喷射火灾环境下LPG储罐热响应规律模拟研究

Numerical Simulation Study of Thermal Response Rules of LPG Tank under the Jet Fire Environment

为研究喷射火灾环境下,热流密度和受热位置两个主要外界因素对LPG卧式储罐热响应规律的影响,利用CFD软件建立喷射火灾环境下LPG卧式储罐热响应模型,以Birk等人的现场火灾实验来验证模拟模型的有效性。结果表明:储罐压力上升与热流密度成正比;在高热流密度情况下,热流密度的变化对罐内液相温度影响较小,最高温差为22 K,然而对罐壁温度和气相温度影响较大。高热流密度侵袭储罐时,加热位置对罐内压力影响较小,液相介质的汽化作用对压力上升起主导作用;不同加热位置对储罐热响应影响程度从大到小依次是:气液两相同时受热,封头部位受热,储罐底部受热。

The thermal response model of LPG tank under the environment of jet fire is established based on the fluid software CFD to research the influence made by heat flux and heating position two main external factors on the thermal response of LPG horizontal tank and meanwhile,the valid of simulation model is verified according to the scene of the experiments made by Birk and others. The results show that tank pressure rise is proportional to the heat flux value.Under the condition of high heat flux,heat flux changes has a relatively little effect on the tank liquid temperature,the maximum temperature difference is 22 K,but greatly affects the temperature of the tank wall and vapor zone.When the high heat flux invades the tank,vaporization of the liquid medium plays a dominant role on the pressure rise,conversely,a small effect on pressure by heating position. The influence made by different heating position on LPG tank thermal response from large to small is in turn： gas- liquid heated simultaneously,head parts heated and the bottom of tank heated.