Prediction of performance and pollutant emission from bituminous and sub-bituminous coals in utility boilers

Computational Fluid Dynamic (CFD) models give good predictions of coal combustion in utility boilers if the coal combustion kinetic parameters are known. We developed a three-step methodology to provide reliable prediction of the behavior of a coal in a utility boiler: (1) Obtaining the combustion kinetic model parameters from a series of experiments in a test facility, CFD codes and optimization algorithm. (2) Validation of the combustion kinetic parameters by comparison of different experimental data with simulation results obtained by the set of combustion kinetic parameters. (3) The extracted kinetic parameters are then used for simulations of full-scale boilers using the same CFD code. Three to four bituminous and sub-bituminous coals with known behavior in Israel Electric Corporation (IEC) 550MW opposite-wall (3 coals) and 575MW tangential-fired (4 coals) boilers were used to show the capability of the method. An unfamiliar bituminous coal was then examined prior of its firing in the utility boilers and prediction of its combustion behavior in the two boilers was carried out. This methodology was used to examine a Venezuelan coal that was found to yield high LOI.