Numerical simulation of high-temperature fusion combustion characteristics for a single biomass particle

A single particle fusion combustion model considering the effect of ash fusion is established. The comparison of the predicted data with experimental data reported in the literature validates the model. The accuracy of the prediction results is improved with the model. The fusion combustion characteristics of the single particle are investigated. Results show that the char could not convert to ash completely due to the pore space is taken up by the fused ash, thereby resisting the further diffusion of oxygen at 1673–1873 K. The burnout rate decreases linearly with the particle density and the attenuation slope increases with the temperature. The burnout rate decreases from nearly 100% to about 88% as the particle size increases from 1 mm to 10 mm. The fused ash decreases the char combustion rate. The effect increases with particle density, particle size as well as temperature. The total combustion time decreases from nearly 19 s to about 3 s as the surface-area-to-volume ratio increases from 0.6 to 6 mm−1.