摘要
作为典型的挥发性有机液体,甲醇泄漏后的蒸发过程是影响可燃气云生成的关键环节。通过自主设计的甲醇蒸发特性试验平台获得了甲醇液池蒸发的时空演化特征,并阐释了液池直径(0.5 m、1.0 m、1.5 m、2.0 m)、地面温度(30~60℃)对开敞空间甲醇蒸发特性的影响机制。结果表明,甲醇的蒸发速率随液池直径增大而增加,然而蒸发过程受饱和蒸气压制约,甲醇气云体积分数随时间呈现先快速上升后逐渐趋缓的变化趋势,所有工况在约2000 s后达到动态平衡。相较于液池直径,地面温度对甲醇蒸发过程的影响更为显著,这与温度升高导致的甲醇饱和蒸气压上升、液体分子动能增强有关。同时,基于甲醇平均蒸发速率修正了经典Mackay-Matsugu蒸发模型,修正后的蒸发模型预测误差降低至6.7%,能够良好地预测试验过程中甲醇液池的蒸发速率。研究结论揭示了甲醇液池的蒸发行为,为甲醇的安全性研究提供了有力支撑。
This article presents the spatiotemporal evolution characteristics of methanol pool evaporation,obtained through a selfdesigned experimental platform.It elucidates the influence mechanisms of pool diameter(0.5 m,1.0 m,1.5 m,and 2.0 m)and ground temperature(3060℃)on the evaporation characteristics of methanol in open spaces.Building on this data,we modified the standard Mackay-Matsugu evaporation formula with adjusted coefficients.The findings reveal that increasing the diameter of the liquid pool significantly accelerates the kinetics of methanol evaporation,establishing a direct proportionality between the evaporation rate and the surface area of the liquid pool.Furthermore,as the evaporation temperature rises,the impact of the liquid pool diameter on the evaporation rate gradually diminishes.However,the evaporation process is hindered by saturated vapor,resulting in the volume fraction of the methanol gas cloud experiencing a rapid increase initially,followed by a gradual slowdown over time.Consequently,while increasing the diameter of the liquid pool can reduce the time needed for the methanol vapor cloud to achieve saturation equilibrium,it does not affect the final vapor volume fraction or the equilibrium pressure.All operating conditions achieve dynamic equilibrium after approximately 2000 s.However,the saturated vapor pressure of methanol is solely determined by its temperature.An increase in temperature raises the saturated vapor pressure of methanol and enhances the kinetic energy of the liquid molecules,enabling more molecules to overcome the surface energy barrier and escape from the liquid phase,thus accelerating the evaporation rate.Consequently,the impact of temperature on the methanol evaporation process is more comprehensive and significant compared to the diameter of the liquid pool.Additionally,utilizing the observed variations in the methanol vapor cloud volume fraction from the experiments,we calculated the average evaporation rate of methanol under different initial conditions.Building on this data,we modified the classical Mackay-Matsugu evaporation model,successfully reducing the prediction error of the modified model to 6.7%.This enhanced model effectively predicts the evaporation rate of the methanol pool throughout the experimental process.
作者
刘振翼
孙浩轩
吴俊婕
马建博
李明智
刘旗旗
LIU Zhenyi;SUN Haoxuan;WU Junjie;MA Jianbo;LI Mingzhi;LIU Qiqi(State Key Laboratory of Explosive Science and Safety Protection,Beijing Institute of Technology,Beijing 100081,China)
出处
《安全与环境学报》
北大核心
2026年第2期458-467,共10页
Journal of Safety and Environment
基金
国家自然科学基金项目(12202064)
国家重点研发计划项目(2022YFC3006301)。
关键词
安全工程
甲醇
蒸发特性
液池直径
地面温度
safety engineering
methanol
evaporation characteristics
pool diameter
surface temperature
