The energy accumulation in the reaction zone of lean premixed combustion in porous media was analyzedDimensionless excess enthalpy function was theoretically derived based on a onedimensional

twotemperature modelIt was shown that the superadiabatic temperature was controlled by the combined effect of the modified Lewis number

the thermal conductivity ratio between solid and gas phases

the porosity of packed bed and the dimensionless combustion wave speedAn examination of the four source terms in the H-equation indicated that the modified Lewis number was the dominant one among the four terms and basically determined the distribution of the excess enthalpy function.