实验室核心区域火灾最佳通风口选择仿真

Simulation of Selecting the Best Vent for Fire in the Core Area of the Laboratory

实验室发生火灾时室内设备和药品受高温影响,危险系数较大,且火灾面积较大时还易产生爆炸和有毒浓烟。利用仿真方法,设计实验室核心区域火灾最佳通风口选择方法。计算火灾发生时产生相应羽流运动的平均温度和最高温度。分析横向风对质点的影响,明确火源羽流歪斜位移和质量流率产生的改变值。考虑到羽流高度变化状态,得出顶部通风口烟气质量分数值与侧壁值的比较结果,分析烟气浓度变化情况,对通风口选择进行仿真。根据实验室顶部和侧壁通风口的室内烟气和气体含量可知,顶部通风口烟气排出后,烟气层升高,不会出现再次燃烧,有效降低了火灾的危险性。

When a fire occurs in a laboratory,indoor equipment and drugs are often affected by high temperature,and the risk factor is too large.When the fire area is large,it is easy to cause explosion and produce toxic smoke.Therefore,an optimal method for selecting vents when a fire occurs at the core area of the laboratory was designed based on simulation.Firstly,we calculated the mean and maximum temperatures of plume movement when the fire broke out.Secondly,we analyzed the influence of cross wind on mass points and determined the change values of skew displacement and mass flow rate of the fire plume.With the consideration of the change state of plume height,we compared the smoke mass fraction of the top vent with the value of side wall vent.Moreover,we analyzed the smoke concentration changes and simulated the selection of vents.According to the indoor smoke and gas content of the top and side wall vents of the laboratory,we can see that the smoke layer will rise after exhausting smoke and gas from the top vent,and it will not burn again,so this method effectively reduces the risk of fire.