The Effects of Using Porosity Profiles on Performance and Emission of Pollutants in the Porous Media Burners

In this paper, a two-dimensional axisymmetric model for premixed methane/air combustion in porous media has been developed. For this aim, a numerical model with chemkinII library is used along with its database. This code solves the continuity, navier stokes, the solid and gas energy and the chemical species transport equations using the finite volume method. The pressure and velocity have been coupled with the simple algorithm. In this paper, an attempt is made to apply the profile of porosity instead of constant porosity for two zones of the burner. The results showed that by applying the varying porosity along the burner, the peak temperature can be decreased by about 4.5%, and subsequently, the amount of exhaust pollutants such as NOx can also be decreased while increase in pressure loss along the burner is negligible. The effects of increasing the inlet velocity and the wall temperature are also investigated. The results showed that by increasing the inlet velocity, the peak temperature and the emission of NOx will be decreased and also by increasing wall temperature, the peak temperature and the emission of NOx will be increased.