基于最小中毒剂量的有毒气体泄漏人员优化疏散路线研究

Evacuating route optimization based on the minimum toxic dose in toxic gas-leaking accidents

针对有毒气体泄漏扩散后的疏散路线优化问题,以高斯烟羽模型为基础,以降低人员疏散过程受到的毒害水平为目标,采用变分法推导优化疏散路线满足的微分方程和边界条件,并建立数值求解方案。同时,对影响疏散路线长度和最小中毒剂量的因素进行分析。结果表明:随初始疏散位置距泄漏源水平距离的增大,疏散路线长度先增后减,最小中毒剂量快速减小;随初始疏散位置垂直距离增加,二者均呈线性降低;泄漏源强度增大对疏散路线长度影响较小,但最小中毒剂量快速提高;疏散路线长度随大气稳定度增加先增后减,最小中毒剂量快速增加;风速增加时疏散路线长度线性减小,而最小中毒剂量在低风速时很大,且随风速增加快速降低。

The present paper is aimed at introducing our study of the method of evacuating route optimization based on the minimum toxic dose in toxic gas leakage accidents based on the Gaussian Plume Model.As is known,the toxic dose is usually defined in terms of concentration per unit time of exposure raised to a power multiplied by the duration of the exposure.In case of continuous release,toxic dose can be estimated by integrating or summarizing the increments of more than one time.In this paper,we prefer to use the Gaussian Plume Model for describing the concentration distribution when the gas leakage gets to a stable state.According to the needs of the minimum toxic dose,it is possible to use the calculus of variations to get the differential equation and the boundary conditions that the optimized evacuation route is likely to meet.However,we can adapt the algorithm of Runge-Kutta to the numerical solution of the differential equation and analysis of the effects of various factors,such as the initial position,leak intensity,atmospheric stability,and the surrounding wind speed.The results show that with the increase of the abscissa of initial position,the evacuation distance tends to increase rapidly and then decrease,whereas the minimum toxic dose decreases quickly.It is also necessary to point out that both the evacuation distance and minimum toxic dose tend to decrease linearly with the increase of the ordinate of initial position.In addition,the leak intensity has little effect on the evacuation distance,though the minimum toxic dose increases fast.Moreover,while the atmospheric stability becomes more stable,the evacuation distance tends first to increase quickly and then decrease,though the minimum toxic dose increases readily with the increase of the atmospheric stability.And,finally,the evacuation distance proves to be decreasing linearly with the increase of the environmental wind speed,even if the minimum toxic dose remains high in the case of low wind speed,and then may decrease with the increase of the wind speed.