摘要
采用考虑了湍流效应和辐射传热的扩散燃烧模型,对某长隧道在不同火灾规模和通风条件下的拱顶温度场进行模拟。通过计算分析了隧道火灾中混凝土拱顶衬砌温度的分布规律以及火灾规模、通风条件对其影响。结果表明,以混凝土拱顶衬砌不超过300℃为安全临界温度,低于10MW规模的隧道火灾基本不会造成拱顶衬砌结构发生破坏;对于20、50MW规模的隧道火灾,需要分别保持2.0、4.0m/s的通风速度,才能使拱顶衬砌结构不受损坏。加大通风在改善隧道散热条件的同时也加强了高温烟气的对流,扩大了隧道拱顶升温的范围,从而在火灾发展到一定时间后,可能会引起更大范围的拱顶衬砌结构破坏。
A temperature field simulation of arch crown in long tunnel fires, under different fire loads and ventilation velocity, was carried out, employing non-premixed combustion model which considered turbulence effect and radiation. Furthermore, the temperature distribution of arch crown and the corresponding changes caused by different fire loads and ventilation velocity during tunnel fires were analyzed. The results indicate that, taking 300 ℃ as critical temperature, the structure of arch crown won＇t be damaged when the fire load is lower than 10 MW; and this can also be insured when the fire load is 20 MW,50 MW, as long as the ventilation velocity is kept at 2. 0 m/s, 4. 0 m/s respectively. It can also be concluded that increasing the ventilation velocity can improve the heat dissipation and meanwhile, reinforce the convection of high temperature smoke and extend the temperature rising area of arch crown, which may consequently induce an even larger range of damaged arch crown＇s structure after the fire lasting for some time.
出处
《消防科学与技术》
CAS
北大核心
2009年第4期162-165,共4页
Fire Science and Technology
基金
浙江省交通厅科研计划项目(2004H58)
关键词
隧道火灾
拱顶
扩散燃烧模型
数值模拟
tunnel fires
arch crown
non-premixed combustion model
numerical simulation
