Estimation of Radiation Efficiency of Cylindrical Porous Reactor for Combustion of Lean Premixed Methane–Air Mixture

The aim of this study was to estimate the radiation efficiency inside a cylindrical porous reactor consisting of two coaxially mounted quartz tubes. The porous medium was made of two different fractions of zirconium dioxide balls, which helped to stabilize the combustion wave for a wide range of combustible mixture flow rates, from 12.4 to 74.4 L/min. All experiments were performed using a premixed lean methane–air mixture. To estimate the radiative heat flux inside the porous reactor, the flow calorimetry method was utilized. The study found that the heat flux absorbed by water does not vary with the volume flow rate of the water. Furthermore, the experiment revealed that lower combustible mixture flow rates result in maximum radiative efficiency. This configuration of the porous reactor has the potential to be used as a heater for non-contact heating of materials through heat flow.