Aleksandar V. Saljnikov
Ph. D. Thesis, Mechanical Engineering Faculty, University of Belgrade, Yugoslavia,
February 1999
Supervisors: Prof. Dr. Simeon Oka, Prof. Dr. Milan Radovanović
In dissertation, the results of investigating processes and parameters relevant for combustion of pulverized coal in swirl burners and furnaces are outlined. A complex mathematical model of PC combustion in swirl flow was developed. Closure of Reynolds turbulent flow equations is accomplished by the k-e model of turbulence, considering the presence of particles. Solved are equations of conservation of mass, momentum, kinetic energy of turbulence and its dissipation, energy and each particular gas component.Radiation heat transfer is modelled by the 6 flux method. Motion of particles is treated via the Lagrangian stochaistic-deterministic model of particle dispersion. Solved are the : equations of convective and radiative heat transfer between the particles and the surrounding gas ie. furnace walls, and the equations of particle mass change due to combustion. Within the framework of this complex model, global combustion model was chosen. Phenomena of devolatilization, homogeneous and heterogeneous combustion are treated together, considering the global reaction rate based upon the experimental observations in laboratory conditions. Determined are, to date non existing values of parameters (pre-exponential term and energy of activation in the Arrhenius expression for reaction rate) characteristic for combustion of PC of 6 domestic lignites based upon the results of experiments performed at the laboratory tubular furnace. These values were used as the initial conditions during the computations performed by using the developed model.