【作者】 王庆慧；

【导师】 戴光；

【作者基本信息】 东北石油大学 ， 化工过程机械， 2011， 博士

【摘要】 液化气体通常采用压力容器储存,很多种类液化气体属于易燃、易爆、或有毒物质。这些物质一旦发生泄漏,迅速气化并扩散,短时间内即可形成大范围的危险区域,遇点火源,将导致重、特大火灾和爆炸事故。盛装液化气体或超过常温沸点的高温液体的压力容器发生泄漏后,内部物质由于失压、过热,发生蒸汽爆炸(也叫BLEVE),从而引起内部超压。较大的超压可使裂口扩展,造成局部大范围甚至整体失效,继而引发更大的事故。但目前还缺少一种模型或经验公式能够比较准确地说明发生BLEVE现象的临界条件。本文采用热力学原理、爆炸力学原理研究压力容器发生BLEVE现象的临界条件；应用断裂力学原理、有限元方法分析在发生BLEVE临界条件下裂口尖端的应力情况,对临界条件下泄漏后果进行仿真。应用热力学理论,对发生BLEVE的压力容器,在泄漏过程中内部的压强变化情况进行了理论分析。利用气相空间的饱和蒸汽比体积与质量关系公式及压缩气体泄漏速度公式,根据理想气体状态方程体积与密度变化关系,建立了比体积与泄漏时间关系的数学模型；建立了液化气体或超过常温沸点的高温液体发生BLEVE滞止时间模型。运用建立的比体积与泄漏时间关系的数学模型、滞止时间模型、BLEVE超压公式,建立了发生BLEVE的临界面积计算模型。由热力学理论,得出了发生BLEVE现象临界面积与压力容器内部气相体积、压强、泄漏速度、液面高度、液体密度之间的关系计算模型。可依据发生BLEVE临界面积与压力容器内部气相体积、压强、泄漏速度、液面高度、液体密度之间的关系计算模型,判定在给定压强条件下存在的裂口是否发生BLEVE现象。通过高温、高压热水泄漏实验以及采用参考文献中的实验结果,验证了所建模型得出的计算结果与实际结果基本吻合。在以上研究的基础上,分析了2000m3液氨球型压力容器在正常工作压力下,以及最高工作压力下发生BLEVE现象的临界温度、临界压强以及临界面积。采用环境风险评价系统软件(Risk System),仿真了2000m3液氨球型压力容器在BLEVE临界条件下发生泄漏后果的危害性。更多还原

【Abstract】 Liquefied gases, many of which are inflammable, explosive or toxic substances, are usually contained in pressure vessels. Once leakage occurs, these substances will gasify and spread rapidly and form a wide range of dangerous area in a while. It can lead to heavy, big fires and explosive accidents when facing fire hazard. After leaking of the pressure vessel, in which liquefied gases or high temperature liquids over normal boiling point are loaded, the internal substances explode due to its pressure loss, overheating (it is also called BLEVE), and lead to internal overpressure. Large overpressure can make the split expand, and it can even cause local big scope or the overall failure, leading to more accidents.This thesis studies the pressure vessel BLEVE phenomenon in critical condition by using thermodynamics principle, explosion mechanics principle; it analyzes the pressure of cracking tip and the simulation under the critical condition after leaking by using fracture mechanics theory.It analyzes the internal intensity of pressure changing situation during the leakage in the pressure vessel when it explosives by using thermodynamics theory. According to the gas phase space saturated steam specific volume and quality formula and compressed gas leak velocity formula, and the changing relations between ideal gas state equation volume and density, we establish a specific volume and leakage time model, and also a exploding stagnation time model for liquefied gases or high temperature liquid over the normal boiling point.The critical area calculating model of BLEVE is established by using an established specific volume and leakage time model, stagnation time model and vapor explosion overpressure formula.By using the thermodynamics theory, it gets the model formula between the critical area of BLEVE phenomenon and internal gas phase volume, intensity of pressure, leakage speed, liquid surface height, and liquid density in pressure vessel. We can judge whether BLEVE phenomenon occurs in existing crack under the certain intensity of pressure according to the formula of the internal gas phase volume, intensity of pressure, leakage speed, liquid surface height, and liquid density in pressure vessel, as a judgment basis of the BLEVE phenomenon.Through the high temperature and high pressure hot water leakage experiment and the experimental results by references, we verify that the calculation results in established models are basically in accordance with the actual results.On the basis of above research, we analyze the critical temperature, critical intensity of pressure, and critical area when BLEVE phenomenon occurs in normal working pressure and under the highest pressure in the 2000m3 liquid ammonia ball pressure vessel. The hazard of leakage when in BLEVE critical condition in 2000m3 liquid ammonia sphere pressure vessel is simulated by adopting environmental Risk assessment system software (Risk System).更多还原