基于SLAB的化工园区重气泄漏扩散模型研究

发布时间：2018-02-13 17:57

本文关键词： SLAB 重气扩散模型参数优化临港经济区　出处：《天津科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：重气指常温下为气态,且密度或气团密度比空气大的化学物质,广泛存在于化工行业的各个环节。化工园区是各类重质气体较为集中的区域,存在较高的环境风险隐患。由于此类物质的密度较大,泄漏后扩散的过程较为复杂,且危害性更大。传统的大气扩散模型无法模拟其重力沉降的过程,应使用适用性更强的模型来完成这项任务。本文在分析SLAB模型计算原理的基础上,采用国外重气泄放实验Burro实验的相关数据,应用误差分析方法对SLAB模型的拟合优度进行表征,并将其与其它两种适用于重气泄漏扩散的模型ALOHA和HEGADAS进行比较,得到三种模型的拟合优度排序为：SLAB ALOHA HEGADAS。证明SLAB模型在重气泄漏扩散模拟方面具有先进性。在临港经济区内以二氟一氯甲烷(R22)为泄放介质,进行了重气泄放实验,采集不同时刻下风向不同距离处的气体样品,应用气相色谱法进行目标气体浓度分析,得到了R22泄放扩散过程曲线,与理论分析结果具有较好的一致性,为模型参数的优化提供依据。对SLAB模型所需参数进行归类分析,筛选出需要进行优化的模型参数为：地表粗糙度(R)、大气稳定度等级和浓度平均时间(TAV)；以R22泄放实验所得数据为优化目标值,应用目标函数和响应面最优求解相结合的方法对参数进行优化,得到优化后的参数结果为：R=0.32；大气稳定度等级为C；TAV的取值应参考泄放持续时间(TSD)和安全暴露标准对应时间(TLEVEL)综合确定。应用优化后的SLAB模型分别对苯水平喷射泄漏和氯液池蒸发泄漏两种形式的假设事故案例进行模拟,采用不同的安全暴露准则对事故危害区域进行划分,分析不同季节典型气候条件下的事故风险区域范围变化。在此基础上探究事故风险区范围对各个环境因素的敏感性,结果为：风速(S)气温(T)相对湿度(RH)。因此,在实际事故应急管理工作中,应根据不同环境条件,提前制定针对性更强的应急预案。SLAB模型可与化工园区环境监测系统结合,为相关事故的应急指挥工作提供辅助决策信息。
[Abstract]:Heavy gas refers to the chemical substances which are gaseous at room temperature and whose density or air mass density is higher than that of air, and widely exists in all aspects of the chemical industry. The chemical park is a region where all kinds of heavy gases are concentrated. Because of the high density of this kind of material, the diffusion process after leakage is more complicated and harmful. The traditional atmospheric diffusion model can not simulate the process of gravity sedimentation. A more applicable model should be used to accomplish this task. Based on the analysis of the calculation principle of the SLAB model, this paper uses the relevant data of the Burro experiment of heavy air discharge experiment abroad, and uses the error analysis method to characterize the goodness of fit of the SLAB model. It is compared with the other two models, ALOHA and HEGADAS, which are suitable for heavy gas leakage diffusion. The results show that the SLAB model is advanced in the simulation of heavy gas leakage and diffusion. In the coastal economic zone, difluoromethane (R22) is used as the releasing medium, and the experiments of heavy gas discharge are carried out. The gas samples with different wind direction and distance at different times were collected, and the gas concentration of the target gas was analyzed by gas chromatography. The diffusion process curve of R22 was obtained, which is in good agreement with the theoretical analysis results. To provide the basis for the optimization of the model parameters. The parameters required by the SLAB model are classified and analyzed. The model parameters that need to be optimized are as follows: surface roughness, atmospheric stability grade and mean concentration time, and the data from R22 discharge experiment are taken as the optimized target value. The method of combining objective function and response surface optimal solution is used to optimize the parameters. The optimized parameters are: 1: RV 0.32; the value of atmospheric stability grade CnTAV should be determined with reference to the release duration and the corresponding time of safety exposure standard. The optimized SLAB model is applied to the horizontal emission leakage of benzene, respectively. And the hypothetical accident cases of chlorine pool evaporation leakage, Different safety exposure criteria are used to divide the accident hazard area, and the range variation of accident risk area under typical climatic conditions in different seasons is analyzed. On the basis of this, the sensitivity of accident risk area to various environmental factors is explored. The results are as follows: air speed and temperature are relative humidity. Therefore, in the actual emergency management of accidents, according to different environmental conditions, the Slab model with stronger pertinence should be developed in advance, which can be combined with the environmental monitoring system of chemical industry park. Provide auxiliary decision information for emergency command of related accidents.
【学位授予单位】：天津科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X78

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