is integrated into system level simulation of the coal power plant.…”

Evaluation of the potential of retrofitting a coal power plant to oxy-firing using CFD and process co-simulation

“…The governing equations for the conservations of mass, momentum, energy and species are solved [29]. The steady state Reynolds Averaged Navier-Stokes (RANS) approach is used and the turbulence is modelled by the realizable k ε − method, which has been successfully applied previously in many coal combustion simulations [18,[30][31][32]. The sub-models for the coal combustion used in this CFD approach are reported in Szuhánszki et al [30].…”

“…However, CFD is incapable of modelling all components of a complex power plant efficiently and economically, in particular in an integrated manner. In order to take advantages of the efficiency of process modelling and accuracy of the CFD modelling techniques, we have linked the CFD simulations to a power plant model of a 500MW e pulverised coal combustion boiler in one of our previous papers [18], in addition to the attempts made by [15][16][17] for air-firing systems. In this paper, in order to investigate the potential of retrofitting an existing power plant to oxy-firing and to predict the safe operational regime that matches the designed air-firing conditions, an efficient reduced order model (ROM) has been developed to combine the CFD simulations with the whole plant process simulations.…”

Reduction of Nitrogen Oxides Emissions from a Coal-Fired Boiler Unit

“…Technologies of solid fuel staged combustion with air portion supply above the main burners are known to allow reducing the concentration of nitrogen oxides by 40-50% [2][3][4][5][6][7][8]. But implementing these technologies the gas temperature at the outlet of the furnace increases.…”