基于FDS的办公大楼火灾数值模拟研究

发布时间：2018-06-24 22:02

  本文选题：办公大楼 + 数值模拟　； 参考：《河北工程大学》2015年硕士论文

【摘要】：随着城市化进程的加快,越来越多的中高层建筑出现在城市中,然而困扰建筑安全的火灾问题一直没能很好的解决。其中办公大楼作为主要的办公场所,可燃物种类繁多而且数量很大,发生火灾的概率很高。一旦发生火灾,火灾产生的高温气体会通过走廊和楼梯间在整栋楼里蔓延开来,这将给办公大楼里的人员的生命带来巨大的威胁,也会造成巨大的而且是无可挽回的经济损失。因此,研究火灾烟气在办公大楼里的蔓延规律具有很重要意义。本文主要研究的是办公大楼发生火灾时的烟气流动状况。首先通过pyrosim建立办公大楼的物理模型;然后合理选择的火源类型,热释放速率以及火灾增长因子等相关参数,为后续的FDS模拟做好了足够的准备;最后采用大涡模拟的方法,对办公大楼以及地下车库的火灾烟气的蔓延状况做了全面的模拟研究。通过Pathfinder对办公大楼内的人员疏散做了细致的分析。对模拟结果表明:(1)无论是窗户开启还是关闭,火灾产生的高温都已经超过了人体忍受的极限值[2]。对房间内部人员会构成严重的威胁;对于烟气层高度和烟气层能见度而言,从窗户新进的新鲜空气会与火灾产生的烟气进行混合,从而对烟气层高度及能见度造成扰动。但是窗户关闭时,烟气层高度会在火灾发生后50s内迅速降低到1m以下,不利于人员逃生;走廊和其他各楼层的温度变化主要是受烟气的热辐射的影响,但都低于人体的耐受温度,楼层越高,烟气沉降越厉害[2]。(2)火源在中间层即二层的房间内时,火灾几乎对一层没有影响。但是三层至六层的温度比火源在一层时明显要高出的值约为10℃。3到6层烟气层能见度,烟气层高度与火源在一层时基本上相同。(3)火源在顶层,火灾所带来的严重后果基本上不会对1至5层带来多大的影响。(4)在使用了无风管诱导通风的地下车库,烟气层高度开始会下降,短时间后会迅速上升。而没有使用机械通风的地下车库烟气层高度会随着时间的推移逐步下降,在170s后烟气层高度已经不足1m,影响了人员逃生。本文的研究对于办公大楼的火灾烟气蔓延规律,为以后的人员安全逃生有一定的意义[2]。也为以后类似建筑的防火措施能够提供合理化的指导意见。对消防模拟训练也能提供一定的帮助。
[Abstract]:With the acceleration of urbanization, more and more high-rise buildings appear in the city. However, the fire problem which puzzles the building safety has not been solved well. As the main office space, the office building has a great variety of combustible materials and has a high probability of fire. In the event of a fire, the high temperature gas generated by the fire will spread through the hallways and stairways throughout the building, which will pose a great threat to the lives of people in the office building and will cause enormous and irreparable economic losses. Therefore, it is of great significance to study the spread of fire smoke in office buildings. In this paper, the smoke flow in office buildings is studied. At first, the physical model of office building is established by pyrosim, then the relevant parameters such as fire source type, heat release rate and fire growth factor are selected reasonably, which makes sufficient preparation for the subsequent pyrosim simulation. Finally, the method of large eddy simulation is adopted. The fire smoke spread in office buildings and underground garages is simulated. Through Pathfinder, the evacuation of people in the office building is analyzed in detail. The simulation results show that: (1) whether the windows are open or closed, the high temperature caused by fire has exceeded the limit of human endurance [2]. For the height of smoke layer and visibility of smoke layer, fresh air from window will be mixed with smoke produced by fire, which will disturb the height and visibility of smoke layer. However, when the windows are closed, the height of the flue gas layer will rapidly fall below 1 m within 50 seconds after the fire, which is not conducive to the escape of the personnel. The temperature changes in the corridors and other floors are mainly affected by the thermal radiation of the smoke. But the temperature is lower than the human body's tolerance temperature, the higher the floor, the more the smoke deposition [2]. (2) when the fire source is in the room of the middle floor, that is, the second floor, the fire almost has no effect on the first floor. However, the temperature of the three to six layers is obviously higher than that of the fire source in the first layer. The visibility of the smoke layer is about 10 鈩，

本文编号：2063153