有毒气体泄漏下的公众最优疏散路线研究

Optimal public evacuation route under toxic gas leakage

为优化有毒气体泄漏条件下的人员疏散过程,根据气体扩散高斯烟羽模型,建立以公众吸入毒气剂量最小为目标的最优疏散路线所应满足的泛函;通过可动边界变分问题求解,获得公众疏散的最优疏散路线;开展不同影响因素的公众疏散吸入毒气剂量分析和极差分析,并计算公众无防护条件下疏散的死亡区域。结果表明:在有毒气体泄漏事故条件下,最优公众疏散方向与环境风的侧风相一致,而不是沿逆风向,建议公众疏散时垂直于风向疏散;位于泄漏源周边及其下风向一段距离的公众具有最大疏散危险;影响公众疏散中毒的最大因素是泄漏速率,其次为大气稳定度,平均疏散速度的影响可忽略,不建议公众在无防护条件下盲目疏散;建议高死亡概率包围区域内的公众就地庇护,低死亡概率包围区域外的公众方可疏散。

In order to optimize public evacuation process under conditions of toxic gas leakage,based on Gauss plume model of gas dispersion,a function for optimal evacuation route was established with smallest dose of inhaled toxic gas for public as the objective.Then,the function was solved by variational method with moving boundaries so as to obtain optimal evacuation route.Then analysis on inhaled dose of toxic gas by the public and range analysis under different influencing factors were conducted,and death zone due to public evacuation without protection was calculated.The results show under conditions of toxic gas leakage,directions of optimal evacuation routes are consistent with side wind of ambient wind,rather than along headwind direction.It is recommended that the public evacuate towards the direction that is perpendicular to wind direction.Those near to and at a distance from the leak source face the greatest danger during evacuation.The biggest factor that causes gas poisoning during evacuation is leakage rate,followed by atmospheric stability,and impact of average evacuation speed can be negligible,so it is not recommended to evacuate blindly without protection.The suggestion is that in areas with a high probability of death,the public should be sheltered in place,while those outside areas with a low probability of death could be evacuated.