Modelling and simulation of combustion kinetics in industrial furnaces based on a dynamical systems approach

An approach is made to model combustion kinetics in industrial furnaces following a path based on Dynamical Systems (DS) method. A set of coupled ordinary differential equations (ODE) describing combustion kinetics of C, O-2, CO and CO2 is developed, for the four essential participants in the very early stages of combustion of Pulverised Coal (PC) at high heating rates. This is a prerequisite for quantification of the overall kinetics of PC combustion. The simplification made through reduction to the above four essential participants in PC combustion process at high heating rates, targets on controlling the combustion process itself in the specific aggregate. The model developed serves as a tool that can be applied to different combustion environments. The overall target is to extract information about and the main features of the kinetics of the above four participants which are contained in the structure of the system of the coupled differential equations itself, i.e. in the dynamical system they define. To face the overall combustion kinetics on the basis of the chemical dynamics of the four mentioned participants is equivalent to neglecting other factors and parameters like grain size distribution of the PC and flow conditions. This restriction will allow to investigate the basic, stoichiometric structure of the equations system and their coupling behaviour qualitatively. Following the development of the mathematical model, simulation runs are applied to the combustion within the tuyere for PC injection into the blast furnace of ferrous metallurgical operation. Reproducibility of expected and measured behaviour qualitatively, supports model validation. Further, questions of stability of the modelled system are investigated. Application of the model to the combustion process within the tuyere of PC injection into the blast furnace contributes further to understanding the overall stability of blast furnace operation. Full, quantitative validation needs exact knowledge or at least transferability of the values of the kinetic coefficients involved, which is presently poor, due to the high complexity of operation.