State Key Laboratory of Multi-phase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences
School of Chemical Engineering,University of Chinese Academy of Sciences
Liaoning Lvyuan Energy EnvironmentalProtection Technology
Sino-Danish College,University of Chinese Academy of Sciences

在双碳资源背景下,为实现煤炭的高效清洁利用,采用层燃复合细颗粒煤流化的燃烧方式可提升层燃炉上粗颗粒煤的燃烧效率。为了对这一现象给出理论解释,进行了相关机理实验研究。首先通过管式炉等温燃烧实验验证了复合燃烧方式的可行性:实验通过对比粗细煤混合燃烧与粗颗粒煤单独燃烧时的烟气组分变化、颗粒表面温度、着火时间和燃尽时间等参数,探究流化细煤存在下的燃烧效果;并结合气相和固相侧数据分析分别对照说明了流化细煤的促燃作用。其次,系统地研究了床层温度、细煤占比以及空气风量对粗细混煤燃烧的影响,重点考察了着火时间、燃尽时间、碳转化率、颗粒表面温度和反应指数,为复合燃烧方式在层燃炉上的实践提供理论指导。此外,为了深入了解煤燃烧难易程度,采用等转化率法对粗细混煤燃烧进行动力学分析。等温燃烧实验结果表明,在流化细煤存在的情况下,着火时间提前了59%,燃尽时间缩短了26%,燃烧6min后固体失重率高达98%,表现出良好的引燃和促燃效果。因素探究实验显示,燃烧的流化细煤在粗煤周围产生了高温区,粗细煤混合燃烧时在较低工作温度(550℃)下即可快速引燃,最佳细煤占比为33%。增大空气风量能提前着火,并且显著缩短燃尽时间,但较高风速会带来对流冷却。动力学计算给出平均表观活化能为26.37kJ/mol。

Abstract:In the context of dual-carbon resources,in order to achieve efficient and clean utilization of coal,an improved layercombustion method coupled with fluidized fine coal particles is adopted to enhance the combustion efficiency of coarse coal in gratefurnace. Experiments are conducted to provide theoretical explanations for this phenomenon. Firstly,the feasibility of the compositecombustion method was confirmed by isothermal combustion experiments within the tube furnace. Combustion characteristics arecompared between cases of mixed fine/coarse coal and single coarse coal particle,in terms of flue gas composition,particle surfacetemperature,ignition time,and burn-out time. Both gas phase and solid phase data were analyzed to verify the combustion-promotingeffect of fluidized fine coal. In addition,the influence of bed temperature,proportion of fine coal,and air flow on the combustion of mixedfine and coarse coal was systematically studied,with a focus on ignition time,burnout time,carbon conversion rate,particle surfacetemperature,and reaction index. This provides theoretical guidance for the practical application of the composite combustion method inlayer combustion furnaces. To gain a deeper insight,an isoconversion method was used to analyze the combustion of mixed fine andcoarse coal. The data indicate that,in the presence of fluidized fine coal,the ignition time is advanced by 59%,the burnout time is shortened by 26%,and the solid weight loss ratio is up to 98% within 6 minutes,demonstrating excellent ignition and combustionpromotion effects. Factorial experiments show that the burning fluidized fine coal creates a high-temperature zone around the coarse coal.When the coarse and fine coals are mixed and burned,they can be ignited quickly at lower temperature (550°C). The optimized finecoal proportion is 33%. Furthermore,increasing the air flowrate can lead to early ignition and significantly shorten the burn-out time,buthigher wind speeds will bring about convective cooling. Finally,kinetic calculations give an average apparent activation energy of 26.37kJ/mol.

中国科学院战略性先导科技专项课题“工业锅炉高效燃烧关键技术与示范”资助项目(XDA29020400)

朱双,郭强,范垂钢,等.细颗粒煤流化强化层燃燃烧机理分析与实验[J].洁净煤技术,2025,31(2):1−10.

ZHU Shuang,GUO Qiang,FAN Chuigang,et al. Mechanism analysis and experiment for fluidized fine coals assistingstoker furnace combustion[J].Clean Coal Technology,2025,31(2):1−10.