Numerical simulation of entrained flow coal gasifiers. Part I: modeling of coal gasification in an entrained flow gasifier

A comprehensive three-dimensional simulation model was developed for entrained flow coal gasifiers. In the model, the numerical methods and the submodels conventionally used for the pulverized coal combustion modeling were used. An extended coal gas mixture fraction model with the Multi Solids Progress Variables (MSPV) method was applied to simulate the gasification reaction and reactant mixing process. Four mixture fractions were employed to separately track the variable coal off-gas from the coal devolatilization, char-O-2, char-CO2, and char-H2O reactions. The influence of turbulence on the gas properties was taken into account by the pdf model with a clipped Gaussian distribution function. A series of numerical simulations were performed for a 200 td (- 1) two-stage air blown entrained flow gasifier recently developed for the IGCC process. The predicted gas temperature profile and the exit gas composition were in general agreement with the measurements. Model simulations illustrating the importance of accounting for varying coal off-gas and the effects of turbulence/reaction affecting the prediction capability were also presented. (C) 2000 Elsevier Science Ltd. All rights reserved.