Direct Numerical Simulation of biomass pyrolysis and combustion with gas phase reactions

7th European Thermal-Sciences Conference

Awasthi, A.^1 ; Kuerten, J.G.M.^1,2 ; Geurts, B.J.^2,3

Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands^1

Multiscale Modeling and Simulation, Faculty EEMCS, University of Twente, Enschede, Netherlands^2

Anisotropic Turbulence, Department of Applied Physics, Eindhoven University of Technology, Eindhoven, Netherlands^3

关键词: Biomass pyrolysis;    Gas-particle interaction;    Gas-phase reactions;    Higher gas temperature;    Homogeneous reaction;    Particle tracking;    Particle volume fractions;    Turbulent channel flows;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/745/3/032119/pdf
DOI  :  10.1088/1742-6596/745/3/032119

来源: IOP

【 摘 要 】

We present Direct Numerical Simulation of biomass pyrolysis and combustion in a turbulent channel flow. The model includes simplified models for biomass pyrolysis and char combustion along with a model for particle tracking. The gas phase is modelled as a mixture of reacting gas species. The gas-particle interactions for mass, momentum, and energy exchange are included by two-way coupling terms. The effect of two-way coupling on the conversion time of biomass particles is found noticeable for particle volume fractions > 10-5. We also observe that at constant volume fraction the effect of two-way coupling increases as the particle size is reduced, due to the higher total heat exchange area in case of smaller particles. The inclusion of gas phase homogeneous reactions in the DNS model decreases the biomass pyrolysis time due to higher gas temperatures. In contrast, including gas phase reactions increases the combustion time of biomass due to the lower concentration of oxygen at the particle surface.