【作者】 吴洁；

【导师】 吕品；

【作者基本信息】 安徽理工大学 ， 安全科学与工程， 2020， 硕士

【摘要】 氨是化工行业不可或缺的物质,即可以作为制冷剂,又在化肥、硝酸和炸药等制作过程中充当重要角色。一般以液氨形式存储,一旦存储容器失效,发生泄漏,将造成人员中毒与环境污染,若再引起火灾或爆炸事故,会造成更大危害。所以进行科学有效的液氨泄漏事故预防与救援处置相当重要。为了研究液氨储罐泄漏扩散规律及风险区域,以淮化液氨储罐作为研究对象,该研究内容为淮化氨罐区的日常安全管理防护提供了对策,并有利于风险评估与救援处置的应用。本文通过对泄漏扩散数学模型理论的分析研究,选取了 UDM模型作为本文所研究的液氨储罐泄漏事故的数学模型,同时对模型中相关的系数进行了修正,提高模型的精度。接着,运用PHAST软件分别对泄漏孔径、位置(初始条件),环境温度、湿度和风速(大气条件),以及地表粗糙度与大气稳定度等因素进行数值模拟,研究它们对液氨储罐泄漏扩散危害的影响,并以模拟结果为基础,进行初始条件和大气条件对液氨储罐泄漏扩散危害范围的拟合。结果表明:警戒范围随着泄漏孔径增大、环境温度升高而增大;警戒范围随着泄漏位置升高、风速增大以及地表粗糙度增大而缩减;夜间比白天的大气稳定度等级高,造成的危害大。得到关系式的拟合度高达0.998和0.99,可以准确的反应出各因素与泄漏扩散伤害距离的关系。利用正交试验设计方法得出泄漏孔径为最主要的影响因素,并确定最有利于液氨储罐泄漏扩散的条件。根据最有利扩散条件对液氨储罐泄漏扩散后的毒性死亡概率与扩散浓度范围进行研究,结果表明在下风向0-300m内致死率达到100%,在下风向820.33m范围外人员致死的可能性较低。运用SAFETI软件对液氨储罐泄漏扩散所造成的个人风险与社会风险进行风险评估,并通过卫星云图将风险区域与实地进行拟合,研究发现西南面居民区个人风险等值线在1×10-6/a和1 ×10-7/a居多,社会风险曲线在1×10-5/a至1×10-3/a之间的居多,应扩大淮化氨罐区与西南村落的距离。通过液氨储罐泄漏扩散的研究,可为淮化氨罐区的日常安全监管提供合理对策。该研究内容为液氨储罐泄漏事故的有效预防与应急处置提供了科学技术手段。图[21]表[24]参[77]更多还原

【Abstract】 Ammonia is an indispensable substance in the chemical industry.It can be used as a refrigerant and also plays an important role in the production of fertilizers,nitric acid and explosives.Usually stored as liquid ammonia.Once the storage containers fail,the leakage accident will lead to poisoning and environmental pollution.If it is accompanied by a fire or explosion accident,will cause a greater impact.So it is very important to carry out scientific and effective prevention and rescue of liquid ammonia leakage accidents.In order to study the leakage diffusion law and risk area of liquid ammonia storage tank,Huaihua liquid ammonia storage tanks are taken as the research object.The research content provides countermeasures for the daily safety management and protection of the ammonia tank farm in Huaihua,and is conducive to the application of risk assessment and rescue disposal.The article based on the analysis and research of the mathematical model of the leakage diffusion model,the mathematical model of the UDM model is selected,and the relevant coefficients in the model are modified to improve the accuracy of the model.Using PHAST numerical simulation technology,respectively to the initial conditions(leakage aperture size,the leakage location),atmospheric conditions(wind speed,temperature)and the surface roughness and atmospheric stability factors on the liquid ammonia tank leakage diffusion analysis.According to the simulation results,the relationship between the initial conditions and the atmospheric conditions on the leakage and diffusion hazard range of the liquid ammonia storage tank was fitted.The results show that:as the leakage aperture increases,the ambient temperature increases,and the alert range increases;as the leak location increases,the wind speed increases,the surface roughness increases,and the alert range decreases;the higher the level of atmospheric stability,the greater the harm caused.The fitting degree of the relation is up to 0.998 and 0.99.The fitted relationship can accurately reflect the relationship between each factor and the leakage diffusion damage distance.Using the orthogonal test design method,the leakage pore size is the main influencing factor,and the conditions that are most conducive to the leakage and diffusion of the liquid ammonia storage tank are determined.To study the probability of toxic death and the diffusion concentration range after the leakage of liquid ammonia storage tank The results show that the lethal rate is 100%in the downwind direction of 0-300m,and the probability of death outside the downwind direction of 820.33m is low.SAFETI software was used for risk assessment of personal risk and social risk,and the risk area was fitted with the field through satellite cloud map.It was found that the personal risk contour line in the southwest residential area was in the majority of 1 × 10-6/a and 1 × 10-7/a,and the social risk curve was in the majority of 1 × 10-5/a to 1 × 10-3/a.The distance between the ammonia tank area in Huaihua and the southwest village should be expanded.This study provides scientific and technical means for the effective prevention and emergency treatment for leakage accident of liquid ammonia storage tank.Figure[21]table[24]reference[77]更多还原