转底炉分区域供热研究

Research on the heat supply of different sections in a rotary hearth furnace

  • 摘要: 基于国内转底炉直接还原炼铁在起步阶段亟待解决的热工系统问题,分别以系统分析、热模拟实验和数值模拟为手段,对转底炉分段热工参数进行了研究.建立了转底炉冶金模型和热模型(涉及变量83个、参数20个),模拟计算结果表明,每生产1t金属化球团,需铁精粉1213kg,消耗煤粉283kg、煤气615kg.基于转底炉分区域系统分析,分别进行了预热段、加热段、还原段条件下的热模拟实验研究,确定出不同工况下(nCnO=0.8~1.2)含碳球团于各段的实时还原进度,并依据含碳球团自还原吸热与热工参数的匹配,确定出各段燃料供应参数.使用Fluent模拟软件对分段热工参数进行了验证,结果表明分段热工参数设计合理,能有效实现转底炉的分段职能,为转底炉的优化设计提供了基础.

     

    Abstract: To solve the urgent problems in the thermal system at the initial stage of producing direct reduced iron(DRI) in a rotary hearth furnace(RHF) in China,thermal parameters in different sections of RHF were analyzed by systematic analysis,thermal simulation experiments,and numerical simulation. The RHF mathematical model and heat supply model were established with 83 variables and 20 parameters. The result of numerical simulation indicates that producing every 1 t metalized pellet needs 1213 kg iron ore fines,283 kg pulverized coal,and 615 kg coal gas. Based on the systematic analysis on different sections of the rotary hearth furnace,thermal simulation experiments on preheating,heating,and reducing sections were studied separately. Under different conditions(nC:nO=0.8~1.2),the real-time reduction progresses of carbon-bearing pellets in these sections were confirmed. According to the matching of the self-reduction decalescence of carbon-bearing pellets and thermal parameters,the fuel supply parameters of each section were determined. Fluent simulation software was used to verify the thermal parameters of the three sections. And the results show that the designed parameters are reasonable,and can effectively implement the functions of all the sections of a rotary hearth furnace,which provide the theoretical basis for the optimization design of the rotary hearth furnace.

     

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