大空间火灾中屋盖倾角对温度分布的影响  

The influence of roof inclination on temperature distribution in fire of large space

作　　者：褚倩 张健[1] 宋志刚[1] 陈磊 CHU Qian;ZHANG Jian;SONG Zhi-gang;CHEN Lei(Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Yunnan Kunming 650500, China)

机构地区：[1]昆明理工大学建筑工程学院

出　　处：《消防科学与技术》2019年第4期497-501,共5页Fire Science and Technology

摘　　要：针对平滑无障碍的大空间斜屋盖,基于斜屋盖顶棚射流温度计算模型,分析倾角对屋盖温度分布的影响,给出了10°~30°斜屋盖温度分布近似计算公式。将近似计算公式与FDS模拟结果进行对比,验证其有效性,并结合案例分析水平屋盖温度分布公式用于斜网架时对其应力和位移的影响。结果表明:在距羽流作用中心4.7倍特征半径内或钢屋盖倾角不超过10°时,可忽略屋盖倾角对火灾温度分布的影响;屋盖倾角会导致火源投影点下侧屋盖温度降低,上侧屋盖温度增大,钢屋盖温度最大增幅在7%左右。斜屋盖温度近似计算公式在火源投影点上侧与模拟结果一致性较好,而在下侧则高于模拟结果。采用水平屋盖温度分布计算斜网架温度对其应力和位移影响不大。Aiming at large spatial inclined roof which is smooth and barrier- free, based on the calculation model of jet temperature for inclined roof, the temperature distribution effected by inclination angle was analyzed. An approximate calculation method was pro? posed for inclined roof with angles ranging from 10° to 30°. The accuracy of calculation formula was validated by the simulation result of FDS. The stress and displacement of inclined truss influenced by inclination angle were analyzed when the temperature distribu? tion formula was used to inclined truss with an example. The results showed that the influence of inclined roof on the temperature distribution can be neglected when the radial distance is within 4.7 times the characteristic radius or the angle of steel roof does not exceed 10°.The temperature of inclined roof decreases on the underside of projection and increases by 7% on the upside of projection. The result of approximate calculation method is consistent with the results of simulation on the upside of projection but higher on the underside of projection, and the stress and displacement of inclined truss has not change much when the temperature distribution of flat roof was used to inclined truss.

关 键 词：大空间建筑 火灾 斜屋盖 温度分布 应力 位移 

分 类 号：X913.4[环境科学与工程—安全科学] TU391[建筑科学—结构工程]