摘要
针对无烟煤在锅炉中燃烧时灰渣易熔融沉积、影响运行安全与经济性的问题,通过搭建 0.4 MW 一维沉降炉中试系统,开展了多种负荷、配风比例及过量空气系数条件下的燃烧试验;结合灰熔融特性、SEM、XRD、XRF 及激光粒度分析等手段,系统研究了灰渣形貌、成分与粒度特性随工况的演变规律。结果表明,灰渣主要元素为 C、O、Si 和 Al,主要晶相为石英、莫来石和赤铁矿,不同工况下晶相类型保持稳定。负荷由 0.2 MW 提高至 0.3 MW 时,灰渣变形温度由 1259℃提高至 1312℃,结渣指数由 1268 增至 1319,结渣风险显著增强。一/二次风比由 2/8 提高至 4/6,灰渣未燃碳质量分数可由约 37.5%提高至40%,中位粒径由约 22μm 可增大至约 28μm,沉积倾向明显加剧;相比之下,过量空气系数由 1.2 提高至 1.4 对灰熔融特性及结渣指数的影响较小。粒度分布以细颗粒为主、粗颗粒并存的双峰特征,细颗粒形成黏附基底层,粗颗粒通过惯性撞击强化沉积,共同促进结渣发展。研究表明,负荷是影响无烟煤结渣行为的主导因素,配风方式通过调控燃尽与颗粒特性间接影响结渣倾向。本研究为宽负荷工况下无烟煤锅炉的结渣预测与燃烧优化提供了中试数据支撑。
Abstract
This study investigates the ash deposition behavior of anthracite during combustion, which significantly affects boiler safety and efficiency due to slagging tendencies. A pilot-scale one-dimensional settling furnace system was employed to conduct combustion experiments under varied operating conditions, including different loads, primary/secondary air ratios, and excess air coefficients. Ash samples were analyzed by fusion tests, SEM, XRD, XRF, and laser sizing. Results show ash composition (C, O, Si, Al) and crystalline phases (quartz, mullite, hematite) remain stable. Increasing the load from 0.2 MW to 0.3 MW raises the ash deformation temperature from 1259 °C to 1312 °C, while the slagging index increases from 1268 to 1319, indicating a significantly enhanced slagging tendency. When the mass ratio of primary air to secondary air is increased from 2/8 to 4/6, the unburned carbon content in ash increases from approximately 37.5% to 40%, and the median particle size enlarges from 22 μm to about 28 μm, resulting in a pronounced promotion of ash deposition. Excess air coefficient had limited impact on fusibility and slagging. Ash exhibited a bimodal size distribution: fine particles form an adhesive layer, while coarse particles deposit by impaction, jointly accelerating slagging. The results demonstrate that boiler load dominates slagging behavior, with air distribution affecting burnout and particle characteristics. This study provides pilot-scale experimental data and mechanistic insights for slagging prediction and combustion optimization of anthracite-fired boilers under wide-load operation.
关键词
无烟煤燃烧 /
一维沉降炉中试实验 /
灰渣特性 /
矿物转化 /
结渣倾向
Key words
Anthracite coal combustion /
One-dimensional settling furnace pilot-scale experiment /
Ash Characteristics /
Mineral Transformation /
Slagging tendency
葛文韬, 陈 猛, 王晨宇, 穆 林, 东 明, 王 储.
无烟煤中低负荷燃烧结渣特性及成分演化的实验研究[J]. 分布式能源, 0 https://doi.org/10.16513/J.2096-2185.DE.26110061.
GE Wentao , CHEN Meng , WANG Chenyu , MU Lin , DONG Ming , WANG Chu.
Experimental Study on Slagging Characteristics and Composition Evolution of Anthracite Coal at Low to Medium Loads[J]. Distributed Energy, 0 https://doi.org/10.16513/J.2096-2185.DE.26110061.
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基金
国家重点研发计划(2024YFB4104801);国家自然科学基金(52306283);中央高校基本科研业务费资助(DUT24RC(3)073)