Numerical evaluation of the effect of swirl configuration and fuel-rich environment on combustion and emission characteristics in a coal-fired boiler
Numerical evaluation of the effect of swirl configuration and fuel-rich environment on combustion and emission characteristics in a coal-fired boiler
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DOI：
10.1016/j.energy.2022.126591
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发表时间：
2022-12
期刊：
影响因子：
9
通讯作者：
Minsung Choi;Tae-Gu Hwang;Yeseul Park;Xinzhuo Li;Junsung Kim;Kibeom Kim;Yonmo Sung;G. Choi
中科院分区：
文献类型：
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作者：
Minsung Choi;Tae-Gu Hwang;Yeseul Park;Xinzhuo Li;Junsung Kim;Kibeom Kim;Yonmo Sung;G. Choi
采用网格和模型进行数值评估，并与实验结果进行比较，研究旋流配置和富燃料环境对16kWth燃煤锅炉火焰现象、煤颗粒均匀性和燃烧特性的影响。此外，通过基于生命周期评估方法计算环境成本，评估现有技术应用于燃煤发电以减少污染物排放和提高燃烧效率的适宜性。由于内部回流区和排气管涡流的产生，同旋火焰的煤颗粒比反旋火焰的煤颗粒分散更均匀。因此，锅炉内部形成均匀的燃尽区。反旋火焰在氮氧化物排放和未燃烧煤颗粒 (UCP) 与旋流强度的增加或减少方面表现出成比例的结果。然而，同旋火焰具有协同效应，可以将 NOx 和 UCP 排放量分别降低至 102.4 ppm (@6%O2) 和 1.23 g/m3。考虑到所有富含燃料的环境中NOx、SO2、CO2和UCP排放的外部环境成本，空气分级技术的应用可以将环境成本从每天0.003美元降低到0.015美元。
A numerical evaluation using mesh and models verified by comparison with experimental results was performed to investigate the effects of swirl configuration and fuel-rich environment on the flame phenomenon, uniformity of coal particles, and combustion characteristics in a 16-kWthcoal-fired boiler. In addition, the suitability of the application of existing technologies to coal-fired power generation to reduce pollutant emissions and enhance the combustion efficiency was evaluated by calculating environmental costs based on the life cycle assessment method. The coal particles of the co-swirling flame were more uniformly dispersed than those of the counter-swirling flame because of the generation of the inner recirculation zone and exhaust tube vortex. Therefore, the burnout zone was evenly formed inside the boiler. Counter-swirling flames exhibit proportional results in terms of the increase or decrease in NOxemissions and unburned coal particles (UCPs) with swirl intensity. However, co-swirling flames have a synergistic effect that can reduce the NOxand UCPs emissions up to 102.4 ppm (@6%O2) and 1.23 g/m3, respectively. Considering the external environmental costs for NOx, SO2, CO2, and UCPs emissions for all fuel-rich environments, the application of air staging technologies can reduce the environmental costs from $0.003 to $0.015 per day.