液氮容器内支撑玻璃钢管隔热的有限元分析.docVIP

液氮容器内支撑玻璃钢管隔热的有限元分析 摘 要 在了解低温容器的国内外研究现状的基础上，对低温储罐的内支撑结构进行有限元热分析。先比较几套网格划分方案，分析内支撑模型中，单元数与节点数对计算精度的影响，确定出合理的划分网格。再根据支承结构的特点建立玻璃钢管内支承结构有限元热分析简化模型，分析了长度、直径和厚度数据对玻璃钢管内支承漏热量的影响规律，并进行比较。分别绘出温度场、热流分布以及温度梯度图表，通过对图表的分析和比较，得到玻璃钢管长度、直径和厚度对传热量的影响规律。当长度L、直径D固定不变，厚度δ越大，造成玻璃钢上的温度差缩小，总传热量增大，平均热流随厚度δ的增加下降。当长度L、厚度δ固定不变，直径D越大，玻璃钢上的温度场分布变化不大，热流略有增大，漏热量增大，且平均热流随D的增大而增大。当厚度δ、直径D固定不变，长度L越大，玻璃钢上的温度场分布变化不大，总传热量减小；平均热流随长度L的增加下降。为今后工程设计以及热应力分析提供依据。 关键词：液氮低温储罐，内支撑结构，玻璃钢，网格划分，热应力，温度梯度 FINITE ELEMENT ANALYSIS OF HEAT INSULATION FOR THE FIBER GLASS INNER SUPPORTS OF LIQUID NITROGEN VESSEL ABSTRACT The main task of this thesis is to analysis thermal finite element for fiber glass inner supports of liquid nitrogen vessel. According to knowledge of cryogenic liquid nitrogen vessel in and abroad, the inner supports structure and the thermal properties of fiber glass pipe are studied based on the demands of the Mission of Graduate Design. Then the solution is operated after modeling. During the procedures above, the author compares several schemes with different numbers of element and node in order to establish the proper meshing control for the number of element and node affect the exactness when computing. Models of fiber glass pipe with different length, diameter and thickness are computed with ANSYS respectively, and the results are compared. According to the diagrams of temperature field, heat flux and temperature gradient, we can draw the graph of discipline of heat flow and obtain that: heat flow increases with the increasing of diameter and thickness, and decreases when length increases. The reliable gist is offered for thermal stress analysis and engineering design of special nitrogen vessel. KEY WORDS: liquid nitrogen vessel, inner support, fiber glass, mesh, thermal stress, temperature gradient. 目 录 第一章 概论…………………………………………………… 课题研究对象………………………………………………………………………………… 低温容器国内外研究现状……………………………………………………………… 有限元法在低温压力容器设计中的应用…………………………… 本人所做的主要工作……………………………………………………………… 第二章 液氮容器分析的有限元理论基础………………………………