The aim of this study is to analyze the temperature field, the specie concentrations of MILD coal combustion in a pilot furnace through the CFD. The attention is focused especially on the effect of the position of coal guns and their distance from the central air jet, in order to investigate both temperature and specie concentration distributions. The authors have performed several simulations in three dimensional steady-state condition of a quarter of the IFRF furnace using a high bituminous A coal. The Eddy Dissipation Model has been used to describe and model the interaction between turbulence and chemistry, while the P1 model has been used for the radiation. In order to describe the solid phase and the combustion process, the Lagrangian description has been used and sub-models have been implemented for devolatilization and char burnout. In particular has been used the Chemical Percolation Model (CPD) for the devolatilization and the intrinsic model for the oxidation of char. The turbulence phenomenon has been modeled resorting to the standard k-epsilon model, considering the standard wall functions for the wall treatment. The results show that the mild condition is obtained for all three configurations. When the distance between the coal guns and the center air jet are furthest, the oxygen concentration is lowest, consequently the combustion takes place in a fuel-rich zone. This condition can influence the NOx emissions.
Numerical Simulation of MILD (Moderate or Intense Low-Oxygen Dilution) Combustion of Coal in a Furnace with Different Coal Gun Positions
Perrone D;AMELIO, Mario
2016-01-01
Abstract
The aim of this study is to analyze the temperature field, the specie concentrations of MILD coal combustion in a pilot furnace through the CFD. The attention is focused especially on the effect of the position of coal guns and their distance from the central air jet, in order to investigate both temperature and specie concentration distributions. The authors have performed several simulations in three dimensional steady-state condition of a quarter of the IFRF furnace using a high bituminous A coal. The Eddy Dissipation Model has been used to describe and model the interaction between turbulence and chemistry, while the P1 model has been used for the radiation. In order to describe the solid phase and the combustion process, the Lagrangian description has been used and sub-models have been implemented for devolatilization and char burnout. In particular has been used the Chemical Percolation Model (CPD) for the devolatilization and the intrinsic model for the oxidation of char. The turbulence phenomenon has been modeled resorting to the standard k-epsilon model, considering the standard wall functions for the wall treatment. The results show that the mild condition is obtained for all three configurations. When the distance between the coal guns and the center air jet are furthest, the oxygen concentration is lowest, consequently the combustion takes place in a fuel-rich zone. This condition can influence the NOx emissions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
