Stabilization operation region and operational variables effect on a reciprocal flow burner

A reciprocal gas flow burner is computationally simulated for obtaining its stable operation region in terms of equivalence ratio and filtration velocity, for two energy losses configurations schemes. Equivalence ratio and filtration velocity were considered over the range [0.1, 1.0] and [0.25, 1.0] (m/s). The one-dimensional mathematical model consider that porous media is made by alumina bolls of 5.6 mm diameter , which fill up a quartz hollow cylinder of 5 cm diameter and 50 cm high. The mathematical model includes total mass preservation laws, momentum and enthalpy for the solid as for the gas. Combustion is modeled through global chemical reaction in one step. Chemical kinetic of methane combustion is treated on the base of Arrhenius approximation. It is considered besides that system heat transport occurs at conditions without local thermal equilibrium and includes convections mechanisms, conduction and thermal radiation. Lateral heat losses from the system to environment through cylinder lateral surface were studied at two scenarios: reactor coupled with and without heat exchangers. Mathematical model are discretized by finite differences method through implicit scheme and its solution reached by TDMA algorithm. Uniform grid with 801 nodes and time step ∆t = 0.01 (s) gave solution independence. Results demonstrated increased stabilization in temperature profile, thus increased stabilization region for the reactor coupled with heat exchangers. Key-Words: Reciprocal Flow Burner (RFB); porous media; filtration combustion; numerical simulation