受限空间LNG爆炸后果模拟与吸能型防爆墙设计

发布时间：2018-05-05 09:48

本文选题：液化天然气(LNG) + 受限空间　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：随着液化天然气(LNG)在工业生产和人民生活中的广泛应用,天然气事故也逐渐涌现,尤其是在受限空间LNG发生泄漏爆炸事故,可能会引发连锁反应,从而造成重大的人员伤亡与财产损失。因此,非常有必要对LNG接收站容易发生气体泄漏并形成受限空间的区域进行风险分析,研究调压站等狭义受限空间以及场站广义受限空间的LNG泄漏爆炸事故后果,并依此有针对性的设计新型抗爆墙,实现降低爆炸冲击波对周围建筑及设备的破坏作用这一目的,从而为LNG产业顺利发展提供支持和保障。本文依托国家科技支撑计划课题“化学工业园区火灾防治技术研究”(2011BAK03B08),以LNG泄漏爆炸事故为研究对象,主要开展以下几个方面的研究:1、LNG接收站储罐区风险评估首先,以LNG接收站储罐为研究对象,建立储罐区发生气体泄漏燃爆事故树,找出导致罐区燃爆事故的基本事件和最小割集,分析计算各个基本事件的结构重要度,并对各基本事件结构重要度大小进行排列。其次,根据LNG接收站罐区以及液化天然气的特点,计算并确定火灾、爆炸危险指数与等级,并与采取各种补救措施之后计算的危险指数进行比较,通过定性与定量的分析提出合理的对策措施。2、LNG调压站受限空间泄漏模拟根据调压站的具体图纸尺寸以及站内管道高压气体泄漏具体参数,利用Fluent软件建立受限空间内天然气泄漏扩散的数学计算模型和物理模型,根据选定的天然气状态,对天然气泄漏扩散进行模拟,研究空间约束、通风条件及泄压窗开启与否等因素对扩散的影响,揭示其变化规律并获得气云在时间和空间上的分布特征,同时为AutoReaGas软件提供数据支持。3、受限空间内LNG爆炸后果模拟及敏感因素分析利用AutoReaGas软件建立调压站密闭空间爆炸模型,设定相应泄漏气体的爆炸初始参数值。以LNG泄漏模拟得到的空间内气体平均浓度值为输入,应用爆炸数值模型对受限空间气体爆炸进行讨论分析。研究空间约束、气体浓度值和有无泄压窗及泄压窗尺寸比值等因素对天然气爆炸压力分布的影响,获得某些特定时间的压力分布规律及超压分布场,为最终确定作用在结构上的爆炸载荷提供依据。4、缓冲吸能型防爆墙设计及抗爆效果模拟及结构优化设计针对LNG接收站内易发生爆炸的区域,充分利用吸能材料所具有良好吸收爆炸冲击波载荷的能力,设计具有较好抗爆效果的新型防爆墙。首先利用ANSYS/AutoDyn软件分别模拟普通型和吸能型防爆墙对爆炸冲击波加载的削弱影响,分析不同材料墙体对爆炸能量吸收作用的差异,然后研究吸能材料厚度长度等特征参数对爆炸能量吸收效果的不同,最终形成附着吸能材料的新型防爆墙优化设计方案,为其他建筑物和人员提供更好的防护作用。
[Abstract]:With the widespread application of liquefied natural gas (LNG) in industrial production and people's daily life, natural gas accidents are emerging gradually, especially in restricted space LNG leakage and explosion, which may lead to a chain reaction. Thus causing heavy casualties and property losses. Therefore, it is necessary to analyze the risk of the area where the gas leakage is easy to occur in the LNG receiving station and form the restricted space, and to study the consequences of the LNG leakage and explosion in the narrow restricted space such as the pressure regulating station and the generalized restricted space of the field station. In order to reduce the damage of blast wave to the surrounding buildings and equipments, a new type of anti-explosion wall is designed in order to provide support and guarantee for the smooth development of LNG industry. Based on the national science and technology support project, "study on fire prevention technology in chemical industrial park", and taking the LNG leakage and explosion accident as the research object, this paper mainly carries out the following research on the risk assessment of the storage tank area of the W1 LNG receiving station. Taking the storage tank of LNG receiving station as the research object, the tree of gas leakage and igniting accident occurred in the tank area is established, the basic events and minimum cut sets that lead to the explosion accident in the tank area are found out, and the structural importance of each basic event is analyzed and calculated. The importance of each basic event structure is arranged. Secondly, according to the characteristics of LNG receiving station tank area and liquefied natural gas, the fire and explosion risk index and grade are calculated and determined, and compared with the hazard index calculated after various remedial measures are taken. Through the qualitative and quantitative analysis, the reasonable countermeasures are put forward. The limited space leakage simulation of LNG regulating station is made according to the specific drawing size of the station and the specific parameters of the pipeline high pressure gas leakage in the station. The mathematical and physical models of natural gas leakage and diffusion in restricted space are established by using Fluent software. According to the selected natural gas state, the gas leakage diffusion is simulated, and the spatial constraints are studied. The effects of ventilation conditions and the opening of pressure relief windows on diffusion are revealed, and the distribution characteristics of gas clouds in time and space are obtained. At the same time, it provides data support for AutoReaGas software .3. the simulation of LNG explosion consequences in confined space and the analysis of sensitive factors. The airtight space explosion model of pressure regulating station is established by using AutoReaGas software, and the initial explosion parameters of the corresponding leaking gas are set up. Taking the average concentration of gas in space obtained from LNG leakage simulation as input, the explosion numerical model is applied to discuss and analyze the gas explosion in confined space. The effects of space constraints, gas concentration and the ratio of pressure relief window and pressure relief window on the pressure distribution of natural gas explosion are studied, and the pressure distribution law and overpressure distribution field at certain time are obtained. For the final determination of the explosion load acting on the structure. 4, the design of the buffered and energy-absorbing explosion-proof wall, the simulation of the anti-explosion effect and the optimization design of the structure are aimed at the explosive-prone areas in the LNG receiving station. A new type of explosion-proof wall with good anti-explosion effect is designed by making full use of the energy absorbing material's ability to absorb blast wave load. At first, the ANSYS/AutoDyn software is used to simulate the weakening effect of the blast wave loading on the common type and the energy absorbing type blast proof wall, and the difference of the energy absorption effect of different materials wall on the explosion energy absorption is analyzed. Then the energy absorbent material thickness length and other characteristic parameters on the energy absorption effect of the different, finally form a new type of energy absorption materials attached to the anti-explosion wall optimization design scheme, for other buildings and personnel to provide better protection.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE88

【参考文献】