单室火灾数值模拟及混凝土梁热分析  

Numerical simulation of single-room fire and thermal analysis of concrete beams

作　　者：廖艳芬[1] 徐艳[1] 马晓茜[1] 

机构地区：[1]华南理工大学电力学院,广东广州510640

出　　处：《消防科学与技术》2011年第8期659-663,共5页Fire Science and Technology

基　　金：亚热带建筑科学国家重点实验室开放基金(2008KB34);能源高效清洁利用广东普通高校重点实验室(KLB10003)

摘　　要：基于简化的固体可燃物燃烧模型,利用Fluent软件,将建筑内部支撑结构梁作为实体构件,与烟气发展过程进行耦合计算,模拟单室房间失火情况下的烟气发展情况及梁的温度场分布和历程。模拟结果显示,火场中通风处温度场明显提高,压差作用下烟气向门外形成高温射流,并与卷吸回流的环境空气形成漩涡,进一步加快燃烧过程。横梁能够部分阻隔烟气的蔓延,同时使梁体两侧呈现非对称受火,导致热量从外侧逐步向梁内部的累积呈现非线性。火灾中混凝土的热惰性为横梁提供了热缓冲。该温度分布梯度在梁墙结合处及跨中处最大,容易发生热应力集中从而引发梁破坏导致建筑坍塌。Based on a simplified model of solid fuel combustion,the fire process and the smoke development process in a single chamber room was simulated with the employment of software Fluent.Coupling with the smoke development process,the temperature-rising process and the temperature distribution of the internal support structure（i.e.,the beams,as the entity component）,were simulated.Results shows that the temperature around the vent was significantly improved and a high-temperature smoke jet outside the door was formed due to the pressure difference.With the return and entrainment of the ambient air,the smoke jet formed a vortex,which further speeded up the combustion.Beams partially obstructed the spread of the smoke and made the heating condition of two sides asymmetric,which induced the nonlinear development of the heat conduction from the surface gradually to the medial of the beams.The thermal inertia of concrete provided a thermal buffer for the beams.The temperature gradient at the midspan,also at the junction of wall and beam was the most,which was apt to cause thermal stress concentrated and induced the beams damaged,even to building collapse.

关 键 词：火灾 数值模拟 混凝土梁 热分析 

分 类 号：X913.4[环境科学与工程—安全科学] TU375.1[建筑科学—结构工程]