PDF《博士学位论文公示材料》

最后,在 铜冷却壁最优管型选择的基础上,为降低高温失效的风险,模拟高炉正常工况条件对开炉初期椭圆型 冷却水管铜冷却壁镶砖热面未覆盖渣皮的炉腹传热模型进行热力耦合计算,从铜冷却壁本体温度安全 性角度出发,基于响应面法和 Monte-Carlo 模拟分析法以铜冷却壁本体厚度、冷却比表面积、冷却水水 速和冷却水温度为比较序列,以铜冷却壁本体最高温度为指标,定量化计算各参数与指标参数间的相 互关联程度,并将响应面模型和 NSGA-Ⅱ遗传算法相结合以铜冷却壁本体最大热应力为优化目标,对 炉腹区结构进行结构参数和长寿技术优化.通过对比发现优化后的炉腹区结构在传热特性和力学性能 方面均得到明显改善,同时减少了冷却水流量和减薄了冷却壁本体厚度,降低了企业炼铁成本,于此 同时也验证了响应面法和 NSGA-Ⅱ遗传算法相结合对高炉炉腹区结构进行优化分析的有效性. (4)高炉新建或大修的烘炉是一个重要的提高炉体耐火材料砌筑结构性能的工艺过程.本文以某 1750m3 高炉为例, 首先利用 CFD 流体软件建立炉缸炉底烘炉炉气流动模型来对高炉烘炉过程中炉缸炉 底区域的炉气流动特性规律进行分析,探讨了高炉烘炉过程中烘炉炉气与炉缸炉底热面材料间的综合 ―2― 对流换热系数随各因素变化的规律关系;

其次,对炉缸炉底烘炉传热模型进行烘炉条件下的传热特性 分析,得到炉缸炉底各层结构温度场随各因素变化的关联式;

最后,对高炉烘炉制度的重点环节:炉 气温升曲线、炉气风量曲线及冷却水流速调节这几方面存在的问题,通过理论分析并结合以往高炉烘 炉实践经验,提出更科学、合理、优化的烘炉制度,使高炉烘炉更高效、节能. ―3― 论文摘要(英文) With the continuous improvement of ironmaking level, the longevity of blast furnace has become a common concern of ironmaking workers and researchers, and also an important guarantee for high efficiency and low consumption in iron and steel enterprises. The middle and lower part of BF mainly includes high heat load areas such as furnace belly and furnace waist directly washed by gas flow and furnace charge, as well as hearth and furnace bottom areas in direct contact with liquid molten iron. The life and safety of the lining in the middle and lower part of BF is the main limit of its service hours. How to prolong the service life of BF and realize a scientific furnace blowing out under the premise of safety and ensuring certain smelting intensity and productivity are important issues related to safety and production cost. The basis and foundation of long life of BF mainly depends on the proper selection of refractory materials, reasonable lining masonry structure and size parameters, efficient lining cooling equipment and scientific and standardized heating-up system. This article mainly researches the above aspects, and in the process of simulating and analyzing the thermodynamic coupling characteristics under the condition of furnace heating and opening in the middle and lower part of BF, the basic long-life technology which is used to realize the longevity operation of BF, is analyzed and optimized as well. The main contents of this paper are as follows: (1) High-quality refractory is the most basic condition for a reasonable lining masonry structure. Therefore, a reasonable, accurate and true evaluation of the changing laws of thermophysical properties and mechanical properties of refractories for BF is not only of guiding significance for the preparation of refractories, but also provides security for the reliable and stable operation of refractories in the service process of BF. Based on the lack of data, this article conducts a multi-factor regular contacted experiment on the thermal properties and mechanical properties of unshaped refractory closely related to the thermodynamic coupling calculation of the furnace lining structure with professional instruments, and comprehensively describes the mechanical properties of carbon ramming material in an uncured state through the triaxial variable confining pressure cycle experiment, it can not only select high-quality refractory materials for new or overhaul blast furnaces, but also provide parameters that meet the actual state for the simulation calculation of coupling characteristics. (2) On the premise of selecting high-quality refractory materials, reasonable masonry structure and size parameters of hearth and bottom become the main factors that determine the service life of the furnace. This article firstly analyzes the heat transfer characteristics of different masonry structures of BF hearth, aiming at the problem of whether large or small carbon bricks are used in the masonry structure of BF hearth at present, and the characteristics of heat transfer characteristics of the two types of hearth masonry structures are obtained according to whether the furnace hearth tamping filler layer can reach the optimal solidification temperature in the furnace baking state and the difficulty of forming a stable slag iron protective layer on the brick lining hot surface in the furnace opening state;