Numerical Simulation of Spontaneous Ignition in Rice Husk

The spontaneous ignition of the rice husk in the cube basket inside a convection oven was studied numerically in this research. In the study, a cubic rice husk mass was considered as a porous media that allowed oxygen from the environment to get into and interact with the bagasse matrix. In COMSOL Multiphysics, a set of coupled partial differential equations for conductive heat transfer and diffusive transport were numerically solved. Then, the simulated results were contrasted with the results of the experiments. Between the simulated and measured center temperatures of the cubic rice husk basket, there was generally good agreement. The time to self-ignition increased as the cubic sample size increased. In the range of temperatures 9 °C –17 °C, the center temperatures predicted by 2D modeling were slightly lower than the results of the experimental investigation.