Theoretical and numerical investigation on the EDC-model for turbulence–chemistry interaction at gasification conditions

The present work describes results of the CFD modelling of a high-pressure gasification process. For the CFD modelling of combustion processes in industrial-scale reactors the eddy dissipation concept (EDC) is often used to couple chemical reaction mechanisms to the computed flow field. However, in modelling gasification processes the EDC-model yields results, which only partly agree with the experimentally gained data. Since the available EDC-model does not accurately represent the important reformation reactions for gasification modelling, a variation of the EDC parameters for the mixing time and the fine scale fraction of a cell was accomplished. Hence, the experimental values were approached but not reached. In the present contribution on the basis of an analysis of the EDC-model and the involved time scales weaknesses of the EDC-scheme in reforming zones are discussed and a possible solution is demonstrated.