LNG薄膜型液舱围护系统设计与分析研究

发布时间：2018-05-18 07:27

本文选题：围护系统 + 晃荡冲击荷载　；参考：《大连理工大学》2015年硕士论文

【摘要】：因传统能源造成的环境污染问题越来越显著,清洁能源天然气的开发成为世界各国能源战略重点。由于更多的天然气能源分布于深远海及散布的小型气田,这促使新型浮式液化天然气装置(Floating Liquid Natural Gas, FLNG)开发形式成为研究的重点。而低温储液舱是浮式液化天然气装置上储存液化天然气的重要组成装备。但由于舱容不断地向大型化容积发展且装载率没有限制,使得低温储液舱的设计与制造困难重重。其中在晃荡冲击荷载和超低温环境共同作用下围护系统结构的安全性是最关键的力学问题。为此本文基于模型试验和有限元方法研究分析围护系统结构力学性能及保温性能。在部分装载的情况下,对液舱围护系统结构安全造成严重威胁的关键因素之一是晃荡冲击荷载。大比尺室内晃荡模型试验能比较真实地反映液舱内液体晃荡现象,是研究分析晃荡冲击荷载最广泛的方法和手段。本文利用先进的晃荡模型试验研究方法,分析晃荡冲击荷载的基本特点。采用合理有效的极值统计方法,统计分析并设计用于结构分析的晃荡冲击荷载。在此基础上,建立围护系统截面单元有限元模型,对围护系统结构承受晃荡冲击荷载作用下的动力响应进行分析,找到围护系统结构的关键失效位置,并展开晃荡冲击荷载大小和形式以及结构尺寸参数对关键失效位置的响应影响分析。同时,通过建立液舱结构模型对其进行了热传导稳态分析,获得了液舱段在不同边界条件下的温度场分布情况,计算了液舱内的日蒸发率和结构的低温热应力,分析校核了围护系统结构的保温绝热性能。本文研究内容可以为薄膜型液舱围护系统的性能评估及设计提供一定的参考和分析基础。
[Abstract]:Because of the environmental pollution caused by traditional energy, the development of clean energy natural gas has become the focus of energy strategy all over the world. Because more natural gas energy is distributed in the deep sea and scattered small gas fields, the development of new floating liquefied natural gas plant (Liquid Natural Gas, FLNG) becomes the focus of the research. The cryogenic tank is an important equipment for storing liquefied natural gas on floating liquefied natural gas (LNG) plant. However, the design and manufacture of cryogenic storage tanks are difficult because of the continuous development of tank capacity to large volume and the unlimited loading rate. The safety of the enclosure structure under the joint action of sloshing impact load and ultra-low temperature environment is the most critical mechanical problem. Therefore, based on the model test and finite element method, the mechanical properties and thermal insulation properties of the retaining system are analyzed. In the case of partial loading, the sloshing impact load is one of the key factors that pose a serious threat to the structural safety of the tank enclosure system. The large scale indoor sloshing model test can reflect the liquid sloshing phenomenon in the tank. It is the most extensive method and means to study and analyze the sloshing impact load. In this paper, the basic characteristics of sloshing impact load are analyzed by using advanced sloshing model test method. A reasonable and effective extreme value statistical method is used to analyze and design the sloshing impact load for structural analysis. On this basis, the finite element model of the section element of the enclosure system is established, and the dynamic response of the supporting system structure under the load of sloshing impact is analyzed, and the key failure position of the structure is found. The effects of the size and form of the sloshing impact load and the structural dimension parameters on the critical failure position are analyzed. At the same time, the heat conduction steady-state analysis of the tank structure model is carried out, the temperature field distribution of the tank section under different boundary conditions is obtained, the daily evaporation rate in the tank and the low temperature thermal stress of the structure are calculated. The insulation and adiabatic performance of the envelope structure is analyzed and checked. The research in this paper can provide a reference and analysis basis for the performance evaluation and design of the membrane tank envelope system.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE96

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