【作者】 王健；

【导师】 白明华； 郭延军；

【作者基本信息】 燕山大学 ， 机械工程， 2013， 硕士

【摘要】 非高炉炼铁是钢铁工业发展的前沿技术之一，炼钢技术也从当初的长流程向短流程发展，要发展电炉短流程就需要大量的废钢，而国内的废钢还是比较短缺的，直接还原铁就可以很好的作为废钢的替代品。因此，研究直接还原相关技术与设备是有重要而深远的意义。研究直接还原技术先要了解目前的直接还原工艺，在仔细分析了希尔法、MIDREX法之后，主要针对直接还原过程中最少还原气量进行了分析探讨，并分析了影响直接还原速度的主要因素及提高其速度的途径。主要从反应热力学的角度对反应吉布斯自由能、平衡常数、理论最大生产量、热力学温度等进行了分析研究。在之前分析研究的基础上采用ANSYS软件建立了DRI竖炉还原段的数值模型，采用FLUENT对其还原过程进行了气固传热数值求解，获得了DRI竖炉的还原段的温度分布情况、DRI还原竖炉的热效率、还原气体在DRI竖炉内的分布情况，还原气量、还原气温度、还原气压力对其温度分布的影响。气流的分布情况直接影响着还原气的利用率、直接还原铁的金属化率等，而竖炉内的物料稀疏分布及运动规律对气流的分布起着至关重要的作用。竖炉内的物料运动又受到竖炉出料装置控制。分析了竖炉内物料的运动规律，针对螺旋出料装置，分析了不同螺旋结构下的物料运动情况，通过分析对比得出最适合DRI竖炉的螺旋出料装置。由于该螺旋卸料装置长时间工作在850℃高温的环境中，在高温条件下，即使是采用耐高温材料制造螺旋叶片，它的磨损速度也是非常快的。为了提高该装置的使用寿命，采用冷却水对该设备进行冷却；并且采用热-力共同求解方法对冷却效果进行分析。更多还原

【Abstract】 With the development of short steel-making instead of traditional BF-BOF process inthe world and the increasing shortage of appropriate scraps as iron resource, the directreduction iron production technology as an alternative method has attracted researchersmore and more concern day by day.First of all, the minimum requirement of direct reduction gas was calculated andanalyzed on the basis of dominant gas-based HYL and MIDREX technology, duringwhich the main factors of influencing the speed of direct reduction were also analyzed, theways to increase its speed were raised, and thermodynamics reaction gibbs free energy,equilibrium constant, theoretical maximum output and thermodynamic temperature werestudied.Secondly, a numerical model was established for simulating the reduction section ofthe DRI shaft furnace through ANSYS software. The FLUENT software was adopted toget the numerical solution for heat transfer between gas and solid during its reductionprocess. In this way, the temperature distribution in the shaft furnace, thermal efficiencyand reduction gas distribution in DRI shaft furnace were obtained. The affect of volume,temperature, and the pressure of the reducing gas on its temperature distribution wasanalyzed.At last the materials movement in the furnace was analyzed because it played a vitalrole in the gas flow distribution, which was directly related with the efficiency ofreduction gas and metallization ratio of DRI. Research showed that the movement wascontrolled by the discharge device of the furnace. Materials motion under different screwstructures conditions were compared, and the most suitable one of which was selected tobe the discharge device.The wearing rate of the screw was very rapid because of the high environmenttemperature up to850℃in a continuous long time, even though the screw blade wasmade of heat-resisting material. In order to improve the service life of the device, thecooling water was prepared for cooling the equipment. The heat-force interaction method was adopted to analyze the cooling effect.更多还原