(222k) Experiment On Superadiabatic Radiant Porous Burner With Augmented Preheating

Most radiant porous burners use only a small portion of combustion heat (less than 30%), though they adopt the internal heat recirculation concept. A new radiant porous burner (i.e., superadiabatic radiant porous burner) configuration in which combustion heat is recovered internally as well as externally is suggested, computationally investigated and designed. A preheater that consists of several preheating pipes is used to externally recuperate heat from the exiting flue gas and preheat the inlet air for the burner. Also, radiation rods with high thermal conductivity are used to extract heat from flame and transfer it to radiating disk surfaces. Results show that the thermal efficiency over 40% can be obtained for the high-efficiency radiant porous burner due to the internal and external heat recirculation, indicating the superadiabatic radiation temperature higher than the subadiabatic flue gas exit temperature, and that the burner can be operated even at very low fuel-equivalence ratios. Using the computational results, the superadiabatic radiant porous burner (alumina, Al₂O₃, and silicon carbide, SiC) has been fabricated.