Modeling of solid fuel combustion in oxygen-enriched atmosphere in circulating fluidized bed boiler Part 2. Numerical simulations of heat transfer and gaseous pollutant emissions associated with coal combustion in O2/CO2 and O2/N2 atmospheres enriched with oxygen under circulating fluidized bed conditions

摘要

The results of numerical computations for 670t/h CFB boiler are shown in this paper. The calculations have been carried out for two different so-called oxyfuel conditions, i.e. when combustion runs in a gas mixture based on O2 and N2, and another, when combustion takes place in N2-free atmosphere of O2-CO2, with various fraction of oxygen in both cases. Compared to conventional air-combustion, two crucial differences were taken into consideration in this paper: reduced volume of flue gas for oxygen-enriched environments and changed heat duty inside combustion chamber following from an increase in adiabatic temperature.