Experimental characterization of anthracite combustion and NO emission for a 300-MWe down-fired boiler with a novel combustion system: Influence of primary and vent air distributions

NOx emissions of pulverized coal combustion in high‐temperature flue gas

“…During stable combustion, the maximum temperature in the CC was approximately 1,181°C, and the temperature difference in the 0–3,000 mm zone along the combustion path was within 230°C. In conventional combustion, the temperature difference in the main combustion zone is usually above 500°C 32–34 . Therefore, a more uniform temperature distribution was reached in the main combustion zone under this combustion mode, and there was no local high‐temperature zone in the main combustion zone; the local oxidation zone was avoided.…”

“…As the secondary air was injected incrementally, the combustible content in the fuel gradually decreased, and the combustion temperature decreased accordingly. The temperature of the tail flue gas was 619 C. During stable combustion, the maximum temperature in the CC was approximately 1,181 C, and the temperature difference in the 0-3,000 mm zone along the combustion path was within 230 C. In conventional combustion, the temperature difference in the main combustion zone is usually above 500 C. [32][33][34] Therefore, a more uniform temperature distribution was reached in…”

“…The original emissions of NO x were only 187.2 mg/m 3 (@6% O 2 ), and the conversion ratio of fuel-nitrogen to NO x was approximately 16.6%. Compared with the original NO x emissions (600-800 mg/m 3 @6% O 2 ) in conventional pulverized coal combustion technology, 33,34 the advantages of this technology route are great.…”

Multi-injection multi-staging combustion mechanistic studies and down-fired boiler technology

“…(3) 二次风引射浓煤粉气流, 浓煤粉气流入炉后速 度大幅度升高 图6为英巴350-MW W火焰锅炉额定负荷模化工 况下不同三次风率前墙侧下行气流的最大竖直速度衰 减曲线 [40] . 拱部下行气流自离开喷口后, [38,41] ; 煤粉在 氧化性气氛下燃烧, NO x 生成量大 [42] . .…”

Impact of the upper/lower furnace depth ratio on the strengthened low‐NOx combustion performance in a two‐stage W‐shaped flame furnace

“…Steer et al 12 and Liu et al 13 trialed a co‐firing solution by respectively adding biomass and bituminous coal to replace the sole anthracite fuel scheme and gained improved combustion performance and reduced NO x emissions. With respect to B&W furnaces uniquely equipped with swirl burners, Wang et al 14 relied on (i) raising the swirl burner's primary air velocity to improve ignition and increase the downward main flame penetration in the lower furnace for high burnout and (ii) deepening the air‐staging by positioning overfire air (OFA) so as to lower NO x emissions. For MBEL furnaces, Liu et al 15 took the fuel‐lean coal/air flow (positioned in the near‐wall side with low temperature levels) as the major cause for the final poor‐burnout problem, while Ma et al 16 attributed it to the unreasonable staged‐air box configuration with a large air‐box space but narrow staged‐air port area.…”