综合管廊电缆舱断面高宽比对火灾和排烟的影响

应用火灾模拟软件PyroSim,对综合管廊电缆舱火灾进行数值模拟,讨论不同断面高宽比对火灾烟气流动、温度和排烟效果的影响。分析得到:舱内温度主要以烟气为载体,火源上部区域温度最高,越往两边温度越低;断面形状影响燃烧速率,高宽比越小燃烧速度越快,顶棚温度越低;距火源较近区域,随着高宽比的减小,温度衰减速率也减小,距火源较远区域,高宽比对温度衰减速率几乎没影响。排烟过程中,下部区域排烟效率高于上部区域且距离送风口越近排烟效果越好。高宽比对于排烟效率影响较大,高宽比越小,其整体排烟效率越高。

Study on the Influence of the Aspect Ratio of Utility Tunnel on Fire and Smoke Exhaust

Using the fire simulation software PyroSim, the numerical simulation of the fire in the cable duct of the utility tunnel is carried out, and the influences of the aspect ratio of different sections on the smoke flow, temperature and smoke exhaust effect of fire are discussed. The analysis shows that, the temperature in the cabin is mainly based on the flue gas, and the higher temperature in the upper part of the fire source, the lower temperature on both sides. The shape of the section affects the burning rate and the smaller the aspect ratio, the faster the burning speed and the lower the ceiling. Near the fire source, as the aspect ratio decreases, the temperature decay rate decreases also. Far away from the fire source, the aspect ratio has little effect on the temperature decay rate. During the smoke exhausting process, the exhaust efficiency of the lower area is higher than that of the upper area, and the closer to the air supply port, the better the smoke exhausting effect. The aspect ratio has a great influence on the efficiency of exhausting smoke, and the smaller the aspect ratio, the higher the efficiency of exhausting smoke.