考虑热—应力耦合作用和地震作用的顶燃式热风炉炉壳分析与优化设计

发布时间：2019-05-23 22:16

【摘要】：热风炉是炼铁生产中的重要设备，作为一种新型热风炉，顶燃式热风炉具备高风温、高热效率和长寿命等优点，自从被投入使用就受到了广泛关注，拥有良好的应用前景。目前我国对顶燃式热风炉的设计依据主要为《炼铁工艺炉炉壳结构技术规范》和以往经验，然而规范中关于温度作用、地震作用等对炉壳所产生的影响未做出明确的要求，炉壳厚度的计算公式也缺乏足够的理论依据。所以对顶燃式热风炉进行多种工况下的有限元分析，并对炉壳厚度进行合理的优化对于今后同类热风炉的设计具有指导意义，，同时最终的优化方案也具备一定的工程价值。本文所做的工作主要有三个方面：一、以有限元理论和相关的壳体理论知识为基础，借助有限元分析软件Ansys的APDL语言，建立了与实际炉壳结构相符的有限元模型，对炉壳模型进行了合理的板带划分并且对炉壳厚度实现参数化，为后续的优化工作打好了基础；二、考虑热-应力耦合作用、静力荷载作用以及地震作用三种影响因素，对炉壳结构分别进行了各种工况下的有限元分析得到了各工况下的应力分布和位移形变，并按照规范要求进行了最不利荷载的组合和最不利荷载作用的分析；三、通过对最不利荷载组合作用下的炉壳结构进行有限元分析，以炉壳的厚度为设计变量、各板带的最大应力为状态变量、容许应力值为约束条件实现了最终的优化目标——炉壳结构用钢量最少，并将优后的设计方案与优化前进行了对比分析。通过以上三个方面的工作本文得出以下主要结论：（1）与其它各荷载作用相比，炉壳在内部气体压力作用下产生的应力最大，所以炉壳内部气体压力是影响炉壳厚度的主要因素；（2）热-应力耦合作用对炉壳的位移形变影响较大，位移形变受到约束的部位是应力产生的主要部位；（3）地震作用对炉壳整体的影响较小，但是对于炉缸段的影响在设计时不应完全忽略；（4）经过优化得到的最终优化方案比原设计方案的用钢量减少了14.3%，优化后炉壳结构的薄弱部位（部分孔口边缘及炉缸段等）厚度有所增加，其它部位炉壳厚度明显减小，整体应力分布更加均匀。
[Abstract]:Hot blast stove is an important equipment in ironmaking production. as a new type of hot blast furnace, top combustion hot blast furnace has the advantages of high air temperature, high thermal efficiency and long life. It has been widely concerned and has a good application prospect since it was put into use. At present, the design basis of top combustion hot blast furnace in our country is mainly "Technical Specification for shell structure of ironmaking process furnace" and previous experience. However, there are no clear requirements for the influence of temperature action and seismic action on furnace shell in the code. The formula for calculating the thickness of furnace shell is also lack of sufficient theoretical basis. Therefore, the finite element analysis of the top combustion hot blast furnace under various working conditions, and the reasonable optimization of the shell thickness is of guiding significance for the design of the same kind of hot blast furnace in the future, and the final optimization scheme also has certain engineering value. There are three main aspects of the work done in this paper: first, based on the finite element theory and the related shell theory knowledge, with the help of the APDL language of the finite element analysis software Ansys, a finite element model consistent with the actual shell structure is established. The shell model is divided reasonably and the thickness of the furnace shell is parameterized, which lays a good foundation for the subsequent optimization work. Second, considering the thermal-stress coupling, static load and seismic action, the finite element analysis of the shell structure under various working conditions is carried out to obtain the stress distribution and displacement deformation under each working condition. According to the requirements of the code, the combination of the most unfavorable loads and the analysis of the most unfavorable loads are carried out. Third, through the finite element analysis of the shell structure under the action of the most unfavorable load combination, the thickness of the furnace shell is taken as the design variable, and the maximum stress of each plate and belt is taken as the state variable. The allowable stress value is the constraint condition to achieve the final optimization goal-the minimum amount of steel used in the shell structure, and the optimized design scheme is compared with that before optimization. Through the above three aspects of work, this paper draws the following main conclusions: (1) compared with other loads, the shell produces the greatest stress under the action of internal gas pressure. Therefore, the gas pressure in the shell is the main factor affecting the thickness of the shell. (2) the coupling of heat and stress has a great influence on the displacement deformation of the furnace shell, and the part where the displacement deformation is constrained is the main part of the stress generation; (3) the influence of seismic action on the whole furnace shell is small, but the influence on the cylinder section should not be completely ignored in the design; (4) compared with the original design scheme, the steel consumption of the optimized final optimization scheme is reduced by 14.3%, and the thickness of the weak part of the shell structure (part of the orifice edge and cylinder section, etc.) increases after optimization. The thickness of furnace shell in other parts is obviously reduced, and the overall stress distribution is more uniform.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU273.2;TF321

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