檩高对明清古建筑感烟探测器响应特性影响研究  

Effect of purlin height on the response performance of smoke detectors in ancient buildings of the Ming and Qing dynasties

作　　者：蒋慧灵 杨雷音 周亮 JIANG Huiling;YANG Leiyin;ZHOU Liang(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;Research Institute of Macro-Safety Science,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]北京科技大学大安全科学研究院,北京100083

出　　处：《清华大学学报(自然科学版)》2025年第4期634-643,共10页Journal of Tsinghua University(Science and Technology)

基　　金：国家重点研发计划项目(2021YFC1523504);北京市自然科学基金面上项目(8222021)。

摘　　要：明清时期“有檩式”古建筑具有构造独特、形态复杂的屋顶结构,对火灾烟气的流动产生显著影响,但现有火灾探测器的布置方案较少考虑这一因素,难以实现有效的早期火灾探测。为加强对明清时期古建筑的火灾防控,该文以硬山顶建筑为例展开研究,采用FDS(fire dynamics simulator)进行火灾数值模拟,分析不同火源位置和不同檩高条件下烟气的蔓延情况,通过设置感烟探测器阵列,进一步探究檩高对各个位置探测器响应特性的影响。研究发现,烟气蔓延过程与探测器响应时序密切相关;火源位于正脊轴线下方,当檩高不超过30 cm时在正脊中心处的探测器最先响应,超过30 cm后在靠近正脊中心两侧的顶棚处布置探测器则可以实现快速响应;火源位于墙角位置,当檩高不超过20 cm时正脊处的探测器均可在60 s之内做出响应。该研究结果可为明清时期同结构类型建筑火灾探测器的合理布置提供技术支撑。[Objective]The unique design and complex morphological characteristics of roof structures in the“purlin-type”ancient buildings of the Ming and Qing dynasties significantly influenced the spread of smoke.However,the existing fire detection systems used in ancient structures lack sufficient consideration of the impact of roof architecture on the placement of smoke detectors,which makes it challenging to realize early fire detection effectively and accurately.Therefore,further research on the response time of fire detectors considering purlin height is necessary to strengthen fire prevention and control in ancient buildings.[Methods]Through the job-site survey of several gable-roofed buildings in the Forbidden City,the existing smoke detectors were found to be primarily installed on the purlins below the ridge or both sides of the ceiling.However,the scientific basis for these installation positions remains unclear.Thus,this study selected typical gable-roofed buildings with a slope of 27.41°constructed during the Ming and Qing Dynasties as the research object.Fire dynamics simulator was utilized for numerical fire simulation to analyze smoke movement in the different fire source positions(center,edge,and corner)and various purlin heights(low:10-20 cm;middle:30-40 cm;high:50-60 cm).The research further explored the influence of smoke detector response performance on each fire position and purlin height by setting up a 9×11 smoke detector array and several slices of smoke mass fraction.In this model,as the purlin height increased,the detectors arranged under them maintained their x and y coordinates,while the z coordinate moved down the corresponding height.The position of the detectors on the ceiling remained unchanged.[Results]The findings showed the following:1)The variation law of the smoke propagation path:In the scenarios of central and edge fires,smoke primarily spread along the horizontal direction of the main ridge.In those of corner fire,when the purlin height was low,the smoke tended to expand upward

关 键 词：硬山顶 檩高 烟气蔓延 感烟探测器 响应特性 

分 类 号：X932[环境科学与工程—安全科学]