喷淋系统对地铁火灾不同排烟方案的影响

Study on the influence of automatic sprinkler system on different smoke extraction schemes of subway fire

以上海市某地下两层岛式地铁站作为研究对象,采用FDS软件对站台区域火灾进行了数值模拟。分析了站台层公共区域火灾在喷淋系统与排烟系统耦合作用下的烟气层特性。通过解析火灾区域内2.0 m高处的温度、烟气层高度、能见度以及喷淋区域内各排烟口流速等相关火灾参数的变化规律,探讨地铁站火灾时自喷系统和排烟系统的相互影响,并确认喷淋系统设置的必要性。分析结果表明:当喷淋压力较低时,喷淋系统和排烟系统耦合作用可以有效降低烟气层温度且不破坏烟气层稳定性。随着喷淋压力增大至某一特定值,排烟效率降低,烟气层稳定性丧失,大量烟气会积聚在喷淋区域,影响火灾区域人员安全疏散。

An underground two-story island subway station in Shanghai was taken as the research object,and FDS was used to numerically simulate the fire in the station area.The characteristics of smoke layer under the coupling effect of sprinkler system and smoke exhaust system in platform floor public area fire was analyzed.By analyzing the changes of temperature at height of 2.0 m,smoke layer height,visibility and velocity of smoke exhaust outlets in the fire area,the interaction between the automatic sprinkler system and the smoke exhaust system in subway station fire was discussed,and whether the automatic sprinkler system has the necessity of opening and whether the smoke exhaust system needs to be opened at the same time were confirmed.The analysis results showed that:when the pressure is low,the temperature of the smoke layer can be effectively reduced without destroying the stability of the smoke layer under the coupling effect of the automatic sprinkler system and the smoke exhaust system.As the pressure increases to a certain value,the efficiency of smoke exhaust system decreases,the stability of the smoke layer will be lost,and a large amount of smoke will accumulate in the spray area,affecting the evacuation of people near the fire.