Experimental study on temperature variation in a porous inert media burner for premixed methane air combustion

The detailed axial temperature variations of the porous media burner during startup and switch-off processes were experimentally measured and analyzed for the premixed methane air combustion. A tubular burner filled by alumina pellets with diameters of 10 mm and 4.3 mm, respectively, was used as the porous media burner to study the effect of the burner inlet gas flow rate, equivalence ratio, and diameter of alumina pellets on the combustion temperature distribution along the burner axis and the combustion wave velocity. The results showed that the superadiabatic combustion could be achieved for the combustion wave velocity greater than zero, and the critical equivalence ratio corresponding to the superadiabatic combustion was bigger for the smaller pellet diameter or higher inlet air flow rate. This study can provide the useful information for the design and operation of the porous media burner, and is significant to understand the combustion phenomena in the porous media burner. •The burner startup and switch-off processes were measured and interpreted.•Effect of gas flow rate on temperature profile and wave velocity was studied.•Effect of equivalence ratio on temperature profile and wave velocity was studied.•Effect of pellets diameter on temperature profile and wave velocity was studied.•Critical equivalence ratio to achieve superadiabatic combustion was discussed.