Numerical Prediction of Pulverized Coal Flame in Utility Boiler Furnaces

Abstract

In optimization of a utility boiler furnace operation, special attention is given to the flame geometry and position. As an illustration of possibilities for application of mathematical prediction and numerical experiment in efficient optimization of the flame, the paper presents selected results of simulations of processes in pulverized coal tangentially fired furnace of Kostolac-B 350 MW electric boiler unit. To analyze the furnace working under different conditions, a differential 3D mathematical model of two-phase turbulent reactive flow with heat and mass transfer and corresponding computer code have been developed. Using the model and the code, previously carefully verified and validated against field measurements, an extensive numerical study has been performed to investigate the dependence of the furnace flame characteristics on different operating conditions, including distribution of the coal, air flow rates, and particle size classes over the burner tiers, as well as the quality and grinding fineness of coal and the operation scheme of the coal mills. The numerical predictions of the flame characteristics enable a specific tool for optimization of the boiler unit with respect to efficiency and ecology.

Review of the investigations of pulverized coal combustion processes in large power plants in laboratory for thermal engineering and energy: Part A

“…Input of data was enabled through user-interface of the code itself, or by coupling with the computer program for prediction of air-coal dust mixture and preheated air distribution between the burners' tiers [70]. A proper distribution of both the fuel and air over individual tiers of tangentially arranged jet burners critically affected the entire flow and temperature situation in both the combustion chamber and the boiler unit [71,72]. The control of the flame vertical position and FEGT by means of the pulverized fuel distribution over the burner tiers is presented in fig.…”

Modeling of pulverized coal combustion for in-furnace NOx reduction and flame control

“…dicting the influence of pulverized coal and combustion air distribution over the burners and tiers on the flame characteristics [21].…”

“…In this paper, combustion modifications in 350 MW e Kostolac-B utility boiler TFF were investigated, affecting both the NO x emission and the pulverized coal flame. An in-house developed 3-D differential mathematical model of furnace processes, including the fuel-and thermal-NO formation/destruction reactions, validated against available measurements in the case-study boiler units [7,[21][22][23], was used for the analysis. The comprehensive combustion code offers a balance between sophistication of submodels describing individual processes and computational practicality.…”

The Study and the Mechanism of Nitrogen Oxides’ Formation in Combustion of Fossil Fuels

“…An in-house developed 3D differential mathematical model of furnace processes, including the fuel-and thermal-NO formation/destruction reactions, validated against available measurements in the case-study boiler units [9][10][11][12][13][14], was used for the analysis. The comprehensive combustion code offers a balance between the sophistication of submodels describing individual processes and computational practicality.…”