An innovative swirl burner for burning ultra-low carbon solid waste: Pilot scale combustion test and numerical...

To realize the feasibility of using low-carbon powdered solid waste as an alternative fuel for large-scale co-firing in power plant boilers, and solve issues of poor stable combustion, incomplete burnout, and high NO_x emissions, this study developed a novel swirl burner with a strong stable combustion precombustion chamber for ultra-low-carbon coal gasification fine slag (CGFS) combustion, and built a 0.5 MW precombustion chamber swirl combustion pilot system. Combustion performance and NO_x emission characteristics of CGFS-bituminous coal blends at different ratios were studied, with numerical simulation verifying the swirl combustion-tangential combustion coupling scheme. Pilot tests showed that as CGFS ratio rose, furnace outlet NO_x first dropped from 355 mg/m³ to 107 mg/m³ then rose to 147 mg/m³, while burnout rate fell from 97% to 92.7%. Numerical simulations indicated 98% burnout for all blends, low NO_x emissions under all conditions, and consistent furnace combustion state with pilot tests. Considered fuel burnout and NO_x emissions, the 0-100% blending ratio maintained ignition and stable combustion. This technology enables efficient combustion of ultra-low-volatile CGFS without auxiliary fuel; the precombustion chamber swirl-tangential combustion scheme suits full-size power plant boilers. The study confirms the feasibility of using the swirl burner for large-scale co-firing of powdered solid waste in power plant boilers, supporting solid waste resource utilization, power plant energy conservation, carbon reduction, and cost control.