Analysis of wood chip combustion system for hot air generation in the industrial drying process

Abstract

A two-dimensional steady state packed bed CFD model is developed for the combustion of wood chip in a moving grate.The model is validated using an industrial moving bed hot air generator used in Tea industry.Various empirical models have used for thermophysical property modeling.For this purpose free-board region of the hot air generator is also simulated including volatile reactions and turbulent combustion.Modeling and simulation carried out using open source CFD software OpenFOAM.Radiation heat incident on the packed bed is unknown and it is assumed in the first packed bed simulation.Therefore, CFD simulation involves number of iterative runs of the packed bed model and free board model to obtain the radiation temperature incident on packed bed due to free board heat.According to the validation results the developed packed bed model can be used to predict temperature of the packed bed wood chip combustion of thermally thin wood particles. The gas compositions could not be validated using the model.Further improvements to the model have suggested.