毕业论文示例讲义.doc

2015 届毕业设计（论文） 题 目：加氢反应器弓形格栅数值模拟研究 专 业：机械工程及自动化 班 级： 机械1107 姓 名： 赵 冬 指导老师： 周建新 起讫日期：2015.3.1—2015.6.10 2015年 6月摘 要 本文针对某化工厂加氢反应器中弓形格栅催化剂泄露问题，采用ANSYS软件对加氢反应器321不锈钢弓形格栅在使用温度和过温条件下的温度场和变形进行数值模拟研究。模拟过程中按照实际弓形格栅尺寸建立了三维实体模型，并采用顺序耦合对弓形格栅进行了模拟计算。在高温条件下，格栅温度不均匀，最高温差约为70-80℃。由于格栅整体热膨胀，导致格栅产生较大内应力。390℃和486℃条件下对称面上最大压应力分别为-140MPa和-200MPa，冷却到室温变为拉应力，均约为250MPa。在高温390℃条件下，两弓形格栅对称面下端最大间隙为2.64mm，按照计算结果催化剂。在高温486℃条件下，两弓形格栅对称面下端最大间隙为4.58mm，按照模拟计算结果，催化剂两格栅间隙仍不会泄漏，但如果两弓形格栅在装配时有2mm及以上间隙，则两弓形格栅间隙将大于6.58mm，将会导致催化剂仍泄漏。 ABSTRACT Aiming at catalyst leakage on arch grille in the hydrogenation reactor for a chemical plant, the temperature field and deformation of 321 stainless steel arch grille in hydrogenation reactor under operating temperature and overheat conditions were simulated using ANSYS software. Three-dimensional solid model was established according to the actual arch grille size, and the arch grille was calculated by sequential coupling method. At high temperatures, the temperature on grille is uneven, and the maximum temperature difference is about 70-80℃ Due to overall thermal expansion of grille, grille causes greater internal stress. The maximum compressive stresses on symmetrical surface at 390℃ and 486℃ conditions are -140MPa and -200MPa. It changes to a tensile stress of about 250MPa when cooling to ambient temperature. The lower grille maximum gap is 2.64mm under 390℃ at the bottom of two arch grilles. According to the results, catalysts do not leak. The lower grille maximum gap is 4.58mm under 486℃ at the bottom of two arch grilles. According to the results, catalysts do not still leak. However，if there is more than 2mm gap between two arch grilles, the gap between two arch grilles will reaches 6.58mm and catalysts will leak. Keywords: hydrogenation reactor; arcuate grid; finite element; deformation; temperature field 目 录 摘 要 I ABSTRACT II 第一章 绪论 1 1.1 课题研究的意义及背景 1 1.2 加氢反应器的发展概况 1