基于数值模拟的细水雾在汽车涂装车间喷漆室的应用研究

采用FDS软件对细水雾扑救汽车涂装车间喷漆室火灾的灭火效能进行数值模拟分析,着重探讨了喷漆室纵向通风、细水雾雾滴粒径、雾滴喷射速度、汽车障碍物等对扑灭油漆火的影响。模拟结果表明:在细水雾与油漆火的相互作用过程中,细水雾对火源的表面冷却和隔氧窒息作用显著;为了防止室内氧气得到补充,在开启细水雾灭火的同时应当联动控制关闭纵向通风系统;在模拟工况条件下雾滴粒径为100μm~300μm的细水雾灭火效果优于粒径为400μm、500μm的细水雾;雾滴在一定喷射速度范围内速度越大灭火效果越好,喷射速度为10m/s的雾滴灭火效果明显优于3m/s和5m/s的雾滴,但是为了防止火焰横向蔓延,喷射速度不宜过高;在汽车障碍物火灾中部分微小的细水雾雾滴受到火焰的卷吸作用,可以绕过障碍物进入火区发挥冷却作用,细水雾灭火系统能够有效控制障碍物火灾,可以应用于汽车涂装车间喷漆室。

Application research of water mist system in the spray paint room of car coating workshop based on numerical simulation

Efficiency of fire extinguishing by water mist system in spray paint room of car coating workshop is investigated by FDS software, with focuses on the longitudinal ventilation, water mist particle diameter, the droplets injection speed and the influences of car obstacles. Simulation results show significant enhancement of water mist in cooling the surface of fire and isolating from oxygen during the interaction between water mist and the paint fire. When the water mist system is opened, longitudinal ventilation system must be closed by linkage control to prevent indoor oxygen from being replenished. Under the simulated conditions, the water mist particles with diameters of 100~300 microns have higher extinguishing efficiency compared to the particles with diameters of 400~500 microns. Within certain range of injection speed, greater speed will lead to higher extinguishing efficiency, and the injection speed of 10 m/s is apparently better than 3 m/s and 5 m/s. However, to prevent fire lateral spread, the injection speed should not be too high. Under the condition of car obstacles fire, some tiny water mist droplets can bypass obstacles into the fire area to play a role of cooling because of the flame entrainment effect.