Novel burner concept for premixed surface-stabilized combustion

Surface-stabilized combustion is credited with high burning rates, extended lean flammability limits, wide modulation range and other advantages. This makes it an attractive technology for compact low-emission combustors. The experimental gas turbine surface burners reported to this date are produced from compressed and sintered Fe-Cr-Al fiber mats. The authors have developed a new concept of surface burner fabricated by braiding ceramic cords around a ceramic frame. This simple method produces a basket-type surface suitable for stabilizing lean premixed flames over a broad range of operating conditions. The use of ceramics extends possibilities for operation at very high inlet temperatures with reduced risks of material sintering and oxidation. This paper presents test results with an experimental burner on a pressurized combustion rig with optical access. The experiments were performed under the following conditions: inlet temperatures of 22–740 C, pressures of 1–3 bar, thermal power between 4 kWTh and 32 kWTh and equivalence ratios of 0.28–0.95. Measurements of flue gas composition and pressure drop are also reported in the paper. The operating window for low-NOx and low-CO combustion is analyzed. With the demonstrated performance, the burner could cover the operating envelope of a 3 kWe recuperated micro turbine [1]–[2] with no pilot and no staging. This would also limit NOx to <40 ppm @ 0% O2 within the micro turbine load range of 100% to 50%.