Low-Calorific Gas Combustion in a Two-Layer Porous Burner

To promote the effective utilization of different varieties of low-calorific gas mixtures in a porous media burner, combustion behaviors of three typical low-calorific gas mixtures in a two-layer porous burner are simulated with a two-energy and one-dimensional transient model. The equivalence ratio and inlet velocity are kept constant. A baseline simulation for the three mixtures is presented, and partial results are compared against the experimental measurement of axial temperatures and emission levels. A parametric study is conducted on the conductivity and convective coefficient of up- and downstream sections. The study shows that the upstream convective coefficient has more influence on temperature behaviors than that in the downstream. The solid conductivity effect on temperature behaviors is closely associated with the reaction zone location relative to the interface. CO emission behavior is found to be fairly sensitive to the change in upstream material properties. The results suggest that, for clean combustion of low-calorific gases in a two-layer burner, thermal conductivity of the upstream section should not be too large.