基于质量流率离散方法的液氨储罐泄漏扩散模型的研究

Study on Accident Model of Liquid Ammonia Storage Tank Leakage Based on Mass Flow Rate Discretization

针对高斯模型中忽略物质质量流率的变化导致模拟结果与实际存在偏差的问题,将物质质量流率根据泄漏持续时间进行离散化处理,获得不同时间段的物质泄漏量,以此对高斯烟团叠加模型进行修正,得到若干烟团不同时刻的浓度分布模型,并以液氨储罐泄漏事故为研究对象,获得较恒速泄漏条件具有明显差异的有毒云团危害区域。针对其后果偏差产生的原因——罐内初始压力Pn及储罐的充装水平α进行研究,分别比较在不同的Pn及α取值情况下泄漏后果的变化及差异。研究表明,增大Pn或减小α能够有效减小液氨泄漏的危害距离,并且会减小恒速泄漏条件分析后果的偏差,对液氨等罐区的管理提供依据。

For the deviation of the result that is got by Gauss model without variation of leakage rate, mass flow rate is disereted aeending to duration of leakage to calculate the mass in different time units, in order to improve Gauss puff superposition model and obtain eoueentration distribution models of different puffs at different times. The result that is different from the previous is received by studying liquid ammonia storage tank. The comparison among accident consequences shows that Pn and a ean significantly affect accident consequence . It can help to manage tank district when hazardous distances are reduced by increasing Pn or decreasing a ;moreover, the error of ealeulatiou with eenstant mass flow rate can be cut down.