HEAT-TRANSPORT MODEL FOR FIBER BURNERS

A model for the heat transport in a fibre burner is presented. The model contains heat transfer by conduction in the fibres as well as in the gas. Radiation inside the fibre material is modelled by the two-flux formulation, i.e. isotropical scattering is not assumed. Constant thermophysical values and a heat release function are used. The combustion inside the fibre layer is modelled with a heat release function. The system of differential equations is solved by the method of finite differences. The radiation components, temperatures of the gas and solid material are shown as functions of the input power, the excess air and the location. The results are in a qualitatively agreement with measurements. The apparent emissivity of the porous layer is also found as a function of the input power and the excess air.