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.

朱双(1998—),女,四川成都人,硕士研究生。E-mail:zhushuang212@mails.ucas.ac.cn

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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.