高压容器平盖区域有限元应力分析

发布时间：2018-01-12 07:10

本文关键词：高压容器平盖区域有限元应力分析　出处：《河北科技大学》2011年硕士论文　论文类型：学位论文

【摘要】：高压容器由于承受较高的压力,有些情况下还同时承受较高温度,一旦失效后果十分严重。因此,高压容器的安全问题倍受科学界和工程界的关注。在常规设计中,高压容器各部件强度设计一般根据相应公式进行计算,通过取较大的安全系数来保障其安全性,因此会造成较大的材料浪费。有限元方法的引入为高压容器设计理念和设计方法的进步带来了新的契机,本文采用有限元方法,运用ANSYS12.1软件对高压容器平盖进行了分析研究,主要工作及结论如下: (1)本文以氨合成塔平盖为例,通过材料属性定义、三维有限元模型建立、划分网格、施加载荷、计算求解和结果分析,完成了氨合成塔平盖的分析设计,分析结果表明应力值较大的区域为平盖上开孔和开槽等结构不连续处,会产生较大的集中应力,多个集中应力作用在同一个平面上,会导致危险截面的形成,最先引起平盖失效。 (2)分别建立了氨合成塔平盖的位移场、温度场和热—结构耦合场,通过对两种工况,即单纯机械载荷作用下和机械载荷与温度载荷共同作用下应力分布结果进行分析对比,结果表明热—结构耦合场中计算出的应力值与位移场中计算出的应力值相比较均有不同程度的增加,最大应力值增加了97%,即使这样该平盖的应力值仍然远小于设计应力强度值,说明在常规设计方法中,平盖的设计偏于安全。 (3)针对上述结果分析出的不合理现象,提出了两套改进方案。方案一优化了平盖的开孔位置,通过改进前后热—结构耦合场路径计算结果的对比,得出减少危险截面上结构不连续区域可以改善平盖的受力情况。方案二在改变平盖开孔位置的基础上厚度减小55mm,重量减少12%,热—结构耦合场校核结果仍然满足强度要求,说明改进成功,体现了分析设计的优越性。
[Abstract]:Because of the high pressure, the high pressure vessel is also subjected to higher temperature in some cases, once the consequences of failure are very serious. The safety of high pressure vessel has attracted much attention from the scientific and engineering circles. In the conventional design, the strength design of each component of the high pressure vessel is generally calculated according to the corresponding formula. By taking a larger safety factor to ensure its safety, it will cause a large waste of materials. The introduction of finite element method brings a new opportunity for the development of the design concept and design method of high pressure vessel. In this paper, the finite element method is adopted. The flat cover of high pressure vessel is analyzed by using ANSYS12.1 software. The main work and conclusions are as follows: 1) taking the flat cover of ammonia converter as an example, through the definition of material attribute, the establishment of three-dimensional finite element model, the mesh division, the application of load, the calculation solution and the result analysis, the analysis and design of the flat cover of ammonia synthesis tower are completed. The analysis results show that the region with higher stress value is the discontinuity of the structure such as opening and grooving on the flat cover, which will produce greater concentration stress, and many concentrated stresses acting on the same plane will lead to the formation of dangerous section. The flat cover was first invalidated. 2) the displacement field, temperature field and thermal-structure coupling field of the flat cover of ammonia converter are established respectively. That is to say, the stress distribution results under the simple mechanical load and the combined mechanical load and temperature load are analyzed and compared. The results show that the calculated stress values in the thermal-structural coupling field are increased in varying degrees compared with the stress values calculated in the displacement field, and the maximum stress value has increased by 97%. Even then, the stress value of the flat cover is still much smaller than the design stress intensity value, which shows that the design of the flat cover is more safe in the conventional design method. 3) aiming at the unreasonable phenomenon analyzed by the above results, two sets of improvement schemes are put forward. One is to optimize the opening position of the flat cover, and to compare the calculated results of the thermal-structure coupling field path before and after the improvement. It is concluded that reducing the discontinuous area of the structure on the dangerous section can improve the stress of the flat cover. The second scheme reduces the thickness and weight by 55 mm and 12% on the basis of changing the orifice position of the flat cover. The results of thermal-structural coupling field check still meet the strength requirement, which shows that the improvement is successful and shows the superiority of analysis and design.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH49

【引证文献】