【作者】 刘晖；

【导师】 陈国华；

【作者基本信息】 华南理工大学 ， 化工过程机械， 2011， 硕士

【摘要】 罐区火灾事故危害大,扑灭较困难,常造成严重的财产损失和人员伤亡。当前对起火部位的认定较大程度上仍依靠调查人员的经验。现有的物证技术应用于罐区火灾起火点认定,需要以罐区火灾扩展过程中高温、辐射等灾害特性的分布特点为依据。若进行全尺度罐区火灾模拟实验,其成本过高,周期较长,实施难度太大。因而运用数值模拟技术,获得火灾事故扩展过程中的灾害特性,推断出事故现场可能的物证特点,对指导罐区火灾事故扩展过程及起火部位的认定具有重要意义。本文在储罐油池火模拟实验的基础上,研究CFD技术在储罐油池火灾数值模拟方面的适用性,并用该方法对典型的罐区火灾扩展类型进行了分析,推断事故现场的物证特点。主要分为以下四个方面:(1)储罐油池火灾害特性及其影响因素分析。通过建立储罐油池火模拟实验平台,研究储罐油池火燃烧过程特性,对火焰的发展过程、几何形状、温度、辐射等灾害特性进行分析。并对不同充装率对火焰灾害特性的影响进行研究,分析储罐火灾事故中的火焰灾害特性规律。为研究CFD技术在储罐油池火模拟方面的应用提供对比。(2)钢材受火后力学性能变化研究。通过实验研究金属试样在储罐油池火中不同位置(对应不同温度)、不同时间后力学性能变化情况,探讨金属材料在承受不同火焰强度和时间下力学性能的变化特点,分析面向起火点认定的金属物证规律。(3)研究CFD技术在储罐油池火数值模拟方面的应用。针对模拟实验,选用PDF非预混燃烧模拟方法和带浮力修正的CFD湍流模型对储罐油池火特性进行分析,对火焰重要几何参数、火场温度、辐射分布规律进行数值研究。通过与实验的对比,检验该方法在储罐油池火数值模拟方面的合理性。(4)应用CFD技术推断罐区火灾扩展过程及起火点位置认定的物证依据。以某罐区为例,运用上述CFD数值模拟方法分析罐区火灾事故中典型扩展类型的灾害特点,结合钢材灾后力学性能变化的规律,推断事故现场关键位置的物证特点,为事故扩展过程和起火点的分析提供科学指导。更多还原

【Abstract】 Oil tank fires always result in severe damage to people and property, reasoning the characteristic of harms and the difficult-to-put out. It used to depend on the experience of dispatcher to identify the fire source location when fire accidents are investigated. In addition to material evidence techniques, the investigation of fire source location should have the character and rule of high-temperature and radiation as guide. Furthermore, because of high cost and risk, it is impossible to carry out full-scale tests of oil tank fires. Therefore, applications of CFD Technology to get the characteristics of disaster are of great significance during the investigation of the fire point.Based on the results of the experiment of oil tank fires, the application of CFD numerical stimulation in oil tank fires was analyzed. The numerical stimulation method was used to infer the physical evidences of the fire process and analysis of original point of fire. It was carried out from the following aspects:(1) Analysis of combustion characters and the influence factors of oil tank fires. The research of oil tank fires was carried out through the platform for fire experiment of storage tanks. The characters of the fire audient, such as evolution, geometry, temperature and radiation, were analyzed. The experiment conditions, such as whether the tank has a subcrust of water or not, the different thickness of oil in tank and the different filling ratio, were changed regularly. The effects of the variation of these conditions to the characters of oil tank fires were analyzed. And in order to verify the availability of the numerical method, the results were used to make a contrast with the numerical results.(2) Research of Mechanical properties changes of metallic materials after fire disaster. By experimental studies of metal samples in different locations in fire (corresponding to different temperatures) and different time to fire, mechanical properties characteristics of metal change in the fire was studied, which help to recognize the rules of fire source location identification.(3) Research of CFD numerical simulation of tank fire in application. On the basis of the experiment, PDF non-premixed combustion method and CFD turbulence model with a buoyant source were chosen to analyze the characteristics of oil tank fires, the important geometrical parameters of flame, fire temperature, the distribution of radiation was studied. Comparison with the experiment, the numerical simulation method was proved to have certain accuracy.(4) Application research of CFD technology to tank fire developing process analysis and fire point identification. Took a certain tank zone as an example. The typical characteristics of developing types of fire were studied by CFD numerical simulation. Rules of physical evidence of the key location of the accident scene were forecasted. Basis of the typical developing type and the fire source location identification was studied, which could be guidance of fire point identification and cause analysis of the accident.更多还原