"MODELING AND THEORETICAL INVESTIGATION OF COMBUSTION IN A r POROUS INERT MEDIA

Abstract

In recent years, new and improved burner concepts, especially for gaseous fuels, have provided the basis for development of very low NOx and CO emission S combustion systems. Research and development work has been carried out towards a low emission, high energy density combustion reactor that does not operate with free flames. The entire combustion takes place in a porous matrix. Taking advantage of the innovative, highly integrated porous burner technology, development activities are presented which deal with the application of this novel combustion technology in various fields of energy and heat engineering. The porous medium combustion technology offers several advantages over conventional free flame burners. These benefits can be summarized as an extremely high power turndown ratio, a very small and compact design, and load-independent pollutant emissions. Additionally, complex combustion chamber geometries, which are not feasible with conventional state of the art combustion techniques, are now possible. This thesis analyzes the combustion in a porous media combustor, built on base of alumina spheres placed inside of a axis symmetric cylindrical tube of 60mm in length with the three sections. First one is preheat section then combustion chamber and last one is after burning zone. Methane and air mixture are used as the working medium and mathematical model for porous inert media combustion has been prepared by defining the conservation equations for the mixture and considering the a single step chemical reaction. The model has been simplified by assuming several assumptions. The governing equations are discretized by finite difference method and upwind scheme. Appropriate boundary conditions are applied to the equations. The algorithm for the code and program has been developed in the "C" language to solve the coupled, strongly non-linear system of equations by using the finite difference method, along with the Tri-Diagonal Matrix Algorithm. Results obtained out have been discussed.