Combustion optimization in consolidated porous media for thermo-photovoltaic system application Using Response Surface Methodology

Motivated by the need to optimize the operation of an MTPV system, three consolidated porous media (PM) geometries namely spherical, conical and cylindrical and a non-PM combustor are numerically simulated. The geometry with the best methane conversion rate is identified and optimized with the right porous media and combustor diameter ratio. Using Response Surface Methodology, a design of experiment (DOE) approach is adopted to examine the effects of three independent parameters namely: wall thermal conductivity, chamber radius and O2 mass fraction on output parameters critical to the operation of the MTPV system specifically radiation heat transfer rate and emitter efficiency. Results show that PM combustion produces higher and uniform wall temperatures compared to the non-PM combustor. The spherical shape consolidated PM produces the highest average methane conversion rate of 96.8% and highest mean wall temperature of 1032 K even though it produces the least flame temperature. The highest radiation heat transfer rate predicted by DOE and CFD simulations are 3.25 W and 3.17 W respectively. The best conditions to realize the optimal MTPV performance is by employing the spherical PM combustor with diameter ratio of 0.7, porosity of 0.5, equivalence ratio of 0.8, wall thermal conductivity of 22.99 W/(m∙K).