Study on oxy-fuel combustion behaviors in a S-CO2 CFB by 3D CFD simulation

摘要

The supercritical CO2(S-CO2) power cycle CFB with oxy-fuel combustion is considered as a perspective carbon capture technology with high net efficiency. A three-dimensional (3D) CFD simulation using MP-PIC method was developed to predict oxy-fuel combustion in a 12 MWth S-CO2 CFB. This model couples the gas-solid flow, the heat transfers with combustion reactions, and takes into account of the particle size distribution. The effects of the different thermal wall boundary conditions and various O-2 concentration on the particle motion, combustion characteristics and gaseous pollutant emissions were systemically studied in this work. Results show that the combustion efficiency and the emission of CO, NO and SO2 in the S-CO2 boiler were higher than those in the conventional steam boiler. The increase in the inlet O-2 concentration increased the temperature of gas phase, the combustion efficiency and the desulfurization efficiency in the S-CO2 boiler. (C) 2019 Elsevier Ltd. All rights reserved.